key: cord- -gqdylj n authors: snyder, william m.; wenger, etienne title: our world as a learning system: a communities-of-practice approach date: journal: social learning systems and communities of practice doi: . / - - - - _ sha: doc_id: cord_uid: gqdylj n we live in a small world, where a rural chinese butcher who contracts a new type of deadly flu virus can infect a visiting international traveller, who later infects attendees at a conference in a hong kong hotel, who within weeks spread the disease to vietnam, singapore, canada, and ireland. fortunately, the virulence of the severe acute respiratory syndrome (sars) was matched by the passion and skill of a worldwide community of scientists, health care workers, and institutional leaders who stewarded a highly successful campaign to quarantine and treat those who were infected while identifying the causes of the disease and ways to prevent its spread. in such a world, we depend on expert practitioners to connect and collaborate on a global scale to solve problems like this one – and to prevent future ones. as global citizens. what does it mean to 'think globally and act locally'? does global stewardship primarily imply building international organisations that address social and environmental issues to compensate for the economic focus of global corporations? is such a global perspective sufficient to address issues that are essentially local? how can we connect the power and accessibility of local civic engagement with active stewardship at national and international levels? what are the design criteria for such a system and what might it look like? we believe there are three fundamental design criteria that help specify essential characteristics of a world learning system capable of addressing the scope and scale of the global challenges we face today. problems such as overpopulation, world hunger, poverty, illiteracy, armed conflict, inequity, disease, and environmental degradation are inextricably interconnected. moreover, they are complex, dynamic, and globally distributed. to address such challenges, we must increase our global intelligence along several dimensions: cognitive, behavioural, and moral. we must increase, by orders of magnitude, our societal capacity for inquiry; our ability to continuously create, adapt, and transfer solutions (churchman, ) . a world learning system that can match the challenges we face must meet three basic specifications: • action-learning capacity to address problems while continuously reflecting on what approaches are working and why -and then using these insights to guide future actions. • cross-boundary representation that includes participants from all sectors -private, public, and nonprofit -and from a sufficient range of demographic constituencies and professional disciplines to match the complexity of factors and stakeholders driving the problem. • cross-level linkages that connect learning-system activities at local, national, and global levels -wherever civic problems and opportunities arise. civic development is essentially a social process of action learning, in which practitioners from diverse sectors, disciplines, and organisations work together to share ideas and best practices, create new approaches, and build new capabilities. the full potential of this learning process is only realised when it connects all the players at various levels who can contribute to it. there are a number of organisations -including the united nations, the world bank, and an array of nongovernmental organisations such as doctors without borders, the world council of churches, oxfam international, major foundations, and many others -whose mission is to address worldwide problems. but these organisations typically focus on solving the manifestations of problems -eliminating land mines from war-torn regions or reducing the incidence of aids, for instance. given the urgency of these problems, it is understandable that these organisations do not focus on the underlying learning capacity of a city or country. while it is essential to address these and other urgent problems on their own terms, our society's longterm capacity to solve them at both local and global levels will nevertheless require step-change increases in our foundational capacity for intelligent social action. what is the nature of large-scale learning systems that can operate at local and global levels? how can we take steps to create such learning systems? to what extent can they be designed and what does design even mean in such a context? these learning challenges are among our world's most urgent as we find ourselves today in a race between learning and self-destruction. fortunately, we have examples of transformative, inquiry-oriented learning systems in hundreds of private-sector organisations, with a growing number in public and nonprofit organisations as well -at both organisational and interorganisational levels. strong, broad-based secular forces are driving this movement. most organisations today, including domestic firms as well as multinationals, have been forced to confront large-scale learning issues to compete in the knowledge economy. there is much we can learn from the experience of organisations about how to increase our society's collective intelligence. the most salient lesson is that managing strategic capabilities primarily entails supporting self-organising groups of practitioners who have the required knowledge, use it, and need it. we call these groups 'communities of practice' to reflect the principle that practitioners themselves -in active collaboration with stakeholders -are in the best position to steward knowledge assets related to their work. a well-known private-sector example of such practitioner stewardship is the network of 'tech clubs' that chrysler engineers formed in the early s (see wenger et al., , chapter ) . the company had just reorganised its product-development unit into 'car platforms' focused on vehicle types (small cars, large cars, minivans, etc.). design engineers with specialties related to the various vehicle components -such as brakes, interior, and windshield wipers -organised communities of practice to foster knowledge sharing across car platforms. the cross-boundary sharing of these communities was a critical success factor for the reorganisation. we are now seeing a proliferation of organisations fostering the development of communities of practice across industry sectors, geographic locations, and various elements of the value chain. communities of practice are not new. they have existed since homo sapiens evolved , years ago, but organisations have now become increasingly explicit about cultivating these communities. distinctive competencies in today's markets depend on knowledge-based structures that are not restricted by formal affiliation and accountability structures. the most distinctive, valuable knowledge in organisations is difficult or impossible to codify and is tightly associated with a professional's personal identity. developing and disseminating such knowledge depends on informal learning much more than formal -on conversation, storytelling, mentorships, and lessons learned through experience. this informal learning, in turn, depends on collegial relationships with those you trust and who are willing to help when you ask. informal learning activities and personal relationships among colleagues are the hallmarks of communities of practice. hence, we see an increasing focus on informal community structures whose aggregate purpose is to steward the learning of an organisation and its invaluable knowledge assets. communities of practice have three basic dimensions: domain, community, and practice. a community's effectiveness as a social learning system depends on its strength in all three structural dimensions. • domain. a community of practice focuses on a specific 'domain,' which defines its identity and what it cares about -whether it is designing brakes, reducing gun violence, or upgrading urban slums. passion for the domain is crucial. members' passion for a domain is not an abstract, disinterested experience. it is often a deep part of their personal identity and a means to express what their life's work is about. • community. the second element is the community itself and the quality of the relationships that bind members. optimally, the membership mirrors the diversity of perspectives and approaches relevant to leading-edge innovation efforts in the domain. leadership by an effective 'community coordinator' and core group is a key success factor. the feeling of community is essential. it provides a strong foundation for learning and collaboration among diverse members. • practice. each community develops its practice by sharing and developing the knowledge of practitioners in its domain. elements of a practice include its repertoire of tools, frameworks, methods, and stories -as well as activities related to learning and innovation. the activities of a community of practice differ along several dimensionsface-to-face to virtual; formal to informal; public to private. further, activities are orchestrated according to various rhythms -for instance, in one community, listserv announcements come weekly, teleconferences monthly or bi-monthly, projects and visits occur when an opportunity presents itself, back-channel e-mails and phone calls are ongoing; and the whole group gathers once or twice a year face-to-face (see fig. . ). these activities form an ecology of interactions that provide value on multiple levels. beyond their instrumental purpose of creating and sharing knowledge, they increase the community's 'presence' in members' lives and reinforce the sense of belonging and identity that are the foundation for collective learning and collaborative activities. communities of practice do not replace more formal organisational structures such as teams and business units. on the one hand, the purpose of formal units, such as functional departments or cross-functional teams, is to deliver a product or service and to be accountable for quality, cost, and customer service. communities, on the other hand, help ensure that learning and innovation activities occur across formal structural boundaries. indeed, a salient benefit of communities is to bridge established organisational boundaries in order to increase the collective knowledge, skills, and professional trust of those who serve in these formal units. for instance, at daimlerchrysler, brake engineers have their primary affiliation with the car platform where they design vehicles. yet they also belong to a community of practice where they share ideas, lessons learned, and tricks of the trade. by belonging to both types of structure, they can bring the learning of their team to the community so that it is shared through the organisation, and, conversely, they can apply the learning of their community to the work of their team. pioneering, knowledge-intensive organisations have recognised that beyond the formal structures designed to run the business lies a learning system whose building blocks are communities of practice that cannot be designed in the same manner as formal, hierarchical structures. communities of practice function well when they are based on the voluntary engagement of members. they flourish when they build on the passions of their members and allow this passion to guide the community's development. in this sense, communities of practice are fundamentally self-governed. our experience suggests, however, that while communities do best with internal leadership and initiative, there is much that organisations can do to cultivate new communities and help current ones thrive. the intentional and systematic cultivation of communities cannot be defined simply in terms of conventional strategy development or organisational design. rather, sponsors and community leaders must be ready to engage in an evolutionary design process whereby the organisation fosters the development of communities among practitioners, creates structures that provide support and sponsorship for these communities, and finds ways to involve them in the conduct of the business. the design of knowledge organisations entails the active integration of these two systems -the formal system that is accountable for delivering products and services at specified levels of quality and cost, and the community-based learning system that focuses on building and diffusing the capabilities necessary for formal systems to meet performance objectives. it is crucial for organisational sponsors as well as community leaders to recognise the distinct roles of these two systems while ensuring that they function in tandem to promote sustained performance. the fundamental learning challenges and nature of responses in business and civic contexts are very similar. the size, scope, and assets of many businesses create management challenges that rival those of large cities, or even small countries. in both cases, one needs to connect practitioners across distance, boundaries, and interests in order to solve large-scale problems. organisations have found that communities of practice are extremely versatile in complementing formal structures. they are known for their ability to divide and subdivide to address hundreds of domains within and across organisations; they lend themselves to applications where scalability, broad scope, and the need for extensive, complex linkages are relevant. hence there is much we can learn from the early, highly developed business examples. the approaches for building largescale learning systems in organisations -by combining both formal and informal structures -provide a blueprint for thinking about how to build such systems in the messy world of civil society. communities of practice already exist in the civic domain, where they complement place-based communities as well as the ecology of formal organisations, including businesses, schools, churches, and nonprofits. in the civic arena as well as in organisations, our challenge is not to create communities of practice so much as to foster them more systematically. our analysis of societal learning systems -whether at local, national, or international levels -focuses on cities (which we define as an entire metropolitan region) as highleverage points of entry for a number of reasons. for one, as of the year , there are more humans on the planet living in cities than outside them. in , there were twenty megalopolises in the world with more than million people, and by there will be nearly forty. cities have always been the font of new ideas, new applications of technologies, new cultural movements, and social change. they constitute natural nodes in a network for disseminating innovations. in the problems they face and the opportunities they offer, they also provide a microcosm of the world. finally, cities possess an organisational infrastructure and established leadership groups with the potential to see the value and to sponsor the design of a local learning system. in many cities, multisector coalitions or alliances are formed to take on a pressing issue such as improving urban schools, increasing access to low-income housing, cleaning up a business district, or building a stadium, park, or cultural facility (see grogan and proscio, ) . these coalitions, however, generally do not take sustained responsibility for stewarding a civic domain or for bringing together the full array of stakeholder constituencies to identify and address short-and long-term priorities. one way to assess the level of civic stewardship in any city or region is to map the prevalence, inclusiveness, and effectiveness of civic communities of practice (also known as coalitions, associations, partnerships, and alliances, among other terms) who take responsibility for clusters of issues related to particular civic domains, such as education, economic development, health, housing, public safety, infrastructure, culture, recreation, and the environment. the reality is that in many cities these domains have no explicit stewardship, or they are left to public agencies the city as a learning system: stewarding the 'whole round' of civic domains or to a menagerie of disparate, often competitive and conflicting organisations that carve out small pieces of the puzzle -regarding housing availability, for examplebut do not coordinate efforts or leverage a common base of expertise and resources. the city, re-imagined as a learning system, consists of a constellation of crosssector groups that provide stewardship for the whole round of civic domains (see fig. . ) . cultivating a learning system at the city level means taking stock of the current stewardship capacity in the city and accounting for the array of civic disciplines and the quality of active communities of practice stewarding them. this city-level assessment provides a template for what a nation can do. at the nation level, leaders might evaluate a representative sample of major cities and regions as a baseline assessment of its civic stewardship capacity. by extension, an evaluation of the top strategic cities in the world could provide a benchmark for our civic learning capacity at a global level. at the national and global levels, the analysis also considers the strength and quality of linkages across cities both within and across nations. of course, even at the city level, there are subsectors and neighbourhoods that are fractal elements of the city, each with its own whole round of civic practices, and among which neighbourhood-to-neighbourhood linkages are as instrumental as ones that connect cities and nations. a city-based initiative to promote economic development in chicago provides an example of an effort designed to leverage communities as agents of civic development. in , the city of chicago established a cross-sector coalition, the mayor's council of technology advisors, to create , new high-tech jobs in the chicagoland region. the coalition leaders began by pulling together a group of forty-five civic leaders to brainstorm ways to achieve this goal. according to a study commissioned before the group met, the greatest challenge they faced was encouraging business development in high-tech industries such as telecommunications and biotech. a related challenge was cultivating local sources of seed capital for start-ups in these industries. the result of the group's first meeting was a slate of long-and short-term initiatives -including the introduction of technology in schools; encouraging young women and minorities to explore technology careers; and building a stronger digital infrastructure in the city, especially in underserved areas. several of the groups focused on initiatives specific to the industry sectors identified in the initial study: telecommunications, software development, biotech, venture capital, and emerging areas such as nanotechnology. the industry groups were particularly successful in this initiative, largely because they were able to coalesce communities specific to development challenges in each industry sector. the civic leaders in chicago understood that coalescing communities of practice -in this case, along industry lines -was the foundation for building relationships, generating ideas, and catalysing business initiatives. as one leader put it, 'our first objective was to create communities, period. the technology industries were fragmented without a sense of commonality. for example, we have more software developers than in silicon valley, but here it's only % of the workforce. so we started getting people connected and networked and building a sense of community in our high-tech sectors.' the chicago biotech network (cbn) is one of the more mature high-tech communities in chicago and provides an illustration of the influence and stewardship such a community can have over time. cbn started as a grassroots group that held about five seminars a year for diverse constituents interested in biotech developments. at first, it was more for individuals interested in life sciences. then companies (such as abbott laboratories and baxter, two fortune pharmaceuticals located in the chicago area), started to attend the meetings as well, and they brought different perspectives. over time, the community came to include scientists, university deans, lawyers, venture capitalists, angel investors, city and state business development staff, and others. anywhere from twenty-five to two hundred people showed up at the meetings, which were held at various places and sponsored by members. these gatherings provided an opportunity for members to discuss science and industry trends and build relationships. one of the leaders summarised the community's evolution: 'early on, people mostly came for the personal value of networking and discussing ideas. now the domain of the community is to promote science and business development in the biotech sector in the chicago area. we focus on science ideas, business development know-how, and knowledge transfer processes.' offshoots of community activities include targeted events that link scientists, angel investors, and large pharmaceuticals to fund biotech startups that can commercialise promising innovations coming out of university labs. on a broader level, the community has helped increase biotech lab space in the city, lobbied at state and federal levels for increased research funding, and recruited biotech companies to locate in chicagoland. the leader of the chicago-based biotech community estimated the value of the community's activities for generating start-ups and, by extension, job creation in the region: 'i can't point to anything specific, but our events have brought structure to the interface between r&d scientists and the venture community; and we've gone from very little venture funding to the point where we now have $ million coming to various biotech companies this year.' the chicago biotech network illustrates how an industry-based community of practice can serve as a powerful force for civic development. in this case, the focus was on economic development, but the key point is that strong stewardship of civic issues, even in the hard-nosed area of industry development, depends on vital communities of practice. the purpose of the communities was not only to provide professional development and networking opportunities but also to cultivate thriving high-tech industries in chicagoland. these communities advocated for their domain as a strategic focus for the city, built relationships among community members from various backgrounds, and shared know-how among practitioners. finally, as one community leader stated, they worked to serve the city they loved, and ultimately their children, who would inherit their civic legacy. communities of practice can also provide powerful stewardship for civic issues at the national level by connecting innovative civic groups across cities. the safecities community, for example, was organised in march by vice president al gore's reinventing government initiative to reduce gun violence in the united states. the announcement of the safecities community coincided with publication of the fbi's crime-rate statistics, which showed significant variation across cities in injuries and fatalities caused by gun violence. senior executives in the national partnership for reinventing government (npr) office began by convening officials from relevant agencies and developing a shared vision for what the network would be about and how they would work together. they sent out an invitation to cities and regions nationwide and selected ten coalitions to participate in the safecities communitybased on criteria that included multisector collaboration, a track record of innovation, and commitment to improved results. these local coalitions provided stewardship for public safety issues in their cities as did the industry-focused communities in chicago. a striking characteristic of the initiative was that it offered participants no funding -the value of participation was to get connected, to learn, and to enhance the capacity to reduce gun violence. the scale of the initiative was also distinctiveconnecting civic coalitions from across the nation for the purpose of sharing ideas, collaborating on innovation initiatives, and helping to shape policy at local, state, and federal levels. the safecities community can be described in terms of the three structural dimensions of communities of practice. each of the coalition members was focused, broadly speaking, on issues related to the domain of public safety. their specific domain targeted a subdomain within this area -defined as reducing injuries and fatalities due to gun violence. the specificity of this domain was crucial for coalescing a community with overlapping interests, focusing its learning activities, and attracting sponsors. the community was composed of members at local and national levels and from various disciplines and constituencies, such as officials from the fbi, the bureau of alcohol, tobacco, firearms and explosives, and an assortment of divisions within the justice department at the national level; and mayors, police chiefs, faith leaders, hospital and social workers, school principals, neighbourhood activists, and district attorneys at the local level. finally, the practice of safecities members included community policing strategies, after-school programs, crimemapping methods, prosecutorial strategies, the design of local gun-possession laws, and ways to improve the interaction between at-risk youth and law-enforcement professionals. after a couple of preliminary teleconferences, safecities was launched at a faceto-face meeting in washington, d.c., explicitly billed as a community-of-practice launch. the sponsors and community coordinating team (based in the npr office) posed three basic questions for the group to address during the -day conference: what is safecities about (domain)? who is part of safecities (community)? what does safecities do (practice)? the conference included opportunities for members to meet informally, including an evening reception and knowledge-sharing 'fair'. a nationally renowned police chief from highpoint, north carolina, gave a talk about his city's success at reducing gun violence through both rehabilitation and enforcement efforts that focused on the city's most violent individuals. (he was so impressed with the gathering that he asked npr officials if his coalition could join, and they agreed to make his group an honorary member.) during the conference, members outlined a design for how they would learn together -including teleconferences, visits, a website, and other activities. the issues they identified became topics for their biweekly teleconferences. the conference was instrumental in coalescing members around a shared agenda and building trust and reciprocity. the safecities teleconferences subsequently became more active and members were more forthcoming about selecting topics and offering to speak to the group about their experiences. fostering 'community' -a sense of mutual trust, shared identity, and belonging -took on more prominence as an important structural element that made safecities successful. one of the outcomes of the initial conference illustrates the value of network participation for members. after hearing the highpoint police chief talk about his success, groups from ft. wayne, indiana and inkster, michigan -including police chiefs, mayors, and faith leaders from both cities -visited highpoint and observed programs in action. both coalitions then adapted the highpoint model for their own locales with coaching from highpoint. safecities operated successfully from march until june , spanning the transition from a democratic to a republican administration. political appointees from both parties, as well as senior civil servants in the justice and treasury departments (where the sponsorship was primarily based) believed in the crosslevel, cross-sector approach that safecities embodied. sponsors were impressed to see such active participation on the part of senior civic leaders, even though they received no government funding for participating. these local leaders felt strongly about the value safecities provided -in terms of ideas, access to expertise, and opportunities for national visibility and influence based on local success. agency sponsors ultimately decided to close the safecities community in favour of a more conventional federal program. the decision confused many of the participants, given the minimal federal costs associated with the initiative, principally the cost of funding the community's full-time coordinator (a junior staff person, albeit a talented leader) and intermittent attention by agency champions. the coordinator's role was particularly important -arranging speakers for teleconferences, documenting insights on the website, arranging peer-to-peer visits, and coordinating with state and federal officials. the loss of the coordinator and agency attention was a fatal blow to the community. in its place, the us justice department enacted a new program, called safeneighborhoods, which provided funding for local initiatives such as after-school programs. the program managers intended to build on the safecities foundation, but they did not appreciate the distinctive characteristics of the community -opportunities for peer-to-peer learning and collaboration across cities, sectors, and levels of government. while safecities members were glad that the government was providing new funds to support local initiatives, they passionately argued that such funding could never substitute or compensate for the value of the safecities community. the safecities story thus validates the power of cross-city communities of practice while highlighting a key challenge: how to educate senior leaders with the power to sponsor such initiatives -from public, private, or nonprofit sectors (including foundations). these and other questions about starting, sustaining, and scaling such initiatives must be addressed for communities to succeed at local, national, and international levels. at the international level there are a myriad of professional groups and organisations that focus on global civic issues. in recent years a number of these have developed a stronger emphasis on peer-to-peer learning and innovation among members from diverse disciplines. the ayuda urbana initiative was started in conversations about developing municipal capabilities between world bank urban specialists and several mayors of capital cities in the central american and caribbean region. they recognised the value of connecting with peers across borders to address problems and challenges that all cities in the region face. a group of ten cities decided to participate in the initiative: guatemala city, havana, managua, mexico city, panama city, san josé, san juan, san salvador, santo domingo, and tegucigalpa. the people involved in the project include the mayors and their staff in each of the ten cities. additional partners include the world bank, which provides overall coordination, some regional organisations to provide local legitimacy, and the british and dutch governments to provide funding. the project was to create a constellation of communities of practice that would take advantage of the knowledge available in the participating cities. the domains would focus on a challenge of urban development and management the cities shared, including e-government, urban upgrading, environmental sanitation, municipal finances, urban transportation, renovation of historical city centres and poverty alleviation, and disaster prevention and management. the communities would consist of urban specialists in each domain from the participating cities and from local organisations. together they would build their practice by comparing experiences and sharing resources across cities, with input from world bank experts about what had been learned elsewhere. the communities of practice were officially launched through a series of -day workshops, each focused on one of the topics. each workshop brought together specialists from the participating cities as well as a few world bank experts. the purpose of the workshops was to • create an initial forum to develop relationships and trust through face-to-face interactions among participants • provide an opportunity for each participating city to share its experience • engage participants in a discussion of lessons learned based on presentations by world bank experts • establish a prioritised list of the most pressing issues and most frequently asked questions • introduce web-based tools for use in facilitating an ongoing learning process and train participants to use the system • choose a person to coordinate the collection of resources to be shared via e-mail and the web site. the project has created an interactive website, available to the public, which serves as a repository for the various communities of practice. the site includes a library of resources, downloadable manuals, bibliographic references, and proceedings of meetings. in addition, the site hosts an online forum to give participants the opportunity to discuss issues, ask questions, share relevant information, and stay in touch. for example, a community member asked how to price waste management services. another member from san salvador responded with a posting that explained how his city determined the price of such services. the ayuda urbana initiative illustrates the value of collaboration across borders to address urgent issues in urban development, and it raises salient issues common to international communities. creating communities of practice among cities from different countries is not all that different from similar efforts within a country, but there is additional complexity. the regional focus of ayuda urbana meant that participants spoke the same language and shared a cultural context. the situation would have been more complex if the project had expanded beyond the region. another issue is the role of the convener when members do not share the same national government. sponsorship has to come from an organisation like the world bank, which can appreciate the vision of cross-border communities and the subtleties involved in cultivating such communities. indeed, ayuda urbana represents the latest development of a broader initiative at the world bank to focus on knowledge as a key lever in the fight against poverty. the bank started an initiative in to support the development of communities internally, and since then the number of communities has grown from twenty-five to more than a hundred -and the influence of several has been considerable. an external study of the communities found that they were the 'heart and soul' of the bank's new strategy to serve its clients as a 'knowledge bank.' the ayuda urbana initiative highlights the importance of a skilled convener who is committed to a community-based approach as a way to address societal challenges. in this case, the world bank is applying the same knowledge strategy with client countries that it has been applying internally. indeed, the bank's experience in cultivating communities of practice was critical to the success of the ayuda urbana project. the result is a new model for facilitating knowledge development among countries. experts at the bank consider it their task not just to provide their knowledge to clients but to build communities of practice among them as a way to develop their capabilities. the bank experts still have a role to play, but not in a one-way transfer. instead, their contribution takes place in the context of a community of practice that emphasises peer-to-peer learning. this approach models a shift in the traditional relationship between sources and recipients of knowledge. cultivating civic learning systems involves many of the challenges that organisations face in cultivating internal learning systems, but many of these become amplified in the civic context. the domains are especially complex; the communities tend to be very diverse; and the practices involve different disciplines, varied local conditions, and less well-defined opportunities to work together on projects. but perhaps the greatest challenge is the scale required for civic learning systems to leverage their full potential and match the scale of the problems they address. how do you significantly increase the scale of a community-based learning system without losing core elements of its success -identification with a well-defined domain, close personal relationships, and direct access to practitioners for mutual learning? the principle to apply is that of a fractal structure (see gleich, ; wheatley, ) . in such a structure, each level of substructure shares the characteristics of the other levels. applying such a design principle, it is possible to preserve a small-community feeling while extending a system from the local to the international level. local coalitions such as the chicago biotech network and each of the safecities partners created a local focus of engagement that made it possible for members to participate in broader networks at national and international levels. the idea is to grow a 'community of communities' in which each level of sub-communities shares basic characteristics: focal issues, values, and a practice repertoire. each dimension of a community of practice provides opportunities for the constitution of a fractal learning system. fractal domain. in many cases, domains may start more broadly and eventually subdivide as members discover nuances and opportunities to focus on different subtopics or to apply a topic to different localities. ayuda urbana, for example, is spawning subdomains related to particular civic practices and engaging members with particular expertise and interest in those areas. the city-based coalitions of safecities focused on the same issues but within the context of their situations. all these subdivisions retain a global coherence that gives the entire system a recognisable identity and allows members to see themselves as belonging to an overall community even as they focus on local issues. fractal community. topical and geographic subgroups help create local intimacy, but they must be connected in ways that strengthen the overall fabric of the network. a key to this process is multimembership. members such as those in the safecities network join at the local level but end up participating in multiple communities in ways that help interweave relationships in the broader community. as a result, they become brokers of relationships between levels in equivalent types of communities. this works because trust relationships have a transitive character: i trust people trusted by those i trust. the police chief in highpoint, for example, had developed strong relationships with fbi officials, which in turn encouraged his peers to work more closely with federal agents. fractal practice. useful knowledge is not of the cookie-cutter variety. local conditions require adaptability and intelligent application. a fractal community is useful in this regard because it allows people to explore the principles that underlie a successful local practice and discuss ideas and methods in ways that make them relevant to circumstances elsewhere. a fractal community can create a shared repertoire and develop global principles while remaining true to local knowledge and idiosyncrasies. moreover, if one locality has a problem or an idea, the broader community provides an extraordinary learning laboratory to test proposals in practice with motivated sites. in the safecities community, local coalition members were ready and willing to share results quickly and convincingly with peers and then translate these into action. a safecities member from michigan reported, for example, that a visit to meet with innovating colleagues in highpoint 'added ideas and motivation to an initiative that we had been planning for a year. once our mayor visited, he wanted to do it.' highpoint members then helped the michigan coalition adapt their model successfully. each locality constitutes a local learning experiment that benefits from and contributes to the overall learning system. the key insight of a fractal structure is that crucial features of communities of practice can be maintained no matter how many participants join -as long as the basic configuration, organising principles, and opportunities for local engagement are the same. at scale, in fact, the learning potential of the overall network and the influence at local levels can increase significantly. the key challenge of a large-scale learning system is not whether people can learn from each other without direct contact but whether they can trust a broader community of communities to serve their local goals as well as a global purpose. this depends on the communities at all levels -local, state, national, and international -to establish a culture of trust, reciprocity, and shared values. developing this social capital across all levels is the critical success factor for going to scale. the evolution of a learning system must therefore be paced at the time-scale of social relationships, not according to an externally imposed objective to achieve short-term results. organisers need be careful not to scale up too fast. they need to establish trust and shared values at different levels of aggregation through various mechanisms, including a network of trusted brokers across localities. in the civic domain, the institutional context can be fragmented and the issues politically charged. this presents particular challenges for finding sponsorship, organising support, and managing potentially conflicting constituencies. sponsorship. all three communities depended on sponsorship from executives such as the mayor of chicago, the vice president of the united states, or representatives of the world bank and funding governments. sponsorship is especially important for large-scale learning systems that will require additional activities to connect localities. it can be difficult, however, to identify the 'client' who benefits when a learning system is so dispersed. when you try to engage a city to sponsor a constellation of cross-sector communities of practice to address an array of civic domains, where do you start? a civic community of practice is such an innovative approach that leaders typically do not have enough context to see its value. sustained sponsorship, furthermore, requires community members to make the value visible enough to demonstrate the payoff of sponsor and stakeholder investments. finally, the legitimacy of sponsorship can be contested in a politically fractious context, where the role of institutions such as the world bank or the federal government in orchestrating local affairs is not universally welcome. support. process support was key to the communities we have described. they needed help with local event planning, finding resources, coordinating projects across levels, finding others to connect with, and designing ways to connect. all three communities needed facilitation at meetings, and safecities and ayuda urbana both required moderation for their online interactions. a challenge for civic learning systems is that there may be no clearly defined institutional context or financing model for process support. the ayuda urbana experience also suggests that one must be ready to provide a lot of support at the start to help develop members' local capabilities and prepare the group to operate more independently. civic communities of practice also need help to build a technology infrastructure for communicating across geographies and time zones, and for building accessible knowledge repositories. this can be particularly difficult when communities span multiple organisational contexts. conflict management and collaborative inquiry. civic communities of practice organised around contentious issues such as housing, education, and health will face considerable obstacles from formal and informal groups with entrenched and opposing views and interests. there are good reasons these basic conflicts have been so intractable: views and values are divergent and trust among players is often low. moreover, businesses, nonprofits, governments, and universities have reasons to resist the development of communities of practice. these formal organisations and their leaders have developed established, privileged positions in society, and changes initiated by community members may not be welcomed. inevitable mistakes early on could further diminish low trust levels and reduce the low-to-medium public readiness to invest time in these unfamiliar social commitments. communities that face such tensions will have to develop expertise in collaborative inquiry and conflict management and learn to build trust over time through activities that enable members to find common ground. there is an emerging, global zeitgeist about community and learning. these issues have become commonplace in multinational organisations -private, public, and nonprofit. still, when one looks at the learning requirements of the world, the complexity of the required learning system may seem so overwhelming as to discourage action. but the advantage of a community-of-practice approach is that it can be evolutionary -starting small and building up progressively, one community at a time. it is not necessary to have broad alignment of the kind required for designing or changing formal structures. we can start wherever there is opportunity, energy, and existing connections. we can build on what already exists. indeed, we have found successful examples of initiatives to cultivate learning systems: within cities, across cities at a national level, and across cities internationally. taken together, these early examples paint a picture of what a mature world learning system may look like, and they give some indication of what it will take to cultivate such a system. we now need to develop frameworks for describing the organisational nature of civil society as a community-based action-learning system -and tools and methods for cultivating such systems. this chapter is thus not only a call to action and a proposal for what is possible. it also calls for a new discipline. a discipline that expands the field of organisation design and applies analogous principles at the world level. a discipline that promotes the development of strategic social learning systems to steward civic practices at local, national, and global levels. a discipline whose scope is the world and whose focus is our ability to design the world as a learning system -a discipline of world design. this chapter is only a beginning. there are many established and emerging disciplines -political science, economic sociology, social network analysis -that can inform the work in this domain. a community-based approach to world design is not a silver bullet for solving the problems of the world. while the emphasis here has been on community, a complete discipline of world design would address how the power of communities can be most fully realised by aligning community activities within a broader ecology of formal and informal structures -institutions, cultural groups, laws, and social networks. to steward such a discipline, we need a community of practice ourselvesor indeed a constellation of communities on the topic of world design, at local, national, and global levels. for instance, a small group of people passionate about civic development may gather to outline an approach to cultivating the city as a learning system. they might connect with various civic leaders and extant initiatives, and organise a gathering for the purpose of assessing the implicit structure of the city today as a practice-based learning system. which practices have active stewardship? what groups are providing it with what sorts of initiatives and results? who is represented? where is the focus of sponsors -such as local government, corporations, universities, the media, and foundations? to what degree is there a shared language and understanding across constituencies of the nature of crosssector civic governance and how to participate effectively? these questions become the concerns of 'meta-communities' at various levels, which can link together -as a community of meta-communities -and build their own practice to support the development, effectiveness, and influence of civic communities at all levels. the complexity and intelligence of such a social learning system must match the complexity of world-design challenges and the knowledge requirements associated with them. the messy problems of civil society require a commensurate capacity for learning, innovation, and collaboration across diverse constituencies and levels. the challenge to intentionally and systematically design and develop the world as a learning system must be a global, diverse, interwoven social movement. this social movement is not simply about advocacy; nor is it a political revolution. rather, it is about the transformation of civic consciousness -a way of thinking about governance as an action-learning process, as a role for civic actors across sectors, as a process that links the local and global in clear and concrete ways. and it depends, fundamentally, on individuals finding a way to participate locally -whether that means a community of place or practice, or both -a way that gives them access to the entire learning system. let us begin. the division of labor in society chaos: making a new science organizing for economic development in chicago: a case study of strategy communities of practice: a new tool for managers,' ibm endowment for the business of government our world as a learning system: a communities-of-practice approach ayuda urbana: a constellation of communities of practice focused on urban issues and challenges in central america, mexico, and the caribbean region. written for the beep project of the european union cultivating communities of practice leadership and the new science key: cord- -h ld authors: wood, d. brian; jordan, jaime; cooney, rob; goldfam, katja; bright, leah; gottlieb, michael title: conference didactic planning and structure: an evidence-based guide to best practices from the council of emergency medicine residency directors date: - - journal: west j emerg med doi: . /westjem. . . sha: doc_id: cord_uid: h ld emergency medicine residency programs around the country develop didactic conferences to prepare residents for board exams and independent practice. to our knowledge, there is not currently an evidence-based set of guidelines for programs to follow to ensure maximal benefit of didactics for learners. this paper offers expert guidelines for didactic instruction from members of the council of emergency medicine residency directors best practices subcommittee, based on best available evidence. programs can use these recommendations to further optimize their resident conference structure and content. recommendations in this manuscript include best practices in formatting didactics, selection of facilitators and instructors, and duration of individual sessions. authors also recommend following the model of clinical practice of emergency medicine when developing content, while incorporating sessions dedicated to morbidity and mortality, research methodology, journal article review, administration, wellness, and professionalism. supporting data, the authors based recommendations on their experience and consensus opinion. the entire cord best practices subcommittee reviewed the manuscript after which time it was posted on the cord website for review by the entire cord community. many factors may influence programmatic decisions regarding timing, frequency, and duration of didactic curricula in addition to the desire to optimize education. these may include regulatory requirements, clinical work schedules, locations of faculty and trainees, personnel (teachers and learners), and space availability. the concentrated blocked weekly didactic format (i.e., a single, dedicated conference half day per week) is highly prevalent in other specialties such as family medicine and neurology, in addition to em. , residents appreciate having protected educational time and, compared to shorter daily formats, the blocked weekly didactic structure has demonstrated higher learner satisfaction, improved attendance, and fewer interruptions. [ ] [ ] [ ] [ ] while learners perceive improved learning with this format, studies have failed to demonstrate differences in objective outcomes such as scores on standardized tests or board examinations. [ ] [ ] [ ] [ ] [ ] however, given the perceived and logistical benefits, including improved attendance, which is essential to maintaining accreditation, combined with the nature of em clinical schedules, the authors recommend the blocked weekly format. the acgme places certain requirements on programs regarding faculty participation in didactics. these include that each core faculty member must attend at least % of planned didactic experiences and that em faculty members must present at least % of resident conferences. while there is limited data evaluating faculty conference attendance and objective learning outcomes, one study found that higher faculty conference attendance was associated with higher pass rates on em oral boards for trainees. additionally, residents perceive that faculty presence at conference facilitates learning. , one approach to increase faculty presence at conference would be to offer incentives for attending conference. providing continuing medical education credit for didactic conferences can also increase faculty attendance. conference didactics are most often presented by faculty or residents. , , , , some have advocated for residents to give didactic lectures to ease the burden on faculty time and sharpen resident public speaking skills. while residents perceive that faculty lectures greatly contribute to their educational experience, ,l limited data has demonstrated that residents can learn from resident-given lectures, and that no difference in learning outcomes (e.g., test scores, board passage rates) were found between resident-given lectures vs faculty-given lectures. , , additionally, it may be appropriate to incorporate other professionals (e.g., nurses, pharmacists) as lecturers depending on the topic. smith et al found no difference between lecture evaluation scores for nurse-given lectures compared to conference didactic planning and structure faculty-and resident-given lectures. given that the specialty of em interfaces with many other disciplines, it may also be beneficial to incorporate multidisciplinary conferences with other medical professionals into the didactic curriculum to enable collaborative learning, coordinated patient care, and a better understanding of the roles of other professions. [ ] [ ] [ ] the acgme recommends the inclusion of multidisciplinary conferences as part of the resident didactic experience. limited research suggests that trainees value this type of experience , ; however, robust objective data on learning outcomes are lacking. instruction should be tailored to the level of the learner. , however, this may be especially challenging in program-wide didactic conferences in which the learners differ significantly in terms of stages of training and faculty are at varying career stages and experience. in recent years, we have seen the development of a national em curriculum specific to the training level and the nearly universal presence of a dedicated intern orientation in residency programs. , to date, there are no objective data evaluating training level-specific didactics on learning outcomes; however, faculty and residents have been shown to view this targeted instruction positively. , resident didactic instruction has traditionally been delivered via lectures despite calls for alternatives. , common criticisms of lectures include lack of engagement due to an emphasis on passive learning, overwhelming students' ability to learn by providing too much information, and waning attention due to the duration of the session. despite calls to minimize the use of lectures, data support their continued effectiveness as a teaching modality. [ ] [ ] [ ] the common criticisms can be overcome through intentional learner-centered instructional design. cognitive load theory states that there are three main components involved in the creation of long-term memories: intrinsic load; extraneous load; and germane load. while intrinsic load and germane load are generally fixed, extraneous load is highly modifiable and heavily influenced by the manner in which material is presented to learners. since the amount of working memory is generally fixed for a given person at a set time, increases in extraneous load (i.e., presenting information in an overly complex manner) will detract from learning and retention. therefore, instructors should focus on ensuring that talks are focused on delivery of information, while limiting unnecessary information or overly complex presentations of the information. multimedia learning theory informs principles of slide design and is one effective method that can be used to increase the long-term retention of taught material (table ) . with regard to the duration of lectures given at conference, the notion that shorter may be better is based on data of learner attention spans. in a classic study of medical students, stuart and rutherford found that the attention span peaked at - minutes and fell steadily thereafter, with the authors recommending that lectures not exceed - minutes. in more recent years, we have seen the implementation of shorter lectures in em both at the local and national level. , limited studies have compared shorter ( -to -minute) segments compared to the more traditional -to -minute lecture and found the learners typically prefer the shorter format [ ] [ ] [ ] ; however, few have looked at objective learning outcomes. one study by bryner did evaluate knowledge acquisition and retention between -minute and -minute lectures and found no significant difference. more research is needed to determine the optimal length of didactic sessions with an emphasis on outcome-based evaluations. when it is not possible to reduce the duration of a lecture, incorporating pauses, interactive questioning, and intermittent summarization can re-engage learners and improve attention to the content. handouts are an additional method to increase the effectiveness of lectures. while many lecturers will distribute copies of their presentations, a more effective technique is the . coherence principle: avoid extraneous words, pictures, and sounds. they can detract from learning. . signaling principle: add cues to highlight the essential materials. on-screen text can detract from learning. people learn better from graphics and narration alone as opposed to graphics, narration, and on-screen text. . spatial contiguity principle: corresponding words and pictures should be presented near each other rather than far from each other on the screen. corresponding words and pictures should be presented simultaneously rather than successively. . segmenting principle: multimedia lessons should be presented in learner-controlled segments rather than as a continuous unit. . pre-training principle: when students already know the names and behaviors of system components, they will learn more from the session. . modality principle: learning is more effective when words are presented as narration rather than on-screen text. . multimedia principle: learning is more effective when words are combined with pictures as opposed to include words alone. . personalization principle: information delivery is more effective when words are presented in a conversational style rather than formal style. . voice principle: learning is more effective when narration is spoken in a friendly human voice rather than a machine voice. . image principle: learning is not necessarily more effective when the speaker's image is added to the screen table . mayer's principles of multimedia learning. , concept of guided notes. guided notes are a hierarchical outline of the presentation with key information intentionally left blank. learners will "fill in the blanks" as the lecture progresses, thus increasing attention and discovering the relationships in the presented material. additionally, the fact that the notes are mostly complete allows for effective note-taking and allows attention to be directed at the presenter instead of the notebook. while lectures can still be effective, active learning has been shown to positively impact objective learning outcomes, by incorporating other instructional techniques. [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] active learning is "any instructional method that engages students in the learning process" and can include techniques such as games, flipped classroom, audience response systems, casebased problems, and team-based activities. real-time electronic broadcasts of lectures and video conferencing can be another good use of technology to support resident education. this has been demonstrated to be an effective educational model that is positively viewed by trainees and can improve access and attendance at didactic offerings for both residents and faculty. [ ] [ ] [ ] for training programs with multiple sites or that have struggled with maintaining the required attendance percentage for accreditation, this may be a valuable option to consider. our understanding of how learning occurs has evolved as cognitive scientists continue to refine effective methods for teaching and learning. unfortunately, effective methods are often not incorporated into medical curricula. educators should avoid using or encouraging the use of learner-initiated summarization, highlighting and underlining, mnemonics, imagery, and rereading as these techniques have not been shown to enhance learning. effective techniques with a strong effect size include practice testing and distributed practice. additionally, there is likely some benefit from the use of elaborative interrogation, self-explanation, and interleaving. practice testing is the use of no-or low-stakes tests that can be completed independently by the learners. these can include recall via flashcards, practice problems, or traditional types of test questions. teachers may choose to implement this technique using shared card decks or applications (apps), or web-based asynchronous question banks. anonymous audience-response systems are popular and have also been shown to improve student learning in medical education. , distributed practice (also known as spaced repetition) refers to the spreading out of learning over time as opposed to massed practice or "cramming." implementation of this technique can be accomplished by content mapping that allows for repeated exposure to the concepts from prior didactics, the use of handouts or summarization materials between didactic sessions, or by using email to re-expose learners to the material. elaborative interrogation involves the use of selfquestioning to enhance learning. this would involve the learner seeking out the underlying rationale or etiology using questions such as "why does this occur?" similarly, self-explanation involves directing learners to explain their logic during task completion. educators can easily incorporate this technique through simple questioning exercises during their lectures. interleaving is an education organizational technique in which multiple topics and themes are mixed and covered over time instead of having discrete blocks dedicated to single topics. the flipped classroom, also known as the reverse classroom, is an instructional design method in which independent learning, often via previously-viewed video lectures or pre-reading, is combined with face-to-face classroom activities. when studied, the flipped classroom appears to be effective [ ] [ ] [ ] ; however, caution should be exercised as recent systematic reviews have found high methodological diversity, inconsistent results, and risk of bias. , [ ] [ ] [ ] gamification is another active learning technique, which involves the utilization of games and competition to support learning. as a technique, gamification may support learning of skills, emergency department (ed) throughput, decision-making, and medical knowledge. [ ] [ ] [ ] [ ] team-based learning (tbl) is an instructional method used with increased frequency in both undergraduate medical education and graduate medical education, which is often combined with the flipped classroom model. [ ] [ ] [ ] [ ] prior to tbl, learners are expected to prepare and complete a pre-session test individually ahead of time. during the tbl sessions, learners then work in teams to solve a series of realistic, complex problems. faculty serve as facilitators encouraging peer-learning, cooperation, and ensuring the discussion stays on track. this approach requires upfront training of faculty in discussion facilitation and learner buy-in to prepare for sessions. , best practice recommendations: . didactic lectures should be administered as blocked, weekly sessions (level b; grade b). . encourage faculty attendance and participation in conference (level b; grade b). . lecture can still be an effective method to present didactic content. when this technique is used, the lecturer should ensure that their presentation complies with cognitive load theory, multimedia learning theory, and active learning principles (level a; grade b). . real-time video conferencing can be considered to improve access and attendance (level b; grade c). . educators should incorporate the use of spaced repetition and no-or low-stakes testing into didactic instruction to increase long-term retention of content (level a; grade a). . utilization of recorded lectures, flipped classroom, and gamification can supplement or replace the traditional lecture (level a; grade b). after a thorough review of the literature, we found no prospective studies evaluating which specific topics should be included in the conference didactic curriculum. for this reason, conference didactic planning and structure the core content as described by the model of the clinical practice of emergency medicine, or the "em model," is most commonly used as the de facto foundation of the conference curriculum in most residencies. while this was designed using expert consensus data, it is heavily informed by those areas most relevant to the emergency physician. in fact, during the creation of the em model, hospital data from over million ed visits were compared to its content and found to have % overlap, validating the content of the em model. the em model is further refined every three years to identify new areas to cover. as it is used to inform board certification examinations, it is important for residents to be familiar with all of the topics covered and is a critical initial reference for most conference planners. while there is no strong data to help prioritize specific subject matter during conference time, intraining examination coverage of various areas may help guide emphasis on high-yield topics. while the em model may be used as a guide for resident education, conference didactics should be viewed only as one component of resident education with its unique strengths and weaknesses. as such, rather than focusing solely on "covering" all topics in the em model, the priority of conference didactic design should be on maximizing the learning potential of this modality. additionally, some topics can best be taught through other components of resident education including clinical experience, outside reading, simulation and use of free open access medical education (foam). the acgme program requirements for graduate medical education (gme) in em mandate specific conference content to be taught as part of didactics. these include five main components listed in table . additionally, the acgme requires a number of other specific themes to be included in residency training. we suggest incorporating the following into your conference topics to assure completion of these requirements. residents should be educated in a culture of safety, including understanding safety goals, diagnostic error, response to adverse events, continuous quality improvement, and ultimate accountability of the physician for the care of the patient. this can also be combined with m&m conference sessions. professionalism residents must be aware of their professional responsibilities toward their patients and peers, as well as their relationship with the health system on a local and national level. residents should also appreciate the necessity of their own need for ongoing education after residency and how to obtain and maintain board certification. in recognition of the prevalence of depression, burnout, substance abuse, and suicidality among residents and medical students, the acgme now mandates teaching on the identification and mitigation of these concerning issues. while there is no set curriculum provided or recommended by the acgme itself, materials are available, such as the educational toolkit provided by the resident wellness consensus summit. this incorporates modules on second victim syndrome, mindfulness and mediation, and positive psychology. all residents must be able to recognize limitations in their ability to care for patients due to sleep deprivation and fatigue; they should be made aware of options for fatigue management and transition of care to another provider, should the need arise. given the limited evidence-based data on curricular content of didactics further dedicated research on possible curricular content and the weighting of topics taught may be beneficial. . curriculum presentations . quality improvement/morbidity and mortality . research seminars (including education on how to conduct and understand research in a clinical context) . journal review and evidence-based medicine concepts . administrative seminars (to include operations and administrative practices in emergency medicine) table . main components of conference didactics. . core content topics for conference should be derived from the conditions and skills described in the em model (level , grade d). . curriculum presentations, morbidity and mortality sessions, research seminars, journal review, and administrative seminars should be included as part of the conference design (level , grade d). there are several limitations to consider for this review. first, it is possible that some articles were not identified using our search strategy; however, an experienced medical librarian conducted the search with a broad search strategy using multiple databases. additionally, we searched bibliographies of all included articles, contacted topic experts, and underwent pre-submission peer review by the entire cord community. given the breadth of this topic, we were unable to address all aspects of conference planning and some components (e.g., simulation, journal club) were therefore not included in the current review. however, journal club was previously covered available at: https:// www.acgme.org/what-we-do/accreditation/common-program-requirements acgme program requirements for graduate medical education in emergency medicine pfassets/programrequirements/ _emergencymedicine_ . pdf? journal club in residency education: an evidence-based guide to best practices from the council of emergency medicine residency directors individualized interactive instruction: a guide to best 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that affect board performance increasing faculty attendance at emergency medicine resident conferences: does cme credit make a difference? the pedagogic characteristics of a clinical conference for senior residents and faculty an academic relative value unit system: do transparency, consensus, and accountability work? increasing faculty participation in resident education and providing cost-effective self-assessment module credit to faculty through resident-generated didactics the effectiveness of grand rounds lectures in a community-based teaching hospital residents as educators: a modern model resident learning and knowledge retention from resident-prepared chest radiology conferences nursing lectures during conference time are well received by both residents and faculty mental health education for medicine trainees through a primary care interprofessional case conference: promoting collaborative learning and addressing challenges cler look at morbidity and mortality conferences. th annual meeting -society of general internal medicine presented at the: celebrating generalism: leading innovation and change development of a multidisciplinary curriculum for education af trauma teams during weekly emergency medicine residency conference cross-specialty integrated resident conferences: an educational approach to bridging the gap ten cate o. cognitive load theory: implications for medical education: amee guide no the adult learner: a neglected species emergency medicine resident orientation: how training programs get their residents started a needs assessment for a longitudinal emergency medicine intern curriculum pgy-specific conference in emergency medicine alternatives to the conference status quo: addressing the learning needs of emergency medicine residents lecture halls without lectures: a proposal for medical education a controlled trial of active versus passive learning strategies in a large group setting effects of lecture information density on medical student achievement lectures for adult learners: breaking old habits in graduate medical education effectiveness of an adult-learning, selfdirected model compared with traditional lecture-based teaching methods in out-of-hospital training adult learning models for large-group continuing medical education activities comparison of the effect of lecture and blended teaching methods on students' learning and satisfaction teaching for understanding in medical classrooms using multimedia design principles cognitive constraints on multimedia learning: when presenting more material results in less understanding e-learning and the science of instruction: proven guidelines for consumers and designers of multimedia learning medical student concentration during lectures trends in national emergency medicine conference didactic lectures over a -year period bstmode (bite-sized teaching mode): an innovative approach to maximizing residents' educational efficiency through a faculty-coached peer teaching 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learning in comparison with lecture-based learning among medical students a novel teaching tool combined with active-learning to teach antimicrobial spectrum activity comparison of chiropractic student scores before and after utilizing active learning techniques in a classroom setting student knowledge and confidence in an elective clinical toxicology course using active-learning techniques comparison of lecture and team-based learning in medical ethics education learning outcomes of "the oncology patient" study among nursing students: a comparison of teaching strategies does active learning work? a review of the research tracking active learning in the medical school curriculum: a learning-centered approach rethinking residency conferences in the era of covid- residency building from your home office: effectiveness of videoconference based tele-education for emergency medicine residents and providers in vietnam e-conferencing for delivery of residency didactics videoconferencing of a national program for residents on evidence-based practice: early performance evaluation improving students' learning with effective learning techniques: promising directions from cognitive and educational psychology do questions help? the impact of audience response systems on medical student learning: a randomised controlled trial effect of an audience response system on resident learning and retention of lecture material spaced learning using emails to integrate psychiatry into general medical curriculum: keep psychiatry in mind teaching the science of learning the reverse classroom: lectures on your own and homework with faculty academic outcomes of flipped classroom learning: a meta-analysis improved learning outcomes after flipping a therapeutics module: results of a controlled trial the flipped classroom: a course redesign to foster learning and engagement in a health professions school flipping the classroom to improve student performance and satisfaction does the flipped classroom improve learning in graduate medical education? a systematic review of the effectiveness of flipped classrooms in medical education flipping the classroom in graduate medical education: a systematic review creating gridlocked: a serious game for teaching about multipatient environments serious games and blended learning; effects on performance and motivation in medical education the use of "war games" to enhance highrisk clinical decision-making in students and residents using game format to teach psychopharmacology to medical students survivor torches "who wants to be a physician? educational games in an obstetrics and gynecology core curriculum learning clinical neurophysiology: gaming is better than lectures free open access medical education (foam) resources in a team-based learning educational series a pilot study of team-based learning in one-hour pediatrics residency conferences use of learning teams to improve the educational environment of general surgery residency use of team-based learning pedagogy for internal medicine ambulatory resident teaching a narrative review and novel framework for application of team-based learning in graduate medical education the model of the clinical practice of emergency medicine creating the model of a clinical practice: the case of emergency medicine the model of the clinical practice of emergency medicine the model of the clinical practice of emergency medicine understanding by design stop the blame game: restructuring morbidity and mortality conferences to teach patient safety and quality improvement to residents educator toolkits on second victim syndrome, mindfulness and meditation, and positive psychology: the resident wellness consensus summit key: cord- -yc rbml authors: mutambara, david; bayaga, anass title: understanding rural parents’ behavioral intention to allow their children to use mobile learning date: - - journal: responsible design, implementation and use of information and communication technology doi: . / - - - - _ sha: doc_id: cord_uid: yc rbml faced with many challenges resulting in learners’ poor performance at the matriculation level, emphasis on science, technology, engineering and mathematics (stem) education is in its infancy in south african’s high schools. however, studies have shown that mobile learning (m-learning) can be used to mitigate the challenges of stem education. despite, the benefits of mobile learning to rural stem learners, its full potential has not been realized because the adoption of m-learning depends on users’ acceptance. prior studies focused on teachers’ and learners’ acceptance of mobile learning. however, little is known about parents’ acceptance of m-learning, especially in rural areas. this study explores the acceptance of m-learning by parents of rural high school stem learners. the study proposes the parents’ acceptance of m-learning model, which extends the technology acceptance model by introducing perceived social influence and perceived resources. stratified random sampling was used to select parents in the survey. partial least squares structural equation modeling (psl-sem) was used to analyze data from valid questionnaires. the proposed model explained % of the variance in parents’ acceptance of mobile learning. attitude towards the use was found to be the best predictor and the only factor that have a direct effect on behavioral intention to use mobile learning. however, all other factors have an indirect influence on behavioral intention. the findings revealed that for mobile learning to be successfully implemented in rural areas, resources need to be provided. the integration of science, technology, engineering and mathematics (stem) education is a growing area in both developed and developing countries [ ] . despite, stem's fast growth, there is a lack of a universally accepted definition of stem education [ ] . in the study [ ] , stem education was defined as "…fostering sustained engagement with the stem disciplines where students can become competent contributors and critical participants in a range of stem-related activities." what can be drawn from this definition is that stem education aims at shifting teaching practices from teacher-centered into learner-centered and problem-based learning. as stem education is in its infancy in south african's high schools, it is faced with many challenges resulting in learners' poor performance at the matriculation level [ , ] , especially in rural areas. makgato [ ] attributed this poor performance in stem-related subjects in rural areas to lack of learning materials, science laboratory and equipment to promote effective teaching and learning. lack of parental involvement in their children's education also contributes to learners' poor performance in stem-related subjects [ ] . all the challenges that rural high school stem learners face lead to demotivation when learning stem-related subjects [ ] . based on these studies [ , ] , one can conclude that there is no effective stem teaching and learning in rural high schools. studies have shown that m-learning can be used to mitigate the challenges of stem education [ ] [ ] [ ] . m-learning enables the use of visualized science experiments. this can positively influence learners' knowledge of science, which can enable them to give complete descriptions of scientific concepts [ ] . furthermore, m-learning makes studying materials available to learners anytime anywhere [ ] . one can conclude that even though there are challenges in rural high schools, learners can still benefit from mlearning as they have access to learning materials and to visualize experiments using their mobile devices [ , ] . according to kong [ ] , m-learning improves parents' involvement in their children's learning, which in turn improves learners' motivation and performance in stem-related subjects. however, despite the positive effects m-learning can bring to rural stem learners and the ubiquity of mobile devices, its adoption into the classroom is far below the expected rate [ ] . davis [ ] stated that the successful adoption of any information system contingent on the user's acceptance. as a consequence of davis' [ ] assessment, it could be argued that successful implementation of m-learning in high schools of developing countries requires investigation of all stakeholders' attitudes. a plethora of studies has been conducted to identify factors that affect the acceptance of mobile learning [ ] [ ] [ ] [ ] . however, a key issue is whether academics have adopted an adequately broad approach when investigating the attitudes of the main players in a high school instructional setting [ ] . most of these m-learning acceptance studies have concentrated on teachers [ , ] and learners [ , ] . little is known about the parents' attitude towards m-learning, especially in rural areas of developing countries. teacher and learner preferences aside, parents have the last decision on whether to use m-learning. parents' roles in m-learning include; financial support, encouragement, purchasing of the mobile device and data, monitoring that the devices are used in a meaningful way that enhances learning [ ] . in spite of parents playing an important role in the adoption of m-learning, their attitude towards mobile learning has not been given the attention it deserves [ ] . ford [ ] stressed the need to carry out studies on the acceptance of m-learning in the south african context and not to blindly follow examples in developed countries. on the basis of the argument thus far, the current research sought to examine the perceptions of parents of rural high school stem learners towards m-learning. identifying and understanding these factors is important for the successful implementation of m-learning. hence, this study used the technology acceptance model (tam) to investigate the factors that predict rural high school stem learners' parents' attitudes towards m-learning. specifically, the study seeks to answers the following research questions: rq : what is the effect of parents' perceived usefulness, perceived ease of use, attitude towards the use, perceived resources and perceived social influence on their behavioral intention to use m-learning? rq : what is the relative importance of each of these factors in explaining parents' behavioral intention to use m-learning? the findings of this study may provide more insight on m-learning acceptance in developing counties, and help policymakers and all other stakeholders in education on how to successfully implement m-learning in rural areas. literature review and model development traditionally, the integration of m-learning has considered the home environment as the basis for extending formal learning beyond the wall of the classroom [ ] . however, there is a big difference between what teachers hoped for and what mobile devices are actually being used for at home. at home mobile devices are mostly used for communication and playing games [ ] . the most effective way of integrating mlearning into schools is through involving parents [ ] . parents' beliefs about m-learning influence their children's use [ ] . studies have shown that parents have contradictory attitudes towards the integration of m-learning in children's education [ , , ] . in a study carried out by genc [ ] on the perception of parents towards mobile learning, the results show that about . % of parents were having negative perceptions, while . % were neutral while . % were having positive perceptions towards mobile learning. genc's [ ] results were congruent to bourgonjon et al's [ ] findings, who stated that some parents expressed negative perception towards the use of mobile digital games-based learning. in both studies [ , ] , parents who had positive perceptions towards the integrating technology cited the usefulness of it in their children's education. however, parents were concerned about the health and social issues associated with overexposure to technology [ ] . a plethora of studies has shown that parents' peou has a positive effect on their att and pu [ , , , , , ] . however, there is some inconsistency when it comes to the relationship between parents' peou and their bi to allow their children to use m-learning. studies [ ] and [ ] found that peou does not necessarily have a direct effect on bi. on the contrary, alshmrany et al. [ ] reported that peou has a positive direct effect on bi. tsuei [ ] studied the effect of parents' psi on their pu and peou. the results showed that parent-teacher communication positively influenced both pu and peou. however, the communication between children and their parents only influenced parents' pu but not peou [ ] . these results show that social influence plays an important role in parents' acceptance of information and communication technology (ict) learning. tsuei [ ] highlighted the need to build partnerships between schools and parents for the successful integration of ict learning. tam and the unified technology of acceptance and use theory (utaut) are the commonly used models to study factors that affect the acceptance of m-learning. in this study, tam was selected because it is considered to be robust and it is mostly used model for the study of the adoption of technology in educational contexts [ , ] . tam expounded upon the ideas of the theory of reasoned action [ ] . perceived usefulness and perceived ease of use are the two pillars of tam. these two pillars predict users' attitudes toward the use, which, in turn, affect behavioral intention to use an information system [ ] . venkatesh [ ] suggested that more variables that are context-related can be added to tam to improve its explanatory power of the acceptance of the technology in question as further explained [ ] . behavioral intention to use (bi) bi was defined by fang [ ] as," … the cognitive representation of a person's readiness to perform a given behavior", and it is considered to be the best antecedent of behavior." thus, tam assumes that parents' adoption is determined by their bi to use m-learning [ ] . attitude toward a behavior is defined as, "… the degree to which a person has a favorable or unfavorable evaluation or appraisal of the behavior studied" [ ] . that is beliefs and attitudes play an important role in rejecting or accepting m-learning [ ] . parents' attitudes towards m-learning positively affect their behavioral intention to use [ ] . this finding is congruent to the finding of davis [ ] and dutota et al. [ ] . therefore, the hypothesis: h : attitude toward use has a positive effect on behavioral intention. in the m-learning context, pu is explained as a person's perception that using mlearning will improve his or her teaching and learning [ ] . one of the main factors behind parents' adoption of m-learning is the perception that m-learning is going to improve the performance of their children [ , ] . bourgonjon [ ] studied the factors that make parents accept digital game-based learning and found that learning opportunities were the single best predictor of parents' preference for video games. if parents perceive advantages in using m-learning, their attitude towards the use of these technologies will be more positive. therefore, the hypotheses: h : perceived usefulness has a positive effect on perceived attitude towards the use. h : perceived usefulness has a positive effect on behavioral intention to use. in the m-learning context, peou can be defined as the extent to which users believe that adopting m-learning would be free from effort. when parents perceive that their children can use m-learning for learning stem-related subject with minimum effort, they will have a positive attitude towards it, will realize its utility and adopt it. thus, the hypotheses: h : perceived ease of use has a positive effect on perceived usefulness. h : perceived ease of use has a positive effect on behavioral intention to use. h : perceived ease of use has a positive effect on attitude towards the use. pr is defined as "… the extent to which an individual believes that he or she has the personal and organizational resources needed to use an information system" [ ] . perceived resources was found to have a positive effect on pu, peou and att [ ] [ ] [ ] . in the studies [ ] [ ] [ ] , researchers investigated the effects of the availability of resources on teachers' acceptance of ict into the classroom. they found that lack of laptops, computer technical support from peers negatively affected the integration of ict into the classroom. mboweni [ ] found that most of the rural parents rely on social grants and have financial problems. m-learning requires money for purchasing of devices and data. basing on the results of lim [ ] and mboweni [ ] , one can learn that rural parents' perceived resources will affect their pu and peou towards the use of m-learning. therefore, the hypotheses: h : perceived resources has a positive effect on perceived usefulness h : perceived resources has a positive effect on perceived ease of use. psi is similar to the theory of reasoned action's subjective norm [ ] , which was defined as "… a person's perception that most people who are important to him think he should or should not perform the behavior in question". in this study, psi is when parents of high school stem learners consider the view of those who are important to them whether they should or should not allow their child to use m-learning. parents of stem learners in rural areas are influenced by messages about m-learning. this was suggested by venkatesh et al. [ ] who stated that people internalize the beliefs of other people and make them part of their own belief system. if parents think that their community, children, and teachers are expecting them to accept the use of m-learning, they would have a positive attitude towards m-learning. therefore, the hypothesis: h : perceived social influence has a positive effect on perceived usefulness h : perceived social influence has a positive effect on attitude towards the use. on the basis of the theoretical underpinning, a hypothetical model is in fig. . methods the research followed a quantitative approach, where survey demographic and opinion-related data were collected from parents using a questionnaire. firstly, the data from parents were explored using descriptive statistics. secondly, the partial least squares structural equation model (pls-sem) was used to test the hypothesized model. the study adopted stratified sampling to collect data [ ] . all high schools in rural areas in king cetshwayo district were grouped using their quintiles. to ensure that homogenous elements form a stratum, schools in the same quintile were grouped. three strata were formed. simple random sampling was then used to select four schools in each stratum. simple random sampling was also used to select grade, stem learners, from the selected schools. the selected learners were given questionnaires to give to their parents and ( %) valid questionnaires were collected. using chin's [ ] recommendation of times larger than the number of items of the construct with most items, the sample size exceeds the recommended . firstly, the parents filled in questions about demographical information. secondly, respondents answered the main part of the questionnaire, which comprised of scales measuring the constructs of the model. the questionnaire was adopted from previous studies [ , ] and modified to suit the needs of the current study. the measurement instrument consists of six constructs making a total of items. the questionnaire was developed and translated into isizulu and distributed both in english and isizulu. the respondents were asked to choose the language they are comfortable with. all items were measured on a -point likert-type scale with corresponding to "strongly disagree" and to "strongly agree." partial least squares structural equation modeling (pls-sem) was used to analyze data making use of the software smartpls . one of the functions of pls-sem is the prediction of the target variable [ ] in this case rural parents whose children are pursuing stem's behavioral intention to allow their children to use m-learning. pls-sem was also used to assess the predictive power of antecedent variables. the study followed chin's [ ] two-stage approach of model analysis. first, the reliability and validity of different model variables were assessed to confirm the quality of the outer model. in the second step, the relationships within the structural model were assessed by testing the significance of the relationships, explained variance of the endogenous variables and predictive power of different variables [ ] . the outer model describes the association between items and the latent variables. convergent validity and discriminant validity of the outer model needs to be assessed [ , ] , in order to ascertain the goodness of fit of the out model. convergent validity assesses the degree to which there is a high correlation between the latent variable which are theoretically identical, while discriminant validity assesses the degree to which a construct differs from other constructs [ , ] . the results (see fig. ) show that almost all reflective indicators have loadings higher than . [ ] except att ( . ), pr ( . ) and pu ( . ). the items were returned due to the exploratory nature of the study and removing them did not result in an increase in the composite reliability [ ] . the results confirm item reliability. the results (appendix ) also confirm convergent validity as well, with cronbach's alpha (a) greater than . , composite reliability (cr) above . and average explained extracted (ave) values greater than . [ ] . the heterotrait-monotrait ratio of correlations (htmt) and the fornell-larcker criterion were used to assess discriminant validity [ ] . results (appendix ) show that all the root of ave values were higher than inter-construct correlations and all the htmt values were under . [ ] . the results confirm discriminant validity. overall, the indicator reliability, internal consistency reliability, convergent validity and discriminant validity tests conducted on the measurement model were satisfactory. after ascertaining the suitability of the outer model, the inner model was examined, and the hypotheses were tested. before assessing the inner model, the variance inflation factor (vif) was used to assess collinearity issues. all the vif values were less than [ ] , indicating that there were no collinearity issues. results in (appendix ) and fig. summarize the inner model and the hypotheses testing results. figure shows the r of the model. the model explains % of pu % of peou, % att and % of the variance of rural parents' bi for their children to use m-learning. the variance explained in rural parents' att and bi is considered moderate, while, variance explained in pu and peou is considered small [ ] . the results of fig. also shows the standardized path coefficients. the results show that all model's antecedents predict rural parents' behavioral intention to allow their children to use mobile learning for learning stem. results (appendix ) show the results of the bootstrapping procedure. the results show that all the hypotheses were supported except h and h . additionally, the results in (appendix ) show the effect size of these relations. two relations (att -> bi and peou -> att) have large effect size, pr -> peou has a [ ] . to answer research question , the observation of total effects (appendix ) was used. the results show that the best predictors of parents' bi to allow their children to use mobile learning to stem-related subjects are att, peou and pr. rq : this study sought to examine the effects of pu, peou, att, psi and pr on the behavioral intention to allow children to use m-learning for rural parents. the results show that the model was appropriate for determining the rural parents' acceptance of m-learning as it explains % of the variance in bi. it was found that all the antecedents predict behavioral intention to use m-learning. however, only parents' att has a direct effect on bi. it would be reasonable to infer that when rural parents have positive feelings towards the use of m-learning, these positive feelings will reinforce their intention to allow their children to use m-learning to learn stem-related subjects. parents' att mediates the effect of their pu, psi, pr and peou on their bi. the results show some notable differences from prior adoption studies [ , , ] . in contrary to the previous finding, pu has an insignificant effect on rural parents' bi [ , ] . the results show that rural high school stem learners' parents are not acquainted with the usefulness of mobile devices in the classroom. however, the results also confirm the finding of [ ] , who found that pu indirectly influences users' bi by the mediation of att. this might mean that even though rural parents have limited knowledge about the benefits that m-learning bring into stem learning, that little knowledge they possess positively affects their attitudes towards the use of m-learning for stem learning. in contrary to the findings of davis [ ] , the current study found that peou predicts att, better than pu. this shows that rural parents consider the effort needed to learn to use m-learning more important when adopting it than its utility. the finding might be due to parents belonging to the "digital immigrants" generation which struggle to use mobile devices to carry out specific tasks. the results also show that parents are not indifferent to what other people (teachers, society and children) think about m-learning, as their att towards m-learning was influenced by their psi better than their pu. these results are line with the findings of tsuei [ ] , who found that teacher-parent and children-parents communication influenced parents' technology acceptance. psi also positively affect pu and bi by the mediating of att. the results suggest that rural parents value what people important to them say about the use of mlearning for stem learning. therefore, it is important for teachers and learners to provide rural parents with an awareness of the potential of m-learning for stemrelated subjects. regarding pr, the results show that it positively affects both pu and peou. the results also show that pr has an indirect effect on bi through peou and att. this finding was not surprising due to the rural environment in which the study was carried. most of the families in rural areas are living in poverty and depend on social grants as their source of income [ ] . it is also interesting to note that pr has indirect effects on att and pu by the mediating effect of peou. the results suggest that for rural parents, the availability of resources affects the usefulness and ease of use, which in turn affects parents' attitudes towards m-learning. the conclusion that can be drawn from these results is that, for a successful implementation of m-learning for stem learning in rural areas, resources need to be provided. based on the current findings, the following suggestions can be made to mobile developers and instructional designers and the department of basic education (dbe), in line with li et al. [ ] and nikou et al. [ ] who studied learners' and teachers' acceptance of m-learning. mobile developers should make m-learning platforms user-friendly and contain as much learning material and assessments as possible. this is because rural parents, teachers and learners consider utility and ease of use to be important when adopting m-learning. the dbe should provide resources needed for mobile learning. the researchers suggest that the dbe should supply rural stem learners with tablets. furthermore, the dbe should use offline portals to support m-learning in rural areas, make some partnerships with cellular network service providers to allow some educational platforms and websites to be accessed freely, this will remove the burden of buying data from rural parents. rq : the ordinal strength of the predictors of rural parents' bi to use mobile learning is as follows: att (b = . , p < . ), peou (b = . , p < . ), pr (b = . , p < . ), psi (b = . , p < . ) and lastly pu (b = . , p < . ). one limitation in the current study is that it focuses on parents of stem learners. therefore, the generalization of the findings of this study to all high school and primary parents of rural areas should be done with caution. future studies should study perceived resources by clearly differentiating the different resources needed to support mlearning. it would be interesting to study perceived social influence to clearly determine the actual group (teachers, children or society) that affect rural parents' attitudes towards m-learning. based on the results of this study, contrary to the findings of davis [ ] , only parents' attitudes towards m-learning have a direct effect on rural parents' behavioral intention to allow their stem learners to use m-learning. additionally, the results support the suggestion by venkatesh et al. [ ] , who proposed that more variables that are contextrelated can be added to tam to study the acceptance of an information system. in this study perceived social influence and perceived resources were added to tam. the results showed that perceived social influence and perceived resources had a positive indirect influence effect on their behavioral intention to use mobile learning. the results also show that all the variables in the model predict behavioral intention to use mlearning. the predicting power of these variables is as follows: att, peou, pr, psi and pu. the lessons that can be drawn from the study are that rural parents' attitudes towards m-learning and the perceived ease of use are the most important factors that they consider when accepting m-learning. this might mean that parents expect their children to be trained on how to use m-learning before its implementation. furthermore, infrastructure, mobile devices and data need to be made available for mobile learning to be 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student perceptions of resources affect technology acceptance in online learning courses challenges and factors contributing to learner absenteeism in selected primary schools in acornhoek research design: qualitative, quantitative, and mixed methods approaches the partial least squares approach for structural equation modelling a primer on partial least squares structural equation modeling (pls-sem) factors affecting the e-learning acceptance: a case study from uae parents' perceptions about the mobile technology use of preschool aged children key: cord- -jtdc a w authors: jirapanthong, waraporn title: a tool for supporting the evaluation of active learning activities date: - - journal: advances in swarm intelligence doi: . / - - - - _ sha: doc_id: cord_uid: jtdc a w active learning becomes a strategical approach for an educational principle. the student engagement become a wider concern. many researches have been proposed to support the approach. however, one of issues is how to effectively evaluate the performance and progress of students’ learning. although, having student engagement in a classroom is vital, the evaluation of students’ performance is more important. however, keeping up the details or records of students’ progress is a difficult task. we therefore propose a support for instructors to evaluate the performance of their students. in particular, a prototype tool is designed and developed in order to facilitate the evaluation of activities based on an active learning class. the tool also encompasses the web service for a function of face feature recognition. two scenarios of active learning classrooms are created in order to evaluate the prototype tool. we also plan to create a larger number of scenarios which involve different class objectives. the results show that the tool can detect and determine students with high precision values. however, the prototype tool takes a long time to be processed depending on the size and number of photos. the concept of student engagement is becoming a concern. active-learning techniques have emerged as strategies for instructors to promote engagement during learning classes. the engagement of students at high level increases learning and retention of the students. the engagement with students may occur outside the classroom. for in the classroom, student engagement involves the participation of students such as interaction between instructors and students or between students themselves. the advantages of active learning are numerous: i) classroom time can be utilized in discussing higher order thinking skills rather than wasting time on lower order activities; ii) collaboration, communication and leadership skills are enhanced amongst learners; iii) students are actively engaged in a realistic learning experience. even though the active learning is becoming as an important approach for educational learning, it has still some challenges which include resistance from students, unprepared students, lack of access to technology, and heavy workload prior to and during class. moreover, the evaluation method for the active learning approach is also concerned. our research relies on the method and supporting tool for enhancing the active learning approach to be successful. in this paper, we present a tool for supporting instructors to evaluate the learning progress. this is to facilitate the tasks of evaluation on learners. the instructors therefore can identify participating learners and analyse the learners' performances more effectively. in this paper, the background of active learning and facial recognition analysis is provided in sect. . our approach is presenting in sect. . the experimental results, discussion and future work are following. active learning is generally defined as any instructional method that engages students in the learning process. in short, active learning requires students to do meaningful learning activities and think about what they are doing [ ] . while this definition could include traditional activities such as homework, in practice active learning refers to activities that are introduced into the classroom. the core elements of active learning are student activity and engagement in the learning process. active learning is often contrasted to the traditional lecture where students passively receive information from the instructor. active learning methods that can be incorporated in the classroom: i) having multiple pauses during lectures to allow students time to reflect on what is being learnt and to consolidate their notes; ii) having brief demonstrations, or ungraded exercises, followed by a class discussion to increase student engagement; iii) incorporating small group study periods during lectures to stimulate creativity and discuss the subject matter; and iv) using case studies to involve students in doing things and thinking about what they are doing [ ] . the researchers introduced engaging activities throughout traditional lectures as they stimulate learning and retention, improve students' attitudes regarding education, and enhances academic achievement [ ] [ ] [ ] [ ] [ ] . an active learning environment notably increases student participation and collaboration with peers, where knowledge is enthusiastically shared [ ] . it has further been known to stimulate creativity by promoting individual and group ideas [ ] . therefore, in a time when individuals need to be critical thinkers and problem-solvers, active learning provides students with the necessary tools to develop those life skills that were not necessarily on the forefront with traditional education methods. facial recognition systems become more common. industries and organizations are provides the services embedded with facial recognition systems. however, some experts are still concerned regarding the algorithms, particularly when it comes to performance on faces with darker skin. some research published by the mit media lab found that some facial recognition systems performed worse when identifying an individual's gender if they were female or darker-skinned by mit's joy buolamwini. particularly, in the research, it focused on amazon rekognition [ ] that the testing system made no mistakes when identifying the gender of lighter-skinned men. otherwise, it mistook women for men % of the time and mistook darker-skinned women for men percent of the time. considering with the facial analysis software built by microsoft, ibm, and chinese firm megvii, they are concerned to improve identifying similar racial and gender biases. recently, a number of tech companies have voiced concern about the problems with facial recognition. as bias in algorithms is often the result of biased training data. however, many researches keep studying to improve the regulation and to ensure higher standards. although, there are little to engage with this performance, many applications and systems are still suggested to apply with the technology. a lot of researches are going on to find out the best outcome for benefits in use. for example, the gender identification test was facial analysis which spots expressions and characteristics like facial hair. basically, the following are the types of detection and recognition that common recognition analysis software are provided. firstly, labels: a label refers to any objects (e.g. flower, tree, or table), events (e.g. a wedding, graduation, or birthday party), concepts (e.g. a landscape, evening, and nature) or activities (e.g. getting out of a car). the software can detect labels in images and videos. however activities are not detected in images. secondly, custom labels: the software can identify the objects and scenes in images that are specific to some business needs by training a machine learning model. for example, a user can train a model to detect logos or detect engineering machine parts on an assembly line. thirdly, faces: the software can detect faces in images and stored videos. the software shall learn where faces are detected in an image or video, facial landmarks such as the position of eyes, and detected emotions such as happy or sad. moreover, some software have provided face searching function which is indexed into a collection of faces. the software can then be matched with faces detected in images, stored videos, and streaming video. particularly, some software can identify the celebrities in images and stored videos. fourthly, people paths: the software can track the paths of people detected in a stored video. some software provides path tracking, face details, and in-frame location information for people detected in a video. fifthly, text detection: the software can detect text in images and convert it into machine-readable text. this allows the analysis is further applied in other systems. sixthly, unsafe content: the software can identify images or videos for adult and with violent content. to support the evaluation of activities during active learning, we proposed a tool to facilitate instructors to evaluate the performance and competency of learners. the prototype tool is developed. it can analyze images that are supplied as image bytes or images stored in a source folder. as shown in the figure, a part of source code allows a user to choose an image and view the estimated ages of faces that are detected in the image. the chosen image is loaded by using the displaying the image. this example shows how to unencode the loaded image bytes. the program then estimated orientation of an image and to translate bounding box coordinates. an image is loaded and its height and width are determined. the bounding box coordinates of the face for the rotated image. the program is implemented with javascript and json. particularly, it encompasses the amazon web service [ ] which provides a function of image recognition. the steps to execute the program are: i) provide photos capturing the activities in the classroom in the images folder. ii) provide photos of each student in the classroom in the ref folder. iii) execute the program, entitled node; which implements the algorithm as shown in figs. and . iv) the program calls the web services of face recognition to identify the picture of a face. particularly, the photos including students in various gesture are computed. when single facial features are identified, the face features are determined comparing with the individual photos. the overall configuration can be described by a vector representing the position an size of the main facial features, such as eyes and eyebrows, nose, mouth, and the shape of face outline. and v) the feature matching based on measured distances between features will be then concluded. the sets of photos for each student are created. to work with the program, an instructor has to capture photos during activities of active learning in a classroom. the photos then become resources for the program. as shown in fig. , the photos are taken during the activities in the classroom. to evaluate the prototype, we created two scenarios of classroom. firstly, we have a classroom with students. the class is run based on active learning. totally, the students involved the class twelve hours. the photos are captured during the activities. also, the photos of each student are provided. as shown in fig. , the program computes by analyzing each picture. in particular, it detects the face features of each student based on reference photos. the program then create a folder of photos for each student as shown in fig. . for the first scenario, there are students with taken photos. folders are created by the prototype. the photos of each student are detected based on their face features. there are folders identified the student correctly %. otherwise, recognition of other folders are partly incorrect. one folder included mismatched photo. other two folders includes mismatched photos. for the second scenario, there learners with photos taken during the activities. there are four folders created by the prototype. the photos of each student are detected based on their face features completely. they are totally corrected identified. on average, the performance of our approach in terms of precision measurements in two scenarios seems to be consistently high (ranging from % to %). our research focuses on how to support the active learning approach. one of remaining issues is how to evaluate the performance or participating of learners effectively. basically, recording the details of students' progress is a clumsy and tedious task. our work here is to support the instructors to evaluate the performance of their students. the prototype tool is implemented in javascript in order to facilitate the evaluation of activities based on an active learning class. the tool also encompasses the amazon web service for a function of face feature recognition. the photos of students during participating the activities in the classrooms are captured and the prototype tool then generates the folders of each student collecting only the student's photos. this assists the instructors to determine the performance and participating of each student. they then can evaluate the students' progress more effectively. we plan to create a larger number of scenarios which involve different class objectives. it is therefore believed that the approach could be extended and enhanced to support a better way. in addition, sophisticated techniques for visualization could support the use of the prototype tool more efficiently. however, the prototype tool takes a long time to be processed depending on the size and number of photos. more work needs to be done to optimize the processing time. active learning: creating excitement in the classroom using active learning instructional strategies to create excitement and enhance learning active learning in secondary and college science classrooms: a working model for helping the learner to learn using active learning in college classes: a range of options for faculty the variation of memory with time for information appearing during a lecture transformation of classroom spaces: traditional versus active learning classroom in colleges key: cord- -f ibgn i authors: jawed, shayan; grabocka, josif; schmidt-thieme, lars title: self-supervised learning for semi-supervised time series classification date: - - journal: advances in knowledge discovery and data mining doi: . / - - - - _ sha: doc_id: cord_uid: f ibgn i self-supervised learning is a promising new technique for learning representative features in the absence of manual annotations. it is particularly efficient in cases where labeling the training data is expensive and tedious, naturally linking it to the semi-supervised learning paradigm. in this work, we propose a new semi-supervised time series classification model that leverages features learned from the self-supervised task on unlabeled data. the idea is to exploit the unlabeled training data with a forecasting task which provides a strong surrogate supervision signal for feature learning. we draw from established multi-task learning approaches and model forecasting as an auxiliary task to be optimized jointly with the main task of classification. we evaluate our proposed method on benchmark time series classification datasets in semi-supervised setting and are able to show that it significantly outperforms the state-of-the-art baselines. modern deep learning architectures have taken the fields of computer vision, natural language processing and recommender systems by storm. time series classification is no stranger to recurrent neural networks and convolutional neural networks (convnets) too [ , ] . although proven to learn high level features across a broad domain of time series classification problems, the success of convnets hinges on the availability of large amounts of labeled training data. in reality, however, there is a high cost associated in acquiring such labeled data. as a result, there have been efforts to utilize semi-supervised learning algorithms catered especially for time series classification [ , , , , , ] . the idea behind semi-supervised learning is to exploit unlabeled data for training purpose in the presence of only few labeled instances. the applicability of this learning paradigm naturally extends to time series data as plentiful of it can be acquired trivially. for example, a single polysomnography (sleep study) can generate up to , heartbeats but it takes the time and expertise of a cardiologist to annotate individual heartbeats [ ] . hence, effective methods for semi-supervised learning can lead to mining vast amounts of time series data for which only comparatively few labels might be available. a related stream of works has been dedicated to learning high level convnets based representations that do not require any manual annotation of data. selfsupervised learning has emerged as a prominent learning paradigm among such, where the idea is to define an annotation-free pretext task that is inherent in the data itself. the task stands to provide a surrogate supervision signal for feature learning. example tasks include classifying image rotations [ ] , colorizing images [ ] solving jigsaw puzzles [ ] to learn transferable representations for high-level tasks such as object detection and semantic segmentation. until so far, applications have been limited to the computer vision domain. in the same spirit of learning generalizable representations, we now introduce multi-task learning. multi-task learning is an important paradigm in machine learning which builds upon the idea of sharing knowledge between different tasks [ ] . a set of tasks is learned in parallel, aiming to improve performance over each task compared with learning one of these tasks in isolation. a multi-task learning problem can also be formulated with respect to main and auxiliary tasks. auxiliary tasks are motivated by the intuition that for most problem settings, performance over one particular task is of primary importance. however, in order to still reap the benefits of multi-task learning, related tasks could be modeled as auxiliary tasks [ ] . these exist solely for the purpose of learning an enriched representation that could increase prediction accuracy over the main tasks. in our work, we bring together ideas from these high-impact research ideas of self-supervised learning and multi-task learning to propose an auxiliary forecasting task that is inherent in labeled and unlabeled time series data both. this auxiliary task stands to provide a strong surrogate supervision signal for feature learning which when learned in parallel with the main task of classification of time series boosts the performance of the classifier especially in semi-supervised setting. more specifically, we first define a sliding window function parametrized by hyper-parameters of stride and horizon to be forecasted. next, we augment the training set with generated samples for the forecasting task by providing labeled and unlabeled samples as input to this function. the convnet model is trained jointly to classify the labeled samples and forecast future series values. this exploitation of the unlabeled samples leads to learning representations that help boost the classification accuracy. the intuition is that these unlabeled samples come from the same distribution and if the model learns the complex task of forecasting series values accurately, then the same latent representations could be leveraged for classification. in our experiments we show that is indeed the case and our proposed method excels in semi-supervised setting where only a few labeled instances might be available for the model to learn from. to recap, our contributions are: • a novel self-supervised task that is intuitive, requires close to no changes in the base network structure and provides a strong surrogate supervisory signal for feature learning in the realm of time series classification. • a multi-task network which enables the forecasting and classification task to share latent representations and learns high-order interactions automatically. • extensive experimental evaluation of our self-supervised method in the domain of semi-supervised learning for time series classification and show that it outperforms state-of-the-art baselines. the problem of learning with both labeled and unlabeled data is of central importance in machine learning [ ] . we specifically review works that have focused on time series classification. we note the seminal work in the field from wei et al. [ ] . they proposed a self-training approach based on a nearest neighbor classifier. the work from [ ] later improved the method significantly by proposing a new meta-feature based distance. in [ ] a clustering approach was proposed combined with self-training. another ssl algorithm in [ ] also is in essence a clustering based method. the authors of [ ] proposed a graph theoretic ssl algorithm that constructs graphs relating all samples based on different distance functions and consequently propagates labels. the current state-of-the-art method in the field [ ] is based on shapelet learning [ ] on both labeled and unlabeled time series data. on the other hand, we note recent works [ , , , , ] which showed that strong supervision could be leveraged by describing a task that is inherent in the data itself (requires no manual annotation). we consider the pioneering work by [ ] which leveraged spatial context in an image for self-supervised learning by predicting relative location of one sampled patch to another. similar selfsupervised tasks were image colorization [ ] , solving jigsaw puzzles [ ] and classifying image rotations [ ] . more closely related to our work is a multi-task self-supervised network [ ] . the work firstly tries to compare how the representations learned from recent proposed self-supervised approaches like above compare with each other, and then shows that combining these tasks even in a bare-bones multi-task network without catering for any controlled parameter sharing lifted the accuracy compared with the single-task networks compared before. moreover, we also note the works that cater for temporal structure. such temporal structure is inherent in video data, work in [ ] proposed a sequential verification task to determine whether a sequence of frames was in correct order. it was shown that with this simple but intuitive task, the convnet captures temporally varying information such as human poses and ultimately lifted the accuracy on benchmark action recognition datasets. another closely related example is [ ] where the task was to recognize whether the video is playing forwards or backwards. with motivations behind our method set from the literature review, we now draw the following insights: firstly there exist semi-supervised learning approaches similar to ours that learn from unlabeled data, most notably current state-of-the-art shapelet learning approach [ ] if we consider shapelets to be similar to convolutional filters. however, with our work we exploit deep learning based methods which solve an auxiliary self-supervised task of forecasting which forces the network to learn filters to solve this particular complex task. secondly, there have been a plethora of works that proposed novel self-supervised tasks, however to the best of our knowledge, there are no examples for the time series domain and neither that cast a self-supervised task as an auxiliary task. our aim is to learn a convnet model that can estimate a forecasting function f (.) and a classification function g(.) jointly. to put it in concrete terms, we have a set of univariate time series samples .., x u k } a set of unlabeled samples, and a labeled set comprising of note that k + l = n and total series length is t . furthermore, we define a sliding window function w(.) which is parametrized by a stride s and horizon h. this function takes as input time series from x, and segments each in forecasting samples for e.g., .., y ,t=p+ h } which denote the first sample i.e x 's first window. the next sample is chosen with regard to p = p + s and complete set of forecasting samples is given by it is worth noting that these windows have a total length of h < t of which the later half consists of targets to be forecasted. and, the total number of forecasting samples, m = n × ( × h + )/s where s > . to fix ideas, our objectives are y f = f (x f ) and y l = g(x l ). the loss function for the objective with respect to f (.): specifically, we wish to learn the set of parameters θ f that minimize the loss with respect to predictions,Ŷ f . the model does multi-step predictions for the horizon h and the loss stated above captures this with the outer sum. moreover, for the classification task, the model outputs a probability distribution over all possible classes, c. in contrast to the forecasting samples, the input corresponds to the complete length, t . we also emphasize here the difference in parameters by denoting θ c as the classification task parameters. the loss to be minimized with respect to predicting classes c for samples x l : we adopt this architecture from [ ] where it was shown to outperform variety of baselines on a majority of datasets. we reuse the same parameters for f (.) up-to the last convolutional block, from where a dedicated linearly fully connected layer denoted by fc outputs for the horizon. the core intuition to model forecasting as an auxiliary task is to force the con-vnet model to learn a set of rich hidden state representations from unlabeled but structured data. in the case of only few labeled instances being available as in semi-supervised setting, a fully-supervised approach can overfit on the training instances by learning a poor set of features which can hardly distinguish different classes. however, since training proceeds, by using the same set of features repeatedly the model can be more assuming of its predictions which would decrease the training loss in turn. in order to avoid this, a self-supervised task on unlabeled data could be leveraged that can learn comparatively more discriminative features for training and ultimately lead to a significant lift in accuracy on unseen data. additionally, forecasting is well-studied and easily formulated, but at the same time is complex enough which does not open any doors for cheating, as there are no trivial shortcuts for the model to exploit for solving the task [ ] . moreover, the task allows us flexibility in terms of data generation. by configuring the different values of the horizon and stride, h and s respectively, one could control the number of samples needed to configure an optimal balance between the classification and forecasting task samples. central to the theory of multi-task learning is the leveraging of hidden state representations from multiple tasks simultaneously in order to create a more robust model. this begs the question as to whether there exist tasks that could mutually benefit each other by sharing parameters between. naturally, forecasting fits well with a classification task in a multi-task model as both tasks share the same input space. moreover, the learned feature spaces are expected to be correlated in turn also [ ] . however, designing a multi-task learning network poses two key challenges. firstly, how to divide the feature space in shared and task-specific feature sets. secondly, how to balance the weights between the different loss functions so as to distinguish between the main and auxiliary tasks. we rely on the hard-parameter sharing scheme, in which the learning parameters are all shared between the tasks up to the final fully connected layer in a layered architecture. from thereon, task-specific final layers output predictions for each task. this is illustrated in the fig. where we indicate shared parameters between the two tasks with same colored space. on the other hand, by adopting task specific weights we aim to cast the forecasting as an auxiliary task. we formulate the multi-task learning approach as an optimization process over the weighted sum of the two loss functions. λ is a hyper-parameter that controls parameter updates of the network relative to forecasting loss. it is thus crucial to tune for λ as too high of a value could bias the network weights for the forecasting task. on the other hand, if it is set too low, then the network would not learn for the forecasting task at all [ , ] . so far we have not drawn a link between the two feature sets of the tasks. in order to do so, consider that in a multi-task setting, the model is able to accurately forecast an unlabeled sample. the intuition is, if this unlabeled sample belongs to the same class as the very labeled sample the model is now trying to classify, and hence both are similar, then the latent features that were activated for the unlabeled sample could be leveraged to classify. additionally, since the model is trained end-to-end, we also hypothesize that the model automatically learns to share latent representations between tasks and their corresponding high-order interactions based on this latent space. we compare our proposed multi-task model to multiple baselines on realworld public time series datasets [ ] . since the data generating processes are completely different , the proposed method's performance can be judged without bias to similar data generating processes. previously proposed methods were compared on the same in [ ] . a summary of the datasets is given in table . all experiments were run with pytorch and code is published online to encourage reproducibility. wei's method [ ] is based on self-training through which the classifier iteratively augments the labeled set by adding a sample from the unlabeled set. the choice as to which sample to add is based on the (nearest neighbour) classifier's prediction of which sample was the closest to any of its labeled counterpart in euclidean distance. the newly added sample is then given the same class as its closest neighbour. is a meta-feature based distance. this distance was defined as the ratio of dtw to the euclidean distance. the intuition is to exploit the difference between the two distance's performance mainly the benefit of choosing dtw over the euclidean distance. self-training is then carried out based on this distance. success [ ] does constrained hierarchical clustering of the complete set of training samples, irrespective of labels. the distance metric utilized is dtw and all unlabeled samples are given the top-level seed's label. xu's method [ ] is a graph theoretic ssl algorithm that constructs graphs relating all samples based on different distance functions such as dtw or wavelet transform. a probabilistic method optimally combines these various graphs after which a well studied harmonic gaussian field based method [ ] is adopted for label propagation. bag-of-words [ ] leverages a sliding window procedure to generate local segments from time series data. these local segments are used to create histograms to train an svm model for classification. it is worth noting that this method differs from above as it uses only labeled samples. sssl [ ] is the current state-of-the-art method in the field. it uses shapelets to classify unlabeled samples thereby producing pseudo-labels. a coordinate descent solver wraps the optimization process by iteratively solving for the classification of labeled samples, pseudo-labels and shapelets respectively. base [ ] is a single-task variant of our proposed method that is only trained on the labeled samples to do classification. Π-model [ ] is well-known semi-supervised learning method for image classification task. the basic idea is rooted in incorporating stronger regularization via ensembling. the method relies on dropout and asks the network being trained to output consistent labels for the same input. the input albeit goes through different dropout conditions leading to stochastic outputs. this makes it a welldefined task to exploit especially for unlabeled data. as the training proceeds, it is expected for the network's self-ensembled predictions to converge to the same labels for both labeled and unlabeled data. we sandwiched dropout layers after the batch-normalization layers and trained with dropout values of % and %. transfer learning is common in the regime of self-supervised learning based methods [ , ] . following these works, we train a non-linear classifier on top of each of a network's layers trained particularly for forecasting the datasets under consideration. the forecasting network in question is composed of stacking convolutional layers in successive order with filter numbers , , , , , respectively. moreover, we sandwich maxpooling layers between halving the input in temporal dimension after each convolutional layer. next, flattening and training non-linear fully connected layers with dimensions and . the very final layer's dimensionality corresponds to the horizon. this network is the result of an extensive grid search over multiple forecasting tasks from concurrent work. as we motivated, this network is geared towards forecasting in sharp contrast to the network in fig. adopted for the classification task. we trained this network with a grid search in s × h where, s ∈ { . , . , . } and h ∈ { . , . } , and used the configuration resulting with the least loss in eq. . this baseline serves to evaluate the self-supervised learned features from the forecasting task, by measuring classification accuracy that they achieve when we train a classifier on top of them without any fine-tuning [ ] . this classifier has two non-linear layers corresponding to dimensions of and respectively. we hypothesize that if the features do correlate between the classification and forecasting task, then this non-linear classifier is expected to perform well. we begin this section by shedding light on the evaluation protocol. we randomly split each dataset into train and test splits with % and % of the samples. secondly, we split the train split further into labeled and unlabeled sets by randomly discarding % of the labels. this evaluation protocol is kept in line with the previous published methods, so as to report a direct fair comparison. the metric of evaluation is classification accuracy throughout the experiments. given that the initial splits can bias the maximum achievable accuracy, similar to the works before ours, we report the maximum achieved accuracy on the test split by running the experiments times with different hyper-parameters altogether. table shows the comparison of accuracies for the proposed method and the baselines. the results are also stated for the best performing transfer learning scheme and the Π-model. a number of interesting observations can be drawn from these results. firstly, we observe that our proposed method is able to outperform all other methods by a wide margin across almost all benchmark datasets considered. this is only made possible because of the exploitation of the unlabeled data better than other methods. given that we consider here only % labeled samples, the difference between the performance of the methods boils down to how these cater for the unlabeled samples. by leveraging the forecasting task, the model is able to pick up useful representations that directly effect the final accuracy. we observe that the proposed model fails to correctly model the underlying distribution of the wordsynonyms dataset. firstly, we observe that in contrast to other datasets, the number of classes is the highest and hence we hypothesize that due to intra-class variances the model simply needs more labeled samples to model the underlying distribution. moreover, we plot samples from the dataset together with our forecasts for last window of each of these samples in fig. . our second intuition is that given the dataset is based on handwriting, it can be a difficult task to forecast it correctly. the mean squared error that we achieve also hints in this direction, though exceptionally for these handwriting samples it does not convey explicit meaning. perhaps surprisingly, the base method, is able to come at a close second. with exception to wordsynonyms and the lightning datasets, it is able to beat the current state-of-the-art by a considerable margin. we posit that this relates to the powerful non-linear modeling of the convnet in contrast to other algorithms. also worth considering is that this architecture is the result of an extensive search over a wide variety of benchmark datasets as evident in [ ] . hence because of these reasons, even with few labeled samples available it is able to lead over rest of the baselines. additionally, we notice that the Π-model does not lead to fruitful results. although the underlying architecture is the same as in base model, we observed that the model was unfortunately not able to properly cater for the consistency regularization term for the unlabeled data. as a result, the multi-task loss it optimizes for diverges resulting in poor performance over the test splits not outperforming the base model. despite initially considering to orthogonally integrate the Π-model with our proposed multi-task model, we refrained because of poor performance for this standard configuration. we also summarize the results for the transfer learning based approach which serves to quantify the usefulness of features learned purely for the self-supervised forecasting task. we can see that without any fine-tuning, by learning a nonlinear classifier on top of the layers provides useful results. although, results reported here are generalized over the layers, by reporting only the maximum possible accuracy regardless of the layer, it still serves as a validation of our initial hypothesis that feature spaces correlate heavily among the forecasting and classification tasks. to point out the effect of hyper-parameters on our proposed multi-task model, we state the results with respect to different stride and horizon values in table . it can be noted that for a subset of datasets the search was fruitful. indeed, we find out that performance varies considerably with respect to the size of forecasting samples generated with particular stride and horizon, as it has direct effect on the learned representations. we also wish to highlight further observations here though briefly. we observed that the final forecasting loss (eq. ) was consistent across s and h configurations albeit least at the extremities of stride and horizon values i.e those that lead to maximum possible forecasting samples. also, we observed that network was robust to the different values of λ altogether. more importantly, as we posited earlier, the network performance was indeed biased to labeled samples resulted from random splits. we plot here the qualitative results for the forecasting task. we observe that the network is able to model the underlying distribution, albeit not perfectly. we proposed a novel semi-supervised learning algorithm for time series classification based on a self-supervised feature learning task. we trained a con-vnet model that jointly classified and did auxiliary forecasting by sharing latent representations and learning high-order interactions end-to-end. as a result of exploiting the unlabeled data more effectively, our method was able to outperform state-of-the-art baselines. future work includes extending our method to multivariate time series and researching additional ways to incorporate consistency regularization, which might yield better performance. multitask learning dtw-d: time series semi-supervised learning from a single example the ucr time series classification archive unsupervised visual representation learning by context prediction multi-task self-supervised visual learning deep learning for time series classification: a review unsupervised representation learning by predicting image rotations learning time-series shapelets lars: invariant time-series factorization multi-task learning using uncertainty to weigh losses for scene geometry and semantics temporal ensembling for semi-supervised learning success: a new approach for semi-supervised classification of time-series shuffle and learn: unsupervised learning using temporal order verification positive unlabeled learning for time series classification unsupervised learning of visual representations by solving jigsaw puzzles an overview of multi-task learning in deep neural networks time series feature learning with labeled and unlabeled data bag-of-words representation for biomedical time series classification time series classification from scratch with deep neural networks: a strong baseline learning and using the arrow of time semi-supervised time series classification time series analysis with graph-based semi-supervised learning colorful image colorization semi-supervised learning using gaussian fields and harmonic functions semi-supervised learning literature survey acknowledgements. this work was co-funded by volkswagen financial services through the data-driven mobility services project. key: cord- -i rdhipz authors: jankowski, natasha a. title: guideposts for assessment during covid‐ date: - - journal: nan doi: . /au. sha: doc_id: cord_uid: i rdhipz nan guideposts for assessment natasha a. jankowski u ncertainty is the word of the day as institutions of higher education move from covid- triage responses-entailing a pivot to remote learning-to planning for an unknown fall . with questions of the quality of the educational experience in view (eaton a) , the role of student learning outcomes assessment is more crucial than ever to counteract future concerns over transfer, quality of degree completion, and alignment with quality standards. judith eaton ( b) of the council for higher education accreditation states that higher education has an opportunity to shift toward innovation for the longer term and asks of accreditation, "what will be appropriate norms for quality when remote learning is carried out on a larger scale over a long period of time?" (p. ). the same question could be asked of assessment. what are the appropriate norms for assessment when remote instruction will be carried out into the fall or longer and while students, faculty, and staff live, learn, and work in a global pandemic? there is no assessment pandemic playbook, and while online assessment "best practices" provide a useful reference point, not all practices are applicable to the current situation. best practices in online assessment assume things that do not currently hold. the first is about course design and the second about students who partake in online learning. best practices imply that courses have been intentionally designed with clear alignment between learning outcomes, content, assessments, and activities-all led by faculty members fluent in the online system and clear on their role as learning support. connected with intentional design are the students who willingly signed up for online learning, who readily have all the required technology in order to fully participate, and who are clear on the expectations required of an online learner. put those two pieces together and you have the makings of an impactful online program. yet, faculty teaching in the shift to remote instruction have differentiated comfort levels and knowledge bases related to technology supports, and students have differentiated access to technology and comfort levels with online instruction. some students do not have a computer at home, and some do not have access to reliable internet or data plans to partake in online learning experiences. some do not have space to work or focus on schooling at home, are taking care of family, are homeschooling children, and are dealing with changes in employment such as shifting work hours or lost jobs, and concerns over health-mental and otherwise. some might not even have a home to which they could return. what norms do we enforce around assessment and learning in a context such as this? should students be penalized for simply being a student in a pandemic? should credit transfer be hindered due to decisions made about pass/fail options to support students in stressful times? should additional barriers to student engagement in learning be included in order to block cheating? what is decided at this juncture will say quite a bit about assessment-what it is and what it isn't-to faculty, staff, and students. further, as much as this is not a test of online learning by faculty who shifted to remote instruction, this is also not a test of online learning for students. staff at the national institute for learning outcomes assessment have been examining unfolding practices and covid- responses within the assessment community. it is from this examination that several possible norms for assessment in a global pandemic are offered, along with several to avoid: . return to assessment basics. faculty who taught courses that were intentionally designed from clear learning outcomes-with alignment between learning outcomes, assignments/assessments, and evaluative criteria-were in a better position to make the abrupt shift to remote instruction. a return to examine the learning outcomes not yet addressed, identify relevant assignments, and then send clear signals to students on what to focus their attention provided the necessary means to pivot. clarity in design, driven by learning outcomes, allowed for relevancy as opposed to quantity in assessments. further, the return to learning outcomes allowed for curricular conversations about the role of a specific course within a larger learning trajectory, including conversations on which learning outcomes students would apply elsewhere. these programmatic conversations are relevant because the learning outcomes desired by programs do not happen in a single course in a single semester. students have to run into it on multiple occasions in different ways; thus, assessment is a means of not only educational design but future programmatic planning for learning based on holistic alignment (jankowski and marshall ) . . lead with equity. inequities in the educational system were starkly apparent in covid- responses, as well as for which learners could actively participate in remote instruction. within institutions, there was disparity in understanding of circumstances of students and learners, sometimes furthering inequities. websites created by institutions to assist students and faculty during a crisis had titles such as "keep learning" and "keep educating." few if any responses included a clear statement that it was ok to struggle, that it is fine to take time to breathe, or that the mental health of students and faculty mattered to institutions. instead, the message was "take care of you … but log in, do the work, and turn on your zoom camera after you find a computer." outreach to better understand student needs did occur through surveys and phone calls to students, and assignments were modified in terms of flexible deadlines and removal of unnecessary assignment constraints. however, student access to reliable wi-fi was not well-addressed. some institutions offered student access to the internet through wi-fi parking lots-assuming students had a car, or a home situation that allowed them to go to a parking lot, a computer to use while at the parking lot, and a comfort level with being outside their home in order to access the internet. further, remote instruction assessment policies were implemented without concern for bandwidth access, data plans, software, and home situations. to avoid further disparities and do no harm, leading with equity should be a norm in our assessment practice moving forward. . involve students in the solutions. students are the experts of their lived experience. further, they can provide insight into how they are capable and able to document or show their learning. the onus is not upon the faculty member to find creative solutions to enable student learning demonstrations, but instead to co-create with students the means by which students can successfully indicate their learning. faculty and staff need to widen their lens of what falls into the category of evidence of student learning. peer assessments, reflective assignments, students with the time and interest to create tutorials or videos, phone call debates, and other solutions emerged from students in response to covid- . involving students in discussions of how they are able to demonstrate their learning during a global pandemic may provide new and interesting solutions. . transparency, transparency, transparency. the prior norms are effective when there is clarity, clear communication, and transparency amongst all parties involved in learning. transparency to students involves ensuring students are aware of learning outcomes and the value of those learning outcomes to their assessments or assignments, future courses, and career paths. transparency allows for examination of how learning connects across courses, experiences, and employment. it also ensures that students are aware of what they are learning in a given course-something increasingly important in conversations on the cost of remote instruction. . do not allow compliance to drive decisions for enabling and supporting learning. guidance is flexible in response to decisions institutions make in support of learners. instead, clearly document decisions and reasons for decisions. . do not require a higher level of proof of learning in an online class than face-to-face. period. . do not view students as adversaries in their own learning. it is not the case that left to their own devices and given the opportunity (say, for instance, without a grade to drive them) that students will simply stop trying or learning, do not want to learn, or will not work hard. . do not design policy from a deficit view of students as cheaters, uninterested in their education, and not driven to succeed. design to enable learning, not block cheating and outlier students who-if they are going to game the system-will game it regardless of what is put in place to stop them. an outlier-driven policy adds unnecessary barriers in front of already overburdened students trying to be successful. a final note of caution for covid- norms is to avoid focusing assessment of student learning solely on reporting and meeting reporting mandates and timelines. while assessment of student learning is ongoing, the reporting of assessment might take a different form or different timeline, focused on providing formative information to feed forward into planning. reporting might occur through surveys of faculty, virtual focus groups, or phone-call check-ins. our current times require innovative and compassionate solutions. no examples currently exist. practitioners are designing them as they go, with shared open resources. there will be a story to tell about the decisions made during this time, why they were made, and their impact on students and learning. there will be stories of loss and tragedies. only time will tell what they might entail, but the norms presented here might serve as guideposts. ■ accreditation and the future of quality accreditation, quality and fall : a framework for action degrees that matter: moving higher education to a learning systems paradigm jankowski is the executive director of the national institute for learning outcomes assessment at the university of illinois key: cord- -aagbb ip authors: van teijlingen, alexander; tuttle, tell; bouchachia, hamid; sathian, brijesh; van teijlingen, edwin title: artificial intelligence and health in nepal date: - - journal: nepal j epidemiol doi: . /nje.v i . sha: doc_id: cord_uid: aagbb ip the growth in information technology and computer capacity has opened up opportunities to deal with much and much larger data sets than even a decade ago. there has been a technological revolution of big data and artificial intelligence (ai). perhaps many readers would immediately think about robotic surgery or self-driving cars, but there is much more to ai. this short communication starts with an overview of the key terms, including ai, machine learning, deep learning and big data. this short communication highlights so developments of ai in health that could benefit a low-income country like nepal and stresses the need for nepal’s health and education systems to track such developments and apply them locally. moreover, nepal needs to start growing its own ai expertise to help develop national or south asian solutions. this would require investing in local resources such as access to computer power/capacity as well as training young nepali to work in ai. the growth in information technology and computer capacity has opened up opportunities to deal with much and much larger data sets than even a decade ago. there has been a technological revolution of big data and artificial intelligence (ai). perhaps many readers would immediately think about robotic surgery or self-driving cars, but there is much more to ai. this short communication starts with an overview of the key terms, including ai, machine learning, deep learning and big data. ai as a discipline sets the goal of designing systems capable of reproducing the behaviour of humans in their reasoning activities. such systems are usually referred to as intelligent systems. often, such systems need a mixture of hardware and software to acquire and apply knowledge in an "intelligent" way and have the capabilities of perception, reasoning, learning, and making inferences from existing information. there are two types of ai, referred to as: strong and weak. strong ai aims at developing systems that actually think and execute tasks in the way humans do. weak ai aims at getting systems to work without figuring out how human reasoning works. ai consists of a number of branches, including: machine learning, natural language processing and understanding, pattern recognition, machine vision, robotics, computer audition, and speech recognition. machine learning (ml) is relevant and applicable to all branches for various purposes. as a subfield of ai, ml investigates the mechanisms by which knowledge is acquired through learning from experience. in other terms, ml focuses on designing algorithms/systems that learn from data. such learning algorithms use sample data to generate a model which will be used for decision making in the future from subsequent data emanating from the same data source. we distinguish at least three paradigms of ml algorithms: supervised learning (where learning requires the presence of the desired outputcalled the ground truth), unsupervised learning (where training data does not have the desired output) and reinforcement learning (where learning follows from a sequence of actions informed by interaction with the environment). deep learning is a sub-class of ml methods that are largely based on neural networks and representation learning. artificial neural networks are largely inspired by neural networks in the brain. such networks are organised as layers of neurons interconnected by weighted links (synapses). so, the more layers there are, the deeper the network will be. each layer transforms its input and produces an output that is sent to the next layer. the first layers in a deep network focus on the details at the smallest scales, while the following layers build coarse granularity by combining small-scale features at previous layers. the deeper the layers, the more they are able to represent abstract concepts. think of learning to discriminate images. in a deep network architecture, the first layers might help isolate characteristic elements of object in the images, and the deeper layers will contribute to the emergence of the full object (e.g., person). intermediate layers contribute to the formation of larger elements (nose, mouth, etc.) of the object. deep learning is now considered as the most successful paradigm of ml and ai. finally, big data refers to huge amounts of data that are hard to examine in the traditional way. in its normative definition, big data is characterised by a set of five v's: volume (size), velocity (rapid and continuous growth), variety (structured and unstructured formats), veracity (quality), and value (usefulness). the concept of big data analytics is about learning, discovering and inferring knowledge from large (enormous) data sets. ai algorithms have been successfully applied in various healthcare and medical domains as decision support tools for diagnosis to prognosis (predictive analysis) applications. for instance, medical imaging has been a target for ai tools, especially for deep learning as it is proven to be highly competitive to human medical performance. application of deep learning has been investigated in a range of health fields and diseases, such radiomics, neurosurgical imaging, skin lesion, tumour, chest pain, neurologic diseases such as alzheimer disease [ ] [ ] . other traditional ai and machine learning algorithms have also been applied to various diagnosis areas including breast cancer, drug discovery, therapy selection, and stratified care delivery. to enhance the efficiency of machine learning algorithms, substantially large datasets are required. this is particularly relevant to deep learning algorithms. the concept of (longitudinal) big data becomes quite appealing as data from different sources in various format (text, image, numerical, video) can be combined to make well-informed diagnosis or prognosis decisions. these electronic health databases can allow for a personalized approach to medicine by improving diagnoses and predicting individual therapy responses, within clinical research and practice this would constitute a revolution if successful. although the vision of personalized medicine is exciting, we would argue that it still has major challenges, many of which cannot be overcome by algorithmic ambiguity, and call for collaboration between traditional methodologists and medical ml experts to avoid considerable research waste [ ] . ai in health care ai adds another dimension to the discipline of epidemiology [ ] . epidemiology often uses large data sets to seek out the relative influence of a range of determinants on a patient group or population or to assess the prevalence and incidence of (rare) diseases. ai and its sub-fields have impacted healthcare in many ways from diagnostics, triage, to treatment and planning of care. for example, the ability to predict a patient's risk of having to undergo prolonged mechanical ventilation (pmv) can improve patient outcomes and reduce costs to intensive care units (icus). for example, abujaber and colleagues [ ] designed a ml method which is predictive of the duration a patient will need to undergo pmv after experiencing a traumatic brain injury (tbi), thus allowing doctors to design more appropriate individual care plans and make an earlier decision on whether to perform a tracheostomy which is a key factor in patient outcome. this technological revolution could have a great impact on low-income countries like nepal. especially if ai produces low cost solutions that are otherwise too expensive for most people in a low-income country. we hope to present some examples of ai progress that can be employed in nepal. birth asphyxia is one of the highest causes of new-born mortality worldwide with blood gas analysis of arterial blood being the confirmatory clinical diagnosis. however, this is an often-cost-prohibitive and unavailable technology in lowincome countries resulting in a disproportionality high number of new-born asphyxia deaths occurring in low-and middleincome countries due the delayed diagnosis which comes after visual symptoms have emerged. significant delay in diagnosing asphyxia and reversing may leave the patient with permanent brain damage. ubenwa, a mobile phone app is being developed and tested in nigeria which provides a machine learning algorithm (support vector classifier) which classifies new-born cries to identify asphyxia, this diagnostic tool provides the diagnosis with seconds and allows an earlier intervention with only the requirement of a mobile phone, a tool rapidly growing in circulation within low income countries [ ] . the model in nigeria is trained on new-born cries recorded directly by doctors in mexico [ ] which goes to demonstrate the geographically transitive power of these tools. diabetic eye disease is a very common diseases in ophthalmology and is a growing public health issue. the incidence of vision-threatening diabetic retinopathy in highincome countries is declining, combining improved diabetic management and ophthalmological treatment, but globally it is increasing in low-income countries [ ] . with findings that greatly enhance early detection and widening digital imaging (high resolution retinal photography and optical consistency tomography), combined with the potential for permanent morbidity, diabetic retinopathy is an excellent screening candidate. as far as we know it is the first medical device that is permitted to make a screening decision without clinician supervision, stratifying patients from those needing ophthalmology testing to patients who do not need yearly screening. in dermatology recognizing visual pattern recognition is a key diagnostic skill, and ai has the potential to increase image perception and enhance diagnostic accuracy [ ] . new neural computational networks have been used to diagnose skin disorders through visual image recognition, showing sometimes higher sensitivity and accuracy than professionally trained dermatologists. this field particularly can benefit from the work already carried in digital image processing and ai interpreted computer imagery. in the current covid- pandemic, many are seeking conventional as well as ai solutions [ ] . one conventional public health measure is regular antibodies testing of a subset of a population. however, this is an expensive method confounded by the limit number of test kits the world can produce each day and how they are distributed across high, middle and low income countries. online search trends are a possible pseudo-diagnosis of a population, of the covid- symptoms and their associated probabilities of occurrence. lampos et al. trained a transfer machine learning model (with italian data to train each model prior to training on the relevant countries' data). this model provides a good estimate of trend in number of daily confirmed cases in six countries [ ] . this low budget tracking method provides a resource for low and middle-income nations to track the prevalence of the disease in their countries and take preventative measures, as well as evaluated past measures in accordance with the severity of the situation. training an algorithm to predict outcomes such as death, admission to intensive care units or the need for mechanical ventilation can have a major clinical effect. ml algorithms and procedures are also versatile, new algorithms designed during this pandemic may be used for other respiratory diseases in the future. in terms of patient care ai can be used to rapidly transfer knowledge between institutions on a global scale. an example of this is ultrasound, a widely used imaging method that is applied in a wide range of sub-specialties. high-quality ultrasound images are the basis of expert interpretation, however ai is helping to provide a route for capturing of images automatically, even uninitiated and has the potential to diagnose and monitor covid- patients via ultrasound of the lungs, without having to teach health workers how to interpret results [ ] . the inclusion of ai solutions in clinical trials is a relatively new phenomenon. the spirit (standard protocol items: recommendations for interventional trials) statement aims to increase clinical trial reporting by offering evidence-based guidance on the minimum number of items to be addressed [ ] , in order to promote a transparent appraisal of new therapies. like any new therapy, ai-based health interventions need to be systematically assessed to demonstrate their effectiveness. the spirit-ai extension is the recognized guideline for clinical trial protocols on ai-component interventions and includes new essential elements. spirit-ai encourages researchers to be transparent and clearly describe the ai intervention, including instructions and the required skills, the context in which the ai intervention will be implemented, data management issues, human-ai interaction and error case analysis. in addition, spirit-ai will help journal editors, peer reviewers and readers to understand, evaluate and critically assess the design and risk of bias in a clinical trial. in conclusion, there will be many ai solutions in health care currently under development or already in use elsewhere that can be applied to low-income countries. it is important for a country like nepal to track such developments and apply them locally. this requires policymakers, health care providers (public and private) and universities to put an effort into staying up-to-date with global development in this field. secondly, we recommend that nepal starts growing its own ai expertise to develop national or south asian solutions. this would require local resources for example to access computer power/capacity as well as training young nepali to work in ai. studying epidemiology is good first step, but profiling and indepth statistical analysis of large data set are different from machine learning. an overview of deep learning in medical imaging focusing on mri machine learning for medical imaging time to reality check the promises of machine learning-powered precision medicine dictionary of epidemiology using trauma registry data to predict prolonged mechanical ventilation in patients with traumatic brain injury: machine learning approach cry-based diagnosis of birth asphyxia a system for the processing of infant cry to recognize pathologies in recently born babies with neural networks global prevalence of diabetic retinopathy: protocol for a systematic review and meta-analysis artificial intelligence and dermatology: opportunities, challenges, and future directions observational study of uk mobile health apps for covid- machine learning for covid- -asking the right questions guiding ultrasound image capture with artificial intelligence guidelines for clinical trial protocols for interventions involving artificial intelligence: the spirit-ai extension key: cord- - o bazi authors: peppler, kylie; huang, joey; richey, michael c.; ginda, michael; borner, katy; quinlan, haden; hart, a. john title: key principles for workforce upskilling via online learning: a learning analytics study of a professional course in additive manufacturing date: - - journal: nan doi: nan sha: doc_id: cord_uid: o bazi effective adoption of online platforms for teaching, learning, and skill development is essential to both academic institutions and workplaces. adoption of online learning has been abruptly accelerated by covid pandemic, drawing attention to research on pedagogy and practice for effective online instruction. online learning requires a multitude of skills and resources spanning from learning management platforms to interactive assessment tools, combined with multimedia content, presenting challenges to instructors and organizations. this study focuses on ways that learning sciences and visual learning analytics can be used to design, and to improve, online workforce training in advanced manufacturing. scholars and industry experts, educational researchers, and specialists in data analysis and visualization collaborated to study the performance of a cohort of professionals enrolled in an online training course focused on additive manufacturing. the course was offered through mitxpro, mit open learning is a professional learning organization which hosts in a dedicated instance of the edx platform. this study combines learning objective analysis and visual learning analytics to examine the relationships among learning trajectories, engagement, and performance. the results demonstrate how visual learning analytics was used for targeted course modification, and interpretation of learner engagement and performance, such as by more direct mapping of assessments to learning objectives, and to expected and actual time needed to complete each segment of the course. the study also emphasizes broader strategies for course designers and instructors to align course assignments, learning objectives, and assessment measures with learner needs and interests, and argues for a synchronized data infrastructure to facilitate effective just in time learning and continuous improvement of online courses. effective adoption of online platforms for teaching, learning, and skill development is essential to both academic institutions and workplaces. adoption of online learning has been abruptly accelerated by covid- pandemic, drawing attention to research on pedagogy and practice for effective online instruction. meanwhile, educators and trainers are woefully underprepared for the needs of designing for this space, especially for challenging content areas, such as those with specific physical environment needs. what is needed are more systemic approaches to scaffold high-quality online learning outcomes, grounded in the science of how people learn [ ] and how to design for online skill development. some of the most challenging content areas to adapt concern those requiring hands-on elements and/or three-dimensional visualizations, including computer-aided design (cad), robotics, and additive manufacturing. these topics also encompass critical future skills for manufacturing and related industries [ ] , resulting in federal and local government initiatives that coordinate long-term solutions for higher education institutions and companies to face this upskilling challenge [ , ] . the collective growth of automation and data-driven manufacturing infrastructure foreshadows a disruptive challenge to production processes and human machine interaction and indicates a transformation concerning the future of work. this sociotechnicalnetworked production system will demand emergent skills for production engineers and more flexibility in the production workforce. as production systems shift to intelligent cognitive agents embedded in the flow of work, all aspects of work will be affected; culture, work methods, organization and spans of control, data systems, division of labor, management {page} practices, and communities must adapt. this disruption impacts human labor, employment and professional competencies (e.g., artificial intelligence and machine learning for robotics, intelligent cognitive assistants) will require a new model for collaboration and human-machine cooperation [ ] . the emergence of these new technologies, such as additive manufacturing, and their convergence with other elements within complex manufacturing systems, results in an information gap between employers, employees, and educational institutions. as these technologies mature, the knowledge gap between emergent digital manufacturing and data analytic skills needed by industry grow further apart. even though employers presumably know which skills they value in an employee, it is challenging for workers themselves and educational institutions to match the pace of change required to meet industry needs [ ] . in recent years, online learning platforms and massive open online courses (moocs) have become pervasive for workforce training due to the flexibility in time and location as well as the capability of learning analytics to support the analysis, visualization, communication, and management of learning processes [ , ] . additionally, online courses and brief topical certificates reduce costs regarding physical materials, spaces, and allow for economics of scale, one certificate can teach critical competencies to thousands of learners. moocs promote (a)synchronous learning in which learners are able to follow their own paths to learn the content with sequences of learning modules that enable learners to advance personalized learning [ ] . educational data mining (edm) and learning analytics (la) as a set of emerging practices have been used to examine learners' trajectories, activities, proficiencies and provide useful information for instructors to understand employees' learning [ ] . while these edm and la practices and approaches are used commonly in educational settings, few studies examine {page} how they are applied in workplace settings [ ] . to bridge this gap, various fields have seen an emerging trend where companies and educational institutions work collaboratively to develop courses to meet specific stakeholder goals. while these efforts are laudable, they typically do not benefit from the latest understandings from the learning sciences and do not use data visualization to scale high-quality learning outcomes to the gamut of online skills development offerings required by rapidly accelerating s&t developments. this study illustrates the potential of applying learning design to a course focused on upskilling of employees of a large aerospace manufacturer, offered via mit xpro's edx platform. the mit xpro additive manufacturing (am) certificate represents a new credential that blends industry expertise with traditional academic learning. the collaboration between industry and academic partners in this effort was designed to find a nexus between the learning sciences and engineering education research, uncovering how to improve workplace learning outcomes through the scientific process of exploration, discovery, confirmation, and dissemination. the certificate case studies were created with industry experts and industry tas were enlisted to provide feedback throughout the learning process. the goal of this research is to contextualize evaluation metrics by taking into consideration learner actions, course characteristics, and stakeholder goals. study results include data collection instruments and an evaluation method that makes sense of diverse forms of learner data for action-oriented decisions to support learning and institutional goals, for improvement of the am course and guidance of online learning initiatives more broadly. {page} even outside of pandemic times with stay-at-home orders, many companies value, purchase, and promote online education and upskilling. professional development and workplace training have offered targeted educational experiences and just-in-time resources for years [ ] . while traditional instructor led training (ilt) is considered costly and has certain limitations in terms of scaling company expertise, web-based training is seen as a more cost-efficient alternative as it offers selectable study times, self-paced instruction, and doesn't require the use of physical spaces [ ] . as an example of online training, massive open online courses (moocs) are a form of online learning designed for unlimited participation and open access via the internet. moocs are traditionally developed by universities and other educational providers in an effort to support lifelong network learning as well as create open, participatory, and distributed learning spaces [ ] . in addition to the hosting of asynchronous course materials, such as filmed lectures and readings, moocs often provide interactive elements in the form of user forums and online tools that offer instant assessment feedback to students. the emergence of moocs has evoked a new wave of research and expands the frontier of digital and online learning [ ] . particularly, the implementation of micro-credentials as a certification of skills attained through moocs has captured the interest of universities and workplaces as they provide ways to measure the experiences of continuing education students, nontraditional learners, or employees rising through ranks within an organization [ ] . one of the leading mooc providers is edx, a nonprofit education provider hosting online courses from universities around the world across a range of disciplines. courses run on the edx open-source software platform often involve multiple module types (e.g., html, video, or discussion forum). courses hosted on the edx platform are organized into chapters, each {page} involving a sequence of videos, content pages, and customizable modules, including problem questions, open assessments, interactive visualizations, or discussions; this structure was retained for the mit xpro additive manufacturing course. specifically, mit xpro courses are offered with fixed enrollment periods. more broadly, many edx learning experiences, of which mit xpro's offerings are a subset, combine to create their own form of micro-credentials (e.g., like many online course providers, the mit xpro organization is interested in supporting research on online pedagogy and learning. however, most existing research on mooc pedagogy and learning are limited to academic fields, particularly in higher education [ ] . given the lack of empirical evidence to understand how moocs are used in industry and corporate training, this study aims to expand the body of research on the implementation of moocs in engineering workforce training by examining how engineers learn the topic of additive manufacturing in an online course offered through mit xpro's implementation of the edx platform. the introduction and adoption of interconnected digital systems are changing the nature of work across industries and within organizational roles. consequently, traditional educational paradigms must evolve and scale the instruction of emergent workforce competencies, both in terms of their time requirements and content alignment with key learning objectives. moreover, advances in fields such as artificial intelligence (ai) and robotics are making it increasingly possible for machines to perform not only physical but also cognitive tasks currently performed by humans. this will result in relationships where humans and machines work collaboratively, rather than in a command-and-control relationship, suggesting both the opportunity for new {page} working modes and the impetus for novel instructional methods to meet these new requirements. these trends are reflective of broader changes occurring in society around the exchange and acceleration of knowledge, including information enabled through or by ai and machine learning (ml). in manufacturing and engineering industries, several key technologies that will impact the workforces' knowledge development and learning needs. these include: robotics and automation; industrial internet of things and advanced sensing; digital twins (corresponding data packages for each design and part); cyber security for production systems; augmented and virtual reality, e.g. for inspection tasks; and additive manufacturing (am) technologies; among others (e.g., [ ] [ ] [ ] ). taken in total, these technologies are posed to transform the design and capabilities of complex manufacturing systems, enabling greater operational flexibility (in the forms of reconfigurable production assets) and strategic flexibility (in the form of granular, datadriven business intelligence). in exchange, companies must commit significant resources towards system integration and human capital development, and therefore it will be ever more important to develop the skills of working individuals to engage in creative knowledge work and make sense of increasing complexity as these technologies mature and intersect. one important example of technology-driven organizational change is the case of additive manufacturing (am), which is alternatively known as d printing. the am industry has grown rapidly in recent years, and the global am market for machines and services alone has grown rapidly. in , the industry was sized at us$ . billion and is buoyed by aggressive growth; the -year compound annual growth rate (cagr) is measured at . %, with a growth rate of . % in well-above the historical mean [ ] . importantly, the use of am has expanded from rapid prototyping, where it has been used since at least the early 's, to {page} manufacturing applications, including for volume production of end-use aerospace and medical components. am is considered a revolutionary technology that has will change the design and production approaches of manufacturing firms [ ] . compared to traditional manufacturing processes such as casting or machining, am is unique in that it does not required part-specific production tooling and thereby enables greater design flexibility, resulting in possible advantages in shape-optimization, time-to-market, waste reduction, assembly and supply-chain consolidation, and more [ ] . given am's recent introduction to volume production contexts, most engineers and manufacturing workers were not exposed to, or trained with, the principles or execution of am during their formal education. it is likewise challenging and time consuming for universities to construct new degree programs and commensurate curriculum in am [ ] . additionally, the use of am as a forming process does not necessarily change the typical considerations when designing a given component. rather, am is a new approach to forming a part to fulfill a preestablished function, and the convergence of "gray-hair" industry-or application-specific knowledge with am-specific knowledge is necessary for the technology to be best utilized in manufacturing environments. finally, the nascency of am in many production use-cases, coupled with the rapid growth of industrial interest, has resulted in an industry prone to rapid changes in technological capabilities and demonstrated use-cases. therefore, professional training in am is a key enabler to accelerate the learning process to meet the current needs and demand in the workforce. high-quality courses and instruction in am are needed to fulfill this requirement for training skilled employees. in this study, the aerospace company worked with faculty, learning scientists, and instructional designers to develop an online additive {page} manufacturing course that can be iterated upon to keep pace with rapidly changing industry needs, both in content and in structure. one of the important starting points when iteratively designing a course with the learning sciences in mind (barab & squire, ) is to begin by articulating desired learning objectives [ ] and backward-designing [ ] course activities and assessments to more closely map student activity toward achieving and assessing those objectives. learning objectives are goals that target specific knowledge, skills, and dispositions taught in specific sections of a course [ ] . the revised bloom's taxonomy (see table ), a hierarchical model used to classify educational learning objectives into levels of complexity and specificity, is commonly used by instructors to design and develop their own learning objectives across a range of subjects [ ] . the taxonomy differentiates between cognitive skill levels, emphasizing the hierarchical relationships from lower levels (less complex, less specific) to higher levels (more complex, more specific). these cognitive skill levels are ordered into six categories: . remember, . understand, . apply, . analyze, . evaluate, and . create. these levels are adapted by educators as an instructional tool to design and develop learning objectives [ ] . by identifying these processes as operative nouns and verbs of a given learning outcome, instructors are able to develop an assessment to evaluate specific learning constructs and skills. in ideal learning environments, learning objectives include higher levels of cognitive skills for learners to lead to deeper learning and knowledge transfer to a variety of contexts [ ] . instructional procedures by keeping in mind "aspects of human cognitive architecture that are relevant to instruction along with the instructional consequences that flow from the architecture" {page} [ ] (p. ). this theory explains that learning is a serial process of information from working memory to long-term memory. central to cognitive load theory is the idea that ideal learning occurs when instructors effectively guide learners from lower cognitive level activities (e.g., remember factual knowledge) to higher cognitive level activities (e.g., create new knowledge). construct meaning from instructional messages, including oral, written, and graphic communication. carry out or use a procedure in a given situation. break material into constituent parts and determine how parts relate to one another and to an overall structure or purpose. make judgments based on criteria and standards. put elements together to form a coherent or functional whole; re-organize elements into a new pattern or structure. to understand the cognitive load levels of the mit xpro am course, this study applied the revised bloom's taxonomy to analyze the course content and assessments. each learning activity and assessment was associated ("tagged") with categories from bloom's taxonomy and cross-referenced with analyses of the course's desired learning objectives. ideally, each learning {page} objective should be supported by a gradual progression through the process category hierarchy of the revised bloom's taxonomy, where each objective was taught by first introducing the learner to low-cognitive-load tasks and increasing over the length of the course in terms of complexity and cognitive sophistication. this paper advances this work to offer strategies to visualize and compare this ideal with how learning objectives were implemented in the course. to ascertain the mechanisms of student performance in the course, a range of learning analytics (la) methods were employed. la approaches are widely applied to understanding learning in online and web-based learning [ , ] . learning analytics is an interdisciplinary field which includes the fields of artificial intelligence (ai), statistical analysis, data mining, learning sciences, and machine learning [ , ] . in learning sciences, learning analytics offers various approaches to analyze and interpret learners' data, such as statistics and visualization, data mining, prediction, clustering, and relationship mining regarding the applications and purposes of learning [ ] . the implementation of la provides effective information from a volume of learners in a given population over time to identify learning patterns or learner trajectories. instructors recognize the potential in using la to personalize learning, inform practical experiences, and provide self-regulated learning opportunities. particularly, the application of la creates different views of learner activity data which instructors can use to track learners' performance and styles, training outcomes and histories, and community of practice participation [ ] . building on the approaches of la, visualization methods help instructors to understand and optimize student learning as well as inform their iterative decision-making processes in online learning [ ] . {page} while la is an effective tool for instructors to make sense of diverse student data, it can also directly benefit the learners who are given the tools to quantify and analyze their own performance. building on the implementation of la in moocs, visual learning analytics is a discipline aiming to assistant learners to interpret complex user data. visual la is defined as "the science of analytical reasoning facilitated by interactive visual interfaces" (p. ) [ ] , which integrates areas of user interaction, data science, and visual representation. it provides interactive visualizations to help users in sense and decision-making processes in learning. because it bridges the connections between users and their data, instructors, administrators, and users themselves can deal with data-related tasks more efficiently and effectively [ ] . although visual analytics tools have been employed successfully in studying users' data in mooc platforms (e.g., exploring learning paths or progress) [ , ] , improving instructional design [ , ] and understanding peer collaboration [ ] , there is a lack of studies that "employ sophisticated visualizations and engage deeply with educational theories" [ ] (p. ). this study applies a visual learning analytics approach [ , , ] the course enrolled a total of individuals in engineering and manufacturing-related roles, all employed by a single, major aerospace company. participants had a range of work experience (ranging from little professional experience to more than years) and educational backgrounds (ranging from a high-school degree or equivalent to phd). the demographic information was gathered from an entrance survey required for all participants who took the course. pre-assessment was required for all participants before taking the course. {page} before the deployment of the course, the company engaged in a two-prong approach to evaluating the course: by enlisting a group of employee beta-testers that reviewed a beta-release of the course as a professional development opportunity and provide learner feedback to the course team; and with a group of learning scientists and data visualization experts to look closely at employees' learning outcomes, engagement, and trajectories within the course. the objective was to analyze a range of data related to course deployment and usage to identify areas of success (or areas to improve) within the training. data from an mit xpro course comprises a ( ) course database, which captures course structure, ( ) learner demographics and performance data; and ( ) daily event logs. all three data types are briefly described here; details can be found in the edx documentation [ ] . {page} learner demographic and performance data. learner data, captured in a sql database, includes learner-generated artifacts, system and social interactions, and learning outcomes. among others, the data captures first and last learning module states, final course grade, certificate status, discussion forum posts, and team data. discussion activity for the course was supported via a native discussion forum endemic to mit xpro's edx installation but cannot be linked to other activity data and hence is not used in this study. learning modules were qualitatively coded with a total of learning objectives (los) to examine if these los and associated am skills were well aligned with the course content. learning objectives include both the acquisition of knowledge and the application of that knowledge in the form of discrete skills. for the purposes of this paper, each lo was assumed to be equally important relative to one-another and therefore, in an ideal course deployment which matches this assumption, would receive equal and sufficient attention in instruction and assessment. in the future, one could assign differential weighting to los deemed more central to the objectives of the course versus those which are peripheral or less significant. the los were {page} originally articulated by the course instructors and were later refined by the learning sciences research team. analyses included tagging the course activities (including videos, readings, and course assignments) with one or more of the learning objectives and skills of the course. the goal of this qualitative coding was to visualize and analyze the relationships among the content of course modules, assignments, and learner performance. several learning objectives were covered during each week of the course and throughout each learning module. each of learning modules was coded for up to three of the most pertinent los within the activity. this allowed for the course designers to more granularly look at course outcomes to better understand whether students were (un)able to demonstrate a particular learning objective due to inadequate course materials or insufficient time within the course spent on that learning objective (see s supporting information). for the purposes of examining how increasing complexity within the course related to learners' cognitive load and outcomes, a second set of codes was applied to the learning modules following the revised bloom's taxonomy [ ] . table illustrates the six categories. each course activity (e.g., a video, assignment or page) was qualitatively identified as one of the six categories according to the revised bloom's taxonomy. additionally, the frequency and percentage count of each category within the taxonomy were calculated to demonstrate the distribution of cognitive load by course week. the application of bloom's-informed codes enabled instructors to evaluate whether they considered cognitive load in the sequence of course activities and time spent. in short, this framing would advise that (a) we would see a full range of activities integrated into the course design, and (b) we would expect early units in the course to engage in less-challenging process {page} categories and would build toward more higher-level tasks from a cognitive load perspective. ultimately, the results of the qualitative coding were visualized to cross-compare student's dwell times and grade performance against the course's learning objectives (figs & ) . data processing and visual analysis was completed using r statistical software and packages. the purpose of the analyses was to examine if the content of the course modules and assignments were well designed to evaluate employees' learning which can be reflected in their performance. student learning objective dwell time statistics are calculated using student event logs that were processed using the mit xpro learning analytics pipeline [ ] . to evaluate student performance for the course's stated los, this study relies on course subsection grades calculated by the mit xpro system for each student. subsection grades are captured under sequential modules from a given course chapter, and include a student's identifier, points earned by a student and the points possible for a sequence of content modules. sequential modules without points associated with content were removed from the data set. these data were then aggregated by learning objective and student identifiers to calculate the total points associated with a learning objective, the total points and percentage earned by a student for a learning objective. to understand how the instructional design supported employees' learning, the study examined the learning modules with cognitive load analysis, and then applied visual analytics and qualitative coding to investigate the relationships between learning objectives, performance, and engagement. overall, our analyses confirm that time spent (i.e., engagement) was positively correlated to student performance (r =. , p < . , n = ). while this is not surprising, it is an important measure to run at the end of any course to ensure that students, regardless of background knowledge, can perform well if they invest an adequate amount of time in the course. examining the intersection of student performance, assessment measures, and intended learning outcomes yielded additional insights into how students engaged with the content. should take for students to accomplish a specified learning objective or task. {page} against student assessment outcomes by learning objective (fig ) , we see that generally everyone scored high in the first set of learning objectives, which also required a small amount of time to complete. the learning objectives are numbered, and color coded by learning objective groups, see fig for an alignment of six weeks and learning objectives. comparing these results in the visualization dashboard suggests several things to a course instructor: first, the lo learning objectives group may be relatively easy to achieve in a short period of time, and so less time could be allotted to that course content. second, students coming into the course may be already familiar with these objectives, so this unit could be modified to better account for the background of the learners. for example, effective pre-assessment could be used a selection tool to differentiate student populations which require this material as a prerequisite to more advanced material from those populations which may bypass or "test-out" of the requirement. alternatively, content could be modified based on learner demographics and background to better suit gaps within existing knowledge. these dashboards are intended to have instructors ask questions of their course based on time spent and outcomes achieved to make changes that best fit the needs of employees and businesses. in addition, oftentimes, instructors (as was the case in this particular course) are asked to state the amount of time it would take to complete each unit, often relying on rough estimates the instructor thinks it should take to complete a task. frequently, this can lead to student frustration when a particular unit is disproportionately heavy in terms of time commitment. instead of instructors estimating these numbers, the visualizations show the actual amount of time spent-retrieved from the data logs. instructors can use this information to consider how activities can be shifted between modules to create more balanced workloads, or in the design of narrowly tailored learning objectives. in fig , lo . is associated with significantly more time-spent than lo . and those thereafter; suggesting that, for the purposes of analysis and iteration, the objective, lo . , may be more effectively divided into a series of discrete objectives for purposes of instruction and assessing learning. furthermore, analyzing overall distribution of student performance within each lo and longitudinally can yield additional insights. for instance, for instances where certain los produce very low scores, instructors can look for correlation between performance and time spent. if more time spent on a lo leads to a low score, instructors can infer that students are putting forth effort, but the course content could be improved in future iterations. by mapping los to student performance, instructors are able to determine areas where students may have consistently struggled, thereby identifying areas to inform future iterations. the visualization in fig , which aligns los by assessment measure, reveals that some desired learning objectives lacked a corresponding assessment measure to test whether that objective was achieved through course participation. in other cases, there may be too many measures to quantify a particular objective, to the assessment detriment of other objectives of the course. in fig , each discrete content element within a given module or week (e.g., chapters, pages, and the content within them -videos, html, problems, and so forth) were aggregated into a top-level categorization shown by the monochromatic circles on the left. on the right, each circle corresponds to an lo. the mapping between these two illustrates the relationship between course construction and attention given to each lo. in week , the number of modules was average and equally covered each lo in the week (see fig ) . in week and week , the emphases of los were not evenly distributed across the corresponding modules. particularly, lo . and . were highly emphasized in week ; lo . and . were highly emphasized in week . week and had the highest number of modules across the course, and some of the content was connected back to the los for week . the content of modules in week was addressed evenly across los in the week. this is not entirely unexpected; the course was intentionally designed to scaffold the presentation of concepts and principles which, at first glance, appear disconnected and unrelated (e.g. teaching the use of an advanced design software tool versus using cost-calculation methods to estimate component cost). as the course progresses, these disconnected principles are gradually re-introduced through their relationships on other concepts and principles in the course. arguably, this design choice illustrates a limitation of the current study methodology, since the study assumes that los are canonically presented linearly and ought to be assigned equal attention, and thus the am course's construction was misaligned. conversely, this nuance elevates an important point in the use of visual las for course optimization, insofar as the evaluation of a courses' approach must be designed in lock-step with course design to generate actionable, context-dependent recommendations. another way to view this visualization is to interrogate areas where students collectively score low. cases such as these might suggest that there is a misalignment between assessment {page} measure and learning outcome, especially when students are shown to spend a good amount of time on content teaching that objective. an example, seen in figs and , is where students struggled with lo group , though students spent a disproportionately large amount of time on activities teaching those particular objectives. again, however, this may equally reflect the significance of designing narrowly-tailored learning objectives; in fig , the lo group is associated both with week material and material located within a "supplementary knowledge base." the "supplemental" material is a series of optional, ungraded content comprising many hours of rigorous technical instruction; the amount of content is a multiple of that presented in week , and it is also the most technically advanced and challenging material in the course. the "supplemental" section is also associated with the lo group, which received the second-most attention of any lo grouping behind the lo group (fig ) , lending credibility to this hypothesis. moreover, the lo category in this example is practically multiplicative; each lo within the lo cluster is associated seven times with an individual am process. an lo written to say, for example, "understand the mechanical properties of parts produced by additive manufacturing," is actually applied to each of seven am processes addressed within the lo cluster, and thus could be authored more precisely seven unique times for each lo in the following syntax: "understand the mechanical properties of parts produced for process ( , , …) ." in this case, the convenience of writing broad, truncated los trades-off directly with the utility of visual las to provide course insights, and therefore reinforces the necessity to align retrospective evaluation methods up-front with course design. as shown in the fig , not all objectives were assessed, while some objectives possessing a disproportionate amount of assessment. the learning objectives on which students consistently {page} scored high or low indicate the lack of corresponding assessment measures which efficiently evaluate the course content. for instance, the results of learning objective (lo ) (blue bar in fig ) showed that the course content might not well align with the assessments in week , as both passing and not-passing employee groups showed low achievement on most of the learning objectives in that week. to extend the analysis further, for the two lowest-scoring los within lo , lo . and lo . , significant instruction towards these los is located within the "supplemental" material for the course. this helps explain both why these los commanded significant time, insofar as they were associated with greater amounts of instructional content, and why student outcomes were comparatively low, insofar as these los were associated with limited grading during required modules and no graded assessments during supplemental modules. taking these los as an example, the results allow instructors to know where and when students got hung up on the course content or assessment, and provide initial insights for course designers to revise and modify the learning modules and objectives. in this case, a next revision of the course may include demarcating lo into several learning objective categories, where those taught and assessed during required content are differentiated from those primarily taught and assessed via supplemental content. this differentiation may also occur within each lo to better map objectives against lecture material, rather than aggregating individualized los into broader categories (as was done with lo ), to clarify the practical implications of analysis and design more effective, targeted assessments. in short, this result may indicate that the assessment measure may be misaligned with how the concept was taught, or it could also mean that those course materials were insufficient to address those goals. it is important to underscore that these visualizations are designed to {page} empower the instructor to make sense of this data and to look more closely at their students and materials to ascertain why these outcomes were reached. this should be a normal part of course development cycles. those in the learning sciences would routinely think about and toggle between these understandings in high-quality curriculum design, while instructors may not generally be equipped to think about course design and learning objectives in this manner. therefore, it is hoped that these visualizations help examine and improve the alignment between clear learning objectives, high-quality course materials, and high-quality assessment measures so all learning objectives are met. for each week of the course, materials were tagged with process categories drawn from the revised bloom's taxonomy [ ] , depicted above in table which learning objectives were taught using a robust range of process categories, versus others that were assessed using primarily lower-level processing. as shown in fig , the process of comprehension/understanding was heavily emphasized from week to week . conversely, higher cognitive load processes (i.e., applying, analyzing, evaluating, and creating) were not introduced until weeks - . most of the assessment in weeks - focused on the first and second levels of the revised bloom's taxonomy. visualized in this way, instructors can revisit their assessment means to introduce a fuller range of activity earlier in the course, or to produce a more gradual complexity of the assessment means over time. this analysis helps us to further determine which weeks of the course were given a range of high-level processing, and whether increasing {page} complexity was asked of the learner over the span of the course. importantly, weeks - are comprised of a two-week long "case study" assignment; they do not include instructional materials but rather are spent completing an assignment. unfortunately, due to aforementioned reasons relating to data fidelity, these weeks are not addressed in figs - . however, in the minimum case, this data is still useful as one would expect to see a distribution of activities (irrespective of their frequency) across bloom's taxonomy, which was not evident for each lo and week evaluated. this study examined the learning processes and outcomes of participants through an online course which focused on the topic of additive manufacturing. based on the analyses of learning objectives, processes and outcomes, the results informed potential modifications of future course content and assessments. this process could be applied to courses on many other topics. mooc platforms could integrate simple supporting workflows aimed to articulate learning objectives and tag them in the course assignments and assessment metrics. these components and functions of the platform could address the course design challenges listed above and improve the teaching and learning processes for future courses. although the data and analyses were drawn from a single course, these provided a springboard to further the landscape in using la across online courses and platforms and data structure for the purposes of adaptive assessment. knowledge with a mix of expertise (e.g., aerospace engineers apply am skills through design and manufacturing activities) thus deepening and evolving conceptual understandings within a relevant practical context [ , ] . this is the basic path from novice to expert, and is especially relevant for the field of am. . determine how you will evaluate learning: assessment must go hand-in-hand with course goals and represent the revised bloom's taxonomy that you've outlined for the content. for example, if the goal is to improve problem-solving skills, the exam (as well as any assignments leading up to it) should contain questions that ask students to recall facts as well as specific problem-solving exercises. if one form of assessment dominates the activities throughout the course, be open to revising assignments in order to elevate them to higher order thinking as the course progresses (e.g., incorporating more opportunities for strategy formation, solution monitoring, and creativity to activate higher stages of the bloom's taxonomy). instructors should monitor student progress and make adaptations as needed. if you see that a large percentage of your students are not accessing resources, participating in your community of practice, or completing assignments in a timely manner, be prepared to make changes. be willing to revise, and in some cases, abandon course practices and content based on feedback from learners and from learning analytics. in the case of the am program, course instructors created a detailed exit survey which asked students to reflect on the duration, technical rigor, and constitution of each lo grouping as well as the overall course presentation. fig shows one such question, which asked students to evaluate a series of possible modifications to the program; students indicated strongly that the overall duration of the program should be increased, and that, due to the breadth of content addressed (a principle reinforced by the asymmetry of dwell-time {page} and student outcomes for certain los), more granular or modular course offerings should be presented in the future. these principles were adopted by instructors; the duration of the course was increased to weeks (the most popular response to a separate question dedicated to overall course length), and additional modularization is planned. in summary, the process of upskilling employees in emerging technologies such as am requires close collaboration of learning scientists, data scientists, security experts, learning platform developers, and industry to design and develop learning materials and environments which lead to measurable improvements in work performance. this study shows how learning sciences can improve the design and effectiveness of a large-scale online course delivered to a broad technical audience, and how performance can be assessed from analytics of learner engagement and performance. particularly, the data structures and visualizations inform strategies for course instructors to improve alignment of course content, assessment measures, and learning objectives. how people learn ii: learners, contexts, and cultures reskilling the manufacturing workforce and developing capabilities for the future council of economic a. addressing america's reskilling challenge addressing the employment challenge: the use of postsecondary noncredit training in skills development how moocs are being used for corporate training? elearning & software for education by the numbers: moocs visualizing learner engagement, performance, and trajectories to evaluate and optimize online course design educational data mining and learning analytics what research says about moocs-an explorative content analysis. the international review of research in open and distributed learning through the open door moocs for development: trends, challenges, and opportunities. international technologies & international development employee perspectives on moocs for workplace learning massive open online courses in digital workplace learning architecture and development of an industrial internet of things framework for realizing services in industrial product service systems advances in d printing & additive manufacturing technologies the air force digital thread/digital twin -life cycle integration and use of computational and experimental wohlers report : d printing and additive manufacturing state of the industry: wohlers associates d printing and additive manufacturing wohlers report wohlers associates additive manufacturing: developments in training and education emerging evidence on the use of big data and analytics in workplace learning: a systematic literature review bloom's taxonomy of cognitive learning objectives understanding by design a taxonomy for learning, teaching, and assessing: a revision of bloom's taxonomy of educational objectives: longman cognitive load theory. psychology of learning and motivation learning analytics: drivers, developments and challenges let's not forget: learning analytics are about learning the state of educational data mining in : a review and future visions editor learning analytics: envisioning a research discipline and a domain of practice educational data mining and learning analytics: applications to constructionist research interactive visualization tools to improve learning and teaching in online learning environments. international journal of distance education technologies (ijdet) illuminating the path: an r&d agenda for visual analytics visual learning analytics of educational data: a systematic literature review and research agenda gauging mooc learners' adherence to the designed learning path. international educational data mining society integrating a web-based its with dm tools for providing learning path optimization and visual analytics peakvizor: visual analytics of peaks in video clickstreams from massive open online courses the fourth industrial revolution analyzing collaboration and interaction in learning environments to form learner groups mooc visual analytics: empowering students, teachers, researchers, and platform developers of massively open online courses a comparison of lecture-based and challenge-based learning in a workplace setting: course designs, patterns of interactivity, and learning outcomes online learning based on essential concepts and formative assessment [do not include funding or competing interests information in acknowledgments.] key: cord- - v kxgv authors: bozward, d.; rogers-draycott, m. c. title: value creation programmes: lessons from an early-stage implementation date: - - journal: entrep educ doi: . /s - - - sha: doc_id: cord_uid: v kxgv this paper explores the authors’ efforts to design and deliver a venture creation programme (vcp) at the university of worcester between and . the purpose of the paper is to present critical insights into the manner in which learning can be facilitated through vcps using our own experiences as an example. the paper begins with a discussion of the authors' methodology before moving to a literature review addressing vcp’s and related elements of entrepreneurial education best practice. it then shifts to a critical discussion of the authors' experiences based on insights, student and staff evaluations, and course data. in the process of conducting this review the authors found that good pedagogical design, in a vcp context, needs to focus on ensuring that academics promote constructive alignment between the curriculum that is ‘taught’, the teaching methods used, the learning environment chosen and the assessment procedures adopted. only by minimising inconsistencies which link these factors will students’ experiences of venture creation be fully engaging, promoting more effective, experiential and entrepreneurial development. this paper provides educators with an original and experiential insight into the design of a vcp programme and the pedagogical developments required for their successful implementation. there is considerable value herein for higher education institutions which want to design a new vcp, especially with reference to the curriculum design, experiential learning activities, types and methods of assessments and online learning environments for entrepreneurial students. in september the university of worcester became one of only a small number of institutions in the uk to launch a degree in entrepreneurship where venture creation was a central, assessed, element of learner participation. there are a very limited number (lackéus and williams-middleton ) of this type of 'true' venture creation programme (vcp) globally. the authors define a vcp as a practice-oriented degree, combining the creation of a functioning venture with academic study (lackéus and williams-middleton ) . the term 'true' is used in this context to reflect the fact that there are numerous programmes which utilise competitions, tools and activities to simulate the experience of start-up processes (pittaway and edwards ; scott et al. ), but these do not embed a mandate for the creation of a functioning venture at their core and/or make the development of this a requirement for the completion of the course. as this was the newest 'true' venture creation programme (vcp) in the uk, the authors felt that their experiences, the pedagogical challenges they faced and their reflections upon these, might make a useful contribution to the global literature, especially for anyone considering creating a similar programme. therefore, the aim of this paper is to present the lessons learnt from this early-stage implementation to invigorate the discussion surrounding vcps. the paper will do so by exploring a number of issues central to their successful implementation of the programme with a particular focus on the aforementioned pedagogical challenges, including curriculum design, teaching methods, experiential learning activities, types and methods of assessments, and online learning environments for entrepreneurial students. the process of education evaluation is an important part of the design and ongoing development of any course. the processes which govern this are well established (molenda ) and described in numerous models of education instructional systems design (clark ; sortrakul and denphaisarn ) . the range of methodologies used in evaluating education programmes is as diverse as the programmes themselves (lewy ; dressel ) . the field of entrepreneurship education has been the focus of several publications including fayolle et al. ( ) , vesper and gartner ( ) . these have shown that the evolution of students' attitudes and 'mindset' may be a better criteria than purely evaluating the economic impact or the number of businesses created. as this is an early-stage evaluation of a programme, the methodology adopted should provide the ability to review the outcomes from a longitudinal perspective. therefore, the authors adopted donald kirkpatrick's four levels of evaluation (kirkpatrick and craig ; kirkpatrick ) , which provides a framework that could be used in stages: . level researches the reaction to the learning experience by the learner. this starts with the reaction and reflection of the programme by the students, understanding their likes and dislikes to all aspects of the programme. therefore, the key questions of evaluation are what the student's reaction to the learning environment was. . level measures the learning by assessing what students have gained in the intended domain. what principles, facts, and techniques were learned? the key question at this level is whether the students achieved the desired learning objectives. . level develops an understanding of the changes in behaviour. what changes over time has the programme developed and solidified? this transfer of practice could be a direct or indirect result of a module or the overall programme. the key question at this level is whether the newly acquired skills, knowledge or attitude are being used by the learner after the learning event is completed. . level evaluates the results and the long-term impact of the programme graduate outcome. kirkpatrick introduces the return on investment and the tallying of measurable long-term impacts to a company, gathering of data from the first three levels which correlates with things like graduation rates, job placement rates, and success rates in competitive scholarship or graduate school applications. the key question at this level is whether the student achieved the desired outcomes of the programme. this investigation uses levels and of this framework, providing an evaluation tool in the first year of university education and enabling us to tailor the programme for the later years. levels and could be used on completion of the -year programme supporting the authors to gain a complete view of the vcp education intervention. the paper presents data, insights and reflections collected during the first year in which the course ran, after this the staff running the course left, so further information cannot be presented. the subjects were under-graduate students on the vcp entrepreneurship degree who represented a broad range of ages ( - ), social economic backgrounds and a relatively equal mix of genders. the data used in the analyses were gathered from several sources including curriculum reviews, course meetings, student and staff reflections, meeting notes and other conversations. it is important to note that reflection is used at a number of levels with students reflecting on their experiences in and around the curriculum, staff reflecting on their practice, the programme design and the students' development. osterman and kottkamp ( ) state that reflective practice is located within the older tradition of experiential learning and also the more recently defined perspective of situated cognition. experiential learning theorists, including dewey, lewin, piaget and kolb's ( ) maintained that learning is most effective, most likely to lead to behavioural change, when it begins with experience and specifically problematic experience. as part of the methodology of designing this programme we were faced with a complex pedagogical challenge which required us as entrepreneurship education practitioners to take the time to reflect on this experience. as part of our own reflective practice (osterman and kottkamp ) we wanted to use this as a framework for understanding individual and organisational opportunities for change. the aim of the vcp programme which the authors designed was to encourage students to learn 'for entrepreneurship' (qaa (qaa , developing not only their knowledge and understanding of entrepreneurship and its related skills and abilities but also the practice of entrepreneurial activity. the vehicle for this was gibb's ( p. ) concept of 'learning by doing', contextualising and individualising learning experiences through start-up activity, so that these could synchronise with key moments in the students venture development lifecycle (bozward and rogers-draycott ) to create moments of understanding (rae ) , from which critical insights into the students personal and professional development could be realised and reflected upon. from the outset, the authors were clear that an unambiguous definition of entrepreneurship was important to act as a keystone of programme development, encouraging consistency and continuity which would underpin the course design and development. this was drawn from a board literature (bruyat and julien ; fayolle ; sarasvathy and venkataraman ; lackéus ; shane and venkataraman ; moberg et al. ; qaa ) with the focus being on authors who had specifically addressed the action of venture creation, ideally in an educational context, and whose approaches (either practically or philosophically) were aligned to the goals for the programme (fayolle ; jones et al. ; lackéus ) ; as a result, entrepreneurship would be defined as follows: 'entrepreneurship is finding and developing opportunities to create value'. this framed entrepreneurial activity in broad terms and focused it on the creation of 'value' (lackéus ) a term which has been left deliberately ambiguous to give students an opportunity to develop ventures that encompassed a range of entrepreneurial action; not just the generation of revenue or profit. the definition is also permissive rather than prescriptive, and it assumes nothing and allows students a freedom to explore their entrepreneurial selves without the constraint of a specific direction (farmer, yao and kung-mcintyre ) . this meant that the experience of learning through the programme was most definitely not a 'spectator sport' (tinto ) , as students were actively challenged to participate in a cycle of venture creation, reflection and evaluation which informed their development and future activity. this work formed the basis of the pedagogical methods applied across all the modules either directly as content, or indirectly through an influence on programme design and structure. biggs ( biggs ( , describes the duty of good pedagogical design as one of safeguarding that there are no inconsistencies between the curriculum we teach, the teaching methods we use, the learning environment we choose, and the assessment procedures we adopt. this he defined as constructive alignment. previous pedagogical developments within vcps have been researched and published by gibb ( gibb ( , , ollila and williams-middleton ( ), lackéus and williams-middleton ( ) , mwasalwiba ( ) . these investigated the alignment of entrepreneurship education objectives, target audience, teaching methods and impact indicators, and found that greater focus should be put on the pedagogical alignment when setting or designing entrepreneurship education experiences. to position the degree in an international best practice context, other vcps were reviewed during the programme design (lackéus and williams-middleton , ) . this work was used alongside the authors' definition, input from the business community, and the latest guidance from the subject benchmark statements (qaa ; qaa ) to create the academic foundation for the course. it also provided a means for students and the wider community to understand and compare the context and characteristics of the programme against others around the world. a staged learning narrative was then developed to support the students' entrepreneurial learning (bozward, and rogers-draycott ) which drew on the work of kuratko, morris, and schindehutte ( ) to break the entrepreneurial efforts into nine specific steps, each step comprising a number of focal competencies which would need to be met as part of the students' entrepreneurial development. a number of other researchers (bird ; man ; rasmussen et al. ; sanchez ) have found value in the concept of 'competence' to support the structuring of entrepreneurial education and assessment. competence, in this form, has a wideranging conception encompassing knowledge, skills, attitudes, behaviours, work habits, abilities and personal characteristics (le deist and winterton ) . these focal competencies were then used to underpin the requirements of the curriculum and any assessments at each level within the degree. this framework formed the operational core of the degree, an easily identifiable map of key waypoints for educators and students which needed to be successfully navigated for progression to take place. based on this work, the ba (hons) entrepreneurship programme focused on the active experience of business creation underpinned by relevant academic knowledge and the development of a broad base of entrepreneurial skills and capabilities. this was delivered through a mixture of dedicated sessions, simulations, work-based learning, enterprise events and interactions with entrepreneurs. the programme schedule was designed with formal sessions on one full day each week, thereby maximising the time spent 'on task', while other days were set aside for additional support (mentoring, business clinics, events and team work) and for students to develop their ventures through work-based modules, thereby maximising engagement and, hopefully, student outcomes within the curriculum (lingard ; mioduser et al. ) . the approach and pedagogy positioned the vcp to develop both the student learner and their business. therefore, the -year programme was split into two streams which focused on: . the entrepreneur and . the business venture. in the first year the programme encouraged ideation and venture creation; in the second year, this moved aside to facilitate a focus on marketing, sales and cash flow stabilisation, while the third year was centred around business growth, innovation and investment. the programme was designed to provide flexibility in the final year so that students could tailor their modules and assessments to suit the needs of their developing businesses. these negotiated modules allowed the students to formulate the learning outcomes over the module, recognising that even at this stage both business and personal needs might rapidly develop. this was complemented by the learning environment provided by the university, consisting of not just the classroom but also space whereby students could develop their businesses. every student was therefore provided a place in the university's business incubator, and they have access to this for the duration of the programme. this location acted as a hub for the broader entrepreneurial student community to engage with the students on this programme. the development of a community (zimmer ; kilkenny et al. ) around the programme was seen as very important in embedding the students within the local business ecosystem. the cornerstone of this strategy was recruiting entrepreneurs in residence (eir) from a diverse range of businesses. these business owners acted as entrepreneurial role models (bosma et al. ; lafuente et al. ) as it has been shown as an important factor in the decision to start and influence (van auken et al. ) the growth of businesses. in order to foster an authenticity of experience all of the modules within the programme were taught by experienced entrepreneurs (hopkins and feldman ) with further engagement from local business practitioners who provided mentoring and other associated support. these role models added to the student experience while supporting the practice-oriented pedagogical approach. the programme is structured around % of the credits each year being achieved from work-based learning (wbl) modules (boud and solomon ; raelin ) which is supporting the application of the knowledge developed within the taught modules. this structure is now explored. table provides a breakdown of the taught modules and how they were divided between the two streams. in these, first-year students as entrepreneurs develop their mindset and communication skills, while for their business, the process of starting a business and developing a plan. in the second year they develop leadership skills, financial management, advertising, sales and a negotiated learning outcomes module. in the final year, as an entrepreneur the curriculum is focused on decision making, performance and innovation management, and the business focused modules develop growth through marketing and international trade. the work-based modules (shown in table ) and simulated projects were seen as crucial to the development of core venture skills (timmons and spinelli ; zhong-wei ) and reflective capacity (jack and anderso ; harvey and evans ) linking the theory and practice of entrepreneurship together in practical endeavours. these were structured with varying levels of staff intervention to match the progression of the students. in earlier years there was a greater element of 'control' (jones et al. ) and risk mitigation managed by staff to provide a 'safe space' (jones et al. ) in which the students could experience failure and be guided through the process. as they progress through the degree, these 'training wheels' were progressively removed and students were challenged in a number of new ways including having to negotiate learning outcomes for modules and contented with new assessment challenges alongside the growth of their ventures. each module required the students to complete a journal of critical reflections (cope and watts ; mezirow ) addressing their experiences at regular intervals, bring together the concept of entrepreneurial moments or learning events, especially when initially viewed as discounted (cope ) these series of reflections support the development of higher-level learning. this was used to provide a consistent longitudinal vehicle for reflection of their development throughout the programme. assessment strategies in higher education have been experiencing a period of diversification (fry et al. ) and best practice development (rust ) , meaning that a number of sources are available to inform strategic approaches. for example, pittaway and edwards ( ) highlighted several innovative assessment practices which could be used within these types of programme, and these included self-assessment and peer assessment. carey and matlay ( ) also highlighted best practice assessment strategies from the creative industries which could be applied to entrepreneurship education. both studies developed the importance of industry or degree community in the assessment process and that examinations were not always appropriate for entrepreneurship education. across the programme a mixture of assessment types were utilised in order to maximise opportunities for all students to perform and develop skills relevant to both future study and/or venture development. this was done in conjunction with maintaining the constructive alignment of the programme by developing individual competency aligned to the development of the students venture. it was important to use both a diverse and a consistent set of assessment types throughout the programme. a consistent set of assessments allowed the students' development to be meaningfully measured and also ensured the students' ability to master this assessment type was supported and evidenced. a diverse set of assessments helped to challenge the students' development and provided the opportunity for them to evidence their learning in different contexts which was a key part of the degree's philosophy. consequently, this programme used assessment 'for' learning as well as assessment 'of' learning (gibb (gibb , with a clear view to ensure inclusivity. figure demonstrates the mixture of assessments types used on the programme. this programme did not use examinations as an assessment type as this was highlighted in a number of papers, such as pittaway and edwards ( ) and carey and matlay ( ) that it may not be conducive to an academic environment where students were trying to develop original ideas, articulate these, and had them assessed, especially when considering the implementation of constructive alignment. through their removal the authors felt that they had moved a step closer to our pedagogical ambition of developing a more coherently aligned (biggs ) learning environment which more closely mirrored the realities of entrepreneurial endeavours. this was achieved by supporting entrepreneurial learning activities that were appropriate to the students' context and educational needs and adapting those which were not. for example, prior to the vcp all of the law and accounting modules accredited for use in the business school used examinations as the main assessment type as it was an external requirement and, therefore, careful selection of and/or re-purposing of the modules was needed to ensure they aligned to the programmes philosophy and design. this required the design of the assessment which was based on the student's own business and not simply a case study example. the assessments then became fundamental to the development of the student's venture as they provided staged points by which the student's own development and understanding was evaluated. this analysis of an early-stage evaluation of a programme was using the methodology proposed by kirkpatrick focusing on level and level of the evaluation framework. to accomplish this the authors took materials gathered and their own reflections (diaries, journals, etc.), student assessment data, student's reflection journal and added to this with feedback from the students, colleagues and the external examiner. this process led them to identify three groups of reflective data which emerged as the data were collected: . positive reflections-reflections where content and experience were generally positive; . neutral reflections-reflections where content and experience were mixed; and . negative reflections-reflections where content and experience were generally negative. from these three groups six elements began to coalesce, and these were presented as key learning moments (rae ) using the commonly experienced events which have been encountered within the entrepreneurship learning in the first year of the degree. these addressed important concerns, challenges, achievements, and realisations which have affected the programme and will have a distinct impact on its future form and direction (table ) when the level and analysis is conducted. these six key pedagogical elements will now be discussed in more detail. when the authors compared vcps across the world (lackéus and williams-middleton ) there seemed to be an accepted balance between the time spent in the classroom and the time spent focusing on the learner's venture. therefore % of the module credits were from work-based learning and % from academic study and scholarly activities, aligning the teaching methods to the curriculum. this created a clear narrative focusing the student to work in and on their business, developing the core philosophies of the programme throughout. the taught element was scheduled on the same day each week (wednesday for first years), so that students could maximise the time spent on their business while also having dedicated space to study and develop their other skills. tuesday was set aside to support work-based learning, which included webinars, business clinics and mentoring sessions. friday was used for trading exercises. the students liked this arrangement and most attended tuesday and wednesday throughout the year. those who did not attend the tuesday's programme gained support via webinars and telephone mentoring. to deliver the range of teaching methods the course required a programme team who could facilitate the learning environment and understand the alignment required for successful implementation within a vcp. the team was made up of one programme leader, one enterprise manager, and six part-time staff, all of whom had entrepreneurship experience in starting and running businesses and, therefore, were academic entrepreneurs (de silva ). the part-time members were also practising entrepreneurs who were portfolio working with a proven academic teaching background. the diversity of their backgrounds and current experience encouraged the students to develop greater empathy and respect with the teaching team from the offset. this supported the interactions with the wider degree community and role models for the reflective practice. setting out a clear structure, timetable and expectations from the start provided a set of assumptions which the students understood and also appreciated. this generated positive feedback on open days and through the - - academic tutoring sessions where students discussed planning their time and business meetings. this 'learning agreement' was seen as one of the core successes between the student and programme as it provided a basis for understanding and development (both student and programme) from which both parties could move forward with over the three years. in summary, to ensure the vcp structure had constructive alignment and fulfilled the goals of a vcp, the curriculum was designed around the starting and growth stages of a business; the teaching used a mixture of professional entrepreneurs and educators; and the innovative learning environment was based around the physical spaces and the strong interactions between the local entrepreneurial business community. • setting student expectations from the start (recruitment) provided students with a known schedule and business like interactions; and • developing a personal learning agreement which ensured students could balance learning, their business, and personal life ensured that students received the attention they required and understood the academic development time they must manage. moore ( ) suggested that education may be as much about social engineering as about personal empowerment. this within an action-based entrepreneurship education programme means that we need integrate the programme pedagogy with the local entrepreneurial ecosystem to encourage the development of a social community around the programme. initially, we developed the worcestershire entrepreneurship ecosystem map and shared this with stakeholders, and this promoted awareness of what was happening throughout the region while simultaneously promoting our programme. every one of the organisations on this map we had a working relationship with. the map used the structure and findings from the babson entrepreneurship ecosystem project research (fetters et al. ; isenberg isenberg , to develop the entrepreneurial capacity in defined localities; bringing together the policies, structures, programs, and climate that foster entrepreneurship. this tool was used in a number of ways: • mentoring sessions: the map was provided to all mentors, so they could provide a consistent narrative and discussion on the available entrepreneurial ecosystem support and also discuss openly what was available with the mentee; and • business clinics: when discussing any one aspect of support which was being supplied, we could first show the entire ecosystem before drilling down into the details of one aspect. this ensured that the students could gain an understanding of the whole. mentoring was an important element within the portfolio of pedagogy constructs within the programme. mentoring has been shown (st-jean and audet ) to develop cognitive and affective learning as well as provide additional experience and competency for the novice entrepreneur. the development of the affective or emotional areas supports their development of self-awareness (bacigalupo et al. ) and entrepreneurial self-efficacy (chen, et al. ) which have been shown to be key factors in developing high-performance entrepreneurs. to support this, positions were advertised for volunteer entrepreneurs in residence (eir) to provide support to the programme and the team, and we received seven applications. each was assessed using a practical interview process which consisted of a networking event with staff and current students who were starting a business. the criteria used were from bushardt et al. ( ) which states ( ) that person can help you, ( ) he or she has your confidence, ( ) you can help that person, and ( ) he or she has a successful track record of mentorship. students and staff were asked to provide feedback based on these criteria. this event proved very successful, and we decided to take all those that applied, the only issue being there was a limited diversity. at the end of the first year of operations we had eirs who were from very diverse industries with backgrounds and experience. as a group they had a broad and varied network which supported the introduction to almost all businesses within the country and these contacts had benefited the students. these individuals' mentored the students, provided weekly business clinics and a q&a forum service. all students were offered at least one mentor to support their personal growth, one mentor (megginson ) to support the developmental stage of their business, and another to provide local support relating specifically to the industry or physical location of their business. they also had - - skills development such as telephone cold-calling skills, business process mapping, and even gone with students to supplier meetings. perhaps, most importantly, these people provided invaluable links between the university and the local business community helping the students to network and integrate. this was evidenced by one student's comments 'one of the best things i've got out of this course so far is the amount of access to key people in my industry. the connections i make on a weekly basis through the ba in entrepreneurship course are incredible.' the eirs in the first year of operation invested financially in the entrepreneurship cohort and also in other university graduates, which has also been shown by schwarzkopf et al. ( ) . the diversity of the students, their ideas and their business requirements could not be met by one person or a single organisation and it was only through this community that educators could provide the ultimate student experience and learning outcomes. it was no longer acceptable to just manage a classroom experience. in entrepreneurship there was very often conflicting advice and views and it was only through knowledge, mentoring, experimentation and experience that a way could be found for the individual student entrepreneur. • the development of a cohort of mentors provided numerous benefits as it allowed the education ecosystem to extend from the classroom, to those supporting the students and the wider business community; and • the development of a simple programme philosophy which could be shared and understood by all stakeholders ensured wider buy in within a greater community. the programme assumes that learning is best when it is active, when it incorporates experience and when it can be shared and supported through collaboration. as such, our pedagogy focus is on problem-based learning (hung, jonassen and liu ) , use of authentic assessment and reflective writing (kakouris ; jack and anderson ; harvey and evans ) to develop a lifelong learning approach for our entrepreneurial students. critical reviews of the assessment strategies used in universities and of reflective practice in general (elton and johnston ; findlay ; palomba and banta ) assert that reflection and reflective practice are lacking in the development of a large number of students, but that this can be difficult to encourage as it requires the development (on the students part) of a broad range of skills and faculties to enable them to engage with the process effectively. this use of reflective journals in the development of professional best practice, especially in the disciplines of nursing and education, has been embedded within the curriculum for many years, as it encourages students to integrate theory with practice, appreciate the world on their own behalf, and turn every experience into a new potential learning experience (wong et al. ) . with that in mind it was decided that a reflective journal would be used in the two work-based learning modules each of the three years. to support this, reflective writing sessions were also added to several modules, even those which occurred relatively early in the students learning journey in an attempt to maximise their exposure and normalise the experience. eventually, these were linked together using the vle's journal entry subsite using additional material and videos to create an information hub from which students could draw support, advice and guidance. based on this work, a number of students began to adopt the habits of a reflective practitioner early in the programme and developed a useful weekly reflective journal which, they felt, supported their entrepreneurial development. these students were getting feedback from four members of staff on a regular basis and, in their writing, acknowledged the benefits that reflexivity had on their learning and also on the development of their businesses. however, there were a group of students for whom reflection did not come so naturally and further development was required. this, in itself, was a 'reflection' on the nature of reflective practice; it was a lifelong process and an experiential one (kolb and kolb ) through which individuals were developing and redeveloping learning. no one student approached it from the same starting point, and most required different levels of support to achieve something meaningful. this meaned that even with support de-engagement could be difficult to avoid, in this context it was apparent through poor-quality reflections and a lack of development in some members of the student population. after speaking to the affected students about the reasons why they did not fully engage with the reflective processes we identified several issues. the first was about being judged, both personally and professionally, something which they at times found difficult to accept. the second was that the students' personal lives could take priority over both academic and business development and they found this difficult to share this as they believed it would affect their marks adversely to admit difficulties. at the core of both of these points there was a powerful realisation for the course team that some students did not engage fully with reflective writing because they simply found it difficult to be 'right' and present a positive image of themselves and their endeavours rather than doing, what they felt, was dwelling on the negatives. with this in mind the team planned to add mid-module review sessions both in class and individually during personal tutoring sessions. these discussions would have been directed towards how reflective practice could support the students learning and ultimately their effectiveness (qaa (qaa , as an entrepreneur but only as part of an honest and forthright process. recognising that business school staff were not good at developing reflective practice, we intended to use a professional reflective and reflexive facilitator (from a different subject area such as nursing or education) who would organise regular individual and group sessions and more informal review sessions where students would have discussed reflective issues and investigated different ways of approaching their reflective practice. • reflective practice is a critical part of the development of a practitioner and as such should be an integral part of the assessment and development of the entrepreneur. however, its integration requires insight from other disciplines in which reflection is common practice; and • a clear process of support and reflective development is required to ensure the development of a successful reflective practitioner. beetham and sharpe ( ) state that digital technology is 'like previous innovations, they can be assimilated to pedagogical practice without altering the fundamental truths about how people learn'. the amount of content which is available in digital form has increased, and the ability for students to access this on multiple devices ensures numerous learning opportunities both within and outside the classroom. it was therefore decided that a key element of the degree was the use of virtual learning spaces such as the university's vle (blackboard) to host material including pre-recorded lectures, sessional activities, reading and extensions tasks. the idea behind this was to allow for 'flipped' (sams and bergmann ) approach to learning through both online and in class delivery maximising the one day that students had on campus by extending the learning environment beyond this physical limitation allowing for more delivery via video or audio, for example. to facilitate this, early in the degree design process, formats for delivery were created and circulated, vle areas were established, and best practice was shared between staff. however, while some lecturers championed the format, some resisted this because of time, comfort or technical skills. this immediately sent mixed messages to the students as delivery and experience were not consistent. as a result, some disengaged with the process at this stage and only re-engaged sporadically or when forced to for assignments meaning that key elements of the 'flipped' programmes had to be re-calibrated at the last minute to ensure that students who were not engaging online did not miss any delivery. this in turn led to repetition and also frustration for the students who as 'early adopters' had engaged fully with the online experience. having spoken to staff and students it became clear that students saw the vle as a positive, but the mixed delivery methods were confusing and staff saw it as too time-consuming even given the formatting help and support that was provided to them. however, the first year of a module had considerable amount of development and subsequent years had less. to mitigate this risk the team intended to provide a video introduction for the students on how to use the vle within the programme homepage and additional support during the sessions throughout the year. also, there were intentions to experiment with a 'flipped light' version of the delivery process to create a lower bar for staff to achieve while retaining a consistent approach across the teaching team; this would be more of a blended approach allowing staff with the skills to do more and staff who found it difficult to be supported and take other routes to achieving an engaging product. the use of the vle, learning technologists, video creation support, and peer educator support through the programme delivery team was an important development for the programme, which has been used subsequently during the planning of the covid- response. the key to this would be that it was made clear to the students how each module would approach the issue and that this would remain consistent across the delivery of that module. based on student feedback it was also decided to deliver one of the first modules in the programme via a portfolio assessment based solely within the vle. everyone hoped that this would ensure that the students engaged within the vle more fully during the crucial early part of the degree. to achieve this, we had planned a structure which meant that the students would be fulfilling regular tasks towards their assignment promoting engagement, familiarity and development within the structure. • the professional development of the teaching team so as to provide a consistent pedagogy approach within the vle; and • a dedicated session to introduce the vle and the benefits of using it for students. a learning community has been defined as 'an intentionally developed community that exists to promote and maximise the individual and shared learning of its members (beck and foster ) . they provide an ongoing interaction, relationship, and collaboration among the community's members as they work towards a specified common learning goals' (lenning et al. , p. ) . learning communities offer learning of an interactive nature and targeted to develop multiple social dimensions, such as employability, general enterprise awareness, intrapreneurship, and venture creation, all of which are becoming a major metric within today's uk education environment. the team-based project module began in the first-year induction week so that insurance and other logistics could be resolved before the teams moved forward. students were provided with a module manual which detailed the structure of the module including the standard module information plus additional information such as company structure, insurance requirements, locations, programme timings, team processes, and contact details. however, the module itself did not start until late october, a month, or so later. the delay had been designed to allow the student to gain some theoretical knowledge from the venture creation module which it was felt might support the group work; however, because the link between theory and practice was not yet clear in the students' minds a lot of this work was wasted as they did not really see how the elements linked together. this 'gap' in delivery was further compounded by new students joining the programme late and others leaving it within the first few weeks of term all of which meant that the team formation processes were never really completed; this led to a lack of team structure within the groups throughout the module. additionally, the selection of products to sell on the market stall was left up to the teams. this created problems as the team were newly formed and personalities dictated what got sold and not a logical approach based on customer needs and market demand. each team purchased stock to sell which never sold and detracted from the core tasks of the module of sales and marketing and led the team into a negative mindset and leadership issues. finally, the leadership of the groups moved from one person to another as the module progressed and it was clear that this enabled the team to use the skills to their advantage but also shifted responsibility from one to the next without a clear set of reflections on what went wrong. it was evident that teamwork and this group-based assignment needed further development. therefore, as part of the wider curriculum review, a research project was developed across all entrepreneurship modules to evaluate how to improve entrepreneurship team-based modules which consisted of students. the core findings of the research project have led to the following future actions for this team-based project modules: • a lecture session and video were created to introduce the teamwork aspects of the students. three core aspects will be covered, ( ) what makes a good team member ( ) what makes a good team, and ( ) why good teams get good marks; • a team-building activity will be built into the module. once this is concluded, no other members will be allowed to join; • team size will be between two and four people, starting with four; • facebook will be used for internal communications from the start. (the groups which used this were more successful in their grades); • it is intended to use a similar system as in the apprentice tv programme, where a limited selection of products will be presented to the teams and they then pitch for and then buy the products using their own money; and • a monthly formal board meeting in our boardroom whereby the company reports to the shareholders and publishes minutes. these will then form part of the formative assessment. non-attendance and non-contribution then get reported regularly. • a more structured implementation of the learning communities provides students with how to be a productive member and what others expect from them; and • making the learning community report their actions ensure that all members are engaged in this action-based education. engagement has emerged as a key metric measure (kahu ) of higher education impact over the last decade. it has become a catch-all term most commonly used to describe a compendium of behaviours characterising students who are said to be more involved with their university community than their less-engaged peers. engagement refers to the time, enthusiasm, and resources students devote to activities both in and outside the curriculum to enhance learning while at university. therefore the pedagogy design of our programmes requires a range of activities which include lectures, tutorials, online vle, webinars, personal academic tutoring, team activities, through to mentoring, business clinics, and events which align with the needs of the student and also the learning outcomes. ahlfeldt, mehta, and sellnow ( ) found that the level of engagement was typically higher in those classrooms with more problem-based learning (pbl) and that engagement increases as programme level increases. as a result it was expected that as the programme was targeted to encourage learning 'for entrepreneurship' (a pbl approach), it would have a better result, but because there had only been a completed a first year, this might be balanced by students 'finding their feet' and not yet fully engaging. it was expected that truly entrepreneurial students will be hard to keep in a classroom and, as a result that we might find it more difficult to foster a learning community. however, we did not anticipate: • one student in week three gained a contract for £ , which meant they were away in south east asia for over one month; • two students had childcare issues for over one month which were the result of student loans being delayed; • one student had to go and manage their father's estate after being incapacitated, so they left for another month; and • one student was diagnosed with diabetes and learning difficulties and had over one month off dealing with these issues. student engagement is not a static metric and nor is it a single entity which can be easily quantified. the level of engagement changes on a weekly basis and student engagement is physically, mentally, and also virtually. therefore, student engagement has to be measured and evaluated continuously to gain feedback and develop an ongoing understanding of the situation. the tools used included virtual learning environment, surveys session sign in sheets, class appraisals, posit-it feedback, module evaluation, personal academic tutoring and programme meetings. as in many programmes there was a direct correlation between those attending classes and the grades achieved at the end of the year. extra-curricular activities were attended by around % of the students on a weekly basis which for some programmes was extremely high, but as it was part of a work-based learning programme, it was felt this could be improved. to develop both higher student engagement and also be able to monitor this in a less intrusive manner: • the extra-curricular activities had been planned to be added to the reflective journal so that it was part of the assessment, rewarding good behaviour early on in the programme, and developing good habits; • the first year, first semester mindset module would use a portfolio assessment which would require students to attend each session to be able to complete the portfolio. this would ensure students were active throughout the first semester and engaged in this innovative and thought provoking module; and • mentoring sessions would require the completion of form which highlighted the tasks the student would complete before the next session. this would be handed into the enterprise manager, uploaded to the vle and followed up before the next mentoring session. • the use of extra-curricular and in-curricular activities to provide a reflective portfolio for the student to develop good habits and assessment material; and • the use of portfolio assessments within the first year provided an opportunity to build a better rapport and learning relationship with the student. this paper reviewed the pedagogy used to deliver a 'true' venture creation programme (vcp) at the university of worcester. this practice-oriented degree combined the creation of a functioning venture with academic study (lackéus and williams-middleton ) . therefore, the purpose of the paper is to provide a critical overview of the ways in which learning can be facilitated through vcps and focused on six core aspects of pedagogy: the programme structure, degree community, reflective practice, virtual learning spaces, learning communities and student engagement. the structure is the first stage in developing a constructively aligned programme, and this was done by setting the programme definitions, taught schedule, and the use of academic entrepreneurs (hopkins and feldman ) . however, for a successful implementation the alignment of the students' expectations was critical, especially within a vcp that was creating an environment where managed discourse and opportunity development were the norm. this was a twoway accord with the learning agreement ensuring the commitment from the student. the programme structure must be the stabilising core for all those involved with the vcp, especially the students and the wider business community. the aim of this degree community was to provide a seamless ecosystem of support to the students and was essential in building self-efficacy through mentoring and business opportunities through networking. however, this community needed to gain awareness and understanding of the programme and this had to be done through regular communications. in our case we provided a single programme approach which successfully allowed a wide range of stakeholders to engage. the reflective practice of an entrepreneur is an important aspect for the development of lifelong learning and aligns with our pedagogic focus on problem-based learning. reflective practice has been widely developed in several other disciplines, and therefore, the authors drew on this to propose the use of multidisciplinary teams to develop the effective entrepreneur reflective practitioner. the majority of the reflection was done within the virtual learning spaces as part of an assessment. the virtual learning spaces provide a considerable opportunity to develop resources for students on a vcp. however, the induction for a student starting to use it and the multidisciplinary staff developing material for it, requires considerable thought and management of initially the students, staff and the technology. the use of learning communities within a vcp provides a considerable opportunity for students to work in teams for their greater interaction, relationship, and collaboration among the course members. however, this requires a structured implementation, such as induction sessions, regular reporting, and team-building activities for it to be successfully implemented. student engagement within a true vcp requires a number of tools to build the attendance habit early on, such portfolio assessment within the first semester first year. the development of extra-curricular and in-curricular activities throughout the years provides additional incentives to attend and also engage, providing advantages in terms of education attainment and venture creation. in summary, this paper provides an important insight to the broader ongoing discussion surrounding the development of experiential entrepreneurial education programmes, especially contributing to the development approach of new true vcp and the critical issues around their design. the paper also focuses on how ensuring constructive alignment is a strategic aspect of the pedagogy design for the success of a vcp and its students. measurement and analysis of student engagement in university classes where varying levels of pbl methods of instruction are in use entrecomp: the entrepreneurship competence framework administration and community: considering challenges, exploring possibilities rethinking pedagogy for a digital age: designing for st century learning enhancing teaching through 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learning communities on student success. higher education monograph series the influence of role models on entrepreneurial intentions measuring progress in entrepreneurship education assessing the level of student reflection from reflective journals an empirical study of the relationships between emotional conflicts and entrepreneurship of top management team and business growth performance the art and science of entrepreneurship publisher's note springer nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations authors' contributions all authors participated in data collection and analysis including writing and approving the manuscript for submission. conflicts of interest all authors declare that we have no conflict of interest. key: cord- -v dwt k authors: thomas, michael s. c.; rogers, cathy title: education, the science of learning, and the covid- crisis date: - - journal: prospects (paris) doi: . /s - - -z sha: doc_id: cord_uid: v dwt k in the covid- crisis, the science of learning has two different responsibilities: first, to offer guidance about how best to deal with the impact of the current situation, including lockdown and home-schooling; and second, to consider bigger questions about what this large-scale educational experiment might mean for the future. the first part of this viewpoint summarises advice for parents on mental health, and on becoming stand-in-teachers. the second part, taking the longer view, considers the potential negative impact of the covid- crisis in increasing inequality in education; but also the potential positive impact of driving innovations in technology use for educating children. alongside the many new challenges posed by the covid- crisis is a somewhat familiar one: how to translate scientific evidence into public policy. politicians (in the uk at least) recite the mantra "we are led by the science", but in reality politicians, not scientists, lead. science focuses on mechanisms, the how and the why, while politicians have the daunting job of turning that into the "so what do we do?". on a smaller scale, the science of learning faces the same challenge. how can a scientific understanding of teaching and learning inform the much broader canvas of education policy and educational practices? more specifically, how can the slow, cumulative knowledge built up through research translate to meet classroom teachers' immediate needs? in the current crisis, with schools closed, children at home, and parents expected to take on teaching duties, psychology and the science of learning have two different responsibilities. the first is to offer guidance about how best to deal with the current situation. the second is to consider bigger questions about what this large-scale educational experiment might mean for the future. the association for psychological sciences (apa ) has summarised advice on the social impact of lockdown for both children and adults, as well as considering the implications of the increased anxiety produced by the pandemic. some of the main points concerning mental health include: • loneliness can make you ill by increasing stress, which can severely impact physical and mental health. while epidemiological models are good at measuring tangibles such as infection and mortality rates, they are less able to measure social costs such as loneliness. the consequences are no less real for those suffering. • parents' own mental health is important for children's development since caregivers are children's primary emotion regulators in times of stress. parents need to look after their own mental health, for the sake of their children as well as themselves. • symptoms of anxiety and depression correlate with level of media exposure. since this pandemic saturates us with information hours a day, it is recommended that adults choose only one or two times a day to watch or read news updates. parents also need to be aware of the information passed on to children, both factual and emotional, because children will learn from whatever information is around them. • changing behaviour is hard, particularly when the consequences seem quite abstract (e.g., don't scratch your nose because that'll protect your grandpa). gaining knowledge about how things work can help. for younger children, rule-based information such as "wash your hands" is much less effective without explaining why and how it works (reducing illness transmission, staying healthy). similarly, for those who have become stand-in-teachers overnight, the science of learning can provide some general pointers: • remember that learning can be slow and difficult; maintaining motivation and minimising frustration is key. • make learning meaningful to the child: what do they want to learn about? for younger children, follow their lead. for older children, who are following stricter learning roadmaps, try to relate topics in subjects they don't like to topics in subjects they do, e.g., relate testing for chlorine gas in chemistry to a history lesson on the use of chlorine as a weapon in the first world war. • promote autonomy by giving children choice and flexibility. try encouraging them to create their own timetables, including breaks and snack times. • give frequent, positive verbal feedback; it acts as a powerful reward which can promote better learning. • most important of all, physical exercise, a good diet, and sufficient sleep are the cornerstones of any effective learning. we all hope that covid- 's negative impact on education will be short-lived. but the reality is that many countries in the world are now participants in the biggest unplanned experiment that education has ever seen. what are some of the possible outcomes? on the downside, the requirement for children to continue their studies at home may exacerbate differences in educational progress caused by inequalities. children from homes with fewer resources and less opportunity for parental support risk falling behind, widening pre-existing gaps. worse still, some children may feel unsafe in their homes. children of well-off parents often live in bigger houses, have their own bedrooms, support from two parents rather than one, and better access to technology, books, and other learning resources, not to mention basics such as food. at least in school, pupils share the same spaces, lessons, teachers, and resources, which levels opportunities to some extent. moreover, studying at home will affect some age groups more than others. teenagers, whose emotional development propels them to move away from parents and carers and towards friends and peers, are likely to be more adversely affected. on the potential upside, the new forced reliance on technology in education may accelerate some changes that had already begun. might the pandemic cause educators to think harder about the current models of educational provision, learning faster about which uses of technology are successful and which are not? granted, the initial versions of education at home often look quite like the traditional teacher-led classroom, with teachers setting work to be completed at home, supplemented by some websites or online tutoring for narrow skills such as spelling or arithmetic. but perhaps there are also initial glimpses of what a technology-led revolution in education might look like: teachers serving as curators for virtual learning environments, which children can explore together with classmates to solve problems. in these environments, children can self-regulate their learning, switching to video tutorials or guidance from teachers when they need to learn new skills to proceed. think minecraft, roblox, and youtube. of course, this kind of revolution is some way off. perhaps more importantly, returning to our opening theme of the role of policymakers, policy is not the only driver of these innovations. instead, progress is driven by the cultural and commercial technology ecosystem. this crisis has made it apparent that school-provided it systems for computerbased learning are becoming redundant. they are too expensive, too cumbersome, and too quickly out of date. perhaps we need instead to move to personal devices integrated into schools. just as we turn on airplane mode when we get on a plane, perhaps we will turn on education mode when we enter school. this suggests the policy solutions needed to reshape education through technology are not prescriptive, but regulatory. policy needs to incentivise commercial developers to move into education. the role of policymakers, by contrast, should be to understand and mitigate the possible risks of technology use in children, as documented by research. as a starting point, these risks include screen time addiction and intolerance of boredom, displacement of other activities (e.g., homework, play), social media bullying, unreliable information, sleep disruption, violent or otherwise age-inappropriate content, and data protection issues. the wholehearted engagement of teenagers with computer games demonstrates that such games can, in principle, be powerful tools for affecting behaviour. deliberate attempts to create games that deliver learning-to gamify education-have so far been relatively poor because their focus has been on content and not game mechanics. such mechanics, triggering engagement and curiosity in children, are understood much better by wellresourced commercial game developers. this is where government incentivisation may be effective, to encourage commercial developers to produce engaging and powerful educational games and learning environments. one can hope that, despite the many dark sides of the current pandemic, there might also be a sliver of silver lining for education. human behavior in the time of covid- : learning from psychological science educational neuroscience: development across the lifespan publisher's note springer nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations his work focuses on translational research and the dialogue between educators, psychologists, and neuroscientists. he has just edited a new book on this topic united kingdom) is completing her doctoral studies in educational neuroscience, investigating the relationship between the development of cognitive control skills and creativity in children. previously, she spent twenty years working as a producer, presenter, and creative director in the tv industry key: cord- -ko pnree authors: pikhart, marcel title: the use of technology in the learning environment for business communication: applied linguistics of business communication from the positive psychology perspective date: - - journal: procedia computer science doi: . /j.procs. . . sha: doc_id: cord_uid: ko pnree the paper deals with implementation of a smart learning environment, namely blackboard, into the course of business communication. the new approach was implemented into the course and the research was conducted into the subjective satisfaction of the users of the environment. the first research was conducted in into the users´ satisfaction with the course which was taught using traditional methods, and the second research was conducted in into the users´ satisfaction with the new online course. the idea of the creator of the online course was to keep the contents and the scope of the subject as much similar as possible to create two groups of users, i.e. the first, using the traditional approaches, and the second with the modern technology-enabled class. with this intention, the blackboard class was created, and the users were taught by using blended learning methodology. the research focused merely on personal satisfaction with the course within the intention of positive psychology, i.e. focusing on potential issues regarding personal satisfaction. it did not focus on the differences in the performance of the students as there is a lot of research into this aspect. however, it focused on the individual satisfaction and personal feelings of the users while using blended learning platforms in the context of ubiquitous computing. the findings are that the users expressed their satisfaction regarding easily accessible materials and varied learning environment; however, the dissatisfaction was created by increased screen time and reduces social contacts. the findings are very important for educators who use various mobile platforms and elearning environments as they should be aware of the reservations of the users of these tools. elearning and blended learning as teaching methodologies and practices have become ubiquitous in our higher education environment that nowadays it is almost impossible to imagine any educational process without the utilization of these modern trends [ ] [ ] [ ] [ ] [ ] . it is visible in all areas of education, such as learning languages, science, humanities, medical science, teaching students with special needs, etc. [ ] [ ] [ ] [ ] [ ] [ ] . this ubiquitous elearning environment has brought many advantages which have already been well described in the current research into the topic [ ] [ ] [ ] [ ] [ ] [ ] . however, it can be claimed that after this very optimistic initial phase, we should be careful and also see the dark side of this new trend, or at least, test if there is any. this is also the aim of the paper, i.e. to identify potential risks that are connected to the utilization of technology in the learning environment. the research has proved that the beneficial effects of the use of technology in the learning process are vast and the results of the students´ performance can be increased if used properly and adequately [ ] [ ] [ ] [ ] . the question is what the adequate and proper use of technology is. the use of technology in the educational process should not be intuitive based on our experience but it should rather be a very intentional process that needs our undivided attention if we want to create elearning courses that will be successful and useful [ , ] . the learning process with the use of technology must be well defined because in the long tradition of learning psychology we don't have much experience because the utilization of elearning is a relatively new methodology and the development from elearning . through . , . to . indicated that the process of learning is not simple and very straight forward [ - ]. the positive psychology approaches have been promoted recently in various aspects of human activities focusing mainly on the positive feelings and satisfaction from those activities [ ] [ ] [ ] [ ] . in education, the aspect of positive psychology has not been researched sufficiently yet, however, there is some limited research into the area, and it provides us with optimistic findings. the research summarizes the importance of satisfaction not only for the subjective feelings and satisfaction but mostly for the intrinsic motivation and improved results. it is a well-known fact that when the students are interested in the topic and have positive feelings with the learning process and results, it will necessarily lead to improved performance. this aspect is rather neglected in the current research into the use of technology in the learning process and therefore this paper attempts to supply the practitioners in this area with a solid foundation and further motivation which will lead to an improved learning environment. the trend of digitalization of education has been visible in the past few decades, however, the trend of the past few years is unprecedented [ ] . nowadays, basically all educational institutions have to implement some kind of elearning, mlearning, blended learning or hybrid learning into their curricula and official authorities support this trend towards digitalization very much for the various pragmatic reasons [ ] [ ] [ ] . we can expect that the trend will be even stronger also due to the current situation with the global epidemy of the coronavirus which has led to a massive utilization of elearning throughout educational institutions globally. no other tool is these days as important as any kind of elearning and this trend will continue even in the future when we will want to be ready for repeated occurrence of similar situations of social crises. another very important aspect that is connected to digitalization is interconnectedness [ ] . the social media and various kinds of communication tools utilized in education can be very beneficial and a lot of research proves that these tools can bring advantages to the educational process. to sum it up, these are the aspects of current trends in education as follows: • ubiquitous computing • interconnectedness • digitalization of education the research was conducted in two steps. the research i in with the students of the faculty of informatics and management at the university of hradec kralove, czech republic. the students were the students of both informatics and financial management and all of them were well equipped with technological skills, knowledge and devices. the class taught is called business communication. the contents of the class is not relevant to the research. online questionnaire testing their course satisfaction and general opinion about the utilization of online classes was distributed at the end of the semester. the research i was conducted in during the winter semester of the academic year. the questions of the online questionnaire focused on their satisfaction with the course but also about their general feelings and opinions connected to the traditional methods used in the class. the number of respondents was , both male and female, the age of the respondents ranged from to . they were all students of the faculty of informatics and management of the university of hradec kralove, czech republic. they were not only czech students ( ) but the group also contained a large group of students ( ) from asian countries (taiwan, china, japan, korea). the most important parameter of the questionnaire was -from a positive psychology perspective -to focus on their satisfaction with the course. as already described, this parameter is very important for the tutor also to yield important findings that could be used in the future online course. the research ii was conducted in . the questions of the in-lie questionnaire focused on their general satisfaction with the class but also on their satisfaction with the blended learning methodology. the questionnaire also asked about their opinions about the use of virtual learning environments. the questionnaire focused mostly on the concept of satisfaction, i.e. personal satisfaction and positive feelings while using the blackboard platform. the number of respondents was , both male and female, the age of the respondents ranged from to . they were all students of the faculty of informatics and management of the university of hradec kralove, czech republic. they were not only czech students ( ) but the group also contained a large group of students ( ) from asian countries (taiwan, china, japan, korea). the questionnaire focused, again, on their satisfaction with the implemented course design, i.e. the use of blackboard for the course. the use of the blackboard platform was based on standard elearning strategies that are implemented throughout european universities, i.e. publishing online lectures, tests, additional material and tests so that the students can easily access those materials throughout the semester. following the intention of a positive psychology perspective, the questionnaire focused on these items which were considered crucial to find out what the most important aspects of elearning are for the users regarding their satisfaction with the course. the research questions in research i were as follows: . how will the students be satisfied with the course structure, i.e without any elearning support? . will the implementation of elearning increase their satisfaction with the course (this will be based on their experience with other courses that already use elearning)? author name / procedia computer science ( ) - the research questions in research ii were as follows: . how much will the use of elearning be perceived positively in comparison with traditional approaches such as lectures and discussion with the tutor? . what are the possible sources of subjective dissatisfaction with the on-line course? . what are the possible sources of subjective dissatisfaction with the on-line course? despite a relatively small research sample, the research yielded important findings that can be generalized, with a certain caution, and are transferrable into other areas of research to be analyzed and supported by a more detailed research endeavor. on the other hand, the fact that this is comparative diachronic research could be beneficial to find out the development of the situation and compare the results. therefore, despite the relatively small group of respondents, the results can be considered relevant and just need to be verified on a larger scale. the results clearly showed that the satisfaction of the individual students reached a very high level, nearing %, which is generally a very satisfactory result. the positive feelings associated with the course reached almost %, which is also a very good result. the students expressed their interest in the subject and they liked the methods used in the course, despite the fact that these methods were rather obsolete, i.e. a traditional oral lecture of the teaches followed by a seminar in smaller groups of the students where there was a lot of space for discussion and teamwork. the negative feelings associated with the course were at a very low level, reaching only %, which is considered an excellent result and the students will not connect this subject with any negative feelings. the results of the research show very similar numbers in the overall individual satisfaction with the course. % of the students proved to be satisfied with the way the course was conducted. their positive feelings associated with the course also reached a very high level, accounting for % on the other hand, the negative feelings of the students reached %, which is a dramatic increase compared to the previous year. the questionnaire was also looking for the reasons for this negative result. the students expressed their dissatisfaction with the online course because they lacked more social interaction with the tutor despite the fact that they could discuss the issues online (email) they still expressed their interest in the personal meetings every other week with the other students in a classroom where they could discuss interesting topics in person. they also expressed their interest in the lectures (also every other week) because the lecture could bring more personal experience and insight. the results of the research are as follows in table . the results show that individual satisfaction with the course is more or less the same, however, negative feelings were dramatically different. despite the positive feelings in both research i and research ii, the questionnaires clearly indicated several aspects worth mentioning and analyzing. the overall satisfaction, i.e. with both the traditional course and the online one, can be caused by the simple interest in the subject and the learning environment, regardless of the traditional or electronic approaches used for education. the differences in the results clearly show that after the implementation of online learning into the course the individual satisfaction remained more or less the same, the difference is statistically negligible, however, positive feelings connected to the use of the course have dropped. the drop, again, is not significant, however, this difference is not negligible and must be analyzed. on the other hand, the negative feelings associated with the use of online course methodology have increased dramatically. in research i, the negative feelings were as low as %, the tutor received a very positive score regarding his performance. in research ii, the negative feelings increased significantly to almost %, which indicates a dramatic increase in dissatisfaction. naturally, the reason could be not a well-prepared online course, however, the tutor claims that the course follows a well-established methodology and basically copies other online courses used at the university. therefore, a badly prepared course could play some role in the evaluation, but on the other hand, the majority of the courses are prepared in a very similar fashion. to sum it up, these are the accumulated results: • the students generally do not like using online materials when there is a change of sharing personal experience • the students usually do not like increasing their screen time when there is no need for that • the screen time they have with other activities (entertainment, social networking, etc.) is large enough and there is no need to increase it • the students lacked more social contacts with their peers and the tutor • the time spent in seminars while discussing the issues in person was considered to be more quality time compared to using the blackboard platform while studying online • social isolation caused by online tools must be taken into consideration and its dosage must be done properly this research proves that the use of elearning and blended learning is not straightforwardly positive as we can find in numerous resources. we have to take into consideration potential problems that could arise. obviously, elearning brings very positive outcomes and can speed the process of education dramatically, however, we have to consider these results very carefully so as to optimize the educational process using mobile devices and elearning. these tools and their use are in a massive increase, which is a very positive, trend, but the educators should be aware of the fact that this rise must be somehow more systematic and pragmatic so that we optimize the learning process. the research and its comparative results clearly show that the trend of somehow unsystematic development of elearning and the use of digital tools in the learning process must be made more systematic. these are the recommendation which could be followed to make the trend of the use of electronic tools in education smoother and more impactful: • try not to increase the screen time by using the functions which limit the social aspects of the learning environment • reduce the screen time by more personal contacts with the course participants • the online tool should only be used in the areas which are not substitutable, e.g. videos, audio recordings, data analysis, big data, data mining, in other cases, such as lectures and seminars, the tutor and their personal presence should not be substituted • increase the time of social contacts with the tutor and the online course should be used only in cases when it is necessary and the tutor cannot be substituted (illness or injury time, global infection, distant students, work duties, etc.) • testing should be done through online tools as it is more objective and brings comparable results • online tools can use big data, various algorithms for processing information, and other tools of data mining that will be extremely useful in modern elearning platforms, however, nowadays, they are still not used efficiently, if at all • the implementation of artificial intelligence into the learning platforms will be probably the most important improvement because artificial intelligence can surpass the human brain in the volume of data processes and therefore will increase the efficiency the learning and testing process dramatically further research should replicate the results yielded by our research. it should focus further on user satisfaction as it plays a major role in elearning. if the users are subjectively satisfied with the learning environment, they will more likely use it in their free time and this positive motivation will also enhance their performance and study results. further research should focus more on limitations rather than benefits of elearning and blended learning as the benefits have already been highlighted by numerous research activities globally and there is no need to further justify these teaching methods. it is more important to highlight potential problems that could arise, and which could be potentially eliminated or at least reduced. by realizing these pitfalls of elearning and blended learning, the whole system of education can become more sustainable and competitive in the global learning environment [ , , , , ] . can e-learning replace classroom learning? communications of the acm technology, e-learning and distance education e-learning in organizations web-assisted and online 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of electronic communication. smart education and e-learning intercultural business communication courses in european universities as a way to enhance competitiveness technology enhanced learning experience in intercultural business communication course: a case study lost in translation: adapting a face-to-face course into an online learning experience. health promotion practice applying distributed learning theory in online business communication courses walk, don't run to online learning evidence-based best practices in designing and developing quality elearning for the public health and health care workforce educational technology-related performance of teaching faculty in higher education: implications for elearning management perceptions of the effectiveness of online instruction in terms of the seven principles of effective undergraduate education dialogue, inquiry, and encounter: critical geographies of online higher education effectiveness of elearning in statistics: pictures and stories thinking through positive psychology transforming teaching and learning in elt through critical pedagogy: an international study what (and why) is positive psychology? utilization of linguistic aspects of bloom's taxonomy in blended learning blended learning approach in english language teaching -its benefits, challenges, and perspectives mobile applications and their role in teaching english -methodological basis author name / procedia computer science digital transformation of intercultural communication aspects of intercultural communication in it: convergence of communication and computing in the global world of interconnectedness elearning . as a sustainability strategy for generation z language learners: applied linguistics of second language acquisition in younger adults mobile learning and its impact on learning english vocabulary impact of mobile learning on students' achievement results use of smartphone applications in english language learning -a challenge for foreign language education mobile technology and generation z in the english language classroom -a preliminary study this paper is a part of the project spev / , run at the faculty of informatics and management of the university of hradec kralove, the czech republic. the author would like to thank ales berger for his help with the data collection. key: cord- -e xagi authors: rhim, hye chang; han, heeyoung title: teaching online: foundational concepts of online learning and practical guidelines date: - - journal: korean j med educ doi: . /kjme. . sha: doc_id: cord_uid: e xagi medical schools have been slowly adopting online learning into pedagogical methods for more than a decade. while some medical educators are reluctant to accept these changes, the ongoing coronavirus disease (covid- ) pandemic poses a threat to the delivery of traditional medical education, which has accelerated the inevitable implementation of online learning. this sudden change may be a new challenge to medical educators who are new to this territory. therefore, this review aims to provide foundational concepts of online learning and practical guidelines in the context of medical education. the authors first identify three foundational concepts, which are transactional distance, presence, and independent learners. in online learning, transactional distance, determined by dialogue and structure, becomes more important than physical distance. furthermore, effective and successful online learning requires the achievement and accommodation of cognitive, social, and teaching presences. it is also crucial to recognize learners not as passive recipients of information predefined by a teacher, but as active, capable, and independent individuals. the authors, then, discuss the practical guidelines for designing an effective online curriculum. five online pedagogical guidelines are laid out in this review: design structures and flows to embrace experiential learning, accommodate both synchronous and asynchronous learning, design/facilitate interactions, promote practice opportunities, and promote a learning community. by understanding the foundational concepts and applying these guidelines, the adoption of online learning in the medical school may supplement the traditional medical education or even provide additional benefits in the new normal after the covid- pandemic. although the covid- pandemic has disrupted medical education in unprecedented ways, ironically, the virus seemed to have worked as the catalyst for embracing virtual learning [ ] . in fact, prior to the covid- pandemic, medical schools have been slowly implementing online learning into pedagogical methods for more than a decade [ , ] ; however, they have been still reluctant to accept these changes [ ] . despite the uncertainty regarding how long this pandemic will persist and the possibility of a new pandemic in the future, the pedagogical reevaluation of online learning as the main curriculum environment is undergoing in medical education [ ] . however, this transition requires more than simply recording a lecture and uploading it in online platforms. it is not a simple copy and paste practice of existing face-to-face teaching activities in an online format. it is a re-mediation process of the current instructional practices, requiring to revisit the current assumptions on physical space and time in educational practices [ , ] . the covid- pandemic was unexpected and the changes necessary to continue medical educations were abrupt; thus, the adoption of online learning may be challenging to medical educators, in particular, who are new to this territory. therefore, the purpose of this review is to provide foundational concepts of online learning that can be historically traced back to distance education and discuss the practical guidelines for designing an effective online curriculum. online learning has a historical root in distance education; the latter was an alternative educational practice and program for nontraditional learners who could not have had education opportunities otherwise [ ] . online learning is described as access to learning experiences via the use of the internet and considered a more recent version of distance learning [ ] . although there seem to be subtle differences in the definitions of e-learning, online learning, and distance learning, these terms are used interchangeably and rooted in distance education [ ] . the physical and temporal distance was emphasized in shaping this new form of education centuries ago. the development of the postal system provided opportunities for non-traditional students who worked during the day and lived distant from a college. distance education enabled these students to overcome distance and time, and the subsequent advent of newer technologies such as tv and the internet closed the distance between teachers and students even more. while the current stage of technological innovations allows for faster and easier synchronous and asynchronous communications, transactional distance still needs to be considered in online learning. there are three foundational concepts for effective distance education programs, which become the basis of instructional design of online learning and teaching practices: transactional distance, presence, and independent learners. physical distance is a barrier to traditional education. however, distance in online learning is not defined by physical distance but "transactional distance" [ ] . according to moore [ ] , transactional distance is a social, psychological, and relational distance between teachers and learners that is fluid and manageable based on a function of dialogue and structure. when dialogues, meaningful interactions between teachers and learners for the creation of knowledge, are increased, the transactional distance between them can be reduced. even in a classroom, if a teacher does not have a dialogue with students, the latter would feel a greater transactional distance. the degrees and characteristics of dialogues depend on numerous factors but mainly on the structure of the course and, to a lesser extent, on the medium of communication. here, structure indicates the rigidity or flexibility of the educational program. it depicts the degree to which a course can respond to each learner's different demands and preferences. when the teaching is highly structured without consideration for the learners' differences and individualization in their learning processes with minimal dialogue, the transactional distance becomes high [ ] . online courses not providing ongoing dialogue between a teacher and learners and rarely accommodating individual students' needs would have high transactional distance and become undesirable. therefore, educators need to understand that the medium of communication would not automatically close the distance between teachers and students. furthermore, the transactional distance may remain intact depending on the extent of dialogue and structure. another foundational concept of online education is presence. there are three kinds of presence: cognitive presence, social presence, and teaching presence [ ] . when an individual is involved in online learning, it implies that the individual becomes a member of a "community of inquiry" as a learner or a teacher (or both). effective and successful online learning requires each member to achieve and accommodate these three types of presence [ ] . "cognitive presence" indicates the degree to which the learners can construct meaning through constant exchanges of thoughts-questioning, answering, brainstorming, discussing, and solving a problem [ , ] . in "social presence" can be achieved when learners project their personal feelings, emotions, questions, and characteristics into the community [ , ] . garrison et al. [ ] argued that socio-emotional interactions and support are crucial and essential at times in nurturing cognitive presence and, therefore, leading to meaningful educational outcomes [ ] . social presence helps members in the community reduce psychosocial tension and uncertainty as well as encourages the group to freely discuss and collaborate on a project, exceeding simple interactions and one-way instructions. collaborations draw learners to a shared experience space to construct and confirm meaning. in this respect, a successful online learning community needs to promote collaboration rather than simply exist as a place to download information. "teaching presence" indicates two general functions, design of the educational experiences and facilitation [ , ] . the former function may be the primary responsibility of the teacher who selects, organizes, presents course content, and develops learning activities and assessments, providing clear expectations and a basic guideline on learning activities. facilitation can be achieved by the teacher or the students in an online environment. the role of teaching presence is to support and enrich social as well as cognitive presence to accomplish meaningful educational outcomes. effective online teaching requires a fundamental perspective change regarding learners. learners are not passive recipients of information predefined by a teacher, but active, capable, and independent individuals with their own learning processes to explore their environments in knowledge construction [ ] . as briefly discussed in the previous section of teaching presence, teachers' roles lean toward the facilitation and the design of learning experiences that allow learner autonomy. however, it is also true that students have varying degrees of ability to develop a personal learning strategy, to find resources for study, and to assess their own progress [ ] . a higher transactional distance means that teaching requires more autonomous learners; however, students do not always have a high level of autonomy. the role of teachers in the online environment, then, includes not only providing information but also motivating and empowering students to enrich their learning experience. in sum, teaching online requires three foundational understandings about distance, presence, and learners. transactional distance, cognitive presence, social presence, teaching presence, and independent learners can become guiding parameters in the design of online learning programs. in the following section, we will discuss practical guidelines for online teaching that are based on those three foundational concepts. online teaching is a design of learning experiences and facilitation of those experiences. in this section, we will discuss the design of learning experiences by explaining five online pedagogical guidelines: design structure and flow to embrace experiential learning, accommodate both synchronous and asynchronous learning, design/ facilitate interactions, promote practice opportunities, and promote a learning community. effective online teaching can be achieved by embracing an experiential learning approach [ ] . however, it may extend to small group discussions, team-based learning, cadaver dissection lab during the preclinical years, and even their personal experiences before medical training. a teacher's instruction or lecture can be considered as a stimulus that provides the learner with an opportunity to observe what a content expert thinks and knows [ ] . students absorb what they have been told as a response and ought to have opportunities to connect their experiences with their observations to identify general principles [ , ] . students need to actively engage and interact with their surroundings to test what they learned, that is, students are allowed to experience further to absorb (response) given instruction (stimulus). therefore, online teaching is not one single event of lecturing but continuous facilitation of the experiential learning cycle. the flipped classroom is a pedagogical approach that allows an experiential learning cycle in an online learning environment. in a flipped classroom, students learn didactic materials at their own pace before the class using pre-recorded lectures available asynchronously. students would connect their prior experiences with the newly observed resources to create their own knowledge. then, students would bring their understandings during face-to-face or synchronous online interactions with the teacher, where they can actively test their understandings and engage in problem-solving while interacting with the teacher and peers [ ] . with the expert's scaffolding and guidance on the side, learners can further develop their own knowledge and skills that would feed into future experiences [ ] . there are four interactions that online teachers should consider: students' interaction with resources, interaction with the instructor, interaction with the peer, and interaction with self [ , ] . these interactions have been found crucial for meaningful learning experiences and effectiveness in online learning [ ] . online learning may be seen as an alternative instructional modality just for classroom learning without actual practices or experiences. as discussed in the earlier section, however, concrete experience is a crucial part of any learning process. this becomes more critical in medical education where clinical experience is the central part of medical competency development. despite the physical distance, there are ways that medial educators can facilitate learners to have clinical practices in an online environment. one is a mediated experience. can be mediated and what cannot be. for example, teaching students about working on a night shift and interacting with different healthcare professionals might be hard to mediate in an online environment. however, some experiences can be practiced in an online environment. for example, klamen [ ] argued that third-year medical students cannot possibly see all kinds of patients in clerkship rotations [ ] . even after seeing the patient, practicing clinical reasoning in which students identify differential diagnoses and treatment plans did not occur due to busy workflow in hospitals and clinics [ ] . moreover, it is also challenging for novice medical learners to observe attending physicians' thought processes on a busy clinic day. after recognizing this issue, klamen et al. [ ] adopting online learning means transforming teaching philosophy to embracing organic collective intelligence for a sustainable learning environment [ ] . in online learning, teachers are not the only source for building knowledge; students learn from teaching others, and by observing their peer students. the line between the teacher (knowledge provider) and the learner (knowledge receiver) is blurred in online learning. effective online learning can be sustainable and strengthened by a learning community [ ] . there must be a sense of a learning community at a medical school. teachers can simply recognize and facilitate the existing learning community as well as create a new one even beyond the existing school system. a sense of a learning community can be created by asynchronous interactions as well as synchronous interactions online or in-person. a teacher's asynchronous online presence at an online discussion forum can be beneficial because of the students' extended opportunity to interact with the teacher anytime anywhere. teachers take multiple roles in facilitating a learning community: an information provider, a facilitator for students' participation, collaboration and peer learning, a curator to connect students to other organized resources, and a lifelong learner, not just an evaluator. social presence is crucial in creating a functional online learning community [ ] . members including teachers should feel comfortable being who they are and be able to share struggles as well as although the covid- pandemic poses a threat to traditional medical education, it has also provided an opportunity to recognize online learning as an effective pedagogical method. its effectiveness, however, depends on the degree to which medical educators are aware of the foundational concepts of online learning. unlike a physical distance that was a barrier to traditional education, transactional distance should be considered in online education. the educators need to understand that the advancement in communication technology itself would not automatically close the distance between the teachers and students; instead, educators should try to promote dialogue and social presence as well as minimize structure in order to reduce the transactional distance. also, the role of a teacher is not limited to someone who provides information but also someone who motivates students to enrich their learning experience. we provided five online pedagogical guidelines for designing curriculum in the medical education context. practice opportunities can be more widely available through online platforms in certain patient cases. lastly, efforts need to be made to maintain a sense of a learning community even in an online environment. by understanding the foundational concepts and applying the online pedagogical guidelines (which are summarized in fig. ), the adoption of online learning in the medical school may supplement traditional medical education or even provide additional benefits in the new normal after the covid- pandemic. hye chang rhim: https://orcid.org/ - - - heeyoung han: https://orcid.org/ - - - innovation in response to the covid- pandemic crisis medical student education in the time of covid- flipped classroom improves student learning in health professions education: a meta-analysis the inevitable reimagining of medical education mediation and remediation in online learning liquid modernity learning at the back door: reflections on non-traditional learning in the lifespan e-learning, online learning, and distance learning environments: are they the same? internet high educ theory of transactional distance theory of transactional distance the theory and practice of online learning critical inquiry in a text-based environment: computer conferencing in higher education experiential learning: amee guide no. the reflex arc concept in psychology the flipped classroom in medical education: engaging students to build competency mind in society: the development of higher psychological processes asynchronous and synchronous e-learning a framework for analyzing, designing, and sequencing planned elearning interactions information age publishing three types of interaction building learning communities in online courses: the importance of interaction getting real: aligning the learning needs of clerkship students with the current clinical environment getting real: embracing the conditions of the third-year clerkship and reimagining the curriculum to enable deliberate practice learning in the real place: medical students' learning and socialization in clerkships at one medical school virtual bedside teaching rounds with patients with covid- guidelines for facilitating the development of learning communities in online courses the relationships between higher order thinking skills, cognitive density, and social presence in online learning acknowledgements: none. key: cord- - iedjcr authors: dua, anisha b; kilian, adam; grainger, rebecca; fantus, sarah a; wallace, zachary s; buttgereit, frank; jonas, beth l title: challenges, collaboration, and innovation in rheumatology education during the covid- pandemic: leveraging new ways to teach date: - - journal: clin rheumatol doi: . /s - - -x sha: doc_id: cord_uid: iedjcr the novel coronavirus disease (covid- ) pandemic has significantly impacted the field of rheumatology, in both the delivery of clinical care and didactic education for our trainees. these changes have generated significant strain for program directors and clinical educators who have had to leverage technology and develop new systems to ensure continued trainee education and assessment. we aim to outline the impacts on formal education programs presented by these unprecedented disruptions, describe the development and deployment of online teaching, reflect on the challenges and opportunities for technology-enabled learning and use of social media for education, and give some international perspectives on impacts on postgraduate rheumatology training outside the usa. with the rapid dissolution of barriers in place during the pre-covid- era, we have the opportunity to assess the efficacy of new methods of care and further integrate technology into teaching and assessment. we propose that a hybrid in-person and technology-enabled learning approach, so-called blended learning, is likely to remain the most desirable future model for supporting trainee learning. the novel coronavirus disease (covid- ) pandemic has significantly impacted the field of rheumatology, in both clinical care and education. to implement the physical distancing required to prevent viral transmission-thus protecting our patients, ourselves, and our staff-practices have rapidly converted to telemedicine clinics. likewise, most of our formal teaching activities have moved to online formats. in addition, rheumatologists have been deployed to serve in other settings to help manage the surge of covid- patients. these changes have generated significant strain for program directors and clinical educators who had to quickly leverage technology and develop new systems to ensure the continued provision of excellent patient care and educational programs to support trainee learning. this challenge is compounded by the ongoing uncertainty about how long these changes to clinical practice and teaching will be required. in this manuscript we aim to outline the impacts on formal education programs presented by these covid-related disruptions, describe the development and deployment of online teaching, reflect on the challenges and opportunities for technology-enabled learning, and use of social media for education, and give some international perspectives on impacts on postgraduate rheumatology training outside the usa. we propose that a hybrid in-person and technology-enabled learning approach, so-called blended learning, is likely to remain the most desirable future model for supporting trainee learning. additional benefits include increasing equitability of access to learning as well as scalability. challenges and opportunities for programs and fellows due to covid- the covid- pandemic has created many challenges for rheumatology fellowship programs. rheumatology practice, traditionally centered on delivering face-to-face high-volume outpatient continuity care for patients with rheumatic and musculoskeletal diseases, has been adversely affected. physical distancing to reduce the spread of the novel coronavirus sars cov- has moved patient care to a virtual format, removing the rich environment for bedside teaching for which rheumatologists are known. in addition, collaborative conferences and patient-focused discussions have had to move out of the clinics and conference rooms. the online format requires adaptation of presentation skills and new ways of working. major challenges include maintaining our culture of bedside teaching and focus on collaborative patient care when we are distanced from patients, learners, and colleagues. the impact of these adjustments has been immediate and we anticipate the consequences could be long term. one immediate impact of the pandemic was the conversion of clinics almost entirely to telehealth conducted by telephone or online videoconferencing. telehealth has demonstrated benefits in rheumatologic care, which include increased access for patients in underserved areas, with patient reported outcomes similar after telemedicine compared with usual care visits [ ] . although an in-depth analysis of a telerheumatology service shows this approach increases access to care and meets care needs on most occasions, it is not appropriate in the approximately % of clinical situations where the diagnosis is unclear or significant complexity is present [ ] . the usa faces a rheumatology provider shortage over the next decade, which may negatively affect care for patients with rheumatic disease across the usa [ ] . although the more widespread use of telehealth has been promoted to address this shortage and maldistribution of rheumatologists, there are relatively few studies that assess the feasibility and effectiveness of telehealth in rheumatology [ ] , and the generalizability of findings remains to be tested. in addition, other challenges such as reimbursement for medical services, credentialing of physicians, and informed consent have slowed the incorporation of telehealth into routine rheumatology practice. despite this, the disruption of the pandemic has rapidly required those barriers to be addressed, with swift and widespread implementation of telehealth approaches in rheumatology. this urgent and unplanned expansion of telemedicine must be evaluated to enable further refinements of this remote care to ensure comparable patient outcomes with inperson care. the impact on training also needs to be considered. what training opportunities are reduced or absent in a telehealth consultation? what configuration of telehealth might optimize the platform for learning when attending and fellow are co-located while the patient is remote? what training opportunities, if any, are enhanced or novel in a telehealth environment? the impact on the teaching and learning opportunities for fellows in training has been dramatic. in many programs, didactic teaching, journal clubs, research conferences, and projects were suspended and in-person teaching of physical exam techniques and ultrasound came to an abrupt halt. furthermore, consult services became remote through phone or video calls with patients and their family members. many faculty and fellows were being redeployed to care for the influx of covid- patients, outside their rheumatology capacities. immediate tasks for program directors included adjusting trainee schedules, addressing trainees' very legitimate anxiety around the interruption of training, and protection of their own health. an article on the impact of covid- on medical trainees described "a sense of hopelessness, helplessness, and nervous anticipation at what may yet come to pass" [ ] . promoting resilience and avoiding social and psychological isolation in our trainees is paramount, while still maintaining the physical distancing required to protect physical health. medium-and long-term impacts include how the adaptations made in response to covid- will shift future healthcare delivery and education moving forward. programs have used multiple platforms including zoom, microsoft teams, doximity, webex, and ringcentral for clinical care, and teaching. in addition to delivering didactic programs, we should also commit to providing feedback on trainees' ability to achieve milestones in the virtual setting [ ] . although virtual platforms present challenges to providing feedback on subtlety of clinical signs, they preserve opportunities to provide feedback on clinical reasoning, care planning, and patient and team communication. clinical educators will be faced with the challenge of giving constructive verbal feedback without the benefit of using non-verbal communication. by focusing on the continued education and evaluation of our trainees while remaining flexible and innovative, the global rheumatology community will come out of this pandemic with new skills and with more versatility and resiliency than before. one example of rapid innovation which has left a repository for future learning is the virtual rheumatology learning (virl) collaborative. the virl collaborative was developed to address the need for continued fellow didactic teaching during the pandemic. the concept was introduced by a program director (ad) who quickly assembled rheumatology programs with interest in participating. expert speakers were recruited by the program directors of these institutions to give synchronous online lectures three times weekly. the american college of rheumatology (acr) joined the effort by providing online registration mechanisms, logistical and technical support, and a virtual platform (ringcentral) to host the series. with this support, access to the series was expanded with content made available for live viewing at no cost to registrants and each session recorded and posted to an accessible website (https:// www.rheumatology.org/i-am-a/fellow-in-training/virtual-rheumatology-program/learning-collaborative) for asynchronous viewing by the next day. one faculty and one fellow moderated each lecture, gathering questions during the session via the chat function to initiate discussion after the presentation. the first lecture was delivered on april , , only week after the initial email gauging program interest. robust interest in participating in online learning was demonstrated not only by fellow trainees but also by faculty and community rheumatologists, physician extenders, medical residents, and students, and it quickly expanded internationally. the support of the acr enabled access to all interested learners, with registrants from countries. on average learners participated in each "live" virtual session. recorded videos are hosted through the acr website and are available to all learners. given competing demands during work hours in the usa and international interest from learners around the globe, having the ability to access this information at their convenience-and at any future date-is a strength of this online delivery and repository. we were able to leverage the expertise of national thought leaders to rapidly build a high quality, broadly appealing lecture series on some of the most relevant topics to rheumatology trainees. fellow participation in co-moderating sessions has increased visibility of fellow trainees and allowed increased interaction between fellows and world-renowned experts, which is not always feasible in face-to-face presentations. one limitation of the lecture series includes the lack of a formalized curriculum with set goals and objectives based on a needs-assessment. as all programs were in varying stages of their didactic curriculum, and given the rapid turnaround from conception to launch, speakers were not assigned topics or asked to develop new talks. another limitation of the online format is the lack of small group engagement and active learning. while speakers and learners adjusted to using the technology for content delivery, social aspects of learning such as discussionwhich are central to andragogy-were not able to be accommodated in the short timelines. ideally, future virtual learning sessions will be developed around a specific curriculum, with clear goals and objectives, and include interactive processes that utilize adult learning theories. virl has increased access to educational content and fostered some sense of community amongst learners, which is especially important when facing isolation from usual communities of practice. one positive and unanticipated effect of the use of virtual platforms has been enabling access for more learners to educational content provided by topic experts and expert teachers. the force of this pandemic has been met with the dedication, collaboration, and innovation amongst rheumatology programs nationally and internationally by pooling resources and optimizing structured access to didactic training for our learners. this new and exciting format for medical education may have a lasting impact on the field beyond the limits of this pandemic. while virl has provided a high-quality substitute for suspended in-person teaching, there has been general consensus for many years that medical education, based largely on outdated educational structures that rely heavily on didactic in-person learning experiences, has needed to change [ ] . technology-based learning offers great potential to reduce inequity in medical education worldwide, enhance learnercentered knowledge delivery, address the anticipated rheumatology workforce shortage, and prepare new providers to practice effectively in our twenty-first century health systems. the current covid- pandemic, which has dramatically impaired in-person learning at all levels of medical training, may be the catalyst that galvanizes the medical education community to reassess and innovate so that teaching practices better align with the needs of contemporary healthcare learners. technology-based health learning platforms have the potential to mitigate inequities in medical education that include quality of accessible learning experiences, financial resources, and career development opportunities. while covid- disruptions impact medical education everywhere, resource limited areas and trainees are likely to be disproportionately affected. collaborative technology-based learning, which can be widely shared and is scalable, offers the opportunity to increase access to high-quality medical education resources and content experts worldwide while reducing the costs of medical education. this has potentially far-reaching and long-lasting benefits for growing the healthcare workforce. it also has the potential to impact the well-being of individual healthcare providers, since financial stress related to the high costs of medical education contributes to burnout in healthcare providers [ ] . technology-enabled medical education offers opportunities to integrate the science of learning into the educational framework to optimize cognitive load and increase understanding, retention, and transfer [ ] . the traditional educational structure that relied heavily on one-size-fits-all didactics is mainly institutionally centered. in contrast, technologyenabled medical education offers a learner-centered approach in which technology aids and supports individualized learning and engagement. this opens doors to blended learning strategies that synergistically integrate adult learning principles to enhance and accelerate learning. educational strategies such as personalized learning, adaptive learning, flipped classroom, just-in-time, and effective use of multimedia can all be incorporated into technology-enabled instructional design. some strategies that have been successfully used include case discussion in virtual breakout rooms, recordings for asynchronous learning, and incorporation of polling to allow for dynamic discussion and teaching. this instruction offers opportunities to personalize education to the needs and abilities of diverse learners with variable knowledge, experiences, motivations, attitudes, and goals. designing technology-enabled instruction guided by evidence-based principles of learning can provide medical educators with opportunities to implement effective pedagogy, develop instructional materials that facilitate efficient and effective learning, and ideally make individualization of learning affordable and available to all students. the funding, distribution, access, and support of these initiatives pose potential barriers and are considerations that will need to be addressed. most responses to implementing online versions of inperson learning should be seen for what they are, remote emergency teaching [ ] . designing technology-enabled learning environments is the essential next step but also poses several challenges. the first challenge for medical educators is to uphold a learner-centered approach in which technology aids and supports learning and avoid the pitfalls of slipping into a technology-centered approach. to do this effectively, medical educators should themselves be educated about evidence-based instructional design principles and technology capabilities. second, technology-enabled learning environments should clearly specify learning objectives, be engaging and motivating for learners, and provide opportunities for realtime assessment and feedback [ ] . third, copyright laws can present barriers to widespread dissemination of educational material; support from publishing corporations to permit the use of copyrighted images and videos in widely disseminated instructional materials would greatly enhance accessibility to learners worldwide. finally, due consideration should be made to the influences of adoption of technology by faculty and institutions, which need careful planning and adequate resourcing [ ] . the covid- -related disruptions have made clear that there is a great and urgent need to upskill our faculty in these concepts and invest in developing fit-for-purpose, contemporary technology enabled learning that meets the needs of our rheumatology workforce in training. social media has become a powerful instrument for international collaboration and knowledge and information sharing that supplements traditional learning, and rheumatology medical education has been no exception. recent years have seen increasing trends in the utilization of social media for teaching and learning in the health professions [ ] . twitter, facebook, youtube, whatsapp, and instagram provide learners and facilitators in the health professions a chance to interact, collaborate, and share perspectives and information with each other, as well as facilitate wide dissemination of educational material. the use of twitter proved instrumental in the worldwide dissemination of the virl lecture series and recordings can be viewed via youtube for asynchronous learning. twitter was also the hub for the development of the covid- global rheumatology alliance, which has enabled collaboration internationally to learn and collect data about covid- and rheumatic disease patients. the emerging literature on the use of social media for graduate medical education describes the use of twitter, podcasts, and blogs for engaging learners and disseminating information [ ] . these social media platforms are likely to continue to increase in uptake and further evaluation of use and impact are warranted. limitations to the use of social media in medical education include but are not limited to concerns surrounding professionalism and risks of data protection. medical educators and learners engaging with social media for medical education purposes should be aware of its limitations and challenges, which can be mitigated by training users on appropriate use of social media [ ] . internationally, rheumatology services in high-income countries in europe and australasia have been impacted in very similar ways to the usa: a rapid, unplanned move to telerheumatology, disruption of usual teaching and learning opportunities, and redeployment of trainees and senior staff. training accreditation bodies are working hard to balance competing demands: medical licensing regulators and the public deserve to be confident that sufficient rheumatology training has been available, and that the relevant learning has occurred. we are challenged with simultaneously protecting the wellbeing of our trainees as they continue to learn and provide care in unfamiliar ways, or even outside their current expertise. decisions about assessment progression through training should be made with careful consideration and compassion and additional learning opportunities need to be provided. in smaller countries the ability to rapidly provide online didactic content may be more limited, although the virl content has been made available internationally on request. examining physician training in australia and new zealand does highlight how local training requirements, and the different country-level responses to the pandemic shape education changes. entry to rheumatology training in australia and new zealand requires a medical resident to pass a knowledge examination (multiple choice format), then a full day in-person clinical examination. the clinical examination includes "longcases" (full history, examination and management planning) and "short-cases" (physical examination and synthesis) during which multiple examiners, candidates, and patients travel to examination sites and interact with each other. although community transmission of covid- has been better controlled in these countries, this examination format has been deemed too risky. instead the examination will be split into "long cases" delivered remotely via videoconferencing, and if candidates are successful, short cases will be sat for in-person at a later date, likely at a local site. although the change to examination may seem relatively minor, this has been a large source of anxiety and distress to physician trainees and huge efforts on the part of the training accreditor, the royal australasian college of physicians. it also remains unclear what examination processes will remain on an ongoing basis. overall, rheumatology training has been able to continue relatively uninterrupted; however, the remaining unknown is when it may become feasible again for trainees from australia and new zealand to travel to gain experience training at larger rheumatology centres or to attend international in-person conferences when these resume. access to online conferences is an interim solution. the european league against rheumatism (eular) school of rheumatology (esor) may serve as a good example to illustrate new developments resulting from the pandemic in the field of rheumatology training in europe (more detailed information available here: https://esor.eular.org/). the online courses such as eular course on rheumatic diseases or the eular online course on imaging in rheumatic diseases play the main role, while the esor formats of live courses and meetings that are also offered are currently not feasible. driven by the educational committee, eular continues to make substantial efforts and investments in the further development of e-learning opportunities. achieving a modern, attractive presentation of the teaching content covered by the individual modules is currently the main development focus. this way, eular aims at optimizing quality, range, and acceptance of this teaching and learning format. while we have concentrated on the most tangible aspects of postgraduate educationthe visible and measurable formal and informal teaching-our trainees are also still learning the "art" of rheumatology. the need to rapidly adapt to the covid- impacts on learning, teaching and clinical care will allow ample opportunities for modeling of key characteristics of a rheumatologist: advocating for individual patients, collaborating and working effectively with an interprofessional team, demonstrating professional, compassionate, and ethical behavior and engaging in lifelong learning [ ] . the covid- crisis imposed challenges on our normal approach to medical education that necessitated accelerated innovation. how will this experience and our community's response influence rheumatology education after the pandemic? the successful implementation of telehealth to deliver rheumatologic care during the pandemic suggests that it could play an important role in routine clinical practice. however, this experience also taught us that there are challenges to delivering rheumatologic care virtually, especially for trainees and educators. an advantage of providing virtual care during the pandemic was that the learner, educator, and patient did not need to be in the same room. however, many of the foundational elements of rheumatology education, particularly the physical exam, occur at the bedside where the teacher can show a learner how to examine or aspirate a joint, for instance, and the learner can demonstrate mastery of these skills. in order for the novice trainee to develop proficiency in musculoskeletal ultrasound, hands-on demonstration and practice with the ultrasound machine at the bedside under the guidance of an experienced practitioner is critical. one path forward would be to prioritize keeping a portion of trainee clinics inperson, especially during the first year, but using arrangements in clinic that protect the learner, educator, and patient (e.g., universal masks, hand hygiene, frequent sanitizing, providing adequate space and ventilation in rooms) in consultation with infection control. patients with stable disease or conditions that may not require a frequent physical exam could be prioritized for virtual visits. assuming virtual care will be a part of our routine practice moving forward, we need to consider how to train learners to obtain a history efficiently and effectively over video and by phone and perform a limited physical examination by video. there will also need to be consideration given to how we maximize the educational benefits of virtual precepting for learners and educators. perhaps the learner and educator could conduct virtual visits together from the same clinic office space so that some of the benefits of in-person education like interviewing patients together, discussing the complexities of a case, and reviewing management strategies are retained [ ] . outside of the clinic setting, there will continue to be restrictions on gatherings for educational conferences. the covid- pandemic has demonstrated how virtual didactics (e.g., by zoom or webex) can be used to maintain institutionspecific curricula. however, the pandemic has also provided us opportunities to deliver educational training by experts at a larger scale for trainees across institutions, even internationally. virtual lectures have the potential to improve the education of rheumatology fellows by providing access to the most upto-date information delivered by global experts and by ensuring fellows have equitable access to excellent educational content on a broad range of topics regardless of where they train. obtaining input regarding the needs and best practices from the community of learners should be used to inform evolving education initiatives. despite the opportunities and strengths associated with virtual learning, there are also advantages to in-person didactics and opportunities to further innovate face-to-face learning, which will remain an important component of educational training. educators are being challenged to explore new avenues in teaching by purposely mixing modern teaching formats such as interactive debates, round-table discussions, workshops and seminars. these formats allow for relationship building and networking, as well as the ability to teach new facts, theories and book-knowledge, refresh memories, and gain and improve practical skills. it would seem likely that a mixture of increased online content and discussion and co-located in-person educational activities will become our norm. to maximize the benefits associated with virtual education and in-person learning, one way forward would be to build a hybrid model leveraging the strengths of each format. for instance, a nationwide virtual "foundations" lecture series could be delivered by experts either at the beginning of the academic year or at regular intervals throughout the first year. the lectures could be streamed in order to enable tools such as polling and question/answer but also be available in recorded form for those trainees who are not available during the streaming session given the wide variability in clinical schedules. these could be made available internationally, benefiting both high-resource countries by supplementing local education and low-resource countries by providing most of the rheumatology education in settings without local teaching infrastructure. when available, this virtual series could be supplemented by local in-person didactics that utilize small group collaborative formats and fellow-driven learning. this hybrid approach would give fellows access to a standardized, cuttingedge knowledge base while still fostering the growth that occurs in person with discussion and debate. the covid- pandemic has accelerated the adoption of virtual platforms for both clinical care and didactic education. with the rapid dissolution of barriers in place during the pre-covid- era, we have the opportunity to assess the efficacy of new methods of care and further integrate technology into teaching and assessment. the importance of balancing increased accessibility for patients and learners through leveraging technology with the value of hands-on engagement, teaching and assessment that is enabled through in-person contact is critical. it is important for us as a global rheumatology community to identify the strengths and limitations of the adaptations developed in response to the covid- pandemic in order to preserve and integrate those features that will optimize the education of rheumatology fellows in training. outcomes, satisfaction, and costs of a rheumatology telemedicine program: a longitudinal evaluation telerheumatology: a technology appropriate for virtually all workforce trends in rheumatology telemedicine for patients with rheumatic diseases: systematic review and proposal for research agenda hopelessness, helplessness and resilience: the importance of safeguarding our trainees' mental wellbeing during the covid- pandemic the virtual patient as a learning tool: a mixed quantitative qualitative study health professionals for a new century: transforming education to strengthen health systems in an interdependent world quality of life, burnout, educational debt, and medical knowledge among internal medicine residents applying the science of learning to medical education the difference between emergency remote teaching and online learning creating next generation blended learning environments using mixed reality. video games and simulations techtrends learning technologies: a medium for the transformation of medical education use of smart phones and social media in medical education: trends, advantages, challenges and barriers the use of social media in graduate medical education: a systematic review what is a rheumatologist and how do we make one? the future of telehealth in allergy and immunology training. the journal of allergy and clinical immunology publisher's note springer nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations author contributions all authors made substantial contributions to the conception or design of the work, the acquisition, analysis, or interpretation of data for the work, drafting the work or revising it critically for important intellectual content, final approval of the version to be published, and agree to be accountable for all aspects of the work. conflict of interest the authors have no relevant conflicts of interest or disclosures relevant to this work. outside of this work, rg reports personal and/or speaking fees from abbvie, janssen, novartis, pfizer, cornerstones and travel assistance from pfizer (all < $ , ). outside of this work, ad reports consulting fees from abbvie, novartis, gsk, and chemocentryx. key: cord- - syf upw authors: dong, chuanmei; cao, simin; li, hui title: young children’s online learning during covid- pandemic: chinese parents’ beliefs and attitudes date: - - journal: child youth serv rev doi: . /j.childyouth. . sha: doc_id: cord_uid: syf upw online learning has been widely promoted to replace traditional face-to-face learning during the covid- pandemic to maintain young children’s learning and play at home. this study surveyed chinese parents’ beliefs and attitudes around young children’s online learning during the lockdown of the covid- pandemic. most parents ( . %) in the study reported that their children had online learning experiences during the pandemic, and many ( . %) spent less than a half-hour each time. the parents generally had negative beliefs about the values and benefits of online learning and preferred traditional learning in early childhood settings. they tended to resist and even reject online learning for three key reasons: the shortcomings of online learning, young children’s inadequate self-regulation, and their lack of time and professional knowledge in supporting children’s online learning. also, the hardship caused by the covid- pandemic has made them suffering, thus more resistant to online learning at home. the results suggested that the implementation of online learning during the pandemic has been problematic and challenging for families. the chinese parents were neither trained nor ready to embrace online learning. the paper concluded with implications for policymakers and teacher education. learning, opportunities, and learning experiences children receive at home (erdogan, johnson, dong, & qiu, ) . to fill this research gap, this study endeavors to understand how chinese parents perceive their young children's online learning during the covid- lockdown through a large-scale online survey. online learning refers to "the learning experienced through the internet" either in the synchronous or asynchronous environment where students engage with instructors and other students at their convenient time and place (singh & thurman, , p. ) . online learning has seen a fast growth during the past decade because it has greater flexibility in terms of time, place and pace of the study, easier and more effective access to a wider variety and greater quantity of information, and lower financial cost (chen, ; khurana, ) . in a globalized digital age, government agencies, educational institutions, corporations worldwide are increasingly promoting online learning, resulting in a shift from traditional face-to-face classes to distance and online learning (aldhafeeri & khan, ) . with the advancement of new communication technologies, online learning can provide a rich, authentic learning ecology that can facilitate collaboration and interdependence between learners (aldhafeeri & khan, ) . however, researchers (chen, ; o'doherty, dromey, lougheed, hannigan, last, & mcgrath, ) have expressed their concerns about the quality of online learning and highlighted the main difficulties in creating an online learning community with a high degree of social presence and engagement. in addition, some scholars are also concerned about the major problems of online learning, such as social isolation, lack of interactivity and participation, delayed or insubstantial amount of feedback (khurana, ) . similarly, young children's digital learning has also been debated and criticized. some scholars (jiang & monk, ; radesky, eisenberg, kistin, gross, block, zuckerman, & silverstein, ) highlighted their concerns about online risks and dangers, addiction to videos, social isolation, and physical health issues. others suggested that parents play the mediating role to prevent harm and regulate children's online activities, such as setting up technology use rules for and monitoring their children's media use (nouwen & zaman, ) . all these concerns, however, could not prevent online learning from rapidly expanding in the past decade and extensively reaching millions of young learners at an unprecedented speed (franklin, burdette, east, & mellard, ; silverman, ; zalaznick, ) . more and more online programs have been developed and delivered to support young children with disabilities and/or living in remote or disadvantaged situations to provide learning flexibility (smith, burdette, cheatham, & harvey, ; zalaznick, ) . in addition, online technologies have become the social, cultural, and personal artifacts that inhabit the contemporary child's 'multimodal lifeworld' (arnott & yelland, ) . it thus should be promoted to build a multimodal learning ecology for contemporary children, parents, and teachers. while online learning appears to be more prevalent in the future (franklin et al., ) , a lack of research has addressed online learning in the early years, specifically. this study will fill this gap by surveying chinese parents who have engaged in their young children's online learning during the covid- pandemic. parents' beliefs and attitudes around early digital and online learning have been found polarized in the past decade. on the one hand, parents have started to appreciate the value of digital devices and tended to feel comfortable with young children's use at home (livingstone, mascheroni, & dreier, ; mikelic preradovic, lesin, & sagud, ; sharkins, newton, albaiz, & ernest, ) . they also supported the appropriate use of digital devices in early years settings (isikoglu erdogan, johnson, dong, & qiu, ; kumpulainen & gillen, ) . in particular, parents even held positive attitudes towards young children's computer use and believed that children should gain valuable technical skills and should be educated on how to use computers to enhance their academic development and future opportunities, such as employment (hatzigianni & margetts, , perradvoci et al. ). in the increasingly diverse digital landscape, parents believed that a range of digital and online technologies could offer young children new knowledge and learning. and those parents with a higher education level tended to believe that digital and online learning can develop children's learning competencies, language, self-expression, and social competencies (lepicnik-vodopivec & samec, ) . on the other hand, parents were concerned about the dangerous content on the internet and the risks of unrestricted digital use. they were worried about the impact of digital use on children's social and health development (plowman et al., ; lepinic & samec, ; jiang & monk, ) . more recently, due to the rapid growth of screen technologies (e.g., ipads, smartphones), parents have expressed their uncertainty about whether mobile devices could be beneficial or harmful to their children and how to adopt these mobile screen technologies (radesky et al., , livingstone et al. , erogan et al., . the eu kids online project (livingstone, ) , for instance, revealed that parents with higher income and education had employed a wide range of practices and strategies to manage restrictions for digital device use and had spent efforts to promote offline activities for children while limiting digital activities at home. some parents set rules and limits on the frequency and duration of using digital devices but did not recognize the importance of their role and involvement in supporting young children's technological engagements (plowman , hatzigianni & margartts, . the studies, as mentioned above, have explored parents' perspectives and practices on children's digital use in general, leaving their beliefs and attitudes about online learning unstudied. in particular, during the covid- pandemic, the sudden shift to online learning has presented new opportunities and unexpected challenges to the affected young children and their parents. under such unique circumstances, there is a need to examine parental beliefs and attitudes concerning online learning and readiness and acceptance to make this drastic shift. furthermore, most of the existing studies are western-centric and may not represent views from the eastern countries, where the culture and educational philosophies might differ. indeed, parental beliefs about digital technologies and media are not formed in a vacuum; instead, they are shaped by cultural norms (mansour, ) . thus, it is of great theoretical importance to understand chinese parental beliefs and attitudes around young children's online learning during the lockdown as a unique study in terms of time and place. the outbreak of covid- in wuhan started spreading in china in december , and then was declared as the public health emergency of international concern by the world health organization (who) on january . the national authorities worldwide have responded to this crisis by implementing travel bans, lockdowns, workplace hazard controls, and facility closures. preschools, schools, and universities have been closed either on a nationwide or local basis in countries, affecting approximately . % of the world's student population (unesco, ) . china is no exception. as an urgent response to the covid- pandemic, in early february , the ministry of education of china ( a) mandated that all schools and universities stop face-to-face teaching and use internet platforms to deliver online learning. school children were required to attend online classes to continue their education. although preschools were not required to deliver online learning and had no mandatory online educational programs, ece stakeholders including educators from public sectors and private curriculum developers were proactively engaged in designing digital curriculum resources and introducing educational apps and platforms to guide parents to support their children's learning and play at home (ministry of education, b). under such circumstances, many chinese parents followed the suggestions from teachers and educational authorities to provide online learning to their children during the lockdown. such influences on parents in adopting online learning are not difficult to understand in chinese sociocultural contexts. chinese early childhood education is shaped by its social culture and educational tradition. confucian culture has strongly influenced the relationships between teachers and children in chinese society (llasera, ) , which has laid great emphasis on adoring authority and respecting teachers (hargreaves, ) . tobin et al., ( , p. ) found that the role played by chinese preschools and teachers in the relationship with families is "explicitly political and ideological." preschools are viewed as social representatives, so they have the "right and responsibility" to correct the deficiencies of indulgent parents. preschool teachers, "as government employees with a governmental mandate," carry authority into their interactions with parents and see their roles as supporting and correcting parents (tobin et al., ) . accordingly, the controversial digital and online learning for young children has been conducted under this unique and special circumstance in china. without training and preparation for online teaching, chinese parents and teachers have been engaged in this brand new experiment of digital and online learning for young children. naturally and expectedly, these parents and teachers might have encountered many difficulties, problems, obstacles in this unexpected experiment. thus, this unique scenario has provided an ideal arena for us to understand chinese parents' beliefs and attitudes around young children's online learning at home. accordingly, this study aims to address the following research questions through an online survey: . what were chinese parents' attitudes towards online learning for their young children? this survey study was conducted in an inland city of henan province, which is located in the central area of china. altogether parents whose children were enrolled in local early childhood education programs voluntarily completed the online survey. the majority of them were aged between - years ( . %), and between - years ( . %), few were aged between - years ( . %), very few were years or above ( . %), and none was under years. their educational levels were very diversified: junior secondary school, high school, associate degree, bachelor, and postgraduate degree. and their occupation also varied greatly: government/public organizations, state-owned enterprise, private enterprise, personal owned business, freelancer, and unemployed. most of the parents have one or two children; very few of them have three or four plus. half parents ( . %) reported their children were - years old, and some ( . %) were - years old. the background information of the sample is presented in table below. the questionnaire consists of three parts and includes closed questions and two open- part iii: parents' beliefs and attitudes around online learning. this section adopted a five-point likert scale (ranging from "strongly disagree" to "strongly agree") to ask for parents' perspectives about online learning. the questions could be classified into three subscales. the questions could be classified into three subscales. subscale one is about the pros and cons of online learning ( items): parents were asked to compare online learning with the traditional face to face approach. to generate an initial pool of question items for measuring parents' beliefs and attitudes, previous studies on online learning (aldhafeeri & khan, , o'doherty, dromey, lougheed, hannigan, last, & mcgrath, , singh & thurman, were identified and reviewed. in particular, the two doctoral theses on the role and the effects of online learning were used to guide the design of the questionnaire items (chen, , khurana, . in their doctoral work, they compared both traditional and online education and examined the pros (e.g. convenience) and cons of online learning (e.g. lack of social presence) for learners. the main advantages and shortcomings identified in their study were 're-examined' in this study. specifically, the questions were centered on the efficiency, content, cost, effect, learning atmosphere, outcomes of online learning for young children and families. subscale two is focused on the value of online learning for young children ( items): parents were asked to evaluate the value of online learning based on the five learning and developmental areas ( wellbeing, language, society, science, and arts) outlined by the educational authorities (ministry of education, ). as indicated earlier in the literature, specific research studying online learning in the early years is limited, this study aimed to fill this research gap by studying parents' beliefs about and attitudes towards the value of online learning for young children. as a result, the frequent topics and heated debates (e.g. brady & hill, ; elkind, ; house, , plowman, mcpake, & stephen, parents were asked to evaluate the impact of online learning on parenting and family education suggested by the educational authorities (ministry of education, ). since this study was conducted during the pandemic, online learning was provided as an alternative approach to supporting children's learning and family education at home. the questions were also used to examine the impact of online learning on parenting and family education (see the questionnaire in an appendix). the internal consistency of part iii was measured, and the reliability for its three subscales was . , . , and . , respectively, indicating satisfactory reliability. the survey was administrated in middle march after parents and children had been quarantined at home for two months since china imposed national lockdown in late january. all the parents and young children had gained substantial experiences with online learning. the participants were invited by their children's preschools to complete this online survey conducted on wenjuanxing (www.wjx.cn), the leading online survey platform in china that provides functions equivalent to amazon mechanical turk. the participants were clearly informed throughout the study that participation in this research was completely voluntary, and they could withdraw their participation at any time without any reason. both quantitative and qualitative approaches were adopted in analyzing the data in this study. first, the quantitative data were analyzed using ibm spss . software. first, data cleaning was conducted, and the very few missing values (< . %) were replaced with the mean of the concerned variable. second, descriptive statistical analysis was performed to calculate the frequency, mean, and sd of parents' characteristics and children's online learning activities during the outbreak of covid- . finally, for analysis, the responses were given a score for each item from one to five: =strongly disagree; =disagree; =neutral; =agree; =strongly agree. items that were phrased negatively were subsequently re-coded to make the scales read in the 'positive' direction, lower scores, therefore, reflecting negative or less positive beliefs. the mean scores were calculated for each scale, which provides an overall picture of the parental responses. second, the qualitative data collected from the two open-ended questions were analyzed using nvivo software. the two questions are: ( ) what areas would you allow your child/ren to continue to learn online after the pandemic? ) what are your comments or opinions on young children's online learning? the research team collaboratively conducted data coding and analysis. the process of coding the data was cyclical and iterative, involving numerous conversations among the two coders to eliminate inconsistencies in interpreting the data due to who was coding. throughout the coding process, coders worked from the same codebook, as exemplified in table , which allows each coder in the research team to consistently and reliably analyze the data. the qualitative data were parents' brief comments to the open-ended questions, and they were mainly - short sentences. generally, the qualitative data collected were straightforward for generating categories. the two coders also met to discuss any disagreements of coding and used strategies (e.g. redefining the codes) to reach agreement on coding. thematic analysis (braun & clarke, ) was employed to identify, analyze, and report patterns generated from the data. the qualitative data analysis followed their step-by-step guide in six phases. ( ) familiarising ourselves with the data; ( ) generating initial codes, such as opposing online learning; ( ) searching for themes; ( ) refining and reviewing themes; ( ) defining and naming themes; and ( ) writing qualitative results. for instance, parents' comments were first coded into two broad categories: supporting online learning and opposing online learning. the initial categories were then reorganized and sorted into themes around reasons for and against online learning. among all the reasons identified, the three themes emerged: shortcomings of online learning, young children's inadequate selfregulation, and parental lack of time and professional knowledge. overall, most parents ( . %) reported that their children had online learning experiences during the pandemic, and many ( . %) spent less than a half-hour each time. specifically, these parents indicated that their children learned online once ( . %) or multiple times ( . %) per day, whereas some had only once or twice or three times per week. in addition, about one-third of the children had less than minutes of online activities per time, and some had an average between - minutes. the majority of the parents used free online learning resources with no or meager cost. and the children's online learning was mainly delivered and guided by preschool teachers or other staff; some were guided by online apps, webs, and others, as shown in table . table presents the analysis results about the young children's online learning activities during covid- . first, many young children watched the recorded lessons online once, or multiple times per day, some children watched only once or twice or three times per week, only a small percentage of them never did so. the children's online learning content was varied, including literacy, brain exercises, and science, as well as arts. a small number of parents commented in the open question that their children were learning physical exercise and language online. second, many young children attended the live class online once, or multiple times per day, some children attended only once or twice or three times per week, about of them never did so. third, many young children used wechat once, or multiple times per day, some children used it only once or twice or three times per week, and many of them never did so. fourth, many young children used the learning apps once, or multiple times per day, some children did it only once or twice or three times per week, but half of them ( . %) never did so. fifth, majority of the children attended online with parent presence once ( . %) or multiple times ( . %) per day, some children did it only once ( . %) or twice or three times ( . %) per week, very few of them ( . %) never did so. sixth, many children interacted with the instructor online once or multiple times per day, some children did this only once or twice or three times per week, many of them ( . %) never did so. last, many parents interacted with the instructor online once ( . %), or multiple times per day, half of them interacted only once or twice or three times ( . %) per week, whereas many of them ( . %) never did so. the quantitative data showed that the parents had relatively less positive beliefs about the value of online learning. the subscale one measured parental beliefs about the pros and cons of online education compared to traditional learning in educational settings. the mean for this scale was . , with a medium standard deviation of . . only a small percentage of participants believed that online learning has better learning content ( . %), better learning outcomes ( . %), and is more efficient ( . %) than the traditional approach. about half parents neither agreed nor disagreed on the statements about the pros and cons of online learning, indicating a neutral position on the value of online education. there were very few parents ( . %) among those who provided the comments, indicating that under the special pandemic situation, online education can be used to support children's learning. furthermore, the qualitative data indicated that the parents believed that traditional learning in educational settings was better than online learning in creating a learning atmosphere with better learning outcomes. some parents even commented that "online learning at home does not have a learning atmosphere" (parent ), "the efficiency of online learning is not high " (parent ), and "online learning atmosphere is not good " (parent ). these parents also explained their negative beliefs on online learning: lacking social interactions with peers, children did not treat online learning as a formal class; therefore were unable to focus on the learning. in addition, parents found it difficult to manage children's online learning at home as they did not have teachers' authority, as shown in the following quotes from their responses to the two open questions. the quantitative analysis indicated that the parents were less positive about the benefits of online learning. the subscale two had a mean of . and a medium standard deviation of . . a small percentage of parents believed that online learning could enhance young children's language development ( . %), literacy ( . %), social skills ( . %), independent skills ( . %), arts ( . %) and physical health ( . %). in general, more parents perceived that online learning could help children gain more science knowledge ( . %). approximately half of the participants had a neutral attitude towards the role of online learning for supporting children's development in language, literacy, independence, social skills, science knowledge, and arts. the qualitative analysis found that some parents commented that "during the special [pandemic] situation, children can learn online" (parent ). in contrast, others argued that "although children can learn via online approaches, the learning quality is not good" (parent ), and "the learning effect of online learning is bad" (parent ). some parents further explained that young children had weak self-regulation and a short attention span thus could not engage in online learning. for instance, they commented " children are too young, and their mind can't concentrate" (parent ) and "online learning efficiency is low, and children's self-regulation is poor, " (parent ) and "their initiative is not high, although they were learning the content as they were in school." in addition, the parents indicated their strong resistance and opposition towards online education caused by their concerns about the negative effects on children's development. as shown in the following quotes from their responses to the two open questions, the parents believed that online learning had more harm to young children than its benefits. among all the concerns, the most critical one is about the negative effect on young children's eye vision. some parents emphasized the potential harm to young children's social development and physical health, especially eye vision. there was a dilemma for parents to adopt online learning for their children, as revealed by a parent: children can learn some knowledge via online approaches, but they would develop an interest in watching smartphones and tv, which is not good for their eyes. in general, many parents stated harm and challenges caused by online learning without mentioning any benefits, as shown in the following quotes. the quantitative data from subscale three measured parents' beliefs and attitudes about the impact of online learning on parenting and family education, with a mean of . and a standard deviation of . . approximately half parents believed that online learning kept their children from doing nothing at home during the outbreak of covid- ( . %) and improved parent-child relationship ( . %) and inspired their educational ideas ( . %), and allowed them to see that children can participate in many forms of activities ( . %). overall, the parents had slightly more positive perceptions of the impact of online learning on their family education. in contrast, the qualitative data found that some parents perceived children's online learning as inconvenient, challenging, and time-consuming. about . % of the parents expressed that "[online learning] wastes too much adults' working time (parent ) and adds burden to parents (parent ) and affects parents' work significantly (parent ). this is because children do not have adequate self-control abilities (parent ), and children's online learning needs parents to stop their job to accompany them at home (parent ) and cost time and efforts (parent ). in addition, these parents mentioned various barriers for them to implement home online learning, including time constraints and professional knowledge in teaching children. notably, the parents who had more than one child identified more barriers to their younger children's online learning and juggled between their carer and worker responsibilities. in total, about . % of the parents commented that they would not recommend online learning in the early years, and they hoped online learning to be ceased as soon as possible after the pandemic. for instance, one parent wrote "disapprove online learning after the kindergarten reopens," while another commented, "hope to start kindergarten soon to implement traditional education." among these parents, some questioned the 'appropriateness' of online learning and similarly stated, "children are too young with weak self-regulation, and online learning is not appropriate," and ' online learning is not suitable for young children" (parent ). such finding is also supported by the quantitative findings that only a few parents ( . %) were willing to pay for online learning after the pandemic, and more than half of parents indicated that they would not allow their children to learn online once the covid- lockdown is over. as the first exploration of chinese parents' beliefs and attitudes around online learning during the covid- pandemic, this study has found that many young children had online learning experiences that were delivered by their kindergarten teachers or online learning apps at no or low cost. their parents, however, had different views about this online learning experience. this section will discuss these findings and their implications for future studies and practical improvements. firstly, this study found that the parents held a belief that online learning is less effective than traditional learning in early childhood educational environments. they believed that online education lacked a learning atmosphere and social interactions to engage young children, resulting in poor learning outcomes. these generally negative beliefs about online learning could be related to the two major causes. the first one is that the lockdown of covid- has caused a sudden shift to online learning. thus, it has challenged the traditional parental understanding of childhoods and expectations about early childhood educational practices, which should include free play and outdoor activities (stephen & edwards, ) . as noted by arnott and yelland ( , p. ) , "challenges remain in our understanding of childhoods in the st century and in integrating new technologies into children's learning cultures." the dominant ideas and popular discussion about childhoods in a digital age are either passive/at-risk or empowered (craft, ; dong, ; mertala, b; stephen & edwards, ) . such polarised debates have led parents and educators to believe that young children's use of digital technology is inappropriate and often caused dilemma and confusion for those seeking to incorporate digital technologies into young children's learning (dong & mertala, ; house, ; isikoglu erdogan et al., ) . to support educators, parents, and children to use new technologies better, researchers advocated a reconceptualization of 'childhoods' and 'play' in the digital age so digital artifacts can be embraced as unique and distinct resources to provide them with new opportunities for learning and play (arnott & yelland, ; edwards, ) . therefore, these chinese parents need to update their knowledge and develop a new understanding of 'childhoods,' 'learning,' and 'play' through parental education or family-school partnership programs. the second cause might be the major shortcomings of online learning, as noted by the critics (khurana, ; chen, ; doherty et al., ) : social isolation and lack of interactivity, which have repeatedly been reported by the parents during this unexpected experiment. vlachopoulos and hatzigianni ( ) have emphasized the need to address critical issues around students' online learning experiences and course outcomes. this study, however, found that all these critical issues had not been solved, even though many advancements had been made in digital and online technologies. therefore, chinese parents tended to have negative perceptions of digital and online learning. secondly, this study found that most chinese parents had a major concern about vision problems caused by online and digital learning. such concern has been shared by many parents and early childhood educators internationally (hatzigianni & kalaitzidis, ; mertala, a; sharkins et al., ; wartella & jennings, ) . in china, the prevalence of myopia appears to have rapidly increased in recent years, and more and more young children are reported to be short-sighted (ku, steptoe, lai, hu, chu, yen, & chen, ) . this problem has been attributed to the increased screen-time by the public (guarino, ) . therefore, the ministry of education and the seven other national authorities jointly issued (ministry of education, ) to regulate children's technology use by limiting the screen time. therefore, this concern reported by the chinese parents in this study is sensible and should be carefully addressed by the developers and designers of digital and online learning programs. thirdly, this study found that the parents were also worried about the lacking of physical activity as well as the addiction to screens such as tv and smartphones caused by digital and online learning. this concern is also reasonable and understandable, given that all the young children were quarantined at home during the covid- pandemic, and digital and online learning became their only channel to interact with teachers and peers. this finding is consistent with the existing ones that have suggested that parents and educators were concerned about the negative effect of screen time on young children's health development (edwards et al., ; livingstone et al., ; radesky et al., ; rhodes, ) . the chinese parents in this study reported using different strategies to restrict digital device use and making many efforts to promote offline activities for children while limiting digital activities at home. and some chinese parents have even planned to stop children's access to online learning once the pandemic is over. all these findings jointly indicated that chinese parents tended to view digital and online learning negatively. though this study was conducted in a different context (china) at a unique time , the findings of chinese parents' negative beliefs and attitudes around online learning are consistent with some western studies conducted in eu countries (livingstone, et al.,) and australia(australian government, ), which found that parents have been concerned about online risks and too much online time. specifically, the recent national survey of parents of children aged - that parents believed that their children spent too much time playing games, using social media, and streaming tv shows. however, the chinese parents tended to be more worried about children's eye vision deterioration caused by watching screens, which may be due to their younger age of their children in this study. first, this study found that chinese parents tended to reject online learning because their children had no or low self-regulation. this finding provides empirical evidence to support the claim that self-regulation is a prerequisite for successful online engagement and learning (vlachopoulos & chatzigianni, ) . furthermore, the chinese parents highly valued the linkage of self-regulation to the confucianism heritage that children should be self-restraint and self-regulate to follow the social rules and norms. this is more than the definition of self-regulation: "self-generated thoughts, feelings, and behaviors oriented to attaining goals" (zimmerman, , p. ) . however, this finding indicates that chinese parents might expect their children to learn and show self-control and self-regulation at a young age (luo, tamis-lemonda, & song, ) . second, this study found that chinese parents tended to reject online learning because their children were uninterested, inactive, and unfocused during online learning. this finding suggests that the young chinese children could not be regarded as self-regulated learners, who should be "metacognitively, motivational and behaviourally actively participants in their learning" (zimmerman, , p. ) . this finding, however, contradicts with the existing ones that young children were strongly interested in media and technology (sharkins et al., ) and that chinese children were curious and excited about digital programs (dong, ; dong & mertala, ; jiang & monk, ) . this discrepancy might be caused by the difference in the quality of digital and online learning, as one parent said that "the content of online learning is not very attractive to children" (parent ). therefore, it might be the poor quality and boring content of online learning that has caused the resistance and even rejection of chinese children and parents. the media of digital and online learning itself might not be the cause. this is why vlachopoulos and hatzigianni ( ) suggested that the design of online learning played an important role in shaping learners' perceptions of online learning. third, this study found that many parents, especially those with more than one child, tended to reject online learning because they had no time to support children's online learning at home. this finding is consistent with that study by (li, shi, wu, & li, ) , who found chinese parents of only-child tended to have more opportunities and educational resources than those of non-only children. the parents of only-child would invest more time and energy to help their child to excel in academic performance. besides, the chinese parents in this study generally perceived online learning as time-consuming and burdensome. similarly, smith et al. ( ) found that online learning required parents' significant time commitment. but the american parents in their study still wanted to be engaged in their children's online learning, even though they were shocked by the time required to support their child's online learning. the chinese parents in this study, however, did not realize the importance of their involvement and tended to reject to support their children's online learning. last but not least, this study found that the parents were negative about online learning because the covid- lockdown had made them suffering from the hardships and the unexpected demand from online learning. they felt unable to educate young children as their conventional role was not the teacher of a child, and they were not trained to do so. chinese parents and grandparents were often blamed by teachers for spoiling their children (tobin, hsueh, & karasawa, ) and allowing too much screen time (dong & mertala, . therefore, they tended to feel unconfident to teach their children at home and believed that their "children listen more to their teachers and have a better learning atmosphere at school" (parent ). accordingly, they were so eager to send their children back to preschools. digital and online learning is gaining popularity due to its advantages, such as greater flexibility, wider access, and low cost (khurana, ; chen, ) . however, this study found that the implementation of online learning during the covid- pandemic has been problematic and challenging for chinese families. chinese parents generally had negative beliefs and attitudes about the values and benefits of online learning and preferred traditional learning in early childhood educational environments. this is because they were neither trained nor ready to embrace online learning. the hardship caused by the covid- pandemic has made them suffer, thus more resistant to online learning at home. and these chinese parents were more concerned about the shortcomings of online learning, their children's inadequate self-regulation, and their lack of time and professional knowledge in supporting online learning. this study, however, has certain limitations. first, a large-scale quantitative study can provide representative and diversified evidence about the target topic. still, it has no way to gain an in-depth understanding of individualized situations and problems. interview or mixed-methods studies should be conducted to thoroughly explore chinese parents' authentic views, concerns, and difficulties. second, this online study simply collected self-report data, which might have a socially desirable bias. further studies with triangulation of methods (i.e., teacher-, self-, and peer-report) are needed to cross-check the results. nevertheless, for the first time, this study has investigated chinese parents' beliefs and attitudes concerning digital and online learning during the outbreak of covid- . the national lockdown has unavoidably affected many children's physical attendance at educational settings and made online learning an emergent alternative to maintain the continuity of learning and play at home (early childhood australia, ; silverman, ). even though online learning has been widely promoted in china to replace traditional education during the pandemic, the findings of this study indicate that the chinese parents were neither trained nor ready for doing so. this implies that the educational authorities need to do more to get chinese parents ready for online learning and to consider more about young children's age and learning interests. the findings from this study have implications for policymakers and educators globally who are promoting online learning as an alternative to young children and their families during the pandemic. the promotion and implementation of online learning to replace traditional early childhood education during emergent situations like covid- need to be carefully considered and well planned to support families, rather than adding extra burdens to them. this means that the promoters should consider the complexity and diversity of families (e.g. more than one child learning online and parents' working full time at home) when suggesting an online class to young children, and provide parents with flexibility and convenience. in addition, the provider of online learning should improve the design of online programs (e.g. easy login) to make parents effortless in using the program. elkind, d. 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(equity). district administration self-regulated learning and academic achievement: an overview becoming a self-regulated learner: an overview. theory into practice: becoming a self-regulated learner ☒ the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.☒the authors declare the following financial interests/personal relationships which may be considered as potential competing interests:there is no research fund fo the project and the research has followed ethical procedure throughout the study. there is no conflict of interest. key: cord- - e o j authors: popa, simona title: reflections on covid- and the future of education and learning date: - - journal: prospects (paris) doi: . /s - - -z sha: doc_id: cord_uid: e o j nan will do to change education and learning as we know them. furthermore, the discussion has been driven in wildly different directions by different notions of what sort of knowledge, of what sort of reality, to what sort of end, they are supposed to produce. we talk about what we owe the future, but what about our obligations to the present? we owe it to the million children and adolescents who are not proficient in either reading or mathematics (uis ) to have the chance to gain foundational skills that stem from literacy and numeracy. and we owe it to those students to ensure that they are all given equitable learning and equal opportunities. we also owe it to the teachers, to provide them with the necessary tools to translate the goals and objectives of their education systems into learning outcomes. however, it is not enough to readily acknowledge our duties to our contemporaries or to those who come after us. to understand the complexity of the changes ahead, we need to be acutely conscious of the history of our time in terms of the unmanageable, overwhelming reality of what still needs to be done. globally, we have been moving backwards rather than forwards (world economic forum ), and, five years since the adoption of the un sustainable development goals, tangible progress is still to come. we have not changed the world for the better; rather, as tony judt ( ) would have put it, "the world changed obligingly for us". we also need to be acutely conscious of the history of our time in terms of the unmanageable, overwhelming reality of the covid- pandemic. without urgent action, the covid- crisis could push half a billion more people into poverty globally (oxfam ) . the ilo ( ) estimates that nearly million jobs could be lost globally due to the coronavirus. the crisis will hit the poorest the hardest, entrenching extreme levels of inequality. the economic and social effects of lockdowns, loss of production and business confidence, and global recession will cast a long shadow over education systems (keith lewin, in this special issue). covid- presents education and learning with a unique challenge: to further define their nature and purpose against the backdrop of the current, highly volatile context, and to fulfill an important, concretely transformative role with regard to the post- global education agenda. however, talking about the future of education and learning right now can easily create a quagmire of statements of all sorts, artifices, and self-deceptions. bit by bit, words like "reimagining", "redefining", "reconceptualizing", "reinventing", or "reorienting" education and learning become part of our lofty academic vocabulary. to be sure, they express a significant degree of discomfort with the current metanarrative, but there is certainly more at stake here than the use of provocative metaphors to unravel bedrock assumptions and to incite further discourse. the exercise of repositioning education and learning or even shifting these paradigms forces us to tackle the issue of their "nature" honestly and represents an important advance that cannot be ignored or easily dismissed. what may on the surface look like an overlying terminology detail is a matter of enormous potential impact and relevance for the future of education and learning. thus, i argue that our main task right now is to not still be talking about the things we have not accomplished yet. the most important thing for us to do is to imagine better worlds, while taking action on what we should still be caring about today. clearly, our modes of thought and action should be brought into harmony with the new objective conditions of the world. however, we need to be rationally aware of what we still need to achieve, and we should be able to act according to that awareness. virtually every detail of the current situation serves to remind us that to think and act as though we were living in the past of only a few months ago is at best useless and at worst fraught with great risks. we should do more than pick up the pieces and carry on as before. more to the point, we just cannot go on living like this. urgent action is needed if this situation is not to become another pandemic, threatening the very survival of our world. the audacity of this much-needed action, which is set against the foil of real suffering, can be felt most immediately in its ambition: can we transform this crisis into a renewing wave? will it help bring about a better education system, a better society, and a better world? included in this special issue are authors whose names stand out: inspiring thought leaders and bold practitioners who bring to prospects an astonishing range of knowledge, a commitment to an idea of public good and community, and an intense intellectual and emotional engagement. this engagement is -how else?political. in what they write, there is always that moral edge, but there is also a call to action. how do they address the pressing issues of the day? how do they address the completely unknown, even if, at times, intensely familiar future? this issue opens with a superb piece by sir ken robinson: "a global reset of education". sent to prospects shortly before his untimely death, it now takes on a whole new meaning. sir ken writes that as the world looks to the future and for ways of safely returning to normal, we have a unique opportunity to reset our priorities and redefine what this normal looks like. what type of normal do we want to get back to, and is it the normal that we have left behind us? he believes that it should not be, and that we are at an exceptional moment in time to redirect our course. for education communities, this is a chance to take a close look at aspects of education systems that we have taken for granted for far too long. hans d'orville, former unesco assistant director-general for strategic planning, asks a similar question: what should a "new normal" look like for future generations? how can countries use the innovativeness of the recovery period to "build back better"? his viewpoint highlights the unesco-led global education coalition initiative, which is seeking solutions to support learners and teachers, as well as governments, throughout the recovery process, with a principal focus on inclusion, equity, and gender equality. d'orville contends that the current crisis is an opportunity for stronger international collaboration, which might provide a better focus and deliver solutions including digital tools. resilience and adaptability will be crucial for the next generations to navigate through the present pandemic-and any in the future. in his article, keith lewin discusses the fact that covid- is reshaping the debate about education and development. the simple truth, he says, is that no one has a clear idea of how the current pandemic will unravel over anything but the short term. therefore, he advances ten propositions that will shape policy dialogue and whatever iteration of the sustainable development goals is needed to ensure they remain fit for purpose. testing these propositions over the coming year will open the door to an evidence-based approach to reconstruction and sustainable development and juxtapose immediate concerns of the present with aspirations for the future. michael fullan reasons that school systems around the world were stagnant before covid- and had been for some time. therefore, he writes, there was considerable pent-up energy to make changes. covid- has both exposed and exacerbated what was wrong with the system, but it has also provided opportunities to make changes amidst the confusion. change doesn't get more complex than is the case right now, and the complexity becomes more convoluted every day. change will happen-we just do not know what it will look like. we have "the battle of the decade" on our hands with respect to publiceducation systems. yong zhao suggests that covid- represents an opportunity to rethink education, and that the rethinking should not be about improving schooling but should focus on the what, how, and where of learning. while school closures have prompted innovation and institutional self-examination, the chance of large-scale, long-term changes is largely dependent on how we treat covid- in education. if we treat covid- as a short-term crisis, zhao warns, then whatever we do to help extend learning when schools are closed will be only temporary. antónio nóvoa and yara alvim argue that the debates about the future of education and the need to rethink the school model started long before the pandemic crisis, but that the situation we are experiencing has magnified this need, while also showing that change is possible. the dynamics of transformation and metamorphosis of schools have emerged, reinforcing education as a public and common good. nóvoa and alvim clarify the dynamics that redefine the three foundations of the school model: the social contract around education, the organizational structure of the school, and the pedagogy of the lesson. in his contribution, robert arnove writes that the covid- crisis offers a unique chance to imagine more equitable societies and education systems. the pandemic's disproportionate, terrible consequences for health and livelihoods-for individuals, their communities, and even whole societies-underscore institutionalized forms of discrimination rooted in race, ethnicity, class, gender, sexual orientation, age, and abilities. the lessons of covid- compel us to imagine education systems in which students of all ages can thrive, and we need to take meaningful action to bring about that desired future. nelly stromquist argues that covid- and the likely long economic recovery from it are worsening the already low budgets confronting many governments in developing nations. but we should remember that the erosion of the public sector in those countries has been going on for four full decades. the climate of state austerity and the growing privatization of education have brought new priorities for political leaders and parents, leaving issues of social justice, such as the indispensable transformation of the social relations of gender, to be tackled at only superficial levels. while efforts must continue to achieve universal primary and secondary education at the global level for both boys and girls, the concern with access and thus enrollment and completion parity has blinded many governments from seeing the crucial need to examine what is actually learned in school. stronger concern with curriculum would bring a stronger focus on the formal knowledge conveyed in schools and on the ways in which this knowledge might (or might not) facilitate a substantial change in the social relations of gender. in their article, colette chabbott and margaret sinclair claim that covid- once again reveals the inherent weaknesses in relying on classroom-based schooling and ict to sustain learning, a danger already familiar from earlier disasters, both natural and caused by humans. a lack of textbooks and of guidance for caregivers to support home-based learning limited the effectiveness of efforts to provide continuity of learning. these same elements are the key to preparing better for the next crisis and to keeping sdg goal on track. crain soudien calls for a more developed understanding and approach to the questions of inequality and education. while much of the current discussion is, correctly, focused on learners' material realities and how covid- is exacerbating inequalities, what is largely overlooked is how the core activity of the education experience-learning-is managed, both at the macro-level of the state and at the micro-levels of the individual learner. we now know how complex learning is, and our new knowledge is informed by new understandings of the relationship between the biomedical and the social. soudien writes that it is necessary to deconstruct and make sense of the complexities of these realities for the quality of the learning experience, both during this crisis and going into the future. conrad hughes reasons that the "industry of modern schooling" leads to surface learning of exaggeratedly voluminous curricula and excessively high-stakes assessments that instrumentalize the pursuit of knowledge. in order to return to a more mindful, authentic, and humanly paced approach, some disruption from the present model is needed. paradoxically, the covid- pandemic might be the catalyst that will bring this about. miguel Ángel escotet declares that the absence of worldwide social ethics is at the root of our present social, political, and economic crises. more to the point, the current covid- pandemic is, in part, a consequence of insufficient scientific research, inappropriate education systems, and globally fragile health structures and human services. radhika iyengar asserts that covid- has disrupted education for millions of children across the globe. the education community is reimagining and redesigning to build back better. iyengar uses the principles behind unesco's futures of education initiative to highlight their importance in the post-covid- recovery. the pandemic has shown how communities can come together to educate children, and iyengar argues that, post-covid- , education systems should recognize community-driven support systems, use technology to overcome the digital divide in learning, and focus more on sdg goal . and its links to climate crises. kate moriarty writes that the covid- pandemic is an emergency of an exceptional scale, with major impacts on education globally and with significant new challenges for education in existing humanitarian contexts. she reflects on the immediate challenges of continuing education in humanitarian contexts and on the experience of the inter-agency network for education in emergencies (inee) as a network supporting collective action of education in emergencies (eie) practitioners globally. moriarty also looks at inee's plans to support quality distance education and issues to consider on the reopening of schools. she concludes with some thoughts on the needs and risks for eie for the longer term. michael thomas and cathy rogers argue that the science of learning has two different responsibilities in the covid- crisis: first, to offer guidance about how best to deal with the impact of the current situation, including lockdown and homeschooling; and, second, to consider bigger questions about what this large-scale educational experiment might mean for the future. they summarize the advice for parents about mental health and about becoming stand-in teachers. then, taking the longer view, they consider not only the potential negative impact of the covid- crisis in increasing inequality in education but also the potential positive impact of driving innovations in technology use for educating children. sir john daniel, former unesco assistant director general for education, believes that the covid- pandemic poses a huge challenge to education systems and offers guidance to teachers, institutional heads, and officials on addressing the crisis. what preparations should institutions make in the short time available, and how do they address students' needs based on level and field of study? reassuring students and parents is a vital element of institutional response. in ramping up capacity to teach remotely, schools and colleges should take advantage of asynchronous learning, which works best in digital formats. as well as the normal classroom subjects, teaching should include varied assignments and work that puts covid- in a global and historical context. when constructing curricula, designing student assessment first helps teachers to focus. sir john also suggests flexible ways to repair the damage to students' learning trajectories once the pandemic is over and gives a list of resources. almost million jobs could be lost worldwide as a result of covid- , says ilo. press release revolutionaries (nyr daily) dignity not destitution. briefing paper more than one-half of children and adolescents are not learning worldwide unesco ( ). #learningneverstops. covid- education response we're all in the same boat on the sdgs: here's how we steer a course key: cord- - t pu i authors: garip, gulcan; seneviratne, sanju rusara; iacovou, susan title: learners’ perceptions and experiences of studying psychology online date: - - journal: j doi: . /s - - - sha: doc_id: cord_uid: t pu i this study aimed to explore the lived experiences of six international and mature online learners studying on an undergraduate psychology course to identify barriers and facilitators to studying online. a secondary aim was to deductively explore the applicability of the capability, opportunity, motivation, and behaviour model to participants' narratives related to self-regulated online learning. online interviews with six demographically diverse participants were conducted and analysed using interpretative phenomenological analysis. the overarching theme was 'the balancing act of online learners', which consisted of three major themes (and respective subthemes): ( ) 'identity as an online learner' ('in today's world, we're all very busy'), ( ) 'access to resources' ('importance of location' and 'comparing online to on-campus teaching and learning'), and ( ) 'changing nature of social interactions' ('tutors as a crutch' and 'peer-to-peer interactions'). a number of facilitators and barriers related to these themes were identified, which are applicable to the com-b model. the com-b model offers a novel approach in designing and delivering learning materials and activities that may instil or help maintain self-regulated learning in online psychology students. online learning has made education accessible to those previously restricted by factors such as geographic location or employment (allen and seaman ; christensen et al. ; kumar et al. ; zhu et al. ; larmuseau et al. ) . 'online learning' in the context of this paper will refer to any form of learning and teaching through a primarily electronic medium; with interaction between learners and their educational materials and activities, and engagement with peers and tutors taking place synchronously or asynchronously in a virtual environment (e.g. via blackboard, moodle, etc.; yanuschik et al. ; mayer ) . while the popularity of online learning can be attributed to the flexibility inherent to its medium, research has identified concerns related to student engagement (prior et al. ) , retention rates (mubarak et al. ; jo et al. ) , and reported perceptions of missing out on traditional classroom experiences (ragusa ; martinez et al. ) . current trends indicate that a greater proportion of students engage in online learning than in the past (li et al. ). this highlights the need for educators and researchers to examine practical and evidence-based models that support the development of online courses that foster self-regulated learning. self-regulated learning can be defined as "an activity that students do for themselves in a proactive way" (zimmerman and schunk , p. ) or as an "interaction" through which learning is constructed (rhode ). self-regulated learning requires the effective management of time and learning resources; selfregulated learners set goals, plan ahead, and regularly reflect on and monitor their learning process (zimmerman ; wong et al. ). previous research demonstrates that self-regulated learners persevere in challenging learning situations (e.g. cho and kim ; cochran et al. ; shea and bidjerano ; li et al. ) . consequently, the skills and strategies associated with self-regulated learning can support successful learning in an online context (yeh et al. ) . research in this field has focused on remedying poor student engagement and retention rates among online learners, with particular attention given to the selfregulated learning strategies recognised as being key correlates of student success (wei and chou ; kahu and nelson ; tsai et al. ) . several well-established models of self-regulated learning in educational psychology draw on social cognitive learning theory (bandura ), self-determination, and constructivist approaches to provide a framework for developing and delivering courses (panadero, ) . schraw and colleagues ( ) discuss the implications of self-regulated learning in science education, wherein self-regulated learning is conceptualised as consisting of cognition (i.e. cognitive, problem solving, and critical thinking strategies), meta-cognition (i.e. knowledge of cognition and regulation of cognition), and motivation (i.e. self-efficacy and epistemology). according to this theory of self-regulated learning, learners engage in a combination of intra-individual strategies and processes to understand and control their learning environments. while these strategies may be shaped by the learners' interactions with others and their contexts, this view of self-regulated learning does not explicitly take the learning context into consideration. this paper introduces an interdisciplinary and dynamic model that considers the learning context when examining the mechanisms of self-regulated learning in online psychology students (see crutzen and peters ) . more recent research indicates that educators are increasingly drawing on theoretical models to increase student engagement in online courses for specific subject areas (arvaja ; garrison ; hersman and schroeder ; mastel-smith et al. ) . further, the present study responds to the fifth international summit on information and communication technology in education's call to action to understand the learning landscape in a digital age, as it undergoes fundamental changes (voogt and knezek ) . therefore, it is imperative that we identify the experiences and expectations, as well as perceived barriers to, and facilitators of online learning that may differ in students across subject areas. the capability, opportunity, motivation, and behaviour (com-b) model proposed by posits that behaviour is influenced by the interaction of the following constructs: • capability: an individual's psychological and physical capacity to engage in the activity concerned, relies on the individual having the necessary knowledge and skills to perform the behaviour; • opportunity: all the factors that lie outside the individual that make the behaviour possible or prompt it; • motivation: all those brain processes that energise and direct behaviour, not just goals and conscious decision-making. it includes habitual processes, emotional responding, as well as analytical decision-making. according to this model, motivation and opportunity influence an individual's capability to generate behaviour . behaviour, in the context of this study, refers to actions associated with being a self-regulated learner. as this is a dynamic model, it also explains how self-regulated learning may in turn influence the three constructs. each psychological construct is well supported in terms of its influence on behaviour . this is the first study to explore the application of the com-b model in the context of self-regulated online learning in psychology. this model is unique in that an individuals' context is taken into account in relation to the behaviour of interest. the model states that behaviour occurs when the individual perceives they are capable of carrying out the behaviour, they have the opportunity to engage in the behaviour, and are motivated to perform the behaviour. self-regulated learners may engage in a number of behaviours that help them understand and control their online learning environments. the model has primarily been applied to developing and understanding interventions (including online interventions) to equip people with the skills to engage in health behaviours, which rely on self-regulation. there are parallels between the skills and strategies needed to learn in the context of one's health and to learn in a subject area (e.g. psychology; aunger and curtis ; wong et al. ) , which highlights the relevance of the model in this context. we build on previously established conceptualizations of online educational courses as complex online behavioural interventions (wong et al. ) to explore the utility of the com-b model ) when examining how behaviours associated with self-regulated learning are impacted in online psychology learners. shih et al. ( ) predicted that qualitative research would become a popular method for exploring student experience in an online context, due to its utility in the identification of new avenues and opportunities for research (kember and leung ; symeonides and childs ) . symeonides and childs ( ) conducted a qualitative interview study with online learners and emphasised the need "…to recognize learners as experts of their own experience" (p. ) to help educators identify and develop more effective ways to facilitate online learner engagement. interpretative phenomenological analysis (ipa; smith and osborn ) was developed to uncover and interpret how individuals (i.e. the participants) make sense of their lived experiences, making it an ideal method to understand the perceptions and experiences of learners studying psychology online. further, ipa-derived from phenomenology, hermeneutics, and idiography (smith et al. )-accepts personal perceptions and subjective accounts to contribute to existing theory or to generate new research questions. it also acknowledges the interpretative role of the researcher in bringing the participants' accounts together. purpose of the study . taking the above together, the present study answers the following research questions that were designed to build on each other: what does online learning mean to learners studying psychology online? . what are the facilitators and barriers to studying online in this group? . to what extent is the com-b model applicable to self-regulated learning in an online context? the present study explored the lived experiences of online learners studying an undergraduate psychology programme at a higher education institution based in the united kingdom, in accordance with the principles of ipa (smith and osborn ) . these experiences were then used to identify perceived facilitators of and barriers to studying online in this group. finally, the applicability of the com-b model was examined to potentially identify and explain the mechanisms of self-regulated learning in this sample. this study is notable for its detailed examination of the lived experiences of online psychology students from varied backgrounds, which builds on previous research that has identified the importance of human factors when considering self-regulated learning in online platforms (wong et al. ) . the integration of human factors and learning theories in the development of online learning environments will facilitate more adaptive support systems that optimise learning at an individual level (wong et al. ). the study is also unique in that it uses the com-b model, which has not been used in this context previously (keyworth et al. ) , to interpret self-regulated learning behaviours in online psychology students. additionally, research utilising the com-b model is widespread in health psychology, e.g. guiding data collection and analysis in qualitative studies (atkins et al. ) , and informing intervention development (barker et al. ) . it is essential, therefore, to consider the com-b model within the context of online learning as it addresses wide-ranging influences on self-regulated learning behavior, which in turn can support educators in improving and enhancing online learning environments (grant et al. ) . beyond this, understanding and preparing students to become self-regulated learners has been made all the more relevant in these times, with the landscape of learning evolving due to the th industrial revolution (hirschi ) and the shift towards remote learning as a result of the coronavirus pandemic (bishop ) . the present study was designed, conducted, and analysed according to the principles of interpretative phenomenological analysis (ipa; smith and osborn ) , which "invite[s] participants to offer a rich, detailed, first person account of their experiences" (smith et al. , p. ) . this study utilises semi-structured interviews, which are better suited to gaining insight into previously unexplored samples. there are several examples of interview studies of online student experiences but these studies favour descriptive accounts and lack interpretation (cochran et al. ) . all authors were involved in the development of an interview guide containing open-ended, non-directive questions. this was an iterative process, involving the trial and revision of the questions by the study team. this process involved a consideration of what the interview was likely to cover, as well as any potential difficulties likely to arise due to the wording of the questions (smith & osborn, ) . the interview questions were intentionally left openended to avoid restricting lines of conversation and to encourage participants to produce rich narrative accounts of their experiences studying psychology online. box presents a sample of the questions that were included in the final interview guide. can you please tell me why you chose to study psychology online? what were your expectations of studying online? what does 'studying online' mean to you? could you describe your online experience so far? have you experienced any opportunities while studying online? have you faced any challenges while studying online? could you describe your typical study habits? could you describe your interaction with your peers online? could you describe your interaction with your tutors online? could you tell about how studying online may influence other life commitments? ethical approval for the study was granted by the host university's research and ethics committee. participants were deemed eligible if they were an online student enrolled in an undergraduate psychology programme at a uk-based higher education institution, had completed at least three modules, and had been studying online for at least a year to ensure that they had sufficient experience of online learning to share. based on the eligibility criteria, it was anticipated that participants would be well positioned to share their experiences of online learning, including their perceptions of barriers to and facilitators of online learning. an invitation to potential participants was advertised on internal course webpages. participation was voluntary and no incentives were offered. a "relatively homogenous" (smith et al. , p. ) sample was sought to ensure that in-depth data was gathered relating to the research questions. six participants took part in a single online interview with the second author. smith et al. ( , p. ) state that "there is no right answer to the question of […] sample size", however, smaller sample sizes are dictated by the idiographic aspect of ipa. mastel-smith and stanley-hermanns ( ) recommended a sample size between and participants, with an addendum to adjust the sample size according to the richness of the data collected. therefore, the sample size of was considered the ideal median for our study. given that significant insight into the lived experience of a fairly homogenous sample of students had been already reached by participant , we concluded that we had reached saturation of themes and decided to maintain the sample size of to allow for a deeper examination of each individual case as per the tenets of ipa methodology. table presents the participants' demographic characteristics; including interview duration, the participants' location at the time of interview, their age, marital status, gender, nationality, employment status, and years since starting online study, as well as the number of modules completed at the time of interview. the participants were categorised as being mature students by the higher education funding council for england ( ) . informed consent was obtained from all participants taking part in the study. all names were replaced with pseudonyms to protect participants' identities during transcription by the second author. participants contacted the second author and arranged an online interview (via skype™). the participant and the second author were the only individuals present during the interview in an effort to maintain confidentiality and ensure participant interested participants contacted the second author to arrange the online interviews. regular supervision meetings were held to review the interview process and analysis stages with the first author. all interviews were audio recorded and transcribed verbatim before being analysed in accordance with ipa. there were two stages to data analysis: ( ) the iterative and inductive ipa stage to explore participants' experiences of online learning, and ( ) a deductive stage involving the mapping of the com-b constructs against participants' reported experiences of online learning. first, interview transcripts were read and re-read by the first and second author, and a paper trail of handwritten notes were maintained in conjunction with the initial stages of familiarisation and coding. the second stage involved inductively identifying themes by each author separately. these themes were then inputted into a spreadsheet to be organised into higher level themes. an example of this process is depicted in table (the raw analysis is available upon request from the corresponding author). throughout this process, the first two authors met to discuss the development of themes between those initially identified, and to organise said themes into higher level categories. the third stage involved the development of a coding manual for each of the major themes and the elucidation of the inter-relationship among these themes. at this stage, the third author checked for validity and reliability of the themes by working backwards from the coding manual against the transcripts. the four broad principles presented by lucy yardley ( )-sensitivity to context, commitment and rigour, transparency and coherence, and impact and importance-were used to assess the validity and reliability of the study. we have demonstrated sensitivity to context through an appreciation of the interactional nature of the ipa interview process employed, which was specifically required to show empathy and put the participant at ease (smith et al. ). further, all of the researchers were involved in the development of the interview schedule and in-depth analyses of each case to demonstrate rigour and commitment to the ipa methodology. throughout these stages, the researchers interpreted how participants' made sense of their experiences and perceptions of studying psychology online while acknowledging our own influence in the development of the themes presented in the paper (smith et al. ). following completion of the ipa, a deductive approach was taken by the first author to explore whether the com-b model constructs were applicable to participant transcripts, which was then confirmed by the rest of the research team. data analysis identified 'the balancing act of online learners' as being the overarching theme. this related to the participants' experiences of balancing the following: extraneous commitments with online study (e.g. family, work, etc.), expectations arising when comparing online and on-campus teaching/learning, and lastly, social interactions with peers and lecturers online. three major themes were identified: (i) identity as an online learner, (ii) access to resources, and (iii) the changing nature of social interactions. these three themes are interrelated and inherently linked to the overarching theme as demonstrated in the paragraphs below, and depicted in table . illustrative quotes from participants are provided to support themes. a majority of the participants (i.e. andrea, jade, karen, sophie, and tae) recognised their interest in psychology at a young age, which motivated them to pursue a psychology degree. in contrast, edward recognised his interest in psychology due to recent life experiences as a football coach. all the participants reported their motivations for studying psychology online in order to facilitate a career change. they viewed online learning as being a means to pursue this goal in spite of the varied obstacles that might have impeded them. for most of the participants (i.e. karen, jade, tae, edward, and sophie) studying psychology was a means to an end, whereas andrea focused on the inherent enjoyment and satisfaction gained from studying psychology online. to andrea, who reported experiencing chronic pain, online learning meant the "…freedom to be anywhere i want and be able to connect and still do study". the availability, accessibility, and flexibility afforded by online learning were common motivators for choosing online learning, as reported by the participants. karen perceived online learning as being the more appropriate, though less desirable alternative to on-campus teaching and learning, at a time when she was very busy: "...i have to say, in today's world when we are all very busy with our own lives, its, uh, its better, it's more appropriate… i cannot say it's more effective, but participants discussed the decision-making processes that were involved in the juggling of their online studies with other commitments that included work, family, social lives, and leisure activities. "…but for me my biggest hobby, well, sort of passion is football. ehm, and i have a season ticket holder for my local football team. that's one thing that i'm not giving up and i refuse to give up football for studying or anything. so, on a saturday, saturday afternoon, my brother and i go off to football and i go home and i study. …but i think you reign your social life in a wee bit, a little bit just to, you know, you can't have everything, when you think about your life before studying you know, you just didn't have time to study, so you have to make that time". (jade) for jade, online learning required a re-prioritisation of some activities and social encounters to make time for studying. her account suggests that she felt the need to defend these decisions when viewed from her friends' perspectives. similarly, sophie reported that online learning has resulted in her becoming more organised than she had been previously: "…i think doing online learning is a different way of learning. because obviously, coz it is self-directed i think it makes you, it is making me much more um organised, i am so so much more organised than i have ever been in my life or having to be, having to be. because i'm not only studying obviously, i'm working, and i have a family, you know i have to sort of have to juggle everything, and it's making me organise everything". (sophie) when reflecting on her experience as a mature online student, sophie concludes that she is more likely to be successful in her studies now than she would have been at a younger age: "was a very very scary thing for me doing a degree, because obviously i'm not a young year old… and i think now i'm not , i think its, i'm a better, i'm a better student because i'm older, and yeah, i think its been really good for me for my professional development. i'm very proud of myself actually [laugh]". edward shared that, in his experience, approaching online learning with an open mind and a curiosity about the subject allowed him to maintain the focus he needed to 'get the job done' (i.e. obtain his psychology degree). andrea echoed this sentiment to some extent, as she believed that a curious attitude towards the subject made it more rewarding to learn. her curiosity also meant she was keen to make the most of available opportunities to learn, at the risk of scattering her attention across many different elements (i.e. modules, massive open online courses, research projects). jade talked about having to disguise her true motivation for studying psychology (i.e. career change to become a psychologist) to potential employers out of concern that she may not be perceived as a committed accountant: "…i'm applying for accountancy jobs, whereas, in complete honesty, i don't want to be an accountant in five years' time. d'you know like, ehm, and it's almost like that whole acting thing, so i'm going to these interviews and i'm completely being myself until they ask that question of where do you see yourself and i'm not, i don't like lying or deceiving or that sort of thing and its. i'm very open and i tell them at the end that i am doing degree and they'll get all interested and they ask what's it in and whenever i say psychology, they kind of, it's almost like first question is "why?!" d'you know and that's. and i'm sure like, one of my, my last role actually, we ended the conversation where basically i just went, 'as a hobby' (laugh). d'you know like, 'i do it in my spare time' (laugh) but it's not a hobby, it's what i want my future career. but i can't tell people that in an interview. because they'll look at me as not committed to being an accountant. when i, whereas i am but i don't want to do it forever. so, that to me is quite tricky". (jade) jade's account detailed the tension stemming from her balancing her current role as an accountant with her identity as an online psychology student in training for a career in psychology. the authors designed the interview guide to focus solely on online learning, without encouraging participants to compare online and campus-based teaching and learning. it is therefore noteworthy that all participants, at various stages of the interview, made positive and negative comparisons between the two mediums. tae, edward, and jade highlighted the importance of the online degree leading to an accredited qualification that was similar to, or the same as, what was awarded on-campus. jade explains how the meaning of online learning has changed for her since she started studying online: "…for me, if you'd asked me before i did this degree, ehm, online learning. i was probably one of those people that viewed online learning as not as good as attending university. ehm, but since doing the degree, i'm seeing how much hard work it is and how much dedication it takes and i view online learning as.. same as usual, people are still working hard to do it, and i'm working hard to do it. so, i.. you know, when people say to me, oh, where do you study, i say derby and they say, oh is it an online course, and i was like, well, yeah, but it is still the same degree. so i find myself now pushing back on people because for me i value online learning a lot more now i'm actually doing it and part of a course". (jade) karen raised concerns relating to her level of english proficiency, and worried that it was not of the same standard as her english-speaking peers. this resulted in some hesitation at contributing to discussion board activities in the virtual learning environment: "sometimes i have to say i do feel a bit shy, because in a group we have … [other students'] english is very proficient, in the comments it's like 'wow!' so i feel a bit shy, and i won't do my activity, because i think 'oh my god if i give my thoughts or express myself it will look funny,' you know, because they sound so professional, which actually is not good, so i'm pushing myself to [do the activities]". (karen) the com-b constructs, when mapped against participants' narratives of selfregulated learning, can be taken into consideration by educators to better facilitate self-regulated learning. the participants reported varied motivations for studying psychology online and opportunities that either facilitated or hindered how they managed their online studies. with the exception of karen, all participants appeared confident and capable as self-regulated online learners. karen's concern around her english language skills clearly demonstrates her perceived lack of capability to contribute to online activities, although she recognised the detrimental impact that this was having on her online learning experience. all participants, with the exception of edward, compared the mediums of online and on-campus teaching and learning. this tendency could have shaped participants' expectations and experiences of online learning, and may be suggestive of a need for online education providers to establish expectations of online learning as being qualitatively different from campus-based learning. while, it is unlikely that the participants were comparing their online programmes to on-campus study on a regular basis, it was clear that using on-campus study as a reference point was useful to some participants when discussing the opportunities and challenges that arise when accessing resources online: "...and as long as there is an internet connection, then i can do this. it means i'm not, i'm not having to worry and look at a calendar every time i want to do something. …i'm not hauling a whole load of books with me… i mean if you are on a campus, you have set term times, you're aware that you can miss a class or two but there is always the worry about what if i miss this…" (andrea) being able to access the psychology programme from different geographical locations was the most commonly identified advantage of online learning. however, for some participants, being physically removed from academic institutions, services and resources meant that disengagement from their studies when other life events took priority was perceived as being more likely than if they had been studying on-campus. "and i guess you take more action when, if you have to go to the campus for example. whereas, if you study online i feel, it feels very relaxing and casual when you can just stay at home in front of your computer, the same place you watch netflix and chill, it feels very, the atmosphere feels very different, is what i mean to say". (tae) while most participants focused on the ease of access to online learning materials, karen, who was based in qatar at the time of the interview, highlights the difficulties in accessing resources (e.g. books and journals) in developing versus developed counties. karen expresses a fear of missing out arising from her geographic location (qatar vs london) rather than the medium of study (online vs on-campus): "…if you are in a big city, like in london, any actually economically developed countries, you can probably find the good libraries, but bit outside, it's really difficult, even me living in qatar… there is nothing when it comes to psychology, nothing. i mean there is national library, there is nothing when it comes to that particular subject…" (karen) this subtheme maps exclusively against the opportunity construct of the com-b model as it focuses on factors outside of the participants and educators' control. taking the experiences of varied living arrangements (e.g. household, employment, location, etc.) among online learners into consideration, may help educators and providers to tailor expectations for prospective learners. all participants reported feelings of isolation in relation to online learning as being a challenge. despite the participants having used a variety of online mediums to communicate with others, the absence of face-to-face interaction and instant feedback appeared to be a point of tolerable apprehension in this sample: "…sometimes i think it's nice just to get some feedback right away as if you're meeting them face to face. but studying online, i mean okay, there's a forum where you can provide some questions and get some answers out of that. but sometimes, perhaps our supervisor isn't there, isn't available or maybe they are occupied with something else, so we don't get the answers right away when we kind of need it. so, it could be a little bit inconvenient because of that". (tae) for edward, keeping 'a low online presence' was a personal choice that was necessary and allowed him to manage his other commitments. edward talked about interacting with peers as being 'a luxury, an added extra' that he couldn't afford due to his particular approach to online learning: "i find it beneficial when i can pick things up and let it go when it suits me…my main focus is to pass the course". alongside his studies, edward balanced a full-time job at a bank, and worked parttime as a football coach. for him, social interaction with peers and lecturers did not appear to have been perceived as being necessary to the completion of the programme: "…i'll use [lecturers] as a crutch, if and when i need their support". other participants had doubts about interacting with lecturers, particularly when they first started online learning. as andrea puts it, "i wondered about when you should contact a tutor". andrea's confidence in contacting her tutors when she had questions grew in conjunction with her familiarity with them. further, sophie explained how her confidence had increased over time to the point that she felt able to provide support to others; as a result she experienced increased interactions with her peers. for jade, reading other students' posts was daunting but as she got to know her peers through group work, she developed an appreciation for, and valued their contributions. when considering the com-b model, this theme includes examples related to the participants' capability (i.e. the ability and confidence to interact with others online), opportunity (i.e. asynchronous communication modality), and motivation (i.e. reasons for or against interacting with others) to interact with peers and tutors. the social dynamics involved in online learning have the potential to either foster or impede self-regulated learning. the primary aims of this study were to explore the experiences of learners studying psychology online and to identify potential barriers and facilitators to online study across the sample. the participants were mature students, three from non-uk countries, engaging in online learning in pursuit of a career change. as an increasing number of individuals opt for a career change, it is worth exploring means by which to support individuals balancing their existing careers with their studies. the present study identified the balancing act of online learners as the overarching theme, which has been overlooked in the field as research tends to focus on instructional design, learning outcomes, and student satisfaction (e.g. symeonides and childs ; mayer ; tanis ; altinpulluk et al. ) . when considering this, our findings are novel and carry implications of future value in pedagogic practice in the field of online learning. the first theme, 'the identity of an online learner', reflected balancing one's identity as an online learner with other commitments, roles, and responsibilities. this suggests that a truly student-centric approach requires that online learning practices consider the impact of learner identity (oztok et al. ) . it is, therefore, critical that students develop an online learner identity to facilitate self-regulated learning behaviours in their online learning experience. students who fail to do so may find it difficult to remain engaged in online learning when faced with other commitments or distractions and may not succeed in their studies. this is supported by research conducted by wong and colleagues ( ) that identified time management strategies and the regulation of effort as being critical to academic performance. the second theme, 'accessing resources', showed participants weighing the advantages and challenges of online learning. the emergence of this theme is in support of research that has established the importance of the e-learning environment in creating and maintaining positive learning attitudes, specifically an environment that considers student preferences and is adapted to specific learning situations (wongwatkit et al. ; zhu et al. ; larmuseau et al. ) . a conscious decision was made by the authors to avoid questions that specifically required that the participants compare online and on-campus study. interestingly, all participants but one spontaneously used on-campus study as a reference point when sharing their experiences and perceptions related to online learning. providers and educators that use campus-based learning as a reference point when presenting resources and opportunities in online learning may be contributing to unrealistic expectations of online learning and the fear of missing out on-campus-based learning (ragusa ) . the findings from the present study support previous research that revealed the opportunities and challenges of online learning compared to on-campus study. for example, the freedom and flexibility of online learning was viewed as a facilitator, whereas feelings of isolation and the lack of face-to-face interaction with peers and lecturers were generally seen as a disadvantage of studying online (bernard et al. ). the final theme, 'the dynamic nature of social interactions online', highlighted the variety of ways participants approached interactions with peers and tutors. while some participants favoured an isolated experience, others desired engagement with peers and tutors, despite reporting hesitation in doing so. those who had interacted with peers and tutors reported increased confidence in the prospect of future interaction. wong and colleagues ( ) highlighted the importance of these interactions in encouraging 'help-seeking actions'. additionally, previous research identified the 'student-lecturer interaction' to be critical in academic and social development in students, as well as academic achievement (alshahrani et al. ; warner et al. ; ouyang et al. ) . online educators have a responsibility to ensure that students who are not fluent in the language of learning (in this case, english) are not hesitant at participating in discussion forums, which is described by jenkins ( ) as the 'participation gap'. further, research suggests that it is important that educators reduce the fear of asking questions, and encourage help-seeking behaviours when necessary . while some students, such as edward, preferred to keep a low online profile due to other commitments, encouraging students to be proactive may lead to students shifting from self-doubt when engaging with peers and tutors to taking pride in working with and helping other students, as was evident with jade, sophie, and karen. the present study and previous research suggest that studentto-student mentoring may be an effective strategy for improving student retention and engagement in online learning (boyle et al. ) . therefore, the provision of tools and resources that facilitate these interactions can contribute to building confidence and capability in students, motivating them to engage with other students (prior et al. ) , and provide opportunities for collaborative regulated learning. the final goal of the present study was to explore whether the capability, opportunity, motivation, and behaviour (com-b) model constructs were applicable to the experiences of the sample. the results demonstrated the utility of the com-b model, and presents how it might be used to support online psychology students to achieve and maintain self-regulated learning. similarly, wong and colleagues ( ) suggested that self-regulated learning required the combination of learning motivation and strategies to affect academic performance. the com-b constructs could guide pedagogic approaches. for example, online educators can provide students with resources and activities that facilitate and help overcome barriers to behaviours associated with self-regulated learning (e.g. asking students to identify and reflect on their motivations for studying psychology). this supports research showing that learners perform better when they are aware of their role in the learning process . further, the constructs of the com-b model can be used as a guide to develop self-assessment tools for students to identify the extent to which they demonstrate self-regulated learning strategies. such tools and resources would benefit from being tailored to specific subject areas, and could be examined in future pedagogic research into online learning. the present study successfully demonstrates the potential of com-b model in guiding the development of strategies to facilitate mature psychology students in achieving or maintaining self-regulated online learner status. further, this study is limited in that the sample was self-selecting, with all participants tending to be progressing well and reporting mostly positive experiences of studying online. the participants were undertaking online studies specifically to facilitate a career change; different experiences and challenges might have arisen if online students undertaking studies as part of their initial career aspirations were sampled. while the size of the sample examined in this study raises questions as to the generalizability of its findings, the nature of ipa calls for an analysis into the perceptions and experiences of a specific group within a unique setting. further, smith and osborn ( ) posit that ipa research ought to be considered in terms of theoretical generalizability. the present study identified several facilitators and barriers to studying psychology online. a number of experiences reported by the participants can be mapped against the com-b constructs, suggesting that educators may be able to reinforce and highlight these experiences as contributing to developing a self-regulated learner identity. bjork et al. ( ) conclude that self-regulated learning is a vital skill for formal and informal learning across one's lifespan. online educators can design teaching and learning materials that create opportunities and foster capability and motivation, as well as setting expectations and putting contingencies in place to counter factors that might hinder students' self-regulated learning experiences. this study derives useful insight from the experiences of online psychology students from diverse backgrounds, which highlights the need for future research to explore self-regulated online learning in other subject areas. future research could also explore students' experiences at varied stages of their studies to identify which characteristics remain consistent and which shift over time. changing course ten years of tracking online education in the united states the influence of online resources on student-lecturer relationship in higher education: a comparison study the influence of segmented and complete educational videos on the cognitive load, satisfaction, engagement, and academic achievement levels of learners experiences in sense making: health science students'i-positioning in an online philosophy of science course reversing the pipeline? 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distance education supporting self-regulated learning in online learning environments and moocs: a systematic review internet-based medical education: a realist review of what works, for whom and in what circumstances how to facilitate self-regulated learning? a case study on open educational resources moderating effects of gender differences on the relationships between perceived learning support, intention to use, and learning performance in a personalized e-learning e-learning as a way to improve the quality of educational for international students how college students' achievement goal orientations predict their expected online learning outcome: the mediation roles of self-regulated learning strategies and supportive online learning behaviors motivational sources and outcomes of self-regulated learning and performance self-regulated learning and academic achievement: theory, research, and practice university students' online learning attitudes and continuous intention to undertake online courses: a self-regulated learning perspective acknowledgements this study was funded by the university of derby undergraduate research scholarship scheme and the paper was written up during a residential writing retreat supported by the university of derby. key: cord- - rtt authors: teele, sarah a.; sindelar, anthony; brown, david; kane, david a.; thatte, nikhil; williams, ryan j.; gueverra, joy; wolbrink, traci a. title: online education in a hurry: delivering pediatric graduate medical education during covid- date: - - journal: prog pediatr cardiol doi: . /j.ppedcard. . sha: doc_id: cord_uid: rtt in the setting of the coronavirus disease (covid- ) pandemic, an emergency hospital-wide ework policy was enacted at boston children’s hospital on march , . the number of clinicians on campus was restricted to only essential personnel, guidelines limited clinical care delivery to solely non-elective patients, and strict maximums were placed on the numbers of people allowed to congregate in the same physical space. with this abrupt transition to social distancing and electronic communication, the established approach to educating graduate medical trainees became obsolete overnight. anticipating significant impact on trainee and faculty professional and personal lives, the importance of adaptive teaching strategies was evident. this document details one approach to redesigning the clinical learning system including a description of the learners and environment, the pedagogical principles that guided the approach, and technological tools used in implementation. additionally, available literature pertinent to this topic is explored, assessment of the work to date is presented, and suggestions are provided regarding future directions related to online graduate medical education. identifying learning and engagement goals early in the initiative helped us focus on the use of technology as a solution to the challenges, as opposed to a gimmick or distractor. this approach is known to be important for learner and faculty buy-in, especially for those not already familiar with the tools. ( , ) we therefore created learning goals and desired results as the first step in the process: a. provide high-yield synchronous and asynchronous learning opportunities that engage trainees and faculty using remote technology b. create an online community that provides social support for one another by solidifying personal and professional relationships despite physical isolation c. utilize and curate high-quality resources readily available to us (faculty and trainee expertise, pre-existing online resources, unstructured time) under extraordinary circumstances to create a learning tool that will be useful today, and in the future d. centralize currently available learning tools/resources from across the cardiovascular program e. elicit real-time informal and formal feedback in order to modify and adjust the intervention to best meet the needs of our learners and educators in order to rapidly deploy the initiative, we used a combination of pre-existing content and real time content creation. anticipating rapid expansion in educational resources, we created clearly labeled folders assigned to topics such as "electrophysiology" and "cardiac imaging" (figure ), each with its own set of sub-folders for organization and ease of use. task force reports coordinated by the society of pediatric cardiology training program directors (spctpd) were included in each of the relevant sub-specialty folders to provide structure. ( ) we identified divisional educational champions across the department of cardiology to help populate folders in the sub-specialty topics with vetted, high quality content related to their area(s) of expertise (e.g. electrophysiology). standards and guidelines for the care of patients with congenital or j o u r n a l p r e -p r o o f journal pre-proof acquired heart disease were included. as the group site developed, it became increasingly easier to link resources which now number in the hundreds. for example, faculty teaching an imaging session on cardiac tumors could refer to the relevant pathology lecture and the surgical technique references already available on the bch cardiovascular program group site. synchronous learning is defined as the education of a group of people that occurs simultaneously in real time. at the start of the pandemic, online conferences were immediately identified by global educators as an important solution for synchronous learning when learners could not be face-to-face. bch had an established relationship with zoom (https://zoom.us), however, many members of the department were not familiar with its features. one of the chief fellows was tasked with creating a user-friendly document on how to host a zoom meeting. this was circulated to the faculty and trainees on march , . prior to the ework policies, our department hosted in-person teaching sessions one to two hours daily, monday through friday. the approach to these teaching sessions varied but included traditional lecture format and case-based learning. after a brief pause of a week, our core conference schedule was redeployed online, march , . we added additional sessions at the request of the learners and interested faculty with a focus on important threshold concepts in the field of pediatric cardiology. within several weeks, trainees had the option to attend two to three one-hour sessions per day and could choose amongst a variety of topics in the field of pediatric cardiology. synchronous educational opportunities continued to increase in number throughout j o u r n a l p r e -p r o o f journal pre-proof april and may, further complemented by national and international initiatives. two to four hours of online pediatric cardiology content per day continues to be standard even though the department has resumed much of its pre-covid- activity. if local sessions do not contain patient health information, they are recorded and uploaded to the private openpediatrics group site for future viewing. lecture references are linked with the recorded material for learners interested in additional content or reviewing sentinel literature. asynchronous educational opportunities occur independent of a specific place or time and therefore offer increased flexibility. learners may work independently or collaborate with others. this approach presents tremendous potential for active learning where the learner is compelled to engage with the subject material. additionally, it allows the trainee control over when the learning will take place. with these pedagogical goals in mind, we created a voluntary team- (figure ), . identify three key references as "must read" articles for a learner interested in the designated lesion, and . create three accreditation council for graduate medical education-type board questions based on the lesion with answers and explanations. four teams were created. all components of the project were completed for the following lesions chosen by respective team members: isolated atrial septal defects, pulmonary atresia with intact ventricular septum, total anomalous pulmonary venous connection, and tetralogy of fallot with absent pulmonary valve. an example of a complete project can be found in appendix . faculty coaches reviewed all of the content for accuracy and provided feedback to the learners. the first step of the project was to address the components of the lesion flow chart. in essence, this provided the scaffolding for a concept map of a specific congenital heart lesion over a patient's lifespan. each trainee was likely to have prior experience with some aspects of the map. the key component of the exercise was to elaborate on one's own pre-existing mental model of the lesion by connecting new information in a more sophisticated web. ideally, combining the varied components of the lesion map (e.g. pathophysiology, management strategies, outcomes) into a complete clinical picture using their own words, helped trainees consolidate and solidify knowledge. our survey response rate was % ( / ). respondents reported a high level of motivation for participating in online learning. the top three motivating factors were: "i feel continuing my education through online learning is important", "i feel it is my professional responsibility to do this online learning", and "online learning provides a way to stay professionally connected to my peers and faculty mentors". the most common barriers to participating in online learning were reported to be limitations on time due to clinical obligations, too many options for online learning, and distractions attributable to the covid- pandemic. eighty-nine percent ( / ) j o u r n a l p r e -p r o o f respondents agreed that the online learning in this intervention was translatable to daily realworld work. sixty-two percent ( / ) of our learners agreed that they felt more comfortable using technology tools at the time of completing the survey than they had before the online learning initiative. unfortunately, because our group on openpediatrics is designated as private, we were unable to obtain statistics on platform utilization. data that would have been helpful and complementary to the survey included click counts, log-in time of day, time spent on the site by a user, and consistency of engagement by faculty and learners over time. as the covid- pandemic rapidly swept the globe, the international medical education community quickly mobilized to support collaborative real-time solutions to the challenge. previously accepted approaches for many aspects of our existences were reimagined, including the delivery of graduate medical education. the bch department of cardiology initiative embraced the video conference format for synchronous learning while simultaneously developing an innovative asynchronous educational opportunity. although asynchronous activities are not a new concept, they were not part of the bch cardiology fellowship curriculum prior to the pandemic. the extraordinary circumstances offered our trainees unstructured time not typically available to them and therefore an opportunity for inventive approaches to our training program. our local approach prioritized quality of content creation through engagement of our learners and faculty. this required a substantial time commitment across the department. rapid access to globally shared high-quality education and medical content resources was an important facet of our initiative. in a remarkably prescient document from , a global commission dedicated to health professional education cited global threats, including infectious disease, as motivation to harness the potential power of technology for distance learning and collaborative connectivity. this approach to transitioning graduate medical education from an entirely face-to-face experience to completely online learning environment had challenges. thankfully, all of our learners had reliable access to the internet and therefore digital equity was not a factor. additionally, none of our learners required assistive technologies to provide access, but it is an important consideration for educators attempting to design a similar kind of intervention. technological literacy and the generation gap between the learners and the faculty was our biggest hurdle. in general, the age of current trainees in graduate medicine qualifies them as "digital natives" and generally fluent in technology. in , a large number of educators in academic medicine are "digital immigrants" with an enormous range of technological literacy. ( ) many of the faculty participating in the learning initiatives required substantial remote j o u r n a l p r e -p r o o f support from more technologically fluent faculty and learners. in hindsight, a survey of our faculty to assess technological literacy at the start of the initiative would have been helpful. even for those comfortable with the technology tools, online teaching and learning presents challenges to those not familiar with the format. teaching on a computer screen is a very different experience than working with an overflowing lecture hall or intimate small group session. physical separation and limited face-to-face contact can lead to feeling of disconnection and isolation by either the learner or the educator or both. there is a risk of disengagement and the promotion of superficial learning. despite the need for rapid deployment of educational interventions, adherence to established concepts in adult learning were prioritized. important considerations included ensuring that educational materials were relevant and meaningful to the learners' professional work, information was applicable to everyday problems, and learners were engaged with and feel connected to faculty and peers. high levels of connectivity and collaboration in synchronous and asynchronous activities were encouraged. online learning was a dynamic and expanding field prior to the pandemic with virtual reality, augmented reality, and gaming viewed as meaningful learning experiences which may engage our learners. ( ) these approaches, however, require more established resources than were available at the time of this intervention. additional exploration of these themes warrants further investigation and will be important to better understand and improve future educational interventions. j o u r n a l p r e -p r o o f perhaps most importantly, our educational goals, no matter how noble or grounded in theories of adult learning, were situated in the context of a devastating and historic international crisis. this was an incredibly challenging time for clinicians, professionally and personally. openly acknowledging that all members of the department were navigating multiple stressors was critical during this initiative. innovative, resourceful, and dynamic initiatives were required to manage the challenges highlighted by the covid- pandemic and will be necessary to navigate the uncertainties of the future. online learning cannot replace the physical examination of patients and the power of human touch. it is, however, an opportunity to deliver high quality learner-centered education in non-traditional settings while simultaneously cultivating intrinsic motivation in our trainees and faculty. it is clear that healthcare professionals yearn for lifelong learning, practice development, and connection to their local and global communities. additional reflection and ongoing formal evaluation of new initiatives will be essential to understand the implications of these types of innovations. j o u r n a l p r e -p r o o f e-learning and the science of instruction: proven guidelines for consumers and designers of multimedia learning physician internet medical information seeking and on-line continuing education use patterns comparison of healthcare professionals' motivations for using different online learning materials. pediatric investigation spctpd/acc/aap/aha training guidelines for pediatric cardiology fellowship programs (revision of the training guidelines for a guide to quality in online learning -academic partnerships question-writing as a learning tool for students -outcomes from curricular exams make it stick: the science of successful learning repeated testing improves long-term retention relative to repeated study: a randomised controlled trial development of an instructional design evaluation survey for postgraduate medical e-learning: content validation study : evaluating teaching: a new approach to an old problem health professionals for a new century: transforming education to strengthen health systems in an interdependent world. the lancet covid- and medical education. the lancet infectious diseases adapting the educational environment for cardiovascular fellows-in-training during the covid- pandemic reinforcing cardiology training during a pandemic: an open letter to our leaders medical student education in the time of covid- #mededpearls: mastering adaptive teaching in the midst of covid- developing online assessments of student learning in a hurry teaching effectively during times of disruption r e -p r o o f steps-for-a-smoother-transition-to-online-teaching free open access medical education (foam) for the emergency physician the top ten websites in critical care medicine education today cjem and the changing landscape of medical education and knowledge translation heart university: a new online educational forum in paediatric and adult congenital cardiac care. the future of virtual learning in a post-pandemic world? educational resources for fellows key: cord- -kab f authors: longhurst, georga j.; stone, danya m.; dulohery, kate; scully, deirdre; campbell, thomas; smith, claire f. title: strength, weakness, opportunity, threat (swot) analysis of the adaptations to anatomical education in the united kingdom and republic of ireland in response to the covid‐ pandemic date: - - journal: anat sci educ doi: . /ase. sha: doc_id: cord_uid: kab f the covid‐ pandemic has driven the fastest changes to higher education across the globe, necessitated by social distancing measures preventing face‐to‐face teaching. this has led to an almost immediate switch to distance learning by higher education institutions. anatomy faces some unique challenges. intrinsically, anatomy is a three‐dimensional subject that requires a sound understanding of the relationships between structures, often achieved by the study of human cadaveric material, models, and virtual resources. this study sought to identify the approaches taken in the united kingdom and republic of ireland to deliver anatomical education through online means. data were collected from different universities in the united kingdom and republic of ireland and compared adopting a thematic analysis approach. once themes were generated, they were collectively brought together using a strength, weakness, opportunity, threat (swot) analysis. key themes included the opportunity to develop new online resources and the chance to engage in new academic collaborations. academics frequently mentioned the challenge that time constrains could place on the quality and effectiveness of these resources; especially as in many cases the aim of these resources was to compensate for a lack of exposure to cadaveric exposure. comparisons of the actions taken by multiple higher education institutions reveal the ways that academics have tried to balance this demand. discussions will facilitate decisions being made by higher education institutions regarding adapting the curriculum and assessment methods in anatomy. the coronavirus pandemic is an unprecedented emergency that has affected all global industries, including education (ayittey et al., ) . with the widespread implementation of social distancing and self-isolation policies, it is not feasible for educators and students to attend lessons or assessments as they have previously. the covid- pandemic has disrupted our long-standing educational practices and has precipitated an urgent need for many institutions to rapidly implement alternative educational and assessment strategies. on st december , the world health organization (who) was informed of a small cluster of pneumonia cases with unknown etiology in the wuhan city, hubei province, china (who, a: zhu et al., ) . the novel coronavirus was isolated on th january and genetically sequenced on th january (who, a; wong et al., ) . the virus was confirmed to have subsequently spread to thailand, japan, and the republic of korea, on th , th and th january, respectively (who, a). on january rd , the government of china imposed a modern form of quarantine, shutting down all transportation in and out of wuhan. the lockdown expanded to twelve other cities in the hubei province (rubin and wessely, ) . covid- was first confirmed in the united kingdom (uk) and republic of ireland (roi) on th january and th february , respectively (holmes, ; hpsc, ) . on th march , the who officially declared the outbreak a pandemic (who, b) . to control the outbreak of the virus, public health england (phe, ) and the department of health and department of the taoiseach in the roi (dh&dt, ) introduced increasingly restrictive policies governing the movement and gathering of people. social distancing was implemented in the uk on th march (mahase, ) and even greater restrictions to movement were implemented on rd march (phe, ). historic pandemics, such as the severe acute respiratory syndrome (sars) also saw changes to educational practices and important lessons were learned. during the sars epidemic, chinese and canadian medical schools were forced to cease their clinical clerkships and electives (ahmed et al., ) . chinese medical schools supplemented their students learning experiences with the introduction of online problem-based learning (ahmed et al., ) . at the same time in hong kong, university policies decreed that the external examiner must be present for final-year medical distinction examinations (patil and yan, ) . these examinations traditionally took place as viva voce examinations; however, because the external examiner could not be present, these examinations took place by phone call. due to concern regarding the stability of the phone connection, the first part of the examination was conducted by an external examiner and no interruptions were reported (patil and yan, ) . these solutions could similarly be utilized by anatomists in addressing the challenges that have arisen due to the covid- pandemic. education institutes across all levels (pre-primary, primary, secondary and tertiary) have closed in countries across the globe, impacting over % of the world's student population (unesco, ) . universities in the uk started to close from the th of march. universities in the roi were formally closed on th march (rtÉ, ) and face-to-face teaching was suspended from th march, following government advice. universities have moved all teaching activities online and set up communication platforms, such as webpages and email streams to inform students of the ever-changing circumstance. the majority of higher education institutions in the uk and roi begin their academic term in august or september, and this cessation of face-to-face teaching occurred during the second or third semesters. educators were forced to rapidly find solutions to many challenges; for some this meant moving to online delivery within days. governmental education departments released guidance for students and educators in response to this (des, ; gov.uk, a, b) . there are over , medical students in the uk and roi (gmc, ; heffron and socha-dietrich, ) . approximately half of these students are completing formal anatomical education during the early years of their program (heylings, ) . therefore, alternative educational and assessment strategies will impact a large cohort of approximately , students with immediate effect. for final years, the general medical council (gmc) urged medical schools to fast track the graduation and registrations of these students to supplement the healthcare workforce (msc, ). the google hangouts (google meet) video conferencing application (google inc., mountain view, ca) has successfully been used to deliver lessons to medical students assigned to surgical specialties and it has been speculated that these could similarly be implemented to supplement anatomical education (moszkowicz et al., ) . at imperial college london, teleteaching and telemedicine modalities have been implemented to supplement the clinical needs of final-year medical students, and these students are currently perfecting their clinical judgment using an online repository of patient interviews and clinical cases (mian and khan, ) . in related fields, such as dentistry, there have also been recommendations to shift education toward online platforms (meng et al., ) . there are medical schools in the uk and seven in roi. recently, five new medical schools in the uk were created but have not been included in the sample as they are either not currently taking students or are under the umbrella affiliation of another medical school and are hence using their curriculum. the number of hours dedicated to anatomy teaching and the number of anatomical staff members significantly varies throughout the uk. anatomy is taught through systems-based curricula, problem-based curricula, or in the traditional regional format. lancaster university medical school, peninsula college of medicine and dentistry, and university of limerick medical school are the only institutions that do not use human cadavers to teach anatomy (heylings, ) . educators across the globe have been forced to replace traditional learning modalities with distance and blended learning approaches. distance learning has been described as an information delivery mechanism where the educator and learner are separated in both time and space (billings, ) , whereas blended learning combines traditional classroom methods of learning with online learning modalities (green and whitburn, ) . neither approach is novel, and both have been used successfully as part of anatomy education (pereira et al., ; ferrer-torregrosa et al., ) . however, these approaches are usually implemented after strategic planning, collaboration with other academics, and careful consideration of the pedagogical evidence. in order to utilize online approaches, educators must invest considerable time up-front to learn how to create online learning material. in many cases, academics are required to develop these new skills and create or adapt resources in parallel with a time frame that reflects the normal progression of student learning. the storage, maintenance, and embalming of cadaveric specimens poses a further challenge to anatomy departments with limited on-site access. with the body donation program largely halted in the uk and roi (hta, a), there may be a reduced number of available specimens for teaching in the following academic year. guidance from the international committee of the red cross (icrc) has also suggested that medical schools may provide body storage facilities as a contingency for mortuary overflow (finegan et al., ) , with updated guidance on licensing of emergency mortuaries concurrently released by the human tissue authority (hta) to support this (hta, b). this may result in existing cadaveric material being compromised, placing further strain on availability of specimens going forward. due to the unprecedented demand that the covid- pandemic has placed on public health services, clinically trained anatomists have been encouraged to return to the clinical workforce (willan et al., ) . in addition, non-clinical academic staff may contract covid- , or have caring responsibilities placing additional demands on the remaining members within a team of anatomists, disproportionately affecting universities with smaller academic teams, or in locations where only one anatomist is employed placing considerable burden on them. the negative impact on the mental wellbeing of healthcare workers due to anxieties and pressure in relation to covid- has already been documented (shaw, ) . this research aimed to understand the variety of solutions being utilized across institutions in the uk and roi and to facilitate easier decision-making surrounding changes to curriculum and assessment strategy. the two research questions were: ( ) what strategies have been adopted by uk and roi anatomy departments in response to what strengths, weaknesses, opportunities, and threats does the instant move to online learning bring? the questionnaire was conceptualized by the researchers for this study (g.j.l., d.m.s., k.d., d.s., and t.c.) in order to obtain information from anatomy departments across the uk and roi on their institutional and departmental responses to the covid- pandemic. all questions proposed by the researchers were selected for review. only the questions that were agreed by all contributors were selected. the seven questions that were selected focused around three themes: ( ) location of university and size of anatomy team, ( ) adaptations to teaching and resources used in lectures and practical sessions and ( ) major challenges and opportunities (see supporting information ). all feedback was solicited by way of free-text responses. a pilot study was completed in the respective institutions of the researchers (g.j.l., d.m.s., k.d., d.s., and t.c), and on review there were no postpilot modifications made. the questionnaire was tabulated in a microsoft word document (microsoft corp., redmond, wa) and emailed to anatomists in higher education institutions in the uk and roi. the list of anatomists and institutions selected for this study was created using a convenience sample of known contacts. a total of responses were received from the medical schools that were contacted ( % response rate). the adaptations to lectures, practical, and assessment were collated and summarized and a thematic analysis was carried out on the opportunities and challenges. all responses were analyzed using thematic analysis by the researchers (g.j.l., d.m.s., k.d., d.s., and t.c.) (glaser and straus, ; braun and clarke, ) . to achieve this, the six-phase process described by braun and clarke ( ) was followed. first, all authors read through the entire data set to familiarize themselves with the data. initial codes were then manually generated using an open-coding approach by highlighting interesting and relevant aspects of the responses. this was done individually and then any discrepancies discussed in order to minimize bias. codes were then collated into more general themes. these themes were reviewed by all authors to ensure they fully reflected the responses. due to the small sample size, themes were generated without digital programs. the most commonly reoccurring themes were then used to inform the next stage of the analysis, as well as other essential themes as identified by the authors. the authors assigned these themes to either strengths, weaknesses, opportunities, or threats for the purpose of swot analysis, an analytical approach commonly used to inform strategic planning and decision making (helms and nixon, ; teoli and an, ) . a swot analysis was originally developed as a business tool to aid decision making, but has since been used to analyze strategies in higher education, including medical education (sharma, ; burr, ; liu, ; hazzan et al., ; leiber et al., ) . due to the urgent and rapidly evolving nature of covid , it was not possible to secure ethical approval. to mitigate this, it was made clear that respondents were providing data and by doing so were consenting for the data to be used. the authors are planning a follow-up study from different stakeholders' perspectives and this will go through full ethical approval and the data presented here will be considered as pilot data. fourteen universities provided information on the departmental response to covid- . twelve universities were uk based and two were based in the roi. the results presented here represent % and % of medical schools in the uk and roi, respectively. ten of the uk-based universities are located in england, one is located in wales and another one in northern ireland. the two irish universities are located in dublin. lectures. universities opted to replace lectures with recorded presentations and accompanying audio that was uploaded to the virtual learning environment. the most common lecture recording platform used was "panopto" (panopto inc., seattle, wa), with % of universities citing its use. thirty-six percent of universities also provided live sessions and tutorials via platforms such as "zoom" (zoom voice communications inc., san jose, ca), "collaborate ultra" (blackboard inc., new york, ny), and "big blue button" (big blue button inc., ottawa, canada). practical sessions. all bar two universities in the sample group used cadaveric material to teach anatomy prior to the pandemic. universities replaced practical sessions by supplementing virtual learning environments with additional resources. twenty-nine percent of universities used digitized cadaveric resources only, seven percent used d virtual resources only, and % used a combination of cadaveric and d virtual resources (table ). digitized cadaveric resources included "acland's video atlas of human anatomy" (acland, ) , high-quality cadaveric images, bespoke videos of prosected/ plastinated specimens, youtube (tm) videos (youtube, san bruno, ca), and the visible human project (u.s national library of medicine, bethesda, md) ( table ) . three-dimensional virtual resources included "visible body" (argosy publishing, inc., newton, ma), "complete anatomy" ( d medical/elsevier, dublin, republic of ireland), d models using "sketchfab" (sketchfab, new york, ny), "anatomy tv" (primal pictures ltd., colchester, uk), and "sectra" (a virtual dissection table; sectra ab, linköping, sweden) ( table ) . forty-three percent of universities provided further support for practical sessions by hosting live tutorials and sessions using platforms such as "zoom" (zoom voice communications inc., san jose, ca) and "microsoft teams" (microsoft corp., redmond, wa). assessment. fourteen percent of universities did not have a summative practical assessment in their curriculum, a further % of universities canceled their assessment and % completed online digital spotter examinations (table ) . written examinations were canceled in seven percent of universities (table ) . thirty-six percent opted for online multiple-choice questions (mcqs)/extending matching questions (emqs)/ single-answer questions (saqs)/single-best-answer (sbas) examinations and % opted for open-book examinations (table ). there were no regional differences noted with regard to assessment. opportunities and challenges. despite chronic disruption to curricula, the covid- pandemic has presented many opportunities to universities. the opportunity to develop new online resources was highlighted by % of universities. fifty percent of universities cited academic collaboration as an important opportunity, and % highlighted the importance of working from home. universities identified other opportunities such as upskilling in new technologies ( %), incorporation of blended learning ( %), development of alternative examination methods ( %), and free access to online resources ( %) ( table ). the most commonly expressed concern was the time investment associated with the development of new resources to replace lectures and practical classes. this challenge was highlighted by % of universities. fifty percent of universities were concerned about lack of practical sessions/cadaveric exposure, and % of universities identified reductions in student engagement. universities also highlighted concerns regarding the teacher-student relationship ( %), assessment ( %), working from home ( %), suspension of body donor programs ( %), and lack of technical support ( %) ( table ). many universities documented similar pedagogical opportunities and challenges. themes from the responses to top opportunities and challenges are sorted into a swot analysis and used to form the basis of this discussion. reoccurring strengths included the development of new resources and skills. time constraints, lack of exposure to cadaveric material, and changes to assessment were identified as weaknesses. opportunities identified included academic collaboration and working remotely, as well as with the opportunity to implement blended learning in future curriculum development. the reduction in quality of resources, reduced student engagement, and diminished student-teacher relationship were considered threats (fig. ). the approaches taken by higher education institutions and the effect these have on the strengths, weaknesses, opportunities, and threats currently faced are also discussed to elicit which approaches could prove most effective. development of new online resources. in response to the covid- lockdown, both digitized cadaveric resources and d virtual anatomy platforms were used by % of universities, in an attempt to emulate canceled practical sessions. twenty one percent of universities created unique videos. bespoke resources have been shown to lead to a significant increase in student satisfaction (mandernach, ) . new resources created and developed by academics include videos, virtual dissections, formative quizzes, and updating practical dissection notes that will be available to students through virtual learning environments. previous studies have elucidated that students appreciate anatomical videos and they have the potential to improve test scores (pereira et al., ; dilullo et al., ; topping, ) . to date, there are limited data on the effectiveness of virtual dissections; however, the results have been positive, when used in conjunction with cadaveric material (yammine and violato, ; darras et al., ) . a significant number of medical students have reported that they find online resources helpful (smith et al., ) this echoes a statement by one academic who stated gaining "free access to high quality resources from publishers" was a positive aspect of the pandemic. interestingly, the usefulness of online resources for individual students has been linked to personality preference, and thus the switch to distant learning may prove harder for certain groups of students (mcnulty et al., ) . the context of the anatomical learning environment has undergone a paradigm shift since the lockdown, and this may result in students adopting different strategic approaches to their learning (smith et al., ) . thus, it is imperative to ensure that these new resources are based upon sound pedagogical theory in order to foster deep learning strategies (kreber, ) . in addition, the number of new resources has the potential to overwhelm the learner, having negative implications for their extraneous cognitive load. extraneous cognitive load is affected by how information is presented by the instructor (leppink and van den heuvel, ) . upskilling in new technologies and resources. three institutions ( %) noted that this is an opportunity to develop technological skills. one academic stated this was a "chance to upskill and incorporate alternative software and novel resources into our teaching." this sudden leap in upskilling and innovation by a large proportion of academics has the potential to transform medical education by incorporating online learning to all aspects of the curricula (skochelak and stack, ; rose, ) . one academic stated that that this was an "opportunity to improve staff awareness of online teaching methods and their confidence in using them." for anatomists, this is a unique opportunity to assess the educational benefits of this software, encouraged by free licenses offered by many companies during this time, such as "visible body" (argosy publishing, inc., newton, ma) and "human biodigital" (biodigital inc., seoul, south korea). furthermore, it has triggered the development of new skills in assessment modalities. as all universities have adopted an online approach to written examinations, new skills in utilizing the full capabilities of virtual learning environments are being explored. virtual learning environments allow academics to easily build question banks and design assessments that can be marked automatically or manually. virtual learning environments also facilitate randomized presentation of questions, time constraints, and prohibit backtracking in order to prevent collaborative answering. for example, "brightspace" (d l corp., kitchener, canada) facilitates precise keystroke recording-an important feature to prevent cheating during online spotters. the move to online assessment has identified an opportunity to improve examination conditions (dennick et al., ) . specifically, this is true for summative continuous assessments that often involve image-based spotter examinations as there is a high workload associated with designing and implementing station-based spotter exams. schubert et al., ( ) reported that designing, implementing, and invigilating a station-based gross anatomy examination encompassed . days' work (shubert et al., ). dennick et al., ( ) showed that student performance on gross anatomical examination is no different between traditional spotter examinations compared to digital online modes. the development of skills in online assessment modalities may be of benefit for future academic practice without endangering academic integrity or student performance (meyer et al., ) . time constraints. time is ultimately of the essence when it comes to creating additional anatomical resources in response to covid- , with universities identifying it as the top challenge in the delivery of anatomical education. one academic noted that the "time needed to learn how to use technologies" was an issue. creating new resources can take at least three times as much work compared to a traditional format (gewin, ) . this may be attributed to the steep learning curve required to learn how to use technologies effectively. the added pressure of producing "high-quality resources," in addition to fulfilling other academic duties in a limited time period may put undue pressure on academics. therefore, it is imperative to weigh-up the cost-benefit implications of the time needed to create new resources against the educational benefit for the students. indeed, it was observed that instructor-made videos lead to no measurable improvements in student achievement (mandernach, ); however, it may have an impact in student engagement as discussed in the section outlining potential threats. furthermore, well-renowned anatomical educational resources already exist, so one must decide if it is worth 're-inventing the wheel', so to speak. for example, "acland's video atlas of human anatomy" (acland, ), recurrent themes in the context of the swot paradigm. the frequency of recurring themes was calculated based on respondent survey data (a total of responses from the contacted medical schools in the united kingdom and republic of ireland). the authors subsequently assigned these themes to the most appropriate heading of the swot paradigm. created in , is still used by medical schools today along with other useful online resources as outlined by participating universities ( table ) . lack of practical sessions and cadaveric exposure. the results show that a major concern for academics is the loss of cadaveric-based teaching, as expressed by % of participating universities. cadavers are utilized as the pillar pedagogical tool in many medical schools across the globe (habicht et al., ) . indeed, one academic stated that "not physically attending practical sessions will limit haptic understanding and reduce discussions concerning variations and pathology." the benefits of cadaveric-based teaching have been eluded in a number of studies (aziz et al., ; estai and bunt, ) . cadavericbased teaching has been shown to lead to a deep understanding of the three-dimensional relationships of the human body and allows students to appreciate anatomical variations and pathologies (azer and eizenberg, ; smith and mathaias, ; fruhstorfer et al., ; hafferty and o'donnell, ) . cadaveric dissection can be a sensory explosion, arguably one that cannot be stimulated by technology (korf et al., ) . in addition, it allows students to develop competencies of medical profession and gain attributes through the hidden anatomical curriculum, for example, encountering death, empathy, and professionalism, in addition to communication and teamwork skills (estai and bunt, ; kumar ghosh and kumar, ) . additionally, students themselves believe that working with cadaveric material helps them learn anatomy and is an important component of becoming a healthcare professional (smith et al., ; flack and nicholson, ) . in the uk and roi, fortunately the lockdown occurred nearer the end of the academic term, thus students will have been exposed to cadaveric material for approximately six or seventh months. conversely, this is not the case for other countries, e.g., in australia and new zealand, where the academic term begins in february/march. all medical students may be disproportionately affected by the lack of cadaveric-based classes. although further studies will elucidate how the current covid- crisis will affect students' understanding of anatomy, a previous report revealed that students participating in gross anatomy laboratories received significantly higher grades, compared to those taking an online course (mathiowetz et al., ) . with many institutions looking to produce new online content to replace cadaveric dissection the hta have released a new statement regarding the use of cadaveric images, reiterating the importance of protecting the dignity of the deceased (hta, a). where cadaveric images are to be used to supplement online teaching, it is imperative to check if the donor provided consent for their remains to be used in images and videos. (hta, ; hennessy et al., ) . some institutions have also put in measures to limit sharing of cadaveric material now available on virtual learning environments by ensuring students are able to view but not download this content. issues with assessment. twenty-nine percent of the institutions surveyed did not have pre-existing summative assessments based on practical content. of those that did, % canceled the summative element, and % switched to online assessments to maintain normal student progression (table ) . however, online assessments pose their own unique challenges. one key principle that needs to be considered is the preservation of constructive alignment of the assessment task to the intended learning outcomes and teaching/learning activities (biggs and tang, ) . many higher education institutions teach through cadaveric dissection and assess the practical element of learnings through a traditional spotter style format. this will encourage students to construct their knowledge of anatomy through learning activities with a focus on cadaveric material. however, online assessments cannot replicate the wealth of information available in a cadaveric specimen that can act as a retrieval cue for learning that took place during practical classes (ali et al., ) . a switch to online assessment could cause a breakdown of constructive alignment between the teaching learning activity and assessment task. the results highlighted that % of universities identified compromised assessment standards as a significant concern, with "questions around validity and practicality of delivering exams online." one way of mitigating this would be to ensure that images used in online assessments reflect those used during teaching and learning activities. research has suggested that assessment modality does not significantly influence student achievement (attardi and rogers, ) and highlights the need for carefully chosen images with clear orientation (meyer et al., ) . in order to maintain constructive alignment, it is important that new assessment modalities are chosen that best assess the skills students are expected to achieve through their learning. academic collaboration and working remotely. the covid- pandemic presented opportunities for online collaboration between academic peers, both within and between institutions to gain "insight and inspiration" from others that "are facing similar challenges." these were ranked as the main opportunities by % of the universities in this study. additionally, four institutes commented on the opportunity to create new and effective online working environments which particularly highlights the opportunity for remote working in the future. while there were two responses regarding the negative aspects of working from home, they both reflected the impact of the current covid- crisis (i.e., lack of textbooks and childcare responsibilities). already, there has been a wealth of support and resources offered by numerous academics on twitter (tm) (twitter inc., san francisco, ca), facebook (tm) (facebook inc., menlo park, ca), and other social media platforms. in addition, the anatomical society has a collaborative database containing online resources (as, ). an online network, particularly in circumstances such as these can have an impact on academic success (maican et al., ) . external collaborations can act as a source of support and are particularly important in institutions with small teams of anatomists. nurturing these collaborations and developing an online community of practice in the future is a huge opportunity for the anatomical community. this is especially important for the next academic year as the impact of covid- on the body donor program and anatomical education is yet to be fully appreciated. additionally, as many anatomy departments are developing new technological skills in teleconferencing, there is a potential to pool expertise among institutions. it gives departments the opportunity to have "online connections made between peers," to share expertise in anatomical sub-specialties and to showcase cutting-edge anatomical research across satellite campuses, and indeed across institutions worldwide. incorporation of blended learning in future curriculum development. academics reported being excited at the chance to develop new resources as it was the most frequently cited opportunity among the cohort ( % of responders). the decline in the priority of cadavers, and indeed anatomy as a subject, within medical curricula is well documented (drake et al., ; drake et al., ) . with diminished resources including curricula time, budgets, and staffing, in conjunction with increased student numbers, innovative and novel approaches are needed to solve these pressing issues. perhaps covid- could act as a catalyst to do so. fourteen percent of academics suggested that this crisis presented them with an opportunity to develop resources that can be used in the upcoming academic year, allowing them to incorporate more blended learning techniques and review the curriculum. therefore, it is imperative that enough time can be dedicated in order to create high-quality references. reduced student engagement. a frequently expressed concern was diminished student engagement as a function of the rapid implementation of distance learning ( % of responders). on consideration, this may be compounded by the fact that many universities are no longer pursuing typical mandatory attendance policies for teaching sessions. moreover, the current covid- crisis may cause an increased risk of isolation, anxiety, and boredom among the population (rubin and wessely, ) . this was also highlighted by one institution as a major concern among the student population where they were worried about the levels of "anxiety" that students face on "the future of their education." previous studies have shown a decrease in quality of life and stress negatively impacts student motivation and academic results (artino et al., ; lyndon et al., ) . specifically, the responses from this study included comments that highlighted their concerns with "creating resources that students will actively engage with" as well as how to "encourage and maintain student engagement." thus, academics adapting their approach to anatomical education should consider the need for support, interactivity, and social engagement with and between the students. a reduction in these elements may ultimately impede academic progress and student satisfaction. ultimately, one academic expressed they wanted to ensure that students "were getting value for money" from their course. additionally, technical issues, for example, unstable internet connections or lack of suitable electronic devices, will also impact student engagement (wimpenny and savin-baden, ; ilgaz and gülbahar, ) . the unexpected shift to distance learning means that some students may not be technically prepared for distant learning and assessment. therefore, due consideration to accessibility must also be considered as a potential threat to delivery of distance learning and assessment. in conjunction with potential issues in relation to the student population, staff may not have proficient knowledge of pedagogical techniques specific to the delivery of online teaching. some staff members may not have been able to fully evaluate the theoretical and practical implications of distance learning prior to the cessation of face-to-face teaching. this may also impact on their ability to boost student engagement (wimpenny and savin-baden, ) . teacher-student relationship. maintaining the teacherstudent relationship was considered a threat ( % of responders) as online resources lead to a perceived improvement in the online instructor social presence (draus et al., ) . the online instructor presence effectively reduces the transactional distance between student and instructor (attardi et al., ; stone and barry, ) by increasing the likelihood of interaction. one way to address this issue is to host synchronous (live) classes (mcbrien et al., ; o'flaherty and laws, ) . this approach was taken by % of universities that hosted live lectures and % hosted live tutorials to support practical sessions. many synchronous software packages contain interactive polls that can be used to assess knowledge, encourage engagement, and provide instant feedback to students. studies have shown that timely feedback from instructors is hugely important in maintaining engagement (martin and bolliger, ; ragusa and crampton, ) . interactive polling can therefore be utilized in a flipped-classroom approach, shown to increase student interactivity as all levels of bloom's taxonomy can be assessed if correctly designed (gilroy et al., ) . providing clear guided instructions for problem solving and linking content to clinical practice and prior knowledge are other methods that are proven to improve engagement (wimpenny and savin-baden, ; boton and gregory, ; ilgaz and gülbahar, ; buelow et al., ; martin and bolliger, ) . thus, within the synchronous classes, staff can potentially utilize anatomical education software programs to incorporate applied anatomy and clinical scenarios into their sessions. in this regard, there is evidence that virtual synchronous conferencing methods may increase peer-peer and peer-teacher interactions (mcbrien et al., ; o'flaherty and laws, ) . however, in the covid- crisis, synchronous teaching may be deemed unsuitable for a proportion of the student population. students living in different time zones or those with parental and caregiving responsibilities may be unable to attend scheduled synchronous sessions. as synchronous sessions offer potential for interactivity, students unable to attend may feel particularly isolated if departments solely relied on synchronous teaching methods. to address this, interactive asynchronous teaching methods have been employed, for example, twitter (tm) and discussion boards or padlet (tm) (padlet, inc., san francisco, ca) (table ) . a strong teacher-student relationship results in students feeling more comfortable engaging with online communication platforms such as discussion boards (griffiths and graham, ; rose, ). the use of social media has been shown to diminish anxiety and foster a sense of community (hennessy et al., ) . however, if these options are unavailable, adapting resources that are already used across ten institutions in our study can include interactive elements within asynchronous teaching. this includes creating a short video content of problem-solving tasks with recorded audiovisual input from the tutor. such an approach permits students to consistently see and hear their tutor, with the potential to aid in student engagement (wimpenny and savin-baden, ; boton and gregory, ; ilgaz and gülbahar, ; buelow et al., ; martin and bolliger, ) . it is also important to consider the limitations of the methodologies employed and the data presented. first, the presented data are representative of a subset of the total number of medical schools in the uk and roi. it is conceivable that adaptions utilized by an individual institution or minority of universities may have been missed due to inadequate sampling. second, during the data collection process only a single individual was contacted from each institution. it is our presumption that respondents' answers accurately reflect the most commonly utilized adaptations at their respective institutions-though our methodology did not establish this. third, the authors did not sample any universities in scotland. this is important to consider as differing national practices could affect the various adaptations utilized by universities in response to the pandemic. fourth, our survey sought to establish information pertaining to the education of medical students only and did not consider the allied health disciplines. it would be interesting to also identify the adaptations utilized by universities to manage this cohort's education as any niche solution employed could also be translated to the medical cohort. fifth, the survey did not explicitly state that respondents should describe the strengths and weaknesses of the various adaptations implemented by their respective university. the authors believed that incomplete responses would be returned if respondents were required to provide more information. in hindsight, the utility of these adaptations would have been better contextualized if the authors had formally sought for respondents to comment on the strengths and weaknesses of the adaptations implemented at their university. sixth, due to the small sample size, statistics for interval validity were not possible. everyone is currently amid an unprecedented global event. the effects of covid- upon anatomical education, and medical education, are not yet fully understood. changes to curriculum normally take years to research, enforce, and evaluate. however, the current crisis has forced academics to make radial adjustments in a short period of time. the swot analysis and embedded pedagogical theory of these changes has been presented in the hope that anatomists feel more confident in their decision-making. additionally, as the change in anatomical education has been so sudden over the course of the next few months, academics' responses may change and new threats and opportunities may arise. currently, negative effects, such as the time pressure, changes to assessment, and implications in students' engagements and relationship, are somewhat balanced by, positive consequences, such as the potential to create new resources and foster academic collaborations, also arise. indeed, this crisis may be a catalyst for the integration of novel technological resources and the development of stronger ties and collaborations between anatomy departments. it is evident that anatomy departments across the uk and roi are putting tremendous effort into the delivery of high-quality education in the midst of the pandemic. it is hoped that the adaptations utilized by universities will ultimately translate to a lasting positive change in the delivery of anatomical education; and as such there are plans to assess the sustainability of these modalities with a follow-up survey. the authors would like to express their sincerest gratitude to the fellow anatomists who contributed to this study. it is our hope that this crisis leads to the beginning of many new collaborations. georga j. longhurst, b.sc., m.sc. s.p. cert., is a lecturer in anatomical sciences at st george's university of london in london, uk. she teaches anatomy to medical and allied health students. she has a research interest in anatomical education. danya m. stone, b.sc., m.sc., f.h.e.a., is a lecturer in anatomy brighton and sussex medical school (brighton), falmer, uk. she teaches anatomy to medical students and contributes to teaching on multiple external courses. her research interest is in medical education. kate dulohery, b.sc., m.sc., ph.d., f.h.e.a., is a lecturer in anatomy in school of medical education at newcastle university, newcastle upon tyne, uk. she teaches anatomy to medical, dentistry and allied health students and her research interests include incorporation of technology in anatomical education. deidre scully, b.sc., m.sc., ph.d., is a teaching fellow in the department of anatomy, school of medicine at trinity college dublin, the university of dublin, dublin, republic of ireland. she teaches medical and allied health students and her research interests include reproductive biology and anatomical education. thomas acland's video atlas of human anatomy ® covid- and medical education lancet inf dis the perception of anatomy teaching among uk medical students second-year medical students' motivational beliefs, emotions, and achievement improving online interactions. lessons from an online anatomy course with a 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(social distancing) sense of connection, identity and academic success in distance education: sociologically exploring online learning environments student perceptions of the use of instructor-made videos in online and face-to-face classes medical student education in the time of covid- rtÉ. . raidió teilifís Éireann. coronavirus in ireland -a timeline the psychological effects of quarantining a city assessment of spatial anatomical knowledge with a 'three-dimensional multiple choice test' ( d-mc) health education in india: a strengths, weaknesses, opportunities, and threats (swot) analysis hopelessness, helplessness and resilience: the importance of safeguarding our trainees' mental wellbeing during the covid- pandemic key: cord- -n hza vm authors: xu, jie; glicksberg, benjamin s.; su, chang; walker, peter; bian, jiang; wang, fei title: federated learning for healthcare informatics date: - - journal: j healthc inform res doi: . /s - - - sha: doc_id: cord_uid: n hza vm with the rapid development of computer software and hardware technologies, more and more healthcare data are becoming readily available from clinical institutions, patients, insurance companies, and pharmaceutical industries, among others. this access provides an unprecedented opportunity for data science technologies to derive data-driven insights and improve the quality of care delivery. healthcare data, however, are usually fragmented and private making it difficult to generate robust results across populations. for example, different hospitals own the electronic health records (ehr) of different patient populations and these records are difficult to share across hospitals because of their sensitive nature. this creates a big barrier for developing effective analytical approaches that are generalizable, which need diverse, “big data.” federated learning, a mechanism of training a shared global model with a central server while keeping all the sensitive data in local institutions where the data belong, provides great promise to connect the fragmented healthcare data sources with privacy-preservation. the goal of this survey is to provide a review for federated learning technologies, particularly within the biomedical space. in particular, we summarize the general solutions to the statistical challenges, system challenges, and privacy issues in federated learning, and point out the implications and potentials in healthcare. the recent years have witnessed a surge of interest related to healthcare data analytics, due to the fact that more and more such data are becoming readily available from various sources including clinical institutions, patient individuals, insurance companies, and pharmaceutical industries, among others. this provides an unprecedented opportunity for the development of computational techniques to dig data-driven insights for improving the quality of care delivery [ , ] . healthcare data are typically fragmented because of the complicated nature of the healthcare system and processes. for example, different hospitals may be able to access the clinical records of their own patient populations only. these records are highly sensitive with protected health information (phi) of individuals. rigorous regulations, such as the health insurance portability and accountability act (hipaa) [ ] , have been developed to regulate the process of accessing and analyzing such data. this creates a big challenge for modern data mining and machine learning (ml) technologies, such as deep learning [ ] , which typically requires a large amount of training data. federated learning is a paradigm with a recent surge in popularity as it holds great promise on learning with fragmented sensitive data. instead of aggregating data from different places all together, or relying on the traditional discovery then replication design, it enables training a shared global model with a central server while keeping the data in local institutions where the they originate. the term "federated learning" is not new. in , patrick hill, a philosophy professor, first developed the federated learning community (flc) to bring people together to jointly learn, which helped students overcome the anonymity and isolation in large research universities [ ] . subsequently, there were several efforts aiming at building federations of learning content and content repositories [ , , ] . in , rehak et al. [ ] developed a reference model describing how to establish an interoperable repository infrastructure by creating federations of repositories, where the metadata are collected from the contributing repositories into a central registry provided with a single point of discovery and access. the ultimate goal of this model is to enable learning from diverse content repositories. these practices in federated learning community or federated search service have provided effective references for the development of federated learning algorithms. federated learning holds great promises on healthcare data analytics. for both provider (e.g., building a model for predicting the hospital readmission risk with patient electronic health records (ehr) [ ] ) and consumer (patient)-based applications (e.g., screening atrial fibrillation with electrocardiograms captured by smartwatch [ ] ), the sensitive patient data can stay either in local institutions or with individual consumers without going out during the federated model learning process, which effectively protects the patient privacy. the goal of this paper is to review the setup of federated learning, discuss the general solutions and challenges, and envision its applications in healthcare. in this review, after a formal overview of federated learning, we summarize the main challenges and recent progress in this field. then we illustrate the potential of federated learning methods in healthcare by describing the successful recent research. at last, we discuss the main opportunities and open questions for future applications in healthcare. there has been a few review articles on federated learning recently. for example, yang et al. [ ] wrote the early federated learning survey summarizing the general privacy-preserving techniques that can be applied to federated learning. some researchers surveyed sub-problems of federated learning, e.g., personalization techniques [ ] , semi-supervised learning algorithms [ ] , threat models [ ] , and mobile edge networks [ ] . kairouz et al. [ ] discussed recent advances and presented an extensive collection of open problems and challenges. li et al. [ ] conducted the review on federated learning from a system viewpoint. different from those reviews, this paper provided the potential of federated learning to be applied in healthcare. we summarized the general solution to the challenges in federated learning scenario and surveyed a set of representative federated learning methods for healthcare. in the last part of this review, we outlined some directions or open questions in federated learning for healthcare. an early version of this paper is available on arxiv [ ] . federated learning is a problem of training a high-quality shared global model with a central server from decentralized data scattered among large number of different clients (fig. ) . mathematically, assume there are k activated clients where the data reside in (a client could be a mobile phone, a wearable device, or a clinical institution data warehouse, etc.). let d k denote the data distribution associated with client k and fig. schematic of the federated learning framework. the model is trained in a distributed manner: the institutions periodically communicate the local updates with a central server to learn a global model; the central server aggregates the updates and sends back the parameters of the updated global model n k the number of samples available from that client. n = k k= n k is the total sample size. federated learning problem boils down to solving a empirical risk minimization problem of the form [ , , ] : where w is the model parameter to be learned. the function f i is specified via a loss function dependent on a pair of input-output data pair {x i , y i }. typically, x i ∈ r d and y i ∈ r or y i ∈ {− , }. simple examples include: in particular, algorithms for federated learning face with a number of challenges [ , ] , specifically: -statistical challenge: the data distribution among all clients differ greatly, i.e., ∀k =k, we have e . it is such that any data points available locally are far from being a representative sample of the overall distribution, i.e., -communication efficiency: the number of clients k is large and can be much bigger than the average number of training sample stored in the activated clients, i.e., k (n/k). -privacy and security: additional privacy protections are needed for unreliable participating clients. it is impossible to ensure all clients are equally reliable. next, we will survey, in detail, the existing federated learning related works on handling such challenges. the naive way to solve the federated learning problem is through federated averaging (fedavg) [ ] . it is demonstrated can work with certain non independent identical distribution (non-iid) data by requiring all the clients to share the same model. however, fedavg does not address the statistical challenge of strongly skewed data distributions. the performance of convolutional neural networks trained with fedavg algorithm can reduce significantly due to the weight divergence [ ] . existing research on dealing with the statistical challenge of federated learning can be grouped into two fields, i.e., consensus solution and pluralistic solution. most centralized models are trained on the aggregated training samples obtained from the samples drawn from the local clients [ , ] . intrinsically, the centralized model is trained to minimize the loss with respect to the uniform distribution [ ] :d = k k= n k n d k , whered is the target data distribution for the learning model. however, this specific uniform distribution is not an adequate solution in most scenarios. to address this issue, the recent proposed solution is to model the target distribution or force the data adapt to the uniform distribution [ , ] . specifically, mohri et al. [ ] proposed a minimax optimization scheme, i.e., agnostic federated learning (afl), where the centralized model is optimized for any possible target distribution formed by a mixture of the client distributions. this method has only been applied at small scales. compared to afl, li et al. [ ] proposed q-fair federated learning (q-ffl), assigning higher weight to devices with poor performance, so that the distribution of accuracy in the network reduces in variance. they empirically demonstrate the improved flexibility and scalability of q-ffl compared to afl. another commonly used method is globally sharing a small portion of data between all the clients [ , ] . the shared subset is required containing a uniform distribution over classes from the central server to the clients. in addition to handle non-iid issue, sharing information of a small portion of trusted instances and noise patterns can guide the local agents to select compact training subset, while the clients learn to add changes to selected data samples, in order to improve the test performance of the global model [ ] . generally, it is difficult to find a consensus solution w that is good for all components d i . instead of wastefully insisting on a consensus solution, many researchers choose to embracing this heterogeneity. multi-task learning (mtl) is a natural way to deal with the data drawn from different distributions. it directly captures relationships among non-iid and unbalanced data by leveraging the relatedness between them in comparison to learn a single global model. in order to do this, it is necessary to target a particular way in which tasks are related, e.g., sharing sparsity, sharing low-rank structure, and graphbased relatedness. recently, smith et al. [ ] empirically demonstrated this point on real-world federated datasets and proposed a novel method mocha to solve a general convex mtl problem with handling the system challenges at the same time. later, corinzia et al. [ ] introduced virtual, an algorithm for federated multi-task learning with non-convex models. they consider the federation of central server and clients as a bayesian network and perform training using approximated variational inference. this work bridges the frameworks of federated and transfer/continuous learning. the success of multi-task learning rests on whether the chosen relatedness assumptions hold. compared to this, pluralism can be a critical tool for dealing with heterogeneous data without any additional or even low-order terms that depend on the relatedness as in mtl [ ] . eichner et al. [ ] considered training in the presence of block-cyclic data and showed that a remarkably simple pluralistic approach can entirely resolve the source of data heterogeneity. when the component distributions are actually different, pluralism can outperform the "ideal" iid baseline. in federated learning setting, training data remain distributed over a large number of clients each with unreliable and relatively slow network connections. naively for synchronous protocol in federated learning [ , ] , the total number of bits that required during uplink (clinets → server) and downlink (server → clients) communication by each of the k clients during training is given by: where u is the total number of updates performed by each client, |w| is the size of the model and h ( w up/down ) is the entropy of the weight updates exchanged during transmitting process. β is the difference between the true update size and the minimal update size (which is given by the entropy) [ ] . apparently, we can consider three ways to reduce the communication cost: (a) reduce the number of clients k, (b) reduce the update size, (c) reduce the number of updates u . starting at these three points, we can organize existing research on communication-efficient federated learning into four groups, i.e., model compression, client selection, updates reducing, and peer-to-peer learning (fig. ). the most natural and rough way for reducing communication cost is to restrict the participated clients or choose a fraction of parameters to be updated at each round. shokri et al. [ ] use the selective stochastic gradient descent protocol, where the selection can be completely random or only the parameters whose current values are farther away from their local optima are selected, i.e., those that have a larger gradient. nishio et al. [ ] proposed a new protocol referred to as fedcs, where the central server manages the resources of heterogeneous clients and determines which clients should participate the current training task by analyzing the resource information of each client, such as wireless channel states, computational capacities, and the size of data resources relevant to the current task. here, the server should decide how much data, energy, and cpu resources used by the mobile devices such that the energy consumption, training latency, and bandwidth cost are minimized while meeting requirements of the training tasks. anh [ ] thus proposes to use the deep q-learning [ ] technique that enables the server to find the optimal data and energy management for the mobile devices participating in the mobile crowdmachine learning through federated learning without any prior knowledge of network dynamics. the goal of model compression is to compress the server-to-client exchanges to reduce uplink/downlink communication cost. the first way is through structured updates, where the update is directly learned from a restricted space parameterized using a smaller number of variables, e.g., sparse, low-rank [ ] , or more specifically, pruning the least useful connections in a network [ , ] , weight quantization [ , ] , and model distillation [ ] . the second way is lossy compression, where a full model update is first learned and then compressed using a combination of quantization, random rotations, and subsampling before sending it to the server [ , ] . then the server decodes the updates before doing the aggregation. federated dropout, in which each client, instead of locally training an update to the whole global model, trains an update to a smaller sub-model [ ] . these submodels are subsets of the global model and, as such, the computed local updates have a natural interpretation as updates to the larger global model. federated dropout not only reduces the downlink communication but also reduces the size of uplink updates. moreover, the local computational costs is correspondingly reduced since the local training procedure dealing with parameters with smaller dimensions. kamp et al. [ ] proposed to average models dynamically depending on the utility of the communication, which leads to a reduction of communication by an order of magnitude compared to periodically communicating state-of-the-art approaches. this facet is well suited for massively distributed systems with limited communication infrastructure. bui et al. [ ] improved federated learning for bayesian neural networks using partitioned variational inference, where the client can decide to upload the parameters back to the central server after multiple passes through its data, after one local epoch, or after just one mini-batch. guha et al. [ ] focused on techniques for one-shot federated learning, in which they learn a global model from data in the network using only a single round of communication between the devices and during the computation, no computation node is able to recover the original value nor learn anything about the output (green pie). any nodes can combine their shares to reconstruct the original value. b differential privacy. it guarantees that anyone seeing the result of a differentially private analysis will make the same inference (answer and answer are nearly indistinguishable) the central server. besides above works, ren et al. [ ] theoretically analyzed the detailed expression of the learning efficiency in the cpu scenario and formulate a training acceleration problem under both communication and learning resource budget. reinforcement learning and round robin learning are widely used to manage the communication and computation resources [ , , , ]. in federated learning, a central server is required to coordinate the training process of the global model. however, the communication cost to the central server may be not affordable since a large number of clients are usually involved. also, many practical peer-to-peer networks are usually dynamic, and it is not possible to regularly access a fixed central server. moreover, because of the dependence on central server, all clients are required to agree on one trusted central body, and whose failure would interrupt the training process for all clients. therefore, some researches began to study fully decentralized framework where the central server is not required [ , , , ] . the local clients are distributed over the graph/network where they only communicate with their one-hop neighbors. each client updates its local belief based on own data and then aggregates information from the one-hop neighbors. in federated learning, we usually assume the number of participated clients (e.g., phones, cars, clinical institutions...) is large, potentially in the thousands or millions. it is impossible to ensure none of the clients is malicious. the setting of federated learning, where the model is trained locally without revealing the input data or the model's output to any clients, prevents direct leakage while training or using the model. however, the clients may infer some information about another client's private dataset given the execution of f (w), or over the shared predictive model w [ ] . to this end, there have been many efforts focus on privacy either from an individual point of view or multiparty views, especially in social media field which significantly exacerbated multiparty privacy (mp) conflicts [ , ] (fig. ). secure multi-party computation (smc) has a natural application to federated learning scenarios, where each individual client uses a combination of cryptographic techniques and oblivious transfer to jointly compute a function of their private data [ , ] . homomorphic encryption is a public key system, where any party can encrypt its data with a known public key and perform calculations with data encrypted by others with the same public key [ ] . due to its success in cloud computing, it comes naturally into this realm, and it has certainly been used in many federated learning researches [ , ] . although smc guarantees that none of the parties shares anything with each other or with any third party, it can not prevent an adversary from learning some individual information, e.g., which clients' absence might change the decision boundary of a classifier, etc. moreover, smc protocols are usually computationally expensive even for the simplest problems, requiring iterated encryption/decryption and repeated communication between participants about some of the encrypted results [ ] . differential privacy (dp) [ ] is an alternative theoretical model for protecting the privacy of individual data, which has been widely applied to many areas, not only traditional algorithms, e.g., boosting [ ] , principal component analysis [ ] , support vector machine [ ] , but also deep learning research [ , ] . it ensures that the addition or removal does not substantially affect the outcome of any analysis and is thus also widely studied in federated learning research to prevent the indirect leakage [ , , ] . however, dp only protects users from data leakage to a certain extent and may reduce performance in prediction accuracy because it is a lossy method [ ] . thus, some researchers combine dp with smc to reduce the growth of noise injection as the number of parties increases without sacrificing privacy while preserving provable privacy guarantees, protecting against extraction attacks and collusion threats [ , ] . federated learning has been incorporated and utilized in many domains. this widespread adoption is due in part by the fact that it enables a collaborative modeling mechanism that allows for efficient ml all while ensuring data privacy and legal compliance between multiple parties or multiple computing nodes. some promising examples that highlight these capabilities are virtual keyboard prediction [ , ] , smart retail [ ] , finance [ ] , and vehicle-to-vehicle communication [ ] . in this section, we focus primarily on applications within the healthcare space and also discuss promising applications in other domains since some principles can be applied to healthcare. ehrs have emerged as a crucial source of real world healthcare data that has been used for an amalgamation of important biomedical research [ , ] , including for machine learning research [ ] . while providing a huge amount of patient data for analysis, ehrs contain systemic and random biases overall and specific to hospitals that limit the generalizability of results. for example, obermeyer et al. [ ] found that a commonly used algorithm to determine enrollment in specific health programs was biased against african americans, assigning the same level of risk to healthier caucasian patients. these improperly calibrated algorithms can arise due to a variety of reasons, such as differences in underlying access to care or low representation in training data. it is clear that one way to alleviate the risk for such biased algorithms is the ability to learn from ehr data that is more representative of the global population and which goes beyond a single hospital or site. unfortunately, due to a myriad of reasons such as discrepant data schemes and privacy concerns, it is unlikely that data will eve be connected together in a single database to learn from all at once. the creation and utility of standardized common data models, such as omop [ ] , allow for more wide-spread replication analyses but it does not overcome the limitations of joint data access. as such, it is imperative that alternative strategies emerge for learning from multiple ehr data sources that go beyond the common discoveryreplication framework. federated learning might be the tool to enable large-scale representative ml of ehr data and we discuss many studies which demonstrate this fact below. federated learning is a viable method to connect ehr data from medical institutions, allowing them to share their experiences, and not their data, with a guarantee of privacy [ , , , , , ] . in these scenarios, the performance of ml model will be significantly improved by the iterative improvements of learning from large and diverse medical data sets. there have been some tasks were studied in federated learning setting in healthcare, e.g., patient similarity learning [ ] , patient representation learning, phenotyping [ , ] , and predictive modeling [ , , ] . specifically, lee et al. [ ] presented a privacy-preserving platform in a federated setting for patient similarity learning across institutions. their model can find similar patients from one hospital to another without sharing patient-level information. kim et al. [ ] used tensor factorization models to convert massive electronic health records into meaningful phenotypes for data analysis in federated learning setting. liu et al. [ ] conducted both patient representation learning and obesity comorbidity phenotyping in a federated manner and got good results. vepakomma et al. [ ] built several configurations upon a distributed deep learning method called splitnn [ ] to facilitate the health entities collaboratively training deep learning models without sharing sensitive raw data or model details. silva et al. [ ] illustrated their federated learning framework by investigating brain structural relationships across diseases and clinical cohorts. huang et al. [ ] sought to tackle the challenge of non-iid icu patient data by clustering patients into clinically meaningful communities that captured similar diagnoses and geological locations and simultaneously training one model per community. federated learning has also enabled predictive modeling based on diverse sources, which can provide clinicians with additional insights into the risks and benefits of treating patients earlier [ , , ] . brisimi et al. [ ] aimed to predict future hospitalizations for patients with heart-related diseases using ehr data spread among various data sources/agents by solving the l -regularized sparse support vector machine classifier in federated learning environment. owkin is using federated learning to predict patients' resistance to certain treatment and drugs, as well as their survival rates for certain diseases [ ] . boughorbel et al. [ ] proposed a federated uncertaintyaware learning algorithm for the prediction of preterm birth from distributed ehr, where the contribution of models with high uncertainty in the aggregation model is reduced. pfohl et al. [ ] considered the prediction of prolonged length of stay and in-hospital mortality across thirty-one hospitals in the eicu collaborative research database. sharma et al. [ ] tested a privacy preserving framework for the task of in-hospital mortality prediction among patients admitted to the intensive care unit (icu). their results show that training the model in the federated learning framework leads to comparable performance to the traditional centralized learning setting. summary of these work is listed in table . an important application of federated learning is for natural language processing (nlp) tasks. when google first proposed federated learning concept in , the application scenario is gboard-a virtual keyboard of google for touchscreen mobile devices with support for more than language varieties [ , ] . indeed, as users increasingly turn to mobile devices, fast mobile input methods with auto-correction, word completion, and next-word prediction features are becoming more and more important. for these nlp tasks, especially next-word prediction, typed text in mobile apps is usually better than the data from scanned books or speech-to-text in terms of aiding typing on a mobile keyboard. however, these language data often contain sensitive information, e.g., passwords, search queries, or text messages with personal information. therefore, federated learning has a promising application in nlp like virtual keyboard prediction [ , , ] . other applications include smart retail [ ] and finance [ ] . specifically, smart retail aims to use machine learning technology to provide personalized services to customers based on data like user purchasing power and product characteristics for product recommendation and sales services. in terms of financial applications, tencent's webank leverages federated learning technologies for credit risk management, where several banks could jointly generate a comprehensive credit score for a customer without sharing his or her data [ ] . with the growth and development of federated learning, there are many companies or research teams that have carried out various tools oriented to scientific research and product development. popular ones are listed in table . in this survey, we review the current progress on federated learning including, but not limited to healthcare field. we summarize the general solutions to the various challenges in federated learning and hope to provide a useful resource for researchers to refer. besides the summarized general issues in federated learning setting, we list some probably encountered directions or open questions when federated learning is applied in healthcare area in the following. -data quality. federated learning has the potential to connect all the isolated medical institutions, hospitals, or devices to make them share their experiences with privacy guarantee. however, most health systems suffer from data clutter and efficiency problems. the quality of data collected from multiple sources is uneven and there is no uniform data standard. the analyzed results are apparently worthless when dirty data are accidentally used as samples. the ability to strategically leverage medical data is critical. therefore, how to clean, correct, and complete data and accordingly ensure data quality is a key to improve the machine learning model weather we are dealing with federated learning scenario or not. -incorporating expert knowledge. in , ibm introduced watson for oncology, a tool that uses the natural language processing system to summarize patients' electronic health records and search the powerful database behind it to advise doctors on treatments. unfortunately, some oncologists say they trust their judgment more than watson tells them what needs to be done. therefore, hopefully doctors will be involved in the training process. since every data set collected here cannot be of high quality, so it will be very helpful if the standards of evidence-based machine are introduced, doctors will also see the diagnostic criteria of artificial intelligence. if wrong, doctors will give further guidance to artificial intelligence to improve the accuracy of machine learning model during training process." -incentive mechanisms. with the internet of things and the variety of third party portals, a growing number of smartphone healthcare apps are compatible with wearable devices. in addition to data accumulated in hospitals or medical centers, another type of data that is of great value is coming from wearable devices not only to the researchers but more importantly for the owners. however, during federated model training process, the clients suffer from considerable overhead in communication and computation. without well-designed incentives, self-interested mobile or other wearable devices will be reluctant to participate in federal learning tasks, which will hinder the adoption of federated learning [ ] . how to design an efficient incentive mechanism to attract devices with high-quality data to join federated learning is another important problem. -personalization. wearable devices are more focus on public health, which means helping people who are already healthy to improve their health, such as helping them exercise, practice meditation, and improve their sleep quality. how to assist patients to carry out scientifically designed personalized health management, correct the functional pathological state by examining indicators, and interrupt the pathological change process are very important. reasonable chronic disease management can avoid emergency visits and hospitalization and reduce the number of visits. cost and labor savings. although there are some general work about federated learning personalization [ , ] , for healthcare informatics, how to combining the medical domain knowledge and make the global model be personalized for every medical institutions or wearable devices is another open question. -model precision. federated tries to make isolated institutions or devices share their experiences, and the performance of machine learning model will be significantly improved by the formed large medical dataset. however, the prediction task is currently restricted and relatively simple. medical treatment itself is a very professional and accurate field. medical devices in hospitals have incomparable advantages over wearable devices. and the models of doc.ai could predict the phenome collection of one's biometric data based on its selfie, such as height, weight, age, sex, and bmi. how to improve the prediction model to predict future health conditions is definitely worth exploring. funding the work is supported by onr n - - - and nsf . fw would also like to acknowledge the support from amazon aws machine learning research award and google faculty research award. deep learning with differential privacy cpsgd: communication-efficient and differentially-private distributed sgd federated ai technology enabler human activity recognition on smartphones using a multiclass hardware-friendly support vector machine efficient training management for mobile crowd-machine learning: a deep 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for adaptive privacy preserving federated learning in healthcare ketos: clinical decision support and machine learning as a service-a training and deployment platform based on docker one-shot federated learning distributed learning of deep neural network over multiple agents deep compression: compressing deep neural networks with pruning, trained quantization and huffman coding robust federated training via collaborative machine teaching using trusted instances federated learning for mobile keyboard prediction private federated learning on vertically partitioned data via entity resolution and additively homomorphic encryption central server free federated learning over single-sided trust social networks the rationale for learning communities and learning community models distilling the knowledge in a neural network observational health data sciences and informatics (ohdsi): opportunities for observational researchers patient clustering improves efficiency of federated machine learning 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learning with heterogeneous resources in mobile edge dissecting racial bias in an algorithm used to manage the health of populations multiparty differential privacy via aggregation of locally trained classifiers large-scale assessment of a smartwatch to identify atrial fibrillation federated and differentially private learning for electronic health records the eicu collaborative research database, a freely available multi-center database for critical care research modern framework for distributed healthcare data analytics based on hadoop a model and infrastructure for federated learning content repositories accelerating dnn training in wireless federated edge learning system braintorrent: a peer-to-peer environment for decentralized federated learning learning in a large function space: privacypreserving mechanisms for svm learning a generic framework for privacy preserving deep learning federated learning for ultra-reliable lowlatency v v communications robust and communication-efficient federated learning from non-iid data preserving patient privacy while training a predictive model of in-hospital mortality biscotti: a ledger for private and secure peer-topeer machine learning privacy-preserving deep learning federated learning in distributed medical databases: meta-analysis of large-scale subcortical brain data an investigation into on-device personalization of end-to-end automatic speech recognition models using the adap learning algorithm to forecast the onset of diabetes mellitus federated multi-task learning multiparty privacy in social media unfriendly: multi-party privacy risks in social networks federated learning: rewards & challenges of distributed private ml a hybrid approach to privacy-preserving federated learning federated learning of electronic health records improves mortality prediction in patients hospitalized with covid- medrxiv deep reinforcement learning with double q-learning split learning for health: distributed deep learning without sharing raw patient data ai in health: state of the art, challenges, and future directions -edge ai: intelligentizing mobile edge computing, caching and communication by federated learning federated learning for healthcare informatics federated patient hashing federated machine learning: concept and applications a federated learning framework for healthcare iot devices federated learning with non-iid data mobile edge computing, blockchain and reputationbased crowdsourcing iot federated learning: a secure, decentralized and privacy-preserving system multi-objective evolutionary federated learning federated reinforcement learning publisher's note springer nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations conflict of interest the authors declare that they have no conflict of interest. key: cord- -qbmm st authors: nguyen, thanh thi title: artificial intelligence in the battle against coronavirus (covid- ): a survey and future research directions date: - - journal: nan doi: nan sha: doc_id: cord_uid: qbmm st artificial intelligence (ai) has been applied widely in our daily lives in a variety of ways with numerous successful stories. ai has also contributed to dealing with the coronavirus disease (covid- ) pandemic, which has been happening around the globe. this paper presents a survey of ai methods being used in various applications in the fight against the covid- outbreak and outlines the crucial roles of ai research in this unprecedented battle. we touch on a number of areas where ai plays as an essential component, from medical image processing, data analytics, text mining and natural language processing, the internet of things, to computational biology and medicine. a summary of covid- related data sources that are available for research purposes is also presented. research directions on exploring the potentials of ai and enhancing its capabilities and power in the battle are thoroughly discussed. we highlight groups of problems related to the covid- pandemic and point out promising ai methods and tools that can be used to solve those problems. it is envisaged that this study will provide ai researchers and the wider community an overview of the current status of ai applications and motivate researchers in harnessing ai potentials in the fight against covid- . t he novel coronavirus disease (covid- ) has created tremendous chaos around the world, affecting people's lives and causing a large number of deaths. since the first cases were detected, the disease has spread to almost every country, causing deaths of over , people among nearly , , confirmed cases based on statistics of the world health organization in the middle of july [ ] . governments of many countries have proposed intervention policies to mitigate the impacts of the covid- pandemic. science and technology have contributed significantly to the implementations of these policies during this unprecedented and chaotic time. for example, robots are used in hospitals to deliver food and medicine to coronavirus patients or drones are used to disinfect streets and public spaces. many medical researchers are rushing to investigate drugs and medicines to treat infected patients whilst others are attempting to develop vaccines to prevent the virus. computer science researchers on the other hand have managed to early detect infectious patients using techniques that can process and understand medical imaging data such as x-ray images and computed tomography (ct) scans. these computational techniques are part of artificial intelligence (ai), which has been applied successfully in various fields. this paper focuses on the roles of ai technologies in the battle against the covid- pandemic. we provide a comprehensive survey of ai t. t. nguyen is with the school of information technology, deakin university, victoria, , australia. e-mail: thanh.nguyen@deakin.edu.au. applications that support humans to reduce and suppress the substantial impacts of the outbreak. recent advances in ai have contributed significantly to improving humans' lives and thus there is a strong belief that proper ai research plans will fully exploit the power of ai in helping humans to defeat this challenging battle. we discuss about these possible plans and highlight ai research areas that could bring great benefits and contributions to overcome the battle. in addition, we present a summary of covid- related data sources to facilitate future studies using ai methods to deal with the pandemic. an overview of common ai methods is presented in fig. where recent ai development is highlighted. machine learning, especially deep learning, has made great advances and substantial progress in long-standing fields such as computer vision, natural language processing (nlp), speech recognition, and video games. a significant advantage of deep learning over traditional machine learning techniques is its ability to deal with and make sense of different types of data, especially big and unstructured data, e.g. text, image, video and audio data. a number of industries, e.g. electronics, automotive, security, retail, agriculture, healthcare and medical research, have achieved better outcomes and benefits by using deep learning and ai methods. it is thus expected that ai technologies can contribute to the fight against the covid- pandemic, such as those surveyed in the next section. we separate surveyed papers into different groups that include: deep learning algorithms for medical image processing, data science methods for pandemic modelling, ai and the internet of things (iot), ai for text mining and nlp, and ai in computational biology and medicine. while radiologists and clinical doctors can learn to detect covid- cases based on chest ct examinations, their tasks are manual and time consuming, especially when required to examine a lot of cases. bai et al. [ ] convenes three chinese and four united states radiologists to differentiate covid- from other viral pneumonia based on chest ct images obtained from a cohort of cases, in which cases are from the united states with non-covid- pneumonia whilst cases are from china positive with covid- . results obtained show that radiologists can achieve high specificity (which refers to the proportion of actual positives that are correctly identified as such) in distinguishing covid- from other causes of viral pneumonia using chest ct imaging data. however, their performance in terms of sensitivity (which fig. . an overview of common ai methods where machine learning constitutes a great proportion. the development of deep learning, a subset of machine learning, has contributed significantly to improving the power and capabilities of recent ai applications. a number of deep learning-based convolutional neural network (cnn) architectures, e.g. lenet [ ] , alexnet [ ] , googlenet [ ] , visual geometry group (vgg) net [ ] and resnet [ ] , have been proposed and applied successfully in different areas, especially in the computer vision domain. other techniques such as autoencoders and recurrent neural networks are crucial components of many prominent natural language processing tools. the deep learning methods in particular and ai in general may thus be employed to create useful applications to deal with various aspects of the covid- pandemic. refers to the proportion of actual negatives that are correctly identified as such) is just moderate for the same task. ai methods, especially deep learning, have been used to process and analyse medical imaging data to support radiologists and doctors to improve diagnosis performance. likewise, the current covid- pandemic has witnessed a number of studies focusing on automatic detection of covid- using deep learning systems. a three-dimensional deep learning method, namely covid- detection neural network (covnet), is introduced in [ ] to detect covid- based on volumetric chest ct images. three kinds of ct images, including covid- , community acquired pneumonia (cap) and other non-pneumonia cases, are mixed to test the robustness of the proposed model, which is illustrated in fig. . these images are collected from hospitals in china and the detection method is evaluated by the area under the receiver operating characteristic curve (auc). covnet is a convolutional resnet- model [ ] that takes a series of ct slices as inputs and predicts the class labels of the ct images via its outputs. the auc value obtained is at . , which shows a great ability of the proposed model for detecting covid- cases. another deep learning method based on the concatenation between the location-attention mechanism and the threedimensional cnn resnet- network [ ] is proposed in [ ] to detect coronavirus cases using pulmonary ct images. distinct manifestations of ct images of covid- found in previous [ ] for covid- detection using ct images. max pooling operation is used to combine features extracted by resnet- cnns whose inputs are ct slices. the combined features are fed into a fully connected layer to compute probabilities for three classes, i.e. non-pneumonia, community acquired pneumonia (cap) and covid- . predicted class is the one that has highest probability among the three classes. studies [ ] , [ ] and their differences with those of other types of viral pneumonia such as influenza-a are exploited through the proposed deep learning system. a dataset comprising ct images of covid- cases, influenza-a viral pneumonia patients and healthy cases is used to validate the performance of the proposed method. the method's overall accuracy of approximately % is obtained on this dataset, which exhibits its ability to help clinical doctors to early screen covid- patients using chest ct images. in line with the studies described above, we have found a number of papers also applying deep learning for covid- diagnosis using radiology images. they are summarized in table i for comparisons. a modified stacked autoencoder deep learning model is used in [ ] to forecast in real-time the covid- confirmed cases across china. this modified autoencoder network includes four layers, i.e. input, first latent layer, second latent layer and output layer, with the number of nodes correspondingly is , , and . a series of data points ( days) are used as inputs of the network. the latent variables obtained from the second latent layer of the autoencoder model are processed by the singular value decomposition method before being fed into clustering algorithms in order to group the cases into provinces or cities to investigate the transmission dynamics of the pandemic. the resultant errors of the model are low, which give confidence that it can be applied to forecast accurately the transmission dynamics of the virus as a helpful tool for public health planning and policy-making. on the other hand, a prototype of an ai-based system, namely α-satellite, is proposed in [ ] to assess the infectious risk of a given geographical area at community levels. the system collects various types of large-scale and real-time data from heterogeneous sources, such as number of cases and deaths, demographic data, traffic density and social media data, e.g., reddit posts. the social media data available for a given area may be limited so that they are enriched by the conditional generative adversarial networks (gans) [ ] to learn the public awareness of covid- . a heterogeneous graph autoencoder model is then devised to aggregate information from neighbourhood areas of the given area in order to estimate its risk indexes. this risk information enables residents to select appropriate actions to prevent them from the virus infection with minimum disruptions in their daily lives. it is also useful for authorities to implement appropriate mitigation strategies to combat the fast evolving pandemic. chang et al. [ ] modify a discrete-time and stochastic agent-based model, namely acemod (australian censusbased epidemic model), previously used for influenza pandemic simulation [ ] , [ ] , for modelling the covid- pandemic across australia over time. each agent exemplifies an individual characterized by a number of attributes such as age, occupation, gender, susceptibility and immunity to diseases and contact rates. the acemod is calibrated to model specifics of the covid- pandemic based on key disease transmission parameters. several intervention strategies including social distancing, school closures, travel bans, and case isolation are then evaluated using this tuned model. results obtained from the experiments show that a combination of several strategies is needed to mitigate and suppress the covid- pandemic. the best approach suggested by the model is to combine international arrival restrictions, case isolation and social distancing in at least weeks with the compliance level of % or above. a framework for covid- detection using data obtained from smartphones' onboard sensors such as cameras, microphones, temperature and inertial sensors is proposed in [ ] . machine learning methods are employed for learning and acquiring knowledge about the disease symptoms based on the collected data. this offers a low-cost and quick approach to coronavirus detection compared to medical kits or ct scan methods. this is arguably plausible because data obtained from the smartphones' sensors have been utilized effectively in different individual applications and the proposed approach integrates these applications together in a unique framework. for instance, data obtained from the temperature-fingerprint sensor can be used for fever level prediction [ ] . images and videos taken by smartphones' camera or data collected by the onboard inertial sensors can be used for human fatigue detection [ ] , [ ] . likewise, story et al. [ ] use smartphone's videos for nausea prediction whilst lawanont et al. [ ] use camera images and inertial sensors' measurements for neck posture monitoring and human headache level prediction. alternatively, audio data obtained from smartphone's microphone are used for cough type detection in [ ] , [ ] . an approach to collecting individuals' basic travel history and their common manifestations using a phone-based online survey is proposed in [ ] . these data are valuable for machine learning algorithms to learn and predict the infection risk of each individual, thus help to early identify high-risk cases for quarantine purpose. this contributes to reducing the spread of the virus to the susceptible populations. in another work, allam and jones [ ] suggest the use of ai and data sharing standardization protocols for better global understanding and management of urban health during the covid- pandemic. for example, added benefits can be obtained if ai is integrated with thermal cameras, which might have been installed in many smart cities, for early detection of the outbreak. ai methods can also demonstrate their great effectiveness in supporting managers to make better decisions for virus containment when loads of urban health data are collected by data sharing across and between smart cities using the proposed protocols. a hybrid ai model for covid- infection rate forecasting is proposed in [ ] , which combines the epidemic susceptible infected (si) model, nlp and deep learning tools. the si model and its extension, i.e. susceptible infected recovered (sir), are traditional epidemic models for modelling and predicting the development of infectious diseases where s represents the number of susceptible people, i denotes the number of infected people and r specifies the recovered cases. using differential equations to characterize the relationship between i, s and r, these models have been used to predict successfully sars and ebola infected cases, as reported in [ ] and [ ] respectively. nlp is employed to extract semantic features from related news such as epidemic control measures of governments or residents' disease prevention awareness. these features are then served as inputs to the long short-term memory (lstm) deep learning model [ ] to revise the infection rate predictions of the si model (detailed in fig. ). epidemic data of wuhan, beijing, shanghai and the whole china are used for experiments, which demonstrate the great accuracy of the proposed hybrid model. it can be applied to predict the covid- transmission law and development trend, and thus useful for establishing prevention and control measures for future pandemics. that study also shows the importance of public awareness of governmental epidemic prevention policies and the significant role of transparency and openness of epidemic reports and news in containing the development of infectious diseases. fig. . an ai-based approach to covid- prediction that combines traditional epidemic si model, nlp and machine learning tools as introduced in [ ] . a pre-trained nlp model is used to extract nlp features from text data, i.e. the pandemic news, reports, prevention and control measures. these features are integrated with infection rate features obtained from the si model via multilayer perceptron (mlp) networks before being fed into lstm model for covid- case modelling and prediction. in another work, lopez et al. [ ] recommend the use of network analysis techniques as well as nlp and text mining to analyse a multilanguage twitter dataset to understand changing policies and common responses to the covid- outbreak across time and countries. since the beginning of the pandemic, governments of many countries have tried to implement policies to mitigate the spread of the virus. responses of people to the pandemic and to the governmental policies may be collected from social media platforms such as twitter. much of information and misinformation is posted through these platforms. when stricter policies such as social distancing and country lockdowns are applied, people's lives are changed considerably and part of that can be observed and captured via people's reflections on social media platforms as well. analysis results of these data can be helpful for governmental decision makers to mitigate the impacts of the current pandemic and prepare better policies for possible future pandemics. likewise, three machine learning methods including support vector machine (svm), naive bayes and random forest are used in [ ] to classify , covid- related posts collected from sina weibo, which is the chinese equivalent of twitter, into seven types of situational information. identifying situational information is important for authorities because it helps them to predict its propagation scale, sense the mood of the public and understand the situation during the crisis. this contributes to creating proper response strategies throughout the covid- pandemic. being able to predict structures of a protein will help understand its functions. google deepmind is using the latest version of their protein structure prediction system, namely alphafold [ ] , to predict structures of several proteins associated with covid- based on their corresponding amino acid sequences. they have released the predicted structures in [ ] , but these structures still need to be experimentally verified. nevertheless, it is expected that these predictions will help understand how the coronavirus functions and potentially lead to future development of therapeutics against covid- . an ai-based generative chemistry approach to design novel molecules that can inhibit covid- is proposed in [ ] . several generative machine learning models, e.g. generative autoencoders, gans, genetic algorithms and language models, are used to exploit molecular representations to generate structures, which are then optimized using reinforcement learning methods. this is an ongoing work as the authors are synthesising and testing the obtained molecules. however, it is a promising approach because these ai methods can exploit the large drug-like chemical space and automatically extract useful information from high-dimensional data. it is thus able to construct molecules without manually designing features and learning the relationships between molecular structures and their pharmacological properties. the proposed approach is cost-effective and time-efficient and has a great potential to generate novel drug compounds in the covid- fight. on the other hand, randhawa et al. [ ] aim to predict the taxonomy of covid- based on an alignment-free machine learning method [ ] using genomic signatures and a decision tree approach. the alignment-free method is a computationally inexpensive approach that can give rapid taxonomic classification of novel pathogens by processing only raw dna sequence data. by analysing over unique viral sequences, the authors are able to confirm the taxonomy of covid- as belonging to the subgenus sarbecovirus of the genus betacoronavirus, as previously found in [ ] . the proposed method also provides quantitative evidence that supports a hypothesis about a bat origin for covid- as indicated in [ ] , [ ] . recently, nguyen et al. [ ] propose the use of ai-based clustering methods and more than genome sequences to search for the origin of the covid- virus. numerous clustering experiments are performed on datasets that combine sequences of the covid- virus and those of reference viruses of various types. results obtained show that covid- virus genomes consistently form a cluster with those of bat and pangolin coronaviruses. that provides quantitative evidences to support the hypotheses that bats and pangolins may have served as the hosts for the covid- virus. their findings also suggest that bats are the more probable origin of the virus than pangolins. ai methods thus have demonstrated their capabilities and power for mining big biological datasets in an efficient and intelligent manner, which contributes to the progress of finding vaccines, therapeutics or medicines for covid- . this section summarises available data sources relevant to covid- , ranging from numerical data of infection cases, radiology images [ ] , twitter, text, natural language to biological sequence data (table ii) , and highlights potential ai methods for modelling different types of data. the data are helpful for research purposes to exploit the capabilities and power of ai technologies in the battle against covid- . different data types have different characteristics and thus require different ai methods to handle. for example, numerical time series data of infection cases can be dealt with by traditional machine learning methods such as naive bayes, logistic regression, k-nearest neighbors (knn), svm, mlp, fuzzy logic system [ ] , nonparametric gaussian process [ ] , decision tree, random forest, and ensemble learning algorithms [ ] . deep learning recurrent neural networks such as lstm [ ] can be used for regression prediction problems if a large amount of training data are available. the deeper the models, the more data are needed to enable the models to learn effectively from data. based on their ability to characterize temporal dynamic behaviours, recurrent networks are well suited for modelling infection case time series data. radiology images such as chest x-ray and ct scans are high-dimensional data that require processing capabilities of deep learning methods in which cnn-based models are common and most suitable (e.g. lenet [ ] , alexnet [ ] , googlenet [ ] , vgg net [ ] and resnet [ ] ). cnns were inspired by biological processes of visual cortex of human and animal brains where each cortical neuron is activated within its receptive field when stimulated. a receptive field of a neuron covers a specific subarea of the visual field and thus the entire visual field can be captured by a partial overlap of receptive fields. a cnn consists of multiple layers where each neuron of a subsequent (higher) layer connects to a subset of neurons in the previous (lower) layer. this allows the receptive field of a neuron of a higher layer covers a larger portion of images compared to that of a lower layer. the higher layer is able to learn more abstract features of images than the lower layer by taking into account the spatial relationships between different receptive fields. this use of receptive fields enables cnns to recognize visual patterns and capture features from images without prior knowledge or making hand-crafted features as in traditional machine learning approaches. this principle is applied to different cnn architectures although they may differ in the number of layers, number of neurons in each layer, the use of activation and loss functions as well as regularization and learning algorithms [ ] . transfer learning methods can be used to customize cnn models, which have been pretrained on large medical image datasets, for the covid- diagnosis problem. this would avoid training a cnn from scratch and thus reduce training time and the need for covid- radiology images, which may not be sufficiently available in the early stage of the pandemic. alternatively, unstructured natural language data need text mining tools, e.g. natural language toolkit (nltk) [ ] , and advanced nlp and natural language generation (nlg) data type links johns hopkins university [ ] web-based mapping global cases https://systems.jhu.edu/research/public-health/ncov/ c. r. wells's github [ ] daily incidence data and airport connectivity from china [ ] , text-to-text transfer transformer (t ) [ ] , binary-partitioning transformer (bpt) [ ] and openais generative pretrained transformer (gpt- ) [ ] . the core components of these tools are deep learning and transfer learning methods. for example, elmo and ulm-fit are built using lstm-based language models while transformer utilizes an encoder-decoder structure. likewise, bert and ernie use multi-layer transformer as a basic encoder while xlnet is a generalized autoregressive pretraining method inherited from transformer-xl. transformer also serves as a basic model for t , bpt and gpt- . these are excellent tools for many nlp and nlg tasks to handle text and natural language data related to covid- . analysing biological sequence data such as viral genomic and proteomic sequences requires either traditional machine learning or advanced deep learning or a combination of both depending on problems being addressed and data pipelines used. as an example, traditional clustering methods, e.g. hierarchical clustering and density-based spatial clustering of applications with noise (dbscan) [ ] , can be employed to find the virus origin using genomic sequences [ ] . alternatively, a fuzzy logic system can be used to predict protein secondary structures based on quantitative properties of amino acids, which are used to encode the twenty common amino acids [ ] . a combination between principal component analysis and lasso (least absolute shrinkage and selection operator) can be used as a supervised approach for analysing single-nucleotide polymorphism genetic variation data [ ] . advances in deep learning may be utilized for protein structure prediction using protein amino acid sequences as in [ ] , [ ] . an overview on the use of various types of machine learning and deep learning methods for analysing genetic and genomic data can be referred to [ ] , [ ] . typical applications may include, for example, recognizing the locations of transcription start sites, identifying splice sites, promoters, enhancers, or positioned nucleosomes in a genome sequence, analysing gene expression data for finding disease biomarkers, assigning functional annotations to genes, predicting the expression of a gene [ ] , identifying splicing junction at the dna level, predicting the sequence specificities of dna-and rna-binding proteins, modelling structural features of rna-binding protein targets, predicting dna-protein binding, or annotating the pathogenicity of genetic variants [ ] . these applications can be utilized for analysing genomic and genetic data of severe acute respiratory syndrome coronavirus (sars-cov- ), the highly pathogenic virus that has caused the global covid- pandemic. the covid- pandemic has considerably affected lives of people around the globe and the number of deaths related to the disease keeps increasing worldwide. while ai technologies have penetrated into our daily lives with many successes, they have also contributed to helping humans in the tough fight against covid- . this paper has presented a survey of ai applications so far in the literature relevant to the covid- crisis's responses and control strategies. these applications range from medical diagnosis based on chest radiology images, virus transmission modelling and forecasting based on number of cases time series and iot data, text mining and nlp to capture the public awareness of virus prevention measures, to biological data analysis for drug discovery. although various studies have been published, we observe that there are still relatively limited applications and contributions of ai in this battle. this is partly due to the limited availability of data about covid- whilst ai methods normally require large amounts of data for computational models to learn and acquire knowledge. however, we expect that the number of ai studies related to covid- will increase significantly in the months to come when more covid- data such as medical images and biological sequences are available. current available datasets as summarized in table ii are stored in various formats and standards that would hinder the development of covid- related ai research. a future work on creating, hosting and benchmarking covid- related datasets is essential because it will help to accelerate discoveries useful for tackling the disease. repositories for this goal should be created following standardized protocols and allow researchers and scientists across the world to contribute to and utilize them freely for research purposes. among the published works, the use of deep learning techniques for covid- diagnosis based on radiology imaging data appears to be dominant. as summarized in table , numerous studies have used various deep learning methods, applying on different datasets and utilizing a number of evaluation criteria. this creates an immediate concern about difficulties when utilizing these approaches to the realworld clinical practice. accordingly, there is a demand for a future work on developing a benchmark framework to validate and compare the existing methods. this framework should facilitate the same computing hardware infrastructure, (universal) datasets covering same patient cohorts, same data pre-processing procedures and evaluation criteria across ai methods being evaluated. furthermore, as li et al. [ ] pointed out, although their model obtained great accuracy in distinguishing covid- with other types of viral pneumonia using radiology images, it still lacks of transparency and interpretability. for example, they do not know which imaging features have unique effects on the output computation. the benefit that black box deep learning methods can provide to clinical doctors is therefore questionable. a future study on explainable ai to explain the deep learning models' performance as well as features of images that contribute to the distinction between covid- and other types of pneumonia is necessary. this would help radiologists and clinical doctors to gain insights about the virus and examine future coronavirus ct and x-ray images more effectively. in the field of computational biology and medicine, ai has been used to partially understand covid- or discover novel drug compounds against the virus [ ] , [ ] . these are just initial results and thus there is a great demand for ai research in this field, e.g., to investigate genetics and chemistry of the virus and suggest ways to quickly produce vaccines and treatment drugs. with a strong computational power that is able to deal with large amounts of data, ai can help scientists to gain knowledge about the coronavirus quickly. for example, by exploring and analyzing protein structures of virus, medical researchers would be able to find components necessary for a vaccine or drug more effectively. this process would be very time consuming and expensive with conventional methods [ ] . recent astonishing success of deep learning in identifying powerful new kinds of antibiotic from a pool of more than million molecules as published in [ ] gives a strong hope to this line of research in the battle against covid- . compared to the spanish flu pandemic [ ] , we are now fortunately living in the age of exponential technology. when everybody, organization and government try their best in the battle against the pandemic, the power of ai should be fully exploited and employed to support humans to combat this battle. ai can be utilized for the preparedness and response activities against the unprecedented national and global crisis. for example, ai can be used to create more effective robots and autonomous machines for disinfection, working in hospitals, delivering food and medicine to patients. aibased nlp tools can be used to create systems that help understand the public responses to intervention strategies, e.g. lockdown and physical distancing, to detect problems such as mental health and social anxiety, and to aid governments in making better public policies. nlp technologies can also be employed to develop chatbot systems that are able to remotely communicate and provide consultations to people and patients about the coronavirus. ai can be used to eradicate fake news on social media platforms to ensure clear, responsible and reliable information about the pandemic such as scientific evidences relevant to the virus, governmental social distancing policies or other pandemic prevention and control measures. in table iii , we point out groups of problems related to covid- along with types of data needed and potential ai methods that can be used to solve those problems. we do not aim to cover all possible ai applications but emphasize on realistic applications that can be achieved along with their technical challenges. those challenges need to be addressed effectively for ai methods to bring satisfactory results. it is great to observe the increasing number of ai applications against the covid- pandemic. ai methods however are not silver bullets but they have limitations and challenges such as inadequate training and validation data or when data are abundantly available, they are normally in poor quality. huge efforts are needed for an ai system to be effective and useful. they may include appropriate data processing pipelines, model selection, efficient algorithm development, remodelling and retraining, continuous performance monitoring and validation to facilitate continuous deployment and so on. there are ai ethics principles and guidelines [ ] , [ ] that each phase of the ai system lifecycle, i.e. design, -challenging to collect physiological characteristics and therapeutic outcomes of patients. -low-quality data would make biased and inaccurate predictions. -uncertainty of ai models outcomes. -privacy and confidentiality issues. [ ]- [ ] machine learning techniques, e.g. naive bayes, logistic regression, knn, svm, mlp, fuzzy logic system, elasticnet regression [ ] , decision tree, random forest, nonparametric gaussian process [ ] , deep learning techniques such as lstm [ ] and other recurrent networks, and optimization methods. predict number of infected cases, infection rate and spreading trend. time series case data, population density, demographic data. -insufficient time series data, leading to unreliable results. -complex models may not be more reliable than simple models [ ] . [ ] , [ ] , [ ] covid- early diagnosis using medical images. radiology images, e.g. chest x-ray and ct scans. -imbalanced datasets due to insufficient covid- medical image data. -long training time and unable to explain the results. -generalisation problem and vulnerable to false negatives. [ ]- [ ] and works in table i . deep learning cnn-based models (e.g. alexnet [ ] , googlenet [ ] , vgg network [ ] , resnet [ ] , densenet [ ] , resnext [ ] , and zfnet [ ] ), aibased computer vision camera systems, and facial recognition systems. scan crowds for people with high temperature, and monitor people for social distancing and mask-wearing or during lockdown. infrared camera images, thermal scans. -cannot measure inner-body temperature and a proportion of patients are asymptomatic, leading to imprecise results. -privacy invasion issues. [ ]- [ ] analyse viral genomes, create evolutionary (phylogenetic) tree, find virus origin, track physiological and genetic changes, predict protein secondary and tertiary structures. viral genome and protein sequence data -computational expenses are huge for aligning a large dataset of genomic or proteomic sequences. -deep learning models take long training time, especially for large datasets, and are normally unexplainable. [ ], [ ] , deepminds alphafold [ ] , [ ] -sequence alignment, e.g. dynamic programming, heuristic and probabilistic methods. -clustering algorithms, e.g. hierarchical clustering, k-means, dbscan [ ] and supervised deep learning. discover vaccine and drug biochemical compounds and candidates, and optimize clinical trials. viral genome and protein sequences, transcriptome data, drug-target interactions, protein-protein interactions, crystal structure of protein, cocrystalized ligands, homology model of proteins, and clinical data. -dealing with big genomic and proteomic data. -results need to be verified with experimental studies. -it can take long time for a promising candidate to become a viable vaccine or treatment method. [ ], [ ] - [ ] heuristic algorithm, graph theory, combinatorics, and machine learning such as adversarial autoencoders [ ] , multitask cnn [ ] , gan [ ] , [ ] , deep reinforcement learning [ ] , [ ] , [ ] . making drones and robots for disinfection, cleaning, obtaining patients vital signs, distance treatment, and deliver medication. simulation environments and demonstration data for training autonomous agents. -safety must be guaranteed at the highest level. -trust in autonomous systems. -huge efforts from training agents to implementing them to real machines. [ ]- [ ] deep learning, computer vision, optimization and control, transfer learning, deep reinforcement learning [ ] , learning from demonstrations. track and predict economic recovery via, e.g. detection of solar panel installations, counting cars in parking lots. satellite images, gps data (e.g. daily anonymized data from mobile phone users to count the number of commuters in cities). -difficult to obtain satellite data in some regions. -noise in satellite images. -anonymized mobile phone data security. [ ], [ ] deep learning, e.g. autoencoder models for feature extraction and dimensionality reduction, and cnn-based models for object detection. types of data challenges related ai methods real-time spread tracking, surveillance, early warning and alerts for particular geographical locations, like the global zika virus spread model bluedot [ ] . anonymized location data from cellphones, flight itinerary data, ecological data, animal and plant disease networks, temperature profiles, foreign-language news reports, public announcements, and population distribution data, e.g. landscan datasets [ ] . -insufficient data in some regions of the world, leading to skewed results. -inaccurate predictions may lead to mass hysteria in public health. -privacy issues to ensure cellphone data remain anonymous. bluedot [ ] , metabiota epidemic tracker [ ] , healthmap [ ] deep learning (e.g. autoencoders and recurrent networks), transfer learning, and nlg and nlp tools (e.g. nltk [ ] , elmo [ ] , ulmfit [ ] , transformer [ ] , googles bert [ ] , transformer-xl [ ] , xlnet [ ] , ernie [ ] , t [ ] , bpt [ ] and openais gpt- [ ] ) for various natural language related tasks such as terminology and information extraction, automatic summarization, relationship extraction, text classification, text and semantic annotation, sentiment analysis, named entity recognition, topic segmentation and modelling, machine translation, speech recognition and synthesis, automated question and answering. understand communities' responses to intervention strategies, e.g. physical distancing or lockdown, to aid public policy makers and detect problems such as mental health. news outlets, forums, healthcare reports, travel data, and social media posts in multiple languages across the world. -social media data and news reports may be low-quality, multidimensional, and highly unstructured. -issues related to language translation. -data cannot be collected from populations with limited internet access. [ ]- [ ] mining text to obtain knowledge about covid- transmission modes, incubation, risk factors, nonpharmaceutical interventions, medical care, virus genetics, origin, and evolution. text data on covid- virus such as scholarly articles in cord- dataset [ ] . -dealing with inaccurate and ambiguous information in the text data. -large volume of data from heterogeneous sources. -excessive amount of data make difficult to extract important pieces of information. [ ]- [ ] mining text to discover candidates for vaccines, antiviral drugs, therapeutics, and drug repurposing through searching for elements similar to covid- virus. text data about treatment effectiveness, therapeutics and vaccines on scholarly articles, e.g. cord- dataset [ ] and libraries of drug compounds. -need to involve medical experts knowledge. -typographical errors in text data need to be rectified carefully. [ ], [ ] - [ ] making chatbots to consult patients and communities, and combat misinformation (fake news) about covid- . medical expert guidelines and information. -unable to deal with unsaved query. -require a large amount of data and information from medical experts. -users are uncomfortable with chatbots being machines. -irregularities in language expression such as accents and mistakes. [ ]- [ ] development, implementation and ongoing maintenance, may need to adhere to, especially when most ai applications against covid- involve or affect human beings. the more ai applications are proposed, the more these applications need to ensure fairness, safety, explainability, accountability, privacy protection and data security, be aligned with human values, and have positive impacts on societal and environmental wellbeing. who coronavirus disease (covid- ) dashboard gradientbased learning applied to document recognition imagenet classification with deep convolutional neural networks going deeper with convolutions very deep convolutional networks for large-scale image recognition deep residual learning for image recognition performance of radiologists in differentiating covid- from viral pneumonia on chest ct. radiology artificial intelligence distinguishes covid- from community acquired pneumonia on chest ct. radiology deep learning system to screen coronavirus disease pneumonia chest ct findings in novel coronavirus ( -ncov) infections from wuhan, china: key points for the radiologist. radiology ct imaging features of novel coronavirus ( -ncov). radiology estimating uncertainty and interpretability in deep learning for coronavirus (covid- ) detection a deep learning algorithm using ct images to screen for corona virus disease (covid- ). medrxiv predicting covid- malignant progression with ai techniques. medrxiv development and evaluation of an ai system for covid- . medrxiv ai-assisted ct imaging analysis for covid- screening: building and deploying a medical ai system in four weeks. medrxiv unet++: a nested u-net architecture for medical image segmentation automatic detection of coronavirus disease (covid- ) using x-ray images and deep convolutional neural networks covid-net: a tailored deep convolutional neural network design for detection of covid- cases from chest radiography images rapid ai development cycle for the coronavirus (covid- ) pandemic: initial results for automated detection and patient monitoring using deep learning ct image analysis can ai help in screening viral and covid- pneumonia diagnosing covid- pneumonia from x-ray and ct images using deep learning and transfer learning algorithms densely connected convolutional networks aggregated residual transformations for deep neural networks squeezenet: alexnet-level accuracy with x fewer parameters and < . mb model size artificial intelligence forecasting of covid- in china α-satellite: an ai-driven system and benchmark datasets for hierarchical community-level risk assessment to help combat covid- conditional generative adversarial nets modelling transmission and control of the covid- pandemic in australia urbanization affects peak timing, prevalence, and bimodality of influenza pandemics in australia: results of a census-calibrated model investigating spatiotemporal dynamics and synchrony of influenza epidemics in australia: an agent-based modelling approach. simulation modelling practice and theory a novel ai-enabled framework to diagnose coronavirus covid- using smartphone embedded sensors: design study use of a smartphone thermometer to monitor thermal conductivity changes in diabetic foot ulcers: a pilot study smartphone-based human fatigue detection in an industrial environment using gait analysis fatigue detection during sit-to-stand test based on surface electromyography and acceleration: a case study smartphone-enabled videoobserved versus directly observed treatment for tuberculosis: a multicentre, analyst-blinded, randomised, controlled superiority trial neck posture monitoring system based on image detection and smartphone sensors using the prolonged usage classification concept a comprehensive approach for cough type detection nocturnal cough and snore detection in noisy environments using smartphone-microphones identification of covid- can be quicker through artificial intelligence framework using a mobile phone-based survey in the populations when cities/towns are under quarantine on the coronavirus (covid- ) outbreak and the smart city network: universal data sharing standards coupled with artificial intelligence (ai) to benefit urban health monitoring and management predicting covid- using hybrid ai model a double epidemic model for the sars propagation a simple mathematical model for ebola in africa long short-term memory understanding the perception of covid- policies by mining a characterizing the propagation of situational information in social media during covid- epidemic: a case study on weibo improved protein structure prediction using potentials from deep learning computational predictions of protein structures associated with covid- , deepmind website potential covid- c-like protease inhibitors designed using generative deep learning approaches machine learning using intrinsic genomic signatures for rapid classification of novel pathogens: covid- case study mldsp-gui: an alignment-free standalone tool with an interactive graphical user interface for dna sequence comparison and analysis genomic characterisation and epidemiology of novel coronavirus: implications for virus origins and receptor binding a pneumonia outbreak associated with a new coronavirus of probable bat origin origin of novel coronavirus (covid- ): a computational biology study using artificial intelligence. biorxiv covid- : a survey on public medical imaging data resources epidemiological dynamics modeling by fusion of soft computing techniques gaussian processes for machine learning neural network ensemble operators for time series forecasting a survey of the recent architectures of deep convolutional neural networks natural language processing with python deep contextualized word representations universal language model fine-tuning for text classification attention is all you need bert: pre-training of deep bidirectional transformers for language understanding transformer-xl: attentive language models beyond a fixed-length context xlnet: generalized autoregressive pretraining for language understanding ernie: enhanced language representation with informative entities exploring the limits of transfer learning with a unified text-to-text transformer bptransformer: modelling long-range context via binary partitioning language models are unsupervised multitask learners a density-based algorithm for discovering clusters in large spatial databases with noise multi-output interval type- fuzzy logic system for protein secondary structure prediction a hybrid supervised approach to human population identification using genomics data genomic mutations and changes in protein secondary structure and solvent accessibility of sars-cov- (covid- virus), biorxiv machine learning applications in genetics and genomics applications of deep learning and reinforcement learning to biological data an interactive web-based dashboard to track covid- in real time impact of international travel and border control measures on the global spread of the novel coronavirus outbreak covid- image data collection covid-ct-dataset: a ct scan dataset about covid- pocovid-net: automatic detection of covid- from a new lung ultrasound imaging dataset (pocus) a twitter dataset of + million tweets related to covid- (version . ) [data set cord- ). ( ) version - - ai can help scientists find a covid- vaccine a deep learning approach to antibiotic discovery reassessing the global mortality burden of the influenza pandemic ethics guidelines for trustworthy ai a novel high specificity covid- screening method based on simple blood exams and artificial intelligence. medrxiv predicting mortality risk in patients with covid- using artificial intelligence to help medical decision-making. medrxiv a novel triage tool of artificial intelligence assisted diagnosis aid system for suspected covid- pneumonia in fever clinics the role of artificial intelligence in management of critical covid- patients towards an artificial intelligence framework for datadriven prediction of coronavirus clinical severity artificial intelligence in the intensive care unit prediction of criticality in patients with severe covid- infection using three clinical features: a machine learningbased prognostic model with clinical data in wuhan. medrxiv regularization and variable selection via the elastic net why is it difficult to accurately predict the covid- epidemic? predicting covid- in china using hybrid ai model modified seir and ai prediction of the epidemics trend of covid- in china under public health interventions artificial intelligenceenabled rapid diagnosis of patients with covid- clinically applicable ai system for accurate diagnosis, quantitative measurements, and prognosis of covid- pneumonia using computed tomography radiological findings from patients with covid- pneumonia in wuhan, china: a descriptive study covid- pneumonia: what has ct taught us diagnosis of coronavirus disease (covid- ) with structured latent multi-view representation learning automated detection of covid- cases using deep neural networks with x-ray images medical image analysis using wavelet transform and deep belief networks coronet: a deep neural network for detection and diagnosis of covid- from chest x-ray images coronavirus (covid- ) outbreak: what the department of radiology should know application of deep learning technique to manage covid- in routine clinical practice using ct images: results of convolutional neural networks deep learning covid- features on cxr using limited training data sets covid- identification in chest x-ray images on flat and hierarchical classification scenarios inf-net: automatic covid- lung infection segmentation from ct images explainable deep learning for pulmonary disease and coronavirus covid- detection from x-rays covidgan: data augmentation using auxiliary classifier gan for improved covid- detection a hybrid covid- detection model using an improved marine predators algorithm and a ranking-based diversity reduction strategy review of artificial intelligence techniques in imaging data acquisition, segmentation and diagnosis for covid- sample-efficient deep learning for covid- diagnosis based on ct scans deep learning-based model for detecting novel coronavirus pneumonia on high-resolution computed tomography: a prospective study visualizing and understanding convolutional networks coronavirus france: cameras to monitor masks and social distancing as coronavirus surveillance escalates, personal privacy plummets. the new york times how russia is using facial recognition to police its coronavirus lockdown potentially highly potent drugs for -ncov. biorxiv mathdl: mathematical deep learning for d r grand challenge aiaided design of novel targeted covalent inhibitors against sars-cov- . biorxiv de novo design of new chemical entities (nces) for sars-cov- using artificial intelligence preliminary bioinformatics studies on the design of a synthetic vaccine and a preventative peptidomimetic antagonist against the sars-cov- ( -ncov, covid- ) coronavirus network bioinformatics analysis provides insight into drug repurposing for covid- covid- coronavirus vaccine design using reverse vaccinology and machine learning how artificial intelligence is changing drug discovery a data-driven drug repositioning framework discovered a potential therapeutic agent targeting covid- combating covid- -the role of robotics in managing public health and infectious diseases the uses of drones in case of massive epidemics contagious diseases relief humanitarian aid: wuhan-covid- crisis from high-touch to hightech: covid- drives robotics adoption robotics, smart wearable technologies, and autonomous intelligent systems for healthcare during the covid pandemic: an analysis of the state of the art and future vision deep reinforcement learning for multiagent systems: a review of challenges, solutions, and applications solarnet: a deep learning framework to map solar power plants in china from satellite imagery satellites and ai monitor chinese economys reaction to coronavirus anticipating the international spread of zika virus from brazil landscan global population database pneumonia of unknown aetiology in wuhan, china: potential for international spread via commercial air travel metabiota epidemic tracker contagious disease surveillance top concerns of tweeters during the covid- pandemic: infoveillance study the impact of covid- epidemic declaration on psychological consequences: a study on active weibo users the outbreak of covid- coronavirus and its impact on global mental health deepmine-natural language processing based automatic literature mining and research summarization for early stage comprehension in pandemic situations specifically for covid- . biorxiv covidnlp: a web application for distilling systemic implications of covid- pandemic with natural language processing understand research hotspots surrounding covid- and other coronavirus infections using topic modeling. medrxiv word embedding mining for sars-cov- and covid- drug repurposing text and networkmining for covid- intervention studies. chemrxiv information mining for covid- research from a large volume of scientific literature identification of pulmonary comorbid diseases network based repurposing effective drugs for covid- bioactivity profile similarities to expand the repertoire of covid- drugs an artificial intelligence-based first-line defence against covid- : digitally screening citizens for risks via a chatbot who health alerts facebook messenger chatbot who viber interactive chatbot who's health alert on whatsapp unicefs europe and central asia regional office and the who regional office for europe ( ) ibm watson assistant for citizens covid- risk assessment chatbot rona (covid- bot) covid chat bot dr. nguyen has been recognized as a leading researcher in australia in the field of artificial intelligence by the australian newspaper in a report published in . he is currently a senior lecturer in the school of information technology, deakin university, victoria, australia. key: cord- -c awh y authors: elzainy, ahmed; el sadik, abir; al abdulmonem, waleed title: experience of e-learning and online assessment during the covid- pandemic at the college of medicine, qassim university date: - - journal: j taibah univ med sci doi: . /j.jtumed. . . sha: doc_id: cord_uid: c awh y objectives: during the covid- pandemic, academic institutions are promptly shifting all educational activities to the e-learning format. the present work describes concurrent procedures for online teaching and assessment performed at the college of medicine, qassim university, ksa. we also explored the impact of e-learning and assessment on the performance of students and faculty, and the challenges to their sustainability. methods: in this descriptive cross-sectional study, we recorded the number and duration of different online educational activities during the covid- pandemic. training sessions for various procedures of virtual classrooms and online assessments were organised for teachers and students. a newly established e-assessment committee arranged different online assessments. a comparison between the mean problem-based learning (pbl) grades of the same students was conducted either face-to-face or online. a student satisfaction survey and online staff focus group about the online learning experiences were conducted, and weekly staff perception reports were prepared. the results obtained were then analysed. results: a total of virtual classrooms were successfully implemented over h including theoretical lectures, pbl sessions, seminars, and tutorials. a significant increase in the mean pbl grades was observed for female students during the online sessions. out of the basic year students and staff, . % reflected their high satisfaction towards virtual classrooms, online assessment, and online workshops. conclusion: the present study elaborates on the benefits of e-learning and assessment. we observed higher student achievements and promising staff perceptions with obvious improvement in their technological skills. these findings support the shift towards future implementation of more online medical courses. ‫ﺖ‬ ‫ﻟ‬ ‫ﺠ‬ ‫ﻨ‬ ‫ﺔ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﻘ‬ ‫ﻴ‬ ‫ﻴ‬ ‫ﻢ‬ ‫ﺍ‬ ‫ﻹ‬ ‫ﻟ‬ ‫ﻴ‬ ‫ﻜ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﻭ‬ ‫ﻧ‬ ‫ﻲ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻤ‬ ‫ﻨ‬ ‫ﺸ‬ ‫ﺄ‬ ‫ﺓ‬ ‫ﺣ‬ ‫ﺪ‬ ‫ﻳ‬ ‫ﺜ‬ ‫ﺎ‬ ‫ﻣ‬ ‫ﺨ‬ ‫ﺘ‬ ‫ﻠ‬ ‫ﻒ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﻘ‬ ‫ﻴ‬ ‫ﻴ‬ ‫ﻤ‬ ‫ﺎ‬ ‫ﺕ‬ ‫ﺍ‬ ‫ﻹ‬ ‫ﻟ‬ ‫ﻴ‬ ‫ﻜ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﻭ‬ ‫ﻧ‬ ‫ﻴ‬ ‫ﺔ‬ . ‫ﺗ‬ ‫ﻢ‬ ‫ﻣ‬ ‫ﻘ‬ ‫ﺎ‬ ‫ﺭ‬ ‫ﻧ‬ ‫ﺔ‬ ‫ﻣ‬ ‫ﺘ‬ ‫ﻮ‬ ‫ﺳ‬ ‫ﻂ‬ ‫ﺩ‬ ‫ﺭ‬ ‫ﺟ‬ ‫ﺎ‬ ‫ﺕ‬ ‫ﻧ‬ ‫ﻔ‬ ‫ﺲ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻄ‬ ‫ﻠ‬ ‫ﺒ‬ ‫ﺔ‬ ‫ﺃ‬ ‫ﺛ‬ ‫ﻨ‬ ‫ﺎ‬ ‫ﺀ‬ ‫ﺟ‬ ‫ﻠ‬ ‫ﺴ‬ ‫ﺎ‬ ‫ﺕ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﻌ‬ ‫ﻠ‬ ‫ﻢ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻘ‬ ‫ﺎ‬ ‫ﺋ‬ ‫ﻢ‬ ‫ﻋ‬ ‫ﻠ‬ ‫ﻰ‬ ‫ﺣ‬ ‫ﻞ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻤ‬ ‫ﻌ‬ ‫ﻀ‬ ‫ﻼ‬ ‫ﺕ‬ ‫ﺳ‬ ‫ﻮ‬ ‫ﺍ‬ ‫ﺀ‬ ‫ﻋ‬ ‫ﻘ‬ ‫ﺪ‬ ‫ﺕ‬ ‫ﻭ‬ ‫ﺟ‬ ‫ﻬ‬ ‫ﺎ‬ ‫ﻟ‬ ‫ﻮ‬ ‫ﺟ‬ ‫ﻪ‬ ‫ﺃ‬ ‫ﻭ‬ ‫ﺗ‬ ‫ﻢ‬ ‫ﻋ‬ ‫ﻘ‬ ‫ﺪ‬ ‫ﻫ‬ ‫ﺎ‬ ‫ﺇ‬ ‫ﻟ‬ ‫ﻜ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﻭ‬ ‫ﻧ‬ ‫ﻴ‬ ‫ﺎ‬ . ‫ﻛ‬ ‫ﻤ‬ ‫ﺎ‬ ‫ﺗ‬ ‫ﻢ‬ ‫ﻋ‬ ‫ﻤ‬ ‫ﻞ‬ ‫ﻭ‬ ‫ﺗ‬ ‫ﺤ‬ ‫ﻠ‬ ‫ﻴ‬ ‫ﻞ‬ ‫ﺍ‬ ‫ﺳ‬ ‫ﺘ‬ ‫ﺒ‬ ‫ﺎ‬ ‫ﻧ‬ ‫ﺔ‬ ‫ﺭ‬ ‫ﺿ‬ ‫ﺎ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻄ‬ ‫ﻼ‬ ‫ﺏ‬ ، ‫ﻭ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﻘ‬ ‫ﺎ‬ ‫ﺭ‬ ‫ﻳ‬ ‫ﺮ‬ ‫ﺍ‬ ‫ﻷ‬ ‫ﺳ‬ ‫ﺒ‬ ‫ﻮ‬ ‫ﻋ‬ ‫ﻴ‬ ‫ﺔ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﺼ‬ ‫ﻮ‬ ‫ﺭ‬ ‫ﺃ‬ ‫ﻋ‬ ‫ﻀ‬ ‫ﺎ‬ ‫ﺀ‬ ‫ﻫ‬ ‫ﻴ‬ ‫ﺌ‬ ‫ﺔ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﺪ‬ ‫ﺭ‬ ‫ﻳ‬ ‫ﺲ‬ ‫ﺑ‬ ‫ﺎ‬ ‫ﻹ‬ ‫ﺿ‬ ‫ﺎ‬ ‫ﻓ‬ ‫ﺔ‬ ‫ﺇ‬ ‫ﻟ‬ ‫ﻰ‬ ‫ﺧ‬ ‫ﺒ‬ ‫ﺮ‬ ‫ﺍ‬ ‫ﺕ‬ ‫ﺟ‬ ‫ﻠ‬ ‫ﺴ‬ ‫ﺔ‬ ‫ﻣ‬ ‫ﺠ‬ ‫ﻤ‬ ‫ﻮ‬ ‫ﻋ‬ ‫ﺔ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﻛ‬ ‫ﻴ‬ ‫ﺰ‬ ‫ﻋ‬ ‫ﻦ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﻌ‬ ‫ﻠ‬ ‫ﻢ‬ ‫ﺍ‬ ‫ﻹ‬ ‫ﻟ‬ ‫ﻴ‬ ‫ﻜ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﻭ‬ ‫ﻧ‬ ‫ﻲ‬ . ‫ﺍ‬ ‫ﻟ‬ ‫ﻨ‬ ‫ﺘ‬ ‫ﺎ‬ ‫ﺋ‬ ‫ﺞ‬ : ‫ﺗ‬ ‫ﻢ‬ ‫ﺗ‬ ‫ﻨ‬ ‫ﻔ‬ ‫ﻴ‬ ‫ﺬ‬ ٦٢٠ ‫ﻓ‬ ‫ﺼ‬ ‫ﻼ‬ ‫ﺍ‬ ‫ﻓ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﺍ‬ ‫ﺿ‬ ‫ﻴ‬ ‫ﺔ‬ ‫ﺑ‬ ‫ﻨ‬ ‫ﺠ‬ ‫ﺎ‬ ‫ﺡ‬ ‫ﻋ‬ ‫ﻠ‬ ‫ﻰ‬ ‫ﻣ‬ ‫ﺪ‬ ‫ﻯ‬ ٩٩٤ ‫ﺳ‬ ‫ﺎ‬ ‫ﻋ‬ ‫ﺔ‬ ‫ﺷ‬ ‫ﻤ‬ ‫ﻠ‬ ‫ﺖ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻤ‬ ‫ﺤ‬ ‫ﺎ‬ ‫ﺿ‬ ‫ﺮ‬ ‫ﺍ‬ ‫ﺕ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻨ‬ ‫ﻈ‬ ‫ﺮ‬ ‫ﻳ‬ ‫ﺔ‬ ، ‫ﻭ‬ ‫ﺟ‬ ‫ﻠ‬ ‫ﺴ‬ ‫ﺎ‬ ‫ﺕ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﻌ‬ ‫ﻠ‬ ‫ﻢ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻘ‬ ‫ﺎ‬ ‫ﺋ‬ ‫ﻢ‬ ‫ﻋ‬ ‫ﻠ‬ ‫ﻰ‬ ‫ﺣ‬ ‫ﻞ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻤ‬ ‫ﻌ‬ ‫ﻀ‬ ‫ﻼ‬ ‫ﺕ‬ ، ‫ﻭ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻨ‬ ‫ﺪ‬ ‫ﻭ‬ ‫ﺍ‬ ‫ﺕ‬ ‫ﻭ‬ ‫ﺣ‬ ‫ﻠ‬ ‫ﻘ‬ ‫ﺎ‬ ‫ﺕ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻨ‬ ‫ﻘ‬ ‫ﺎ‬ ‫ﺵ‬ . ‫ﻻ‬ ‫ﺣ‬ ‫ﻈ‬ ‫ﻨ‬ ‫ﺎ‬ ‫ﺯ‬ ‫ﻳ‬ ‫ﺎ‬ ‫ﺩ‬ ‫ﺓ‬ ‫ﺫ‬ ‫ﺍ‬ ‫ﺕ‬ ‫ﺩ‬ ‫ﻻ‬ ‫ﻟ‬ ‫ﺔ‬ ‫ﺇ‬ ‫ﺣ‬ ‫ﺼ‬ ‫ﺎ‬ ‫ﺋ‬ ‫ﻴ‬ ‫ﺔ‬ ‫ﻓ‬ ‫ﻲ‬ ‫ﻣ‬ ‫ﺘ‬ ‫ﻮ‬ ‫ﺳ‬ ‫ﻄ‬ ‫ﺪ‬ ‫ﺭ‬ ‫ﺟ‬ ‫ﺎ‬ ‫ﺕ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻄ‬ ‫ﺎ‬ ‫ﻟ‬ ‫ﺒ‬ ‫ﺎ‬ ‫ﺕ‬ ‫ﺃ‬ ‫ﺛ‬ ‫ﻨ‬ ‫ﺎ‬ ‫ﺀ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺠ‬ ‫ﻠ‬ ‫ﺴ‬ ‫ﺎ‬ ‫ﺕ‬ ‫ﺍ‬ ‫ﻹ‬ ‫ﻟ‬ ‫ﻜ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﻭ‬ ‫ﻧ‬ ‫ﻴ‬ ‫ﺔ‬ ‫ﻟ‬ ‫ﻠ‬ ‫ﺘ‬ ‫ﻌ‬ ‫ﻠ‬ ‫ﻢ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻘ‬ ‫ﺎ‬ ‫ﺋ‬ ‫ﻢ‬ ‫ﻋ‬ ‫ﻠ‬ ‫ﻰ‬ ‫ﺣ‬ ‫ﻞ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻤ‬ ‫ﻌ‬ ‫ﻀ‬ ‫ﻼ‬ ‫ﺕ‬ . ‫ﻋ‬ ‫ﻜ‬ ‫ﺲ‬ ‫ﺃ‬ ‫ﻛ‬ ‫ﺜ‬ ‫ﺮ‬ ‫ﻋ‬ ‫ﺪ‬ ‫ﺩ‬ ‫ﻣ‬ ‫ﻤ‬ ‫ﻜ‬ ‫ﻦ‬ ٥٢.٨٢ ٪ ‫ﻣ‬ ‫ﻦ‬ ‫ﻃ‬ ‫ﻼ‬ ‫ﺏ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺴ‬ ‫ﻨ‬ ‫ﻮ‬ ‫ﺍ‬ ‫ﺕ‬ ‫ﺍ‬ ‫ﻷ‬ ‫ﺳ‬ ‫ﺎ‬ ‫ﺳ‬ ‫ﻴ‬ ‫ﺔ‬ ‫ﺑ‬ ‫ﺎ‬ ‫ﻹ‬ ‫ﺿ‬ ‫ﺎ‬ ‫ﻓ‬ ‫ﺔ‬ ‫ﺇ‬ ‫ﻟ‬ ‫ﻰ‬ ‫ﺃ‬ ‫ﻋ‬ ‫ﻀ‬ ‫ﺎ‬ ‫ﺀ‬ ‫ﻫ‬ ‫ﻴ‬ ‫ﺌ‬ ‫ﺔ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﺪ‬ ‫ﺭ‬ ‫ﻳ‬ ‫ﺲ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺮ‬ ‫ﺿ‬ ‫ﻰ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻌ‬ ‫ﺎ‬ ‫ﻟ‬ ‫ﻲ‬ ‫ﺗ‬ ‫ﺠ‬ ‫ﺎ‬ ‫ﻩ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻔ‬ ‫ﺼ‬ ‫ﻮ‬ ‫ﻝ‬ ‫ﺍ‬ ‫ﻻ‬ ‫ﻓ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﺍ‬ ‫ﺿ‬ ‫ﻴ‬ ‫ﺔ‬ ، ‫ﻭ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﻘ‬ ‫ﻴ‬ ‫ﻴ‬ ‫ﻢ‬ ‫ﺍ‬ ‫ﻹ‬ ‫ﻟ‬ ‫ﻴ‬ ‫ﻜ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﻭ‬ ‫ﻧ‬ ‫ﻲ‬ ‫ﻭ‬ ‫ﻭ‬ ‫ﺭ‬ ‫ﺵ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻌ‬ ‫ﻤ‬ ‫ﻞ‬ ‫ﺍ‬ ‫ﻹ‬ ‫ﻟ‬ ‫ﻜ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﻭ‬ ‫ﻧ‬ ‫ﻴ‬ ‫ﺔ‬ . ‫ﺍ‬ ‫ﻻ‬ ‫ﺳ‬ ‫ﺘ‬ ‫ﻨ‬ ‫ﺘ‬ ‫ﺎ‬ ‫ﺟ‬ ‫ﺎ‬ ‫ﺕ‬ : ‫ﺃ‬ ‫ﻭ‬ ‫ﺿ‬ ‫ﺤ‬ ‫ﺖ‬ ‫ﻫ‬ ‫ﺬ‬ ‫ﻩ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺪ‬ ‫ﺭ‬ ‫ﺍ‬ ‫ﺳ‬ ‫ﺔ‬ ‫ﻓ‬ ‫ﻮ‬ ‫ﺍ‬ ‫ﺋ‬ ‫ﺪ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﻌ‬ ‫ﻠ‬ ‫ﻢ‬ ‫ﺍ‬ ‫ﻹ‬ ‫ﻟ‬ ‫ﻜ‬ ‫ﺘ‬ ‫ﺮ‬ ‫ﻭ‬ ‫ﻧ‬ ‫ﻲ‬ ‫ﻭ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﺘ‬ ‫ﻘ‬ ‫ﻴ‬ ‫ﻴ‬ ‫ﻢ‬ . ‫ﻻ‬ ‫ﺣ‬ ‫ﻈ‬ ‫ﻨ‬ ‫ﺎ‬ ‫ﺍ‬ ‫ﺭ‬ ‫ﺗ‬ ‫ﻔ‬ ‫ﺎ‬ ‫ﻋ‬ ‫ﺎ‬ ‫ﻓ‬ ‫ﻲ‬ ‫ﺇ‬ ‫ﻧ‬ ‫ﺠ‬ ‫ﺎ‬ ‫ﺯ‬ ‫ﺍ‬ ‫ﻟ‬ ‫ﻄ‬ ‫ﻼ‬ ‫ﺏ‬ ‫ﻭ‬ ‫ﺗ‬ ‫ﺼ‬ ‫ﻮ‬ ‫ﺭ‬ ‫ﺍ‬ ‫ﻭ‬ objectives: during the covid- pandemic, academic institutions are promptly shifting all educational activities to the e-learning format. the present work describes concurrent procedures for online teaching and assessment performed at the college of medicine, qassim university, ksa. we also explored the impact of e-learning and assessment on the performance of students and faculty, and the challenges to their sustainability. methods: in this descriptive cross-sectional study, we recorded the number and duration of different online educational activities during the covid- pandemic. training sessions for various procedures of virtual classrooms and online assessments were organised q for teachers and students. a newly established e-assessment committee arranged different online assessments. a comparison between the mean problem-based learning (pbl) grades of the same students was conducted either face-to-face or online q . a student satisfaction survey and q online staff focus group about the online learning experiences were conducted, and weekly staff perception reports were prepared. the results obtained were then analysed q . results: a total of virtual classrooms were successfully implemented over h including theoretical lectures, pbl sessions, seminars, and tutorials. a significant increase in the mean pbl grades was observed for female students during the online sessions. out of the basic year students and staff, . q % reflected their high satisfaction towards virtual classrooms, online assessment, and online workshops. the present study elaborates on the benefits of e-learning and assessment. we observed higher student achievements and promising staff perceptions with obvious improvement in their technological skills. these findings support the shift towards future implementation of more online medical courses. the covid- pandemic has led to the global disruption of medical education which necessitated working online. urgent response to the current situation required an increase in medical educators' awareness towards online teaching. several researches determined the effectiveness of digital technologies for life-long e-learning and continuous professional development. e-learning has been established worldwide in response to the shortage of health educators and the need to switch into teal q . , e-learning has several advantages q , such as encouraging students for self-directed learning and updating the curricula. the college of medicine at qassim university, established in , adopted the pbl system as an interactive educational strategy. the college shifted into digitalised pbl materials for one year, which was a good preparation for complete online pbl sessions. recent technologies allowed the progressive innovation of e-learning. , several studies have investigated the benefits of these technologies in medical education, especially the pbl system. , official online platforms, mainly through the blackboard learning management system (lms) version . (blackboard, washington, dc), are used in qassim university to conduct educational sessions including lectures, tutorials, pbl sessions, seminar presentations, and open discussion forums. online formative assessments, through the blackboard, were also performed. these assessments reflect the nature of online learning and give the students more responsibility for their q learning. online assessment allows the learners to demonstrate their capabilities in critical thinking and solving problems, which are the key benefits of shifting from traditional teaching to e-learning where the teacher is mainly a facilitator. the present study described the procedures performed to facilitate the urgent transition to e-learning and online assessment during the covid- pandemic and to highlight its expected benefits and impact on student and staff satisfaction and performance. it also aimed to compare the scores of male and female students during both face-to-face and online pbl sessions, and to explore the expected challenges of this experience to sustain its future implementation after the covid- pandemic. this was a descriptive observational study conducted q over days. during this period, four weeks of pbl sessions were accomplished for the basic year students. the study collected data from all the undergraduate students, involved in this e-learning experience, of preclinical phase (n ¼ ) (male students ¼ ; female students ¼ ) and clinical phase (n ¼ ) (male students ¼ ; female students ¼ ), and instructors ( basic and clinical). data of students were not included as they dropped out from both the basic and clinical phases q . the aim and procedure of the study were clarified to the participating students and staff, and their consents were obtained. students' identity will not be disclosed for ethical reasons. the confidentiality of the information obtained was maintained. all theoretical activities, including lectures, pbl, tutorials, and seminar sessions, in college of medicine at qassim university were adapted to the e-learning modality through the blackboard, version . (blackboard, washington, dc) and zoom cloud meetings . the authors contributed to the rescheduling of timetables for all these activities. all practical or clinical sessions were postponed. webinars about virtual classrooms and online assessments were presented for staff and students. an e-assessment committee was established for the first time consisting of thirteen membersdnine basic scientists and four clinical staff. this committee formulated, revised, and uploaded the online assessments with their logistics and evaluated the results using item analysis. the educational strategies for the live streaming sessions, during the covid- pandemic, at the college of medicine at qassim university included lectures, pbl sessions, tutorials, and seminar presentations to achieve the course objectives. comparisons of the mean pbl marks during control (face-to-face) and online (virtual) sessions were done for male and female students of the first and third years. secondyear students were excluded as they started a new block with the shift to e-learning. the students completed an online satisfaction survey on their perceptions of the e-learning experience, with a -point likert scale. weekly reports concerning staff perceptions on the effectiveness of live streaming activities were collected with a -point likert scale. the cronbach's alpha test was used for testing the internal consistency and reliability of the students' and staff's perceptions q . kendall's tau b, a nonparametric measure of association that exists between two variables, was used to test the correlation of the items of the students' survey. an online focus group for the staff, using the focus-groupit software (https://www.focusgroupit.com/), was performed. the questions were presented in the form of a swot analysis (figure ). the group was composed of one moderator, one observer, and seven participants (the supervisors of basic sciences departments and one radiology staff). the two-hour-long online synchronous focus group discussion was recorded. the analysed data were reviewed and interpreted by an independent investigator. the data were analysed using the statistical package for the social sciences (spss) software, version (ibm corp., armonk, ny). descriptive statistics (percentages, mean, q and standard errors of the mean) were used to describe the quantitative variables with their analysis through pairedsamples (to compare the male and female mean pbl marks) and independent t-tests (to compare the mean marks of the face-to-face and online pbl sessions). a p-value of < . was considered significant. weekly reports though the official learning management systemdblackboarddregarding the number, duration, and modality of different educational activities including the live streaming sessions and students' attendance rate were collected from the course organisers in coordination with the e-learning unit, phase coordination, and e-assessment committees. evaluation of students during their e-learning experience was done based on their assessment during the online pbl sessions. tables and present the details regarding the virtual classrooms, conducted mostly through blackboard, of the preclinical and clinical phases q . they represent the numbers of e-learning activities successfully implemented. significant increase in the mean pbl marks of the female students of both first and third years was observed during the online sessions than in the face-to-face sessions of the relevant year. additionally, there was a significant increase in the mean pbl marks of the female students of the first and third years than that of the male students of the relevant year in both face-to-face and online sessions (tables and ) . two hundred and fifty q students of the preclinical phase ( . %) completed the perception survey. students' satisfaction towards the new modality of e-learning and online assessment was reported (table ). the items covered in the students' survey included the following: the success of elearning in compensating for the urgent suspension of faceto-face teaching during the covid- pandemic, efficiency of instructions announced before the online teaching, staff's resistance and experience in e-learning requirements, and effectiveness of online assessment in testing their knowledge and skills levels. the cronbach's alpha test performed for all items of this survey resulted in an overall score of q . . kendall's tau b was used to test the correlation of these items. the correlation coefficient ranged from . to . . open-ended comments were received from out of students ( %), which were classified into two categoriesdone for teaching activities and the other for online assessment. eighty-seven per cent q (n ¼ ) of the students reflected their enthusiasm towards the e-learning modality: for example, 'very amazing; online teaching experience is the future of learning' and 'online lectures are super-satisfying' q . they expressed their satisfaction in having the same staff delivering the lectures for both male and female students. e-learning provided a chance for the shy studentsdas they could participate freely through online chattingd and motivated them for verbal discussions: 'initially, i was shy and shared my opinions during the open discussions only through chat; by the time i was encouraged to share orally q '. they expressed satisfaction with the rescheduling of educational activities and their allocated time and duration; for example, 'modification of the timetable allows more time for educational and recreational activities, thus allowing to live like a normal human'. the students expressed that some of the staff lacked adequate experience in conducting open discussions during online teaching. seventy per cent (n ¼ ) of the students reported that frequent online quizzes motivated them to study; for example, 'online quizzes are very helpful to improve my grades'. they appreciated the conduction of the mock quiz; for example, 'mock exam was very helpful for training before the online exams'. electronic assessment ensured fewer errors carried out by the students while filling out bubbles in q their answer sheets. lastly, they recommended that some courses could be implemented online in the future. staff satisfaction in virtual classrooms was also observed (tables and ) , which reflected that the live streaming sessions were very effective. the online focus group discussion was categorised into four themes based on the swot analysis. concerning the strengths, most of the staff agreed that the new arrangement of educational activities efficiently compensated for the suspension of face-to-face teaching q . they were satisfied with the university's efforts to improve staff awareness regarding virtual classrooms and online assessment through webinars q . the majority of them appreciated the tremendous shift to implement online summative assessments; for example, 'online assessment assured the staff about students' achievement of learning outcomes' and 'conduction of live oral exams based upon clear standardised checklist was highly effective'. the concerns expressed by the participants included some staff's limited online teaching experience and q the insufficient number of it technicians which interferes with proper digitalisation. regarding the opportunities that could be gained, the staff acknowledged the constitution of the e-assessment committee in the focus group; 'such committee was an urgent requirement to tackle the full first second third total bb: blackboard. a. elzainy et al. responsibility for online assessments'. they reflected the improvement of their expertise towards the novel pedagogical e-learning techniques and their enthusiasm to construct online courses; for example, 'adoption of electronic courses allows better arrangement of educational activities and gives more chances for students' self-directing learning'. two staff members reported the inconvenience of some students in taking the online quizzes, especially during the initial period, while the others specifically talked about q those who live in distant rural areas with insufficient internet coverage. four staff members emphasised the limited capabilities of the official version of blackboard, particularly in conducting the morning sessions. advanced technologies emerged during the covid- pandemic to sustain world productivity. the horizon teaching and learning report highlighted the role of advanced technology in medical education. the present study represents the major change in the educational culture. e-learning was highly beneficial for competent educators as it decreased the needs for in-class attendance. in agreement with mccoy et al., students and staff reflected that live streaming lectures efficiently compensated the suspension of face-toface teaching and provided more chances for open discussions. nomination of the same staff to virtually present each topic for both male and female students encouraged more peer sharing and competition among the students q . the rescheduled educational activities were more convenient to the students, as reflected in their attendance. recent technologies resolved the lack of physical attendance and increased learning effectiveness. , the horizon report highlighted the effectiveness of online teaching in overcoming the restrictions such as shortage of venues for large group lectures. however, one of the main challenges of e-learning, as reflected in the current work, is in teaching the psychomotor, practical, and clinical skills efficiently. murphy recently reported that most medical schools suspended q the clinical settings during the covid- pandemic. this could be overcome by using virtual-reality simulators. , unfortunately, most of the students were unsatisfied with how some staff members practiced e-learning. a previous study performed in a similar culturedunited arab emiratesdobserved that the teachers felt worried about the shift into a new educational strategy. psychological assurance was recommended to encourage them to deal with the unknown consequences. multiple webinars about proper virtual classrooms and peer sharing of experiences between the staff members solved this problem. goh et al. claimed that live streaming applications will improve the technological skills of the educators. pivot meded appreciated the free elearning webinars for health professional educators worldwide and the national coordination between medical schools in sharing such training courses. successful collaborative online learning demanded the support of it technicians, as previously reported. , the cronbach's alpha test implied that the survey tool had a good level of internal consistency and reliability for both the students' survey and staff's overall satisfaction in the live streaming experience. the correlation coefficient indicated that the items in the students' survey were well correlated. however, the application of kendall's tau b test on the staff perception was non-feasible since it measures the association between two variables, unlike the current study which focused on the staff perception on the effectiveness of virtual classrooms. the higher achievement level detected in the mean marks of online pbl compared with face-to-face sessions could be attributed to the easier access to the explanation of the phenomena. the students' assessment during the pbl sessions in this work was based upon their commitment, team spirit, interaction with peers and tutors, presentation skills, and ability for brain storming and analysing the phenomena. the students' assessment during the pbl sessions was based upon their performance during the session rather than their achievements through other summative assessment methods such as multiple choice questions which are associated with higher chances of cheating q . these findings are in agreement with the previous study which observed that online pbl enhanced critical thinking and fulfilled the intended learning objectives. therefore, online pbl could enhance the metacognitive skills, ability to solve problems, and team working. collaborative interaction in the online environment helped enhance peer sharing. after the sars epidemic, one medical school in china adopted online pbl as an educational strategy for the subsequent years. the higher pbl scores in female students could be attributed to the difference in the style of thinking, learning, and capabilities of problem-solving. makonye detected that female students have more ability for knowledge perception and reflection of their own ideas, and a higher competitive attitude. additionally, this gender variation in pbl scores could be due to a higher commitment of female students in attending different educational activities. however, ajai and imoko observed equal performance of male and female students in pbl sessions, and q recommended further studies to examine the underlining causes. validity and reliability of assessment should be established to ensure students' achievement of the learning objectives. the ability to solve any technical obstacle met during the online mock exam helped the e-assessment committee to manage the subsequent exams appropriately. results of the online assessments and their item analysis represented evidence-based high-quality evaluation. this perception was supported by jawaid et al. and bandele et al. who reported that students expressed a more positive attitude towards online exams. similar findings were also observed by martin et al. who emphasised that ideal assessment was based upon optimal evaluation strategies. the online tests were revised by the e-assessment committee, in coordination with the supervisors of the relevant departments, to estimate sufficient time for each exam. redistribution of students' grades towards more objective assessment strategies such as pbl, seminar presentations, and oral assessments was kept in consideration. this minimised the subjectivity of grading, as expressed in the feedback gained from the focus group, and discrepancy in students' grades, in agreement with ozden et al. . the procedures implemented during the online exams to minimise the chance of cheating and unauthorised collaboration with peers included scheduling of brief exams of not more than min with a timer set for the whole exam and also for each individual q question. formulation of a considerable number of scenario-based questions was implemented focusing on higher-order critical thinking, following the bloom's taxonomy. questions and answer choices were randomised; each question was presented on a separate page with forced completion of these questionsdstudents were not allowed to return to the previously-submitted questionsdin agreement with fontanillas et al. . a backup version of the questions with the same difficulty index was prepared for those students who experienced technical difficulties during submission. the answers were not displayed to the students until the examiner's permission was obtained and all participants had completed answering q . the potential use of teal in medical educationdthe future learning eradis expected after the resolution of the covid- pandemic. analysis of the benefits of e-learning in the present study could help the decision-makers of educational policies and committees of curriculum reform to implement them in the future. goh and sandars pointed out that the medical educators worldwide, being deeply involved in the current tremendous shift towards e-learning, have to adapt to the current major educational challenges. appropriate e-learning resources should be available to guarantee the implementation of these enormous changes. more use of technological tools will enable the medical schools to establish the active process of e-learning. the horizon report focused on 'learning engineering' such as the virtual reality simulators to facilitate the rapid development of teaching and learning. online courses form one of the key success factors to achieve the program learning outcomes of medical graduates. the current work explored the benefits of the shift towards e-learning and online assessment, which is a promising strategy with great educational potentials, after the who's declaration of the covid- pandemic. this successful digital learning environment was observed in terms of student and staff satisfaction, achievement, and improvement of technological educational skills. the present study recommends a sustained monitoring and updating of the e-learning resources, particularly the official lms, and availability of sufficient number of information technology personnel. multiple webinars and workshops suggested increasing the student and staff awareness of online teaching and assessment via q improving the current faculty development program. furthermore, the adoption of teaching through complete and partially online courses, and a total shift from physical attendance for pbl sessions to online ones are encouraged in the future. all data are available from the corresponding author upon reasonable request. researchers would like to thank the deanship of scientific research, qassim university for funding the publication of this project. the authors have no conflict of interest to declare. ethical approval was taken from the ethical committee of qassim university. written informed consents were obtained from all the participants. waa conceived and designed the study, conducted research, provided research materials, and collected and organised the data. ae and aes analysed and interpreted the data. all authors wrote the initial and final drafts of the article, and provided logistic support. all authors have critically reviewed and approved the final draft and are responsible for the content and similarity index of the manuscript. jtumed _proof ■ october ■ / covid- and medical education online learning 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acknowledge the college of medicine, qassim university for the generous facilitation of the required learning resources. key: cord- -jkscwdjh authors: adarkwah, michael agyemang title: “i’m not against online teaching, but what about us?”: ict in ghana post covid- date: - - journal: educ inf technol (dordr) doi: . /s - - -z sha: doc_id: cord_uid: jkscwdjh globally, information and communication technology (ict) is regarded as a dependable vehicle for facilitating educational reform and development, a platform for communication, and as a means to achieve the sustainable development goal four (sdg ). since the enactment of the no child left behind act (nclb) and declaration of the sdg , many countries have opted to embrace the lifelong education for all by integrating ict in teaching and learning at all school levels. the ghanaian government’s initiative to ensure “education anytime anywhere for everyone” by revolutionizing teaching and learning through ict has faced a lot of challenges and criticisms. the main mission of the ghana ict for accelerated development (ict ad) in was to transform ghana into an information and technology-driven high-income economy through education, but this goal is yet to be realized. in the wake of the covid- which has forced many countries and educational sectors to adopt online learning, there is a need to discuss the effectiveness of online learning and barriers to online learning in the developing contexts, and how to successfully integrate ict in schools for online learning, especially rural schools where students’ educational careers are in jeopardy because they benefit less from online learning. the paper identifies critical factors that affect online learning, recommends post covid- strategies to promote e-learning for policymakers in education and the government, and concludes with a conceptual model for emergency transition to e-learning. online learning is hailed as an essential force in democratizing education (jones ) . it is a way of opening education to populations who had restricted access because of geography, status or physical handicap (carr-chellman ) . khan ( ) defines it as an innovative method to instruct students in remote areas, which involves all types of learning that is done using the computer or other ict resources. since the term was first introduced in , it is used as an overlapping concept with blended learning, elearning, online courses, and online or distance education (singh and thurman ) . the advancement of ict has called for online learning as a feasible and economically appropriate means of extending quality higher education (asunka ) . the role of ict in education, specifically higher education, cannot be downplayed, it is beneficial for teachers and students (aljaraideh and bataineh ) . however, the challenge associated with online learning is the access to ict resources because online learning thrives on the availability of ict facilities (arthur-nyarko and kariuki, , b) . there is an uneven spread of access to ict among different populations, households, and spaces because network is not the same everywhere (lembani, gunter, breines, tapiwa, & dalu, ) . the significant role ict plays in the development of any nation has called for countries to produce ict literate citizens (crisolo, ) . ict has gained a solid reputation in the education systems of both developed and developing countries (law, pelgrum, & plomp, ) . ict in education can provide the twenty-firstcentury skills needed to adapt and compete in this knowledge and information society (haji, moluayonge, & park, ) . according to the authors, ict in education enhances student learning, provides education to students with no or limited access to education, aid in facilitating the training of teachers, and enhances the skilled workforce and promote social mobility. ict is also considered as essential for quality higher education (liebenberg, chetty, & prinsloo, ) . ict has the ability to enhance learning, make a subject appealing, facilitate problem-solving, communication, research skills, and decision-making process (hong, ) . waluyo ( ) adds that ict is a positive predictor of the academic achievement of students in mathematics, science, and reading. ict also facilitates teaching and e-learning, which ultimately have a positive effect on teaching, learning, and research activities. a general assumption is that for ghana to meet economic, social, and political global demands, ict should be prioritized. in light of this, the ministry of education of ghana introduced the "one laptop, one student" policy where , laptops were dispensed to schools (three schools in each region) across the country (education sector performance report, ). another , laptops were also purchased to be distributed to junior high schools (education sector performance report, ) . according to amanortsu, dzandu, & asabere ( ) , most of the government initiatives to ensure quality and accessible ict education for all in ghana has failed to achieve its goals. for example, agyemang & dadzie ( ) found in their study that a policy statement for supplying ict based-support for distance education (de) learners were available but were yet to be implemented. the integration of ict in teaching and learning is still at the early stage in the education systems of most developing countries (antwi, bansah, & franklin, ) . over a decade ago, ghana introduced de as a means to provide learners with access to quality education and promote human resource development (addah, kpebu, & kwapong, ) . one of the major challenges in the ghanaian education system is the inequality of educational resources which includes usage of computers and other ict materials (buabeng-andoh, ) . antwi et al. ( ) mentioned that the provision of ict in secondary schools for learning is skewed towards schools categorized as premier ("a") schools and located in urban areas. also, at the primary level, provision of ict is also skewed towards private schools (ayebi-arthur, aidoo, & wilson, ) . governments should fund ict projects that emphasizes on the needs, capacities, perspectives, and aspirations of the greater number of people living in rural areas (david, ) . the main objective of the study is to provide possible solutions for successful transitioning, implementation and sustenance of e-learning programs. the paper first identifies the e-learning challenges in the ghanaian context based on respondent's views and then provide strategies for smooth delivery of e-learning derived from extant literature the research questions leading this investigation are; what are the perceived effectiveness of the online learning, what are the perceived barriers to online learning and what are the perceived strategies for a successful ict integration in education for students who are unable to partake in e-learning process because of environmental and contextual factors related to ict in lieu of the covid- crisis. there are limited studies that thoroughly examines the effectiveness of and barriers to the online learning, and identify critical contextualized factors to enhance online learning in developing countries like ghana since the inception of the covid- . the government of ghana has invested several resources and initiated many promulgated policies to ensure ict is accessible to every student in ghana because of its pivotal role in education. the first governmental policy on ict was the ict for accelerated development (ict ad) in which outlined a framework that sought to transform ghana into an information and knowledge-driven ict literate nation (ministry of education, ) . this policy was reviewed twice (in and ) until a revised policy document was made available in . the main goal of the revised version was to facilitate the integration, utilization, and modernization of ict in schools in ghana. it was proposed that ict should be integrated as a core subject, an elective subject, and as a teaching tool for all other subject areas. the policy highlighted that ict access and literacy is low in ghana. one of the main goals of the educational reforms is to ensure that all students in ghana in the pre-tertiary institutions acquire basic ict literary skills (which also include the use of internet), and apply the skills in their studies and in their daily activities (mereku, yidana, hordzi, tete-mensah, & williams, ) . a survey of lecturers and students in accra polytechnic revealed that access to ict facilities was inadequate, time to access ict was inadequate, and there was little use of ict software (amanortsu, dzandu, & asabere, ) . another study in ghana found that % of the respondents teaching ict in the early years of school had knowledge about ict, and % of the teachers did not integrate ict in their teaching (asante, ) . boni ( ) in his study concluded that both teachers and students in ghana lacked the efficacy and creativity in using ict for teaching and learning. mubashir-ahmed ( ) attributes the the challenges associated with ict integration in ghanaian schools to lack of internet access, lack of quality teachers, insufficient number of computers, high cost of ict gadgets, and lack of electric power in some communities. another study in ghana revealed that access to electricity is a major factor affecting online learning in the country (arthur-nyarko and kariuki, , b) . despite the unprecedented efforts by successive governments to ensure ict is integrated in teaching and learning, the process have been fraught with a lot of challenges in ghana, especially in the rural areas. ghana ranked th among countries in the global ict development index in after being ranked rd in (international telecommunication union, ; international telecommunication union, ) . in lieu of the covid- crisis, the government of ghana announced the suspension of all school operations both pre-tertiary and tertiary on march , , as parts of the efforts to stop the spread of the virus (cromwell, ) . the closure of universities and schools have disrupted the learning of students and have deprived students opportunities for growth and development (unesco, ) . digital learning emerged as an ultimate response to the disruption in education due to the covid- lockdown of schools. since the lockdown, the government of ghana has considered the possibility of initiating online courses for students. instead of been proactive in ensuring rigorous implementation of online teaching and learning, the education system was stagnant until it was prompted by the covid- crisis. the minister of education, matthew opoku prempah announced that the center for national distance learning and open schooling (cndlos) has rolled out an online platform that will make core content accessible to all students in the senior high school (shs) level. he further declared that the ministry had plans in place to broadcast more contents to the junior high school (jhs) and upper primary students. however, the national union of ghana students (nugs) has petitioned the government to halt all online academic activities launched in the universities across the country (anyorigya, ) . the nugs referred to the online learning as "challenge-ridden online learning". the association cited inadequate bundle incentives for schools (lecturers and students), lack of properly laid framework for the implementation of online learning, and the plight of needy students who have been left out of the online learning platforms because of their inability to settle school bills. another concern raised by the nugs is the possibility of compulsory exams and assignments on e-learning platforms that will disadvantage students who are unable to participate in the online learning because of factors beyond their control. online learning in sub-saharan africa is a great challenge because it relies on the availability of ict facilities (asunka, ) . according to the unesco ( ), there is a gap between the availability of ict infrastructure and the capability of agrarian communities to integrate ict to boost the economy. also, the report mentioned that african universities and teacher education institutions do not have the adequate ability to help integrate ict in schools. with the limited access to ict resources and institutional challenges in its implementation in sub-saharan countries such as ghana, there is a need for the government and education sectors across the country to address contextual and environmental difficulties faced by needy and rural school students who are excluded from the e-learning platforms which are no fault of theirs. e-learning is beneficial (arthur-nyarko and kariuki, , b), but its effectiveness is contextualized (lembani, gunter, breines, tapiwa, & dalu, ) . students from developing countries score lower in online learning and are likely to withdraw from the online courses compared to their colleagues in developed countries (kizilcec & halawa, ) . in the us, a meta-analysis of existing data revealed that students engaged in online learning performed better than those in face-to-face sessions while students who blended online and traditional learning performed the best of all (the council of independent colleges, ). a student may be part of the online learning but may not actively use the service or follow the tutor (bean, et al., ) . barriers identified in literature include; high cost, inadequate infrastructure, lack of ict skills, rejection of e-learning by faculty members, and lack of accessibility to quality internet connection and electricity. start-up cost for online learning may be expensive (queiros & de villiers, ) . the high cost of purchasing ict equipment affect the adoption of online learning (sinha & bagarukayo, ) . technology and gadgets needed to make learning effective may not be cheap, affecting the online process negatively (srichanyachon, ) . limited funding can affect institutions from hosting online learning (bean, et al., ) . online education may cost more to develop and deliver than face-to-face courses (turk & cherney, ) . in tanzania, % of teachers declared they lacked access to computer, while % revealed they experienced low internet bandwidth (mtebe & raisamo, ) . teaching and learning can take place at anywhere and at anytime with the help of ict tools (cradler & bridgforth, ) . inadequate access to technology, studying materials and computers can leave students marginalized and anxious, which affect the online learning process (queiros & de villiers, ) . asunka ( ) , he concluded that only out of students had access to computer and internet connectivity at home. lack of technology skills and inadequate background experience with online learning are constraints to online education (olesova, yang, & richardson, ) . tutors ought to have required advanced technological skills which sometimes require schools to hire tutors from outside companies who already have the skills (bean, et al., ) . lack of experience with online teaching is a barrier to organizing online education (luongo, ) . students who do not have prior knowledge and experience in online learning sometimes also lack technical assistance and support systems (srichanyachon, ) . according to mtebe & raisamo ( ) , % of teachers engaged in online learning in tanzania lacked the skills needed to create or use online educational resources. most faculty members reject online learning as alien to them and are skeptical about it (bacow, bowen, guthrie, lack, & long, ) . some faculty members also consider developing online courses as time consuming in comparison to traditional methods of teaching (the council of independent colleges, ). hesitance by faculty members to teach online courses and their lack of acceptance of online instruction is a perceived barrier to online learning (turk & cherney, ) . slow and unreliable network connections affect the quality of online learning (bean, et al., ) . instructions can be delayed as a result of poor internet connections (srichanyachon, ) . in the study. limited internet access which includes poor internet connection and low speed demotivate institutions for pursuing online education (sinha & bagarukayo, ) . rural communities involved in online learning find it difficult to fund and attract qualified teachers to instruct advanced courses (de la varre, keane, & irvin, ). lack of internet access and computers in homes in rural areas affect the progress of online learning (depaul, ). lack of constant supply of electricity and internet access in rural communities also makes it difficult to assimilate the online education process (ivala, ) . in education, ict integration involves many interrelated factors such as curriculum, teacher characteristics, training and development, infrastructure, organisational factors like school leadership, school culture and supportive framework (judge, ) . ict integration concerns with the application of technology to aid student learn traditional academic subjects (grabe & grabe, ) . according to the authors, successful ict integration has transformed communities and shaped their lives and thoughts. in , the british columbia ministry of education announced the integration of ict in kindergarten to grade throughout the country to ensure that the education system remains important and actively engage students (birch & irvine, ) . successful integration of ict in schools still face myriads of obstacles (hew & brush, ) . integration of ict in developing countries is still a challenge (aksal & gazi, ) . one of the first steps to ensure successful ict integration is to consider the structural (availability of resources and classroom space, availability of ict support and maintenance) and cultural (mission and vision of the school for ict integration) elements of the school where ict is being integrated (tondeur, devos, van houtte, van braak, & valcke, ). bingimlas ( ) outline some necessary steps to ensure successful ict integration; provision of ict resources (both hardware and software), training new pedagogical approaches to faculty members resistance to change, provision of training courses on how to deal with new gadgets and modern technologies, providing sufficient time for daily lessons, and provision of continual reliable technological support. sarkar ( ) lists the critical elements for to be considered during the implementation of ict in learning; leadership issues, equitable distribution of ict resources and sustainability, and financial issues. the study adopted a qualitative method using a narrative inquiry approach to explore the perceptions of students on online learning in ghana and how to successfully integrate ict in education to improve online learning for students, especially those in urban poor and rural areas in ghana. in a qualitative study, a central phenomenon is the process, key concept or idea that is studied, and a researcher learns more from participants through exploration (creswell, ) . data was collected through interviews. a list of post-covid- strategies was formulated from extant literature based on respondents' views. the researcher used a semi-structured interview guide comprising of a list of prepared questions related to the research questions to conduct the interview. the instrument was prepared based on recurring themes in extant literature and was screened for accuracy and validity by a researcher in ghana. this allowed the researchers to ask open-ended questions to ensure respondents give their broad perspective about the topic of the study. interviews allow a researcher to probe and get an in-depth meaning of the feelings, perceptions and attitudes of participants (gaffas, ) . all tertiary students from urban poor and rural areas who took part in the online learning in ghana formed the target population. fifteen ( ) of the students were randomly selected to be part of the study. five ( ) students were taken each from the most cosmopolitan regions in ghana (greater accra, ashanti region, and central region) to make up the total sample of the study. the student came from the universities, teacher and nursing training schools in the country (table ) . students from the tertiary institutions in ghana who were taking part in the online learning in ghana were recruited to find answers to the research questions. an introductory letter was sent to the randomly selected students about the purpose of the study and to seek their consent to be part of the study. after the consent of the study respondents were gained, the researcher scheduled an appointment with each of the participants to conduct the interview. all interviews were conducted in english using the "whatsapp" application. the researcher transcribed the recorded interviews verbatim and the data was analyzed into themes and sub-themes using the nvivo . software. the interviews were replayed severally to ensure the accuracy of the transcription. the researcher used pseudonyms for each of the participants to ensure confidentiality. almost all the barriers associated with e-learning in literature reviewed earlier were prevalent in the ghanaian context (see table ). the findings of the interviews conducted suggest that the online learning in ghana is not effective enough and is also fraught with a lot of challenges. the section concludes with innovative and some novel solutions found in extant literature to the problems identified in the study and a conceptual framework for transitioning to e-learning. most of the students interviewed indicated that the online learning is the best alternative approach to teaching and learning during this pandemic. however, because of its spontaneous nature, and not an approach to education carefully thought of my school leaders and the government, they felt the online learning was not effective as they hoped for. social interaction an ample amount of the students felt the lack of student-student interaction and teacher-student interaction negatively affected the effectiveness of the course. "oh ok, personally, i think this online learning is not that effective. let me take campus for example, on campus you go for lectures, you meet the lecturer, you will have this interaction, like face-to-face, so that makes you really comprehend what the lecturer is putting across, and aside that you even have the teaching assistants who are willing to help you understand or if you have any difficulty they are able address that issue." [lucy-university] student outcomes only few of the students believed students' outcomes in the online learning would be better than the traditional approach. many believed that the difficulty with internet access and network challenges will result in a negative effect on the outcomes "the student outcome of online learning as compared to the traditional approach is very sad and heartbreaking. let me take the quiz for example, you will take a quiz online, and the system gets jammed, you've really learnt, not that you didn't learn, you've really learnt, and you go, and you're able to answer the questions, let me say if it is out of , you are able to get or correct, and then you get an f, it just saddens my heart" [ellen-university] communication some of the students were of the view that sometimes communication between teacher and students is not possible because the e-learning system can go off for a while before it starts functioning. "the intercommunication between lecturers and students is very poor. communication is not good. you will be having a class, and then the network starts misbehaving, meanwhile, the teacher is talking! how do you retrieve the words he has already said? what if the words he has said is the stepping stone to understand the next sentences?" [sandra-nursing training] traditional versus online approach more than half of the participants interviewed believed that the traditional approach to teaching and learning is more suitable for them as compared to the online learning they were experiencing. "ok, what i can say is my university, for example, am reading chinese and political science, so with chinese the lecturer is supposed to write down the characters on the whiteboard for us to really eerrm know the stroke orders. also, there are instances that you need you need to even, eerrm for chinese oral you need to listen to the lecturer, like look at the lecturer's mouth, the expression that she makes for you to be able to understand whatever she is saying. so i think i prefer the marker-board because taking my course, for example, it really helps, yes." [ellen-university] cost one of the major challenge mentioned by almost all of the participants was the financial commitments they have to make to ensure they actively take part of the course. according to the students, the online method of learning was expensive than the traditional approach to learning they experienced. "online learning is quite expensive. so far the has given us a data sim which gives us . gigabytes every month. but the problem is, this bundle is just something small. it doesn't get us anywhere. i remember my first zoom class was not more than minutes, and megabytes was already gone." [ted-university] online platform persistently, the students lamented about the breakdown of the online platform. "with the accessibility to the online platform, i think with that is okay. sometimes you log in, and the site just jams, so that really hurt and when you have quiz to take, and you log in and the system jams and just log you out of the system." [paul-university] study materials the students believed that study materials were readily available to download at any time. "oh okay, every course has its learning materials on the site provided they have not given us already" [ted-university] ict tools a considerable amount of the respondents asserted that ict tools were not given to them prior learning. every student had to get an ict tool for himself/herself to engage in the online mode of delivery. "we use our own ict tools, like phones and laptops. the school does not provide us with ict tools. if you don't have these ict tools, you have to share that of a friend." [joe-university] prior knowledge most of the participants had little exposure to online mode of learning prior to their current online method of learning. "mmmm as for background knowledge i don't have much experience but per our experience of sending messages through e-mail and using other platforms to send documents that is what helped us in using the online learning platform, since we couldn't have an orientation on how to engage in e-learning." [bright-teacher training] internet access accessing the internet was one of the major challenges students mentioned. "good internet access is a huge challenge. so most of the students we adopted that midnight is when we will log into the online learning site to download and upload materials. it is effective as compared to the normal day hours. however, this has affected our sleep" [paul-university] electricity there were mixed views on the availability of electricity for the online learning. some believed lack of electric power affected their learning while others were okay with it. "hmmm electricity is another impediment. recently our transformer got spoilt, and it took almost two weeks for the local government to fix it. meanwhile, tests and studies were ongoing." [mercy-university] education many students indicated orientation of teachers and students on ict for teaching and learning is integral for successful integration of online learning in schools. "for me, i think it is not only students who have to be educated on e-learning. my brother is not ict teacher and has no special skills in ict, but he is also supposed to use online learning platforms. he likes to use social media than to use the online platform for sending documents." [ted-university] provision of ict tools some students called for the provision of ict tools for schools and students who can't afford the tools for themselves. "the government should provide laptops to students in the middle or high school so that by that the time the student comes to the tertiary level, he or she has a laptop and can have access to many things online." [joe-university] motivation the students believed the motivation of both teachers and students would improve the online learning. "personally, i think the government should motivate teachers and students to engage in the e-learning. e-learning can be effective when there is motivation. the government can give allowances to teachers and reduce our school fees". [julius-university] "we students in the rural areas have no joy in this online learning. the challenges are too much. electricity and internet access are a major problem. if the government wants ict to be effective, all these problems should be solved." [prince-teacher training] school leadership students mentioned that school leaders should liaise with the government to improve the online learning. they believed school leaders could act as a channel for their voices to be heard. "school leaders like principals and vc have to eerrm, we have open forum where students bring their grievances on board, so as the src also take eerrm an active role in presenting the pleas and plights of students the school authorities, they also have to make the students' grievances known to the government so that the government can put the necessary measures in place to provide the tools that are needed to help the teachers and the students as well." [ellen-university] . post covid- strategies to promote e-learning providing electricity solar power gadgets and human-powered electricity have emerged as a promising solution to the increasing digital divide as a result of lack of electric supply (wyche & murphy, ) . the authors states that although solar photovoltaic-powered devices can charge mobile phones and some ict gadgets for e-learning, human-powered electricity are more preferable because human power is abundant worldwide. human-powered electricity is when human activities such as cranking (by hand) and pedalling (using the legs) are captured to turn a dynamo to generate electrical charges for electronic applications. in kenya, the researchers found the two models effective for providing micro-electricity for electronic devices. jimba & ogundele ( ) opined that solar power supply, biomass, standby power generators and wind power supply are promising solutions to generating electricity for virtual classrooms in nigeria. according to the authors, this makes teaching and learning effective without any disruption in power. hamajoda ( ) is of the same view that solar power supply and standby generators can facilitate e-learning by dealing with the challenges associated with electricity in rural areas. fostering acceptance of e-learning academics are often slow to embrace e-learning but are required to adapt positively to changes resulting from technology (flavell, harris, price, logan, & peterson, ) , and one of the best ways to foster adaptive learning of technology is to improve instructor and student self-efficacy (solangi, shahrani, & pandhiani, ) . flavell et al. ( ) state that one of the ideal ways to empower academics to be adaptive with e-learning is to engage them in recreational activities such as reading on technological devices for pleasure, playing games, or using social media. this makes users comfortable with the e-learning and also increases their self-efficacy. media literacy (such as the use of social media) can foster acceptance of e-learning and increase digital literacy (nowell, ) . collaborative e-learning also promotes exchange of experiences and ideas among students, encourage students to work together, develop their academic competence, increase their self-efficacy, develop their social skills and also fosters both their social and cognitive qualities for e-learning (ngai, lee, ng, & wu, ) . a wide range of e-teaching and e-learning methodologies can be introduced to encourage both teachers and students to embrace e-learning such as podcast and vodcast (uren & uren, ) . also, to ensure rapid acceptance of e-learning, a clear pedagogical rationale for online teaching which is rooted in instructor's personal philosophy for teaching and learning should be communicated to instructors (donnelly and o'rourke, ) . user-need analysis for adaptive e-learning adaptive e-learning has to do with the personalization of e-learning in accordance with individual user's knowledge and behavior, and one way to ensure that is through user-need analysis (agustini, ) . developers of e-learning platforms need to perform a user-need analysis; they have to take into account the learning styles of individual learners when creating, selecting, and evaluating e-learning platforms (muhammad, albejaidi, & akhtar, ) . according to the authors, user needs can be solicited by employing mix techniques including direct observation, expert review, administering web-based and paper questionnaires, and interviewing teachers and students. online learning should be planned to meet the learner's expectations (hachey & lachapelle, ) . alhabeeb & rowley ( ) adds that identifying both student and instructor characteristics for e-learning is a critical success factor for e-learning, "success" for one group does not necessarily connote "success" for another group. learners on e-learning platforms should be thought of as customers by making it easy to use, making effective use of learner's time, and it has to be attractive and comfortable (morrison, ) . leaner preferences and experiences are integral for a flexible mode of e-learning delivery (arthur-nyarko and kariuki, , b). teacher's presentations and course materials for e-learning should also be prepared based on students' needs and learning styles (osubor & chiemeke, ) . digital literacy of users the training of digital users is instrumental to ensure the successful transition and integration of e-learning platforms (muhammad, albejaidi, & akhtar, ) . training has been recognized as having a positive influence on the usage of e-learning systems (solangi, shahrani, & pandhiani, ) . training is a critical success factor for e-learning and should be provided for both learners and instructors (alhabeeb & rowley, ) . professional development training programs provide teachers with "hands-on" activities, it is essential for them to develop ict competence and technological pedagogical content knowledge for twenty-first-century learning (alt, ) . course facilitators should be trained on computer literacy and application for effective e-learning (jimba & ogundele, ) . one way to ensure digital literacy for students is to embed digital literacy skills in the curriculum (johnston, ) . school leaders can ensure students develop their own skills by supporting them during orientation activities on technology, peer learning, and encouraging them to use personal technology (sharpe & benfield, ) . workshops and training on ict for e-learning are crucial for users especially teachers, for a flexibility in online delivery (forsyth, pizzica, laxton, & mahony, ) . infrastructure support infrastructure and technical support that provides an opportunity for teachers and students to adopt e-learning should be made available (solangi, shahrani, & pandhiani, ) . availability of telecenters which are equipped with computers and internet connectivity in a poor rural community can help in the integration of ict in developing countries (avgerou, ) . research findings on ict in ghana revealed that institutions engaged in online learning need technology infrastructural support from the government, such as ict devices (arthur-nyarko and kariuki, , b). the "one student one laptop" policy by the ghanaian government failed to realize its goal and was an expensive investment. heeks ( heeks ( , argues that mobile devices can now be used to surf the internet and create new content, it could be used as an alternative for poor households in accessing the internet for learning purposes to defray the cost of expensive laptops, mobile technologies can be an alternative. school leaders can lassie with the government to also establish e-learning centers in the various tertiary institutions (piña, lowell, & harris, ) . the e-learning centers may be staffed with professionals such as technology specialists, media, administrators, and faculty support specialists who provide training support and training for effective engagement with e-learning tools. funding aside fees from students and government which are made available to schools, institutions which are new to online learning can establish e-learning centers and charge some type of fee (convenience fee) or online tuition rate (piña, lowell, & harris, ) . funds from the general student population and the government are often claimed by other areas. according to the authors, students who prefer the flexibility of taking online courses are willing to pay this extra fee. the institution can decide to access an online learning fee or a higher online tuition rate, which could serve as direct source of funds to e-learning centers on campus. it is near to impossible to reassign such funds to other areas. the institution receiving such funds would have the capacity to run e-platforms effectively. motivation incentives and reward systems can motivate teachers and students to engage smoothly in e-learning (o'doherty, et al., ) . when teachers are rewarded on the time spent instructing students on e-platforms, they are motivated to spend extra time and dedicate more efforts in instructing students. in a study conducted in russia, students decision to engage in online courses was due to available incentives (markova, glazkova, & zaborova, ) . incentives for teachers can be in the form of allowances and compensation. students can be provided with free wifi or subsidized cost of internet charge. this would encourage them to spend more time surfing for information on the internet, downloading course materials and uploading assignments. the government of ghana can work with internet service providers in the country such as mtn and vodaphone to provide internet access with high bandwidth to prevent them from withdrawing from e-platforms. supervision and evaluation an uninterrupted technical support is required from elearning users (teachers, students, and administrators) in addressing hardware and software problems associated with the computer application (muhammad, albejaidi, & akhtar, ) . rigorous supervision will help address glitches associated with eplatforms to ensure its continual functional. it personnel and e-platform administrators can be assigned to monitor the progress of the online learning to identify and solve all hardware and software challenges. academics involved in e-learning need assistance on shifting from the conventional mode of teaching and learning to a virtual teaching and learning environment (donnelly and o'rourke, ) . this assistance can be provided by "e-champions" and ict skilled personnel hired by the school. the authors mentioned that feedback of users on e-platforms are also essential for evaluating the success of e-learning, and this can inform school leaders on what to include in subsequent workshops for e-learning users. also, using data derived from users of eplatforms will help the administrators and designers of the e-platform on how to structure the platform to meet students' needs and the unique culture of the institution. blended learning picciano ( ) define blended learning as a combination of both online and face-to-face interaction. response from the participants suggests that a blended learning approach could help address the differences among students. picciano also mentioned that a blended learning approach could mitigate the challenge associated with geographical distance. students who are far away from their institutions and prefer an online mode of delivery can learn from home through their e-learning platforms while those who prefer the traditional face-to-face interaction can learn at the classroom. onguko ( ) believes that a blended mode of delivery is more ideal for universities who are not yet ready for only online learning. the author indicated that some universities in kenya incorporated a face-to-face session in their virtual classes to address some difficulties connected with online learning. the model serves as a framework for universities and academic institutions for an emergency transition to e-learning. this is adapted from texas tech university health science center el paso (ttuhsc ep) in their response to rapid transition to e-learning during the novel coronavirus pandemic (mulla et al., ) . quality e-learning programs require time and unprecedented efforts to ensure successful implementation. the model suggests that for successful implementation and sustenance of e-learning programs, school leaders must first inform faculty leaders about available resources and the best method to ensure the transition; a simulation course should be created, faculty staffs need to be trained and assisted, as well as soliciting their feedback and suggestions; the course can then be submitted; an e-learning compliance committee (elcc) should be set up for peer evaluation and for acquiring copyright permissions to keep the e-learning platform functioning (fig. ) . the paper adds value to prior literature on ict and online learning by first identifying the challenges associated with online learning in the developing context like ghana during the covid- pandemic. the study concluded by highlighting on some practical strategies for the adoption and usage of online learning in institutions in developing countries new to online learning. findings from the study suggest that the mulla et al. ( ) online learning in ghana is fraught with a lot of challenges apart from high cost and infrastructure (asunka, ; bean, et al., ; cradler & bridgforth, ; turk & cherney, ) . to address the problem of cost, school leaders are encouraged to establish e-learning centers which can generate funds solely for the purpose of online learning. also, the limited amount of electric supply for e-learning activities can be mitigated by using affordable solutions like solar power gadgets, biomass, and humanpowered electricity which are readily accessible in the country. again, school leaders are to employ recreational approaches like the use of social media and games to increase the self-efficacy of students for online learning. collaborative e-learning for teachers and recreational approaches are essential for fostering acceptance of e-learning by both faculty staffs and students. in addition, to effectively develop an e-platform tailored to the needs users, a user-need analysis has to be performed to know individual preferences and need. the university administration also has to set up professional training programs for teachers to improve their digital literacy. courses needed to improve students' it skills can be mounted during the first year at school or during the few weeks of orientation. moreover, because of geographical distance and individual learning styles and behavior, a blended mode of delivery is preferable such that students can choose either a face-to-face session or an online mode of delivery. it was also identified that the motivation of teachers and students is integral for smooth online learning. school leaders should motivate teachers and students in the form of incentives, allowances, free wifi and subsidized cost of data bundle. the school administrators can laisse together with the government to employ mobile technologies to replace the high cost of laptops. furthermore, because e-learning often experience hardware and software issues, school administrators should put in place a team of experts and technical resources for routine supervision and the evaluation of the elearning program. overall, findings of the study provide novel insights for educators and policymakers for the transition and usage of e-learning in the and post covid- pandemic. despite the significant investment of most low-income countries such as ghana in ict, challenges such as access to ict, reluctance by both teachers and students to use ict, network and electricity issues still persists in ghana. in lieu of the online learning activity taking place in most institutions in ghana, the study revisits how ict is fundamental to online learning and education in general. the principal objective of the study was identify possible solutions to some perceived barriers in e-learning and ict integration in ghana. findings from the study suggests that access to ict resources in ghanaian schools is still a challenge. as a result, students perceived the online learning is not effective. according to the students, although the online learning is a good initiative, they prefer the traditional approach as opposed to the online learning, which is fraught with a lot of challenges. the lack of social interactions, poor communication, and poor students' outcomes were associated with the perceived ineffectiveness of the e-learning. the students cited a lack of ict tools, internet, electricity as some of the barriers to online learning. most of the students interviewed did not have prior exposure to online learning or using ict tools to study. the students believed that orientation of both teachers and students on ict for online learning, motivation, and school leadership practices affect the integration of ict in education. the usage of solar power gadgets, the establishment of e-learning centers, acquiring funds from e-learning centers, adoption of blended learning, and providing infrastructural support such as using mobile technologies to replace the cost of procuring laptops are some of the listed strategies for educators to consider. ict plays an integral role in education and the economy of any country, help in resolving the barriers associated with online learning, and facilitates the successful integration of ict in education to enhance online learning. dessalegn & dagmawi ( ) opined that developed countries benefited from the integration of ict in education, unlike developing countries. the fact that higher education plays a vital role in the success of students and countries but there is limited access in africa, online learning can help bridge this gap (lembani, gunter, breines, & dalu, ) . it is therefore vital for stakeholders in education to integrate ict in education in ghana, and implement realistic and rigorous ict policies to ensure effective online learning where the needs of both urban, urban poor, and rural students are taken into consideration. the author recommend that future research examine the 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education barriers of administrators and faculty at a u.s. university in lebanon ict-enhanced teacher standards for africa (ictetsa) covid- educational disruption and response eteaching and elearning to enhance learning for a diverse cohort in engineering education the effects of ict on achievement: criticizing the exclusion of ict from world bank's education sector strategy powering the cellphone revolution: findings from mobile phone charging trials in off-grid kenya publisher's note springer nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations acknowledgements the author sincerely expresses his special thanks to professor yu zeyuan (southwest university, china), robert kyei (nsawam presby basic school), and edna agyemang (university of ghana). key: cord- - jjg qw authors: kiendrébéogo, joël arthur; de allegri, manuela; meessen, bruno title: policy learning and universal health coverage in low- and middle-income countries date: - - journal: health res policy syst doi: . /s - - -z sha: doc_id: cord_uid: jjg qw learning is increasingly seen as an essential component to spur progress towards universal health coverage (uhc) in low- and middle-income countries (lmics). however, learning remains an elusive concept, with different understandings and uses that vary from one person or organisation to another. specifically, it appears that ‘learning for uhc’ is dominated by the teacher mode — notably scientists and experts as ‘teachers’ conveying to local decision/policy-makers as ‘learners’ what to do. this article shows that, to meet countries’ needs, it is important to acknowledge that uhc learning situations are not restricted to the most visible epistemic learning approach practiced today. this article draws on an analytical framework proposed by dunlop and radaelli, whereby they identified four learning modes that can emerge according to the specific characteristics of the policy process: epistemic learning, learning in the shadow of hierarchy, learning through bargaining and reflexive learning. these learning modes look relevant to help widen the learning prospects that lmics need to advance their uhc agenda. actually, they open up new perspectives in a research field that, until now, has appeared scattered and relatively blurry. advancing universal health coverage (uhc) to improve population health is a long-term objective that many low-and middle-income countries (lmics) have committed to. since the release of the world health report , entitled 'health systems financing: the path to universal coverage' [ ] the flagship document that popularised the conceptextensive research and initiatives have focused on the subject matter at national and international level. such research and initiatives have helped to map the many challenges, identify best approaches to spur countries' progression [ , ] ; assess progress made by countries and build databases describing the situation prevailing in countries [ ] . yet, in many countries, challenges remain. research findings are not always properly integrated into policy and practice [ ] . above all, uhc is a complex endeavour at the crossroads of technique and politics, applied to health systems that are themselves complex and, thus, to some extent unpredictable [ , ] . for instance, a policy that has succeeded in one place may fail in another [ ] or the results of a policy designed and implemented in a country may be quite the opposite of what was expected [ ] . therein, it has been argued that the ability to continually learn and adapt is essentiallearning should then be at the heart of uhc-related policy processes [ ] [ ] [ ] . indeed, there is growing interest among global health actors towards 'learning for uhc'. some of them even have an explicit learning-oriented mandate in their support to countries such as the 'joint learning network for uhc', 'p h network', 'uhc partnership' and 'uhc ′. yet, there is not much scientific literature on learning processes related to uhc [ ] and questions abound, some highlighted in table . these questions, to a large extent, remain either not answered or only partially answered, probably because learning, itself, is an elusive conceptit is framed, defined, understood and used differently from one person or organisation to another [ ] . this article is not intended to provide a specific answer to each of these questions but to enrich our knowledge and understanding of what 'learning for uhc' could entail. it is worth mentioning that, if the attention to learning is relatively new in health policy, the concept has a long tradition in academia and has been extensively studied in other disciplines such as psychology, education, international relations, sociology, organisational studies and political science [ ] . learning can be approached through different theoretical and pragmatic perspectives, the most prominent ones including cognitivism, behaviourism and constructivism [ ] , or even social constructionism if we add a social dimension [ ] . from the cognitive stance, learning is related to the acquisition of new insights, assumptions, understandings and awareness resulting in new mental models or belief systems [ ] . the behavioural stance, meanwhile, insists on the need that such cognitive changes be followed, simultaneously or after, by 'shifts in actions or behaviours'the so-called 'cognitive-behavioural perspective' [ ] . changes in actions or behaviours in turn influence the cognitive aspects of learning in a kind of iterative loop [ ] , as observed in the 'action learning', 'after action review', 'action research' and 'learning-by-doing' approaches. as for the social constructionism stance, learning emerges from social interactions and realities through formal and informal networks such as communities of practice defined as "groups of people who share a concern, set of problems, or a passion about a topic, and who deepen their knowledge and expertise in this area by interacting on an ongoing basis" ( [ ] , p. ); for instance, when young practitioners learn by interacting with experienced medical staff in a hospital [ ] . this paper adopts and adapts the definition of learning put forward by two political scientists, dunlop and radaelli [ ] learning is the updating of knowledge, beliefs and actions based on lived or witnessed experiences, analysis or social interaction. beyond its synthetic nature, this definition meets our special interest for public policies, specifically uhc-related policy processes. the political science literature provides us with the concept of 'policy learning', which is learning applied to policy-making processes. it "occurs through the very practice of policy-making" ( [ ] , p. ). moyson and scholten define it as "the cognitive and social dynamic leading policy actors to revise or strengthen their policy beliefs and preferences over time" ([ ] , p. ). policy learning can manifest itself in a variety of ways, notably "as updates to our understanding of instrumental or technical aspects of a policy problem, as changes to our underlying policy beliefs or values about societal priorities in responding to problems, and as fundamental alterations to the institutions that target these problems" [ ] and also as adoption of new and innovative ideas. in the next sections of this paper, we first give a (nonexhaustive) overview of the literature on learning and how we came up to adopt the analytical framework by dunlop and radaelli [ ] . thereafter, we critically reflect on how this framework could help lmics widen the learning prospects they need to advance their uhc agenda. actually, without claiming to be exhaustive, we find this framework relevant to account for and capture a multitude of learning situations encountered empirically during uhc processes. these learning situations (or learning modes) could serve as reference points for national and international actors engaged in promoting learning for uhc to gain more insights on what they are doing and to help them make deep analyses and critical reflections on their actions in order to improve them. navigating the literature on policy learning is a daunting task since the latter is 'characterised by concept stretching' [ , , ] and resembles a maze where the risk of straying is ever present. this is exemplified by a recent bibliometric study conducted by goyal and howlett [ ] , which identified publications on the topic from to , and other literature reviews performed by leading scientists in the field [ , , ] . actually, the taxonomy of learning is rich, depending for instance on the content, direction and framing of learning [ ] or the methods and tools used. hence, learning types are diverse and not necessarily mutually exclusive, including, among table examples of relevant questions related to 'learning for uhc' • how does 'learning for uhc' occur at country level? • what type(s) of learning predominate or are favoured at country level and why? • what is the role of learning in policy-making processes? • what dynamics (actors and factors) facilitate or hinder learning processes at country level? specifically, how does context, including organisations' features and dynamics, shape learning and affect learning outcomes? • how and by whom are countries' learning needs identified? are they properly identified? • what actions are being taken to address these needs? are they successful? others, instrumental learning, social learning, political learning (may [ ] , hall [ ] ), policy-oriented learning (sabatier [ ] ), government learning (etheredge and short [ ] ) and organisational learning (argyris and schön [ ] ). besides, other concepts are closely linked to learning such as those of policy transfer (dolowitz and marsh [ ] ), policy diffusion (shipan and volden [ ] , marsh and sharman [ ] ), policy convergence (bennett [ ] , holzinger and knill [ ] ) and lesson drawing (rose [ ] ). in general, policy learning is studied in relation to policy change and fits best into the large group of cognitive approaches to public policy analysis, a school of thought that emphasises the role of ideas, beliefs, values and norms in public policy [ ] . actually, before heclo ( ) [ ] , the hitherto dominant paradigm was that only conflicts and power relations convincingly explain changes in public policy. heclo [ ] and followers of his school of thought challenge such prospect and emphasise the crucial role of ideas and learning. indeed, heclo argues that "politics finds its sources not only in power, but also in uncertaintymen collectively wondering what to do" ( [ ] , p. ); learning is thus seen as an answer to "the problem of managing and reducing radical uncertainty" ( [ ] , p. ) in policy-making. then, policy learning somehow opens perspectives in the analysis and understanding of complex interactions between knowledge, policy and power [ ] . moreover, it has been postulated that learning does not only generate positive effects and could have its setbacks. indeed, learning is not risk-free if one does not rely on the right actors, if its content is poorly understood and/or if its goals are diverted. for instance, it may happen that one is "persevering in listening to the wrong teachers", "implementing the wrong lesson" or "applying the right lesson to the wrong institutional context" ( [ ] , p. ), especially if there are no self-critical processes and/or iterative learning loops. furthermore, if learning purposes are ill-defined or poorly specified, it can be manipulated and used to legitimise choices already made and/or serve private or hidden interests [ ] . finally, as usual in any policy process [ ] , learning and its effects on subsequent policies can have political, economic or social implications, with vested interests of major players at stake. it is therefore important to analyse and consider the political economy surrounding learning endeavours [ , ] . by delving into the political science literature on learning, a book chapter has particularly attracted our interest since it was helpful in navigating the vast literature on 'policy learning'. this chapter concerns the allegorical description by dunlop et al. [ ] in the form of a family tree, of the evolution of the concept from the founding fathers (notably john dewey, harold lasswell, karl deutsch, charles lindblom, herbert simon and hugh heclo) to the most recent developments. dunlop et al. [ ] distinguish three main periods: the late s to the s (corresponding to the roots of 'policy learning'), the s to the s (assimilated to the trunk of the tree) and s to the present (representing the branches of the tree). they assert that recent work is "less concerned with the type of learning per se (instrumental, political, social …) and more focused on the characteristics of the policy process that determine varieties or modes of learning" ( [ ] , p. ). for example, the policy process can hold epistemic, hierarchical, bargaining-oriented or reflexive trait [ ] . this strong connection between learning features and policy process features resonated with recent work that dunlop and radaelli have pioneered, sparking our interest in the analytical framework they proposed [ ] . dunlop and radaelli [ ] use the 'concept formation' approach proposed by sartori [ ] and the 'exploratory typologies' technique described by elman [ ] to make the concept of policy learning more tangible. for that, they identify, from the literature, two main dimensions that matter in the social and learning mechanisms of policy processes. the first one is 'problem tractability', which relates to the level of uncertainty regarding the policy issue under discussion, the degree of solvency of the problems subject to learning [ ] -"a repertoire of solutions, algorithms, or ways of doing things" exists ( [ ] , p. ). low tractability is equivalent to high uncertainty and vice versa. when tractability is high, the transferability and diffusion of lessons learned and solutions from one setting to another is easier, and vice versa. the second one is 'actors' certification', that refers to "the authority and legitimacy of some key actors or venues" ( [ ] , p. )certified actors have a privileged position to influence decision/policy-making and the higher their level of certification, the higher this privilege. drawing on adult education science, dunlop and radaelli [ ] metaphorically assimilate 'learners' to decision/policy-makers or policy implementers and 'teachers' to knowledge holders or producers (e.g. experts, scientists, interest groups, think tanks) striving to influence decision/policy-making or institutional rules. in this perspective, low actors' certification equates to a low divide between the learner and the teacherthere is no knowledge hierarchy. by crossing these two dimensions, 'problem tractability' and 'actors' certification', dunlop and radaelli [ ] end up with a four-quadrants matrix and subsequently classify the vast literature on policy learning according to these four quadrants. in doing so, they identify four learning modesepistemic, reflexive, bargaining and hierarchical learningsdepending on the level of uncertainty or actors' certification vis-à-vis the policy issue ( fig. ) . we postulate that these four learning modes could help better understand the scope and variety of configurations that 'learning for uhc' can take. epistemic learning and learning in the shadow of hierarchy, typically, are vertical and prescriptive ways of learning. in epistemic learning, you have ( ) someone who 'knows' and someone who is likely to learn, ( ) intractable policy issues looking for technocratic answers. 'expert power' [ ] is actually used to look for solutions to well-identified problems. experts and scientists are at the heart of the policy process and enlighten policymaking through their authoritative knowledge. as for learning in the shadow of hierarchy, it piggybacks on the exercise of authority, such as a principal who creates some pressure on an agent to learn [ ] , for example, because of frequent supervisions. such learning may be used to achieve specific or predefined goals or results. if epistemic learning and learning in the shadow of hierarchy are two vertical learning modes, reflexive learning and learning through bargaining are rather horizontalthere is no pecking order in knowledge. reflexive learning entails open, deep, inclusive and critical discussions without (self) censorship between policy actors to gain mutual meaningful insights on issues at stake. learning through bargaining, meanwhile, implies repeated social interactions and "is often the unintended product of dense systems of interaction between politicians and bureaucrats" ( [ ] , p. ). dunlop and radaelli's approach to policy learning modes enriches the field of public policy analysis by highlighting the role of learning in policy-making and decision-making spaces, both conceptually and empirically. this is relevant from the uhc perspective regarding the critical role that learning could play in uhc processes, especially with the complexity of health systems [ , ] . our hypothesis is that dunlop and radaelli's work offers an opportunity to pursue a reflection in this direction, starting with the learning modes they propose. in the next sections, we offer some personal reflections on how these learning modes already contribute and could probably be even more applied to uhc in lmics. due to our professional history, we are probably privier or more acquainted to epistemic forms of learning through our own engagement in epistemic communities. however, where appropriate, we strived to ignore this posture and took the critical distance needed to explore/illustrate the other forms or modes of learning occurring in uhc processes. when relevant, we also highlight how learning intertwines with power relationships. epistemic learning is probably the most visible, analysed and rationalised mode of learning today in global health [ ] . this is probably also true for the uhc agenda, something which might be explained by its strong technical dimension and health financing lineage [ , ] . when we are facing a question, we look for an expert or an actor able to implement a rigorous approach to remove the uncertainty. it is so prevailing that it is actually our main understanding or expectation of how learning should take placethis seems particularly true within a scientific community so committed to research and the prospect of evidence-informed policy. epistemic learning takes several configurations in our 'collective action for uhc' in lmics. epistemic learning encompasses situations such as ( ) reading a policy-brief or even a scientific article, particularly a systematic review or a metaanalysis; ( ) attending national, regional or international meetings or training workshops; ( ) the release of conceptual or analytical frameworks to better understand the concept of uhc or its linkages with health system pillarsexamples include the health financing functions [ , ] or the 'uhc cube' [ ] ; or ( ) specialist agencies or researchers sharing lessons learned in other countries [ , ] or developing policy guidance notes on how to move quickly towards uhc [ ] [ ] [ ] . epistemic learning can also take a more active form, for instance, as technical assistance to countries in various possible arrangements -'fly-in/fly-out' or longterm technical assistance [ ] , with local and/or international experts who are embedded or not in government institutions, and acting as individuals or as part of national, bi-multilateral or international bodies. in any case, their mandate would be to assist countries implementing complex reforms or still struggling to find the 'right' policies tailored to their context and/or the proper way to design and implement them, including institutional arrangements and policy instruments [ ] . examples include how to improve healthcare services utilisation and quality, how to improve public financial management or how to make health care services purchasing more strategic. decision/policy-makers are thus expected to rely on the knowledge of scientists and experts, sometimes in the form of a coaching or mentoring approach [ ] to find solutions to these intractable issues. ideally, these scientists and experts should be people familiar with the technical and non-technical (e.g. political, social, cultural, economic) intricacies of the context a condition not always fulfilled [ , ] . they would then have both legitimate, expert and informational power [ ] to advise countries or technical departments of ministries in charge of uhc on how to successfully implement specific policies or processes, taking into account path-dependency and other local specificities [ ] . however, sometimes, even deep contextual knowledge, mobilised for instance through reliance on national experts, is not a guarantee of success. uhc policy processes are complex with many unknowns. for instance, we still do not know much on how to sequence steps towards uhc [ ] . it may happen that, because of haste or oversimplification, experts do not see the limits of their toolbox, including analytical frameworks or generic political guidance developed by international agencies. this is particularly problematic if critical thinking is poorly developed among decision/policy-makers. scientists and experts can also be seen just as useful contributors to policy processes. this situation is encountered in some middle-income countries [ ] ; an issue then is that experts may be used instrumentally to justify certain choices. scientists and experts may also be facing governments that know very well where they want to go but are in great need of advice on which path to take and are looking for experts willing to support them. in these situations, scientists and experts could be used as 'facilitators' since processes are country led. examples include rwanda or ethiopia, which show strong leadership in their uhc policy choices and bring external partners to follow the path set by the government [ , ] . the challenge for scientists and experts here is not to lose their independence vis-à-vis the government or the politicians and, sometimes, to push for more reflexivity. lastly, one can imagine a ministry or an actor that has some resources and capacities but appreciates external guidance on what to do and achieve. scientists and experts could thus play the role of 'producers of standards', with the big challenge to produce high quality standards tailored to country needsthis is not obvious if the scientists or experts lack in-depth contextual knowledge. however, this could also include the use of normative frameworks produced by individual scientists or experts, or international agencies [ ] [ ] [ ] . it seems to us that the international uhc community has so far paid little attention to this second mode of learning. in reality, it is taking place but it is not highlighted in the literature nor made explicit. in the context of uhc, a typical example of reflective learning could be the learning that emerges from what is coined "démocratie sanitaire" [health democracy] in the francophone systemthat is, a process promoting citizen participation in health policies development and implementation through consultation, public debates and dialogue [ ] . actually, community actors are directly involved in policy processes and learning is collective, arising through the co-production of ideas and discussions. another example of reflexive learning is deliberative processes bringing together various stakeholders to collectively reflect on complex issues to get better insights and suggest possible solutions [ , ] . there are flat power relations between policy actors and no knowledge hierarchyall types of knowledge are equally esteemed. here, we can draw a parallel with the facilitation techniques using the rules of brainstormingall the participants are equal, no idea is stupid and everyone participates. in the face of uncertainty, in a context of reforms, or in a situation where certain values and social norms must be questioned and new perspectives adopted, these open approaches based on dialogue, discussion, exchange of information and ideas are welcome rather than being an issue [ ] . indeed, they allow to gain mutual meaningful insights on issues at stake and there is room for serendipity as well as bold and innovative ideas. concretely, this learning mode seems little used in countries where decision-making is highly centralised. indeed, reflexive learning in some way would constitute a kind of 'endangerment' as it involves losing some control over the policy process. the national health assemblies in thailand, originating from the concept of the 'triangle that moves the mountain' [ ] (described below), which started in the early s, and the societal dialogue for health system reform, launched in tunisia in [ ] , are typical examples of situations where reflexive learning could occur. the societal dialogue in tunisia aims to develop a health system more responsive to citizens' expectations with a new mode of governance based on decentralisation and 'health democracy' [ ] . however, as in any process where decisions have to be taken by many at the same time, this dialogue turned out to be quite complex [ ] . learning through bargaining is probably the most overlooked mode of learning in the health policy literature. yet, we think that it happens daily, as policymakers constantly learn from their interaction with stakeholders. such learning arises when there are exogenous or endogenous attempts to shift policy objectives or instruments. learning will emerge from efforts done to reach an agreement. examples include ( ) the adoption (or not) of output-based financing mechanisms [ ] ; ( ) the degree of autonomy to be granted to health facilities in terms of organisation, service delivery and use of resources [ ] ; ( ) how health insurance funds should be collected [ ] , pooled, allocated and the benefit package designed [ ] ; ( ) changes in the market structure of healthcare provision, including the promotion (or not) of the private sectorthe so-called public-private partnerships [ ] ; and ( ) more generally, the adoption of some reforms, laws and regulations in the health sector [ ] . learning through bargaining is also a distinctive feature of certain permanent mechanisms such as priority-setting and budgetary negotiations [ ] , discussions between donors and their countries counterpart to set up health policies [ ] or, as part of the global fund, proposal developments for funding applications or principal recipients nominations by the country coordinating mechanisms [ ] . another example of learning through bargaining is the 'triangle that moves the mountain', a nice metaphor showing how sound interactions between key stakeholders in thailand, namely researchers producing policy-relevant knowledge, civil society organisations and communities leading a social movement, and politicians providing required resources, have been able to promote social learning and yield major changes in a difficult context [ ] . learning through bargaining focuses on the preferences of stakeholders [ ] and stems from a dialectical process. government officials negotiating with each other (e.g. ministry of health with other ministries such as social welfare or finance) and with external partners, civil society or unions to find out how to develop a coherent uhc policy are learning a lot. for instance, in morocco, such learning occurred when several ministries with divergent views gathered around the same table to discuss ramed (régime d'assistance médicale; a health coverage scheme for the poor) options, each bringing their own knowledge and experience [ ] . bargaining is essential as uhc policies may not be consensual and require trade-offs or choices that are eminently political, often involving resources redistribution and disruption of power relations. there seems to be little guidance today on how to institutionalise this learning mode; knowledge mainly remains tacit, as 'experience' and can 'evaporate' quite quickly [ , ] . in the context of uhc, learning in the shadow of hierarchy emerges from the very exercise of public authority. it is therefore practiced by all health authorities, although in varying ways and quality. hierarchical learning is particularly cherished by disease programmes and international agencies with an operational mandate such as unicef. indeed, like epistemic learning, hierarchical learning is directed and prescriptive. it corresponds to the situation where an actor uses his/her/its 'legitimate', 'coercive' or 'reward power' [ ] to purposively orient policy actions in a desired direction in order to enforce a policy or achieve specific goals or results. let us mention that some people in a high hierarchical position can also be scientists or experts (e.g. scientists or experts being decision-makers or politicians)we propose to consider these situations as learning in hierarchy instead of learning in epistemic contexts. in any case, the quality of learning will depend on the compliance of the governed, the clarity on the roles of stakeholders and the effectiveness of instructions. such learning, for example, is supported by field supervision visits, good monitoring and evaluation systems with adequate metrics to analyse policy actors' performance, or annual policy reviews. it thus values deliverables and measurable results. generally, knowledge is acquired both by the person holding authority who provides supervision or performs the monitoring and by the 'street-level bureaucrats' who make the effort to understand the instructions. learning can be enhanced if the supervisor is able to take advantage of the lay knowledge of the grassroots actors and not necessarily believe that his/her own hierarchical position or seniority means superior knowledge. in fact, hierarchical learning can be supported through the proper use of internal routine data. this is probably one of the great learning opportunities that remains minimally exploited for uhc [ ] . furthermore, like learning through bargaining, knowledge gained during the monitoring remains very tacit (embodied knowledge) and can get lost if, for example, a group of people is not stabilised at the head of uhc policy processes or if health workers are regularly deployed to other positions. several important points emerge from our research. it has shown that there are many ways to learn, materialised by the learning modes proposed by dunlop and radaelli. in-depth analyses of what mode(s) of learning is occurring, with whom, when, where, why, how, at what level and with what results, in relation to specific uhc processes in lmics, deserve being empirically investigated and, we trust, will be the subject of future research. further research exploring their triggers, constraints and pathologies [ ] would also be relevant. for instance, as hindrances, tacit knowledge gained during learning can get lost if people are not stabilised at their positions or if the turnover is too high. consequently, health authorities would lose learnings accumulated. learning for uhc naturally occurs. however, learning can also be organised or directed. among 'uhc promoters', there seems to have been so far an operational bias towards epistemic learning, often under a teacherlearner model. it is undeniable that this learning mode demonstrates some effectiveness to tackle technical knowledge and capacity gaps in many lmics, but this bias possibly stems also from power structures or unchallenged assumptions (e.g. donors knowing more than governments; academia knowing more than practitioners). in any case, there are probably missed opportunitiescountries do not leverage the large array of learning situations that have great potential to spur their progress toward uhc. today, too few ministries or technical departments are purposely investing in their own systemic learning capacities [ ] [ ] [ ] . beyond the illustrations we provided in this paper, applied work is needed to know more about what learning modes occur, when, where, how, at what level and under what circumstances. for instance, akhnif et al. [ ] already observed, in their case study on ramed, that "learning changes in nature across the different stages of the policy process"our study allows to deepen this subject matter by highlighting a grid to better categorise and analyse these different moments of learning. it would also be compelling to investigate what learning modes are mobilised or emerge at each stage of the strategic planning process, as proposed by who [ ] . furthermore, digitisation has created great potential for learning, both at the decision-making level and at the operational level, but this remains largely untapped [ ] and further research is needed to unravel ways to better exploit this potential. other studies could also explore the contribution of different hybrid models, that is, varying degrees of mixtures of different learning modes. indeed, learning modes are not mutually exclusive; they co-exist, occurring sometimes at the same time. a good example of a hybrid model is the 'coaching and mentoring' support provided by the strategic purchasing africa resource centre (sparc) to an expert panel of kenya's national hospital insurance fund to comfort it as a strategic purchaser of health services [ ] . this experience was rich in reflexive (through the engagement of various stakeholders), bargaining (to accommodate divergent opinions and reach consensus through formal and informal discussion channels) and epistemic (the mentor giving expert advice only when requested) learnings. learning generated through pilot schemes, as was the case for performance-based financing with rwanda [ ] , health equity funds in cambodia [ ] , the ramed in morocco [ ] , or user fees removal policies in burkina faso [ ] , is also an interesting case. policy actors and experts knew what they were looking for but they also acknowledged that there were many unknowns. by combining their assets (public authority, ideas and experimental methods), they together constituted an original body of knowledge that could be used to inform decision-making and scale-up processes [ ] . in the cases reported above, policy actors' learning seemed to have combined at least the epistemic and reflexive modes, both enhanced by experimental action, as promoted by garvin [ ] . similar hybrid learning is probably in application with the practice of study tours: there is an epistemic component (learning from another country with a more 'advanced' experience) and a reflexive component (since visitors, and possibly guests, informed by their own observations collectively reflect), before any experimentation or application back home. this paper aimed at illustrating the possibility and relevance of using the concept of 'policy learning' to analyse learning in uhc processes in lmics. dunlop and radaelli's framework allowed us to throw a new light on existing processes but also to widen the learning prospects that countries could tap into to advance their uhc agenda. the new perspectives highlighted in this article also echo implementation activities or research carried out by multiple actors involved in the field of learning for uhcthey could validate certain hypotheses, clarify grey areas and, above all, spark new reflections and ideas. all in all, there is room for action and building countries' systemic learning capacity for uhc. however, establishing an ambitious research and learning programme is crucial. our contribution fits in this voluntarist perspective. lmics: low-and middle-income countries; uhc: universal health coverage; ramed: régime d'assistance médicale the world health report: health systems financing: the path to universal coverage universal health coverage: friend or foe of health equity? going universal: how developing countries are implementing universal health coverage from the bottom up the update of the health equity and financial protection indicators database: an overview integrating evidence from research into decision-making for controlling endemic tropical diseases in 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the case of a ugandan hospital development cooperation as learning in progress: dealing with the urge for the fast and easy the global fund: managing great expectations triangle that moves the mountain and health systems reform movement in thailand the place of learning in a universal health coverage health policy process: the case of the ramed policy in morocco routine health facility and community information systems: creating an information use culture pathologies of policy learning: what are they and how do they contribute to policy failure? world health organization. strategizing national health in the st century: a handbook barriers and facilitators to health information exchange in low-and middle-income country settings: a systematic review advice from a mentor: legitimacy, flexibility & credibility from scheme to system (part ): findings from ten countries on the policy evolution of results-based financing in health systems translating knowledge into policy and action to promote health equity: the health equity fund policy process in cambodia how burkina faso used evidence in deciding to launch its policy of free healthcare for children under five and women in ownership of health financing policies in lowincome countries: a journey with more than one pathway learning in action: a guide to putting the learning organization to work publisher's note springer nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations the authors would like to thank wim van damme and maxime k. drabo for inputs they provided in this study. they also thank four anonymous peer reviewers who provided insightful comments that helped improve the paper. authors' contributions jak and bm performed study conceptualisation. jak made an extensive literature review and wrote the first draft of the study. bm and mda revised it thoroughly and mda provided further inputs into the study conceptualisation. jak drafted the final version that was revised by bm and mda. all authors read and approved the final manuscript. this article is part of jak phd thesis work. jak benefits from a grant for this thesis, funded by the belgian development cooperation.availability of data and materials not applicable.ethics approval and consent to participate not applicable. not applicable. the authors declare that they have no competing interests. key: cord- -v o uayk authors: bjursell, cecilia title: the covid- pandemic as disjuncture: lifelong learning in a context of fear date: - - journal: int rev educ doi: . /s - - -w sha: doc_id: cord_uid: v o uayk the covid- pandemic has caused a number of fundamental changes in different societies, and can therefore be understood as creating “disjuncture” in our lives. disjuncture is a concept proposed by adult educator peter jarvis to describe the phenomenon of what happens when an individual is confronted with an experience that conflicts with her/his previous understanding of the world. faced with a situation that creates disjuncture, the person is compelled to find new knowledge and new ways of doing things; i.e., he/she must embark on a learning process. the recent introduction of social distancing as a measure aiming to reduce transmission of the covid- virus has dramatically changed people’s behaviour, but this measure does not only have preventive and desirable effects. there is an associated risk for increased isolation among the older generations of the population, as well as a change in intergenerational relationships. although the current pandemic (as disjuncture) may potentially initiate major learning processes in the human collective, we should remember that disjuncture is often theorised within neutral, or even positive, contexts. in a context of fear, however, learning may result in a narrowing of mindsets and a rejection of collective efforts and solidarity between generations. in terms of the types of learning triggered by the current pandemic (as disjuncture), one problem is non-reflective learning, which primarily occurs on a behavioural level. we need to recognise this and engage in reflective learning if we are to make the choices that will lead to a society that is worth living in for all generations. our goal must be to learn to be a person in a post-pandemic society. the covid- pandemic has created a major "disjuncture" in our existence. within a short period of time, our lives have been turned upside down, in a way no one could have imagined. on march , the world health organization (who) officially classified the spread of a novel coronavirus, sars-cov- , as a pandemic, prompting many communities to act by closing their borders and imposing curfews on the movement of people. to reduce the spread of infection, national governments recommended that their citizens should engage in "social distancing". social distancing means keeping a physical distance (in the current pandemic, the stipulated space varies between . to metres) from other human beings. the term refers to measures that people can/should take to reduce personal proximity, an integral part of their social interaction with other people, and thus help reduce the transmission of an infectious disease such as the coronavirus. these directives to change what was hitherto entirely "normal" behaviour among human beings has caused "disjuncture" in people's lives; namely, a disharmony between the world as we knew it and the state of the world during the current pandemic. disjuncture is a concept proposed by adult educator peter jarvis to describe the phenomenon of what happens when an individual is confronted with an experience that conflicts with her/his previous understanding of the world. our lives comprise a series of experiences made up in such a way that our biography appears as continuous experience added to by each unique episode of learning which we call an experience. but each of these unique episodes begins with the same type of question […] : why has this occurred? how do i do this? what does this mean? and so on. it can be cognitive, emotional or a combination of the two: it is this that i call disjuncture (jarvis a, p. ). according to lifelong learning theory, disjuncture triggers learning, but what is it that we learn during a pandemic? italian philosopher giorgio agamben argues that panic has paralysed his country (italy) and that people have sacrifice [d] practically everything -the normal conditions of life, social relationships, work, even friendships, affections, and religious and political convictions -to the danger of getting sick (agamben ) . fear and panic can have serious long-term outcomes for individuals and society, including the worsening of existing problems, such as isolation among the older generations of the population and the gap between generations. it therefore seems likely that an examination of the changes that occur during a pandemic will be key to understanding the learning that takes place in a context of fear. as this article is being written during an ongoing pandemic, readers should bear in mind that the situation may change dramatically and we do not know how this might impact people's learning at different points in time. the discussion in this paper is intended to inform and stimulate debate and further research. the purpose of this article is to revisit the concept of disjuncture (jarvis a) and to invoke lifelong learning theories because they have the potential to: ( ) allow us to conceptualise the current pandemic as a learning process; ( ) connect the the holistic concept of lifelong learning is discussed in more detail in the next section. briefly, in practical terms, it comprises "cradle-to-grave" learning throughout a person's life and includes formal, nonformal and informal learning. formal learning occurs in education or training institutions (e.g. schools), non-formal learning (e.g. swimming classes, amateur music etc.) takes place outside the formal system; and informal learning is experience-based and often accidental, occurring e.g. at home, during a leisure activity or in the workplace. a doctoral student at the university of chicago who investigated this found the earliest mention in english in , but the first use of its current meaning in in the context of airborne illness and sars (waxman ) . footnote (continued) practice of social distancing to ongoing, long-term changes in society; and ( ) highlight certain risks and possibilities which need to be addressed if our goal is to support people's engagement in the kind of learning that is directed towards achieving a better post-pandemic life and a better post-pandemic society. when lifelong learning became a central concept in global policy half a century ago, its proponents highlighted that: ( ) learning is not only about child development, but continues throughout adult life; and ( ) learning takes place in every context, not just within the confines of the school classroom. one of the seminal reports marking the establishment of lifelong learning as a concept was learning to be: the world of education today and tomorrow (faure et al. ) . often referred to as "the faure report", it emphasised a humanist, holistic vision of education that was applicable to all members of society. since the release of this report, lifelong learning policies have addressed social problems on a global scale in conjunction with the emergence of key institutions in this field. moosung lee and tom friedrich ( ) discuss differences in underlying ideology between the united nations educational, scientific and cultural organization (unesco) on the one hand, and the organisation for economic cooperation and development (oecd), the european union (eu), and the world bank on the other. while unesco has had its own unique impact on international discussions, contemporary ideologies with respect to lifelong learning advanced by the other three organisations have been dominated by a neoliberal capitalist perspective (ibid.). this is unfortunate, because unesco's enlightenment tradition (which is based on rationalism, progress, freedom, emancipation, and the concept of human beings as masters of their own destiny) is at odds with, and is actually undermined by, the utilitarian view of education that comes with adopting a neoliberal capitalist perspective (elfert ) . this conflict is of particular interest during a pandemic such as the one we are currently experiencing, because many people will lose or have already lost their jobs, which is likely to strengthen the utilitarian view of education even more. maren elfert (ibid.) argues that the adoption of such an instrumental approach presents an obstacle to placing education in a wider societal context for those who aim to solve social problems on a global scale. instead of reducing the process of education to the mere creation of productive economic units, the purpose of education should be to offer learning opportunities which foster the development of people who think critically, but not cynically, which then enables them to act as responsible citizens (stanistreet ) . one effort in particular that should be made to effectively address social problems, namely, the promotion of an intergenerational society, is discussed later in this article. the concept of lifelong learning may lead to some confusion because in addition to being a core policy concept, it can also be invoked to refer both to an individual's spectrum of learning and to institutions which offer educational opportunities (jarvis (jarvis , . a singular focus on institutions which offer formal education is too narrow, because learning also takes place in professional settings, work environments, and in groups and gatherings of various kinds. it is therefore impossible to create a fully institutionalised system of lifelong learning; irrespective of where learning takes place, such learning must be recognised as part of the person's total learning. a shift in terminology from education to learning entails a shift in meaning and focus. it might be said that education gives the active part to the teacher, while learning represents the active learner's perspective. we thus observe a shift in focus from formal education to how an individual creates and transforms experiences into knowledge, skills, attitudes and values at every age, throughout this individual's life. another drawback that can be associated with an instrumental/utilitarian approach to education is that it excludes the possibility of adopting a holistic understanding of human learning. if one is to understand learning as something which grows out of the experience of living, being and becoming, this demands that one understands that the self is shaped through thinking and doing over time, and is embedded in overlapping and contradictory life-worlds (jarvis (jarvis , a . as a philosophy of education, lifelong learning awards the individual's learning a central position and highlights the fact that this must be the starting point if we are to properly understand what learning is about. learning must be understood in its entirety and as the result of interaction between the individual and the individual's environment. it is important to note that it is the learner who enters situations that provide experiences by which learning takes place (jarvis ). jarvis emphasises the point that, by starting with the learner (and not with what is being learned) we are led to the understanding that the learner's biography is changed as a result of learning, irrespective of the person's age. when experience is processed, it is integrated into the person's being. this entails that a person experiences being and becoming in a lifelong process. jarvis opposes the dualistic view of the division between body and soul because, he claims, it is impossible to separate one from the other (jarvis ). to ground learning in the framework of being, rather than in a framework of having, entails that one accepts fluidity and dynamic movement as one strives to grasp one's manner of existing (su ) . to think of learning as the mere acquisition of knowledge is, therefore, insufficient. learning takes place by means of lived relationships in a cultural context, as instantiated by a particular society. each individual person's process of shaping their identity is key to learning, because lifelong learning involves the continued development of a new understanding of "the self", something which also entails a re-negotiation of one's identity. during the current pandemic, many activities have moved online, including, for example, adult education. even though teaching as such takes place in much the same manner as previously, this move to a digital environment entails a great deal of change and demands new competencies from teachers. these changes are so substantial that they give rise to questions concerning the individual's perception of their self and their professional performance as teachers. this shift from the classroom to a digital environment via the internet is not just a practical issue; it also entails a shift from one state of existence to another. in a similar manner, the implementation of a lockdown and social distancing creates a state of existence which prompts people to reflect on their selves and their situation. this can influence their perceptions of themselves and others. a pandemic such as the one we are currently experiencing influences individual people's lives as well as the behaviour displayed by society as a whole. according to the terminology used in the context of lifelong learning as a philosophy of education, we thus conclude that a pandemic causes a disjuncture. disjuncture has meanwhile become an established concept in lifelong learning which is used to explain a condition that enables learning. peter jarvis ( b) proposed that learning in our everyday lives is often triggered by a gap between our expectations and an experience, i.e. disjuncture. disjuncture refers to a state of disequilibrium, where we feel uneasy, out of our depth. in response to this feeling, we seek change -in order to achieve equilibrium and stability again. the process of striving towards a new state of equilibrium triggers the learning that takes place: indeed, this state of disequilibrium is a fundamental cause of learning that is inextricably intertwined with being-in-the-world: it is a part of the human condition (jarvis (jarvis [ , p. ). disjuncture, the gap between what we know and what we experience, provokes within us our initiative to understand and deal with particular situations, so that we can return to a harmonious state (jarvis b), albeit a new one. in other words, the need to learn is a fundamental need. as mentioned above, our learning takes place in interaction with our physical and social surroundings. learning can be said to be the bridge that links the self to the world. when disjuncture occurs, a person may perceive a sense of detachment from the former self, because it no longer fits the new situation. learning is the activity that enables a person to deal with disharmony and involves the movement from one state of being to another. this transition from one state to another requires that learning reformats a person's previous knowledge and experience in relation to the new experience in a manner that could not be understood (by the individual) in terms of previously existing frameworks. eventually, the individual will initiate a concluding phase of the learning process when new knowledge is incorporated into her/his state of being and new frameworks emerge. by means of the process thus described, we say that the individual has learned something. this could also be regarded as the end of the learning process initiated by the disjuncture. however, it is in fact also part of the continuous flow of learning that takes place throughout a person's life and thus sets a new direction for future learning. in his book on learning in later life, peter jarvis notes that it is recognized here that more than ever before in the history of humankind we have the opportunity to create our own biography through the choices that we make and we recognize that learning is the force through which our biographies develop and expand (jarvis (jarvis [ , p. ). being (and learning) always occurs in relation to a social situation. jarvis states that being is driven by the moral imperative about achieving potential as human beings for the community in which we live (jarvis b) . engagement in the social world cannot be mastered by instinct. instead, it has to be mastered by learning if we are to obtain the knowledge that is needed to cope with living in the world. a pandemic such as the one we are currently experiencing presents a new social situation, and we need the process of learning to deal with the situation. however, there is also a risk that learning will not take place. with respect to an analysis of the effects of a pandemic as disjuncture, a typology of learning and non-learning is, therefore, of some help. the analysis i present below is guided by three categories of responses to new experiences, namely: ( ) non-learning; ( ) nonreflective learning; and ( ) reflective learning (jarvis (jarvis [ ). within each category, there are three types of learning or non-learning (table ) . first, the three types of non-learning are presumption, non-consideration and rejection. the three different types of non-learning all refer to the fact that people do not always learn from their experiences. "presumption" is a typical response to an experience that is familiar to the individual and the individual knows what to do, and therefore, there is no need for change. non-learning can also occur when a person experiences something that could be a potential learning experience, but either because they do not understand the situation or they are not conscious of the situation ("non-consideration") learning fails to take place. in addition, non-learning may be the case in situations where the person is aware of the potential for learning but they reject this possibility (hence the label "rejection"). the three types of non-reflective learning include preconscious learning, skills learning and memorisation. "preconscious learning" takes place when an individual monitors their actions on a low level of consciousness, such as when driving a car. "skills learning" occurs when skills are acquired in action through imitation. "memorisation" is the process of verbal imitation, for example, when a person memorises the words of the instructor so as to be able to reproduce them at a later time. nonreflective learning represents processes associated with social reproduction. these processes are commonly on the level of bodily experience, in contrast to the level of communicative interaction. lastly, the three types of reflective learning are contemplation, reflective skills learning and experimental learning. "contemplation" consists of focused thinking about an experience as one reaches a conclusion about the experience. "reflective skills learning" involves learning a skill whilst simultaneously learning the concepts that undergird the practice that one is engaged in, thus providing one with an understanding of why a skill should be performed in a certain way. "experimental learning" occurs when theory is tried out in practice, and leads to new practical knowledge for the individuals' everyday life. it should be noted that the non-reflective and reflective forms of learning can lead to either conformity or to change and innovation. furthermore, as stated above, individuals learn in relation to a social situation, and, as argued in this article, the introduction of social distancing changes the character of our social situation. lifelong learning is, as explained above, embedded in a cultural context. when a pandemic such as the one we are currently experiencing causes disjuncture, people find themselves in a situation where a major learning process is initiated. the point of interest in this article is the introduction of regulations for social distancing and how these regulations have already affected relationships as well as their longerterm effect. soon after the outbreak of the covid- pandemic, social distancing was introduced in several countries as a general code of conduct to maintain a physical distance between oneself and others. in addition, people who are over the age of have been identified as an especially "vulnerable group" who should stay at home and avoid social contact, even within the family. thus, the practice of social distancing has had, and continues to have, an impact particularly on people over the age of , but it also impacts other age groups in society. this is a situation where the elders of society are perceived as constituting a problem to be dealt with by means of special measures. potentially, this may, for example, contribute to strengthening ageism. in fact, categorising people by the label of being "over the age of " in these national directives may in itself be a kind of ageism, since age is the only variable at play. certain governmental actions, such as the introduction of social distancing, will inevitably cause re-actions in society. these re-actions may be understood as expressions of learning processes, and they demonstrate that humans develop in ways which are often beneficial for the community, such as people's engagement in volunteering and performing acts of solidarity. however, certain other re-actions also reveal prejudices and negative perceptions which are sometimes associated with age. one aspect that we cannot review yet (since the pandemic is still ongoing at the time of writing), is how we will live together after the pandemic is over. nevertheless, we do know that our supposedly established models of coexistence have been challenged; not least by the phenomenon of social distancing. it is highly probable that these new social rules will have a long-term impact on interaction patterns and on the level of trust in society, even after the current pandemic is over. trust is a central concept in understanding how social ties serve as a resource in society. john field, professor emeritus in education at the university of stirling, has published a number of thoughts on the social effects of the lockdown on his blog (field a (field , b . he reports that studies of social capital, including preliminary results from a number of covid- studies, show that the higher the level of social capital that is enjoyed within a society, the lower the rate of transmission of infection (field a ). field also mentions that when the variable of "income" is included in the analysis, it has been observed that people with a high income or high-speed internet access are more likely to follow directives about staying at home. a combination of high income and high-speed internet could thus explain a high propensity for people to stay at home (chiou and tucker ) . "social capital" should, however, not be confused with "social connectedness"; i.e., the structure and interaction patterns of social networks. the structure of social networks can also be used to understand the spread of disease (kuchler et al. ). the primary results of these studies show that the disease is spread within families and between friends, i.e. among people who know each other well and trust each other. while this observation lends credence to the idea of keeping a physical distance, it is expected that in the longer term, this will entail a number of deep-rooted changes in the ways that social bonds are made, reinforced, and broken (field b) . one direct, concrete effect of the kind of social distancing currently stipulated within our societies is isolation and loneliness. in several countries worldwide, isolation and loneliness already constituted a problem among the older generations in society before the current pandemic. socio-demographic changes, the crisis of the welfare state, and breakdowns in social norms have been identified as causing separation between generations (donati ) . from research in the domain of healthcare, we know that loneliness has a negative impact on a person's health. examples from the current situation caused by the implementation of social distancing include the presence of negative emotions. besides anger, covid- "is associated with anxiety, depression, distress, sleep disturbances and suicidality" (sher , p. ) . these increased in china during the initial covid- epidemic, while positive emotions and life satisfaction decreased (ibid.). in the care of older adults, profound isolation has become the norm. the extreme loneliness felt by many older people raises concern, because it is a known risk factor for poor health outcomes. however, some degree of social connectedness and information sharing between care facilities and families can be maintained with the support of digital tools (edelman et al. ; eghtesadi ) . in addition to global and national initiatives that are aimed at preventing the spread of covid- , it is suggested in the literature that agencies setting up prevention regimes, such as who and national health authorities, also need to address the issue of social isolation so as to prevent the health hazard effects that are associated with social isolation. supporting intergenerational relationships is one way in which societies can deal with issues of loneliness and promote well-being. matthew kaplan and mariano sánchez ( , p. ) refer to "seven imperatives to justify our interest" in intergenerational issues: ( ) demographic changes; ( ) mutual support and reciprocal care in the family and in the community; ( ) active aging; ( ) improving social cohesion; ( ) making communities more "livable"; ( ) ensuring cultural continuity; and ( ) strengthening our relational nature (ibid., pp. - ) . a loss of intergenerational contextual continuity is not only a problem for older generations; it also has consequences for the life courses of young people (donati ) . the perspective with respect to the concept of "generation" that is usually found in the field of intergenerational relationships is different from "generation" as a social category, which is comparable to the notion of "social class" or "cohort". by employing the concept in the context of generational theory, we draw attention to the dynamics of socialisation and generativity that exist in the relationships between members of different generations (lüscher et al. ) . the point of using the term intergenerational is found in its prefix, inter -which highlights that which is between -i.e., the relationship (sánchez and díaz ) . however, the social advantages that can be built by strengthening bonds between generations are currently being put at risk because the measures adopted by society in response to the pandemic affect interpersonal contacts and restrict the spaces where social encounters can take place. in response to this situation, a group of international scholars and practitioners have joined forces in support of a manifesto entitled intergenerationality adds up lives (barragán et al. ) , which was published on april . in view of the fact that social distancing can have serious negative effects on people and society, the next section provides an analysis of the covid- pandemic as disjuncture and what this entails in terms of learning. to frame a pandemic as disjuncture, and thereby as a learning process, is one way of approaching an understanding of what it is that is going on, and how a pandemic might change us and society in a post-pandemic era (in the present case, the covid- pandemic). the typology of "non-learning", "non-reflective learning", and "reflective learning" (jarvis (jarvis [ ) described above (and summarised in table ) will inform the analysis that follows with respect to becoming, during and after a pandemic more generally, but also with respect to the covid- pandemic specifically. as with all such typologies, it is important to acknowledge the possibility of varying overlaps between the types, and although this typology may be a bit schematic, it is a useful way of structuring an analysis. with respect to the first type, "non-learning", it would be difficult to imagine someone who is not aware of the current global pandemic, but although a person whose reaction to the experience is non-learning is likely to recognise a disjuncture, they may still reject the learning potential of the situation and merely wait for things to get back to normal. "normal" is attractive because normal circumstances correspond to our previous experiences where we knew what to do and how to act. nonlearning is, therefore, one highly probable outcome after the current pandemic. with regard to intergenerational relationships, non-learning entails that we will return to behaving in the same way as we did before the current pandemic. the second type of learning, "non-reflective learning", can be said to represent the learning that does not involve conscious thought and is not mediated by means of language. instead, it refers to learning that takes place at a preconscious and bodily level. it may transpire that this is the most interesting type of learning occurring during the covid- pandemic. consequently, it is discussed in more detail below. "reflective learning" refers to situations where people consciously think about something and make an intentional effort try to understand why things are the way they are. this includes drawing on knowledge which is relevant to how a situation might be mastered and reaching conclusions which, in turn, become part of a new frame of reference. for example, a recurring reflective practice which has emerged in my own network in response to the current pandemic generates insight into how we can use digital tools in meetings with colleagues around the world. we have learned to provide online courses, conduct academic theses defences and convene board meetings, and these online activities have worked surprisingly well. there are many people who now understand the potential of combining online and faceto-face meetings to save time reduce travelling, and many of us want to see online options as a permanent alternative to "traditional" ways of working, in a post-pandemic society. the same conclusions have been reached in many private settings, where digital tools now connect family members separated by social distancing. but while it is easy to recognise the existence of learning on the level of functionality (for example, how to use digital tools), what is less frequently discussed is learning that concerns the understanding of cultural context and the self. furthermore, issues such as how the current situation might change our view of age and/ or of social interaction also remain a topic that has, so far, been neglected. in fact, this area of human experience might primarily be subject to examination on the nonreflective level, as discussed below. returning to "non-reflective learning", it is interesting to note that the covid- pandemic and the recommendations and directives that have been issued with respect to social distancing have already changed the way in which we behave. when people over years of age self-isolate at home, other people have to go food shopping for them. thus, their children or grandchildren may only meet them in the carpark or outside the house when they hand over the shopping bags. there are a number of neighbourhood volunteer groups who have organised themselves via the internet who are willing to help people who do not have a "social safety net" within their family to fall back on in the current situation. numerous businesses have adapted their procedures and offer new types of services which are suited to times when social distancing is being practised, such as delivery of groceries and special hours for older people in shops, or online healthcare. in many instances, people have helped other people out and have shown a willingness to care for others. we thus note that these new behaviours and services which emerge during a pandemic constitute examples of learning where people develop in a positive way. at the same time, however, there exists a great deal of concern and even fear in society. this fear is also a driving force which may influence how individuals, companies and society behave and what they concern themselves with. on the one hand, the current pandemic has contributed to supporting relationships between the generations and between people in general, as demonstrated, for example, by volunteer services and acts of solidarity. on the other hand, however, different interests have been pitted against each other, for example by putting the economy in competition with public health and the protection of people from the virus. these tensions between competing interests create fear, and it is important that we acknowledge that fear is a negative driving force to be reckoned with in our efforts to direct events and developments associated with the current pandemic in a constructive manner. fear is an emotion which emerges when one's environment or some specific object is apprehended as a threat. this emotion may arise in response to an actual or an imagined threat. if the threat is real, our instinctive fear may well assist us in behaving in a manner which will allow us to avoid a risk or move ourselves away from a dangerous situation. unfortunately, however, fear itself can give rise to dangerous situations, for example, when people arm themselves with weapons out of fear of attack, but the weapon itself then creates unsafe situations. fear can also give rise to conflict, be a driving force for political change, and even influence what and how people learn. there are a large number of things to be fearful of during a pandemic, which also give rise to concern for the future. for example, the fact that we live in a globalised society may well create the feeling that we are all "citizens or the world" and that we have a shared responsibility to help each other. however, fear may cause some people to view others as a threat to their well-being. if we become bogged down with fear, we run the risk of entering a downward spiral of behaviour that puts our future development in jeopardy. the emotion of fear is a natural emotion, and sometimes a necessary one. fear is a driving force which can be exploited in different ways. but when fear gives rise to a persistent concern which dominates how we live our lives, then it is perhaps time to take a step back and ponder the consequences. there is a risk that the outcomes of the learning that takes place during a pandemic, in a context of fear, are not behaviours and ideas that contribute to the improvement of individuals and society. instead, such learning may cause isolation and loneliness, and lead to the "dehumanisation" of communities. in their manifesto, Ángel barragán and colleagues ( ) warn that "preventive" attitudes regarding limiting contact between people of different ages, and especially between the young and the elderly, may reshape our social bonds and reduce inter-age relationships during the current pandemic and in the future. they argue that society needs to adapt existing policies that promote intergenerational contact to include new modes of communication and expand the range of opportunities where people of different ages can come into contact with each other. the intergenerational perspective proposed in the manifesto argues for the implementation of a new social model that integrates visions of people of all ages, and promotes the establishment of meeting spaces where people can interact with each other. in practical terms, this can be done by designing public services and community spaces that actually encourage interaction across generations. this may serve as a fruitful model for "learning to be a person" in a post-covid- society worth living in. if we perceive the current pandemic as disjuncture, we are confronted with a disconnect between the world as we knew it and the world as it is. the disjuncture between an individual's experience and a situation, which cannot be understood based on this experience, is the beginning of a learning process. in other words, the current pandemic does not only cause change, a transfer from one state to another, but is in effect a disjuncture that triggers learning, which entails a reshaping of the individual's frame of reference. the individual who faces a crisis and survives it will not be the exact same individual that s/he was before the crisis. this learning, as peter jarvis points out (jarvis ), lies at the heart of the processes through which we develop our own humanity. notwithstanding this observation, in certain lifelong learning theories, it is assumed that the individual will strive to become his or her best self. however, in the discussion presented above, questions have been raised regarding whether nonreflective learning can result in outcomes that are not conducive to the benefit of the individual or society. one view is to regard a pandemic as a crisis that leads to feelings of fear, prompting people to act on this fear without thinking of the (shortterm or long-term) consequences of their behaviour. the other view is to regard a pandemic as an opportunity to develop our own humanity and engage in constructive patterns of behaviour. to ensure that the outcome of the learning process we are currently engaged in is a positive one, we should engage with ideas about the world as we would like it to be. lifelong learning is based on a view that includes the concept of "unfolding potential", and is based on a fluid co-existence between being and becoming. learning is concerned with where we are and where we are going. the covid- pandemic has created a disjuncture which holds the potential to initiate major learning processes in the human collective. however, the relation between age, isolation, situation and learning is complex, and future studies are needed to better understand how they affect each other. a central assumption in lifelong learning, as a philosophy of education, is that learning starts with the individual, but always takes place in relation to an environment. the argument presented in this article endorses this assumption. consequently, the community and collective are emphasised as central elements, based on the idea that we constitute each other's environments. just as we belong together in society, we also become together. the covid- pandemic has created a disjuncture that introduced fear and uncertainty in this process of becoming. one dilemma i have addressed in this article is the introduction of social distancing as a protective measure. while measures which are intended to protect vulnerable groups, including the directive or recommendation to practise social distancing, make sense in terms of curbing infection rates, they may simultaneously increase the isolation experienced by members of older generations before the outbreak of the pandemic. it is important to remember that for this group, isolation was already a serious problem before the outbreak of the current pandemic. the other, related, dilemma is that there is also a risk that non-reflective learning takes place, the potential outcome of which is the strengthening or normalisation of a disconnection between generations. by verbalising this risk, and by consciously moving from non-reflective learning to reflective learning, we can identify and understand patterns of what takes place in a society which is subject to a pandemic. this is an important task, because, although lifelong learning theories tend to assume that all learning is good learning, the outcomes of learning during a pandemic may well result in the construction of a society that we do not want to live in. based on this insight, it is up to each person to ask themselves: how do we make the choices that will lead to a world worth living in, for all generations? funding open access funding provided by jönköping university. open access this article is licensed under a creative commons attribution . international license, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the creative commons licence, and indicate if changes were made. the images or other third party material in this article are included in the article's creative commons licence, unless indicated otherwise in a credit line to the material. if material is not included in the article's creative commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. to view a copy of this licence, visit http://creat iveco mmons .org/licen ses/by/ . /. translated into english by adam kotsko. itself.blog [blog post intergenerationality adds up lives. manifesto marking the forms of capital social distancing, internet access and inequality report to unesco of the international commission on education for the twenty-first century intergenerational solidarity: old and 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trends parasitol doi: . /j.pt. . . sha: doc_id: cord_uid: z ikuqc the covid- pandemic has disrupted parasitology curricula worldwide, which is expected to lead to the reshaping of parasitology education. here, we share our experiences of remote teaching and learning of veterinary parasitology and discuss opportunities offered by remote teaching during covid- lockdowns, enabling the development of interactive online parasitology courses. since the beginning of the st century, several face-to-face and blended (i.e. face-to-face and online) learning practices, including the disciplinary-based and problem-oriented approaches have been used to teach various disciplines of parasitology worldwide [ ] . for example, various learning theories for online and/or blended parasitology education, including community of inquiry [ ] , connectivism [ ] and online collaborative learning [ ] have been used. recently, the blending with pedagogical purpose model [ ] has most commonly been used for teaching and learning in parasitology [ ] and other disciplines [ ] , where students are the learning community and multiple technologies (e.g. learning management systems) and multi-media are utilised to (i) scaffold and deliver the content of subjects/courses; (ii) promote reflective blog journals, with collaboration and peer-to-peer learning among students; and (iii) evaluate student learning. however, the social presence in a learning setting is often achieved by face-to-face teaching and interactions among students, which are key components of a learning environment. in the last two decades, these blended, student-centred learning practices [ ] using adaptable digital technologies [ , ] have become useful tools for effective and engaging parasitology teaching and learning. the covid- pandemic has challenged the existing teaching and learning practices from primary schools through to tertiary institutions in almost every country of the world [ ] . for veterinary parasitology. our goal is to share our experiences in the midst of the covid- pandemic which has brought about great uncertainty and challenges in almost every walk of life. the rapid shift seen across the tertiary education system might be the beginning of a new era in course delivery. the adoption and/or modification of teaching and learning practices tested (out of necessity) during the covid- lockdown may guide or influence the re-design of parasitology curricula. on tuesday th march , the melbourne veterinary school suspended all face-to-face teaching and we, as educators, were given three days to prepare for the online delivery of lectures and practical parasitology classes scheduled the following week. our parasitology team at the university of melbourne has extensive experience in teaching parasitology to animal science and veterinary students. prior to the covid- pandemic, we adopted new approaches to enhance learning outcomes utilising a combination of conventional face-toface teaching and digital technologies [ ] . through reflective practice and considering the original intended learning outcomes (ilos), we rapidly adapted the face-to-face lectures and practical classes in parasitology to online modules for doctor of veterinary medicine students (second-and third-year levels within a -year degree, students/cohort) and bachelor of agriculture students (third/final year level, students). in support, the university offered various professional development courses through the department of learning environments i to staff and students to aid with the transition to remote/online teaching. based on our experiences of online teaching and learning in the field of veterinary parasitology, we have proposed a toolkit (box ) for parasitology educators; our teaching j o u r n a l p r e -p r o o f journal pre-proof module received appreciation from students (supplemental table s ) and academic peers alike. for timely lecture delivery, we uploaded pre-recorded lectures on a learning management system (e.g. canvas ii ) to allow student self-directed, independent learning and to avoid possible network access issues during live streaming of lectures. subsequently, we held weekly flipped classroom [ ] sessions (i.e. live question and answer (q&a)) via zoom iii and used polls iv to provide opportunities for cognitive, social and teaching presence for the online learning experience of students, as per the learning theory of community of inquiry [ ] . for practical classes, we used a number of approaches and utilised pre-developed resources available online (supplemental box s ), circumventing the difficulties associated with preparing, at short notice, a semester's worth of high-quality material, especially videos using the loom application v . our typical veterinary parasitology practical class involves the identification of a group of parasites, assorted hands-on techniques to isolate and identify parasites in various organs of a range of hosts, and problem-based clinical scenarios for veterinarians. we developed the -hour face-to-face practical classes into online modules using various asynchronous and synchronous teaching approaches to encourage deep learning, while promoting student engagement, the interaction between students and teachers and meta-connective pedagogy [ ] . for each online practical class, we developed a powerpoint presentation (supplemental box s ) which outlined all components of the practical and provided links to external online available resources, and these slides were uploaded on canvas one week prior to the practical class. the online practical contained an introduction to the class via a - min live interactive session using zoom, followed by multiple independent and collaborative sessions for students via breakout rooms in zoom, ending with a min j o u r n a l p r e -p r o o f journal pre-proof summary via a live zoom session using polls. the zoom breakout room feature allowed student collaboration and lecturers to interact within smaller groups of students ( per group). students were also provided with the opportunity to ask questions directly via zoom unmute, a zoom chat (typed) as well as through an online discussion page in canvas. in addition to recorded lectures, the entire practical class was recorded and made available to students via canvas for later viewing, and for students unable to attend the session, or those that were in another state or country. this method of online delivery of our veterinary parasitology subject received very positive feedback from students (see supplemental table s ). additionally, we tried to mimic virtual microscopy sessions by preparing high-quality videos, high-resolution scanning of slides or photography of gross specimens (supplemental box s ) and presenting them via several user-friendly commercially available platforms vi . the best network platform, in particular, is highly interactive as it not only allows a virtual microscopic experience but also permits annotation which is an invaluable tool for both students and teachers. in addition to positive student feedback, the average exam scores for pre-and post-pandemic cohorts was comparable, indicating that the modified methods of content delivery were effective. strategically targeted questions using flipped classroom approach [ ] were also posed to students during the online q&a sessions/practicals (using a polling application) which allowed live gauging of the level of student understanding. some use existing 'active' resources and specify the parts that need to be viewed. provide interactive group activities (e.g. online quizzes, polls, discussion boards, subject dedicated facebook page, etc.) which support peer learning and collaboration. communicate clear instructions and expectations about the assessment. emotional openness is a great instructional strategy, so don't hide your feelings and use "icebreakers" during teaching and learning activities. for example, ask at the beginning of a lesson "what is a new skill/interest you have undertaken during isolation?" use virtual office hours using platforms like zoom to interact and provide social support to students. this can be a great way to collect student feedback on your online teaching and identify any issues which need immediate addressing. once you find a teaching style working for you, feel free to repeat it each week until you are back in your classroom! editorial special issue -learning and teaching of veterinary parasitology assessing social presence in asynchronous text-based computer conferencing connectivism: a learning theory for the digital age learning theory and online technologies promoting self-directed learning through the implementation of cooperative learning in a higher education blended learning environment theories and frameworks for online education: seeking an integrated model can new digital technologies support parasitology teaching and learning? covid- and rapid adoption and improvisation of online teaching: curating resources for extensive versus intensive online learning experiences e-learning, online learning, and distance learning environments: are they the same? online design education: meta-connective pedagogy asynchronous and synchronous online teaching: perspectives of canadian high school distance education teachers from bricks and mortar to remote teaching: a teacher education programmer's response to covid- we are grateful to professor robin b. gasser for his advice and suggestions during the rapid adoption and improvisation of online parasitology teaching as well as providing feedback on the manuscript. key: cord- - kjjjbp authors: kusunose, kenya title: steps to use artificial intelligence in echocardiography date: - - journal: j echocardiogr doi: . /s - - - sha: doc_id: cord_uid: kjjjbp artificial intelligence (ai) has influenced every field of cardiovascular imaging in all phases from acquisition to reporting. compared with computed tomography and magnetic resonance imaging, there is an issue of high observer variation in the interpretation of echocardiograms. therefore, ai can help minimize the observer variation and provide accurate diagnosis in the field of echocardiography. in this review, we summarize the necessity for automated diagnosis in the echocardiographic field, and discuss the results of ai application to echocardiography and future perspectives. currently, there are two roles for ai in cardiovascular imaging. one is the automation of tasks performed by humans, such as image segmentation, measurement of cardiac structural and functional parameters. the other is the discovery of clinically important insights. most reported applications were focused on the automation of tasks. moreover, algorithms that can obtain cardiac measurements are also being reported. in the next stage, ai can be expected to expand and enrich existing knowledge. with the continual evolution of technology, cardiologists should become well versed in this new knowledge of ai and be able to harness it as a tool. ai can be incorporated into everyday clinical practice and become a valuable aid for many healthcare professionals dealing with cardiovascular diseases. electronic supplementary material: the online version of this article ( . /s - - - ) contains supplementary material, which is available to authorized users. artificial intelligence (ai) is the process of having a computational program that can perform tasks of human intelligence (e.g. pattern recognition) by mimicking human thought processes [ ] . these programs have been developed since the s. it's been used in gaming, social media, and robotics for a long time. machine learning has been developed since the s. machine learning is relevant for medicine as a precursor to ai. conventional machine learning is a method in which a computer automatically provides appropriate judgments from inspection images by giving control rules (e.g., features). after , deep learning has been developed by automated learning of features extracted through repetitive trial and error. deep learning is a type of machine learning, the sophistication of its internal structure and learning methods enabling more accurate results than conventional machine learning [ ] . deep learning identifies patterns progressively from large databases without being explicitly programmed. in the last years, deep learning has led to new strategies of machine learning and plays a central role in image recognition as a breakthrough method [ ] . ai has influenced every field of cardiovascular imaging in all phases from acquisition to reporting [ ] [ ] [ ] . such examples of this are ai-developed computed tomography and magnetic resonance image measurement of lumen diameter, recognition of coronary calcium score, recognition of obstructive coronary disease, automated acquisition, segmentation, and report generation [ ] [ ] [ ] . compared with these methods, there is an issue of high observer variation in the interpretation of echocardiograms. ai can help minimize the observer variation and provide an accurate diagnosis in the field of echocardiography. in this review, we summarize the necessity for automated diagnosis in the echocardiographic field, and discuss results of ai application to echocardiography and future perspectives. the online version of this article (https ://doi.org/ . /s - - - ) contains supplementary material, which is available to authorized users. with the development of echocardiography, the number of echocardiographic parameters in routine examinations has increased and examination techniques have become more complex. commercially available portable devices have expanded the range of physicians who perform echocardiography, not only cardiologists but also physicians in emergency medicine, anesthesiology, and general internal medicine. thus, there may be a need for these nonspecialists to make decisions based on echocardiographic findings. moreover, the outbreak of covid- infection [ ] , all lifestyles and industries affected to some extent, such as lockdown on movement and a greater dependence in telecommunications. this wave of infections has also affected how we approach cardiovascular care and echocardiography. as shown in supplemental fig. , before the covid- era, the patient was moved to the echo room and underwent an echocardiogram by expert sonographer or cardiologist. however, in an environment with a rapidly increasing number of confirmed/suspected covid- patients, non-specialists, such as emergency physicians, are more likely required to perform this examination in the infection control room. in the usual settings of echocardiography, the risk of infection is high because practitioners must be in close proximity to the patient. thus, personal protection is crucial in the covid- era [ ] [ ] [ ] . many infected and sick patients need a quick, accurate, and reproducible diagnosis. importantly, scanning time should be reduced to limit possible exposure. there have been many recommendations to reduce the scanning time by acquiring limited images, and measuring off site [ ] . the problem with this approach is that we could miss important findings when we are mainly focused on taking many images instead of doing a thorough echocardiographic study. also, when we are performing the measurements off site, we might realize that we have not taken the necessary images at the appropriate angles. all of this can relate to poor patient outcomes from missed diagnosis. ai can be an essential aid for solving these problems. to understand the role of deep learning in echocardiography, it is necessary to clarify the difference between conventional machine learning and deep learning. the biggest difference between deep learning and conventional machine learning is that deep learning uses multilayer neural networks. using neural networks, the accuracy of models has been dramatically improved, especially in the fields of visual object recognition, object detection, and word recognition. learning with artificial intelligence can be classified into three categories: supervised learning, unsupervised learning, and reinforcement learning ( fig. ) . supervised learning is a method of learning by labeling training data with the correct answers. many medical image analysis studies have been conducted on images that humans correctly labeled beforehand. in the echocardiographic field, thousands of images with predefined labels should be included when making new models. notably, no unlearned answer would be presented in any training model. for example, if a model for myocardial infarction is trained with only the options "with myocardial infarction" or "without myocardial infarction", the training model cannot determine the culprit coronary artery due to the lack of specific training. unsupervised learning is a method of learning without labels, one famous example being the ai google created in , that could recognize a cat without manual training [ ] . this ai came to recognize a "cat" autonomously as it read web images and videos without labels, its learning process similar to human learning. reinforcement learning, an example being google's alphago ai beating a professional go player, is a method for finding ways to "maximize future value" through trial and error [ ] . it is similar to supervised learning, but the machine predicts future values in a broader sense (in the case of go, winning moves). unsupervised learning and reinforcement learning are not yet something that we generally use in imaging, so here we focus more on supervised learning in this review. an overview of the studies for the diagnostic ability of current deep learning models in the field of echocardiography in table [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] . the accuracy of ai models has been achieved around - %. sample sizes in these studies ranged from hundreds to tens of thousands. recently, the method of ai is sophisticated and it has become possible to create accurate ai models without using a large number of images. in the future, many institutions will develop research from a reasonable sample size. echocardiography is a useful tool in the diagnosis and management of cardiovascular diseases. accurate and reproducible echocardiographic studies are required for good clinical practice. echocardiography requires not only the adequate acquisition of images but also proper interpretation of images. the same physician may come to different conclusions on the same images. thus, more objective and reproducible methods are needed. the process of applying ai to echocardiography involves four steps. we humans subconsciously perform these steps during each examination. however, when we develop the application of ai, it is necessary to divide these steps into separate tasks to reach a diagnosis (fig. ). the first step in the application of ai to echocardiography is the evaluation of image quality. in humans, experience must obtain accurate images. poor-quality images are often acquired by inexperienced examiners. since image quality is directly linked to diagnostic accuracy, it is important to evaluate image quality correctly [ ] . a recent paper showed that the accuracy of ai-based classification for image quality was excellent (score error: . ± . ). this proposed approach could also be generalized to other images involving deep learning in the cardiovascular field, where there are frequent gaps in clinical labeling [ ] . in february , the u.s. food and drug administration (fda) approved the first ai based echocardiographic device with "guiding to acquire appropriate images with good quality". the system guides the user on which way to adjust the probe for the acquisition of a better image, and is designed to be easy to use even for beginners [ ] . the condition for use of this device is that a cardiologist must review and approve the acquired images for patient evaluation, rather [ ] lv function > , studies subjects r = . -kusunose et al. [ ] lv function , images subjects r = . -leclerc et al. [ ] lv function subjects -r = . -ghorbani et al. [ ] than leaving everything to the machine. the extent to which everything can be trusted the machines, is an important problem that should be discussed in the future. the next step is the view classification and segmentation of cardiovascular structures. echocardiographic images require many types of recordings because of the complexity of the cardiac structure. the view classification of cardiovascular structures can be useful in automated scans or detection of appropriate views. several investigators reported a good accuracy for view classification models (accuracy: around - % for -view classification) [ , ] . recently, we reported on our newly developed view classification model, based on convolutional neural network using , images. in this model, there were . % mislabeled images. clustering analyses showed that the neural network could sort heterogeneous input images into five pre-determined views (fig. ). in addition, to determine if the . % accuracy rate was acceptable for creating a feasible prediction model, we tested the prediction model for ejection fraction (ef) using the learning data with a . % error rate. the accuracy of the prediction model for ef was warranted, even with training data containing . % mislabeled images. thus, this approach may provide a clinically feasible method of view classification for the analysis of echocardiographic data [ ] . upon inspection of the misclassified images, we found that many of them were difficult even for experts to judge, suggesting that deep learning had been used to successfully imitate human reorganization (supplemental fig. ). once the image quality has been assessed and appropriate views have been determined, the next step is to measure and quantify the morphological structure. for example, the different frameworks between conventional machine learning and deep learning for the ejection fraction (ef) estimating method are shown in fig. . in conventional machine learning for prediction of ef, after pre-processing of images, a human data scientist manually configures a point to focus [ ] . their model showed a mean percentage error of approximately % for ef from the apical -chamber view, and % for ef from the apical -chamber view. another paper showed that the ef based on ap / ap views correlated well with reference ef (mean absolute deviation = . %) [ ] . our recent report adds to this by demonstrating better performance of a deep learning algorithm when five views are used. results of receiver operating characteristic (roc) analysis were used to assess the diagnostic ability of classification of reduced ef (< %) are shown in fig. a . for the classification of patients with reduced ef, we have compared the area under curves (aucs) from each model, and the model with largest auc was based on averaged views (auc: . ± . on fivefold cross validation). the auc of estimated lvef based on the averaged views was larger to the auc of estimated lvef based on the other views (auc by ap and ap : . ± . , auc by ap : . ± . and auc by ap : . ± . on fivefold cross validation, compared p value < . ) [ ] . according to these results, it may be more accurate to make a prediction model for lvef from multilevel images in the clinical setting. the last step is the detection of abnormality. one of the most important evaluations in echocardiography is the detection of regional wall motion abnormalities (rwmas). the presence of wall motion abnormalities is directly linked to the treatment decisions. detection of regional wall motion abnormalities by echocardiography is a class i recommendation in multiple cardiovascular guidelines in patients complaining of chest pain [ , ] . however, the evaluation of regional wall motion abnormalities has been traditionally subjective and relies on visual judgment, such examples being endocardial motion and myocardial thickness. thus, an adequate objective method has long been desired. machine-learning models have been developed to identify and quantify rwmas [ , ] . recently, our group developed an ai model for automated detection of rwmas in myocardial infarction, using a deep learning algorithm including resnet, densenet, inception-resnet, inception, and xception for a convolutional neural network [ ] [ ] [ ] . we have compared the aucs by several deep learning algorithms for detecting wall motion abnormalities. the largest auc was resnet (auc: . ), but there was no significant difference among algorithms except for the xception model (fig. b) . according to our findings, detection system of rwmas may be of great value in the clinical setting. building models using deep learning require a lot of data. to overcome this problem, the japan society of ultrasonics in medicine and japanese society of echocardiography have begun a joint multicenter study to collect labeled echocardiographic data from onward. with this dataset, an effective ai model could be developed in the near future. the lack of interpretability of ai solutions was often considered as a major disadvantage. the overcoming of this limitation should be addressed in future studies. currently, there are two roles for ai in cardiovascular imaging. one is the automation of tasks usually performed by humans, such as image segmentation and measurement of cardiac structural and functional parameters. another is the discovery of clinically important insights. most reported applications were focused on the automation of tasks. moreover, algorithms that can obtain cardiac measurements are also being developed. in the next stage, ai can be expected to expand and enrich existing knowledge. with the continual evolution of technology, cardiologists should become well versed in the new knowledge of ai and be able to harness it in the clinical setting. ai can be incorporated into everyday clinical practice and become a valuable aid for many healthcare professionals dealing with cardiovascular diseases. beginnings of artificial intelligence in medicine (aim): computational artifice assisting scientific inquiry and clinical art-with reflections on present aim challenges deep learning in neural networks: an overview deep learning nat utilization of artificial intelligence in echocardiography artificial intelligence in cardiology artificial intelligence in cardiovascular imaging: jacc state-of-the-art review automatic calcium scoring in low-dose chest ct using deep neural networks with dilated convolutions deep learning analysis of left ventricular myocardium in ct angiographic intermediate-degree coronary stenosis improves the diagnostic accuracy for identification of functionally significant stenosis deep learning for diagnosis of chronic myocardial infarction on nonenhanced cardiac cine mri coronavirus disease (covid- ) information for cardiologists-systematic literature review and additional analysis ase statement on protection of patients and echocardiography service providers during the novel coronavirus outbreak: endorsed by the american college of cardiology review of the efforts of the japanese society of echocardiography for coronavirus disease (covid- ) during the initial outbreak in japan identifying the extent of oral fluid droplets on echocardiographic machine consoles in covid- era unsupervised learning of generative and discriminative weights encoding elementary image components in a predictive coding model of cortical function the evolution of computing: alphago on modelling label uncertainty in deep neural networks: automatic estimation of intra-observer variability in d echocardiography quality assessment fast and accurate view classification of echocardiograms using deep learning fully automated echocardiogram interpretation in clinical practice deep learning for segmentation using an open large-scale dataset in d echocardiography automated echocardiographic quantification of left ventricular ejection fraction without volume measurements using a machine learning algorithm mimicking a human expert deep learning for assessment of left ventricular ejection fraction from echocardiographic images deep learning interpretation of echocardiograms a deep learning approach for assessment of regional wall motion abnormality from echocardiographic images automated technique for coronary artery disease characterization and classification using dd-dtdwt in ultrasound images quantification of cardiac bull's-eye map based on principal strain analysis for myocardial wall motion assessment in stress echocardiography cardiac ultrasound uses artificial intelligence to produce images clinically feasible and accurate view classification of echocardiographic images using deep learning automatic quality assessment of echocardiograms using convolutional neural networks: feasibility on the apical four-chamber view guideline on diagnosis and treatment of acute coronary syndrome esc guidelines for the diagnosis and treatment of acute and chronic heart failure: the task force for the diagnosis and treatment of acute and chronic heart failure of the european society of cardiology (esc) developed with the special contribution of the heart failure association (hfa) of the esc xception: deep learning with depthwise separable convolutions rethinking the inception architecture for computer vision imagenet: a large-scale hierarchical image database. computer vision and pattern recognition conflict of interest kenya kusunose declares that they have no conflict of interest.human rights statements and informed consent all procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the helsinki declaration of and later revisions. informed consent was obtained from all patients for being included in the study.informed consent informed consent was not obtained from the patients because of not patient study. key: cord- -meqjy p authors: al-balas, mahmoud; al-balas, hasan ibrahim; jaber, hatim m.; obeidat, khaled; al-balas, hamzeh; aborajooh, emad a.; al-taher, raed; al-balas, bayan title: distance learning in clinical medical education amid covid- pandemic in jordan: current situation, challenges, and perspectives date: - - journal: bmc med educ doi: . /s - - - sha: doc_id: cord_uid: meqjy p background: as covid- has been declared as a pandemic disease by the who on march th, , the global incidence of covid- disease increased dramatically. in response to the covid- situation, jordan announced the emergency state on the th of march, followed by the curfew on march. all educational institutions have been closed as well as educational activities including clinical medical education have been suspended on the th of march. as a result, distance e-learning emerged as a new method of teaching to maintain the continuity of medical education during the covid- pandemic related closure of educational institutions. distance e-learning is defined as using computer technology to deliver training, including technology-supported learning either online, offline, or both. before this period, distance learning was not considered in jordanian universities as a modality for education. this study aims to explore the situation of distance e-learning among medical students during their clinical years and to identify possible challenges, limitations, satisfaction as well as perspectives for this approach to learning. methods: this cross-sectional study is based on a questionnaire that was designed and delivered to medical students in their clinical years. for this study, the estimated sample size (n = ) is derived from the online raosoft sample size calculator. results: a total of students have completed the questionnaire, among them, students ( . %) have participated in distance learning in their medical schools amid covid- pandemic. the overall satisfaction rate in medical distance learning was . %, and it was significantly higher in students with previous experience in distance learning in their medical schools as well as when instructors were actively participating in learning sessions, using multimedia and devoting adequate time for their sessions. the delivery of educational material using synchronous live streaming sessions represented the major modality of teaching and internet streaming quality and coverage was the main challenge that was reported by . % of students. conclusion: with advances in technologies and social media, distance learning is a new and rapidly growing approach for undergraduate, postgraduate, and health care providers. it may represent an optimal solution to maintain learning processes in exceptional and emergency situations such as covid- pandemic. technical and infrastructural resources reported as a major challenge for implementing distance learning, so understanding technological, financial, institutional, educators, and student barriers are essential for the successful implementation of distance learning in medical education. conclusion: with advances in technologies and social media, distance learning is a new and rapidly growing approach for undergraduate, postgraduate, and health care providers. it may represent an optimal solution to maintain learning processes in exceptional and emergency situations such as covid- pandemic. technical and infrastructural resources reported as a major challenge for implementing distance learning, so understanding technological, financial, institutional, educators, and student barriers are essential for the successful implementation of distance learning in medical education. keywords: covid- , distance learning, e-learning, medical education, covid- has been declared as a pandemic disease by the who on march th, . the disease started in wuhan province in china in late december . since that time, the global incidence of covid- disease has increased dramatically. in early march ; the first diagnosed case of covid- disease had been reported in jordan for a jordanian citizen who had returned from italy weeks before jordan has declared quarantine for jordanians returning from outside. by the end of march, the total number of infected persons was cases. the number of diagnosed cases showed a steady slow increase, and by the end of april, a total of diagnosed cases with deaths were reported. on the th of march, the emergency state was announced in jordan followed by the curfew on march. similar to other sectors, the educational sector has been affected by this pandemic situation. all educational institutions have been closed as well as educational activities have been suspended on the th of march. as part of that, the six medical schools in jordan in stopped all their teaching and training activities. distance e-learning has emerged as a new method of teaching to maintain the continuity of medical education during the covid- pandemic related closure of educational institutions. medical education programs in jordan are six-year programs, in which clinical medical years are the last years in the curriculum. during clinical education, students receive both in-class theoretical lectures and seminars, and in-hospital clinical rotations. before the era of covid- , distance e-learning was not adopted as a modality of teaching within medical schools. distance e-learning in medical education may represent a suitable alternative to traditional learning to deliver high-quality education. the availability of essential infrastructures and efficient institutional strategies represent a major challenge for integrating distance learning in medical education [ ] . even blended education (i.e. distance and on-campus) is well adopted in different word countries, the effect of distance electronic learning is likely to be revolutionary specially in low-middle income countries. distance e-learning is defined as using computer technology to deliver training, including technologysupported learning either online, offline, or both [ ] . it is aimed at the effective construction of knowledge regarding individual experience, practice, and knowledge of the learners and students [ ] . internet-based learning, computer-based learning, virtual classrooms, and digital collaboration all represent different types of e-learning. there are modes of e-learning: distance learning and computer-assisted interaction (cai). moore et al. defined distance e-learning as providing access to learning for those who are geographically remote from the instructor [ ] , while cai is an interactive technique whereby instructional material is presented by and a computer, and students' progress is monitored and evaluated during this process. distance e-learning has been proved as an efficient modality of learning in different educational and governmental studies [ ] [ ] [ ] . data from the institute of educational studies in canada showed that learners revealed a more active attitude in learning when various methods such as electronic books and on-line articles were implemented in the teaching process [ , ] . anderson et al. in their paper have described three generations of distance education pedagogy. these generations are cognitive-behaviourism, constructivism, and connectivism. each one of these generations has distinguished utilized technology, learning activities, learner and content granularity, evaluation modality, scalability and instructor role. these generations have developed in concordance with available technologies. they stated that no single modality has provided all answers, and each of these generations has built on achievements of previous generation [ ] . according to the sustainable development goals (sdgs) for health including good health well-being and quality of education, effective and affordable educational strategies need to be addressed critically especially in low and middle-income countries (lmic) [ ] . adopting distance e-learning in different fields of knowledge in low and middle-income countries (e.g. jordan) can add a great benefit to achieve sdgs. this study aims to explore the situation of distance e-learning among medical students during their clinical years and to identify possible challenges, limitations, satisfaction as well as their perspectives for this the approach of learning. to the best of our knowledge, no published study discussing the current situation of distance e-learning among jordanian medical students in their clinical years is available. students' satisfactions, limitations, and perspectives have been addressed in our study as well. this is a cross sectional study based on a questionnaire of questions that was designed by a team of faculty members from all participating medical schools in jordan. participating students are medical students in their clinical medical years (i.e. th, th and th years) from the all medical schools (i.e. university of jordan, jordan university of science and technology, yarmouk university, hashemite university, mutah university, and al-balqa'a university)). the questionnaire was distributed on may th, using previously created students facebook and whatsapp groups that were adopted by medical schools for communication with their students. questions were in two formats, multiple-choice and rating questions on a five-point scale (likert scale). for simplifying statistical analysis, the five categories were regrouped into three categories, and were labeled as agree, neutral and disagree. these questions were mainly about student's demographics (age, gender, academic years and medical school), prior and current experience with distance learning, available technologies, distance learning benefits, drawbacks, their instructors' influence, challenges, attitudes towards the effectiveness of distance learning in medical education, and their perceptions about the future of distance learning in medical education. for this study, the estimated sample size is derived from the online raosoft sample size calculator [ ] . the sample size was calculated based on a response rate of %, a confidence interval of %, and a margin of error of %, with a total th, th, and th medical student population around (i.e. university of jordan (n = ), jordan university of science and technology (n = ), hashemite university (n = ), yarmouk university (n = ), mutah university (n = ) and albalqa'a university (n = )), the largest required sample size is . accordingly, this study included a convenient sample of students who are currently enrolled in their clinical years. objectives and goals were explained at the beginning of the questionnaire to all participating students, and their enrollment was after they consent to participate in the study. data were analyzed using the statistical package for the social sciences version (spss inc., chicago, il) statistical software. the analyses included descriptive statistics and chi-square test. a p < . was considered statistically significant. the mean age of participants was . years (range: - ). as illustrated in table , among the students who completed their questionnaire, ( . %) were female. other demographics are explained in table . two hundred and sixty-two students ( . %) declared their enrollment in at least one distance learning course before or during the covid- pandemic that is not part of their medical school curriculum while students ( . %) have participated in a distance learning course in their universities previously. amid the covid- pandemic, the majority of the student (n = ; . %) have participated in distance learning in their medical schools. further analysis of the non-participating students showed that th-year students were the least to be involved in distance learning as the majority of them have completed their academic courses before the covid- curfew. among the students, smartphones were the most commonly used single device in e-learning ( . %) followed by computers either laptops or desktops ( . %). two hundred and sixty seven students according to the participating students, the delivery of educational material using synchronous live streaming sessions represented the major modality of teaching, in which . % of students were engaged. only prerecorded sessions and a mix of live and pre-recorded lessons were used in . and % respectively. various platforms and applications had been implemented in distance learning including zoom, microsoft teams, whatsapp groups, facebook groups, youtube channels, moodle, and skype. while most students reported using multiple platforms in their learning ( . %), zoom was the most commonly used single platform in delivering educational sessions ( . %). regarding reported benefits, drawbacks, and challenges of distance learning, . % reported having multiple advantages including time-saving, flexibility of class, improved interaction with instructors and classmates. a minority of students ( %) reported no benefits in comparison to traditional learning. the main drawbacks were the low quality of teaching reported by ( . %) of responders and poor interaction with instructors reported by ( . %) of responders. internet streaming quality and coverage was the main challenge that was reported by students ( . %). a summary of reported benefits, drawbacks, and challenges is summarized in table . based on students' opinions regarding instructors' role and performance in distance learning, . % of students had agreed that instructors were actively participating in their discussions and . % of students admitted that instructors approached them using multimedia to achieve desired course objectives. the majority of students reported an efficient response to their inquiries from instructors (i.e. . % reported response in less than h). on the other hand, the time dedicated to distance learning sessions was not adequate according to . % of students. overall, only students ( . %) were satisfied with their experience in medical distance learning (fig. ) . factors that were significantly linked to the level of satisfaction includes students previous experience in distance learning within universities, instructors' role, using multimedia and devoting adequate time for educational sessions. on the other hand, students' academic level or previous enrollment in distance learning courses out of the university curriculum was not related to the level of satisfaction (table ) . based on students' perspectives, implementing distance e-learning in medical education is challenging ( table ) ; . % of students think that preference of traditional approach by faculty members will be the main barrier and . % believe that lack of cooperation from instructors will affect this approach. poor financial capacity of students might also impede distance learning according to students ( . %). besides that, . % of students predict that lack of commitment to distance learning courses by students more than half of students ( . %) admit that young staff members are more willing to participate in distance e-learning while . % disagreed with that. according to students ( . %), distance e-learning can replace traditional class learning in delivering theoretical knowledge while students ( . %) replied that distance elearning will represent a major challenge to acquire adequate clinical medical skills. according to students ( . %), blended approach (a mix of traditional and elearning classes) is the preferred way to deliver medical education in the future, and adopting future distance learning was significantly related to the degree of overall satisfaction. this study aimed to evaluate clinical medical students' experiences in computer mediated distance e-learning, which is considered a newly adopted approach in jordanian medical schools. distance e-learning has emerged as a new method of teaching to maintain the continuity of medical education during the covid- pandemic. in this study, we explored student's opinions toward major challenges they faced during their new experience of learning, limitations, faculty staff performance, overall satisfaction as well as future perspectives. traditional (i.e. face to face) teaching is considered an essential long-standing approach in medical education [ ] . as traditional approaches in medical education are facing increased challenges because of the increase in clinical demands and reduction in available time [ ] , a shift in traditional medical education practice to online, distance, or electronic learning has been noticed in the last few decades [ ] . in , almost % of students were enrolled in distance learning during their undergraduate bachelor's degree according to the us national center for educational statistics [ ] , but actually this is not the case in undergraduate education in jordan. distance e-learning has been reported to provide easier and more effective access to a wider variety and greater quantity of information, as well, learning delivery allows a personalized approach in learning, so students have more control over the educational content, learning sequence and time [ ] [ ] [ ] . another advantage of e-learning is the easier and faster update and distribution of the educational content in comparison to printed references. in this study, main reported advantages were saving time and flexibility of classes as being reported by and . % respectively. implementation of distance e-learning in medical education is challenging, especially in low-middle income countries. barrier against adopting distance e-learning [ , ] , and this was demonstrated in participants reported challenges (table ) . another important challenge against distance learning is the reluctance and avoidance of educators to engage in new technologies and applications because of their limited knowledge or lacking proper training in these fields [ ] . as institutional support is essential for the success of distance learning, and institutional strategy should be designed to facilitate the implementation of key skills and the adoption of methodologies by faculty [ ] . in this study, the overall medical students' early experience in distance learning is unsatisfactory. previous experience in distance learning was significantly associated with higher satisfaction among our students. despite their low level of satisfaction, they expect that distance e-learning can partially replace the traditional method in delivering theoretical but not clinical skills. they believe that a blended approach (traditional and e-learning) will be the most suitable for future medical training. based on our review, this is the first paper discussing clinical medical distance e-learning in jordan. we have involved medical students during their clinical years in all jordanian medical universities. major limitations for this study was the inability to measure educational outcomes linked to distance e-learning and comparing them to traditional learning. further studies are required to address educational outcomes as well as faculty members' perceptions and opinions towards distance elearning. based on the results, medical institutions in jordan need to address previously mentioned challenges in near future to optimize the experience of distance e-learning among their students. it is mandatory to collaborate with telecommunication companies to provide students and instructors with high-quality internet coverage with affordable costs, also to improve instructors' skills in using technology in their distance learning. the need to establish a unified educational platform for all medical schools might be the optimal solution to overcome the variation between students' satisfaction in distance learning secondary to variation in instructors' performance. with advances in technologies and social media, distance learning is a new and rapidly growing approach for undergraduate, postgraduate, and health care providers. regardless of reported benefits, medical students preferred the blended approach in teaching as distance learning represented a major challenge to acquire adequate clinical medical skills. satisfaction in distance learning is strongly linked to students' prior experience in distance learning as well as instructors' experiences and interactions. technical and infrastructural resources reported as a major challenge for implementing distance learning, so understanding technological, financial, institutional, educators, and student barriers are essential for the successful implementation of distance learning in medical education. opatija: electronics and microelectronics (mipro) e-learning, online learning, and distance learning environments: are they the same? internet high educ transforming information search and evaluation practices of undergraduate students medical education as a science: the quality of evidence for computer-assisted instruction remote teaching of histopathology using scanned slides via skype between the united kingdom and nigeria how does distance education compare with classroom instruction? a metaanalysis of the empirical literature guide of internet sites for the study of cardiology three generations of distance education pedagogy e-learning for undergraduate health professional education. a systematic review informing a radical transformation of health workforce development. world health organisation raosoft® sample size calculator education in a technological world: communicating current and emerging research and technological efforts educational technology to facilitate medical students' learning: background paper of the medical school objectives project differences between traditional and distance education academic performances: a meta-analytic approach. the international review of research in open and distributed learning summary health statistics for us adults: national health interview survey information technology in medical education: current and future applications use of e-learning in education: attitude of medical students of shiraz, iran evolution of web site design: implications for medical education on the internet computer literacy and e-learning perception in cameroon: the case of yaounde. faculty of medicine and biomedical sciences barriers in implementing e-learning in hormozgan university of medical sciences barriers and solutions to online learning in medical education -an integrative review publisher's note springer nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations study limitations a total of students responded out of students. we concluded data acquisition once the minimum required convenient sample size ( ) was reached. availability of data and materials all data and supplementary material are available upon request from the corresponding author. the statement of ethical approval was obtained from the institutional review board (irb) committee at hashemite university, and an informed written consent was obtained from participants before their enrollment in the questionnaire. not applicable. yarmouk university, irbid, jordan.received: june accepted: september the authors declare that there is no conflict of interest regarding this project and they approved it for publication. key: cord- -qsk zf authors: alkhowailed, mohammad s.; rasheed, zafar; shariq, ali; elzainy, ahmed; el sadik, abir; alkhamiss, abdullah; alsolai, ahmed m.; alduraibi, sharifa k.; alduraibi, alaa; alamro, ahmad; alhomaidan, homaidan t.; al abdulmonem, waleed title: digitalization plan in medical education during covid- lockdown date: - - journal: inform med unlocked doi: . /j.imu. . sha: doc_id: cord_uid: qsk zf background: the covid- pandemic has enhanced the adoption of virtual learning after the urgent suspension of traditional teaching. different online learning strategies were established to face this learning crisis. the present descriptive cross-sectional study was conducted to reveal the different digital procedures implemented by the college of medicine at qassim university for better student performance and achievement. methods: the switch into distance-based learning was managed by the digitalization committee. multiple online workshops were conducted to the staff and students about the value and procedures of such a shift. new procedures for online problem-based learning (pbl) sessions were designed. students’ satisfaction was recorded regarding the efficiency of live streaming educational activities and online assessment. results: the students were satisfied with the overall shift into this collaborative e-learning environment and the new successful procedures of virtual pbl sessions. the digital learning tools facilitated the performance of the students and their peer sharing of knowledge. the role of informatics computer technologies was evident in promoting the students, research skills, and technical competencies. conclusions: the present work elaborated on the procedures and privileges of the transformation into digitalized learning, particularly the pbl sessions, which were appreciated by the students and staff. it recommended the adoption of future online theoretical courses as well as the development of informatics computer technologies. scientific technology and digitalization have a tremendous impact on escalating the efficiency and productivity of work in nearly all the fields in the modern era, from farming to health services and innovations and has proved itself as an efficient tool to make human life better and easier [ , ] . online learning is considered a feasible and compliant method for training and scientific meetings and the sustainability of learning [ ] . the expansion in global virtual learning is dependent on the availability of technology-enhanced active learning tools, and the options of online learning and their role in the field of medical education cannot be disregarded [ , ] . the use of digital technology in medical education is now believed to have a crucial aspect of learning resources [ ] [ ] [ ] . it does not only augment the understanding of the subject, but it also prepares the students to deal with the real-life scenario in a more practical way [ ] . the pandemic of coronavirus disease (covid- ) demands for virtual classrooms to foster creative thinking and solving problems capabilities of the students. the existing digital platform enabled communication with learners with a lower barrier and the online teaching was found to be a method that challenged our traditional approach [ ] [ ] [ ] [ ] . a previously conducted study on twenty-two thousand students in the united kingdom using digital education organization revealed that the technology as a learning tool is yet to be realized for effective pedagogy and learning [ ] . another study conducted in australia, including more than one thousand students, revealed that digital learning was the most valuable technology for studying [ ] . this study was conducted to disclose the digital resources used in teaching of the medical students at the college of medicine at qassim university. currently, there are two sections for male and female students in j o u r n a l p r e -p r o o f digital processes used by the college of medicine in qassim university for better performance and achievement in the field of medical education. this is a cross-sectional study performed on undergraduate medical students (n= ) from the th of march till the end of april in the college of medicine at qassim university in ksa. ethical approval was obtained from the research ethics committee at qassim university and the confidentiality of the information obtained was kept in consideration. a committee was formed, which included faculty members of the college of medicine and the task was given to digitalize the teaching activities through utilization of the available learning recourses required to provide effectual medical education. the digitalization process was subdivided into two main functional parts. the first one was to digitalize the different learning activities, which included pbl, lectures, seminars, and assignments. the second task was to construct digital evaluation and feedback sheets. students of the basic years were subdivided into groups for virtual pbl on the blackboard with one faculty member assigned for each group for facilitating and evaluating the pbl sessions. after each session, anonymous electronic feedback from the staff about the pbl materials was sent to the pbl reviewing committee. the complete steps of the pbl digitalization are summarized in figure . qassim college of medicine used blackboard learning management system as the primary tool for virtual teaching. in case of its interruption, the zoom cloud meetings platform was utilized as an alternative tool. live webinars for the detailed instructions on the proper digitalization of educational activities were implemented to increase the competencies of the students and staff during online teaching. for any obstacle facing the students or staff during the e-learning process, different communication tools were suggested, such as using the social media application whatsapp to respond promptly to any inquiry. an exam committee was formed, comprised of senior faculty members. the task for the committee was to design digital exams composed of clinical scenario-based multiplechoice questions, which were prepared through the contribution of the relevant department of the medical college. the students' performance was evaluated after online j o u r n a l p r e -p r o o f exams based upon the marks they obtained. in order to assess the clarity, difficulty level, and quality of the digital evaluation activity, students were provided with online feedback. after the suspension of study due to the covid- pandemic, all college meetings were conducted using blackboard collaborate ultra for web conferencing. in case of any technical issue facing the live streaming via blackboard, zoom cloud meetings was purchased by qassim university, and the login details using university domain identification were provided to each faculty member was used as an alternative for conducting the meetings. an online satisfaction survey was performed to collect the student's perception of the whole online learning process using a -points likert scale. analysed data were revised and analysed by an independent investigator. qassim university, such as dentistry and nursing colleges ( table ). the feedback of the students on their perception about the whole digitalization process was recorded through an online survey (fig. ) . . % of the students were satisfied with online teaching for all theoretical courses. about % agreed that the live- this study described the procedures of the transformation from the traditional medical learning into the digital during the complete lockdown of covid- pandemic. as the world is converting into a global village, technology has a tremendous contribution, especially in health sciences and medical care [ ] . the covid- pandemic has enhanced the adoption of virtual learning being the only safe and satisfactory educational option to ensure students' engagement, fulfilling their knowledge gaps as well as competencies of the health professional educators [ ] . according to the current needs, it is a vital step to prepare the medical students and staff to cope with the modern technological innovations. medical education is speedily upgraded under the influence of various factors that included the diversity in societal prospects and the health care system [ , ] . in concretion to this vision, the college of medicine at qassim university adapted the pathway of virtual classrooms under the supervision of the digitalization committee. the success of this committee in the organization of logistics and procedures of the distant learning and online evaluation was conveyed from the positive reflection of the students regarding the live-streaming sessions, online assessment, and overall satisfaction. in this scope, the accomplishment of virtual learning began with the obligatory social distancing due to the covid- . most importantly the financial support provided by qassim university to all students and high standard living status of saudi society through which they utilized high-speed internet services played a vital role for the successful implantation of the digitization plan during this pandemic. digitalization of educational materials has a considerable impact on the environment in which medical students learn [ ] . the present study elaborated that blackboard was the main software j o u r n a l p r e -p r o o f utilized for conducting most of the teaching activities. the rest of the live streaming session was conducted via zoom cloud meetings as an alternative online platform utilized if the access to the official blackboard was non-feasible. this was made possible due to our staff and students as they were accustomed previously by handling the various online activities such as they were officially using blackboard, an official learning management system for the last three years. in addition, the faculty development unit organized multiple training sessions every year for the effective utilization of the elearning, and switch to cope with the advance in the informatics and distant learning. moreover, the expert staff was also selected in dealing with the online teaching, particularly in the first week of practicing the e-learning. in spite of these, the staff experiences were unsatisfactory for about % of the students. this could be due to the overloaded burden of both the staff and students to prepare didactic materials and to adopt the online learning process in a very short period of time. different medical colleges around the globe utilized a variety of digital software for distance-based learning. the university of sarajevo, located in bosnia and herzegovina, had implemented the virtual classrooms as a learning strategy on their e-learning website [ ] . our newly designed steps of the online pbl sessions were effective and enhanced the performance of students and tutors, which was evident from the students' perception. this successful application of distant learning and assessment motivated the college to construct efficient online procedures for other educational activities such as team-based learning (tbl) and the digital learning tools facilitated the performance of the students and their peer sharing of knowledge. the evaluation of students is an integral step in assessing the knowledge they have gained during the learning process. putten et al., in their study, found that conducting the online assessments by digital means is a beneficial strategy [ ] . in view of these, the college of medicine at qassim university conducted all exams via digital means on blackboard software. during digital learning, the students were evaluated not only on the basis of their performance in the summative exams built on multiple choice questions, but their evaluation was also conducted on the basis of various other modalities such as pbl. the students were evaluated in the pbl sessions according to their peer interaction, commitment, team spirit, problem solving and critical thinking. in addition, the evaluation of the presentation skills and cognitive learning domains were performed through their seminars. enthusiasm among the students who are attending the distancebased learning courses is also an important aspect, since if the students are not mounting interest, it will lead to a high dropout rate [ ] . a few students were inconvenienced with the online assessment to test their knowledge precisely. this could be explained by the fact that the students were not adapted yet to online exams, being the first time they were assessed by such a method. according to a recent perception survey performed by the imperial college london, some students mentioned that online exams were imperfect as they did not have a quiet surrounding environment at their homes while giving a timed online exam [ ] . routine online surveys and feedback were taken from the students in order to become aware and overcome the deficiencies in virtual teaching. the motivation of most of the students to implement online theoretical courses in the future was observed. however, the psychomotor skills performed in the practical and clinical settings required direct hands-on training as in real life. the students have to deal with j o u r n a l p r e -p r o o f practical laboratory procedures and real patients that require direct human interaction. according to a study conducted by warnecke et al., most medical students looked on elearning as a pleasurable and efficient mode of learning; however, they do not perceive it as a replacement of traditional educational methods [ ] . another study, conducted on medical students, had shown that learning was comparatively superior in a blended learning environment in which both e-learning and traditional teaching was merged [ ] . conversely, this contentment is not correlated with exam scores in which there was no significant distinction between the two pedagogic methods [ ] . the level of satisfaction of the students about the interaction and open discussion during the live streaming sessions was average as it depended upon the type of educational activity as well as the role of faculty member moderating this activity [ ] . this also could be attributed to the urgent switch into this new teaching modality. during this digitalization based learning, we also encountered several limitations including insufficient learning resources, such as the overload on the official learning management system that necessitated sustained upgrade and maintenance. in addition, there was a lack of information technologists as well as a lack of optimal online learning experience of staff and students. these could be overcome by developing and integrating informatics computer technologies in the field of medical education, collaboration with other universities having a good practice of distance-based teaching methods, and enhancement of digital literacy among students as well as faculty. j o u r n a l p r e -p r o o f the current work elaborated on the procedures, privileges, and challenges of the shift into distance-based learning, particularly online pbl. this switch was appreciated by both students and staff. the study recommended the development of informatics computer technologies to promote technologically-enhanced learning and the implementation of online courses in subsequent years. the value of sts in medical and health humanities pedagogy witnessing the advance of science and technology in life sciences in the new era barriers and solutions to online learning in medical education -an integrative review e-learning as new method of medical education evaluation of e-learning for medical education in 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students' perceptions of using e-learning to enhance the acquisition of consulting skills comparison of the effect of lecture and blended teaching methods on students' learning and satisfaction blended learning versus traditional lecture in introductory nursing pathophysiology courses researchers would like to thank the deanship of scientific research, qassim university for funding publication of this project. the authors declare no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. mohammad s. alkhowailed: data collection and interpretation and manuscript drafting. key: cord- -fc xnbju authors: jha, amrit kumar; arora, alisha title: the neuropsychological impact of e-learning on children date: - - journal: asian j psychiatr doi: . /j.ajp. . sha: doc_id: cord_uid: fc xnbju nan the covid- pandemic has forced school closures worldwide leading nearly . billion children being out-of-classrooms or away from school in almost countries (tandon a; unesco, ) . this has resulted in the boom of e-learning, defined as the use of internet technologies to deliver a broad array of solutions that enhance knowledge and performance (rosenberg and foshay, , p. ) . built upon the fabric of internet and communication technology, e-learning is being touted as the most viable alternative to the traditional classroom teaching and learning in days ahead. the covid- pandemic has led to a massive upsurge in the demand for the e-learning platforms worldwide as children have been instructed to attend classes online from their homes to maintain continuity of formal learning (li and lalani, ) . while neuroplasticity offers opportunity to adapt the sudden change in the modality of classroom transaction from face-to-face interaction to the technology mediated learning, it may wreak havoc for the growing brain of children. indeed, being the new partner in their mode of education, e-learning, poses an adaptability risk for the young brains. brain's plasticity sheds light upon how neural circuitry in young brains respond to digital learning, given the fact that the formation of higher-order j o u r n a l p r e -p r o o f functions take place during childhood years (zelazo and muller, ) . several studies indicate that multi-method screen exposure leads to structural changes such as reduced volume of the cortex with loss of integrity pertaining to the white matter region (takeuchi et al., ) and decreased grey matter in prefrontal regions viz. the right frontal pole and anterior cingulate cortex (loh and kanhai, ) . such alterations, consequently, impede attentional competence, processing speed, verbal intelligence, and sustained attention, respectively. additionally, searching, locating, and reading online content reduces the functional connectivity of regions around temporal gyrus, responsible for long-term memory formation and retrieval of learned material (liu et al., ) . it may also be note that the overuse of visual modality and exposure to the computer screen for long hours may yield adverse effects of the visual system. a study by firth et al. ( ) has indicated how functional changes impair attentional capacities, memory processes, and social cognition abilities in individuals. the online platform of learning requires the brain to rapidly switch between tasks, consuming the metabolic energy, and time at the neural level. the visual stimuli presented are usually complex and multi-method based (involving audio-visual graphics, text, and animations), prompting digital multitasking, resulting in impaired recall. one major reason is the overload upon working memory, which impedes an individual's ability to register, process, and remember information with accuracy. cognitive overload, as a product of multi-method based learning and divided attention, impacts the quality of comprehension, prioritization, and deep-level processing of incoming information, which in turn, critically determines consolidation of memory into long-term memory (carr, ) . consequently, it leads to poor processing and understanding of what is taught or said. besides, the absence of a school setting impairs social cognitive abilities such as empathy, teaming, and peer relationships among children. new challenges demand novel approaches to the process of teaching-learning. educators can provide individualized goals, the scope for individual discussions, and provide visual reminders to combat digital distractions. besides, there is also a need for sensitizing teachers for dealing with the heterogeneity of executive functioning at the grade level by custom designing the contents to be delivered. the daily screen time and access to the devices by children need to be judiciously regulated and supported by all the stakeholders (jamir et al., ; tandon, b) . it is relevant to note that the sars outbreak in year proved as a tipping point to the e-commerce industry, leading to its widespread surge. however, projecting the same trajectory to the e-learningwould be unfair and detrimental for the children in the long run cognitively, emotionally, and socially. they cannot be treated as a commodity to be packed and sold in the market, rather an active agent for a vibrant future. co-opting the use of technologies for education has been a long-standing controversy. the content taught through various platforms may be relevant, but a class devoid of reflection and review may not plant the seeds of critical and deep thinking skills required in the trajectory of their lives. while presenting the guidelines for a healthy lifestyle for children, the who director had recently opined that "achieving health for all means doing what is best for health right from the beginning of peoples' lives" (who, ) . this needs to be followed earnestly as an overarching principle for setting the right precedent for the future of tomorrow. the authors did not receive any fund for this work. the authors have no conflict of interests. j o u r n a l p r e -p r o o f the shallows: what the internet is doing to our brains the "online brain": how the internet may be changing our cognition epidemiology of technology addiction among school students in rural india . the covid- pandemic has changed education forever internet search alters intra-and inter-regional synchronization in the temporal gyrus how has the internet reshaped human cognition? theneurosci e-learning: strategies for delivering knowledge in the digital age impact of frequency of internet use on development of brain structures and verbal intelligence: longitudinal analyses covid- and mental health: preserving humanity, maintaining sanity, and promoting health the covid- pandemic, personal reflections on editorial responsibility billion learners are still affected by school or university closures, as educational institutions start reopening around the world, says unesco to grow up healthy, children need to sit less and play more executive function in typical and atypical development in all gratitude, we would like to express our sincere respect to mrs. anju jha, prof.girishwar misra, and ms. shipra saini for their timely and insightful contribution towards enhancing the depth and readability of the manuscript. key: cord- -dbgs ado authors: rieke, nicola; hancox, jonny; li, wenqi; milletari, fausto; roth, holger; albarqouni, shadi; bakas, spyridon; galtier, mathieu n.; landman, bennett; maier-hein, klaus; ourselin, sebastien; sheller, micah; summers, ronald m.; trask, andrew; xu, daguang; baust, maximilian; cardoso, m. jorge title: the future of digital health with federated learning date: - - journal: nan doi: nan sha: doc_id: cord_uid: dbgs ado data-driven machine learning has emerged as a promising approach for building accurate and robust statistical models from medical data, which is collected in huge volumes by modern healthcare systems. existing medical data is not fully exploited by ml primarily because it sits in data silos and privacy concerns restrict access to this data. however, without access to sufficient data, ml will be prevented from reaching its full potential and, ultimately, from making the transition from research to clinical practice. this paper considers key factors contributing to this issue, explores how federated learning (fl) may provide a solution for the future of digital health and highlights the challenges and considerations that need to be addressed. research on artificial intelligence (ai) has enabled a variety of significant breakthroughs over the course of the last two decades. in digital healthcare, the introduction of powerful machine learning-based and particularly deep learning-based models [ ] has led to disruptive innovations in radiology, pathology, genomics and many other fields. in order to capture the complexity of these applications, modern deep learning (dl) models feature a large number (e.g. millions) of parameters that are learned from and validated on medical datasets. sufficiently large corpora of curated data are thus required in order to obtain models that yield clinical-grade accuracy, whilst being safe, fair, equitable and generalising well to unseen data [ , , ] . for example, training an automatic tumour detector and diagnostic tool in a supervised way requires a large annotated database that encompasses the full spectrum of possible anatomies, pathological patterns and types of input data. data like this is hard to obtain and curate. one of the main difficulties is that unlike other data, which may be shared and copied rather freely, health data is highly sensitive, subject to regulation and cannot be used for research without appropriate patient consent and ethical approval [ ] . even if data anonymisation is sometimes proposed as a way to bypass these limitations, it is now wellunderstood that removing metadata such as patient name or date of birth is often not enough to preserve privacy [ ] . imaging data suffers from the same issue -it is possible to reconstruct a patient's face from three-dimensional imaging data, such as computed tomography (ct) or magnetic resonance imaging (mri). also the human brain itself has been shown to be as unique as a fingerprint [ ] , where subject identity, age and gender can be predicted and revealed [ ] . another reason why data sharing is not systematic in healthcare is that medical data are potentially highly valuable and costly to acquire. collecting, curating and maintaining a quality dataset takes considerable time and effort. these datasets may have a significant business value and so are not given away lightly. in practice, openly sharing medical data is often restricted by data collectors themselves, who need fine-grained control over the access to the data they have gathered. federated learning (fl) [ , , ] is a learning paradigm that seeks to address the problem of data governance and privacy by training algorithms collaboratively without exchanging the underlying datasets. the approach was originally developed in a different domain, but it recently gained traction for healthcare applications because it neatly addresses the problems that usually exist when trying to aggregate medical data. applied to digital health this means that fl enables insights to be gained collaboratively across institutions, e.g. in the form of a global or consensus model, without sharing the patient data. in particular, the strength of fl is that sensitive training data does not need to be moved beyond the firewalls of the institutions in which they reside. instead, the machine learning (ml) process occurs locally at each participating institution and only model characteristics (e.g. parameters, gradients etc.) are exchanged. once training has been completed, the trained consensus model benefits from the knowledge accumulated across all institutions. recent research has shown that this approach can achieve a performance that is comparable to a scenario where the data was co-located in a data lake and superior to the models that only see isolated singleinstitutional data [ , ] . for this reason, we believe that a successful implementation of fl holds significant potential for enabling precision medicine at large scale. the scalability with respect to patient numbers included for model training would facilitate models that yield unbiased decisions, optimally reflect an individual's physiology, and are sensitive to rare diseases in a way that is respectful of governance and privacy concerns. whilst fl still requires rigorous technical consideration to ensure that the algorithm is proceeding optimally without compromising safety or patient privacy, it does have the potential to overcome the limitations of current approaches that require a single pool of centralised data. the aim of this paper is to provide context and detail for the community regarding the benefits and impact of fl for medical applications (section ) as well as highlighting key considerations and challenges of implementing fl in the context of digital health (section ). the medical fl use-case is inherently different from other domains, e.g. in terms of number of participants and data diversity, and while recent surveys investigate the research advances and open questions of fl [ , , ] , we focus on what it actually means for digital health and what is needed to enable it. we envision a federated future for digital health and hope to inspire and raise awareness with this article for the community. ml and especially dl is becoming the de facto knowledge discovery approach in many industries, but successfully implementing data-driven applications requires that models are trained and evaluated on sufficiently large and diverse datasets. these medical datasets are difficult to curate (section . ). fl offers a way to counteract this data dilemma and its associated governance and privacy concerns by enabling collaborative learning without centralising the data (section . ). this learning paradigm, however, requires consideration from and offers benefits to the various stakeholders of the healthcare environment a parameter server distributes the model and each node trains a local model for several iterations, after which the updated models are returned to the parameter server for aggregation. this consensus model is then redistributed for subsequent iterations. (b) decentralised architecture via peer-to-peer: rather than using a parameter server, each node broadcasts its locally trained model to some or all of its peers and each node does its own aggregation. (c) hybrid architecture: federations can be composed into a hierarchy of hubs and spokes, which might represent regions, health authorities or countries. (section . ). all these points will be discussed in this section. data-driven approaches rely on datasets that truly represent the underlying data distribution of the problem to be solved. whilst the importance of comprehensive and encompassing databases is a well-known requirement to ensure generalisability, state-of-the-art algorithms are usually evaluated on carefully curated datasets, often originating from a small number of sources -if not a single source. this implies major challenges: pockets of isolated data can introduce sample bias in which demographic (e.g. gender, age etc.) or technical imbalances (e.g. acquisition protocol, equipment manufacturer) skew the predictions, adversely affecting the accuracy of pre-diction for certain groups or sites. the need for sufficiently large databases for ai training has spawned many initiatives seeking to pool data from multiple institutions. large initiatives have so far primarily focused on the idea of creating data lakes. these data lakes have been built with the aim of leveraging either the commercial value of the data, as exemplified by ibm's merge healthcare acquisition [ ] , or as a resource for economic growth and scientific progress, with examples such as nhs scotland's national safe haven [ ] , the french health data hub [ ] and health data research uk [ ] . substantial, albeit smaller, initiatives have also made data available to the general community such as the human connectome [ ] , uk biobank [ ] , the cancer imaging archive (tcia) [ ] , nih cxr [ ] , nih deeplesion [ ] , the cancer genome atlas (tcga) [ ] , the alzheimer's disease neu-roimaging initiative (adni) [ ] , or as part of medical grand challenges such as the camelyon challenge [ ] , the multimodal brain tumor image segmentation benchmark (brats) [ ] or the medical segmentation decathlon [ ] . public data is usually task-or disease-specific and often released with varying degrees of license restrictions, sometimes limiting its exploitation. regardless of the approach, the availability of such data has the potential to catalyse scientific advances, stimulate technology start-ups and deliver improvements in healthcare. centralising or releasing data, however, poses not only regulatory and legal challenges related to ethics, privacy and data protection, but also technical ones -safely anonymising, controlling access, and transferring healthcare data is a non-trivial, and often impossible, task. as an example, anonymised data from the electronic health record can appear innocuous and gdpr/phi compliant, but just a few data elements may allow for patient reidentification [ ] . the same applies to genomic data and medical images, with their high-dimensional nature making them as unique as one's fingerprint [ ] . therefore, unless the anonymisation process destroys the fidelity of the data, likely rendering it useless, patient reidentification or information leakage cannot be ruled out. gated access, in which only approved users may access specific subsets of data, is often proposed as a putative solution to this issue. however, not only does this severely limit data availability, it is only practical for cases in which the consent granted by the data owners or patients is unconditional, since recalling data from those who may have had access to the data is practically unenforceable. the promise of fl is simple -to address privacy and governance challenges by allowing algorithms to learn from non co-located data. in a fl setting, each data controller not only defines their own governance processes and associated privacy considerations, but also, by not allowing data to move or to be copied, controls data access and the possibility to revoke it. so the potential of fl is to provide controlled, indirect access to large and comprehensive datasets needed for the development of ml algo-rithms, whilst respecting patient privacy and data governance. it should be noted that this includes both the training as well as the validation phase of the development. in this way, fl could create new opportunities, e.g. by allowing large-scale validation across the globe directly in the institutions, and enable novel research on, for example, rare diseases, where the incident rates are low and it is unlikely that a single institution has a dataset that is sufficient for ml approaches. moving the to-be-trained model to the data instead of collecting the data in a central location has another major advantage: the high-dimensional, storage-intense medical data does not have to be duplicated from local institutions in a centralised pool and duplicated again by every user that uses this data for local model training. in a fl setup, only the model is transferred to the local institutions and can scale naturally with a potentially growing global dataset without replicating the data or multiplying the data storage requirements. some of the promises of fl are implicit: a certain degree of privacy is provided since other fl participants never directly access the data from other institutions and only receive the resulting model parameters that are aggregated over several participants. and in a client-server architecture (see figure ), in which a federated server manages the aggregation and distribution, the participating institutions can even remain unknown to each other. however, it has been shown that the models themselves can, under certain conditions, memorise information [ , , , ] . therefore the fl setup can be further enhanced by privacy protections using mechanisms such as differential privacy [ , ] or learning from encrypted data (c.f. sec. ). and fl techniques are still a very active area of research [ ] . all in all, a successful implementation of fl will represent a paradigm shift from centralised data warehouses or lakes, with a significant impact on the various stakeholders in the healthcare domain. if fl is indeed the answer to the challenge of healthcare ml at scale, then it is important to understand who the various stakeholders are in a fl ecosystem and what they have to consider in order to benefit from it. the aggregation may happen on one of the training nodes or a separate parameter server node, which would then redistribute the consensus model. b) peer to peer training: nodes broadcast their model updates to one or more nodes in the federation and each does its own aggregation. cyclic training happens when model updates are passed to a single neighbour one or more times, round-robin style. c) hybrid training: federations, perhaps in remote geographies, can be composed into a hierarchy and use different communication/aggregation strategies at each tier. in the illustrated case, three federations of varying size periodically share their models using a peer to peer approach. the consensus model is then redistributed to each federation and each node therein. clinicians are usually exposed to only a certain subgroup of the population based on the location and demographic environment of the hospital or practice they are working in. therefore, their decisions might be based on biased assumptions about the probability of certain diseases or their interconnection. by using ml-based systems, e.g. as a second reader, they can augment their own expertise with expert knowledge from other institutions, ensuring a consistency of diagnosis not attainable today. whilst this promise is generally true for any ml-based system, systems trained in a federated fashion are potentially able to yield even less biased decisions and higher sensitivity to rare cases as they are likely to have seen a more complete picture of the data distribution. in order to be an active part of or to benefit from the federation, however, demands some up-front effort such as compliance with agreements e.g. regarding the data structure, annotation and report protocol, which is necessary to ensure that the information is presented to collaborators in a commonly understood format. patients are usually relying on local hospitals and practices. establishing fl on a global scale could ensure higher quality of clinical decisions regardless of the location of the deployed system. for example, patients who need medical attention in remote areas could benefit from the same high-quality ml-aided diagnosis that are available in hospitals with a large number of cases. the same advantage applies to patients suffering from rare, or geographically uncommon, diseases, who are likely to have better outcomes if faster and more accurate diagnoses can be made. fl may also lower the hurdle for becoming a data donor, since patients can be reassured that the data remains with the institution and data access can be revoked. hospitals and practices can remain in full control and possession of their patient data with complete traceability of how the data is accessed. they can precisely control the purpose for which a given data sample is going to be used, limiting the risk of misuse when they work with third parties. however, participating in federated efforts will require investment in on-premise computing infrastructure or private-cloud service provision. the amount of necessary compute capabilities depends of course on whether a site is only participating in evaluation and testing efforts or also in training efforts. even relatively small institutions can participate, since enough of them will generate a valuable corpus and they will still benefit from collective models generated. one of the drawbacks is that fl strongly relies on the standardisation and homogenisation of the data formats so that predictive models can be trained and evaluated seamlessly. this involves significant standardisation efforts from data managers. researchers and ai developers who want to develop and evaluate novel algorithms stand to benefit from access to a potentially vast collection of real-world data. this will especially impact smaller research labs and start-ups, who would be able to directly develop their applications on healthcare data without the need to curate their own datasets. by introducing federated efforts, precious resources can be directed towards solving clinical needs and associated technical problems rather than relying on the limited supply of open datasets. at the same time, it will be necessary to conduct research on algorithmic strategies for federated training, e.g. how to combine models or updates efficiently, how to be robust to distribution shifts, etc., as highlighted in the technical survey papers [ , , ] . and a fl-based development implies that the researcher or ai developer cannot investigate or visualise all of the data on which the model is trained. it is for example not possible to look at an individual failure case to understand why the current model performs poorly on it. healthcare providers in many countries are affected by the ongoing paradigm shift from volume-based, i.e. fee-for-service-based, to value-based healthcare. a value-based reimbursement structure is in turn strongly connected to the successful establishment of precision medicine. this is not about promoting more expensive individualised therapies but instead about achieving better outcomes sooner through more focused treatment, thereby reducing the costs for providers. by way of example, with sufficient data, ml approaches can learn to recognise cancer-subtypes or genotypic traits from radiology images that could indicate certain therapies and discount others. so, by providing exposure to large amounts of data, fl has the potential to increase the accuracy and robustness of healthcare ai, whilst reducing costs and improving patient outcomes, and is therefore vital to precision medicine. manufacturers of healthcare software and hardware could benefit from federated efforts and infrastructures for fl as well, since combining the learning from many devices and applications, without revealing anything patient-specific can facilitate the continuous improvement of ml-based systems. this potentially opens up a new source of data and revenue to manufacturers. however, hospitals may require significant upgrades to local compute, data storage, networking capabilities and associated software to enable such a use-case. note, however, that this change could be quite disruptive: fl could eventually impact the business models of providers, practices, hospitals and manufacturers affecting patient data ownership; and the regulatory frameworks surrounding continual and fl approaches are still under development. fl is perhaps best-known from the work of konečnỳ et al. [ ] , but various other definitions have been proposed in literature [ , , , ] . these approaches can be realised via different communication architectures (see figure ) and respective compute plans (see figure ). the main goal of fl, however, remains the same: to combine knowledge learned from non co-located data, that resides within the participating entities, into a global model. whereas the initial application field mostly comprised mobile devices, participating entities in the case of healthcare could be institutions storing the data, e.g. hospitals, or medical devices itself, e.g. a ct scanner or even low-powered devices that are able to run computations locally. it is important to understand that this domainshift to the medical field implies different conditions and requirements. for example, in the case of the federated mobile device application, potentially millions of partici-pants could contribute, but it would be impossible to have the same scale of consortium in terms of participating hospitals. on the other hand medical institutions may rely on more sophisticated and powerful compute infrastructure with stable connectivity. another aspect is that the variation in terms of data type and defined tasks as well as acquisition protocol and standardisation in healthcare is significantly higher than pictures and messages seen in other domains. the participating entities have to agree on a collaboration protocol and the high-dimensional medical data, which is predominant in the field of digital health, poses challenges by requiring models with huge numbers of parameters. this may become an issue in scenarios where the available bandwidth for communication between participants is limited, since the model has to be transferred frequently. and even though data is never shared during fl, considerations about the security of the connections between sites as well as mitigation of data leakage risks through model parameters are necessary. in this section, we will discuss more in detail what fl is and how it differs from similar techniques as well as highlighting the key challenges and technical considerations that arise when applying fl in digital health. fl is a learning paradigm in which multiple parties train collaboratively without the need to exchange or centralise datasets. although various training strategies have been implemented to address specific tasks, a general formulation of fl can be formalised as follows: let l denote a global loss function obtained via a weighted combination of k local losses {l k } k k= , computed from private data x k residing at the individual involved parties: where w k > denote the respective weight coefficients. it is important to note that the data x k is never shared among parties and remains private throughout learning. in practice, each participant typically obtains and refines the global consensus model by running a few rounds of optimisation on their local data and then shares the updated parameters with its peers, either directly or via a pa-rameter server. the more rounds of local training are performed without sharing updates or synchronisation, the less it is guaranteed that the actual procedure is minimising the equation ( ) [ , ] . the actual process used for aggregating parameters commonly depends on the fl network topology, as fl nodes might be segregated into sub-networks due to geographical or legal constraints (see figure ). aggregation strategies can rely on a single aggregating node (hub and spokes models), or on multiple nodes without any centralisation. an example of this is peer-to-peer fl, where connections exist between all or a subset of the participants and model updates are shared only between directly-connected sites [ , ] . an example of centralised fl aggregation with a client-server architecture is given in algorithm . note that aggregation strategies do not necessarily require information about the full model update; clients might choose to share only a subset of the model parameters for the sake of reducing communication overhead of redundant information, ensure better privacy preservation [ ] or to produce multitask learning algorithms having only part of their parameters learned in a federated manner. a unifying framework enabling various training schemes may disentangle compute resources (data and servers) from the compute plan, as depicted in figure . the latter defines the trajectory of a model across several partners, to be trained and evaluated on specific datasets. for more details regarding state-of-the-art of fl techniques, such as aggregation methods, optimisation or model compression, we refer the reader to the overview by kairouz et al. [ ] . fl is rooted in older forms of collaborative learning where models are shared or compute is distributed [ , ] . transfer learning, for example, is a well-established approach of model-sharing that makes it possible to tackle problems with deep neural networks that have millions of parameters, despite the lack of extensive, local datasets that are required for training from scratch: a model is first trained on a large dataset and then further optimised on the actual target data. the dataset used for the initial training does not necessarily come from the same domain or even the same type of data source as the target dataset. this type of transfer learning has shown better algorithm example of a fl algorithm [ ] in a clientserver architecture with aggregation via fedavg [ ] . require: num federated rounds t : procedure aggregating : initialise global model: for t ← · · · t do : for client k ← · · · k do run in parallel end for : return w (t) : end procedure performance [ , ] when compared to strategies where the model had been trained from scratch on the target data only, especially when the target dataset is comparably small. it should be noted that similar to a fl setup, the data is not necessarily co-located in this approach. for transfer learning, however, the models are usually shared acyclically, e.g. using a pre-trained model to finetune it on another task, without contributing to a collective knowledge-gain. and, unfortunately, deep learning models tend to "forget" [ , ] . therefore after a few training iterations on the target dataset the initial information contained in the model is lost [ ] . to adopt this approach into a form of collaborative learning in a fl setup with continuous learning from different institutions, the participants can share their model with a peer-to-peer architecture in a "round-robin" or parallel fashion and train in turn on their local data. this yields better results when the goal is to learn from diverse datasets. a client-server architecture in this scenario enables learning on multi-party data at the same time [ ] , possibly even without forgetting [ ] . there are also other collaborative learning strategies [ , ] such as ensembling, a statistical strategy of combining multiple independently trained models or predictions into a consensus, or multi-task learning, a strategy to leverage shared representations for related tasks. these strategies are independent of the concept of fl, and can be used in combination with it. the second characteristic of fl -to distribute the compute -has been well studied in recent years [ , , ] . nowadays, the training of the large-scale models is often executed on multiple devices and even multiple nodes [ ] . in this way, the task can be parallelised and enables fast training, such as training a neural network on the extensive dataset of the imagenet project in hour [ ] or even in less than seconds [ ] . it should be noted that in these scenarios, the training is realised in a cluster environment, with centralised data and fast network communication. so, distributing the compute for training on several nodes is feasible and fl may benefit from the advances in this area. compared to these approaches, however, fl comes with a significant communication and synchronisation cost. in the fl setup, the compute resources are not as closely connected as in a cluster and every exchange may introduce a significant latency. therefore, it may not be suitable to synchronise after every batch, but to continue local training for several iterations before aggregation. we refer the reader to the survey by xu et al. [ ] for an overview of the evolution of federated learning and the different concepts in the broader sense. despite the advantages of fl, there are challenges that need to be taken into account when establishing federated training efforts. in this section, we discuss five key aspects of fl that are of particular interest in the context of its application to digital health. in healthcare, we work with highly sensitive data that must be protected accordingly. therefore, some of the key considerations are the trade-offs, strategies and remaining risks regarding the privacy-preserving potential of fl. privacy vs. performance. although one of the main purposes of fl is to protect privacy by sharing model updates rather than data, fl does not solve all potential privacy issues and -similar to ml algorithms in generalwill always carry some risks. strict regulations and data governance policies make any leakage, or perceived risk of leakage, of private information unacceptable. these regulations may even differ between federations and a catch-all solution will likely never exist. consequently, it is important that potential adopters of fl are aware of potential risks and state-of-the-art options for mitigating them. privacy-preserving techniques for fl offer levels of protection that exceed today's current commercially available ml models [ ] . however, there is a trade-off in terms of performance and these techniques may affect for example the accuracy of the final model [ ] . furthermore future techniques and/or ancillary data could be used to compromise a model previously considered to be low-risk. level of trust. broadly speaking, participating parties can enter two types of fl collaboration: trusted -for fl consortia in which all parties are considered trustworthy and are bound by an enforceable collaboration agreement, we can eliminate many of the more nefarious motivations, such as deliberate attempts to extract sensitive information or to intentionally corrupt the model. this reduces the need for sophisticated countermeasures, falling back to the principles of standard collaborative research. non-trusted -in fl systems that operate on larger scales, it is impractical to establish an enforceable collaborative agreement that can guarantee that all of the parties are acting benignly. some may deliberately try to degrade performance, bring the system down or extract information from other parties. in such an environment, security strategies will be required to mitigate these risks such as, encryption of model submissions, secure authentication of all parties, traceability of actions, differential privacy, verification systems, execution integrity, model confidentiality and protections against adversarial attacks. information leakage. by definition, fl systems sidestep the need to share healthcare data among participating institutions. however, the shared information may still indirectly expose private data used for local training, for example by model inversion [ ] of the model updates, the gradients themselves [ ] or adversarial attacks [ , ] . fl is different from traditional training insofar as the training process is exposed to multiple parties. as a result, the risk of leakage via reverse-engineering increases if adversaries can observe model changes over time, observe specific model updates (i.e. a single institution's update), or manipulate the model (e.g. induce additional memorisation by others through gradient-ascentstyle attacks). countermeasures, such as limiting the granularity of the shared model updates and to add specific noise to ensure differential privacy [ , , ] may be needed and is still an active area of research [ ] . medical data is particularly diverse -not only in terms of type, dimensionality and characteristics of medical data in general but also within a defined medical task, due to factors like acquisition protocol, brand of the medical device or local demographics. this poses a challenge for fl algorithms and strategies: one of the core assumptions of many current approaches is that the data is independent and identically distributed (iid) across the participants. initial results indicate that fl training on medical non-iid data is possible, even if the data is not uniformly distributed across the institutions [ , ] . in general however, strategies such as fedavg [ ] are prone to fail under these conditions [ , , ] , in part defeating the very purpose of collaborative learning strategies. research addressing this problem includes for example fedprox [ ] and part-data-sharing strategy [ ] . another challenge is that data heterogeneity may lead to a situation in which the global solution may not be the optimal final local solution. the definition of model training optimality should therefore be agreed by all participants before training. as per all safety-critical applications, the reproducibility of a system is important for fl in healthcare. in contrast to training on centralised data, fl involves running multiparty computations in environments that exhibit complexities in terms of hardware, software and networks. the traceability requirement should be fulfilled to ensure that system events, data access history and training configuration changes, such as hyperparameter tuning, can be traced during the training processes. traceability can also be used to log the training history of a model and, in particular, to avoid the training dataset overlapping with the test dataset. in particular in non-trusted federations, traceability and accountability processes running in require execution integrity. after the training process reaches the mutually agreed model optimality criteria, it may also be helpful to measure the amount of contribution from each participant, such as computational resources consumed, quality of the local training data used for local training etc. the measurements could then be used to determine relevant compensation and establish a revenue model among the participants [ ] . one implication of fl is that researchers are not able to investigate images upon which models are being trained. so, although each site will have access to its own raw data, federations may decide to provide some sort of secure intra-node viewing facility to cater for this need or perhaps even some utility for explainability and interpretability of the global model. however, the issue of interpretability within dl is still an open research question. unlike running large-scale fl amongst consumer devices, healthcare institutional participants are often equipped with better computational resources and reliable and higher throughput networks. these enable for example training of larger models with larger numbers of local training steps and sharing more model information between nodes. this unique characteristic of fl in healthcare consequently brings opportunities as well as challenges such as ( ) how to ensure data integrity when communicating (e.g. creating redundant nodes); ( ) how to design secure encryption methods to take advantage of the computational resources; ( ) how to design appropriate node schedulers and make use of the distributed computational devices to reduce idle time. the administration of such a federation can be realised in different ways, each of which come with advantages and disadvantages. in high-trust situations, training may operate via some sort of 'honest broker' system, in which a trusted third party acts as the intermediary and facilitates access to data. this setup requires an independent entity to control the overall system which may not always be desirable, since it could involve an additional cost and procedural viscosity, but does have the advantage that the precise internal mechanisms can be abstracted away from the clients, making the system more agile and simpler to update. in a peer-to-peer system each site interacts directly with some or all of the other participants. in other words, there is no gatekeeper function, all protocols must be agreed up-front, which requires significant agreement efforts, and changes must be made in a synchronised fashion by all parties to avoid problems. and in a trustless-based architecture the platform operator may be cryptographically locked into being honest which creates significant computation overheads whilst securing the protocol. future efforts to apply artificial intelligence to healthcare tasks may strongly depend on collaborative strategies between multiple institutions rather than large centralised databases belonging to only one hospital or research laboratory. the ability to leverage fl to capture and integrate knowledge acquired and maintained by different institutions provides an opportunity to capture larger data variability and analyse patients across different demographics. moreover, fl is an opportunity to incorporate multiexpert annotation and multi-centre data acquired with different instruments and techniques. this collaborative effort requires, however, various agreements including definitions of scope, aim and technology which, since it is still novel, may incorporate several unknowns. in this context, large-scale initiatives such as the melloddy project , the healthchain project , the trustworthy federated data analytics (tfda) and the german cancer consortium's joint imaging platform (jip) represent pioneering efforts to set the standards for safe, fair and innovative collaboration in healthcare research. ml, and particularly dl, has led to a wide range of innovations in the area of digital healthcare. as all ml methods benefit greatly from the ability to access data that approximates the true global distribution, fl is a promising approach to obtain powerful, accurate, safe, robust and unbiased models. by enabling multiple parties to train collaboratively without the need to exchange or centralise datasets, fl neatly addresses issues related to egress of sensitive medical data. as a consequence, it may open novel research and business avenues and has the potential to improve patient care globally. in this article, we have discussed the benefits and the considerations pertinent to fl within the healthcare field. not all technical questions have been answered yet and fl will certainly be an active research area throughout the next decade [ ] . despite this, we truly believe that its potential impact on precision medicine and ultimately improving medical care is very promising. financial disclosure: author rms receives royalties from icad, scanmed, philips, and ping an. his lab has received research support from ping an and nvidia. author sa is supported by the prime programme of the german academic exchange service (daad) with funds from the german federal ministry of education and research (bmbf). author sb is supported by the national institutes of health (nih). author mng is supported by the healthchain (bpifrance) and melloddy (imi ) projects. deep 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fmri analysis using privacy-preserving federated learning and domain adaptation: abide results federated optimization in heterogeneous networks communication-efficient learning of deep networks from decentralized data federated learning with non-iid data data shapley: equitable valuation of data for machine learning key: cord- -odzrco q authors: drake, john m.; chew, suok kai; ma, stefan title: societal learning in epidemics: intervention effectiveness during the sars outbreak in singapore date: - - journal: plos one doi: . /journal.pone. sha: doc_id: cord_uid: odzrco q background: rapid response to outbreaks of emerging infectious diseases is impeded by uncertain diagnoses and delayed communication. understanding the effect of inefficient response is a potentially important contribution of epidemic theory. to develop this understanding we studied societal learning during emerging outbreaks wherein patient removal accelerates as information is gathered and disseminated. methods and findings: we developed an extension of a standard outbreak model, the simple stochastic epidemic, which accounts for societal learning. we obtained expressions for the expected outbreak size and the distribution of epidemic duration. we found that rapid learning noticeably affects the final outbreak size even when learning exhibits diminishing returns (relaxation). as an example, we estimated the learning rate for the outbreak of severe acute respiratory syndrome (sars) in singapore. evidence for relaxation during the first eight weeks of the outbreak was inconclusive. we estimated that if societal learning had occurred at half the actual rate, the expected final size of the outbreak would have reached nearly cases, more than three times the observed number of infections. by contrast, the expected outbreak size for societal learning twice as effective was cases. conclusion: these results show that the rate of societal learning can greatly affect the final size of disease outbreaks, justifying investment in early warning systems and attentiveness to disease outbreak by both government authorities and the public. we submit that the burden of emerging infections, including the risk of a global pandemic, could be efficiently reduced by improving procedures for rapid detection of outbreaks, alerting public health officials, and aggressively educating the public at the start of an outbreak. rapidly spreading outbreaks of infectious diseases are an increasing concern for global public health [ , ] and security [ ] . emerging infections, which are typically defined as infectious diseases that have newly appeared in a population or are rapidly increasing in incidence or geographic range [ ] , are a particular concern because at the time of emergence little is known about their epidemiology, particularly pathology, symptomatology, and transmissibility. thus, the crucial tasks of assessing epidemic risk and determining what public health interventions should be taken are complicated by uncertainty that borders on complete ignorance. of course, this uncertainty is rapidly reduced as the outbreak progresses and information concerning symptoms of infection, the biology of the infectious agent, the epidemiology of transmission, and the effectiveness of health precautions and intervention is collected and disseminated. this learning process has not been considered in theories of outbreak control [ , ] or in near real-time models of emerging infections [ , ] (compare correspondence in refs [ , ] ). here, we study the collective effects of various processes (including possibly unidentified phenomena) on the change in the rate at which infectious persons are isolated. we refer to this set of processes collectively as ''societal learning''. a partial list of the processes contributing to societal learning includes isolation and identification of the infectious agent, development of tests for clinical diagnosis, disseminating information to public health and medical personnel, disseminating information to the public, and implementing public health policies including restrictions on individual movement or quarantine. disease control theory focuses on an quantity called the reproductive ratio, designated here as r at the start of the outbreak and, if changing over time, r t at time t. outbreaks are considered to be under control when r t , , implying that outbreak conditions are such that on average disease prevalence will decline. most research in theoretical epidemiology has focused on how r t is related to disease and population parameters in order to understand how to induce the change from r . , during emergence, to r t , . recent developments include techniques for estimating r from the initial stages of an outbreak [ , ] and a model to ascertain the effect of a delay between the onset of an outbreak and the implementation of public health policies aimed at controlling disease spread [ ] . here, we contribute to this developing toolbox for disease forecasting a model to understand how societal learning affects the expected final size and duration of disease outbreak. though some computational disease-specific models have recognized the importance of time-varying rates in disease spread, particularly with respect to the outbreak of sars in [ , ] (compare [ ] ), we believe this is the first analytical treatment of the concept. we also retrospectively explore the effect of societal learning during the outbreak of sars in singapore, using weekly data on the time between onset of symptoms and removal of infectious individuals. we speculate that societal learning will generally exhibit diminishing returns because increasing the removal rate becomes more difficult as individual isolation approaches a theoretical maximum rate. in such a case, the rate of societal learning is said to relax. we introduce statistical models to distinguish between relaxing and non-relaxing learning and test for relaxation during this outbreak. finally, we discuss societal and epidemiological factors that might affect societal learning, we observe that a difficult task during the early stages of an outbreak is to estimate the learning rate and suggest that the rate estimated here might be used as prior information in future outbreaks, and we conclude by recommending rapid investment in research at the time of initial detection when actions taken to reduce disease spread can be most efficient and cost effective. public health officials routinely make judgments whether or not to raise alarms about developing outbreaks. this decision is complicated by severe uncertainty during the early phases of an outbreak. further, bureaucratic inertia and the ignorance that necessarily accompanies emerging infections discourage rapid response. by contrast, false alarms resulting from hasty and premature assessment of outbreak risk can be very costly, and must be avoided if possible. understanding the role of societal learning in disease outbreaks is important for properly balancing these competing objectives. our concept of societal learning is characteristically reflected in outbreak dynamics as an increase over time in the rate at which infectious individuals are removed from circulating in the population. that is, we expect that as information about clinical symptoms, modes of transmission, the duration of incubation, etc., is collected and disseminated, the average time between the onset of symptoms and individual self-removal from the population (for instance by admission to hospital) or forced isolation (e.g., quarantine) will decline. from a dynamical perspective, we represent the average removal rate of individual cases as a function of time since the outbreak began, marked by the time at which the index case became infectious. for emerging diseases we assume that direct transmission between infected persons is the primary source of infection and that development of immunity and removing infectious individuals have negligible impact on the susceptible population. these assumptions are reasonable for outbreaks that ultimately do not infect more than a small fraction of the total population, i.e., emerging infections with relatively low prevalence. finally, we assume that transmission is a markov process, an approximation that amounts to assuming that individual infectious contacts are independent (compare [ ] ). thus, representing the individual rate of infection by the constant parameter b and the rate of removal as a function of time c(t), these assumptions imply that the growth of the epidemic is a timeinhomogeneous stochastic birth-death chain [ ] [ ] [ ] . accordingly, the change over time in the probability distribution of the number of infected individuals x is given by this model has been previously studied and applied to problems ranging from population dynamics to astronomy [ , , ] . in particular, the expected final epidemic size for this model is [ ] : where and i is the initial number of infected individuals. further, the distribution function for the duration of the outbreak with i = is: this is a very general model, as we have only specified that the transmission rate b is constant and that the rate of removal c(t) changes over time, consistent with the concept of societal learning. conceptually, we decompose the removal rate, c(t), into two components. the first component represents removal in the absence of societal learning (i.e., through unexceptional health procedures or natural recovery) and is referred to as the base removal rate. the second component is an effect of societal learning and is assumed to be additive to the base removal rate. consequently, we represent the total removal rate as function of time c(t) = a(t)+b where b is the base removal rate and a(t) is a function for the additional effect of societal learning. (refer to table for biological interpretations of parameters discussed in this section.) next, we consider two different learning scenarios. first, we suppose that societal learning is constant, i.e., that over any interval a doubling in time since the outbreak began corresponds to a doubling in the learned component of the removal rate. then, the effect due to learning can be represented as a line a(t) = a t, where a is called the 'basic learning rate', and the removal rate is linear: c (t) = a t+b. special cases of this model have a = , where there is no effect of societal learning (resulting in the simple stochastic epidemic), and b = where there is no natural recovery. the model with linear removal rate implies that the average time between infection and removal over time follows a hyperbola, g(t) = (c (t)) = (a t+b) , and that there is no upper bound to the rate at which infected individuals can be isolated; effectively, we suppose that the average time between infection and removal can be brought arbitrarily close to . for most (perhaps all) diseases this is an unreasonable assumption in the long run (though it may be a reasonable approximation at the start of an outbreak). in particular, the effect of societal learning probably decreases as the removal rate gets high and the interval between the onset of symptoms and isolation approaches a minimum biologically plausible quantity. this is a scenario in which cumulative number of removed patients is a decelerating function of time marked by diminishing returns. to incorporate such relaxation in our model we should generalize a(t) for instance a(t) = a t a , with a # . where a = this model is equivalent to the linear model discussed above. of course, there is no principled theoretical reason why a cannot be greater than . such a case is unlikely, however, and would imply acceleration not only in removals, but in the removal rate. in either case we have the general model for the removal rate c (t) = a t a +b and the associated model of the duration of the interval between onset of symptoms and removal g (t) = c (t) = (a t a +b) . in this case g(t) is approximately a power law with respect to time. we remark that learning relaxation could also result from diminishing returns on methods for disseminating information. for instance, if diagnostic information is transmitted by word-of-mouth, models for the spread of a rumor suggest that the fraction of the population which remains uninformed declines roughly logistically: first approximately proportional to the number of people who are in possession of the rumor but declining constantly over time as uninformed individuals become increasingly rare [ , ] . examples of c and c and the associated g and g are shown in figure . substituting the above model for societal learning in eqns ( ) and ( ) obtains two quantities of special interest: the expected outbreak size, and the distribution of extinction times, from which the probability density of the duration of outbreaks is obtained as the derivative with respect to time, finally, in this representation of the epidemic process, the concept of the reproductive ratio (designated by r at the beginning of the outbreak, r t thereafter) is deterministic and is given by setting this equation to one and solving for t obtains the time until the outbreak is brought under control. for the case c(t) = c (t), the time to control is given by t c = (b b)/ a .still more models could be considered. however, we report below that the final epidemic size is affected mostly by the parameter a , the rate of societal learning at the beginning of the outbreak, so that the precise shape of the removal function does not greatly matter. to test for societal learning in the outbreak of sars in singapore, we used the mean number of days between the onset of clinical symptoms and removal, by week, to fit different models for the removal process c. these data are slightly different than those that appeared previously as figure in [ ] and include some reclassified cases based on serological tests (s. ma, unpublished data). societal learning models were fit to the reciprocal of the mean of observed lags between onset of symptoms and removal c i = /g i for each week i, using nonlinear least squares regression. model fit was assessed using akaike's information criterion (aic) assuming the observations are drawn from a normal distribution with mean c i and homogeneous variance. we tested three hypotheses: (i) the null hypothesis of no base removal rate corresponding to b = ; (ii) the null hypothesis of no saturation in learning corresponding to a = ; finally, (iii) the null hypothesis of no societal learning at all is given by a = for a = . to represent the full epidemic process for sars the societal learning theory developed above must be modified to account for a significant latent period [ ] . accordingly, we adopt the familiar s-e-i-r modeling framework (figure a in [ ] ), modified to represent stochastic (markov) dynamics with time-inhomogeneous parameters. as before, we adopt the reasonable assumption that the population is large compared to the eventual size of the outbreak so that s remains constant throughout. thus, by substituting b = as and ignoring the dynamics of removed individuals, we obtain the two-compartment model in figure b , where x and y designate the classes that were formerly e and i. finally, consistent with our earlier definition of societal learning, we allow the removal rate c to be a function of time, designated c(t). we assume that each state variable x and y can take only integer values (demographic stochasticity) and that individual transitions between classes are markovian. this model is a pair of coupled birth-death chains and is a generalization of the model studied in the earlier part of this paper. we obtained parameter values for these simulations as follows. using a bayesian approach, lipsitch et al. [ ] determined that the basic reproductive ratio (r ) for this outbreak was in the range [ . , . ] . these values accord well with the likelihood-based estimate of wallinga and teunis [ ] , who report a point estimate ofr ~ : and % confidence interval [ . , . ]. interpreting the estimates of lipsitch et al. [ ] as the rate of secondary infection in a wholly susceptible population, r is related to our parameters through the relation b = r c . recognizing that uncertainty in both r and c will affect the accuracy of model projections we obtain an upper limit on b (not a confidence interval because the parameters are not independent) from b + = r + c + and a lower limit from b = r c , where (+) and ( ) indicate the upper and lower limits on the estimate intervals for the respective parameters. to obtain a central (''best'') estimate of b we take the midpoint of the range [ . , . ] = . and multiply by the point estimate of our regressionĉ ~ : to obtainb~ : . throughout, we used the point estimate from the regression analysis above ( . , see also results) for the basic learning rate after dividing by seven to convert from weeks to days: a = . . as the learning rate never declined over the course of this outbreak, no relaxation was included in the model. finally, the transition rate between latent and infectious individuals (g) is approximately equal to the reciprocal of the duration of the incubation period. we used a transition rate of . d , corresponding to an average incubation period of approximately . . days. this is roughly consistent with, e.g., the ranges of estimates compiled by the world health organization (table in [ ] ) and the estimate ( . d) and % confidence interval [ . , . ] reported by donnelly et al. [ ] , but slightly larger than the estimate of . d ( % confidence interval: [ . , . ] ) obtained by kuk and ma [ ] under the assumption that incubation times are drawn from a weibull distribution. retrospectively comparing model-based estimates of the expected outbreak size with the observed cases (a partially circular comparison to begin with) is complicated by the fact that the number of initially infected individuals (the initial condition) is not defined by the model but must be asserted. one possibility is to assume that the outbreak begins with the index patient (i = ), but then the outbreak size of the theoretical model is biased by a significant portion of outbreaks that fail due to stochastic fadeout [ ] . an alternative is to compare the observed outbreak size with the theoretical distribution of outbreak sizes for outbreaks initialized at i = conditioned on a 'major' or 'observable' outbreak occurring. however, this simply pushes back the problem of specifying the initial condition as some number of cases must be in four compartments corresponding to susceptible, exposed, infectious, and removed (or recovered) individuals. the rate at which individuals move from susceptible to exposed is according to massaction dynamics with proportionality constant a. individuals move from exposed to infectious at rate g and from infectious to removed at rate c. (b) by assuming that the number of susceptible individuals is approximately constant (an appropriate approximation for outbreaks in which prevalence is never a large fraction of the total population) we introduce the new variable b = as and reduce the four-compartment s-e-i-r model to a two-compartment model, designated here by the state variables x and y. doi: . /journal.pone. .g specified to correspond with 'major' or 'observable'. we adopted a third alternative. we reasoned that the first time medical personnel are alerted to the fact that there might be an emerging outbreak is the time that the index patient is observed to be infectious, corresponding to the removal of the patient from the population. at this time, the patient has infected an expected additional r individuals (by the definition of r ) and these infectious, or soon-to-be-infectious individuals are circulating in the susceptible population. we refer to this as the 'second generation initialization'. alternatively, the hospitalization of one individual with an anomalous infection is unlikely to attract significant attention. consideration of a possible outbreak more likely corresponds to the admittance in quick succession of several patients with anomalous infections, that is when the second generation of infected individuals is isolated and a third generation of individuals is infected. this is the 'third generation initialization'. accordingly, we simulated two distributions of final outbreak sizes. first we initialized at i = , which is the midpoint of the estimated interval for r identified by lipsitch et al. [ ] , i ~r ~ : , rounded to the nearest integer, corresponding to second generation initialization. second, we initialized at i = , which is the rounded value of the expected number of infected individuals in the third generation, i ~r & : . to understand the importance of societal learning during the actual outbreak in singapore, we simulated , iterations of the stochastic s-e-i-r model described above using gillespie's direct method [ ] with double and half the estimated basic learning rate while all other parameters were set to their best estimates and with initial condition i = . empirical quantiles and the coefficient of variation (a measure of dispersion, the ratio of the standard deviation to the mean) were used to summarize the distributional properties of simulations. to look at the effects of societal learning and relaxation on outbreak control, we studied the average outbreak size over a range of scenarios (figure ). for simplicity, we assumed b = throughout and compared different versions of the removal and learning process by tuning the parameters for the basic learning rate (a ) and the relaxation rate (a ). the temporal resolution of this model is therefore not explicit. thus, for concreteness assume that all rates are in units of days and that the baseline infectious period (g = c ) is d. then, the basic reproductive ratio is r ~b =c~ and we obtained the average epidemic size from eqn these ranges illustrate the range of cases between extremes in which societal learning is slow and relaxation is rapid (practically no effect of societal learning) and where societal learning is fast and no relaxation occurs at all (similar to the outbreak of sars). figure shows that a , the basic rate of societal learning, can be important for controlling outbreaks. the effect of relaxation can be examined by comparing the average outbreak size at various values of a , with the value at a = , where there is no relaxation. evidently, relaxation must be extremely rapid (around a = . ) for the effect to be noticeable. of course, this phenomenon is accentuated by its interaction with the basic societal learning rate so that if learning is extremely slow the effect of relaxation becomes more important. the observed removal rate increased consistently over the course of the sars outbreak in singapore (figure ) . we found no effect of relaxation in the rate of societal learning, although there was strong evidence for both a baseline removal rate and an effect of learning (table ) . we first fit the full model, but failed to reject the null hypothesis of no relaxation. consequently, we fit the reduced model with a constant learning rate, which is equivalent to the full model with exponential parameter a = . in this model, both the base removal and learning parameters were highly significantly different than zero (base: p = . ; learning rate: p, . ). we remark that the reciprocal of the estimated base removal rate (b) can be interpreted as the duration of the infectious period in the absence of special intervention. accordingly, we obtained an estimate of . d ( % confidence interval: [ . , . ] , obtained by inverting the confidence limits reported in table ). inspection of the plots in figure suggests that the observation in week may be of exceptional importance to the final model. in terms of regression diagnostics, it may have high leverage (greatly affecting the uncertainty in parameter estimates) and high influence (greatly affecting the estimates themselves). a plot of standardized residuals versus leverage for the reduced model shows that this point is indeed matched by only one other point (week ) for leverage ( figure ). overlaying contour intervals for cook's distance, a measure of influence, shows that this point also has high influence. accordingly, so that the reader may compare we re-fit both the full and reduced models after dropping this point ( table ). in this case the aic difference is less than two, so that neither model is better supported by the data. further while the maximum likelihood estimate for a is quite low (a = . ; to be interpreted as considerable relaxation), the confidence interval barely fails to include , so the evidence is not conclusive. to study the effect of the duration of the latent period on average outbreak size, we simulated iterations of the model at each of different durations for the average latent period. the average outbreak size decreased with the duration of the latent period as shown in figure . the average size of simulated outbreaks initiated with the second generation initialization condition (i = ) was cases. the . % and . % quantiles were and cases, respectively. the coefficient of variation in the final outbreak size was . . the average size of simulated outbreaks initiated with the third generation initialization condition (i = ) was cases. the . % and . % quantiles were and cases, respectively, with coefficient of variation . . thus, the observed total outbreak size ( cases; [ ] ) is consistent with either the second or the third generation initialization conditions. outbreak simulations in which learning occurred at half the observed rate had average final outbreak size of cases while outbreak simulations in which learning occurred at twice the observed rate had average final outbreak size of cases. we found little evidence for relaxation in the learning rate for sars in singapore. first, restricting our discussion to the analysis with all data, we find that the maximum likelihood estimate of the relaxation parameter is extraordinarily close to one (differing by . %), perfect non-relaxation. admittedly, the confidence interval on this parameter is large. one interprets this to mean that the vigilance of the public health community as a whole continued throughout the outbreak and that improvement in intervention effectiveness continued unabated. however, we also found that one relatively uncertain data point was important to this analysis (week ). whether this point should be excluded from interpretation is unclear. on one hand, it is a real observation and (because of its high influence) is known to contain a great deal of information. therefore, one is inclined to allow this observation considerable weight. on the other hand, its importance, especially at the end of the data series is suspicious. if we exclude this point from analysis post hoc, we find that we are unable to make any strong conclusions at all. what most likely occurred is that the distribution of average infectious period at the point where the outbreak was rapidly brought under control was highly dispersed (high variance) and highly skewed. accordingly, the mean removal rate probably does relax, but the data that were available to this study are too aggregated to make this inference conclusively. it is unknown if the rate of learning estimated in this study is unique to this outbreak or if it might be more representative. we remark that both parameters in the learning rate model are readily interpreted, and that theoretical effects of improvement in surveillance, mechanisms for informing public health personnel and the public, and rapid research response could be studied by extending this simple model to represent more realistically the effects of alternative policies as covariates. the final size of an outbreak is greatly affected by transmission events early during the outbreak process. outbreaks can be curtailed when public health interventions are rapid and efficient. but the severity of an outbreak is often unclear during these initial stages of transmission when intervention can be most effective [ , ] . further, there are limits to how quickly diagnostic information about an emerging infection can be obtained and disseminated to health care providers. this is not the first model to consider the effect of changes in the removal rate (e.g., [ , ] ). however, in contrast to earlier studies, we first explicitly considered societal learning parametrically in a theoretical model. our model also more realistically represents the ramping up of intervention in contrast to models that simply have ''before control'' and ''after control'' regimes (e.g., [ ] ). we showed that the final outbreak size decreases rapidly with a modest investment in learning. we also found strong evidence of learning in data from the outbreak of sars in singapore. public health interventions for sars include encouragement to report to hospital rapidly after the onset of clinical symptoms, contact tracing for confirmed and suspected cases, and quarantine, monitoring, and restricting the travel of contacts [ , ] . we believe these interventions were highly effective at reducing the final size of the sars outbreak. a limitation of this analysis is that we only consider temporal changes in removal, though information dissemination and public concern almost certainly led to a decline in transmission (b ) too [ ] . unfortunately, this effect is much more difficult to independently estimate and must instead be inferred from the information provided by the epidemic curve together with observations of the onset-of-symptoms to removal interval. in general, however, the model studied here (eqn ) and its solution (eqn ) will also apply to this situation and can be used wherever such data are available. the effects of biological and social factors that might bring about changes in transmissibility is an important area for further theoretical research. our estimate of the duration of the infectious period ( . d, % ci: [ . , . ] ) is consistent with measures of viral shedding, obtained by peiris et al. [ ] using quantitative reverse transcriptase on sequential nasopharyngeal aspirates/throat and nose swabs (npa/tns), in which maximum virus excretion occurs around the tenth day of illness (compare also [ ] ). indeed, only about % of npa/tns continued to test positive by the third week since the onset of symptoms [ ] . figure . relationship between the average latent period (x-axis) and average total outbreak size in simulations (y-axis). latent period is log transformed (to illustrate a wide range of possible values) and ranges from d to d (, y). the approximate location of sars is indicated by the arrow. doi: . /journal.pone. .g these results underscore the value of immediate action at the start of an outbreak (high a ). the processes considered to contribute to societal learning include such publicly visible actions as declaring a state of emergency, global health alert, or (minimally) disseminating information to the public. the societal and economic costs of mistakenly declaring a state of emergency can be tremendous, but are probably small in comparison to the costs of failing to intervene in a major preventable outbreak. thus, we echo anderson et al. [ ] in concluding that the major lessons of the outbreak of sars are to improve surveillance and detection, including real-time data collection; develop capability for rapid response by the research community; and devise mechanisms for immediate implementation of effective interventions. important topics for research include estimating the effect of learning on transmission (the parameter b in the model), and identifying the different activities that contribute to learning (a ) and relaxation (a ) and their costs. then, a cost sensitive model should be developed to balance the competing goals of raising unnecessary alarm and preventing a major outbreak. such a model would be most useful if it had reference points that would trigger alerts at different levels (i.e., to function as an early warning system) and could guide intervention efforts. such a model would not need to be purely economical, but could incorporate loss of human life and well-being as constraints on the decision set. of course, learning rates (and possibly relaxation) will vary geographically reflecting different societal conditions, research institutions, levels of emergency preparedness, etc. further, these phenomena may also differ among emerging diseases, for instance depending on their similarity to diseases that are well understood or their resistance to laboratory isolation and characterization. despite these limitations, we suggest that our estimate of the basic learning rate ( . d ; % confidence interval [ . , . ]) could be used as prior information during future outbreaks. the difficulty of forecasting the total epidemic curve at an early stage is well appreciated [ ] . by eliminating the need to simultaneously estimate highly correlated parameters, a good understanding of the dynamical consequences of public health response would enable real-time modeling to focus on estimating disease parameters like transmission rates [ ] . then, estimated disease components and known or conjectured models for response, including models of societal learning, could be integrated in a single modeling framework for projections. a systematic analytic approach to pandemic influenza preparedness planning heading off an influenza pandemic factors in the emergence of infectious diseases infectious diseases of humans: dynamics and control epidemic modelling: an introduction sars, lay epidemiology, and fear severe acute respiratory syndrome epidemic in asia sars epidemiology modeling (reply) estimation and inference of r of an infectious pathogen by a removal method appropriate models for the management of infectious diseases limits to forecasting precision for outbreaks of directly transmitted diseased transmission dynamics of the etiological agent of sars in hong kong: impact of public health interventions transmission dynamics and control of acute severe respiratory syndrome a branching mode for the spread of infectious animal diseases in varying environments realistic distributions of infectious periods in epidemic models: changing patterns of persistence and dynamics on the generalized birth-and-death process the elements of stochastic processes with applications to the natural sciences uncertainty in sars epidemiology stochastic processes and population growth all-or-none elements and mathematical models for sociologists different epidemic curves for severe acute respiratory syndrome reveal similar impacts of control measures consensus document on the epidemiology of severe acute respiratory syndrome (sars) epidemiological determinants of spread of causal agent of severe acute respiratory syndrome in hong kong the estimation of sars incubation distribution from serial interval data using a convolution likelihood superspreading and the effect of individual variation on disease emergence a general method for numerically simulating the stochastic time evolution of coupled chemical reactions summary of probable sars cases with onset of illness from public health measures implemented during the sars outbreak in singapore clinical progression and viral load in a community outbreak of coronavirus-associated sars pneumonia: a prospective study epidemiology, transmission dynamics and control of sars: the - epidemic we thank members of the penn state center for infectious disease dynamics for helpful discussion of this study. a referee suggested fitting the model to the data without the observation at week . key: cord- -ig i authors: philippe, stéphanie; souchet, alexis d.; lameras, petros; petridis, panagiotis; caporal, julien; coldeboeuf, gildas; duzan, hadrien title: multimodal teaching, learning and training in virtual reality: a review and case study date: - - journal: virtual reality & intelligent hardware doi: . /j.vrih. . . sha: doc_id: cord_uid: ig i it is becoming increasingly prevalent in digital learning research to encompass an array of different meanings, spaces, processes, and teaching strategies for discerning a global perspective on constructing the student learning experience. multimodality is an emergent phenomenon that may influence how digital learning is designed, especially when employed in highly interactive and immersive learning environments such as virtual reality (vr). vr environments may aid students' efforts to be active learners through consciously attending to, and reflecting on, critique leveraging reflexivity and novel meaning-making most likely to lead to a conceptual change. this paper employs eleven industrial case-studies to highlight the application of multimodal vr-based teaching and training as a pedagogically rich strategy that may be designed, mapped and visualized through distinct vr-design elements and features. the outcomes of the use cases contribute to discern in-vr multimodal teaching as an emerging discourse that couples system design-based paradigms with embodied, situated and reflective praxis in spatial, emotional and temporal vr learning environments. digital teaching and learning embrace active pedagogy and learner-centred approaches. the basic assumption is that learners are unique and therefore learning should be personalized. as argued by reigeluth et al. [ ] , learner's centred activities value intrinsic motivation [ , ] as well as metacognition [ ] for a more personalized and meaningful learning process. for achieving an active, situated and embodied learning experience, meta-cognitive knowledge seems to enhance learning [ ] . in line with this assumption, one can consider specific pedagogical methods such as active learning, learning by doing, collaborative learning, problem-based learning and game-based learning. prince indicates for instance that active learning has a positive but weak effect on students' academic achievement [ ] . vernon and blakes metaanalysis indicates that problem-based learning may yield metacognitive learning over traditional methods [ ] . this is also supported by dochy et al. meta-analysis that concludes for robust positive effects on student's skills without studies reporting negative effects [ ] . those conclusions are also in line with walker and leary's meta-analysis [ ] . based on previous meta-analysis and systematic reviews [ ] [ ] [ ] [ ] [ ] [ ] , serious games [ ] may also be efficient in various contexts, if combined with informed learning instructions. in line with the idea of "active pedagogy" and "learner-centred approaches" the concept of "multimodality", was developed in the early s [ , ] . multimodality refers to "multiple" modes of representation, with combined elements of print, visual images and design. this shift from paper-based education to multimodal education involves rethinking the way in which teaching, and learning are designed, approached and practiced. this promotes the way in which pedagogies, content and technology are designed and used to enable multimodality to take place in a variety of contexts and social relationships [ ] . whether digital tools are employed to scaffold new ways of learning or they are just reproducing traditional modes of teaching and learning is still an open research question [ ] . digital tools are at least as efficient as non-digital tools, when integrated into a consistent pedagogic strategy, with clearly defined training objectives and instructions. therefore, the purpose is not to replace traditional methods by digital tools. rather, one should consider digital tools for the actual value they can bring, for instance regarding the personalization of the content, in combination to non-digital tools and methods. digital tools are part of the toolbox available for the trainers and they can contribute to the development of multimodal, active and learner-centred approach. in this context, virtual reality (vr) was recently introduced to the consumer market [ ] and deployed in digital educational interventions [ ] . education and training are pointed out as promising fields of vr implementation [ ] . the advent of immersive and high-fidelity digital technologies such as virtual reality may supplement or enhance analogue learning spaces as modes of expression. for example, Öman and hashemi suggested that technology may be used to increase students' communicative and collaborative skills instead of focusing on how to use the technology from a technical perspective [ ] . vr is shown to offer self-regulated and multiple learning choices compared to other learning platforms which lead to high quality of experience and retention [ ] [ ] [ ] [ ] [ ] . however, the use of vr in the context of multimodality for teaching and learning has not been investigated yet. as an example, a search using the terms vr and multimodality and teaching or learning for any peer reviewed article published between and on science direct (elsevier) led to hit. the ieee database only retrieved articles. the first one relates to the use of listening strategies by learners in second life vr environment [ ] . a second one relates to multimodality in vr but without teaching and learning purpose [ ] . the three other papers are totally unrelated to the topic of interest [ ] [ ] [ ] . this shows that virtual reality and multimodality are rarely tackled scientifically as a connected issue. we propose that multimodality may be investigated as a teaching and learning process in terms of ways of enacting it within a vr's semiotic domain as a design space that affords constructivist and activity-based learning. multimodality may be viewed as the vehicle for students to design and orchestrate their own modes of learning that are meaningful to them in the form of multimodal ensembles and semiotic resource [ ] . such multimodal ensembles may include images and language along with more static modalities resembling frozen actions [ ] such as classroom objects and equipment incorporating desks, tables, displays, chairs, books and chalkboards. there is a plethora of evidence on how multimodality may be deployed in traditional learning environments [ ] [ ] [ ] , in blended learning spaces [ ] [ ] [ ] and online learning spaces [ ] [ ] [ ] . there are constellations of evidence on employing multimodality as means to experience teaching and learning in digital and analogue semiotic domains. yet, there is infrequent substantiation on how meanings of words, images, communication processes, teaching strategies, roles and learning activities may be situated in a vr semiotic domain. this paper attempts to illuminate the application of multimodal teaching and learning as a pedagogically rich strategy that blends, couples and combines constructivist-led practice. such strategy constitutes distinct ways of thinking, acting and interacting. essentially, it allows to experience teaching and learning in unique ways. in section hereafter, we present an overview of the literature supporting how vr may be used in learning and teaching as means to increase learning efficiency, based on recent developments in designing and representing learning content and activities through vr. in section , we propose a methodology for integration of vr into multimodal learning path and we illustrate this methodology in section with eleven different vr case-studies resembling different design approaches to map multimodal learning with vr features and components. finally, in section , we evaluate this proposition considering the current situation of the pandemic and how vr and emerging xr (extended reality) technologies can contribute to reshaping the learning and teaching fields while physical distancing tends to be normalized. digital learning technologies aim to help learners increase their capacity for innovation, leadership, multiand inter-disciplinary collaboration, emotional intelligence, critical skills, collective problem identification and solving skills, in a participatory environment [ ] . multimedia resources and tools in these environments include, e. g.: videos, interactive images, recorded presentations, online quizzes, discussion forums (synchronous and asynchronous), visual representations of learner data to describe progress (summative analysis) and what learners are doing to learn [ ] . the increasing use of multimedia in education and training offers the possibility of presenting content in multiple representations (text, images, video, audio, ubiquitous media) to accommodate different teaching and training strategies, learning outcomes, assessment methods and feedback mechanisms. key aspects are the use of a range of tools, resources and services in a pedagogical manner to enhance the students' experience. the integration of multimedia learning into different modes of learning seems to encourage learners to develop a more flexible approach based on inquiry and information retrieval. hazari [ ] and mayer et al. [ ] argue that student learning is deeper and more meaningful when a range of interactive tools and resources are deployed rather than using text alone. shah and freedman [ ] list the benefits of using visualizations in learning, such as ( ) external representation of information, ( ) deeper learning, ( ) triggering learners' attention and concentration by making information more complete, thus simplifying ill-defined concepts and ideas. these tools can be serious games, and virtual reality. these technologies allow us to go beyond standard forms of written and spoken language [ ] . vr environments are being envisaged as a medium that aid learners' efforts to be active. learners consciously attend to, and reflect on, critique leveraging reflexivity and novel meaning-making leading to a conceptual change. there is an enlightening research spectrum on measuring the instructional effectiveness of immersive virtual reality [ ] [ ] [ ] , understanding trainers' conceptions of teaching in vr [ , ] , students' attitudes towards vr [ , ] and trainer professional development using vr [ ] [ ] [ ] . there are also studies that investigate associations between specific pedagogies and theories with vr [ , ] embroiling constructivist models of learning with the premise to individually and collaboratively construct knowledge and experience through critical learning and thinking. in summary, these previous works indicate that learners respond to the environment with an interaction-reaction opposition: they build their own knowledge and social interactions are primordial to that building [ ] . the advent of vr head-mounted displays has encouraged the development of an array of vr environments particularly used for augmenting the student learning experience [ ] . in this context, vr may be broadly described as an experience in which students interact within a d dimensional world with body and gestural movement, experiencing interactive content such as images and sounds [ ] . a distinctive characteristic of a vr system is that students can interact and manipulate objects by emulating how objects are manipulated in the real-life [ ] . commentators and researchers alike have attempted, through metaanalyses and systematic reviews, to discern the processes, strategies and methods that are most likely to be aligned with vr tools, elements and features (e.g. for language learning) [ ] . there is consensus that vr may promote activity based and student-centred learning, as proliferated in the constructivist learning paradigm, whilst attaining student motivation, self-regulation and self-assessment. a key advantage of learning using vr is that students can view objects and content from multiple perspectives and thereby situating learning in line with subject contexts. for example, vr allows rich learning environments such as factories or real-life like working spaces, particle physics events and brain anatomy. it affords opportunities to learn through interacting with virtual objects leading to creating new cognitive schemata tied to situated learning instances. in conjunction to this, spatial perception and cognition such as acquiring navigation and localization skills within a vr environment may be codified and represented as thirdperson symbolic experiences increasingly supporting and amplifying a sense of social and selfpresence [ , ] . cooper and thong highlights four distinctive elements of vr as an educational tool: ( ) experiencing as the ability of students to respond physically and emotionally to a range of stimuli, ( ) engagement as the multisensory experience that may enhance student's engagement, ( ) equitability as ways of responding to sameness and differences in schools and ( ) everywhere as offering exciting possibilities in relation to location, timeliness and how the learning process emerge [ ] . usual vr advantages listed in the literature are embodying, acting, repeating [ ] , and increasing motivation while learning compared to other media [ , ] . yet, leaners' acceptance and learning instructions' creation are still restraining large adoption [ , ] . in education and training this can be explained by lack of on-campus experiments [ , ] . globally, previous meta-analyses ( studies), systematic reviews ( study) and reviews ( studies) documented vr efficiency for learning [ , , , , ] . but, according to lanier et al. experimental quality in vr is sometimes questionable due to the methodological challenges faced on the study design, data analysis reporting and disseminating the knowledge gained [ ] . within the issue of learning with vr in the context of a multimodal path, the ability to create efficient teaching and learning environments as well as strong experimental proofs depends on design principles that are applied. despite the considerable uptake of vr for learning and teaching, there is little, if any, evidence on designfocused studies that illuminate in-vr elements and features that focus on the affordances and constraints as well as the dynamics perpetuated to support multimodal teaching using vr. an early study from dickey [ ] investigated the potential of a vr to support activity-based multimodal teaching and learning through an evaluative case study. vr elements that afforded an activity-based and multimodal approach to teaching included an in-vr chat tool as the primary means for presenting a concept for discussion. responsive feedback and interaction with the students were the main learning affordances along with multimodal information presented as visual illustrations. another affordance was granting unique names for students to establish unique virtual identities for maintaining control over the learning environment. such virtual identities were inextricably connected with avatar representations [ ] . pre-selecting, modifying or creating new avatars helped students to distinguish their virtual appearance and learning about and coming to appreciate design in their efforts to apply design principles for creating their avatars by manipulating avatar objects, shapes, colours and attributes. kinesthetics and point-of-view aspects for avatars to interact with objects, within the virtual learning space were directly linked with the provision of an 'avatar' mode for individual and collaborative activities. an integrated web-browser was also viewed as a feature that can instigate multimodal learning especially when connected to in-vr learning objects via sensors for allowing students to make relationships between the vr object and its underlying information found on the web. this inter-connection between in-vr objects and information about them on the web alludes to the employment of distinct semiotic principle [ ] . learning occurs through interrelations within and across multiple sign systems (symbols, objects, images, facts, information) as an inter-related and connected knowledge from different semiotic domains. more recently, doumanis et al. investigated the impact of a multimodal learning interaction of gamified tasks in a collaborative virtual world [ ] . multimodal interactions within the vr seemed to improve learning in comparison to the non-multimodal control group. specifically, the multimodal interactions observed improved students' ability to generate ideas thus facilitated a sense of presence and immersion with the vr condition. doumanis et al. triggered three types of immersion (e. g. spatial, emotional and temporal) aligned with vr features. navigation in the vr world with speech control and virtual representation with an avatar along with access to information, user grouping, textual communication and dialogue log were central features for encouraging active, multimodal and critical, as opposed to passive and unimodal, learning. principles of active learning were embedded in the use of the vr features creating certain dynamics and controlling essential features. for example, teachers should have full control of the vr classroom in terms of controlling student navigation or a "proxy option" to temporarily take control of a student's avatar as means to facilitate their effort to learn the system or grouping students for collaborative in-vr projects having students working in teams and taking on assigned roles. therefore, vr allows more interaction opportunities for learners with peers, content (e. g. information) and objects (digital assets). designing in-vr group dialogic learning experiences enables for distributed knowledge and collaborative problem-solving, encouraging perception of thinking and reasoning as inherently social processes. designing vr elements creates learning situations for students to think with others by using and manipulating vr tools and places emphasis on the distributed knowledge product generated by a web of students working for resolving a common problem. innocenti et al. developed a virtual environment for learning how to play musical instruments [ ] . similarly, to dickey [ ] and doumanis et al. [ ] , navigation elements is a key multimodal feature as means to provide spatial orientation cues for learning and usability aspects. for example, to mitigate vr sickness while students are interacting and manipulating d objects for designing a prototype or researching an object, a virtual locomotion technique [ ] may be induced to offer natural, usable and efficient ways for multimodal driven activities to be navigated through and enacted in the vr environment. navigation elements need to be tied to in-vr collaborative scenarios for aiding students to perform tasks, set by the teachers or by peers, for practicing the intended learning outcomes. collaborative scenarios may encompass pre-determined designs of the vp-space such as scaffold for helping the students to move within the vr environment, progressively learning how to interact with objects, making the in-vr goals clear and distinguishable and encouraging exploration, inquiry and observation of how the different modes reveal intended meanings. vr is a semiotic domain that triggers students to learn in different ways, applying an array of developmental skills and competencies as they move from one vr scenario to the next. the role of the teacher and the student within the vr space are changing depending on the scenario, as the general premise is that there is no single master of knowledge. rather each member takes roles with associated skills to master such as being the researcher, developer, designer or project manager in different settings. in that way, people with varied skillsets and dexterities have the possibility to exchange their roles and learn from each other. as opposed to designing unimodal online learning environments (e.g. creating a moodle page for students to download content, developed by the teacher), vr scenarios may be designed in a way that afford both a change in practice but also a change in identity [ ] . this can be done by distributing and re-distributing students into diverse vr groups, switching different roles interchangeably and sharing knowledge mastered from participating in previous vr groups through employing reciprocal problem-based in-vr learning scenarios. the premise is that there is no 'master' of knowledge in the sense that knowledge construction and especially knowledge building is a collaborative process through a network of people that distributes pervasive multimodal information, roles and responsibilities. multimodality as a context-based and situated learning instantiation may be designed for and represented through collaborative vr, as part of xr. the most common collaborative vr features are: ( ) focusing attention, ( ) connecting learners to the learning materiel [ ] . collaborative vr [ ] may encourage multiple perspectives on a given phenomenon through conversation and interaction and joint construction of knowledge [ ] (it echoes the four pillars of learning [ ] ) by providing feedback to facilitate the adoption of learning reflexes [ ] and monitoring of scenario development; allowing distant learning [ ] . such collaborative practices in vr may encourage the formation of social identities and viewing knowledge as a social construct developed through a network of individuals having common goals and interests [ ] . by employing collaborative vr teachers may design virtual places that afford collaborative learning processes that take social interactions into account offering a more diverse and richer forms of dialogue that would be challenging to design or construct in other learning environments [ ] . individually or collaboratively, vr allows for learning instances to be embodied (to be represented by an avatar) [ ] . such embodiment gives a unique dimension illuminating a learning by doing orientation rather than only passively memorising and acquiring information [ ] . this offers richer and more diverse forms of dialogue and interaction between students and contextualized learning objects for vicarious forms of learning [ ] . being immersed in vr creates a sense of presence, it allows learning from each other and adapting performance in response to meaningful pseudo-natural feedback [ ] generated from interactions with dobjects. reflecting on this pseudo-natural-occurring feedback may cause to transform a daunting learning experience to a harmonious learning situation [ ] which can improve learning effectiveness compared to other modalities [ ] . vr allows unique teaching and learning experiences which, by design, makes it interesting to implement in existing multimodal paths. currently, the industry may not always seize the opportunity to apply such design principles, yet vr is starting to be introduced in multimodal paths across different subject areas and disciplines. the purpose of this section is to illustrate the variability of vr application into existing learning paths with examples coming from the field, schools, universities and companies in france and singapore. some were implemented in france, others in singapore, or both and in other countries as well. accordingly, the games are available in several languages, as illustrated in the following figures to . each example, connected to a general purpose, is described according to certain in-vr teaching and learning goals: knowledge transmission, practicing, feedback, evaluation. for each goal, we identify the activity which can be implemented. we distinguish the paths according to the nature of the vr experience that is integrated: serious games, simulations, collaborative vr (see table ). ( ) serious game [ ] section: we describe several use cases integrating a serious game in vr, single player, including feedback to the player. the user is facing a situation with a non-playing character, embodied with an avatar or only a voice. feedback are provided immediately during the game as well as at the end of the game and help the user to improve. such application is particularly relevant to train soft skills, such as how to behave with a client, a patient, a colleague. ( ) simulation [ ] section: we describe several use cases integrating simulation in vr, which purpose is to provide a relevant representation in vr of a target system to be learned (a machine, an organ, a network, etc.). such a tool is relevant to train users to interact with said system and learn procedural sequences or gestures. ( ) collaborative vr [ ] section: we describe several use cases integrating collaborative vr, i. e. a virtual environment where participants can join and are embodied with a personalized photorealistic avatar. participants can be distant or in the same room. they can share immersive content, such as interactive d models, °videos or role-playing game. such paths, embedding vr experiences along with other activity-oriented multimodal activities, could infer specific in-vr features, representations and visualizations mapped with intended learning outcomes. in addition, the association of multimodal activity-based teaching strategies would enable both individual and collaborative practices in the wider semiotic vr domain within which they occur. such deployments are being evaluated through quality of experience in order to collect user's state with such apparatuses [ ] . the vr tool is proposed as a practicing activity opening a seminar to foster equality behaviour by managers, regarding gender, disability and diversity. in gender awareness scenarios, the user can play whether a man or a woman. the game points discrimination and stereotypes through dialogue choices the learner must complete. it is part of a general company awareness policy regarding gender inequalities, aiming at understanding how many stereotypes about women drive once thoughts in the work environment, and how much these stereotypes influence our choices when it comes to promoting women. other scenarios relate to physical and cognitive disabilities as well as sexual orientation. figure illustrates situations and the options that are offered to the player, following the last statement of the non-playing character (npc), in english, as deployed in singaporian company. in this example, we aim at generating empathy by playing the role of some else, a woman or a disabled person. using the same approach, we propose another application, which will be integrated as part of a medical and dentistry and resulting from a french-singapore partnership. the purpose is to play the role of a child in the medical environment to better understand his.her point of view and anticipate his.her fear and anxieties. this application will be used for practicing. figure illustrates the point of view of the child as a patient in different situations: on the dentistry chair (left) and during a discussion with the doctor and a parent (right). clues in the field of view support the role of the child, such as the view of the child body (figure , left) . the vr tool is proposed as a practicing activity opening a course in a business school to train students to customer relationship management in a shop. the vr game, including an individual feedback, is played in the classroom and followed by a general discussion with the teacher. then evaluation takes place using traditional paper and pen methods, in the classroom. this program organization is very close to the previous one, although it takes place at school. figure illustrates the overall view of the shop (right figure single user serious game in vr for social norms and behaviour changes relating to discriminations. picture) and a zoom on a particular shop area, juice machine, where actions are required from the player (left). the vr tool is proposed as a practicing exercise on top of other applied exercises of a one-week training program for future shop managers. learners play one half of a day a serious game training them to the management of costumers' satisfaction. the purpose is to be able to answer questions for the best customer service experience possible. the game allows learners to memorize typical issues customers can encounter in respect with companies wording and policy. figure illustrates the shop where the game takes place (left) and the client npc the player is interacting with during the game (right). the red dot represents the player gaze direction allowing the interaction with the environment, such as the selection of answers. the vr tool is proposed as a practicing exercise embedded in a path for developing skills for front desk employees in the hospitality industry. the overall program also includes several individual debriefing sessions with a trainer, who can be distant from the trainee, flashcards to contribute to the retention. the entire path is validated through an assessment quiz certifying learning (retention). figure illustrates several situations of the game: with client npcs and possible answers from which the player has to select (left, in english) and a single client npc (right, in french). a "pause" button is shown as well as the score, showing the player progression in the game. this score contributes to immediate feedback to the player, indicating whether the selected answers are good or not regarding the quality of the customer relationship management. the vr tool is proposed as a practicing and evaluating activity, used as a closing applied exercise. the serious game consists in playing a thief trying to steal sensitive and confidential information from pcs, usb memory device but also paper notes. the purpose, as a player, is to steal as many information as possible during a short period of time. learners' identify sensitive information unprotection behaviours. the game also provides feedback and an evaluation of the player. in this context, the vr game is added to a face-to-face (physical) training program for any worker in companies for them to learn cybersecurity rules. figure illustrates some objects the player can interact with to determine those that can present a risk regarding cybersecurity, these objects are identified with yellow circles. this learning scenario is implemented in france, in singapore and other countries. the vr tool is provided as a practicing and evaluating activity among multiple applied exercises in a training program for operators on production line in pharmaceutical industry. the vr consists in a simulation of a true machine with the actual procedure for performing assembly task. each step is written and an agent (a voice) is guiding the player step by step through the process. the purpose is to allow learners to get confronted with the actual machine and pieces before doing it in real life. several modes allow progressive learning: a guided and a semi-guided mode for practicing and non-assisted mode for evaluation. the training program also includes several activities, collective and individual. figure shows game interface elements: the different steps of the game are presented on the left picture, showing the player is currently playing step , instructions are presented to guide the player (here "take the grease tube and grease the joints"), the objects required for the action are highlighted with blue halo (here the joints and the grease tube), on the right picture the player can see his/her hand manipulating the spanner. the vr tool is proposed as a practicing exercise for two players integrated into a training program for developing skills communication skills along an inter-job process. in two different vr environments, one learner is driving the train while the other learner is communicating at distance from the control place to give indications to the driver. during that time, the trainer is supervising the simulation without intervene. the trainer is annotating the scenario so he can do a debriefing of specific points with learners after the simulation. the purpose is to make learners memorize procedures while communicating and driving a train. figure illustrates the game environment. the vr tool is provided as a practicing tool, which can be used by neurosurgeon students to get used to brain anatomy and d manipulation. vr is added to help student to improve their d navigation skills, it consists in merged neuroimaging from patients' brain, with addition of artefact mimicking tumours. students have to identify their precise localization and size. a collaborative mode allows teachers and students to use the application collectively. such application contributes to downing and replacing part of real brain tumour surgery training. figure shows the user interface with a measurement tool (left) and the control panel to set the various display parameters (right). the controllers are represented in the virtual environment to facilitate the manipulation and interactions. the collaborative vr tool is provided for knowledge transmission as an innovative medium to share contents relating to process engineering in a common virtual environment, with students and teacher located in the same classroom. the course takes place in an engineering school. the vr is added as a new mode of the pedagogical multimodal path, integrated with traditional lecture, group assignment, and pen and paper evaluation. figure shows the setup of the students in the classroom (left) and the setup in the virtual classroom (right). virtual reality & intelligent hardware vol issue ： - the collaborative tool is provided for knowledge transmission as a new mode of the pedagogical multimodal path, allowing to share immersive content ( d interactive models and °videos and pictures). the purpose of using vr is to allow students to better understand the actual dimensions of equipment used in particle physics (i.e. colliders) and have a more realistic representation of the experimentation site, without physically visiting switzerland. during a regular session, high-school students follow introductory courses to particle physics in the morning, then individually sit in front of a computer to identify and sort real particle-collision events. they finish by sharing and piling up their results (together and with other classes around the world), to reach and experience the statistical methods and thresholds of particle discovery. vr is used to lecture students about the real size and lay-out of the gigantic apparatus that allow particle discoveries: an interactive d sketch of the cms (compact muon solenoid) detector (the lecturer and students are teleported to scale on the cms detector) with particle collision events and then °images and video to show the "real" images. the main advantage is to show an environment that cannot be illustrated in a regular classroom, because of its size and inaccessibility. figure shows the setup of the students in the classroom (left) and the setup in the virtual classroom (right). a view of the virtual environment is shown on the screen in the physical classroom for non-vr participants. the d model is shown at real scale, so that the students can better measure it. the collaborative vr tool is added at different time points for knowledge transmission, practicing and providing feedback as a communication tool in a multimodal path. the general purpose of the training program is to promote learners' leadership skills. it is implemented in an international company with managers from several countries. the use of vr allows participants to connect more easily and regularly without needs for traveling. the trainer can control participants' audio, allowing everyone to hear each other or isolating tables from each other for specific activities. this program has notably been implemented with an international company with managers from countries in asia-pacific area, including singapore. figure illustrates the view of the virtual environment from the desktop interface of the trainer. it shows the participant list and allows the management of the participants groups (the "tables"). in this paper, we highlight the connection between vr learning and multimodality and the instruction concepts related to it. this paper concentrates on vr but new hardware allow varying degree of "virtuality" [ ] . new generations of vr hmds also offer ar modules with a "see-through" capability for rapid switch from computer generated environment to real environment and any mixture thereof. tracking, voice tracking and body tracking. haptics and brain computing are also fields undergoing rapid progress and will be launched soon. all these technologies enable natural user interface [ ] . this comes along with deployment of g networks and possibility for streaming and cloud-based application architectures. this is already used for gaming, this will soon benefit to vr. shadow, a cloud gaming platform, is launching what it calls a "vr exploration program", i.e. a closed beta test for vr streaming [ ] . these new generations of hmds combined with opportunities of beyond- g networks will allow the development of genuine mixed reality experiences with fully natural interactions. changing the habits may take time, said alvin graylin, ceo of htc china, but for the benefit of users. hardware companies' strategies thus strongly impact the design of learning and teaching solutions that can be developed in france, in singapore and globally. this paper concentrates on learning and teaching but in the covid- crises context, other uses of xr are wildly discussed. prior to that crisis, vr was still emerging in some sectors. several factors are limiting the adoption, including the cost of equipment and complexity of implementation. from a business point of view, these limitations to adoption may be observed both in france and in singapore. in contrast, adoption of mobile technologies is much more significant, in line with the smartphone mobile equipment rate. while the future of vr was highly associated with entertainment and gaming in some recent market studies [ ] , one may expect that these trends will be impacted by the current context of physical distancing and climate issues. therefore, it could be assumed that the evolution of the vr and xr technologies will support the development of new experiences for remote working, authentic and content rich mediated learning and healthcare contexts. limiting people travels is a key aspect of the strategy to control pandemics, such as constraints as an opportunity and proposed a virtual version of the event. it has been the case of the v ec , the virtual vive ecosystem conference that was planned by htc in china in march [ ] and laval virtual planned in france in april [ ] . these are in line with preliminary attempts such as the idc conference hold in the netherlands in september , with the ibc live system initiated by tiledmedia and intel to live stream the five-day ibc conference globally in k, °virtual reality [ ] . of note, the use of vr for remote interaction, as described in use case # allows to significantly reduce traveling costs. as a consequence, the initial investment for individual equipment can be rapidly amortized. the impact of sanitary constraints has been significant, and it may last for to months more from now at a certain level. this will induce deep changes in habits notably with the support of technologies precluding a return to what the world was before covid. some describe a fully digital world, where xr technology will be the must-have, that's the position of alvin graylin, htc china ceo. at least for the coming years, an adoption phase will be characterised by coexistence in hybrid systems, for instance with organisation of physical events with virtual version, increased use of home office and flex office, blended learning with on-campus and remote learning, etc. more than % of the world's students' population have been impacted by the pandemic and the closures of schools, estimates unesco [ ] . the next school year may also be significantly impacted. this situation has revealed strong inequalities among teaching systems regarding their digital maturity and their capacity to ensure pedagogical continuity. although digital tools can bring significant advantages, for remote learning context as well as with the personalisation of education that undoubtedly bring support to students in difficulties, a strong private-public partnership will be essential to design and transform the education system, says marie-christine levet, ceo of educapital, the first european edtech vc fund [ ] . this transformation will require support and training of the teachers and parallel adaptation of the technologies to their specific needs and requirements. additionally, to hold the promise of a digital society, for learning, working and any other activities, xr technologies must be fully inclusive, and ensure accessibility to everyone, despite disabilities, would they be cognitive or physical. in this context, experimentation is the key to evaluate how technologies can be integrated into the teaching practice, especially in a multimodal perspective. this paper stipulated a review on designing and using vr for multimodal teaching, learning and training. vr and xr are highly versatile tools, which can be used for collaborative or individual activities, with distant or physically related participants at any step of the learning process: knowledge transmission, practicing, feedback and evaluation. we have described three main types of tools based on vr: serious games, mostly for soft skills training, simulation, mostly for procedural learning and collaborative vr for immersion with innovative content and to facilitate interactions between distant participants. these are only a few examples and the advent of technologies will allow to combine them more easily (e. g. collaborative serious game and simulation). the concept of adaptive learning and deep learning are also progressing along which will allow to create even more personalized and interactive learning experience as well as to provide indicators of individual progression to the trainer. however, we also identify a lack of robust evaluation framework to evaluate how these tools can be used in an optimized way and generate relevant synergies with existing tools, for the benefit of users: trainers and trainees. our purpose is therefore to increase researchers' attention in terms of designing vr experimentations that could be inspired by the use cases we have described. moreover, insights from this paper motivate us to list a certain number of research issues that need to be tackle. they are particularly aiming to apply scientific findings to the filed by pushing specific matters: -how to design learning in vr based on a multimodal strategy? -how to collect and analyse user data obtained in vr to discern a multimodal path? -how to determine whether a vr system should replace or complement an existing multimodal teaching and learning intervention enacted in the classroom? -what learning taxonomies may be mapped as means to enable in-vr multimodal teaching and learning for hybrid or purely online and distance forms of teaching and learning? a gap seems to be prevalent between scientific knowledge and industrial practices when vr is deployed in multimodal learning paths. communicating about use cases and choices that have been made might help to create a framework facilitating the process of 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serious games, and simulations an analysis of vr technology used in immersive simulations with a serious game perspective affordances of virtual reality for collaborative learning virtual classroom ' s quality of experience: a collaborative vr platform tested augmented reality: a class of displays on the reality-virtuality continuum brave nui world: designing natural user interfaces for touch and gesture marché des technologies immersives (vr/ar/mr) htc conducts its first virtual "vive ecosystem conference" (v²ec) fully in vr allowing global attendees to join virtual sessions laval virtual key: cord- -g pe ad authors: moss, emanuel; metcalf, jacob title: high tech, high risk: tech ethics lessons for the covid- pandemic response date: - - journal: patterns (n y) doi: . /j.patter. . sha: doc_id: cord_uid: g pe ad the covid- pandemic has, in a matter of a few short months, drastically reshaped society around the world. because of the growing perception of machine learning as a technology capable of addressing large problems at scale, machine learning applications have been seen as desirable interventions in mitigating the risks of the pandemic disease. however, machine learning, like many tools of technocratic governance, is deeply implicated in the social production and distribution of risk and the role of machine learning in the production of risk must be considered as engineers and other technologists develop tools for the current crisis. this paper describes the coupling of machine learning and the social production of risk, generally, and in pandemic responses specifically. it goes on to describe the role of risk management in the effort to institutionalize ethics in the technology industry and how such efforts can benefit from a deeper understanding of the social production of risk through machine learning. and technological structures that seem to operate autonomously. these structures are pervasive and deeply intertwined with technologies of bureaucratic control in vivid (as automated decision systems for welfare services and predictive policing) and banal forms (as accounting norms, quarterly shareholder dividends, and unscalable unemployment insurance portals running on cobol). the risks that define contemporary life are not just socially produced, but are actively managed by technocrats and technologies that calculate risk thresholds for pollutants and automotive safety, by a financial system that creates a market for risk so that it can be hedged against, and by business managers who offer customers the ability to outsource infection risk by arbitraging weak and outdated labor laws. caitlin zaloom, an anthropologist who studies risk, identifies two modes of understanding risk from a sociocultural perspective-how groups understand risk as a threat or vulnerability, and how groups attempt to exert control over an uncertain future by limiting exposure to risk. we apply those understandings of risk to applications of machine learning in the covid- pandemic to ask how those who build machine learning applications construct and act upon risk. this necessarily leads us to also ask how they maintain and build socioeconomic power by exerting control over the distribution of risk. this framing extends ongoing conversations about the social implications of machine learning beyond those of algorithmic bias , to point to a type of harm that occurs not when machine learning ''gets it wrong'' due to various forms of bias. rather, we interrogate what happens when machine learning ''gets it right'' by acting as expected but doing so while reinforcing and exacerbating social and economic inequity. despite recent debates within the machine learning community showing how resistant some quarters are to acknowledging the social, cultural, and economic dimensions of the field (against the ample evidence from others), the question of how to properly bound which aspects of sociotechnical systems machine learning practitioners have agency upon and responsibility for has become vitally important. pandemics are not strictly a microbial phenomenon, they follow the contours of society the contagion encounters, some of which shift medical risk toward the impoverished or oppressed. as each of us are made responsible to minimize our own risk of spreading the coronavirus, it becomes all too clear that ''responsibility'' is, to some extent, coterminous with a social and economic status that allows us to externalize risk onto others. in recent years, this capacity for nearly autonomous, unquestioned risk externalization has been mediated through machine learning applications to a remarkable extent. machine learning, because of its versatility in dealing with problems across domains, because of the wealth of financial and computing resources at its practitioners' disposal, and because teams of machine learning engineers can collaborate remotely, has found no shortage of potential applications to the current crisis. therefore, we suddenly find our personal and societal responses to the pandemic emerging through machine learning applications that act as a ubiquitous tool for distributing societal, health, and economic risks. machine learning applications already shape the distribution of risk across the labor, health, and surveillance landscapes that are central to distributing risk as part of our pandemic response. gig worker platforms, instant delivery, supply chain management, and automated scheduling applications determine who is exposed to how much risk from the disease, while the workers themselves attempt to navigate continually shifting affordances on those platforms. the machine logics of these systems are determinative of risk, whether human technocrats could have orchestrated these processes in identical ways or not, and early evidence suggests some of the ways that such applications are proving brittle in their response to the covid- pandemic. these applications financialize and arbitrage risk from app users (whether individual consumers or enterprise users) to gig workers, waged staff, and warehouse laborers, with stockholders reaping the difference. the tech companies that are driving the technological response to the covid- pandemic have arranged their business models and organizational practices around building products that distribute upsides and downsides according to socio-historical patterns, as interpreted by machines, yet lack the capacity to ''understand just how pervasively. technology is being used to marginalize many groups of people,'' as leading machine learning researcher timnit gebru and colleagues have observed. , machine learning applications are ultimately exercises in distributing attention and resources, both in how we understand the risks we face and how those risks are distributed across society. increasingly, the calculation, production, and management of risk has been accomplished through the application of machine learning techniques. machine learning is used to understand threats and vulnerabilities, and also as a means of exerting control over such threats. indeed, risk is foundational to machine learning. loss functions, central to the applied power of machine learning, were developed to analyze and minimize risk. all objective functions can be thought of as minimizing the risk of a prediction being wrong, but machine learning has been applied to more ''human readable'' understandings of risk across a vast array of domains. these include predicting cardiovascular risk, estimation of genetic risk factors, consumer credit risk, and risk of individuals attempting suicide. machine learning is used not only to understand the nature of threats to health, safety, and finance but also to intervene in these threats by allocating scarce resources toward interventions that minimize risk the most for those who control or own the algorithmic tools. in this way, a rideshare platform produces risk for drivers who take on the liability of car payments and vehicle maintenance, while minimizing risk for the platform itself through its freedom from maintaining a fleet of vehicles for the service it ostensibly offers. machine learning, then, is deeply implicated in the social production of risk that beck and zaloom describe above. by seeing machine learning as productive of risk, it becomes possible to recognize the responsibilities machine learning practitioners hold for the ways they produce risk. in constructing representations from data, in crafting classifiers and evaluating their utility, and in optimizing for desired performance behaviors, machine learning shapes and distributes risk across society. machine learning can identify for bankers which individuals are at the ll open access greatest risk of not repaying loans, for police which neighborhoods are at the greatest risk of certain kinds of criminal activity, and for doctors (and insurers) patients who are at the greatest risk of diabetes, heart disease, cancer, pneumonia, or covid- . and in all too many cases, machine learning actively produces risk while also distributing it unevenly across society, as predictive policing algorithms focus police attention on already over-policed (largely black and latinx) neighborhoods. algorithmic methods for deciding where risk lies would be a purely academic exercise if not for the real-world impacts to people's lives that this entails. machine learning applications operate upon theoretical constructs that are not directly observable-creditworthiness, health, and recidivism cannot be directly measured-but rather are inferred from proxies for such constructs. models built from such proxies, because they are operationalized as part of algorithmic decision-making systems, often seem like a concrete instantiation of the theoretical constructs they purport to represent but may instead become like self-fulfilling prophecies, actually producing the phenomena they purport to measure. and they are often used in ways that produce concrete negative impacts to people's lives. individuals classified as risky loan applicants have trouble buying homes and building wealth. neighborhoods classified as high-risk crime areas get policed more heavily and see more arrests for petty crimes. over time, heavily policed neighborhoods see more re-arrests, and therefore steeper penalties for residents who become re-offenders. , patients classified as being at high risk of certain diseases may receive life-saving early testing and have better long-term outcomes, but may also see higher healthcare costs and dangerous side effects from maintenance medications, be seen as having pre-existing conditions by their insurers, or be triaged to a lower degree of medical urgency by a racially biased algorithm trained to seek price efficiency. to be clear, these impacts are not a first-order result of machine learning but neither are they entirely external to machine learning. rather, they are the result of complex sociotechnical responses to risk in specific domains. the role of machine learning in producing ''risk'' as an actionable construct for some and not for others cannot be ignored, as machine learning practices rely on, recreate, and often amplify already-existing patterns of how risk is distributed across society, irrespective of whether that risk is fairly or justly distributed. this is particularly apparent in how racial disparities are algorithmically encoded in many machine learning applications, as when overrepresentation of non-white inmates in criminal justice records leads to the over-estimation of risk for non-white defendants in pretrial detention models. however, it is also evident in how such applications themselves participate in the perpetuation of unjust institutions, such as the carceral system. on top of this, the role that machine learning plays in producing crime, for some and not for others, cannot be ignored. machine learning practitioners have invested significant effort in adjusting technical systems to blunt downstream risks, but the role machine learning might play in the reproduction of patterns of risk is also operative in less-apparent ways as well. even when datasets are balanced, optimization functions are constrained to minimize bias for disadvantaged groups, and instances of algorithmic bias are measured and mitigated, a long tail of social effects remain embossed on the data creation and collection processes that underlie the machine learning economy. given the profound threat of covid- , it is crucial to consider how the application of machine learning to the social challenges of a global pandemic can produce and distribute risk across society. these risks are socially constructed, as are specific harms produced by machine learning systems, and so we must ask what is being done to make sure that one is not amplifying the other. since the pandemic was declared in early march of , hundreds of articles have been published to pre-print archives, such as arxiv, biorxiv, and medrxiv reporting potential advances in machine learning applications for combatting the pandemic. these applications include natural language processing for combing through the existing literature on covid- , machine learning models that attempt to infer the asymptomatic spread of the virus, models of the effect of quarantine policies on viral transmission, facial recognition applications for use in emergency room triage, and deep learning for covid- diagnoses through medical imaging. these studies point to the ways machine learning participates in how risk is both understood and managed, through attempts to understand the nature of the threat and to respond to it. more recently, a host of machine learning applications have been developed to track, treat, and limit the spread of the virus. , these applications include automated contact tracing used to notify those who have been exposed that they ought to self-quarantine (for which machine learning algorithms assist in estimating the strength of contacts between people based on bluetooth signal strength), , but also natural language processing-based early warning systems (available on a subscription basis) for outbreaks, and computer vision systems that detect mask-wearing and crowding on public transportation systems to inform potential riders that they may want to choose alternate modes of transportation during busy times. while these efforts are doubtless well intentioned, each suggests a machine learning intervention into the already-existing distribution of risks and potential harms for society. in the us we are seeing the most severe cases of covid- striking black and latinx communities in drastically disproportionate ways, and it is clear that this is in large part because of how risk and inequality map onto each other along racial dimensions. this is in part because of long-standing disparities in health outcomes for black and latinx communities, environmental racism that places environmental determinants of health near black and latinx communities, as well as the disproportionate number of black and latinx workers in job roles that cannot be filled at home and do not have adequate sick leave or healthecare. for contact tracing, the ability to make use of a notification to minimize one's own risk by self-quarantining is far too dependent on one's personal wealth and capacity to afford to stay home (either because of a generous workplace sick leave policy, the ability to work from home, or one's own savings). any contract tracing is a sociotechnical system that depends on how different parts of social life fit together-telling people they should stay home does not mean that they will be able to stay home. for contact tracing to work at all, its designers must be attuned to the context of social life in which such systems can produce harmful, difficult-to-foresee effects that replicate or amplify inequalities already present in society. rather than individualizing the risk through contact tracing systems currently being proposed, attending to the contextual use of such a system could collectivize risk by identifying and emphasizing the necessary forms of social support for self-quarantine and medical care: adequate sick leave and quarantine leave policies, robust testing, and economic relief that targets individual workers over large companies. automated contact tracing notifications are useful to those who already possess the means to work from home and are less useful to those who cannot self-quarantine without losing their job. an automated update about a crowded subway car will not help someone who has no other means of transportation and cannot be late to return home to care for a child. others, meanwhile, will maintain their freedom of movement-the delta between who can move about freely and who cannot will have profound consequences for those who have and those who do not have compatible mobile devices, or who lack the resources to maintain their income or care for their dependents while unable to work or cohabitate with others. in this way, automated technologies that construct and manage the shared risks of the pandemic can perniciously codify and reinforce unjust social and economic dynamics that are the context in which the infectious disease spreads. machine learning applications may construct risk such that individuals can act upon it to their own advantage without addressing the social conditions that make such risks unevenly distributed, thereby presenting a false sense of risk reduction. those who build and deploy automated tools to track and treat the pandemic should not treat risk as if it were flat across the population, but as something that they are actively engaged in constructing and distributing and are responsible for doing so justly. understandings of how the production and distribution of risk through algorithmic technologies leads to sociotechnical impacts of machine learning are still in their infancy, and such technologies are only just beginning to be thought of as capable of being brought under any sort of governance regime. [ ] [ ] [ ] [ ] professional organizations have attempted to mitigate harmful impacts from applying data-driven and machine learning solutions to the problems of the covid- pandemic. some of these are quite robust, if non-binding, sets of recommendations, while others attend to a limited definition of privacy rights without attending to the range of sociotechnical impacts discussed above. over the past years, we have been studying how those inside of silicon valley tech companies, which build the machine learning models that are most likely to directly affect people, go about understanding the impacts of machine learning and developing organizational practices to manage the effect they have on how risk is distributed across society. , under the mantle of ''ethics,'' silicon valley companies manage the emerging risks their products and services pose for individuals, society, and for their own firms. in response to the unprece-dented public health challenges represented by the covid- pandemic, many of these companies are rushing to play a role in producing technological solutions. in the rush to produce solutions, however, it is even more important to think through the lessons the tech industry has learned from managing organizational risk in the years leading up to the current crisis, and not to jettison those lessons out expediency. reading the potential applications of technology to the current crisis through the recent history of tech ethics, several lessons stand out: context is key, the upside benefits of technology are in tension with downside risks, and leadership and organizational culture matters. these lessons are made explicit through the applications of machine learning to the covid- pandemic, but can also be extended to examining how machine learning, and digital technologies more broadly, produce and distribute risk across society. any framework to identify and manage risk within an organization must deliberately and methodically consider the context in which it operates. context includes not just the social milieu at which a product is targeted, but also the intentions, worldview, and the necessarily partial knowledge of those who build the product. including producers of technology in any consideration of context is important because the way they are positioned in the world can have an outsized influence on what are chosen as problems to be solved, what data are selected to serve as proxies for unobservable phenomena, , and what forms of risk are visible. this is particularly true for the use of technology to manage the risks covid- presents to society. technological applications for the pandemic offer a compelling set of technical challenges for engineers and designers, but not all technical challenges present opportunities to improve outcomes. a deep learning tool for hypoxia detection intended for use in emergency room triage sounds useful, but given the speed at which health professionals can visually detect hypoxia (by noting pallor of complexion or blue lips), such a technological intervention is an additional step on top of what needs to happen in triage already, not necessarily a time-saving tool for busy hospital workers. recent research demonstrates the importance of recognizing the additional work integrating new tools into the existing practices of workplaces they are intended for requires from all those who interact with them. given the enthusiasm for using covid to accelerate the adoption of artificial intelligence (ai) in healthcare settings, it is reasonable to ask whether solving relatively simple diagnostic (but scientifically interesting) tasks is really as useful as predicting and managing resources that vulnerable human caretakers truly need, such as adequate personal protective equipment. perhaps diagnostic applications of ai receive so much attention because diagnosing is a type of activity that powerful and economically valued physicians do, whereas supply chain management that keeps the nurses, janitors, and technicians-who have far more contact with patients than physicians-safe is mundane and less economically valued. there is less money to be had in keeping nurses alive than in displacing physician labor, for no reason other than how risk has been financialized and distributed. technologists should ask themselves: if an automated tool for tracking and treating a pandemic is not useful ll open access for the most vulnerable, then in what sense is it useful enough to merit investment and justify the effort of integrating it into existing practices? upsides and downsides inside product and legal teams at tech companies, it has often been easier to argue for limiting the risk of a product that might harm users than it is to argue for changes to a product that benefit users. this is particularly true if those positive outcomes for users or society cannot be straightforwardly accounted for in the company's bottom line. this is at least in part because limiting the riskier aspects of a product aligns with mechanisms companies already have to limit their liabilities. conversely, additional investment in a product ''merely'' to generate a social good is seen as reducing the return on investment because it raises the cost of investment without raising the financial return in a manner that can be booked. amid the current pandemic, however, this tendency is inverted, and within the closed loop of technology vendors and enterprise clients, it may appear there is only upside to adapting the ad-serving and data brokerage surveillance apparatus to the purpose of contract tracing or epidemiological modeling. however, this upside comes with significant downside risks that covid- tracking systems might pose to individuals and groups outside that closed loop in the near and distant future. these risks are often framed as threatening privacy, and there are various technical methods for limiting such risks for individuals, including differential privacy, encrypted computation, and decentralized computation (particularly for contact tracing and other diagnostic applications). yet such technical methods have trade-offs in terms of accuracy and time-to-market-a not insignificant issue given the urgent demand and short contracting windows for such systems. but ''privacy'' is an inadequate frame for these risks, because it individualizes responsibility to manage one's own data without attending to how these risks are produced through the design of technical systems and their integration into society. furthermore, privacy unburdens the legal system from adequately protecting the rights of those who might be harmed by the systematic misuse of personal data, and forestalls any possibility of ''collective determination over the infrastructures and institutions that process data and that determine how it will be used.'' having a framework in place to work through the internal and external risks to the firm, and to society, is crucial for maximizing the upside benefits of any machine learning applications. to accomplish these aims, such a framework would need to be supported by the necessary resources to achieve the substantive outcomes that are desired. for a company building an intervention as sweeping as contact tracing, success depends on having financial, social, emotional, and medical resources already in place to enable people to deal with the risk a digital contact tracing app assigns to them. a smartphone alert is useless if people do not have the ability to isolate themselves without suffering or failing those who depend on them, which means that the distribution of those capacities also determines the distribution of the upsides and downsides of a contract tracing interventions. machine learning applications are (thus far) not useful for rectifying this type of risk distribution despite that there are plenty of data proxies for economic inequity. because so many machine learning applications are built around arbitraging risk from an advantaged to a disadvantaged party we should expect the same from pandemic solutions that are not subject to critical interrogation. therefore, product managers, engineers, policy teams, legal consuls, executive boards, marketing teams, and user experience researchers need to ask themselves if the necessary social support is in place where their product is intended to be used. they also would need to ask themselves if their product will conceive of and distribute risks in a manner that is just, and what measures, metrics, and other signals they would need access to know that such questions have been answered adequately. while some companies have begun to invest in the capacity to ask such questions, , the industry as a whole does not yet have such frameworks in place. approaches that can identify and redistribute risk so that it does not fall disproportionately on those least able to bear its burden exist, but are often not required to be brought into practice. inside tech firms, choices about investing in upside benefit over limiting downside risk get made at the top, as are decisions about how much time, energy, and cost to invest into context alignment. as our research indicates, without clear signals from the ceo that efforts to enact good governance, build products with responsible safeguards, and prioritize users' rights would not be scrapped for a bottom-line calculation, those efforts cannot amount to much. in recent years, activist employees and a vigilant public have provided a check on some companies when their ceos pursue contracts with repressive regimes or military applications. however, not all companies have experienced this kind of pressure internally (the possible reasons for this run the gamut from a lack of diversity inside to an environment in which such dissent is actively discouraged), and others have not proven responsive when faced with pressure. some of the most recalcitrant of these companies are in the running for contract tracing application contracts, and will require a different form of pressure to conform to expectations for the responsible deployment of such a system (if this is even possible). leadership matters when it comes to the government response to pandemic disease, and when it comes to provisioning contact tracing algorithmic systems from tech companies, too. many companies, big and small, are racing to build contact tracing applications and related infection tracing tools for governments to use. some will be safer for users, in terms of digital rights, than others. having options is great, but there is little obligation for federal, state, or local governments to choose the option that is best able to preserve digital rights. as it stands in the us, there are very few legal protections for civil rights and liberties that might be harmed by the misuse of the kind of data contract tracing systems depend on. draft legislation, like the ny state geolocation tracking ban would provide a modicum of protection from unreasonable police use of such data, but government contracts for contract tracing systems will be written under the legal frameworks we have now, not the ones we wish we had. trust in those at the very top-of companies, of public health institutions, and (perhaps most importantly) national governments-to do what only leadership can do is paramount. only those who hold final authority can prioritize alternatives that distribute risk equitably rather than toward those who are most vulnerable. in practice this can mean only building in contexts where the necessary social infrastructure for product goals to be met can be ensured. it can also mean refraining from turning the tools of emergency response to covid- toward other, more nefarious purposes. in the absence of regulation, or other forms of social pressure, the incentives for pursuing opportunities to squeeze additional profit by selling data or licensing a machine learning product to unsavory actors can be difficult to resist. similarly, the resolve needed to dismantle emergency tools when the crisis passes is currently the limiting factor for leadership in determining how the risks we all face of getting sick, losing loved ones, and losing our livelihoods unfolds. historically, risk distribution is a key conceptual and economic feature of machine learning applications. this type of risk is not a natural phenomenon, such as where lightning might strike, but a social construction of technocratic systems through which people must pass to have access to the economy, justice system, and health care. machine learning has already shaped the landscape on which our society is responding to the covid- pandemic by distributing risk, and the pandemic has accelerated the role that data-driven technology has in directly determining the conditions of our lives. however, despite the efficiency and utility promised by machine learning applications, there lurks a fundamental challenge: are machines good for distributing risk in the ways we actually should distribute it? consider for a moment, whether it is possible to build machine learning applications that distribute risk up the socioeconomic ladder rather than down. not just ''is it conceivable,'' but would those of us involved in the research and development of these technologies know what that looks like and how to get there? this would, in part, look like subverting existing power hierarchies, as demonstration projects tracking white-collar crime zones have done. it would also look like reconfiguring who builds machine learning applications (machine learning teams in industry, and corporate ethics teams, have had notorious difficulties retaining black and latinx team members) and how they are governed. if not, then is it just to build high-tech pandemic solutions that distribute risk only downward? approaches that can identify and redistribute risk so that it does not fall disproportionately on those least able to bear its burden exist, but are not required to be brought into practice. inside tech firms, choices about investing in upside benefit over limiting downside risk get made at the top, as do decisions about how much time, energy, and cost to invest into context alignment. as our research indicates, without clear signals from the ceo that efforts to enact good governance, build products with responsible safeguards, and prioritize users' rights would not be scrapped for a bottom-line calculation, those efforts cannot amount to much. in recent years, activist employees and a vigilant public have provided a check on some companies when their ceos pursue contracts with repressive regimes or military applications. but not all companies have experienced this kind of pressure internally, and others have not proven response when faced with it. some of the most recalcitrant of these companies are in the running for contracts applying machine learning to the covid- pandemic, and will 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statement regarding the ethical implementation of artificial intelligence systems (ais) for addressing the covid- pandemic -ieee spectrum on the responsible use of digital data to tackle the covid- pandemic owning ethics: corporate logics, silicon valley, and the institutionalization of ethics ethics owners: a new model of organizational responsibility in data-driven technology companies translation tutorial: positionality-aware machine learning the science question in feminism fairness and abstraction in sociotechnical systems the human body is a black box'': supporting clinical decision-making with deep learning strategies to optimize the supply of ppe and equipment today's covid- data will be tomorrow's tools of oppression (the daily beast privacy versus health is a false trade-off we need to talk about digital contact tracing data-driven responses to coronavirus are only as good as the trust we place in them google the latest company to face worker revolt over immigration policy apple and google are building a coronavirus tracking system into ios and android (the verge a facial recognition company wants to help with contact tracing. a senator has questions welcomes introduction of ny geolocation tracking ban five years of tech diversity reports-and little progress (wired) about the authors emanuel moss is a doctoral candidate in anthropology at the cuny graduate center and researcher for the ai on the ground initiative at data & society. he is also a research assistant for pervade, an nsf-funded multisite project jacob metcalf is a researcher for the ai on the ground initiative at data & society. he is a pi for pervade, an nsf-funded multisite project and also serves as the ethics subgroup chair for the ieee p standard key: cord- -llsgpyrm authors: damiati, safa a. title: digital pharmaceutical sciences date: - - journal: aaps pharmscitech doi: . /s - - - sha: doc_id: cord_uid: llsgpyrm artificial intelligence (ai) and machine learning, in particular, have gained significant interest in many fields, including pharmaceutical sciences. the enormous growth of data from several sources, the recent advances in various analytical tools, and the continuous developments in machine learning algorithms have resulted in a rapid increase in new machine learning applications in different areas of pharmaceutical sciences. this review summarizes the past, present, and potential future impacts of machine learning technologies on different areas of pharmaceutical sciences, including drug design and discovery, preformulation, and formulation. the machine learning methods commonly used in pharmaceutical sciences are discussed, with a specific emphasis on artificial neural networks due to their capability to model the nonlinear relationships that are commonly encountered in pharmaceutical research. ai and machine learning technologies in common day-to-day pharma needs as well as industrial and regulatory insights are reviewed. beyond traditional potentials of implementing digital technologies using machine learning in the development of more efficient, fast, and economical solutions in pharmaceutical sciences are also discussed. there has been a remarkable increase in the amount of data-including pharmaceutical data-that are generated each day. the term "big data" has gained increasing interest in various research areas. in addition, data-driven companies currently show how various industries are able to profit from the massive generation of data. several definitions have been proposed for the term "big data." one of the widely recognized definitions used is the " vs" definition. the definition was first proposed by douglas laney and encompasses " vs" which consist of volume, velocity, and variety ( , ) . this definition was later extended by ibm to include the fourth "v" for veracity ( ) . however, the reported definitions of "big data" usually lack consistency and quantification. because of its potential value, data has been considered as the new oil ( , ) . textbooks and publications, social media, user-generated content, electronic health records, genomics, sensor networks, and many other types of data all form "big data" and contribute to its diversity and complexity. the remarkable increase in the amount of data can be attributed to advancements in data storage and innovative technologies ( ) . almost . million new scientific papers are published annually ( ) . in addition, there were more than , pubmed-reported publications on "pharmaceutical sciences" in only ( ) . thus, "big data" in pharmaceutical sciences can be viewed as both a challenge and an opportunity. the evolution of artificial intelligence (ai), particularly machine learning technologies in which computers can "learn" and perform tasks, has improved the potential of using big data in pharmaceutical sciences. the scope of this review is specific to machine learning because, among all ai branches, machine learning is the most currently used ai technology in the field of pharmaceutical sciences. other ai fields, such as natural language processing (nlp), expert systems, and robotics, are becoming very popular in many healthcare settings, such as in the diagnosis of diseases, patient monitoring, and robotic surgeries ( , ) . these methods, however, have not yet received as much attention as machine learning in pharmaceutical sciences settings. the aim of this review is to summarize the past, present, and potential future impacts of machine learning on different areas of pharmaceutical sciences, including drug design and discovery, preformulation, and formulation. this review covers different machine learning algorithms that are commonly implemented in different areas of pharmaceutical sciences, with a special emphasis on the use of artificial neural networks (anns). notably, compared with other machine learning methods, anns have displayed superior performance in various pharmaceutical settings, as will be discussed in the following sections. despite its long history, as will be discussed below, there is still no standard definition of ai. however, mimicking human intelligence using computer systems is the basic concept of ai. the physiology and function of neurons in the brain inspired warren mcculloch and walter pitts ( ) to propose a computational model of artificial neurons. similar to human neurons, artificial neurons are characterized by being "on" or "off" in response to sufficient stimulation from neighboring neurons ( ) . the term "artificial intelligence" was officially introduced by john mccarthy at the dartmouth conference in the summer of ( ) . since then, ai has had cycles of success as well as so-called "ai winters" ( ) . recently, ai has significantly advanced and gained increasing interest in a wide range of fields, including healthcare ( ) , engineering ( ) , and transportation ( ) . this increased focus on ai applications has been fueled by the growing availability of big data in healthcare and the rapid advancement of numerous analytical techniques ( ) . machine learning is a popular ai technique ( fig. ) whereby computers can accurately adapt or modify their actions (e.g., making predictions). machine learning algorithms can be classified into two major categories: supervised learning and unsupervised learning ( ) . in supervised learning, the algorithm uses generalizations to respond appropriately to a set of training examples. training examples are input-output data that are provided in the dataset to be learned. because the output data here are known to be the correct responses (or correct answers), they are termed as "targets." the machine learning model eventually aims to predict an output that is closer to the target. examples of supervised machine learning methods include regression analysis, support vector machines (svms), random forests (rf), and anns. unsupervised learning is based on feature extraction methods in which no examples are provided ( ) , such as principal component analysis (pca). some supervised machine learning models may also support unsupervised machine learning models such as svms and anns ( ) . table i shows a comparison of several machine learning methods commonly used in pharmaceutical research. linear regression, anns, knn, svm, dt, and rf are common machine learning methods used in pharmaceutical sciences; pca is considered as an unsupervised dimensionality reduction technique usually integrated into computing transformation of unlabeled data to find a lowerdimensional set of axes ( ) . although pct may be considered as a statistical technique used to analyze multidimensional data, it is usually incorporated as a preprocessing tool in machine learning ( ) . in addition, there are other machine learning methods used in pharmaceutical sciences such as the fuzzy logic algorithm. in this method, reasoning with logical expressions is used to describe membership in fuzzy sets ( ) . this method has the advantage of eliminating the need for expert knowledge regarding the system, considers the noise in the data, and produces easily interpretable predictions ( ) . fuzzy logic algorithm provided good prediction models for analyzing gene expression data ( ) . additionally, genetic algorithm (ga) is a population-based method commonly used as an optimization technique. this algorithm also offers the advantage of modeling nonlinear relationships. in pharmaceutical research, ga is mainly used in quantitative structure-activity relationship (qsar) studies as a feature selection tool ( , ) . recently, there is an emergence of several novel machine learning applications in pharmaceutical settings using non-conventional machine learning techniques such as light gradient boosting machine (lightgbm). this method has offered numerous useful features as compared to the other classic machine learning methods as shown in table i . furthermore, an emerging machine learning technique is the transfer learning. transfer learning is based on reusing a pre-trained model in order to build a new, improved model to address the intended target ( ) . in transfer learning, a relatively large dataset size of the original model is an important determinant for optimum transfer learning performance. important recent progress of using transfer learning has been achieved in the field of pharmaceutical sciences ( ) as will be discussed in a following section. moreover, machine learning models can be classified into two categories: parametric and nonparametric models (table i) . parametric models summarize data with a set of constant number of parameters (regardless of the number of training examples), whereas nonparametric models are dependent on the number of parameters and therefore on the number of training examples ( ) . table i summarizes the common parametric and nonparametric machine learning methods encountered in different drug research and development studies. note that each of these machine learning methods may have further subtypes, and a general comparison among these models can be unfair. for example, although certain machine learning methods may require large datasets, an optimum dataset size is usually lacking. the reader is encouraged to refer to the cited references for details. additionally, no machine learning method is generally considered superior to all others, and each problem (classification or regression) should be addressed individually. anns are biologically inspired computational models that mimic the brain's ability to learn by example (fig. ) . our brains consist of billions of processing units called neurons. these neurons are fully interconnected through an enormous number of synapses that connect one neuron to another ( ) . a biological neuron consists of a cell body that contains a nucleus and controls cell activities, dendrites, which compose the fine threads among neurons and carry the information to the cell, and axons, which consist of one long thread that transports information to the next cell ( ) . similar to human neurons, anns consist of artificial neurons or processing elements (pes) that are connected via coefficients (weights) ( ) . a typical ann (fig. ) consists of three main structural components: input, hidden, and output layers. the first layer of an artificial neuron is the input layer, which corresponds to the dendrites of the biological neuron and transfers information to the next layer. the following layer is the hidden layer, which is the middle layer between the input layer and the output layer. the hidden layer connects these two layers through certain coefficients (weights). each hidden layer consists of a number of neurons (also called nodes). the choice of the number of neurons in the hidden layer of anns is generally achieved by a trial-and-error approach ( ) . although there is no definite number of neurons to be used, using too few neurons in the hidden layer may result in a reduction in the ann learning ability, whereas too many neurons in the hidden layer may result in the memorization or overfitting of the training data, ultimately decreasing the generalization ability of the ann. thus, the number of hidden neurons in the neural network that will give the highest correlation coefficient (r ) and lowest error (i.e., the minimum difference between observed and predicted values) should be selected as the optimal ann. the final layer of an artificial neuron is the output layer, which consists of the outputs (targets). moreover, by examining the magnitude of the ann connection weights, anns can provide quantitative estimates of the relative importance of the input variables for the output in question ( ) . figure illustrates a schematic representation of a typical biological neuron (a) and an ann (b). the process of designing a neural network that can learn to ultimately solve a problem occurs through iterative use of examples with known answers (targets). this process is called learning or training. the learning/training process as illustrated in fig. starts with receiving signals (inputs) from the input layer. these inputs are multiplied by connection weights and summed in the hidden layer. the results are then sent to the output layer through a transfer function. several activation functions are available including identity, logistic, tanh, and exponential functions ( , ) . the sigmoid function is a commonly used activation function in pharmaceutical research. during neural network learning, a process called "error back-propagation" is usually implemented ( ) . in back-propagation, the weights are adjusted to minimize the error between the calculated (predicted) output and the observed (target) output. anns are particularly powerful in modeling nonlinear relationships and can make highly accurate predictions due to their ability to analyze complex data primarily based on generalization and pattern recognition ( , ) . nevertheless, some challenges with using anns can be encountered, such as trapping at local minima, controlling noise, and overfitting/ underfitting. to avoid local minima and control noise, a timeinvariant noise algorithm (tina) can be implemented ( ) . in addition, there are various ways to overcome overfitting/ underfitting problems, including splitting the data into training and validation sets ( ) . this technique can reduce overfitting. moreover, stopping the training process at the right point can also prevent both overfitting and underfitting ( ) . figure illustrates the optimum stopping point for ann training. dl is a machine learning technique that is also a representation learning method ( ) . the state-of-the-art of dl methods includes recent advances in neural networks. the major difference between anns and dl is that dl includes larger numbers of hidden layers (usually more than three), and each layer comprises many more nodes. therefore, dl uses multiple levels of representations that can ultimately learn very complex functions. generally, dl requires very large training sets, which may limit the use of such methods. there are different types of neural network architectures in dl, including convolutional neural networks (cnns), recurrent neural networks (rnns), and fully connected feed-forward networks, which have been comprehensively discussed elsewhere ( ) . dl has become very popular and has gained interest in diverse research areas of pharmaceutical research such as in pharmaceutical formulation development ( ) , drug discovery ( ) , and drug repurposing ( ) . their predictability and generalization performance are generally better than that of other machine learning methods, such as svms and rfs ( ) . this can be due to the improvements in algorithms, computers, and the availability of large datasets. specific dl applications in pharmaceutical sciences is an interesting topic for future reviews. machine learning has been utilized in different pharmaceutical applications from the early stages of drug discovery to the late phases of drug development. the following sections present three major areas of pharmaceutical sciences that have witnessed a considerable use of anns together with a number of other machine learning methods. these studies can be categorized into drug design and discovery, preformulation, and formulation studies. drug discovery accounts for a significant share of the machine learning applications in pharmaceutical sciences, mainly due to the use of high-throughput screening, combinatorial chemistry, and computer-aided drug design ( , ) . one of the early areas in which anns were applied is qsar studies ( ) ( ) ( ) . the qsar approach correlates the physicochemical properties of a compound with the corresponding chemical or biological activities ( , ) . the most commonly used physicochemical properties in qsar studies include molecular weight, partition coefficient (logp), and hydrogen bonding capacity. because qsar studies usually involve complex and nonlinear characteristics, anns were among the best available qsar modeling tools. additionally, due to their usefulness and success, the importance of neural networks has continued to grow in drug discovery with the rapid rise of qsar studies based on anns ( ) . table ii summarizes several input-output data used to build various machine learning models in different qsar studies. preformulation is the stage of drug development in which the physicochemical properties of a drug substance are assessed. determining the physicochemical properties of a drug substance is very important because it governs various parameters, such as its solubility, stability, interaction with excipients, and ultimately, bioavailability ( ) . determining the aqueous solubility of a new drug substance is an essential first step in preformulation. any drug to be absorbed must possess a certain degree of water solubility. this is true for oral, parenteral, ophthalmic, topical, and other routes of administration. various solubilization techniques are used to improve the aqueous solubilities of drug substances, such as using surfactant, complexation, salt formation, using hydrotropes, or forming cocrystals ( , , ) . the in silico prediction of the aqueous solubility of drug substances has gained significant interest using different computational approaches, such as molecular dynamics simulations ( ) and machine learning techniques ( ) . for example, damiati et al. ( ) developed a machine learning application using anns to predict the solubility enhancement effect of several hydrotrope molecules. the input data consisted of experimental data together with physicochemical properties (used as descriptors) related to hydrotrope molecules at different hydrotrope concentrations. the physicochemical properties included logp, melting point, and hydrogen bonding capacity. the developed ann model was subsequently used to predict the solubility enhancement of another potential hydrotrope molecules from an external dataset. the trained model was also able to identify new prospective hydrotropes for the drug molecule. in addition to providing accurate predictions, by determination of the connection weights, the developed ann was able to provide a quantitative assessment of the relative importance of various physicochemical properties that are required for a good hydrotrope ( ) . the reported use of anns in the prediction of solubility enhancements for drug substances and their successful use in other solubility applications in various research areas ( , ) are encouraging for further exploration of their potential uses in more pharmaceutical preformulation research. moreover, based on the pharmacokinetic profile of a drug substance, a suitable pharmaceutical formulation can be . eight molecular descriptors have been used for approved drug molecules. descriptors included molecular weight, hydrogen bond donor count, hydrogen bond acceptor count, rotatable bond count, topological polar surface area, heavy atom count, complexity, and covalently bonded unit count. the developed model showed good performance and generalization ability compared to other conventional machine learning techniques including partial least-squares regression (plsr), svm, anns, rf, and knn ( ) . in preformulation studies, transfer learning is a promising machine learning approach for further exploration. another stage of drug development is the formulation of pure drug substances into drug products to be administered by patients. anns have gained significant interest in this area and became the most popular machine learning tool in pharmaceutical formulation prediction ( ) . table iii summarizes numerous pharmaceutical researches that have been performed utilizing anns (as the only method used or as an approach that outperformed other machine learning methods) in the area of pharmaceutical formulation development in the past years. this table compares these studies from different machine learning aspects including the diverse input-output data used, amount of data (dataset sizes), input variables, and purpose(s). notably, a large number of these studies have utilized anns for the development and optimization of formulations and the prediction of formulation-and process-related factors associated with different parameters, such as drug dissolution and release. additionally, the *the top-ranked machine learning methods in each of these studies demonstrated better predictive ability than the other machine learning methods tested. ann artificial neural network, svm support vector machine, dt decision tree, rf random forest, knn k-nearest neighbor, rbfnn radial basis function neural network optimization of formulations (including the optimization of ingredients and/or operating conditions) using machine learning tools-particularly anns-has provided considerable success and displayed great promise for future applications that usually require fast and efficient manufacturing. recently, non-traditional machine learning techniques have been utilized in the development of in silico predictive models in pharmaceutical formulation. lightgbm has recently shown high potential predictive ability compared to conventional machine learning methods in pharmaceutical formulation researches. zhao et al. ( ) compared lightgbm, rf, and dl for the prediction of complexation free energy between cyclodextrins (cds) and guest molecules with a dataset consisting of data points. over numerous descriptors related to the guest molecule, cd, and experimental conditions have been implemented in designing the machine learning models. lightgbm showed better prediction performance compared to the other models including rf and dl ( ) . gao et al. ( ) also implemented the lightgbm method for prediction of complexation performance of drugs/phospholipid complex formulations described by over molecular descriptors related to the properties of the drugs, solvents, and experimental conditions. compared with other conventional machine learning techniques such as svm and dt, lightgbm model showed the best predictive performance for predicting drug/phospholipid complexation ( ) . also, in , he and co-workers used lightgbm to predict the particle size and polydispersity index (pdi) of nanocrystals prepared by different methods. the dataset consisted of experimental size data and pdi data under various conditions and using various api-, stabilizer-, and nanocrystal preparation-related descriptors. the prediction performance of lightgbm was better than that obtained from several classic machine learning methods including deep neural networks (dnn), svm, and dt for both size and pdi datasets ( ) . in all these lightgbm studies, it has been proved that lightgbm is a powerful and promising machine learning technique that can be further explored in the future for various pharmaceutical applications not only for its ability to provide accurate predictions but also due to its capability to provide an informative assessment of the importance of the input descriptors. in terms of applying ai and machine learning technologies in common day-to-day pharma needs, a number of aspects are to be considered including the benefits, risks, and efforts. the benefits of machine learning applications in pharmaceutical sciences are evident. this is true for both the classic machine learning tools such as anns as well as for the newly emerging tools such as lightgbm. accelerating advances across the entire spectrum of the development of drug substances and drug products by dramatically reducing the timeline in unnecessary attempts is a substantial benefit of ai in pharmaceutical settings. this may not only allow for improving outcomes in less time, but it also can help to find more efficient solutions in order to sustain manufacturing efficiency and rapid throughput. in addition, depending upon the therapeutic class, the problem of high drug attrition rates ( ) can be reduced. thus, the high costs associated with drug research and development processes can be significantly reduced if performed in silico using data digitalization and reduced extensive laboratory testing. for instance, considering a real pharmaceutical problem in which substantial efforts are needed is the problem of low aqueous solubilities of drugs. it is estimated that approximately % of drug candidates in research and development pipelines are poorly water-soluble ( ) . considering that only small quantities (< mg) of a drug substance exist in early preformulation ( ) , determining the baseline solubility and subsequently the optimum solubilization technique for each drug substance may require extensive screening and laboratory work, as well as substantial resources. if well-trained and well-validated machine learning models can be incorporated in such settings, only drug candidates that show positive results in silico may then undergo laboratory testing. thus, successful drug candidates can ultimately reach the intended patient in less time and with less material waste. based on the type of data, there is an important advantage of machine learning is that no restrictions are encountered while implementing machine learning algorithms. different types of data, including binary classification, multiple classes, and continuous data all can be modeled and analyzed by machine learning. moreover, machine learning models may be used individually or in combination. compared with traditional statistical models, a number of machine learning technologies (e.g., anns) offer the advantage of modeling complex and nonlinear relationships that are frequently encountered in pharmaceutical sciences. traditional models are usually used to find inference about relationships in the data, whereas machine learning models are designed to model complex relationships which can ultimately produce accurate predictions. for example, the nature of the solubilization effect using hydrotropes is complex, nonlinear, and do not follow a constant pattern ( ) . traditional statistical tool would not be able to provide accurate predictions for the solubilizing effect of these systems, whereas machine learning models not only were able to produce highly accurate predictions, but also proved to be powerful tools that can provide useful insights into the relative importance of the different input features in determining the outputs by interrogation of the connection weights. in addition, the machine learning approach also provided valuable insights that eventually lead to the identification of new prospective solubilizing compounds ( ) . the quality of data is one of the challenges that must be considered when using ai and machine learning in the pharmaceutical sciences. quality encompasses the consistency, reliability, accuracy, availability, and accessibility of the data. the dataset size also should be considered. small dataset size can be modeled using simple machine learning methods; if the dataset size is large and more complex to be modeled using simple machine learning methods, the advanced ann models based on dl approach can offer a potential solution. other challenges that must also be considered include the training/learning time, underfitting, and overfitting. therefore, the risk of applying unreliable machine learning models can be eliminated if these challenges were appropriately considered, and well-trained and well-validated machine learning models were carefully designed. hence, digitalizing pharmaceutical data using ai may require domain ( ) experience and the ability to train algorithms; each machine learning method should be implemented "task specifically." the pharmaceutical industry would greatly benefit from the use of ai and machine learning, due to its wide range of applications as discussed in this review. from proof of concept to product evaluation and marketing, ai can be applied to nearly every aspect of drug development. with the long-standing figures of an average of $ . billion and over years to develop new medicines ( ) , ai can offer a substantial investment to hasten and improve this process. in the last years, there is a remarkable growing number of pharmaceutical companies and startups using ai in drug research and development. a number of pharma companies either collaborated with or acquired ai technologies such as novartis and pfizer with ibm watson ( ). mak and pichika ( ) provided a comprehensive list of ai and pharmaceutical companies and the corresponding collaboration areas in drug development such as drug repurposing, personalized medicine, and drug discovery ( ) . other areas where pharma companies have been actively investigating in ai applications include process automation, robotic manufacturing, and targeted marketing ( ) . investing in data management and ai power can sustain manufacturing efficiency and rapid throughput of data digitalization which is powered by advancing algorithms as well as the availability of the diverse, complex, and large amount of data. ai may, therefore, improve decision-making and eventually create new and better medicines. nonetheless, it has been reported that ai has not yet influenced the pharma industry significantly due to several reasons/challenges suggested by henstock ( ) including data management (e.g., managing diversity and large amount of data), finding solutions for a large number of problems, insufficient skillsets, shifting towards alternatives to traditional scientific approaches, and lack of investments. to overcome these challenges, the author also suggested internal investment in data management and ai talent ( ) . mary and co-workers in conducted a survey-based study to clarify and understand the adoption and effect of ai in pharmaceutical and biotechnology companies. across organizations, a number of important ai activities have been identified including the use of ai for patient selection and recruitment for clinical trials, in addition to identification of medicinal products data gathering. major factors for not utilizing ai technology have been identified including lack of skilled staff, safety, regulatory, and compliance concerns, and budget constraints ( ) . in terms of regulatory and recommendation insights, food and drug administration (fda) recently published a discussion paper "proposed regulatory framework for modifications to artificial intelligence/machine learning (ai/ml)-based software as a medical device (samd) -discussion paper and request for feedback" which discusses the current approach made to subject software as a medical device driven by ai and machine learning to a premarket review in order to ensure safety and effectiveness. several types of changes/modifications which may have an impact on users (including patients, healthcare professionals, and others) using these softwares have been reviewed. for example, changes/modifications related to re-changing the inputs, training with new data sets, and change in the ai/ml architecture. to ensure lifecycle safety and effectiveness from its premarket development to postmarked performance, fda also proposed a total product lifecycle regulatory approach for ai/ml-based samd (tplc) to acquire evaluation and monitoring of a software product ( ) . the growing success of machine learning technologies, particularly anns, in many pharmaceutical settings showed great potentials for the development of beyond traditional machine learning applications. this trend has already begun in areas such as drug and gene delivery. therapeutic agents are often transported into the cell using special transporter systems such as cell-penetrating peptides (cpps). the efficiency of cpps is usually investigated and screened based on extensive laboratory work, which has recently been successfully performed in silico using anns. the developed cpps/ann model provided highly accurate predictions and informative assessments for different input features ( ) . additionally, drug repurposing also can highly benefit from these technologies ( ) . at present, although the first ai-designed drug has not reached the market yet, there is an ongoing race to find a treatment for the current covid- pandemic. ai plays an important role in the ongoing efforts by identifying potential molecules that could be used as anti-covid- drugs. for example, benevolent ai ( , ) reported the use of machine learning to identify drugs for covid- in which clinical trials are already underway. digitalizing pharmaceutical sciences is a very promising area in which numerous ai and machine learning technologies can be discovered and effectively employed. the growing success of machine learning technologies in many 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access inf soc doi: . /s - - - sha: doc_id: cord_uid: qu a q nan recent advances in information and communication technologies (icts) have fostered the development of new methods and tools for exploring the increasingly large amounts of data that come from pedagogical domains [ ] [ ] [ ] [ ] [ ] . these data have the potential to transform education into a personalized experience [ , ] that meets the needs of each individual student [ ] . educational data research is becoming highly relevant in massive online courses [ ] , especially moocs (massive open online courses) [ ] [ ] [ ] [ ] and spocs (small private online courses) [ ] [ ] [ ] . educational data are also the basis for learning analytics [ ] [ ] [ ] , with an increasing focus on the way educational data are presented [ ] [ ] [ ] , how users interact with the data [ ] [ ] [ ] [ ] , and data privacy and security [ ] [ ] [ ] [ ] . there are many types of data that can support student's learning [ ] , but the type and nature of the data, how they can be accessed, and who can access them, vary significantly. whether educational data are collected from collaborative learning environments [ ] [ ] [ ] , course management systems [ , ] , gamified training applications [ , ] , or administrative systems from schools and universities [ ] [ ] [ ] , valuable properties, patterns, and insights often emerge. when combined with other factors such as timing and context, these factors play an important role in understanding how students learn [ ] , the settings in which they learn [ ] , and the effectiveness of the educational approaches [ ] . extracting information from data to ultimately turn it into knowledge [ , ] can contribute to draw a more comprehensive picture of student's learning, which can empower students, parents, and educators as well as education stakeholders and policymakers [ ] . educational data usability and accessibility is even more relevant in the context of the global pandemic due to the sars-cov- virus, which causes covid- disease. this situation is having an unprecedented impact on education. according to unesco [ ] , in the first months of , the pandemic has affected . % of the total number of students enrolled worldwide: over . billion people have been unable to receive face-to-face instruction because of the closure of schools and universities [ ] . the consequences are more severe in emerging countries [ , ] and to families affected by poverty and risk exclusion [ ] , presenting digital inequalities [ ] , and causing exclusion and inequality situations in vulnerable groups, ethnic minorities, and people with disabilities [ ] . significant challenges have been reported in the online transformation of educational activities [ , ] , particularly assessment processes [ ] . consequently, it is vital to improve access to educational technologies and reduce gaps in use and literacy [ ] . a multi-disciplinary approach is required to deploy technological ecosystems [ , ] that favor blended or online training, teacher and student training for the efficient use of educational technologies [ ] , and policies for both government and academic leaders to define strategies and manage uncertain scenarios [ ] . in the context of educational data access, it is critical to ensure transparency, ethics, and individuals' rights. this uais special issue builds on the work started in a number of previous special issues [ ] [ ] [ ] [ ] and two international events: • the invited session entitled "emerging interactive systems for education", in the thematic area "learning and this special issue focuses on how to improve universal access to educational data, with emphasis on (a) new technologies and associated data in educational contexts: artificial intelligence systems [ ] , robotics [ ] [ ] [ ] , augmented [ ] [ ] [ ] and virtual reality (vr) [ ] [ ] [ ] [ ] [ ] , and educational data integration and management [ ] ; (b) the role of data in the digital transformation and future of higher education: personal learning environments (ple) [ , ] , mobile ple [ , ] , stealth assessment [ ] , technology-supported collaboration and teamwork in educational environments [ ] , and student's engagement and interactions [ , ] ; (c) user and case studies on icts in education [ , ] ; (d) educational data in serious games and gamification: gamification design [ ] [ ] [ ] [ ] , serious game mechanics for education [ , ] , ubiquitous/pervasive gaming [ ] , and game-based learning and teaching programming [ , ] ; and (e) educational data visualization and data mining [ ] : learning analytics [ ] , knowledge discovery [ ] , user experience [ , ] , social impact [ ] , good practices [ ] , and accessibility [ , ] . the special issue comprises the following accepted papers. collaborative learning systems are a niche for analyzing educational data. for example, virtual reality and d modeling applications can leverage the integration of collaborative approaches in medicine [ ] , architecture [ ] , or urbanism [ ] . huang et al. developed a study devoted to construct a d modeling practice field based on virtual reality technology, in which students can learn d modeling through a new vr design collaboration framework and complete design goals. the proposed design collaboration model includes the concept of a learning community. the results of this study indicate that the system usability of the vr modeling practice field is superior to that of the traditional modeling learning field and learners are more creative and motivated. the authors emphasize that through the new design collaboration model, students can effectively learn d modeling in vr. conde et al. explore the assessment of instant messaging tools for the acquisition of teamwork competence throughout a case study about the use of the instant messaging app whatsapp. from the results, the authors conclude that students prefer instant messaging tools in teamwork activities over other interaction tools such as forums; and that the use of those tools has a positive impact on students' grades. in an effort to demonstrate the potential of virtual worlds in education [ ] , especially in distance education [ ] , krassmann et al. introduce a framework to prepare the implementation of virtual worlds. their approach emphasizes requirements that distance education students need to meet in order to have a successful learning experience. the authors present an exploratory study and propose eight guidelines to harness the potential of the technology of virtual worlds for distance education. pervasive games [ ] enhance the gaming experience and level of engagement by including real world aspects into the game space. arango-lópez et al. propose geopgd, a methodology that integrates the design of geolocated narrative as the core of the game experience. this methodology guides designers and developers through the different stages of building a pervasive game by providing tools for defining the narrative components, places, and interactions between the user and the game. gallego-durán et al. tackle the challenges of learning programming as a universal ability [ , ] . the authors propose a radically different perspective to this issue, teaching students with a bottom-up approach, starting from machine code and assembly programming. their results suggest that such a small intervention could have a limited positive influence on the students' programming skills. pazmiño et al. did a systematic literature review [ ] to answer the question: what is the baseline of scientific documents on learning analytics in ecuador? the selected documents were analyzed using statistical implicative analysis after removing duplicates and applying inclusion, exclusion, and quality criteria. the outcome of this research has allowed building up a baseline of scientific knowledge about learning analytics in ecuador. user experience analysis in the educational realm is directly linked to the levels of user acceptance and satisfaction [ ] of the new wave of educational technological ecosystems and the personalization of learning [ ] . barneche-naya and hernández-ibañez describe the results of a case study intended to compare three different user movement paradigms (metaphoric, symbolic and natural) designed to control the visit to virtual environments for a nui-based museum installation. the study evaluates the performance of each movement scheme with respect to the navigation of the environment, the degree of intuitiveness perceived by the users, and the overall user experience. the results show that the natural movement scheme stands out as the most adequate for the contemplation of the virtual environment and the most balanced at a general level for the three variables considered. the symbolic scheme proved to be the most efficient. the natural movement and symbolic schemes appear to be the most appropriate to navigate digital environments such as museum installations. in another paper related to user experience, zardari et al. introduce an e-learning portal for higher education that was assessed from a user experience standpoint using an eye-tracking system. the results emphasize students' satisfaction with the learning portal. finally, toborda et al. analyze metrics to measure effectiveness and engagement levels in pervasive gaming experiences. regarding the analytics of accessibility, martins et al. present a study that assesses accessibility in mobile applications, which may be applicable to education and tourism [ ] . fourteen mobile applications were analyzed using a manual and automatic methodology through an evaluation model based on quantitative and qualitative requirements, as well as the use of features such as voiceover and talkback. the results show a high number of errors in most quantitative requirements as well as non-compliance with most qualitative requirements. also, in the context of accessibility, romero yesa et al. share a good practice in 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collaborative technological ecosystems for improving academic motivation and engagement learning and collaboration technologies. designing learning experiences. th international conference, lct , held as part of the st hci international conference, hcii learning and collaboration technologies. designing learning experiences. th international conference, lct , held as part of the st hci international conference, hcii teem' proceedings of the seventh international conference on technological ecosystems for enhancing multiculturality visualizing artificial intelligence used in education over two decades garcía-peñalvo fj robosteam project systematic mapping: challenge based learning and robotics robotics from stem areas in primary school: a systematic review social steam learning at an early age with robotic platforms: a case study in four schools in spain augmented reality and pedestrian navigation through its implementation in m-learning and e-learning: evaluation of an educational 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games: theory and design exploring the computational thinking effects in pre-university education computational thinking unplugged guidelines for performing systematic literature reviews in software engineering. version . school of arkaevision vr game: user experience research between real and virtual paestum measuring user experience on personalized online training system to support online learning towards a social and context-aware mobile recommendation system for tourism bridging the accessibility gap in open educational resources the guest editors would like to thank the universal access in the information society journal editors-on-chief, dr. constantine stephanidis and dr. margherita antona, for their confidence in our responsibility to lead this special issue. we want to express our gratitude to all the researchers that have made this special issue a reality. this work was partially funded by the spanish government ministry of economy and competitiveness throughout the defines project (ref. tin - -r). key: cord- -tpu oidi authors: sajnani, nisha; mayor, christine; tillberg-webb, heather title: aesthetic presence: the role of the arts in the education of creative arts therapists in the classroom and online date: - - journal: arts psychother doi: . /j.aip. . sha: doc_id: cord_uid: tpu oidi literature about the integral role of the arts in learning is widely available, but much less has been written about how the arts and aesthetics support education in the creative arts therapies, particularly in the online learning environment. this article introduces the concept of aesthetic presence within the community of inquiry pedagogical model in line with values espoused within a universal design for learning framework. the authors contextualize this concept with examples of how attention to the use of aesthetic and multimedia strategies in the classroom and in the online learning environment may foster openness and connection, encourage flexibility, humor, critical thinking, and animate and facilitate conversations about emergent and emotionally difficult themes while increasing accessibility for different kinds of learners. we need to advance our understanding of the role of the arts and aesthetics in the education of creative arts therapists in person and online. a primary contribution of creative arts therapists, as compared to verbal psychotherapists, is that we create an aesthetic framework, embedded in a socio-cultural context, from which to explore and examine experience as it arises between the client as artist, art-making, and a witness, in reference to the client's capacities to witness j o u r n a l p r e -p r o o f themselves, a group's capacity to witness each other, and the therapist's capacity to bear witness to what unfolds. we seek to facilitate aesthetic distance, an encounter within a representational realm that enables both emotional arousal and cognitive reflection (landy, ) . it follows, then, that the arts should play a formative role in training. this is particularly true in online learning environments where, given the absence of a physical encounter and the ubiquity of multimedia, attention to multisensory engagement would have particular relevance. in this article, we introduce the concept of aesthetic presence and discuss its importance in the education of creative arts therapists (cats) with specific attention to the online learning environment. we begin with a synthesis of literature on the arts in education and online learning in the cats. we then argue the relevance of aesthetic presence within a community of inquiry (coi) model of online learning design and pedagogy and connect this to values espoused with the universal design for learning (udl) framework, an inclusive approach to pedagogy that attends to the needs of different kinds of learners (cast, ) . we conclude with practical suggestions on how aesthetic presence may be enhanced in course design and instruction in the creative arts. while the recent coronavirus pandemic has forced us to make a rapid adjustment to how we teach and practice in the creative arts therapies, our hope is that these strategies may be useful going forward as we contend with course design, instruction and practice in blended in-person and online environments. despite the marginal status of the arts in education, many have written about the role of arts in facilitating learning (beardsley, (beardsley, , (beardsley, , berleant, ; clapp & edwards, ; croce, ; dewey, dewey, , duke, ; gardner, gardner, , gardner, , garrison ; goldberg & phillips, ; granger a; greene ; hausman, ; jackson ; maslak ; munro, ; sawyer, ; simmons & hicks, ; shusterman, shusterman, , shusterman, , j o u r n a l p r e -p r o o f webster & wolfe, ) . some literature exists on the pedagogical use of the arts in the training of creative arts therapists (butler (butler , (butler , a (butler , b deaver, ; gaines, butler, & holmwood, ; knight & matney, ; landy, hodermarska, mowers, & perrin, ; landy, mclellan, & mcmullian, ; mcmullian & burch, ; young, ) . even less focuses on online education in the arts therapies (beardall, blanc, cardillo, karman, & wiles, ; blanc, ; pilgrim, ventura, bingen, faith, fort, reyes, richmond, rosenthal-schutt, schwinn, & butler, ; sajnani, beardall, stephensen, estrella, zarate, socha, & butler, ) . the arts, including sound/music, movement/dance, drama/theatre, visual, literary, and media arts, offer teachers and students multiple forms of expression and facilitate skills in sensing, perceiving, observing, listening, thinking, problem-solving, and collaborating (clapp & edwards, ) . the value of attending to the aesthetic dimension of pedagogy has been argued by dewey ( ) , suggesting that learning occurs through experience and that aesthetic encounters deepen reflection and integrate theory with practice. dewey suggested the artist is able to "actively internalize, then externalize in their art, landscapes, events, relationships and ideas," thus facilitating new insights and possibilities (quoted in goldblatt, , p. ) . the artist transfers values from one field of experience to another, attaches them to the objects of everyday life and by imaginative insight make these objects meaningful. therefore, art, as symbolic of lived and potential experience continues to change with every interaction to offer multiple, contextual readings and perspectives. dewey's observations were reflected in contemporary and subsequent ideas about how people learn. for example, jung described the concept of active imagination, where the verbal free association of ideas, images, and beliefs could be expressed in visualizations, written and spoken narratives, drawn and painted images. from a learning perspective, active j o u r n a l p r e -p r o o f imagination creates a bridge by allowing the unconscious mind to teach the conscious body by facilitating new relationships between latent ideas, feelings, and desires (semetsky, ) . building on dewey's ideas, bruner ( ) described a learning process that oscillates between enactive representation (doing), iconic representation (images of real situations), and symbolic representation. working with the arts in education encourages socio-emotional engagement, integrates understanding, and fosters inquiry even in subjects that do not traditionally involve the arts. for example, sutherland ( ) explored the ways in which the integration of arts and nonverbal methods into traditionally "core" classes such mathematics have helped to develop these skills. furthermore, research in this area has demonstrated how symbolic, metaphoric, and poetic thinking shapes reasoning (thibodeau & boroditsky, ) . as webster & wolfe ( ) wrote in a harvard education review survey of the arts in education: aesthetic pedagogy allows students to create connections through imagining ideas and exploring how they relate to everything else one understands and feels. such a 'scenic' appreciation is not a luxury which teachers may indulge in as 'an extra,' but rather we contend that these aesthetic aspects are essential for learning experiences in order to help assist students to make important connections. (p. ) freire ( ) contributed significantly to how we understand the value of the arts in education through a critical lens. he described codification as the gathering of localized information and lived experience in order to create visual images of real situations that could then be used to catalyze dialogue and critical thinking. boal ( ) extended freire's ideas through enactive learning wherein participants act out, replay, apply, and actively seek out, rather than passively receive, information as a means for learning and liberation. lorde ( ) saw the arts, poetry specifically, as a liberatory epistemology of learning and unlearning, particularly for women, j o u r n a l p r e -p r o o f racialized people, and/or members of the queer community. as she wrote, "poetry is not a luxury. it is a vital necessity of our existence [...] poetry is the way we help give name to the nameless so it can be thought. the farthest external horizons of our hopes and fears are cobbled by our poems, carved from the rock experiences of our daily lives" (lorde, (lorde, , p. ). hooks ( has similarly written extensively about her use of expressive writing, storytelling, arts-based experiences, and consideration of the role of the body in the classroom, seeing education as a practice of affective and interpersonal freedom and transgression. the arts have been used in order to engage with and more fully include different kinds of learners (simmons & hicks, ) . bloom's ( ) widely used taxonomy of learning included an affective domain, and gardner's ( ) theory of multiple intelligences included musicalrhythmic, visual-spatial, and bodily-kinesthetic ways of knowing. most recently, the universal design for learning (udl) framework calls attention to the relationship between emotion and learning and the domination of text in pedagogical materials. a udl framework emphasizes the need for multiple means of engagement, expression, and representation so that students have various pathways "for accessing and comprehending information, for demonstrating what they know, and for increasing motivation and persistence" (udl on campus, n.d.) . the arts support these goals by strengthening socio-emotional coping skills, and self-awareness so as to allow students to find the right personal balance of demands and resources, sustain effort, foster collaboration, and self-regulation (farrington et al., ) . it is clear that the aesthetic dimension of learning engages a powerful mix of higher order thinking skills, imagination and creativity, self-regulated learning, interpersonal interaction, and affective, socio-emotional engagement. with the wealth of insight available on the importance of j o u r n a l p r e -p r o o f arts in education, it is imperative that we examine how the arts are integrated in the training of creative arts therapists where the arts are privileged as a way of sensing, knowing, regulating, and representing lived experience. there is a small but growing literature on how the arts are utilized in the teaching and training of cats, whether in person or online. several have written about the essential nature of art making in art therapy education (deaver, ; gerber, ; wix, ) . deaver and mcauliffe ( ) and fish ( ) explored the use of art-making in supervision and internship training. cahn ( ) specifically addressed the use of studio-based art therapy education. julliard, gujral, hamil, oswalk, smyk, and testa ( ) discussed the use of arts-based evaluation in research education. deaver's ( ) mixed-methods study pointed to the personal and professional importance of the consistent use of the arts across the curriculum. in dance/movement therapy, dance has been explored as a source of knowledge (capello, ) , a method for the personal and embodied growth of trainees (federman, ; payne payne , , and as a way to expand an educator's movement repertoire in order to strengthen their approach to teaching future dance/movement therapists (young, ) . in music therapy, the curriculum requires music therapy trainees to first learn a series of musical competencies in a primary instrument/voice, percussion skills, composition, and improvisation, and then practice applying these skills to a music therapy context (goodman, ) . matney ( , ) highlighted the value of teaching functional percussion skills through a simultaneous contextualization of these skills in a music therapy approach. these authors also pointed to the rarity of the term "pedagogy" in music therapy writing and suggest that there is a need for further research into the training of future music therapists due to the lack of empirical studies on the topic. j o u r n a l p r e -p r o o f butler ( butler ( , a butler ( , b ) has written about the use of drama exercises in drama therapy classrooms and asserts that such approaches are necessary in drama therapy education. his qualitative research pointed to the complexity of training students in therapeutic work without it becoming therapy, as well as the importance of learning through arts-based practice. he suggested that drama therapy education must engage students in "continual embodied reflective practice rather than a merely cognitive reflection" (p. ). several have built on landy's ( ) four-part education model, suggesting additional ways to incorporate embodied and drama-based forms of learning (landy et al., ) , including the use of existing theatrical characters and monologues to learn about clinical diagnoses (mcmullian & burch, ) , embodying clients and therapists in supervision (landy et al., ) , and weaving situated, psychodynamic, and enactive learning with experiential activities (butler, a). only six publications to date are known to have explored teaching cats online (beardall et al., ; blanc, ; lagasse & hickle, ; pilgrim et al., ; sajnani et al., ; vega & keith, ) . vega and keith ( ) focused their research on the scope of online learning in music therapy courses and conducted the first in-depth study in the us. their research revealed that many of the music therapy educators who were surveyed had received queries about online learning, suggesting a growing interest in the adaption of music therapy in online and distance settings. this initial survey research provided a snapshot of the state of online learning in music therapy and confirmed that, as of their publication date, no training program was offered fully online. lagasse and hickle's ( ) mixed methods study compared the perception of community and learning for music therapists in an online and residential graduate course. their quantitative results found no significant difference in perceptions of community. their qualitative data suggested that the presence of the instructor, peer interaction, and multiple online tools were important in creating a sense of community for those enrolled in the online course. online students did have a statistically significant higher perception of learning score than their residential peers, which the researchers attribute to the online students having more experience in the field and thus more investment in the learning process. no qualitative or quantitative measures examined the role of music or aesthetics in perceptions of community or learning. beardall et al. ( ) outlined the development of a comprehensive hybrid low-residency training program for dance/movement therapists. the authors described their attempts to develop an "embodied online presence," as a way for students and faculty to create and sustain a kinesthetic and affective presence online. they articulated the importance of creating opportunities for their dance/movement students to develop and trust their "bodily-felt sense" (p. ) through a variety of explicit activities involving filmed and synchronous dance and movement exercises and assignments, as well as instructors' "listening to and observing students' verbal and non-verbal cues and responding sensitively" (p. ). the authors spent a significant part of their article articulating their use of a range of synchronous and asynchronous tools for teaching, discussion, and assignments, which may be helpful for others interested in developing or improving online and hybrid learning options for cats. blanc's ( ) phenomenological pilot study explored more deeply this concept of embodied presence for dmt hybrid students, finding importance in artsbased responses and layered engagement between movement, other arts responses, and cognitive learning. she provided a sample of these layered assignments and indicates the importance of the most recent publication, co-authored by pilgrim et al. ( ) , presented findings on the first low-residency drama therapy cohort at lesley university. this phenomenological study explored this cohort's experiences, finding that virtual methods for creating experiences of embodiment, connection, and relationship using a combination of technology and artistic expression were seen as critically important. the study also found that several students began to shift away from the dramatic medium during the online teaching components of the hybrid program. furthermore, this study reported that the most substantial critiques of the program centered on some course instructors' lack of relational presence and communication. we see this article as a contribution to addressing ways in which instructors might develop an aesthetic presence to support relationship building and artistry in their course design and instruction in order to mitigate the kinds of difficulties that students face in an online learning environment. a foundational model for conceptualizing a successful online learning experience has been the community of inquiry model (coi) (garrison, anderson, & archer, ). the coi model presents three "presences" required in a successful learning experience: teaching presence, cognitive presence, and social presence integrated seamlessly in an online environment (garrison j o u r n a l p r e -p r o o f & cleveland-innes, , p. ). the coi model clarified the importance of the educational experience culminating in more than simply the mastery of content or cognitive engagement. it arose naturally to meet the challenge of creating a strong sense of community within a text-based environment . what follows below is a brief overview of the teaching, social, and cognitive presences articulated by coi, as well as some of the critiques of this model. teaching presence is the "design, facilitation, and direction of cognitive and social processes for the purpose of realizing personally meaningful and educationally worthwhile learning outcomes" (anderson, rourke, garrison, & archer, , p. ). whereas in a traditional classroom environment, teaching presence may be intuitive and communicated strongly through non-verbal cues; teaching presence in the online environment needs to be an intentional process. for example, glazier ( ) conducted a study of rapportbuilding strategies in the online classroom to improve student success, including providing video updates, personal emails, and personalized comments on assignments. students receiving these rapport-building communications from their instructor were observed to have both higher grades and lower attrition rates. social presence. social presence, particularly in the context of computer-mediated communication, is the degree to which the environment can facilitate immediacy. as rourke et al. ( ) describe, social presence includes verbal and nonverbal communication practices that increase closeness and interaction with instructors and students alike. social presence "supports cognitive objectives through its ability to instigate, sustain, and support critical thinking in a community of learners" (rourke et al., , p. ) , facilitating learning that is both socially and emotionally engaged. it has been identified as a key predictor of student satisfaction; in one study, j o u r n a l p r e -p r o o f it accounted for % of satisfaction (gunawardena & zittle, ) . sung and mayer ( ) identify five facets of social presence that impact student success and satisfaction, namely, "social respect (e.g. receiving timely responses), social sharing (e.g., sharing information or expressing beliefs), open mind (e.g., expressing agreement or receiving positive feedback), social identity (e.g., being called by name), and intimacy (e.g., sharing personal experiences)" (p. ). it is important to note that some have argued that social presence does not need to be included as a separate presence in coi and have been critical of its inclusion (annand, ). cognitive presence. finally, cognitive presence is fundamental to a learning environment that cultivates critical thinking skills ) and while it is held by the learner, it is heavily guided by the interactions in the learning experience. the underlying principle of cognitive presence is engagement in the practical inquiry process, and "the extent to which the participants in any particular configuration of a community of inquiry are able to construct meaning through sustained communication" (garrison et al., , p. ). garrison and cleveland-innes ( ) conclude that cognitive presence is reliant on the quality of interactions that occur throughout the instructional experience, and suggest instructors provide clear expectations and structuring of activities, conduct assessment aligned with intended goals, and select manageable and appropriate online content. as garrison et al. ( ) articulate, cognitive presence facilitates students' working through problems or issues that emerge in learning through exploration and meaning making. limits of coi. the coi model by its very nature is reductionist, dissecting the components of a learning community for analysis by instructors and learning designers interested in ensuring a full learning experience. in terms of its comprehensiveness, various authors have explored whether there are other "presences" or gaps. lam ( ) and shea and bidjerano ( ) j o u r n a l p r e -p r o o f observed that coi lacks an explicit focus on the learner. vladimirschi ( ) identified the need to consider cross-cultural implications. cleveland-innes and campbell ( ) suggested a need for developing emotional presence as part of social presence. kang et al. ( ) also explored emotional presence, through the components of perception, expression, and management, arguing it requires its own attention. anderson ( ) suggested agency be added as a fourth presence. agency also is relevant to the often-ignored conative domain (reeves, ) , which emphasizes the development of a learner's self-regulation. beardall et al. ( ) and blanc ( ) our proposed concept of aesthetic presence does not suggest a fourth, separate domain within the coi framework. rather, when deconstructing our online and hybrid graduate learning experience, it became clear that there was something missing in the coi model, both when explicitly teaching cats and other courses. our experience indicated that attending to the aesthetic dimension of online learning enhanced all three domains. the skillful use of images, sound/music, poetry, video and audio logs, and performances, for example, offered teachers and students multiple approaches to communicate and express themselves (teaching presence), open j o u r n a l p r e -p r o o f up and engage with concepts (cognitive presence), and interact with one another (social presence) (see fig ) . by paying attention to the use of arts and aesthetics, learning often resulted in rich dialogue, particularly when students were learning about sensitive topics (e.g., course material focused on privilege and oppression in the therapeutic relationship). indeed, parrish ( ) describes aesthetic experiences as "heightened, immersive, and particularly meaningful ones" and that they are "important to us because they demonstrate the expressive power of life" (p. ). this is not to suggest that text-based feedback cannot build an effective learning community; however, the use of technologies that take advantage of a multi-sensorial learning environment have been shown to increase a sense of community for students online (kumar et al., ) . for example, a study conducted on the use of asynchronous audio feedback in online learning found that audio feedback was more effective than text-based feedback for conveying nuance and was associated with students' feelings of increased involvement and learning community interactions, increased retention of content, and perceptions of care about the student (ice et al., ) . in this study, students were three times more likely to apply content when audio commenting was provided than when text commenting only was provided, suggesting greater engagement with the course's content. to this end, we propose a definition for aesthetic presence and suggest how it might be applied in online learning environments in order to enhance learning experience. aesthetic presence involves a dynamic interplay of symbols, metaphors, and multisensory technologies to facilitate a complex representation of experience wherein imagination, cognition, and affect are optimally engaged. as previous literature has suggested, attention to the use of j o u r n a l p r e -p r o o f enactive, iconic, symbolic, embodied, and other sensory strategies may animate conversation, foster openness and connection, encourage flexibility and critical thinking, and facilitate conversations about emergent and emotionally difficult themes. aesthetic presence can be embodied in the instructor's approach, embedded in face to face, hybrid, and online course design, included in curricular activities and assignments, and fostered in and between students. in this section, we describe the necessary institutional commitment to acquire and use adequate technology to support online learning with a view to enhance aesthetic presence. we then include examples drawn from our own experiences designing and instructing courses to offer possibilities for cultivating an aesthetic presence in the virtual classroom. these serve as examples of how cognitive, social, and teaching presence can be enhanced by the arts. we are living in a visual economy where affect, experience, and content are communicated through animation, video, and biometrics. perhaps it is not surprising then that, while traditional instructional design models and literature are lacking in this area, recent literature in instructional design emphasizes the value of the aesthetic experience. as our capacities to capture and share images and video have become increasingly commonplace, our capabilities in online learning have been transformed (nakamura, ) . the relative ease with which one can now incorporate aesthetic presence into online and blended teaching has directly benefited from available technologies that readily allow for audio recordings, video recordings, image sharing, and live interaction time. today's learners can easily take photos or video and upload those multimedia objects to share with others through an ever-growing number of social media platforms, and can j o u r n a l p r e -p r o o f do so privately within the instructional experience if tools provided by the institution are able to support this. for example, investment in key platforms that integrate with learning management systems to support students and faculty in integrating multimedia and video into the learning experience seamlessly and privately such as voicethread (multimedia), kaltura (video streaming), and livetext (eportfolio) are recommended. because the tools are integrated into the learning management system and were selected because of their intuitive user interface, little technical expertise is required for either instructors or students to use these tools. ensuring that technology decision-making is aligned with instructional needs is a component of the decision-making process for acquiring technology tools to support instruction. and a conceptual and technical skill-set in aesthetics, the online environment is greatly enhanced. for example, learners and instructors need to be attentive to the environment and background in which they are recording video to ensure that it does not distract from their message. similarly, they need basic orientation in framing an image to ensure they capture critical visual data and in basic audio to ensure that the audio is adequate for the instructional audience. finally, a commitment to aesthetic presence should inform the design of the user interface in online learning platforms. from our perspective, a beautifully laid out, intuitive interface communicates care for the learning experience that will unfold and enhances an online community learning environment. when moving from a face-to-face to virtual instructional context, one of the biggest challenges is creating opportunities for immediacy and emotional engagement. the emotions embodied in the learning process can range from: positive emotions that motivate learners and enhance creative thinking, to negative emotions (such as situational anxiety) which, if not managed j o u r n a l p r e -p r o o f well, can undermine the learning process. meyer and jones ( ) articulate the ways in which technology might inhibit affective engagement and, more critically, engagement in the learning process as a whole. they write, "email, for example, works against the individual's ability to perceive accurately the other's emotional state because the other person cannot be seen or felt, thereby muting empathy and perhaps providing an explanation of the "online disinhibition effect," which occurs when one does not deal face-to-face with the effects of one's rudeness (p. ). the use of emojis, emoticons, and other forms of affective representation have recently been assessed for their utility in online learning. as dunlap and colleagues ( ) wrote, one way people make up for the lack of nonverbal behaviors and cues in primarily textbased environments is by using paralanguage, specifically emoticons. [...]for instance, people use :-) to show that they are happy or smiling. when used in text-based emc (e.g., email, threaded discussion forums, texting, social networking), emoticons function as textual representations of the nonverbal behaviors and cues prevalent in face-to-face communication, designed to convey clarity of intent and emotion in efficient, direct, and transparent ways. (p. ) emoticons may serve to facilitate a nuanced exchange between students and may be used to instill a sense of humor in the virtual classroom, as well as provide cues to both instructors and students of embodied, affective aspects of learning. similarly, orr ( ) has also suggested the use of emoticons and textually based description of body language or emotions when providing distance supervision. additionally, meyer and jones ( ) offered a synthesis of the use of humor in online courses in order to increase: learning, motivation for participation, enjoyment, and social bonding, and the sense of "bringing life" to the community. recognizing that laughter is less common online than in a face to face setting, meyer and jones ( ) called for a better understanding in how people "go online and feel emotion, including laughter and anger" (p. ). goodboy et al. ( ) introduced the concept of instructional humor processing theory, which posits that humor connected to course content may be motivating; whereas other types of humor j o u r n a l p r e -p r o o f might be distracting and interfere with learning. rourke et al. ( ) discussed the importance of humor and the expression of emotions in order to help instructors establish a social presence that is ideal for online learning. from a practical standpoint, this involves investing in user interfaces that permit the use of emoticons and avatars. it also means that online education may necessarily need to make use of personalized learning environments (phones, tablets, ipads, etc.) that permit an exchange of advanced personalized emotion technology such as bitmoji which are personalized avatars (dabbagh & kitsantas, ; walton, ) . sajnani ( ) used bitmojis to explore landy's notion of role, counter-role, and guide in drama therapy. in the online classroom, one of the authors (ns), used this strategy to explore identity which seemed to be motivating in that students found it fun to create and share. opportunities to cultivate affective immediacy and humor in online learning begins with the tone set by initial communications and assignments through the modeling of the instructor. when facilitating online learning, we have found that modeling the use of emoticons and/or textual descriptions of nonverbal affective cues early on in the semester helps to facilitate broader adoption of interweaving emotional cues in the online space. the use of icebreakers in online learning is already a best practice (chlup & collins, ; goodyear et al, ; mcgrath et al, ) . however, icebreakers also present an excellent opportunity for students to interact using a full range of multisensory technologies. for example, the instructor might assign a "check in" or introduction assignment in which students are invited to upload a written paragraph along with a video or image of a cartoon, photograph, dance, song, comic strip, or poem that represents something about who they are or why they have chosen to take a particular course. another icebreaker example used by one of the authors (cm) at the beginning of a synchronous virtual class was to ask attendees to make a sound and movement over j o u r n a l p r e -p r o o f video to demonstrate how they were feeling about their capstone research project. members of class portrayed a wide range of movements, sounds, and affect that demonstrated some levels of stress. as they witnessed the others in the class and themselves making these sounds and movements, many burst into spontaneously laughter and verbally reflected feeling both more connected to their classmates and their bodies. this permission for play, embodiment, and affect expression through an icebreaker also allowed students to engage with the research content of that lesson with more presence and engagement. in this example, the instructor also intentionally chose to make a sound and movement from her position teaching the course, which students reflected as important in demystifying the process of research and writing. indeed, instructors are encouraged to create their own arts-based introductions in order to model risk taking and to enhance their teaching and social presence online. having the instructor engage with the same artful assignments asked of students can cultivate a sense of trust. as lowenthal and dunlap ( ) suggest, the distance barriers can, "dull or even nullify online instructors' humannesstheir emotion, humor, sympathy, and empathy. these human qualities, established through personal sharing, help students develop a sense of trust in and connection with an instructor, which is foundational for cultivating the social presence needed" (p. ). their experiments with the use of digital storytelling and self-disclosure from the instructor and embedded throughout assignments in the course facilitated a deeper and more meaningful social presence and served to decrease the sense of isolation often articulated by many online learners. further, humor can forge bonds between classmates, deepen one's curiosity and desire to learn, aid in the retention of information, and help students to tolerate "difficult" or emotionally contentious learning material (anderson, ; bacay, ; shatz & loschiavo, ; stambo, ) . intentionally selecting some materials that include humor as part of the teaching method j o u r n a l p r e -p r o o f can be particularly effective when teaching online about potentially emotionally-loaded topics. for example, in a course that included content learning about racial microaggressions, one of the authors (cm) blended a traditional scholarly article (sue et al., ) with a buzzfeedyellow video that addresses similar content through humor and role reversal (boldly, ) . the instructor asked students to consider reflecting on the difference in their learning when reading the article versus the humorous video. their responses indicated that both were important and that the video made it possible for them to remain focused and able to engage with each other about what many agreed was difficult material. of course, humor and emotional expression are both culturally constructed and embedded, therefore, instructors should approach their use of humor from a critical and cross-cultural perspective in terms of difference, power, and social norms. for further reading on this topic, see bell ( ) , ellingson ( ) , and lu, martin, usova and galinsky ( ). teaching might be best understood through the metaphor of performance, where aspects like role, affect, embodiment, voice, delivery, and play are critical in engaging the imaginations and curiosity of the "audience" of students (lessinger & gillis, ; sawyer, ; timpson & tobin, ) . in an online setting, there is greater risk of the instructor becoming a faceless, lifeless entity, providing little in the way of performance in order to energize and enrich the learning environment. further, because of changes to technology, there is a shift in the expectation from learners about the manner in which they will engage with their instructors and peers. page et al. ( ) noted the shift in user expectation stating, "they do not want to stay in a passive role with different media… they want active participation and emotional engagement, to manipulate the presented objects and expect a degree of emotion and interactivity" (p. ). indeed, we have j o u r n a l p r e -p r o o f observed an increase in the expectations of learners engaging in online and blended instruction who anticipate interacting with the instructor authentically and through a range of media. incorporating improvisation makes it possible to avoid a deadened delivery in online settings where pre-recorded lectures, pre-scripted written materials, and rigidly scheduled online discussions and interactions are the norm. this is not to say that structured practices are not useful. rather, as sawyer ( sawyer ( , observed, disciplined innovation involves an interplay between repeating routines and improvised interaction. expected activities online provide a strong foundation from which creative improvisation and flexibility might emerge. similarly, in improvisation forms (dramatic form, jazz, etc), a set structure (or melody in the jazz metaphor) provides the steady beat against which creative and spontaneous moments can be created. from a practical perspective, aesthetic presence in online teaching includes a range of strategies. having clear expectations and schedules for learners is important, but should not preclude opportunities for improvisation, which keep the energy and engagement high. for example, in one course design, the instructors (ns & cm) created a schedule where a student was designated as a weekly discussion leader on the assigned readings and was responsible for posting a question for their classmates to answer within a designated time frame. by having the students create the questions, rather than the instructor, this structure maintained a sense of "new-ness." this approach also privileges a multiplicity of perspectives and voices, encouraging the instructor to respond in an improvised way to the flow of largely text-based discussions. in another example, students were invited to create an artistic response to the weekly readings and to use that as a common reference point for complex ideas conveyed in the assigned readings. the aesthetics of instruction involve a dance between offering framing or additional thoughts, probing questions, additional perspectives, summaries, and space for others to participate (mazzolini & maddison, j o u r n a l p r e -p r o o f ). depending on the topic of the course, instructors may incorporate additional articles, videos, art-making or news items that are related to the weekly content which also ensure that courses that are repeatedly taught each year are met with a renewed sense of purpose and content. live improvisation through synchronous video also heightens engagement. using programs such as periscope, youtube live, and facebook live make it possible for students to interact immediately with course content. another faculty member at the same university, angelica pinna-perez, held monthly gatherings to enable on-campus and low residency students to form community and interact. these 'create on the th' sessions involved live streaming from a maker space in which on campus students were engaged in making art, writing, singing, and reading their own poetry while other students participated from their respective locations (beardall et al., ) . we suggest that course design and instructors that experiment with ways in which the arts and multi-sensory technologies might offer new possibilities for engaging learners. the arts can encourage students to participate in praxis wherein personal experience is brought to into conversation with the material presented, applied, and reflected upon. in one class, filming weekly video lectures made it possible to not only frame the topic and the required readings for the week, but also modeled self-reflexivity and the use of personal experience as the beginning of learning. when teaching a module on religion and spirituality in the arts therapies, one of the assigned readings discussed the role of music and religion. as part of the introductory video for that module, the instructor (cm) included a brief story about her grandmother who had been quite ill for several months before her death, where playing hymns at her bedside resulted in an increased orientation to time and space, a brightening of affect, and less discomfort. sharing this story with j o u r n a l p r e -p r o o f students provided a concrete example of some of the intersecting dynamics of aging, music, religion, and pain, worked to enhance the instructor's social presence online, and encouraged students to make the material they were reading meaningful. students were invited to share their own stories about religion and music in relation to the assigned readings, with multiple students uploading musical audio clips alongside their video or textual storytelling. in another course pertaining to trauma and recovery in the context of global mental health, the instructor (ns) asked participants, all of whom were health care providers or humanitarian aid specialists, to create a video in which they used images, music, and/or video to communicate how they contributed to a healing environment. despite their initial hesitation, students almost unanimously proclaim this to be one of the best aspects of the course each year, commenting that the creative process of selecting and editing images, sound, and footage facilitated their reflection on this important topic. collaborative art making also facilitates cognitive connections in the online classroom and opportunities should be woven throughout courses. in general, small groups create the opportunity for students to commit to their colleagues and allow learners to problem-solve collectively (fink, ) . group work promotes positive interdependence, social skills, verbal interaction, individual accountability and group processing (kaufman et al., ) , all of which can be better supported in online instruction through the incorporation of aesthetic presence. indeed, part of the work of instructional design and delivery is including opportunities for cognitive capacities to be strengthened alongside social and emotional capacities, which can be enhanced through the use of the arts and aesthetic presence. from an implementation perspective, for team-based learning to work well, teams should be assigned early in order to anticipate and plan for working together on specific assignments. similarly for these types of group projects, it is important to orient learners to a variety of tools j o u r n a l p r e -p r o o f that might aid their collaboration, including, but not limited to, options for their own synchronous collaboration space online (e.g., through zoom, microsoft teams, blackboard collaborate, adobe connect, google docs). ideally, team-based cooperative projects are scaffolded so that there are regular check-ins and adequate time in between those check-ins for groups to convene and make forward progress on their collective work (paulus, ) or students can be guided in strategies for collaboration on project co-creation. if the final product is an academic paper or text-based project, including a visual representation of the work as part of the final deliverables can effectively support learners in demonstrating their own use of aesthetic presence. for example, a hybrid course (designed by ns and taught by ns and cm), included a group project focusing on cultural literacy. groups of - participants were formed during the inperson residency and presented their final work later in the semester online. in this assignment, group members chose a film or television show addressing issues relating to identity and were asked to critically analyze their chosen media through the concepts of power, privilege, and oppression. they were then asked to represent their collaboration and their perspectives through a co-created work of art (music, imagery, video with movement, etc.) and to then present this artwork in a minute presentation using voicethread. this technology made it possible to present their artwork, slides, and an oral presentation in a single platform. other students were able to leave audio feedback which heightened the sense of interactivity in the class. for example, one group (taught by cm) focused their presentation on what is gained and potentially lost in crosscultural communication used their art as a way to engage and demonstrate this learning. one group member created a piece of visual art and sent it to the next member electronically with no explanation of their piece. the next member witnessed this visual art piece and filmed a dance/movement video based on their own reaction to the original film and the visual art piece j o u r n a l p r e -p r o o f they were sent. the third and final member watched this dance/movement video and created their own poem in response to the original film and the film that was created by their teammate. in their voicethread presentation, this group uploaded all three arts pieces and then discussed the intention behind their individual art-making, how they viewed their teammate's piece, and moments of disagreement, surprise, or new learning in hearing what they others had taken from their artmaking, all serving as a beautiful example of what assumptions arise about another and potential challenges and growth opportunities in cross-cultural communication. this assignment required that students not only engage with one another, but also to do so creatively and collaboratively through arts processing, in order to heighten engagement with the material and foster a community of learning. in course evaluations, students regularly highlight this project as a way to interweave new learning with aesthetic processing, as well as an opportunity to connect with other students. what differentiates the creative arts therapies from traditional forms of psychotherapy is that this practice unfolds within an aesthetic frame. aesthetic engagement should, therefore, be reinforced within the process of learning in both in-person and online settings. a stronger integration of the arts in classroom instruction and online may also encourage students to retain their unique aesthetic sensibilities in practice, especially in environments dominated by verbal or textual intervention. the integration of various modes of symbolic communication also increases access to learning for different kinds of learners. while two of the three authors are educators within the creative arts therapies, aesthetic presence should not be seen as limited to courses that explicitly involve the arts. rather, aesthetic presence should be considered in design, instruction, and delivery for any subject area. in the context of remote education, conscious attention to aesthetic presence in online teaching and learning may help to mitigate disengagement and j o u r n a l p r e -p r o o f enhance existing cognitive, social, and teaching presences. finally, we believe that aesthetic presence is something that each of us will need to cultivate in this new era marked by social distance. it is therefore critical that we continue to innovate ways of creating and sustaining holistic, multi-sensory learning environments and assess their impact in the training of creative arts therapists from the perspective of educators, practitioners, students, and those we serve. treated in school-based settings, and the use of the arts as a way of knowing. she is an adjunct professor at wilfrid laurier and in the low-residency program at lesley university. christine is the associate editor of drama therapy review. heather tillberg-webb, phd is the associate vice president of academic resources and technology at southern new hampshire university, where she oversees the strategic implementation 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of inquiry: instructor perspectives and challenges do you even bitmoji? reify media incorporating the aesthetic dimension into pedagogy udl on campus (n.d.). udl in higher education bringing my body into my body of knowledge as a dance/movement therapy educator bct is associate professor and director of the program in drama therapy and the theatre & health lab at new york university. she is the editor of drama therapy review phd candidate, ma, bct/rdt is a drama therapist and phd candidate at wilfrid laurier university where she specializes in the racialization of how trauma is defined and key: cord- -e jb sex authors: fourcade, marion; johns, fleur title: loops, ladders and links: the recursivity of social and machine learning date: - - journal: theory soc doi: . /s - - -x sha: doc_id: cord_uid: e jb sex machine learning algorithms reshape how people communicate, exchange, and associate; how institutions sort them and slot them into social positions; and how they experience life, down to the most ordinary and intimate aspects. in this article, we draw on examples from the field of social media to review the commonalities, interactions, and contradictions between the dispositions of people and those of machines as they learn from and make sense of each other. a fundamental intuition of actor-network theory holds that what we call "the social" is assembled from heterogeneous collections of human and non-human "actants." this may include human-made physical objects (e.g., a seat belt), mathematical formulas (e.g., financial derivatives), or elements from the natural world-such as plants, microbes, or scallops (callon ; latour latour , . in the words of bruno latour ( , p . ) sociology is nothing but the "tracing of associations." "tracing," however, is a rather capacious concept: socio-technical associations, including those involving non-human "actants," always crystallize in concrete places, structural positions, or social collectives. for instance, men are more likely to "associate" with video games than women (bulut ) . furthermore, since the connection between men and video games is known, men, women and institutions might develop strategies around, against, and through it. in other words, techno-social mediations are always both objective and subjective. they "exist … in things and in minds … outside and inside of agents" (wacquant , p. ) . this is why people think, relate, and fight over them, with them, and through them. all of this makes digital technologies a particularly rich terrain for sociologists to study. what, we may wonder, is the glue that holds things together at the automated interface of online and offline lives? what kind of subjectivities and relations manifest on and around social network sites, for instance? and how do the specific mediations these sites rely upon-be it hardware, software, human labor-concretely matter for the nature and shape of associations, including the most mundane? in this article, we are especially concerned with one particular kind of associative practice: a branch of artificial intelligence called machine learning. machine learning is ubiquitous on social media platforms and applications, where it is routinely deployed to automate, predict, and intervene in human and non-human behavior. generally speaking, machine learning refers to the practice of automating the discovery of rules and patterns from data, however dispersed and heterogeneous it may be, and drawing inferences from those patterns, without explicit programming. using examples drawn from social media, we seek to understand the kinds of social dispositions that machine learning techniques tend to elicit or reinforce; how these social dispositions, in turn, help to support according to pedro domingos's account, approaches to machine learning may be broken down into five "tribes." symbolists proceed through inverse deduction, starting with received premises or known facts and working backwards from those to identify rules that would allow those premises or facts to be inferred. the algorithm of choice for the symbolist is the decision tree. connectionists model machine learning on the brain, devising multilayered neural networks. their preferred algorithm is backpropagation, or the iterative adjustment of network parameters (initially set randomly) to try to bring that network's output closer and closer to a desired result (that is, towards satisfactory performance of an assigned task). evolutionaries canvas entire "populations" of hypotheses and devise computer programs to combine and swap these randomly, repeatedly assessing these combinations' "fitness" by comparing output to training data. their preferred kind of algorithm is the so-called genetic algorithm designed to simulate the biological process of evolution. bayesians are concerned with navigating uncertainty, which they do through probabilistic inference. bayesian models start with an estimate of the probability of certain outcomes (or a series of such estimates comprising one or more hypothetical bayesian network(s)) and then update these estimates as they encounter and process more data. analogizers focus on recognizing similarities within data and inferring other similarities on that basis. two of their go-to algorithms are the nearest-neighbor classifier and the support vector machine. the first makes predictions about how to classify unseen data by finding labeled data most similar to that unseen data (pattern matching). the second classifies unseen data into sets by plotting the coordinates of available or observed data according to their similarity to one another and inferring a decision boundary that would enable their distinction. machine learning implementations; and what kinds of social formations these interactions give rise to-all of these, indicatively rather than exhaustively. our arguments are fourfold. in the first two sections below, we argue that the accretive effects of social and machine learning are fostering an ever-more-prevalent hunger for data, and searching dispositions responsive to this hunger -"loops" in this paper's title. we then show how interactions between those so disposed and machine learning systems are producing new orders of stratification and association, or "ladders" and "links", and new stakes in the struggle in and around these orders. the penultimate section contends that such interactions, through social and mechanical infrastructures of machine learning, tend to engineer competition and psycho-social and economic dependencies conducive to evermore intensive data production, and hence to the redoubling of machine-learned stratification. finally, before concluding, we argue that machine learning implementations are inclined, in many respects, towards the degradation of sociality. consequently, new implementations are been called upon to judge and test the kind of solidaristic associations that machine learned systems have themselves produced, as a sort of second order learning process. our conclusion is a call to action: to renew, at the social and machine learning interface, fundamental questions of how to live and act together. the things that feel natural to us are not natural at all. they are the result of long processes of inculcation, exposure, and training that fall under the broad concept of "socialization" or "social learning." because the term "social learning" helps us better draw the parallel with "machine learning," we use it here to refer to the range of processes by which societies and their constituent elements (individuals, institutions, and so on) iteratively and interactively take on certain characteristics, and exhibit change-or not-over time. historically, the concept is perhaps most strongly associated with theories of how individuals, and specifically children, learn to feel, act, think, and relate to the world and to each other. theories of social learning and socialization have explained how people come to assume behaviors and attitudes in ways not well captured by a focus on internal motivation or conscious deliberation (miller and dollard ; bandura ; mauss ; elias ) . empirical studies have explored, for instance, how children learn speech and social grammar through a combination of direct experience (trying things out and experiencing rewarding or punishing consequences) and modeling (observing and imitating others, especially primary associates) (gopnik ). berger and luckmann ( ) , relying on the work of george herbert mead, discuss the learning process of socialization as one involving two stages: in the primary stage, children form a self by internalizing the attitudes of those others with whom they entertain an emotional relationship (typically their parents); in the secondary stage, persons-in-becoming learn to play appropriate roles in institutionalized subworlds, such as work or school. pierre bourdieu offers a similar approach to the formation of habitus. as a system of dispositions that "generates meaningful practices and meaning-giving perceptions," habitus takes shape through at least two types of social learning: "early, imperceptible learning" (as in the family) and "scholastic...methodical learning" (within educational and other institutions) (bourdieu , pp. , ) . organizations and collective entities also learn. for instance, scholars have used the concept of social learning to understand how states, institutions, and communities (at various scales) acquire distinguishing characteristics and assemble what appear to be convictions-in-common. ludwik fleck ( fleck ( [ ) and later thomas kuhn ( ) famously argued that science normally works through adherence to common ways of thinking about and puzzling over problems. relying explicitly on kuhn, hall ( ) makes a similar argument about elites and experts being socialized into long lasting political and policy positions. collective socialization into policy paradigms is one of the main drivers of institutional path dependency, as it makes it difficult for people to imagine alternatives. for our purposes, social learning encapsulates all those social processes-material, institutional, embodied, and symbolic-through which particular ways of knowing, acting, and relating to one another as aggregate and individuated actants are encoded and reproduced, or by which "[e]ach society [gains and sustains] its own special habits" (mauss , p. ) . "learning" in this context implies much more than the acquisition of skills and knowledge. it extends to adoption through imitation, stylistic borrowing, riffing, meme-making, sampling, acculturation, identification, modeling, prioritization, valuation, and the propagation and practice of informal pedagogies of many kinds. understood in this way, "learning" does not hinge decisively upon the embodied capacities and needs of human individuals because those capacities and needs are only ever realized relationally or through "ecological interaction," including through interaction with machines (foster ) . it is not hard to see why digital domains, online interactions, and social media networks have become a privileged site of observation for such processes (e.g., greenhow and robelia ), all the more so since socialization there often starts in childhood. this suggests that (contra dreyfus ) social and machine learning must be analyzed as co-productive of, rather than antithetical to, one another. machine learning is, similarly, a catch-all term-one encompassing a range of ways of programming computers or computing systems to undertake certain tasks (and satisfy certain performance thresholds) without explicitly directing the machines in question how to do so. instead, machine learning is aimed at having computers learn (more or less autonomously) from preexisting data, including the data output from prior attempts to undertake the tasks in question, and devise their own ways of both tackling those tasks and iteratively improving at them (alpaydin ) . implementations of machine learning now span all areas of social and economic life. machine learning "has been turning up everywhere, driven by exponentially growing mountains of [digital] data" (domingos ) . in this article, we take social media as one domain in which machine learning has been widely implemented. we do so recognizing that not all data analysis in which social media platforms engage is automated, and that those aspects that are automated do not necessarily involve machine learning. two points are important for our purposes: most "machines" must be trained, cleaned, and tested by humans in order to "learn." in implementations of machine learning on social media platforms, for instance, humans are everywhere "in the loop"-an immense, poorly paid, and crowdsourced workforce that relentlessly labels, rates, and expunges the "content" to be consumed (gillespie ; gray and suri ) . and yet, both supervised and unsupervised machines generate new patterns of interpretation, new ways of reading the social world and of intervening in it. any reference to machine learning throughout this article should be taken to encapsulate these "more-thanhuman" and "more-than-machine" qualities of machine learning. cybernetic feedback, data hunger, and meaning accretion analogies between human (or social) learning and machine-based learning are at least as old as artificial intelligence itself. the transdisciplinary search for common properties among physical systems, biological systems, and social systems, for instance, was an impetus for the macy foundation conferences on "circular causal and feedback mechanisms in biology and social systems" in the early days of cybernetics ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) . in the analytical model developed by norbert wiener, "the concept of feedback provides the basis for the theoretical elimination of the frontier between the living and the non-living" (lafontaine , p. ) . just as the knowing and feeling person is dynamically produced through communication and interactions with others, the ideal cybernetic system continuously enriches itself from the reactions it causes. in both cases, life is irrelevant: what matters, for both living and inanimate objects, is that information circulates in an everrenewed loop. put another way, information/computation are "substrate independent" (tegmark , p. ). wiener's ambitions (and even more, the exaggerated claims of his posthumanist descendants, see, e.g., kurzweil ) were immediately met with criticism. starting in the s, philosopher hubert dreyfus arose as one of the main critics of the claim that artificial intelligence would ever approach its human equivalent. likening the field to "alchemy" ( ), he argued that machines would never be able to replicate the unconscious processes necessary for the understanding of context and the acquisition of tacit skills ( , )-the fact that, to quote michael polanyi ( ) , "we know more than we can tell." in other words, machines cannot develop anything like the embodied intuition that characterizes humans. furthermore, machines are poorly equipped to deal with the fact that all human learning is cultural, that is, anchored not in individual psyches but in collective systems of meaning and in sedimented, relational histories (vygotsky ; bourdieu ; durkheim ; hasse ) . is this starting to change today when machines successfully recognize images, translate texts, answer the phone, and write news briefs? some social and computational scientists believe that we are on the verge of a real revolution, where machine learning tools will help decode tacit knowledge, make sense of cultural repertoires, and understand micro-dynamics at the individual level (foster ). our concern is not, however, with confirming or refuting predictive claims about what computation can and cannot do to advance scholars' understanding of social life. rather, we are interested in how social and computational learning already interact. not only may social and machine learning usefully be compared, but they are reinforcing and shaping one another in practice. in those jurisdictions in which a large proportion of the population is interacting, communicating, and transacting ubiquitously online, social learning and machine learning share certain tendencies and dependencies. both practices rely upon and reinforce a pervasive appetite for digital input or feedback that we characterize as "data hunger." they also share a propensity to assemble insight and make meaning accretively-a propensity that we denote here as "world or meaning accretion." throughout this article, we probe the dynamic interaction of social and machine learning by drawing examples from one genre of online social contention and connection in which the pervasive influence of machine learning is evident: namely, that which occurs across social media channels and platforms. below we explain first how data hunger is fostered by both social and computing systems and techniques, and then how world or meaning accretion manifests in social and machine learning practices. these explanations set the stage for our subsequent discussion of how these interlocking dynamics operate to constitute and distribute power. data hunger: searching as a natural attitude as suggested earlier, the human person is the product of a long, dynamic, and never settled process of socialization. it is through this process of sustained exposure that the self (or the habitus, in pierre bourdieu's vocabulary) becomes adjusted to its specific social world. as bourdieu puts it, "when habitus encounters a social world of which it is the product, it is like a 'fish in water': it does not feel the weight of the water, and it takes the world about itself for granted" (bourdieu in wacquant , p. ) . the socialized self is a constantly learning self. the richer the process-the more varied and intense the interactions-the more "information" about different parts of the social world will be internalized and the more socially versatile-and socially effective, possibly-the outcome. (this is why, for instance, parents with means often seek to offer "all-round" training to their offspring [lareau ]) . machine learning, like social learning, is data hungry. "learning" in this context entails a computing system acquiring capacity to generalize beyond the range of data with which it has been presented in the training phase. "learning" is therefore contingent upon continuous access to data-which, in the kinds of cases that preoccupy us, means continuous access to output from individuals, groups, and "bots" designed to mimic individuals and groups. at the outset, access to data in enough volume and variety must be ensured to enable a particular learnermodel combination to attain desired accuracy and confidence levels. thereafter, data of even greater volume and variety is typically (though not universally) required if machine learning is to deliver continuous improvement, or at least maintain performance, on assigned tasks. the data hunger of machine learning interacts with that of social learning in important ways. engineers, particularly in the social media sector, have structured machine learning technologies not only to take advantage of vast quantities of behavioral traces that people leave behind when they interact with digital artefacts, but also to solicit more through playful or addictive designs and cybernetic feedback loops. the machine-learning self is not only encouraged to respond more, interact more, and volunteer more, but also primed to develop a new attitude toward the acquisition of information (andrejevic , p. ). with the world's knowledge at her fingertips, she understands that she must "do her own research" about everything-be it religion, politics, vaccines, or cooking. her responsibility as a citizen is not only to learn the collective norms, but also to know how to search and learn so as to make her own opinion "for herself," or figure out where she belongs, or gain new skills. the development of searching as a "natural attitude" (schutz ) is an eminently social process of course: it often means finding the right people to follow or emulate (pariser ) , using the right keywords so that the search process yields results consistent with expectations (tripodi ) , or implicitly soliciting feedback from others in the form of likes and comments. the social media user also must extend this searching disposition to her own person: through cybernetic feedback, algorithms habituate her to search for herself in the data. this involves looking reflexively at her own past behavior so as to inform her future behavior. surrounded by digital devices, some of which she owns, she internalizes the all-seeing eye and learns to watch herself and respond to algorithmic demands (brubaker ). data hunger transmutes into self-hunger: an imperative to be digitally discernible in order to be present as a subject. this, of course, exacts a kind of self-producing discipline that may be eerily familiar to those populations that have always been under heavy institutional surveillance, such as the poor, felons, migrants, racial minorities (browne ; benjamin ) , or the citizens of authoritarian countries. it may also be increasingly familiar to users of health or car insurance, people living in a smart home, or anyone being "tracked" by their employer or school by virtue of simply using institutionally licensed it infrastructure. but the productive nature of the process is not a simple extension of what michel foucault called "disciplinary power" nor of the self-governance characteristic of "governmentality." rather than simply adjusting herself to algorithmic demands, the user internalizes the injunction to produce herself through the machine-learning-driven process itself. in that sense the machine-learnable self is altogether different from the socially learning, self-surveilling, or self-improving self. the point for her is not simply to track herself so she can conform or become a better version of herself; it is, instead, about the productive reorganization of her own experience and self-understanding. as such, it is generative of a new sense of selfhood-a sense of discovering and crafting oneself through digital means that is quite different from the "analog" means of self-cultivation through training and introspection. when one is learning from a machine, and in the process making oneself learnable by it, mundane activities undergo a subtle redefinition. hydrating regularly or taking a stroll are not only imperatives to be followed or coerced into. their actual phenomenology morphs into the practice of feeding or assembling longitudinal databases and keeping track of one's performance: "step counting" and its counterparts (schüll ; adams ) . likewise, what makes friendships real and defines their true nature is what the machine sees: usually, frequency of online interaction. for instance, snapchat has perfected the art of classifying-and ranking-relationships that way, so people are constantly presented with an ever-changing picture of their own dyadic connections, ranked from most to least important. no longer, contra foucault ( ) , is "permanent self-examination" crucial to self-crafting so much as attention to data-productive practices capable of making the self learnable and sustaining its searching process. to ensure one's learnability-and thereby one's selfhood-one must both feed and reproduce a hunger for data on and around the self. human learning is not only about constant, dynamic social exposure and world hunger, it is also about what we might call world or meaning accretion. the self is constantly both unsettled (by new experiences) and settling (as a result of past experiences). people take on well institutionalized social roles (berger and luckmann ) . they develop habits, styles, personalities-a "system of dispositions" in bourdieu's vocabulary-by which they become adjusted to their social world. this system is made accretively, through the conscious and unconscious sedimentation of social experiences and interactions that are specific to the individual, and variable in quality and form. accretion here refers to a process, like the incremental build-up of sediment on a riverbank, involving the gradual accumulation of additional layers or matter. even when change occurs rapidly and unexpectedly, the ongoing process of learning how to constitute and comport oneself and perform as a social agent requires one to grapple with and mobilize social legacies, social memory, and pre-established social norms (goffman ) . the habitus, bourdieu would say, is both structured and structuring, historical and generative. social processes of impression formation offer a good illustration of how social learning depends upon accreting data at volume, irrespective of the value of any particular datum. the popular insight that first impressions matter and tend to endure is broadly supported by research in social psychology and social cognition (uleman and kressel ) . it is clear that impressions are formed cumulatively and that early-acquired information tends to structure and inform the interpretation of information later acquired about persons and groups encountered in social life (hamilton and sherman ) . this has also been shown to be the case in online environments (marlow et al. ) . in other words, social impressions are constituted by the incremental build-up of a variegated mass of data. machine learning produces insight in a somewhat comparable way-that is, accretively. insofar as machine learning yields outputs that may be regarded as meaningful (which is often taken to mean "useful" for the task assigned), then that "meaning" is assembled through the accumulation of "experience" or from iterative exposure to available data in sufficient volume, whether in the form of a stream or in a succession of batches. machine learning, like social learning, never produces insight entirely ab initio or independently of preexisting data. to say that meaning is made accretively in machine learning is not to say that machine learning programs are inflexible or inattentive to the unpredictable; far from it. all machine learning provides for the handling of the unforeseen; indeed, capacity to extend from the known to the unknown is what qualifies machine learning as "learning." moreover, a number of techniques are available to make machine learning systems robust in the face of "unknown unknowns" (that is, rare events not manifest in training data). nonetheless, machine learning does entail giving far greater weight to experience than to the event. the more data that has been ingested by a machine learning system, the less revolutionary, reconfigurative force might be borne by any adventitious datum that it encounters. if, paraphrasing marx, one considers that people make their own history, but not in circumstances they choose for themselves, but rather in present circumstances given and inherited, then the social-machine learning interface emphasizes the preponderance of the "given and inherited" in present circumstances, far more than the potentiality for "mak[ing]" that may lie within them (marx (marx [ ). one example of the compound effect of social and automated meaning accretion in the exemplary setting to which we return throughout this articlesocial media-is the durability of negative reputation across interlocking platforms. for instance, people experience considerable difficulty in countering the effects of "revenge porn" online, reversing the harms of identity theft, or managing spoiled identities once they are digitally archived (lageson and maruna ) . as langlois and slane have observed, "[w]hen somebody is publicly shamed online, that shaming becomes a live archive, stored on servers and circulating through information networks via search, instant messaging, sharing, liking, copying, and pasting" (langlois and slane ) . in such settings, the data accretion upon which machine learning depends for the development of granular insights-and, on social media platforms, associated auctioning and targeting of advertising-compounds the cumulative, sedimentary effect of social data, making negative impressions generated by "revenge porn," or by one's online identity having been fraudulently coopted, hard to displace or renew. the truth value of later, positive data may be irrelevant if enough negative data has accumulated in the meantime. data hunger and the accretive making of meaning are two aspects of the embedded sociality of machine learning and of the "mechanical" dimensions of social learning. together, they suggest modes of social relation, conflict, and action that machine learning systems may nourish among people on whom those systems bear, knowingly or unknowingly. this has significant implications for social and economic inequality, as we explore below. what are the social consequences of machine learning's signature hunger for diverse, continuous, ever more detailed and "meaningful" data and the tendency of many automated systems to hoard historic data from which to learn? in this section, we discuss three observable consequences of data hunger and meaning accretion. we show how these establish certain non-negotiable preconditions for social inclusion; we highlight how they fuel the production of digitally-based forms of social stratification and association; and we specify some recurrent modes of relation fostered thereby. all three ordering effects entail the uneven distribution of power and resources and all three play a role in sustaining intersecting hierarchies of race, class, gender, and other modes of domination and axes of inequality. machine learning's data appetite and the "digestive" or computational abilities that attend it are often sold as tools for the increased organizational efficiency, responsiveness, and inclusiveness of societies and social institutions. with the help of machine learning, the argument goes, governments and non-governmental organizations develop an ability to render visible and classify populations that are traditionally unseen by standard data infrastructures. moreover, those who have historically been seen may be seen at a greater resolution, or in a more finelygrained, timely, and difference-attentive way. among international organizations, too, there is much hope that enhanced learning along these lines might result from the further utilization of machine learning capacities (johns ) . for instance, machine learning, deployed in fingerprint, iris, or facial recognition, or to nourish sophisticated forms of online identification, is increasingly replacing older, document-based ones (torpey )-and transforming the very concept of citizenship in the process (cheney-lippold ). whatever the pluses and minuses of "inclusiveness" in this mode, it entails a major infrastructural shift in the way that social learning takes place at the state and inter-state level, or how governments come to "know" their polities. governments around the world are exploring possibilities for gathering and analysing digital data algorithmically, to supplement-and eventually, perhaps, supersede-household surveys, telephone surveys, field site visits, and other traditional data collection methods. this devolves the process of assembling and representing a polity, and understanding its social and economic condition, down to agents outside the scope of public administration: commercial satellite operators (capturing satellite image data being used to assess a range of conditions, including agricultural yield and poverty), supermarkets (gathering scanner data, now widely used in cpi generation), and social media platforms. if official statistics (and associated data gathering infrastructures and labor forces) have been key to producing the modern polity, governmental embrace of machine learning capacities signals a change in ownership of that means of production. social media has become a key site for public and private parties-police departments, immigration agencies, schools, employers and insurers among others-to gather intelligence about the social networks of individuals, their health habits, their propensity to take risks or the danger they might represent to the public, to an organization's bottom line or to its reputation (trottier ; omand ; bousquet ; amoore ; stark ) . informational and power asymmetries characteristic of these institutions are often intensified in the process. this is notwithstanding the fact that automated systems' effects may be tempered by manual work-arounds and other modes of resistance within bureaucracies, such as the practices of frontline welfare workers intervening in automated systems in the interests of their clients, and strategies of foot-dragging and data obfuscation by legal professionals confronting predictive technologies in criminal justice (raso ; brayne and christin ) . the deployment of machine learning to the ends outlined in the foregoing paragraph furthers the centrality of data hungry social media platforms to the distribution of all sorts of economic and social opportunities and scarce public resources. at every scale, machine-learning-powered corporations are becoming indispensable mediators of relations between the governing and the governed (a transition process sharply accelerated by the covid- pandemic). this invests them with power of a specific sort: the power of "translating the images and concerns of one world into that of another, and then disciplining or maintaining that translation in order to stabilize a powerful network" and their own influential position within it (star , p. ) . the "powerful network" in question is society, but it is heterogeneous, comprising living and non-living, automated and organic elements: a composite to which we can give the name "society" only with impropriety (that is, without adherence to conventional, anthropocentric understandings of the term). for all practical purposes, much of social life already is digital. this insertion of new translators, or repositioning of old translators, within the circuits of society is an important socio-economic transformation in its own right. and the social consequences of this new "inclusion" are uneven in ways commonly conceived in terms of bias, but not well captured by that term. socially disadvantaged populations are most at risk of being surveilled in this way and profiled into new kinds of "measurable types" (cheney-lippold ). in addition, social media user samples are known to be non-representative, which might further unbalance the burden of surveillant attention. (twitter users, for instance, are skewed towards young, urban, minority individuals (murthy et al. ).) consequently, satisfaction of data hunger and practices of automated meaning accretion may come at the cost of increased social distrust, fostering strategies of posturing, evasion, and resistance among those targeted by such practices. these reactions, in turn, may undermine the capacity of state agents to tap into social data-gathering practices, further compounding existing power and information asymmetries (harkin ) . for instance, sarah brayne ( ) finds that government surveillance via social media and other means encourages marginalized communities to engage in "system avoidance," jeopardizing their access to valuable social services in the process. finally, people accustomed to being surveilled will not hesitate to instrumentalize social media to reverse monitor their relationships with surveilling institutions, for instance by taping public interactions with police officers or with social workers and sharing them online (byrne et al. ) . while this kind of resistance might further draw a wedge between vulnerable populations and those formally in charge of assisting and protecting them, it has also become a powerful aspect of grassroots mobilization in and around machine learning and techno-social approaches to institutional reform (benjamin ) . in all the foregoing settings, aspirations for greater inclusiveness, timeliness, and accuracy of data representation-upon which machine learning is predicated and which underlie its data hunger-produce newly actionable social divisions. the remainder of this article analyzes some recurrent types of social division that machine learning generates, and types of social action and experience elicited thereby. there is, of course, no society without ordering-and no computing either. social order, like computing order, comes in many shapes and varieties but generally "the gap between computation and human problem solving may be much smaller than we think" (foster , p. ) . in what follows, we cut through the complexity of this socialcomputational interface by distinguishing between two main ideal types of classification: ordinal (organized by judgments of positionality, priority, probability or value along one particular dimension) and nominal (organized by judgments of difference and similarity) (fourcade ) . social processes of ordinalization in the analog world might include exams, tests, or sports competitions: every level allows one to compete for the next level and be ranked accordingly. in the digital world, ordinal scoring might take the form of predictive analytics-which, in the case of social media, typically means the algorithmic optimization of online verification and visibility. by contrast, processes of nominalization include, in the analog world, various forms of homophily (the tendency of people to associate with others who are similar to them in various ways) and institutional sorting by category. translated for the digital world, these find an echo in clustering technologies-for instance a recommendation algorithm that works by finding the "nearest neighbors" whose taste is similar to one's own, or one that matches people based on some physical characteristic or career trajectory. the difference between ordinal systems and nominal systems maps well onto the difference between bayesian and analogical approaches to machine learning, to reference pedro domingos's ( ) useful typology. it is, however, only at the output or interface stage that these socially ubiquitous machine learning orderings become accessible to experience. what does it mean, and what does it feel like, to live in a society that is regulated through machine learning systems-or rather, where machine learning systems are interacting productively with social ordering systems of an ordinal and nominal kind? in this section, we identify some new, or newly manifest, drivers of social structure that emerge in machine learning-dominated environments. let us begin with the ordinal effects of these technologies (remembering that machine learning systems comprise human as well as non-human elements). as machine learning systems become more universal, the benefits of inclusion now depend less on access itself, and more on one's performance within each system and according to its rules. for instance, visibility on social media depends on "engagement," or how important each individual is to the activity of the platform. if one does not post frequently and consistently, comment or message others on facebook or instagram, or if others do not interact with one's posts, one's visibility to them diminishes quickly. if one is not active on the dating app tinder, one cannot expect one's profile to be shown to prospective suitors. similarly, uber drivers and riders rank one another on punctuality, friendliness, and the like, but uber (the company) ranks both drivers and riders on their behavior within the system, from canceling too many rides to failing to provide feedback. uber egypt states on its website: "the rating system is designed to give mutual feedback. if you never rate your drivers, you may see your own rating fall." even for those willing to incur the social costs of disengagement, opting out of machine learning may not be an option. failure to respond to someone's tag, or to like their photo, or otherwise maintain data productivity, and one might be dropped from their network, consciously or unconsciously, a dangerous proposition in a world where self-worth has become closely associated with measures of network centrality or social influence. as bucher has observed, "abstaining from using a digital device for one week does not result in disconnection, or less data production, but more digital data points … to an algorithm, … absence provides important pieces of information" (bucher , p. ) . engagement can also be forced on non-participants by the actions of other users-through tagging, rating, commenting, and endorsing, for instance (casemajor et al. ) . note that none of this is a scandal or a gross misuse of the technology. on the contrary, this is what any system looking for efficiency and relevance is bound to look like. but any ordering system that acts on people will generate social learning, including action directed at itself in return. engagement, to feed data hunger and enable the accretion of "meaningful" data from noise, is not neutral, socially or psychologically. the constant monitoring and management of one's social connections, interactions, and interpellations places a nontrivial burden on one's life. the first strategy of engagement is simply massive time investment, to manage the seemingly ever-growing myriad of online relationships (boyd ). to help with the process, social media platforms now bombard their users constantly with notifications, making it difficult to stay away and orienting users' behavior toward mindless and unproductive "grinding" (for instance, repetitively "liking" every post in their feed). but even this intensive "nudging" is often not enough. otherwise, how can we explain the fact that a whole industry of social media derivatives has popped up, to help people optimize their behavior vis-a-vis the algorithm, manage their following, and gain an edge so that they can climb the priority order over other, less savvy users? now users need to manage two systems (if not more): the primary one and the (often multiple) analytics apps that help improve and adjust their conduct in it. in these ways, interaction with machine learning systems tends to encourage continuous effort towards ordinal self-optimization. however, efforts of ordinal optimization, too, may soon become useless: as marilyn strathern (citing british economist charles goodhardt) put it, "when a measure becomes a target, it ceases to be a good measure" (strathern , p. ) . machine learning systems do not reward time spent on engagement without regard to the impact of that engagement across the network as a whole. now, in desperation, those with the disposable income to do so may turn to money as the next saving grace to satisfy the imperative to produce "good" data at volume and without interruption, and reap social rewards for doing so. the demand for maximizing one's data productivity and machine learning measurability is there, so the market is happy to oblige. with a monthly subscription to a social media platform, or even a social media marketing service, users can render themselves more visible. this possibility, and the payoffs of visibility, are learned socially, both through the observation and mimicry of models (influencers, for instance) or through explicit instruction (from the numerous online and offline guides to maximizing "personal brand"). one can buy oneself instagram or twitter followers. social media scheduling tools, such as tweetdeck and post planner, help one to plan ahead to try to maximize engagement with one's postings, including by strategically managing their release across time zones. a paying account on linkedin dramatically improves a user's chance of being seen by other users. the same is true of tinder. if a user cannot afford the premium subscription, the site still offers them one-off "boosts" for $ . that will send their profile near the top of their potential matches' swiping queue for min. finally, wealthier users can completely outsource the process of online profile management to someone else (perhaps recruiting a freelance social media manager through an online platform like upwork, the interface of which exhibits ordinal features like client ratings and job success scores). in all the foregoing ways, the inclusionary promise of machine learning has shifted toward more familiar sociological terrain, where money and other vectors of domination determine outcomes. in addition to economic capital, distributions of social and cultural capital, as well as traditional ascriptive characteristics, such as race or gender, play an outsized role in determining likeability and other outcomes of socially learned modes of engagement with machine learning systems. for instance, experiments with mechanical turkers have shown that being attractive increases the likelihood of appearing trustworthy on twitter, but being black creates a contrarian negative effect (groggel et al. ) . in another example, empirical studies of social media use among those bilingual in hindi and english have observed that positive modes of social media engagement tend to be expressed in english, with negative emotions and profanity more commonly voiced in hindi. one speculative explanation for this is that english is the language of "aspiration" in india or offers greater prospects for accumulating social and cultural capital on social media than hindi (rudra et al. ) . in short, wellestablished off-platform distinctions and social hierarchies shape the extent to which on-platform identities and forms of materialized labor will be defined as valuable and value-generating in the field of social media. in summary, ordinality is a necessary feature of all online socio-technical systems and it demands a relentless catering to one's digital doppelgängers' interactions with others and with algorithms. to be sure, design features tend to make systems addictive and feed this sentiment of oppression (boyd ). what really fuels both, however, is the work of social ordering and the generation of ordinal salience by the algorithm. in the social world, any type of scoring, whether implicit or explicit, produces tremendous amounts of status anxiety and often leads to productive resources (time and money) being diverted in an effort to better one's odds (espeland and sauder ; mau ) . those who are short on both presumably fare worse, not only because that makes them less desirable in the real world, but also because they cannot afford the effort and expense needed to overcome their disadvantage in the online world. the very act of ranking thus both recycles old forms of social inequality and also creates new categories of undesirables. as every teenager knows, those who have a high ratio of following to followers exhibit low social status or look "desperate." in this light, jeff bezos may be the perfect illustration of intertwining between asymmetries of real world and virtual world power: the founder and ceo of amazon and currently the richest man in the world has . million followers on twitter, but follows only one person: his ex-wife. ordinalization has implications not just for hierarchical positioning, but also for belonging-an important dimension of all social systems (simmel ) . ordinal stigma (the shame of being perceived as inferior) often translates into nominal stigma, or the shame of non-belonging. not obtaining recognition (in the form of "likes" or "followers"), in return for one's appreciation of other people, can be a painful experience, all the more since it is public. concern to lessen the sting of this kind of algorithmic cruelty is indeed why, presumably, tinder has moved from a simple elo or desirability score (which depends on who has swiped to indicate liking for the person in question, and their own scores, an ordinal measure) to a system that relies more heavily on type matching (a nominal logic), where people are connected based on taste similarity as expressed through swiping, sound, and image features (carman ) . in addition to employing machine learning to rank users, most social media platforms also use forms of clustering and type matching, which allow them to group users according to some underlying similarity (analogical machine learning in domingos's terms). this kind of computing is just as hungry for data as those we discuss above, but its social consequences are different. now the aim is trying to figure a person out or at least to amplify and reinforce a version of that person that appears in some confluence of data exhaust within the system in question. that is, in part, the aim of the algorithm (or rather, of the socio-technical system from which the algorithm emanates) behind facebook's news feed (cooper ) . typically, the more data one feeds the algorithm, the better its prediction, the more focused the offering, and the more homogeneous the network of associations forged through receipt and onward sharing of similar offerings. homogenous networks may, in turn, nourish better-and more saleablemachine learning programs. the more predictable one is, the better the chances that one will be seen-and engaged-by relevant audiences. being inconsistent or too frequently turning against type in data-generative behaviors can make it harder for a machine learning system to place and connect a person associatively. in both offline and online social worlds (not that the two can easily be disentangled), deviations from those expectations that data correlations tend to yield are often harshly punished by verbal abuse, dis-association, or both. experiences of being so punished, alongside experiences of being rewarded by a machine learning interface for having found a comfortable group (or a group within which one has strong correlations), can lead to some form of social closure, a desire to "play to type." as one heavy social media user told us, "you want to mimic the behavior [and the style] of the people who are worthy of your likes" in the hope that they will like you in return. that's why social media have been variously accused of generating "online echo chambers" and "filter bubbles," and of fueling polarization (e.g., pariser ). on the other hand, being visible to the wrong group is often a recipe for being ostracized, "woke-shamed," "called-out," or even "canceled" (yar and bromwich ) . in these and other ways, implementations of machine learning in social media complement and reinforce certain predilections widely learned socially. in many physical, familial, political, legal, cultural, and institutional environments, people learn socially to feel suspicious of those they experience as unfamiliar or fundamentally different from themselves. there is an extensive body of scholarly work investigating social rules and procedures through which people learn to recognize, deal with, and distance themselves from bodies that they read as strange and ultimately align themselves with and against pre-existing nominal social groupings and identities (ahmed ; goffman ) . this is vital to the operation of the genre of algorithm known as a recommendation algorithm, a feature of all social media platforms. on facebook, such an algorithm generates a list of "people you may know" and on twitter, a "who to follow" list. recommendation algorithms derive value from this social learning of homophily (mcpherson et al. ) . for one, it makes reactions to automated recommendations more predictable. recommendation algorithms also reinforce this social learning by minimizing social media encounters with identities likely to be read as strange or nonassimilable, which in turn improves the likelihood of their recommendations being actioned. accordingly, it has been observed that the profile pictures of accounts recommended on tiktok tend to exhibit similarities-physical and racial-to the profile image of the initial account holder to whom those recommendations are presented (heilweil ) . in that sense, part of what digital technologies do is organize the online migration of existing offline associations. but it would be an error to think that machine learning only reinforces patterns that exist otherwise in the social world. first, growing awareness that extreme type consistency may lead to online boredom, claustrophobia, and insularity (crawford ) has led platforms to experiment with and implement various kinds of exploratory features. second, people willfully sort themselves online in all sorts of non-overlapping ways: through twitter hashtags, group signups, click and purchasing behavior, social networks, and much more. the abundance of data, which is a product of the sheer compulsion that people feel to self-index and classify others (harcourt ; brubaker ) , might be repurposed to revisit common off-line classifications. categories like marriage or citizenship can now be algorithmically parsed and tested in ways that wield power over people. for instance, advertisers' appetite for information about major life events has spurred the application of predictive analytics to personal relationships. speech recognition, browsing patterns, and email and text messages can be mined for information about, for instance, the likelihood of relationships enduring or breaking up (dickson ) . similarly, the us national security agency measures people's national allegiance from how they search on the internet, redefining rights in the process (cheney-lippold ). even age-virtual rather than chronological-can be calculated according to standards of mental and physical fitness and vary widely depending on daily performance (cheney-lippold , p. ). quantitatively measured identities-algorithmic gender, ethnicity, or sexuality-do not have to correspond to discrete nominal types anymore. they can be fully ordinalized along a continuum of intensity (fourcade ) . the question now is: how much of a us citizen are you, really? how latinx? how gay? in a machine learning world, where each individual can be represented as a bundle of vectors, everyone is ultimately a unique combination, a category of one, however "precisely inaccurate" that category's digital content may be (mcfarland and mcfarland ) . changes in market research from the s to the s, aimed at tracking consumer mobility and aspiration through attention to "psychographic variables," constitute a pre-history, of sorts, for contemporary machine learning practices in commercial settings (arvidsson ; gandy ; fourcade and healy ; lauer ) . however, the volume and variety of variables now digitally discernible mean that the latter have outstripped the former exponentially. machine learning techniques have the potential to reveal unlikely associations, no matter how small, that may have been invisible, or muted, in the physically constraining geography of the offline world. repurposed for intervention, disparate data can be assembled to form new, meaningful types and social entities. paraphrasing donald mackenzie ( ), machine learning is an "engine, not a camera." christopher wylie, a former lead scientist at the defunct firm cambridge analytica-which famously matched fraudulently obtained facebook data with consumer data bought from us data brokers and weaponized them in the context of the us presidential election-recalls the experience of searching for-and discovering-incongruous social universes: "[we] spent hours exploring random and weird combinations of attributes.… one day we found ourselves wondering whether there were donors to anti-gay churches who also shopped at organic food stores. we did a search of the consumer data sets we had acquired for the pilot and i found a handful of people whose data showed that they did both. i instantly wanted to meet one of these mythical creatures." after identifying a potential target in fairfax county, he discovered a real person who wore yoga pants, drank kombucha, and held fire-andbrimstone views on religion and sexuality. "how the hell would a pollster classify this woman?" only with the benefit of machine learning-and associated predictive analytics-could wylie and his colleagues claim capacity to microtarget such anomalous, alloyed types, and monetize that capacity (wylie , pp. - ) . to summarize, optimization makes social hierarchies, including new ones, and pattern recognition makes measurable types and social groupings, including new ones. in practice, ordinality and nominality often work in concert, both in the offline and in the online worlds (fourcade ). as we have seen, old categories (e.g., race and gender) may reassert themselves through new, machine-learned hierarchies, and new, machine-learned categories may gain purchase in all sorts of offline hierarchies (micheli et al. ; madden et al. ) . this is why people strive to raise their digital profiles and to belong to those categories that are most valued there (for instance "verified" badges or recognition as a social media "influencer"). conversely, patternmatching can be a strategy of optimization, too: people will carefully manage their affiliations, for instance, so as to raise their score-aligning themselves with the visible and disassociating themselves from the underperforming. we examine these complex interconnections below and discuss the dispositions and sentiments that they foster and nourish. it should be clear by now that, paraphrasing latour ( , p. ), we can expect little from the "social explanation" of machine learning; machine learning is "its own explanation." the social does not lie "behind" it, any more than machine learning algorithms lie "behind" contemporary social life. social relations fostered by the automated instantiation of stratification and association-including in social mediaare diverse, algorithmic predictability notwithstanding. also, they are continually shifting and unfolding. just as latour ( , p. ) reminds us not to confuse technology with the objects it leaves in its wake, it is important not to presume the "social" of social media to be fixed by its automated operations. we can, nevertheless, observe certain modes of social relation and patterns of experience that tend to be engineered into the ordinal and nominal orders that machine learning (re)produces. in this section, we specify some of these modes of relation, before showing how machine learning can both reify and ramify them. our argument here is with accounts of machine learning that envisage social and political stakes and conflicts as exogenous to the practice-considerations to be addressed through ex ante ethics-by-design initiatives or ex post audits or certifications-rather than fundamental to machine learning structures and operations. machine learning is social learning, as we highlighted above. in this section, we examine further the kinds of sociality that machine learning makes-specifically those of competitive struggle and dependency-before turning to prospects for their change. social scientists' accounts of modes of sociality online are often rendered in terms of the antagonism between competition and cooperation immanent in capitalism (e.g., fuchs ). this is not without justification. after all, social media platforms are sites of social struggle, where people seek recognition: to be seen, first and foremost, but also to see-to be a voyeur of themselves and of others (harcourt ; brubaker ) . in that sense, platforms may be likened to fields in the bourdieusian sense, where people who invest in platform-specific stakes and rules of the game are best positioned to accumulate platform-specific forms of capital (e.g., likes, followers, views, retweets, etc.) (levina and arriaga ) . some of this capital may transfer to other platforms through built-in technological bridges (e.g., between facebook and instagram), or undergo a process of "conversion" when made efficacious and profitable in other fields (bourdieu ; fourcade and healy ) . for instance, as social status built online becomes a path to economic accumulation in its own right (by allowing payment in the form of advertising, sponsorships, or fans' gifts), new career aspirations are attached to social media platforms. according to a recent and well-publicized survey, "vlogger/youtuber" has replaced "astronaut" as the most enviable job for american and british children (berger ) . in a more mundane manner, college admissions offices or prospective employers increasingly expect one's presentation of self to include the careful management of one's online personality-often referred to as one's "brand" (e.g., sweetwood ) . similarly, private services will aggregate and score any potentially relevant information (and highlight "red flags") about individuals across platforms and throughout the web, for a fee. in this real-life competition, digitally produced ordinal positions (e.g., popularity, visibility, influence, social network location) and nominal associations (e.g., matches to advertised products, educational institutions, jobs) may be relevant. machine learning algorithms within social media both depend on and reinforce competitive striving within ordinal registers of the kind highlighted above-or in bourdieu's terms, competitive struggles over field-specific forms of capital. as georg simmel observed, the practice of competing socializes people to compete; it "compels the competitor" (simmel (simmel [ ). socially learned habits of competition are essential to maintain data-productive engagement with social media platforms. for instance, empirical studies suggest that motives for "friending" and following others on social media include upward and downward social comparison (ouwerkerk and johnson ; vogel et al. ) . social media platforms' interfaces then reinforce these social habits of comparison by making visible and comparable public tallies of the affirmative attention that particular profiles and posts have garnered: "[b]eing social in social media means accumulating accolades: likes, comments, and above all, friends or followers" (gehl , p. ) . in this competitive "[l]ike economy," "user interactions are instantly transformed into comparable forms of data and presented to other users in a way that generates more traffic and engagement" (gerlitz and helmond , p. )-engagement from which algorithms can continuously learn in order to enhance their own predictive capacity and its monetization through sales of advertising. at the same time, the distributed structure of social media (that is, its multinodal and cumulative composition) also fosters forms of cooperation, gift exchange, redistribution, and reciprocity. redistributive behavior on social media platforms manifests primarily in a philanthropic mode rather than in the equitypromoting mode characteristic of, for instance, progressive taxation. examples include practices like the #followfriday or #ff hashtag on twitter, a spontaneous form of redistributive behavior that emerged in whereby "micro-influencers" started actively encouraging their own followers to follow others. insofar as those so recommended are themselves able to monetize their growing follower base through product endorsement and content creation for advertisers, this redistribution of social capital serves, at least potentially, as a redistribution of economic capital. even so, to the extent that purportedly "free" gifts, in the digital economy and elsewhere, tend to be reciprocated (fourcade and kluttz ) , such generosity might amount to little more than an effective strategy of burnishing one's social media "brand," enlarging one's follower base, and thereby increasing one's store of accumulated social (and potentially economic) capital. far from being antithetical to competitive relations on social media, redistributive practices in a gift-giving mode often complement them (mauss ) . social media cooperation can also be explicitly anti-social, even violent (e.g., patton et al. ) . in these and other ways, digitized sociality is often at once competitive and cooperative, connective and divisive (zukin and papadantonakis ) . whether it is enacted in competitive, redistributive or other modes, sociality on social media is nonetheless emergent and dynamic. no wonder that bruno latour was the social theorist of choice when we started this investigation. but-as latour ( ) himself pointed out-gabriel tarde might have been a better choice. what makes social forms cohere are behaviors of imitation, counter- an exception to this observation would be social media campaigns directed at equitable goals, such as campaigns to increase the prominence and influence of previously under-represented groups-womenalsoknowstuff and pocalsoknowstuff twitter handles, hashtags, and feeds, for example. recommendation in this mode has been shown to increase recommended users' chance of being followed by a factor of roughly two or three compared to a recommendation-free scenario (garcia gavilanes et al. ). for instance, lewis ( , p. ) reports that "how-to manuals for building influence on youtube often list collaborations as one of the most effective strategies." imitation, and influence (tarde ) . social media, powered by trends and virality, mimicry and applause, parody and mockery, mindless "grinding" and tagging, looks quintessentially tardian. even so, social media does not amount simply to transfering online practices of imitation naturally occuring offline. the properties of machine learning highlighted above-cybernetic feedback; data hunger; accretive meaning-making; ordinal and nominal ordering-lend social media platforms and interfaces a distinctive, compulsive, and calculating quality-engineering a relentlessly "participatory subjectivity" (bucher , p. ; boyd ) . how one feels and how one acts when on social media is not just an effect of subjective perceptions and predispositions. it is also an effect of the software and hardware that mediate the imitative (or counter-imitative) process itself-and of the economic rationale behind their implementation. we cannot understand the structural features and phenomenological nature of digital technologies in general, and of social media in particular, if we do not understand the purposes for which they were designed. the simple answer, of course, is that data hunger and meaning accretion are essential to the generation of profit (zuboff ), whether profit accrues from a saleable power to target advertising, commercializable developments in artificial intelligence, or by other comparable means. strategies for producing continuous and usable data flows to profit-making ends vary, but tend to leverage precisely the social-machine learning interface that we highlighted above. social media interfaces tend to exhibit design features at both the back-and front-end that support user dependency and enable its monetization. for example, the "infinite scroll," which allows users to swipe down a page endlessly (without clicking or refreshing) rapidly became a staple of social media apps after its invention in , giving them an almost hypnotic feel and maximizing the "time on device" and hence users' availability to advertisers (andersson ) . similarly, youtube's recommendation algorithm was famously optimized to maximize users' time on site, so as to serve them more advertisements (levin ; roose ) . social media platforms also employ psycho-social strategies to this end, including campaigns to draw people in by drumming up reciprocity and participation-the notifications, the singling out of trends, the introduction of "challenges"-and more generally the formation of habits through gamification. prominent critics of social media, such as tristan harris (originally from google) and sandy parakilas (originally from facebook), have denounced apps that look like "slot machines" and use a wide range of intermittent rewards to keep users hooked and in the (instagram, tiktok, facebook, …) zone, addicted "by design" (schüll ; fourcade ) . importantly, this dependency has broader social ramifications than may be captured by a focus on individual unfreedom. worries about the "psychic numbing" of the liberal subject (zuboff ) , or the demise of the sovereign consumer, do not preoccupy us so much as the ongoing immiseration of the many who "toil on the invisible margins of the social factory" (morozov ) or whose data traces make them the targets of particularly punitive extractive processes. dependencies engineered into social media interfaces help, in combination with a range of other structural factors, to sustain broader economic dependencies, the burdens and benefits of which land very differently across the globe (see, e.g., taylor and broeders ) . in this light, the question of how amenable these dynamics may be to social change becomes salient for many. recent advances in digital technology are often characterized as revolutionary. however, as well as being addictive, the combined effect of machine learning and social learning may be as conducive to social inertia as it is to social change. data hunger on the part of mechanisms of both social learning and machine learning, together with their dependence on data accretion to make meaning, encourage replication of interface features and usage practices known to foster continuous, data-productive engagement. significant shifts in interface design-and in the social learning that has accreted around use of a particular interface-risk negatively impacting data-productive engagement. one study of users' reactions to changes in the facebook timeline suggested that "major interface changes induce psychological stress as well as technology-related stress" (wisniewski et al. ) . in recognition of these sensitivities, those responsible for social media platforms' interfaces tend to approach their redesign incrementally, so as to promote continuity rather than discontinuity in user behaviour. the emphasis placed on continuity in social media platform design may foster tentativeness in other respects as well, as we discuss in the next section. at the same time, social learning and machine learning, in combination, are not necessarily inimical to social change. machine learning's associative design and propensity to virality have the potential to loosen or unsettle social orders rapidly. and much as the built environment of the new urban economy can be structured to foster otherwise unlikely encounters (hanson and hillier ; zukin ) , so digital space can be structured to similar effect. for example, the popular chinese social media platform wechat has three features, enabled by machine learning, that encourage openended, opportunistic interactions between random users-shake, drift bottle, and people nearby-albeit, in the case of people nearby, random users within one's immediate geographic vicinity. (these are distinct from the more narrow, instrumental range of encounters among strangers occasioned by platforms like tinder, the sexual tenor of which are clearly established in advance, with machine learning parameters set accordingly.) qualitative investigation of wechat use and its impact on chinese social practices has suggested that wechat challenges some existing social practices, while reinforcing others. it may also foster the establishment of new social practices, some defiant of prevailing social order. for instance, people report interacting with strangers via wechat in ways they normally would not, including shifting to horizontallystructured interactions atypical of chinese social structures offline (wang et al. ). this is not necessarily unique to wechat. the kinds of ruptures and reorderings engineered through machine learning do not, however, create equal opportunities for value creation and accumulation, any more than they are inherently liberating or democratizing. social media channels have been shown to serve autocratic goals of "regime entrenchment" quite effectively (gunitsky ) . likewise, they serve economic goals of data accumulation and concentration (zuboff ) . machine-learned sociality lives on corporate servers and must be with regard to wechat in china and vkontakte in russia, as well as to government initiatives in egypt, the ukraine, and elsewhere, seva gunitsky ( ) highlights a number of reasons why, and means by which, nondemocratic regimes have proactively sought (with mixed success) to co-opt social media, rather than simply trying to suppress it, in order to try to ensure central government regimes' durability. meticulously "programmed" (bucher ) to meet specific economic objectives. as such, it is both an extremely lucrative proposition for some and (we have seen) a socially dangerous one for many. it favors certain companies, their shareholders and executives, while compounding conditions of social dependency and economic precarity for most other people. finally, with its content sanitized by underground armies of ghost workers (gray and suri ), it is artificial in both a technical and literal sense-"artificially artificial," in the words of jeff bezos (casilli and posada ). we have already suggested that machine-learned sociality, as it manifests on social media, tends to be competitive and individualizing (in its ordinal dimension) and algorithmic and emergent (in its nominal dimension). although resistance to algorithms is growing, those who are classified in ways they find detrimental (on either dimension) may be more likely to try to work on themselves or navigate algorithmic workarounds than to contest the classificatory instrument itself (ziewitz ) . furthermore, we know that people who work under distributed, algorithmically managed conditions (e.g., mechanical turk workers, uber drivers) find it difficult to communicate amongst themselves and organize (irani and silberman ; lehdonvirta ; dubal ) . these features of the growing entanglement of social and machine learning may imply dire prospects for collective action-and beyond it, for the achievement of any sort of broad-based, solidaristic project. in this section, we tentatively review possibilities for solidarity and mobilization as they present themselves in the field of social media. machine learning systems' capacity to ingest and represent immense quantities of data does increase the chances that those with common experiences will find one another, at least insofar as those experiences are shared online. machine-learned types thereby become potentially important determinants of solidarity, displacing or supplementing the traditional forces of geography, ascribed identities, and voluntary association. those dimensions of social life that social media algorithms have determined people really care about often help give rise to, or supercharge, amorphous but effective forms of offline action, if only because the broadcasting costs are close to zero. examples may include the viral amplification of videos and messages, the spontaneity of flash mobs (molnár ) , the leaderless, networked protests of the arab spring (tufekci ) , or of the french gilets jaunes (haynes ), and the #metoo movement's reliance on public disclosures on social media platforms. nonetheless, the thinness, fleeting character, and relative randomness of the affiliations summoned in those ways (based on segmented versions of the self, which may or may not overlap) might make social recognition and commonality of purpose difficult to sustain in the long run. more significant, perhaps, is the emergence of modes of collective action that are specifically designed not only to fit the online medium, but also to capitalize on its technical features. many of these strategies were first implemented to stigmatize or sow division, although there is no fatality that this is their only possible use. examples include the anti-semitic (((echo))) tagging on twitter-originally devised to facilitate trolling by online mobs (weisman ) but later repurposed by non-jews as an expression of solidarity; the in-the-wild training of a microsoft chatter bot, literally "taught" by well-organized users to tweet inflammatory comments; the artificial manipulation of conversations and trends through robotic accounts; or the effective delegation, by the trump campaign, of the management of its ad-buying activities to facebook's algorithms, optimized on the likelihood that users will take certain campaign-relevant actions-"signing up for a rally, buying a hat, giving up a phone number" (bogost and madrigal ) . the exploitation of algorithms for divisive purposes often spurs its own reactions, from organized counter-mobilizations to institutional interventions by platforms themselves. during the black lives matter protests, for instance, kpop fans flooded rightwing hashtags on instagram and twitter with fancams and memes in order to overwhelm racist messaging. even so, often the work of "civilizing" the social media public sphere is left to algorithms, supported by human decision-makers working through rules and protocols (and replacing them in especially sensitive cases). social media companies ban millions of accounts every month for inappropriate language or astroturfing (coordinated operations on social media that masquerade as a grassroot movement): algorithms have been trained to detect and exclude certain types of coalitions on the basis of a combination of social structure and content. in , the british far right movement "britain first" moved to tiktok after being expelled from facebook, twitter, instagram, and youtube-and then over to vkontakte or vk, a russian platform, after being banned from tiktok (usa news ). chastised in the offline world for stirring discord and hate, the economic engines that gave the movement a megaphone have relegated it to their margins with embarrassment. the episode goes to show that there is nothing inherently inclusive in the kind of group solidarity that machine learning enables, and thus it has to be constantly put to the (machine learning) test. in the end, platforms' ideal of collective action may resemble the tardean, imitative but atomized crowd, nimble but lacking in endurance and capacity (tufekci ) . mimetic expressions of solidarity, such as photo filters (e.g., rainbow), the "blacking out" of one's newsfeed, or the much-bemoaned superficiality of "clicktivism" may be effective at raising consciousness or the profile of an issue, but they may be insufficient to support broader-based social and political transformations. in fact, social media might actually crowd out other solidaristic institutions by also serving as a (feeble, often) palliative for their failures. for example, crowdsourced campaigns, now commonly used to finance healthcare costs, loss of employment, or educational expenses, perform a privatized solidarity that is a far cry from the universal logic of public welfare institutions. up to this point, our emphasis has been on the kinds of sociality that machine learning implementations tend to engender on the social media field, in both vertical (ordinal) and horizontal (nominal) configurations. we have, in a sense, been "reassembling the social" afresh, with an eye, especially, to its computational components and chains of reference (latour ) . throughout, we have stressed, nonetheless, that machine learning and other applications of artificial intelligence must be understood as forces internal to social life-both subject to and integral to its contingent properties-not forces external to it or determinative of it. accordingly, it is just as important to engage in efforts to reassemble "the machine"-that is, to revisit and put once more into contention the associative preconditions for machine learning taking the form that it currently does, in social media platforms for instance. and if we seek to reassemble the machine, paraphrasing latour ( , p. ) , "it's necessary, aside from the circulation and formatting of traditionally conceived [socio-technical] ties, to detect other circulating entities." so what could be some "other circulating entities" within the socio-technical complex of machine learning, or how could we envisage its elements circulating, and associating, otherwise? on some level, our analysis suggests that the world has changed very little. like every society, machine-learned society is powered by two fundamental, sometimes contradictory forces: stratification and association, vertical and horizontal difference. to be sure, preexisting social divisions and inequalities are still very much part of its operations. but the forces of ordinality and nominality have also been materialized and formatted in new ways, of which for-profit social media offer a particularly stark illustration. the machinelearnable manifestations of these forces in social media: these are among the "other circulating entities" now traceable. recursive dynamics between social and machine learning arise where social structures, economic relations and computational systems intersect. central to these dynamics in the social media field are the development of a searching disposition to match the searchability of the environment, the learnability of the self through quantified measurement, the role of scores in the processing of social positions and hierarchies, the decategorization and recategorization of associational identities, automated feedback that fosters compulsive habits and competitive social dispositions, and strategic interactions between users and platforms around the manipulation of algorithms. what, then, of prospects for reassembly of existing configurations? notwithstanding the lofty claims of the it industry, there is nothing inherently democratizing or solidaristic about the kinds of social inclusiveness that machine learning brings about. the effects of individuals and groups' social lives being rendered algorithmically learnable are ambivalent and uneven. in fact, they may be as divisive and hierarchizing as they may be connective and flattening. moreover, the conditions for entry into struggle in the social media field are set by a remarkably small number of corporate entities and "great men of tech" with global reach and influence (grewal ) . a level playing field this most definitely is not. rather, it has been carved up and crenellated by those who happen to have accumulated greatest access to the data processing and storage capacity that machine learning systems require, together with the real property, intellectual property, and personal property rights, and the network of political and regulatory lobbyists that ensure that exclusivity of access is maintained (cohen ) . power in this field is, accordingly, unlikely to be reconfigured or redistributed organically, or through generalized exhortation to commit to equity or ethics (many versions of which are self-serving on the part of major players). instead, political action aimed at building or rebuilding social solidarities across such hierarchies and among such clusters must work with and through them, in ways attentive to the specifics of their instantiation in particular techno-social settings. to open to meaningful political negotiation those allocations and configurations of power that machine learning systems help to inscribe in public and private life-this demands more than encompassing a greater proportion of people within existing practices of ruling and being ruled, and more than tinkering around the edges of existing rules. the greater the change in sociality and social relations-and machine learning is transforming both, as we have recounted-the more arrant and urgent the need for social, political and regulatory action specifically attuned to that change and to the possibility of further changes. social and political action must be organized 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the publisher's note springer nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations as well as numerous articles that explore and theorize national variations in political mores, valuation cultures, economic policy, and economic knowledge. more recently, she has written extensively on the political economy of digitality, looking specifically at the changing nature of inequality and stratification in the digital era since , she has been conducting fieldwork on the role of digital technology and digital data in development, humanitarian aid, and disaster relief-work funded, since , by the australian research council. relevant publications include "global governance through the pairing of list and algorithm" (environment and planning d: society and space ); "data, detection, and the redistribution of the sensible acknowledgments we are grateful to kieran healy, etienne ollion, john torpey, wayne wobcke, and sharon zukin for helpful comments and suggestions. we also thank the institute for advanced study for institutional support. an earlier version of this article was presented at the "social and ethical challenges of machine learning" workshop at the institute for advanced study, princeton, november . key: cord- -dz qx authors: rasheed, jawad; jamil, akhtar; hameed, alaa ali; aftab, usman; aftab, javaria; shah, syed attique; draheim, dirk title: a survey on artificial intelligence approaches in supporting frontline workers and decision makers for covid- pandemic date: - - journal: chaos solitons fractals doi: . /j.chaos. . sha: doc_id: cord_uid: dz qx while the world has experience with many different types of infectious diseases, the current crisis related to the spread of covid- has challenged epidemiologists and public health experts alike, leading to a rapid search for, and development of, new and innovative solutions to combat its spread. the transmission of this virus has infected more than . million people as of august , , with over half a million deaths across the globe; the world health organization (who) has declared this a global pandemic. a multidisciplinary approach needs to be followed for diagnosis, treatment and tracking, especially between medical and computer sciences, so, a common ground is available to facilitate the research work at a faster pace. with this in mind, this survey paper aimed to explore and understand how and which different technological tools and techniques have been used within the context of covid- . the primary contribution of this paper is in its collation of the current state-of-the-art technological approaches applied to the context of covid- , and doing this in a holistic way, covering multiple disciplines and different perspectives. the analysis is widened by investigating artificial intelligence (ai) approaches for the diagnosis, anticipate infection and mortality rate by tracing contacts and targeted drug designing. moreover, the impact of different kinds of medical data used in diagnosis, prognosis and pandemic analysis is also provided. this review paper covers both medical and technological perspectives to facilitate the virologists, ai researchers and policymakers while in combating the covid- outbreak. first china, then worldwide [ ] to tackle the pandemic of covid- , scientists and medical experts are trying to come up with state-of-the-art solution to control the spread, identify infected patients, monitor virus growth and develop vaccines. many researchers are working with computer-based diagnosis techniques using clinical blood samples, radiography images, and respiratory-related datasets. ai and machine learning techniques are helping medical personnel in monitoring, analysis and prediction of various critical applications such as survival mortality assessment, forecasting models, virions sequence formation and drug discovery models. in order to help stop the pandemic, the early detection of positive cases is crucial as it facilitates the containment and isolation of the virus, thus reducing its spread. currently, the standard procedure followed for identification of covid- positive cases is performed by reverse-transcription polymerase chain reaction (rt-pcr) [ ] . to further improve and hasten the early detection process, there is room for the development of new and innovative tools that may improve the early detection and tracking of the virus [ , ] . as there is a clear need for these innovative technical solutions, there has, logically, been a large amount of rapid-paced development of these tools. however, due to the speed and number of these developments, it is easy to become overwhelmed, thus limiting the ability to critically examine, explore, and understand what a given solution does, how it performs, and whether or not it may or may not be beneficial. thus, with this in mind, the main objective of this comprehensive review is to provide an in-depth account of covid- and various advancements in ai techniques that have been currently developed to help manage or combat covid- . the review was conducted between july and august , using the keywords -covid- ‖ and (combined with one of the following: -ai‖, -machine learning‖, -deep learning‖) as well as -covid- ‖ and -ai‖ and (combined with one of the following: -clinical blood samples‖, -forecasting models‖, -drug discovery models‖). this approach is, admittedly, broad, but allowed for a large number of relevant papers to be identified. additionally, due to the nature of this study being a relatively new research subject, pre-print papers (such as those submitted to arxiv) were not precluded. as recommended by [ ] , we selected google scholar as our electronic bibliographic databases to remove any kind of biasness for any specific scientific publisher. we then excluded papers not written in english, duplicates, guest editorials, poster sessions, and blogs. once the papers were identified, they were analyzed and grouped based on their aims and approaches. based on this conducted study, it is hoped that this paper will serve as a common ground for both medical experts and computer scientists to better understand the current state-of-the-art associated with covid- with this in mind, the main contributions of this study are as follows:  detailed history, characteristics, taxonomy, symptoms, behavior, and patterns of covid- are outlined.  presentation and discussion of ai (both traditional ml and advanced dl) approaches applied to covid- in a variety of aspects and domains.  description of major covid- diagnosis techniques using clinical blood samples, radiography images, respiratory-related data for various critical applications such as survival mortality assessment, forecasting models, virions sequence formation and drug discovery models.  a detailed discussion on issues, challenges, and recommendations to tackle the pandemic through ai and timely facilitate effective decision making is presented. in order to meet these objectives, the rest of the paper is organized as follows. section lays out the historical overview, origin and means of transmission, and global dispersion of the virus. section highlights the novel ai techniques that have been applied to covid- , and furthermore, it explores non-applied, but potentially useful, ai-based applications for vaccine discovery, mortality and survival rate prediction, and outbreak forecasting. section discusses the challenges in covid- research. finally, the review is concluded in section by presenting a summarized overview of the conducted studies. the type of coronaviruses that cause infections in humans belongs to a subfamily called coronavirinae which is part of a larger [ ]. the name corona comes from the fact that the viral particle has spike-like projections or structures on its outer layer that can be seen under a scanning electron microscope. the rna of coronaviruses is single-stranded, positive sense, has a diameter of around to nm and a nucleic acid length from to kbs [ ] . they are classified under four variants or genera entitled as alpha (α), beta (β), gamma (γ) and delta (δ) [ ] . it has been observed that mammals typically get infected by the α-and β-cov while the other two (γ-and δ-cov) mostly infect birds. from the α-cov group, hcov-nl and hcov- e have been found to affect humans, normally causing a mild respiratory illness, similar to the common cold. from the β-cov group, sars-cov and mers-cov both tend to cause moderate to severe respiratory illnesses with a higher morbidity and mortality rate [ , ] . the most recent addition to the coronaviruses is that of sars-cov- , which became known in late after a number of atypically presenting pneumonia cases were identified in wuhan china; it was initially speculated that these cases might originate from the huanan seafood market [ ] . the hallmark sign of many of the cases was the development of certain symptoms including dry cough with fever, breathing difficulty and a-typical presentation of pneumonia. on january th , bangladesh have also registered a high number of cases; figure shows the top countries for coronavirus infections and deathsbased on the latest who situation reports [ ] . the disease itself is so pervasive due to the ease with which it is able to transmit itself, via small respiratory droplets (such as those created when talking, sneezing, coughing, and breathing) and has a higher level of danger to a person's health due to the current absence of targeted pharmaceutical solutions such as vaccines or antiviral drugs. pandemics are an ever-present threat to human society, health, and wellbeing and, therefore, attention must be dedicated to understanding how they occur, how they can be prevented, and how we can strategically mitigate the negative effects they cause. the current pandemic associated with covid- is unique in that it represents the first and largest pandemic in modern times where new technological solutions, e.g. ai, are not only applicable to the pandemic, but able to be created by a large group of stakeholders from scientists to doctors to ai-hobbyists alike. as the pandemic has caused great disruption to normal day-to-day operations and created a sense of unknown amongst the public, many motivated scientists and citizens have tried to assist in the covid- response by developing their own unique ai-based tools to solve a large number of problems, in a variety of applied domains, such as: coivd- disease detection and classification, mortality rate prediction and severity assessment, outbreak forecasting and tracking, biological insight of sars-cov- strain, and drug discovery. in order to explore the different approaches that are currently being developed and trialed, this section presents a selection of the different ways in which ai-based solutions have been applied to the covid- pandemic. in order to provide a visual representation of how an ai-based covid- system may work, a generic model has been created in figure . the system can process various types of raw data including images, blood samples, crowed sourced data, even gps information for tracking positive cases, etc., which can be stored in a repository. data mining techniques are usually applied to clean the raw data that is and then stored in a database for further processing and retrieval. ml and dl methods can be applied to this data for better visualization, diagnosis, and forecasting, which can help the end-users making better decisions and taking actions to mitigate the disease. early diagnosis of covid- is important to ensure better outcomes for those who have been infected. at the beginning of the pandemic, due to the sense of the unknown that surrounded the new disease, one way that was being used to diagnose patients was via radiographic imagery (such as ct scans or x-rays) of the lungs. table ii . there has also been a large number of dl-based approaches proposed to identify covid- from radiographic imagery in the literature. for example, brunese et al. [ ] exploited the transfer learning technique and fine-tuned dl-based modified visual geometry group (vgg- ) model. the proposed framework was divided into models that considered chest x-rays ( belongs to patients with pulmonary diseases, of covid- infected patients, while related to healthy patients). the first model discriminates between healthy and pulmonary diseases patients, while the second model classifies the chest xray (cxr) of pulmonary disease patient as covid- or other pneumonia. in the end, if a cxr is classified as covid- , the framework provides a visualization of the cxr highlighting the potentially sars-cov- infected area. from the experimental data, it was observed that the discriminatory model (model ) achieved accuracy, sensitivity, specificity and f-measure of %, %, % and % respectively, whereas the disease classification model (model ) yielded an accuracy of %, sensitivity of %, specificity of %, and an f-measure of %. similarly, to identify sars-cov- infected cases from cxr images, various cnn frameworks such as vgg , mobilenet v , inception, xception, and inception resnet v have been evaluated using transfer learning by apostolopoulos and mpesiana [ ] . from their conclusion, it was observed that mobilenet v outperformed the other tested state-of-the-art architectures by securing . % sensitivity, . % specificity, . % accuracy on the two-class problem and . % accuracy on the threeclass problem. in that paper, the models were trained and evaluated on a dataset of cxr images that constitutes images of bacterial pneumonia infected patients, images of covid- infected cases, and belonging to normal patients. mobilenet v also performed well yielding a sensitivity, specificity, two-class problem accuracy, and three-class other identified dl-based methods and approaches are highlighted in table iii . another type of covid- diagnostic tool that has been developed is related to respiratory wave data, such as developed in wang et al. [ ] . in this paper, the authors proposed a respiratory pattern classification model that was based on a novel gru neural network [ ] , which extends gru networks with bidirectional and attentional mechanisms (bi-at-gru) by using time-series real-world and stimulated respiratory data. the model detects and distinguishes the tachypnea respiratory pattern, a more rapid respiration symptom that occurs in covid- infected patients, from other viral infection patterns. a novel respiratory stimulated model (rsm) was used to generate stimulated breathing patterns to fill the scarce real-world data. the trained model was evaluated on real-world data captured by a depth camera. the proposed bi-at-gru model resulted in precision, recall, f -score, and accuracy of . %, . %, . % and . % respectively. table v lists the other identified covid- ai-based applications that utilize respiratory or coughing data. outside of just diagnosis of covid- , ai-based tools have also been applied to identifying the severity of the disease in a patient, as well as to develop and optimize treatment strategies. for example, in order to attempt to help to reduce the mortality of covid- , and to optimize potential treatment strategies, a novel dl-based framework, combined with a multivariate logistic regression model, was proposed by bai et al. [ ] . multi-layer perceptron (mlp) was used to convert each statistical sample containing clinical data characteristics to a -dimensional feature vector. the proposed model was then evaluated using a dataset of patients and achieved an overall accuracy of . % and . % auc under -fold cross-validation repeated times. the researchers found six key risk factors (age, lymphocyte, comorbid with hypertension, albumin, hypersensitive c-reactive protein level, and progressive consolidation in ct images) plus fibrosis in ct as a predictive factor for malignant progression. albahri et al. [ ] also proposed an ml-based rescue framework that was combined with a novel multi-criteria decision- chen et al. [ ] developed a fatality rate predictive model for severe sars-cov- patients based on five distinct ml approaches, namely: elastic net, bagged flexible discriminant analysis (bagged-fda), logistic regression, random forest and partial least squares regression. the model used data of severely infected covid- patients, out of which survived and found four key features and clinical pointers (age, d-dimer level, lymphocyte count, and high-sensitivity c-reactive protein level) for survival/mortality assessment. moreover, the developed models were evaluated on an external validation set that consisted of severe covid- confirmed cases, out of which were survivals. the experimental results concluded that the logistic regression model was to be preferred over other ml models due to its high interpretability and simplicity; it obtained sensitivity, specificity and auc of . %, . % and . % respectively. table vi shows other identified ai-based approaches related to severity and fatality assessment models. one of the first areas where ai was applied to the covid- pandemic was related to the development of outbreak forecasting models, which had the potential to help decision makers understand the potential progression of covid- in their area. one such approach was developed by kavadi et al. [ ] who suggested a partial derivative regression and non-linear machine learning (pdr-nml) model to predict the covid- transmission dynamics in india. the presented model achieved better performance in terms of accuracy and prediction time over linear regression and state-of-the-art ai-based models. it secured an accuracy of . % with a prediction time of ms for samples. another approach was offered by carrillo-larco and castillo-cara [ ] who presented a model based on k-means clustering that categorized countries sharing similar numbers of confirmed sars-cov- cases. in this study, researchers not only used covid- prevalence data (deaths, confirmed cases etc.), but also considered open access predictors like the prevalence of diseases such as hiv/aids, diabetes, and tuberculosis in countries along with their standard health system metrics, air quality, and social-economic parameters such as the gross domestic production. a third approach was developed by hu et al. [ ] , who attempted to develop an ai-based modified auto-encoder (mae) that modeled multiple public health interventions by using real data to forecast a potential covid- pandemic outbreak in a large geographic region and subsequently calculating the potential impact of interventions to curb the pandemic. the proposed architecture consisted of two single auto-encoders, each having three feedforward neural network layers. the used data pertained to confirmed positive covid- cases and covid- attributed deaths across countries over the period of january th to march th , . the estimate includes pandemic peak time, end time, and future cases. it concludes that mae performed better in forecasting daily new cases in china (with an error of . ) when compared with susceptible-exposedinfected-recovered (seir) model as used by sameni [ ] . beyond conventional ml-based approaches, advanced dl techniques have also been used to estimate future cases. paul et al. [ ] suggested a convolutional lstm-based multivariate spatiotemporal model to forecast the pandemic outbreak at the world-level. the proposed framework converted the spatial features into groups of temporal/non-temporal component-based d images and used data from usa and italy to train the network. the model performed well for predicting the number of cases over a -days period, with a mean absolute percent error (mape) of . % and . % for italy and usa respectively. other identified approaches for the development of potential covid- medications and vaccinations are highlighted in table viii . the investigation of this paper reveals several ai-based approaches that have been proposed as potential ways to help, with the covid- pandemic, covering everything from initial diagnoses via image diagnostics up to the presentation of models that help to understand the spread of covid- and identify potential new outbreak areas. by providing this comprehensive overview and identification of the current state-of-the-art, this structured review may help assist medical and research stakeholders currently involved in the covid- response. when it comes to potential barriers to the use of ai for covid- responses, one of the foremost inaccuracies is related to the failure of forming diagnostic programs that fail differentiate by symptomatic basis. therefore, in order to attain more accurate and precise prediction models, the patient's history of other existing ailments such as diabetes, heart, liver or other chronic conditions along with his age and gender should also be taken into account. the significance of these factors greatly influences the characteristics of covid- for a specific patient compared with other pneumonia diseases known so far. as many countries around the world are opening up their data related to covid- , it becomes possible for anyone to create new ai-based services, and, additionally, if these statistics are provided in an effective way, tools for the prediction of covid- diagnoses and spread could, in theory, be developed. another issue regarding the covid- pandemic is urgency. as the government needs high-quality statistical data in almost real-time to understand the current epidemiological situation in their area and to regulate quarantine in that same area, effort should be focused on improving the availability and provision of data first. as at the beginning of the pandemic, data was often not of high quality (though this depends on a large amount on which country's data is being examined) the initially used scientific datasets were often constructed in a quick manner and may not be as precise or adequate as one would ideally like. while considering the statistical analysis of the covid- disease, the crucial challenge is to secure real-time high-quality data. as this disease is still in a rapid growth phase, the fast nature of data makes it extremely difficult to produce reliable models. collection of regularly updated region-specific values of covid- is crucial in order to overcome this issue. a final challenge, and one of the most important, is the lack of understanding of epidemiological theory, beliefs, and knowhow of many ai researchers. this leads to a situation where many of the ai-based systems are created without input from medical professionals, thus limiting their usefulness and reliability. thus, to this end, it is important that any implemented aibased system aims to involve medical experts in the design and implementation. whilst it does appear to be the case that many ai-based approaches have been proposed, there is a limited real-world implementation of these tools. what this paper has shown, however, is that there is clearly a wide variety of potential methods that could be applied. moving forward, it is imperative for ai-designers and researchers to work together with medical professionals to create and develop these systems that are applicable to real-world datasets and relevant to the work of the given stakeholder group (e.g. policymakers or health care workers). ai is not a cure-all that can fix the covid- crisis, but it does have the potential to augment a given person's ability to handle and manage the crisis, thus, potentially, limiting the spread of the virus and leading to potentially better outcomes for infected patients. as covid- has permeated throughout the world, there is no one who has not felt its impact in some way. thus, scientific and medical researchers are working rapidly to find a viable cure against the disease. one tool that may well help aid this effort is artificial intelligence (ai) by assisting front-line workers in numerous ways. this paper has initially presented the details of the covid- viruses including taxonomy, signs and symptoms, cause of spread, affected body organ, and hazardous impact on human society over the last century. secondly, we mentioned the structural genome and origin of covid- infectious virus, compared it with other coroviridae family viruses, its transmission behavior and impact on global health. we presented an overview of potential use cases and ai-based implementations currently being developed and trialed. for instance, technological experts have developed ai-based programs for the rapid analysis, scanning and diagnosis of the coronavirus through pneumonia radiographic images or clinical blood sample data. these approaches offer an additional way to detect covid- , in addition to the more commonly used pcr test. as testing capabilities continue to improve, ai-based tools become more useful to assist in clinical settings rather than to replace medical professionals. however, where ai is likely to see an increased use and benefit moving forward in the future, especially as more and higher quality data becomes available, is its use in predicting potential new areas of outbreak and forecasting the spread of covid- . these models are based on parameters such as the number of positive patients in different regions of a city and tracking their movements to anticipate the potential spread through contact. for example, it could be possible to apply an ai-based model to data gathered via a contact tracing application or sewer covid- prevalence data, though other data could also be used, to better predict the scale and size of a new outbreak. the results thus obtained could help to manage and implement precautionary actions by defining guidelines in pandemic affected areas. it is important that ai-based tools are relevant, accurate, and impactful. in order to do this, cooperation is needed between ai-based researchers, medical professionals, and governmental agencies. thus, further research should identify real-world empirical examples of ai being used on real-world data. this paper has made initial steps in gathering and highlighting the current state-of-the-art, but it does not differentiate between examples working -in the wild‖ and those that are done under laboratory conditions. so, while in theory, these approaches may well be useful, until they are evaluated within an applied context it is hard to quantify their level of usefulness, in fact, it may well be the case that ai-based tools actually inhibit effectiveness if they discreetly contain some level of bias, or replace the decision making capability of a more competent human actor. ☒ the authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. ☐the authors declare the following financial interests/personal relationships which may be considered as potential origin and evolution of pathogenic coronaviruses covid- : animals, veterinary and zoonotic links zoonoses. in: encyclopedia of food and health defining epidemics in computer simulation models: how do definitions influence conclusions? defining epidemics in computer simulation models: how do definitions influence 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break repair in mammalian cells. view project matrix-isolated systems modeling view project competing interests: key: cord- - zyqqgs authors: nan title: scientific and educational exhibits date: journal: nan doi: . /s - - - sha: doc_id: cord_uid: zyqqgs nan learning objectives: to describe principles of ct perfusion studies. to describe standard perfusion protocol for -mdct in abdominal and pelvic neoplasia. to show theoretical deconvolution model for perfusion analysis. background: -mdct enables an adequate anatomic coverage and temporal resolution for perfusion analysis of solid tumor of abdomen and pelvis. perfusion studies offer an in vivo evaluation of tumor neo-vascularity. perfusional parameters evaluated by means of ct perfusion are blood volume, blood fl ow, mean transit time and permeability surface area product. procedure details: in our experience, we evaluated some cases of pancreatic tuomr, recatal cancer, urinary bladder and prostate cancer using a -mdct scanner (vct; ge). using the follwing parameters: ma, kv, . sec gantry rotation time, mm slice thickness acquired for seconds during i.v. administration of iodinated contrast medium (xenetix ; guerbet). the anatomic coverage of the scan was of cm. image analysis was performed on off-line workstation (adw . ; ge) using a dedicated software based on deconvolution alghorithm. software calculate a colored map pf different perfusional parameters and quantitative data of the same parameters in a region of interest. perfusional index may correlate with cancer response to neoadjuvant treatments. conclusion: ct perfusion studies represent a feasible and non invasive tool for in vivo evaluation of tumour neovascularity. -mdct offer the adequate temporal and spatial resolution for the application of perfusion study to solid tumor of the abdomen and pelvis. t mri of the abdomen: challenges and solutions for clinical application m. kataoka , t. koyama , h. isoda , a. kido , k. tamai , s. umeoka , y. nakamoto , y. maetani , n. morisawa , k. fujimoto , k. togashi ; cambridge/uk, kyoto/jp, wakayama/jp (mk @cam.ac.uk) learning objectives: . to outline some challenges and solutions for t mri of the abdomen. . to illustrate some promising areas where t mri has a clinical impact, with the use of emerging techniques. background: theoretical doubling effect of snr is the main reason of improving images at t mri. however, t mri of the abdomen seems challenging; susceptibility artifact is more prominent in abdomen due to abundant air-non air interface. weak rf penetration and rf inhomogeneity at t degrades image quality in body trunk. with fourfold increase of specifi c absorption rate (sar), sar limit and heating effect can be critical. in this exhibit, solutions to these diffi culties are proposed. then potentially useful clinical applications of t are discussed. procedure details: mr images of abdomen were obtained by t (trio:siemens) unit using phased array coil. for solutions, a more homogeneous rf fi eld can be obtained by using dielectric pads. sar reduction can be achieved by modifying parameters or using specially-designed sequence. furthermore, the emerging technique of variable fl ip angle turbo-spin echo sequences can reduce the sar and provides high-resolution d images in the order of millimeter. promising techniques for t include mrcp, breath-holding images. high-resolution images for the pelvis can provide better depiction for carcinomas of the uterine cervix, prostate and bladder. experimental techniques such as dwi /dti of abdominal organs can also take advantage of increased snr at t. conclusion: despite some challenges, t mri of the abdomen has a potential to improve image quality in a clinical setting. effect of diffusion-weighted image quality on abdominal apparent diffusion coeffi cient measurements t. yoshikawa, y. ohno, h. kawamitsu, m. fujii, k. sugimura; kobe/jp purpose: to assess the effect of diffusion-weighted image (dwi) quality on abdominal apparent diffusion coeffi cient (adc) measurements and the usefulness of anisotropic images. methods and materials: twenty-six patients ( men and women; mean, . years) who underwent dwi and were diagnosed not to have any abdominal diseases were analyzed. single-shot spin-echo echo-planar dwi was performed and one isotropic and three orthogonal anisotropic images were created. adcs were calculated for liver (four segments), spleen, pancreas (head, body, tail) , and renal parenchyma. image quality for each organ part was scored visually. we estimated the correlation between adc and image quality and evaluated the feasibility of using anisotropic images. results: adcs and image quality were affected by motion probing gradient directions in the liver and pancreas. a signifi cant inverse correlation was found between adc and image quality. the r values for isotropic images were - . , - . , - . , and - . for the liver, spleen, pancreas, and renal parenchyma, respectively. anisotropic images had the best quality and lowest adc in at least one organ part in patients. conclusion: dwi with the best quality among isotropic and anisotropic images should be used in the liver and pancreas. uncommon localisation of echinococcosis in the humans d. passomenos, a. athanassopoulou, m. michalakou, k. dalamarinis, l. fois; athens/ gr (dempasso@yahoo.com) purpose: we retrospectively reviewed the fi les of patients who have been hospitalized with the diagnosis of hydatid disease (hd) for the past years in order to fi nd unusual sites on the human body hosting this disease. methods and materials: patient fi les were checked out and patients' mean age was . years. all patients had a computed tomography study while mri study was done in of them. diagnosis was made by imaging features and laboratory studies and verifi ed by pathologic study wherever feasible. results: echinococcal cysts were identifi ed in the spleen ( ), kidneys ( ), abdominal cavity ( ), heart ( ), thigh musculature ( ), spinal canal ( ), seminal vesicles ( ), testis ( ) and ribs ( ). abdominal hd was manifested with symptoms of hydatidemesis in a case of a solitary left subdiaphragmatic calcifi ed cyst with gastro-cystic fi stula while abdominal obstruction was the fi rst sign of a disseminated intraperitoneal disease. cysts were calcifi ed in ( %) while cyst diameter ranged from to cm. primary disease was evident in while abdominal hd was disseminated in . iv administered contrast media was given in , while typical confi guration of hd was identifi ed in cases. surgical excision was undertaken in cases. conclusion: although liver and pulmonary hd is the most common form of the disease, uncommon locations do exist with low incidence. imaging studies are of great value in depicting the nature, extend and possible complications of hd. mri is valuable in musculoskeletal forms, while ct in abdominal disease. focal splenic lesions: role of us, ct and mr imaging in their detection and characterisation i. delgado, j. puig, a. malet, a. darnell, d. gil-bello, j. martin; sabadell/es (idelgado@cspt.es) learning objectives: to illustrate the spectrum of non-traumatic spleen abnormalities. to describe the imaging workup for the most common splenic diseases. to determine the current role of us, ct and mr imaging in the detection and characterization of focal spleen lesions. background: spleen abnormalities have received little attention in the scientifi c literature. however, recent us, ct and mr imaging advances open new possibilities in the study of splenic diseases. procedure details: for educational purposes, we can classify focal splenic lesions into vascular disorders (infarcts), infectious diseases (granulomas, abscesse, and so on), benign tumours (cysts, hemangioma, hamartom,and so on), malignant tumours (metastases, lymphoma and sarcoma), and other hematologic and metabolic disorders (haemochromatosis, gamna-gandy bodies, extramedullary haematopoiesis). conclusion: although most splenic lesions are detected as incidental fi ndings and have a non-specifi c appearance, the combined use of current imaging tools can often reach the correct diagnosis. us, ct and mr imaging all play an important role in the detection and characterization of focal splenic lesions, and with suffi cient clinical information, they enable the differential diagnosis of these lesions. parallel imaging techniques for accelerated volumetric interpolated breathhold examination (vibe) magnetic resonance imaging of the upper abdomen d.y.h. huang, r. fernando, d. svasti-salee, j. dark, n. jeyadevan; london/uk (dr.deanhuang@gmail.com) learning objectives: to illustrate the concept of parallel imaging. to describe the use and indications of parallel-imaging accelerated vibe in upper abdominal mr study based on a series of patients. the vibe is an established sequence which permits abdominal imaging in a single breath-hold. parallel imaging is a novel technique whereby parallel coils permit more rapid spatial localisation of signal independent of conventional spatial acquisition. this allows shortening of image acquisition time. it has previously been used largely with sequences that had high intrinsic signal. reports on the use of parallel imaging with sequences with low signal to noise such as the vibe sequence in abdominal imaging are limited. imaging findings: thirty-eight consective patients referred for abdominal mr imaging were included. all patients underwent abdominal mr study that included dynamic post gadolinium sequences with vibe. in addition, patients underwent further accelerated vibe sequences with parallel imaging optimised to minimise scanning time ( s vs. s). the images obtained with accelerated and conventional vibe sequences were reviewed by two experienced radiologists. the accelerated vibe sequence was comparable to conventional vibe sequence in providing clinically acceptable images. in addition, less motion artifacts were observed in the accelerated images in the sub-group of patients who had diffi culty in breath-holding, resulting in improved image quality. conclusion: we demonstrated the feasibility of parallel-imaging accelerated vibe sequence in upper abdominal mr imaging. the application of parallel imaging minimises scanning time and may be useful in patients who have diffi culty in breath-holding. spectrum of imaging fi ndings of autoimmune diseases of liver, biliary system and pancreas m.c. freund, i. graziadei, a. tzankov, k.m. unsinn, w. vogel, w. jaschke; innsbruck/at learning objectives: to be familiar with pathogenesis, pathology, clinical features, and management of autoimmune diseases of liver, biliary system and pancreas relevant to the radiologist. to be familiar with typical fi ndings of various imaging modalities (sonography, mdct, mri, mrcp, ercp) as well as complications and differential diagnosis of autoimmune diseases of liver, biliary system and pancreas. background: autoimmune diseases of liver, biliary system and pancreas are recognized as chronic progressive infl ammatory disorders of unknown etiology characterized by immunologic and autoimmunologic features, e.g. circulating autoantibodies and hypergammaglobulinemia. these diseases are associated with characteristic clinical and histologic fi ndings and include autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis, and autoimmune pancreatitis. imaging findings: this pictorial assay demonstrates relevant imaging fi ndings with emphasis on typical patterns for early recognition of autoimmune diseases of liver, biliary system and pancreas. also imaging fi ndings of complications of these diseases are shown, e.g. various types of cirrhosis, hepatocellular carcinoma, cholangiocellular and cholangiocarcinoma, biliary strictures, cholestasis, cholangitis, cholelithiasis and differential diagnosis displayed by cross-sectional imaging modalities peculiar for mentioned autoimmune disease. also, percutaneous imageguided procedures will be shown including biopsy, transhepatic cholangiography and drainage as well as endoscopic procedures including ercp and drainage for diagnosis and therapy. conclusion: although autoimmune diseases of liver, biliary system and pancreas are rare, early diagnosis with recognition of typical patterns can help avert the consequences of progressive disease and unnecessary surgery. role of contrast-enhanced ultrasound in the assessment of spleen hemangiomas t.v. bartolotta, a. taibbi, m. galia, g. malizia, l. la grutta, m. midiri; palermo/ it (tv_bartolotta@yahoo.com) learning objectives: to illustrate the enhancement patterns of splenic hemangiomas (shs) evaluated with contrast enhanced ultrasound (ceus). background: hemangioma, although infrequent, is the most common primary benign neoplasm of the spleen, with a prevalence ranging from . % to % at autopsy. sh is often discovered as incidental fi nding during an abdominal scan conducted for other reasons and more frequently observed in adults with age range from to years, with equal frequency among men and women. some studies have demonstrated that ceus is helpful in diagnosing liver hemangiomas. procedure details: two experienced radiologists retrospectively reviewed by conensus baseline and sonovue ® -enhanced us of patients ( men, women; mean age: . years) with shs (mean size: . cm) -confi rmed by splenectomy (n= ), ct (n= ) and/or mri (n= ) -evaluating baseline echogenicity and dynamic enhancement pattern of each lesion, in comparison with adjacent spleen parenchyma. at ceus, / shs showed an isoechoic appearance throughout the vascular phase, whereas / sh was isoechoic in the arterial phase but became hypoechoic in portal-venous and delayed phases. / shs showed a rapid and complete fi ll-in in the arterial phase, but appeared isoechoic (n= ) and hypoechoic (n= ) in delayed phase respectively. / shs showed peripheral hyperechoic nodules in the arterial phase, followed by progressive centripetal fi ll-in. / hemangiomas appeared as hypoechoic lesion in all phases. conclusion: the majority of shs evaluated with ceus presented an isoechoic appearance throughout the vascular phase, showing in some cases contrast-enhancement patterns similar to that of liver. implementation of diffusion-weighted imaging in routine mr imaging of the abdomen t. gerukis, r. thomaidis, a. fotiadou, a. petridis, m. pilavaki, v. kalpakidis, p. palladas; thessaloniki/gr purpose: to evaluate the use of apparent diffusion coeffi cient (adc) measurements in the study of variable (histologically proven) abdomen lesions. methods and materials: single-shot echo-planar diffusion-weighted mr imaging (dwi) was added to the routine abdomen mr examination with a . t mr unit in patients. images were obtained in b-values ( , , s/mm ) with generation of adc maps. quantitative analysis of adc was made by region-ofinterest measurements in normal and pathologic tissue of different abdominal organs (liver , pancreas , kidney , adrenal , bowel , ovaries , bladder , peritoneum patients). the mean adc value of two patients with gist was . (x - mm sec - ); in patients with tumor recurrences ( colon and ovary cancers) it was . ; in pancreatic cancer patient it was . ; in adrenal metastasis from renal cancer it was . ; in patient with desmoid tumor it was . ; in hepatocellular carcinomas it was . . the mean adc of malignant lesions was in all occasions lower than that of the benign lesions. conclusion: evaluation of adc can give further information and may be used as a tool (in adjunction to the other available sequences and techniques) in successful characterization of malignant lesions in different abdominal organs, and we believe that it must take its place in everyday clinical practice. further accumulative experience is needed to defi ne the ranges of pathologic in each occasion. can we refi ne our use of mri in the management of breast cancer patients undergoing neoadjuvant chemotherapy? b.j.g. dall, s. kumar, k. franks; leeds/uk (j.mclenachan@btinternet.com) purpose: to review and refi ne the use of mri in breast cancer patients undergoing neoadjuvant chemotherapy. we performed a retrospective audit of patients. everyone had a pre-treatment mri scan, a second scan following or cycles of chemotherapy and a third scan at the end of treatment. the volume, extent and activity of the disease was assessed and the response to chemotherapy scored (- =progressed; =no response; =minimal response; =partial; =almost complete; = complete). the third mri scan was compared to the histology at surgery. results: extent of disease (fi rst mri): mri matched mammography and ultrasound in patients ( %) and identifi ed additional disease in patients ( %). sixteen of these patients had multifocal disease. response to chemotherapy (second mri): patients who had a complete pathological response scored or on the second scan. extent of residual disease (third mri): size at mri equalled size at histology in patients ( %), mri<histology patients ( %), mri>histology patients ( %). conclusion: it is now the policy of our multidisciplinary team to use mri after cycles to change chemotherapy regimes, to plan surgery and to prompt u/s guided marker clip placement if wide local excision (wle) is likely to be a future option and mri shows a good response. the third mri does not always accurately refl ect residual disease, particularly if it is multifocal but it may not be necessary if a mastectomy is planned. it does provide important information in conjunction with mammography and ultrasound if wle is planned. role of diffusion-weighted mr imaging for characterization and differentiation of breast lesions f. pediconi, e. moriconi, f. altomari, a. roselli, s. padula, v. dominelli, c. catalano, r. passariello; rome/ it (federica.pediconi@uniroma .it) purpose: to evaluate the role of diffusion-weighted mr imaging for the characterization and differentiation of breast lesions. methods and materials: thirty consecutive women (age range: - years) with histologically confi rmed benign and malignant breast lesions were prospectively evaluated. all patients were examined at . t using a dedicated bilateral breast coil. the mr imaging protocol included axial fse t -weighted sequences with fat-suppression, axial epi sequences sensitised to diffusion along orthogonal directions, and pre-and post-contrast axial d gre t -weighted sequences (gadobenate dimeglumine, gd-bopta; . mmol/kg). the average apparent diffusion coeffi cient (adc) value along the orthogonal directions was calculated for all lesions. differences in main diffusivity (md) among the lesions were evaluated by means of a non-parametric two-tailed mann-whitney test. results: the lesions evaluated comprised fi broadenomas, cysts, invasive ductal carcinomas (idc), invasive lobular carcinomas (ilc), ductal carcinomas in situ (dcis) and papilloma. the md was signifi cantly higher for cysts than for benign fi broadenomas (p < . ) or malignant lesions (p < . ). furthermore, the md was signifi cantly lower in malignant respect to benign lesions (p < . ). conclusion: diffusion-weighted mr imaging is an inexpensive quantitative procedure that can potentially serve as a corollary to established mr techniques for characterization of breast lesions. based on diffusion properties, md maps provide valuable information for the characterization and differentiation of breast lesions. the effect of magnetic resonance mammography (mrm) on the clinical management of women with suspected lesions during x-ray mammography or ultrasound f. pediconi, s. padula, f. altomari, a. roselli, v. dominelli, e. moriconi, c. catalano, r. passariello; rome/ it (federica.pediconi@uniroma .it) purpose: to assess the impact of bilateral breast magnetic resonance mammography (mrm) on the clinical management of patients with suspected lesions during x-ray mammography or ultrasound. methods and materials: consecutive patients with suspected lesions during x-ray mammography or ultrasound were evaluated with contrast-enhanced bilateral mrm between october and february . indications of mrm included pre-operative staging (n= ; group ), undetermined or suspected lesions (n= ; group ), evaluation of mammarian prosthesis (n= ; group ), and cancer screening in patients with familial risk (n= ; group ). mrm, x-ray mammograms, sonograms, and histology were compared to determine the effect of mrm on clinical management in each group. results: mrm determined changes in clinical management in / ( . %) patients in group . the altered management was due to a greater lesion size in / cases, multifocality or multicentricity in / cases, multifocality/multicentricity and greater lesion size in / cases, contralateral foci in / cases, and suspected pectoral muscle infi ltration in / cases. in group , mrm confi rmed possible benign lesion in / patients,suspected malignant lesion in / patients, and no lesion in / patients. in group , mrm confi rmed a suspected broken prosthesis in / patients and confi rmed an intact prosthesis in / patients. in group , breast mrm identifi ed an occult tumor in / women. conclusion: mrm demonstrates high sensitivity for the detection and characterization of suspected lesions. mrm can determine important changes in clinical management and can provide accurate guidance for per-surgical treatment. learning objectives: to describe and illustrate the sonographic appearances of various benign and malignant lesions encountered in the male breast, correlate them with the pathologic fi ndings, and determine recommendations for management. background: a majority of male breast lesions are benign, with gynecomastia being the predominant pathology. male breast cancer represents less than % of all male breast disease. the most common indication for breast imaging in a male patient is a palpable mass. sonography, in addition to mammography, is often performed for the evaluation of these lesions. imaging findings: the sonographic appearance of the normal male breast is reviewed. sonographic features of various male breast lesions are illustrated and the specifi c disease entities are reviewed. benign entities include gynecomastia, infection (abscess formation), and benign masses (lipoma, fi broadenoma, papilloma, sebaceous cyst). malignant entities include primary breast carcinoma (invasive ductal cancer, papillary carcinoma) and lymphoma. the sonographic and mammographic imaging features are reviewed and correlated with the pathologic fi ndings. the various disease entities are discussed along with their management. conclusion: sonography has been shown to aid in distinguishing benign from malignant male breast lesions. familiarity with the sonographic appearance of various breast lesions is essential in the prompt diagnosis and management of diseases of the male breast. the signifi cance of ultrasound detected masses within the pectoralis muscle m. diaz, a. alonso-burgos, m. pons, m. herraiz, l. pina, g. zornoza, b. zudaire; purpose: to assess the signifi cance of masses within the pectoralis muscle detected on routine breast ultrasound studies and the diagnostic management with percutaneous procedures. methods and materials: from may to september , , routine breast ultrasound scans were performed at our institution. these cases were retrospectively reviewed searching for ultrasound detected masses within the pectoralis muscle that were diagnosed with percutaneous procedures ( g needle core biopsy and fi ne needle aspiration). clinical (age, palpation, previous surgery…), mammographic, ultrasonographic and pathologic fi ndings were studied. results: eight patients ( . %) had eight intramuscular masses (mean age . yrs; range - ). all patients had a previous malignant diagnosis (seven breast infi ltrating ductal carcinomas and one hodgkin´s lymphoma). two cases were palpable. mammograms were normal in all cases. ultrasound depicted fi ve irregular ill-circumscribed masses, two well-circumscribed masses and one seroma. seven g needle core biopsies and one fi ne needle aspiration (seroma) were performed, with good tolerance and no complications. pathology results were consistent with fi ve metastatic infi ltrating ductal carcinomas (including the intrapectoral seroma), one lymphoma, one fat necrosis and one schwannoma. conclusion: masses within the pectoralis muscle are extremely rare. a biopsy should be performed in these cases because of the high rate of malignancy, especially if the patient has a previous history of a malignant tumor. multiple logistic regression analysis of tumour descriptors for breast nodules diagnosed on ultrasonography j.t.s. ho, s.-w. hee, n. gupta; singapore/sg (ddihts@nccs.com.sg) purpose: breast ultrasonography (us) is a useful adjunct to mammography in characterising solid breast masses. we set out to develop and validate a simplifi ed diagnostic score from multiple logistic regression of us features to determine the likelihood of malignancy of a solid mass. methods and materials: patients with biopsies performed in the department of oncologic imaging, national cancer centre, singapore, from october to june were included in the study as a training set. images were reviewed in consensus by two radiologists blinded to the results of the biopsy. another group of lesions that were biopsied from april to july in the same centre was used as a validation set. the categories of the tumour descriptors were: shape, margin, echo texture, echogenicity, sound transmission, calcifi cations, surrounding tissue and ductal extension. results: the training set comprised ( %) benign and ( %) malignant nodules. the simplifi ed diagnostic score with the form ds = + c + t + m + et + s + eg - st with a possible minimum value of and a maximum value of was used. based on the roc curve from the simplifi ed ds, a score of > was considered to be malignant.results of the validation set were comparable to the training set, confi rming the validity of the simple diagnostic model. conclusion: a combination of us features may be used to predict malignancy, potentially allowing follow-up rather than biopsy in % of lesions in our validation set in this preliminary study. pregnancy; patients with previous breast surgery, radiotherapy or chemotherapy; tumours located less than mm next to the skin or thoracic wall. informed consent was obtained from all subjects. rfa was carried out under local anaesthesia. the electrode probe was placed in the centre of the lesion under us guidance. all patients underwent conservative surgical therapy - weeks after rfa. complete limphadenectomy was done when axillary node metastases were demonstrated. sentinel node biopsy was done in the remaining cases. pathologic study included the conventional haematoxylin-eosin stein and the specifi c nadh-diaphorase study in a freezed specimen. results: ages: from to years (x: ± . ). tumour sizes: between and mm. (x: . ± . ). complete ablation with negative nadh-diaphorase test was achieved in cases. one case showed a slightly positive test. in another case, the intraductal component was found out of the rfa effect ring. no signifi cant complications were observed. conclusion: offi ce-based rfa under local anaesthesia is a safe, feasible and comfortable procedure, accurate in % of the pibc smaller than mm. wider series are necessary to evaluate the technique. additional studies have to be directed to compare local recurrence taxes of rfa alone versus surgery. the background: papillomas are generally solitary tumors of the mammary ducts epithelium and are usually located near the nipple. patients typically report nipple discharge. imaging features of papillary neoplasms correlate to the gross pathology. mammograms and us are frequently normal. occasionally, we may fi nd in mammography cluster of suspicious microcalcifi cations, gross calcifi cations, benign-appearing mass or a combination of these fi ndings. us may reveal a welldefi ned, smooth-walled, hypoechoic mass or a smooth-walled, cystic lesion with solid components. galactography usually shows a fi lling defect. doppler sonography may demonstrate arterial fl ow. imaging findings: we have retrospectively reviewed the imaging fi ndings of intraductal papillomas from our pathology database. out of a total of patients, mammography was performed in , us in and ductography in . core-needle biopsy was performed in cases with a positive result for intraductal papilloma. intraductal papilloma was silent in mammography in % ( / ). a solid intraductal lesion was found in us in % ( / ). ductography showed a fi lling defect in % ( / ). conclusion: intraductal papilloma has a wide spectrum of imaging manifestations depending on their hystologic subtype. we visualize them as intraductal lesions in galactography and usually in us. ackowledgment of the typical imaging fi ndings help the radiologist to make the correct diagnosis approach. mucinous carcinoma of the breast: mammographic, ultrasonographic and mri fi ndings with pathologic correlation e. domínguez-franjo, j. oliver goldaracena, s. alonso roca, m. arguelles pinto, e. peña fernandez; madrid/es (edfranjo@gmail.com) learning objectives: . to evaluate the mammographic, ultrasound and mri appearance of mucinous breast carcinoma and to correlate the imaging features with the histologic fi ndings. . to learn the clinical and radiological fi ndings that can forecast prognosis. background: mucinous carcinoma of the breast is a rare breast neoplasm that accounts for - % of all breast carcinomas. they are more commonly found among elderly women. its prevalence is strongly age related. histologically, mucinous carcinoma can be divided into pure mucinous and mixed carcinoma depending on the volume of extracellular mucin. pure mucinous carcinoma has better prognosis and lower incidence of metastases. imaging findings: the mammographic, ultrasound and mri features are described and illustrated. the most common mammographic and ultrasonographic feature is an oval or lobular microlobulated mass with very high signal intensity on t -weighted images, and such imaging fi ndings should suggest a diagnosis when present in an elderly patient. conclusion: it is important for radiologists to be familiar with a variety of imaging features of mucinous carcinoma and their histologic type. this exhibit shows our experience with mucinous carcinoma focused on: .clinical and imaging characteristics that should suggest diagnosis of mucinous carcinoma. . the mammographic, ultrasound and mri features of mucinous carcinoma that can predict prognosis. the multiple facets of breast fi broadenomas r. rakheja, m. el-khoury, k. khetani, l. kadoche, b. mesurolle, m.p. dufresne; montreal, qc/ca (rajan.rakheja@gmail.com) learning objectives: to illustrate the broad range of sonographic presentations and associated uncommon pathological fi ndings of fi broadenomas. background: fibroadenomas are among the most common breast lesions in pre-menopausal women. fibroadenomas typically present as palpable, oval, freely mobile, rubbery masses in young women. on ultrasound, a well-circumscribed, oval-shaped, homogenous hypoechoic mass is the most common fi nding. however, clinical presentation and sonographic appearance can be highly variable, while pathologic examination can very seldom demonstrate unusual accompanying pathological entities, such as carcinoma. imaging findings: review of our database found fi broadenomas that were sonographically assessed and biopsied between september and march in our institution. fibroadenomas can be considered atypical either by their localization, occurrence in accessory breast tissue in the axilla, or by their sonographic features according to the bi-rads classifi cation, displaying suspicious or unusual sonographic appearance. fibroadenomas can also be associated with unusual pathologic components including extensive lobular carcinoma in situ, atypical ductal hyperplasia, ductal carcinoma in situ or even invasive ductal carcinoma. these cases will be illustrated and presented with special emphasis on their unusual features with pathological correlations. conclusion: while most fi broadenomas are easily diagnosed by a typical clinical and sonographic presentation, the radiologist should be aware of the possibility of rare presentations, ultrasound fi ndings and even associated malignancies. model independent perfusion parameters of breast tumors: potential for pathological characterization s. makkat, v. dewilde, m. dujardin, t. stadnik, s. sourbron, r. luypaert, j. de mey; brussels/be (smitha. makkat@vub.ac.be) purpose: to evaluate the usefulness of the regional perfusion parameters obtained with a model-independent analysis of second bolus t -weighted dynamic contrast enhanced -weighted (t -dce) data in the differential diagnosis of breast tumors. methods and materials: female patients ( - years) with histologically proven breast tumors underwent the routine mr mammography protocol which included whole breast t -dce and high-resolution fat suppressed sequences. a second bolus of . mmol/kg gd-dtpa was injected and a dynamic single slice turbofl ash acquisition (tr/te/fa/ti . / . / / , images with a temporal resolution of . s) was performed at the slice where the lesion enhanced maximally. the relative signal changes of the second bolus sequence were deconvolved pixelwise by a model independent method to yield the impulse response function (irf). the tumor blood fl ow (tbf) and the tumor volume of distribution (tvd) were calculated as the maximum and the time integral of the irf respectively and the mean transit time (mtt) as the ratio tvd/tbf. mean values of these parameters were compared between benign and malignant groups. results: final diagnosis included: benign and malignant lesions. in all the malignant lesions, the parametric maps clearly delineated tumors from the surrounding breast tissue. mean tbf and tvd values were signifi cantly higher and mean mtt values were lower in the malignant tumors compared to the benign ones (p < . ). conclusion: a pixelwise model-independent perfusion analysis of the t -dce data of breast tumors provides parameters of tbf, tvd and mtt. these perfusion parameters have the potential for the differential diagnosis of breast tumors. sono-mammographic diagnosis of gynecomastia n.m. abdel razek; cairo/eg (naglaabdelrazek@yahoo.com) learning objectives: to orient radiologists to the mammographic and ultrasonographic appearance of gynaecomastia, patterns of gynaecomastia and diagnosis procedures. the relation between the different mammographic patterns to the duration and the correlation between the mammographic and the ultrasonographic appearance to the histopathological types of gynaecomastia, and fi nally when to ask for fnb in gynaecomastia. background: gynaecomastia is the most important disease of the male breast; it is the commonest problem affecting the male breast, accounting for about % of breast masses. imaging findings: three mammographic appearances of gynaecomastia have been described: nodular, denderitic and diffuse patterns. nodular gynaecomastia b d e f a g appears as a focal retroareolar density. denderitic gynaecomastia appears as a retroareolar density with prominent extensions that radiate into the deeper adipose tissue. diffuse glandular gynaecomastia has a mammographic appearance similar to heterogenosly dense female breast; the glandular densities are either limited to the subareolar region or scattered throughout the whole breast. by ultrasonography, gynaecomastia has either focal hypoechic retroareolar lesion or diffuse echogenic hyper-refl ective parenchyma with or without prominent ducts, indicating development of the tldu. it was found that the denderitic type correlates with fi brous gynaecomastia and the nodular type correlates with fl orid type. these fi ndings are directly proportionate to the duration. fnb is reserved only in suspicious cases. conclusion: sono-mammography has provided satisfactory results in diagnosing gynecomastia as the commonest cause of breast lump in males. moreover, it correlates well with the radiographic fi ndings of different histological patterns. rare breast tumors: imaging fi ndings and radiologic -pathologic correlation c. martínez lara, b. arenas garcía, t. zamora martínez, m. baizán garcía, j. sevillano sánchez; zamora/ es (cmartinezl@ono.com) learning objectives: to illustrate the imaging fi ndings on mammography and sonography of rare breast tumors. we add a radiologic -pathologic correlation of each entity. background: the uncommon breast lesions cause a diagnostic dilemma and need a triple approach encompassing clinical, radiological and histological features. an exact diagnosis is crucial for the adequate management of the patient. procedure details: retrospective review was performed of breast lesions diagnosed in our department between january and june . all patients underwent diagnostic mammography or mammography and breast sonography. the accurate diagnosis was made by core needle biopsy. we present the imaging fi ndings and radiologic -pathologic correlation of selected cases of uncommon breast tumors: six benign tumors ( hamartoma, granular cell tumor, phyllodes tumor, lactating adenoma and intracystic papilloma) and twelve malignant tumors ( mucinous carcinoma, medullary carcinoma, primary non-hodgkin lymphoma, invasive papillary carcinoma, malignant phyllodes tumor, carcinosarcoma and metastases from carcinoid tumor). the radiologist must know the imaging fi ndings of these unusual breast tumors and take them into account to make a correct differential diagnosis, which has a great impact on therapeutic strategies. diagnostic accuracy of dynamic multidetector row ct to evaluate axillary lymph node in patients with breast cancer d. kang, j. kim, y. jung; suwon/kr purpose: to investigate the usefulness of dynamic multidetector row ct (mdct) in the detection of axillary lymph node (ln) metastasis using morphologic criteria and quantitative analysis. methods and materials: fifty-nine patients with breast cancer underwent mdct preoperatively. -slice dynamic mdct was performed before, and sec and min after an administration of nonionic contrast material. the morphologic features and contrast enhancement of the axillary ln were evaluated using multiplanar reformation and three-dimensional maximum-intensity projection. short diameter of ln, s/l (short diameter/long diameter) ratio and cortical change were evaluated as morphologic features of ln. contrast enhancement was quantitatively analyzed using a region-of-interest method to evaluate the enhancement rate and time-density pattern. results: the hilar obliteration and eccentric cortical thickening was the most sensitive predictor for metastatic ln. the density values at each scanning time were signifi cantly different for metastatic and non-metastatic ln. the sensitivity, specifi city, positive predictive value (ppv), negative predictive value (npv), and accuracy of mdct to detect metastatic ln using morphologic criteria were %, %, %, % and %, respectively, and the corresponding performances using quantitative analysis were %, %, %, % and %, respectively. in combined analysis of morphologic criteria and quantitative analysis, the overall sensitivity, specifi city, ppv, npv, and accuracy were %, %, %, % and %, respectively. conclusion: morphologic features detected on mdct help distinguish metastatic ln from non-metastatic, and was a more valuable diagnostic criteria than that of quantitative analysis. the quantitative analysis of axillary ln improved the overall specifi city and positive predictive value. quantitative refraction-based computed tomography with high resolution using synchrotron radiation e. hashimoto , a. maksimenko , s. ichihara , y. arai , h. sugiyama , k. hirano , d. shimao , k. hyodo , t. yuasa , t. endo , m. ando ; tsukuba/jp, nagoya/jp, shiojiri/jp, inashiki/jp, yonezawa/jp (ehashi@post.kek.jp) purpose: the ability of refraction-based contrast ct to depict breast cancer nest was tested by observing breast cancer of the human with synchrotron x-rays. reconstructed images of breast cancer show much detail that is noted in absorption-based ct. methods and materials: recently, we have developed a new computed tomography algorithm for refraction contrast that uses the optics of diffraction-enhanced imaging. we applied this new method to visualize soft tissue, which is not visualized by the absorption contrast. the meaning of the contrast that appears in refractioncontrast x-ray ct images must be clarifi ed from a biologic or anatomic point of view. it has been reported that the contrast is made with the specifi c gravity map with a range of approximately µarc sec. the relationship between the contrast and biologic or anatomic fi ndings has not been investigated. we compared refraction-contrast x-ray ct images with microscopic x-ray images, and we evaluated refractive indexes of pathologic lesions on phase-contrast x-ray ct images. results: we focused our attenuation of breast cancer as samples. x-ray refraction-based computed tomography appeared to be the pathological ability to depict the boundary between cancer nest and normal tissue, and inner structure of the disease. the properties of the refraction contrast provide certain advantages over other contrasts such as absorption and phase-shift. the refraction contrast can show tiny details of the inner structure, which are invisible in other types of x-ray imaging techniques. another advantage of the contrast is the sensitivity to the low z materials. purpose: to analyze the clinical and imaging fi ndings of bi-rads category breast lesions by mammographic and ultrasonographic (us) assessment ultimately diagnosed as malignancy in retrospect methods and materials: of , cases of us-guided core needle biopsy for years, category was given after biopsy, based on mammographic and sonographic evaluation, in , lesions ( . %) that were composed of palpable and nonpalpable lesions. the fi nal pathology was malignancy in lesions ( . %). each lesion was retrospectively described using bi-rads mammographic and us lexicons, and it was assessed whether the lesions were compatible with category , and if not, which fi ndings suggested malignancy. results: of the malignant lesions that were palpable in ( %) and nonpalpable in ( %), lesions were compatible with category both on mammography and on us, even in retrospect. of lesions improperly categorized as category , ( %) were palpable. four lesions ( . %) were suspicious on mammography alone (calcifi cation: ; hyperdense mass: ), and ( . %) were suspicious on us alone (microlobulated or nonparallel mass: ; skin retraction: ; hypervascularity: ) and ( %) was suspicious on both examinations. conclusion: despite the retrospective nonblinded evaluation of mammography and us, many cases are placed in category . palpable bi-rads category lesions should be more carefully assessed and should be safely managed by biopsy. papillary learning objectives: our purpose is to make a retrospective review of the imaging findings of the papillary carcinoma of the breast, and to correlate them with the histological results. background: papillary carcinomas represent - % of breast carcinomas. histologically, they can be divided into in situ carcinomas, including intracystic and intraductal types, and invasive carcinomas. as a group, they are considered to have better prognosis than other breast carcinomas because of their usual slower growth. imaging findings: mammography and ultrasound (including doppler) were performed in all of the patients in our series. evaluation of lesions with both techniques allowed us to consider most of the lesions as suspicious of malignity ( . % or of cases), classifying them as or bi-rads categories. mri was performed in order to reject multicentricity in patients. histologically, % ( of ) was classifi ed as invasive carcinomas. correlation between the different histological types and the imaging fi ndings is made observing solid nodules more often associated with invasive carcinoma than cystic lesions. we also review other different aspects in our series such as age of presentation, location, size and clinical signs. conclusion: acknowledgement of mammography and sonography features in papillary lesions allows the radiologist to suspect carcinoma. in our experience, solid papillary carcinomas are more frequently associated with histological invasion than cystic papillary carcinomas. radiofrequency ablation in breast tissue: experimental study for evaluation of heat conduction in the bovine udder b.m. stoeckelhuber , c.u. bergmann-koester , i. rudolf , f. noack , s. kapsimalakou , a. lubienski , t.k. helmberger ; luebeck/de, birmingham, al/us (stoeckel@medinf.mu-luebeck.de) purpose: to evaluate the conduction of heat in radiofrequency ablation (rfa) in the bovine udder as a model for breast tissue. especially in superfi cial lesions near the skin surface, heat conduction and demarcation of the ablated tissue is an important issue. methods and materials: rfa in a lactating and a non-lactating bovine udder was performed. the needle was deployed under ultrasound guidance. the temperature was applied in -degree steps between and ºc and maintained for minutes at the tips of the prongs. the experiment was repeated three times for each temperature step in the lactating and non-lactating tissue. histopathologic assessment of the resected specimens was made. the diameter of the ablation zone and demarcation of the ablated tissue margin against the surrounding tissue with respect to the temperature applied was measured. results: in the non-lactating tissue, there is a direct correlation of the temperature and diameter of the necrosis zone. the maximum ablation diameter was . in the non-lactating tissue and . cm in the lactating tissue. there was a sharp demarcation between . and . cm in the non-lactating tissue. the transition zone in the lactating tissue was not well visualized below ºc, ranging between and . cm. conclusion: there is little conduction of heat in bovine breast tissue. sharp demarcation of the ablation zone suggests accurate control of the heat, hence, ideal conditions for rfa in human breast tissue. b d e f a g impact of physiological bradycardia on myocardial high-energy phosphate metabolites measured by -p d csi c. wolf , g. klug , m. faulhaber , t. trieb , m. frick , b. metzler , w. jaschke , m. schocke ; innsbruck/at, würzburg/ de (christian.wolf@uibk.ac.at) purpose: -p-magnetic-resonance-spectroscopy ( p-mrs) is a unique tool to investigate in vivo high-energy phosphates (hep) in human heart. we intended to evaluate the impact of low-heart rates on myocardial high-energy phosphates (heps). furthermore, we aimed at comparing training induced. methods and materials: twenty-one male volunteers (mean age ± years) with a physiological heart rate (hr) below bpm were compared to a group of age-matched normofrequent volunteers (hr > bpm). all volunteers underwent -phosphorous -dimensional chemical shift imaging ( p- d-csi) and cine mr images in short and long-axis acquired using breathhold ecg-triggered cine bright blood sequences to assess their myocardial hep metabolism by determining phosphocreatinine to beta-atp ratios (pcr/b-atp) on the one side and heart morphology and function on the other side using a . tesla scanner. results: all volunteers were free of known cardiovascular disease. the detailed results of heart function (ventricular wall thickness, ventricular mass, volume of heart chambers, ejection fraction, stroke volume a.s.o). will be presented. in the spectroscopic evaluation, volunteers with a hr< bpm showed signifi cantly higher pcr/b-atp ratios than volunteers with a hr> bpm ( . ± . vs. . ± . , **: p < . ). conclusion: in this study, we observed a difference in myocardial hep metabolism between volunteers with bradycardia and normofrequent volunteers. to further determine the effects of endurance training or drug-induced bradycardia on myocardial hep metabolism, p-mrs might be of clinical importance since pcr/b-atp is a prognostic marker in patients with structural heart failure. high-resolution myocardial perfusion imaging at . t: comparison to standard . t perfusion studies and diagnostic accuracy in patients with suspected cad c. meyer, k. strach, d. thomas, m. hackenbroch, u. schwenger, h. schild, t. sommer; bonn/ de (carsten.meyer@ukb.uni-bonn.de) purpose: to evaluate high resolution myocardial rest perfusion (hrrp) in healthy volunteers at . t in comparison to . t and the technical feasibility and diagnostic accuracy of . t high resolution myocardial stress perfusion (hrsp) in patients with suspected cad. methods and materials: all perfusion studies were performed using a t -tfe-sequence. seventeen healthy volunteers underwent a hrrp at . t (pixel size: . mm ) and . t (pixel size: . mm ). myocardial signal intensity (si) increase was assessed for . t and . t. image quality was evaluated on a four-point grading scale ( : excellent, : non-diagnostic) with respect to homogeneity of myocardial enhancement, blurring and presence of artifacts. nineteen patients with suspected cad hrsp was qualitatively assessed for stress-induced hypoperfusion. hemodynamically signifi cant cad was defi ned as stenosis > % in conventional coronary angiography. results: si increase in hrrp at . t was not signifi cantly different from that at . t ( % ± vs. % ± , p> . ). image quality was signifi cantly improved at . t ( . ± . vs. . ± . , p < . ). mean score of image quality was . ± . . the mean si increase was % ± . sensitivity and specifi city of hrsp studies at . t for the detection of signifi cant cad was % and %, respectively. conclusion: hrrp at . t permits signifi cantly improved spatial resolution and provides signifi cantly improved image quality in comparison to a standard approach at . t. . t hrsp is feasible in patients yielding promising results for the detection of signifi cant cad. ( ) to determine the usefulness of a new diffusion/convection (medium size) mr contrast media p in defi ning reperfusion after myocardial ischemia; ( ) to compare the kinetics of p in occlusive and reperfused ischemically injured myocardium using inversion recovery echo-planar imaging (ir-epi), ) to chrono-logically measure the extent of myocardial injury on p -enhanced t -weighted spin-echo imaging (t -se). in this experimental study, rats were subjected to either of the following myocardial injuries: min lad occlusion followed by . h reperfusion (n= ) to produce non-transmural infarction, or complete lad occlusion (n= ) to produce transmural infarction. mr imaging was performed before and after administration of . mmol/kg p . ir-epi and t -se sequences were repeatedly acquired to measure t and injury extent. histopathology was performed to measure true infarcted size. results: after administration of p , reperfused infarct showed immediate enhancement on the t -se images. this fi nding was confi rmed by the sequential measurement of t in the infarcted and peri-infarcted zones. in contrast, occlusive infarcts appeared as hypo-enhanced core surrounded by an enhanced rim after contrast administration. the slow wash-in and wash-out of p from myocardium provided differentiation between occlusive and reperfused myocardial injury for min. the t values in the occlusive infarcted gradually increased in the -min observation period, but it did not reach those values that were obtained in the reperfused infarct. conclusion: p provides prolonged window of discrimination between occlusive and reperfused myocardial injury. p provided persistent ( min) enhancement of peri-infarcted and infarcted myocardium. mri of cardiac and paracardiac masses: a pictorial review g.k. schneider, p. fries, m. boehm, h.-j. schaefers, i. kindermann; homburg a.d. saar/de (ragsne@med-rz.uni-sb.de) learning objectives: the purpose of this exhibit is to present mri fi ndings in both benign and malignant cardiac tumors as well as tumor-like lesions. when helpful ct imaging, catheter angiography and echocardiography as well as histologic specimens are presented, important fi ndings for diagnosis, staging and therapy planning will be highlighted. background: although cardiac masses are most frequently detected on echocardiography, mri is the method of choice to accurately evaluate and further characterize cardiac tumors. imaging findings: an overview of imaging techniques in cardiac mri together with proposed protocols to evaluate cardiac masses will be presented. based on mri fi ndings and other clinical data, algorithms that give the reader a large spectrum of information to characterize cardiac and paracardiac masses will be presented. case studies include common and rare benign and malignant as well as tumor-like lesions, with typical and atypical manifestation, and these will be correlated with histology and surgical images. conclusion: mri is a valuable tool in the evaluation of cardiac and paracardiac masses. the maximum information is gained if all clinical information together with results of other imaging modalities are taken into consideration. the minimal mr protocols to characterize a lesion should be understood to add important information in the work-up of cardiac and paracardiac masses. safety of cmr adenosine stress perfusion imaging in patients with coronary artery disease d. piotrowska, l. kownacki, o. rowinski, m. golebiowski, g. opolski, l. krolicki; warsaw/pl (dpiotrowska@plusnet.pl) purpose: the aim of this study was to assess safety of stress perfusion cmr imaging during adenosine infusion in high risk patients with three vessel coronary artery disease and early after acute myocardial infarction. methods and materials: examination reports of high risk patients who underwent cmr in stress condition during adenosine infusion ( ug/kg b.w./ min, over . min) were included in the study. of studied patients had stable three vessel coronary artery disease and patients were scanned within one week after acute myocardial infarction. we analyzed response pattern to adenosine infusion and frequency of adverse events. results: adverse events during infusion of the adenosine were observed in patients ( %). the frequency of adverse events ranged from % for warm feeling, % for dyspnea and % for chest pain/discomfort to % for temporary atrio-ventricular block. all adverse events disappeared quickly without treatment. signifi cant systolic blood pressure drop (more than mmhg) was seen only in patients with tree vessel disease and occurred mostly in fourth minute of adenosine infusion. only in cases stress perfusion was not performed because of pressure drop. conclusion: stress cmr perfusion using . minutes adenosine infusion protocol is safe in patients with advanced coronary artery disease as well as early after acute myocardial infarction. sion scores between acute and chronic phases were also signifi cantly correlated (r= . , p < . ) and adhesion score in chronic phase was signifi cantly reduced compared with that in acute phase ( . ± . versus . ± . , p < . ). in chronic phase, compared with acute phase, pericardial thickness was reduced and new lesion of pericardial adhesion was not found. conclusion: tagging mri is useful for assessment of pericardial adhesion and the image obtained one month after cardiac surgery can predict pericardial adhesion in a few years. fast cine sequences for evaluation of valvular heart diseases l. natale, a. meduri, a. lombardo, l. bonomo; rome/ it (lnatale@rm.unicatt.it) learning objectives: to understand relationships between fl ow disturbancies and different cine-mri techniques. background: valvular diseases cause fl ow disturbances and consequent fl ow voids on gre images depending on a variety of factors, especially echo time. procedure details: in patients with mitral or aortic valvulopathies we compared area, length and subjective grading of turbulence jets using fast-gre ( and khz receiving bandwidth, prospective or retrospective gating) and ssfp cine sequences with echocardiography as gold standard. results: gre cine sequences with - msec tes display well the turbulence jets but require long scanning times and are often degraded by breathing artefacts. fast-gre sequences allow breath-hold acquisition but te is forced to a minimum default value, with consequent impaired detection of fl ow voids. in fast-gre with prospective gating, reduction of receiving bandwidth to - khz allows - msec tes, with more marked turbulence jets; fast-gre with retrospective gating allows the choice of any te coupled with a higher temporal resolution (at least phases are required). in ssfp blood signal is due to t /t ratio with variable turbulence jets evidence. good correlation with echocardiography and velocity mapping data has been obtained for retrospective gated fast-gre cine sequences. conclusion: turbulence jets assessment with fast sequences allows rapid semiquantitative evaluation of valvular function identifying patients needing velocity mapping measurements. fast-gre techniques showed different sensitivities mainly depending on echo time, but are generally suitable for fl ow assessment. ssfp techniques are not adequate for fl ow evaluation. left atrial remodeling after left atrial circumferential ablation for atrial fi brillation r.j. perea, t.m. de caralt, d. tamborero, l. mont, m. sanchez, r. salvador; barcelona/es (rjperea@clinic.ub.es) purpose: the purpose of this study is to evaluate the effect of left atrial circumferential ablation (laca) for af treatment in left atrial (la) volumes. methods and materials: forty-one patients who underwent laca for symptomatic drug refractory af were included. mri was performed only when patients were in sinus rhythm before laca and - months after it. la maximal volume (lamax), la minimal volume (lamin) and la ejection fraction (la ef) were compared. results: pre-procedural lamax and lamin were smaller and la ef was higher in the patients ( %) with no arrhythmia recurrences during the follow-up. there was a signifi cant reduction of lamax, lamin and la ef after laca in the entire group. lamax and lamin reduction occurred in those patients with recovered sinus rhythm ( ± to ± ml and ± to ± ml, respectively; p < . ), as well as in those patients with relapsed af ( ± to ± ml and ± to ± ml, respectively; p < . ) after ablation. no changes were appreciated in la ef in patients with successful laca ( ± % to ± %; p < . ), but a reduction was noted in patients with af recurrences ( ± % to ± %; p < . ). conclusion: la inverse remodeling was present in all patients submitted to laca, regardless of the clinical outcome. intramyocardial injection of adeno-associated viral vector encoding vegf gene improves cardiovascular magnetic resonance measurements of perfusion and infarct resorption a. jacquier, d. saloner, a. martin, l. do, c.b. higgins, m. saeed; san francisco, ca/us (alexis.jacquier@ap-hm.fr) purpose: to determine the effects of cardiac-specifi c adeno-associated viral vector (aav) encoding for vascular endothelial growth factor (vegf) on regional myocardial perfusion and infarct resorption using magnetic resonance imaging (mri). methods and materials: mri was performed in swine at days and weeks after reperfused infarction. aav-vegf was injected h after reperfusion into the the role of mr imaging in various cardiomyopathies e. chun , s.i. choi , w. lee , j.-h. park ; seong-nam/kr, seoul/kr (drsic@radiol.snu.ac.kr) learning objectives: to learn the merit and the potential role of cardiac mri in the evaluation of various cardiomyopathies. background: the cardiomyopathies include a variety of diseases where the primary pathology directly involves the myocardium. cardiac mr (cmr) is proving increasingly valuable in the identifi cation and management in these conditions. procedure details: we will illustrate the various mr techniques such as delayed enhancement, stress perfusion mri, cine mri, tagged mri using harp software, and venc-mri (for the evaluation of diastolic function) in patients with cardiomyoaphty. also, we will present the characteristic mr fi ndings of ischemic, dilated, restrictive cardiomyopathy, arrythmogenic rv dysplasia, constrictive cardiomayoapthy, lv diverticulum, stress-induced cardiomyopahty, non-compaction, and myocarditis on the basis of our experiences. conclusion: familiarity with mri techniques and features of various cardiomyopathies is considered to be helpful for the accurate diagnosis and proper management. evaluation of tissue iron overload in b-thalassaemia patients: a comparative study between . t and . t i. seimenis, c. economides, e. eracleous, s. kokkis, t. posporis; nicosia/cy (yseimen@phys.uoa.gr) purpose: tissue iron overload in b-thalassaemic patients is routinely assessed with mri at . t. this work focuses on the differences and advantages of high fi eld measurements. methods and materials: t and t * proton relaxation measurements in the heart and liver of twelve b-thalassaemic patients were obtained at . t and . t, using a respiratory-triggered multi-echo, carr-purcell-meiboom-gill spin-echo sequence (tr= ms, te ,te ,…,te = , ,…, ms) and a breathold multi-echo, k-space segmented, gradient-echo sequence (tr= ms, te ,te ,…,te = . . . ,…, . ms), respectively. both sequences were electrocardiographically gated and prescribed along the short cardiac axis. moreover, sequence optimization was pursued for . t measurements. the increased snr at . t can be used to increase in-plane spatial resolution, which is important for accurate myocardium delineation. since the water-fat-shift is larger at . t, fat suppression is suggested for high fi eld measurements. in the patient group studied, there was no signifi cant difference between t values measured at . t and . t, in terms of iron overload classifi cation (low, medium or high). with regard to t * determination, heart t * values obtained at . t were considerably shorter than the corresponding values obtained at . t in fi ve subjects. this may be attributed to the increased susceptibility effects at . t, and may suggest a tool for assessing iron distribution in ferritin and haemosiderin deposits. additionally, the advanced performance gradient system on the . t system allows the use of submillisecond tes, which are necessary for t * determination in severe myocardial iron overload. conclusion: the use of . t seems to benefi t liver and, particularly, heart iron level determination in b-thalassaemic patients. assessment of pericardial adhesion after cardiac surgery by tagging magnetic resonance imaging a. ichinose, i. yoshioka, k. takase, s. takahashi; sendai/jp (azusa@rad.med.tohoku.ac.jp) purpose: assessment of pericardial adhesion after cardiac surgery is very important in the conduct of repeat surgery or prediction of right-sided cardiac function. in this study, we hypothesized that tagging magnetic resonance imaging (mri) is useful for assessment of pericardial adhesion. we performed tagging mri in consecutive patients who underwent cardiac surgery one month ago (acute phase) and repeated the examination in of them after more than years (chronic phase). pericardial adhesion was visually scored ( =no adhesion, = mild adhesion, = severe adhesion) at two sites (post sternal bone site and right ventricular site) by one radiologist and one cardiovascular surgeon independently. the sum of scores at two sites (adhesion score) was obtained and compared between two readers or between acute and chronic phases. results: there was a signifi cant correlation between adhesion scores by two readers using spearman rank order correlation coeffi cient (r= . p < . ). adhe- b d e f a g infarcted and peri-infarcted myocardium (n= ), the other pigs served as control. cine sequences (tr/te= / ms, phases), gd-dota fi rst pass perfusion (sr-gre: tr/te= / . ms) and delayed contrast enhancement (ir-gre: tr/te= . / . ms, ti= - ms) were performed to measure lv function, area at risk (aar) and infarct size. at postmortem, the hearts were stained with histochemical ttc, masson's trichrome and isolectine b to characterize myocardium. results: aav-vegf prevented the deterioration of lv ejection fraction in treated animals at weeks. aav-vegf animals showed greater reduction in the aar ( ± % at days to ± % lv at weeks) versus control animals ( ± % to ± %, p < . ). aav-vegf improves the reduction in extent of hyperenhanced myocardium in treated ( ± % at days to ± % lv at weeks) versus control animals ( %± % to ± %lv, p < . ). ttc infarct size was smaller in treated ( ± % of lv) compared with control animals ( ± % of lv, p < . ). histology showed increase in thin-walled arterioles ( ± /mm² in treated versus ± /mm² in control) and capillaries ( ± /mm² in treated versus ± /mm² in control) in the injection sites. conclusion: intramyocardial injection of aav-vegf signifi cantly improved mri measurements of myocardial function and perfusion. the therapy also increases infarct resorption by promoting angiogenesis. role of cardiac magnetic resonance imaging (mri) in the follow-up assessment of tetralogy of fallot (tof) repair p. serrano gotarredona, s. navarro herrero, l. aguilar sánchez, l. garcia camacho, i. gutierrez jarrín; sevilla/es (mp.serrano.sspa@juntadeandalucia.es) purpose: to assess the value of cardiovascular mri in the follow-up of tetralogy of fallot after complete reparative surgery. we include all the patients who were survivors of tof surgical repair and were explored by mri in our institution during the last two years. the protocol included d mr angiography (mra) to delineate pulmonary arteries anatomy; spin-echo and gradient echo sequences to delineate right ventricular outfl ow tract (rvot); balanced steady state free precession (b-ssfp) cine-imaging to quantify ventricular function; and phase-contrast velocity mapping (vec-mr) to quantify pulmonary regurgitation (pr). results: we studied patients aged between and , of them older than eighteen years. the estimated value of ejection fraction of the right ventricle was over % in eight subjects, and under % in fi ve. up to thirteen had pr. vec-mr sequences concluded regurgitation fraction equal or over % in three cases, between and % in two, between and % in other seven. the last one had a pr of %. d mra showed pulmonary artery branches stenosis in seven cases. it was severe at the level of the anastomoses a case of prosthetic conduit placement because of rvot re-stenosis. b-ssfp sequences showed residual ventricular septal defect in two patients. conclusion: cardiac mri is a valuable method to evaluate and follow-up tof patients who had undergone complete surgical repair. it not only provides valuable anatomic information about rvot and pulmonary arteries, but also quantifi es ventricular function and pulmonary regurgitation. cardiovascular magnetic resonance in the follow-up of adults with corrected tetralogy of fallot: a useful tool to indicate reoperation? f. baudraxler, m. bret-zurita, e. cuesta, a. aroca, j. oliver, a. sánchez-recalde; purpose: to demonstrate that cmr can be a useful imaging modality to indicate reliably a re-operation in patients with repaired tetralogy of fallot (tof). to show the indications for reoperation in our patients. methods and materials: seventy-six cmr imaging studies of patients with repaired tof performed between january and september were reviewed. a . t signa lx . echo-speed ge mr system, body or cardiac array coils were used. se t ecg-gated, fiesta, pc flow sequences and mr-angiography d with mpr and vrt reconstructions were employed. morphology and size of cardiac cavities and aneurysms of the right ventricular outfl ow tract (rvot), right ventricular ed and es volume, stroke volume, cardiac output, ejection fraction (ef), pulmonary blood fl ow, and morphology of the pulmonary tree were analyzed. results: parameters provided by cmr which indicated reoperation were the following: right ventricular ed volume> ml, ef less than %; regurgitation fraction more than % and aneurysm of rvot > - cm. forty-six reoperations were performed in patients. the most common indications referred to aortic root and valve (n= ), right ventricle to pulmonary artery (rv-pa) conduit obstruction (n= ), and enlargement of the rvot inserting a pulmonary valve prothesis (n= ). mean age at reoperation was years and the average time between the corrective repair and reoperation was years. conclusion: cmr is a diagnostic imaging modality to indicate reoperation in all our patients with repaired tof. however, we still need new techniques for a better interpretation of cmr parameters in order to determine the right moment for reoperation. cardiac mri in patients with previously treated congenital heart disease: long term follow-up results a. sias, a. balestrieri, c. politi, g. mallarini; cagliari/ it (alessandrosias@hotmail.com) purpose: the purpose of this study is to display the fi ndings of cardiac mr examinations performed on a group of patients treated for congenital heart disease when infants or children, after a period of relative well being which lasted for several years. methods and materials: among a sardinian population of about , patients surgically treated for congenital heart disease on an average of years before we randomly selected of them and examined with standard cardiac mr to evaluate the heart morphology, and whether they had any abnormalities which could have gone undetected with other follow-up examinations to which they had been routinely subjected. we discovered a number of pathological fi ndings which were not noted, or underevaluated with other imaging examinations and/or clinical examinations. conclusion: follow-up cardiac mr examinations in patients with congenital heart disease surgically treated, even after a long term interval after the intervention, can be useful in defi ning the evolution of cardiac morphology and the development of iatrogenic or surgery related abnormalities, which might go undetected by standard follow-up examinations. aortic coarctation: evaluation with cardiovascular magnetic resonance angiography using time-resolved imaging of contrast kinetics ( background: cardiac magnetic resonance (cmr) in children may be limited in unravelling all details concerning the heart and great vessels. cmr is very attractive, however, for it allows an optimal anatomical and functional analysis and does not require iodine nor radiation exposure. standard d magnetic resonance angiography ( d-mra) series may not reveal all anatomical abnormalities because of incorrect timing of peak enhancement. for a better display of the cardiovascular fi ndings, it would be desirable if one could reconstruct such structures at different contrast transit times. the d-mra with tricks, available in ge mr scanners, furnishes sequential mra gadolinium-enhanced series and allows the selection of the best contrast-enhanced series to study a particular vessel. it would, therefore, be very useful in the evaluation of aortic coarctation. imaging findings: patients' mean age was . years ( - ) and they were referred to either diagnose aortic disease or to post-treatment follow-up. all images underwent extensive time-resolved reconstructions at dedicated workstations and dvr data sets were reconstructed in order to unravel the anatomy of the aorta and its main branches. conclusion: tricks is a powerful tool in the evaluation of aortic coarctation for it allows precise identifi cation of the aorta disease and of additional cardiovascular malformations, such as pda. this was the fi rst mra technique to provide d temporal display of the fl ow-abnormalities. evaluation by mri of left ventricular remodelling and global functional recovery in patients treated with granulocyte-colony stimulating factor (g-csf) after acute myocardial infarction (ami) l. natale, a. bernardini, a. meduri, a. leone, f. crea, l. bonomo; rome/it (lnatale@rm.unicatt.it) purpose: to assess by mri the effect of i.v. administration of g-csf on global myocardial function after ami. recent data suggest better outcome and functional recovery in patients with ami treated with stem cells therapy, both with intracoronary delivery or hematopoietic precursor mobilization by g-csf. methods and materials: eight patients with anterior ami, treated with primary ptca (timi ) and i.v. administration of g-csf ( µg/kg for days), were studied c b d e f a g by . t mri within days and after - months. functional, perfusion (fp) and delayed enhancement (de) studies were obtained. values were compared with eight control patients (anterior ami, primary ptca). fp and de were scored basing on number of segments involved and on transmural extension. correlation of fp and de with functional outcome and differences between the two groups, accounting for fp and de extent, were assessed with univariate (lr) and multivariate linear regression (mlr) and covariance analysis (ancova). results: lr showed signifi cant correlation between de-score and follow-up edv (fu-edv), esv (fu-esv), and ef (fu-ef). no signifi cant linear correlation with fp-score was found. mlr and ancova showed a positive trend in g-csf group for all functional indexes, accounting for differences in de (effect of g-csf, expressed as ls-means: fu-edv= - . ± . ml; fu-esv= - . ± . ml; fu-ef= + . %± . ). the effect of g-csf approached statistical signifi cance only for fu-esv (p= . ). conclusion: we found a positive trend with partial statistical signifi cance regarding global functional recovery in patients treated with i.v. g-csf after ami. these data, however, need to be confi rmed in a larger series. delayed enhancement in patients with dilated cardiomyopathy is unrelated to virus persistence or the presence of infl ammation in myocardial biopsies s. langner, j. ruppert, k. hegenscheidt, a. staudt, n. hosten; greifswald/de (langso@uni-greifswald.de) purpose: dilated cardiomyopathy (dcm) is a frequent cause of heart failure. some patients show delayed enhancement (de) in contrast-enhanced mri (cemri). the pathologic surrogate of de is unknown in dcm. virus persistence and myocardial infl ammation can be shown in a considerable proportion of myocardial biopsies of patients with dcm. the study compares the histological fi ndings with the presence of de in the cemri of dcm patients. methods and materials: twenty-two patients with dcm underwent cemri after myocardial biopsy. biopsies were taken from the right ventricular part of the interventricular septum (ivs) and analyzed for viral genomes and infl ammation. mri was performed on a . t mri scanner. images for de were acquired minutes after injection of gd-dtpa and were visually assessed for de. this was categorized regarding the location in the myocardium and the distribution pattern. the most abundant pattern of de was a stripe-like lesion in the midwall portion of the ivs. there was no signifi cant correlation for de and the cardiac parameters. seven myocardial biopsies were positive for viral genomes ( . %). three of the virus-positive patients ( . %) showed de versus of the virus-negative patients ( . %), with no statistically signifi cant difference. myocardial infl ammation was detected in patients ( . %). de was present in of these patients ( %) and in of the remaining patients ( %), with no signifi cant difference. the presence of delayed enhancement does not correlate to myocardial virus persistence or to the presence of myocardial infl ammation in myocardial biopsies of patients with dcm. meta-analysis: coronary calcium score as a predictor of atherosclerotic cardiovascular disease events in asymptomatic patients s.k. ternovoy, v.e. sinitsyn, s.p. morozov; moscow/ ru (spmoroz@mail.ru) purpose: to defi ne predictive value of coronary artery calcium (cac) scoring in identifying asymptomatic patients at higher risk of atherosclerotic cardiovascular disease (cvd) events (non-fatal myocardial infarction, coronary death, and coronary revascularization). the data from previously published studies (indexed in pubmed medline) were extracted for the meta-analysis. the studies should have reported cac scores and prospective registration of cvd events in order to be included in the meta-analysis. relative risk (adjusted for traditional risk factors) was used as a meta-meter for cvd events in cac score subgroups of patients. we tested data for publication bias, applied q-test for heterogeneity, and analyzed individual weights of the studies. results: our meta-analysis included studies. the studies were very heterogeneous in terms of patients' age, sex, race, and duration of follow-up. the pooled relative risk calculated on the basis of random effects model was . for cac scores - ; . for cac scores - ; and . for cac scores > . the analysis of the infl uence of individual studies on the pooled relative risk allowed identifying the outlying studies. the results of the meta-analysis demonstrate that relative risk of cvd events signifi cantly increased with higher cac scores. we conclude that cac score is the risk factor independent of cvd events, since the pooled relative risks were adjusted for traditional risk factors. the effect of outlying studies on the pooled estimates may be explained by the different representation of genders, blinded endpoint validations and registrations, and longer follow-up. the use of a ct cardiac bowtie to improve image quality and reduce patient dosage j. gao, x. sun, j. li, r. dai, g. wang, n. li; beijing/ cn (jianying.li@med.ge.com) learning objectives: to demonstrate the potential of using an application-specifi c bowtie to improve cardiac image quality and reduce patient dose. background: using application-specifi c bowties can reduce x-ray dose for ct imaging. ge vct provides a cardiac bowtie (cb) that redistributes x-ray fl ux to concentrate on the heart. this study evaluates the dose-reduction potential of such bowtie by comparing it to the use of traditional large bowtie (lb) using patient scan data. imaging findings: thirty cardiac patients in each group with similar sex, age, height, weight and heart rate distributions were scanned with lb and cb, respectively. two experienced radiologists quantitatively evaluated the image quality blindly in terms of the number of coronary arteries identifi ed, vessel edge sharpness and contrast agent clarity in the vessel using scores of - , with being the highest. ctdiw values and image noises for the two sets were measured and statistically analyzed using t-test. the image quality scores for the cb and lb groups were . ± . and . ± . , respectively, with no statistical difference (p> . ). however, the ctdiw values for groups cb and lb were . ± . mgy and . ± . mgy, respectively, with t-test of p= . indicating statistically signifi cant lower dosage with cardiac bowtie. in addition, the noise measurements for the cb group was statistically lower than those of lb ( . ± . vs. . ± . with p= . ). the application-specifi c cardiac bowtie on vct reduced the overall dosage to cardiac patients and image noise without adverse impact on other clinically relevant parameters. ( ) with neither ncp nor cp. groups were compared as to age, sex, coronary risk factors (crfs). results: the groups had . , , and subjects, respectively. the incidence of hypertension and diabetes mellitus (dm) were higher in group ( ) ( % and %) than in ( ) ( % and %). the incidence of crfs, number of males, dm, hyperlipidemia (hl), and smoking were signifi cantly higher in ( ) than in ( ). in logistic models, hl and obesity (relative risks . and . ) were associated with incidence of fcp adjoining ncps. furthermore we divided group ( ) into two groups: ( a) with exclusive ncp without any cp or ( b) with ncp separate from cp. crfs were . ( b) and . ( a) and that of ( a) was similar to ( ). conclusion: crfs were more frequent in subjects with fcp adjoining ncp than in other groups. fcp adjoining ncp may indicate the advanced arteriosclerosis. conversely, crfs were less frequent in subjects with exclusive ncp than in other groups with any ncp and/or cp but similar in subjects with neither ncp nor cp and presence of exclusive ncp may indicate early staged arteriosclerosis. presence of focal fatty infi ltration of the right ventricular wall in asymptomatic patients undergoing screening coronary calcium scoring on ebct j. kirsch, e.e. williamson, j. glockner; rochester, mn/us purpose: macroscopic focal fat deposition along the free wall of the right ventricle (rv) has been historically associated with arrhythmogenic right ventricular dysplasia. recently, it has been shown that this fi nding can be seen in patients without arvd. in this investigation, we assess the incidence of fatty infi ltration of the rv in a cohort of patients without clinical evidence of arvd. methods and materials: consecutive patients undergoing non-contrast ecggated ebct for coronary calcium scoring comprised the study group. images were evaluated for the presence or absence of rv fatty infi ltration as well as additional fatty proliferation in the mediastinum, lipomatous hypertrophy of the interatrial septum, and changes of thoracic surgery. medical records were assessed to obtain age, gender, body-mass index, and arrhythmias detected on ecgs obtained within months of imaging. patients with surgical changes were excluded to avoid falsenegatives secondary to artifact. images were evaluated, by consensus, by of dedicated cardiac radiologists. results: of the patients, were excluded due to lack of required information in the medical records and/or surgical changes. / ( %) patients had fatty deposition along the rv wall. conclusion: focal fatty infi ltration of the rv is a fairly common fi nding in the patient population, and should not be considered as defi nitive evidence of arvd. three learning objectives: to describe the wide spectrum of the anomalous pulmonary venous return. to understand pathophysiology and radiologic features of this entity and diverse post-operative anatomical and hemodynamic changes. to evaluate the utility of three-dimensional ct angiography in the diagnosis and management of this entity. background: anomalous pulmonary venous return shows diverse anatomical and hemodynamic spectrum, which range from isolated incidental fi ndings to components of more complex anomalies, most often congenital heart disease. correct diagnosis with ct angiography affects the patient's treatment and allows avoiding unnecessary invasive studies. procedure details: we retrospectively reviewed ct angiography with d reconstruction images of consecutive patients with anomalous pulmonary venous return ( papvr and tapvr) from june to march . twenty-nine pre-operative ct angiography were available and post-operative ct angiography were available; among them, both pre-and post-operative ct angiography were available in cases. we will show the diverse spectrum of anomalous pulmonary venous return and remind the check points in imaging interpretation to provide critical information for surgical planning and post-operative evaluation. conclusion: three-dimensional ct angiography provides precise and excellent overview of the diverse spectrum of anomalous pulmonary venous return, noninvasively. in addition, it allows in assessing other anomalies involving the bronchial tree or visceral organs. this exhibit will help you to understand the characteristic imaging features and diverse post-operative anatomical and hemodynamic changes of this entity, and to remind the information critical for surgical planning and postoperative evaluation. initial experiences of 'snapshot cine' -low dose prospective electrocardiograph (ecg)-triggering coronary -slice ct angiography (cta) m. kiguchi , j. horiguchi , k. ito , k. marukawa , c. fujioka , m. ishifuro , t. furukawa , y. shen , f. watanabe ; hiroshima/jp, tokyo/jp (kiguchi@hiroshima-u.ac.jp) learning objectives: to demonstrate low radiation dose in -slice coronary cta using prospective ecg-triggering. to demonstrate reduction of banding and cone beam artifacts by d back projection ( dbp) algorithm. background: diagnostic capability of -slice cta for coronary artery disease has been already accepted and become a widely spread use. the major drawback of the technology is the high radiation dose caused by data acquisition with retrospective-ecg gating on which the raw data includes cardiac phases not contributing in image reconstruction. advancement of ecg-modulated retrospective-ecg gating technique and prospective ecg-triggering scan are strongly desired to overcome this problem. procedure details: a -row x . mm-collimation confi guration ( mm) (ge healthcare) is used for data acquisition with prospective ecg-triggering. three or x-ray exposures per examination with mm overlapping cover cm or . cm in z-axis. banding artifacts, which are caused by misregistration of data and have been observed so far on retrospective-ecg gating scan, are reduced. conebeam artifacts seen on multi-slice ct technology are also reduced by dbp algorithm. we present initial experiences of this software as to dose saving and image quality. the image quality was assessed on motion artifacts and data continuity (occurrence of banding artifacts), with relation to the scanning time and heart rate. conclusion: 'snapshot cine' -slice coronary cta using prospective ecg-triggering, with signifi cantly reduced dose, has a potential to replace retrospective-ecg gating cta. cardiac ct for the stratifi cation of cardiovascular risk in patients undergoing major non-cardiac surgery: background, rationale and possible diagnostic algorithm l. damiani, a.l. la fata, e. maffei, a.a. palumbo, f. notarangelo, a. aldrovandi, f. cademartiri; parma/ it (damianilaura@virgilio.it) learning objectives: to provide current methods and guidelines for stratifi cation of cardiovascular risk in patients undergoing major non-cardiac surgery. to understand the rationale for stratifi cation of cardiovascular regarding different implications of inducible myocardial ischemia in the surgical theatre. to provide an algorithm for stratifi cation of cardiovascular risk in patients undergoing major non-cardiac surgery that includes cardiac-ct. background: in daily clinical practice, patients undergoing major non-cardiac surgery need a stratifi cation of their cardiovascular risk. this is performed by means of scoring methods and diagnostic tests (i.e. ecg, stress-ecg). however, these tests are sub-optimal and because of their low sensitivity and specifi city may under/over-estimate the potential risk. conventional coronary angiography, which is the diagnostic gold standard, cannot be performed in all patients since it is invasive and the prevalence of signifi cant disease is intermediate or low. cardiac-ct is a non-invasive method for assessment of signifi cant coronary artery disease characterized by a high sensitivity and negative predictive value. in addition, it can provide the coronary atherosclerotic plaque burden and the type of lesions associated with an individual patient undergoing surgery. these additional informations can change surgical and anaesthesiological management. procedure details: . description of current scoring methods and guidelines for pre-operative cardiovascular risk assessment. . description of cardiac-ct features that may improve stratifi cation of cardiovascular risk. . description of a diagnostic algorithm for patients undergoing major non-cardiac surgery including cardiac-ct. conclusion: cardiac-ct may become in the future a standard diagnostic method for the stratifi cation of cardiovascular risk in patients undergoing major non-cardiac surgery. thrombi in the left cardiac appendix with state-of-the-art multislice ct: a reason for discussion between radiologists and cardiologists? to provide examples of discrepancy between those techniques (ultrasound positive and ct negative and viceversa). . to explain the possible reasons for this discrepancy. background: tte is not an optimal technique for the examination of the left appendix. tee is the current clinical gold standard but it is invasive and operator dependent. -slice ct is a non invasive modality providing a non operator dependent assessment of the cardiac chambers. the current generation of multislice ct scanners uses ecg-gating, sub-millimiter spatial resolution and good temporal resolution to provide increasingly accurate assessment of coronary artery. it also allows the detection. basics of ecg for ct of the heart: what radiologists need to know a.a. palumbo , e. maffei , l. damiani , l. la fata , a. aldrovandi , f. notarangelo , f. cademartiri ; parma/it, palermo/it (alepalumbo@gmail.com) learning objectives: . to provide ecg fundamentals for correct ct setting. . to correlate ecg traces and ct appearance of coronary arteries. . to give tips and tricks for ecg post-processing editing for good image quality in patients with irregular heart rates. background: ecg and physical examination are the primary evaluations performed to overview heart conditions. the knowledge of ecg is becoming familiar to radiologists involved in non invasive cardiac imaging. several studies have demonstrated that the synchronization of the scan with an optimal ecg track (i.e. sinus rhythm, heart rate < bpm, no premature beats) minimizes image motion artifacts and signifi cantly increases image quality. in clinical practice, patients with coronary artery disease may have irregular heart rates and software upgrades for ct-ca can help the radiologists to handle premature beats, bigeminism, irregular heart rhythms and other abnormalities. procedure details: drawings for the explanation of ecg basics are presented. several examples of heart beats abnormalities are shown and improvement of image quality is reported before and after ecg editing. a correct placement of ecg electrodes is mandatory to avoid signal artifacts: it is described how to get the best ecg signal. conclusion: in clinical practice, patients with coronary heart disease may have irregular heart rates. in the near future, irregular heart rhythm will be not considered as an exclusion criteria for ct of the heart and ecg-editing will become routine in enhancing the image quality and allowing the inclusion of more patients for cardiac ct. non background: atrial septal defects (asd) and patent foramen ovale (pfo) are one of the most common cardiac abnormalities. they predispone to cerebral ischemia as a result of paradoxical thromboembolism by right-to-left shunting under conditions or physiologic maneuvers that raise right atrial pressure (valsalva maneuver). percutaneous defect closure is reliable for a decade and it needs an accurate depiction of atrial anatomy for a correct surgical planning. since now, trans-esophagel echocardiography has provided the anatomical and functional informations. cardiac ct, thanks to an higher spatial resolution, a non-invasivity, a better reproducibility of measurements can provide excellent images of atrial anatomy, helping to correctly choose the best occluder device. procedure details: -slice ct allows a motion-free d images of asd and pfo. all dimensions of tissue surrounding the defect are measured in systole (during ventricular dyastole) and in dyastole (during ventricular systole). in particular, distance between atrial defect and aortic root and inferior vena cava is measured in ct and echocardiography. atrial defects and closure devices are compared in d visualization, before and after closure procedure. conclusion: this fi rst experience with ct for percutaneous defect closure of the atrium seems promising. cardiovascular malformations with intra and extracardiac shunts in adults: the to review congenital heart diseases with shunts. background: the prevalence of congenital heart diseases is approximately % of all births. detection of some of them, especially when combined with great vessels' anomalies, may cause some diffi culties using routine diagnostic techniques. application of msct for cardiac imaging is increasing and becoming more precise along with higher resolutions achieved in modern scanners. that enables both accurate visualization of central circulatory system and adjacent anatomical structures. imaging findings: examinations of adult patients with variable cardiovascular defects performed with -row and -row scanner were processed. selected group contained: asd, vsd, patent ductus arteriosus, univentricular heart with transposition of great arteries, corrected transposition of great arteries, fallot's tetralogy, left and right sided partial anomalous pulmonary venous returns and persistent left superior vena cava. in addition, ct examinations after surgical corrections of some of the defects were presented. multiplanar and d reconstructions were acquired and shown with respect to educational purpose. conclusion: msct allows precise diagnosis of complex cardiovascular malformations and postoperative evaluation, being a valuable tool for imaging even complicated and infrequent anomalies of central circulatory system. moreover, multiplanar and d reformations allow visualization of congenital heart defects as ideal educational material. morphological atherosclerotic plaque analysis on coronary artery autopsy specimens using dual source computed tomography, micro computed tomography, and histopathology w. kristanto, r. dikkers, p.m.a. van ooijen, m.j.w. greuter, t.p. willems, m. oudkerk; groningen/nl (w.kristanto@rad.umcg.nl) purpose: to compare visualization of atherosclerotic plaques by dual source computed tomography (dsct), micro computed tomography (microct) and histopathology. methods and materials: eleven autopsy specimens of human coronary vessels were scanned with microct (siemens microcatii, siemens molecular imaging, knoxville, tennessee) without contrast agent and with dsct (somatom defi nition, siemens medical solutions, forchheim, germany) with contrast agent (mean hu). the images were reconstructed at µm voxel size (microct) and . mm slice thickness (dsct). histopathology analysis was performed afterwards for reference. from the reconstructed images, the morphology of the plaques was compared to the histopathological results. results: some calcifi ed spots found by histopathology were detected by dsct, but were overestimated in size. some soft plaques observed by histopathology were vaguely shown by dsct. smaller calcifi ed plaques and plaque ruptures were observed by histopathology, but could not be detected on dsct. microct clearly showed small calcifi cations and vessel wall thickening. a lower density structure, suspected as lipid pool, was observed inside one of the large calcifi ed plaques and a possible plaque rupture was also observed in one of the specimens on microct. conclusion: dsct tends to overestimate medium and large calcifi ed plaques whereas it misses the small ones. soft plaques are shown but vaguely. microct shows much more details on plaque morphology, as can be expected by its high spatial resolution. our fi ndings show that current clinical ct is mainly limited by spatial resolution. analysis of the fi ndings from microct and histopathology may help interpret the clinically available ct data. why do we misinterpret lesions on cardiac ct while compared with catheter coronary angiography? a critical review series collaborated with cardiologists t. lee, i. (sillyduck@ms .url.com.tw) learning objectives: to understand the limitations and artifacts of ct coronary angiography. to understand when, how and why we misdiagnose in ct coronary angiography. to understand the possible reasons for the discrepancy between ct and catheter coronary angiography. background: ct coronary angiography is recently a hot topic. with the advent of mdct, this technique is gradually integrated into the clinical practice. but this technique is so new that the standards of training, interpretation and clinical practice are not established yet. what are the basic requirements of an 'interpretable' scan? when and why do we misinterpret? are the misinterpretations avoidable? these are important questions we will try to answer by this review series. procedure details: we retrospectively review cases that underwent both the -detector row ct coronary angiography and catheter coronary angiography. all initial reports and images are critically reviewed by collaboration of two cardiac radiologists and a senior interventional cardiologist. using catheter coronary angiography as reference, all the misinterpretations are critically discussed. all the lessons learned are summarized with consensus. about the ct aspect, the discussed topics include respiratory motion, heart rate, heart rate stability, arrhythmia, image noise, interpretation skill, post-processing technique, reconstruction phase selection and window settings. some misinterpretations of catheter coronary angiography are also found during the review process and will be demonstrated and discussed in the exhibit. conclusion: most misinterpretations in ct coronary angiography are related to the techniques in interpretation, image acquisition and processing. most of them are potentially avoidable. multidetector purpose: to show typical anatomic pattern and variance of the left atrium-pulmonary veins complex (la-pv) studied by slices multidetector ct (mdct) in atrial fi brillation (af) patients candidated to percutaneous ablation. the exact knowledge of this anatomic region is extremely important to increase the effi ciency and effi cacy of the procedure, and to reduce the related complications. methods and materials: in the last three years, af patients ( females, males) underwent mdct cardiac examination using retrospective gating and dose modulation with reconstruction of % of rr ecg interval. results: in the patient population, we identifi ed right pv, of which were suprannumerary; left pv, of which common trunk and suprannumerary. in % of patients, the anatomic pattern was typical ( right and left pv) and in the remaining % atypical ( % right pv and left common trunk; % right pv and left pv; % right pv and left common trunk). in the defi nition of branching, mdct identifi ed branchings of the right inferior pv, of the right superior pv, of the left superior pv, of the left inferior pv and of the suprannumerary veins. conclusion: mdct represents a fundamental diagnostic imaging tool in the anatomic defi nition of the pv that is characterized by great variability. radiologists must be familiar with anatomic variants and understand the importance of these variants to the refering cardiac interventional electrophysiologist. data was also collected on the extent of coronary artery disease (cad), peripheral vascular disease (pvd), and the treatment given to that patient. data regarding presence of associated cardiovascular and cerebrovascular disease in the pvd group were obtained from the patient's medical record. results: age and sex distribution were similar in both groups. prevalence of risk factors in both groups was as follows (cad/pvd): %/ % hyperlipidaemia, %/ % hypertension, %/ % smoking, %/ % positive family history and %/ % diabetes. in the pvd group, % and % had symptomatic cad and cerebrovascular disease, respectively. in the cad group, % had symptomatic cerebrovascular disease. coronary disease on investigation was more severe than in comparable studies conclusion: this study has shown that the prevalence of risk factors and associated co-morbidity are either comparable or higher than studies carried out elsewhere. higher prevalence of smoking and diabetes was noted in the pvd group. findings of the coronary and peripheral angiograms and the resulting treatment will be discussed. learning objectives: to discuss the acquisition protocol and reconstruction algorithm which provide optimal image quality of bypass grafts and native coronary arteries with dual-source ct. to address artifacts and interpretative strategy for ct coronary angiography in patients after bypass surgery. background: the recently introduced dsct scanner permits coronary imaging with high resolution ( ms), which provides improved image quality in patients with higher heart rates when compared to earlier scanner generations. moreover the entire heart and graft course can be acquired within a single breath-hold of to s. procedure details: in this exhibit, we provide examples of dsct coronary angiography in the evaluation of normal and diseased and occluded bypass grafts. different bypass surgery techniques are discussed and various examples shown. in addition, we address possible artifacts originating from graft orifi ce indicators, surgical clips and sternal wires, and discuss pitfalls in the evaluation of both bypass grafts and native coronary arteries. conclusion: dsct allows high-resolution scanning of the entire thorax within a single breath hold. we demonstrate image quality of dsct coronary angiography in patients with various heart rates after bypass surgery. we discuss the acquisition protocol and reconstruction algorithm, which provide optimal image quality of both cabg and native coronary arteries. learning objectives: . to modify the standard protocol of coronary imaging studies in order to depict ivs and right ventricle. . to recognize different kinesis pattern of ivs related to various cardiac diseases. background: regional kinesis alteration of ivs is associated with different cardiac conditions which may have both pathological and physiological meanings of which the most important are the following: a) left bundle branch block that may determine intra-left ventricular asynchrony and may represent an independent predictor of severe cardiac events in heart failure patients; b) pulmonary embolism that increase right ventricle pressure; c) constrictive pericarditis; d) restrictive cardiomyopathies; e) post-operative cardiac surgery. procedure details: a -msct scanner (lightspeed vct, general electric, milwaukee) was employed, using the following parameters: x . collimation, pitch . , ma, kv, rotation time msec.; i.v. iodinate contrast agent was administrated with a double phase injection : cc at cc/sec followed by cc at cc/sec. beta-blockers were administered to patients with heart rate above beats per minute (bpm). axial images were then reconstructed at multiple phases covering the cardiac cycle in increments of % of the r-r interval between % and %. after the reformatted images were transferred to a workstation, contiguous multiphase short-axis and long-axis images were generated using semiautomated interactive software (advantage windows . , cardiq iii function, ge healthcare). conclusion: -msct is an effective imaging modality in depicting ivs contraction anomalies. learning objectives: to understand normal imaging characteristics of contrastenhanced ct images of myocardium and pericardium, together with a great variety of common and more rare pathologic conditions involving these structures. background: since the introduction of -and especially -slice, ct radiologists are increasingly involved in the execution and interpretation of ct images of the heart and coronary arteries. while there is extensive literature on the imaging of the coronary arteries, ct imaging features of the myo-and pericardium have been scarcely reported. imaging findings: it is the aim of this pictorial review to familiarize the radiologist with the common presentation on ct examinations of myo-and pericardium, including normal anatomy variations. furthermore, a wide variety of diseases like myocardium infarctions of different ages, congenital entities like non-compaction cardiomyopathy, pericardial cysts and other pathologies are reviewed. the images are collected from more than -and -slice cardiac ct examinations gathered between - . conclusion: pathology in the myocardium and pericardium is frequently encountered during ct examination of the heart and coronary arteries. solid knowledge of both normal and abnormal presentation of these structures will increase the diagnostic accuracy of the radiologist, as such limiting errors of interpretation. the infl uence of heart rate fl uctuation on cardiac image quality and the improvement by combining varispeed scan technique (vst) and multi sector reconstruction algorithm (msr) j. liao , y. shen , x. ge , s. wu , j. li , j. at and bpm, the image quality with . s/r was better than the one with . s/r. but at bpm, the image quality with . s/r was better than the one with . s/r. . at the higher hr ( bpm, bpm) and wider hr fl uctuation range, msr could improve the image quality signifi cantly (p < . ). conclusion: hr fl uctuation is an important reason that degrades the image quality. vst could optimize the matching of rotation speed and hr to improve image quality. msr could provide the better temporal resolution and it is effective in reducing the infl uence of hr fl uctuation. mdct-ca volume rendering/auto track vs. mpr/mip analysis to assess coronary artery stenosis v. alaimo , g. runza , l. la grutta , m. galia , g.f. lo re , t.v. bartolotta , f. cademartiri , m. midiri ; palermo/it, parma/ it (valalaimo@libero.it) learning objectives: to display as a correct approach to detect coronary artery disease is based on a careful evaluation of coronary tree by using manual track vessel analysis and mpr/mip reconstructing approach. to demonstrate as the degree of coronary arteries stenosis is infl uenced by different post-processing techniques. background: cardiac mdct is a non-invasive technique to recognize presence of coronary disease, thanks to the capability to identify vessels remodelling and coronary stenosis. in this exhibit, we will describe the use of different post-processing techniques for the assessment of coronary artery stenosis, such as vr/auto track approach and mpr/mip conventional assessment, which are compared. imaging findings: post-processing procedures were performed using auto-cage bone removal/auto track and mpr-mip/manual track vessels analysis. images obtained with the methods were compaired. conclusion: vr images of lad, crx and rca, clearly show the non-calcifi ed stenotic tract of the vessels, but often overstimate the degree of stenosis compared with mpr/mip assessment. stenosis of the marginal and diagonal arteries with a small diameter are diffi cult to assess with vr and auto track analysis. the correct approach for an accurate and complete evaluation of coronary tree cannot exclude the vessels analysis by mpr/mip reconstruction. utility of multislice computed tomography with a -data acquisition system for four-dimensional volumetric analysis using a pulsating phantom and considering pulsation rate and reconstruction methods n. funabashi , n. mizuno , k. suzuki , m. terao , k. nakamura , f. maeda , m. uehara , i. komuro ; chiba/jp, tateyama/jp purpose: to evaluate -das msct (light speed vct, ge) at . mm slicethickness, . s/rotation, tube kv at ma, ecg-gated for -d volumetric analysis, we used pulsating phantoms to measure end-diastolic (edv) and endsystolic (esv) volume and ejection fraction (ef) to assess reconstruction methods especially for higher pulsation rates. a pulsating device (az- n, anzai medical) with contrast material ( mgi/dl) diluted x with saline was moved at - to-and-fro movements/min. ecg-gated msct was performed x per pulsation rate. the edv and esv were measured using workstation (virtual place advance plus, aze). the mean edv and esv were , , , , , and % and , , , , , , and %, respectively, compared coronary fl y-through or virtual angioscopy using dual source mdct data p.m.a. van ooijen, m. oudkerk; groningen/nl (p.m.a.van.ooyen@rad.umcg.nl) purpose: coronary fl y-through, or virtual angioscopy (va), has been studied ever since its invention in . however, its application was limited because of the requirements for an optimal ct scan and time consuming post-processing. recent advances in post-processing software facilitate easy construction of va but until now, image quality was insuffi cient in most patients. the introduction of dual source mdct could prove to enable va in all patients. methods and materials: twenty patients were scanned using a dual source mdct (defi nition, siemens, forchheim, germany) using a standard coronary artery protocol. post-processing was performed on an aquariusworkstation (terarecon, san mateo, ca). length travelled per major branch was recorded in mm together with the time required in minutes. results: va could be performed in every patient for each of the major coronary arteries. the mean (range) length of the automated fl y-through is ( - ) mm for the left anterior descending, ( - ) mm for the left circumfl ex artery, and ( - ) mm for the right coronary artery. calcifi cations and stenoses are visualized, as well as most side branches. mean time required was min for lad, . min for lcx, and minutes for the rca. conclusion: dual source mdct allows for high quality visualization of the coronary arteries in every patient because scanning with this machine is independent of the heart rate. this is clearly shown by the successful virtual angioscopy in all patients. potential clinical value of the va should be determined in the near future. and ef between ct and ilvg were . ± . ml, . ± . ml, and - ± %, respectively. in subjects with omi, the correlation coeffi cients between ct and ilvg for edv, esv, and ef were . , . , and . , respectively (all p < . ), and the averages± sd of the differences of edv, esv, and ef between ct and ilvg were . ± . ml, . ± . ml, and - . ± . %, respectively. conclusion: in all subjects, estimates of edv, esv, and ef were signifi cantly correlated between ct and ilvg, but ct tended to underestimate ef. in subjects with omi, ct tended to overestimate edv and esv, and estimates of ef were less correlated between ct and ilvg in subjects with omi. these discrepancies may be due to capability of ct to estimate lv wall asynergy -dimensionally more accurately than ilvg. quantitative annual effect of atorvastatin on size and content of noncalcifi ed plaques of coronary arteries following atorvastatin treatment by multislice ct n. results: patency was confi rmed in % des ( , and % with . , , and . mm diameters, respectively), and in %bms ( , , and % with , . , , and . mm diameters, respectively). patency of % des ( , , and % with . , , and . mm diameters, respectively) and % bms ( , , , and % with , , , , and . mm diameters, respectively) could not be confi rmed because of partial volume effects due to small size. % bms revealed a low ct area inside the stents ( each with , . , and mm diameters). % bms revealed total occlusion ( each with . and mm diameters). conclusion: -slice msct is a non-invasive diagnostic modality with the potential for evaluating patency of des with a low incidence of restenosis, especially des with . mm diameter. however, due to partial volume effects, it remains diffi cult if the lumen is or . mm. bms had a thinner slice thickness and bigger lumens, and their patency was easier to evaluate by msct. background: within the patients with chest pain and overt coronary artery disease, there are a large number of negative fi ndings. a small niche of these patients present with chest pain that mimics coronary artery disease and they may carry unusual fi ndings. in these patients, the diagnostic challenge may be diffi cult using the conventional diagnostic tools (i.e. history, physical examination, ecg, biomarkers, chest x-ray). ct coronary angiography is increasingly applied in the er settings for the assessment of patients with atypical chest pain because of its high negative predictive value in populations with low-to-intermediate prevalence of disease. a diagnostic spin-off of ct coronary angiography relates to its capability of showing any thoracic fi nding and therefore several different fi ndings, such as non coronary causes of chest pain, may arise (i.e. pulmonary embolism, aortic dissection, pulmonary artery fi stula, coronary fi stula, bronchogenic cyst, pericarditis, oesophageal disease, pulmonary sequestrum, mediastinal masses, etc). imaging findings: this exhibit will overview all causes of cardio-thoracic syndrome mimicking coronary artery disease. examples will be provided with patho-physiological explanation. conclusion: ct coronary angiography applied to cardio-thoracic syndromes is able to detect all major non-coronary causes of chest pain. for this reason, it is becoming the gold standard for chest pain assessment especially in er settings. coronary artery anomalies at -slice coronary ct angiography c. thilo, p. costello, u.j. schoepf; charleston, sc/us (thilo@musc.edu) learning objectives: the aim of this exhibit is: ) to review the classifi cation of coronary artery anomalies. ) to differentiate clinically signifi cant and insignifi cant variations. ) to illustrate coronary anomalies based on -slice coronary ct angiography (ccta). ) to emphasize small vessel anatomic variations. background: the increased use of cardiac ct leads to more frequent detection of coronary anomalies. improved temporal and spatial resolution of -slice ct enables visualization of small anomalies, which have been insuffi ciently described to date. imaging findings: the following imaging fi ndings will be reviewed and discussed: coronary anomalies: frequency and clinical signifi cance -normal variants -benign coronary anomalies -malignant coronary anomalies -coronary artery fi stulas -small vessels of the heart: anatomy and variants of the sinus node artery, conus branch, septal perforators, etc. conclusion: ) coronary artery anomalies are more frequently detected since the introduction of ccta. ) ccta with -slices enhances our knowledge on small vascular anatomy and small vessel variation. ) in most cases, congenital anomalies are asymptomatic and incidentally detected. ) in symptomatic patients with suspicion of coronary artery anomalies, ccta is emerging as the diagnostic modality of choice. comparison between iodine and gadolinium-enhanced multidetector ct coronary angiography: preliminary report p. carrascosa , c. capuñay , m. bettinotti , a. goldsmit , j. carrascosa , r. pissinis ; san isidro/ar, capital federal/ar (patriciacarrascosa@diagnosticomaipu.com.ar) purpose: to determine the sensitivity (s) and specifi city (sp) of gadolinium-enhanced ct angiography (gd-cta) and iodine-enhanced mdct (i-cta) for the detection of signifi cant coronary stenosis compared to digital angiography (da). methods and materials: eighteen patients with known coronary artery disease underwent gd-cta, i-cta and da. cts were performed with a -row ct scanner. for gd-cta, a volume of . mmol/kg of body weight of gadolinium was administered. for the i-cta, a volume of ml of contrast material containing mg/ml of iodine was administrated. the axial images and reconstructions of the coronary tree of both acquisitions were reviewed independently and directly compared. the degree of enhancement, the capability of an adequate delimitation of the coronary tree and the detection of coronary artery disease were evaluated. both acquisitions determined the presence of plaques and measured the coronary stenosis. those equal or above % where considered as positive fi ndings. results: gd-mdct angiography was successfully completed for evaluation in all patients. axial and multiplanar reconstruction images showed adequate visualization of the main coronary artery. the effects of injection of contrast materials on the heart rate and its fl uctuation in the -slice ct coronary angiography y. liu , x.z. lin , k.m. chen , y. shen , z. hao ; shanghai/cn, shenyang/cn (lxzmm@yahoo.com.cn) purpose: to evaluate the effects of contrast medium (cm) injection on the heart rate and its fl uctuation in -slice ct coronary angiography (ctca). methods and materials: cases that underwent -slice ctca were included in the study. during calcium scoring and ctca, waves of electrocardiogram (ecg) were recorded in two fl oppy disks. values of heart rate were recorded, and the differences between the sequential heart beats (d-hr) were calculated. all cases were classifi ed into three groups according to their heart rate: group : < bpm; group : - bpm; and group : > bpm. the ecg data of the three groups were compared statistically. ecg data of all the heartbeats and the fi rst fi ve beats after the cm injection were also compared. results: ecg were included in total, in which ecg were before cm injection and after. the mean bpm of groups , and before cm injection were . , . and . bpm and after cm injection were . , . and . , respectively. mean d-hr of groups , and before cm injection were . , . and . bpm and after the cm injection they were . , . and . , respectively. mean d-hr of all the heartbeats and the fi rst fi ve beats after the cm injection were . and . bpm, respectively. conclusion: though the mean heart rate after cm injection was a little lower than that before cm injection, the fl uctuation of heart rate increased after cm injection during the -slice ctca. shortening the scanning time may decrease the fl uctuation of heart rate. to assess the incidence of pulmonary vein stenosis in patients submitted to atrial fi brillation ablation and to increase awareness of this clinical syndrome a. bajaj, d.t.d. barnes, p.a. vlachou, t. siva, j.j. entwisle; leicester/uk (amrita. bajaj@uhl-tr.nhs.uk) purpose: to assess the incidence of pulmonary vein stenosis in patients submitted to atrial fi brillation ablation and to increase awareness of this clinical syndrome. methods and materials: consecutive cases had catheter ablation for atrial fi brillation over a period of two years - . these were retrospectively reviewed on the radiology information system to look for any cross-sectional imaging of the thorax (multi-detector row ct/mr) performed within months following the ablation. the images were then retrospectively reviewed to look for pulmonary vein stenosis. results: eighteen of the patients had ct/mr within months of the procedure. six of the cases queried pulmonary vein stenosis on the initial request. six of the cases were done to evaluate the anatomy for redo procedure. of the remaining , queried pulmonary embolism, queried bronchiectasis and was unclear. five patients presented with haemoptysis on the initial request. in patients, the history of ablation was not stated on the radiology request. six ( . %) patients had pulmonary stenosis. left superior pulmonary vein was the most commonly involved. remaining important radiological fi ndings also seen in the cases of pulmonary vein stenosis were consolidation and lung nodule. conclusion: pulmonary vein stenosis after catheter ablation is an important complication associated with signifi cant morbidity. our series showed a complication rate of . %, with severe stenosis in a still smaller percentage. the reported incidence ranges from % to %. radiologist and clinicians should be aware of this condition in patients presenting acutely following ablation. learning objectives: ) to remind of the major features of the most frequent congenital heart diseases (chd), including atrial septal defect (asd), ventricular septal defect (vsd), tetralogy of fallot (tof), transposition of the great arteries (tga) and coarctation of the aorta. ) to expose ct and mr advantages and limits in these indications. ) to give radiologists clues to better understand clinicians' questions and therefore to answer them better. background: because life expectancy of patients with a congenital heart disease (chd) has improved, thanks to better medical and surgical managements, and thanks too to great improvements in ct and mr imaging, radiologists are more and more faced with these particular conditions. moreover, as surgical techniques have become more sophisticated and complicated, the need for a precise anatomical description and for functional analyses has become crucial. ct and mri have these abilities and are complementary. but they also have some drawbacks. procedure details: we will illustrate this topic using numerous cases taken from our experience as a chd care center. all ct exams were performed on a multislice ct, either a or a detectors, whereas mr were performed on a . t magnet. ct and mr protocols varied, depending upon the congenital heart disease. conclusion: ct and mri are powerful tools for the non-invasive evaluation of chd. anyone performing these exams has to understand their advantages and limits in order to be able to answer clinicians' questions. immunologic lung diseases other than asthma and collagen-vascular disorders: an electronic teaching fi le c.m. plank, c. grosse, a. koller, l. stiebellehner, c. müller-mang, a.a. bankier; vienna/ at (christina.plank@meduniwien.ac.at) learning objectives: to familiarize radiologists with immunologic lung diseases other than asthma and collagen-vascular disorders. to elaborate classical patterns of presentation, clinical history, and radiological features of these disorders. to propose a systematic diagnostic approach based on clinical and radiological fi ndings. background: immunologic lung diseases other than asthma and collagen-vascular disorders include: ) lung vasculitides (wegener's granulomatosis, churg-strauss syndrome, hypersensitivity vasculitis); ) diffuse pulmonary hemorrhage; ) eosinophilic lung disease (acute and chronic eosinophilic pneumonia, drug-induced lung disease); ) extrinsic allergic alveolitis; and ) amyloidosis. although these diseases are relatively common, there is little awareness of their etiology, their underlying pathomechanisms, their classifi cation, and their clinical and radiological manifestations. the purpose of the proposed electronic teaching fi le, therefore, is to elaborate a comprehensive diagnostic approach based on combined clinical and imaging fi ndings. imaging findings: the ct imaging fi ndings of the diseases will be the central part of our presentation. the ct fi ndings will be correlated with pathological specimens, and combined to typical clinical histories and presentations. the overall structure will follow most recent classifi cations of immunologic lung diseases other than asthma and collagen-vascular disorders. the format of the electronic teaching fi le will allow easy navigation through the information and provide an integrative comprehensive approach. conclusion: in the appropriate clinical setting, ct fi ndings in immunologic lung diseases other than asthma and collagen-vascular disorders are suggestive of the underlying disorders and allow in making the correct diagnosis with a reasonable level of confi dence. radiologic-pathologic correlations between intratumoral macroscopic and microscopic components in lung neoplasms e. quaia; trieste/it (quaia@units.it) learning objectives: to describe those intratumoral components in lung neoplasms that are depicted by imaging. background: different intratumoral components in lung neoplasms, which were evident at macroscopic and/or microscopic analysis, may be recognized in un-enhanced and contrast-material-enhanced computed tomography (ct) images. imaging findings: seventy lung masses ( - cm in diameter) in patients ( males, females, mean age ± sd, ± ) were imaged by ct before and seconds after intravenous injection of iodinated contrast agent (iodine mg/ml; ml; i.v. bolus injection). surgical/bioptic/autoptic specimens were analysed by macroscopic and microscopic/histologic analysis (hematoxylin and eosin staining, x -x magnifi cation), and two observers identifi ed in consensus those intratumoral components that were depicted by ct images. macroscopic components: ( ) internal colliquative necrosis in squamous cell carcinomas (n= ) appeared hypodense at un-enhanced ct, and without enhancement after contrast injection; ( ) fi brotic component in adenocarcinomas (n= ) manifested as peripheral strands; ( ) bronchiolo-alveolar carcinomas (n= ) presented as diffuse/confl uent parenchymal consolidations; ( ) coagulative necrotic and haemorrhagic changes in small cells (n= ) and anaplastic carcinomas (n= ), which appeared, respectively, hypodense and hyperdense at un-enhanced ct, and without enhancement after contrast administration; ( ) air-leak syndromes in hematopoietic stem cell transplant recipients with chronic gvhd-related bronchiolitis obliterans: thin-section ct fi ndings e. granell, r. guerrero, t. franquet, a. giménez, a. hidalgo, f. plancarte; purpose: to determine the incidence and the thin-section ct fi ndings of air-leak syndromes in a large group of hematopoietic stem cell (hsc) transplant recipients with chronic graft-versus host disease (cgvhd) related bronchiolitis obliterans (bo). a retrospective review of the medical records and imaging fi ndings identifi ed allogeneic hsc transplant recipients with a proven diagnosis of cgvhd between january and december . of the transplant recipients, had air-leak syndrome and proven cgvhd. the patients were men and woman ranging in age from to years (mean age, years). the thinsection ct scans were retrospectively reviewed by two thoracic radiologists for the presence, appearance, and distribution of abnormalities. results: all cases were allogeneic hsc transplant recipients with cgvhd who acquired new respiratory symptoms and/or radiologic abnormalities. nine cases of air-leak syndrome occurred during the analyzed study period, for a -year estimated cumulative incidence of . %, whereas its prevalence was . %. among all the patients, pneumomediastinum (n= ) and pneumothorax (n= ) accounted for the majority of air-leak syndromes in our series; the remainder were due to subcutaneous emphysema (n= ) and pulmonary interstitial emphysema (n= ). a combination of different air-leak syndromes was observed in cases. in all cases there existed an association between air-leak syndromes and cgvhd-related bo. conclusion: air-leak syndromes represent an uncommon late complication in hsc transplant recipients related to cgvhd and bo. the many faces of bronchioloalveolar carcinoma: a radiologic-pathologic pictorial review d. chourmouzi, e. papadopoulou, k. xinou, t. zaraboukas, a. drevelegas; thessaloniki/gr (dchourm@hol.gr) learning objectives: to describe the pathologic and radiologic types of bronchioloalveolar carcinoma (bac). to present the imaging features of each type of bac. to outline the main differential diagnosis. to emphasise the role of imaging evaluation in treatment and follow-up. background: bronchioloalveolar carcinoma (bac) is classifi ed as a subset of lung adenocarcinoma but has a distinct clinical presentation, tumor biology, response to therapy, and prognosis compared with other subtypes of non-small-cell lung carcinoma (nsclc). it is characterized by growth along alveolar septae without evidence of stromal, vascular, or pleural invasion. nonmucinous bronchioloalveolar carcinoma tends to be more localized and has a lower frequency of bronchogenic spread than mucinous bronchioloalveolar carcinoma. bac has received increasing attention in recent years due to its increasing incidence and its rate of sensitivity to epidermal growth factor-tyrosine kinase inhibitors (egfr-tkis). imaging findings: at computed tomography (ct), the single nodular form appears as a peripheral nodule or localized ground-glass attenuation with or without consolidation, frequently associated with bubble like areas of low attenuation and open bronchus signs. the lobar consolidative form may demonstrate the ct angiogram and open bronchus signs. the diffuse nodular form appears as multiple nodules or areas of ground-glass attenuation or consolidation. conclusion: understanding the radiologic fi ndings of bronchioloalveolar carcinoma on the basis of various morphologic and growing patterns is essential in the initial evaluation of patients with bac. high-resolution lung ct-scan is necessary to evaluate pulmonary involvement. imaging evaluation is also essential to assess therapeutic response and follow-up. pattern recognition in lobar collapse: can you read the signs? e. sonnex, r.a. coulden; leicester/uk (emer@prdg.demon.co.uk) learning objectives: to understand plain fi lm appearances and recognise the patterns of lobar collapse. these fi ndings are fully explained and corroborated by a -dimensional ct reconstruction. background: the diagnosis of lobar collapse is the 'bread and butter' of chest radiology but as -d imaging takes over, plain fi lm reporting skills are being lost. procedure details: we describe the classic patterns of lobar collapse on the plain chest radiograph with the aid of ct correlation to explain the appearances of: collapse and why it looks the way it does; how to use the silhouette sign; the causes of collapse; the features of collapse. conclusion: accurate diagnosis is based on recognised patterns. this presentation uses -d ct images to explain the recognised patterns of collapse in plain chest radiographs. (dad) . trali, the transfusion related acute lung injury is an uncommon complication of allogenic blood transfusion typically manifested by bilateral oedema, dyspnea, hypoxemia, fever and hypotension, in presence of a normal cardiac function. the main patterns are pulmonary infi ltrates and eosinophilia, acute pulmonary oedema and upper airway obstruction from laryngeal oedema. some drugs can also induce severe ali, such as valproic acid in treatment of neurological epilepsy that can induce alveolar haemorrage or gemcitabine during treatment for breast cancer. imaging findings: acute lung injury presents radiological and ct challenges. the chest x-ray demonstrates bilateral infi ltrates without signifi cant increase in cardiac size or vascular pedicle. ct demonstrates ground glass attenuation (a hazy increase in the lung attenuation with preservation of bronchial and vascular margins) in the middle regions and consolidation (increase in lung attenuation that obscures the broncho vascular margins, but the bronchogram sign can be present). the cyto/histological patterns of different ali stages explain the imaging features. the organic dust: radiographic and high resolution ct fi ndings of hypersensitivity pneuomonitis z. khaleel, r. lavakumar, c. viswanathan, g. avery, n. kennan; hull/uk (ziyadlk@hotmail.com) learning objectives: to illustrate pathogenesis of hypersensitivity pneuomonitis (hp). to demonstrate the natural history and physical fi ndings in hp. to defi ne and review the radiographic and hrct appearances of hp. background: hypersensitivity pneuomonitis, also known as extrinsic allergic alveolitis, is an infl ammatory lung disease in which inhalation of certain organic antigens repeatedly induces immunologically mediated reaction with granulamtous tissue formation. the targeted lung structures are the distal bronchioles and the alveoli. imaging findings: we will be reviewing the radiographic and the hrct fi nding in the clinical subtypes of hp. ) acute phase: air-space opacifi cation with lower lobe predominance on radiographs and the fi ne nodules and diffuse alveolar consolidation on hrct. ) subacute phase: fi ne reticulonodular pattern on radiographs and ground glass opacities with centrilobular nodules on hrct. ) chronic phase: coarse reticulation with upper lobes predominance on radiographs and intraseptal and interseptal thickening, honeycombing and traction bronchioectasis on hrct. the defi nitive diagnosis of hp relies on a constellation of clinical, radiological, and laboratory fi ndings. although the imaging fi nding of hp can be nonspecifi c, certain pattern particularly on hrct would strongly suggest the diagnosis and facilitate prompt management of the disease. diffuse granulomatous lung diseases: high-resolution ct and pathologic fi ndings t. franquet , n.l. müller , t.v. colby ; barcelona/es, vancouver, bc/ca, scottsdale, az/us ( tfc@comb.es) learning objectives: to illustrate hrct fi ndings of the most common granulomatous disorders of the lung, and to present a working differential diagnosis based on pathologic -radiologic correlation. background: diffuse granulomatous lung diseases are a group of lung diseases in which granulomas are an important component of the histologic fi ndings. the term granuloma has been used historically for all reactions rich in histiocytes and mononuclear cell infl ammation; more recently the term has been restricted to cases showing cohesive epithelioid histiocyte clusters usually with associated giant cells (i.e. sarcoid-like granulomas). we use the more restricted defi nition of granuloma in this review, but also include for completeness entities for which the term granuloma has been used historically. imaging findings: depending on the anatomic location and histologic characteristics of the abnormalities, diffuse granulomatous lung diseases may result in several ct patterns: a) nodules greater than cm in diameter, b) small nodules, c) centrilobular nodules and branching lines (tree-in-bud pattern), d) bronchiolocentric infi ltrates, e) ground-glass opacities and consolidation, and f) low-attenuation and mosaic perfusion. conclusion: this review presents an approach to the differential diagnosis of pulmonary granulomatous disorders based on their hrct features and compares the hrct with the pathologic fi ndings. in the future could help the quantifi cation of these disorders. conclusion: mdct offers a new approach to the study of diffuse lung cystic disease. it allows a better characterization of the lesions and an easier visualization of the regional distribution of the cysts. four-dimensional multislice helical ct of the lung: comparison of retrospectively gated and static images in an ex-vivo system j. purpose: to analyze the image quality of retrospectively gated helical ct based on a comparison with static scans. methods and materials: five porcine lungs were infl ated inside a dedicated chest phantom and prepared with - nodules of ~ cm. a water-fi lled diaphragm simulated contractions at a frequency of /min. images were acquired in a dynamic mode with a pitch of . (slice collimation x . mm, rotation time s, slice thickness . mm, increment mm). static scans at / / / / % inspiration were obtained with the same protocol, but without respiratory motion. the visual evaluation of image quality was based on multiplanar reformations of the d-data sets. stepladder-artifacts, partial projection artifacts and noise were judged semiquantitatively by two independent observers for the upper, middle and lower parts of the lung. scores of - were given for absent, minimal, large and diagnostically relevant artifacts. results: partial projection effects were only present in the dynamic scans (average artifact scores: . ). stepladder artifacts were prominent in dynamic series but also visible on static scans. both artifacts were less prominent in end-in-and end-expiration and predominated close to the. image noise predominated close to the diaphragm independently from the dynamic condition. a score of was given times ( / for kymographic artifacts), all for the region close to the diaphragm. the realistic ex-vivo study with direct comparison of retrospectively gated and static scans shows tolerable artifacts of retrospective respiratory gating and confi rms the high quality of d-ct. the acute lung injury (ali): a clinico-radiological correlation s. piciucchi , c. learning objectives: ) to demonstrate the imaging appearances of the respiratory complications of rheumatoid arthritis, systemic lupus erythematosus, mixed connective tissue disease, progressive systemic sclerosis, dermatomyositis, polymyositits and sjogren's syndrome. ) to discuss the imaging features suggestive of each of the above conditions and the diagnostic pitfalls. background: the connective tissue diseases are autoimmune multisystem conditions that can affect the lungs. all components of the respiratory system including pleura, alveoli, interstitium, lymphatics, airways and vasculature can be involved. although there is a great deal of overlap between the imaging fi ndings in these conditions, there are features that can point the radiologist towards a particular diagnosis. imaging findings: patterns of respiratory involvement include pleural effusion or thickening, organising pneumonia, usual interstitial pneumonia (uip), nonspecifi c interstitial pneumonia (nsip), bronchiectasis, lymphoid interstitial pneumonia, lymphoma, obliterative bronchiolitis and nodules. acute pathologies such as alveolar haemorrhage and pulmonary embolism are also seen. these and others are shown on plain radiographs and ct images. the purpose of this exhibit is to show the wide spectrum of pleuropulmonary manifestations of connective tissue disease, and to point the radiologist towards a more specifi c diagnosis based on the imaging fi ndings. paraquat poisoning of the lung: initial and follow-up thin-section ct fi ndings in relation to ingestion amount of the paraquat m. park , s. song , s. park ; uijeongbu/kr, seoul/kr (namaste-india@hanmail.net) purpose: to evaluate the patterns, distribution, and extent in relation to the ingestion amount of paraquat poisoning and evaluate the temporal lung changes on thin-section ct (hrct) scans. the study included patients with urine-positive paraquat kit and pulmonary abnormalities in hrct scans. scans after hemodialysis were assessed for the presence, extent, and distribution of pulmonary abnormalities. six of the patients, underwent follow-up ct scanning - days after initial ct. the abnormal fi ndings on the initial hrct scan consisted of ground-glass attenuations (n= ), consolidations (n= ), irregular lines (n= ), nodules (n= ), traction bronchiectasis (n= ), pleural effusion (n= ), and pneumothorax (n= ). the most common predominant fi nding that has the largest extent was ground-glass attenuation (n= ). on initial ct scan, the lesions showed bilateral (n= ), lower (n= ) and subpleural (n= ) zonal predominancy. the extent of lung involvement was well correlated to the amount of paraquat ingestion. the follow-up ct was performed in six patients. the ground-glass attenuation might be improved in extent (n= ) or progressed to consolidation (n= ). the new parenchymal abnormalities such as traction bronchiectasis and architectural distortion developed in the remaining two patients. conclusion: in paraquat poisoning, the most predominant fi nding at initial presentation was ground-glass attenuation and it was bilateral, lower and subpleural in distribution. the extent of lung involvement was well correlated to the amount of paraquat ingestion. on follow-up ct, fi brosis such as traction bronchiectasis and architectural distortion might develop. background: lymphomatous involvement of the lung is often asymptomatic or has non-specifi c symptomatology, thereby making diagnosis diffi cult. cavitating pulmonary lymphoma is a rare entity in both primary and secondary pulmonary lymphoma. diagnosis if also often hindered as infection (including superimposed infection), granulomatous disease, primary and secondary carcinomas, and drug reactions may have similar radiological fi ndings. imaging findings: from our experience with a number of cavitating pulmonary lymphoma patients and a review of literature, we will provide a diverse review of its pathophysiology, clinical and radiological presentations (location, distribution), and appearances (wall features, progression, and response to treatment). conclusion: this exhibit will provide an informative thorough guide and review of pulmonary lymphoma, its rare cavitating form, highlighting its presentation, radiological features, and progression, and distinguishing aspects from other cavitating lung pathologies. idiopathic interstitial lung disease: an analysis of the main radiological fi ndings. an integrated clinical, radiologic and histologic approach to diagnosis m. prieto del rey, x. gallardo cistare, e. castaner gonzalez, j. mata duaso, i. delgado alvarez, s. perez aguilera; barcelona/es (mprieto@cspt.es) learning objectives: to describe and illustrate the principal radiological and histological fi ndings for idiopathic interstitial lung diseases. to explain a strategy for the diagnosis of different types of idiopathic interstitial disease and determining their severity and prognosis. background: we review the radiological fi ndings for idiopathic interstitial lung diseases, grouped according to the american thoracic society/european respiratory society international multidisciplinary consensus classifi cation (ats/ers imcc) of into: usual interstitial pneumonia, non-specifi c interstitial pneumonia, desquamative interstitial pneumonia, respiratory bronchiolitis interstitial lung disease, cryptogenic organizing pneumonia, acute interstitial pneumonia, and lymphocytic interstitial pneumonia. imaging findings: we present representative cases of each of the seven ats/ers imcc categories, describing the clinical, radiological and histologic fi ndings. we provide high-resolution ct images showing the most characteristic fi ndings for each entity and discuss the differential diagnosis. conclusion: careful and thorough evaluation of the distribution, extension, and evolution of the radiological fi ndings together with the relevant clinical information enables a strategy to orient the diagnosis of the different types of idiopathic interstitial disease, their severity, and clinical prognosis. the diagnosis of interstitial lung diseases requires an integrated, dynamic evaluation of the clinical, radiological, and histological fi ndings. high-resolution ct is an important tool in the diagnostic work-up of diseases that affect the pulmonary interstitium. learning objectives: this poster should give an overview about the ct scan fi ndings and differential diagnosis of diverse pulmonary fungal infections in immunocompromised patients. pneumonias caused by aspergillus, cryptococcus, candida, histoplasma, mucor and geotrichum capitatum are illustrated. background: the importance of pulmonary fungal infections has increased substantially during the last decades, occurring in patients with neutropenia caused by malignancies, solid organ or stem-cell-transplantation, chemotherapy, corticosteroid-therapy or hiv-infection. because of unspecifi c clinical symptoms and the high morbidity and mortality of these infections, an early and non-invasive diagnose is very important. imaging findings: pulmonary aspergillosis comprises a broad spectrum of disorders. allergic broncho-pulmonary aspergillosis (abpa) is typically associated with upper lobe consolidations, mucous-plugging and central bronchiectasis. semi-invasive aspergillosis is characterized by progressive upper lobe consolidation that may cavitate and harbor mycetomas. the ct halo-sign and, later in the disease, the air crescent sign are characteristic fi ndings of invasive aspergillosis. cryptococcosis may manifest as a solitary lung mass, as multiple nodules or as segmental or lobular consolidations. in patients with candidiasis, air-space consolidation is most commonly seen with a lower lobe distribution. histoplasmosis presents with diffuse nodules, small linear opacities or focal or patchy areas of consolidation. the radiological manifestations of mucor mycosis can mimic those of invasive aspergillosis. geotrichum capitatum can present with bilateral non-cavitated nodules, consolidations and ground-glass-opacity. the ct fi ndings of fungal diseases may overlap. however, the knowledge of the various radiological appearances of fungal infections in combination with the patient's immunologic status allows narrowing of the differential diagnosis. . pleural effusion was only seen in patients ( %). seventeen patients ( %) had single lobe involvement and the rest had multiple lobe involvement. in patients with single lobe involvement, % had the right upper lobe involved. in patients with multiple lobe involvement, % had all the lobes involved. apical involvement was seen in patients ( %). there was a very high mortality; patients ( %) did not survive. no signifi cant correlation can be made with the chest radiograph fi ndings and the outcome and duration of symptoms. conclusion: chest radiograph fi ndings in patients with melioidosis are very variable. it is also not frequently associated with cavitations and apical involvement, which were frequently seen in patients with pulmonary tuberculosis. the fi ndings may mimic other pulmonary infections. infl ammatory myofi broblastic tumor of the lung: ct -pathology correlation s.j. theodorou , d.j. theodorou , y. kakitsubata , k. nabeshima , s. kakitsubata , s. tamura , p.j. friedman ; san diego, ca/us, miyazaki/jp purpose: infl ammatory myofi broblastic tumor of the lung is a rare, benign pseudotumor. the purpose of this study was to describe the ct fi ndings of infl ammatory myofi broblastic tumor of the lung with histopathologic correlation. methods and materials: ct images were obtained in patients submitted to our institution over a -year period. there were male and female patients, with an age range of - years (mean age of years). the presenting symptoms were chest pain and cough in cases. for cases, myofi broblastic tumor was an incidental fi nding on chest radiographs. histopathologic fi ndings were correlated with the imaging fi ndings in all cases. results: on radiographs and ct images, an ill-defi ned mass or nodule was seen in patients ( lesions), and a well-defi ned lesion was present in patients ( lesions). seven lesions were peripheral, and were centrally located. during ct, lesions were of heterogeneous attenuation, and were homogeneous. increased perilesional parenchymal abnormalities, which were caused by peribronchial infl ammatory infi ltrates, were seen in cases. the predominant histopathologic feature was organizing pneumonia type in cases, lymphoplasmacytic type in cases, and both organizing pneumonia and lymphoplasmacytic type in cases. variable degree of fi brous histiocytoma type was noted in all cases. conclusion: because of variable imaging features, myofi broblastic tumor of the lung is often misdiagnosed as lung cancer. ct fi ndings combined with certain histopathologic features can suggest specifi c diagnosis. learning objectives: to illustrate radiological fi ndings of asbestos-related disease (ard) involving pleura and lung parenchyma with chest radiographs, conventional ct and high resolution ct. to emphasize diagnostic features enabling differentiation from benign and malignant lung masses associated with asbestos exposure. background: asbestos has been recognised as a potential hazard since the s. ard is an occupational disease with a long latency period. our population had a great number of shipyard workers in contact with this dust. a long-term-follow-up of these workers is necessary. procedure details: ard comprises from pleural effusion and pleural plaques to asbestosis, term reserved to interstitial fi brosis, benign masses and malignant lung masses including mesothelioma and bronchogenic carcinoma. plain fi lms are used to identify presence and extension of asbestos related pleural and lung disease. conventional ct has been shown to be much more sensitive than chest radiographs in demonstrating these changes and can also identify fi ndings of parenchimal fi brosis such as pulmonary arcades, subpleural lines, parenchimal bands, reticulation and honeycombing. in addition, hrct can demonstrate thickened interlobular and intralobular lines. finally, this review will highlight typical characteristics that allows a specifi c diagnosis to determine benign and malignat lung masses, and will focus on spectrum of pseudotumor lesions including round atelectasis, fi ssural pleural plaques and mass-like fi brotic sheets. conclusion: rates of ard remain high in our population due to past occupational exposure and long latency period. typical imaging features of ard are described, with special attention to lesions that can mimic neoplastic masses. malignant mesothelioma: pictorial review of radiological-pathological correlation s. narayanaswamy, p. rao, a. george; plymouth/uk (arunagag @yahoo.com) learning objectives: to illustrate the spectrum of imaging and histological appearances, and to discuss the advantages and limitations of these investigations in the diagnosis and follow-up of patients with malignant mesothelioma. background: malignant mesothelioma is a highly aggressive tumour with an incidence progressively increasing with time. malignant mesothelioma has got a grim prognosis attributable to the late detection of the disease. the diagnosis is based on a combination of clinical history, radiological appearances and histology. despite all these modalities, diagnosis remains a challenging task to the medical profession as symptoms, imaging and the histological features often mimic other pathologies. imaging findings: computed tomography, magnetic resonance imaging, pet and histology play an important role in the diagnosis and staging of malignant mesothelioma. the spectra of radiological abnormalities noted are pleural effusion, plerual thickening, calcifi ed pleural plaques, interlobar fi ssural thickening, contracted ipsilateral hemithorax, evidence of local and distant metastasis. histologically, it is divided in to distinct types, ) epitheliod ( %), ) sarcomatoid ( %) and ) biphasic ( %). we present a pictorial review of all these distinct radiological and histological appearances, and also discuss briefl y the importance of these features in the diagnosis and staging of malignant mesothelioma. conclusion: a good understanding of the radiological and histological appearances is important as this will simplify and fasten the process of diagnosing malignant mesothelioma, enabling a larger number of patients to be diagnosed in the initial stages and undertake more successful treatment options. feasibility of micro-computed tomography in quantifi cation of murine bleomycin-induced lung fi brosis in in-vivo and postmortem conditions: correlation with pathologic score h. lee, j. goo, j.-g. im, k.-r. son, c. lee, c. park, e. chun; seoul/kr (rosaceci@dreamwiz.com) purpose: bleomycin-induced lung fi brosis (bilf) is an animal model of pulmonary fi brosis. the aims of this study were: ( ) to quantify bilf using micro-ct in in-vivo and postmortem conditions and ( ) to correlate the micro-ct scores with pathologic ones. methods and materials: after intratracheal instillation of bleomycin in eight mice, in-vivo baseline and weeks ( w) (n= ), weeks ( w) (n= ), or weeks ( w) (n= ) follow-up micro-ct (skyscan ; skyscan, belgium) in in-vivo and immediate postmortem state were performed with µm spatial resolution. on micro-ct, ground-glass opacities, consolidation, reticular opacities, honeycombing, and bronchial dilatation were scored. pathologic scores including infl ammation, parenchymal fi brosis, and airway fi brosis were obtained. spearman's correlation analysis to correlate micro-ct and pathology, kruskal wallis with duncan test to compare the w, w, and w groups, and wilcoxon signed rank test to compare in-vivo and postmortem micro-ct were performed. results: consolidation score in both of in-vivo (rho= . , p= . ) and postmortem (rho= . , p= . ) showed correlation with infl ammation score. score of bronchial dilatation in in-vivo (rho= . , p= . ) and postmortem (rho= . , p= . ) showed correlation with airway fi brosis score. in w group, consolidation score was higher than in w or w (p= . ). in w and w groups, score of bronchial dilatation was higher than in w (p= . ). only consolidation score of micro-ct was higher in in-vivo than in postmortem (p= . ), and other scores showed no difference. the scores of micro-ct and pathology were well correlated. the results of quantitative assessment in in-vivo and postmortem state were nearly comparable. left-sided injuries are more frequent, the posterolateral aspect of diaphragm being the most common site of rupture. the preoperative diagnosis is often diffi cult because dr may be overlooked due to associated thoracoabdominal lesions. if the diagnosis is missed, intrathoracic herniation of abdominal organs may occur. subsequent gastrointestinal strangulation/obstruction will have a mortality rate of up to %. supine chest radiograph remains the initial screening tool after blunt trauma. helical ct, particularly multidetector-row scanners, allows more accurate analysis of the diaphragm, with the subsequent improvement in diagnosis. imaging findings: we reviewed chest radiographs and helical ct scans of patients with surgically proved blunt dr. % were left-sided. we describe specifi c chest radiographic fi ndings and several ct signs indicative of dr, such as intrathoracic herniation of abdominal content, dependent viscera sign, collar sign, discontinuity of the diaphragm, absent diaphragm sign, and diaphragmatic thickening. five patients showed delayed presentation, of them with severe complications: intrathoracic gastric volvulus, transverse colonic strangulation/obstruction. conclusion: dr usually requires prompt surgical repair to avoid delayed complications. diagnostic tools include chest radiograph and helical ct. familiarity of radiologists with diaphragmatic anatomy and radiology of dr is required to guide the management of polytraumatized patient. fibrosing mediastinitis -the spectrum of contrast-enhanced ct fi ndings a. devaraj, n. griffi n, a.g. nicholson, s. padley; london/uk learning objectives: to illustrate the spectrum of ct fi ndings of fi brosing mediastinitis. background: fibrosing mediastinitis is a rare condition characterised by excessive fi brous tissue deposition within the mediastinum. it may present as either an idiopathic condition or as a consequence of an underlying process such as tb or histoplamosis. procedure details: we retrospectively reviewed the clinical, pathological and imaging fi ndings on cases of fi brosing mediastinitis obtained from our database from to . fibrosing medisatinits diffusely infi ltrated the mediastinum in patients and was localized in . eleven of cases had narrowing of mediastinal structures, including with pulmonary artery narrowing ( . %), with bronchial narrowing ( . %), with tracheal narrowing ( %) and one with narrowing of the pulmonary vein ( . %). the presenting complaint was often associated with compression of a relevant mediastinal structure. the disease was considered idiopathic in cases ( . %) with a demonstrable aetiology in cases ( . %). eight out of patients ( . %) had additional pulmonary fi ndings on ct, including all patients with a known aetiology. conclusion: obstruction of vital structures by fi brosing mediastinitis frequently gives rise to complications and is accurately illustrated by contrast-enhanced ct. there is a high incidence of concomitant pulmonary fi ndings, in particular when an identifi able aetiology is present. congenital bronchial atresia: imaging fi ndings and endoscopic correlation y. pallardó-calatayud , e. castañer-gonzalez , a.j. revert-ventura , j. camps-herrero , a. caño-gomez , e. mollá-olmos ; alzira/es, sabadell/es (ypallardo@hospital-ribera.com) learning objectives: to describe and illustrate the characteristic imaging fi ndings of this rare entity and provide guidelines for its diagnosis. to show the correlation between imaging and endoscopic fi ndings. background: we retrospectively studied patients ( m and f; mean age: . yrs). all patients underwent chest x-ray and ct and also underwent mri. all patients underwent bronchoscopy and clinical follow-up. imaging findings: chest x-ray fi ndings were branching tubular opacity (n= ), nodular opacity (n= ), consolidation (n= ), distal parenchymal hyperinfl ation (n= ), and parenchymal translucency (n= ). ct showed a mucous plug in all cases (n= ), with (n= ) or without air (n= ), severe stenosis of a segmental bronchus (n= ) with surrounding hyperinfl ation in of these. five patients were studied with a -row multidetector ct. learning objectives: to familiarize with fetal thoracic mri in order to be able to recognize normal lung images and the most common thoracic abnormalities. to know the mr indications for the diagnosis of fetal thoracic abnormalities. background: ultrasonography is the primary imaging modality for prenatal assessment of fetal abnormalities. limitations of us include restricted fi eld of view, dependence on the skills of the operator and the diffi culty to obtain quality images due to maternal obesity or oligohydramnios. in spain, prenatal us is usually performed by gynaecologists rather than radiologists, and our experience is scarce. when a pulmonary fetal anomaly is detected, different options should be considered, such as in utero surgery, early neonatal surgery or therapeutic abortion, depending on the severity of the abnormality and the availability of a specialized hospital. it is fundamental to establish a precise antenatal diagnosis and the cases where us is inconclusive and doubts arise, must be solved by other reliable imaging modality. mr is safe during pregnancy, and the development of ultrarapid t -weighted sequences makes it suitable for confi rming us fi ndings. imaging findings: we present our experience in fetal thoracic mri describing the characteristic imaging features of the normal lung and the thoracic abnormalities studied: congenital diaphragmatic hernia ( ), congenital cystic adenomatoid malformation ( ), pulmonary sequestration ( ) and situs ambiguous with asplenia ( ). conclusion: mri is the best choice for confi rming thoracic fetal anomalies when us is not conclusive. as radiologists, we must be familiar with its use and with the basic imaging features of these pathologies. the diaphragm is a musculotendinous structure that separates the thoracic and abdominal cavities. mri offers multiplanar capabilities and good tissues contrast resolution. review the anatomy and diaphragmatic and paradiaphragmatic processes and its appearances in mri. emphasis will be placed on diaphragmatic hernia and traumatic pathology. imaging findings: to assess hernias and their contents is the most common indication for diaphragmatic mri and coronal and sagital. t -weighted offers an optimal visualisation of the hypointense diaphragm to evaluate the anatomy. mri also provides tissues characterization of the hernia contents. mri can be useful in evaluating for transdiaphragmatic extension of disease, primary or metastatic diaphragmatic or juxtadiaphragmatic tumors. conclusion: mri of the diaphragm permitted to evaluate small lesion or hernia anatomy and it can answer clinical diagnostic questions with important management implications that others studies of imaging cannot. knowing normal and abnormal processes allows for the best diagnosis. assessment of diaphragmatic motion after lung resection using magnetic resonance imaging r. takazakura, m. takahashi, n. nitta, k. murata, n. tezuka, s. sawai, s. fujino; otsu/jp (rtryu@belle.shiga-med.ac.jp) purpose: to quantitatively assess the impairment of diaphragmatic motion after lung resection using magnetic resonance imaging. in patients ( males and females, mean age: . years) with lung cancer, diaphragmatic motion was measured during maximal deep slow breathing using a spoiled gradient-recalled-echo sequence before and after lung resection. the study group consisted of patients who were examined using a . -t unit in the supine position and patients using a vertically open . -t unit in both the sitting and supine positions. the infl uence of surgery sites and postures of the patients on the diaphragmatic motion after lung resection was investigated. the protocol of this study was approved by the institutional review board. we received written informed consent from all subjects. results: in all cases after the lung resection, the diaphragmatic motion of the operated side signifi cantly decreased (p < . ) and that of the non-operated side increased signifi cantly (p = . ). after left upper lobectomy and right bilobectomy, the diaphragmatic motion of the operated side decreased signifi cantly (p < . ), and that of the other side increased signifi cantly (p < . ). after right middle lobectomy, the diaphragmatic motion had not changed signifi cantly. the diaphragmatic motion of the operated side was impaired signifi cantly more (p = . ) in the supine position than in the sitting position. conclusion: our results indicated that magnetic resonance imaging (mri) was useful for quantifying the impairment of the diaphragmatic motion after lung resection. tubes, lines, and catheters in plain chest fi lms: an abc guide for the assessment of normal and pathological fi ndings d.d. cokkinos, g. giannakopoulou, e. daskalaki, m. avlianos, a. bouga, a. kontogiannis, n. gavalas; athens/gr (ggiannakopoulou@gmail.com) learning objectives: to illustrate the essentiality of evaluating the position of tubes, lines and catheters in chest x-rays. background: tubes, lines and catheters are common fi ndings on everyday radiographs, especially chest studies. it is essential to evaluate the placement and position of tubes and lines, such as central venous and arterial catheters, endotracheal and nasogastric tubes, thorax drains, and cardiac pacemakers. unfortunately, lack of familiarity with these devices leads to misjudgement of proper positioning, and therefore immediate or delayed complications. procedure details: we inspected retrospectively chest radiographs from patients (neonates, children, and adults) and concentrated on identifying all tubes, lines and extraneous devices. we reviewed the fi lms with respect to normal positioning and malpositioning. we also looked out for complications associated with inappropriate positioning or malfunctioning devices, such as pneumothorax, air embolism, perforation and bleeding. in addition, we assessed the device's integrity and alignment, receiving valuable information for the patient's general health or lack thereof. conclusion: familiarisation with normal and abnormal fi ndings of tubes, lines and catheters is essential and leads to proper management and treatment of the patients. molecular targeted anti-cancer therapeutic agents for non-small cell lung cancer: mode of action, current results, and radiologic fi ndings after treatment using these agents c. . the knowledge about molecular targeted anti-cancer agents and familiarity with the images of the patients treated with these agents will be mandatory for the radiologists to determine the accurate tumor-response to the molecular targeted agents. the spectrum of diseases causing airway mucoid impaction j. euathrongchit , n. learning objectives: to systemically review the imaging aspects of the spectrum of diseases causing mucoid impaction of the airways. background: mucoid impaction, mucus plugs, and bronchial mucocele are similar conditions resulting from accumulation of inspissated secretions such as mucus/ pus/ infl ammatory products within the bronchi, which are usually dilated. mechanisms resulting in this condition are abnormal mucociliary transport, excessive production of mucus, and collected mucous in bronchi distal to an airway obstruction. procedure details: in this exhibit, we follow the above mechanisms to display the variety and spectrum of presentations of mucoid impaction. conclusion: this educational computer exhibit reviews the spectrum of the radiographic features of mucoid impaction on chest radiographs, ct and mri and the underlying mechanisms responsible. c b d e f a g pleuropulmonary manifestations of asbestos-related disease: computed tomography (ct) fi ndings z. khaleel, c. viswanathan, r. lavakumar, n. kennan, g. avery; hull/uk (ziyadlk@hotmail.com) learning objectives: to review and illustrate the imaging spectrum of asbestosrelated disease of the lungs and the pleura with emphasis on computed tomography (ct) fi ndings. background: asbestos fi bres inhalation is known to induce a range of pleural and pulmonary disorders. high levels of asbestos exposure have gradually been prohibited since the s in many countries. prevalence of this disorder is still rising; however, this is secondary to the long latency period ( years or longer) between initial exposure and development of the disease. imaging findings: benign pleural disease is the commonest encountered manifestation and includes pleural effusion, pleural plaques, rounded atelactasis and diffuse pleural thickening. although lung parenchyma is thought to be less sensitive to the effects of the fi bres than the pleurae, asbestosis is a well-recognised sequel to prolonged asbestos inhalation. malignant manifestations include bonchogenic carcinoma and malignant mesothelioma. owing to the accuracy of imaging in asbestos-related disease and the medicolegal implications of the diagnosis, the radiologist plays a pivotal role in the disease management. we aim to present a review of the ct/hrct fi ndings of this debilitating illness. spectrum of radiological appearance of chest ports and catheters: an exhibit for non-interventional radiologists m. diaz, a. villanueva, g. bastarrika, j. noguera, j. del pozo, a. alonso-burgos; learning objectives: to describe the radiological features (chest x-ray, ct and us) of chest ports and reservoirs (cr) commonly used for chemotherapy administration. to describe the radiological fi ndings of the complications that may occur with these devices. background: chest ports play an important role in the management of oncology patients who need frequent blood products, chemotherapy and other intravenous drugs. chest port related complications may arise during their placement, removal or the meantime and they may be asymptomatic. many cases of catheter-induced central thrombosis go unrecognized, but the incidence of pulmonary embolism in this group may be as high as %. plain fi lms, ultrasound and ct are useful for the prompt diagnosis of these complications. general and oncology radiologists rather than interventional radiologists play an important role in their detection. imaging findings: normal imaging fi ndings (plain fi lms, us, and ct) of the different ports and reservoirs and some common interpretation pitfalls, such as thrombus formation inside a vein, are described. radiological fi ndings of reservoir associated complications such as rotation, thrombosis, and infection and catheter related complications such as mural, tip and sleeve thrombosis, displacement, breakage, migration and infection are discussed. conclusion: appropriate knowledge of the normal cr appearance and radiological fi ndings of cr related complications is important in order to facilitate a prompt and effective diagnosis. general radiologists are encouraged to consider the cr as an area of interest when interpreting imaging studies. the knowledge of pathologic processes that affect the chest wall and its radiological fi ndings allow us to establish a specifi c diagnosis in a great percentage of the cases. however, when chest wall lesions show a non-specifi c radiological behaviour, imaging techniques provide a strategy in the workup of an accurate diagnosis, and is a useful guide for biopsy and for the surgical approach. thoracic manifestations of sickle cell disease in children e.j. helm, p.s. babyn, p. parkin; toronto, on/ca (paul.babyn@sickkids.ca) learning objectives: to illustrate the spectrum of thoracic pathology seen in sickle cell anemia as demonstrated by plain radiography, ct and mri background: sickle cell disease (scd) is a hemoglobinopathy characterized by changes in all major organ systems. the lung and heart are major target organs in this disease. specifi c manifestations of pulmonary disease include the acute chest syndrome and sickle chronic lung disease. cardiovascular manifestations include pulmonary hypertension, multiple chamber dilatation, myocardial ischemia and infarction. thoracic disease is frequently associated with other severe manifestations of sickle cell anemia such as neurological disease and bone infarction. imaging findings: we will illustrate the common and uncommon manifestations of scd including acute chest syndrome, chronic lung disease and pulmonary hypertension. in the acute chest syndrome, plain fi lm fi ndings may be subtle or absent. a rapid progression to multifocal consolidation and an ards type picture may occur. ct may demonstrate hypoperfusion and ground glass shadowing and better depicts early changes. plain fi lm fi ndings in chronic sickle lung disease include fi brosis and cor pulmonale. ct changes include interlobular septal thickening, reticular abnormalities, pleural tags and lobar volume loss. echocardiographic fi ndings of chamber dilatation and pulmonary hypertension have been extensively reported. spect imaging can demonstrate further fi ndings of ischemia or infarction. conclusion: thoracic disease due to sickle cell anemia has many different manifestations. although the chest radiograph has traditionally been used for assessment, other imaging modalities frequently add additional important information. congenital cystic adenomatoid malformation: is ct a useful predictor of histological type? n. griffi n, a. deveraj, a. nicholson, s. padley; london/uk (nyreegriffi n@hotmail.com) purpose: congenital cystic adenomatoid malformations (ccams) are rare congenital lung lesions recently reclassifi ed into subtypes ( - ). subtype may undergo malignant transformation. there is also overlap between type- ccams and type- pleuropulmonary blastomas. the aim of this study was to determine if pathological subtypes , and show characteristic changes on ct that may aid preoperative diagnosis methods and materials: ct studies were reviewed for consecutive patients referred postnatally with the histological diagnosis of ccam on surgical resection. results: median age at the time of resection was . years (range: . - . ). five patients were females. five patients had type- histology; were type- ccam; and were type- ccam. no type- or type- lesions were encountered. ct review indicated the following: most lesions were in the lower lobes ( ). lesion size and cyst number were variable (from to over cysts), and did not depend on histological type. type- lesions had well-defi ned cysts, with maximum cyst diameter exceeding cm. type- lesions had cystic change in cases, with maximum cyst diameter measuring less than cm. areas of reduced attenuation were also seen ( ). type- lesions showed either microcystic ( ) or macrocystic change ( ), with mass effect demonstrated in all cases, and contralateral mediastinal shift seen in cases. one patient also had pleural nodules. imaging findings: imaging fi ndings are based on chest radiography and computed tomography. most frequent fi ndings in pulmonary infections are patchy, bilateral and rapidly progressive condensations associated with severe respiratory failure. in addition, patients had brain lesions secondary to embolic dissemination. imaging fi ndings are fairly similar to those encountered in disseminated aspergillosis; however, all these patients had a fatal and rapid evolution, because this fungus is resistant to all anti-fungal therapies known. autopsy demonstrated necrosis and hyphae proliferation inside the thoracic and brain lesions. conclusion: scedosporium prolifi cans must be included in the differential diagnosis of rapid lung infi ltrates in deep immunocmpromised patients in some western regions of europe and australia. non pulmonary primary thoracic malignancies: a radio-pathological correlation a. donuru , v. kandula , a. barbieri , j.j. entwisle ; leicester/uk, northampton/uk learning objectives: the purpose of this exhibit is to describe the radiological fi ndings of various non-pulmonary primary thoracic malignancies. all the cases illustrated are pathologically proven. background: thoracic cancer comprises many different types of cancer that strike the thorax. some types are common, such as lung cancer and esophageal cancer. some are rare. imaging findings: the pathologies included are lymphoma (hodgkin's and non hodgkin's), breast cancer, oesophageal cancer, mesothelioma, sarcoma, thymoma, angiosarcoma, leiomyosarcoma, chondrosarcoma, ganglioneuroblastoma, malignant fi brous histiocytoma, rhabdomyosarcoma, haemangioendothelioma, plasmacytoma and neurilemmoma. conclusion: it is important for the radiologists to have an awareness of the imaging fi ndings of the above mentioned thoracic malignancies. when the diagnosis is not clear on a chest radiograph or on computed tomography it is strongly recommended that a biopsy is performed for pathologic confi rmation. normal variants-congenital thoracic anomalies in adults year old ( - years old) were included. cases were analyzed. the ratio of primary and metastases was : . mean tumor dimension is . mm. pathology were squamous cell ca ( ), adenocarcinma ( ), metastases (hepatocelluar ca ( ), renal cell carcinoma ( ), colon cancer ( ), soft tissue sarcoma ( )). ct guided cryoablation was performed under the local anesthesia by guidance of ct. mean ablation is . per patient. sequential ct was acquired on , , mo. ct fi ndings were analyzed (maximal dimension, mean attenuation). we analyzed sequential changes of volume and mean roi. nine of them were correlated with pet-ct for evaluation of viable component. major symptoms (cough, dyspnea, and hemoptysis) were assessed and showed improvement in symptoms. mean admission was less than week. complications were pneumothorax ( ), hemothorax ( ), hemoptysis ( ), pleural effusion ( ). patients were followed for a mean period of months ( - months). in metastases, perilesional necrosis was more prominent in immediate ct (within week). six cases were increased dimension. necrosis was shown in fi ve cases. five have increased ct attenuation than initial ct. conclusion: cyoablation plays an important role in palliation of advanced cancer, post operative recurrence, or metastases. our study suggests that adequate palliation may be achieved by cryoablation applied to advanced cases. it was recently reported that the who classifi cation refl ects the clinical features of and is one of the prognostic factors for thymic epithelial tumors. fdg-pet exhibits accumulation, also refl ecting the malignancy of the tumor; it is useful in differential diagnosis according to the who classifi cation. it is believed that the procedure plays a key role in the diagnosis of thymic epithelial tumors. were reviewed by two radiologists in consensus. . mm thin-section ct fi ndings were evaluated about the size, density, shape, border margin, marginal irregularity, spiculation and lobulation. the density was measured by setting of roi in size of a maximum short-axis diameter of the lesion. the uptake of fdg was represented as maximum standardized uptake value (suv). these ct fi ndings and suv were statistically compared. results: tumor size and density were signifi cantly correlated with suv (p < . ). mean suv of lesions with lobulation and without lobulation were . and . , respectively and suv of lesions with lobulation was signifi cantly higher than that without lobulation (p < . ). mean suvmax of lesions with spiculation and without spiculation were . and . , respectively and suv of lesions with spiculation was signifi cantly lower than that without spiculation (p < . ). the other fi ndings were not signifi cantly correlated with suv. conclusion: a low fdg uptake of lung lesions in small size, with low ct density or spiculation are not reliable fi ndings to deny lung cancer. in contrast, a low fdg uptake of the lesion with lobulation-like fi nding or high ct density may suggest the lesion benign. value seventy-nine patients ( f, m; mean age years) referred for suspicious of lung cancer based on chest radiography fi ndings were studied. patients with previous diagnostic ct were excluded. image acquisition was performed with a combined pet-ct in-line system from head to mid-thigh, minutes after intravenous administration of mbq f-fdg, and with administration of iodinated intravenous contrast, and water as oral contrast. biopsy and/or fi ne needle aspiration were obtained in all cases and served as standard of reference. results: pet-ct correctly classifi ed patients as neoplastic. twenty-seven corresponded to adenocarcinoma, to squamous-cell carcinoma, to large-cell carcinoma and to small-cell carcinoma. the remaining patients were falsepositives corresponding to infl ammatory-infectious processes ( abscesses, tuberculosis and neumonia) that simulate lung cancer. the sensibility and the predictive positive value were and . %, respectively. in all the patients, pet-ct avoided the performance of other imaging modalities such as contrastenhanced body ct and bone scintigraphy. conclusion: our initial results indicate that fdg pet-ct may be useful as fi rstline imaging modality in patients with suspected lung cancer and help in avoiding other diagnostic procedures. the comparison of pet-ct and chest ct for staging in lung cancer d. kim, j. yang, j. byun, y. kim; gwangju/kr (dhk @hanmail.net) purpose: the goals of this study are to estimate the effi cacy of pet-ct and chest ct, alone and combined, in tumor staging and to exhibit various false (positive or negative) fi ndings mimicking true fi ndings. this study enrolled patients with lung cancer who had undertaken pet-ct and chest ct. the age range of the consecutive patients is - years (mean age: . years). both studies were done within . days. two independent readings were obtained from each test, and discrepancies were solved by consensus. bronchoscopic biopsy or percutaneous transthoracic lung biopsy was performed by one radiologist and one physician. all cases were confi rmed pathologically. the correlation of tumor stages by pet-ct or chest ct, and both studies combined were evaluated. also, various false-positive or false-negative fi ndings of pet-ct were demonstrated, thereby causing diffi culties in accurate staging. results: agreement in pet-ct for staging of lung cancer is . % ( cases). overestimated stage for lung cancer by pet-ct was seen in cases ( . %) and cases ( . %) were interpreted to be in an underestimated stage. in cases ( . %), malignancy was not proved. diseases causing false-positive fi ndings were infl ammatory granuloma, reactive lymphadenopathy, and infl ammations such as pneumonitis, pneumonia, lymphoma. small cancer or small malignant lymph nodes showed false-negative pet fi ndings. conclusion: pet-ct and chest ct showed similar results in staging of lung cancer. two studies represented high conditional dependency. also, for the proper interpretation and accurate diagnosis of lung cancer by pet-ct, the various false fi ndings of pet-ct should be understood. dual results: pathology was of squamous cell ca and of adenocarcinoma. the stages were ia, ib, iia, iib, iiia, iiib, and iv. there is a signifi cant correlation between suv of primary lesion and presence of nodal or distant metastases and ri value were higher than squamous cell carcinoma than adenocarcinoma. mean suv of each group is . : . (squamous:adenocarcinoma). the ri ratio is . : . (squamous:adenocarcinoma). the suv of the lymph nodes were similar pattern ri to the primary mass. conclusion: pet suv, independent of size, is a marker of biologic aggression that can predict the specifi c histopathology for non small cell cancer. higher level suv of primary mass favors squamous cell carcinoma than adenocarcinoma. b d e f a g chest vascular perforating branches of the internal thoracic artery: an anatomical study using mdct angiography k. nakatani, h. maeda, n. hamada, t. yamanishi, k. miyatake, a. nishioka, y. ogawa; nankoku/jp (jm-nakakimi@kochi-u.ac.jp) purpose: breast reconstruction is a crucial technique for patients after breastconserving surgery. breast reconstruction with consideration of the breast blood supply offers the potential of avoiding complications such as breast scleroses and adiponecrosis. the present study aimed to determine the locations, courses and distributions of perforating branches of the internal thoracic artery (ita), the major artery infl ow to breast tissue from the inner side, using multi-detector row-computed tomography (mdct) angiography. methods and materials: subjects in this prospective study comprised women with suspected breast cancer who underwent mdct angiography between april and december . perforating branches of the ita were identifi ed on a dedicated workstation using transverse sections and -dimensional images. distributions of the identifi ed perforating branches were investigated. depth of perforating branches was measured and analyzed using simple regression analysis. results: a total of perforating branches were found, with branches ( . %) originating in the second intercostal space and branches ( . %) originating in the third intercostal space. most branches from the second intercostal space turned horizontally after running cranially. most branches from the third intercostal space ran horizontally. a strong correlation was identifi ed between distance from skin to branches and adipose thickness at the shallowest and deepest points (p < . ). we succeeded in detailing the course, length and distribution of ita perforating branches using mdct angiography. these results for distribution and depth of ita-perforating branches will prove helpful in performing immediate breast reconstruction following breast-conserving surgery. and learning objectives: to review the embryologic features of the aortic arch specially focussed on right-sided aortic arch development. to describe the most relevant fi ndings of the right arch, great vessels and associated anomalies to aid potential surgical procedure. background: the right-sided aortic arch is an uncommon congenital defect of the aorta. it is present in . % to . % in radiological series. deletion in chromosome q is associated in % of isolated anomalies of laterality of branching of the aortic arch. using edward´ s hypothesis, three types are described: type , with mirror-image branching of the major arteries; type , with an aberrant subclavian artery; and type , with isolation of the subclavian artery. congenital heart anomalies are usually present in types and . the initial fi ndings by the chest-x ray and barium swallow suggest the anomaly. however, cta or mra should be performed to confi rm the defi nitive diagnosis. background: ph is a complex life-threatening condition with numerous aetiologies. symptoms such as breathlessness on exertion, fatigue and chest pain are non-specifi c and are often attributed to more common disorders such as asthma delaying diagnosis. treatment has a profound impact on outcome. a specifi c diagnosis is important as therapeutic options range from surgical intervention to targeted medical therapy. since biopsy may be hazardous in this patient population, imaging plays a central role in establishing a diagnosis and guiding therapy. imaging findings: imaging features in ph can be divided into those that are common to all aetiologies and those that are disease specifi c. an understanding of the pathophysiology and classifi cation of the ph aids diagnosis. we will present imaging data from patients presenting to a national centre for ph and pulmonary thromboendarterectomy with pathologic correlation in specifi c cases. the radiologist plays a central role in the diagnosis of ph. it is important to be aware of the general and more specifi c imaging features in the spectrum of diseases associated with ph as early diagnosis and targeted therapies can improve the outcome. the importance of looking at the heart when interpreting standard thoracic ct e. castaner , y. pallardó , x. gallardo , m. prieto del rey , s. perez aguilera , j. mata ; sabadell/es, alzira/es (ecastaner@cspt.es) learning objectives: to familiarize viewers with the normal anatomic structures of the heart and pericardium to avoid mistaking them for pathologic processes. to explain the signifi cance of some incidental fi ndings. to emphasize the importance of looking at the heart when interpreting a thoracic ct study, especially in some particular clinical settings. background: important information concerning the heart can be obtained on both un-enhanced and contrast-enhanced ct of the thorax. cardiac disorders can often complicate or coexist with extracardiac thoracic disease, and may often remain unsuspected or underevaluated. correct analysis of images of the heart and surrounding structures depends on a thorough understanding of cardiac anatomy and on the ability to recognize the normal and abnormal appearances of the heart commonly observed on ct. imaging findings: we show anatomic structures that can be misinterpreted (crista terminalis, eustachian valve, fossa ovalis, coronary sinus, valves, pericardial recesses, paracardiac structures); some incidental fi ndings and their clinical value (calcifi cations, dilatations, fat deposition, increased or decreased myocardial density) classifi ed considering the structure involved: valves, chambers, pericardium. we comment on some clinical situations with possible cardiac repercussion: pulmonary hypertension, pulmonary embolism, neoplasms, and chest wall disorders. conclusion: knowledge of cardiac anatomy is essential to avoid mistaking normal anatomic structures for pathologic processes. it is important to know the clinical relevance of some incidental fi ndings and which of them will require further examinations. radiologists need to know conditions that may have an important effect on cardiac structure and function. msct and mri of the pulmonary veins: anatomy, anatomic variations and anomalous pulmonary venous drainage a. alonso -burgos, l. diaz, j. noguera, e. de luis, a. villanueva, j. larrache, g. bastarrika; pamplona/es (alonso@unav.es) learning objectives: to describe msct and mri features of the normal anatomy, anatomical variations, and anomalous returns of the pulmonary venous system. to emphasize the capability of msct and mri to non-invasively map pulmonary venous and left atrial anatomy before the percutaneous ablation. background: assessment of pulmonary venous and left atrial anatomy has become a hot topic among cardiac electrophysiologists, as radiofrequency catheter ablation is being increasingly used for atrial fi brillation. both msct and mri provide detailed and accurate anatomic information about the pulmonary veins and additional anomalies that are commonly associated with the development of atrial fi brillation. axial images and especially volume-rendered reconstructions allow to precisely determine the anatomy, anatomic variations, anomalous returns, and total number of pulmonary veins, thereby facilitating the interventional procedure. imaging findings: in this exhibit, normal pulmonary venous msct and mri anatomy and anatomical variations will be discussed. anomalous pulmonary venous returns as well as associated anomalies will also be illustrated. the role of msct and mri to non-invasively depict pulmonary venous and left atrial anatomy before the ablation will be emphasized. conclusion: msct and mri allow a rapid non-invasive assessment of normal pulmonary venous anatomy and associated anomalies. preprocedural exact delineation of these structures might facilitate the percutaneous intervention in patients with atrial fi brillation. background: central venous catheters and other devices are routinely used in the hospitable practice; for this reason, the correct knowledge of the thoracic venous anatomy is basic. mdct angiography is the best non-invasive method to describe it, and it offers us the possibility to diagnose thoracic venous disorders that could be important for placing catheters and, consequently, to avoid iatrogenic complications. procedure details: we employed slice mdct for study of all chest on a single section helical. a table feed of mm per rotation, and a reconstruction increment of . mm are used. ml of non-ionic contrast material is injected at ml/second, immediately followed by injection of - ml of saline solution at the same injection rate. the images were acquires at seconds. at the workstation, we performed multiplanar reconstructions. conclusion: mdct angiography is the most reliable method in the non-invasive diagnosis of thoracic venous disorders. comparative analysis of methods for determination of blood fl ow parameters in non-small-cell lung cancer results: rbv pa from ed and ld were . ± . ml/ ml tissue and ± ml/ ml tissue, respectively. rbv idt was . ± . ml/ ml. ps from ed and ld were . ± . ml/ ml/min and . ± . ml/ ml/min. the rbv pa and rbv idt values showed signifi cant correlation (r= . , p < . ). relevant correlation between rbv pa as well as ps from ed and ld were not found. conclusion: our results support the statement that rbv and ps measurements are time-dependent and probably may not be calculated using late data sets. further research is needed for the determination of the appropriate time of data acquisition. the optimization of the dce-ct study protocol could improve the qualitative and quantitative assessment of functional tumor data. these parameters could serve as prognostic factors or may be used for follow-up studies. shortest guide to anatomy of pulmonary arteries evaluated in multislice computed tomography angiography g.j. staskiewicz, e. assessment of a pulmonary angiography -row mdct protocol using kvp in comparison to a kvp protocol: a prospective randomized trial p. mohr, s.a. peters, s.p. lemburg, v. nicolas, c.m. heyer; bochum/ de (christoph.heyer@rub.de) purpose: to implement a pulmonary angiography mdct protocol using kvp, and to compare vessel enhancement, snr, cnr, radiation exposure, and subjective image quality to a protocol using kvp. methods and materials: sixty patients were referred for evaluation of suspected pulmonary embolism by ct angiography on a -row scanner. patients were randomly assigned to a ct protocol using or kvp, respectively. all other scan parameters including tube current, collimation, and gantry rotation time were kept constant. contrast media was injected using bolus tracking. based on density measurements, pulmonary vessel opacifi cation and image noise were quantifi ed and snr / cnr were calculated. subjective vessel contrast was assessed by two radiologists in consensus. effective dose was calculated based on dlp/ctdi values. results of both protocols were compared using chi-square-test and student's t-test. the kvp protocol showed a non-signifi cant higher mean vessel density than the kvp protocol ( ± hu to ± hu; p= . ) and a non-significant higher image noise ( ± hu to ± hu; p= . ), resulting in almost identical snr ( ± to ± ; p= . ) and cnr ( ± to ± ; p= . ). furthermore, subjective image quality showed no signifi cant differences between the two protocols. mean effective dose of the kvp protocol was signifi cantly lower compared to the kvp protocol ( . ± . msv to . ± . msv; p < . ). conclusion: reduction of tube kilovoltage from to kvp resulted in significant reduction of effective dose in pulmonary -row mdct angiography without signifi cant loss of objective and subjective image quality. the post-processing of multi-slice ct in the interpretation of chest traumas w. yang , c. beigelman-aubry , a. brun , p.a. grenier ; shanghai/cn, paris/fr learning objectives: to outline the indication and advantage of multislice ct post-processing in the interpretation of chest traumas. to demonstrate several potential pitfalls in the interpretation and the method of avoiding these pitfalls with the post-processing technique. background: chest traumas are responsible for approximately % of traumarelated deaths. they are associated with high morbidity and mortality rates. ct, especially with the post-processing technique, including mpvr, mip, mip, volume rendering, provides fast, sensitive, and accurate evaluation of vascular, pulmonary, airway, skeletal and diaphragmatic injuries. imaging findings: d reformations provide a panoramic view of all the chest structures, allowing the detection of minor fractures. curved reformations provide information of excellent value in case of spine injuries. mip-mpvr may be used in the evaluation of vessel injuries as and costal cartilage injuries. mini-ip is useful in the detection of all lucent lesions, including pneumothorax. pneumomediastinum, tracheobronchial ruptures or pulmonary hernia. volume rendering is particularly helpful in case of thoracic cage trauma. the post-processing techniques used in the diagnosis of chest trauma are highly informative. a rigorous protocol with optimized use of reconstructions is required. computer-aided detection (cad) in lung cancer screening at chest mdct: roc analysis of cad vs. radiologist performance f. fraioli, l. bertoletti, m. mennini, r. lezoche, c. catalano, r. passariello; rome/it (francesco.fraioli@uniroma .it) purpose: our aim was to compare the performance of radiologists against a cad algorithm for pulmonary nodule detection on mdct. methods and materials: three radiologists independently analysed scans and assigned each nodule a confi dence score ( - ). cad was applied to all scans, successive readers re-evaluated all fi ndings of the cad, assigning, in consensus, a confi dence score ( - ). the reference standard was established by other two experienced chest radiologists. results were used to generate an froc analysis. the reference standard showed nodules. sensitivity for readers i-ii-iii was: , , and %. a double and triple reading resulted in an increase in sensitivity up to %. with cad, sensitivity was increased to , , and % for readers i, ii, and iii. the area under the froc curve (az) was . , . , . , and . for readers i, ii, iii, and the cad. differences between all readers and the cad were signifi cant (p < . ). for nodules > mm az was . , . , . and . for readers i, ii, iii, and the cad. p was signifi cant between reader i and the cad and between reader iii and the cad, it was not signifi cant (p= . ) between reader ii and the cad. for nodules < mm, az was . , . , and . for readers i-iii and . for the cad. differences between all readers and the cad were signifi cant (p < . ). conclusion: cad can aid in daily radiological routine detecting a conspicuous number of nodules unseen by radiologists. pathological diagnosis was achived by surgery in patients and with a follow-up in . sensitivity, specifi city and accuracy of malignant nodules was calculated by considering single slice vs total volume wash in and wash out of c.m. thirty pn with benign and malignant were included in our analysis. diagnostic criteria of malignancy included those nodules with a wash in of hu and a wash out less than hu. results: an almost perfect agreement was obtained between the two measurements in the diagnosis of benign nodules while a disagreement occurred in pn histological malignant. in those nodules, a wash in enhancement greater than hu was shown for both measurements but with a wash out respectively greater and smaller than hu when single axial or volumetric assessment were performed. conclusion: volumetric assessment of the wash in and wash out curves appears more accurate and reproducible allowing a better evaluation of densitometric curves and reducing limits of single slice evaluation. moreover, dedicated software may provide a semi automatric analysis with a reduction in the evaluation time and more comparable results. impact of the digitalization of a radiology department in the detection of lung cancer in the emergency department i. herrera, m. garcía hidalgo, c. varela, c. ruiz, c. romero, j. pinto; purpose: to evaluate the impact of the digitalization of a radiology department in the detection of lung cancer in the emergency department (ed). we retrospectively reviewed and compared the number of lung cancer cases detected in the ed by using conventional (year ) and digital (year ) chest radiography. our radiology department became completely digital in . this new situation brought the opportunity of having the images available at any time and made possible the later review of the images acquired at the ed by an expert radiologist. we analyzed the role of an expert radiologist together with the availability of previous images. results: in , lung cancers were detected and histologically confi rmed at our institution. thirty-eight ( . %) were detected at the ed. twenty ( . %) of them were detected by a radiologist and ( . %) patients had previous radiographs at our institution although no image was available. in , lung cancers were detected and histologically confi rmed. forty-fi ve ( . %) of these cancers were detected at the ed. a radiologist reported as abnormal . % of those cases. thirty-three ( . %) were previously imaged at our institution. twenty-two ( . %) were reported by a radiologist and ( . %) of them had the image available in digital format. the digitization of the ed increased the rate of lung cancers detected at this department. the number of cases interpreted by an expert radiologist, the availability of previous images and reports has also increased due to the digitization of the radiology department. towards international standardization of medical images distribution workfl ow through portable media e. avraham; plano, tx/us (eli@kodak.com) learning objectives: to demonstrate limitations in distributing medical images through portable cd media. to present a reliable workfl ow for importing and reconciling medical images using the ihe profi les "portable data for imaging" (pdi) and "import reconciliation workfl ow" (irwf). to demonstrate use cases for distributing and reconciling medical images through portable cd media. to enhance the portable media distribution workfl ow for non-imaging health it documents. background: the healthcare information distribution on cd media is rapidly increasing and reduces cost and network dependency. for example, operating rooms, dental and referral physicians increase their use of sharing images through cd media. the lack of standardization on the health cd data organization and data types reduces the client's capability to access the data and display it correctly. this educational exhibit proposes a standard solution, based on ihe profi les: pdi and irwf, to provide a reliable distribution of imaging information on interchange media for import, display and print. procedure details: this educational exhibit includes but is not limited to ( ) demonstrating current limitations on distributing medical images through portable cd media, ( ) presenting a reliable workfl ow for importing and reconciling medical images using ihe profi les pdi and irwf, ( ) demonstrating the use cases for sharing medical images through portable media, ( ) extend the portable cd media distribution for other non-imaging, health it ehr information. the standardization of the portable media distribution is improving the medical image distribution and sharing, which is a key in improving the patient health practices and reducing healthcare operational cost. internet guide for radiologists d. volpe, n. volpe, n. masiello, a. saponaro, a. carriero; novara/it (dvolpe@sirm.org) learning objectives: to describe the principal possibilities offered by the web and provide basic indications that will encourage inexpert people to embark on a personal exploration adapted to their needs and abilities. background: information interesting to physicians accounts for a large part of the multimedia world of the internet in both quantitative and qualitative terms. hundreds of the many sites containing medical information are dedicated to imaging diagnostics, their number is constantly growing, and their nature is constantly changing. this means that the information is dispersed and often half hidden in a vast range of site categories or local resources, thus making it diffi cult to evaluate its quality and reliability in an objective manner. procedure details: among the vast range of resources of radiological interest on the internet, we propose a classifi cation of the sites that facilitate navigation to the greatest extent and directly supply the type of information being sought. the sites have been grouped into seven ideal folders: catalogue sites, institutional sites, specialised sites, radiological image databases, on-line journals, sites offering teaching material, and discussion forums. conclusion: our aim is to propose a digital guide of free internet resources for radiologists. e-anatomy.org: a free interactive atlas of whole body sectional anatomy a. micheau, d. hoa; montpellier/fr (denis.hoa@campusmedica.org) learning objectives: to provide an e-learning website about sectional anatomy of the human body, with interactive self-study and assessment tools, based on more than mr and ct slices. background: on one hand, information and communication technologies (ict) act as a catalyst for innovation in learning, giving access to relevant, interactive, high-quality content. on the other hand, improvements in ct (e.g. multisection ct) and mr imaging (improved spatial resolution) deliver highly detailed images of internal anatomy. thus, interactive computer-based content and flash animations could be used to create new ways to teach sectional anatomy. procedure details: we chose normal ct and mr exams. more than slices were selected in order to cover the entire sectional anatomy of the human body. images were labeled using terminologia anatomica. we built a user-friendly interface, which allows to cine through multi-slice image series combined with textual information, d models and anatomy drawings. learning assessment is provided b d e f a g by self-tests. all these teaching modules are available on the internet. conclusion: e-learning and interactive flash animation combined with the latest multi-slice ct and mr imaging technologies offer new ways to teach radiological whole body human anatomy. we provide a useful, free, interactive tool for the radiologist's everyday use; available online at http://www.e-anatomy.org. massachusetts, usa) was used for writing codes of both mathematical equations and the graphical user interface. technical aspect presented by this system can provide the parts: ( ) image processing and analysis using full-fi eld digital mammography, ( ) quality control (qc) tools improved the effi ciency of periodic tests, and ( ) gui-based checker for clinical breast examination and mammography fi ndings. granulometry was implemented in this program with basic imaging fi lter (smoothing, edge-enhancement and adaptive wiener fi lter). granulometry determines the size distribution of the region of interest (roi) in a mammogram. the software we developed for supporting breast cancer screening had a benefi cial effect to improve the effi ciency of qc and the diagnostic work of mammography. virtual colonoscopy: car versus non-car a. koshman; moscow/ru (falko @rambler.ru) purpose: to compare the results of d endoluminal analysis using computer assisted reading (car) with d endoluminal analysis non-car by experts for colorectal polyps detection. methods and materials: twenty-eight patients ( males, females, age range - years) underwent virtual colonoscopy procedure. all of them had undergone optical colonoscopy which revealed polyps and was used as a reference standard. two radiologists read the datasets from virtual colonoscopy: one after the procedure, non-car; the other radiologist read the data sets using car. sensitivities were calculated. all reading times and number of false-positive results were documented. results: sensitivities for clinically signifi cant polyps of - mm and mm or larger in diameter were: % and %, respectively for d non-car and % and % for d car (p= . ). false positive rates (mean) were . and . for d non-car and d car, respectively (p= . ). the average reading time for d non-car was . minutes (sd± . ) and . minutes (sd± . ) for d car (p= . ). conclusion: using d car system provides higher sensitivity, lower false-positive rate and less time per case than d non-car. a novel wall thickness-mapped approach of clinical virtual bronchoscopy s. park, j. kim, j. goo, k. kim, h. lee, s. lee; seoul/kr (lunao @snu.ac.kr) learning objectives: to understand an algorithm of automated assessment of airway wall thickness in chest ct images. to experience the wall thickness-mapped virtual bronchoscopy that visualizes color-mapped wall thickness at each part of airway. to appreciate effi ciency of pc-based application for the virtual bronchoscopy through developed-software. background: measurements of bronchial tree airway geometry can be used to evaluate and track the progression of disease affecting the airways, such as asthma, copd and cystic fi brosis, and to assess the effi cacy of new therapeutic approaches. this exhibit demonstrates a new method for wall thickness-mapped virtual bronchoscopy through measurement of airway wall thickness with a proposed algorithm. procedure details: we present an enhanced virtual bronchoscopy that allows assessment of wall thickness during the virtual fl y-through using the steps below. firstly, the airway trees are segmented, and then airway center-lines and bifurcation points at each generation are acquired with morphological analysis. then, we can calculate every wall thickness of each generation of the volumetric airway tree by using a proposed method based on vector analysis with perpendicular plane to airway. finally, our own software visualizes color-mapped virtual bronchoscopy that refl ects airway wall thickness, fl ying through the inner path of airway. conclusion: using ct scans of human cases, we present results showing that this new approach is convenient, accurate, automatic and well-visual in estimating airway wall thickness. our proposed method can provide pre-operative planning of the intervention for lung surgery with enhanced functional virtual bronchoscopy as a complementary tool for clinical diagnosis and several airway diseases. a statistical model for the geometric correspondence between differentview breast x-rays taken isochronically from a single breast j. teubl , h. bischof , m. blumenthal ; graz/at, munich/ de (teubl@icg.tugraz.at) purpose: we investigated the reduction of false-positive detections of a mammographic cad system using a new statistical correspondence model. there is no accurate physical model available to solve the geometric correspondence problem between two different views of the breast; therefore, we propose a new statistical model derived from the cases of a large database. instead of a direct point-to-point correspondence, we infer the correspondence probability using a probability-estimation technique. the crucial point is the normalisation of point correspondences. in our method, one of the breasts is arbitrarily chosen as the norm breast. the lesions from all other breasts are normalised to this norm breast. this approach provides us with a suffi cient number of point correspondences in one breast to compute a statistical model. in the fi rst experiment comprising breasts from the ddsm, we compared our statistical model with the recently proposed stripe model. we showed that the statistical model performed better (i.e. using % of the breast area as search space, we fi nd % of the lesions using our new method compared to % when using the stripe model). in the second experiment comprising a smaller set of breasts, we showed that the geometrical correspondence was useful to reduce the number of false-positive detections. conclusion: if the geometric correspondence information is used, a mammographic cad system can achieve a higher accuracy. the method introduced in this paper outperforms the recently proposed geometric correspondence models. using dicom header to improve interventional radiology practice: purpose: to present the usefulness of the information contained in the dicom header of archived images for patient dosimetry and automatically audit the interventional procedures, and to introduce the consensus of the european sentinel consortium in this topic. methods and materials: information on dose, radiographic techniques, beam geometry, c-arm angulations, fi ltration, fi eld of view, collimation, acquisition protocols, post-processing, number of frames that are included in the dicom header were analysed using cd-roms from different interventional x-ray systems installed in several european hospitals. the usefulness of the different parameters to audit the clinical procedures is discussed. results: when looking at the dicom header, it is evident that a signifi cant amount of information for dosimetric purposes is contained in private tags. their format and meaning is unfortunately not easily available and even not well defi ned in the dicom conformance statement. the dose reports produced by most of the interventional x-ray systems are useful documents, which could help in the audit of patient doses and procedures allowing rough skin dose maps to be calculated retrospectively. the consensus document issued by the sentinel group states that dosimetric, technical and geometric parameters allowing the automatic audit of patient dose and radiological procedures should be contained in public fi elds of the dicom headers. the work in progress started by iec to standardize the structure of the dose reports will improve the present situation. development of software facilitating the extraction of dicom header information for patient dosimetry and quality control on line should be promoted. analysis of nine years of experience with "a walk through radiology" f. sendra, m.j. ruiz-gómez, o. torales, m. martínez-morillo; malaga/es (sendra@uma.es) learning objectives: to present a multimedia project focused on training medical students in the visual perception of radiological images and to review the experience in our institution since . background: e-learning radiology resources are used to be focused on residents or specialists training, our project is addressed to medical students or general practitioners. it does not pretend to be an exhaustive lesson about radiology, but a practical tool to train the user's visual perception. procedure details: the application is a powerpoint based case collection of different image modalities, organized in normal and pathological series. after seeing each case, the user must go to the response screen where several commentaries and marks are shown with animated transitions. since , this project has taken a part of the practical activities for last course of the medical students in our institution. questionnaires about performance with computers, evaluation of the application and open suggestions have been collected during this time. two cd-rom editions have been published in and and the next one will appear at the end of . the purpose of these editions is to distribute to the students and professors at low cost. this project has also been adapted to html to be integrated as a web-based-training resource and version . is translated into fl ash presentations. conclusion: this exhibit presents the evolution of this project and the actual . version, which is presented into six languages spanish, english, french, german, italian, and portuguese, trying to spread "a walk through radiology" within european countries. web-navigation guidelines dedicated for radiologists a.n. chalazonitis , g. tsimitselis , j. tzovara , v. nikolaou , a. kontogiannis , n. ptohis ; athens/gr, larissa/gr (red-rad@ath.forthnet.gr) learning objectives: . to demonstrate simple and advanced web searching strategies. . to provide a list of reference and targeted engines for radiologydedicated search. . to identify useful web resources for radiologists. background: it is well known that the web or internet is a rich illimitable electronic source of information. however, navigation in this unbounded space requires a quiver of valuable tools named "search engines". three main types of search tools exist: search engines, metasearch engines and subject directories/guides. any radiological search depends on the strategy used. procedure details: in this exhibit, simple and advanced web searching strategies will be shown. methods on how to limit or increase results will also be presented combined with various examples. the technique of automated content-based image retrieval, needed to search into image databases, will be also discussed. a complimentary list of references with radiological resources, online databases and targeted engines for the most thorough search will be also provided for the participant. conclusion: even though there are several ways to search the web, a strategy map of radiology-focused navigation should be always available so that any radiologist can get the most information on the least number of web pages. its underlying architecture is based on a highly-scalable community framework that is ideally suited to support teaching, research, and administration rols allows users and administrators to defi ne different kinds of communities, where each community can be equipped with different tools and resources for shared work, dialogue, and investigation. rols "out-of-the-box" consists of a robust portal system, a comprehensive suite of collaborative applications, and an enterprise infrastructure layer based on open standards. the muols system and its architecture are based on four foundational ideas. . learning is inherently social and takes place most successfully in the context of communities. . there is no "right" pedagogical model for learning. . the source of innovation is the user, not the manufacturer. . successful online communities (learning communities even more so) must provide extraordinary amount of feedback to participants and administrators. first background: nine patients affected by: atypical pancreatic pseudocyst, endovascularly repaired abdominal aorta aneurysms, foreign bodies retained in soft tissues were submitted to multidetector ct and to us-ceus examination. two imaging modalites were coupled, then correlated us probe position to the volume acquired by ct, using an electromagnetic tracker. in pancreatic pseudocyst and in endovascular grafts, ceus was performed as well. imaging findings: ceus-ct fusion imaging correctly defi ned a small lesion attached to cystic wall as "not solid". ceus-ct fusion imaging provided functional and morphologic information about aortic endoprostheses. us-ct fusion imaging rapidly identifi es the us position of foreign body in small parts, guiding surgical resection. conclusion: us-ct fusion imaging offers advantages in terms of cost-effectiveness, time and diagnostic accuracy in different fi elds of application. a web-based, user tailored and free of charge annotation and image editing program for interactive presentations and teaching fi les r. talanow , m. grunewald ; cleveland, oh/us, erlangen/de (roland@talanow.info) learning objectives: to develop an image annotation and presentation program available anytime and anywhere, for creating interactive annotations for teaching fi les and presentations in realtime, free of charge, user tailored, easy to use, with no programming skills and no additional program fi le download necessary. background: at this time there is no image annotation and presentation program available which creates interactive annotations in realtime, is free of charge, accessible from every computer worldwide and is user tailored. procedure details: we developed the multilingual online program annotate, which allows to create interactive image annotations and presentations. it is available over the internet and accessible worldwide from every computer with internet connection. the author does not need to have programming experience. the image edition as well as the linking and the source code are created automatically by the program. the created website is immediately available worldwide over the internet. the author can change the annotations and presentations at any time and the changes will be done in realtime. there is no need for a fi le transfer after each change. the program can be tailored for the individual user's needs. conclusion: annotate (www.annotate.org) is an image annotation and presentation program which is available anytime and anywhere, for creating and changing interactive teaching fi les and presentations in realtime. it is user tailored, easy to use and free of charge. there are no programming skills and no additional program fi le downloads necessary. the user's learning experience may be enhanced by offering multiple modes of presentation. interactive volume rendering d images for anatomy learning on lowend computers Ö. smedby , s. wirell , j. kvist , c. silén , g. , volume rendering visualizations of high-resolution d ct datasets have been produced in quicktime vr format for self-study by medical and physiotherapy students. the images can be accessed on any network-connected computer with the free quicktime player installed. as demonstrated by this exhibit, the user can freely rotate the volume around both vertical and horizontal axes by dragging the mouse in the image. in addition, the user can easily zoom in and out. the images produced so far include the heart and great vessels as well as parts of the musculoskeletal system. the use of semi-opaque structures facilitate the presentation of, e.g., the relationship between coronaries and heart chambers or between patella and femur. in preliminary evaluations, the students give the material high ratings. conclusion: easy access over the internet and good interaction capabilities on low-end computers make this format attractive as an aid for anatomy learning. a new software platform for interactive vertebra radioanatomy and ct guided interventions learning s. aubry, a. pousse, p. sarliève, e. delabrousse, l. laborie, b. kastler; besançon/fr (radio.aubry@free.fr) learning objectives: to become familiar with advanced software for d interactive radio-anatomy learning. to learn about basics in rachidian radio-anatomy. to experience fundamentals of simulated ct guided interventions. background: the range of rachidian ct guided interventions is widening from day to day. this practice requires a perfect vertebra radio-anatomy knowledge and a high degree of interventional procedure culture. we present a software platform dedicated to vertebra radio-anatomy and ct guided interventions learning. procedure details: based on d high resolution modelisation of vertebra segments and of their vasculonervous environment from multidetector ct acquisitions, the presented tool simultaneously offers multiplanar reconstruction (mpr), d surface rendering, objects outlining on mpr. opengl based development allows interactive shading such as lighting or opacity modifi cations. furthermore, virtual d objects have been inserted in the volume in order to simulate the best of rachidian ct guided interventions (infi ltration, cementoplasty, rf). conclusion: this d modelisation package has the potential to improve radiologist's knowledge of the spine. radiologists are thus able to virtually practice approaches aimed at safe planning of a variety of ct guided interventions. automatic segmentation of the rectal tube in computer-aided detection for virtual colonoscopy p. boda, s. agliozzo; turin/it (piergiorgio.boda@i-medlab.com) purpose: computer-aided detection (cad) for virtual colonoscopy (vc) is a tool that allows to detect polyps from vc exams. during the exam, a rectal tube (rt) is placed in the patient for air insuffl ation. this tube is the origin of false positive (fp) detections in the cad system. we present a method for the automatic segmentation of the rt. methods and materials: two types of rts were used, which differ for their diameter and the plasticity. the fi rst rt (rt ) has a maximum diameter of mm, whereas the second one (rt ) has a diameter of mm and is more fl exible. exams were acquired on a multislice helical ct scanner with a tube current of ma at kv, a slice thickness of . mm and an interval reconstruction of . mm. patients were scanned in both supine and prone positions, after bowel cleansing and air insuffl ation. we studied cases, for a total of ct scans, four of them with rt s and the rest with rt s. the algorithm detected % of rts ( / ) and in all of these cases rts were completely tracked. it failed once for a rt of the second type. the visual inspection of this case showed that the lumen of the rt was almost entirely fi lled with fecal residus. we developed a robust automatic method for the segmentation of two types of rts for cad for vc. organic re-circulation of the information on network ( the purpose of this study is to develop a ct scanner system to reproduce key images that are specifi ed in a prior diagnosis. the ct scanner retrieves a dedicated dicom object from an image server and extracts a scan protocol of a previous study for application in the present study. the object is associated with a series of prior studies and includes information about scan protocol, scan range and the position of key images in the series. after acquiring a ct localizer in the present study, the operator registers the ct localizer to a prior one in the object, in order to fi t the patient's position using the anatomical landmarks. this operation enables the operator to fi t the scan range and image reconstruction range automatically. the ct scanner creates the new dedicated dicom objects associated with the present study that have spatial offset value for comparable images to prior key images. results: the acquired images have same scan conditions and same position of prior images within one slice difference. we developed a ct scanner that makes it easy to acquire comparable images to those of a prior study. a time of additional operation of current study does not give much effect for study throughput of the ct system. now, we are planning to standardize this dedicated object to make interoperability between different vendors and modalities. image retake analysis in digital radiography using dicom header information e. vano, j.i. purpose: retake analysis is a key aspect in any quality assurance programme and a basic tool to avoid unnecessary doses to patients in a radiology department. a methodology to automatically detect potential retakes using dicom header information is presented. methods and materials: a system called qconline was developed to help in the management of images and patient doses in a digital radiology department. images are sent to the pacs and to a dedicated workstation where the qconline runs. dicom header information is extracted and transferred to a database. relevant images can also be archived for inspection. the initial criterion for potential retakes was that or more images have the same patient id, modality, description, projection and date. this criterion was applied over the , abdomen and , chest images. a sample of the images was assessed to determine the goodness of the method. the initial rejection criteria lead to a . % retake rate in the abdomen examinations and a . % for the chest examinations. after a thorough analysis of the supposed repeated images, the need for additional criteria such as orientation of the cassette (landscape/portrait) was demonstrated. the fi nal retake fi gures were roughly % of the automatic fi ltering from the database. conclusion: automatic retake analysis is a critical aspect in digital radiology. it allows detecting defi ciencies like wrong identifi cations, positioning errors, wrong radiographic technique, bad image processing, equipment malfunctions, artefacts, and so on. in addition, retake images fi ltered automatically and collected can be used for continuous training of the staff. feasibility of showing radiologic images on ipod: can pod save the space? h. funatsu, h. takano, m. kogure, a. imamura, t. kasai; chiba/jp purpose: ipod, a portable media player, is capable of displaying images and movies. carrying radiologic images in ipod would be useful for educating residents, communicating with other radiologists or referring physicians, or informing patients at bedside. the purpose of our study is to evaluate lesion conspicuity on ipod. methods and materials: fifty sets of key images of either computed tomography or magnetic resonance imaging were randomly collected from computerized database in our department. any lesions equal or less than mm in diameter were excluded while collecting images. these images with any fi ndings and images without any fi ndings were installed on ipod. size and site of the each lesion were recorded. five blinded radiologists reviewed the images both on ipod and dicom viewer with a -week interval between sessions. conspicuity of the lesions was evaluated by using response receiver operating characteristic (roc) curve analysis. (d-ust@yandex.ru) purpose: to determine optimal compression settings and parameters for mr image compression. methods and materials: investigation included patients with various pathologies and consisted of mathematical and visual approaches. the mathematical approach included searching for the quantitative quality index of compressed mr images (with analysis of currently approved quality index-compression ratio), compressibility tests, estimation of coders behavior. visual image evaluation was performed on nine -bit head and spine mr images by four observers. test images were compressed in jpeg, jpeg , jpeg-ls at various quality settings (q). results: image compression ratio (e.g. : , : etc). is often used as a term equal to image quality, but it is unacceptable, because the visual quality of images with the same compression ratio may widely vary. visually lossless threshold depends on resolution (the lower resolution the higher quality settings required) and body zone (e.g. compressibility of spine images is better than head images). in our study the visually lossless threshold was between q jpeg = - and q jpeg-ls = - for four observers. jpeg-ls was the best coder for high quality mr images compression, while jpeg is concluded to be unfi t. jpeg shows a little worse result than jpeg-ls. conclusion: compression ratio cannot be quantitative quality index. in visual analysis, jpeg-ls provided the best image quality with maximum compression. jpeg can be still useful due to good compatibility and high quality. jpeg seems unacceptable because of high resolution and high compression orientation. quantitative evaluation of nodule kinetics using temporal subtraction in dynamic chest radiography with a fl at panel detector y. tsuchiya , y. kodera ; shizuoka/jp, nagoya/jp (yuichiro-rt@k .dion.ne.jp) purpose: this study was performed to develop a method of using a temporal subtraction technique for evaluating the quantitative kinetic function of a lung nodule by dynamic chest radiography, and to investigate the clinical application of our technique by using a simulated nodule. methods and materials: dynamic chest radiographs ( × , bit, fps, sec) were obtained using a modifi ed fl at-panel detector system (cxdi- g, canon inc, tokyo, japan). for respiratory phase synchronization, analysis of diaphragm kinetic was performed, and continuous subtraction in the expiratory phase was performed to obtain a temporal-subtraction image as output. the clinical effectiveness was investigated using radiographs of eight healthy volunteers ( - y/male) with a simulated nodule. the range of the enhanced region that appeared on the output image was manually measured. the differences between the known kinetic amount and result were calculated as detection error. signifi cance of difference was then evaluated by paired t-test. the movement tracks of the nodule could be visualized as a white region on the output image. the detection rate of the radiographs with nodules was % ( / ). the maximum difference of ranges that were measured was less than mm; the average of the absolute value of the difference was . ± . mm. no statistically signifi cant differences were found between the known and measured amounts (p=. ). conclusion: dynamic chest radiograph with our computer analysis can clarify kinetic information regarding nodules and is effective as a screening examination for checkup or initial planning of radiation therapy. imaging biomarkers in colorectal cancer: texture analysis of hepatic ct b. ganeshan, k.a. miles, r.c.d. young, c.r. chatwin; falmer/uk (b.ganeshan@sussex.ac.uk) purpose: to assess the potential for computer analysis of liver texture during ct to provide biomarkers for patients with colorectal cancer and to identify possible biological correlates for relevant texture features. methods and materials: a feasibility study comprised patients undergoing ct after primary resection of colorectal cancer, followed by an evaluation group of a further patients. hepatic ct perfusion and survival data were available for both groups, with fl uorodeoxyglucose pet results accessible in the evaluation group. texture was assessed within regions of interest manually constructed over apparently normal liver whilst excluding major blood vessels and fat, and comprised band-pass image fi ltration at different spatial frequencies, followed by quantifi cation of liver texture. the feasibility study demonstrated that liver texture during the portal phase correlated with the hepatic perfusion index (r=- . , p= . ), and survival (r= . , p= . ). in the evaluation study, texture in apparently normal liver tissue in patients with hepatic metastases was different from patients with no tumour recurrence on unenhanced (p= . ) and arterial phase images (p < . ), and from patients with extra-hepatic disease on unenhanced images only (p= . ). among patients with no visible liver metastases on ct, texture analysis of portal phase images could identify those with extra-hepatic disease on pet (p= . ) and impaired survival (p= . ). the hepatic phosphorylation of glucose was identifi ed as a possible biological correlate for texture (r=- . , p= . ). conclusion: texture analysis of hepatic ct images obtained during routine clinical practice can provide biomarkers that refl ect hepatic physiology and identify patients with extra-hepatic disease and poor survival. novel approach to evaluate regional parenchymal pulmonary and aortic blood supply selectively with self-developed dual phase perfusion software in -slices ct x. xie, g. zhang, y. chen, z. li; shanghai/cn (adrianxie@ .com) learning objectives: to demonstrate that pulmonary arterial phase images and aortic phase images can be acquired with slices ct. to develop windows-based software for processing semi-qualifi ed dual phases perfusion. background: pulmonary blood supply includes pulmonary and systematic circulation. regional blood supply imbalance is complex in some diseases, such as copd. with complicated scanning technique, non-contrast images, pulmonary arterial phase images and aortic phase images were acquired in one breath-hold with slices spiral ct. delay time was determined by a time-density curve. contrast was pushed forward by saline for better enhancement. then, pulmonary arterial phase and aortic phase data sets can be acquired. windows based software (dualx . ) was developed to analyze these selective dual phase images with delphi . . procedure details: after image correction, pulmonary enhancement and bronchial enhancement can be calculated by subtraction technique. then, pulmonary ratio was calculated, which is the proportion of pulmonary enhancement in total enhancement. pseudo-color map also can be rendered to illustrate these parameters over non-contrast images. conclusion: pulmonary phase perfusion and aortic phase perfusion can be evaluated separately. purpose: to compare the dynamic information obtained from contrast-enhanced ultrasonography (ceus) and contrast-enhanced magnetic resonance (cemr) on two experimental tumor models exhibiting notable differences in vessel anatomy. methods and materials: six animals subcutaneously injected with a carcinosarcomatoid (a ) cell line and six animals injected with a carcinoma (bb ) cell line underwent ceus and cemr. ceus was performed on a technos (esaote, italy) with a bolus injection ( . - . ml) of sulphur hexafl uoride microbubbles (sonovue, bracco, italy) into a tail vein. the curve of enhancement (time-intensity) obtained by locating a roi over the tumor was used to calculate maximal intensity (mi) and slope (s). cemr was performed on a biospec scanner (bruker, germany) by injecting gd-dtpa-albumin (contrast media laboratory, university of california, usa). by locating a roi over the tumor, we calculated fraction plasma volume (fpv) and transendothelial permeability (kps). all the tumors were removed and analyzed histologically and immunohistochemically (cd ). the vascularity of the two different tumor histotypes was comparatively evaluated by immunohistochemical, cemr and ceus analyses. results: considering the viable areas of the tumor, the vessels of a were signifi cantly (p < . ) more numerous and smaller than those in bb tumors. cemr fpv and kps parameters were signifi cantly (p= . ) higher for the a tumors than for the bb tumors. ceus mi and s values were smaller in the a tumors than in the bb tumors (p= . ). conclusion: our data demonstrate that particular histologic features, such as collapsed intratumoral vessels, can lead to a mismatch between ceus and cemr in studying tumor vascularization. learning objectives: to discuss the optimisation of acquisition parameters to maximize the ability of ferumoxtran- enhanced mr imaging (uspio-mri) at tesla. to demonstrate tips and tricks for evaluating uspio-mri in combination with dedicated software for visualizing d localisation of lns. background: uspio-mri is shown to be extremely accurate for assessment of the ln status in prostate cancer patients. since positive ln smaller than mm can be accurately detected with uspio-mri, appropriate high-resolution imaging is essential to maximize its clinical usefulness. clinical t whole-body mr system, which is increasingly becoming available, is expected to enable imaging with a higher spatial resolution. aids with dedicated computer software are now essential in evaluation for numerous high spatial resolution images. imaging findings: the exhibit is based on our experiences of uspio-mri at t in years, including t-mri scanner with total imaging matrix. positive lns with to mm in diameter can now clearly visualised on uspio-mri at t. thanks to multi-channel capability, both t and t *-weighted image can be obtained with dft-volume data acquisition, which enable to acquire isotropic voxel t *-weighted images, as well as t -weighted images. these volume data are evaluated on dedicated software for visualizing d localisation of lns. conclusion: combination of novel techniques, t-mri with tim technique and uspio, enable to visualise tiny positive lns on mri. optimisation of the acquisition parameter is essential to maximize the ability of uspio-mri. the help of computer technology is vital in handling numerous data to be evaluated. purpose: to assess the effi cacy of harmonic gray-scale ultrasonography using second-generation contrast agents (sonovue) in evaluating the response of hepatocellular carcinoma (hcc) after percutaneous treatment, and to compare the fi ndings of this imaging modality with those of dynamic magnetic resonance imaging (mri). a total of patients with hcc treated by transarterial chemoembolization ( ), ethanol ablation ( ) or radiofrequency ablation ( ) were included in the study. all of them were examined with second-generation contrast agents ultrasonography (cus) one month after the last percutaneous treatment. vascular fi ndings at cus were compared with the results of dynamic mri. contrastenhanced mri fi ndings were taken as the gold standard. tumoral response criteria considered at cus were: ( ) persistence or absence of tumoral enhancement during arterial phase, ( ) necrotic tumoral size. results: cus and mri, performed one month after hcc percutaneous treatment, found complete response in of the patients ( %) and no response in patients ( %), respectively. comparing both imaging techniques, we obtained an agreement of % (kappa . ), a sensitivity of %, a specifi city of %, a positive predictive value of %, a negative predictive value of % and an accuracy of %. in cases, cus and mri found different results. conclusion: cus is useful to detect residual hcc when compared with dynamic mri results. because of its low cost and high disponibility, it may reduce the frequency of dynamic mri in the follow-up of treatment response. learning objectives: to provide an educational review of the multifactorial elements of contrast-induced nephropathy. to review the current literature on etiology and prevention of contrast-induced nephropathy. to provide evidence-based approach/algorithm when assessing patients undergoing contrast enhanced procedure. to establish a protocol for patient care and follow-up. background: contrast-induced nephropathy has become an important cause of iatrogenic acute renal impairment and currently ranks as the third most common cause of hospital-acquired acute renal failure. although clinical presentation of cin is well described, precise mechanisms and management strategies for this complication continue to be a matter of debate. the incidence of cin (contrast induced nephrotoxicity) is dependent on both the defi nition of cin and the patient population investigated. the incidence of nephropathy is low in the general population, but patients with increased risk (patients with renal impairment and diabetes) have reported signifi cantly higher frequency ( - %). procedure details: through a medline literature search and review of a number of current guidelines, we will establish an algorithm of best practice for all patients undergoing contrast-enhanced procedures. we will assess the current evidence on potential prophylaxis (prehydration, acetylcysteine, bicarbonate, fenoldopam, discontinuation of nephrotoxic medications prior to contrast-enhanced scans) and those patients that should be targeted for these treatments. we provide a thorough and concise review of this intricate area, which could be applied in all radiology departments to optimise patient care in a practical manner. effi purpose: to assess the diagnostic accuracy of gd-dota mra over tof mra for non-coronary arterial disease by comparing the percent agreement at the subject level of each mra method with x-ray angiography (defi ned as number of segment scores in agreement/ total number of segments evaluated for the subject x ). multicenter, open-label, fi xed sequence, paired trial in subjects > years [ men, women; mean age (±sd) . ± . years] with suspected non-coronary arterial disease and scheduled to undergo x-ray angiography were included and received an iv bolus of gd-dota . mmol/kg. results: the regions imaged for arterial disease were: renal ( . %); aorto-iliac ( . %); femoral ( . %); carotid ( . %); popliteal ( . %); and calf ( the essence of iodinated contrast media: what every radiologist must know ( ) to discuss the factors that infl uence image quality. ( ) to evaluate the risk of anaphylaxis, nephrotoxicity or nonrenal adverse reactions, and to discuss the role of pre-medication regimen.( ) to be aware of the decisions one has to make before injecting iodinated cm. ( ) to become acquainted with the appropriate treatment of such adverse reactions. ( ) to discuss special situations (dialysis, metformin, pregnancy and lactation). background: iodinated contrast media (cm) are sterile iodine-containing solutions used in almost all diagnostic imaging methods. since their advent in the s, they have revolutionized diagnostic imaging. although the diagnostic value of cm is enormous, other less desirable side effects also occur. procedure details: the purpose of this review is to address some of the main concerns that arise with the day-to-day use of iodinated cm. this presentation is divided by topics. it provides guidelines recommending precautions to prevent possible iodinated cm reactions. the authors discuss the need for informed consent and measurement of renal function, as well as the risk factors that may predict adverse events, and how to deal with patients who have had a prior reaction. the types and treatment of adverse reactions are discussed. conclusion: although iodinated cm are safe and widely used, adverse events occur and questions remain about their use, safety and interactions. every radiologist should be intimately familiar with cm. sixty methods and materials: ninety consecutive patients ( men, women; mean age: years) were randomly assigned to one of three cta protocols: in group : ml of contrast medium ( mg iodine per milliliter [mgi/ml]; fl ow rate: ml/s); in group : ml of contrast medium ( mgi/ml; fl ow rate: ml/s); and in group : ml of contrast medium ( mgi/ml; fl ow rate: ml/s) were intravenously administered. all contrast medium applications were followed by ml of saline fl ush. the attenuation in hounsfi eld units (hu) was assessed from the ascending aorta to the thoracic aorta at the level of the aortic hiatus at fi ve different locations. the patients of all the three study groups showed diagnostically acceptable attenuation values of the thoracic aorta. the overall mean aortic attenuation was ± hu in group , ± hu in group and ± hu in group . group had the most constant opacifi cation of the thoracic aorta and showed a trend to lower mean and maximum, but higher minimum and median attenuation values than groups and ; group and group showed a trend to lower attenuation values in the distal thoracic aorta than group . conclusion: different contrast medium ct protocols were evaluated and this resulted in acceptable diagnostic attenuation values in cta of the thoracic aorta. therefore, -detector row ct allows reducing the amount of contrast medium down to ml, when an iodine concentration of mgi/ml and a fl ow rate of ml/s are used. the basic procedural knowledge of ultrasound contrast agents: a how-todo dvd rom-based audiovisual teaching guide p.s. zoumpoulis, i. . to present a step-by-step visual guide on how to prepare the patient, how to administer the solution, how to make control adjustments on us machine, and how to evaluate the sonographic fi ndings. . to establish a safe and credible procedure that minimizes complications and ensures true-positive results. background: the interaction between the "bubbles" and the us beam is explained with analytical drawings and real-time us videos. procedure details: contrast-enhanced ultrasound improves the detectability of pathology by revealing regions of increased vascularity. this medical e-book illustrates the steps taken to perform an ultrasound exam with use of ultrasound contrast agents. a detailed description of ultrasound contrast agents, how to prepare the solution, how to prepare the patient, administration of the solution, control adjustments of us machine to enable high-analysis contrast detection such as mi, tgc, gain, depth and focus and sonographic appearance of ultrasound contrast agents are provided in a user-friendly manner. the proper technique is demonstrated step by step. educational double video presentations included a simultaneous presentation of the real-time ultrasound exam and the examiner's technique. conclusion: user-friendly dvd rom-based visual guide with step-by-step procedural instructions on how to perform an ultrasound examination with ultrasound contrast agents. purpose: to evaluate the mechanisms of cytotoxicity of an iodinated contrast medium on renal tubular cell cultures. methods and materials: llc-pk -cells were incubated with iomeprol and corresponding mannitol solutions ( . - mg i/ml, - h). metabolic activity was assessed with -( . -dimethyl- -thiazolyl)- . -diphenyl- h-tetrazoliumbromid (mtt)-assay. the trypan-blue test was used to assess cell viability. to detect apoptosis, an elisa for the determination of oligonucleosomes in the cell lysate was performed. -bromo- '-deoxyuridin (brdu)-incorporation into the dna was measured to assess proliferation. results: iomeprol induced a time-and dose-dependent inhibition of mtt-conversion ( - %, at . - mg i/ml at h; - %, at - h at . mg i/ml), which was signifi cantly stronger than that induced by mannitol ( - % at h, p < . ). after h incubation with iomeprol and a recovery time of h after removal of the contrast medium, there was only a small inhibition of mtt-conversion ( % and % at . and mg i/ml, respectively). there was no signifi cant increase in the number of necrotic cells ( % in control; % and % after h incubation with iomeprol at . and mg i/ml, respectively; p> . ). as an indicator for apoptosis, the number of oligonucleosomes increased signifi cantly ( % difference to control at . mg i/ml after h, p < . ). iomeprol induced a signifi cantly stronger inhibition of proliferation than mannitol ( % and % vs. % and % at . and . mg i/ml, respectively; h, p < . ). the iomeprol-induced inhibition of mtt-conversion is mostly reversible, and is not associated with cell necrosis. the irreversible part may be due to apoptosis and decreased proliferation. evaluation of low-dose contrast protocols for d-cta of the aorta using -row multislice ct t. sakamoto , d. utsunomiya , s. okumura , j. urata , k. anami , a. taniguchi ; kumamoto/jp, bunkyo-ku,tokyo/jp (taka-sakamoto@skh.saiseikai.or.jp) purpose: -row multislice ct provides detailed data over a wide range in a short time, and reducing the amount of contrast medium used for d-cta has been attempted at many facilities. we conducted studies to investigate the optimization of contrast enhancement and to evaluate the usefulness of low-dose contrast protocols for d-cta of the aorta, based on clinical data. methods and materials: d-cta of the aorta was performed in patients. nonionic contrast medium ( mgi/ml) was injected at a rate of . ml/s, followed by a ml saline fl ush injected at . ml/s. two protocols that differed in the amount of contrast medium injected [protocol a: ml ( patients) and protocol b: ml ( patients)] were evaluated and compared. the mean ct numbers and sd values in the ascending aorta, descending aorta, pulmonary artery, diaphragm, aortic branches, and external iliac artery were compared. the appropriate dose of iodinated contrast medium per kilogram body weight was also investigated for protocol b. the fi ndings of the present study indicate that the appropriate dose of contrast medium is mgi/kg body weight to ensure optimal contrast enhancement in aortic d-cta. evalutation methods and materials: one hundred and thirty-four patients with nodules of hcc treated with tace (n. ) and with rfta (n. ) were admitted to our department for follow-up. nodules treated with rfta were divided retrospectively into two groups: ) group ( / ): immediate post-ablation evaluation using ceus was performed and, when necessary, immediate contrast-enhanced ultrasound-guided targeted re-treatment was carried out; and ) group ( / ): ceus was performed only for follow-up. therapeutic response was evaluated at one month with dynamic ct and ceus. sensitivity and specifi city of ceus and dynamic ct were calculated. results: after rfta, complete response was observed in . % (group ) and in . % (group ) with dynamic ct and in . % (group ) and . % (group ) with ceus. sensitivity and specifi city of ceus were % and %. after tace, complete response was observed in . % of nodules with dynamic ct and in . % with ceus. sensitivity and specifi city were % and % for dynamic ct and % for ceus. conclusion: contrast-enhanced ultrasound may be a more suitable technique to evaluate intratumoral residual blood fl ow following tace treatment. evaluation of the results between the two groups who underwent rfta showed a signifi cant difference in the ablation success rates. is contrast-enhanced ultrasound useful? principal radiological and clinical applications d. volpe, n. volpe, a. saponaro, n. masiello, p. neri, a. carriero; novara/it (dvolpe@sirm.org) learning objectives: to show the technical principles underlying ultrasound (us) contrast agents, imaging fi ndings, and principal radiological and clinical applications. background: the introduction of contrast agents has led to one of the most important advances in ultrasonography. us contrast agents are intravenously injected substances that are distributed by the blood fl ow to all organs, where they modify the characteristics of the tissues by increasing their ultrasonographic refl ectance. given the different types of vascularization of normal and pathological tissues, they offer a better means of characterizing focal lesions than b-mode echography. procedure details: contrast-enhanced us is more accurate than conventional echography in determining the number and size of focal lesions, and revealing capsular involvement, because it reduces the number of false-negative results. this more precise classifi cation of lesions has a considerable diagnostic and prognostic impact. we provide an overview of its principal radiological and clinical applications: focal lesions, trauma of solid abdominal viscera, vescicoureteral refl ux, and vascular diseases. the introduction of second-generation contrast media is changing the diagnostic perspective by giving radiologists an effective product of immediate use that eliminates all interpretative doubts and facilitates diagnosis. effects of non-ionic iodinated contrast media (cm) on patient heart rate during intra-cardiac or intra-arterial injection i. schmid , d. purpose: to compare heart rate (hr) and systolic/diastolic blood pressure (bp) after intra-cardiac or intra-arterial injection of a non-ionic low-osmolar cm (iomeprol) and a non-ionic iso-osmolar cm (iodixanol). double-blind, randomized studies were conducted in patients undergoing cardiac angiography (ca) and patients undergoing peripheral intra-arterial digital subtraction angiography (ia-dsa). patients undergoing ca received iomeprol- (n= ) or iodixanol- (n= ). hr and systolic/diastolic bp was determined before and after initial injection during left and right ca (lca and rca) and left ventriculography (lv). differential effects were assessed using t-tests. patients undergoing ia-dsa received iomeprol- (n= ) or iodixanol- (n= ). hr and systolic/diastolic bp were evaluated before and after the fi rst injections. repeated-measures anova and t-tests compared mean hr changes across the fi rst injections and after the fi rst injection, respectively. monitoring for adverse events (ae) was performed in both studies. results: no signifi cant differences between iomeprol and iodixanol were noted in terms of mean changes in hr during lca (p= . ), rca (p= . ), and lv (p= . ). in patients undergoing ia-dsa, no differences between cm were noted for effects on mean hr after the fi rst injection (p= . ) or across the fi rst injections (p= . ). no differences between cm were noted regarding effects on systolic or diastolic bp. purpose: to evaluate the diagnostic advantages of intravenous uspio administration on t-staging of uterine carcinoma. methods and materials: seventeen female patients referred for gynecological carcinomas, with corpus uterine cancer and with cervical carcinoma underwent mr scan of the pelvis on a . t magnet. gre t *w sequences (tr/te/fa/matrix/ acq. time: msec/ msec/ °/ x / . min) were acquired on multiple planes before and hours after iv administration of . mg/kg of body weight of sinerem (guerbet, paris, france). image analysis were performed by consensus by two radiologists and it included qualitative and quantitative analysis of signal intensity (si) of both normal myometrium and neoplastic lesions before and after sinerem administration. s/n and c/n were calculated. modifi cation of t-staging in images obtained after sinerem administration was also evaluated. statistical analysis was performed using wilcoxon test (p < . ). results: qualitative analysis showed a signifi cant decrease of si of normal myometrium after sinerem administration leading to a better lesion conspicuity. quantitative analysis showed a statistically signifi cant difference between si of myometrium on plain and sinerem-enhanced mr images assessed by means of t-test. c/n between lesion and normal myometrium signifi cantly increased following sinerem administration. in patients sinerem-enhanced images provided additional information leading to more accurate t staging. conclusion: intravenous injection of sinerem provides a signifi cant decrease of si of normal myometrium with higher c/n between neoplastic lesion and normal myometrium increasing the conspicuity of neoplastic lesions. the learning objectives: we will explain the etiology of round ligament varices (rlv) in pregnancy and elucidate why they may have a similar clinical picture to an irreducible hernia. knowledge of this condition is clinically signifi cant as this may be misdiagnosed as an obstructed hernia, leading to unnecessary surgical intervention during pregnancy. as ultrasound (us) is the imaging modality of choice, we will review the us features that establish an accurate diagnosis. background: anatomically the round ligament extends from the lateral uterus to the labium majorus containing veins, arteries, lymphatics and nerves. pregnancy promotes increased venous fl ow and reduced venous tone, thereby predisposing patients to varicosities. clinically, rlv and inguinal hernias can be indistinguishable with similar anatomical sites, comparable positive cough impulses and both demonstrating reducibility with positional change. imaging findings: dilatation of the veins of the broad ligament and ovarian plexi cause a clinical entity called the pelvic congestion or pelvic pain syndrome. when this process extends into the round ligament, it becomes a more diffi cult diagnosis. however, the ultrasound and doppler appearances of this condition are unique and can be easily recognized. the true incidence of round ligament varices is unknown but is suspected to be higher than the small amount of reported cases in the literature through our series, we demonstrate that the diagnosis of rsv should be entertained in pregnant women presenting with a painful groin mass, and ultrasound should be performed in such cases to avoid unnecessary surgical exploration. hypointense ovarian lesions on t -weighted magnetic resonance imaging: radiologic-pathologic correlation m. takeuchi learning objectives: to demonstrate various benign and malignant ovarian pathologies presenting as hypointense masses on t -wi with pathologic correlation. background: hypointensity on t -wi is an unusual fi nding of ovarian tumors and form a special diagnostic category. these lesions have some histopathologic characteristics, which shorten the t relaxation time of tissues and help to make differential diagnosis. imaging findings: t shortening due to dense collagenous tissue was observed in benign fi brous tumors such as fi bromas, thecomas, adenofi bromas, and brenner tumors, but rarely also observed in malignant tumors such as krukenberg's tumors with reactive stromal proliferation and malignant carcinoid tumors with neoplastic stromal proliferation. intense contrast-enhancement refl ecting hypervascularity of malignant tumors may be the diagnostic clue. rare solid malignant tumors with honey-combing appearance fi lled with mucinous materials or coagulated necrosis such as mucinous tumors or solid clear cell carcinoma may mimic benign fi bromas, and reticular contrast-enhanced internal patterns may suggest these tumors. coagulated necrosis with hemorrhagic clots in malignant germ cell tumors may show hypointensity, and elevation of specifi c tumor markers may be helpful for diagnosis. mucinous, or viscous proteinous materials in mucinous cystic tumors, and struma ovarii with colloid cysts may cause hypointensity in the cystic portions. repeated intra-cystic hemorrhage in endometrial cysts may cause hypointensity as "shading", but similar appearance may also be observed in some dermoid cysts and tubo-ovarian abscesses. conclusion: hypointensity on t -wi may usually suggest its benign nature, but some malignant tumors also show hypointensity and preoperative diagnosis is important. www.cancerstaging.info: a free and customized online tool to facilitate quick and accurate staging of common female pelvis cancers based on imaging fi ndings r. talanow, s. shah; cleveland, oh/us (roland@talanow.info) purpose: to provide a free, comprehensive, web-based, on-the-fl y solution which is easy to use and aids in accurate staging of common female pelvis cancers, based on imaging fi ndings. the program runs on a mhz pentium ii quad processor with microsoft server operating system. script languages include perl, javascript, dhtml. information about tumor classifi cations is stored in a mysql database. on-the-fl y staging is done by calculating and comparing the information provided by the user with the tumor classifi cation database saved on the server. the user may provide the information in several offered modes for the user's convenience. output of information is also offered in several modes to increase fl exibility and better integration into the reader's workfl ow. results: this web-based and customized program easily integrates into the radiologist's daily work from any monitor or pacs station. the interface is fl exible and easily adapts to the individual physician's preferences by seamlessly incorporating into the workfl ow. furthermore, it offers hyperlinks to more comprehensive websites for access to therapeutic and prognostic information for a particular malignancy. conclusion: www.cancerstaging.info is a free, web-based, customized tool that allows staging of common female pelvis cancers (i.e. cervical, ovarian, uterine and endometrial) based on imaging fi ndings, with hyperlinks to more informative and in-depth websites. it is an intuitive, user friendly educational program which makes staging of common female pelvis malignancies easy and accurate. learning objectives: to illustrate the value of color doppler us as an adjunct technique in the evaluation of those uterine pathologies in which detection and characterization of vascular structures allow an early diagnosis. background: ultrasonography (us) is the initial diagnostic modality in gynecological assessment. the transvaginal via is recommended, except in contraindicated cases (intact hymen, pregnancy of more than three months, and so on). color doppler us as an adjunct technique has become an effective tool in the evaluation of those uterine pathologies in which detection and characterization of vascular structures allow establishing early diagnosis, when the gray-scale ultrasound images are nonspecifi c or confusing. in this exhibit, we describe the value of color doppler us in the diagnosis of endometrial polyps, the distinction of leiomyomas and adenomyomas, the evaluation of de arteriovenous malformations, and the diagnosis of aneurysms and pseudoaneurysms. imaging findings: color doppler us contributes to the diagnosis of endometrial polyps by the identifi cation of vascular structures in the pedicle; permits the distinction between leiomyomas and adenomyomas bythe vascular distribution patron; plays an important role in the evaluation of de arteriovenous malformations, allows distinction from myomas with degenerative changes, and detects the presence of arteriovenous shunting. color doppler us also plays an important role in the diagnosis of aneurysms and pseudoaneurysms. conclusion: color doppler us with conventional techniques and power-angio are very useful in early diagnosis and the follow-up of many uterine pathologies. benign cystic ovarian masses with solid components mimicking malignancy: radiologic-pathologic correlation m. takeuchi learning objectives: to demonstrate various benign ovarian pathologies presenting as cystic masses with solid components on imaging mimicking malignancy with pathologic correlation. background: solid components of ovarian cystic masses may usually suggest their malignant nature, but some benign pathologies may also show the similar appearances mimicking malignancy. imaging findings: solid fi brous tumors (brenner tumor and adenofi broma) coexisting with cystadenomas show characteristic hypointensity on t -wi refl ecting dense fi brous proliferation. small tiny cysts within hypointense solid portion (black sponge-like appearance) of adenofi broma are diagnostic. mural nodules with intense contrast-enhancement and very high intensity on diffusion-weighted images (dwi) may suggest malignancy, but benign dermoid nipple may show surface slight contrast-enhancement and very high intensity on dwi. solid portion of struma ovarii also show intense contrast-enhancement, and lobular appearance with hypointense colloid contents on t -wi is characteristic. benign cystadenomas may contain small papillary vegetations with no or slight contrast-enhancement. pregnant decidual changes of endometriomas may show broad-based hyperintense mural nodules on t -wi. irregular clots within endometriomas may mimic malignant component, and the absence of contrast-enhancement on subtraction images is the diagnostic clue. daughter cysts of mucinous cystadenomas, and ovarian parenchyma within peritoneal retention cysts may mimic solid mural nodules on ct or ultrasonography, and t -wi can provide better tissue contrast for the correct diagnosis. conclusion: benign cystic lesions with neoplastic components (brenner tumors, adenofi bromas, teratomas and vegetations), reactive components (decidualized endometriomas), and non-solid components simulating solid portion (mucinous daughter cysts) should be differentiated from malignancy to avoid excessive surgical procedure. malignant transformation of mature cystic teratoma: analysis of imaging fi ndings and clinical data j. kim, s. park, j. kim, k. cho; seoul/ kr (lola @freechal.com) purpose: to evaluate the imaging fi ndings and clinical data predicting malignant transformation of mature cystic teratoma. in patients with histopathologically confi rmed diagnosis, we analyzed the ct and mr fi ndings with regard to the presence of soft tissue components, tumor size, the angle between the soft tissue components and the inner wall of the cyst (acute or obtuse), and the confi guration of the inner border (regular or irregular). clinical and laboratory data including patient's age and tumor marker such as ca- , ca - , and afp, were also analyzed. in the analysis of the imaging fi ndings, nine ( %) of tumors had soft tissue components and eight ( %) of nine soft-tissue-containing tumors showed an obtuse angle between the soft tissue components and the inner wall of the cyst. in nine ( %) patients, the maximum tumor diameter was greater than cm and the patient's age was greater than years. ca- was greater than u/ml in six ( %) of nine patients and ca - was greater than u/ml in three ( %) of four patients. conclusion: malignant transformation of cystic teratoma can be preoperatively predicted by combination of imaging fi nding and clinical data. spectrum of fi ndings of mullerian duct anomalies at mri p. paolantonio, r. ferrari, f. iafrate, c. de cecco, p. lucchesi, a. laghi; learning objectives: to illustrate some crucial mri technical features for the evaluation of normal uterine morphology and mullerian duct anomalies. to show spectrum of fi ndings of several mullerian duct anomalies at mri. to illustrate mri fi ndings useful in predicting the clinical impact of uterine anomalies in terms of infertility or risk of miscarriage. to illustrate mri fi ndings useful for treatment regimens assessment. background: since , the american fertility society (afs) established a classifi cation of uterine malformations. because mullerian ducts defects are the result of a spectrum of mullerian ducts non-fusion, defi cient development and/or defective canalisation of the uterine cavity, the process may become arrested at any point in development. a complete assessment of uterine anatomy is mandatory in order to evaluate the impact of uterine malformation on women fertility and also to plan the optimal strategy of treatment. procedure details: in this exhibit, we describe an optimised mri protocol including high resolution t weighted tse sequence acquired on dedicated oblique planes for the evaluation of uterine morphology. we describe mr fi ndings of several mullerian duct anomalies according to the afs classifi cation with emphasis on different subtypes of septate uterus describing fi ndings useful to predict risk of recurrent miscarriage and to programme histeroscopical surgical treatment. conclusion: mri is a safe, non invasive and ionizing free method for diagnosis of uterine anomalies. mri allows a complete evaluation of uterine morphology useful in surgical approach planning. mri of the pelvis in mullerian duct abnormalities: is there a role in selecting patient for histerocopic metroplasty? p. paolantonio , f. iafrate , r. ferrari , c. de cecco , a. carnevale , c. de angelis , a. laghi ; latina/it, rome/it (paolantoniopasquale@hotmail.com) purpose: selection of patient for histeroscopic metroplasty requires a complete assessment of uterine morphology usually achieved by laparoscopy that represent the gold standard in the evaluation of uterine morphology. the aim of our study was to assess the role of mri in selecting patients with mullerian duct fusion defect for hysteroscopic metroplasty. we prospectively investigate females with known mullerian duct defect assessed at hysteroscopy. examination were performed using . t magnet equipped with phased-array coil acquiring high-resolution tse t w sequence (tr: msec/ teeff msec / etl: / matrix x ) parallel to the long axis of the uterus. final diagnosis was assessed in all patients at surgery using laparoscopy in the assessment of uterine morphology. in patients, hysteroscopic metroplasty was also performed. image analysis was performed by two radiologist in a blind consensus fashion. they qualitatively evaluate morphology of both uterus and endometrial cavity. mr fi ndings were compared with laparoscopic and hysteroscopic fi ndings. results: mri revealed uterine abnormalities in all patients. in detail, patients b d e f a g were diagnosed as incomplete septate uterus, as complete septate uterus, four patient as arcuate uterus and one patient as bicornuate uterus. mri fi ndings were correct in all cases, as confi rmed by hysteroscopy and laparoscopy. conclusion: mri is a valuable tool in the evaluation of uterine morphology. its use will help in sparing patients from laparoscopy, selecting patients for hysteorplastic metroplasty. diffusion-weighted mr imaging in uterine myometrial lesions with pathologic correlation k. tamai, t. koyama, n. morisawa, k. fujimoto, s. fujii, k. togashi; kyoto/jp learning objectives: ) to illustrate mr features of uterine myometrial lesions on diffusion-weighted images (dwi) in correlation with pathologic fi ndings. ) to discuss the advantages and limitations of dwi and adc measurement in evaluating uterine myometrial lesions. background: dwi can provide tissue contrast based on diffusion motion of water molecules, different from that of conventional mr sequences. adc values calculated from dwi are infl uenced by nuclear-to-cytoplasm ratio and cellular density that may be attributed to decreased adc values of malignant tumors. since dwi has been recently applied to the female pelvis, knowledge of its advantages and limitations is necessary for evaluating myometrial lesions. imaging findings: on dwi, the normal myometrium shows low intensity and the normal endometrium shows high intensity. the vast majority of ordinary leiomyomas and adenomyosis, which show low intensity on t wi, also exhibit low intensity on dwi. in contrast, uterine sarcomas show prominent increased intensity on dwi. however, even benign lesions such as cellular leiomyomas and adenomyosis with proliferating ectopic endometrial tissues show high intensity on dwi, which can mimic malignancy. thus, careful evaluation of t wi is mandatory for avoiding misinterpretation. although adc values of these myometrial lesions are usually lower relative to the normal myometrium, distinction between benign and malignant based on adc values may be diffi cult because of a considerable overlap. conclusion: dwi and adc measurements may have a limited role in distinguishing between benign and malignant myometrial lesions. however, careful interpretation of both dwi and t wi may aid in estimating tissue characteristics of uterine myometrial lesions. results: ovv was revealed in ( . %) patients. the frequent clinical complaints were: low abdominal pain, disturbance of menstrual cycle. in % of cases, a combination of ovv with structural changes in ovaries was noted (multicystic or polycystic ovaries, the syndrome of ovary inanition). also, in % cases, along with ovarian structural changes the following were also noted: chronical infl ammatory disease in %, myoma in %, and endometriosis in %. in % ovv were noted bilaterally, in % on the left side, and in % on the right side. based on the diameter and location of varicosis, we defi ned degrees of oov: i -one side dilatation of ovary vein to mm, ii -bilateral ovv and dilatation of plexus venus uterovaginalis from to mm, iii -the dilatation above mm in cases of total pelvic veins varicosis. reno-ovarian refl ux was positive in % by valsalvas maneuver. conclusion: tvcd is an effective and noninvasive modality in the diagnosis of ovv as a cause of female infertility. in %, this pathology with secondary changes in ovaries was combined with various dishormonal gynecological pathologies. learning objectives: to evaluate several points to meet the patient selection guidelines in screening pelvic mri for mr-guided focused ultrasound surgery (mrgfus) of uterine fi broids. background: currently, all treatment options for uterine fi broids are invasive and require several days of hospitalization and a few weeks of recovery. mrgfus is newly developed non-invasive procedure to reduce symptoms of uterine fi broids in an outpatient procedure. it combines mri to visualize the body organs, plans and guides the treatment, and monitors the treatment outcome in real time, with high-intensity focused ultrasound waves, which destroy the tissue. patients go home after the procedure and usually return to normal activities within a day or two. unfortunately, it cannot be applied to every patient with uterine fi broids. the decision to perform the mrgfus in patients with uterine fi broids is made according to the patient-selection guidelines in screening pelvic mri. imaging findings: in screening pelvic mri, several points must be evaluated carefully to meet the selection guidelines for mrgfus in uterine fi broids. these include the fi ndings of fi broids itself, obstacles to sonication pathway and relation to adjacent structure. conclusion: it must be requisite to know thoroughly the fi ndings in screening pelvic mri to select suitable patients for mrgfus in uterine fi broids. abdominal wall endometriosis: imaging -pathologic correlation e. de lama, l. aja, r. llatjos, j.a. narvaez; barcelona/es learning objectives: to review the underlying pathologic changes that create the imaging appearances of abdominal wall endometriosis at us, ct and mri. to learn the imaging appearances of abdominal wall endometriomas and to illustrate the usefulness of imaging-guide preoperative biopsy. to review the main differential diagnosis. background: abdominal wall endometriosis occurs in up to % all women who have had cesarean deliveries, and may be diffi cult to diagnose. procedure details: we will review: ) pathologic changes in abdominal wall endometriomas. ) us, ct and mri fi ndings correlated with pathologic changes. ) usefulness of imaging-guide preoperative biopsy. in addition, differential diagnosis including nonneoplastic conditions, such as suture granuloma, ventral hernia, postsurgical hematoma or abscess, and neoplasms, such as a desmoid tumor, sarcoma, lymphoma, or metastasis will be reviewed. abdominal wall endometriomas are often non suspected clinically, but should be included in the differential diagnosis of a symptomatic mass in women who had cesarean deliveries. pathologic characteristics of abdominal wall endometriomas (surrounding infl ammatory reaction and fi brosis, degraded blood products) explain most of the imaging features. mr imaging of uterine cervical carcinoma: optimization of local staging and evaluation after therapy s.m. dias, a. ferrão, c. pina vaz; porto/pt learning objectives: to review the spectrum of magnetic resonance (mr) fi ndings clinically relevant for staging cervical carcinoma. to purpose technical strategies to optimize disease evaluation. to discuss clinical usefulness of mr for differentiation between recurrent disease and post-treatment complications. background: worldwide, cervical uterine cancer is second only to breast cancer as the most common malignancy in incidence and the third cause of death after breast and lung cancers in women. the féderation internationale de gynécologie et obstétrique (figo) classifi cation is the most commonly used staging system but it has recognized limitations that can be overcome with mr imaging. procedure details: the authors present the spectrum of mr fi ndings useful for staging and differentiate treatment complications from recurrent disease. technical strategies that can optimize local disease evaluation, such as intravaginal gel fi lling, are discussed. pitfalls, advantages and limitations of mr when compared to other imaging methods, namely mdct and positron emission tomography (pet), are listed and illustrated comprehensively. conclusion: magnetic resonance imaging is a powerful tool in the work-up of cervical carcinoma. it optimizes selection of the most suitable therapeutic strategy for each patient, as it provides a more effi cient staging of the disease, evaluating accurately important prognostic factors as tumour volume and presence of lymphatic disease. it has also interest in detection of recurrent disease and in evaluation of treatment effi cacy and associated complications. diagnostic pitfalls in evaluating mr gynecological disorders s. gispert, r. domínguez, x. merino, v. pineda, s. roche; barcelona/es (gisppi@yahoo.es) learning objectives: to review the possible pitfalls in the evaluation of gynecological disorders by mr imaging. background: mr imaging has an increasing role in evaluating female pelvis. the aim of the exhibit is to review the pitfalls in evaluating gynecological disorders. these pitfalls are roughly divided into physiological conditions that simulate organic lesions, benign conditions that simulate malignancy and malignant diseases that simulate benign conditions. according to the organ affected, we will show possible diagnostic pitfalls: uterus (pseudolesions related to uterine contraction that mimic leiomyoma or adenomyosis, adenomyosis that resembles uterine malignancies), ovary (appendicular mucocele or peritoneal cysts simulating ovarian tumors, ovarian atrophy simulating adenopathies), cervix (cervical carcinomas mimicking endometrial carcinomas), fallopian tube (hidrosalpinx resembling cystic masses), and vulva and vagina. conclusion: it is important to know the wide variety of mr pitfalls in gynecological disorders in order to distinguish possible mimicking lesions from real organic lesions. purpose: to evaluate the capability of mri in assessing pattern of recurrence threedimensional tumor volume and tumor response in patients with locally recurrent uterine cancer treated with concomitant chemo-radiation. methods and materials: twenty-four women who had undergone radical hysterectomy and with locally recurrent uterine cancer were enrolled in our study. all patients underwent gynecologic examination and mri to assess local recurrence. the recurrences were distinguished based on site: vagina, vaginal vault with or without pelvic wall extension, pelvic side wall. after diagnosis, the patients received concomitant chemo-radiation; then they underwent follow-up mri days after the end of treatment and then periodically every six months. pre-and post-treatment volumes were calculated by mri with ellipsoid formula and compared determining tumor response: complete, partial, no change, progression of disease. image analysis: mri showed patients with central pelvic recurrence, with recurrence in the pelvic side wall. the mean pre-treatment d-volume was . mm (range . - . mm ). the mean post-treatment d-volume was . mm (range - . mm ). patients had complete response, partial response, no change, progression of disease. results: the site of response was associated to different prognosis; patients with recurrent tumor limited to vagina and vaginal vault showed better loco-regional control rates compared to patients with recurrence in the pelvic side wall. recurrent d tumor volumes < mm had better diagnosis than larger tumor volumes. furthermore, mri is an accurate non invasive method of distinguishing tumor from fi brosis. conclusion: mri permitted a good evaluation of pelvic recurrences and tumor response following chemo-radiotherapy. optimization of t -weighted fast spin-echo sequence for female pelvis at t mr imager k. fujimoto, t. koyama, k. tamai, n. morisawa, y. nakamoto, k. togashi; kyoto/jp (kfb@kuhp.kyoto-u.ac.jp) purpose: to optimize t -weighted fast spin-echo sequence for female pelvis at t mr imager. methods and materials: mri were obtained at t-imager (siemens; trio) using ch phased-array coil in eight healthy volunteers. all scans were performed with sagittal section with thickness of mm, interslice gap of . - . mm, fov of x mm without parallel imaging. scans were performed: ) before and after injection of anticholinergic agent (buscopan), ) with variable tr ( , , , ), ) with variable etl ( , , ) ) with variable band-width (bw) ( , , , , ) , and ) with variable te ( , - , ) with different types of rf pulse (low sar vs normal mode). sar of all scans was recorded. all images were qualitatively evaluated concerning artifacts, contrasts between b d e f a g both inner, outer layer of the myometrium, the endometrium, and those between cervical epithelium and stroma. quantitative measurement (snr, cnr) of these structures was also performed. results: scans without buscopan were considerably degraded by intestinal movements. longer tr generally provided better snr, although tr= images in fi ve subjects were degraded by motion artifact from small intestine. tr= were associated with high sar ( - %) and decreased cnr in the uterine corpus (p < . ). etl= provided best images qualitatively. although lower bw images provided better snr, bw= images were associated with greater blurring. qualitative evaluation did not reveal remarkable difference between bw= - , te= - images, although bw= and te= images had decreased snr. low sar rf pulse provided better snr without statistical signifi cance. conclusion: our preliminary data suggest that the optimal parameters of t wi at t include tr= - , etl= , bw= - , te= - with rf pulse of low sar type. administration of bustopan is essential. congenital mullerian anomalies: three-dimensional ultrasound fi ndings m. belloch ramos, f. raga baixauli, p. naranjo romaguera, f. bonilla bartret, f. bonilla musoles, j. palmero da cruz; valencia/es purpose: to asses the diagnostic value and the usefulness of three-dimensional ( d) ultrasound in detection of congenital mullerian anomalies, compared with other diagnostic methods (magnetic resonance, two-dimensional ultrasound, hysterosalpingography, laparoscopy and hysteroscopy). mullerian anomalies are related to reproductive problems, but true incidence is unknown. d ultrasound represents a useful noninvasive tool to evaluate these anomalies. a prospective study was undertaken from to . a total of , women who went to a routine gynecological revision, were examined by d transvaginal ultrasound. all studies were stored in the hard disk and reviewed by three of the authors. mullerian anomalies were classifi ed according to american fertility society (asrm) classifi cation of . results: mullerian duct anomalies were detected in , patients ( . %). arcuate (n= , . %) and septate (n= , . %) uteri were the most common malformations observed. the rest of anomalies observed were bicornuate (n= , . %), unicornuate (n= , . %) uteri and four des-exposed uteri. conclusion: this study with noninvasive and cheap technique suggests that the prevalence of these anomalies is near . %. the most frequent malformation was arcuate uterus considered nowadays like a normal variant. des drug related uterus is rare today. improves diagnostic accuracy, with endometriotic cysts typically appearing with high signal intensity on t -weighted images and demonstrating "shading" on t -wi. small implants and adhesions are not well evaluated radiologically; therefore, laparoscopy remains the standard of reference for diagnosis and staging. although mr imaging is limited in its ability to depict small endometrial implants and adhesions, the advantages of mr imaging over laparoscopy include the ability to characterize endometriotic lesions and to evaluate extraperitoneal sites of involvement, contents of a pelvic mass, or lesions hidden by dense adhesions. the roles of the two modalities are therefore complementary. knowledge of the variety of mr imaging appearances of endometriosis and organ involvement is important for guiding a subsequent laparoscopic examination. the monsters of the female pelvis: pelvic teratomas revisited a. ghiatas, d. keramopoullos, c. tsagari; athens/gr (abraham@otenet.gr) learning objectives: to illustrate the imaging fi ndings of teratomas on various imaging modalities. to discuss the appropriate selection of imaging modalities and techniques and how to avoid imaging interpretation pitfalls. background: pelvic teratomas is a frequent incidental fi nding in the course of imaging evaluation of the female pelvis for pathology unrelated to teratomas. differential diagnosis of teratomas from other pelvic masses may be diffi cult unless the most optimal imaging modalities and techniques have been selected, which are able to demonstrate the specifi c features of this pathological entity. procedure details: cases of pelvic masses were diagnosed as teratomas by ct, mri or ultrasound, or a combination of them. all cases underwent surgery and pathology results were compared to the imaging fi ndings. conclusion: in cases, the imaging diagnosis of teratoma was in complete agreement with the surgical/pathology fi ndings, and in the remaining cases, the diagnosis of teratoma was in agreement with the fi rst diagnoses. factors selective uterine arteriography of consecutive patients who underwent uae for symptomatic fi broids or adenomyosis were reviewed in regard to visualization of anastomosis with ovarian arteries. factors including arterial spasm, uterine volume, location of lesion, birth history, and history of abdominal surgery were analyzed. results: uteroovarian anastomosis was demonstrated in of patients ( . %) and of uterine arteries ( . %). there were patients ( . %) with visualization of anastomosis due to arterial spasm at the origin of the uterine artery, where the catheter was engaged. anastomosis was seen in fi broids at subserosal ( . %), intramural ( . %), submucosal ( . %), and adenomyosis ( . %). signifi cant difference was seen in the mean uterine volume: . cm with anastomosis and . cm without anastomosis (p= . ). anastomosis was demonstrated in . % of patients with multiple fi broids and . % with solitary fi broid (odds ratio . ), . % with multigravida and . % with nullipara (odds ratio . ), and . % in patients with a history of abdominal surgery and . % without surgery (odds ratio . ). uteroovarinan anastomosis is often demonstrated during uae irrespective of type and location of lesion. arterial spasm by catheterization is a defi nite technical factor. smaller uterine volume, multiple fi broids, and multigravida were considered as signifi cant factors of visualization of anastomosis. use of colour doppler for early detection of hemorrhage in ultrasound guided renal biopsies k. brabrand, a. günther, p. bache marthinsen, a.e. berstad; oslo/ no (knut.brabrand@rikshospitalet.no) purpose: to evaluate the use of colour doppler (cd) for early detection of hemorrhage after ultrasound guided renal biopsy. a linear cd signal may be observed along the biopsy tract showing blood fl ow out of the kidney into the perirenal tissue immediately after withdrawing the needle indicating a post biopsy hemorrhage. to evaluate the incidence and duration of cd bleeding after renal biopsies, a prospective study was performed using an acuson seqouia with a v transducer (cd frequency . mhz, scale . m/s). patients were included. there were biopsy procedures in renal transplants and seven native kidneys with a total number of biopsy needle passes. for each needle pass the presence and duration of cd bleeding were registered. if cd bleeding was seen, cd guided compression was applied. results: cd bleeding was seen after needle passes in biopsy procedures. the incidence of cd bleeding increased with the number needle passes per procedure. the duration of cd bleeding exceeded four minutes in seven patients, of whom six developed a post biopsy hematoma. eight of nine of the post biopsy hematomas (mean diameter . cm) were preceded by cd bleeding. cd guided compression was applied in biopsy procedures. conclusion: cd is useful in renal biopsies for early detection of post biopsy hemorrhage. the study shows that the duration of cd bleeding correlates with the severity of the bleeding. cd guided compression could possibly reduce the duration and volume of post biopsy bleeding. renal learning objectives: to familiarize the radiologist with the fi ndings of contrastenhanced ultrasonography (ceus) of the commonest primary renal tumors. to present these fi ndings in the setting of an integrated diagnostic approach. background: the high frequency of detection of renal lesions and the innovations in their treatment have increased the need for an accurate imaging diagnosis. this exhibit is based on the study of renal tumors that were scanned before and after i.v. injection of a second-generation ultrasound contrast agent (sonovue, bracco). representative ceus images and the corresponding fi ndings of baseline and color doppler us, ct, mr and dsa are displayed. microscopic and macroscopic sections of the excised tumors confi rm these fi ndings and establish the fi nal diagnosis. imaging findings: numerous cases of renal cell carcinomas (clear cell, papillary and cystic varieties), urothelial neoplasms, angiomyolipomas, oncocyttomas (typical and atypical) and a multilocular cystic nephroma are depicted. several patterns of enhancement are described. the increased sensitivity of ceus in outlining the pseudocapsule, small cystic areas and heterogeneity in the perfusion of renal tumors is demonstrated. the tortuous pathologic vessels at the periphery of the rccs and the spoke-wheel pattern of the oncocyttoma are displayed. challenging cases, such as isoechoic tumors that mimic normal variants and small lesions that are imperceptible on baseline us, are also included. conclusion: compared to fundamental us of renal tumors, ceus may provide valuable additional information. ceus fi ndings correlate well with those of other imaging methods and can contribute to an accurate diagnosis. purpose: to investigate the perfusion characteristics of renal mass parenchyma and renal cortex in affected and normal kidney on -slice ct. totally patients with renal mass were enrolled. slice spiral ct (siemens somatom sensation ) was used for renal perfusion scan that began with a contrast bolus injection of ml ( mgi/ml) at a rate of ml/s. surgical and pathological outcomes were collected for comparison. perfusion characteristics, including blood fl ow (bf), blood volume (bv) and permeability (pm) of renal mass parenchyma and renal cortex in affected and normal kidney were calculated from 'siemens body pct (vb b)' software. results: renal clear cell carcinoma (rccc), renal pelvic transitional cell carcinoma (rptcc) and renal angiomyolipoma (raml) was pathologically confi rmed in , and of subjects, respectively, while the remaining subjects were with renal simple cyst (rsc). technical failures were experienced in ( . %) patients. perfusion parameters of tumor parenchyma were measured as follow: rccc: bf= . ± . , bv= . ± . , pm= . ± . ; rptcc: bf= . ± . , bv= . ± . , pm= . ± . ; raml: bf= . ± . , bv= . ± . , perme-ability= . ± . ; rsc: bf= . ± . , bv= . ± . , permeability= . ± . . in all groups, perfusion parameters showed signifi cant differences (p < . ) between mass parenchyma and renal cortex in normal kidney, while there were no signifi cant difference (p> . ) in perfusion parameters between renal cortex in affected and normal kidney. there were signifi cant differences (p < . ) in perfusion parameters between parenchyma in any two kinds of renal masses, except for rptcc and raml (p> . ). conclusion: these four kinds of renal masses all have decreased perfusion characteristics. perfusion imaging with msct has potential clinical application value in differential diagnosis of renal mass. vascular complications after renal transplantation: us fi ndings i. de la pedraja, n. gomez, j. hernandez, m. ciudad, e. vaño; madrid/es learning objectives: ) to illustrate the different types of vascular complications after renal transplantation, with emphasis on their characteristic chronology. ) to be familiar with the ultrasound fi ndings that allow us to diagnose vascular complications in renal allografts. background: renal transplantation is the treatment of choice for severe endstage renal failure. because of this, it is very important for the common radiologist to know enough about the diagnosis and management of renal grafts complications, especially the vascular ones, which are a very frequent and severe reason of early graft failure and reject, and a common request of diagnostic procedures in the emergency room. imaging findings: we illustrate some examples of the different types of vascular complications associated with renal transplants, including graft artery and recipient iliac arterial system stenoses, arterial and venous thromboses, focal and diffuse infarcts, pseudoaneurysms and arteriovenous fi stulas. some examples not only of single kidney grafts complications but of "en bloc" transplants complications are presented. we also discuss the imaging features of vascular complications in grayscale sonography and doppler sonography, and, in some cases, the appearance of the subsequent fi ndings in mri and angiography. in addition, we emphasize the characteristic chronology of each vascular complication. conclusion: although angiography is still the "gold standard" in the diagnosis of vascular complications in renal transplantation, ultrasound is usually the fi rst step in the diagnostic procedure, and is a valuable technicque that allow the radiologists to make an early diagnosis of them. correlation of hemodialysis duration with enthesal site changes of hemodialysis patients by lower limb ultrasonographic examination u. kerimoglu, m. hayran, f.b. ergen, a. kirkpantur; ankara/tr (ulku @yahoo.com) purpose: to evaluate the enthesal site changes of the lower limb of patients on hemodialysis utilizing glosgow ultrasound enthesitis scoring system, and to assess the correlation between the duration of hemodialysis and the score of patients. methods and materials: forty-nine patients who are on hemodialysis for at least years were included in the study. the patients were subgrouped according to the duration of hemodialysis; to years (group , n= ), to years (group , n= ), to years (group , n= ) and more than years (group , n= ). for each patient, the total score of guess, the mean score of guess for each group, total score for enthesophyte and erosion were correlated with the duration of hemodialysis. the mean of the total guess scores ( . ± . , . ± . , . ± . , . ± . for groups - , respectively) increased signifi cantly among gropus (p < . , jonckheere-terpstra test). there was statistically signifi cant correlation between the duration of hemodialysis and total guess scores (p < . , r s = . ), especially for men. signifi cant correlation was seen between the duration of hemodialysis and total enthesophyte and erosion scores (p < . ). if severe enthesitis was to be defi ned as a total guess score of more than , a receiveroperating characteristic curve analysis reveals a cut-off point of years (with % sensitivity and % specifi city) that results in severe damage (area under the roc b d e f a g curve: . , % confi dence limits: . - . ). conclusion: kidney transplantation performed as early as possible, especially before years, would prevent severe enthesitis. laparoscopic cryoablation (lc) of small renal cell carcinoma (rcc): mediumterm outcome after -year magnetic resonance (mr) imaging follow-up g. cardone, c. iabichino, a. cestari, p. mangili, g. guazzoni, g. balconi; purpose: this study aims to determine the safety and effi cacy of lc in the management of small rcc, and to assess its medium-term outcome after -year mr imaging follow-up. methods and materials: seventy-one patients underwent lc for a total of treated tumors. all treatments were administered under laparoscopic us guidance. patients were followed-up clinically, biochemically, and by mr imaging hours after surgery, and subsequently at , , , , , , , , and months. all mr examinations were performed with a . t mr system using gre t w, tse t w sequences and ce dynamic gre fs-t w sequence. results: cryolesions decreased in size by an average of % at month, % at months, % at months and % at months following lc. post-procedural mr ce-t w images showed complete ischemia of all cryolesions. follow-up revealed no evidence of local or distant recurrence in / patients ( %). one patient showed local recurrence at months; patients demonstrated metachronous nodule in the same kidney at , , and months, respectively; patients showed metachronous nodule in the controlateral kidney at and months,respectively; patients showed pancreatic metastatic nodules at and months. in cases, a small perilesional haematoma was evident at and months after surgery. conclusion: our -year medium-term experience suggests that lc is a safe, well tolerated, and minimally invasive therapy for small rcc, and mr is an effective imaging technique in the follow-up of rcc treated with lc. primary renal lymphoma p. filis, e. protopapa, a. gyftopoulos, g. delimpasis, e. sammouti, e. seferos, a. fousteris; athens/gr learning objectives: . to evaluate the role of multislice ct and mri in primary renal lymphoma. . to become familiar with both typical and atypical manifestations of primary renal lymphoma. . to review the basic concepts of primary renal lymphoma. background: renal lymphoma is most often seen in conjunction with multisystemic, disseminated lymphoma. reports on primary renal lymphoma are scarce in the urological literature, the most part of them being secondary on a lymphomatous infi ltration of the kidneys. primary renal lymphoma (prl) as a clinical entity is not undisputed because the kidneys do not contain lymphatic tissue. multislice ct is the most sensitive and comprehensive examination for evaluation of the kidneys in patients with suspected renal lymphoma. in particular, it improves detection and characterisation of lymphomatous renal involvement by optimising contrast dynamics and data acquisition and is the current modality of choice for accurate staging of lymphoma. we report the case of three patients with an incidental mass on the kidney; their diagnosis and management are discussed. a literature review on currently recommended diagnostic practices will be presented. typical and atypical ct patterns which provide a diagnostic challenge will be discussed. procedure details: ct scans were performed on a multislice ct. magnetic resonance imaging was performed on a . tesla scanner. conclusion: multislice ct is useful in the evaluation of patients with suspected renal lymphoma; familiarity with the spectrum of fi ndings in renal lymphoma is important for accurate diagnosis and, when necessary, the recommendation of imaging guided percutaneous biopsy. ct-guided biopsies in patients with renal transplant and suspicion of rejection c. kalogeropoulou, p. kraniotis, p. zampakis, a. tsamandas, t. petsas; patras/gr purpose: renal biopsy is a necessary step in the diagnostic work-up of patients with a renal allograft, presenting with renal dysfunction and suspicion of rejection. we evaluated the safety and effi cacy of ct-guided core biopsies in renal transplant patients with deteriorating renal function and clinical suspicion of transplant rejection. methods and materials: during the last years, we performed ct-guided biopsies in patients ( male), mean age (range - ) years. the indications for biopsy included: increased serum creatinine % ( / ), albuminuria % ( / ), delayed renal function % ( / ) and progressive functional decline % ( / ). the patients underwent pelvic ct and optimal site for tissue sampling was selected. all biopsies were performed using a g automated core biopsy needle. one pass per patient was performed. results: an average of tissue core per biopsy was obtained. adequate tissue sample (≥ glomeruli per specimen) was acquired in all cases. histological examination revealed tubular atrophy % ( / ), acute rejection % ( / ), chronic nephropathy % ( / ), acute tubular necrosis % ( / ), focal segmental tubular sclerosis % ( / ) and interstitial fi brosis % ( / ). technical success reached %. there were no major post-procedural complications. conclusion: core biopsy of the transplant kidney is an essential diagnostic tool for patients with dysfunctional renal transplant and suspicion of rejection. the procedure has a high diagnostic yield, infl uencing in a critical way any further management. ct-guidance offers the advantage of better targeting the kidney allograft in the pelvis, avoiding superimposed bowel loops, and hence decreasing the complication rate. measurement of glomerular fi ltration rate and renal blood fl ow using dynamic contrast- comparison of sonoelastography guided biopsy with systematic biopsy: impact on prostate cancer detection l. pallwein, f. aigner, e. pallwein, v. fischbach, j. gradl, f. frauscher; innsbruck/ at (leo.pallwein@uibk.ac.at) purpose: we performed a prospective study to determine whether a limited biopsy approach with sonoelastography (se) targeted biopsy of the prostate would detect cancer as well as gray scale us guided systematic biopsy with a larger number of biopsy cores. we examined men (mean age: . ) with a total psa of . ng/ml or greater. first investigator performed or fewer se targeted biopsies into suspicious (stiffer) regions in the peripheral zone. hard lesions were considered as malignant. subsequently, another examiner performed systematic prostate biopsies. the cancer detection rates of the techniques were compared. results: cancer was detected in of the patients ( %), including ( %) by se targeted biopsy and in ( %) by systematic biopsy. the overall cancer detection rate by patient was not signifi cantly different for se targeted and systematic biopsy (p = . ). the detection rate for se targeted biopsy cores ( . % or of , cores) was signifi cantly better than for systematic biopsy cores ( . % or of , cores, p < . ). se targeted biopsy in a patient with cancer was . -fold more likely to detect prostate cancer than systematic biopsy. conclusion: sonoelastography targeted biopsy detected as many cancers as systematic biopsy with fewer than half the number of biopsy cores. although an increase in cancer detection was achieved by combining targeted and systematic techniques in this screening population, sonoelastography targeted biopsy alone is a reasonable approach for decreasing the number of biopsy cores. transrectal ultrasound ( background: since trus is the most effi cient way to detect prostate cancer (prca), this e-book aims to teach the trus procedure in detection and staging of prca and correlate it with the histological fi ndings emphasizing the use and effectiveness of usca and local anesthesia prior to biopsy sampling. procedure details: this medical e-book is a multimedia dvd rom-based teaching fi le featuring us prostate images, us video demonstrations, video cases presenting clinical data and detailed description of trus techniques, chapters on prostate anatomy, trus technique for the detection and staging of prca (based on over , cases), color doppler, and the technique of usguided biopsies. the proper trus technique is demonstrated step by step. its educational role is based on video cases and double video presentations. the latter consists of a simultaneous presentation of the real-time ultrasound exam and the examiner's technique. a database is included in aiding the user to reach the correct diagnosis and to compare his sonographic image to histologically proven images of the database. conclusion: user-friendly dvd rom-based teaching fi le on the prostate with chapters on anatomy, pathology, ultrasound physics, sonographic appearance of the normal prostate, trus morphology, detection and staging of prca, local anesthesia, usca and comparative database. learning objectives: review the sonographic fi ndings of non-neoplastic pathologic processes involving the extratesticular structures in the adult patient. background: the scrotum is a fi bromuscular sac divided by a median raphe. it contains the testis, epididymis, spermatic cord, and associated fascial coverings. these structures can be affected by several pathologies including congenital, infl ammatory and neoplastic.ultrasonography is the primary modality for imaging the scrotum. it should be performed with the highest frequency transducer that provides adequate penetration. intratesticular versus extratesticular pathologic conditions can be differentiated with a high sensitivity. imaging findings: in this pictorial review, we describe and illustrate cases selected from our radiology department fi les of non-neoplastic extratesticular disorders in adults. the following pathologic entities are included: ( ) fluid collections: hydroceles, hematoceles and pioceles; ( ) epididymis: acute and chronic epididymitis, cysts, spermatoceles and granulomas; ( ) spermatic chord: hematomas, torsion, lipomatous infi ltration and varicocele; ( ) paratesticular masses: inguinal hernias. the information obtained with gray-scale and color doppler ultrasonography is suffi cient to enable diagnosis in most cases of non-neoplastic extratesticular disorders in the adult patient. because physical examination usually lacks specifi city for scrotal lesions, the radiologist should be in the position of making an early and correct diagnosis in order to direct further work-up and avoid severe complications. pre-treatment evaluation of prostate cancer with mri and threedimensional h-magnetic resonance spectroscopy: our experience s. giusti, m. lazzereschi, f. francesca, a. tognetti, d. caramella, c. bartolozzi; pisa/it purpose: our aim was to assess the accuracy of h-magnetic resonance spectroscopy (mrs) in patients with high prostate-specifi c antigen (psa) levels and biopsy proven prostate carcinoma, candidate to radical prostatectomy. methods and materials: twenty-one patients underwent mri and mrs for the evaluation of tumor location, local extent and aggressiveness of prostate cancer. our imaging protocol included axial, coronal and sagittal t wi fse sequences and an axial t wi fse sequence. for mrs, we used d chemical shift imaging (csi) spin-echo sequence. we divided the prostatic gland into six sextants and sensitivity, specifi city and accuracy of biopsy, mri, mrs, mri+mrs were calculated with pathological correlation. conclusion: combined mri and d h mrs of the prostate have a diagnostic advantage in tumor location over mri alone and over biopsy alone. in particular, a negative result at d h mrs is able to exclude the presence of cancer with high probability. we are further investigating whether there is a correlation between high gleason score and mrs sensitivity. the all studies were performed with a . t superconducting system. twenty-nine prostatic cancers (> mm) in patients were included. radical prostatectomy was performed in all patients within months after mri. t weighted image with fat saturation and adc map by each method were obtained. trace adc map of the normal prostatic tissue (peripheral zone: pz and inner gland: ig) and prostatic cancers were evaluated by each method. results: normal pz adc was . + . (× - mm /s) by ss-epi, . + . (× - mm /s) by lsdi. normal ig adc was . + . (× - mm /s) by ss-epi, . + . (× - mm /s) by lsdi. there was signifi cant difference between ss-epi and lsdi by student's t-test (p < . ). in three normal pzs, susceptibility artifacts arose from the air-fi lled rectum. prostatic cancer adc was . + . (× - mm /s) by ss-epi, and . + . (× - mm /s) by lsdi. two prostatic cancer adc by ss-epi were not calculated, because of susceptibility artifact arising from the air-fi lled rectum. all prostatic cancer adc by lsdi were calculated without susceptibility artifact arising from the air-fi lled rectum. conclusion: there was signifi cant difference between adc by ss-epi and by lsdi. adc by lsdi in both prostatic cancer and normal prostate were inherently insensitive to susceptibility artifacts. b d e f a g intra-and extra-testicular cystic lesions: us and mri fi ndings r. prada gonzález, g. tardáguila de la fuente, j. aguilar arjona, e. santos armentia, c. rivas, g. fernández; vigo/es (rachelpg@terra.es) learning objectives: ) to review the clinical, pathological and imaging manifestations of scrotal cystic lesions. ) to demonstrate the roles of us and mri in the diagnosis of scrotal cystic masses. background: when studying a scrotal mass, the two most important questions to be answered are whether the lesion is intra or extra-testicular, and whether it is cystic or solid. extratesticular masses, both cystic and solid, are usually benign. however, when the mass is intratesticular, the prognosis of cystic and solid masses is quite different. intratesticular solid lesions should be considered malignant, whereas intratesticular cystic lesions are most likely benign. therefore, although intratesticular cystic masses are rare, its recognition is important, in order to avoid unnecessary surgical intervention. procedure details: we study clinical, pathological and imaging manifestations of scrotal cystic masses. intratesticular cystic lesions include simple cysts, tunica albuginea cysts, tubular ectasia of the rete testis, testicular epidermoid cysts (misnamed cyst because it is solid lesion), abscess and, in some cases, infarctions and teratomas. extratesticular cystic lesions are hydrocele, hematocele, varicocele, spermatocele, papillary cystadenoma, spermatic cord cyst and hernia. us is the fi rst choice modality for studying these lesions. mri is seldom needed, but provides useful information when us results are inconclusive. in order to make a correct diagnosis and to prevent unnecessary surgical intervention, it is of the utmost importance to recognize imaging features of intra-and extra-testicular cystic masses. although ultrasound is the primary imaging modality for researching testicular lesions, mri proves to be an useful tool when the results of us are unclear. ultrasound appearances of intra-testicular tumours: gray-scale imaging features with histologic correlation to allow prediction of tissue type t. diagnostic value of pwi in prostate cancer and benign prostatic hyperplasia x. zhao, r. bai; tianjin/cn (xin-cheng@ .com) purpose: to evaluate the diagnosis and differential diagnosis value of pwi for prostate cancer (pca) and benign prostatic hyperplasia (bph). methods and materials: fifty-three cases were divided into three groups: group included cases of pca, group included bph cases, cases were enrolled in group as normal control. all subjects were examined with . t twin-speed infi nity with excite ii (signa; ge medical system). the sequence of pwi was axial single shot gradient recalled echo echoplanar imaging t * wi. then the si-t curve and pwi parameters were obtained. to compare the difference of perfusion-related parameters including rne (relative negative enhancement integral), rmte (relative mean time to enhance) and rmsd (relative maximum slope of decrease) among three groups. results: in the peripheral zone (pz), the value of rnei of pca was higher than that of bph (t= . , p < . ) and normal (t= . , p < . ). the value of rmte of pca was lower than that of bph (t= . , p= . ) and normal (t= . , p= . ). in the central zone (cz), the value of rnei of pca was higher than bph (t= . , p < . ) and normal (t= . , p < . ). according to roc, the rnei had the best differential diagnosis effi ciency. the optimal threshold was calculated as . with a sensitivity of . % and a speciality of . % for differentiating pca. conclusion: rnei is an effective parameter to differentiate pca from bph. comparison purpose: the histologic grade of a prostate needle-core biopsy specimen can determine whether a patient with prostate cancer is a candidate for radical prostatectomy or another treatment. the aim of this study was to illustrate the concordance of gleason score between biopsy and radical prostatectomy. methods and materials: we retrospectively reviewed clinical and pathological data of patients who underwent trus biopsy and radical prostatectomy between and . of the included patients, men had undergone a nonextended sextant biopsy scheme (type a), patients a - extended scheme (type b), and patients a - extended biopsy (type c). clinical parameters were available and sonography fi ndings were included. biopsy and prostatectomy specimens were reviewed by the same staff. the rate of grading concordance and the effect of different biopsy schemes (a,b,c) on the concordance rate was determined. results: the trus fi ndings and the number of cores affected were similar in the groups (p < . ; p < . ) according to the jonckheere-terpstra test. the concordance between prostate biopsy and radical prostatectomy vacurg score was / cases [a scheme ( . %)], / cases [b ( . %)] and / cases [c ( . %)] (z test - . ; p= . ). biopsy understaging was found in / cases ( . %); / cases ( . %) and / cases ( . %), respectively, (z test - . ) b d e f a g (z test - . ; p= . ). primary gleason pattern was predicted exactly by biopsy in / cases ( . %); / cases ( . %) and / cases ( %), respectively (z test - . ; p= . ). conclusion: extended needle biopsy signifi cantly increases the accuracy of biopsy gleason score for assessing fi nal prostate cancer grade. correlating radiological and histopathological staging for prostate cancer in a general nhs setting: do fi ndings live up to national standards? a. raza, s. higgins, r. mason, n. ryley; torquay/uk purpose: preoperative mri staging of prostate cancer is more accurate with higher strength magnets and endorectal coils; however, these are still not widely available in all uk hospitals. we assessed the degree of accuracy using a tesla magnet and a pelvic array coil (a common setup throughout the uk). all patients subsequently underwent radical prostatectomy, and the results of preoperative mri staging were compared with histological fi ndings. methods and materials: thirty-three patients were identifi ed by the urology records from august to . the imaging was performed with tesla magnet without endorectal coils. all patients underwent radical prostatectomy. case notes were retrieved and reviewed in detail along with histopathology. mri studies were reviewed in a blinded fashion. results: / patients had an mri done ( . %). / patients had mri and histopathological concordance ( . %). / patients were non-concordant with histopathological results ( . %). out of these patients, were false -ve and were false +ve. the royal college of radiologists (uk) guidelines for reporting accuracy at mri range from to %. this study using a tesla magnet without access to endorectal coil had poor staging accuracy and possibly refl ects the current situation in many uk hospitals. access to endorectal coils or higher strength magnets is a major factor in increasing staging accuracy. this study arguably reports accuracy fi gures more representative of average nhs radiology services, and therefore raises important concerns about the validity of existing national standards and guidelines. the protocol consisted in fat-sat fast spin-echo t sequences, gd-enhanced dynamic study with d flash sequences ( before and after gadoteridol . mmol/kg, temporal resolution s), t -weighted fat-sat fast spin-echo sequence and d csi proton spectroscopy. dynamic sequences were post-processed with image subtraction (enhanced minus unhenanced) and intensity/time curves for targeted regions of interest. proton spectroscopy data were evaluated generating h spectra voxel-by-voxel, choline maps and choline/citrate ratio maps. conclusion: a complete protocol can be performed in less than minutes, including morphologic images, dynamic study and h-mrs. prostate cancer: mr spectroscopy after radiation therapy -initial experience j. rembak-szynkiewicz, b. bobek-billewicz, w. senczenko; gliwice/pl (remszyn@wp.pl) purpose: to evaluate prostate mr spectroscopy after radiation therapy in patients with complete biochemical remission. methods and materials: combined endorectal mr imaging and mr spectroscopy in patients after radiation therapy of prostate cancer without biochemical signs for recurrent disease was performed. patients with the prostate-specifi c antigen (psa) level below ng/ml were chosen. no increase of psa rate within months post examination was observed. / patients underwent external-beam radiation therapy, / patients underwent external-beam radiation therapy and prostate brachytherapy prior to our study. the mean radiation dose was gy. mr spectroscopy (medrad endocoil) was performed with . t siemens avanto mr scanner. siemens software was used for three-dimensional (te= ms) h-mr spectroscopic data acquisition and processing. the metabolite (cho, cr and cit) peaks were considered and (cho+cr)/cit was calculated. results: voxels with a (cho+cr)/cit ratio of or more were found in / patients in prostate peripheral zone. voxels with value of a (cho+cr)/cit ratio of and less in prostate peripheral zone were found in / patients. voxels with a (cho+cr)/cit ratio of or more were found in / patients in prostate central zone; furthermore, in / patients this ratio was equal or below in prostate central zone. conclusion: increased value of (cho+cr)/cit ratio may be found (appear) in patients with complete biochemical remission even after several months post radiation therapy. that can represent a presence of neoplasmatic cells in prostate months after radiation therapy despite lack of biochemical and clinical evidences of disease. where is the pelvic sidewall? an anatomical depiction with radiological and surgical correlates t.d. suaris, a. sahdev, r. reznek, a. rockall; london/uk (tamarasuaris@hotmail.com) learning objectives: to describe the anatomy of the surgical pelvic sidewall with annotated schematic drawings and ct and mri correlates. to illustrate with video clip the laparascopic dissection of the pelvic sidewall (psw) with cadaveric dissection of the pelvic sidewall, and compare the radiological and laparascopic views. to demonstrate with imaging the alteration of anatomical borders with reference to: primary invasive disease, post radiotherapy changes, post surgical changes, recurrent disease. to demonstrate examples of pelvic malignancies invading the psw to varying degrees. background: the assessment and staging of the spread of malignancy within the pelvis require detailed knowledge of the structures and anatomy of the pelvis. however, the exact delineation of the psw can be diffi cult on cross-sectional imaging. pelvic exenteration is a salvage procedure performed for centrally recurrent gynaecological cancers. the procedure involves en bloc resection of all pelvic structures. the surgery is complex and associated with high-rates of complication. psw involvement in these patients is a contraindication to radical or exenterative surgery. imaging findings: the surgical approach to the pelvic sidewall is based on layers from deep to lateral. understanding this approach, ct and mri images of the psw will be annotated to revise the layers of the pelvic wall. imaging will demonstrate the involvement of ureters, neurovascular structures, obturator nerves and vessels and obturator internus and piriformis muscles. the importance of understanding the complex anatomy of the pelvis on cross-sectional imaging allows correct interpretation of pelvic pathology. average equivalent doses/operation for the surgeon (pcnl) for a crystalline lens and hands: µsv and µsv accordingly. the average effective dose level/operation (pcnl) is . times more than of retrograde operations. the greatest level of doses is measured on the eye which is located more closely to the x-ray source. the right hand dose level of the surgeon is . and left hand is . times more than those of the assistant (pcnl). the descended testes, herniated bowel, and varicoceles. uncommon masses include liposarcomas, testicular tumors, lymphoma, and neurofi brosarcomas. familiarity with the normal anatomy as well as the imaging characteristics of these masses is essential for correct image interpretation. imaging findings: via ct and mri images, this exhibit will review the embryology, male and female anatomy of the normal structures associated with the inguinal canal. we will also present the imaging features and the clinico-pathological background of common and uncommon masses located in the inguinal canal. conclusion: on completion of this exhibit, the attendee will become familiar with the anatomy, pathology, embryology and imaging characteristics of the common and uncommon masses in the inguinal canal. learning objectives: . to illustrate the spectrum of imaging features of tuberculosis of the genitourinary tract. . to review the differential diagnosis of genitourinary tuberculosis. background: tuberculosis is the most common cause of mortality from infectious diseases worldwide. the prevalence of this infection has increased over the past decade in most developed countries and extrapulmonary tuberculosis represents a a progressively greater proportion of the new cases. genitourinary tuberculosis is an important but uncommon form of tb, although it is the second most common form of extrapulmonary tuberculosis. diagnosis is often diffi cult and delayed because tb can mimic many other diseases. radiologic examinations are very useful to determine the presence of tuberculosis and to monitor de therapeutic effi cacy. imaging findings: this pictorial review illustrates the radiological features of genitourinary tuberculosis. it shows intravenous urography, retrograde pyelography, us, ct and mr images of differents stages of tuberculosis affecting the kidney, ureter, bladder and genital tract. conclusion: diagnosis of genitourinary tuberculosis is often diffi cult and delayed, as there are many pathologic conditions that can mimic this entity. although defi nitive diagnosis is established by cultive or histologic examination, radiologic examinations are useful in suggesting the presence of the disease and it is important for the radiologist to be familiarized with the fi ndings of genitourinary tb. demonstration of the anatomy of the right adrenal vein with multidetector row ct t. matsuura, k. takase, t. yamada, a. sato, s. takahashi; sendai/jp purpose: adrenal venous sampling is essential for an accurate diagnosis of primary aldosteronism. information about the anatomy of the right adrenal vein (rav) obtained by ct would be useful in planning adrenal venous sampling. the purpose of our study is to determine how frequently the rav could be identifi ed on mdct and what spectrum of anatomic variations was seen among the rav. methods and materials: post-contrast mdct were retrospectively reviewed in patients. ct scan was performed with a mdct ( -row) scanner ( mm collima-tion, pitch ). contrast material ( ml, mgi/ml) was injected at a rate of . ml/sec. axial slices of -mm thickness were evaluated. the following points were evaluated regarding the rav: the rate of visualization, the relationship to an accessory hepatic vein, the anatomy, including the location of the orifi ce in relation to the ivc, direction from the ivc, length and diameter. results: the rav was detected in ( %) of patients. the rav formed a common trunk with an accessory hepatic vein in %. the rav joined in the right posterior wall of the ivc in % and in the left posterior in %. the direction of the rav from the ivc was posterior and rightward in %, posterior and leftward in %, caudal in % and cranial in %. the length and diameter averaged . mm and . mm, respectively. conclusion: mdct enabled identifying the rav and delineating its anatomy, including the position and relationship to the ivc in most patients. learning objectives: to illustrate the use of additional series following unenhanced ct performed for suspected renal colic, to both improve diagnostic certainty and confi rm other important diagnoses. background: unenhanced ct is widely accepted as the primary investigation for suspected renal colic. renal cell carcinoma and transitional cell carcinoma may both present with loin pain or haematuria and non-urological pathology may mimic renal colic. in a cohort of cases from our institution, we found that additional series were required in % of cases to improve diagnostic certainty. to our knowledge, a review of this subject has not been published in the literature. imaging findings: from our cohort of unenhanced ct scans, we illustrate how additional series clarify an uncertain diagnosis. prone scanning can distinguish a bladder calculus from a calculus at the uretero-vesical junction. ct urography may differentiate a phlebolith from a ureteric calculus. parenchymal contrast enhancement can confi rm the diagnosis of renal or urothelial malignancy as well as characterize incidental complex renal cysts. contrast enhancement may also provide additional important diagnostic information in a range of non-urological pathologies. conclusion: additional series were required in % of cases following unenhanced ct for suspected renal colic to improve diagnostic certainty and confi rm other important diagnoses such as urological malignancy and non-urological pathology, both of which can mimic the presentation of renal colic. genitourinary tract disease in the emergency room: a pictorial review d. learning objectives: to review imaging fi ndings of genitourinary pathology in the emergency room in a third level hospital according to available diagnostic imaging methods (ultrasound, computed tomography, intravenous urography and interventional radiology). background: patients with genitourinary disease represent an important volume of the total number of consultations in emergency services and, therefore, in the daily work of the radiologist on call. the more frequent reasons for consultation in these patients include lumbar or genital pain, febrile syndrome, hematuria, anury or oligoanury, acute renal insuffi ciency and trauma, among others. during the last months (january -june ), over emergency sonography and ct exams were performed at our center. genitourinary pathology was involved in approximately % of these examinations, either suspected or not. the spectrum of fi ndings in these conditions has been reviewed during this period. imaging findings: the detected pathology was classifi ed, fundamentally, in infectious/infl ammatory conditions, obstructive disorders, trauma and complications associated with renal transplantation or other interventional or surgical procedures. imaging techniques were mainly ultrasonography and ct. intravenous urography was less frequently used. interventional radiology had also a therapeutic role in selected cases. the radiologist must be aware of the wide variety and high prevalence of emergency genitourinary pathology and its imaging fi ndings according to the available imaging techniques. he also must be aware of the possibilities of interventional radiology as a therapeutic approach in selected patients. ( %) with hr-t wi. the overall accuracy was ( %) by t wi mri and ( %) by hr-t wi (p= . ). as regards to lymph node staging, t wi and hr-t wi had equal accuracy (sensitivity . %, specifi city % and overall accuracy %). conclusion: hr-t wi is only slightly more accurate than t wi in overall local staging (p= . ) and has equal accuracy in lymph node staging. in invasive stages, however, hr-t wi is signifi cantly more accurate (p < . ). value of multidetector ct in preoperative assessment of ureteropelvic junction obstruction a. mishra, j.n. bhaktarahalli; new dehli/ in (dranujmish@yahoo.com) learning objectives: to assess the role of multidetector computed tomography (mdct) in the evaluation of crossing renal vessel (crv) as the cause for ureteropelvic junction (upj) obstruction and to describe its technique. to outline its advantages over color doppler imaging and digital subtraction angiography (dsa). background: an accessory renal artery crosses the upj in only - % of patients with upj obstruction. crv are usually located anterior to the upj and its preoperative identifi cation is of utmost signifi cance as it changes the surgical management. in this exhibit, we describe the usefulness of mdct and its advantages over color doppler imaging and catheter angiography. procedure details: mdct was done on -row mdct scanner. a plain scan was performed with a mm. collimation through the kidneys to identify the renal poles and aortic bifurcation. mg of injection furosemide was injected intravenously as a diuretic. - minutes later, a helical ct scan was performed from the level of the upper pole of the left kidney till the aortic bifurcation with an intravenous injection of cc of injection iohexol ( mg iodine/ml) at a rate of ml/second with a scanning delay of - seconds, a collimation of . mm, table speed of mm/sec and tube rotation period of . seconds during a single breath-hold. curved multiplanar reconstruction, maximum-intensity projection and volume rendering algorithms were applied. color doppler imaging and dsa were also performed for all the patients. conclusion: mdct angiography was superior to color doppler and dsa and showed % accuracy in detecting crv and establishing it as the cause for upj obstruction as confi rmed at surgery. complications conclusion: imaging techniques are useful in monitoring the placement of a ureteral stent, as they can demonstrate eventual associated complications, thereby allowing quicker and effective diagnosis, with subsequent reduction of the morbidity. purpose: ureteric calculi are the main consideration in the majority of patients presenting with acute fl ank pain. unenhanced spiral ct has become the imaging modality of choice in these patients not only because of its unrivalled ability to identify ureteric stones, but also because of its potential to identify other renal and non-renal pathologies. we report our experience with the use of ct kub and the clinical incidence of non-calculus renal and non-renal pathology in patients presenting with acute fl ank pain with a provisional clinical diagnosis of ureteric colic. we retrospectively reviewed patients who underwent ct kub from jan to dec for suspected renal colic. we excluded patients with a known renal disease or previously diagnosed renal stones. results: patients were included in the study after applying the exclusion criteria. incidence of stone disease identifi ed by ct kub was %. the majority of stones ( %) were found in the distal ureter and vuj. stone size of ≥ mm was found in % of cases. secondary signs were reported in nearly % of patients with stone disease. alternative pathologies were identifi ed in cases ( %). conclusion: unenhanced ct is an excellent modality for imaging patients with acute fl ank pain. non-calculus renal and non-renal pathologies can often be identifi ed on unenhanced low-dose ct performed for suspected renal colic. a careful search for these alternative diagnoses should be made in all cases and particularly when the examination does not identify a ureteric calculus. imaging in urogenital emergencies n.a. al-nakshabandi; riyadh/sa (nizarn@ksu.edu.sa) learning objectives: ) familiarize the audience with the most urgent radiological emergencies in the urogenital system. ) learn the most appropriate approach for these emergencies and how to reach an appropriate differential diagnosis. ) learn the use of the appropriate modality. ) identify the radiological signs associated with each of these emergencies. background: the use of imaging in urological emergencies is important to learn and manage. careful attention to the urogenital involvement in emergency conditions is a very essential step in the radiological evaluation of these conditions imaging findings: flank pain/ureteral colic is experienced by - % of the population, with a - % recurrence rate at years. ct plays a valuable role in detecting the location of the stone and the presence of obstruction. urosepsis occurs secondary to pyelonephritis, cystitis, prostatitis, or any other cause of obstruction. ultrasound plays a valuable role in its diagnosis and intervention by placing a percutaneous nephrostomy catheter. ultrasound is utilized in acute renal failure to assess' renal size, parenchymal thickness and presence of obstruction. ct with or with out cystogram is optimal for blunt abdominal trauma when kidney, ureter or bladder injury is suspected. retrograde urethrogram can be done when a urethral injury is suspected. ultrasound can easily differentiate orchitis from testicular torsion. it is also valuable in confi rming the diagnosis of testicular rupture. the use of imaging in urogenital emergencies is of outmost importance. examples of imaging and management will be given. the role of ultrasound in infl ammatory bowel disease n. bharwani, n. stephens, j. pilcher; london/uk learning objectives: . discussion of the role of bowel ultrasound in infl ammatory bowel disease. . pictorial demonstration of typical ultrasound fi ndings. . advantages and disadvantages of ultrasound in ibd compared with other imaging modalities. background: high-resolution ultrasound has recently become a recognised tool in the evaluation of infl ammatory bowel disease (ibd). with advances in ultrasound equipment and novel imaging techniques, this modality is increasingly being used to diagnose patients at initial presentation, assess disease activity, identify complications, and monitor response to therapy. imaging findings: this pictorial review will highlight the features seen in ibd on high-resolution ultrasound, both in and outside the bowel wall. we will outline the role of spectral doppler in assessing the mesenteric circulation and that of power doppler in the monitoring of patients. the latter half of the discussion will focus on more recent techniques beginning to be employed in the assessment of ibd. this includes the application of microbubble contrast agents using both power doppler and harmonic imaging modes to try and measure mural infl ammation, and the role of non-absorbable, anechoic, oral contrast agents in distinguishing small-bowel strictures. barium studies, ct, and mri correlation will be provided, where appropriate. conclusion: high-resolution ultrasound is an evolving modality in the management of infl ammatory bowel disease. it can effectively be used to evaluate patients with clinically suspected ibd at fi rst presentation, and also to monitor known patients with regard to disease activity, luminal and mesenteric complications. including metachronous adenomatous polyp and cancer and recurred/metastatic cancer. representative cases for each category were selected and are presented with optical colonoscopic correlation. imaging findings: a colonic anastomosis typically presents as a web-like structure with a smooth and sharp border. distortion of the normal shape of an anastomotic ring can be caused by both insignifi cant lesions and signifi cant lesions. polypoid lesions at anastomotic ring are typically insignifi cant with protruded suture materials and suture granulomas being the most common etiology. irregularities of the anastomotic ring such as irregular depression or elevation may represent anastomotic recurrences. metachronous lesions have the usually morphology of a polyp or a mass at ctc elsewhere in the colon. ctc clearly shows perianastomotic recurrence or distant metastasis. peritoneal metastatic implant may also be detected at endoluminal fl y-through of ctc by noting an extrinsic compression by the lesion. conclusion: ctc is a benefi cial and noninvasive surveillance method for post-surgical colorectal cancer. knowledge of and familiarity with the normal and abnormal post-surgical fi ndings at ctc will help increase the role of ctc in post-surgical follow-up of colorectal cancer. colonic angiodysplasia has been increasingly recognized as a common source of acute and chronic bleeding in elderly patients, accounting for up to % of cases of obscure gastrointestinal hemorrhage. currently, imaging assesment of gastrointestinal vascular lesions relies on invasive procedures such as endoscopy or angiography, but mdct has gained acceptance as a minimally invasive technique for imaging of the vascular system. procedure details: we retrospectively reviewed cases of colonic angiodysplasia diagnosed by mdct during past years. in cases, the examination was performed due to acute or chronic recurrent bleeding when colonoscopy failed to show the cause. in cases, colonic angiodysplasia was an incidental fi nding in abdominal vascular studies. the mdct fi ndings include accumulation of ectatic and tortuous vessels within the colonic wall, early fi lling veins due to arterio-venous-type malformation development, enlarged arteries of the target area, and intraluminal contrast material extravastion in cases of active bleeding. conclusion: mdct is a useful tool for the diagnosis of colonic angiodysplasia especially in elderly patients with lower gi bleeeding when colonoscopy fails to establish the diagnosis, avoiding the need of invasive catheter angiography. impact of ct colonography with and without removal of diminutive polyps on colonoscopy demand a. laghi , c. hassan , r. ferrari , f. purpose: to evaluate different combinations of magnetic resonance (mr) colonographic sequences and intraluminal contrast agents. methods and materials: polyps, size from to mm, were created on the porcine colon. forty-nine polyps were mm or smaller and were larger than mm. mr colonography was performed with the three-dimensional t -high resolution isotropic volume excitation (thrive) or multislice two-dimensional balanced fast fi eld echo (bffe), using either the air enema or water-gd. enema. we evaluated the presence or absence of each polyp in the mrc compared to the simulated polyps. the diagnostic performance of each mr sequence-contrast agent combination was assessed for detecting polyps. to compare air and water-gd. enemas, polyp conspicuity was evaluated using a four-point scale under bffe sequence. the results were analyzed using wilcoxon's signed ranks test. the bffe using the water-gd. enema showed greater diagnostic performance. it had a sensitivity of . %, a specifi city of %, a positive predictive value (ppv) of %, and a negative predictive value (npv) of . % for polyps of mm or smaller; and a sensitivity, specifi city, ppv, and npv of % for polyps larger than mm. the bffe using the water-gd. enema was also signifi cantly better at enhancing polyp conspicuity compared to the air enema. conclusion: mrc with bffe using a water-gd. enema provided the greater conspicuity, with excellent diagnostic performance. role of fdg-pet/ct in the local staging of colorectal cancer e. selva, p.p. mainenti, g. avitabile, l. camera, g. storto, l. pace, m. salvatore; napoli/it purpose: to evaluate fdg-pet/ct as a diagnostic tool in the assessment of primary tumor extent (t) and lymph node metastases (n) in patients with colorectal cancer. methods and materials: twenty patients with diagnosis of colorectal cancer underwent fdg-pet/ct before surgery. t and n parameters were evaluated on images. < t lesions were defi ned as tumours confi ned to the bowel wall in absence of extra parietal radio-tracer uptake; t lesions as tumours with spiculated outer contour or with rounded or nodular advancing edges showing radio-tracer uptake; t lesions as tumours infi ltrating into adjacent organs in which radio-tracer uptake was present; n as fdg uptake in a cluster of three nodes each less than cm in diameter or in a single node measuring at least cm; n as fdg uptake in more than three nodes regardless of their size. t and n pet/ct staging was compared to histopathology. results: adenocarcinomas were identifi ed: lesion was classifi ed as t , as t , as t ; lymph-nodal involvement was present in cases ( n and n ). all lesions were correctly identifi ed and localized on pet/ct images. fdg-pet/ct correctly identifi ed t stage in of ( %) patients ( / < t and / t ). n stage was appropriately determined in of ( %) patients ( / n , / n and / n ). conclusion: fdg-pet/ct is a useful diagnostic tool in evaluating t and n parameters in patients with colorectal cancer despite the absence of iv contrast medium on ct scan. why did i miss appendicitis on abdominal ct? a pictorial review of appendix pathology on ct m.a. hanif, r. shukla, r. young; bristol/uk (asadhanif@doctors.net.uk) learning objectives: appendicitis is one of the most common causes for an acute abdomen, which can be missed on ct abdomen by the resident on call. we aim to present this poster as a pictorial review of different appendiceal pathologies with atypical presentations. this will help us analyse the factors leading to false-negative results on ct. background: appendicitis is a great mimicker of disease, not just clinically but also radiologically -especially in the adult patient. the diagnosis of acute appendicitis on computed tomography (ct) of the abdomen can prove to be diffi cult at times. variations in the position, length and location of the vermiform appendix along with the differences in the amount of intra-abdominal fat and clinical presentations contribute to this seemingly simple diagnostic dilemma. criteria for the diagnosis of appendicitis on ct are well documented in the literature. learning objectives: to describe acquisition parameters of ct-colonography protocols using different scanners generations moving from single slice spiral ct to the -mdct. background: nowadays, the "panorama" of technical approaches for ctc is expanding offering a wide spectrum of different possibilities. as technology continues to advance, there will be a continuing need to reassess the relative tradeoffs between scan width, image noise, patient dose, image artefacts, breath-hold times, and the number of reconstructed images to be viewed and archived. procedure details: we will discuss the relationship between collimation, tube current settings, patient dose exposure and accuracy in polyp detection of various ctc protocols valid for different scanner generations. we will offer some practical guidelines for ctc technique based on evidences of literature and on our personal experience of more than ctc examinations performed on different scanners generation including a -mdct (vct; ge). conclusion: a single scanning protocol with identical parameters for all scanners and patients cannot be recommended due to technological differences as well as different clinical indications to ctc. what is possible is to offer general guidelines according to the consensus statement on ctc. collimation should not be larger than mm for ssct and no larger than mm for mdct. with the advent of slice mdct, sub-millimeter collimation will be mandatory, although clinical benefi ts are still unclear. was obtained before and seconds after intravenous administration of gd-chelate. mr images were evaluated in conference by two observers by seeking for bowel abnormalities and were correlated with conventional colonoscopy (cc) in all cases and with surgery in / patients. results: mrc could be successfully performed in all cases, whereas cc was incomplete in / patients. mrc correctly defi ned bowel wall thickening, stenosis and extension of the infl amed colon in / patients with ulcerative colitis. in / patients with crohn disease, involvement of both large and small bowel was demonstrated; perianal abscesses (n= ) and fi stulas (n= ) were also identifi ed. in one remaining case, no abnormality was found at mrc and fi nal histological diagnosis was not surely diagnostic for ibd. conclusion: mrc with fecal tagging technique is a promising, minimally invasive technique for evaluation of the bowel in patients with suspected ibd. it can be used for the assessment of disease's extension, especially for those who cannot have cc due to severe pain and fecal residua. abnormal masses of the right iliac fossa: spectrum of imaging fi ndings a.e. mahfouz, h. sherif, n. morad; doha/qa (mahfouzae@yahoo.com) learning objectives: to learn the differential diagnosis of abnormal masses of the right iliac fossa and to illustrate the peculiar imaging features of each of these different masses with histopathological correlation. background: diagnosis of patients with symptoms related to the right iliac fossa may be diffi cult due to the wide variety of pathological processes which may involve the right iliac fossa. imaging may be helpful in diagnosis. imaging findings: abnormal masses of the right iliac fossa illustrated in this educational exhibit include appendicitis, appendicular abscess, mucinous adenocarcinoma of the appendix, cecal carcinoma, typhlitis, omental strangulation, infl ammatory bowel disease, ileocecal tuberculosis, and ileocolic intussusception as well as abnormalitis outside the gastrointestinal tract, which may be considered in the differential diagnosis. peculiar imaging features on different imaging modalities including ultrasonography, multidetector ct, scintigraphy, barium studies, and mr imaging with their pathological correlation will be presented. conclusion: modern imaging modalities are helpful for the correct diagnosis of of patients with symptoms related to the right iliac fossa. the purpose: preoperative radiotherapy with or without chemotherapy in the management of patients with locally advanced rectal cancer allows to decrease tumor size and stage, improves sphincter preservation and the ability to perform a curative resection. the aim of this study was the estimation of the role of mdct-colonography in the pre-surgical staging and restaging of rectal cancer, treated with pre-operative neoadjuvant therapy. methods and materials: twenty-eight selected patients with histologically proven rectal cancer with initial stage t / , n+ and m were studied. all patients underwent mdct-colonography with use of a standard protocol for preoperative staging before and - weeks after radio/radiochemotherapy. pre-operative tnm staging was correlated with surgical/histological fi ndings. results: histopathological evaluation of the resected tumor revealed complete response in one patient, partial response in and stable disease in . reduction in tumors size was signifi cantly greater in responders than in non-responders and indicated a good reaction to therapy. % patients showed tumor downstaging and only % nodal downstaging after tnm restaging. mdct correctly staged t in ( . %) cases, t was overstaged in ( . %) due to peritumoral post-therapeutic fi brosis. mdct correctly staged n in ( %), overstaged in ( . %) and understaged in ( . %) cases. conclusion: mdct-colonography is an accurate procedure for pre-operative staging and restaging tnm classifi cation in patients with rectal cancer treated with neoadjuvant therapy and can be used for treatment planning. the greatest diffi culty was distinction between t and t stage due to peritumoral post-therapeutic fi brosis. all patients underwent chemoradiation therapy (crt). dwi was performed using a . t whole body scanner equipped with a phased-array body coil. a single-shot spin-echo type of echo-planar sequence that provided diffusion weighting in the direction of slice selection was used to obtain dw images. the corresponding bvalue to the diffusion sensitizing gradients were b= s/mm . we evaluated the dw images measuring the adc value of the tumor and compared it with the effect of crt. the therapeutic effect was assessed according to the who criteria, using contrast-enhanced mdct and esophagography weeks after the treatment. results: eight patients were responder and were non-responder. all tumors were detected by dwi (accuracy %). the mean adc value of the tumor was signifi cantly lower than that of the normal esophagus ( . x - mm /s vs . x - mm /s, p < . ). the mean adc value of the responder group was signifi cantly higher than that of non-responder group ( . x - mm /s vs . x - mm /s, p= . ). conclusion: this non-invasive modality could be a valid clinical diagnostic modality to predict the outcome of crt of advanced esophageal cancer. risk purpose: the aim of the study was to evaluate the role of doppler ultrasonography (us) of the portal vein in assessing the risk of esophageal variceal bleeding in patients with liver cirrhosis. methods and materials: transabdominal doppler us and endoscopy were performed in patients ( male, female, mean age . years) with liver cirrhosis and esophageal varices. the variceal size and the presence of red signs were determined by endoscopy. following us parameters of the portal vein were recorded: diameter and cross-sectional area, blood fl ow velocity and blood fl ow volume, perfusion pressure gradient (ppg), and congestion index (ci). child-pugh score of liver function was also determined. the us parameters were compared to the endoscopic signs of esophageal bleeding risk. results: values of portal diameter, cross-sectional area, blood fl ow volume and ci were signifi cantly higher, while ppg was lower in patients with, than in patients without variceal red signs. only diameter, cross-sectional area, and blood fl ow volume were signifi cantly different among groups of patients with different variceal sizes. the blood fl ow velocity did not depend on the presence of red signs and variceal size. in addition, recorded us parameters did not reach level of significance between groups of patients with different child-pugh score. the sensitivities, specifi cities, and areas under roc curves of the analyzed us parameters were . - %, . - . %, and . - . , respectively. conclusion: according to our results, transabdominal doppler us might be of value in non-invasive assessment of the risk of esophageal variceal bleeding in patients with liver cirrhosis. a digital cineradiography with frames/second acquisition was performed in all patients using bolus of ml of liquid ( % weight/volume) barium. in patients standing in the left posterior oblique position and prone in the right posterior oblique position, the oesophagus and oesophagogastric junction were also examined. the water siphon test was performed at the end of the procedure. results: in all patients, the evaluation of oesophageal motility disorder was possible. in of them, the grade of the disorder was high and barium retention in the oesophagus was also detected. owing to the stagnation of liquid barium in the terminal oesophagus, the evaluation of oesophagogastric junction was possible only in patients. of these patients, presented a hiatus hernia and a gastrooesophageal refl ux. conclusion: digital cineradiography is a suitable technique for evaluating the functional abnormalities of the oesophagus in patients affected by sclerodermia. learning objectives: to present a pictorial review of the radiological appearances of achalasia and pseudoachalasia with emphasis on endoscopic correlation. background: barium swallow remains a valuable imaging modality in patients presenting with dysphagia. pathologies such as achalasia and pseudoachalasia can be diffi cult to distinguish on barium swallow as typical fi ndings may not always be apparent. recognising the various radiographic appearances by the radiologist is critical for prompt and accurate patient management. imaging findings: we present a case series of achalasia and pseudoachalasia on barium swallow encountered at our institution. we emphasise the differences between the two pathologies both on imaging and on text as a learning experience. we also provide a review of the existing literature with reference to our experience. conclusion: barium swallow is an established method for evaluating patients with dysphagia. however achalasia and pseudoachalasia still remain diffi cult to distinguish; so awareness of the potential pitfalls with endoscopic correlation in all cases is emphasised to avoid radiological misdiagnosis. late evaluation of the swallowing function in patients with maxillofacial gunshot injuries by multimodality radiologic and complementary methods z.u. coskun , s. ozturk ; bilkent, ankara/tr, etlik, ankara/tr (unsalcoskun@yahoo.com) purpose: maxillofacial (mf) gunshot wounds having a tract between the mouth fl oor and the naso-orbital region may result in long-term swallowing disorders. here, we aimed to show late functional outcomes of the primary surgical treatments by using objective radiologic and complementary studies. methods and materials: patients were included in the study. the mean age was ± . free osteocutaneous fi bula fl aps, iliac or calvarial bone grafts were used with fasciacutaneous fl aps. dento-palatal restorations were accomplished with dental and prostetic obturator implants. functional outcomes were assessed by: videofl uoroscopy, cine-mri, submental usg, fiberoptic endoscopic swallowing study (fees), functional emg. the results were compared to the control group (n: ) statistically. videofl uoroscopic studies showed pooling in vallecula and pyriform sinuses (n: ), delayed pharyngeal (n: ) and oral transit times (n: ), spilling out due to oral incompetence (n: ), nasal regurgitation (n: ), sublingual pooling (n: ), multiple swallowing action (n: ), and aspiration (n: ). cine-mri revealed reduced laryngeal elevation ( . mm) and epiglottic angle ( . o ). discordance and impaired oral fl oor muscles were observed. submental usg showed insuffi cient tongue movement resulting in bolus formation and transit impairment (n: ), restricted hyoid elevation (n: ), and submental muscle defects (n: ). fees revealed pooling in vallecula and pyriform sinuses (n: ), delayed epiglot closure (n: ) and impaired swallowing apnea (n: ). functional emg showed lower amplitude of submental and pharyngeal constrictors (n: ). conclusion: clinically, knowing the radiopathologic fi ndings in such patients may help the clinician in determining an algorithm to manage the secondary deformities as well as adding new surgical techniques such as replacement of submental muscles by functional muscle fl aps during primary surgery. patients were treated with surgery alone and patients ( with x gy and with gy) were treated with preoperative pelvic radiotherapy. a complete postoperative histopathological examination was used as the gold standard. results: in pathology of ( %) tumors were classifi ed as t -t , and ( %) were classifi ed as t -t . trus had an accuracy of % in detecting penetration of the rectal wall in the patients treated with surgery alone. the accuracy of trus in patients treated with x gy was . % (ns), and in patients treated with gy, the accuracy was . % (p < . ). a high sensitivity was noted in all groups; however, the specifi city of trus rapidly decreased to zero with increased pelvic radiotherapy intensity, as the false-positives increased because of tumour shrinkage. this change in accuracy was not seen to the same extent with regard to lymph node metastases. conclusion: trus has a high accuracy in patients treated with surgery alone. the t-staging accuracy of trus is low in patients receiving high-dose pelvic radiotherapy due to down staging. purpose: the purpose of this study is to evaluate perfusion ct in assessing pathological features of rectal cancer before surgery. methods and materials: forty consecutive patients ( men, women; median age . years) with rectal cancer underwent perfusion ct, using the commercially available ct perfusion software (ge medical systems, milwaukee, wi). all patients were followed by surgery, and we retrospectively investigated the correlations between perfusion parameters and pathological features (wall invasion, histological differentiation, lymph node metastasis, dukes' classifi cation). statistical analysis was performed with mann-whitney u test for comparison of two data sets, and kruskal-wallis test for comparison of multiple data sets. p < . was considered to indicate a statistically signifi cant difference. results: there were no correlations between perfusion parameters and wall invasion. well-differentiated tumors showed signifi cantly higher blood fl ow than the moderately-differentiated tumors (p = . ). there was a signifi cant tendency for the tumor with low blood fl ow, low blood volume or long mean transit time to show lymph node metastasis (p = . , . , . , respectively). and there was a signifi cant correlation between dukes' classifi cation and blood fl ow (p < . ), blood volume (p = . ), mean transit time (p = . ), and permeability surface area product (p = . ). in the near future, perfusion ct may help to assess pathological features of rectal cancer before surgery. within the node versus the size of the total node, categorized as %. this ratio was objectively calculated (ratioa) by the long and short axis diameter measurements of both the area of white region within the node and the total node. regions of interest (roi) were used to measure the signal intensity (si) within muscle (simuscle), total node (sitn), white (siwhite) and dark (sidark) region within the node. these measurements were used to calculate the ratios: siwhite/sidark and sitn/simuscle. a receiver operating characteristic (roc) analysis was performed. results: a lesion-by-lesion analysis of lymph nodes was feasible. the area under the roc curve (auc) of border, short and long axis of the total node were respectively . , . and . . the auc for the estimated percentage and measured ratioa of white region within the node were . and . , respectively. the roi could accurately be positioned in lymph nodes. the auc of the ratios: siwhite/sidark and sitn/simuscle were respectively . and . . the estimated ratio of white area within the node and the measured ra-tioa were very accurate for distinguishing between malignant and benign nodes. pre-surgical evaluation with positron emission tomography (pet) and magnetic resonance imaging (mri) of patients with locally advanced rectal cancer treated with neo-adjuvant radio-chemotherapy l. balestreri, e. borsatti, r. talamini, m. cimitan, s. morassut; aviano/it (lbalestreri@cro.it) purpose: to compare the diagnostic performance of pet and mri in correctly restage patients with advanced rectal cancer treated with neo-adjuvant radiochemotherapy before surgery. twenty-three patients with advanced rectal cancer (t -t ) were studied with pet and mri before and after -fl uorouracil or raltitrexed-based chemotherapy and - gy of radiation therapy. pre-surgical scanning was performed to weeks after the end of the chemoradiation; the results were compared to the surgical specimen. particularly for pet, tumour response was considered evaluating standardized uptake value (suv) percentage decrease related to tumour regression grading (trg) at pathology. for mri, tumour response was considered evaluating: ( ) tumour extension and size according to the tnm system. ( ) circumferential resection margin (crm) measurement assessing the distance between extramural tumour and mesorectal fascia. results: strong correlation (spearman correlation coeffi cient r = - . ) was found in between suv decrease > % and trg values of and (no residual disease or microscopic active disease). strong correlation (specifi city %, sensitivity %) was found between crm measurement with mri and on the surgical specimen. no statistically signifi cant correlation was found between t measurement with mri and on the surgical specimen. while pet provides reliable metabolic information about tumour response to therapy, mri provides reliable measurement of crm. both modalities must be performed to correctly restage patients before surgery. background: although adenocarcinoma is the most frequently encountered rectal tumor, familiarity with the cross-sectional imaging features of less common anorectal tumors as well as of their differential diagnosis is important because their prognosis and treatment are different. in this exhibit, we will describe the ct and mri features of such lesions based on a series of patients treated in our department since with a pathologic correlation. procedure details: mucinous anorectal adenocarcinomas are characterised by a markedly hyperintense content on t -weighted images, an enhancing solid component within the mass and their highly infi ltrative behaviour. villous tumors are large masses fi lling the rectal lumen and displaying frondlike projections. anorectal stromal tumors are large, well-marginated masses expanding the rectal wall and lack perirectal adenopathy. lymphomas display marked concentric wall thickening engulfi ng the rectum, with luminal restriction but minor obstruction and adenopathies. linitis and rectal metastases display a circumferential thickening of the rectal wall over a long segment. other uncommon tumors include carcinoid tumor, melanoma, anal condyloma. differential diagnosis include crohn disease, diffuse rectal angiomatosis, changes after radiotherapy, rectal endometriosis, diverticulitis. identifying key specifi c ct and mr imaging features can be helpful in suggesting a diagnosis. mri is a modality of choice to evaluate unusual anorectal neoplasms. high to review the current role of mri in the evaluation of these lesions. background: developmental cysts are the most common retrorectal cystic lesions in adults. they are classifi ed as epidermoid cysts, dermoid cysts, enteric cysts according to their histopathologic features. they may present with symptoms or with a complication such as infection or malignant degeneration. their differential diagnosis we review the mr imaging fi ndings with pathologic correlation of presacral cystic masses based on a series of patients treated in our department. imaging findings: developmental cysts, among which tailgut cysts are the most frequent are characterized by well-defi ned, multilocular cysts with "daughter cysts". their wall is usually thin unless they are complicated. an enhancing wall with peri cystic infl ammation suggests infl ammation and additional internal enhancement evokes malignant degeneration. their signal intensity is variable, usually homogeneous, either isointense to muscle on t -weighted images and isointense to fat on t -weighted images or hyperintense on t /hyperintense on t depending on their content. differential diagnosis includes anterior sacral meningocele, recurrence of mucinous rectal adenocarcinoma, cystic lymphangioma, necrotic sacral chordoma or leiomyoma, pyogenic abscess, schwannoma, peritoneal pseudocyst. conclusion: most lesions of the retrorectal space are developmental cysts but the differential diagnosis must be known. knowledge of the key imaging features of the retrorectal cystic lesions may help suggest the diagnosis and the information needed to plan treatment. preoperative n staging of rectal cancer evaluating from morphological feature using magnetic resonance imaging t. sazuka, s. okazumi, k. shuto, t. aoyagi, h. makino, r. mochizuki, t. ochiai, n. yanagawa; chiba/jp purpose: the purpose of this study is to evaluate the accuracy of magnetic resonance imaging (mri) in n staging of rectal cancer and to compare histological fi ndings. methods and materials: eighty-six patients of rectal cancer were enrolled in this study. all of the patients underwent surgery and proved histologically. prior to treatment, mri was performed with t -weighted fast spin echo sequences using a . t whole body scanner equipped with a phased-array body coil. following fi lling the rectum with air of - ml from a placed tube, images were acquired with a slice thickness of mm. every reconstruct axial, coronal and sagittal images of each node was evaluated. we classifi ed lymph nodes over mm by morphological features as follows: solitary/ confl uent, margin clear/ spicular, shaped fl at/ round. and we assessed those features in comparison with histological fi ndings. results: a total of nodules were evaluated. all of confl uent nodules (n= ) were histologically metastatic (ppv %, specifi city %). when we defi ne metastatic node as any features of confl uent nodule, irregular margin or round shaped, the sensitivity was % and the specifi city %, ppv % and npv % in comparison with histological fi ndings. conclusion: this diagnostic method classifying by morphological features is noninvasive and may be valid with an acceptable detectability by no means inferior to enhanced or radiological modality. dynamic magnetic resonance imaging (mri) evaluation of levator ani muscle (lam) in patients with wall prolapse and intussusception pathologies of the rectum a. salzano, v. nocera, g. cavallo, e. montemarano, p. de feo, a. nunziata; naples/it (tonikus@libero.it) learning objectives: to describe mri dynamic appearance of lam in patients with rectal wall prolapse and intussusception, outlining the role and the advantages of dynamic mri for the assessment of anatomic and functional study of lam and evacuation disorders. background: dynamic mri allows to evaluate morphology and pathomorphologic changes of the lam during defecation. defecography well assesses rectal prolapses, but does not provide imaging of muscles of pelvic fl oor except indirect signs. dynamic mri provides a whole and direct visualization both anatomical and functional of lam and rectal prolapses. we illustrate a study of female subjects (mean age of years; range - years) previously investigated by defecography in order to obstructed evacuation. imaging findings: dynamic mri was carried out in different dynamic phases of pelvic fl oor, in breathe hold using t -weighted scans. we diagnosed rectal wall prolapses and intussusceptions; all patients had rectocele and perineal descent syndrome. lam had reducted thickness in cases and alterated signal in cases. levator hiatus was large in cases in the coronal plane with a typical shape of large cone. we focused a relationship between hiatal area, movements of rectal walls and descent of pelvic fl oor. conclusion: dynamic mri is considered a novel noninvasive imaging method of investigation in comparison to defecography, to understand the dynamics of lam and the pelvic fl oor descent disorders. mri provides better the relationship of rectal intussusception and wall prolapse related to pelvic organ mobility and dynamic shape changes of lam. diagnosis and follow-up of anoperineal fi stuals with phased-array mri: a pictorial review f. gonzález, g. blanco, c. juanco, n. valle, m. lopez, m. silvan; santander/es learning objectives: to describe the anatomy and imaging features of acquired anorectal fi stulas. to identify the mri fi ndings in the various types of anorectal fi stulas. to review the role of mri in the assessment of acquired anorectal fi stulas. background: the most commonly encountered and known anorectal fi stulas are anorectoperineal fi stulas occuring in crohns disease. however, there is a variety of less common fi stulas involving the anorectum. their causes include infection, infl ammation, neoplasms, trauma and iatrogenic injury. pelvic mri assessment has proved useful in the evaluation of fi stulas and has become an important part of diagnostic work-up before proper case management. imaging findings: we illustrate the mr fi ndings in fi stulas involving the rectum or anal canal or ileal or colonic pouch (in case of previous surgery) and the vagina, uterus, prostate, urethra, bladder, and ileum. we also present the features of complex anoperineal fi stulas. the current role of mri is discussed. we emphasize the role of mri in the follow-up after medical or surgical treatment. conclusion: phased-array pelvic mri is an accurate technique for the identifi cation of acquired anorectal fi stulas and their complications. mri exam is a noninvasive diagnosis method that allows us an accurate diagnosis and follow-up in patients with anoperineal fi stulas. imaging findings: small-bowel lymphomas are presented in wide spectrum of appearances included aneurismal dilatation, intra luminal polypoidal mass, mesenteric mass with irregular infi ltrating borders causing thickening of the walls and narrowing of the lumen and it may present just as diffuse circumferential mural thickening of the bowel walls with irregular narrowed lumen. mr sbft offers the advantage of excellent soft-tissue contrast and multiplanar imaging capabilities and absence of ionizing radiation over other modalities in studying small bowel lymphoma. over a -year period, we reviewed mr sbft examinations for evidence of small bowel lymphoma. in all, cases were identifi ed and subsequently histologically confi rmed. we provide a detailed radiological review of the appearances of these tumors at mr sbft. conclusion: mr imaging of the small bowel has moved in the recent years and the knowledge of the typical mr sbft appearance of small bowel lymphoma may aid the radiologist to suggest the diagnosis. purpose: to evaluate using magnetic resonance the effi cacy of oral infl iximab therapy in perianal fi stulizing crohn´s disease patients. to compare clinical and mri fi ndings in these patients, using the perianal crohn´s disease activity index (pcdai) and magnetic resonance imaging-based score (mrs). to evaluate the effi cacy of mri in the diagnosis and follow-up of this pathology. methods and materials: patients with perianal fi stulas due to crohn´s disease were enrolled into a prospective study, and were evaluated with pelvic mr previous to treatment and after a long-term follow-up of months, in order to observe the evolution of fi stulous pathology. we use a . t system (magnetom avanto siemens®) with a phased-array coil. we applied the mrs modifi ed from assche to the images obtained. the clinical response was evaluated with the pcdai described by irvine. results: twelve patients were included in our study. six ( %) achieved complete responses, verifi ed with both pcdai and mrs. five ( . %) showed no changes in mrs with partial response in the pcdai and ( . %) showed no response in both mrs and pcdai. conclusion: oral infl iximab is an effective treatment for patients with perianal fi stulas due to crohn´s disease. mr is a good method for the diagnosis of the perianal crohn´s disease and for the follow-up and evaluation of the treatment of these patients. the differences of the results in clinical and mr scores may be due to the subjective index that are evaluated in pcdai and the ¨placebo¨effect of the treatment. is virtual enteroscopy an acceptable method for detecting peutz-jeghers poliposis in the small bowel? e. turupoli, g. tóth, k. szeidl, Á. komezei, Á. szilvássyné takács; budapest/hu (turupoli@freemail.hu) purpose: hamartomas are usually considered histologically benign, but in the case of peutz-jeghers patients, there are reports of malignant changes in the polyps. we tried to assess the usefulness of virtual enteroscopy for the assessment of peutz-jeghers polyposis in the small bowel. our goal was to reach a good distension in the small bowel by virtual enteroscopy. in patients with known peutz-jeghers polyposis in the stomach and colon, ct virtual enteroscopy was performed. patients were examined with a -row ct scanner using the following parameters: slice mm, with overlap scans, reconstruction interval . mm. ml i.v. contrast agent was administered at a rate of ml/s with a scan delay of s. we evaluated mural thickening, mural enhancement, stenosis, praestenotic dilatation. the results of mdct enteroscopy were compared with selective enterography and surgery. selective enterography and surgery were considered the gold standard. results: good small bowel distension was obtained in cases, and suffi cient in cases. mdct virtual enteroscopy showed i.v. contrast-enhancing polypoid lesions in patients. thirty-three lesions were smaller than mm and were larger than mm. two polyps caused intussusception. selective enterography showed polyps smaller than mm, and larger than mm. mdct virtual enteroscopy had an overall per-lesion sensitivity of . % for lesions smaller than mm, and % for lesions larger than mm. conclusion: mdct virtual enteroscopy in peutz-jeghers syndrome showed a high sensitivity in detecting polyps smaller than mm. coeliac disease -incidence and radiological fi ndings of associated malignancy e. delappe, c. cronin, c. meehan, c. roche, j. murphy; galway/ie purpose: enteropathic-associated t-cell and b-cell lymphomas are recognised associations of coeliac disease; however, the exact prevalence is unknown. the purpose of this study was to determine the prevalence of associated gastrointestinal lymphoma or other malignancy in patients with chronic gluten-sensitive enteropathy. we describe the radiological features and distribution of these malignancies in our subject population. we retrospectively reviewed the radiological and pathological fi ndings of gastrointestinal tract malignancies in a total of patients with coeliac disease referred to our institution over a fi ve-year period. assessment included disease presentation, location (duodenal, jejunum, ileum), stage and radiological features (wall thickening, abnormal mucosal pattern, local nodal involvement). we also reviewed the radiological fi ndings and prevalence of extragastrointestinal malignancies. results: a total of new cancers were diagnosed in the total population sample ( . %). of these, had a diagnosis of oesophageal cancer ( . %) and ( . %) had lymphomatous involvement of the gastrointestinal tract. there was a signifi cant increased risk of both oesophageal cancer and gastrointestinal lymphoma compared to that of an age-matched population (p < . ). we identifi ed a number of other gastrointestinal and extra-gastrointestinal malignancies in the sampled group including duodenal, colon, bladder, lung, ovarian, and carcinoid with no statistically signifi cant increased risk. conclusion: although coeliac disease has been shown to have an association with gastrointestinal lymphoma, other gastrointestinal malignancies such as oesophageal tumours also occur increasingly in such patients. this possibility must be considered when patients with known coeliac disease present with gastrointestinalrelated symptoms, which are atypical for their primary condition. duodenal and paraduodenal lesions: imaging fi ndings g. pekindil; manisa/tr (pekindilg@yahoo.com) learning objectives: to illustrate imaging features of various developmental, infl ammatory, neoplastic, traumatic and postsurgical processes that are located in or adjacent to duodenum. background: although primary diseases of doudenum are rare, several primary and secondary processes may involve duodenum due to its both intra and extraperitoneal localization, proximity to pancreas, stomach, hepatobiliary and intestinal system. procedure details: duplication, annular pancreas, malrotation and transient paraduodenal hernias are rarely seen congenital anomalies whereas diverticula may be seen more frequently. infl ammatory wall thickening may arise from ulcers, pancreatitis, crohn's disease, coeliac disease, henoch-schonlein purpura. many adjacent infl ammatory pathologies such as appendicitis, pancreatitis, cholecystitis may also have düodenal wall involvement and may cause "sentinel loop" apperence of dilated duodenum with air-fl uid levels. duodenal dilatation may arise from superior mesenteric artery syndrome. primary adenocarcinoma, paraganglioma, liposarcoma, gist, lymphoma, menetrier disease may cause noeplastic involvement of duodenum. also, metastatic lymphadenopathies of seminoma, mesothelioma, lymphoma may locate around duodenum. walls of duodenum may be thickened from adjacent malignancies such as cholangiocarcinoma, adenocarcinomas of stomach, colon and pancreas. cystic extrensic compression may arise from choledococel, intestinal lympangiectatic cysts, choledochal cyst, pseudocysts, policystic disease. foreign bodies located in duodenum such as metallic nail and traumatic hematoma can be revealed by ct. chlodecoduodenostomy, whipple operation and gastrojejunostomy may cause several changes of duodenum. since several different pathologies may affect or may arise from duodenum, radiologist should pay attention to duodenum as much as other adjacent organs in the interpretation of many sectional imaging modalities. utility of mdct enteroclysis in the evaluation of gastro-intestinal bleeding in small bowel diverticulosis: a pictorial review g. tóth, l. tóth, p. magyar, e. turupoli, k. hüttl; budapest/hu (totgez@freemail.hu) learning objectives: while small bowel diverticulosis is a rare entity and usually asymptomatic, it may cause acute or chronic symptoms and complications. because of its rarity, diagnosis is often delayed, resulting in unnecessary morbidity and mortality. nowadays, the diagnosis of small bowel diseases is frequently made by mdct enteroclysis. we present and discuss the typical fi ndings of mdct enteroclysis in cases. background: small bowel diverticulosis is a rare disorder found in . - % of the adult population. most small bowel diverticula remain asymptomatic and are detected as an incidental fi nding, but they can also present a wide spectrum of complications, such as acute diverticulitis, hemorrhage, intestinal obstruction, perforation, malabsoption, and present as diffi cult diagnostic challenge. acquired small bowel diverticulosis predominantly involves the proximal jejunum, and is located on the mesenteric aspect of the small bowel, while the congenital meckel diverticulum is located on the antimesenteric aspect of the ileum, - cm from the ileocecal valve. ninety-three patients with suspected small bowel tumor were examined with a sixteen-row ct scanner (brilliance power ), using the following parameters: coll. x . mm with overlap scans, reconstruction interval mm, after administration of methylcellulose by nasojejunal tube, before and after infusion of ml iv. contrast agent, at the rate of . ml/s, with a scan delay of seconds. in all the cases, multiplanar and curved planer reformatted images were performed. we evaluated mural thickening, mural enhancement, stenosis, praestenotic dilatation, perienteric reactions, lymph node enlargement. results were compared with sbe and surgical fi ndings. results: mdct detected lesions, and sbe showed pathological lesions. the comparison with sbe showed ct false-positive cases due to poor bowel distension. three sbe false-negative cases were due to the small polipod lesions (< mm). the fi nal diagnosis was adenocarcinoma in patients, carcinod tumor in patients, peutz -jeghers poliposis in patient, adenomatous polyps in patients, lymphoma in patients, leiomyoma in patients, leiomyiosarcoma in patient, cd in patients and adhesions in patients. we found enlarged lymph nodes in patients, and liver metastases in patients. mdct fi ndings correlated well with the surgical fi ndings. conclusion: mdct enterography is a useful and reliable method for the diagnosis of small bowel tumors. background: adult small bowel intussusception has been regarded as a condition that always required surgery because up to % of the surgical reports said to be associated with a lead point abnormality. however, with the growing use of cross-sectional imaging in the evaluation of patients with abdominal complaints, the detection of enteric intussusception without a visible lead point disease has increased, creating a challenge in determining its diagnostic signifi cance and therapeutic approach. imaging findings: at ct, the presence of a bowel within bowel confi guration is pathognomonic for intussusception, having three different patterns depending on the severity and duration of the disease process. intussusceptions without a lead mass are usually transient, small and non-obstructing. experiments say they are due to disturbances in peristalsis and require only conservative observation. a lead point intussusception usually appears as a long abnormal target-like mass that may be associated with proximal bowel obstruction. identifi cation of the lead mass is not always easy; however, once recognized, surgical treatment should be recommended. conclusion: incidental enteric intussusceptions are being increasingly diagnosed posing a new diagnostic and therapeutic problem. not all this intussusceptions require aggressive work because most of them are intussusceptions without a lead point and therefore of no clinical importance. therefore, it is important to know the imaging characteristics that permit the distinction between them to prevent unnecessary aggressive therapeutics. results: side effects of the oral application of mannitol were noted in four cases (one case of vomiting and three cases of mild diarhea), no serious complication was present. the evaluable images with suffi cient distension of the bowel loops were obtained in cases. signs of activity -mucosal and submucosal enhancement of thickened bowel wall -with or without fi stulisation were found in cases, non-active cd in cases (including cases of stenosis), ulcerative colitis in cases, enteritis in one case and normal fi nding in cases. conclusion: mr enterography with . mannitol is a safe valuable imaging tool and should be used as the prime imaging modality in patients with suspected or known cd. purpose: the purpose of this study is to evaluate the correlation between tumor blood fl ow calculated with perfusion ct and clinicopathological status of gastric cancer. the study enrolled consecutive patients who underwent surgery for advanced gastric cancer. perfusion ct was performed with a -row mdct using an intravenous injection of iodinated contrast material. sequential dynamic scans were performed on a single level where the tumor was largest in size. these dynamic images were reconstructed in the workstation to create a functional image. the new image was analyzed to calculate tumor blood fl ow (bf, ml/min/ g tissue), using roi. we compared the bf in each patient and evaluated its correlation with the clinicopathological status of the gastric cancer. results: no signifi cant correlation was found between the bf level and the tumor location, diameter, or t-stage. the bf level was higher in the cn group than in the cn / groups, and signifi cantly higher in pstage i/ii compared to pstage iii/iv. pathological examination revealed the bf level of the undifferentiated-scirrhous type, often with high-grade malignancy resulting in poor prognosis, to be signifi cantly lower than that of the differentiated-medullary type. the bf value of the gastric cancer acquired from perfusion ct may refl ect the histopathological structure of the tumor, including tumor vascularity and volume of extracellular matrix components of the tumor. this radiological imaging procedure is a valid modality to visualize the decreased tumor blood fl ow for assessing the malignancy level of gastric cancer, especially in those with high-grade malignancy. evaluation results: the tumor size was . ± . cm in diameter. the suv of all tumors was . ± . , and the mi was . ± . ( hpf). there was a signifi cantl correlation between suv and mi (r= . , p= . ). based on the guideline, suv of the low-risk group (n= ) was . ± . , intermediate-risk group (n= ) . ± . and low-risk group (n= ) . ± . . suv level of high-risk group was higher than that of low group and intermediate group with a statistical difference (p= . , . , respectively). when the cut-off suv level for high-risk group was established as . , the positive predictive value and the accuracy rate was % and %, respectively. conclusion: fdg-pet may be an appropriately quantitative modality to distinguish high-risk group with acceptable diagnostic value. staging of gastric cancer: ct fi ndings and correlation between lymph node size and metastatic infi ltration a. gligorievski, k. gjoreski, a. karagjozov; skopje/mk (atgl@mail.net.mk) purpose: the assessment of lymphatic metastases is an important factor in the staging of gastric cancer. lymph node size has been used as one criterion for possible nodal metastasis. in a prospective morphometric study, the regional lymph nodes from gastrectomy specimens of consecutive patients with primary gastric adenocarcinoma were analyzed. the lymph nodes were counted, the largest diameter of each node was measured, and each node was analyzed for metastatic involvement by histologic examination. the frequency of metastatic involvement was calculated and correlated to lymph node size. results: a total of lymph nodes were present in the specimens examined for this study. a mean number of lymph nodes (range - ) were found in each specimen. of these nodes, ( %) were tumor-free and ( %) contained metastases. the mean diameter of the lymph nodes free of metastases was . mm, whereas that of nodes infi ltrated by metastases was . mm (p <. ). of the tumor-free lymph nodes, ( %) were less than mm in diameter, whereas ( %) nodes containing metastases were less than mm in diameter. of the patients without lymph node metastases, had at least one node that was mm or greater in diameter; similarly, ( %) of the patients with node metastases had at least one node that was mm or greater in diameter. conclusion: lymph node size is not a reliable indicator for lymph node metastasis in patients withgastric cancer. purpose: physiological fdg uptake in the stomach is often seen, especially at the oral end. water ingestion just before scanning would make stomach distention and thin the gastric wall, which may lead to apparent reduction of uptake in area of stomach. in this study, we assessed whether gastric distention using water ingestion suppressed physiological fdg uptake in the stomach. methods and materials: forty patients who had fdg whole-body pet imaging for cancer screening followed by gastric endoscopic examination were registered in this study. all patients took ml of water for hydration and were administered mbq of fdg intravenously. all patients were randomly divided into two groups with or without (additional) water. with water group, patients had additional ml of water immediately before pet imaging. the stomach regions were classifi ed into three areas: u (upper)-area, m (middle)-area, l (lower)-area. the degree of fdg uptakes in these three gastric regions were semi-quantitatively evaluated using suv. results: without water group, the mean suvs in the u-, m-, l-areas was . ± . , . ± . and . ± . respectively, while in water group, . ± . , . ± . and . ± . , respectively. with water group, the suv in the u-and m-area were signifi cantly lower than that of without water group (p <. ). a signifi cant difference in fdg uptake was not observed among the three gastric areas in water group (p <. ). conclusion: additional water-intake immediately before pet imaging suppressed the physiological gastric fdg uptake. therefore, decrease of physiological stomach accumulation with this method has a possibility of improving diagnosing in this area. learning objectives: to be aware of the importance of fat stranding in locating the abdominal urgent pathology. to be familiar with the differential diagnoses depending of the fat stranding location. to differentiate the benign entities that resemble life-threatening diseases. background: ct plays a crucial role in differentiating the underlying causes of the symptoms in acute abdomen. fat stranding is a ct sign that helps in the evaluation of patients with acute abdominal pain in emergency radiology. it is no patognomonic though it warns us where to look at. fat stranding may arise from many causes that should be considered in the differential diagnosis. acute conditions that cause fat stranding include appendicitis, ischemia or perforation of the bowel, cholecystitis, trauma and surgery. imaging findings: we have made a pictorial review showing and describing the ct imaging features of the most common abdominal urgent pathology. we try to demonstrate how fat stranding on abdominal ct can help us to identify the crucial point of the acute abdominal at fi rst sight. once localized it, we describe the specifi c imaging fi nding that will lead us to a fi nal diagnosis. correct non-invasive diagnosis is important because treatment approaches for these conditions range from monitoring to surgery. we show some key-facts to help us to differentiate both groups. conclusion: fat stranding is a useful sign to localize the underlying pathology in acute abdomen. knowledge of ct signs accompanying it helps us to reach a fi nal diagnosis, and therefore a more accurate clinical decision. c b d e f a g evaluation background: bowel and mesenteric injuries are detected in % of blunt abdominal trauma patients at laparotomy and rarely occur isolated. early diagnosis and treatment are critical to decrease morbidity and mortality. ct has become the primary modality for the imaging of these patients. however, radiological signs can be subtle and should be regarded as complementary to meticulous clinical assessment. imaging findings: ct fi ndings in bowel and mesenteric injury include the following: a. direct fi ndings of bowel injury: bowel wall disruption and oral contrast extravasation. b. direct fi ndings of mesenteric injury: intravenous contrast extravasation from mesenteric vessels. c. indirect fi ndings of bowel injury: free intraperitoneal/retroperitoneal air or fl uid. d. indirect fi ndings of mesenteric injury: diffuse bowel wall thickening, diffuse bowel wall enhancement, mesenteric infi ltration or haematoma. when indirect fi ndings of bowel or mesenteric injury are the only ct fi ndings, the need for surgical intervention is highly dependent on clinical judgment and can be necessary reassessment with ct - hours after the initial evaluation to elucidate the signifi cance on such fi ndings. conclusion: ct has been shown to be accurate for detecting bowel and mesenteric injury caused by trauma and is useful in predicting the need for either surgical repair or conservative management. the target sign on multidetector-row ct: spectrum of bowel diseases r. cianci, a. filippone, a. gorgoglione, m.l. storto; chieti/ it (r.cianci@rad.unich.it) learning objectives: to understand the signifi cance of target sign as seen on contrast-enhanced multidetector-row ct (mdct) of the abdomen. to illustrate various bowel diseases in which target sign may be observed. the target sign is a term used to indicate stratifi cation within a thickened bowel wall that consists of three layers: a inner and outer layer of high attenuation, respectively corresponding to contrast-enhanced mucosa and muscularis propria/serosa, and an intermediate layer of decreased attenuation corresponding to submucosa. the target sign is believed to represent hyperemia in the mucosa and the muscularis propria, serosa or both and edema or infl ammation in the submucosa. the target sign is commonly observed in idiopathic infl ammatory bowel diseases (ulcerative colitis and mostly crohn disease) and ischemic enterocolitis; it may be present in intramural intestinal hemorrhage, infectious enterocolitis, vasculitis (henoch-schönlein purpura, lupus erythematosus), radiation enterocolitis and bowel edema in cirrhosis. the fi nding of stratifi ed attenuation in a thickened segment, although non specifi c, most likely represents non neoplastic disease, with the exception of the rare occurrence of this sign in infi ltrating scirrhous carcinoma of the stomach and colon. potential pitfalls in the diagnosis are residual fl uid and oral contrast material fi lling the bowel lumen or the deposition of submucosal fat. the target sign may be seen on contrast-enhanced mdct scans as a non specifi c feature of non neoplastic bowel diseases. correlation with patient clinical history and associated ct fi ndings related to the bowel wall or mesentery may allow to narrow the differential diagnosis. multidetector background: isigo is a rare benign and self-limiting disorder, presenting with aspecifi c clinical symptoms that may mimic other acute abdominal conditions. the cause of isigo has been not established; it has been postulated that precipitating factors resulting in displacement of the omentum, such as sudden increase in abdominal pressure after heavy meals, overexertion, a sudden change in body position, coughing or sneezing, may cause venous stasis and thrombosis leading to omental edema and congestion, with hemorrhagic necrosis and extravasation of serosanguineous peritoneal fl uid. imaging findings: all typical imaging features of isigo are well recognizable on unenhanced ct scans; they include a well circumscribed, oval or cake-like fatty mass with heterogeneous attenuation, containing strands of soft tissue attenuation probably corresponding to fi brous bands and/or dilated thrombosed veins. the mass is usually right sided and most often located deep to the rectus abdominis muscle and anterior to the colon. it appears adherent to infl amed, thickened parietal peritoneum. there is frequently a small to moderate amount of free peritoneal fl uid. major differential diagnoses include appendicitis, cholecystitis, diverticulitis, epiploic appendagitis and, less frequently, primary benign or malignant neoplasms or metastatic peritoneal seeding. conclusion: to recognize mdct fi ndings of isigo is important in making the correct preoperative diagnosis in patients with acute abdominal pain. it may avoid unnecessary surgical explorative intervention. intestinal intussusception in adults: x-ray, us, ct, and mri fi ndings f. sandomenico, o. catalano, a. nunziata, v. de rosa, a. petrillo, a. siani; naples/it (tonikus@libero.it) learning objectives: to describe the imaging appearance of gastro-intestinal intussusception with a large range of diagnostic modalities in patients with a variety of intussusception locations (gastric, jejunal, ileal, ileo-colic, appendicular, colic, and rectal), presentations (acute, chronic, transient), and causes. to make the reader aware of the clues to a diagnosis and of the imaging features of complicated intussusception. background: intussusception is the herniation of one segment of the gastrointestinal tract into another (proximal to the former or, more frequently, distal). in adults, intussusception usually has a leading cause and may develop at different levels with a variety of clinical presentations. we illustrate all x-ray, us, colour-doppler, ct, and mri fi ndings in adult intussusception of the stomach, the small bowel, the appendix, and the large bowel. we report cases of obstructing, subacute, chronic, and even transient intussusception. we highlight the clues to a diagnosis and potential pitfalls. background: abdominal wall is a potential source of many pathologic processes. most of them are secondary to localized or systemic disorders, and primary lesion is uncommon. thus, most of abdominal wall lesion can be clues to the diagnoses of unknown or recurred underlying diseases. ultrasonography is a valuable tool in the initial screening and follow-up study after treatment. therefore, the chances of facing those lesions in us and the importance of recognizing them with a consideration of underlying causes are increasing more and more. imaging findings: in this exhibit, us fi ndings of the spectrum of diseases which are classifi ed into: ) lesion adjacent to umbilicus; metastatic lymph node, urachal cyst, umbilical hernia, collateral vessels, ) lesion associated with surgical incision; incisional hernia, heterotopic ossifi cation of midline incision, metastasis, ) infl ammatory lesion; actinomycosis, abscess, necrotizing fasciitis, ) neoplastic lesion; benign and malignant tumors, ) others will be illustrated with ct and/or pathologic correlations. conclusion: to carefully evaluate abdominal wall lesions is sometimes a great diagnostic clue. gastrointestinal stromal tumours: imaging fi ndings with histopathological correlation s.k. lapsia, s. ramachandra, v. smith, s. ghai, s. ghai; stoke-on-trent/uk (jlapsia@hotmail.com) learning objectives: . recognise the spectrum of imaging features of primary gists with histopathological correlation. . discuss the differential diagnosis of gists. . review the imaging response to imatinib therapy. background: gastrointestinal stromal tumours (gists) are the most common mesenchymal neoplasm of the gastrointestinal tract arising from the interstitial cells of cajal. these cells express a tyrosine kinase growth factor receptor kit (cd ), which has resulted in the advent of targeted molecular drugs such as imatinib. imaging findings: computed tomography (ct) is the imaging modality of choice for the assessment of gists. the majority of gists appears as large exophytic, heterogeneous enhancing masses on ct because of internal necrosis, haemorrhage or cystic degeneration. although, defi nitive diagnosis relies on histopathology, imaging can be suggestive of the diagnosis, and plays an important role in the detection of complications and identifi cation of metastases. differentiation from other primary gastrointestinal tumours can often be made on the basis of these specifi c fi ndings. this exhibit will demonstrate the spectrum of imaging features of gists, their differential diagnosis on imaging, and their behaviour following treatment with imatinib. in this educational exhibit, the typical imaging fi ndings of gists with histopathological correlation are illustrated. differential diagnosis and response to treatment are also reviewed. the importance of imaging in helping to make the diagnosis of gists and in their follow-up after treatment is of increasing importance because imatinib has dramatically improved the survival rates in patients with gists. normal sonographic anatomy of the inguinal canal g. rajeswaran, j. lee, j. healy; london/uk (grajeswaran@hotmail.com) learning objectives: the purpose of this exhibit is to describe the sonographic anatomy of the inguinal canal using ultra-high-frequency sonographic transducers, to aid accurate assessment of disorders involving this region. background: disorders involving the inguinal region can often be clinically diffi cult to assess. the advent of ultra-high-frequency probes has improved our ability to image the inguinal canal. however, a good understanding of the sonographic anatomy is fi rst required to prevent misdiagnosis. imaging findings: in this exhibit, we will document the required sonographic technique as well as common pitfalls encountered, followed by a detailed description and illustration of the sonographic anatomy of the inguinal canal. the structures described include the superfi cial and deep inguinal rings (and their boundaries), the walls of the inguinal canal, the inguinal ligament and the contents of the inguinal canal. conclusion: we have described the ultrasound anatomy of the inguinal canal to enable sonography of this area as a dynamic, non-invasive and inexpensive method of evaluating disorders of this region. retroperitoneal air was not uncommon in duodenal ulcer perforation ( cases). renal infection was also responsible for the presence of pneumoretroperitoneum ( cases) with or without the formation of abscesses. pancreatitis was responsible in patients for the presence of air in the form of abscess or emphysematous pancreatitis. conclusion: trauma is by far the most common cause of retroperitoneal air collections, the second most frequent being perforation of a hollow organ such as duodenum, ascending or descending colon. other conditions may also produce small amounts of retroperitoneal air and they have to be taken into account for a proper diagnosis, especially in diabetics or in immunocompromised patients. activity methods and materials: thirty-four patients with beginning or relapsed ibd underwent us baseline exam and ceus. features of pathological bowel segment at baseline exam were: thickness of the wall more than mm, loss of the echostratifi cation and increase of the vascularization at pwdoppler. after the dynamic study with sonovue, the degree and the pattern of the wall enhancement were evaluated. on the base of these features, the activity degree of the illness has been defi ned as: active, subactive or remittent. the ultrasound data were compared with the clinical activity index: rcp level and clinical symptoms. all the patients were followed up with ultrasound examination (baseline and ceus) in order to evaluate the response to the therapy correlated to the clinical features ( examinations). in the follow-up, reduction of the thickness wall of the vascularization and of the enhancement pattern was considered remission features. learning objectives: to present typical appearances of peritoneal, omental and mesenteric diseases and to narrow the differential diagnosis for each morphological pattern. background: the causes of peritoneal, mesenteric and omental diseases could be divided into four major groups: infectious, infl ammatory, neoplastic, and vascular. the morphological changes in this anatomical region can be classifi ed into three basic patterns: solid well-defi ned masses (including cystic masses), ill-defi ned irregular masses and infi ltrative processes of the mesenteric and omental fat. procedure details: abdominal and pelvic mdct was performed with oral and/or intravenous administration of contrast material. the area between the diaphragmal dome and inguinal ligament was scanned. in each patient, the homogeneity of abdominal fat, the presence, attenuation and enhancement of the intraperitoneal mass, the surface and enhancement of parietal peritoneum, and the presence of mesenteric lymphadenopathy and ascites were analyzed. conclusion: peritoneum, omentum and mesentery can be affected either by primary pathologic conditions, or secondary by direct extension from adjacent organs, lymphatic and hematogenic dissemination, and peritoneal seeding. on the basis of clinical fi ndings and imaging appearance, the broad differential diagnosis of diseases in this region could be signifi cantly narrowed. the possible presence of mesenteric lymphadenopathy, peritoneal thickening and/or ascites can make the fi ndings more conspicuous. learning objectives: to illustrate radiological manifestations of the causes of obscure gi bleeding. to aid the differential diagnosis of gi bleeding. background: up to % of patients with recurrent gastrointestinal (gi) bleeding will remain undiagnosed by standard gastroscopy and colonoscopy. gastrointestinal (gi) hemorrhage is considered obscure when conventional investigations (esophagogastroduodenoscopy and colonoscopy) fail to detect bleeding lesions. on average, % of patients with obscure gi bleeding have small intestinal lesions. the causes of obscure gi bleeding include arterio-venous vascular malformation, angiodysplasia, ectopic varices (duodenal, jejuno-ileal, colonic, and peristoma varices), small bowel lipoma, small bowel stromal tumor, cholesterol crystal emboli, aortoenteric fi stula and radiation enteritis. diagnosing these lesions is frequently diffi cult because they tend to be inaccessible to routine endoscopy. imaging findings: using multidetector-row ct scanner, well-designed barium study, and angiography, we illustrate the various radiological fi ndings of obscure gi bleeding caused by splenic artery pseudoaneurysm, ectopic varices, arteriovenous malformation, and angiodysplasia. the cause of obscure gi bleeding can be detected in many cases by using variable imaging modality such as multislice ct, barium studies, and angiography. imaging features of primary extra-nodal lymphoma: a pictorial review j. quintero, p. puyalto, a. mariscal, c. roqué, i. guasch, a. oriol; badalona/es (jcquintero.germanstrias@gencat.net) learning objectives: the aim of this educational exhibit is to revisit the clinical presentation, classifi cation, distribution and radiological imaging fi ndings of the rare extra-nodal involvement of lymphoma. background: lymphomas are malignant disorders of lymphoid tissues which are subdivided into two broad groups: hodgkin's disease and non-hodgkin's lymphoma. lymphoma classically presents in lymph node sites. extra-nodal involvement may also be due to regional spread of nodal disease or haematogenous dissemination. the classifi cation of lymphoma is complex and still debated. the stage of the disease is classifi ed according to the ann arbor staging system. imaging findings: we reviewed all of radiological reports in the last fi ve years in our institution. we selected the cases with primary extra-nodal lymphoma and they were reviewed by two radiologists who were unaware of radiological fi ndings. we encountered cases of primary extra-nodal lymphoma: thoracic: lung ( ) and pleural ( ); abdominal: gastrointestinal tract ( ), abdominal viscera ( ), urologic and genital tract ( ), peritoneum ( ); musculoskeletal: bone ( ), muscle ( ), skin b d e f a g and subcutaneous tissue ( ); nervous system: brain ( ) and spinal cord ( ); other: salivary glands ( ), breast ( ) and thyroid gland ( ). conclusion: extra-nodal manifestations of lymphoma are greatly diverse and may mimic a variety of both neoplastic and non-neoplastic conditions, depending upon the site of involvement. familiarity with the broad spectrum of primary extra-nodal lymphoma is important for enhancing lesion detection and improving diagnostic accuracy. multimodality imaging plays a critical role in detecting, characterising and staging the disease. ct fi ndings of chronic ambulatory peritoneal-dialysis-related conditions t. ichikawa, t. hashimoto, t. yamashita, j. koizumi, y. imai; isehara/jp (tamaki-i@mars.sannet.ne.jp) learning objectives: to illustrate the ct fi ndings of sclerosing peritonitis (sp) and other conditions related to chronic ambulatory peritoneal dialysis (capd) background: sclerosing peritonitis (sp) is a rare but serious complication of capd. sp is characterized by thickening of the peritoneum that encloses some or all of the small intestine, which could result in bowel obstruction and necrosis. imaging findings: this exhibit illustrates abdominal ct fi ndings of conditions related to capd focusing on sp. other conditions associated with capd are also discussed. we retrospectively reviewed abdominal ct of patients on capd for more than years. findings of sp were peritoneal thickening, peritoneal calcifi cation, located fl uid collections, and small bowel abnormalities. the most serious complication of sp was associated with bowel perforation in case. other conditions such metastatic calcifi cation of soft tissue and joints due to renal osteodystrophy and vascular abnormalities such as atherosclerosis were also well depicted. in addition to axial images, we utilized opitimal multiplanar sections to visualize the entire peritoneal cavity. conclusion: ct is an important tool in the diagnosis of sp and other conditions associated with capd. knowledge of specifi c ct fi ndings of sp will lead to identifi cation of this rare complication of capd, and is benefi cial for differential diagnosis of peritoneal disease. other conditions associated with capd are also excellently depicted on ct. diseases of the mesentery, omentum and peritoneum g. learning objectives: to review the wide range of primary and secondary pathologic conditions that affect the mesentery, omentum and peritoneum. to describe the ct fi ndings of these conditions and to present some rare processes and their specifi c imaging fi ndings. background: the peritoneum, mesentery and omentum are important sources of primary pathologic conditions as well as common sites of secondary involvement from various primary processes. most of these conditions are common, but few others are very rare, and one should be aware of these. ct scan is an excellent tool in detecting disease in these anatomic regions and can be specifi c in diagnosing few of these entities. radiologists should be also aware of very rare conditions affecting these areas. the purpose: the aim of our study was determination of the infl uence of muscles' volume as well as all intraorbital structures' volume for the exophtalamos extend. methods and materials: forty-fi ve patients ( orbits) were the study subjects with the clinically proved exophthalmos in whom the quantity assessment of eye ball muscles, fat tissue and eye ball was carried out using nsi application. nsi, the numerical segmentation image technique, is a new computer software that nearly automatically counts the intraorbital structures volume on the base of mri images. all patients underwent mri examination in . t scanner using head coil. the infl uence of the muscles' volume on the exophthalmos degree was statistically signifi cant: in a clinical method using hertl`s exophtalmometer r= . , p= . in a radiological method in comparison to the interzygomaticus line r= . , p= . e- . the infl uence of all structures' volume on the exophthalmos degree was, respectively, . , p = . e- ; . , p = . e- . conclusion: nsi technique is a clinically useful application providing objective data calculated individually for each orbit. it is justifi ed to use the eye muscles' volume to estimate activity of the pathological processes graves ophtalmopathy. determination of the exophtalamos in a radiological way is more objective than clinically. the , and x-plan radiography to visualize the correct position of the implant. procedure details: the dct scan depicts vibrant site of implant better than x-plan radiography, with lower x-ray dose compared to ct. for cochlear implants, a single x-plan by stenvers projection can directly visualize the electrodes in the cochlea. all patients with brainstem or inferior colliculus implants underwent postoperative ct scan ( hours) to exclude complications, and to assess correct implantation. the follow-up of these implants can be done only by x-plan radiography. conclusion: ct and dct scan could provide a reliable and relatively fast method to precisely determine the location of middle ear implants; we prefer dct in regards to ct because of the lesser x-ray dose administered; a single radiography is enough to visualize and follow-up brainstem or inferior colliculus implants. learning objectives: to outline the specifi c questions to the radiolgist with regard to cochlear implantation. background: cochlear implants are intended for patients with severe to profound sensorineural hearing loss (snhl). successful cochlear implantation depends on a variety of factors, including an intact cochlear nerve and a surgically accessible route for electrode placement. therefore, imaging evaluation consists a major part of the preoperative assessement. procedure details: twenty-eight patients, aged from to years who were candidates for cochlear implants were referred for imaging evaluation. all patients had severe snhl of various causes. high-resolution computed tomography (hrct) scans were performed most on single-detector ct scanner using the classic protocol. mri scans were acquired from a . and tesla scanners with an axial high-resolution two-dimensional or three-dimensional ( d) fast spin echo t -weighted sequence or d gradient echo (ciss or true fisp). non-enhanced and enhanced t -weighted images through the temporal bone and axial fl air images through the brain were taken as well. twenty-four patients had both ct and mr examinations. these were reviewed based on a detailed analysis of known anatomical landmarks and variants related to the procedure. conclusion: ct is superior ino studying the bony structures of the inner ear and middle ear cavity and the course of the fallopian canal for surgical planning, whereas mri is superior in analyzing the soft tissues of the inner ear and the vestibulocochlear nerve. both modalities are equally effective in depicting labyrinth malformations. closed in one patient, anterior chamber was shallow. lens presented an irregular surface in patients and was dislocated in one. hemorrhage was seen in two patients ( vitreous (< %), retina). cts initially read negative were read positive in the retrospective review (lamellar lacerations (ll)); in all, a tiny air bubble was recognised in the cornea or at the sclerocorneal junction. in one of them, a foreign body was recognised. prospectively fractures were diagnosed at ct, retrospectively fracture was not recognised, and was seen only in retrospect. nine patients with orbital fractures had intraorbital air ( extraconal, intraconal, intra and extraconal). conclusion: ct fi ndings in globe trauma are the effect of mechanical impact. radiologists training signifi cantly improved ct accuracy. radiological purpose: the endoscopic surgery of the frontal sinus is confronted with two diffi culties: the nearness of noble organs and the complexity of fronto-ethmoïdal anatomy. the purpose of this work is to clarify radiological anatomy and variants of the frontal sinus and its ways of drainage and to show the importance of imaging in the investigation of this region. methods and materials: patients presenting a sino-nasal infl ammatory disease were investigated between and (complicated acute or chronic sinusitis, mucoceles, sino nasal polyposis). they benefi ted all of a sinus endoscopic exam and a scanning of the facial massif containing an axial study and coronal, sagittal and curvilinear reconstructions in the plan of the fronto-nasal tract. results: imaging in these patients confi rmed diagnoses evoked clinically, permitted the study of complications, notably frontal sinusitis and the exact study of the fronto-ethmoïdal complex anatomy and its ways of drainage. anatomical detailed ct boards and various pathological correlations are presented. conclusion: imaging especially when realized according to a rigorous technique is an indispensable tool in the diagnosis of complications of the frontal sinusitis and in the anatomical study before surgery. results: ct showed a solid unilateral tumour (n= ), or bilateral (n= ), developing with the nasal cavity or paranasal sinuses and extending to the maxillary sinus (n= ), and to sphénoïd and frontal sinuses (n= ). it is associated with bone erosion (n= ) and bone condensation (n= ). mri showed a heterogeneous and lobulated tumour (n= ), and allowed categorizing patients according to the staging proposed by krouse: case of stage , cases of stage , cases of stage , and cases of stage . association with epidermoïde carcinoma was noted in only patient. conclusion: inverted papilloma is a rare benign tumour of nasal cavity and paranasal sinuses. it is locally aggressive. ct and mri assessment can accurately predict the extent of the tumour. preoperative staging by mri may be useful for planning an appropriate surgical approach. other lesions represented images traps for the radiologist gathering the whole of the anatomical structures which can wrongly lend with pathology like a canal confused to a fracture. the anatomical alternatives of the temporal bone to announce to the surgeon are not rare. they are alternatives being able to constitute an embarrassment with the initial surgical way or to predispose to surgical incidents. their knowledge is important for the radiologist and the surgeon to guide and adjust surgical procedure. visualization of ocular motor cranial nerves by d-fiesta f. man, z. wang, y. jiao; beijing/cn (daman @ .com) purpose: to display the oculomotor cranial nerves by mri and to present an update on clinical applications of dominant congenital fi brosis of extraocular muscles (cfeom). methods and materials: mri was performed in volunteers without strabismus and cfeoms on . t mr unit (twinspeed, ge). a head coil was used. . mm thick slices without interslice gap were obtained in axial plane using three dimensional fast imaging employing steady state acquisition (fiesta) sequence without enhancement. oculomotor nerves were observed in oblique-axial and oblique-sagittal planes acquired with mpr. results: both oculomotor cranial nerves (cn ) were demonstrated well in oblique-axial and oblique-sagittal planes in normal subjects ( %) except one. abducens (cn ) of nerves ( %) were displayed in oblique-sagittal planes. trochlear nerves (cn ) of ( %) were showed. different degree hypoplasia of motor nerves, especially cn , was exhibited in cfeoms: all cn s were very thin, in which nerve could be seen normally coursing, not found, and traced superiorly among which coursed to ipsilateral cn . the cn s were strikingly small and normal. the onsets of cn s were shown well and not. conclusion: all ocular motor nerves can be seen in the subarachnoid cisterns by using d-fiesta. this is a precondition for exploiting the diagnostic potential of mr images in cfeoms. magnetic resonance ( fast field echo sequences from the resting position to the position of maximum oral opening. we evaluated signal intensity and morphology, disc position at various degrees of oral aperture, the morphology of the treated condyle, plate integrity, the onset of parotid complications, and the length of the treated mandibular branch in comparison with the healthy side. the follow-up examinations revealed, on the treated side, fi ve cases of anterior dislocations of the disc ( %), one of disc degeneration ( %), one parotid fi stula ( %), and one case of degenerative condylar osteoarthritis ( %). the surgical repositioning of the condyles does not always lead to morphological restoration without late skeletal anomalies. both trauma and surgical intervention can damage the meniscal capsulo-ligamentous containing apparatus. mr allows the identifi cation of complications due to the trauma and/or treatment, and the comparative evaluation of the condyles and joint function. use osteonecrosis and osteomyelitis of the jaws associated with i.v. bisphosphonate therapy for multiple myeloma and metastatic bone cancer: ct fi ndings a. lo casto, f. ganguzza, g. la tona, f. sorrentino, r. restivo, l. solazzo; palermo/it (antoniolocasto@hotmail.com) purpose: the i.v. bisphosphonates are widely used in metastatic bone cancer but in some patients it lead to osteonecrosis and osteomyelitis of the jaws. panoramic radiography and ct with dedicated dental software fi ndings of patients treated with i.v. bisphosphonate therapy for metastatic bone cancer are described. methods and materials: patients ( women and men, age range - years) affected by multiple myeloma ( / patients) or metastatic bone cancer ( / patients) and treated by i.v. bisphosphonate therapy for months to year were submitted to panoramic radiography and ct with dedicated dental software for dental pain and jaw swelling. in / patients, a fi stula in the skin surface of the chin with purulent drainage was also present. results: ct fi ndings in the jaws were: osteolytic area, diffuse hyperdensity of trabecular bone, bone sequestrum, thinning and erosion of cortical bone, periosteal bone reaction. in / patients, a fi stulous tract draining in the skin surface of the chin was also observed in the mandible. in / patient, only the maxilla was involved, in / patients only the mandible was involved and in / patients both jaws were involved. conclusion: ct with dedicated dental software is useful in the detection of osteonecrosis and osteomyelitis associated with i.v. bisphosphonate therapy, allowing a complete assessment of the diseases including the localization of eventual fi stulous tract. the modern ultrasound diagnosis (us) in the combat injuries of eyes v. troyan, k. slobodin; moscow/ru (carina-c@yandex.ru) purpose: the improvement of clinical-and-radiation diagnosis of structural changes in eyes and retrobulbar space after combat injuries. methods and materials: cases of radiation examination for eye injuries occurred during conduct of military operations were analyzed. the ultrasound diagnosis with the help of high-frequency probes by transorbital approach was formed. during investigations, the possibilities of color doppler were used and eye anterior section was examined with the help of water boluses in different modifi cations. results: us method allowed developing the classifi cation groups of eye combat injuries, the us diagnostic syndromes and the radiation examination algorithm. the us high diagnostic informative capacity was noted in differentiation of retinal detachment; vascular tunic and vitreous body; in visualization and topical diagnosis of any intraocular foreign bodies more than mm in size; in diagnosis of intraocular and retrobulbar hemorrhages and their sequelae. it also appeared effective in diagnosis and prognosis of development of infl ammatory posttraumatic changes in the eye based on the analysis of ratio blood fl ow velocity in retinal central artery/orbital artery; the degree of posttraumatic subatrophy and its development; in lens dislocation and change in its transparence. us is the method of choice in cases of "hydrodynamic" rupture of sclera and orbital osteal walls during eye severe contusion and in stab wounds. conclusion: complex us is a universal method for evaluation of structural changes in the eye after combat injuries that can be used for screening, pathologic process verifi cation under conditions of multi-purpose institution and for dynamic follow-up of treatment results. purpose: compare image quality of sinonasal cavities scans obtained with standard radiation dose and % reduced radiation dose with a -detector row ct scanner. the study includes forty patients referred to multislice ct (msct) scan of the sinonasal cavities for suspected chronic sinusits. twenty patients underwent msct examination at standard dose using the following protocol parameters: x . mm detector confi guration, . : pitch, mas, kv and . mm slice thickness. ct scan were obtained in the other twenty patients with half radiation dose by using a pitch of . : . in all patients, . mm axial and coronal images were reconstructed from raw data. all ct scans were reviewed by a neuroradiologist who evaluated, with a three-point quality scale, several anatomical structures and infl ammatory mucosal changes. the graded differences between the two protocols were evaluated using a t test. results: reduced dose scans were performed with a ctdivol of mgy. no signifi cant image quality differences were observed between the two groups of patients. conclusion: dose-reduced msct helical examinations of the sinonasal cavities can be obtained using . : pitch and mgy ctdivol without signifi cant image quality loss. the presence of fi brovascularized area at the level of the equator of the partially wrapped porous ptfe sphere is revealed in patients and was associated with the reduction of si from this zone on t -wi. depth of germination was - mm. porous ptfe does not create any artifacts that allow to differentiate surrounding orbital structures − ocular muscles, optic nerve and orbital fat. magnetic resonance studies seem to be the best-suited imaging modality for assessing the fi brovascular tissue progression into porous ptfe spheres after enucleation and for identifying patients in whom vascularization has failed. preventing fess from turning into a mess: role of the radiologist d. ganeshan , c. barwick , n. purpose: the usefulness of i-imp for the diagnosis of orbital malignant melanoma is well recognized, but the estimation of the uptake is sometimes diffi cult because the images acquired hours after injection may be so faint that the roi we draw becomes arbitrary. we evaluated a new semiquantitative procedure to estimate more easily and objectively the uptake of i-imp in patients with orbital malignant melanoma. methods and materials: first, we obtained the normal mri image of the brain, standardized by the fusion software included in neurostat. the standard rois were determined from the several slices for the orbit, and then they were adjusted to the standardized spect image of the i-imp. the uptake was calculated by voiclassic including the neurostat system. twenty patients with orbital tumor were assessed. we compared the uptake of the affected side of the orbit. retention index was calculated with decay correction. retention index= (delayed ratio-early ratio)/early ratio x (%). results: it was possible to distinguish the melanoma from the other orbital tumors without the fusion image of the co-registered mr and spect images. when we set the cut-off level at ri≥ , sensitivity was . %, specifi city was . %, and accuracy was . %. conclusion: semiquantitative parameters calculated by voiclassic including the neurostat system are useful and provide an objective method for the diagnosis of orbital malignant melanoma. learning objectives: to establish the key radiologic fi ndings to enable the differential diagnosis between craniofacial involvement of paget disease and of fi brous dysplasia. background: paget disease and fi brous dysplasia are bone disorders, with frequent craniofacial involvement, in which imaging studies play a very important role in orienting the diagnosis and planning appropriate surgical treatment. fibrous dysplasia is a skeletal developmental anomaly of the bone-forming mesenchyme that usually affects young people, with craniofacial involvement in up to one third of the cases. paget disease is a bone formation/resorption disorder that normally affects people over years of age, with craniofacial involvement in up to % of cases. like fi brous dysplasia, paget disease can present different radiologic patterns in function of the stage of the disease. imaging findings: we reviewed cases of paget disease and fi brous dysplasia with bone involvement on craniofacial ct seen in our hospital. the key features to consider in the differential diagnosis between craniofacial involvement due to paget disease versus fi brous dysplasia are: a) whether or not bone involvement is symmetrical, b) whether or not it crosses sutures, c) the bone pattern, and d) the presence or absence of disease in the paranasal bones. we determined the key imaging fi ndings to enable the differential diagnosis between paget disease and fi brous dysplasia on the basis of density, involvement, and distribution of the lesions. learning objectives: to understand the pleomorphic presentation of retrobulbar hematomas, occurring after cranio-facial trauma, the radiologic techniques to investigate them, and the principal features useful to achieve the differential diagnosis. background: retrobulbar hemorrhagic lesions can be classifi ed in two groups: intraorbital hematoma and subperiosteal hematoma. subperiosteal hematomas represent a rare but well-defi ned clinical entity; they are more frequently seen in children, due to the loose adhesion of periostium in these patients, which can be easily detached from orbital bones by a hemorrhagic mass, with resultant proptosis and compromise of the optic nerve. infrequently, this kind of retrobulbar hemorrage can be associated to the presence of an extradural intracranial hematoma; and this condition is known as a real diagnostic and therapeutic emergency. diagnosis relies on computed tomography (ct) and magnetic resonance (mr). imaging findings: anatomy and radiologic anatomy; classifi cation; mr and ct features; cases series. conclusion: ct and mr allow a correct classifi cation, and provide critical information to the surgeon for mandatory treatment. correlation between multiplanar reconstruction sections and threedimensional ct images of the normal temporal bone n. fujii, y. inui, k. katada; toyoake/jp learning objectives: to demonstrate three-dimensional ct ( d-ct) images of the whole temporal bone, the mastoid cavity, the tympanic cavity, the auditory ossicles and the inner ear. to correlate multiplanar reconstruction (mpr) sections in various angles with d-ct images. to identify four specifi c sections of the ossicles, the images of which are reconstructed to allow viewing of the ossicular chain. background: recent advances in multislice ct (msct) have made it possible to obtain high-resolution isotropic volume data, allowing us to generate d-ct images of the temporal bone, in which small structures and intricately shaped ossicles are depicted clearly. furthermore, we have been able to reconstruct two-dimensional ( d) sections of the temporal bone, even the ossicles, from any desired direction with mpr without diffi culty. therefore, it has become possible to recognise an object that has small and complicated structures with d- d correlation. procedure details: mpr and d-ct source data from a volunteer were acquired by a . -mm, -row msct system, using a unique high-resolution image reconstruction algorithm. mpr sections showed conventional axial, coronal planes and four specifi c sections of the ossicles, which we have identifi ed for the purpose of viewing the ossicular chain. each structure has been indicated on both mpr and d-ct images and correlated with each other. conclusion: high-resolution mpr and d-ct images with msct depict the complicated anatomy of the temporal bone. d- d image correlation and recognition helps to deepen understanding of conventional d sectional anatomy, and to identify the optimal section for observing a given object. on the lower compartment, the anterior was cochlea nerve foramen which had spiral shape, and the posterior was inferior vestibular nerve foramen. the position of single foramen is uncertain, usually located on in-posterior of iac fundus. in abnormal group, ears were shown as iac fundus disorder and foramina absent, only foramen was shown in ear, foramina in ears, foramina in ears, foramina in ears; abnormal shape of cochlear nerve foramen was seen in ears, spiral shape disappeared completely in ears, small round shape was shown in ears. conclusion: three dimensional imaging can improve the understanding and comprehension of iac fundus. ctve is useful in showing the normal structures and pathological changes of iac fundus. establishment of normal cochlea measurements on standard hrct images to aid diagnosis of cochlea hypolasia g. wuxian, g. ruozhen, c. baoting, w. min; jinan/cn (grz @yahoo.com.cn) purpose: to establish normal measurements of cochlea on standard position images using mpr of hrct to aid diagnosis of cochlea hypolasia. methods and materials: hrct scanning of temporal bone was undergone in volunteers ( ears). the images of all cases were postprocessed using mpr. two standard images (position i and ii) were reconstructed and structures of cochlea (named a-i) were measured. statistical analysis was done on different age groups, male and female groups, left and right groups in spss program. normative data of measurements were established. measurements of cochlea were also done in cases ( ears echo-planar diffusion-weighted mr imaging in the detection of cholesteatomas t. kodama, t. yano, s. tamura; miyazaki/jp (tkodama@med.miyazaki-u.ac.jp) purpose: to evaluate a single-shot echo-planar diffusion-weighted magnetic resonance imaging (mri) (epi-dwi) in the diagnosis of cholesteatoma in comparison with a single-shot fast advanced spin-echo sequence (fase-dwi). twenty-one patients with a primary or postoperative recurrent cholesteatoma were examined by epi-dwi and fse-dwi in addition to standard mri such as t -and t -weighted imaging. epi-dwi was performed by using parallel imaging with a reduction factor of two. because of its higher signalto-noise ratio (snr), epi-dwi was obtained with a thinner slice thickness and a higher spatial resolution than that of fase-dwi. image quality of epi-and fase-dwi was judged from: ) contrast of the lesion, ) image distortion and abnormal signal secondary to susceptibility artifacts, and ) anatomical correspondence with other images. results: a cholesteatoma was correctly identifi ed as an area of obvious hyperintense signal on epi-dwi and fase-dwi in / ( %) and / ( %), respectively. among the six lesions that were missed on epi-dwi, fi ve lesions were smaller than mm. in patients whose cholesteatoma was correctly diagnosed on the epi-and fase dwi, snr of the cholesteatoma and cerebellum, and contrastto-noise ratio of the cholesteatoma to the cerebellum was not signifi cantly different between the both sequences. image quality of epi-dwi was judged inferior to that of fase-dwi in patients mainly because of susceptibility artifacts. conclusion: to use epi-dwi sequences for evaluating middle ear cholesteatomas, susceptibility artifact is still the problem that should be resolved despite the application of parallel imaging. high-resolution computed tomography evaluation of congenital anomalies of the external auditory canal and middle ear a. skorokhoda; kyiv/ua (rdcams@svitonline.com) purpose: congenital anomalies of the external auditory canal are rather common. the degree of congenital deformities runs from total atresia to hypoplasia or stenosis of the eac, to microtia. embriological development of the eac and middle ear is linked so dysplasias are usually combined. we present the experience of patients examination with external auditory canal and middle ear dysplasias from to years. in all cases we used high-resolution ct on somatom plus (siemens, germany) in axial and coronal planes. the study included cases of bilateral atresia ( -bony atresia, -membranous atresia, -atresia of external auditory canal with ossicular deformities and hypoplastic mastoids). unilateral atresia was found in cases: -bony eac atresia; -eac atresia with normal sized middle ear; cases had ossicular deformities but normal mastoids, unilateral atresia cases had ossicular deformities and hypoplastic mastoids, thick atresic plate and no ossicles was found in cases. small tympanic cavities were in cases. mandibular condyles were displastic in unilateral cases. stenosis of eac occurred in unilateral and bilateral cases. combined inner ear mondini deformity was found in case. anteriorly located descending facial nerve canal was noted in cases. conclusion: high-resolution computed tomography is the most important preoperative test in patients with congenital aural atresia and evaluation of the changes in middle ear, otic capsule, ossicles, mastoids, temporo-mandibular joint, facial nerve canal for providing reconstructive and cosmetic operations. although it has been described as a "relatively common" benign neoplasm, study of the literature reveals that the incidence is not very high. it is a slow growing, vascular lesion seen more often in middle age females. usually it is not detected until an imaging study is performed for other reasons. although oca is histologically benign, it can displace intraorbital structures, and cause optic nerve compression or increased iop. painless, gradually progressive proptosis and visual disturbance are the main clinical signs. imaging findings: ultrasound when performed will reveal a smoothly marginated round or oval, hypoechoic lesion with presence of internal fl ow with color-doppler. computed tomography demonstrates a hyperdense intraconal lesion, with marked homogeneous contrast enhancement. commonly orbital bone expansion is seen. calcifi cation is rare. in magnetic resonance imaging, the lesion appears isointense to muscle on t w and hyperintense on t w . it displaces the optic nerve without infi ltrating it. the iv administration of contrast material causes enhancement of the lesion. conclusion: knowledge of the radiological appearance in cases of oca is mandatory for its correct characterization, thus, facilitating optimal treatment. head and neck background: diffusion-weighted imaging is a new imaging modality, which has signifi cant role in the brain and, recently, in the head and neck. procedure details: diffusion-weighted mr imaging was done for patients with head and neck tumor using single-shot echo-planar imaging with reconstruction of apparent diffusion coeffi cient (adc) map. diffusion-weighted mr imaging plays a role in differentiating benign from malignant head and neck tumors, and helps to select the site for biopsy. also, it can be used for differentiating metastatic from reactive lymph nodes and characterization of thyroid nodules. the adc value gives an idea about cellularity of the tumor that correlates with prognosis. after treatment, it can be used for differentiating recurrent tumors from post-treatment changes. conclusion: diffusion-weighted mr imaging can help in discriminating malignant head and neck tumor from benign lesions,and is used for characterization of cervical lymph nodes. also, it has a role in follow-up of head and neck cancer patients after treatment and prediction of outcome. purpose: to report change of diffusion-weighted imaging (dwi) of malignant melanoma in head and neck after carbon-ion radiotherapy. eighteen patients having malignant melanoma in the head and neck regions undertook carbon-ion radiotherapy at the national institute of radiological sciences, chiba, japan. we examined the patients using the dwibs (diffusion-weighted imaging with background body signal suppression) method before and after the treatment. adc (apparent diffusion coeffi cient) value was measurable in of cases (mean age: yrs, age range: - , males and females). we compared the adc value obtained before the treatment with the one obtained after the treatment. intera achieva . t nova dual system (philips medical) was used for the examination. the epi-based diffusion-weighted imaging sequence with spir fat suppression was applied at the settings of b-values, namely and sec/mm , respectively. results: average adc value for all clinical cases were . × - (s.d.: . × - ) at pre-treatment and . × - (s.d.: . × - ) at post-treatment. adc values increased in of cases and decreased in case. there was a signifi cant difference in adc value between pre-and post-treatment (p < . ). conclusion: dwibs examination for malignant melanoma in the head and neck showed signifi cant increase in adc value after carbon-ion radiotherapy. the adc value has the possibility of becoming a criteria when we judge the effect of the carbon-ion radiotherapy in malignant melanoma. learning objectives: to identify those patients who will benefi t a specifi c imaging study to rule out vascular lesions in the head and neck region. to describe the radiologic fi ndings and more frequent locations of these traumatic lesions. to establish which are the optimal imaging techniques to confi rm the presence of a vascular lesion and to characterize them. background: vascular lesions of the head and neck region are a clinical emergency with important morbidity and mortality, and appear frequently in polytraumatized patients who are diffi cult to evaluate. a high suspicion index is required and prompt realization of modern imaging studies is critical for an accurate and rapid diagnosis. imaging findings: we review the radiologic appearance of the main traumatic vascular lesions: arteriovenous fi stula, occlusion, dissection, pseudoaneurysm, and transection. we point out the locations where one should search for these lesions. we analyze the results of the different imaging techniques. conclusion: ct angiography (cta) and mr angiography (mra) allow prompt and accurate diagnosis of traumatic vascular lesions, which is crucial in the prognosis of these patients and ensures their correct management. conventional angiography remains the gold standard for the confi rmation of these lesions and enables an endovascular treatment, but is costly and not optimal as a screening technique, and is not exempt of serious neurologic complications. the use of non-invasive techniques (cta and mra) for the initial assessment of vascular lesions is growing rapidly. these techniques offer several advantages: they are non-invasive, less resourcedependent, and allow simultaneous evaluation of extravascular structures. effi ciency of ultrasonic elastography in the differential diagnosis (metastatic or reactive) of the enlarged cervical lymphnode f. alam, k. naito, t. tachikake, j. horiguchi, h. fukuda, h. yasutomi, n. hirai, k. marukawa, k. ito; hiroshima/jp (falam @yahoo.com) purpose: evaluation of ultrasonic elastographic appearance of enlarged cervical lymph nodes and exploration of the diagnostic reliability in differentiating between metastatic and reactive cervical lymphadenopathy. methods and materials: realtime elastography of enlarged cervical lymph nodes ( metastatic, reactive) from patients ( men, women; age range: - years; head-neck cancer, having no malignancies) was performed. all the lymph nodes were evaluated for distribution and the percentage of stiff areas. then they were classifi ed using a -pattern system ( - ). pattern : stiff areas occupying the whole or almost whole lymph node (ln) with or without a thin rim of peripheral relatively soft areas. pattern : same as pattern with central relatively soft areas. pattern : stiff areas occupying more than % of the ln. pattern : stiff areas occupying not more than % of the ln. pattern : small stiff areas scattered into relatively soft area of the ln. the cutoff line for metastatic lesions was set between and . patterns to were considered malignant and and were considered reactive. histopathological results and clinical fi ndings (including ct fi ndings) were considered as reference standard for analysis of elastographic fi ndings. results: sensitivity, specifi city, positive predictive value, negative predictive value and accuracy were . %, %, %, . % and %, respectively. conclusion: ultrasonic elastography showed excellent performance in the diagnosis of metastatic cervical lymphadenopathy. due to high specifi city of this method, invasive procedures might be reduced when ultrasonic elastographic result is positive for lymphnode metastasis. gnathic bones ( odontogenic tumors are composed of cellular constituents whose primary purpose is to form teeth or toothrelated structures (odontogenesis). numerous lesions can affect the gnathic bones, including odontoma (compound and complex), ameloblastic fi bro-odontoma, calcifying odontogenic tumor (pindborg tumor), odontogenic myxoma, cementoblastoma (cementoma), ameloblastoma, odontogenic keratocyst, and dentigerous cyst. the diagnosis of these processes can be tricky because of non-specifi c imaging features, atypical clinical presentation, and lack of familiarity with certain abnormalities. imaging findings: radiography, the modality most often used for initial evaluation, can be helpful for detecting cortical destruction. however, ct is more sensitive than radiography for detecting calcifi ed tumor matrix and cortical destruction. ct also provides delineation of the anatomic extent of the lesion, and can guide biopsy. in addition to imaging fi ndings, patient history, physical examination and histologic analysis are required to reach the correct diagnosis. the morphologic characteristics of odontogenic tumors and other lesions of the gnathic bones provide key diagnostic clues regarding the aggressive or non-aggressive behavior of the disease process. awareness of the radiologic presentations of abnormalities helps formulation of the most likely diagnostic choices. gnathic bones ( background: odontogenic tumor-mimicker lesions (non-odontogenic lesions masquerading as odontogenic lesions) may further complicate diagnosis. in the gnathic bones, a group of such lesions includes paget's disease, brown tumor, infl ammatory disease, aggressive infantile fi bromatosis, cleidocranial dysplasia, fi brous dysplasia, leukemia, multiple myeloma, maxillary sinus carcinoma, juvenile angiofi broma, and metastatic disease. although several of these conditions share some clinical, radiologic, and pathologic characteristics, they do have very different treatments and prognoses. imaging findings: although the imaging features of many lesions mimicking odontogenic tumors are non-specifi c, knowledge of the typical radiologic manifestations of odontogenic tumor-mimicker lesions often enables their differentiation from odontogenic tumors, and occasionally allows a specifi c diagnosis to be suggested. osseous expansion, an aggressive characteristic, may occur with non-malignant conditions, such as paget's disease. similarly, a rim of bone sclerosis around a lesion is a non-aggressive characteristic that, in rare circumstances, is present in malignant neoplasms. furthermore, local infl ammation is frequently associated with poorly demarcated osteolysis and periostitis, fi ndings that resemble those of a malignant tumor. conclusion: although aggressive lesions are commonly malignant and benign tumors are commonly non-aggressive, this is not uniformly true. consideration of certain imaging fi ndings of a lesion within the gnathic bones can narrow the broad differential diagnosis. evaluation of radiation damage to the microstructure of the parotid gland using mr microscopy t. kan, k. kodani, s. fujii, t. ogawa; yonagoshi/jp (jpfdt @yahoo.co.jp) purpose: radiotherapy for head and neck cancer traditionally includes large parts of the parotid gland in the radiation fi eld and often leads to distressing oral complaints. the aim of this study is to elucidate the radiation damage to the microstructure of the parotid gland using mr microscopy. this study comprised normal subjects without parotid disease and patients treated with radiotherapy for head and neck cancer. mean dose to the parotid glands included in the radiation fi eld was . to . gy (median: . gy). mr imaging was performed using a mm microscopy coil before and after radiotherapy. axial fat-suppressed t -tse images were obtained with a . t scanner. we assessed the radiation damage to the parotid parenchyma and duct using imagej (version . software program). the thickness of the parotid duct wall in the normal group was . to . mm (mean: . mm). in irradiated patients, thickening of the duct wall was observed ( . - . mm, mean: . mm) after radiotherapy. the difference of the wall thickness was statistically signifi cant (p < . ). in normal subjects, reticular pattern refl ecting the microstructure in the gland parenchyma could be clearly visualized, while thickening of the reticular pattern and atrophy of the gland parenchyma were observed in the radiotherapy group. conclusion: mr microscopy allows us to evaluate not only the volume reduction and signal intensity changes of the parotid gland, but also the microstructure of the gland parenchyma, thereby refl ecting the histopathological changes following radiotherapy. multi results: on both mcta and color duplex imaging, carotid body paraganglioma was characterized as highly hypervascular lesions, with anteromedial dislocation of the external carotid artery in cases and posterolateral dislocation of the internal jugular vein in cases. the duplex spectrum in the contributing external and internal carotid arteries showed a high fl ow and low-resistance pattern. in schwannomas and neurophibromas, vessel invasion had not been identifi ed, but close ring enhancement was revealed. on cds, tumor was revealed as hypovascular lesion with high-resistance pattern. neurogenic sarcomas were characterized as hypervascular tumors with invasion in internal jugular vein in four cases, while the distal part of the common carotid artery and its bifurcation could not been identifi ed in three cases. in all cases, intralesional fl ow and tumor relationship with adjacent vessels detected by cds and scta correlated well with the intraoperative fi ndings. conclusion: mcta and cds are an accurate diagnostic method for the precise evaluation of neck tumors. the methods provide valuable preoperative information regarding tumor vascularity and neck vessel compression or invasion. gnathic bones ( imaging findings: conventional (anteroposterior, lateral, and oblique), intraoral dental, and panoramic radiographs remain the mainstay in the assessment of osseous lesions involving the gnathic bones. ct and mr imaging provide further characterization of the intrinsic features of lesions affecting the ganthic bones and allow determination of the extent of involvement of the dentomaxillofacial complex and paranasal sinuses. principles of imaging interpretation include evaluation of the lesion location within the maxilla or mandible, shape, size, and rate of growth, pattern of bone destruction, demarcation, tumor matrix, septation, osseous expansion, cortical erosion, periosteal reaction, relationship of lesion to the adjacent tooth structures and sinuses, associated soft tissue mass, and marrow edema. conclusion: recognition of the key imaging fi ndings of non-odontogenic tumors and tumor-like lesions affecting the maxilla and mandible, combined with clinical evaluation and results from histopathology suffi ce for correct diagnosis. establishment of defi nitive diagnosis can help the surgeon avoid undue extensive or unnecessary surgery. were pathologically proven to be pleomorphic adenomas. the wide range of imaging fi ndings will be discussed. conclusion: all palpable tumors in this series were greater than mm on presentation and most of tumors were unilateral and involved the superfi cial lobe of the parotid (over %). although pleomorphic adenomas had a wide range of size, heterogeneity, and enhancement characteristics, most tumors demonstrated a capsule with circumscribed borders. recognizing the pleomorphic adenoma may avoid unnecessary surgery. results: after administration of sonovue ® , malignant nodules showed absent ( / ), faint dotted ( / ) and diffuse contrast-enhancement ( / ); in this latter case inhomogeneous ( / cases) or homogeneous ( / ). benign nodules showed diffuse contrast-enhancement, both homogeneous ( / ) or heterogeneous ( / ). quantitative data confi rmed subjective fi ndings but ceus never modifi ed precontrast analysis. conclusion: ceus of thyroid gland is a feasible technique but overlapping fi ndings seem to limit the potential of this technique in the characterization of thyroid nodules. the comparative diagnostic yield of freehand versus ultrasound guided fi ne needle aspiration of thyroid nodules r. davis, m. rogerson, i. britton, j. oxtoby; stoke-on-trent/uk (robmdavis@hotmail.com) purpose: despite the risk stratifi cation provided by ultrasound and nuclear medicine, histology is the only discriminator of benign from malignant thyroid nodules. the method of obtaining cytology locally is hybrid, both freehand and ultrasound guided. the aim of this study was to determine which is the most successful at providing an early diagnosis. methods and materials: one hundred and ninety nine consecutive patients undergoing thyroid fi ne needle aspiration (fna) during a two year period (july -july ) were included in a retrospective review. cytology was classifi ed as: ( ) diagnostic or ( ) non-diagnostic by a cytologist. freehand accounted for % ( / ) of samples, whilst the remaining % ( / ) were obtained by ultrasound guidance. results: diagnostic samples were obtained in % ( / ) of patients. this corresponds to a diagnostic yield of % ( / ) in the freehand fna group compared with % ( / ) in the ultrasound guided fna group. comparison of predicted versus observed events was performed with a chi-squared statistic of . (p < . ). conclusion: obtaining cytology by an ultrasound guided method is statistically signifi cantly more successful (p < . ) and should be the primary diagnostic technique in avoiding a delay in diagnosis. ct scans were obtained before and after the contrast medium administration (delay of and sec), with a thickness of . mm, and a reconstruction interval of . mm. ct fi ndings were compared to surgical results. results: ct examination resulted positive in cases, negative in cases and doubtful in cases. / patients underwent surgery: surgery identifi ed lesions ( adenomas, primary hyperplasia); in cases surgery was negative, while in cases the lesions interested an ectopic parathyroid gland. surgery confi rmed ct evaluation in / positive cases; in / doubtful cases, surgery confi rmed the location of the lesion in cases, in cases the lesions resulted to be ectopic, while in case surgical exploration resulted to be negative. in / cases with negative ct fi ndings, surgery identifi ed the lesion in cases, while case resulted to be negative. the sensitivity and specifi city values results were % and %, respectively, with a diagnostic accuracy of %. conclusion: multidetector ct is an accurate second-level diagnostic technique in the detection of a parathyroid lesion, allowing the exploration of the entire cervical and mediastinal regions. radiologic . % of patients showed benign cytologies and . % malignant disease. cases ( . %) were indeterminate (follicular proliferation). on pet studies, % of the lesions showed positive uptake (suv max: . - ). since there was an uptake overlap between benign and malignant lesions, all lesions with positive uptake underwent us-fna. three out of cases with fi ne needle aspiration and biopsy proven malignancies had negative pet studies. nineteen benign lesions showed positive uptake (highest value suv max: ). in our series, the incidence of primary thyroid cancer in patients with previous history of malignancy was % and for breast cancer patients it was %. conclusion: us guided fi ne needle aspiration is a useful method for characterisation of thyroid lesions with a positive pet result. the absence of uptake does not exclude malignancy. patients with previous malignancies, specially breast tumours, with positive pet results have greater incidence of thyroid malignancy. sonographic purpose: to evaluate pretracheal, jugular and paratracheal lymph nodes enlargement at us in patients affected by occult or chronic thyroiditis in active phase. we selected patients who underwent neck high resolution sonography and color doppler. patients were divided into groups: a group: patients ( %) suspected of chronic thyroiditis in active phase; b group: patients ( %) with clinical history of thyroiditis; c group: patients ( %) with positive familiarity of thyroid pathology. in addiction, we considered the thyroid hormones and antibody titers, classifying four levels of gravity: normal (i°), low high (ii°), high (iii°), more high (iv°). results: a group: % showed antibody titers (iv°) and sonographic characteristics of cronic thyroiditis in active phase, with pretracheal ( %), jugular ( %), and paratracheal ( %) lymph nodes reactive enlargement. % showed antibody titers (iii°) and only pretracheal ( %) and jugular ( %) lymph nodes enlargement at us. b group: all patients had antibody titers (ii°-iii°) and sonographics chronic thyroiditis characteristics, with pretracheal ( %), jugular ( %) e paratracheal ( %) lymph nodes lipomatous enlargements. c group: % was negative from clinical-strumental point of view, while % had antibody titers (i°-ii°) and and only pretracheal ( %) and jugular ( %) lymph nodes reactive enlargement at us. the ultrasound evidence of neck lymph nodes enlargements, especially pretracheal, appears to be a very useful us sign of subacute or chronic thyroiditis. colour background: sonography is the main imaging tool in the assessment of patients with thyroid nodules. malignant thyroid nodules show a variety of doppler patterns that should be known in order to prompt further evaluation (cytology). procedure details: malignant nodules usually appear hypervascular, although hypervascularity is not specifi c for malignancy. conversely, absence of vascular signal is highly predictive of benign nature. a complete vascular halo around a nodule is highly predictive of its benign nature. absent vascular halo and intranodular vascularity are not specifi c for malignancy, but a combination of absent halo, microcalcifi cations, and intense fl ow is signifi cantly specifi c for its malignant nature (although insensitive). spectral analysis has a limited practical value. lymph nodes, node-to-vessel relationship, and jugular vein thrombosis can be evaluated. lymph nodes usually demonstrate peripheral vascularization with irregular signal distribution and alternated hypervascular and hypovascular intranodular areas. conclusion: cd and pd imaging has a signifi cant additional role in the us assessment of thyroid cancer and of metastatic cervical lymph nodes. troisier sign (left-sided supraclavicular metastatic lymph node): an old but still possible presentation sign of chest and abdomen tumours f. all parotid gland tumors were histologocally confi rmed: pleomorphic adenomas, warthin's tumors, lymphoepithelial cysts, schwannoma, adenoid cystic carcinoma, small cell carcinoma, salivary duct carcinoma with pleomorphic adenoma, and myoepitheial carcinoma. we obtained axial and coronal t -weighted, t -weighted and gd-t -weighted images. we tried to evaluate prospectively tissue characterization of the parotid gland tumors and also to analyze the relationship of the tumors to the facial nerve. after the surgical resection of the tumors, we performed mr-pathologic correlation and confi rmed the relationship of the tumors to the facial nerve. results: from the mr-pathologic correlation, we could perform tissue characterization of the tumors. this information was useful for the differentiation of parotid tumors. in all cases, except for a few patients with large tumors, primary branches of intraparotid facial nerve were clearly identifi ed. conclusion: high-resolution mr images obtained by mr microscopy using tesla mri is quite useful for differentiating parotid gland tumors and preoperative planning of surgical approaches for parotid gland tumors. preoperative localization of hyperfunctioning parathyroid glands using c- methionine pet: a comparison with f-fdg pet and m tc-mibi scintigraphy h. wakamatsu , s. nagamachi , s. fujita , k. kamimura , r. nishii , s. futami , s. tamura ; kiyotake-cho/jp, miyakonojo/jp purpose: preoperative localization of hyperfunctioning parathyroid glands in patients with hyperparathyroidism (hpt) is important. previously, we reported a direct comparison study using m tc-sestamibi (mibi), m tc-tetrofosmin, and tl. in our previous study, m tc-mibi and m tc-tetrofosmin were equally useful and they were more useful than tl. recent reports have shown the usefulness of cmethionine positron emission tomography (pet), but the role of c-methionine is not well known. we directly compared the detectability for localization of abnormal parathyroid glands using c-methionine pet, f-fl uorodeoxyglucose (fdg) pet and dual-phase m tc-sestamibi (mibi) scintigraphy to clarify the usefulness of c-methionine pet. methods and materials: seven patients ( men and women), primary hpt and secondary hpt, were evaluated. we performed c-methionine pet, f-fdg pet, and dual-phase m tc-mibi scintigraphy on all patients and directly compared the detectability. they were operated and confi rmed histologically. results: in patients with primary hpt ( adenomas), patients ( . %) were correctly localized by c-methionine and dual-phase m tc-mibi scintigraphy. but f-fdg pet could detect only of the patients ( . %). in patient with secondary hpt, c-methionine pet and dual-phase m tc-mibi scintigraphy could detect of the abnormal hyperplastic parathyroid glands ( %), but f-fdg pet could not detect abnormal parathyroid glands. conclusion: in our preliminary study, c-methionine pet and dual-phase m tc-mibi scintigraphy are equally useful for localization of hyperfunctioning parathyroid glands, but f-fdg pet is not satisfactory for the localization of hyperfunctioning parathyroid glands. purpose: we study peripheral lymph (cervical, axillary and inguinal) nodes features in order to differentiate malignant adenomegalies from hypertrophic-reactive nodes. methods and materials: we practised high resolution ultrasonography with . - mhz lineal probes in patients ( women and men). the ages ranged from - years (mean age . years). results: nodes were observed, with benign and malignant nodes. benign nodes ( . %) had oval shape (vasallo index ≥ . ) and echogenic centre. benign nodes ( . %) were oval, without central refringence. nodes ( %) had kidney-like shape with echogenic centre. benign nodes ( . %) showed central arterial signal associated with intranodal vascular branching. nodes ( %) showed central vascular signal alone. in nodes ( . %) there was low resistance (ir< . ) arterial signals and nodes ( . %) showed high resistance doppler signals (ir ≥or . ). malignant lymph nodes ( . %) appeared rounded (vasallo index < . ) without central echoes, heterogeneous and hypoecoic. nodes ( . %) were kidney-shaped, hypoechoic. nodes ( . %) were rounded, with eccentric echoes. malignant nodes ( . %) showed lateral vascular signals without central vascular signals; in nodes ( . %) a central vascular signal was recorded. malignant nodes ( . %) showed high resistance vascular signals. in adenopathies ( . %) the arterial signals were of low resistance. there was no doppler signal in malignant nodes ( . %). neoplastic nodes ( . %) showed vascular intranodal branching. conclusion: we can combine morphologic and vascular nodal features to differentiate accurately between malignant lymph nodes and hypertrophic-reactive nodes. us fi ndings in loco-regional metastasis from malignant melanoma a. cuñat, e. ponce, a. julve, m. pina, v. perez, e. belloch; valencia/es (acunat@telefonica.net) purpose: we describe the us fi ndings in lesions secondary to malignant melanoma. the lesions were located near the place of excision of the primary melanoma or in the fi rst lymphatic region. methods and materials: patients were included from march ' to march ' . the ages ranged between - years (mean age years). all the patients had their malignant melanoma resected - months before the us exam. we practised high-resolution us with . - mhz probes. we observed rounded-oval, solid lesions and fl uid-fi lled nodules. lesions were hypoechoic and one had muscle-like refringence. ( %) lesions were located inside subcutaneous fat over the surgical scar or at a distance - mm from the scar ( nodes). the diameter of the lesions ranged from - mm for the non-palpable nodes ( lesions, %), and . - mm for the palpable ones ( nodes, %). four lesions ( %) showed irregular vascular doppler signals, located in the periphery of the nodes, two with arterial low-resistance spectra, one with high resistance arterial spectra and one with venous fl ow. the remaining nodules did not showed vascular signals. conclusion: us examination of the surgical scar and fi rst lymph node station should be included in the screening for metastasis in patients with malignant melanoma excised. the non-palpable lesions are easily detected. venous chest port implantation in pediatric patients e. akgul, t. : ) and ranged between and days. six ( . %) patients died while ports were still being used. in the follow-up period, complications were encountered in ( . %) patients. in patient, port was extracted because of infection in the fourth month. in another patient, incision of port pocket was resawn because of separation. in patients, the needles could not be inserted into ports because the port base was turned upside down. in these patients, the ports were rotated to normal position manually. conclusion: in pediatric patients, implantation of subcutaneous venous chest ports should be preferably placed under imaging guidance by an experienced interventional radiologist because of the higher technical success and lower complication rates. transarterial embolization for the treatment of benign prostatic hyperplasia: a preliminary study on technical feasibility and safety in pigs sixteen large white adult intact male pigs were randomized into groups: embolization (n = ), control (n = ). under general anesthesia, all animals underwent selective angiography on both sides. in animals of the group embolization, embosphere ( - µm) was used to embolize the prostatic branches. three months later, the animals in both groups, except one from group embolization with lameness of a hind limb, were evaluated on sexual function by breeding with adult female pigs. sexual function of the male pigs was subjectively evaluated by assigning - points. the animals were sacrifi ced following the sex test and the prostates were removed for pathological study. results: technical success was obtained in all animals that received embolization; no associated complication was observed. compared with those in the group control, the prostate size was signifi cantly reduced after embolization (p < . ); no difference on sexual function was noticed between the groups (p > . ). pathological study suggested that particles of embosphere occluded arterioles inside the prostate; partial normal gland structure nearby the occluded arterioles disappeared with glandular atrophy and infi ltration of lymphocytes. conclusion: transarterial embolization of the prostate is technically feasible and safe in the healthy intact pigs. the embolization may reduce the size of the prostate without compromising the normal sexual function. analysis of factors related to restenosis after percutaneous angioplasty for native avf stenosis in patients of hemodialysis j. jang , y. kim , s. yang , d. or ≥ year) , )duration of avf (< year or ≥ year), ) hypertension, ) smoking, )diabetes mellitus, ) type of avf, ) location of stenosis, ) degree of stenosis (< % or ≥ %), ) length of stenosis (< cm or ≥ cm), )degree of dilatation (< % or≥ %), ) thrombus, ) use of stent, and ) type of balloon (conventional balloon or cutting balloon). results: there are fi ve factors related to restenosis after percutaneous angioplasty for native avf stenosis in patients of hemodialysis patency, which are: ) duration of avf, ) use of stent, ) type of avf, )location of stenosis, and ) length of stenosis. longer duration of avf and use of stent in the treatment of native avf stenosis demonstrated higher patency rate. also, cephalic arch of avf, brachio-cephalic stenosis, and longer length of stenosis were demonstrated higher patency rate. conclusion: factors related to restenosis after percutaneous angioplasty for native avf stenosis in patients of hemodialysis were included duration of avf, location of stenosis, use of stent, length of stenosis. budd ) ). advantages/disadvantages of each will be outlined. procedure details: based on a large experience of over optional fi lter placements, technical issues with regard to placement of optional fi lters and complications encountered will be discussed. issues with regard to anticoagulation will also be discussed. conclusion: optional fi lters are now the fi lters of choice for ivc fi ltration. retrieval intervals differ between fi lter types, making the choice of fi lter important if retrieval is planned. continuous regional arterial infusion therapy for acute severe pancreatitis: between cumulative dosage of intraarterial administrated drug for the early stage and outcomes of patients purpose: to evaluate the correlation between cumulative dose of intraarterial administrated drug for the early stage of acute severe pancreatitis and outcomes of patients. thirty-fi ve patients with acute severe pancreatitis have undergone on initiation of continuous regional arterial infusion (crai) protease inhibitor, nafamostat mesilate, or gabexate mesilate, and antibiotics, ipm/cs, and intravenous administration of those. we retrospectively reviewed the day after disease onset, cumulative dose of intraarterial, and intravenous administrated these drugs at that time. cumulative intraarterial administrated doses, intravenous administrated, and total administrated doses were calculated. these factors were compared with outcomes that included mortality rate, periods of admission of the hospital and the intensive care unit (icu), periods that individual laboratory indexes indicated abnormal level. spearman rank correlation was used for statistical analysis. results: each crai was started within hours after the onset on thirty-three patients ( %). the mortality rate was . %. cumulative intraarterial administrated doses of nafamostat mesilate for the early stage had signifi cant correlation with normalization of crp (p=. ) and periods of admission of icu (p=. ). cumulative intraarterial administrated doses of ipm/cs for the early stage had signifi cant correlation with normalization of crp (p=. ). there was no correlation between other parameters and outcomes. conclusion: these results suggest that increased dosage of intraarterial administration of nafamostat mesilate, and ipm/cs at the early stage may reduce the period of high risked condition of acute severe pancreatitis. purpose: tips with bare-stents in patients with budd-chiari syndrome (bcs) has a very high incidence of shunt dysfunction (stenosis and occlusion) and the placement of mm stents have a high incidence ( % according to literature) of encephalopathy. we assessed the medium-term response after placement of mm ptfe-covered stents. in , patients ( child-pugh b, c) underwent tips with ptfe-covered stents (viatorr, gore, usa, mm in diameter). long-term anticoagulation therapy was promptly instituted. patients had a myeloproliferative disorder, genetic thrombophilia, with unknown etiology. patients had ascites, non-responding to diuretic therapy, had bleeding due to portal hypertension, had hepatorenal syndrome. hvpg before and after the procedure was measured. all patients underwent color-doppler and laboratory exams after hours and , , months. after months an angiography was performed. results: in procedures, stents were placed. in patients, a transcaval puncture was needed. hvpg reduced from + mmhg to + mmhg (p < . ). after a medium follow-up of months, patients are alive, dead days after the emergency tips procedure. / patients had an early occlusion, resolved with thrombolytic therapy. / shunts are still open at color-doppler and angiographic study; all these patients had clinical and biochemical improvement. only patients ( %) developed a transitory encephalopathy. conclusion: tips with mm ptfe-covered stents obtained a good technical, clinical and hemodynamic success, at a medium term follow-up, with a lower incidence of transitory encephalopathy compared to mm stents. there was no statistical difference in the clinical tumor response between the two groups. there was also no statistical difference in overall survival rates (p=. ) between the two groups. conclusion: arterial infusion chemotherapy may be suitable for oral cancer and there was no different effi cacy between carboplatin and cisplatin regimens. bilateral vertebral artery aspiration to enhance retrieval of basilar artery embolism t.e. mayer; munich/ de (t.e.mayer@med.uni-muenchen.de) purpose: intra-arterial fi brinolysis has lowered the death rate in patients with brobasilar thrombosis, but recanalisation failures, the time-consuming procedure itself, and haemorrhagic complications are still major limitations of this therapy. therefore, a variety of retrievers are now under investigation, but still not satisfactory, since recanalizazion rates by the retrievers alone only reach %. therefore, we evaluated a novel mechanical recanalisation technique -remote bilateral simultaneous vertebral thromboaspiration -to enhance the effect of retrievers in distal basilar artery embolism. methods and materials: ten patients with acute basilar artery embolism were evaluated. they were treated with bilateral or in case of occlusion or hypoplasia of the contralateral vertebral artery (va) unilateral proximal thromboaspiration during the use of different retrievers or even without the use of a retriever. results: complete recanalisation of the basilar artery was achieved in all cases. no procedure-related complications were seen. eight patients survived. the clinical outcome will be reported. conclusion: this small pilot study showed that remote thromboaspiration in distal basilar artery embolism is safe. it can be successful alone, and might be useful in combination with mechanical retriever devices. larger and randomized studies are needed. percutaneous thrombin treatment of pseudoaneurysms in different arterial territories: pictorial review a. lüttich, j. perendreu, j. falco, j. fortuño, j. branera, p. bermudez; learning objectives: to review and illustrate percutaneous use of thrombin in the treatment of pseudoaneurysms in different arterial territories. background and procedure details: we illustrate our experience in the percutaneous thrombin treatment of pseudoaneurysm with a review of all cases treated in our centre with this method. most of the patients had pseudoaneurysms located in the femoral artery, humeral artery, tibial anterior artery, and splenic artery. we include also one case of an aortic endoleak post-endoluminal treatment treated with percutaneous thrombin injection. we show angiographic, ultrasonographic and ct images before, during, and post-procedure. conclusion: percutaneous thrombin injection to treat pseudoaneurysms is effective, fast and safe, and currently the treatment of choice in most of these cases. radiological treatment of venous stenoses after "piggy-back" technique liver transplantation ( purpose: to describe a new approach to transjugular intrahepatic portal shunt (tips) using percutaneous transhepatic-transjugular technique in patients with portal hypertension, whose hepatic venous anatomy was unsuitable for the standard procedure. methods and materials: portocaval shunts were created using a single percutaneous transhepatic needle pass in patients. under sonographic guidance, we identifi ed on a single plane the left or right portal vein or one of their fi rst branches and its correspondent aligned left or right hepatic vein. both vessels were then punctured with a -gauge, - cm chiba needle. a . inch guidewire was advanced through the needle into the inferior vena cava, then the needle was removed and a fr sheath was placed over the guidewire into the ivc. subsequently, a . inch hydrophilic guidewire was snared into the superior vena cava and withdrawn through the transjugular sheath. the rest of the procedure was completed in the standard fashion. the portocaval shunts were successful in all patients. there were no major complications during the procedures. one patient underwent olt month later. in patients, the shunts were patent at - month follow-up. one patient died due to liver failure month after the procedure. conclusion: direct portocaval shunt creation using sonographic single transhepatic needle pass is a good alternative when standard procedures are diffi cult or impossible due to inadequate venous anatomy or abnormal anatomic relationship between the portal vein branches and hepatic veins. early purpose: severe symptomatic lower limb swelling is a recognised complication of compression or invasion of the ivc by intra-abdominal malignancy. symptomatic relief of symptoms by ivc stenting has been described as an effective means of palliation. however, there has been a reluctance to place stents across the origin of the renal veins due to the possibility of compromising renal function by a suggested reduction in renal blood fl ow. we analyse our experience with trans-renal ivc stenting and determine if there is a deleterious effect on renal function. we review patients with intra-abdominal malignancy and associated symptomatic lower limb oedema that had compression of the ivc by nodes or tumour mass. diagnosis was made using contrast-enhanced ct or gadolinium-enhanced mri. all patients had disease involving the ivc adjacent to the renal veins. using standard techniques, self-expanding stents were used to traverse the stenosis. all patients were monitored post-procedure with ultrasound to establish patency and regular serum creatinine levels to ensure the renal function did not deteriorate. results: there was a signifi cant symptomatic improvement in leg swelling following stenting in all of the treated patients. follow-up imaging demonstrated no delay in renal contrast enhancement. there was no signifi cant increase in serum creatinine levels. conclusion: ivc stenting for the treatment of lower limb swelling due to malignancy is an effective palliative method of reducing symptomatic lower limb oedema due to intra-abdominal malignancy and can probably be safely carried out without concern for renal function compromise. further studies are warranted. results: technical success was obtained in all patients; in control group, technical success rate was %. coil embolization of collaterals was needed in ( %) of patients, which were signifi cantly lower than that in control group ( %) (p < . ). mean amount of sclerosant used was . ml, and was signifi cantly lesser than in control group ( . ml) (p < . ). one patient showed transient ascites for a few days after treatment, but no major complications were encountered. the selective obliteration technique using a coaxial balloon catheter system would reduce the necessity of coil embolization procedure of abundant collateral veins, and can also reduce the amount of sclerosant. this catheter system can simplify the technique for the treatment of gastric varices. the for the sclerosing therapy, used %-ed solution of thrombovar taken into account the calculations % from the volume of cystic content, which developed total contact with epithelial integument of cyst and caused an aseptic infl ammation of cyst walls. some patients after interventional radiology treatment were prescribed slight forms of antihypertensional medicines according to individual. results: among patients, recovery with stable course of arterial hypertension was reached in cases ( %). improvement has been observed in cases ( . %). in ( . %) cases, this treatment turned out to be ineffective. review of intra-arterial thrombolysis as a causative treatment of hyperacute cerebral ischemic stroke c. iosif, m. papathanasiou, a. gouliamos; athens/gr (christinaiosif@yahoo.gr) learning objectives: to review the current imaging and interventional protocols, the indications and requirements for the performance of intra-arterial thrombolysis as a causative treatment of hyperacute ischemic stroke. to describe the methodology and results worldwide of the last years. to discuss the conventions and ideal conditions of function of the stroke units in accordance with the international experience of stroke units of excellence on the fi eld. background: cerebral ischemic stroke is the rd leading cause of death and the st cause of disability in the developed countries (europe . deaths/year, eusi ) with a heavy fi nancial and social cost. the establishment of an effective treatment is a very important medical and social issue. procedure details: intraarterial thrombolysis is effective when there is still viable brain tissue. patient selection is based on the therapeutic window since the symptoms onset, on the lack of clinical and imaging exclusion criteria and on the imaging confi rmation of occlusion of cerebral artery. the imaging protocols with ct-ct perfusion mad mr diffusion-perfusion are discussed, as well as the modifi cation of the time window according to the imaging fi ndings. the therapeutic approach is either intraarterial, with the use of thrombolytic medicine, either combined with intravenous infusion (i.v. glucoprotein inhibitor ΙΙb/iiia). the recanalisation rate is up to % considering the anterior circulation. major complication is hemorrhagic transformation. conclusion: intraarterial thrombolysis when performed in specialized centers is an effective etiological treatment of ischemic stroke and has a low complication rate when the inclusion criteria are kept. effects of continuous regional arterial infusion therapy for acute severe pancreatitis: correlation of pre-treatment disease severity and outcomes of patients purpose: to assess the correlation between severity parameters on initiation of continuous regional arterial infusion (crai) and outcomes of patients. methods and materials: thirty-fi ve patients with acute severe pancreatitis have undergone crai and intravenous administration of protease inhibitor and antibiotics. we reviewed severity parameters in these patients that included pre-treatment apach-ii score, ct severity index, laboratory indexes and the periods between disease onset and crai. these factors were compared with outcomes that included mortality rate, periods of admission of the hospital and the intensive care unit (icu), periods that individual laboratory indexes indicated abnormal level. spearman rank correlation was used for statistical analysis. results: thirty-three patients ( %) had undergone crai within hours after the onset. among all patients, apach-ii score was . ± . (mean ± sd), ct severity index was . ± . . despite disease severity, the mortality rate was extremely low ( . %). there was no correlation between parameters of disease severity and other outcomes. conclusion: these results suggest that disease severity may not directly refl ect outcomes of patients when crai is performed in early stage of acute pancreatitis. biomechanical infl uences for intravascular stent fractures r. suri, e. sprague, d. marton; san antonio, tx/us (suri@uthscsa.edu) learning objectives: . to understand the signifi cance of stent fractures. . to evaluate the individual and synergistic role of vessel deformation, biological properties and biochemical factors that could play role in the disruption of the long term integrity of implanted intravascular stents. background: though percutaneous interventional treatment of stenotic vascular disease has been revolutionized with stent placement, sirocco trials and recent studies are reporting increasing incidence of stent fractures. the etiology and incidence of stent fractures is still unclear. imaging findings: . incidence and clinical signifi cance of intravascular stent fractures. . arterial deformation due to respiration and motion as an implicating factor for stent fractures. . physical and chemical factors (including ion leaching) and biological factors (including infl ammation) at the stent surface which could precipitate stent corrosion. . role of scanning electron microscopy (sem), atomic force microscopy (afm) and secondary ion mass spectroscopy (sims) in the in vitro evaluation of the stent surface. conclusion: various biological, chemical, physical and dynamic factors may play a potential role either alone or synergistically on the integrity of intravascular stents. this exhibit aims to evaluate these individual causative factors for stent fractures and to demonstrate the potential role of in vitro evaluation of the stent surface in predicting corrosion and stent fractures. acceleration of primary liver tumor growth rate in embolized hepatic lobe after portal vein embolization s. hayashi, y. baba, r. higashi, t. yoneyama, m. nakajo; kagoshima-shi/jp (hayashi@m.kufm.kagoshima-u.ac.jp) purpose: portal vein embolization (pve) is now widely accepted as a useful preoperative procedure in selected patients undergoing major hepatic resection. the purpose of this study was to retrospectively evaluate the effects of pve on the growth of liver tumors in the embolized lobe. we studied patients (aged - years, mean age years), of whom had hepatocellular carcinoma (hcc) and had cholangiocellular carcinoma (ccc) primary liver tumors. pve was performed for each segmental portal branch using fl uoroscopy. the growth rates of the tumors in the embolized lobe and non-embolized liver parenchyma were calculated using the ct volume values at the time of tumor identifi cation, and before and after pve. results: the mean tumor growth rate was . ± . cm /day before pve and . ± . cm /day after pve (p= . ). the rate of tumor growth acceleration ranged from . to . ( . ± . ) in the hccs and from . to . in the cccs. there was no apparent correlation between the tumor growth rate after pve and the growth rate of non-embolized liver parenchyma ( . ± . cm /day). these results suggest that the rate of liver tumor growth in an embolized lobe accelerates after pve, especially in cases with hccs; thus, caution is required. transcatheter arterial chemoembolization for an hcc before pve may be a reasonable option to suppress the tumor growth. therapeutic purpose: to study the role of therapeutic arterial embolization in the management of post-traumatic epistaxis. methods and materials: patients with recurrent massive epistaxis (more than ml) following trauma who were referred to our department are included in our study. all the patients did not respond to conventional therapy. each patient had exploratory angiography, which included the study of the internal (ica) and external carotid arteries (eca) on both sides with selective injections in the branches of the eca. the fi ndings were classifi ed as . active bleeding . pseudoaneurysm and . others. the abnormal vessels were embolized. results: of the patients had abnormalities in the internal maxillary artery. of these, three patients showed active bleeding into the ethmoidal sinuses. other nine showed pseudoaneurysms in the distal branch closely related to a sinus. in all these cases, the vessel was embolized with pva particles. one patient had active bleeding from the ophthalmic artery since the external carotid artery was ligated at an other center and could not be embolized. in another patient, bleeding was from a pseudoaneurysm arising from the internal carotid artery, which was embolized by occluding the ica. in one patient, the angiogram was normal and both the internal maxillary arteries were embolized with gelfoam. none of the embolized patients had recurrent epistaxis. conclusion: exploratory angiography and therapeutic embolization is an excellent modality in the control of post-traumatic epistaxis. infrapopliteal purpose: to study the feasibility of infrapopliteal percutaneous transluminal angioplasty (pta) and to review the outcome of consecutive infrapopliteal pta procedures and evolve guidelines for patient selection, procedure and post procedural care. patients with ulcer or gangrene were excluded from the study. the indication for pta was rest pain in and intermittent claudication in . all the patients were diabetics and of them were smokers. the patients were selected for pta when distal run off in at least one vessel was good. all the patients were on ticlopidine mg bd or clopidogrel mg od for at least hours prior to the procedure and it was continued for months post procedure. intravenous heparin was given for hours post procedure. results: there was no technical failure. all the limbs showed clinical improvement in pain by hrs and this improvement was maintained at months in ( %). the actual limb salvage rate at year for patients with critical limb ischemia was %. conclusion: infrapopliteal pta is feasible and safe. appropriate patient selection, premedication and wound-care are important for good results. (n= ), gelfoam (n= ) and coil (n= ), but coil and gelfoam were not used alone. the number and name of each emoblized artery during bae were recorded in addition to the number of baes for each patient. cessation and recurrence of hemoptysis following bae were also documented. the causes for hemoptysis in patients were: pulmonary tuberculosis (n= ), anthracofi brosis (n= ), bronchiectasis (n= ) and lung cancer (n= ). embolized arteries included bronchial (n= ), intercostals (n= ), internal mammary (n= ), inferior phrenic (n= ), subscapular (n= ), lateral thoracic (n= ) arteries and costocervical trunk off the subclavian artery (n= ) in addition to some minor branches off the subclavian (n= ). those arteries off the subclavian arteries were usually affected when there was pleural thickening in the apical area. cessation of hemoptysis was achieved with a single bae (n= , . %), whereas either continuing or recurring hemoptysis was observed after baes. however, after repeated baes, all hemoptysis stopped. conclusion: the cessation of hemoptysis was achieved by bae in all cases, although some were achieved by repeated baes. for a successful bae, it is important to understand the knowledge of various arteries causing hemoptysis. purpose: to evaluate the effi cacy and safety of a hybrid treatment for severe deep-venous thrombosis by combining clot aspiration, mechanical thrombectomy, and local fi brinolytic therapy. methods and materials: within a period of years, patients with severe deep venous thrombosis were treated with hybrid interventional procedures. after insertion of a temporary vena cava fi lter, thrombo-aspiration with a ptca guiding catheter and/or mechanical thrombectomy with oasis or modifi ed rotating pigtail catheter system were performed. additionally, continuous local fi brinolytic therapy and balloon pta/stenting were performed, if needed. the primary endpoint was venographic fi ndings of thrombus extraction. systemic thrombolysis and anticoagulation therapy followed. results: trans-femoral interventional radiological therapy was achieved in patients. the approach was ipsi-lateral in cases and contra-lateral in cases. interventional techniques were as follows: manual clot aspiration ,oasis thrombectomy , mechanical thrombus fragmentation using a modifi ed pigtail catheter , balloon pta , stenting , and continuous local catheter fi brinolytic therapy . successful venographic recanalization was achieved in of patients. a temporary vena cava fi lter was easily removed . days after the insertion in patients. total dose of urokinase was , , i.u./ days. complications: haemo-thorax , retroperitoneal hematoma , and puncture site hematoma . hybrid interventional treatment appears to be a rapid and safe improvement in patients with deep-venous thrombosis. this hybrid treatment may be a therapeutic option in patients presenting severe deep-venous thrombosis. partial background: for hypersplenism, portal hypertension, or hematologic disorders, pse is often performed. however, severe complications such as splenic abscess, gastritis, or pancreatitis may limit the indication. in order to reduce these risks, two different methods of pse were introduced using the mrxo. procedure details: prior to pse, diffusion-weighted images (dwi) including blood oxygenation level dependent (bold) images were performed for the splenic volumetry using a . tesla mr machine. after the celiac and superior mesenteric arteriography, splenic arterio (spa) ct was obtained to evaluate the splenic or pancreatic branches. segmental pse (s-pse) using microcoils with gelfoam particles or lp-nbca, or peripheral pse (p-pse) using microspheres were performed following the exclusion of gastric and pancreatic branches. splenic ischemic range was evaluated on bold images during the procedures and pursued up to - %. conclusion: a control splenic volumetry was semiautomatically obtained using a workstation based on dwi. spa-ct allowed easy recognition of gastric and pancreatic branches and the exclusion before pse. the ischemic foci shown on bold images immediately after the procedures corresponded well to the non-enhanced area on ct one week later. although p-pse produced multifocal infarctions and may theoretically disturb abscess formation, the volumetry of ischemic (infracted) tissue is better evaluated on s-pse than p-pse. the mrxo is useful for safe and effective pse. carcinoids background: carcinoid tumours are one of the more frequently encountered endocrine tumours of the gastrointestinal tract, and can have a wide spectrum of presentations. the radiological appearance of carcinoids varies depending on their size, location, and on their variable biological behaviour, and can often be very diffi cult to diagnose. imaging findings: we retrospectively reviewed the imaging of histologically proven carcinoid tumours in our institutions for the last fi ve years. the clinical symptoms are varied and the diagnosis can be made biochemically or histologically. imaging is playing an ever-increasing role not only just in the diagnosis, but also in the treatment using percutaneous techniques. cases highlighted include carcinoids presenting as acute gastrointestinal bleeding and multifocal intra-abdominal masses. endovascular treatment appearances such as transarterial chemoembolisation (tace) with ct correlation pre-and post-procedure are also presented. conclusion: carcinoid tumours can have variable and unusual clinical and imaging presentations. familiarity with their appearance on imaging can be helpful for radiologists to avoid misdiagnosis and for initiation of proper treatment. interventional procedures have an increasing role in both diagnosis and treatment, leading not only to effective control of symptoms, but may also help prevent potentially dangerous complications. purpose: to assess the clinical effects of transcatheter arterial chemoembolization (tace) under corresponding portal vein occlusion (tace-pvo) for patients with hepatocellular carcinoma (hcc) and marked arterio-portal shunts (ap-shunts). the study subjects were patients with unresectable hcc and marked ap-shunts who underwent embolization of the ap-shunts with coils and/or gelatin sponge particles (group a: n= ) or tace-pvo (group b: n= ). our primary aim was to assess the effi cacy of tace-pvo for patients with unresectable hcc and marked ap-shunts, and our secondary aim was to assess differences in therapeutic effects between groups a and b. results: no major complication resulting directly from the procedures was seen in either group. there was also no inter-group difference in the effectiveness of treatment for the ap-shunts. subsequent tace therapy was possible in patients of group a and of group b after treatment of the ap-shunts. a favorable response in terms of tumor necrosis exceeding % was seen in . % of patients in group a, and in % of patients in group b (including cases of complete tumor necrosis). the -and -year survival rates in group a were . % and %, respectively, whereas the -, -and -year survival rates in group b were . %, . % and . %, respectively. there was signifi cant difference (p=. ) of survival rates between group a and b. the tace-pvo method may be a safe and useful therapy for selected patients with unresectable hcc and marked ap-shunts. exploratory methods and materials: exploratory digital subtraction angiography was performed in patients presenting with hemoptysis. the study included aortography, bronchial, intercostal, and subclavian angiography with selective injection into internal mammary arteries. embolization of all abnormal vessels was performed with pva sponge particles of - microns and - microns. the recurrence of haemoptysis was assessed at hrs, month and year. all the patients had chest radiograph prior to angiography. hrct of the lungs was performed if the radiograph was normal. bronchoscopy was performed when the radiograph did not show a defi nite evidence of tuberculosis. results: single vessel was abnormal in % and multiple vessels in %. on an average, . vessels were abnormal in the latter group with a range of - vessels. the commonest vessel to be involved was the bronchial artery ( %) followed by internal mammary ( %), the intercostal artery ( %) and the thyrocervical trunk ( %). ( %) cases had recurrence of haemoptysis in the fi rst hrs, ( . %) of these patients had an additional vessel, which was missed initially. % of the patients had normal arteriography and continued to have haemoptysis. an overall recurrence of % was seen at year follow-up. if an area of pathology has multi-vessel involvement, embolization of all the vessels with - - microns pva particles gives good long term results. embolic learning objectives: . compare and contrast various embolic protection devices. . pictorially depict and classify procedural adverse events due to embolic protection devices during carotid interventions. . understand techniques to avoid and appropriately manage these adverse events. background: outfl ow embolic protection devices are used during carotid interventions, though their role is still controversial. they enjoy the benefi t of preventing neuroembolic complications; however, the use of these devices increases procedural time with associated increased risk of adverse events. imaging findings: procedural adverse events specifi c to embolic protection devices may be classifi ed into: (i) minor adverse events (resolve with appropriate management), and (ii) major adverse events (persist despite appropriate management and cause morbidity). minor adverse events may occur during device deployment (technical failure, or use of adjunctive procedures), stent/pta (device migration, pseudo-occlusion, arterial spasm responsive to nitroglycerine, transient neurological defi cits), or device retrieval. major adverse events maybe related to intraprocedural events (proximal device migration, arterial spasm refractory to nitroglycerine, fl ow-limiting dissection, persistent neurological defi cits) or device retrieval. knowledge of techniques to avoid and appropriately manage these adverse events is essential. the aim of this exhibit is to compare and contrast embolic protection devices, clarify their role with evidence based literature, classify device related adverse events, and present a pictorial essay of these potential complications with their appropriate management. preoperative diagnosis was performed through spiral computed tomography and in some cases digital subtraction angiography. results: all patients underwent endovascular repair using straight-tube commercial stentgrafts -talent ( ), zenith ( ) and gore ( ). mean follow-up was months ( - months). technically successful implantation was achieved in patients. on patient with a type iii dissection required a hybrid procedure because of the continued growth of his aneurysm. two late migrations were observed on follow-up, which required additional intervention. seventeen endoleaks ( . %) were observed of which ( . %) were present in dissections on the base of retrograde fl ow into the false lumen. conclusion: there is much enthusiasm for the use of endovascular devices, especially for the treatment of thoracic aneurysms; for it may indeed hold the potential for the greatest patient benefi t as conventional open surgical repair continues to offer serious morbidity and mortality rates. preliminary recently, some percutaneous devices have been developed to treat mitral valve insuffi ciency. the design of these devices is undergoing and will be based on non invasive imaging (i.e. ct and/or mri). -slice ct offers extremely high spatial resolution in cardiac imaging and can be platform both for the design of these devices and for the pre-interventional assessment of the individual patient. imaging findings: this exhibit will provide a anatomical and pathophysiological overview of mitral valve insuffi ciency as well as a pictorial essay of mitral valve disease as seen on ct. the percutaneous devices and the technique used for the treatment will be shown and described. the role of ct in the geometrical assessment of mitral valve and in the the planning of the percutaneous procedure will be exploited. conclusion: percutaneous mitral valve repair is becoming a new experimental fi eld in cardiology and new devices are under development. ct can provide anatomical information extremely useful for the planning of the procedure. this information is the benchmark for the design and the sizing of the devices for the individual patients. we anticipated that tearleader stent placement is more comfortable and this stent has a more favourable long-term patency rate for years, but more episodes of dacryocystitis and stent migration have been demonstrated. purpose: percutaneous rfa of liver tumors has been extensively described and is considered safe and effective. targeted co insuffl ation has been described by raman et al. as a way to manipulate intraabominal organs to gain safe access routes. however, these authors stressed several drawbacks to this technique, including possible increased bleeding, limited role of ultrasound guidance, and inherent risks in co insuffl ation. we offer a new approach in using a balloon catheter as a diaphragmatic protective device. methods and materials: a balloon catheter was placed above the level of the hepatic dome in eight pigs under general anesthesia. approximately - ablations were performed with the balloon as a protective device. fourteen control lesions were performed without the balloon. thermal injury to the adjacent diaphragm was examined to determine depth of injury. the balloon catheter provides a protective barrier that is more stable in position than with saline infusion or co insuffl ation. the risk of bleeding was not increased because the point of probe entry into the liver remained closely apposed to the abdominal wall. potential acidosis associated with co insuffl ation was also never a concern. conclusion: our model of using a balloon catheter as a protective device has several advantages over the co insuffl ation model, and provides a safe and effective way of expanding the use of percutaneous radiofrequency ablation of liver tumors that are in the undersurface of the diaphragm. additionally, this novel method may be used in the protection of other organs adjacent to areas being ablated. results were classifi ed as primary success when complete pain relief was obtained after a single ablation session, secondary success when two or three sessions were performed and failure when persistence of pain required another therapy. complications were also recorded. results: osteoid osteomas located in nearly every part of the skeleton including the spine were managed with this technique. primary success was obtained in cases ( %), secondary success in cases ( %), and failure in cases ( %). in cases, the procedure was complicated by secondary algodystrophy. conclusion: laser ablation is a safe and effective technique which could represent the mainstay therapy for osteoid osteoma. an investigation of brightness changes in ultrasound images due to variations of temperature in liver tissue during ex vivo and in vivo radiofrequency ablation a. montaseri, m. mokhtari dizaji, s. akhlaghpour, m. alinaghizadeh; tehran/ir (atmostellae@yahoo.com) purpose: a minimally invasive method for the treatment of liver malignancies is radiofrequency ablation, after which disease recurrence is probable, partially due to inadequate capability of temperature monitoring of the target tissue. the goal of this work was to study the possibility of real-time temperature monitoring of liver tissue undergoing rfa. for this purpose, variations of brightness in ultrasonic images acquired from ex vivo and in vivo experiments were investigated. in our ex vivo experiments, pieces of fresh bovine liver underwent rfa using active and passive needle electrodes and a microthermometer, which were inserted into the tissue using ultrasonography guidance. tissue samples were heated up to °c and corresponding to each centigrade of temperature increase, ultrasonic images were acquired and delivered to a pc. variations of image brightness were investigated. in our in vivo experiments, the changes of brightness were studied in the ultrasonic images acquired during the rfa of liver malignancies of three patients. temperature increase was monitored using thermocouples at the tip of the rf electrode prongs. the ex vivo study showed that during tissue warm-up from °c to °c, brightness in ultrasound images increases linearly. as temperature rises from °c to °c, variation of brightness shows a non-linear behavior due to microbubble formation. the in vivo investigations showed good consistency with ex vivo results in the - °c interval. conclusion: it appears that changes of brightness in ultrasound images can be used for real-time thermal monitoring during rfa. fdg-micropet and diffusion-weighted mr image evaluation of early therapeutic effects of radiofrequency ablation on implanted vx rabbit tumor in the back muscle t. ohira, t. matsuoka, t. okuma, y. wada, k. koyama, k. nakamura, y. watanabe, y. inoue; osaka/jp purpose: to evaluate the early therapeutic effects of radiofrequency ablation (rfa) on implanted vx rabbit tumor in the back muscle using fdg-micropet and mr image. the bilateral back muscles of rabbits were implanted with vx . a week after tumor implantation, a leveen needle electrode was percutaneously inserted under ct guidance and radiofrequency was applied until maximum impedance. the other side of the vx remained as the control tumor. mr imaging was performed with a clinical . t instrument using a knee coil days after rfa. spin-echo t -weighted images (t wi), fast-spin-echo t -weighted images (t wi), gd-enhanced t -weighted images (ce-t wi) and echo-planar-imaging-diffusion-weighted images (dwi) (b= , , sec/mm ) were obtained. apparent diffusion coeffi cients (adc) of ablated lesions and vx were measured. fdg-micropet was obtained days after rfa. emission data were acquired - min after intravenous f-fdg injection. rfa lesion-to-muscle (rf/m) and tumor-to-muscle (t/m) ratios were calculated. results: vx without rfa showed ring-shaped fdg accumulation and hyperintensity on t wi, t wi, ce-t wi, and dwi, while ablated lesions showed less accumulation and hypointensity on all sequences. adc values and t/m ratios of vx without rfa were . ± . × - mm /sec and . ± . , respectively. after rfa, adc values and rf/m ratios were . ± . × - mm /sec and . ± . , respectively. adc values and rf/m ratios were signifi cantly lower than the vx without ablation (p < . ). histology showed coagulative necrosis and no viable on ablated lesions. conclusion: both fdg-micropet and mr images may be useful for evaluating early therapeutic effects of rfa. a new challenge for radiologists: ultrasound guidance in regional anesthesia l. learning objectives: to review the equipment and practical use of ultrasound relevant to the practice of regional anesthesia. to show the sonographic anatomy of the areas most frequently involved in regional anesthesia, and to become familiar with the imaging appearance of nervous structures. to describe and illustrate the sonographic appearance of peripheral nerves. to discuss the advantages of ultrasound-guided plexus and nerve blocks. background: the ultrasound guidance for nerve block was fi rst reported by la grange et al in , but the interest has increased in the last years due to the technological advances experienced in ultrasound and regional anesthesia. an optimal distribution of local anesthetic around the nerve structures is the key requirement for successful regional blocks, and ultrasound allows direct visualization in real time. ultrasound-guided regional blocks improve the quality (faster onset and duration), reduce the performance time and complications, and minimize the amount of local anaesthetic used. procedure details: it is essential to know the specifi c anatomy and the sonographic correlation of the areas usually involved in the regional blocks of the upper (interscalene, infraclavicular, axillar, and peripheral blocks) and lower extremities (femoral, sciatic, popliteal blocks). we describe and illustrate the technique used in our hospital by the department of anesthesia in collaboration with the radiology department. conclusion: utilization of ultrasound guidance for regional blocks is on the rise and has demonstrated to be an alternative to traditional methods of regional anesthesia. it enables quality nerve blocks, avoiding complications by optimal needle positioning. radiological purpose: to describe the technique and to evaluate the results of a radiologicalendoscopic combined approach in patients with biliary ducts iatrogenic damage. eighteen patients with complete biliary ducts transection underwent a radiological-endoscopic rendez-vous. the damage of the biliary ducts was due to trauma in case and to videolaparoscopic colecistectomy in cases. the procedure consists in re-establishing the continuity of the biliary ducts with a combined radiological-endoscopic approach, dilation, and placement of two percutaneous biliary drainages. after - weeks, the drainages are replaced with - endoscopic plastic endoprosthesis that are left for - months. the rendez-vous technique was performed successfully in all cases with fast resolution of the symptoms. two patients underwent surgery, while in patients the biliary drainages were substituted with plastic endoprosthesis. after the removal of the endoprosthesis, patients are asymptomatic after - months. seven patients are still in treatment with biliary endoprosthesis and are asymptomatic after - months follow-up. the radiological-endoscopic combined approach represents the only approach in patients with complete biliary duct transaction to delay or avoid the surgery. slice concept-the needle must remain in the plane of the ultrasound beam slice; angle of needle -poor refl ection at steep angles, good refl ection and therefore visualisation at shallow angles. this can be achieved by "heel toeing" the probe and choosing point of entry carefully; machine settings-adjusting depth, focus and gain plus using an appropriate frequency probe. conclusion: for ultrasound guided procedures to be carried out successfully and safely require visualisation of the needle. this diffi cult task can be simplifi ed by considering some applied physics and following some simple tips. percutaneous parapedicular access to the thoracic and lumbar vertebral bodies d.p. beall; oklahoma city, ok/us (dpb@okss.com) learning objectives: to demonstrate a technique for parapedicular access to the vertebral body. to present the anatomy of the spine as it relates to a safe and reproducible method of percutaneously accessing the vertebral body. background: the thoracic and lumbar vertebral bodies and pedicles differ in size and shape according to level. the method of accessing the vertebral bodies for percutaneous management of vertebral compression fractures and for biopsy has typically been via the parapedicular approach in the thoracic spine and the transpedicular approach in the lumbar spine. while the transpedicular approach is safe and effective, the ability to redirect the needle is limited, and there is a risk of fracturing the pedicle itself. procedure details: the parapedicular approach does not have the risk of pedicular fracture and the needle is more easily redirected with this approach, but the neurovascular structures are important to identify and avoid. the needle is placed in at the pedicle-body junction along the superior half of the pedicle and is directed toward the contralateral inferior vertebral endplate. the medial wall of the pedicle must not be transgressed prior to entering the posterior portion of the vertebral body. we present a technique for parapedicular access to the vertebral body that will provide a relatively avascular and aneural approach to vertebral body, is reproducible in the thoracic and lumbar spine, and will allow a consistent unilateral approach to the center of the vertebral body. ct step-to-step insertion of the needle and application of drugs after suffi cient contrast media application are performed. conclusion: ct guidance helps in avoiding puncture of vessels by direct visualization, thus enhancing safety. a multidisciplinary patient management improves results concerning pain and quality of life. a "how-to-do approach" will introduce the reader to ct-guided interventional pain management of the cervical spine. sedation learning objectives: . to present an overview of pharmacokinetics and pharmacodynamics of most widely used drugs for sedation. . to be acquainted with their principal indications and contraindications. . to explain the basic safety regulations to follow during a sedation procedure. background: nowadays, there are a high number of diagnostic and therapeutic procedures conducted under sedation, analgesia or immobilisation. because of this, radiologists often carry out the sedation procedures by themselves. it is the responsibility of the radiology and anaesthesia departments of every hospital to implement a working pattern based on collaboration among their staff, so that every radiologist becomes profi cient enough to guarantee high levels of safety and quality during a sedation procedure. procedure details: we present the basic pharmacokinetics and pharmacodynamics of the drugs most widely used (propofol, midazolam, etomidate, ketamine and fentanile), and their adverse reactions and treatment as well as their indications and contraindications. the basic notions necessary to recognise and verify (bis ® and entropy) the different consciousness levels are exposed. finally, the main safety rules of the american society of anesthesiologists about this issue are detailed. in order for radiologists to perform sedation procedures, it is of utmost importance for them to be acquainted with the basic pharmacology of the drugs employed, their indications and different options available for each procedure. similarly, it is necessary to become familiar with the management of the airway, the safety devices and basic and advanced cardiopulmonary resuscitation. ct-guided percutaneous radiofrequency ablation of the pulmonary and mediastinal unresectable tumors adjacent to the heart and large vessels c. pusceddu , g. podda , c. urigo , f. meloni , s. profi li , g. meloni ; cagliari/it, sassari/it, tempio pausania/it (curigo@sirm.org) purpose: to verify the feasibility and safety of radiofrequency thermal ablation (rfa) under ct guidance in the treatment of malignant neoplasm adjacent to the heart and large vessels. methods and materials: twelve patients (mean age of years) with unresectable primary and secondary pulmonary and mediastinal tumors ( nsclc, invasive thymoma, mesothelial sarcoma and metastases) were treated by ct-guided rfa. the tumors, of the mediastinum and of the lung, were adjacent to the aorta ( cases), pulmonary artery ( cases) or heart ( cases) with potential thermal damage of these structures. all ablations were performed with a multitined expandable electrode under conscious sedation and local anesthesia. vital signs of the patients b d e f a g were non-invasively monitored continuously. the therapeutic outcomes were evaluated by contrast-enhanced ct after month; the absence of tumor enhancement ct image was considered to indicate complete tumor necrosis. two patients were re-treated. in a patient, an electrode is penetrated in the pericardium. results: in all cases, the procedure was technically successful. no intraprocedural arrhythmia occurred. morbidity existed in cases of pneumothorax and case of asymptomatic thickening of the pericardium. in the control ct after month, there was complete necrosis in cases and partial (from to %) in the remaining cases. conclusion: rfa of mediastinal and lung tumors adjacent to the heart and large vessels is feasible and safe because the blood fl ow causes a "heat-sink" effect adjacent to such structures and prevents undesired thermal damage. new needle guidance system to reduce ultrasound-guided biopsy operator dependence a. shaikh, n. bluvol, a. kornecki, a. fenster; london, on/ca (allisoncanada@hotmail.com) purpose: the speed of accurate ultrasound (us) guided biopsy is dependent on operator experience. we developed a needle guidance system (ngs) to increase the speed and accuracy of biopsy procedures using us. this system is composed of a passive articulated mechanical arm attached to an us transducer, providing real-time projected needle pathway overlay guidance. this ngs coupled to a cnb needle will result in accurate biopsy with shorter procedure time than those of freehand technique, thus potentially limiting the us biopsy operator dependence. methods and materials: biopsy targets composed of . mm blue pvac lesions were implanted within chicken tissue test phantoms. two radiologists experienced with us-guided biopsy and inexperienced radiology residents performed biopsy of these lesions using both the free-hand technique and ngs ( lesions per technique per participant). participants were alternately assigned to start with of the biopsy methods, which were video recorded and analyzed for procedure time. biopsy samples were examined for the presence of blue color, which was indicative of a successful biopsy. results: biopsy procedure time using the ngs was signifi cantly lower than the free-hand technique (p < . ). the average procedure time was shorter among experienced participants than among inexperienced participants when using the free-hand technique (p= . ). equivalence in procedure time was found when physicians, both experienced and inexperienced with free-hand us biopsy, performed biopsy using the ngs (p= . ). conclusion: our needle guidance system is increasing procedural effi ciency by improving the rates of successful biopsy and reducing the required physician experience to perform biopsy. complications of percutaneous rf ablation of primary and secondary liver tumours: report of a single center study p. the magnet-insertion procedure was performed under endoscopic and fl uoroscopic guidance. two coated rare-earth-metal (ndfebr) magnets (br = gauss, d = mm, central hole d = mm) were inserted by guide-wire and duodenal probe into the model. the fi rst magnet was pushed into the fi rst jejunal loop, the second one was placed into the stomach inversely. after reaching the adequate positions, the magnets were pushed down from the guide-wire to let them cohere. results: the exact positioning was possible; the magnets cohered across the gastric and jejunal walls successfully. expectedly, the pressure between the magnets leads to ischaemia and necrosis of the cohered gastric and jejunal walls, while reparing the granulation process along the magnets' edges yields adhesion between them, and fi nally an anastomosis will develop. conclusion: the experiment was executable even with common tools in a short period of time in an exact way. further developments are necessary regarding size, material and form of the magnets. with some slight technical corrections, the method seems to be suitable for animal experiments. percutaneous alcohol ablation and catheter drainage for the treatment of large hydatid cysts in liver s.k. puri, a. dev, s. ghuman, a. agarwal, a.s. puri, p.k. mishra, s.k. sarin; new delhi/ in (skpurigbph@yahoo.co.in) purpose: to evaluate the safety and effi cacy of percutaneous alcohol ablation using a catheter and subsequent drainage of the cavity in large, > cm hydatid cysts in liver. sixteen patients ( men and women, aged to years) with hydatid cysts were subjected to alcohol ablation and catheter drainage. all cysts were of gharbi type i and ii and the size ranged from to cm. the procedure was performed under us guidance (n= ) or ct guidance (n= ) using light sedation and local anesthesia. initial needle puncture and aspiration of fl uid were done to examine scoleces and rule out any biliary communication. to differentiate angiogenic profi le in tumors using α ν β -specifi c uspio c. purpose: angiogenesis is essential for tumor growth and spread. in this study, α ν β specifi c ultrasmall superparamagnetic iron oxide (uspio) was generated and its potential to distinguish tumors with different angiogenic profi le was investigated. methods and materials: aptms-coated uspio with diameters of ± nm were conjugated with rgd-peptides. rgd-uspio or plain particles were injected into nude mice bearing hacat-ras-a- rt and a -tumor xenografts. t -and t *weighted mr imaging and t -relaxometry were performed h after injection. tumor tissues were immunostained against cd and counterstained against cd . area fractions of cd and α ν β integrin positive vessels were determined. results: on t *-weighted images, a strong heterogeneous decrease in signal intensity was found in hacat-ras-a- rt tumors, while signal changes in a tumors were more homogeneous and less pronounced. both in hacat-ras-a- rt and in a tumors, t -relaxation times decreased signifi cantly (p < . ) more after the injection of rgd-uspio than after the injection of plain particles. in addition, the decrease in t -relaxation time in hacat-ras-a- rt tumors ( ± ms) was stronger than in a tumors ( ± ms). in line with the mr results, histological evaluation shows in hacat-ras-a- rt tumors a heterogeneous vascularization with areas of high vessel density and large mature vessels. contrarily, in a tumors, the vessels were small and homogeneously distributed. furthermore, in hacat-ras-a- rt tumors, signifi cantly (p < . ) higher area fractions of cd ( . ± . %) and α ν β integrin positive vessels ( . ± . %) were found than in the a tumors (cd /α ν β integrin area fraction: . ± . %/ . ± . %). conclusion: molecular mri of angiogenesis using α ν β -specifi c uspio can distinguish tumors with different angiogenic profi les in vivo. whole body diffusion weighted magnetic resonance in tumor imaging: technical improvement and preliminary results s. li, f. sun, h.d. xue, z.y. jin; beijing/ cn (lishuo_lee@yahoo.com.cn) purpose: to optimize the free breathing whole body diffusion weighted imaging (wb-dwi) protocol by using short ti inversion recovery diffusion weighted echo planar imaging (stir-dwepi) sequence and build in body coil. high resolution three-dimensional ( d) maximum intensity projection (mip) images were obtained and the feasibility in tumor patient screening was evaluated. methods and materials: ) prescan procedure of stir-dwepi was modifi ed under the data from thirty volunteers scan. during each exam, an optimized center frequency was used to minimize the slice offsets in the consecutive scan station. prescan time was also reduced from seconds to seconds with even better station profi le. total scan time is minutes for stations . m coverage; ) thirty patients with histological proven malignant disease were scanned under the fi nal protocol by build in body coil for feasibility evaluation. the image quality and the degree of background body signal suppression were also assessed. results: free breathing wb-dwi is % successfully performed in this patients' group, without slice misregistration, fat contamination, signifi cant distortion or nonuniformity. the acquired d-mip images were adequate in depicting the malignant lesions on the total patients with high sensitivity and accuracy, compared with pet or spect results. conclusion: high resolution images of wb-dwi can be obtained with these technical improvements. wb-dwi has a great clinical application value in the detection of primary and metastasis lesions of malignancies in the whole body. it has great potential in diagnosis and therapeutic assessment of tumors. changes purpose: to prospectively compare the agreement between low-dose unenhanced pet/ct and full-dose enhanced pet/ct in lesion detection and staging of hodgkin disease and non-hodgkin lymphoma. methods and materials: seventy-two biopsy-proved lymphoma patients underwent fdg pet/ct that included a low dose unenhanced ct and a full-dose enhanced ct for initial staging. every patient had both pet/ct studies, and each one was evaluated by one pair of experienced physicians, a radiologist and a nuclear physician. both pairs were blinded to the other technique. lesion detection, number of sites affected in each anatomical region, and disease stage were assessed with both imaging modalities. agreement among techniques was determined by kappa statistics, and discordances studied by mcnemar's test. clinical, analytical, histopathologic, diagnostic enhanced-ct, pet, and follow-up data constituted the reference standard. results: for region-based analysis, no signifi cant differences were found between low-dose pet/ct and full-dose pet/ct, although full-dose pet/ct showed fewer indeterminate fi ndings and higher number of extranodal sites affected. agreement between both modalities of pet/ct was almost perfect for disease stage (k = . , p < . ). no statistically signifi cant differences were found between both modalities of pet/ct in the initial staging of patients with lymphoma, although full-dose enhanced pet/ct detected a larger number of anatomic sites affected, especially in extranodal regions, and provided fewer indeterminate fi ndings than low-dose unenhanced pet/ct. conjugation of single-chain antibody against human γ-seminoprotein to iron oxide and its in vitro identifi cation y.d. han , y.g. zhang , y. ji , d.x. cui , j.q. xu , y.l. liu ; xi'an/cn, shanghai/ cn (hanyuedong@ .com) purpose: to synthesize the conjugate of single-chain fv (scfv) iron oxide against human γ-seminoprotein, and identify its biological activity in vitro. methods and materials: e b scfv gene was amplifi ed by pcr and then expressed by the rapid translation system. the product was studied by immunoprecipitation, western blotting, and immunofl uorescent staining, and subsequently conjugated with magnetic nanoparticles (mnp) nm in diameter, which were further coated with aminosilane and pamam dendrimer. the conjugated and the unconjugated mnp were separately incubated with the prostate cancer lncap cells and then observed via transmission electrical microscopy (tem). results: the e b scfv gene was successfully amplifi ed and expressed. the result of immunoprecipitation and western blotting showed that the expressed peptide was completely absorbed by the soluble cytoplasmic fraction and cell membrane of lncap cells, which is highly consistent with the result of immunofl uorescent staining. tem showed that the conjugate entered into the cytoplasm within min, and the amount increased over time, unlike unconjugated mnp in the control group, in which the amount inside the cells was markedly less than that of the conjugate at the same time point, although they also entered into the cytoplasm. the scfv peptide against human γ-seminoprotein, and the conjugate of scfv-mnp were successfully fabricated, with the latter being uptaken by lncap cells. our studies indicate that this targeted probe can be developed for further molecular mr imaging. (b= , , sec/mm ). results: tumor size at and weeks after implantation was . ± . cm and . ± . cm (±sd), respectively. the fdg-micropet image shows ring-shaped accumulation in the tumors. the t/m ratios of the tumor rim at and weeks, and tumor core were . ± . , . ± . , . ± . , and . ± . , respectively. the t/m ratio of the rim at week was signifi cantly higher than at weeks (p < . ). mr imaging shows a slightly hyperintense tumor on t wi, hyperintense on t wi and dwi, and ring-like enhancement on gd-t wi. the adc values of the rim at and weeks, and the core were . ± . x - , . ± . x - , . ± . x - and . ± . x - (mm /s), respectively. the adc values of the rim at week were signifi cantly lower than those at weeks (p < . ). conclusion: our preliminary study suggests that fdg-micropet and mr image can be used to characterize the vx tumor. in purpose: to develop a method for labelling human cytotoxic t-lymphocytes with superparamagnetic iron oxide particles (spios) for subsequent depiction with a conventional . t mr scanner. a cmv-specifi c cd + cytotoxic t-lymphocyte (ctl) clone was expanded in the presence of feeder cells, interleukin (il)- and il- and stimulated unspecifi cally with anti-cd . after three days, ctls were labelled either by incubation with resovist or with resovist and lipofectin ( µg/ml) at or µg fe/ml with an incubation time of hours. cells ( x ) were imaged at . t (philips intera) , , and days after labelling using a fast multi-echo readout sequence to determine t * -relaxivity. resovist-uptake was confi rmed by immunofl uorescence using an antibody specifi c for the dextran-coating of resovist. specifi ty of ctls was determined by staining with a cd -antibody and cmv-multimers. specifi c cytotoxicity was quantifi ed by a cr-release-assay. iron uptake was measured by atomic emission spectrometry (aes). results: resovist-labelling of ctls was most effi cient using resovist ( µg fe/ml) and lipofectin. on days and after labelling, pronounced shortening of t -and t * -relaxation times was observed which diminished substantially after and days. the mean iron concentration per cell was . and . pg at and days after incubation and . pg at days. specifi ty and specifi c cytotoxicity of the cells was not altered by the labelling procedure. conclusion: labelling of human ctls can be achieved by incubation with resovist and lipofectin. a possible future application could be the monitoring of ctls after an adoptive cell transfer. molecular imaging of axillary lymph node by equivalent cross relaxation rate s. matsushima , h. nishiofuku , f. sasaki , s. era , y. kinosada ; gifu/jp, nagoya/jp (smts@cc.gifu-u.ac.jp) purpose: equivalent cross-relaxation rate (ecr) imaging (ecri) is a measurement method that can be used to quantitatively evaluate a change in the structural organization of lymph nodes by mri. the aim of this study was to evaluate the utility of ecri as molecular imaging. methods and material: fifteen patients with histologically confi rmed invasive ductal carcinomas of the breast were studied. we adopted the off-resonance technique for preferential saturation of the immobile protons to evaluate the ecr values. the single saturation transfer pulse frequency was employed at the frequency ppm downfi eld from the water resonance. the ecr value was defi ned as the percentage of signal loss between the unsaturated and saturated images. the ecri was constructed on the basis of the percentage of ecr. the rois had a rectangle-sampling area of . mm . the winroof software was used to analyze the number of cells. the normal organization showed that there were many cells and a higher ecr value. the lymph nodes with metastases showed that there were few cells and a lower ecr value. in the adipose tissue there were very few cells and the lowest ecr value. a statistically signifi cant difference was obtained in the ecr values of each tissue (p < . ). both numerical values are present on the fi rst correlation line (correlation coeffi cient = . ). in the axillary lymph node, ecr value related to the number of cells. therefore, ecri is a potentially useful method for molecular imaging in the lymph node. pathological animal models in the experimental evaluation of tumor microvasculature with magnetic resonance n. faccioli, p. marzola, f. boschi, m. d'onofrio, r. pozzi mucelli; verona/it (nfaccioli@sirm.org) purpose: to evaluate the applications of magnetic resonance and in particular of dynamic contrast enhancement magnetic resonance imaging (dce mri) in the study of tumoral microcirculation by means of animal tumoral models, evaluated before and after antiangiogenic treatment. methods and materials: forty-two mr exams were executed with intravascular contrast media in rats: in rats, tumors were induced by the subcutaneous injection of colon carcinoma cells, and in rats by mammary adenocarcinoma cells. perfusional and permeability parameters of the implanted tumors were evaluated with two contrast media (b / and gd-dtpa -albumin) to depict better the tumoral response after administration of two different antiangiogenic drugs (tamoxifen and su ). by means of these parameters and histological examination, it was possible to obtain a map of the microcirculation. results: in all the examined animal models, the dce-mri shows that the enhancement is greater in the peripheral area than in the central area. after the antiangiogenic drug administration, the mean values of permeability and perfusion were decreased to % and %, respectively. the response to the treatment is different for each antiangiogenic drug. different contrast media allow a different capability to visualize the microcircle. conclusion: dce-mri permits the non-invasive evaluation of tumoral microcirculation, and in particular, of its size, dynamic characteristics and vascular grade before and after antiangiogenic treatment. eosinophilic granuloma b. graca, j. brito, a. canelas, p. belo-oliveira, c. marques, f. caseiro-alves; coimbra/ pt (pombas@gmail.com) learning objectives: to provide an educational and pictorial review of the radiological imaging features (plain radiography/ bone scintigraphy/ct/mri) and distribution of eosinophilic granuloma (eg). to illustrate the clinical features and peculiar radiological appearances of eosinophilic granuloma. to discuss differential diagnoses, in particular in differentiating eosinophilic granuloma from other primary bone tumours, metastases or osteomyelitis. background: langerhans cell histiocytosis is a pathological entity characterized predominantly by proliferation of a specifi c histiocyte (langerhans cells). the etiology and pathogenesis is still unknown. eosinophilic granuloma is the unifocal unisystem form of langerhans cell histiocytosis, typically characterized by bone involvement, usually in a monostotic pattern. nonetheless, it is important to be able to recognize this lesion and exclude diffuse involvement, particulary of the bone marrow, lungs, heart, liver, kidney and gastrointestinal tract, conferring an adverse prognosis. eg must be differentiated from neoplastic, infl ammatory and metabolic lesions, which have variable approaches in terms of prognosis and treatment. eosinophilic granuloma may resolve spontaneously. there are good results with intralesional injection of methylprednisolone. surgery, chemotherapy and radiotherapy are reserved for disseminated or complicated cases, which is rarely the case of eg. imaging findings: we divide our presentation by anatomical location, showing lesions of the calvarium, mandible, ribs, vertebra, and long bones, emphasizing the most important aspects in differential diagnosis, in different imaging modalities. conclusion: awareness and early identifi cation of eosinophilic granuloma allow appropriate management. we provide a review of the background, clinical presentation and radiological feature of eosinophilic granuloma. purpose: mri, radionuclide imaging and bone densitometry have been used for quantifying skeletal involvement in patients with gaucher disease (gd). in this study, we compared different quantitative/semiquantitative methods for assessing skeletal involvement in patients with gd based on mri, scintigraphy or dual-energy x-ray adsorptiometry (dexa). thirty-one patients with type- gd underwent mri, mtc-sestamibi scintigraphy and dexa. mri was performed with . t scanner; protocol included t and t w tse sequences of lumbar spine and femora. all images were analysed by radiologists and bone marrow changes were classifi ed on a -point semi-quantitative scoring system. mtc-sestamibi scintigraphy was semiquantitatively scored; dexa of the lumbar spine and femoral neck yielded the z-and t-scores. the relationship between mri, scintigraphic and dexa scores and different disease parameters (bone pain, skeletal complications, hepatomegaly, splenomegaly, platelet count, haemoglobin level, and plasma chitrotriosidase) was evaluated by the spearman's rank correlation test. results: a statistically signifi cant correlation was found between mri and scintigraphic scores (r = . ; p = . ). moreover, both imaging scores were statistically signifi cantly correlated with several clinical parameters including platelet count, hepatomegaly, splenomegaly, haemoglobin level and presence of skeletal complications. on the contrary, the dexa-derived parameters were not correlated with any clinical and/or imaging scores. conclusion: our preliminary data indicate that both mri and mtc-sestamibi scintigraphy are reliable tools for assessing the severity of bone marrow involvement in patients with gd. learning objectives: to describe the clinical, pathological and radiological features of osseus tumours that contain osteoclast-like giant cells. to understand the pathologic basis of the radiologic features of these lesions. to realize the problems and pitfalls in the pathology assessment and discuss the clinical and radiological features that may allow differential diagnosis. background: differential diagnosis of bone lesions that contain giant cells requires the pathologist to consider an important number of possibilities. each lesion should be analyzed as a clinicopathologic entity and, therefore, the pathologist should be aware of the relevant clinical information and the radiologic evaluation of the lesions. procedure details: we have divided these lesions into two groups. the fi rst one includes lesions that can be mistaken for a benign giant cell tumor (bgct) because of its histologic similarity or its location in long bones extremities (chondroblastoma, giant cell reparative granuloma, cherubism, brown tumor of hyperparathyroidism and intraosseus nodular synovitis). the other group consists of lesions that also contain giant multinucleated cells but are histopathologically very different from bgct (osteosarcoma, osteoblastoma, osteoid osteoma, fi brous dysplasia, condromixoid fi broma, cemento-ossifying fi broma, aneurysmal bone cyst, fi brous histiocytoma, eosinophilic granuloma and paget disease) conclusion: the radiologist's role is essential to diagnose and treat osseus tumours that contain osteoclast-like giant cells, because it allows differentiation between them and informs about its biologic potential. periostic reaction, borders, soft tissue mass and calcifi ed matrix are the best radiological features that are helpful in differential diagnosis. location and patient age are the best clinical clues. interobserver reliability of a ct classifi cation system in the calcaneus fracture p. jiménez villares , f. ruiz santiago , a. peralta silva ; cádiz/es, purpose: this study was designed to determine the interobserver reliability of a calcaneus fracture classifi cation scheme. for a fracture classifi cation to be useful, it must provide prognostic signifi cance and intraobserver reproducibility. most studies have found reliability and reproducibility to be poor for fracture classifi cation schemes. methods and materials: eighty-nine cases were selected that had an appropriate study of ct image from a trauma hospital center. two radiologists from the musculoeskeletar department reviewed all these studies. on each viewing, observers were asked to classify the fractures according to both the sanders and crosby-fitzgibbons and zwipp systems. interobserver reliability and reproducibility were assessed with computer-generated kappa statistics. results: sander classifi cation: the mean kappa value for interobserver reliability for fracture types i-iv was . . crosby classifi cation: the mean kappa value for interobserver reliability for fracture types was . . zwipp classifi cation: the mean kappa value for interobserver reliability for fracture types i-vi was . . duparc classifi cation: the mean kappa value for interobserver reliability for fracture types i-v was . . conclusion: although intraobserver kappa values reached substantial levels and the crosby-fitzgibbons system generally showed greater agreement, we were unable to demonstrate excellent interobserver reliability with either classifi cation scheme. the results indicate that in a carefully controlled paradigm, the interobserver reliability with a classifi cation system based on interpretation of a single carefully defi ned ct image was good in all the systems and better in the crosby classifi cation. spinal we studied healthy adults with d-mri of the lumbar spine. rois were placed on each lumbar vertebral body, and mean signal intensity to time (sit) curves were generated for upper (l -l ), lower (l -l ) and all fi ve (l -l ) vertebrae and wash-in and wash-out rates, time to maximum slope and time to peak values were obtained. patient population was stratifi ed into men and women younger or older than years, and sit curves were compared among these subgroups. multiple regression analysis of data was performed to investigate the effect of age and sex. results: perfusion of the upper lumbar spine was signifi cantly higher compared to the lower level (p < . ). individuals younger than years showed signifi cantly higher perfusion compared to older ones for both spinal levels. women demonstrated signifi cantly increased perfusion compared to men of the same age in the upper lumbar spine only. all parameters except time to peak showed a moderate linear correlation with age ( . <r< . , p < . ). multiple regression analysis revealed age as the most signifi cant factor (p < . ) as compared with sex. to understand the pathologic basis of the radiologic features of these lesions. to highlight that anatomopathological fi ndings and radiological features are essential to reach a correct diagnosis. background: some vascular lesions of bone are relatively commonly encountered by radiologists, but are uncommonly seen by pathologists. patients can present with different symptoms and signs and while some tumours manifest as clearly benign, others have non-specifi c imaging features that may simulate malign neoplasms. in addition, sometimes pathology cannot easily differentiate between benign and malign lesions. imaging findings: among a wide sample of vascular bone tumours from our pathologic and radiologic database, the most representative examples have been selected to illustrate their main radiological and pathological characteristics. each tumour has been described and assigned to one of the two groups: benign or malignant. the most illustrative diagnostic images have been chosen from various imaging techniques (in particular, x-ray, ct and mr) and their subsequent anatomopathological images. the benign tumours that have been reviewed are: hemangioma, cystic angiomatosis, glomus tumor and gorham's disease. the malignant tumours that have been analyzed are: hemangioendotelioma, ephitheloid hemangioendothelioma and angiosarcoma. conclusion: after interacting with this exhibit, the radiologist will have an enhanced understanding of vascular bone tumors, including the histopathologic and radiologic features. both diagnostic tools are crucial to distinguish these lesions and to allow their proper management. osteoid osteoma: typical imaging patterns in various skeletal parts t. moser, x. buy, a. gangi; strasbourg/fr (gangi@rad .u-strasbg.fr) purpose: to analyze imaging features of osteoid osteoma in a large series of cases involving the whole skeleton and to defi ne typical patterns for each location. a search in our database was performed to identify all cases of osteoid osteomas. diagnosis of osteoid osteoma was based on typical clinical and imaging fi ndings. additionally most cases underwent image guided ablation in our department and therefore biopsy results and long term follow-up were also accessible. cases were included in our analysis when at least ct scan images were available for review. for each case, we precised the exact distribution within the skeleton, and within the bone both longitudinally (e.g. epiphyseal, metaphyseal, diaphyseal) and transversally (e.g. cortical, cancellous, subperiosteal). a typical imaging pattern was defi ned for each location. results: a total of osteoid osteomas were included in our analysis. distribution in the skeleton was as follows: upper limb ( cases), spine ( cases), femur ( cases), tibia ( cases), and remaining of the lower limb ( cases). we were able to defi ne at least one typical imaging pattern in all major bones. conclusion: recognition of typical imaging patterns in most bones allows a more confi dent diagnosis of osteoid osteoma with ct scan. conclusion: wbld-mdct represents a reliable diagnostic tool for the assessment of multiple myeloma, allowing not only the detection of typical lytic bone lesions, but also of both medullary and extra-medullary myeloma involvement. medullary involvement was encountered in all stages of the disease, including patients without osteolysis, and was associated with signifi cantly elevated levels of ß -microglobulin, a prospective prognostic marker. therefore, we suggest the inclusion of wbmd-ct into the diagnostic workup of mm patients. whole conclusion: evaluation of the course of medullary lesions at follow-up was essential, proving to be even more accurate than a combined evaluation of laboratory parameters and osteolytic lesions. bone fifty-four patients with clinically suspected bone marrow pathology underwent both conventional and dw mr imaging of the spine with adc maps generation and quantitative adc analysis. of these, suffered from multiple myeloma, had a known primary tumor, suffered from lymphoma and presented with acute back pain without medical history. results: in patients with multiple myeloma, quantitative analysis was able to differentiate between active disease (mean adc . ) and response to therapy ( . ). in patients without medical history, the evaluation of the adc maps led to an investigation for a primary tumor. in patients with a known primary tumor, the adc fi ndings were attributed to metastases (mean adc . ), while in of them an osteoporotic fracture was found ( . ). in patients out of , quantitative analysis added critical information that changed the therapeutic strategy. adc values were not signifi cantly lower in tumor infi ltration ( . ± . ) than in normal bone marrow ( . ± . ). conclusion: dwi with adc calculation, a method that studies bone marrow pathology on the basis of altered water-proton mobility, has been proved to be a useful tool (in adjunction to the other available conventional sequences) for differentiating between benign and malignant processes of the spine, and may increase the diagnostic potential of mr imaging in the assessment of spinal lesions. the skeletal manifestations of sickle cell anaemia u. shaikh, r. yaddavali, s. kumar, h. aniq; liverpool/uk (usmansh kh@googlemail.com) learning objectives: to describe the various skeletal presentations of sickle cell anaemia, highlighting imaging fi ndings on conventional radiography and on mri. background: sickle cell anaemia (sca) is the most common inherited haemoglobinopathy. this haemolytic anaemia is characterized by abnormally shaped red blood cells (rbcs), which are removed from the circulation and destroyed by the reticuloendothelial system, leading to anaemia. however, more signifi cantly, the sickled rbcs cause vascular occlusion, leading to tissue ischaemia and infarction. patients with sca are at an increased risk of infection due to abnormalities in host defences and functional asplenia. sca affects multiple organs, with the clinical manifestations of sca being predominantly due to anaemia, vaso-occlusion and infection. imaging findings: the fundamental skeletal abnormalities consist of marrow hyperplasia, which leads to osteopaenia with a coarse trabecular pattern. in severe cases, medullary cavities are obliterated giving the appearance of generalized increased bone density. bone infarction secondary to vaso-occlusion is the hallmark of sca. in adults, it affects the ends of long bones, the central portions of vertebral bodies with typical 'h' shaped vertebrae and the femoral and humeral heads, resulting in avascular necrosis. in older children, the diaphyses of long bones are the site of predilection. areas of bone necrosis are susceptible to superadded infection, especially from salmonella. radiologists play a pivotal role in the clinical management of these patients and they should familiarize themselves with the various skeletal manifestations and complications of sickle cell anaemia, which we present in this pictorial review. purpose: to verify the bone mineral density in children and adolescents having fractures of the forearm and hand compared to children and adolescents without a fracture after similar adequate traumatic injuries. methods and materials: x-ray examinations of the hand or forearm proving a fracture of children and adolescents after adequate trauma underwent a bmd calculation using digital radiogrammetry. all children and adolescents had to fi ll in a questionnaire regarding potential infl uencing factors of bone mineral density (drug intake, diseases, sportive activity, nutrition). bmd-z-score calculation used regional normative data of children and adolescents, which were obtained from images performed to exclude a fracture after adequate trauma. results: / images could be analyzed by dxr technology. / patients with fractures had a z-score of - ( / with a z-score of less than - sd). mean bmd was - . for both males and females. analysis was possible starting with years of age. similar results were obtained for mci values. main reasons of bmd loss according to the questionnaire were defi cit of sportive activity and false nutritional intake (fast food). diseases and drug intake were without relevance conclusion: bone mineralization in childhood and adolescence is disturbed in a signifi cant number of children due to wrong nutritional intake and lack of sportive activity. this causes a higher fracture rate, even during growth. effects on peak bone mass are not yet verifi ed, but can be expected from the defi cit of bmd during growth. cartilaginous tumors in the hand: plain radiographic and mr imaging fi ndings y. an, j. kim; suwon/ kr (jeeykim@catholic.ac.kr) learning objectives: to review the radiographic appearances in various cartilaginous tumors occurring in the hand. background: cartilaginous tumor is the most common bone tumor in the hand. however, occasionally unusual imaging fi ndings or unusual location of tumors make it diffi cult to diagnose these cartilaginous tumors. procedure details: the cases presented include enchondroma, enchondroma protuberans, intracortical chondroma, ollier's disease, extraskeletal chondroma, osteochondroma with chondrosarcoma, and synovial chondrosarcoma. conclusion: examples of each entity as seen as plain fi lms and mr imaging will be presented. differential diagnosis in patients with chondroid tumors will be discussed. techniques sagittal proton-density-weighted and coronal t *-weighted mr images with × matrix, mm section-thickness, and mm fi eldof-view were obtained by using a dedicated -channel knee coil on a . t scanner. for comparison, -matrix images were also obtained with identical sequences. focusing on the above-mentioned structures, paired images with -and matrix were magnifi ed in a same scale on viewers. qualitative image analysis was performed using a four- analysis of errors in the mr imaging evaluation of menisci of the knee p. van dyck; antwerp/be (pieter.van.dyck@uza.be) purpose: to determine mr accuracy for diagnosing meniscal tears and to discuss various causes of discrepancy between mr and arthroscopy. methods and materials: medical records of consecutive patients who underwent mr and arthroscopy of the knee at our institution were retrospectively reviewed. twelve patients underwent prior meniscal surgery. twenty-three patients had discrepancies between mr and surgical fi ndings. these were independently reviewed by two additional musculoskeletal radiologists in a double blinded fashion. original incorrect diagnoses were categorized as either unavoidable, interpretation error or equivocal for meniscal tear. results: mr accuracy was % for the medial and % for the lateral meniscus. of incorrect mr diagnoses, ( %) were unavoidable, ( %) were equivocal b d e f a g and ( %) were interpretation errors. of the medial meniscal tears, ( %) were missed. eight ( %) of these were categorized as equivocal, including postoperative menisci. of the lateral tears, ( %) were missed, ( %) of which were categorized as unavoidable. of these , ( %) showed fraying of the inner edge, which led to minimal resection (n= ) or had minimal tear treated conservatively (n= ). there were false-positive diagnoses, all occuring in the lateral meniscus, of which were unavoidable and was an interpretation error. conclusion: of all missed lateral meniscal tears, most are unavoidable and related to confusion between what represents fraying and what represents a tear. unavoidable false-positive diagnoses are infrequent and may be related to incomplete arthroscopic evaluation. subtle equivocal fi ndings still make mr diagnosis diffi cult, even for experienced radiologists. learning objectives: evaluate the imaging contribution in total hip replacement (thr) management. background: digital or plain fi lm imaging permits the diagnosis of a majority of thr complications. ct scan and mri, usually less useful, are becoming better adapted due to the performance of the latest machines and specialized software. imaging findings: main local complications are acute, consisting of implant fractures, joint dislocation and neighbouring bone fatigue fracture. chronic complications include soft tissue new bone formation, periarticular tendonitis, bursitis, recurent dislocation and, above all, device loosening without infection due to granulomatous reaction or with intercurrent infection. in case of recurrent dislocation, x-ray or ct scan can be used to evaluate the actual position of the devices and the possible wear. conclusion: hip replacement surgery has been one of the most common elective and semi-elective orthopedic operations for the past years. radiography remains the mainstay of imaging evaluation of hip replacements. the various types of hip replacements can be recognized on radiographs, and many complications have specifi c appearances that the radiologist should be familiar with. pitfalls in post-surgical shoulder mri evaluations p. pastore, d. volpe, n. volpe, f. murgante, a. stecco, a. carriero; novara/it (dvolpe@sirm.org) learning objectives: to describe and recognize magnetic resonance imaging (mri) fi ndings that can be confused with pathological abnormalities in post-operative shoulder; to maximize the accuracy of mri imaging by providing the most appropriate pulse sequences. background: imaging post-operative shoulders has always been a matter of debate, the main controversy being whether mri or mr arthrography is the best means of answering diagnostic questions. published data and clinical experience show that conventional mri is effective in assessing full-thickness lesions, but less capable of differentiating partial lesions and normal fi ndings after surgery. procedure details: a number of factors may decrease the accuracy of mri in evaluating post-operative shoulders, including iatrogenic artefacts, surgical distortions of native anatomy, changes in the signal intensity of tissues, and image degradation caused by metallic artefacts. we show the key points for optimizing post-operative shoulder mri protocols and try to identify the best technical parameter among the most widely used pulse sequences. conclusion: when interpreting post-operative shoulder mr images, radiologists must be familiar with all possible pitfalls in order to avoid diagnostic errors. dynamic gadolinium-enhanced mr imaging in characterization of growth cartilage perfusion with epiphyseal vascular occlusion x. li, l. xia, h. zheng; wuhan/ cn (lilyboston @ .com) purpose: to determine the contribution of metaphyseal vascularity to epiphyseal and physeal perfusion with epiphyseal vascular occlusion by using dynamic gdenhanced mr imaging. twelve -week-old piglets were randomly assigned into either control or abduction group ( proximal femurs in each group of piglets). proximal femoral epiphyseal vascular occlusion was induced by maximal bilateral hip abduction for hours. dynamic gd-enhanced mr imaging was performed in normal and abduction hips. for dynamic gd-enhanced imaging, spoiled gradientrecalled echo images with a temporal resolution of . s were performed, and a total of images were obtained. the enhancement ratios (er) in various regions of femoral heads were evaluated and correlated with histological fi ndings. results: in normal hips, we found no signifi cant differences in the er and the timing of enhancement between physeal cartilage and metaphyseal spongiosa (p> . ). however, in abduction hips, the er of physeal cartilage was lower than that of metaphyseal spongiosa and enhanced more slowly than metaphyseal spongiosa (p < . ). meanwhile, the er of epiphyseal cartilage remained lower and enhanced more slowly than physeal cartilage (p < . ). the er of physeal and epiphyseal cartilage in abduction was lower and enhanced more slowly than those in the normal (p < . ). more transphyseal vessels in abduction were found histologically than those in the normal (p < . ). conclusion: with epiphyseal vascular occlusion, enhancement seems to advance from the metaphysis into the physis and epiphysis, the metaphyseal vascularity might contribute to epiphyseal and physeal perfusion. this research is supported by nsfc ( ). imaging the complications of total hip replacement j.m. moriarty, j. kerr, c. shortt, j. o'byrne, s. eustace; dublin/ie learning objectives: the objectives of this exhibit are to describe the anatomic basis behind the complications of total hip replacement, the radiologic features that describe these complications and the new innovations in diagnostic imaging of these features. background: of the , total hip replacements performed worldwide each year, it is estimated that % fail at some stage. the type of surgical approach used, prosthesis inserted and method of fi xation employed all have a role in the prevalence and form of complication that can ensue. the role of radiography, arthrography, ct, and mri in the diagnosis of these complications is rapidly evolving, particularly the use of metal artefact reduction techniques in mri. imaging findings: this exhibit presents a pictorial review of components, methods of fi xation and complications of total hip replacement. the exhibit reviews the role of radiography, scintigraphy, computed tomography, ultrasound, arthrography and mri in the assessment of common complications including loosening, infection, heterotrophic bone formation, muscular avulsions, and prosthesis impingement. furthermore, a detailed review of the use of mri with artefact reduction techniques in the evaluation of deep seated infection, iliopsoas bursitis and abductor avulsion will be presented. the diverse imaging modalities that may be employed in the evaluation of the myriad complications of total hip replacement is being constantly updated, re-evaluated and added to. in particular, the increasing sensitivity of certain mri sequences in the setting of metallic prostheses has led to the routine use of mri as a problem solving tool. to analyze the discordant fi ndings of anterior cruciate ligament (acl) on sagittal and oblique coronal mr images of the knee, and correlate with arthroscopic fi ndings as the standard. methods and materials: one hundred thirty-eight mr images of the knee in patients with suspected internal derangement who subsequently underwent arthroscopic surgery were included. two radiologists, unaware of clinical details, jointly evaluated acl on sagittal t , proton density-weighted images initially and then on oblique coronal images. reviewers determined the status of acl as intact (i), partial (p), or complete tear (c) respectively. when interpretation of acl status was different between both imaging planes, cases were categorized as discordant and correlated with arthroscopic results. results: a discordant mr fi nding of acl was seen in of knees ( . %). correlation of acl status on sagittal, oblique coronal images with arthroscopic fi nding was the following: c-p-p in , p-i-i in , c-i-i in one, c-p-c in , and i-p-c in one case. at arthroscopy, total rupture of ant-med bundle with partly intact post-lat bundle was observed in c-p-p; displaced acl by fat tissue in intercondylar notch and torn meniscal fragment, deformed course by ligamentum mucosum adhesion in p-i-i and one c-i-i; fi brous scar in c-p-c and one i-p-c. a discordant fi nding of acl on sagittal and oblique coronal mr images was not frequent, and attributed to remained post-lat bundle, displaced course, and presence of scar. interpertation of acl on oblique coronal image seems more accurate than on sagittal images. osseous criteria for ankle instability o. magerkurth, a. frigg, b. hintermann, h. ledermann; basle/ch purpose: some patients suffer from recurrent ankle sprains even after operative ligament reconstruction. one reason could be a disadvantageous joint confi guration. the purpose was to evaluate those parameters of the osseous confi guration of the ankle joint that could determine stability. a larger radius of the talus and a smaller tibio-talar sector contribute to osseous instability. these fi ndings are of importance, showing that ankle instability may depend not only on competence of collateral ligaments but also on osseous joint confi guration. magnetic resonance imaging evaluation of articular cartilage after autologous osteochondral grafting i. herrera, s. fernández-zapardiel, y. herrero, m. céspedes, p. calvo, e. fandiño; toledo/es (babel @hotmail.com) learning objectives: to illustrate the appearance and outcome of the articular cartilage after treatment of osteochondral patology with multiple autologous osteochondral plugs (mosaicplasty) using magnetic resonance imaging (mri). background: articular cartilage damage is extremely common in today's society. osteochondral autotransplantation is a surgical technique that is being used increasingly in the treatment of symptomatic focal chondral or osteochondral defect. with more new surgical procedures being used to repair chondral defects, such mosaicplasty, there is an increasing demand for radiologists to evaluate these procedures. procedure details: there were patients with focal chondral lesion ( of the knee and of the ankle) treated with mosaicplasty. clinical examination, x-ray and mri were performed on each patient before surgery. the mosaicplasties were normally done with arthoscopic and transferred autologous bone from the donor site to the recipient site into the cartilage defect. after the surgery, for the assessment of a cartilage repair procedure, we used mri general electric signa horizon lx . t with axial, coronal and sagittal planes with cartilage-sensitive sequences, such as fat-suppressed t -weighted fast spin-echo/proton densityweighted or d gradient echo sequences. we evaluated the number of plugs, the graft integration to the adjacent hyaline cartilage and bone, congruence of the articular surface, the adjacent bone marrow, the status of the graft donor site as well as associated complications. conclusion: with its direct multiplanar imaging capabilities, excellent soft tissue contrast and spatial resolution, mri could be the method of choice for non-invasive follow-up of patients after mosaicplasty. shoulder virtual arthroscopy in glenohumeral instability: image gallery correlation with arthroscopy d. volpe, n. volpe, n. masiello, p. fornara, a. stecco, a. carriero; novara/it (dvolpe@sirm.org) learning objectives: our intent is to correlate virtual arthroscopy images with arthroscopic fi ndings, and to show an image gallery by means of virtual arthroscopic images of main shoulder pathologies. background: shoulder mr arthrography (mra) is now a well-assessed technique based on the injection of contrast medium solution, which fi lls the articular space and fi nds its way between the rotator cuff (rc) and the gleno-humeral ligaments. in case of gleno-labral pathology or partial rc tears, we use an additional sequence that allows obtaining virtual arthroscopy post-processed views to complete the mr evaluation of shoulder pathology. procedure details: mr arthrographic sequences (se t w and gre t fat sat) are provided with a ge . t signa and the supplemental sequence is a d spoiled ge t w positioned in coronal plane. virtual arthroscopy is performed by means of a dedicated software loaded on a work-station. conclusion: shoulder virtual arthroscopy may be useful in diagnostic accuracy, both as an adjunct to clinical and surgical planning, as well as an interactive tool for learning arthroscopic anatomy and pathology. purpose: to assess the value of virtual arthroscopy of the shoulder. methods and materials: forty patients with shoulder dislocation-translation and/or clinical signs of instability underwent slices mdct arthrography and virtual arthroscopic reconstruction. all scans were performed using -detector row helical ct scanners with following parameters: kv; ma; thickness . mm; collimation . ; reconstruction increment . mm; matrix x ; preparation and acquisition time min. the patients were examined in supine positions with the shoulder in neutral position; intra-articular injection was performed posteriorly, without fl uoroscopic control, administering cc of room air. the data were downloaded to a workstation and virtual arthroscopy performed using a pc-based d reconstruction program. a surface rendering algorithm was employed for producing virtual arthroscopic images. prior to applying the surface rendering algorithm, a threshold value was specifi ed, corresponding to the center of the different density between bony tissue (the brightest pixel) and soft tissue. surface models then were calculated and displayed employing an imaginary light source results: mdct arthrography diagnosed bankart lesions, bankart osseous lesions, cuff-rotator tears, hill-sachs lesions and slap lesions. virtual arthroscopy detected and visualized all lesions above-mentioned; it provides a further point of view of shoulder joint which is useful for orthopaedic surgeons planning arthroscopy or arthrotomy; it may also serve as a simulation in the teaching of orthopaedic trainees. conclusion: virtual arthroscopy is a new technique that has the potential to enhance the diagnostic performance of ct arthrography. the scapho-lunate joint and the scapho-lunate ligament: study by ultrasonography a.r. michaelides, a. foteinos, g. setakis, m. kastania, t. giannopoulos, s. chalkias; chios/gr purpose: the ultrasound (us) study of scapho-lunate ligament and scapholunate distance. we studied using us wrist joints ( healthy persons), with a superfi cial linear us transducer of high resolution ( mhz). we measured b d e f a g the distance between the scaphoid and lunate bones in (a) neutral position, (b) radial deviation, (c) ulnar deviation; and characterized the visualization of the scapho-lunate ligament in the palmar and dorsal surfaces. the visualization of the scapho-lunate ligament was characterized as completely visualized, partially visualized and non-visualized. results: the scapho-lunate distance was measured between . mm and . mm, with a mean diameter of . mm. the difference in this distance between left and right arm did not exceed . mm. there was no signifi cant change in the scapholunate distance during ulnar and radial deviation. the scapho-lunate ligament was completely visualized in / cases, and partially visualized in / cases, all being studied dorsally. the scapho-lunate ligament was better visualized by ultrasound in the dorsal surface compared to the palmar one. the scapho-lunate ligament is partially or completely visualized in % of wrist joints studied and this fi nding could help exclude scapho-lunate dislocation or subluxation. imaging patellar complications after knee arthroplasty p. melloni, r. valls, m. veintemillas, s. pérez, i. delgado, m. prieto; sabadell/es learning objectives: to illustrate and describe complications affecting the patella in patients with total or partial knee arthroplasty. background: we retrospectively reviewed consecutive patients treated with total or partial knee arthroplasty in the last two years; ( . %) patients ( women and men) presented patellar complications. mean patient age was years (range: - years). all underwent plain-fi lm radiography periodically. in determinate cases according to the clinical symptoms, patients underwent us. imaging findings: the most common patellar complications after total or partial knee arthroplasty were: fracture (n= ), instability (n= ), dislocation or luxation (n= ), osteonecrosis (n= ), infection (n= ), erosion (n= ), impingement on the prosthesis (n= ), patellar or quadriceps tendon tear (n= ), and loosening or rupture of the patellar prosthetic button (n= ). the mean interval from total knee replacement to patellar complication was years and months (range: months- years). conclusion: patellar complications following knee arthroplasties are generally uncommon but often of potential clinical signifi cance. plain fi lms are essential for the evaluation of patellar complications after surgery and should be the initial imaging study performed. careful attention to initial prosthesis placement and comparison of follow-up images will allow subtle abnormalities to be detected in patellar complications. us may have a special role in the evaluation of soft-tissue structures around the patella. superfi purpose: fat-suppressed three-dimensional ( d) spoiled gradient-echo (spgr) mr imaging has been described to be accurate for detecting % or greater cartilage defects. the purpose of this study was to determine the accuracy of sagittal fat-suppressed d spgr imaging for detecting superfi cial cartilage defects of the medial femoral condyle. methods and materials: fifty patients who had arthroscopically confi rmed cartilage defects by an arthroscopist and had mr imaging were included in this study. sagittal fat-suppressed d spgr mr images were retrospectively reviewed by a radiologist. cartilage thickness was graded: grade , normal; grade , abnormal signal without a contour defect; grade , less than % reduction of cartilage thickness; grade , % or greater reduction of cartilage thickness; and grade , full-thickness cartilage defect. results: after arthroscopy, there were cartilage defects in the medial femoral condyles: grade (n = ), grade (n = ), and grade (n = ). after fat-suppressed d spgr imaging, cartilage defects in the medial femoral condyles were graded as follows: grade (n = ), grade (n = ), and grade (n = ). sensitivity, specifi city, and accuracy for grade cartilage defects were % ( / ), % ( / ), and % ( / ), respectively. cartilage grading showed a signifi cant correlation between fat-suppressed d spgr imaging and arthroscopy (r =. , p <. , spearman's correlation). conclusion: sagittal fat-suppressed d spgr mr imaging is accurate for diagnosing superfi cial cartilage defects. thus, it is helpful for planning treatment that could be different between early and advanced cartilage defects. direct and indirect mr arthrography: advantages and disadvantages t.a.a. macedo , l.p. souza , l. farage ; são paulo/br, uberlândia/br (tamacedo@hotmail.com) learning objectives: to demonstrate the pros and cons of direct and indirect magnetic resonance arthrography (mra). background: direct mra (dmra) with injection of gadolinium (gd) diluted in saline solution can be useful for evaluating certain pathologic conditions in the joints. it is most helpful in the shoulder; especially for outlining labral-ligamentous abnormalities and distinguishing partial-thickness from full-thickness tears in the rotator cuff; but it can be also useful in other joints, demonstrating labral tears in the hip, showing tears of the collateral ligament of the elbow, identifying residual or recurrent tears in the knee following meniscectomy, and assessing the stability of osteochondral lesions in the articular surface of joints. indirect mra (imra) can be done when dmra is inconvenient, or not logistically feasible. in this case, the mr images are acquired after an intravenous administration of gd-contrast media. between april and august , we performed dmra and imra in our institution. procedure details: the direct arthrographies were perfomed using fl uoroscopy and ultrasound guidance and about - ml gd-diluted solution was injected in the shoulder. indirect mra was done after ml ( . mmol/ml) intravenous injection of gd-contrast media (dotaren ® ,guerbet laboratories). all the examinations were performed in patients with rotator cuff, labral or slap lesions. conclusion: although imra is unable to fi ll the joint cavity, it does not require direct gd-contrast media injection and it is superior to conventional mr imaging when there is minimal joint fl uid. in addition, intravenous injection allows demonstrating vascularized or infl amed tissue. evaluation of anterior cruciate ligament (acl) autografts and allografts with magnetic resonance imaging (mri) i. tsifountoudis, i. kalaitzoglou, a. haritandi, i. economou, a.s. dimitriadis; thessaloniki/gr (jtsif@mycosmos.gr) learning objectives: arthroscopic reconstruction of acl is being performed with increasing frequency. although the procedure is performed with good success rates, early and late complications have been documented. our purpose is to demonstrate the normal appearance of the reconstructed acl with mri and to illustrate the diagnostic pitfalls and the postoperative complications. background: sixty-fi ve patients ( males and females; age range: - ) who had undergone acl reconstruction using either autografts or allografts were referred to knee mri ( . t) for acl graft control, between july and september . the imaging protocol included t -weighted, proton density-weighted and t -weighted fast spin-echo images and stir images in all planes. if the graft was not optimally visualized, oblique sagittal t -weighted images were obtained along the course of the graft. finally, gadolinium was administered intravenously in cases. imaging findings: intact graft was depicted in patients with continuous, homogeneous and low signal intensity. signs of roof impingement were found in patients. the graft fi bers were absent due to rupture in cases. localized arthrofi brosis (cyclops lesion) was detected in patients. postoperative infection was diagnosed in patients, migration of the interference screws in cases and cystic degeneration of the graft was depicted in patients. thickening of the harvested patellar tendon was seen in patients and "regeneration" of the hamstring tendons in patients. the knowledge of the normal mr appearance of acl grafts and the recognition of their complications are crucial for the appropriate management of symptomatic patients. magnetic resonance imaging in chronic ulnar-sided wrist pain: pictorial review j.s. sawhney, a. bajaj, r. bhatt, k. jeyapalan; leicester/uk (jasdevsawhney@yahoo.com) purpose: chronic ulnar-sided wrist pain management can be intimidating and confusing because of its vague and intermittent nature, complex anatomy and pathology and frustration that it induces in the patient and the doctor. this pictorial review attempts to present a spectrum of cases illustrating the anatomy and pathologies of this complex region as seen on mri. methods and materials: mri was done for patients over a period of years with chronic pain on ulnar side of wrist. . t scanner was used. sequences used were t axial and coronal, pd fat sat axial and coronal, t sagittal and stir sagittal. the abnormalities are categorised into osseous (bony and degenerative), ligamentous, tendinous, infl ammatory neurologic and miscellaneous. results: fracture non-unions of the hook of hamate ( ), ulnar styloid process ( ), hamate contusion ( ), lunate avn ( ). degenerative processes at pisotriquetral joint ( ), midcarpal (triquetrohamate) articulation ( ), distal radioulnar joint {instability ( ) and synovitis ( )}. ulnar impaction syndrome ( ). ligamentous injuries included scapholunate ( ). tfcc, triangular fi brocartilage complex {tear ( ) and degeneration ( )}. tendinopathies and tensosynovitis noted in e -e compartment ( ), fcu ( ) and diffuse ( ). infl ammation and erosions ( ) related to rheumatoid disease. neurologic processes such as entrapment of the ulnar nerve in guyon's canal ( ). miscellaneous group includes ganglia ( ) and neuroma ( ). no abnormality was found in patients. conclusion: mri extends the possibilities of evaluating chronic ulnar wrist pain. its signifi cance lies in the non-invasive examination of various intraosseous as well as soft tissue abnormalities. evaluation of patellofemoral joint cartilage at high-resolution mr imaging using a microscopy coil: comparison with conventional mr imaging s. takao , h. nishitani , t. yamaguchi , m. uetani ; tokushima/jp, nagasaki/jp (takaos@mue.biglobe.ne.jp) purpose: mr imaging using a microscopy coil provides high-resolution images, which can be useful in demonstrating early cartilage abnormalities. the purpose of this study is to evaluate its diagnostic accuracy in evaluation of patellofemoral joint cartilage abnormalities. methods and materials:we evaluated patellofemoral joints ( patients) with mr imaging using a conventional knee coil and a microscopy coil; t -weighted images and fat-saturated proton-density-weighted images were acquired respectively. retropatellar cartilage was divided into parts and femoral cartilage into parts, where the status of cartilage was graded into (normal) to (full thickness injury). the diagnostic accuracy was analyzed using surgical or arthroscopic fi ndings as a standard of reference. results: in parts of cartilage, accuracy of mr grading using a microscopy coil and a conventional knee coil were . and . , respectively, when grade - was considered to be positive, and . and . , respectively, when grade - was considered to be positive. in parts with grade- surgically confi rmed cartilage lesion (superfi cial lesions, soft indentation and/or superfi cial fi ssures and cracks), mr grading were correct in with a microscopy coil and in with a conventional coil. however, no signifi cant difference was seen statistically in the accuracy of both techniques. conclusion: this preliminary study indicated that high-resolution mr imaging using a microscopy coil could be useful in detecting early cartilage abnormalities. further study is required to obtain a statistically signifi cant result. learning objectives: ) to describe the mr imaging fi ndings in the patellar tendon-lateral femoral condyle friction syndrome. ) to consider the patellar tendonlateral femoral condyle friction syndrome in the differential diagnosis of patients with anterior knee pain. ) to identify the patellar tendon-lateral femoral condyle friction syndrome in order to make a correct treatment. background: patellar tendon-lateral femoral condyle friction syndrome is a rare cause of anterior knee pain related to the clinical entity of fat pad impingement. mr imaging can reliable identify this entity, showing the soft tissue edema in the infrapatellar fat body in the anterolateral aspect of the patellofemoral joint. imaging findings: retrospective review of mr images in knees ( patients) with antero-lateral knee pain and a focal area of abnormal signal intensity in the inferolateral aspect of the patellofemoral joint was performed. patients with a meniscal tear or ligamentous injury were retrieved to exclude these facts as the cause of knee pain. abnormal patellar alignment was demonstrated in knees. patellar tendinitis was noted in cases. patellar confi guration type iii of wiberg was found in knees. conclusion: mr imaging allows identifi cation of changes in patients with patellar tendon-lateral femoral condyle friction syndrome that should be distinguished from other causes of anterior or lateral knee pain. utility of four-dimensional arthrography of the acetabular labrum applying motion-gated multislice computed tomography: comparison with arthroscopy and harris hip score n. funabashi, s. kishida, y. harada, h. moriya, i. komuro; chiba/jp purpose: to analyze the kinesis and morphology of the acetabular labrum (al) non-invasively, we applied four-dimensional ( d) arthrography with motion-gated msct and compared the results with arthoscopy and harris hip score (hhs). methods and materials: forty-nine symptomatic patients ( hips) underwent msct. before ct acquisition, contrast material was injected into the hip joint. the subject performed reciprocating hip fl exion-extension at the same rhythm as a pulsation simulator. then we performed mimic retrospective ecg-gating, that is "motion-gated", acquisition and were reconstructed to divide one movement into segments. the kinematics and morphology of al were evaluated on d fi lms and the fi ndings were classifi ed into three groups: stabilized, irregular, and eccentric motion. hip arthroscopy was performed in hips. labral lesions were classifi ed into four groups according to morphologic features (intact, fray, tear, and detached). hhs was also calculated depend upon patient state at the examination. results: of hips with adequate images, , , and revealed stabilized, irregular, and eccentric motion, respectively. of without adhesive al on arthroscopy, had irregular (average hhs) and had eccentric motion (average hhs) and hhs tend to be higher in the eccentric group than in the irregular groups on d ct. conclusion: d arthrography of the al applying motion-gated msct can reveal both kinetic and morphological changes of al and can perform further stratifi cation in subjects with the american academy of orthopaedic surgeons class , or or without "detached" morphological fi ndings by arthroscopy. impact of whole-body mr in the assesment of extension and follow-up of hemophilic artropathy r. domínguez, c. altisent, s. gispert, x. merino, v. pineda; barcelona/es ( rdo@comb.es) purpose: the hemophilic artropathy (ha) is a progressive osteoarticular disease presumed to result from intra-articular and periarticular hemorrhage. the aim of this study is to defi ne the role of the whole-body mr (wb-mr) in the assessment of extension, degree of joint involvement, and follow-up of the ha. in this prospective study, we performed a wb-mr performed in patients with ha and prophylactic treatment. mr protocol included t -se, stir, and gre-t in the coronal and axial planes using several coils. the parameters evaluated were: ) involvement of the important joints (shoulders, elbows, hips, knees, ankles), ) bone or muscle-tendinous involvement (muscular atrophy, muscular haematoma, pseudotumor), and ) other osteoarticular lesions not related to ha. the extension and degree of he were classifi ed according to the european score. results: in one third of the patients, the wb-mr detected ha in other joints not detected clinically, as synovitis, hemosiderin deposits or early artropathy. one third of the patients with clinical history of hemarthrosis of repetition did not show articular involvement or hemosiderin deposits by mr. other musculoskeletal pathologies not related to ha were identifi ed in % of the patients (meniscopathy, femoroacetabular impingement, labrum disease, avascular necrosis, fi brous defects), being important in order to stablish differential diagnoses. the wb-mr is a new useful imaging technique for the estadifi cation and follow-up of ha. it allows the evaluation of the response to the prophilaxis and treatment of the disease. it is also helpful for the differential diagnosis with intercurrent osteoarticular pathologies. mdct background: functional imaging might increase the role of imaging in muscular diseases, since sole assessment of muscle morphology reveals non-disease-specifi c results. intact sodium homeostasis is crucial for tissue viability. pathological changes of sodium homeostasis can be found in various clinical diseases, such as infarction, infl ammation, neoplasia, and muscular channelopathies. the implemented three-dimensional radial na mri technique detected validly the tissue's sodium content. the acquisition time of minutes and direct reconstruction of images and archiving them in pacs enabled a clinically feasible examination protocol. imaging findings: na mri delivers reproducible data on sodium content within skeletal muscles. in various sodium channelopathies, na mri detects intracellular sodium accumulation that is associated with muscle weakness and stiffness. also, the benefi cial effects of blocking the pathologic sodium channels by a dedicated medication can be quantifi ed. results of na mri in vivo correlate signifi cantly to both electrophysiological in-vitro data of muscle fi bers derived from biopsies and muscle weakness in patients with sodium channelopathies. furthermore, na mri detects altered myocellular sodium content in other ion channelopathies and dystrophic myopathies, as well as altered muscular sodium signal in acute autoimmune myositis. conclusion: na mri can quantify skeletal muscle sodium homeostasis and is a promising functional imaging method, especially for muscular channelopathies. the correlation between sonography and disease severity in carpal tunnel syndrome e. alimoglu, h. ozcanli, s. dogan bayraktar, a. apaydin, s. tuzuner, e. luleci; antalya/tr (ealimoglu@akdeniz.edu.tr) purpose: to investigate the correlation between sonographic fi ndings and severity of carpal tunnel syndrome (cts). methods and materials: wrists of patients with cts symptoms were included in our study. after clinical examination and electrodiagnostic study (enmg), sonography was performed in patients by a radiologist unaware of the physical examination and enmg results. the wrists showing both positive clinical fi ndings and enmg results were diagnosed as cts. the cross-sectional area of median nerve was measured at the level of the psiforme bone in sonography and the measurements over mm² were accepted in favor of cts. the disease was categorized into three groups according to enmg results: mild, moderate and severe. the difference between the mean sonographic area values of the three severity groups was investigated to estimate disease severity. results: fifty-four wrists had positive clinical examination and enmg results. the mean area was . ± . in these cases. the median nerve area was measured under mm² in cases. the sensitivity of sonography in the diagnosis of cts was %. the mean area of the median nerves was . ± . mm², . ± . mm², and . ± . mm² in mild, moderate and severe groups, respectively, and the difference between them was statistically signifi cant (p= . , kruskal-wallis analysis). conclusion: the diagnostic usefulness of sonography in cts has been clearly shown previously. however, little attention has been paid to the correlation between sonographic fi ndings and severity of disease. in addition to its high sensitivity in the diagnosis of cts, sonography may also be helpful in estimating disease severity. the aim of this study is to analyze and correlate the size and mr imaging signal features of aggressive fi bromatosis with its behaviour. march and december , patients with at least two consecutive mri examinations and no surgery or radiation therapy in between were recorded. they underwent mri examinations of lesions, of which were medically treated, while the remaining did not receive any drug administration. each lesion was studied by size and signal changes in time on t -injected and/or t -weighted sequences. for size, we used the recist criteria. we classifi ed the signal in six increasing classes, and then we established the related variations in the time. results: seventy-nine per cent of lesions in the treated group and % in the not-treated group maintained size stability. the initial signal of stable or increase in size of lesions was most frequently high. there was a high rate of signal stability in time, whatever the initial signal and size changes were. the size changes were not correlated with the initial mr signal. only in the treated group, decreases in size associated with signal decrease were observed. conclusion: fibromatoses are a group of soft-tissue tumors with variable characteristics on mri, but it is not possible to predict their behaviour from mri signal. assessment background: functional imaging might increase the role of imaging in muscular diseases, since sole assessment of muscle morphology reveals non-disease-specifi c results. perfusion, i.e. the blood fl ow per tissue and time unit including capillary fl ow, is an important functional parameter. pathological changes of skeletal muscle perfusion can be found in various clinical diseases, such as degenerative or infl ammatory myopathies. contrast-enhanced ultrasound allows for a sensitive detection of microvascularity in real-time. quantifi cation of perfusion is achieved by analyzing replenishment kinetics of the contrast agent. also, the effects of training schemes on muscle microcirculation can be assessed for separate muscle groups. imaging findings: contrast-enhanced ultrasound delivers reproducible perfusion data in volunteers. ceus visualizes exercise-induced hyperperfusion and can separate well-trained subjects from un-trained subjects. ceus-derived perfusion results in vivo correlate signifi cantly to capillarization in biopsies from these muscles. furthermore, ceus detects increased microcirculation in histologically proven acute autoimmune myositis with comparable accuracy as mri and additionally increases specifi city in diagnosis of myositis when a muscle edema -as such a non-specifi c fi nding -is evidenced by mri. moreover, the effects of muscle degeneration on microcirculation can be assessed. conclusion: contrast-enhanced ultrasound allows valid quantifi cation of skeletal muscle perfusion and is a promising functional imaging method for various myopathies. gas learning objectives: to illustrate the wide spectrum of causes of subcutaneous emphysema in the emergency room. to show the key fi ndings on ct and plain radiograph. to discuss the differential diagnoses. background: gas in soft tissue is a relatively common sign at the emergency room. it has a great importance due to its broad casualty, some of them totally benign, but others potentially lethal. we retrospectively reviewed the imaging fi ndings of patients with subcutaneous emphysema from our database of emergency pathology. we analysed the origins and the associated features. imaging findings: gas in soft tissue was found associated to traumatic, iatrogenic (surgical procedures, injection), or infectious causes (necrotizing fasciitis, fournier gangrene). it also was found associated with thoracic pathology causing pneumothorax and pneumomediastinum, and abdominal pathology related to intraperitoneal and retroperitoneal gas. diagnostic diffi culties and differential diagnoses are emphasized. radiologists must be aware of anomalous gas in soft tissue, because it may be the main or even unique sign to lead us to search the underlying pathology, which can be lethal. multi-detector-row ct of the muscles by using volume rendering techniques l. saba, g. caddeo, m. atzeni, f. corrias, d. ribuffo, g. mallarini; cagliari/it learning objectives: to analyze the mathematical concept to obtain vr images to defi ne the muscles. to learn the ct technical parameter to be used, as well as the slice thickness, increment, mas and kvs. to understand the current indications for performing multi-detector-row ct study of the muscles underlining radiation exposure, cost and diagnostic effi cacy background: multi-detector-row ct, by using fast scanning and thin collimation can obtain near-isotropic voxels, producing an excellent image detail. moreover, with the use of post-processing procedures it is possible to obtain volumetric images with an impressive visual impact (dissection-like images). with the use of correct techniques, by using in particular volume rendering (vr) reconstruction, it is possible to defi ne body musculature and to identify pathological alterations. the aim of this education exhibit is to describe how it is possible to obtain a correct visualization of the body muscles and to show volume rendered images that are possible to obtain. procedure details: we studied patients by using a multi-detector-row ct (mdct). data obtained were re-processed and we obtained volume rendered images. for each patient, we generated multiple vr reconstructed images in order to defi ne the better strategies to evaluate different types of muscles. conclusion: mdct can obtain excellent visualization of the superfi cial musculature; in particular, it defi nes with accuracy normal anatomy. hibernoma: review the mri imaging in eleven patients m. de albert , s. martínez , j. narváez , r. mast , e. carreño ; learning objectives: hibernoma is a rare benign soft-tissue tumour of brown fat cells. we describe the mr imaging fi ndings of eleven patients. background: cases were retrospectively identifi ed from the pathology database of two tertiary referral hospitals. patient age, sex and duration of symptoms were recorded. we retrospectively reviewed the mri of eleven patients with histologically proven hibernoma. imaging findings: patient group consisted of seven females and four males, with an average age of years (range - years). six lesions were located in the thigh, one in the chest and four in the upper limb. six of the lesions were intramuscular, three were intermuscular and two were located in the subcutaneous fat. the majority of the cases demonstrated mr fi ndings of a well-defi ned, heterogeneous mass, slightly or clearly hypointense to subcutaneous fat, with prominent thin low signal bands on t w se images. the lesions failed to suppress fully on stir or fat-saturated t -weighted images. six of the seven post-contrast studies evidenced signifi cant enhancement within the lesion. the mr fi ndings described should lead to consider this rare diagnosis in the assessment of an atypical fatty mass on mri. radiologic-pathologic correlation in fat tissue tumours of the extremities f. sandomenico, o. catalano, f. fazioli, a.r. de chiara, a. nunziata, a. siani; learning objectives: to give a comprehensive accurate guide of us, ct and mri fi ndings in various types of soft tissue lipomatous tumours of the extremity, with pathologic correlations during and after surgery. background: soft tissue tumours with prevailing fat tissue areas are lipomas, lipoblastoma, hibernoma and liposarcoma. liposarcoma is the second most common type of soft tissue sarcoma ( - %). its histological subtypes are categorised as: well differentiated, dedifferentiated, myxoid, allomorphic and mixed type. procedure details: the lesions illustrated are identifi ed with relative ease on ct and mri, due to the typical density/signal of the fat. lipomas, however, can reveal small non-fat density/signal areas; in these cases vigilance is necessary. in malignant lesions, one can usually detect fatty areas that allow the diagnosis. in these cases, the non-fat areas, on which the biopsy is to be directed, are picked up with imaging. special attention should be focused on the density/signal intensity in tumour nodules and septation. myxoid liposarcomas have some particularity such as intramuscular position, pseudocystic aspect with peripheral enhancement, small solid nodules, or septa containing fat. the knowledge of the pathological and surgical substrate of the lipomatous tumours of the extremity soft tissues constitutes the base for the diagnostic imaging assessment and is fundamental for optimal patient management. the role of ultrasonography in patients with radial nerve pathology: comparison with magnetic resonance and surgery c. bertocchi, s. colopi, r. adani, p. torricelli; modena/it (clatommy@fastwebnet.it) purpose: to evaluate ultrasonography (us) accuracy in identifying radial nerve (rn) morphology and related pathologies compared to magnetic resonance (mr). methods and materials: fifteen patients with nr paralysis ( had expansive and traumatic pathology) were examined with radiography, electromyography, us (siemens-sequoia; linear probe - mhz) and mr (philips intera . tesla). surgical evaluation was performed in patients. us and mr parameters evaluated were: identifi cation, thickness, integrity and structure of the rn. results: five patients had a spontaneous recovery of rn paralysis. in the remaining , us identifi ed correctly rn morphology, thickness, structure and anatomical relationship, compared to surgical evaluation. rm was unable to identify the rn in cases because of the metallic material artefacts. in traumatic and expansive pathologies, mean rn thickness was . mm and . mm, respectively; the ecographic structure was ipoechoic with loss of the fascicolated normal pattern in traumatic lesions while normal in expansive ones. conclusion: us and mr are both useful for the diagnosis of rn pathologies. us is a dynamic, comparative and brief examination, useful when metallic material obstacles are used in mr evaluation. us, therefore, is also useful in planning surgery and in the follow-up. radiological background: gctts is part of a group of benign proliferative lesions of the sinovium of the joint, bursa and tendon sheath. it represents the most common of this group of lesions, both in its localized and its diffuse form. procedure details: we studied retrospectively patients with gctts localized in hands ( had a single tumor and the remaining patient had a multifocal involvement). diagnosis was made by means of excisional biopsy. in all cases, plain fi lms and mri were performed. size, shape, localization and osseus involvement were analysed, as well as mri characteristics such as signal intensity and contrast enhancement. cases of relapse after surgery were also recorded. regarding mri, in t weighted images all tumors were homogeneous and isointense, but they were more heterogeneous and predominantly hipointense in t . after intravenous paramagnetic contrast administration, a homogeneous enhancement was demonstrated. in all cases, gradient echo sequences showed very low intensity areas. surgery was performed in every patient. in of them, local relapse was detected. conclusion: gctts is one of the most frequent soft tissue masses of the hand, second in frequency only to ganglion. we are obliged to suspect it in every case of hand tumor, specially if it is localized in the fi ngers. mri is useful in the diagnosis due to the characteristic fi ndings of the tumor. benign peripheral nerve sheath tumors in the pelvis: ct and mr fi ndings z. jiang, w. peng, t. yang; shanghai/cn (issyjiang@yahoo.com.cn) purpose: benign peripheral nerve sheath tumors (bpnsts), which include neurilemomas and neurofi bromas, arise in the pelvic space are relatively uncommon. the purpose of our study was to characterize the ct and mr fi ndings of pelvic bpnsts. methods and materials: ct and mr images of patients with a pathologically proven pelvic bpnst ( neurilemomas and neurofi bromas) were retrospectively reviewed. the following morphologic characteristics were evaluated according to tumor shape, size, position, margin, homogeneity and invasion into adjacent structures. when mri had been performed, signal intensity and the pattern of enhancement were also assessed. results: all pelvic bpnsts were round in shape, with well-defi ned margins; the mean diameter was . cm ( - cm); they were usually located in the presacral region ( / ). tumors were typically heterogeneous with cystic change ( / ), but centrally massive cystic attenuation was more common in neurilemomas than in neurofi bromas ( / vs / ). in cases, there was smooth expansion of a sacral foramen with marginal sclerosis ( in each group). patients underwent mri, t wi showed hyperintense cystic areas and solid areas of mixed intensity. on ct or mri contrast-enhanced images, peripheral enhancement was apparent in of neurilemomas, whereas irregular enhancement was evident in of neurofi bromas. conclusion: both pelvic neurilemomas and neurofi bromas are typically round, large, well-circumscribed, heterogeneous tumors that are located in the presacral space. they can occasionally cause bony changes in the sacrum, but do not invade adjacent structures. centrally massive necrosis or peripheral enhancement favors the diagnosis of a neurilemoma. learning objectives: to illustrate the spectrum of typical imaging fi ndings of charcot's spine and to discuss the main differential diagnoses such as infectious spondylodiscitis. background: neuropathic arthropathy of the spine is a rare destructive condition of the spine, which is secondary to the loss of the protective proprioceptive refl exes. infection must be considered as a possible differential diagnosis in case of a charcot's spine with destructive lesions. imaging findings: plain fi lms, ct and mri with gadolinium injection are useful. this destructive process involves the disc space, the vertebral bodies and the facet joints. the thoracolumbar junction and lumbar spine are most frequently affected, and one or more vertebral segments may be involved. sclerosis or osteolysis may predominate, and the spinal changes are often initially thought to be due to vertebral osteomyelitis or metastasis. osseous fragments typically extend beyond the confi nes of the vertebral body margins into the musculature and the spinal canal. bone debris and effusion may result in a paraspinous mass containing calcifi cations. however, solid epidural masses are typically lacking. the presence of vertebral body sclerosis and osseous fragmentation are further imaging fi ndings that help differentiate neuropathic spine from other processes. conclusion: background and imaging are suggestive of the diagnosis. closed needle and even open surgical biopsies are often necessary to fi nally confi rm the charcot's spine and exclude infection. spontaneous vertebral fracture -investigation with conventional and diffusion mr imaging t. gerukis, m. tsoukala, a. fotiadou, e. vafeiadis, v. kalpakidis, p. palladas; thessaloniki/gr purpose: the spine is the most common location of bone metastases in patients with primary malignancy, and also of benign osteoporotic fractures, especially in the elderly and in those who receive long-term steroid therapy. conventional imaging techniques cannot always differentiate benign from malignant lesions. those can be better distinguished with the addition of tissue-apparent diffusion coeffi cient (adc) measurements. a total of acute vertebral body compression fractures were found in patients. twenty-eight fractures in patients were due to osteoporosis (due to age or therapy), whereas fractures in patients were histologically proven to be due to malignancy. signal intensities on t -weighted, short tau inversion recovery (stir) and diffusion-weighted images were compared. adc values of normal and abnormal vertebral bodies were calculated. results: benign acute vertebral fractures were hypointense and malignant acute vertebral fractures were hyperintense with respect to normal bone marrow on diffusion-weighted images. mean adc value was . (± . ) x - mm sec - in metastatic acute vertebral fractures and . (± . ) x - mm sec - in osteoporotic acute vertebral fractures. these values were signifi cantly different. conclusion: diffusion-weighted mr imaging with quantitative evaluation of adc values allows the distinction of benign from metastatic vertebral compression fractures. it is a procedure that provides valuable additional information, and we believe that it must take its place in everyday clinical practice. mri presents no immediate impact on lumbar spine degeneration in adolescent elite athletes versus non-athletes h. hoff, i. platzek, u. reuter, k.-p. günther, m. laniado, p. aikele; dresden/ de (hansjoerg.hoff@uniklinikum-dresden.de) purpose: degenerative spine abnormalities start developing early in life and are frequent even among adolescents. the effects of sports on lumbar degeneration in adolescents have not been comprehensively evaluated yet. the aim of this prospective study was to compare the degree of spine degeneration in adolescent athletes and non-athletes. the lumbar spines of adolescent elite athletes ( m, f; mean age: . years) and non-athletes ( m, f; mean age: . years) were examined using mri. the lumbar spine examination was performed with a . t mri scanner (somatom sonata, siemens, germany). sagittal pd, t , t and tirm images and transverse t images were obtained. two radiologists evaluated the images using a previously designed checklist. results: the prevalence of pathologic fi ndings varied widely in both groups. % of the athletes and % of the comparison group were affected by protrusions. . % of the athletes showed spondylarthrosis (non-athletes: %). decreased signal intensity of vertebral discs on tirm images was found in . % of the athletes (non-athletes: %). there were no cases of nerve root or spinal compression. the chi-square test was used for statistical evaluation. there were no signifi cant differences concerning the most common degeneration signs (protrusions, disc degeneration and spondylarthrosis). the authors conclude that active participation in sports does not have a signifi cant immediate impact on spine degeneration in adolescents. however, in order to evaluate the long-time effect of sports on the spine, further follow-up studies are necessary. multi-slice ct of spinal metal implants: pictorial essay h.r. cairns, j.m. elliott, p. archbold, r.j. winder; belfast/uk (heathercairns@greenpark.n-i.nhs.uk) learning objectives: to recognise the difference in beam hardening artefact, produced by steel and titanium spinal implants, on multi-detector spiral computed tomography (mdct). to appreciate the effect of data acquisition parameters on the degree of artefact. to appreciate the effect of different reconstruction kernels on the appearance of titanium metal artefact. to learn how to reduce the degree of artefact by altering mdct scanning and reconstruction parameters. background: steel and titanium metals are commonly used in spinal surgery with signifi cant impact on post-operative ct image quality. the artefact is due to beam hardening and it appears as streaking with signifi cant change in local ct number values. the streaking artefact can seriously detract our ability to visualise pathology in proximity to the implant, for instance, nerve root irritation, remaining bone/disc protrusion. procedure details: steel and titanium pedicle screws were positioned in a "dry bone" lumbar spine model. this was immersed in water. the model was scanned in a siemens (erlangen) -slice mdct scanner. twelve data sets were obtained using combinations of slice thickness ( . , . , . head protocol, and . mm) and reconstruction kernels (smooth, medium and sharp). artefact in each data set was assessed at the ct workstation and personalised workstation, using identical window settings, ct numbers and a line profi le technique. conclusion: a signifi cant difference was measured between steel and titanium pedicle screw artefact. the images presented have demonstrated that beam-hardening artefact can be reduced depending on the combination of slice collimation and kernel setting. biomechanical model to assess the fl exion/extension mobility of the lumbar spine: consideration of soft tissue artifacts a. curti, f. perona, g.l. ciavarro, g.c. santambrogio, g. andreoni, g. castellazzi, g. cornalba; milan/it purpose: skin-based measures obtained through optoelectronic system maybe a good technique to assess the functionality of the lumbar spine. however, soft tissue artifacts (sta) may be a signifi cant and relevant problem to accurately measure the mobility of the spine and so they had to be considered. methods and materials: healthy people participated in the experimental setup. twenty-four markers (pills of oil e vitamin) were attached onto the skin in correspondence to vertebral reference points. six static fl exion/extension postures were acquired through a vertical mri (vmri). then a fl exion/extension movement of the lumbar spine was acquired through an optoelectronic system. the estimation of the position of vertebral center of rotation (cor) together with the knowledge of sta (obtained from previous studies) allowed the development of a new biomechanical model to assess the mobility of the lumbar spine. finally these data were validated comparing the results of the biomechanical model with a gold standard (vertebral mobility through vmri). results: this biomechanical model shows a metameric error of . ° ± . ° and global error of . ° ± . °. these data are very good with respect to the traditional methods assessing the lumbar spine mobility with a mean error reduction of about %. conclusion: this biomechanical model estimates well the lumbar fl exion/extension mobility starting from d kinematic data acquired through an optoelectronic system, some anthropometrical characteristics, the relations of sta (previously found) and the cor (here estimated). so it may be a useful instrumentation to assess the functionality of the lumbar spine. b d e f a g ultrasound-guided interventional procedures in the foot and ankle m. vlychou, j. teh; oxford/uk (mvlychou@doctors.org.uk) learning objectives: this pictorial illustration of ultrasound-guided interventional procedures of the foot and ankle will review the indications, technique and possible complications. background: foot and ankle pain, both acute and chronic, are common indications for clinical investigation due to degenerative, infl ammatory or osseous pathology and sport injuries. ultrasound is an imaging modality that can be applied not only for the detection of the underlying cause of the problem, but also more importantly as a means of therapeutic and diagnostic intervention. misinterpretation of radiographs by emergency physicians: how big is the problem? y. thian, m. mateo, s. tay; singapore/sg (ylthian@gmail.com) purpose: to evaluate the rate of discrepancies in radiographic interpretation between emergency physicians and radiologists. the pattern of commonly missed radiographs and the nature of clinically signifi cant interpretation discrepancies leading to a change in management or adverse outcome were also studied. methods and materials: all radiographs obtained in our emergency department from january through february were fi rst interpreted by ed physicians and compared with the formal radiology reports. discrepant interpretations were marked for further study and classifi ed into one of four categories: false-negative interpretation by ed physicians, false-positive interpretation by ed physicians, false-negative interpretation by radiologists and false-positive interpretation by radiologists. discrepancies that necessitated intervention and adverse outcomes were also recorded from the clinical summaries. results: of the radiographic examinations generated during the study period, there were ( . %) false-negative misreads by the ed physicians and ( . %) overreads. only examinations ( . %) necessitated an alteration in clinical management as a result of the misreads. three adverse events were recorded during the study period as a result of radiographic misinterpretation, all of which were cervical spine radiographs. the most frequent type of false-negative interpretation was the chest radiograph. conclusion: only a small portion of radiographic misinterpretations by ed physicians necessitated a change in management. ultrasonography in this exhibit, we show the topographic anatomy of the brachial plexus and its distal branches, with special attention to its anatomical relationships and its ultrasonographic appearance. there are three anatomical regions to approach the brachial plexus: a) supraclavicular region, b) infraclavicular or anterior region of the shoulder and c) axilar region or root of the arm. we show the topographic anatomy of each of these three regions, and the different puncture techniques recommended for each area. conclusion: brachial plexus punctures allow the locoregional blockade of several regions of the upper limb. us enables to guide the puncture with great safety, diminishing complication rates and undesired side effects, such as nerve lesion or the intravascular injection of local anesthetic drugs. lesions were classifi ed as hypointense, isointense or hyperintense. results were compared with fi nal diagnosis established by pathologic examination (n= ). statistical analysis was performed with student's t-test. results: benign bone tumours and soft tissue lesions were iso-to hypointense to adjacent normal bone marrow. malign bone and soft tissue tumours and benign bone lesions including infection and aseptic necrosis were hyperintense to normal bone marrow. malign tumours and infectious processes had positive contrast ratios, whereas benign musculoskeletal tumours had negative values (p < . ). conclusion: psif sequence may allow differentiation of malign and benign musculoskeletal lesions. malign tumours show hyperintensity, probably owing to altered water proton mobility in neoplastic tissue. benign lesions, except infection and aseptic necrosis of the bone, show hypointensity, refl ecting free water proton mobility. in infectious processes, hyperintensity may be attributed to infl ammatory cells, mucoid and proteineous matrix decreasing free water fraction in the interstitial space. normal sonographic anatomy of the foot with mri correlation g. ansede, j.c. healy, j.c. lee; london/uk (gonzaloansede@yahoo.com) learning objectives: to demonstrate normal sonographic anatomy of the foot with emphasis on short foot ligaments using schematic drawings and mr imaging for correlation. background: the oblique orientation of the foot ligaments and tendons can result in diffi culty identifying them on mr imaging. however, many of these structures can be identifi ed using high frequency sonography transducers. the four muscle layers of the sole of the foot. conclusion: sonography offers high resolution imaging of the tendons and ligaments of the foot. in addition, sonography is quick, relatively inexpensive, widely available and allows for dynamic evaluation of structures which can be easily clinically correlated at the time of scanning. however, sonography is operator dependent and optimal assessment can only be made with intimate comprehension of the normal sonographic anatomy. do radiologists need to report a&e trauma extremity fi lms? s. hussain, j. heron, l. farrell, a. ahmed; birmingham/uk (drsh @hotmail.com) purpose: plain fi lm reporting still makes up a signifi cant proportion of the reporting work in radiology departments. trauma extremity fi lms on patients admitted via the accident and emergency department constitute the signifi cant majority. with these fi lms being looked at by radiographers (red dotting fi lms), trauma juniors and/or senior doctors, is there still a necessity for reporting of these fi lms by radiologists? previous published studies have shown that junior doctors reported as few as % of fi lms correctly. methods and materials: retrospective analysis was made of all patients who presented through the accident and emergency department at sandwell hospital, birmingham over two separate one-week periods. extremity fi lms were identifi ed and the report in the notes made by the clinician was compared with the consultant radiologist report. discrepancies were identifi ed and any fi lms where there was discord were double reported by another consultant radiologist to provide a "gold standard" report. results: sixty-four percent of the radiographs were agreed to be normal, % were agreed to be abnormal but % were abnormal, which were identifi ed by only one department. after double reporting, a&e had an error rate of %, with a false positive rate (identifying a fracture where none was present) of % and a false negative rate (missing a fracture where one was radiologically present) of %. errors were greatest with the shoulders, elbows and ankle x-rays. radiology had an error rate of %. conclusion: although a&e doctors have a high standard of reporting, with a low false negative rate, there is still a need for radiology to report all trauma fi lms. sonography of the musculoskeletal system: a how-to-do dvd rom-based audiovisual guide g. delimpasis, k. chatzimihail, a. michailidis, s. faitaki, i. bechrakis, a. plagou, g. adamakis, k. pahou, p.s. zoumpoulis; athens/gr (echo@hol.gr) learning objectives: . to outline basic us physics and us technology. . to present the examination technique of the musculoskeletal system. . to illustrate the main indications and limitations of the modality. . to present normal echoanatomy and correlate abnormal sonographic fi ndings with specifi c musculoskeletal disease. background: modern high-resolution sonography is increasingly employed in the diagnosis of musculoskeletal injury and disease. the present dvd rom is based on a series of lectures focused on facilitating training and incorporates technical aspects of proper us examination with features of normal and diseased echostructure of the joints. procedure details: individual topics include the fundamentals of us physics and technology, study of the shoulder (with particular focus on rotator cuff pathology), elbow, wrist and carpal tunnel syndrome, knee, as well as examination of the pediatric patient and us applications in non-traumatic musculoskeletal disease. normal sonographic appearances are identifi ed and juxtaposed to abnormal features associated with specifi c joint pathology. relevant doppler fi ndings, aberrations during dynamic scanning and common artifacts are also discussed. emphasis has been placed on delineating the signifi cance of appropriate transducer manipulation and selection of machine settings so as to optimize diagnostic results. "real-time" video fi les are used to demonstrate the correct technique through the simultaneous screen display of transducer positioning and obtained us images. furthermore, these "hands-on" sessions elucidate the merits of dynamic scanning. a bilingual approach has been carried out by complementing the main greek text with english subtitles. conclusion: sonography is a valuable modality for musculoskeletal imaging, provided it is implemented meticulously. ultrasound suspicion and add useful additional information. direct imaging of peripheral nerves is possible using cross-sectional modalities, such as ultrasound (us), computed tomography and magnetic resonance imaging (mri). in experienced hands, us provides an economic, fast, noninvasive and accurate evaluation of the mn from the axilla to the distal branches. imaging findings: in this article, we will fi rst present the normal anatomy of the mn through schematic drawing and selected images from cadaveric dissections. then, the technique of us examination and the normal us appearance will be illustrated. in the last part, representative us images with mri correlations and schematic drawings will be presented to illustrate a wide spectrum of the pathologic conditions. conclusion: us can effi ciently assess the normal mn and diagnose a wide variety of disorders. accurate knowledge of the us anatomy and scanning technique is an essential prerequisite. tumors conclusion: the incidence of scapular tumors is low. bone tumors involving the scapula as the sole site constitute an uncommon fi nding, with few cases reported. both benign and malignant neoplasms can be found. since early diagnosis is crucial for prompt therapy, imaging plays an essential role. plain radiograph is the primary modality in the diagnosis approach. however, computed tomography (ct) and magnetic resonance (mr) play a major role in establishing diagnosis and staging. extended fi eld-of-view sonography: does this technique provide additional information to conventional b-mode images? f. eksert, c. yucel, s. ozhan oktar, n. kadioglu, h. ozdemir; ankara/tr (cyucel@gazi.edu.tr) purpose: to compare the imaging fi ndings of lesions examined with b-mode and extended fi eld-of-view (efov) sonography and to demonstrate if efov technique provides additional information. methods and materials: sixty patients ( males, females) (age range: - years, mean age: ± . years) with lesions were involved in the study. / ( %) of the lesions were localized in the musculoskeletal system, / ( %) were in the neck area, / ( %) were in the anterior abdominal wall, / ( %) were in the peritoneal cavity, / ( %) was in the scrotum and / ( %) originated from the brachial artery. all lesions were examined with both the conventional b-mode and efov sonography. the fi ndings were evaluated independently by two radiologists. sonographic images obtained with each technique were scored for lesion characterization, and for simultaneous demonstration of the lesions and their relationships with surrounding tissues. wilcoxon signed rank test was used for statistical analysis. kappa scores were calculated to assess inter-observer agreement. results: wilcoxon test revealed that efov sonography was superior to b-mode imaging for both lesion characterization and for the determination of its relationships with neighboring structures (p= . ). kappa scores refl ected moderate to good inter-observer correlation ( . - . ). conclusion: efov sonography is a practical and easily applied technique. this technique overcomes the problem of limited fi eld-of-view, which is one of the most important disadvantages of b-mode sonography. the simultaneous visualization of the lesions and surrounding structures in larger fi eld-of-views makes efov images more apprehensible compared with conventional b-mode images. is it necessary to review all casualty radiographs? s. nayak, m. chandramohan, c. groves; leeds, west yorkshire/uk (sanjeevnayak@hotmail.com) purpose: to check for any discrepancies in the plain fi lm reporting by the a&e doctors when rechecked by a radiologist. to look into the incidence of signifi cant misses that altered the patient management. the duration of the study was days. a retrospective study was conducted at the bradford teaching hospitals, looking at all the casualty radiographs that were double reported by the radiologists. results: a total of a&e fi lms were reviewed by the radiologists. ( %) of them were agreed upon by the radiologists in correlation to the a&e diagnosis. ( %) of the total were disagreed by the radiologists. ( . %) of these were considered as signifi cant misses. out of disagreed fi lms, letters were sent by a&e to the gp. of these, needed further investigations were recalled to the fracture clinic. the radiologists' reports on radiographs of the chest, face, skull, and wrist had the greatest effect on patient management. reports on the radiographs of fi ngers, hands, shoulders, long bones, and toes seldom altered treatment. purpose: thrombolysis has been shown to improve the -month outcome of patients with ischemic stroke, but knowledge of the long-term effect of thrombolysis is limited. the present study compares the long-term outcome of stroke patients who were treated with intra-arterial thrombolysis (iat) using urokinase with the outcome of patients treated with aspirin. the modifi ed rankin scale (mrs) was used to assess the outcome. one hundred seventy-three patients treated with iat and patients treated with aspirin from the bernese stroke data bank were eligible for the study. a matching algorithm taking into account the patients' age and stroke severity on admission (as measured by the national institute of health stroke scale, nihss) was used to assemble an iat and an aspirin group. results: one hundred forty-four patients treated with iat and patients treated with aspirin could be matched and included in the comparative analysis. the median nihss score was in each group. at years, % of the patients treated with iat and % of the patients treated with aspirin achieved functional independence (mrs to ; p = . ). clinical outcome was excellent (mrs to ) in % of the iat and in % of the aspirin patients (p = . ). mortality was % and %, respectively. the present study provides evidence for a sustained effect of iat when assessed years after the stroke. the purpose: the aim of our work was to localize cortical areas involved in the processing of the visual stimuli with different complexities using fmri. in eight healthy volunteers ( - years old), conventional anatomical and fmri were performed on . t mr scanner. we used echo-planar imaging. for visual stimulation, we used matrix from x gabor elements. gabor element is a sinusoid fading under gauss law, which corresponds to receptive fi elds of primary visual cortex cells. in "simple" stimulus, most elements have preferred orientation. in case of "complex" stimulus, only a part of the elements have preferred horizontal or vertical orientation. the size, brightness and contrast of the stimuli were identical for chaotic and ordered patterns. post-processing includes: ( ) calculating statistical map with t-student criterion of more than , where hypothesis h assumes that mr-signal intensity in rest is equal to activation intensity; ( ) for the identifi cation of anatomical structures, the resulting maps were fused with the anatomical image and then both images were transformed to space of atlas talairach. results: "complex" stimuli in comparison with "simple" stimuli caused activation on brodmann fi elds number , and . when a patient must choose the preferred orientation of elements, click the left or right button of the mouse to discriminate between "complex" and "simple" stimuli; "simple" stimulus causes activation in the middle frontal gyros (brodmann fi elds number / ). conclusion: thus, "complex" stimulus causes additional activation in the parietal lobes. cases of active observation demonstrate an additional activation locus in the prefrontal cortex, which presumably, refl ects the work of the "central executive mechanism". anatomy of the normal and pathological visual pathways: a dti-fi ber tracking study a. paniagua bravo, l. muñoz almazán, j. guzmán de villoria lebiedziejewski, g. medrano seoane, j. crespo san josé; madrid/es (alvpaniagua@yahoo.es) learning objectives: mri diffusion tensor imaging (dti) was performed in patients and healthy individuals in order to study the visual pathway (vp). our purpose was to show its normal anatomy as well as the pathological changes in some diseases that involve it. background: diffusion weighted imaging (dwi) is a useful technique to obtain brain maps from the white matter tracts. our study is focused on the assessment of the vp after performing dwi maps to visualize the different parts of the vp. when compared to the results in normal subjects, the pathological features in patients can be classifi ed into items: ) diseases that lead to atrophy of the vp (ocular globe enucleation, multiple sclerosis, hypovitaminosis); ) displacement of the fi bers caused by entities with associated mass effect (tumors); ) infi ltrating lesions of the vp (neoplasms, pseudodotumoral demyelinitation plaques). procedure details: all the studies were performed on a . t mr unit by using a single-shot echo-planar imaging sequence (fl ip angle: º, tr: , te: , nsa: ) with b = mm /sec. this protocol was modifi ed in patients in order to obtain a better visualization of the pathology (tr: , te: , nsa: ). we also acquired an anatomical imaging d/dti. post-processing was made in a workstation using the philips pride software. we get d and d color maps from the vp. conclusion: dti is a useful technique to study the normal and pathological visual pathway. post-thalamic fi bers are easy to map, whereas the visualization of prethalamic fi bers is possible with a specifi c dti acquisition protocol. b d e f a g unavoidable effect of brain radiation. we reviewed fi ndings of routine mri in cases of pathologically proven crn. background: it is imperative to distinguish crn from recurrent tumor in order to avoid unnecessary antineoplastic therapy and to administer therapy appropriate for the crn. there is no defi nitive imaging method to distinguish these conditions. we retrospectively reviewed all clinical cases of crn identifi ed histologically at surgery from hfh in the past years. imaging findings: treated tumors included gliomas, metastases, pnet and ependymoma. central necrosis ( ) and cysts ( ) were common. t hyperintensity without contrast administration was seen in cases. the most common pattern of enhancement seen in patients included ill-defi ned borders, lack of a nodular component, and a central "swiss cheese" appearance. subependymal enhancement was present in cases and corpus callosum enhancement was seen in . a pattern of enhancement in two adjacent lobes separated by the dura was seen in three cases. brain atrophy was present in and leukoencephalopathy in patients. : a "swiss-cheese" and ill-defi ned, non-nodular pattern of enhancement was most common. the high frequency of involvement of the corpus callosum and subependyma was unexpected, as these fi ndings are traditionally reported with tumor infi ltration. a pattern of enhancement in adjacent lobes separated by the dura is uncommon, but may be pathognomonic of crn when the imaging changes are consistent with the radiation fi eld dosimetry. dural lesions mimicking meningiomas: a pictorial review d. chourmouzi, g. boulogianni, k. manolakaki, k. drevelegas, t. zaraboukas, a. drevelegas; thessaloniki/gr (dchourm@hol.gr) learning objectives: to describe a number of neoplastic and nonneoplastic entities that radiographically and clinically mimic meningiomas. to outline the pathological and imaging characteristics of these entities. background: intracranial dural-based lesions can be due to benign or malignant processes. imaging characteristics cannot always discern between different pathologic conditions. a thorough clinical evaluation may reveal likely diagnostic possibilities. procedure details: an overview of the mri characteristics of dural lesions is presented. there is also presentation of some pathologically proven lesions including solitary fi brous tumor, gliosarcoma, hemangiopericytoma, melanocytoma, hodgkin's disease, plasmacytoma, infl ammatory pseudotumor, plasma cell granuloma, rosai-dorfman disease as well as metastatic carcinoma. the role of the advanced magnetic resonance techniques such as spectroscopy, diffusion and perfusion mr imaging is discussed. conclusion: the differential diagnosis of dural-based lesions in the brain varies from incidental and benign to symptomatic and malignant. careful vigilance in patient's history is essential. awareness that such lesions involve the dura may facilitate preoperative recognition and, in some cases, preclude unnecessary surgery. learning objectives: . to review pathophysiology and diagnostic criteria of mitochondrial disorder. . to investigate various neuroradiologic fi ndings in children with mitochondrial disorder and, particularly, unspecifi ed mitochondrial encephalomyopathies. background: mitochondrial disorders are a heterogeneous group of clinical syndromes associated with abnormalities of mitochondrial energy metabolism. the impaired energy production results from the overall dysfunction of mitochondrial respiratory chain, composed of enzymatic complexes embedded in the inner mitochondrial membrane. we investigated the various neuroradiologic fi ndings in children with mitochondrial disorder, and correlated them with the biochemical defect in the mitochondrial respiratory chain complex. imaging findings: children with mitochondrial disorder showed different patterns of brain mr imaging abnormalities. rapid progression of atrophy involving all structures of the brain with variable involvement of white matter were found in patients, and the patients with complex i defi ciency showed more severe changes in serial scans; t prolongation of basal ganglia, thalami, brain stem and cerebellum in patients with complex i or iv defi ciency; predominant cerebellar volume loss in patients with complex i or iv defi ciency; and encephalomalacia of globi pallidi in patients with complex i defi ciency. conclusion: children with mitochondrial disorder showed different features on brain mr imaging from a combination of various defects of mitochondrial respiratory chain complex. defects of different parts of the mitochondrial enzyme could result in the same abnormality on brain mr imaging, whereas identical biochemical defects could cause different imaging manifestations. learning objectives: . to illustrate the wide spectrum of intracranial lesions with ring enhancement on mri. . to categorize these lesions according to imaging fi ndings on dwi and calculated adc values. . to provide an easy-to-follow algorithm for the differential diagnosis of intracranial ring-enhancing lesions. background: ring enhancement is an unspecifi c mr fi nding occurring with a variety of aetiologies. it is most frequently encountered in neoplastic and infectious disorders, such as metastases, gliomas, and abscesses, but is also observed in vascular pathologies, such as resolving haematomas and infarcts. because of the variable clinical course and prognosis of these diseases, an early and correct diagnosis is necessary for choosing the appropriate therapy. procedure details: we present the broad spectrum of intracranial lesions with ring enhancement on mri with emphasis on the diagnostic impact of diffusion-weighted sequences and adc values. additionally, mr features that could be possibly helpful in distinguishing ring-enhancing brain lesions are discussed. conclusion: dwi has recently shown promise in differentiating ring-enhancing lesions such as brain abscesses and malignant neoplasms. combining the information of conventional mri and dwi with adc calculations, the correct diagnosis of ring-enhancing lesions can be achieved in a majority of cases. the dynamic study of csf circulation in hydrocephalic patients by means of magnetic resonance (mr): semeiotic technique and case gallery l. fortunelli , v. annibale , f. favano , p. car , p. spagnolo , a. stecco , a. carriero ; novara/it, monza/it (lorenzofortunelli@virgilio.it) learning objectives: to describe the methodological aspects and advances of the cine pc technique for studying csf. to present a case gallery for each type of hydrocephalus. to describe the mr semeiotics of this technique. background: csf fl ow was previously studied by means of ct, a lumbar puncture (tap test) or ventriculocisternography. dynamic mr investigations are based on phase contrast sequence that provides quantitative and qualitative measurements of fl ow velocity and direction. the automatic planning of acquisition planes has recently become available. the indications for this examination are to characterise normotensive hydrocephalus and treated hydrocephalus. imaging findings: thirty-fi ve examinations were carried out using . tesla mr with an eight-channel phased array coil and cardiac trigger, and post-processing software for quantitative analyses. axial flair and sagittal csf drive sequences were used to localise the aqueduct of silvius, and axial csf qf (fast spin-echo d) for the quantitative analyses. csf pca is a sagittal pc angiography used to visualise csf fl ow. the post-processing analyses included the quantitative and qualitative data, with the creation of a cine-rm that visualises the csf circulation. the technique is optimised using "smartbrain". the technique was feasible in % of cases, all of which showed concordance between the cine pc images and clinical symptoms. the automatic planning method makes the technique easier to perform. virtual mr ventriculoscopy of the brain h. sherif, a.e. mahfouz; doha/qa (sherifhanan@yahoo.com) learning objectives: to introduce the technique of virtual magnetic resonance (mr) ventriculoscopy of the brain and to illustrate the ventriculoscopic appearance of the cerebral ventricles in normal persons and in patients with different diseases of the brain, which involve the cerebral ventricles. background: the recent advances in three-dimensionally acquired and displayed mr images and the use of virtual endoscopic technique in image processing have enabled virtual endoscopic examination of the cerebral ventricles. the present exhibit illustrates the appearance of the normal anatomy of the lateral, third, and fourth ventricles and the appearance of lesions related to the cerebral ventricles from an endoscopic viewpoint. procedure details: three-dimensionally acquired images of the brain have been performed by d fat-saturated t -weighted turbo-flash (fast-low-angle shot) sequence covering the whole brain. images have been reconstructed by virtual endoscopic technique (colon, wizard, siemens, erlangen, germany). conclusion: virtual mr ventriculoscopy of the brain is a new technique of imaging of the cerebral ventricles, which may be useful in three dimensional evaluation of congenital and acquired abnormalities as well as abnormal masses related to the cerebral ventricles. continuously monitoring of the brain during severe insulin-induced hypoglycemia by diffusion-weightened mr imaging p. purpose: severe cerebral hypoglycemia with onset of neurological symptoms is frequently associated with reversible diffusion disturbances, which could be visualized as hyperintense lesions by diffusion weightened brain imaging particular in the splenium and the corona radiata region. this study is focused on the evaluation of hypoglycemic pathogenesis, especially with regard to the severity of insulin-induced reversible hypoglycemia. methods and materials: seven volunteers received an i.v. bolus of . u per kg body weight short acting insulin inducing hypoglycemia, while the individuals were continuously evaluated by a . t scanner (siemens sonata). diffusion-weightened echo planar sequences ( / tr/te) were obtained without interruption. additionally, serum blood glucose levels were also continuously monitored using glucostix test strips; further more serum blood specimen were sampled for later laboratory measurements. examination was stopped as soon as serum glucose level was diminished to < . mmol/l or the subject wished to abandon the trial due to vegetative symptoms. images were independently analyzed by two radiologist. results: all subjects revealed a hypocglycemia < . mmol/l for at least min, mean serum glucose level decreased down to . ± . mmol/l and one patient stopped examination at . mmol/l due to vegetative symtpoms. in the mri diffusion images, no alterations pointing at an infl uence of cerebral diffusion could be observed in all individuals. conclusion: short-time severe hypoglycemia (< min) does not induce visible changes in mri diffusion imaging, suggesting long-time hypoglycemia maybe the relevant cause for observed reversible diffusion disturbance in mr imaging. primary learning objectives: to illustrate the spectrum of mr and proton spectroscopy fi ndings in primary lactic acidosis related to mitochondrial diseases in brain. to describe the advantages of proton mr spectroscopy evaluation. background: mitochondrial diseases constitute a complex and heterogeneous group of metabolic disorders caused by heritable abnormalities of the respiratory electron transport cascade. although mitochondrial dysfunction manifests over a wide range of clinical expressions, it most often affects the muscle and brain, where dependence on oxidative energy metabolism is highest. the most common clinical features are muscle weakness, lactic acidosis and a broad range of neurologic defi cits. in this exhibit, we will analyse mr and proton spectroscopy fi ndings of primary lactic acidosis related to mitochondrial disease. between january and january , we analyzed mr and proton spectroscopy of patients with lactic acidodsis and clinically suspected of mitochondrial disease. procedure details: nine patients had lesions bilateral and simetrics, hyperintense on flair and t -weighted images and hypointense on t -weighted images in brain stem and basal ganglia. three of them had thalamic involvement too. proton spectroscopy revealed elevated lactate and a n-acetylaspartate reduction, both in areas that appeared damaged. in of patients, mr was normal but proton spectroscopy showed similar fi ndings. conclusion: proton spectroscopy is a useful investigational tool in the study of mitochondrial diseases as it supplies additional information to that of conventional imaging, because it documents metabolic anormalies even in areas of the brain that appeared to be normal. observation of metabolic changes in tumour bed with proton mr spectroscopy in patients with primary gliomas during radiation therapy l. zarudzki, b. bobek-billewicz, w. senczenko, a. idasiak; gliwice/pl (lzarudzki@op.pl) purpose: to observe the time course of the proton magnetic resonance spectroscopy ( h-mrs) changes in tumor bed, during radiation therapy, in patients with primary gliomas. we followed patients who received an external radiation therapy for primary gliomas for - weeks (mean: days; median: . days). all patients underwent brain surgery prior to the radiotherapy. the patients received fractioned doses of or gy in the lesion area. each patient underwent single voxel spectroscopy (svs te= ; te= ) before and just after the completion of the radiation therapy. the voxels of interest were chosen in the tumour bed, overlying the planning target volume (ptv). the following metabolite concentrations, normalized concentrations and their ratios were evaluated by the areas of the peaks after peak fi tting: naa, cho, cr, lac, lip . / . , glu+gln, ins. the spectra were verifi ed with lcmodel. results: after the completion of radiotherapy, we observed the increase in the normalized naa concentrations and naa/cr ratio and the decrease in the normalized cho, glu+gln, lip[ . ] concentrations and cho/naa ratio. the h-mr spectroscopy has the capability of detecting early metabolic changes in the irradiated tumour bed after the completion of radiotherapy. the increase of naa and decrease of cho and glu+gln concentrations can be the result of the residual neoplasmatic infi ltrate's regression. the changes in other metabolite concentrations occurred, but were not signifi cant. atypical imaging findings: unusual imaging features of meningiomas are shown, such as infrequent locations (intraventricular, intraosseu); cystic or fatty degeneration; large edema; ring enhancement; low-adc values and increased permeability. we will also show cases that may be diffi cult to differentiate from meningiomas, not only tumoral (mesenchymal tumors, hemangiopericytoma, melanocytic lesions, shwannomas, dural metastases), but also non-tumoral lesions (aneurysms; dermoid and epidermoid cyst) conclusion: meningiomas account for - % of intracranial tumors. the diagnosis is relatively easy when the tumor has characteristic radiological fi ndings. however, the radiologist must be aware of the less frequent imaging features in order to suggest the diagnosis in cases that meningiomas are atypical. most meningiomas are benign ( %), but there are also atypical ( - %) and malignant ( - %) variants that have specifi c histopathological characteristics. these meningiomas show unusual imaging fi ndings more frequently. the distinction between atypical and typical meningiomas is clinically relevant, because benign tumors recur in about - % of cases, where as atypical variants recur in - %. furthermore, the treatment is different in both cases. epileptogenic structural disorders in pediatric patients: mr imaging characteristics a. mallouhi, t. gotwald, e. haberlandt, g. feuchtner, e. trinka, s. felber, d. zur nedden; innsbruck/at (ammar.mallouhi@uibk.ac.at) learning objectives: . to provide an mr imaging overview of epileptogenic structural disorders in pediatric patients. . to familiarize with the key mr fi ndings necessary to assist in rendering a diagnosis. background: epilepsy is a chronic condition that results from abnormal excessive activity of a population of cerebral neurons. several brain structural disorders have been implicated in epilepsy in pediatric patients. imaging findings: in this exhibit, we illustrate a spectrum of brain structural disorders encountered in mr imaging of pediatric patients with intractable epilepsy and their implications on treatment planning including cortical development abnormalities (focal cortical dysplasia, schizencephaly, heterotopia, polymicrogyria), hippocampal sclerosis, vascular malformations, post-traumatic lesions, infections, tumors, neurocutaneous disorders (neurofi bromatosis i, tuberous sclerosis), and mitochondrial disorders. conclusion: magnetic resonance imaging is the radiological method of choice for the detection and characterization of parenchymal abnormalities that provoke epileptic seizures. conventional and high-resolution mr signal characteristics assist in determining a specifi c diagnosis. diffusion tensor imaging in the early stages of stroke can predict dysphage outcome x. wei, j. dai, h. shen, j. ma, l. ai, s. li, x. zhang; beijing/cn (weixinhua @ .com) purpose: to determine whether the degree of impairment of diffusion tensor imaging in the early stages of a stroke can predict the dysphage outcome. methods and materials: twenty-fi ve unilateral hemispheric stroke patients were enrolled to this study. diffusion anisotropy was measured by determining fractional anisotropy (fa) in the rois (region of interests) placed in the bilateral posterior limb of internal capsule (ic) during the early stages of stoke (average . days after stroke onset) and compared with dysphage outcome months after stroke onset. results: seventeen patients with complete recovery were assigned to group one and patients with persistent dysphage were assigned to group two. no signifi cant difference in fa between the bilateral posterior limb of ic in group one (p> . ). however, fa of the bilateral posterior limb of ic in effect side was lower than that of the intact side in group two (p < . ). the degree of impairment in diffusion anisotropy during the early stages of stroke appears to have the potential to predict dysphage outcome. flow-pattern on superselective middle cerebral artery (mca) angiography can predict tissue recovery after local recanalization treatment for hyperacute mca occlusion y. hori, h. kiyosue, h. mori, j. kashiwagi, h. nagatomi, y. sagara, s. tanoue, m. okahara, t. asano, r. shimada; oita/jp (horiyuzo@med.oita-u.ac.jp) purpose: in hyperacute middle cerebral artery (mca) occlusion, viability of brain tissue depends on the residual blood fl ow which could affect the outcome after local recanalization treatment (lrt). the purpose of this study is to investigate whether superselective mca angiography obtained prior to lrt could predict the recovery of ischemic brain tissue. methods and materials: thirty-six patients having hyperacute mca occlusion ( patients of m occlusion, patients of m occlusion) without signs of cerebral infarction on early ct underwent lrt. pretreatment superselective mca angiography via the microcatheter placed just distal to the occlusion site was executed to evaluate the fl ow-pattern in ( anterior trunks, posterior trunks) of trunks. the fl ow-patterns were classifi ed into three types: antegrade (n= ), retrograde (n= ), or stasis (n= ). the relationship between the degree of recanalization and follow-up ct fi ndings in each fl ow-pattern was investigated. results: cortical infarction occurred in of trunk territories. in antegrade type, ( %), ( %), and ( %) territories had cortical infarctions in complete, partial, and failed recanalization, respectively. in retrograde type, ( %), ( %), and ( %) territories had cortical infarctions in complete, partial, and failed, respectively. in stasis type, ( %) territories had cortical infarctions regardless of degree of recanalization. the degree of recanalization is signifi cantly correlated with follow-up ct fi ndings in only antegrade type. conclusion: flow-pattern on superselective mca angiography has signifi cant relationship with brain tissue recovery. cases with antegrade fl ow-pattern would be a good indication for lrt. intraventricular brain tumors: a pictorial review j. sanchez , p. puyalto , c. majos , c. aguilera , l. aja , j. acebes ; learning objectives: to describe the characteristic radiological features of intraventricular tumours that may allow their appropriate recognition and precise diagnosis. background: intraventricular neoplasms are uncommon; they represent only the % of all intracranial tumours. due to their deep location within the brain, they usually have diffi cult surgical access and consequently more potential risks of complications and consequently imaging assessment previous to surgery is essential to evaluate the extension and location of these tumours. imaging findings: imaging features of patients with intraventricular tumours were retrospectively reviewed. they showed a wide spectrum of radiological appearances that were non-specifi c, in many cases, making its differentiation diffi cult. the location of the mass within the ventricular system and the patient's age provided the most useful information, but other radiological features (calcifi cations, cysts, bleeding or enhancement) were helpful too. mr is the best technique to assess location and extent of the disease but in certain cases ct provides complementary evaluation of aspects such as calcifi cations or bleeding. conclusion: based on patient's age, location of the tumour within the ventricles and specifi c radiological features on mr, an accurate diagnosis can be made. regional gray and white matter volume abnormality in obsessive- (ocd) . no studies were found that showed white matter (wm) abnormality. the purpose of this study was to assess both gm and wm volume abnormality in ocd patients using voxel-based morphometry (vbm). in addition, it provides a very important functional information that can be very useful in the differential diagnosis of several lesions including cerebral abscess or herpetic encephalitis. imaging findings: we have reviewed studies performed at our department for evaluation of patients with suspected cns infection. patients for brain abscess, including toxoplasma in aids patients, and pyogenic abscess. ctp showed ring enhancing lesions with vasogenic oedema in contrast enhanced ct with reduced cerebral blood volume (cbv) in the lesion in ctp. tumors have increased cbv. in addition, ctp permits a better depiction of residual enhancement of partially calcifi ed lesions. three patients of herpes simplex virus encephalitis showed regional hyperperfusion in the acute phase and hypoperfusion in the chronic phase. also, other cases of other cns infections including fungal infections are described in our series. conclusion: ct perfusion could be included as a complimentary technique in brain ct studies because it provides useful funcional information, especially useful when mri is not available or for noncollaborative patients. metabolic changes observed with proton mr spectroscopy in normal human brain tissue during radiation therapy l. zarudzki, b. bobek-billewicz, w. senczenko, a. idasiak; gliwice/pl (lzarudzki@op.pl) purpose: to observe the time course of changes in the proton magnetic resonance spectroscopy ( h-mrs) values during radiation therapy in normal human brain tissue. methods and materials: we followed patients receiving an external radiation therapy for primary gliomas for months. all of the patients underwent brain surgery prior to the radiotherapy. the patients received or gy in tumour bed and - gy in the contralateral normal brain hemisphere. each patient underwent single voxel spectroscopy (svs, te= ; te= ) before and just after the completion of the radiation therapy. the voxels of interest were chosen in the contralateral normal brain hemisphere to meet an area between % and % isodose lines in the radiotherapy plan. the metabolite concentrations: n-acetylaspartate (naa), choline compounds (cho), creatine (cr), lactate (lac), lipids (lip), inositol (ins), glutamate and glutamine (glu+gln), their ratios and normalized concentrations were calculated. the spectra were verifi ed with lcmodel. results: there was a statiscally signifi cant decrease of total choline and inositol concentrations, their normalized concentrations and cho/cr, ins/cr ratios. the changes in the other metabolite concentrations were not signifi cant. conclusion: it is possible to detect and to evaluate in vivo early metabolic effects of radiation therapy in the normal human brain tissue with the proton magnetic resonance spectroscopy. the cause of the observed changes is unclear and might be due to the alterations of membrane composition related to the radiotherapy. cerebral organization of language processing for different input modalities in chinese: an fmri study y. yang, k. li, y. xu, h. shu; beijing/ cn (yyh_wj@sohu.com) purpose: the processing of chinese may be different from alphabetic languages such as english not only in the behavior but also in the neural mechanism. in this study, functional magnetic resonance imaging (fmri) was used to investigate the neural mechanism of semantic information processing. methods and materials: twelve normal subjects were scanned with a . t mr scanner. according to different modalities, there were auditory semantic judgment (asj), picture semantic judgment (psj), and word semantic judgment (wsj) involved in our experiment. when subjects heard a word or saw a white-black drawing picture/word, they must decide whether it is dangerous or not and press the corresponding button. a block design was employed and the baseline task was passively listening to a pure tone or viewing a cross. the fmri data were analyzed using the spm . results: bilateral superior temporal gyrus, left inferior and middle frontal gyrus were activated during the auditory task. bilateral occipital regions, left inferior and middle frontal gyrus, and left parietal regions were associated with the processing of all the visual stimuli. however, the word task produced no more activation than the picture task in the prefrontal area or the temporoparietal region, which were reported in similar studies on english. the inferior and middle frontal gyrus may be related with semantic processing of chinese word regardless of the input modalities. it is showed that chinese words are to some extent more similar to pictures and the neural mechanism of chinese words processing is similar to that of pictures. whole brain real-time fmri of language and hand motor areas with prospective acquisition correction for movements (pace) c. zimmermann, s. langner, j. kuehn, m. domin, n. hosten; greifswald/de (christian.zimmermann.hgw@web.de) purpose: mapping of language and hand motor brain areas has become an important clinical application of fmri in neurology and neurosurgery. we assessed the feasibility of real-time fmri with prospective acquisition correction for movements (pace) in routine clinical examinations. methods and materials: twenty normal subjects and patients with temporal lobe epilepsy or intracerebral tumors were examined at . t (siemens symphony). an -channel head coil was used for acquisition of anatomical t gre, t tse and an epi bold sequence. a semantic decision and letter-matching task alternated every s. the motor paradigm was an alternating fi nger-tapping task of ten -s periods of activation. a z-score of was chosen as cut-off. results: table time was under min for language and min for motor fmri. b d e f a g in / subjects language lateralization and in / the hand motor area were identifi ed. imaging was diagnostic in all patients. in all right-handed subjects, speech areas were mainly located in the left hemisphere. two left-handed subjects showed different activation: one in the left and the other mainly in the right hemisphere. for the speech paradigm, of the right-handed subjects showed right hemispheric activation of the cerebellum. one of the left-handed subjects had left and the other right hemispheric cerebellar activation. conclusion: real-time fmri is a feasible technique for noninvasive mapping of language and hand motor areas in clinical routine, providing reliable feedback of activation after s of paradigm runtime. susceptibility weighted ( learning objectives: to demonstrate magnetic susceptibility as a means of contrast in mri. to describe data-acquisition and post-processing of susceptibilityweighted (phase) images (swi). to recognize artifacts. to demonstrate the technique in clinical cases and to compare it with standard mr imaging methods. background: magnetic susceptibility is a physical property of tissue that infl uences the mr-signal via the local precession frequency. different blood-oxygenation levels, cerebral iron concentrations and many pathologies produce contrast in both magnitude and phase of gradient echo images. procedure details: high resolution d fl ow compensated gradient-echo data are acquired at long te. matrix= x x , te/tr/alpha= / / at . t, te/tr/ alpha= / / at t. phase images are unwrapped with either a homodyne fi lter or a region-growing algorithm. the latter produces better results in magnetically inhomogeneous areas. the susceptibility-weighted mr phase images show a unique contrast independent of t and can be directly assessed and compared to the corresponding t /t *-weighted magnitude images from the same scan. multiplying masks computed from the phase with the magnitude produces susceptibility-weighted images, which allow assessment of vascular architecture and function (if acquired during hypercapnia and normoxia). swi of sturge-weber syndrome, tuberous sclerosis, tumors, arteriovenous malformations etc. provides additional information that is not accessible by conventional imaging. conclusion: susceptibility-weighted mr (phase) imaging of the brain provides valuable information at high spatial resolution. it facilitates detection of small lesions which may be missed by conventional methods. at t acquisition time is reduced to - minutes due to shorter te and the option to use parallel imaging because of increased snr. the effi cacy of fusion three-dimensional-computed tomography ( d-ct) for following treated cerebral aneurysms by coil embolization m. ishifuro, j. horiguchi, y. kiura, k. ito, t. furukawa; hiroshima/jp (ishifuro@hiroshima-u.ac.jp) purpose: owing to metallic artifacts, vessels and coils cannot be observed in patients after coil embolization (ce) by cta. thus, the purpose of this study was to examine whether fusion ct could overcome this problem. methods and materials: ten patients underwent ce for cerebral aneurysm. cta was performed before ce, and plain ct was performed after ce. two sets of d images were constructed with d image analyses software (virtual place, aze). postoperative d coil images were fused with preoperative cta images in order to reduce artifacts due to the coils. we compared the coil locations on these fusion ct images to those on postoperative dsa. results: all d fusion images with cta and coils were successfully constructed. fusion ct could reveal postoperative fi ndings as accurately as dsa. also, we could evaluate the cases whose results were classifi ed as neck remnants. conclusion: fusion ct furnished as accurate information for postoperative fi ndings as did dsa; hence, it may be useful in predicting whether coil compaction will occur. brain mri of guadeloupean patients suffering from progressive supranuclear palsy l. giré , a. lannuzel , d. ben salem , p. giré , f. ricolfi ; dijon/fr, pointe-à-pitre/fr (laurentpaulinegire@yahoo.fr) purpose: to describe brain mri features of guadeloupean progressive supranuclear palsy (gd-psp). in guadeloupe, a french territory in west-indies, a cluster of progressive supranuclear palsy-like taupathy has been reported with an unusual high frequency, maybe linked to the consumption of specifi c fruit and derived tea from the annonaceae family. methods and materials: thirty-four clinical gd-psp underwent prospective brain mri studies, from december to september . mri evaluation was performed with a . t mr imaging (philips intera), in the university hospital radiology department of pointe-à-pitre, guadeloupe (france). the standard protocol included sequences: sagittal t -weighted turbo spin-echo, axial t w tse ( mm slices), coronal t w tse ( mm slices), axial t * ffe, axial t w flair, axial protondensity. on each mri, brain atrophy (cortical, subcortical, posterior fossa) and signals abnormalities (hypo or hyper signals on t w images) of midbrain, pons and basal ganglia were respectively measured and evaluated. each mri was reviewed independently by two neuroradiologists. results: eight of gd-psp mri were not reviewable (motion artefacts). on the exploitable cases, interobserver concordance of atrophy was good (p < . ). % had midbrain atrophy of which % presented a "hummingbird sign" on midsagittal t w images. % had frontal atrophy. . % presented an "état criblé" in the basal ganglia, without "hummingbird sign". two patients presented an unusual tegmental t hyperintensity. conclusion: gd-psp present a comparable or higher rate of midbrain atrophy than other psp described in literature. the "état criblé" presented by some of these atypical parkinson's syndromes may have an associated vascular origin. correlation of auditory simple reaction time ( studies propose that inter-individual differences in reaction time are due to physiological white matter differences, especially myelination; however, a proof is still missing. therefore, we aimed to fi nd a correlation between inter-individual reaction time differences and fractional anisotropy (fa), which is known to show white matter differences. methods and materials: twenty-two healthy students (right-handed, age: . ± . years) underwent an auditory simple reaction task based on the classic poffenberger paradigm. blocks of trials were conducted, preceded by blocks of practice trials with an inter-block pause of - s. whole head dti was performed using trse-epi sequence with an isotropic spatial resolution of mm . voxel-based regression analysis was conducted between fractional anisotropy and inter-individual asrt results. results: signifi cant negative correlation [pfwe (family wise error probability) = . ] was found in the right-central cerebellum. potent signifi cance was detected with right-sided stimulus presentation and response. no signifi cant correlation was observed, neither for left handed response nor left ear stimuli. discussion: our results imply an association between fractional anisotropy in the right-central cerebellum and asrt measures. presumably, the reason for this correlation is an infl uence of handedness on fa and asrt. since fa does not characterize specifi c tissue properties but represents an index of wm integrity, the micro-structural/physiological basis of these fi ndings requires further research from which important insights into the mechanisms of behavioral performance may be obtained. axonal damage and infl ammation relationship by h-mrsi and t weighted mri in early relapsing remitting multiple sclerosis: the effects of subcutaneously interferon beta- a treatment m.c. purpose: to examine the relationship between axonal damage in nawm in brainstem and infl ammatory activity in patients with early relapsing remitting multiple sclerosis (rrms) and to assess the effects of interferon beta- a (ifnb a) on metabolic brainstem changes and parameters of infl ammation. methods and materials: sixteen rrms patients treated with ifnb a, twenty rrms patients untreated and ten healthy subjects were prospectively studied for two years. relapse rate (rr) was calculated annually. t -weighted mr and h-mrsi were acquired at recruitment and at two years follow-up. t -weighted lesion volume (t lv) was measured. naa, cr and cho resonances ratios were calculated for the sum of the volume elements that represented the brainstem. disability was rated with edss and msfc. results: basal naa/cho ratio at brainstem was decreased in rrms compared with controls. after follow-up, there was a decrease in naa/cho (- %) and naa/cr (- %) while t lv increased ( %) in rrms, without changes in controls. patients with more than one relapse showed lower naa/cho at follow-up. naa/cho correlated with edss. at follow-up, an inverse correlation was found between naa/cho and t lv (p= . ). ifnb a was effective in reducing disease activity (annual rr and t lv) but ineffective in delaying axonal damage (all rrms suffered metabolic decrements). conclusion: axonal damage begins and progresses from early stages of ms and has been related with clinical and radiological evidence of infl ammation. however, the stabilising effect of ifnb a on infl ammatory activity appears not suffi cient in reducing neuroaxonal damage in a short-term study. longer periods of observations are needed to confi rm these preliminary fi ndings. in the analysis of h mrsi one voxel in each hemisphere including the inferior colliculus was selected for quantitative analysis. jmrui program was used to analyze multivoxel. relations among peak areas of naa, cr and cho in the inferior colliculus were compared among groups in each region. spss . program was used for statistical analysis. results: colliculus showed signifi cant reduction of the ratio naa/cr in both hemispheres in schizophrenic patients compared with control subjects. in the comparation among groups hallucinators showed the smallest value of naa/cr followed by not hallucinators and controls. the comparison of the two types of schizophrenic patients did not show signifi cant differences in this localtion. the biochemistry of inferior colliculus, involved with auditory pathway, could be altered in schizophrenic patient with auditory hallucinations. in this study, mrs has shown metabolic differences between control and schizophrenic patients in these areas, without any signifi cant differences among hallucinators and no hallucinators. the functional connectivity study of acupuncture analgesia effect in human brain h. chen, j. dai, j. tian, w. qin, p. chen, z. zhen, l. ai, l. yang; beijing/ cn (hyc @yahoo.com.cn) purpose: functional connectivity provides the functionally related and connected information among interdependence of brain regions. we used functional connectivity mri analysis to detect if there is a functional network associated with the effect of endogenous analgesia. methods and materials: fourteen right-handed chinese healthy college students [ male and female in the age of - years] were performed two functional mri examinations using t siemens trio scanner. one was a resting state lasting for minutes and the other was performed during a minute acupuncture needle manipulation on the st followed by minutes steady states scan. these two runs had an interval of minutes. all data were preprocessed using spm . the left side amygdala area was chosen as the roi. the seed timecourse was crosscorrelated with all other low-pass fi ltered voxels to form functional connectivity maps for each subject. finally to compare the difference of resting state connectivity and the resting state connectivity after acupuncture, a paired student t-test was implemented across subjects. the compelling similarity existed in the network of resting state before and after acupuncture. the main difference between the two networks was found in the limbic system, brainstem and cerebellum. conclusion: we conclude that the default endogenous analgesia functional network exists in human brain at a low level, and it could be increased to a higher level by acupuncture modulation. the association between the cavernous carotid artery calcifi cation (ccac) on ct and fractional anisotropy (fa) of the brain white matter using t mri a. seko , k. maeda , y. nakano , s. kitahara , k. learning objectives: the aim of this exhibit is to illustrate a wide spectrum of usual and unusual manifestations of primary central nervous system lymphoma (pcnsl) and to highlight the role of ct and different mr sequences in the accurate diagnosis of this entity. background: pcnsl is an uncommon aggressive form of extranodal non-hodgkin lymphoma that originates in the cns without evidence of lymphoma in any other localization at the moment of diagnosis. it represents . - . % of primary malignant lesions of the cns and affects brain, eye, meninges, cranial, spinal, and peripheral nerves. incidence during the last three decades has increased both in immunocom- promised and immunocompetent hosts between - years old and has become the fi rst brain tumour in patients with the acquired immunodefi ciency syndrome. imaging findings: ct and mr show, mostly, an isolated mass involving deep grey matter, periventricuar regions and corpus callosum with or without surrounding edema. after contrast injection, the tumour may enhance diffusely and densely or in its periphery (ring enhancement) if central necrosis is present. if perivascular spaces or meninges enhance as well, the diagnosis of pcnsl should be strongly considerated. calcifi cations or bleeding are rarely seen. surrounding edema and multifocal lesions are more frequently seen in immunocompromised patients. conclusion: due to new therapeutical strategies, the outcome for patients with pcnsl is rapidly improving in recent years; although the fi nal diagnosis relies on stereotactic biopsy demonstrating lymphomatous cells, the radiologist plays an important role in the noninvasive diagnosis of pcnsl thanks to the imaging fi ndings provided by ct and the combination of different mr sequences. prospective results: group included males, - y, and females, - y, with clinical onset - h before cct; mnihss was - . group also included males, - y, and females, - y. onset of symptoms was - h before cct, mnihss was - . sensitivity in group was . %. detection of small ischemias in the basal ganglia was particularly poor. multimodality cct in group showed true positive results in of cases, and false negative in of cases, with a sensitivity of . %. ct angiography was helpful in selected cases for detection of intracranial stenoses/occlusions, but limited by motion artifacts. nine occlusions/stenoses of the intracranial arteries were diagnosed. conclusion: multimodality cct is superior to unenhanced early cct for detection of acute cerebral ischemia, and should serve as a basic diagnostic tool for establishing local stroke units. imaging of the central skull base: anatomic study i. pérez , m. aperribay , g. benito , i. terreros , a. dolado , j. mendiola ; mondragón/es, baracaldo/es (irunepe@hotmail.com) learning objectives: to review the anatomy of the skull base including the skullbase foramina and their content, the osseus anatomy of the pterygopalatine fossa, and the sutures and boundaries of the skull base. after reading this exhibit, the reader will be able to understand the complex anatomy of the skull base, to accurately delineate phatologic processes, and to understand the spread pathways of different lesions involving this complex region. background: the radiologist requires a thorough knowledge of the normal anatomy and the pathologic spectrum of the skull base. imaging plays a central role in the management of skull-base disease, because this region is, in general, inaccessible to clinical evaluation. ct is ideal for outlining the bone architecture, whereas mr imaging provides soft tissue details. the pterygopalatine fossa represents a major pathway of spread of malignancy and infection from the head and neck into the skull base. imaging findings: a pictorial review of the skull base with foramina and their content (foramen ovale, rotundum, spinosum, lacerum, yugular foramen, and carotid canal), the pterygopalatine fossa and its boundaries, and the sutures of the skull base (occipitomastoid, sphenosquamous, petrosphenoid fi ssure, petrooccipital fi ssure, pterygomaxillary fi ssure) is provided. conclusion: familiarity with the complex anatomy of the skull base is a prerequisite for the correct diagnosis and accurate delineation of skull-base lesions. ct and mr imaging are complementary modalities and are often used together to demonstrate the full disease extent. the the aim of this study was to determine whether the anatomy of the cow infl uenced the incidence, severity and location of these lesions. methods and materials: thirty term neonates with hie underwent mri with standard structural sequences and high-resolution d time-of-fl ight mr angiography. the cow was examined for completeness and anatomical variations. the presence and distribution of wm and bgt lesions were noted and the lesions were graded according to predefi ned criteria. the cow was complete in % of infants. bgt or wm lesions occurred in infants, with severe changes in , moderate in and mild in infants. in those with severe changes, had incomplete cow and of these had an absent anterior communicating artery (a-com). the only infants in the study with absence of both anterior and posterior communicating arteries had severe changes. the anatomy of cow did not infl uence the location of the lesions. the presence of specifi c anatomic variations in cow may infl uence the severity of ischaemic wm or bgt lesions in infants with hie. infants with incomplete cow may have limited ability to adequately perfuse the brain following a hypoxic-ischemic insult and therefore present with more severe lesions. imaging spectrum of cerebral amyloid angiopathy j. kim, k. ahn, s. jung, b.-s. kim; seoul/kr (jeeyoungkim@catholic.ac.kr) learning objectives: to demonstrate the various ct and mr imaging fi ndings and pathogenesis of cerebral amyloid angiopathy. background: recently, cerebral amyloid angiopathy (caa) has attracted attention for its close relationship to cerebral hemorrhage (ich), ischemic lesions, alzeheimer's disease (ad), and other types of dementia in the elderly. most common presentation of caa is massive isolated or multi-compartmental intracranial hemorrhage, but it is also found in association with subacute or chronic edematous lesion of the white matter with or without caa-related hemorrhage. procedure details: the ct and mr images of histologically proven or clinically diagnosed caa were described with regard to type (lobar or petechial hemorrhage), location, and relapse of cerebral hemorrhage and presence or absence of white matter change (leukoencephalopathy) with pathogenesis of these lesions. the usual presentation of cerebral amyloid angiopathy is spontaneous lobar hemorrhage in the elderly patients, especially in those patients more than years of age. however, cerebral amyloid angiopathy presents various imaging fi ndings such as cortical petechial hemorrhage and subcortical or deep white matter change with or without cerebral hemorrhage. whole-brain three-dimensional ct perfusion k. yuba, k. ono, k. suzuki, y. yoshimoto, k. wada, d. yamana; meguro-ku,tokyo/jp (mishuku-ct@mishuku.gr.jp) purpose: ct perfusion functional evaluation is a promising method for evaluating blood fl ow in patients with cerebral ischemia. the conventional method suffers from the limitation that the area that can be evaluated is restricted. the present study was conducted to assess a new display method for evaluating the distribution of blood fl ow in the brain by combining whole-brain imaging and multiplanar reconstruction. to cover the entire brain, scanning was performed several times with the scan slice thickness reduced from mm to mm, and the number of scan slices increased from to . saline solution was used in combination to reduce the volume of contrast medium, and a quantum denoising fi lter was used to minimize the exposure dose. for image processing, several data series were bundled into a single series. this technique permits multiplanar display of wholebrain blood fl ow, which is not possible with the conventional method. results: evaluation of this new display method for ct perfusion studies showed that three-dimensional display permits the cerebral blood fl ow distribution to be observed from any desired direction. this method makes it easier to visualize ischemic areas and is expected to prove useful as a new ct perfusion display method. conclusion: three-dimensional ct perfusion permits blood fl ow in the entire brain to be evaluated stereoscopically. this method fully exploits the advantages of a larger number of ct detector rows and is expected to gain widespread acceptance as a useful new ct perfusion imaging technique and display method. evaluation of cerebral metabolite patterns with proton mr spectroscopy in chronic renal failure patients: correlation with duration of hemodialysis s.e. kim, h. baik, h. yu, y. lee, g. kim; seoul/kr (tlwodc@hanmail.net) purpose: to evaluate cerebral metabolite patterns with proton mr spectroscopy (mrs) in chronic renal failure (crf) undergoing hemodialysis (hd) and to clarify if these fi ndings correlate with duration of hd. methods and materials: subjects comprised crf patients undergoing hd and healthy volunteers. short te (= ms) single voxel proton mrs and laboratory data were acquired in crf patients before hd and one day after hd. spectra were obtained from two voxels of interest positioned in the gray and white matter of parietal lobe. changes in n-acetylaspartate (naa), choline (cho), myoinositol (myo), glutamine/glutamate complex (glx) and creatine (cr) were analyzed and the results presented as ratios, with cr as the reference. metabolic ratios and laboratory data before and after hd were compared. correlations between each metabolite ratio and laboratory data, and between each metabolic ratio and duration of hd were evaluated. results: in crf patients, the cho/cr ratio and myo/cr ratio were signifi cantly elevated in gray matter and the myo/cr ratio was signifi cantly elevated in white matter compared with controls (p <. ). after hd, the cho/cr ratio was significantly reduced in white matter of crf patients (p <. ). there were no signifi cant correlation between each metabolic ratio and laboratory data, and between each metabolite ratio and duration of hd. the signifi cant elevation of the cho/cr ratio in gray matter and the b d e f a g myo/cr ratio in gray and white matter was found in crf patients compared with controls. there was no signifi cant correlation between cerebral metabolite ratios and overall time of hd. imaging learning objectives: . to describe and depict cns infections within the different compartments of the brain. . to illustrate characteristic imaging fi ndings attributable to specifi c pathogens. . to demonstrate infectious etiologies specifi c to immunocomprised and hiv patients. background: localizing a lesion within the intracranial compartment is the fi rst critical step in constructing a differential diagnosis. furthermore, certain types of infections have certain propensities for different anatomical regions within the brain and can possess certain imaging characteristics. of course, the imaging fi ndings must be placed in the context of the clinical setting particularly in immunocomprised and hiv patients. imaging findings: we present a pictorial review of infections within different compartments of the brain. pathology proven infectious cases will be presented in both immunocompetent and immunocompromised patients with discussion of the characteristic fi ndings of each pathogen and differential diagnosis. the radiologist plays a crucial role in identifying and narrowing the differential diagnosis of cns infections. a thorough understanding of the intracranial compartment anatomy and characteristic imaging fi ndings of specifi c pathogens as well incorporating the clinical information is essential to arrive at the correct diagnosis. histologic diagnosis of meningioma were studied in our center, ( . %) were atypical and ( . %) malignant. we reviewed the ct and mri fi ndings of these patients with pathologically confi rmed atypical and malignant meningioma diagnosed. we illustrate different appearences of atypical and malignant meningioma. pitfalls, diagnostic diffi culties and differential diagnoses are emphasized. conclusion: after interacting with this exhibit the radiologist will improve his or her knowledge of atypical and malignant meningioma, including histopathology and radiologic features. c-sodium butyrate-pet in neurooncology n.a. kostenikov, l.a. tyutin, n.p. fadeev; st. petersburg/ru (crirr@peterlink.ru) purpose: the aim of the study was to determine the potential in diagnosis of pathological volume brain formations (pvbf) by pet with c-sodium butyrate ( c-sb). methods and materials: pet was performed in patients ( men and women, at the age of - y.o). to identify tumors or to exclude an advance growth of tumors. according to the results of histological data, malignant tumors were revealed in / patients, benign tumors in , arterial venous malformations (avm) in , stroke diseases (sd) in , and cysts in . d-pet scans of the brain with attenuation correction («ecat exact hr+», siemens) were performed in a dynamic mode immediately after intravenous administration of - mbq c-sb. we used tumor/normal tissue ratio (t/nt) as an index for semiquantitative data analysis, as well as analysis of activity/time curves. results: results of the studies showed pet with c-sb proved to be a highly sensitive ( . %) technique in revealing brain tumors and it allowed to visualize clearly malignant and hypervascular benign tumors and to differentiate them from non-tumor masses of the brain. dynamic c-sb-pet allows to assess the grade of vascularity, the level of metabolism, the rate of uptake and utilization of fatty acids (fa), and to estimate indirectly the state of tumors oxygenation. the performed studies showed that dynamic pet with c-sb allows to visualize precisely malignant brain tumors and estimate their morphological state; the latter is of prognostic value in order to plan conservative therapy for brain tumors. susceptibility-weighted imaging ( purpose: to assess the fi ndings of susceptibility-weighted imaging (swi) with -tesla in acute ischemic stroke. methods and materials: twenty patients underwent ct and mr imaging with swi, diffusion-weighted imaging (dwi), and d-tof mra within the fi rst days after the onset of acute ischemic stroke. the swi sequence is a high-resolution threedimensional ( d) imaging technique with -tesla. the susceptibility changes by the intraarterial clots or emboli, hemorrhage, and the enhancement of the regional vein in the abnormal perfusion area of the brain were assessed on swi. results: the intraarterial susceptibility changes by the fresh clots or emboli were visible on swi in cases. swi showed distal clots or emboli that were invisible on both of mra and fl uid attenuated inversion recovery (flair) images in cases. the hemorrhagic infarction occurred in cases. the hemorrhage was shown on swi earlier than on ct image in each case. the enhancement of the regional vein in the abnormal perfusion area of the brain was shown in cases on swi. all of them were within days after the onset of acute ischemic stroke. five of the cases were embolic infarction cases of the mca territory. conclusion: swi is an effective means that can provide additional information about the fresh intraarterial clots, hemorrhage, and the perfusion anomaly in the brain in acute ischemic stroke. bold fmri response in the motor cortex is strongly linked with vasoreactivity in patients with carotid artery disease c. ojango, s. goode, d.p. auer; nottingham/uk (msxco@nottingham.ac.uk) purpose: blood oxygenated level-dependent (bold) functional mri (fmri) has become a widely used technique to investigate brain activation. the method is based on haemdynamic changes and any alteration in neurovascular coupling, baseline blood fl ow or volume is likely to affect results. it has been shown that stroke and carotid artery disease reduce cerebrovascular reactivity (cvr) and this factor infl uences the response to motor tasks. we explored further the interrelation between the motor task induced signal change and the cvr in patients with carotid artery disease. methods and materials: six patients (age - ) with internal carotid artery stenosis (> %) were investigated with motor task and co stimulation. the data analysis was performed with fsl software. the mean percentage of signal intensity change during the motor task and co challenge was calculated separately for both motor cortices. results: there was a signifi cant correlation between the bold responses to the motor task and co stimulation (pearson test . , p= . ). we did not fi nd differences in motor bold responses between the side of the maximum stenosis and the contralateral hemisphere. conclusion: these results confi rm the effect of vasoreactivity on bold response in patients with carotid artery disease and show that neurovascular coupling is linearly and strongly correlated with cvr. in the small sample, no difference emerged between hemispheres suggesting that the degree of stenosis may be less relevant for the bold response than cvr. the observed relationship is important for designing clinical fmri studies to avoid confounding effects from altered vasoreactivity. the value of perfusion mr to differentiate between low and high grade brain gliomas r. rodríguez-romero, j. vivancos-garcía, p. piñero gonzalez de la peña, c. monreal-rodríguez; sevilla/es (raroro@terra.es) purpose: to determine the value of magnetic resonance perfusion imaging to differentiate between low and high grade brain glioma. methods and materials: forty-seven patients with brain glioma were studied with conventional mri followed by dynamic susceptibility-weighted gadoliniumenhanced perfusion-mri. were low grade gliomas (i-ii who) and were high grade gliomas (iii-iv who). studies were performed with a . t philips mr system. region of interest was measured in the - most vascularized areas of the tumor. the maximum cerebral blood volume (cbv) value was recorded for each area and divided by cbv of the contralateral periatrial white matter to obtain the relative cbv (cbvr purpose: endovascular stenting is evolving as the primary treatment option for cervical arterial dissections in symptomatic patients refractory to medical management. the tractability of balloon-or self-expandable stents into the tortuous intracranial vasculature is often diffi cult. six patients at our institution have been treated using the fl exible intracranial neuroform stent in tortuous dissected segments of the distal carotid and vertebrao-basilar arteries. we studied this population to evaluate this treatment approach. methods and materials: six patients with distal internal carotid or vertebralbasilar dissections were treated using intracranial neuroform stent. a total of stents were utilized in procedures. dissecting aneurysms were treated via stent assisted coil embolization. patients were followed with imaging and clinical assessment for a mean of . months. long-term integrity, technical and clinical outcomes were assessed. results: all patients were symptomatic from their dissections. presenting symptoms included tias, persistent pain, hemispheric infarcts, and sah. spontaneous ( ), traumatic ( ), and iatrogenic ( ) etiologies were responsible for dissections. dissections were treated with single (n= ) or overlapping (n= ) neuroform stents. one patient required tandem stents to reconstruct a long segment dissection. technical success was achieved in all patients ( %) with no residual fl ow limitation. dissection related mean stenosis improved from % pre-procedure to % and % on post-procedure and follow-up imaging respectively. there were no recurrent tias, infarcts, or subarachnoid hemorrhages. there were no long term complications. in certain cases of dissections affecting tortuous and redundant vasculature, neuroform stent appears to be a safe option for the endovascular management. background: gioblastoma multiforme is the most common primary malignant brain tumor in adults. accurate diagnosis is important for the establishment of therapy and prognosis. however, diagnosis is often diffi cult as this entity can display various imaging characteristics depending upon its histological structure and growth pattern. imaging findings: we exemplify atypical imaging fi ndings in six cases of histologically confi rmed glioblastoma. imaging features include lack of enhancement after contrast administration, primarily cystic or intraventricular growth pattern, subependymal and subarachnoidal spread as well as negative pet fi ndings. we correlate imaging fi ndings and histological structure to explain the displayed atypical mr morphology and signal properties. we illustrate how to improve diagnosic accuracy with the help of advanced imaging techniques such as mr spectroscopy, diffusion weighted imaging and perfusion weighted imaging. conclusion: atypical glioblastoma should be considered as a differential diagnosis in cerebral space occupying lesions with equivocal clinical and imaging fi ndings. diagnosis of atypical glioblastoma can be improved by the use of advanced mr imaging techniques. imaging in tropical infections of the brain j. singh, r. kulkarni; pune/ in (joshitasingh@hotmail.com) learning objectives: to depict the various infective brain pathologies commonly encountered in the tropical settings in india. to illustrate the various imaging features of these infections. background: tackling neuro-infections constitute an ever growing challenge to the radiologist and the physician alike. they continue to be a major cause of morbidity and mortality with evolving clinical and imaging profi les as the infective organisms adapt to more and more drug regimes. b d e f a g procedure details: we reviewed and compiled the imaging features of various commonly encountered brain infections in india. patients with tuberculosis, neurocysticercosis, chickungunya fever, dengue fever, japanese b encephalitis, herpes simplex encephalitis, neurobrucellosis and fungal infections were included in the study group. opportunistic infections in immunocompromised patients were also included in the study group. in this exhibit, we discuss the imaging features and the differential diagnosis of each of these conditions. areas of restricted diffusion not confi rming to any vascular territory in patients of chickungunya fever and demyelinating lesions in dengue fever were some uncommon characteristic imaging features seen in our study group. conclusion: imaging plays a crucial role in management of neuro-infections. characteristic clinical and imaging features may obviate the need for further investigations in the cost constrained or epidemic settings. background: central nervous system involvement with malignant lymphoma, whether primary or secondary is an uncommon disease, which is increasingly seen in immunocompromised individuals, particularly secondary to hiv or other haematological malignancies. there is high morbidity and mortality associated with cerebral lymphomas. imaging is important in diagnosing lymphomas and differentiating it from other mimics. ct is often the fi rst imaging modality, but mri is the most useful modality. imaging findings: the pictorial review illustrates the spectrum of imaging fi ndings seen in primary and secondary cerebral lymphomas seen in different imaging modalities, with particular emphasis in mri. ct scan shows hyperdense lesion, predominantly in the subspendymal region. mri shows solid, enhancing lesions in subspendymal region. ring enhancement is a feature of lymphomas arising in immunocompromised individuals. differential diagnosis of lymphomas include other solid tumours, toxoplasmosis, abscesses. the review discusses the salient features of each of these differential diagnosis. conclusion: primary and secondary central nervous system lymphomas have characteristic appearances in ct and mri scans. b lymphomas are the commonest to affect the brain. lymphomas are commonly seen in the subspendymal region. primary and secondary lymphomas have different features in imaging. intense enhancement is a feature of ring enhancement. radiological spectrum of lesions involving the hippocampus a. rovira-cañellas , a. rovira-gols , c. auger , n. bargalló , j. alvarez-linera ; barcelona/es, sabadell/es, learning objectives: to illustrate the radiological fi ndings of several lesions that predominantly affect the hippocampus. background: the hippocampus, which forms a part of the limbic system, has a crucial role in cognition and memory, particularly in the formation of long-term memory. in vivo visualization of the hippocampus became possible with the advent of mr imaging, which has allowed the identifi cation of a variety of lesions that mainly affects this formation. imaging findings: many of the mr imaging examinations performed to identify structural abnormalities of the hippocampus are obtained in patients with temporal lobe epilepsy (medial temporal lobe sclerosis) and several forms of primary neurodegenerative dementia, particularly those of the alzheimer type (hippocampus atrophy). however, hippocampal changes can occur in a broad spectrum of disorders beyond dementia and epilepsy, including ischemic lesions (infarction within the posterior cerebral artery territory), primary brain tumours, infl ammatory and infectious diseases (viral and paraneoplastic encephalitis, demyelinating lesions), vascular malformations (cavernoma, arterio-venous malformation), and focal cortical dysplasia, as well as several neuropsychiatric disorders (schizophrenia, post-traumatic depression). the hippocampus may also be selectively affected in patients with neurofi bromatosis type i, and in the acute phase of transient global amnesia and status epilepticus. the hippocampus can be affected by a variety of processes that may present similar clinical fi ndings. mr imaging establishes the proper differential diagnosis with a relatively high specifi city when a suitable imaging protocol is used. the correlation between the fractional anisotropy (fa) value and the pathologic change at different stages of spinal cord injury in rats n. chen, k. li; beijing/ cn (cnddcndd@yahoo.com) purpose: to evaluate the correlation between the fractional anisotropy (fa) value and the pathologic change at different stages of spinal cord injury in rats. a total of sd rats were medially divided into groups. each group (n= ) received a completely transverse injury at the lever of t . on each group, diffusion tensor imaging was performed by using a . necessary. the images were analyzed for patterns of involvement, frequencies and differential diagnosis entertained. results: the dorsolumbar region was commonly affected. in patients, more than two regions were involved. contiguous involvement of adjacent regions was more common than skip lesions. there were three patterns of involvement: disk-vertebral lesion, those confi ned to the body and posterior arch lesion. lesions sparing disks ( %) were nearly as common as those involving both body and disc ( %). nearly % of disk-vertebral lesions were associated with paraspinal/epidural abscesses or cord compression, especially at the dorsolumbar junction. body lesions were also associated a high incidence ( %) of abscesses and cord compression. one-third of these lesions were confi ned to the body (thus mimicking secondaries, lymphoma). isolated posteriro arch involvement occurred in patients. conclusion: spinal tuberculosis has a varied presentation and can mimic any disease of the vertebral column. isolated pedicle involvement and multifocal body involvement can closely mimic malignancy. purpose: mri has become a critical diagnostic imaging modality for spinal disorders. spine arthrodesis and arthroplasty devices are known to result in signifi cant artifacts on mri. we assessed and compared the artifact resulting from four different biomaterials utilized in clinical arthroplasty devices when encountered in the same shape. methods and materials: sheep lumbar spinal segments were harvested and the lower lumbar discs excised. circular discs of the various materials were then used to fi ll the spaces. polyethylene, medical ceramic, titanium, and chrome cobalt (cocr) alloy discs were used. images were obtained with a general electric . t mri unit in both sagital and axial sequences. the scans were reviewed by the authors (neuroradiologist and orthopedist) and the distortion graded between the various materials. the area of fi eld distortion and the device dimensions were also compared. results: the distortion from polyethylene was the least severe and cocr was the most severe on both sagital and axial mri scans. ceramic alone was mild with titanium causing an intermediate fi eld artifact. the cocr disc resulted in severe artifact on the mri image, resulting in artifact which was twice the dimension of the disc. the choice of biomaterial for spinal implants for arthrodesis and arthroplasty, in addition to design shape, will have a profound effect on the magnitude of mri artifact and on whether mri images are of any clinical utility after spinal surgical reconstruction. magnetic evaluation of spinal vessels with ce angiomr in suspicion of vertebral canal avm k. gruszczynska , j. baron , w. brojacz , p. there is a degree of overlap between the imaging fi ndings in these conditions. however, certain fi ndings are helpful pointers towards the diagnosis of specifi c connective tissue diseases and conditions associated with vasculitis. examples of spinal cord compression, focal cerebral infarcts, multifocal white matter lesions, venous sinus thrombosis, intracerebral and subarachnoid haemorrhage, aneurysm, cerebral abscess, cytotoxic and vasogenic oedema in such cases are shown on ct and mr images. the purpose of this exhibit is to illustrate the spectrum of neuroradiological imaging fi ndings in connective tissue diseases and vasculitides, and to show features that allow the radiologist to distinguish between the differential diagnoses. neuroimaging manifestations in von hippel lindau disease: emphasis on unusual fi ndings a. patsalides , e. tzatha , n. patronas ; washington, dc/us, bethesda, md/us (apatsalides@cc.nih.gov) learning objectives: in this exhibit, we present the neuroimaging manifestations of vhl disease, emphasizing on the unusual fi ndings. background: von-hippel lindau (vhl) disease is an autosomal dominant disorder with incomplete penetrance. neuroimaging manifestations include the presence of hemangioblastomas in the retina, brain and spine as well as endolymphatic sac tumors (elst). imaging findings: common and unusual imaging features of hemangioblastomas in the cerebellum, brainstem and spinal cord are presented and evolution in time is assessed. we show hemangioblastomas in uncommon locations such as the suprasellar area, cerebral hemispheres, internal auditory canals, cauda equina and leptomeninges, mimicking other tumors. we present the imaging abnormalities of elst and the range of involvement of the petrous bone as well as a variety of retinal hemangioblastomas and their complications. the spectrum of neuroimaging manifestations in patients with vhl disease is wide. awareness of the variety of imaging fi ndings and evolution in time is important for the complete understanding of this entity. lipomas, dermoids and epidermoids of the brain and spine: a pictorial review s.b. lachanis, a.n. chalazonitis, j. pontikis, g. tsimitselis, n. ptohis, i. tzovara; athens/gr (red-rad@ath.forthnet.gr) learning objectives: . to pictorially review the mr imaging features of cns lipomas, epidermoids and dermoids with various sequences. . to describe their distinguishing imaging features aiding their differential diagnostic approach. . to underline potential pitfalls in their differential diagnosis. background: lipomas, dermoids and epidermoids of the brain and spine, although rarely encountered, enter in the differential diagnosis of many other cns tumors. although their embryology is different, these lesions share a common feature: they represent "tissues at a false place", as mesencymal and cutaneous ectoderm tis- sues within cns structures. imaging findings: in this exhibit, we present a great number of cases of cns lipomas, dermoids and epidermoids. all cases have been drawn up from our teaching fi les. imaging characteristics (with all conventional and newer mr sequences), together with their differential diagnosis are pictorially presented. potential pitfalls in their differential diagnosis will also be discussed. conclusion: lipomas, dermoids, and epidermoids of the cns have distinguishing radiological appearance concerning especially their mri imaging characteristics. by appreciating these, together with their site of predilection and affected age spectrum, any radiologist can reach the specifi c diagnosis in a majority of cases. purpose: central and/or peripheral nervous system involvement (neuroborreliosis) is frequent in lyme disease and is often the fi rst presentation. aspecifi c white matter lesions on t -weighted images (wi) in neuroborreliosis have been published in the literature. cranial nerve enhancement was frequently observed in our series. we present the magnetic resonance (mr) imaging fi ndings in patients with proven neuroborreliosis. methods and materials: nine patients with positive serology for lyme were included in this retrospective study. mr studies of the brain, of the lumbar spine and of the cervical spine were performed. mr imaging of the brain consisted of t -wi, t -wi, fl uid-attenuated inversion recovery (flair) and contrast enhanced t -wi. spinal studies included t -wi, as well as t -wi before and after gadolinium injection. results: one brain study and the mr examination of the cervical spine showed no abnormalities. five brain studies displayed aspecifi c white matter lesions. in four patients, cranial nerve enhancement ( vestibulocochlear nerve, oculomotor nerve, trigeminal nerve, facial nerve, and glossopharyngeal nerve) was observed. in one patient, right hemispheric cerebellitis and leptomeningeal enhancement was described. mr of the lumbar spine showed polyradiculitis of the cauda equina. conclusion: aspecifi c white matter abnormalities are frequently observed in patients suspected for neuroborreliosis. cranial nerve enhancement, cerebellitis, and polyradiculitis may narrow the differential diagnosis in these patients and neuroborreliosis must be considered when these fi ndings are encoutered, especially in endemic regions. contrast high-resolution ultrasound of infl ammatory bowel diseases in children u. zaleska-dorobisz, a. stawarski, d. sokolowska, b. iwańczak, k. moroń; wrocław/pl (atd@vassurg.am.wroc.pl) purpose: to present the usefulness of high-frequency standard and doppler ultrasound in the diagnosis and therapy monitoring of infl ammatory bowel diseases (ibd) in children. we studied children, with mean age . years, with infl ammatory bowel diseases: thirty-fi ve with crohn disease (cd), with colitis ulcerosa (cu), with other ibd. we performed high-resolution d sonography to evaluate the bowel-wall thickness. intraparietal vascularisation was assessed with color doppler. superior or inferior mesenteric arteries fl ow, mean velocity, ri (resistance index) were measured in all patients. we compared clinical active disease, ultrasounds and colonoscopy. results: cd predominantly involved the small intestine. the bowel wall was greatly thickened more than - mm. mucosal ulcerations penetrated into the wall in children; in we found fi stulas and peritoneal abscesses. the mesentery and fat around the bowel was thickened in all children. uc was limited to the left colon. the colon wall was thickened more than - mm. mural infl ammation was located in the mucosal surface with superfi cial ulcerations and pseudo polyps ( %). color doppler revealed hyperemia with increased vascular supply of the involved bowel wall. the ri was signifi cantly lower in active disease. after treatment, ri values increased signifi cantly (p < . ). conclusion: high-resolution and doppler sonography can detect bowel-wall abnormalities in most ibd in children. doppler fl ow parameters in mesenteric arteries correlated strongly with disease activity. doppler us could be used for monitoring the treatment effi ciency. single-shot mrcp in the evaluation of pancreaticobiliary disease in children s. fitoz, a. erden, s. boruban; ankara/tr balloon dilatation of oesophageal strictures following surgical repair of oesophageal atresia f.a. kazmi, d. roebuck; london/uk (drfkazmi@doctors.net.uk) learning objectives: we describe and illustrate the technique, indications and complications of balloon dilatation of oesophageal strictures following surgical repair of oesophageal atresia based on a series of patients. background: balloon dilatation of oesophageal strictures is well described in the adult literature. however, its role in the paediatric population after repair of oesophageal anomalies is less well established. post operative stricture occurs in - % of patients with oesophageal atresia. this carries a high risk of malnutrition and aspiration to the lungs. it is the most common post surgical complication and typically occurs at the primary site of anastomosis. at our institute, we have one of the largest case series of patients undergoing balloon dilatation of strictures after surgical repair of oesophageal atresia. procedure details: all procedures were carried out under general anaesthetic. the oesophageal lumen was opacifi ed with water soluble contrast to correctly identify the location of the stricture. a f catheter and hydrophilic guidewire were passed through the mouth and manipulated under fl uoroscopic guidance across the stricture and into the stomach. a balloon catheter ( - mm in diameter) and - cm long was passed over the guidewire and positioned across the stricture. the balloon was slowly infl ated with diluted water soluble contrast under fl uoroscopy until the waist on the balloon was obliterated. a post procedure oesophagram was then performed to check for oesophageal rupture. conclusion: balloon dilatation of strictures following surgical repair of oesophageal atresia is clinically effective, safe, relatively atraumatic and is without high risk of complications. infl a total of children were enrolled: with crohn's disease (cd) and ulcerative colitis (uc) and healthy siblings as controls. lumbar spine bmd was measured by dxa and z-scores were obtained by comparison with age-and sex-matched normal values. bone age was measured in each patient by the method of greulich and pyle and abmd was calculated again using bone age instead of chronological age. multiple regression analysis was used to evaluate the relationship between ibd and potential risk factors. results: children with cd and uc differed for corticosteroid exposure. total duration of therapy (p= . ), cumulative (p= . ) and daily dose (p= . ) of prednisone were signifi cantly higher in patient with uc. no signifi cant difference was found between cd and uc abmd. prevalence of low bmd (z score<- ) was higher for ibd patients respect to controls (p= . ). abmd z scores were then calculated using bone age instead of chronological age and abmd was found signifi cantly low in uc patients (p < . ). conclusion: children with ibd should be evaluated for bmd and a corret interpretation of dxa results is important for identifying children at real risk for osteoporosis. low bmd has a high prevalence in children with ibd, but it has to be assessed using bone age instead of chronological age to avoid overestimation. purpose: to present an mr imaging protocol for the evaluation of iib disease and to assess its effi cacy in evaluating disease activity. methods and materials: mr imaging of the small bowel was prospectively performed in patients (aged - years) with known or suspected iib disease. . lt of water solution with herbal fi bers was administered over hours through a nasogastric tube prior to mr examination. patients were scanned in the prone position using coronal and axial thin-slice ( . mm) d t -weighted ge and t -weighted bffe fat-suppressed sequences followed by dynamic study after contrast administration. quality of imaging, including small bowel distention, wall conspicuity, motion and susceptibility artifacts, was evaluated by two observers in consensus. disease activity was evaluated by presence and degree of mural enhancement and edema. the procedure was well tolerated by all patients. quality of imaging was considered excellent (n= patients), satisfactory (n= ) and non-satisfactory (n= ). imaging fi ndings included: wall thickening (> mm) of the terminal ileum (n= ), jejunum loops (n= ), large bowel (n= ) and stomach (n= ), and luminal narrowing (n= ). seven patients showed early increased wall enhancement, implying active infl ammation, whereas four patients exhibited delayed mild enhancement of bowel wall consistent with inactive disease. extraluminal manifestations included mesenteric adenopathy (n= ), perienteric fi brofatty proliferation (n= ), ascites (n= ) and patulous ileocecal valve (n= ). conclusion: mri of the small bowel, using the current imaging protocol, is a welltolerable, non-ionising method for evaluating the presence, extent, activity and extraluminal manifestations of iib disease in pediatric patients. detection of tree-in-bud sign in cystic fi brosis by volumetric thin-section low-dose mdct: incidence, natural history and correlation to morphologic score and spirometry k.m. unsinn, h. ellemunter, j. eder, w.r. jaschke, m.c. freund; innsbruck/at purpose: to determine the incidence of tree-in-bud sign (indicating involvement of the peripheral bronchioles by infection and infl ammation) in patients with cystic fi brosis by volumetric thin-section low-dose mdct. to evaluate the natural history (i.e. reversibility) of tree-in-bud sign in patients with cystic fi brosis. to correlate the tree-in-bud sign to ct-morphology measured by bhalla score and to spirometry. methods and materials: all patients had proven cystic fi brosis (cf). volumetric low-dose multidetector ( , , or ) row spiral ct (mdct) of the chest was performed in patients ( - years) every second year without contrast administration in supine position at end-inspiration during single breath-hold with following scan parameters: contiguous . mm slice thickness/intervall, kv, ma, . sec rotation time/ °, standard and lung reconstuction algorithm. dose-length product (dlp) (mgy•cm) was recorded. two radiologists reviewed all images and arrived at consensus opinion regarding incidence and natural history (i.e. reversibility) of tree-in-bud sign with correlation to ct-morphology measured by bhalla score and to spirometry. the tree-in-bud sign was seen in / patients ( %) and occured at higher age (p < . ), at higher level of ct-morphological involvement as measured by bhalla score and at higher level of functional pulmonary impairment measured by spirometry (p < . ). in this patient population, the tree-in-bud sign was never reversible. conversion of recorded dlp (range) . - . (mgy•cm) resulted an effective dose (range) . - . (msv). the tree-in-bud sign represents a non-reversible sign in patients with cf occuring in later stage of disease and presumably indicating involvement of bronchioles. apneac oxygenation using cpap to perform computed tomography of the thorax in paediatric patients b. tagliaferri, u. sonvico, e. battaglia, m. del sante, f. boioli; milan/it (btagliafer@sirm.org) purpose: evaluation of the diagnostic accuracy of multi-slice spiral ct (msct) high-resolution computed tomography (hrct) in paediatric patients for the examination of the pulmonary parenchyma, maintaining continuous expansion of the lung (apneac oxygenation) through the use of cpap. methods and materials: an evaluation of patients between the ages of days and years was conducted using msct-hrct. patients were examined with the siemens somaton sensation -ct scanner, using technical parameters enabling exposure to low doses, and ventilation was ensured manually using an ayres "t" tube for the time necessary for the preparation of the child until the end of the period of apnea. the examinations were carried out with and without peep, with a mean duration of minute. results: in all the patients examined, the thorax was kept immobile and continually extended, enabling the avoidance of interpretative errors, facilitating the differentiation of pulmonary pathology with extreme precision, distinguishing the types of bronchial obstruction associated with air trapping and facilitating the evaluation of the lower segments of the lung parenchyma, where collapse often occurs. the modifi cation of some of the technical parameters (kv and mas) enabled us, furthermore, to carry out examinations at low doses in compliance with the european radioprotection standards. the pulmonary hyper-expansion obtained with this method enables the msct-hrct to be performed in paediatric patients, giving a correct evaluation of the pulmonary parenchyma without the use of artifi cial respirators. overview of paediatric orbital pathology: a pictorial review s. nayak, d. nayak; leeds, west yorkshire/uk (sanjeevnayak@hotmail.com) the spectrum of ocular and orbital pathology in the paediatric age group is quite different from that of adults. imaging studies serve an important role in the diagnosis and management of many of these abnormalities. systemic approach is required to understand the classifi cation and imaging features of orbital pathology. we have described them according to the three orbital compartments, namely, the globe/optic nerve sheath, intraconal and extraconal lesions. this extensive pictorial review outlines the various abnormalities of the paediatric eye and orbit for which imaging studies are often required, including infection, neoplasm, infl ammation and infi ltration, developmental anomalies, and trauma. imaging included in this review includes the relevant plain radiography, ct, ultrasound and mri features of various pathologies. additionally, the pertinent fi ndings are correlated with pictorial description of the relevant histopathology, fundoscopy features and relevant clinical ocular photographs. correlation of the results of imaging studies with pertinent clinical information allows the determination of specifi c diagnoses in most instances of paediatric orbital pathology. control children were neurologically and developmentally normal and also showed normal mri. mri was performed from to years of corrected age in both groups. we measured the ap diameter of the pons, the tegmentum and basis pontis, and corpus callosum length using t -weighted midsagittal image. results: pontine diameters in all regions were signifi cantly smaller in the pvl group than in the control group. pontine diameters in the pvl group and control group were . ± . (sd) and . ± . mm (p < . ), respectively; tegmentum diameters were . ± . and . ± . (p < . ), respectively; basis diameters were . ± . and . ± . (p < . ), respectively; and the corpus callosum lengths were . ± . and . ± . , (p < . ), respectively. when the agerelated pontine diameter differences were examined, there was signifi cant difference in pontine diameters after months of age. we proved that pontine diameter in patients suffering pvl is significantly smaller than normal control. purpose: methylmalonic acidemia (mma) often presents with nonspecifi c neurological symptoms that leads to different imaging work-ups. better recognition of fi ndings of brain imaging (ct/mri) helps physicians suspect to mma diagnosis in earlier reversible stages of the disease. methods and materials: fifty-two brain images of the patients with confi rmed diagnosis of mma including mr and ct images were reviewed. the clinical data were also registered for each patient. the frequency of different radiological fi ndings were compared according to age,gender,clinical presenting symptom and duration of treatment. results: fourteen patients ( . %) had normal brain images.the most common fi ndings of the images were (in order of frequency): ventricular dilation ( . %), diffuse cortical atrophy (sulci dilation)( . %), periventricular white matter change ( . %), corpus callosum thinning ( . %), subcortical white matter lesions ( . %), local cortical atrophy ( . %) and cerebellar atrophy ( . %). basal ganglia calcifi cation was seen in patients both of whom presented clinically in neonacy. treatment duration seems to have an improving effect on the severity of ventricular dilation (less severity in those who have received the classic treatment for more than one year). children who presented with psychomotor delay had usually multiple radiological fi ndings while few fi ndings were seen among those presented with loss of consciousness and those detected by neonatal screening. conclusion: in addition to ventricular and sulci widening, myelination abnormality and basal ganglia changes, some other fi ndings are expected and rise the suspicion to mma including corpus callosum thinning, brain stem thinning, signal change due to focal infarct, bright signal in centrum semioval and putamen calcification. treatment with adequate duration may improve or prevent some structural changes in cns. learning objectives: to describe the principal location of facial fractures in pediatric patients and their radiologic appearance. to discuss the optimal imaging work-up for detection of these fractures in children, with emphasis on the important role of ct. to describe our experience in this fi eld in the last years: epidemiology and main mechanisms of trauma. background: trauma is one of the main causes of morbidity and mortality in the pediatric age group, craniofacial fractures being accountable in a signifi cant part. there is great disparity in the available epidemiologic data and scant radiologic literature on this important subject. interpretation of facial radiographs is specially challenging in children, and ct is required in many cases; therefore, we must be familiarized with the unique characteristics of these fractures. we retrospectively reviewed facial fractures attended in our institution in the last years. the total amounted to diagnosed fractures in patients < years. we analyzed the mechanism of trauma, patient age and sex, fracture location, and radiologic features. we fulfi lled a bibliographic revision and compared our results to those in the literature. imaging findings: the most common were nasal fractures, succeeded by mandibular and orbital fractures. zygomatic, nasoetmoidal, frontal and panfacial fractures were found to be infrequent. the sex ratio was . : (male/female). the main causes were accidental falls, followed by aggressions, motor-vehicle crashes, and sports accidents. conclusion: facial fractures in the pediatric age group have special characteristics, and therefore require subject-specifi c knowledge of the diagnosis, management, and follow-up. for the follow-up, groups were defi ned: newborns with ( ) lethal postnatal course ( ) intensive respiratory care > days and/or pulmonary hypertension ( ) intensive respiratory care < days, and ( ) no need for additional respiratory support. in fetuses with oligohydramnios, fetal lung volumes were signifi cantly reduced (p < . ). the mean defi cit of lung volumes was % compared to normals. fetuses with a modal defi cit of . % of lung volume deceased postnatally. reduced signal intensity of lung tissue was associated with lethal outcome in of newborns. differences of lung volumes and signal intensities between the groups - were less pronounced. fetuses with a high risk of pulmonary hypoplasia (group ) showed signifi cantly reduced amniotic fl uid volumes, early onset and a long persistence of oligohydramnios. conclusion: fetal mr can reveal the degree of pulmonary hypoplasia in fetuses with oligohydramnios. reduction of fetal lung volumes over % of the expected value together with pronounced darkness of lung tissue on t -weighted mr sequences is highly conspicuous for lethal outcome. magnetic resonance and computed tomography fi ndings in childhood background: tb still ranks as one of the most important communicable diseases and represents a major global health problem. although pulmonary tb tends to be the most common form of tuberculosis, the highest mortality and morbidity occurs with tb of central nervous system (cns tb), which develops in % of children with tuberculosis and has an high fatality rate and causes serious sequelae, especially during childhood. imaging findings: available imaging ct and mr studies of patients ( females, males; mean age: . months) were retrospectively reviewed. all patients showed a basilar enhancement. other fi ndings were hydrocephalus ( %), intracranial tuberculomas ( %), and other nodular ( %) and ischemic lesions ( %). edema, either perilesional or diffuse, was found in / patients. severe ventricular dilatation was observed in / cases. two patients, with fatal involvement, showed severe hydrocephalus associated, respectively, with extended ischemic areas and intraventricular haemorrhage. conclusion: cross-sectional imaging, along with clinical data, may provide useful clues in the early diagnosis of cns-tb, and may helpful in preventing unnecessary morbidity and mortality. head and neck tumors in the pediatric age group -more than lymph nodes to be found g.k. schneider, k. altmeyer, p. fries, a. massmann, t. krenn, n. graf; homburg a.d. saar/de (ragsne@med-rz.uni-sb.de) learning objectives: this exhibit will present the wide spectrum of head and neck masses in children. special consideration will be given to describe the lesions ddx according to their anatomic localization. background: masses of the head and neck area are a commonly encountered problem in daily practice. the aim of this exhibit is to review ddx of head and neck tumors in children with special regard to their anatomic localization. mri and ct images will demonstrate the range of lesions from infl ammation to lymphoma, soft tissue tumors, and vascular abnormalities. imaging findings: the exhibit will review the different anatomic spaces to enable the reader to properly allocate a mass to its compartment. ddx will be explained with regards to their typical localization, imaging fi ndings and their clinical appearance. mri and when it is useful for ddx ct images will be demonstrated in case presentations. a special emphasis will be laid on pitfalls such as vessel abnormalities or pseudotumors. finally, readers will have the opportunity to test their knowledge in some quiz cases. conclusion: ddx of masses in the head and neck region of children goes far beyond simple lymph node enlargement versus lymphoma. depending on its localization, cervical cysts or tumors of neural origin may come into focus. soft tissue or bone tumors, pseudotumors, and abscess formations or vessel abnormalities all may present as circumscribed lesions. mri allows for exact tumor localization, and together with ct and cemra may identify lesions that need to undergo biopsy. fetal mri evaluation of anomalies of the neural tube and spine c. martín, a. lüttich, c. escofet, a. martín, i. delgado, s. perez, c. durán; purpose: to analyze the neural tube and spinal column anomalies detected prenatally at our centre over the last years and evaluate the impact of fetal mri in the diagnosis. methods and materials: thirty fetuses with anomalies of the neural tube and spine were studied. all patients underwent obstetric us examination. intrauterine mri was performed in cases; in the remaining , mri was not performed because indications went unobserved at us or further examination was considered unnecessary. mri was performed on a . tesla unit using ultrafast half-fourier acquisition single-shot turbo spin-echo (haste) sequences. images were analyzed by a pediatric radiologist and the fi ndings were compared to those of us. all anomalies were confi rmed after birth or at autopsy. results: the anomalies observed were acrania (n= ), encephalocele (n= ), iniencephaly (n= ), spina bifi da (n= ), diastomatomyelia (n= ), hemivertebra (n= ), kyphoscoliosis (n= ), amniotic band syndrome (n= ), osseous dysplasia with spinal involvement (n= ), caudal regression syndrome (n= ), sacrococcygeal teratoma (n= ), and conjoined twins (n= ). neural tube and spinal column anomalies were associated to anomalies in other organs in cases. fetal mr provided additional information in ( %) cases, and changed the therapeutic approach in ( %). conclusion: prenatal diagnosis of neural tube and spinal column anomalies can predict fetal viability, orient the prognosis and management of the newborn, and has implications for genetic counseling. mr is a noninvasive method of fetal examination that provides additional information to us. in a factor of - if appropriate procedure protocol is used, with optimised setting for the x-ray system. purpose: to assess magnetic resonance urography (mru) in the morphologic evaluation of suspected urinary tract obstruction in infants and children. to try to evaluate the correlation between functional fi ndings in mru and nuclear medicine. methods and materials: patients with sonographicallly suspected urinary tract obstruction were studied with mru ( . t), intravenous urography and nuclear medicine. procedure details: saline solution (nacl %, ml/kg) and low-dose furosemide ( mg/kg) were administered before beginning unenhanced mru (heavily t -w sequences). after minutes, . mmol/kg gd-dtpa was administrated to coincide with the maximal diuretic effect, and dynamic enhanced mru (coronal d frge sequences) was performed. the obstruction site and cause were detected in all cases by mr examination. diagnosis of the kidneys includes: normal system ( ), duplex system ( ), pyeloureteral junction stenosis ( ), ureterocele ( ), ureteric ectopia ( ), multicystic dysplastic kidney ( ), megaureter ( ), ureteral kinking ( ), horseshoe kidney ( ). time difference of seconds in the excretion of normal and pathologic kidneys showed good correlation with the diagnosis of obstruction in nuclear medicine. conclusion: mru provides very high quality images. additional benefi ts include renal arteries evaluation and preprocedural planning for surgery. mru is a nonionizing imaging technique that allows both functional and morphologic evaluation in the same procedure and could replace other imaging modalities. the whole spectrum of sonographic patterns of normal and abnormal renal pyramids in infancy and childhood m. vakaki, p. papadoniou, a. simopoulos, k. tavernaraki, g. pitsoulakis, c. koumanidou; athens/gr (geop@hol.gr) learning objectives: to present the wide spectrum of sonographic patterns of renal pyramids in physiologic, as well as pathologic conditions that affect the renal medulla of pediatric patients. to emphasize the role of sonography, correlating the imaging fi ndings with etiology, which should be the basis for the appropriate differential diagnosis. background: it is well-known that the sonographic appearance of the developing b d e f a g kidney differs from that in adults and changes from birth to adolescence. one of the characteristic unique features of the pediatric kidney is the hypoechoic appearance of its prominent medullary pyramids. various conditions modify this normal appearance. furthermore, the disease processes that affect the renal medulla in children differ from those in adults. imaging findings: the various sonographic patterns of normal and abnormal renal pyramids are illustrated. anatomic details, histopathology and suggested pathophysiologic mechanisms of the different causative pathologic entities are presented. these conditions represent a heterogeneous group of disorders and include the normal transient neonatal renal medullary hyperechogenicity, the severe obstructive urinary stasis and intratubular refl ux, polycystic kidney diseases (mainly autosomal recessive polycystic disease), renal candidiasis, sickle cell anemia, the various common and rare causes and types of nephrocalcinosis, etc. conclusion: renal sonography with state-of-the-art us equipment is very sensitive in the imaging study of renal medullary pyramids in childhood. knowledge of the specifi c sonographic features of the different pathologies affecting the renal pyramids supplemented by the necessary clinical information allows the narrowing of the differential diagnosis directing further diagnostic investigation, when necessary. the role of mr imaging in the pre-surgical evaluation of pre-sinusoidal hypertension secondary to portal cavernomatous transformation in children f. guerra-gutiérrez, j. fernández-cuadrado, j. gomez-patiño, a. alonso-torres, m. lópez-santamaría, n. leal; madrid/es (fl aguers@hotmail.com) learning objectives: to demonstrate the utility of magnetic resonance angiography (mra) in the pre-surgical evaluation of pre-sinusoidal hypertension due to portal cavernomatous transformation (phpct) in children. background: children with phpct may be treated by means of programmed surgery, and a pre-surgical imaging evaluation is crucial to defi ne the venous obstructive pattern, and, subsequently, to choose an appropriate surgical strategy. in that purpose, commonly, these children underwent a conventional angiography, which is an invasive technique. imaging findings: twenty-two children with phpct were evaluated. they all underwent a mra previous to programmed surgery in the past years. we describe four major venous patterns: ) principal portal vein (ppv) obstruction with patent and connected to each other superior mesenteric vein (smv) and splenic vein (sv) (n= ); ) ppv obstruction with thrombosis of smv and patent sv (n= ); ) generalized hypoplasia of the splachnic venous system (n= ); ) any of the previous patterns with normal intrahepatic portal vein (n= ). the surgical procedure was chosen as follows: mesenteric-caval shunt with autologous jugular vein graft (n= ) in the case of the fi rst pattern; distal splenorenal shunt (n= ) and proximal splenorenal shunt, both indicated for the second pattern; mesenteric-left portal vein shunt (rex) for the fi rst pattern in association with the fourth pattern; non-derivative surgery (n= ) in the case of the third pattern. conclusion: mra is a useful tool in the pre-surgical evaluation of children with hpcpt. it gives accurate information that helps the surgeon to choose the most suitable surgical procedure. subcarinal left pulmonary artery sling in fi ve patients: assessing anatomical relationship between air-way and left subcarinal pulmonary artery sling and associated with tracheobronchial anomaly k. choo , y. kim , m. lee ; pusan/kr, pucheon, kyunggi-do/kr purpose: the purpose of our study is to assess anatomical relationship between air-way and subcarinal left pulmonary artery sling and associated with tracheobronchial anomaly. we present chest radiography, ct and echocardiographic fi ndings of subcarinal left pulmonary sling in patients ( male, female, mean age: . months). all patients had respiratory symptoms. echocardiography showed intracardiac anomaly such as vsd, asd, pulmonary atresia in patients and abnormal coursing left pulmonary artery in all patients. single, -slice and slice mdct were performed and axial images with dimensional reconstructions were used for evaluation of anatomical relationships of tracheobronchial anomaly associated with subcarinal left pulmonary artery sling in all patients. results: one of the patients had severe obstruction of left main bronchus by subcarinal left pulmonary sling, resulting in total atelectasis of lt. lung, with basically normal bronchial branch pattern. four of the patients had about % obstruction of left main bronchus by subcarinal left pulmonary sling with associated bridging bronchus. the subcarinal pulmonary sling could cause obstruction of left main bronchus and be often associated with tracheobronchial anomaly, including bridging bronchus. in addition, the ct scan using axial images and dimensional reconstructions could help to assess anatomical relationship between air-way and subcarinal left pulmonary artery sling and associated with tracheobronchial anomaly. (n= ), and cystic lymphangiomas (n= ). the sonographic fi ndings are illustrated and differential diagnosis is discussed. all cases were confi rmed surgically, or with clinical/sonographic follow-up. conclusion: sonography has been shown to be particularly helpful in confi dently evaluating abnormalities of the thoracic and abdominal wall and optimal treatment planning. pediatric radiologists, therefore, should be familiar with the embryology and anatomy, as well as with the sonographic features of various congenital and acquired pathologic disorders involving the thoracic and abdominal wall of children. imaging pediatric pseudo-malignancies: a retrospective review of cases g. castellazzi, d. vanel, d. couanet, c. dufour, r.c. sigal, c. dromain; villejuif/fr purpose: two per cent of the children referred to our cancer center have pseudomalignancy. the aim of this study was to analyze and correlate their clinical and radiological fi ndings. methods and materials: from to , patients with "pseudo" cancers, referred by well-trained clinicians, were seen. twenty-nine had complete imaging and clinical history records and the fi nal diagnosis of proven non-malignant disease. there were males and females, between and years of age. the fi nal diagnoses were made through pathology ( ), follow-up ( ), and serologic analysis ( ). results: frequent symptoms, variously combined and most frequently associated at the beginning, were: pain ( ), fever ( ), a mass ( ), adenopathies ( ), and walking diffi culties ( ). one patient had two pseudo-malignancies. thus, lesions were studied with the following diagnoses: malignant bone tumor ( ), lymphoma ( ), nephroblastoma ( ), neuroblastoma ( ), soft tissue tumor ( ), nervous tissue tumor ( ), small bowell neuroendocrine ( ), and undifferentiated nasopharyngeal carcinoma ( ). various radiological examinations were performed. there were in fact infections, traumatic lesions, chronic diseases, congenital lesions, and in cases no disease corresponding to the clinically suspicious symptoms was found. conclusion: pseudo-malignancies are rare and diffi cult to diagnose, even by welltrained teams. the aim of the poster is to propose a review of images of pediatric pseudo-malignancies referred to an oncologic hospital, to make the reader more familiar with those possible problems, allow an easier and faster diagnosis, and avoid unnecessary and sometimes dangerous treatments. learning objectives: to provide a free program for handheld devices as a reference database in pediatric plain film radiography which serves the well and less experienced pediatric radiologist to differentiate between physiological age-specifi c and pathological fi ndings. background: it is especially diffi cult for the inexperienced radiologist or the resident on-call to differentiate between physiological age-specifi c and pathological fi ndings due to developmental variations in the growing child. the suitable book is often unavailable. to solve this problem, an easy accessible format like handhelds would help in this situation. procedure details: over images in pediatric skeletal radiography can be displayed in radiographic standard settings on a handheld device. all images are categorized by body regions, age and gender. the database can be queried through selection of all three criteria or by choosing each criterion separately. the latter offers itself mostly for determination of bone age using the left hand. each mode provides the user with at least one reference image according to each body region, age and gender. conclusion: this program is a free reference database for almost all standard images in plain fi lm radiography, from infancy to adulthood. the database serves the radiologist on-call and the less experienced pediatric radiologist to differentiate between physiological age-specifi c and pathological fi ndings. learning objectives: to illustrate the spectrum of ultrasound image fi ndings after wrist and distal forearm trauma in children with no fractures detected on plain fi lms. background: wrist and forearm injuries are common in adolescent and become more and more common in younger group of children, mostly due to decreasing age of starting the recreational or professional sport activity. the interpretation of clinical examination in a child is often more challenging than in adults; thus, in the presence of different clinical symptoms (wrist pain, oedema, limited movement) together with normal radiographic examination, the question arises about the nature of the wrist/distal forearm tissue injury. procedure details: in children who attended our paediatric admission unit because of wrist/distal forearm trauma and in whom the standard plain fi lms did not reveal any fracture, a wrist ultrasound examination, according to actual essr guidelines, was performed. we focused on tendons evaluation (continuity, tears), joint effusion or occult fractures depiction and precise assessment of the extent of soft tissue oedema. we tried to discuss the correlation between the most common ultrasound fi ndings and the patient age, as well as the injury mechanism and clinical symptoms. conclusion: wrist ultrasound is a valuable imaging method in children after wrist/distal forearm trauma. it is particularly helpful in cases of an equivocal clinical examination and in the presence of normal radiographic results helps to assess the character of the tissue injury. learning objectives: the purpose of this educational exhibit is to emphasise the role of diagnostic and/or therapeutic ultrasonography (us) in diverse congenital and acquired musculoskeletal diseases in children and adolescents. background: us is a powerful diagnostic tool for the evaluation of musculoskeletal disorders owing to low cost, availability, non-invasiveness, multiplanar capability and real-time studies, which allow dynamic imaging. the absence of ionizing radiation is particularly valuable in children, but experience and proper training is required in the pediatric musculoskeletal pathologies. procedure details: a total of patients who underwent sonographic evaluation in our tertiary center during the last years were retrospectively evaluated. us examination was carried out with a sequoia or an aspen (siemens-acuson), using high resolution technique, dynamic manouvres, contralateral comparison, color and power doppler, extended fov function and interventional procedures. other imaging techniques such as mri, ct or bone scintigraphy were also performed when diagnosis was unconclusive. congenital (dhd), traumatic, infl ammatory, infectious-toxic (transitory sinovitis, arthritis, pyomyositis, infectious bursitis, cat-scratch disease, subperiosteal abscess, infectious lymphadenitis, osteomyelitis), neoplastic (benign and malignant tumors of bones or soft tissues), foreign bodies, and vascular malformations will be presented with a selection of the most representative cases. conclusion: us is a rapid, nonionising and very sensitive technique for imaging musculoskeletal disorders in children and adolescents. it also offers the possibility of performing aspiration or biopsy procedures with diagnostic and therapeutic relevance. fine-streak artifact quantifi cation and removal in reconstructed ct images o.s. pianykh, p.m. boiselle, d. litmanovich, v. raptopoulos; boston, ma/us (opiany@gmail.com) purpose: streak artifacts in ct images can originate from a broad range of factors, and often may be controlled with improved scanning protocol parameters and patient positioning. therefore, a reliable method is needed to quantify the streak presence in the images, guiding the improvements in the scanning protocols and settings. streak-quantifi cation methods can also lead to better streak-removal algorithms. methods and materials: fine streaks, typically originating from the noise and photon starvation, can still be detected numerically in reconstructed ct images. our approach is primarily based on exploring streak-shape linearity, leading to the following image processing steps: ;inear image fi ltering to enhance streak-affected pixels; streak-searching methods, locating straight lines of pixels either raised or lowered compared to the surrounding pixel background; weighting detected streak lines proportionally to their length and severity; building streak "signature" of the image, showing streak presence by streak severity. results: our method provided high accuracy in locating and measuring streak artifacts. this quantifi cation method naturally extended to a streak-removal algorithm, which would "raise" or "lower" image streak pixels to eliminate the streaks. the proposed streak quantifi cation and removal algorithm can be successfully used to: ( ) quantify fi ne streaks in reconstructed ct data. the quantity of image "streakeness" can then be used to improve image scanning parameters and to achieve higher image quality; ( ) remove streak artifacts from the reconstructed ct images without any need for the raw data (generally unavailable). performance characterisitics of dyna-ct acquired by the threedimensional angiography system with fl at panel detector e. minota; kobe/jp (minota@fbri.org) purpose: the three-dimensional angiograph equipped with fl at panel detector (fpd) acquires a complete volume set during a single rotation, which can be used to reconstruct tomographic images similar to ordinary ct. we evaluated the performance characteristics of images acquired thus, including image noise, spatial resolution in the axial plane, section sensitivity profi le in z-plane (sspz), contrast noise ratio (cnr), distortion of an acrylic ball, and clinical images. we used a biplane c-arm angiograph with × cm amorphous silicon fpd (axiom artis dba, siemens medical solutions, germany). the sspz and axial spatial resolution were measured with miniature iron balls of . - . mm. the cnr was measured with a phantom containing agar cylinders of various diameter and contrast media density. the distortion was evaluated for an acrylic ball of cm diameter at various distances from the center. data acquisition times were sec ( projections), sec ( projections), and sec ( projections). results: the image quality degraded as the object was away from the center or when the data acquisition time was short, probably due to the nature of cone-beam d reconstruction and the reduced number of views. correction fi lters improved the image artifacts. the distortion was considered clinically acceptable. although the image quality was lower than the ordinary ct, especially for low-contrast objects, it was considered clinically useful if appropriate data acquisition protocol and fi lters were used. this system is very valuable not only for brain angiography, but also for orthopedics and other fi elds where tomographic images are helpful. variation of the optimal reconstruction phase for cardiac ct imaging: analysis by a rawdata-based kymogram approach d. ertel, t. pfl ederer, s. achenbach, m. kachelrieß, w.a. kalender; erlangen/ de (dirk.ertel@imp.uni-erlangen.de) purpose: to analyze the dependence of the optimal reconstruction phase for cardiac ct imaging on the patient's heart rate by using a rawdata-based approach and to prove a patient-specifi c dependence. the rawdata-based synchronization signal (kymogram) is generated by a center-of-mass tracking [med.phys., ( )] and provides directly a motion function of the heart. we identify the phase in the cardiac cycle with the lowest variation of the center-of-mass as representing the phase with the lowest velocity of the heart, assuming to be the optimal reconstruction phase for providing motion-free images. rawdata of patients were used, scanned with a standard cardiac protocol, slices of . mm, . s rotation time and concurrent ecg recording (sensation , siemens, forchheim). we correlated the identifi ed optimal reconstruction phase derived from our approach with the patient's heart rate to analyze the dependence of the optimal reconstruction phase on the heart rate. the probability to obtain the best achievable image quality in the systolic phase instead of the diastolic phase increased from % to % with increasing heart rate. however, individual analysis showed that the optimal reconstruction phase is more patient-specifi c than dependent on the heart rate. also, the optimal reconstruction phase in the diastolic phase shows a high variation of % over all patients. conclusion: a high patient-specifi c dependence of the optimal reconstruction phase for cardiac imaging was shown. only a slight correlation with the heart rate was observed. algorithms detecting the optimal reconstruction phase seem to be promising and essential. ct scan protocol optimization by the study of focal spot size infl uence on image quality w. qi, x. du, j. li, s. zhang; beijing/ cn (jianying.li@med.ge.com) purpose: to optimize ct scan protocols in various applications by analyzing the infl uence of focal spot size on image quality. methods and materials: a catphan ct phantom was scanned with large and small focal spots with the same dose by adjusting scan time. images were reconstructed using both standard and bone-plus kernels. modulation transfer function (mtf) and slice sensitivity profi le (ssp) were used to evaluate in-plane and z-axis resolutions, respectively. two radiologists evaluated and scored inner-ear images of volunteers with large and small spots without knowing the scan techniques. the mtf values and fwhm values of ssp with small spots were always - % better than those of large spots. with standard algorithm, the % mtf values were . lp/cm and . lp/cm for the large and small focal spots, respectively. for patient inner-ear images reconstructed with bone-plus kernel and cm dfov, small spots outperformed large spots by to . however, the visual advantage of using small spots decreased when the images were reconstructed by standard kernel and cm dfov. the use of small spots improved both in-plane and z-axis spatial resolutions by - % compared to large spots. the improved resolution translated into clinical diagnostic advantage for small dfov, high-resolution applications. however, this advantage decreased when large dfov and standard reconstruction algorithm were used, which suggested that one could have balanced usage of focal spots in these applications. image reconstruction using a combined algorithm for a translating and rotating volume ct ( purpose: we describe a new system, trvct (translating and rotating volume computed tomography), developed for a computed tomography image of a large object. it is a simple method and offers a low price. the key point of this new method is that it handles the movement of an object that is translating and rotating simultaneously. methods and materials: using a vertical linear array detector, one tomogram image can be acquired when the object is translating and rotating simultaneously. this method is completely different from that of a normal x-ray ct. we used a fan-beam x-ray. the direction axis for the detector and rotating axis are parallel. because a hundred or thousand tomograms with z-axis are from just one scanning, this system has excellent z-axis resolution and has the advantage that this technique can improve the resolution in the x-y plane with changing translating speed and frequency of data acquisition. the image reconstruction algorithm is composed of a modifi ed con-beam ct algorithm and parallel beam ct algorithm. radiation dose and risk from fl uoroscopically guided percutaneous transluminal angioplasty and stenting in the abdominal region j. stratakis, j. damilakis, d.k. tsetis, n. gourtsoyiannis; iraklion/gr (jstratak@med.uoc.gr) purpose: to estimate radiation dose and associated risks resulting from fl uoroscopically guided percutaneous transluminal angioplasty and stenting in the abdominal region. methods and materials: examination parameters for renal and aortoiliac procedures were derived using data from consecutive procedures performed in our institute. organ and effective doses were estimated for endovascular procedures using the monte carlo (mc) transport code and an adult mathematical phantom. thermoluminescent dosimeters were used in an anthropomorphic phantom to verify the mc calculations. radiation-induced cancer and genetic risks were estimated using appropriate coeffi cients. results: results are presented as doses normalized to dose area product, so that the patient dose from any technique and x-ray unit can be easily calculated for iliac and renal pta/stenting sessions. the average effective dose varied from to . msv depending on procedure scheme and the sex of the patient. differences of up to % were observed between mc-calculated data and data derived from thermoluminescent dosimetry. conclusion: male patients up to years old are subjected to a signifi cantly fatal cancer risk. radiation-induced cancer risk may be considerable for younger individuals undergoing transluminal angioplasty with stent placement. application of a radiation therapy planning system for measurement of organ-absorbed doses inside the body during whole-body ct acquisition using homogeneous and heterogeneous phantoms and clinical cases n. funabashi, t. fujibuchi, n. tanabe, m. uehara, i. komuro; chiba/jp (toshifujio@ybb.ne.jp) purpose: absorbed radiation doses on the body surface and inside phantoms can be measured using dosimeters during ct examinations, but measurements inside the body are diffi cult. therefore, simulation-based methods are often applied to estimate the latter, but this is rather time-consuming. we investigated a new method that uses a radiation therapy planning system (rtps). we used tough water and rando phantoms as homogeneous and heterogeneous phantoms, respectively, and measured absorbed radiation doses by ionization chamber and photoluminescence dosimeter (pld) compared to rtps estimates. furthermore, in clinical cases acquired by multislice kv ct (aquilion, toshiba), calculated the absorbed dose using an arc beam calculation system. results: in a homogeneous phantom, the difference between values measured by ionization chamber and those estimated by rtp were . ± . % at y axis, - . ± . % at z axis, and . ± . % in the total irradiation fi eld. in a heterogeneous phantom, the difference between pld and rtp values was . ± . % for the body and - . ± . % for the lung. conclusion: the rtp system may be a simple and useful tool for estimation of absorbed radiation doses inside the human body even during whole-body ct acquisition. ( ) and vascular surgery ( ) centres participated in this multi-centre study. individual extremity doses were monitored per procedure with highly sensitive detectors at fi ve positions: the forehead, both hands and both legs. doses to up to three staff members (physician, assistant, nurse) were simultaneously measured during a procedure and relevant exposure data (position, patient-dap-dose, protection) were registered. results: data was collected from a total of procedures. the median dose per procedure to the physician's eyes ( µsv) was signifi cantly lower than the doses to the legs ( µsv) and hands ( µsv) as most centres used an under table x-ray tube exposure geometry. a moderate to strong correlation between patient-dap-dose and dose to the physician was observed. at vascular surgery centres, dap-normalised staff doses were about three times higher than in angiography centres. in centres with a low workload, elevated normalised doses were observed. extrapolated data showed that two physicians may likely exceed both annual dose limits of the eyes ( msv) and the skin of the legs ( msv). about one third of the physicians removed themselves consistently from the patient during image acquisition. this proved to be a very dose effi cient working procedure. procedure details: first, ct numbers from ct images were converted into mass density and elemental weights of tissues required as input for dose calculations with geant , which is a toolkit for the simulation of the passage of particles through matter. they were set by x-y coordinate, slice location, and slice thickness. they were exposed to x-ray from the x-ray tube simulator developed by us in geant . the simulator exposes x-ray of any energy spectrum (tube volt: kv- kv), any expose fi eld, etc. the absorbed doses at skin and at other organs were calculated. the fusion images of ct dose can be displayed by the viewer developed by us. the patient's absorbed dose at skin can be found correctly using monte carlo algorism without tlds. doses at skin and at other organs can both be estimated by the software developed by us. patients and medical staff can calculate the patient's exposure dose distribution by d fusion images of ct dose. d fusion images help them for the explanation of side effects from exposure and for obtaining informed consent from patients. a low-density board placed on the couch reduces a patient's skin doses in interventional procedures a. kawabe, y. nakagiri, y. takeda; okayama-city/jp (akawabe@md.okayama-u.ac.jp) purpose: in interventional procedures, scattered radiation generated on the interventional couch increases a patient's skin doses. here, we assumed that this low-energy scattered radiation is removed by air gaps between the couch and patient. however, it is physically impossible to produce air gaps between the couch and patient. to solve this problem, we have devised a new process. this process involves the use of a low-density polystyrene board, which acts as an air-gap substitute. the purpose of this study was to investigate the air-gap-reproducing effect of the low-density polystyrene board. the entrance skin dose (esd) was measured without interspaces between the couch and phantom ( cm acrylic block), which was defi ned as a reference esd. low-density polystyrene boards ( to cm) were inserted between the couch and phantom, and esds were measured, respectively. these esds were compared with the reference esd. the low-density polystyrene boards with a cm thickness, inserted between the couch and phantom, led to an esd reduction of about %. conclusion: the low-density polystyrene board simulated air gaps. in interventional procedures, these boards can be implemented easily and inexpensively in a clinical setting, resulting in reductions in a patient's skin exposure by as much as %, without affecting image quality. measurement of occupational exposure in a mobile pet unit m. de marco, s. maggi; ancona/it (black_dragon@libero.it) purpose: the routine handling of unsealed f-fdg in a mobile pet unit, that is usually not provided with a hot cell, may result in the production of airborne radioactivity. the aim of our study was to quantify the occupational radiation exposure for a technologist working in a mobile pet unit, evaluating both internal contamination and external irradiation. methods and materials: internal exposure: each technologist was issued with a personal air sampler that collects the air that the worker is really breathing. external exposure: personal dose equivalent hp ( ) has been quantifi ed using electronic dosimeters. occupational radiation exposures have been evaluated twice a week for six months based upon an operating pet effi ciency of procedures/day. learning objectives: to describe the acceptance of radiation proctection courses for health care professionals in germany by an anonymous survey. background: maintaining safe utilization of ionizing radiation and radiation protection of staff, public and environment requires high levels of competencies. in , the german radiation protection and x-ray ordinance put health care professionals employing ionizing radiation under an obligation to recertify theoretical and practical knowledge. personnel, i.e. physicians, physicists, radiographers, nurse-practioners and specialist staff, have to enrol for an offi cially approved radiation protection course every years. or hour classes with a multiple choice tests are held by lecturers, radiation protection offi cers and experts in the fi eld. however, a preconceived opinion across all levels of professionalism declares radiation protection education and training redundant and costly. procedure details: course participants were asked to fi ll in an anonymous questionnaire [n= , radiographers ( %), physicians %, including % consultants and % medical directors]. the survey itemized age, vocational training, professional group, fi eld of practice, course content, stimulus, practicality and course costs. % estimated the theory-practice-performance ratio as balanced. stimulus (great many %, many %, some %). the courses came to participants' expectations (fully %, for the most part %, partly %. full coverage of the expenses ( - euros) by the employer was reported by % of the participants. conclusion: although radiation protection is widely considered as a stepchild in health care delivery, professionals are aware of adequate education needs and training. c b d e f a g principles of k-space sampling p. paolantonio , r. ferrari , f. iafrate , m. rengo , c. de cecco , a. laghi ; latina/it, rome/it (paolantoniopasquale@hotmail.com) learning objectives: to describe principles of k-space sampling. to offer an easy explanation of k-space physics for radiologist. to describe properties of k-space and to illustrate different k-space sampling strategies. to show how different portions of k-space contribute to the fi nal image appearance. to illustrate the rationale for centric, elliptic, spiral and partial k-space sampling strategies. background: k-space sampling represents a crucial step in mr image acquisition. the easy way to sample k-space is represented by a sequential mode that is also a time consuming procedure. k-space sampling strategy may be modifi ed in order to reduce acquisition time. a central or elliptic sampling of k-space is recommended for contrast-enhanced-mr-angiography in order to collect central line of k-space during the peak of vessel enhancement. procedure details: we show in a step by step form the image generation process focusing our attention on k-space sampling. we will describe how k-space is sampled in several pulse sequences commercially available. using graphic examples, we will describe different k-space sampling strategies. the knowledge of k-space sampling strategies is crucial for understanding mr image acquisition process. several k-space sampling strategies are available. using the appropriate k-space sampling strategy is useful in reducing acquisition times and in order to optimise image acquisition for the clinical purpose of mr-studies like happens in centric or elliptic sampling of k-space and contrastenhanced mr-angiography. background: an increased risk for mri-associated skin burns has been described for pictorial tattoos using iron coloured pigments. not until recently, permanent make-up, a new and rapidly spreading cosmetic technique, has been recognized for putting the patients at risk of burns by mr imaging. procedure details: neither iron pigments nor larger tattoo areas are required to induce burns in these patients. to gain a special colour effect cosmetic tattoos contain metals such as iron, copper and zinc. locally, electric current can be induced by any of these metals in a high-frequency magnetic fi eld, even if only subtle eye lining has been performed. this mechanism of locally induced electric current is responsible for possible dysesthesia and burns in patient's skin containing a cosmetic tattoo, e.g. permanent make-up during mri examination. a clinical example, review of the literature and recommendations for addressing this problem in the daily mr practice will be given. conclusion: permanent make-up, for medical purposes better adressed as cosmetic tattoo, can cause severe local damage to the skin during mri studies even if it is free of iron oxides. every mr radiologist should be aware of these risks and direct patient's management and staff training accordingly. combining a body coil for radio frequency transmission and an endorectal coil to receive signal. three-dimensional mri and mrsi data were collected with magnetic fi eld homogeneity in the selected volume obtained by shimming water with lipid suppression accomplished with selective inversion of lipid resonances. peripheral voxels were saturated to suppress periprostatic fat and air. we will review how data is then processed and how to interpret a prostate spectrum. conclusion: in summary, this poster serves to demonstrate the technical aspects of d mrsi including practical aspects of implementation and technical considerations. hopefully, radiologists will understand the basic principles of prostate mrs imaging, and by realising the feasibility and clinical possibility of providing mrsi will be encouraged to initiate prostate spectroscopy. conclusion: understanding the magnetic resonance imaging susceptibility effects and their infl uence on imaging appearance allows the clinical radiologist to make a wise selection among the broad range of imaging sequences available to minimize artefacts, enhance pathology detection as well as limit the differential diagnosis. liver imaging at . t: potential of diffusion-weighted black-blood echoplanar-imaging sequences for large-coverage volumetric imaging i.c. van purpose: to evaluate breath-hold diffusion-weighted black-blood echo-planarimaging (bbepi) as potential alternative for sar-intensive spin-echo sequences for liver imaging at . t. methods and materials: after institutional review board approval and informed consent were obtained, healthy volunteers were scanned at . t, using an asset compatible -channel cardiac coil. parameters were set to cover the entire liver ( cm z-axis) in one -sec breath-hold, and were varied interactively with regard to te, tr, diffusion b-value, slice thickness and voxel size. images were evaluated and compared to fat-suppressed t w fast-spin-echo (fs-t w-fse) for image quality, liver delineation, blurring, geometric distortions, fat-suppression, suppression of the blood signal, cnr and snr. results: the optimized short-( ms) and long-echo ( ms) bbepi provided mm and mm slice thickness with full anatomic, single breath-hold liver coverage ( and slices, respectively), resulting in voxel size . x . x . mm and . x . x . mm . tr was ms. b-values > s/mm showed better suppressed blood signal, but b= s/mm provided improved volume coverage and signal consistency. compared to fs-t w-fse, bbepi provided: ( ) comparable image quality, liver delineation and blurring; ( ) acceptable geometric distortions; ( ) improved suppression of fat-and blood-signal (p < . ); and ( ) higher cnr and snr (p < . ). conclusion: our study shows that bbepi can be used for ultrafast, low sar, thin-slice morphologic imaging of the entire liver in a single breath-hold at . t, providing near-isotropic data with multiplanar reformatting capability. flair absolute purpose: to estimate absolute concentrations from mr spectroscopic measurements reference concentrations are required. commonly, either tissue water concentration or separate phantom solutions with known concentration are used. the purpose of the study was to acquire brain spectra in volunteers and to compare the variability of both methods. overall twelve volunteers were investigated by h- d-csi (steam; te= ms, tr= ms) on a . t whole-body scanner (magnetom sonata, siemens) using the standard head coil. for three volunteers measurements were performed twice with identical sequence parameters except for the water suppression pulse which was switched on only during the fi rst measurement. spectra were evaluated by the lcmodel. results: comparison of absolute concentrations of the metabolites naa, cho and cr obtained with both methods showed stronger differences for voxels located in border areas of the selected volume. the differences between concentrations estimated by using naa and water as a reference were clearly more pronounced in the parietal region (naa: . vs. . mmol/l; cr: . vs. . mmol/l; cho : . vs. . mmol/l) compared to the frontal region (naa: . vs. . mmol/l; cr: . vs. . mmol/l; cho: . vs. . mmol/l). this refl ects the spatial variations of the coil sensitivity. conclusion: as technical parameters like coil-sensitivity and load-factor affect measurements with and without water suppression in the same way, corresponding errors in the estimated absolute intensities can be avoided. therefore, if time allows an internal reference should be preferred compared to estimation by a reference solution without correction of the sensitivity profi le of the coil. assessment of a fast, d mri pulse sequence for use in polymer gel dosimetry i. seimenis , p. baras , p. papagiannis , p. karaiskos , a. angelopoulos , p. sandilos , l. vlachos , b. pantelis ; nicosia/cy, athens/gr (yseimen@phys.uoa.gr) purpose: the use of mri as a readout method for polymer gel dosimetry commonly involves long imaging sessions and, therefore, the technique has not been yet established in the clinical setting. this work evaluates the effi ciency and accuracy of a fast, d, dual-echo, k-space segmented turbo spin echo (tse) imaging pulse sequence. methods and materials: pabig polymer gel dosimeters were irradiated with an ir high dose rate brachytherapy source, the mm and mm collimator helmets of a gamma knife unit and a custom made x-knife collimator of cm diameter. profi le and dose distribution measurements derived from tse data were benchmarked against corresponding fi ndings obtained with the commonly used and optimised carr-purcell-meiboom-gill (cpmg) multi-echo cpmg sequence, as well as treatment planning calculations, monte carlo simulations, and fi lm and pinpoint ion ionization chamber measurements. results: the tse sequence was found to provide dosimetric results of comparable accuracy with those obtained from cpmg multi-echo acquisitions (within one pixel in the mri gel readout session, i.e. < mm), and to accurately predict treatments planning calculations and conventional dosimeter measurements in a range of radiotherapy applications that involve very steep dose gradients and stringent dose delivery requirements and which require high spatial resolution in all three dimensions. conclusion: the signifi cant scan time reduction ( -fold) achieved with the proposed imaging sequence implies that the polymer gel-mri readout method could prove to be a useful and practical tool in modern clinical radiation therapy applications involving high doses and steep dose gradients. scientific and educational exhibits procedure details: we analysed with high resolution skin disorders in all cases. dermis and subcutaneous fat, and epidermis in such cases, changes were studied. mri gave useful informations about thickness, localization, signal changes, extension and relationship with surrounding structures of the lesions. in such cases, as phototherapy of sclerodermia, mri allowed evaluation of the effects of therapy. we obtained substantial informations for differential diagnosis in infl ammatory skin disorders. conclusion: mr imaging provides global analysis with high resolution of the various skin layers down to the hypodermis and the muscular facia. characterization of lesions and evolution with treatment are permitted. skin tumoral lesions are well analysed, mri is useful to reduce the number of skin biopsies on certain indications. "glare" lcd panel improves resolution performance of softcopy display for digital mammography t. yoneda, n. hashimoto; hakusan, ishikawa/jp (yoneda@nanao.co.jp) learning objectives: to improve understanding of the following points about monochrome lcd monitors which have been getting more popular for digital mammography: . surface coating of lcd panel can affect resolution performance of softcopy display. . "glare" panel has better resolution performance than "anti-glare" panel which is currently used for the majority of medical lcd monitors. background: as digital mammography has been getting more popular, monochrome lcd monitors have also been spreading among radiologists. however, higher resolution and contrast performances are required in order to achieve the accurate diagnosis of mammograms, for example detecting microcalcifi cations. we have developed new m-pixel monochrome lcd monitor with "glare" panel which improves resolution performance. imaging findings: established "anti-glare" panel has waffl ed surface to diffuse the refl ection of ambient light. but it also diffuses the light from the monitor's backlight. as a result, the displayed image is blurred especially on outlines compared to the original image. on the other hand, "glare" panel has fl at surface so that there is no blur with the displayed image. it means that there is no degradation of resolution performance with surface coating. conclusion: resolution performances of both panels were compared by measuring mtf (modulation transfer function). "glare" panel showed higher mtf than "anti-glare" panel, which proves the higher resolution performance of "glare" panel. of course, the ambient light in reading room has to be controlled to decrease the specular refl ection, but this higher resolution performance can contribute to the accurate diagnosis of mammograms. purpose: dna double-strand breaks (dsbs) are among the most signifi cant genetic lesions introduced by ionising radiation. during angiography, patients are exposed to x-rays for a long time with changing tube position, pulsing rate and fi eld of view. the biological effect of ionising radiation was examined in patients undergoing angiography using a method which was previously applied only in vitro and in computed tomography. methods and materials: individual dsbs were visualised by using immuno fl uorescence microscopy. the method is based on the phosphorylation of the histone h ax after formation of dsbs. blood was taken from twelve patients undergoing different angiographic procedures before, during and after the examination. additional in vitro irradiation of blood samples was performed ( mgy) to evaluate the individual repair capacity. the dose area product (dap) ranged from to microgy*m , fl uoroscopy time ranged from : to : minutes. in all patients, the irradiation increased the number of dsbs. maximum of dsbs was found minutes after the end of fl uoroscopy and ranged from . to . foci/cell. the number of dsbs showed a linear correlation to dap and fl uoroscopy time (r = . and r = . , respectively). most of dsbs were repaired within hours in vitro and in vivo. conclusion: gamma-h ax immuno fl uorescence microscopy is a reliable method to measure the induction and repair of dna damages caused by ionising radiation during angiography even if very small doses were applied. needle-based versus conventional storage-phosphor radiography in paediatric radiology j.m. fernandez, e. vano, c. prieto, j.m. ordiales; madrid/es (eliseov@med.ucm.es) purpose: to compare exposure requirements for similar image quality with needle-based and conventional computed radiography (cr) systems in paediatric radiography. methods and materials: image quality has been evaluated for both cr systems with a contrast-detail test object covered with varying thicknesses of acrylic to simulate clinical conditions. four series of images were obtained with two thick- b d e f a g nesses: and cm, and increasing tube voltages ( , , and kvp). images were acquired at exposure levels. an image evaluation software was used to determine the threshold contrast of circular holes with diameters ranging from . to . mm. statistical signifi cance of differences between the two digital systems was assessed. phantom and detector surface air kerma were measured, and correlated with cr exposure levels. results: a linear relationship was found between the number of detected holes and the logarithm of exposure. on average, the structured phosphor system required % less phantom entrance air kerma than the conventional phosphor plate. differences in exposure requirements were smaller with decreasing thicknesses of simulated tissue thickness and lower tube voltages ( % at cm and kvp, and % at cm and kvp). all differences were statistically signifi cant. conclusion: structured cr provides improved low contrast detectability and a potential for dose reduction compared with conventional cr. the best performance was achieved with conditions comparable to those for adult radiography ( kvp and cm of pmma). learning objectives: to provide insight into current practices of clinical applications of multi-slice computed tomography (msct) using the new generation of ct systems able to acquire simultaneously at least sections, and to identify specifi c applications that justify the radiation exposure. background: rapid technical developments in ct have had a substantial impact on the applications of this technology. since ct is already associated with a relatively high (collective) patient dose, a review of current practices was performed. procedure details: administrative patient data on diagnostic applications corresponding to one contiguous year, and ct reports corresponding to % of the annual data have been retrieved from the information systems and referral forms of six radiology departments in different european countries. data pre-processing included coding the medical specialties, the age groups, anatomic regions, and most important coding of the diagnoses from medical details mentioned in the reports. the resulting database includes ct examinations, of which were referred by medical specialties concerning patients. to learn from these data, descriptive analyses have been performed. conclusion: ct examinations are predominantly performed on patients in the mid-and higher age categories. the highest referrals are by oncology; followed by surgery, internal medicine, neurology and neurosurgery. a substantial number of patients received more than ct examinations in -year, mostly for oncology. most frequent diagnostic categories are neoplasms; followed by diseases of the musculoskeletal system, vascular system, respiratory system, digestive system, urinary tract, and nervous system. mtf and nps measurements including x-ray scatter -application in a digital mammography system h. perez-ponce , p. monnin , f.r. verdun , a. noel ; vandoeuvre-lès-nancy/fr, lausanne/ch (hpponce@softhome.net) purpose: detector characterization with modulation transfer function (mtf), noise power spectrum (nps) and detective quantum effi ciency (dqe) inadequately predicts image quality when the imaging system includes patient scatter. this contribution investigates the effect of x-ray scatter on the mtf and nps in mammography for characterizing the system in clinical situations. a full-fi eld digital mammography unit was characterized at kv mo/mo at two beam qualities with and without x-ray scatter. pre-sampling mtf and nps without scatter were measured according to the iec - standard. the same imaging parameters were measured again with a mammography test object that simulates x-ray scatter due to the breast. results: x-ray scatter causes a falloff of mtf [ % at very low spatial frequency ( . mm- ) and . % for the rest of the spectra] and adds a constant amount of noise ( % from . to pl/mm, % from . to pl/mm and % from . pl/mm to the nyquist frequency). this increase in image noise is related to the amount of scatter integrated by the detector. the reduction of mtf and the increment of noise implies the drop of the dqe at all frequencies. the properties of an image receptor are properly characterized with a scatter-free beam. in clinical situations, detectors are used with x-ray scatter from the patient. the use of a test object including scatter to measure mtf and nps describes the resolution and noise properties of the imaging system with regard to scatter from the patient. the impact of nikola tesla on x-rays discovery m. hrabak, r. stern padovan, m. prutki, k. potocki; zagreb/hr (maja.hrabak@zg.t-com.hr) learning objectives: to present the role of nikola tesla's ( tesla's ( - research in x-rays discovery and invention of modern imaging technologies. background: discoveries of nikola tesla represent basics of traditional, but also modern imaging techniques. tesla's work is present in every radiological department, including fl uorescent lights in viewboxes, alternating current (ac) supplying the equipment, tesla-knott generator used for x-ray equipment, etc. one of tesla's never completed work was experiments with what would later be called x-rays. procedure details: tesla's articles published on the topic of x-rays and their biological hazards in the new york electrical review in the years and , tesla's biography, as well as medical papers mentioning nikola tesla were analyzed. conclusion: since april , tesla began investigations using crookes tubes, and his own vacuum tube which was a special single-electrode x-ray tube without target electrode. it seems that by , he became aware of what roentgen identifi ed as x-rays effects three years later. he didn't publicly declare his fi ndings nor make them widely known, and much of his research was lost in a fi re in his laboratory in new york in . he was also among the fi rst to comment on the biological hazards of working with x-rays with the conclusion that distance was a useful safety factor. count-rate analysis in pet with lso detectors f. bonutti, r. padovani, o. geatti; udine/it (bonutti.faustino@aoud.sanita.fvg.it) purpose: the optimisation of the acquisition parameters in pet has the purpose to improve the quality of the diagnostic images. optimisation can be done by maximizing the necr that in turn depends on the coincidences rate. methods and materials: for each bed, the scanner (biograph duo, siemens) records the coincidences and the singles rates in a log-fi le. for each patient, we fi gure out the functions trues=t (s), randoms=r (s), scatters=s (s) (where s = single count rates) by fi tting the nema cm phantom count rate curves on the measured clinical points, in order to analytically calculate the personalized pseudonecr (s) curve linked to the necr curve. results: for central beds, we estimate a missing activity of ~ % to get the pnecr_max, but the improvement in terms of snr that we could get is around %. we also estimated the correlation between the patient weight and the pnecr_max, in order to fi gure out which should be the scan duration of a single bed in function of the patient weight to acquire the same pnec. if we normalize the counts at the pnecr_max for the kg patient, the bed duration for a kg patient should be s, which is ~ % longer. conclusion: although the analysis indicates that the fast electronics implemented in the scanner allows the use of higher administered activities, we found that this would involve a poor improvement in terms of necr. the attention can be instead addressed on the usefulness of higher bed duration for heavier patients. radiology learning objectives: to describe our experience in development of 'joint ventures' between a radiology department and a basic research physics department. to analyze pros and cons of this collaboration from little initial projects to participation in large eu projects. background: clinical radiologic departments and basic research physics groups live frequently far away in work and mind from each other. however, to create a collaboration group between a radiology department and a basic physics research group provides great benefi ts for both institutions. procedure details: we describe our experience, projects and lessons learned about how to begin a 'joint venture'. we analyze possible benefi ts for a radiology department from a physics group including: a) experience from informatics management providing different solutions for several problems of our departe-c b d e f a g ment: advice for pacs and workfl ow, creation of an online database of radiologic cases, teleradiology; b) experience with management of european public money sources of money; c) performing basic research: in our case, with cad. possible benefi ts for a physics group from a radiology group: a) lessons from a different point of view b) application of basic research developed in practical applications more easy for marketing in the eu. in addition, basic research scientists have frequently a sensation of null practical application of their work, just the opposite of our daily clinical work. conclusion: creation of joint ventures between basic physics research groups and clinical radiologic departments can provide great benefi ts for both groups in scientifi c, economic and open-mind views. comparative evaluation of lcd with anti-glare panel and glare panel for digital mammography k. oda , m. sawada , a. ishikawa , h. imai , k. ichikawa ; anjo, aichi/jp, nagoya, aichi/jp (oda@kosei.anjo.aichi.jp) purpose: many current lcds use anti-glare panels, which have a waffl ed surface to diffuse the refl ection of ambient light. however, this also diffuses the light from the lcd's backlight. the aim of this study was to compare the spatial resolution (modulation transfer function: mtf) and the noise (noise power spectrum: nps) of high-resolution lcds with anti-glare and glare panel for digital mammography. methods and materials: " lcds ( x ) with a anti-glare panel and a glare panel were evaluated. a uniform image and a bar-pattern image displayed on an lcd were measured with a high-resolution single-lens refl ex type digital camera (d , nikon) equipped with a close-up lens. in order to avoid signifi cant errors caused by periodic components of the pixel structures, noise profi le data was processed by the hanning window. the lcd with a glare panel had better mtf characteristics and displays a sharper image outline. furthermore, the lcd with a glare panel had better nps characteristics than the lcd with an anti-glare panel. the lcd with a glare panel was excellent in physical characteristics by comparison with the lcd with an anti-glare panel for digital mammography. the glare panel was effective in a dark environment with no refl ections of surrounding light. visualization purpose: in certain cases, a coloration occurs under ultrasound investigation with color doppler, which is regarded as an artifact of a pseudo-fl ow. a fi ne-dispersive suspension moving in the direction opposite from the probe can be seen. the reasons and properties behind this phenomenon require further investigation. the experimental research was carried out. the highfrequency probe was submerged into a container fi lled with a suspension of talc in degassed water, and ultrasound scanning was performed. results: in the b-mode, displacement of talc elements to a direction opposite from the probe was visualized. in the color doppler mode with low prf values, this displacement was registered as coloration corresponding to movement from the probe. increase in intensity of the displacement was marked under the following conditions: focus shift to distant zones; implementation of doppler modes, especially power mode; increase of doppler frequencies. reduction of movement intensity was registered in the following cases: reduction of acoustic power level (at % quite stopped), increase of liquid viscosity (the suspension of talc in glycerin practically did not move). conclusion: visualization of streams in liquid accumulations is a refl ection of real liquid untwist, which can be explained by the well-known physical phenomenon -acoustic current. correct understanding of this occurrence enables us to interpret some phenomena that are found in pathological cystic formations. evaluation of patient entrance skin dose with an online measurement system in interventional neuroradiology y. takei the esd were different among interventional procedures greatly. the esd was fi ve times greater with tae than with tai procedure. in patients with tae, the esd exceeded gy, and they underwent transient loss of hair. the esd in tae for vascular diseases counted higher than in other procedures. it could be due to the fact that fl uoroscopy and angiography were performed more to understand the complex vascular structure such as arterovenus malformation (avm). conclusion: simultaneous esd monitoring was useful as an alarm so that doctors can reconsider their treatment strategy on the spot and radiological technologists the x-ray tube load to reduce the total patient dose. dose-reduction experiment during a cervical vertebrae examination r. pedersen, o. muharemovic, m. nielsen; copenhagen/dk (radiograf@privat.dk) purpose: the purpose of this experiment is to examine the possibility of dose reduction during a cervical vertebrae examination by adjusting predetermined parameters, and still maintaining acceptable image quality. methods and materials: data collected from danish x-ray departments show a wide variation in parameter settings prior to a cervical examination. to assess the absorbed dose in the thyroid gland, tld (tablet lithium fl uoride) are used. the tablets are placed in the area of the phantom, which corresponds to the thyroid gland´s anatomical position. image quality is assessed using images of a specially designed plexiglass phantom, which is equivalent to a human phantom in density and overall composition. the plexiglass phantom has a built-in linear phantom and density holes that enable one to measure and assess the contrast in the images. results: signifi cant dose reduction was achieved by using pa instead of ap exposure, resulting in minimal image quality deterioration. by using aec in ap, pa exposure with kv, one can reduce the dose signifi cantly. the best image quality is achieved under ap/pa exposure using grid ratio : . however, with the ratio : , we were able to observe a signifi cant dose reduction of up to %, but at the same time there was a slight deterioration of image quality. conclusion: this experiment shows that with a certain predetermined parameter regulation, a signifi cant dose reduction of - % is achieved in the thyroid gland. at the same time, a slight image resolution reduction is observed that does not affect the diagnostic quality of the image. increased aluminium fi ltration as a dose reducing tool in ap and lateral lumbar spine images of a phantom e. kelliher, c. d'helft, j. thompson, p. brennan; dublin/ie purpose: the cec guidelines ( ) recommend a minimum total fi ltration level of . mm aluminium equivalent for lumbar spine radiography. this phantom based study examined the effects of increasing aluminium fi ltration up to . mm on radiation dose and image quality. dose optimization is of added importance when lumbar spine radiography is performed on females of childbearing age, due to increased risk of cancer induction in young patients and the risk of irradiating an undiagnosed foetus. methods and materials: serial ap and lateral lumbar spine radiographs were taken of a tissue equivalent phantom, beginning at a total fi ltration level of . mm, and increasing in increments of . mm, up to . mm. three exposures were taken for each projection at each fi ltration level. tlds were used to measure entrance surface dose, reproductive organ dose and fetal dose. image quality assessment was performed using anatomical criteria based analysis. results: for the ap lumbar spine exposures, the optimal level of total aluminium fi ltration was . mm. this provided %, %, % and % reductions in entrance c b d e f a g of the colon was carried out with two different methods, depending on which part of the intestinal tract was meant to be examined. method i: to achieve isolated distension of the colon, - ml of air was infl ated - times, then about ml of air was pumped - times. if tension around the coecum was felt, scout view was done. method ii: to achieve distension of the colon and small bowel simultaneously, infl ation was started by pumping ml of air - times, then about - ml of air was pumped - times. with this method, air can pass easily through the bauchim valve. results: distension of the colon was appropriate with both methods. in cases, we wanted to produce isolated colon distension. it was succesful in cases. in cases, we wanted to examine small bowel too. it was successful in cases. conclusion: with these two methods, a higher percentage of cases could be successfully examined. virtual colonoscopy of the colon and small bowel becomes more effective and the patient's unnecessary feeling of discomfort could be lessened. evaluation of optimal cardiac phase determination method using cardiac phase image subtraction in coronary ct studies t. yamaguchi, n. honma, k. satoh, k. urasawa; cyuo-ku,sapporo/jp (yamataka@eagle.ocn.ne.jp) learning objectives: to easily determine the optimal cardiac phases in coronary ct studies. to quantitatively evaluate the "elements of cardiac motion" in each cardiac phase. to compare this optimal cardiac phase determination method against conventional visual evaluation. to automatically determine the optimal cardiac phases. background: in current coronary ct studies, determining the optimal cardiac phases for depicting the coronary arteries is a time-consuming process that is based on visual evaluation. a quantitative evaluation method is therefore eagerly awaited. procedure details: the subjects were patients who underwent cardiac ct studies. using data acquired by ecg-gated reconstruction, images of cardiac phases in the range from % to % were generated for three planes near lad # to # , rca # , and rca # using the relative delay method, and subtraction was performed repeatedly for images in consecutive cardiac phases. the in-plane sd values of the subtraction images were measured, and the mean sd value in each cardiac phase was plotted on a graph. the agreement rate between the phase with the minimum sd value and the optimal cardiac phase determined by visual evaluation was % within the range of % of the cardiac phase. excluding patients with atrial fi brillation, the agreement rate was %. the optimal cardiac phases for depicting the coronary arteries can be determined with good accuracy using this cardiac phase image subtraction method. not only can the optimal cardiac phase be determined automatically without visual evaluation, but the time required for coronary ct studies is substantially reduced. "how to" ct-enteroclysis: a guided step-by-step approach a. la fata , l. damiani , e. maffei , a.a. palumbo , t.v. bartolotta , m. midiri , f. cademartiri ; parma/it, palermo/it (lafatalaura@virgilio.it) learning objectives: . to describe the various methods of ct-enteroclysis (ct-e) of the small bowel. . to give an overview of the different experiences worldwide (italy, germany and american). . to compare the different techniques for ct-e describing advantages and pitfalls. . to provide a pictorial assay of different diseases as they appear on ct-e. background: computed tomography enteroclysis (ct-e) is a technique for the assessment of the small bowel. it is performed after small bowel distension by administration of a high volume of contrast medium via a nasojejunal catheter followed by ct acquisition. ct-e combines the inherent advantages of conventional barium enteroclysis (i.e. homogeneous luminal distension resulting from volume challenge) with those of cross-sectional imaging (i.e. simultaneous detection of intraluminal, mural and extraintestinal abnormalities). however, it is a challenging technique with several steps that have to be optimised. imaging findings: the main variability observed between different protocols regards the choice contrast medium. german investigators use positive contrast agent (i.e. diluted barium sulphate suspension or water iodinated contrast material), american and italian investigators use neutral intraluminal contrast agents (i.e. water or . % methylcellulose). differences are also reported in the choice of nasojejunal catheter (i.e. maglinte or rollandi techniques), in the use of sedation and in the preparation of patients. the optimised protocol for each indication will be provided in the exhibit. ct-e is a novel modality for the assessment of small bowel that may completely vicariate previously used modalities. information helpful for students in understanding isotropic resolution k. tsujioka, y. uebayashi, m. anzui, t. goto, t. sekitani, k. asano; toyoake-city aichi/jp (tsujioka@fujita-hu.ac.jp) learning objectives: this report illustrates a scanning method used to achieve isotropic resolution and a display method that allows for the effi cient use of isotropic resolution in image diagnosis. background: traditionally, we understand that ct scan images come from tomography. however, due to recent developments in helical scanning and multi slice ct technologies, ct scanning equipment has advanced from two-dimensional to three-dimensional data collection, and, similarly, ct images have shifted largely to three-dimensional observation of a section from a two-dimensional one. isotropic resolution is an essential factor in meeting current needs in ct technology. isotropic resolution means that the elements composing ct images hold equal, three-dimensional resolutions. imaging findings: for evaluating spatial resolution, a micro globe . mm in diameter made of tungsten was used. for evaluating contrast resolution, we used a dual glove phantom having a small difference in ct value. we also evaluated artifact. the results of the experiment found that change occurs in the x-y direction and the y axis direction depending on how parameters are set for scanning. in the actual clinical environment, we must consider such characteristics for parameter setting and also be aware of the optimization of isotropic resolution for ct image display. as this report serves to provide a description of parameter setting for ct scan, which has grown more complicated in recent years, we fi nd it helpful for students who are unfamiliar with ct operation. optimal scanning parameters for ct perfusion in patients with esophageal cancer h. sato, n. yanagawa, k. syutou, t. kazama, k. fukuchi, s. okazumi, t. ochiai; chiba/jp (hirotaka-sato @excite.co.jp) purpose: to determine optimal scanning parameters for ct perfusion in patients with cancer of the esophagus. methods and materials: forty-fi ve esophageal cancer patients underwent ct perfusion. scans were performed using a multi-detector row helical ct. the imageacquisition factors were the following: x mm collimation, . sec/rotation, kv. forty ml of intravenous contrast was injected at a rate of ml/sec followed by ml saline. the delay between the start of injection and scanning was sec in cases and sec in cases. the tube current was set , , , , and ma in esophageal cancer patients. all the data were reconstructed with . mm, mm, and mm. the shape of time density curve (tdc) was visually evaluated and the association of prognosis and blood fl ow was evaluated. results: the prognosis and blood fl ow was best correlated when the slice thickness was mm. the shape of tdc was bad scanned at mas in esophageal cancer patients. in one out of esophageal cancer patients with delay time of seconds, arterial enhancement started before the scanning. conclusion: in esophageal cancer patients, scan may be obtained at mm-thickness, more than mas, and delay time of sec. to determine the optimal sd setting level in abdominal ct examinations n. yagi , y. muramatsu , r. sekiguchi , h. sato , s. tsukagoshi , k. takahashi , i. aizawa , k. yokohama ; tochugi/jp, chiba/jp (y_c_h_o_k_u@yahoo.co.jp) purpose: in ct-aec based on image quality (sd) setting, the sd level selected strongly affects the balance between exposure dose and image quality. the purpose of the present study was to determine the optimal sd setting level in abdominal ct examinations. methods and materials: unenhanced and enhanced (arterial-phase and latephase) helical ct images of patients ( men and women) with hepatocellular carcinoma were acquired for follow-up without ct-aec. using this ct raw data, simulated images with different sd levels (sd , sd , sd ) with ct-aec were reconstructed using a computer simulation program (raw-nasu, toshiba, nasu, japan). the images were reviewed by radiologists who were blinded to the sd levels to evaluate the degree of diagnostic accuracy using the continuous confi dence judgment method ( to ). statistical analysis was conducted for the evaluation values of of the radiologists, which showed normality. the mean evaluation values ± standard deviation were . ± . (n= ) for sd , . ± . (n= ) for sd , and . ± . (n= ) for sd . anova did not show a signifi cant difference among the groups (p= . ). however, the paired t-test showed a signifi cant difference between sd and sd (p= . ). paleoradiology: methods and possibilities a. laki , e. riedl , l.a. kristóf , i. szikossy , i. pap , g. forrai ; budapest/hu, györ/hu purpose: radiology is a very useful method in paleopathology, in the diagnosis of pathological changes of ancient human remains. there is not enough reference data about technical parameters of paleoradiological examinations. the aim of our study was to develop and describe the methods of paloradiological examinations and the radiological study of mummies and ancient human bones. methods and materials: sixteen naturally mummifi ed human individuals and bone remains were examined. the bones were at least thousand years old and originated from different places in hungary. the mummies were discovered in the crypts of dominican church, vác, hungary, from burials between and . conventional radiographs on phosphor plates (at least two views), spiral ct and mm hrct examinations were performed. from spiral ct data, d reconstructions were also made. results: in the cases of mummies, the conventional radiography parameters had to be reduced by about % because of the body's lost water content. summation was often unavoidable. obtaining and displaying ct scans also required special settings. the examinations of the bones most frequently revealed traumas and trepanation of the skull. many degenerative changes of the spine and the joint surfaces were detected. signs of rheumatoid arthritis, paget disease, facies leprosa and vertebral tuberculosis could be discovered. in the mummies, vertebral changes, pulmonary tuberculosis, fractures and other traumatic lesions were diagnosed. conclusion: radiological examination of ancient bones and mummies can help to diagnose pathological changes in these human remains. new methods for x-ray and ct examinations are necessary due to the special features. first postgraduate program in medical ultrasound for radiographers in norway i. aabel, r. stokke; gjøvik/ no (ingunn.aabel@hig.no) learning objectives: gjøvik university college, in collaboration with innlandet hospital trust, has developed a postgraduate programmeq in medical ultrasound for radiographers in norway ( ects). the aim of the course is to educate sonographers with an understanding of the scientifi c principles and the practical applications. understanding and knowledge of the scientifi c principles will help radiographers in acquiring the skills necessary to apply this knowledge in practice. clinical competency is an important integral part of the programme. background: norway experiences a shortage of radiologists, especially in rural areas. the purpose of this education is to qualify radiographers to perform selected abdominal ultrasound examinations. procedure details: this course will be a part time study within years and is organized in modules as follows: module : physics of ultrasound, levels and sophistication of equipment image recording, and artefacts. module : topographic anatomy of abdomen, pathology. module : clinical practice, gained under guidance and supervision of radiologist. module : clinical practice and a written project on a set subject. the course is based on the guidelines developed by the european federation of societies for ultrasound in medicine and biology. structured theoretical and practical training are followed by competency assessment. conclusion: through this postgraduate programme in medical ultrasound, gjøvik university college is the fi rst educational institution in norway, providing a qualifi cation of radiographers as sonographers. clinical science of radiography and radiotherapy: a conceptual analytical study on the research focus of a new academic fi eld s. sorppanen; oulu/fi (sanna.sorppanen@oulu.fi ) purpose: the master's programme in radiography has been running in finland since , and development of this new academic fi eld has been active. especially, the relationship with nursing science has been under discussion. this dissertation was purposed to clarify the research focus of this developing academic fi eld, especially in comparison to nursing science. the study was conducted according to the three-phase hybrid method of concept analysis, combining the theoretical and empirical approach. concepts of "nursing", "environment", "health" and "human being" were used as the starting point, because they are commonly applied but not clearly defi ned in radiography. data were collected in forms of literature, expert interviews and written material, and analysed with qualitative content analysis. results: concepts defi ning the research focus were found to be "clinical radiography and radiotherapy" (substitute for "nursing"), "environment", "health and illness" (substitute for "health"), and "human being". these concepts were also found to be connected to each other in several ways. each concept was provided with a theoretical defi nition, and a model was formulated to describe the research focus of this new academic fi eld, which was named as "the clinical science of radiography and radiotherapy". conclusion: results suggest that this new academic fi eld may be profi led by a distinctive research focus, diverging from that of nursing science. results also suggest that this new fi eld must be named as the clinical science of radiography and radiotherapy. results may be exploited in further academic development, theory development and education within radiography and radiotherapy. b d e f a g aortic intramural hematoma: prognostic ct fi ndings in the acute onset and follow-up c. sebastia, s. quiroga, h. cuellar, a. miranda, r. boye, a. alvarez; barcelona/es (mcsebastia@vhebron.net) purpose: the aim of this exhibit is to review the ct fi ndings of acute type b aortic intramural hematoma and to assess the prognostic value of these fi ndings. we evaluated patients with type b (stanford) aortic intramural hematoma (imh) by helical ct at the acute onset and yearly thereafter. the series included men and woman, with a mean age of years (range: - ). patients were followed-up for a mean of . years (range: - years). the initial aortic diameter (≥ mm), imh thickness (≥ mm) of the affected areas, imh length, and presence of tiny ulcers at the acute onset were statistically assessed and correlated with poor evolution. results: evolution was to healing in % of cases and to focal aneurysm formation in % of cases. there was no correlation between poor evolution and initial aortic diameter (≥ mm), imh thickness (≥ mm), or imh length. ten patients had small ulcers at the acute onset, and there was a correlation between the presence of these ulcers and aneurysm formation. no differences were found in the outcome (healing or aneurysm formation) between the fi rst and the last yearly control. the only ct fi ndings in the acute onset of aortic imh with prognostic value were the presence of tiny ulcers in the affected aorta. in addition, the fi rst-year evolution was predictive of the long-term evolution of this entity. emergency learning objectives: to check ct fi ndings of the most frequent causes of abdominal venous system emergency pathology. background: abdominal venous pathology cases presentation, by ct diagnostication, in the radiology department of our hospital in the last two years. imaging findings: we show several cases of: abdominal venous system traumatic pathology; aorta-inferior cava vein fi stula, aorta-gonadal vein fi stula; abdominal venous system primary and metastatic disease; septic thrombosis of the splenic vein, porta, superior and inferior mesenteric veins; acute venous thrombosis of a renal graft; thrombosis of the inferior cava vein and renal veins after pregnancy. the emergency radiologist should consider the abdominal venous system pathology in the differential diagnosis of the acute abdomen in order to achieve a premature diagnostic to reduce morbi-mortality. flat-panel ct as a new perinterventional imaging modality in aortic stentgraft procedures: work in progress e. rabitsch, h. illiasch, w. wandschneider, k.a. hausegger; klagenfurt/at (egonrabitsch@gmx.at) learning objectives: to evaluate the value of fl at-panel ct during aortic stentgraft procedures. background: flat-panel ct was performed in patients immediately after endovascular treatment of aortic aneurysms ( taa, aaa) on the angiographic table. images were acquired with a rotating c-arm (axiom artis; siemens), acquisition time was seconds. during a rotation of degree, projections were acquired. images were displayed in mip and vrt mode. eight patients got intraarterial contrast medium (cm). imaging findings: in all patients, the entire stentgraft was exactly shown and alignment of the prothesis along the landing zones was well displayed. the aneurismal sack was well shown in patients ( patient had traumatic rupture). x an endoleak ii was detected, x an angiographically verifi ed endoleak i was not detected ( x suboptimal cm timing, x no cm administered). aortic side branches were well shown in all contrast enhanced studies except (suboptimal cm timing). in one patient, distal extension was considered due to suspected short stent-graft at the distal neck. flat-panel ct showed suffi cient neck coverage and no extension was inserted. conclusion: flat-panel ct is a promising imaging tool during stent-graft procedures and may be helpful especially in problematic procedures. renal . isotropic data sets of . mm slices were available for review and suitable reconstructions using a dedicated graphic workstation (vitrea , vital images inc, usa). six of these patients were excluded because of aortic stent placement, aortic dissection or surgery, renal atrophy. the fi nal study group for review consisted of patients ( men, women). results: thirty-eight of the patients ( %) had renal artery variants. there were right and left superior polar arteries; right and left inferior polar arteries. accessory renal arteries arose from the aorta, from the right common iliac artery. six accessory right arteries passed anterior to the inferior vena cava. two patients had double renal artery, right, left. two patients had precaval dominant right renal artery. the overall prevalence of precaval arteries was %. conclusion: renal artery variants are commonly observed during routine mdct examinations of the abdomen; -slice mdct scanners allow excellent depiction of these variants along all their course, and evaluation of relationships with adjacent structures. what is the advantage of angio-ct system equipped with -channel mdct? detection of feeding artery during transcatheter arterial chemoembolisation for hepatocellular carcinomas using d-ct angiography generated from the data set of ct hepatic arteriography m. hirata, t. kajiwara, t. tsuda, t. mochizuki; toon ehime/jp (masaaki@m.ehime-u.ac.jp) learning objectives: to demonstrate the usefulness of d-ct angiography ( d-cta) reconstructed from thin-slice data set of ct hepatic arteriography (ctha) obtained from -channel angio-ct system for detection of the feeding artery of hepatocellular carcinomas (hccs) in comparison with digital subtraction angiography (dsa). background: selective catheter placement into the feeding artery is important for effective treatment of hccs and avoidance of hepatic damage after transcatheter arterial chemoembolization (tace). however, it is sometimes diffi cult to recognize three-dimensional vascular anatomies on two-dimensional dsa alone. d-cta generated from ctha enables us to identify the exact feeding artery, which is sometimes diffi cult to depict by intravenous cta, because direct opacifi cation of hepatic artery allows us to produce very precise d-cta. information of the detailed vascular anatomy and bifurcation point of feeding artery is simultaneously available when we perform tace. procedure details: patients were injected with ml of nonionic iodinated contrast material at . ml/sec via a . or f catheter placed in the common hepatic artery. ctha was performed at seconds after the start of injection. d-cta was rapidly generated on the imaging workstation equipped for angio-ct system. the vascular anatomies and the target artery for chemoembolization could be recognized easily, especially on the movie display of the d-cta, which gave hints of suitable selection of devices and helped us to make the effi cient strategy for selective tace. conclusion: d-cta generated from ctha is useful for the detection of feeding artery of hccs during tace. effi ciency of via dorsum pedis d-ct venography for varicose veins of lower extremities m. ishifuro, j. horiguchi, k. ito, t. sueda, k. sato, m. kiguchi, t. furukawa, c. fujioka; hiroshima/jp (ishifuro@hiroshima-u.ac.jp) purpose: the opacifi cation of lower extremities in ct venography (ctv) by intravenous injection of contrast media (cm) via an upper extremity vein is often poor for three-dimensional ( d) display. we assessed whether d ctv obtained via dorsum pedis, using the same scanning protocol as for ct arteriography, was useful for understanding the complicated structures of the venous system. methods and materials: in cases, diluted cm ( : ratio of water and mgi/ ml cm) of a total amount of ml was injected into the dorsum pedis at a rate of . ml/sec. scanning was performed from foot to head after a delay of sec. the total volume of cm was intended to acquire enough enhancement levels in the entire lower extremities. it was tested whether ct values of hu or higher were obtained in the venous systems. results: both varicous and deep veins were enhanced over hu in all cases. superfi cial veins sometimes did not reach hu; however, they were well demonstrated on d ct. the d ctv helped surgeons in the ligation therapy of the saphenous vein. conclusion: three-dimensional ctv via dorsum pedis for lower extremities is a useful tool for the delineation of the venous systems, and helps surgeons as a navigator for ligation therapy. effect a prospective parallel-group randomized study of the abdominal aorta and splancnic arteries was performed with a mdct (ge lightspeed vct) in patients divided in groups. a non-ionic c.m. was injected with an iodine concentration of mg/ml in group - : ( ml; injection rate or ml/sec) and of mg/ml in group - ( ml; injection rate or ml/sec). arterial enhancement of the aorta at levels (celiac trunk, sma, renal arteries) and of iliac arteries was measured, mean values were calculated and statistical signifi cance was assessed. results: concentration of mg/ml (injection rate ml/sec) led to a signifi cantly higher enhancement of the aorta in comparison with mg/ml at the level of celiac trunk ( vs , p < . ), sma ( vs p < . ), renal arteries ( vs p < . ) and iliac arteries ( vs p= . ; vs p= . ). ml/sec patients showed a lower enhancement but differences were not statistically signifi cant at the same levels. conclusion: an iodine concentration of mg/ml leads to an higher enhancement and better delineation of abdominal aorta and smaller arteries compared to mg/ml. difference between injection rates of and ml/sec is non statistically signifi cant. early postoperative bleeding following living donor liver transplantation: ct fi ndings compared with angiography s. hong, a. kim; seoul/kr (hongses@paran.com) purpose: the purpose of this exhibit is to discuss the clinical impacts of early postoperative bleedings after ldlt and ct fi ndings or ct angiographic fi ndings compared with angiography according to the various bleeding causes. emphasis is laid on evaluation of the possible bleeding arteries according location of hematoma and contrast leakage on ct scan. methods and materials: between march and oct , early postoperative bleeding in transplants among adult liver transplants were confi rmed by conventional angiography. all patients underwent twophase multidetector row ct scan before conventional angiography. the early postoperative bleedings after ldlt were caused by inferior phrenic artery bleeding ( . %), jenunal branch bleeding ( . %), rupture of a hepatic artery pseudoaneurysm ( . %), right renal capsular artery bleeding ( . %), intercostal and lateral thoracic artery bleeding after chest tube insertion site ( . %), inferior epigastric and superior epigastric artery bleeding ( . / . %), anastomotic site leakage ( . %), liver surface oozing ( . %), biopsy site bleeding ( . %), gastroduodenal and pancreatoduodenal arcades bleeding ( . %/ . %), circumfl ex iliac artery ( . %), and dissection of common hepatic artery ( . %). conclusion: sudden developed hematoma as well as extravasation of contrast material in the same region on ct scan is thought to be predictive ct fi nding of early postoperative bleeding in posttransplant patients. careful consideration for these fi ndings can prevent the progression into catastrophic status that requires surgical management. b d e f a g aortas and intramural hematomas of the ascending aorta) with a -row msct unit. in all cases, we performed a retrospective ecg-gated technique, followed by conventional msct study of the thoracic aorta. all cases were reconstructed in multiplanar, mip and vr reformations. dynamic cine-mode imaging of the aortic valves and thoracic aorta was also done in all cases. imaging findings: images of ascending aorta diseases and postoperative changes are depicted without cardiac motion artifacts; the coronary arteries and their relationship with aortic disease and surgery are assessed. dynamic studies of the aortic valves and thoracic aorta are presented. artifacts due to a loss of cardiac synchronization, breath motion and insuffi cient aortic coverage are shown. conclusion: ecg-gated msct allows precise evaluation of diseases and surgery of the ascending aorta and coronary arteries. dynamic studies allow evaluation of the aortic valve, movement of the intimal fl ap, detection of intimal tears and visualization of patent ductus arteriosus. thirty-two-detector row ct angiography of carotid and cerebral arteries: comparison of ml and ml of contrast material with a bolus chaser h. shinjyo , n. takeyama , y. ohgiya , y. takahashi , m. obuchi , t. kitahara , s. matsui , y. kinebuchi , t. gokan , m. ishikawa ; tokyo/jp, yokohama/jp (momiji@mtc.biglobe.ne.jp) purpose: to compare the diagnostic performance of mdct angiography (cta) of the brain and neck, using ml and ml of contrast material (cm). methods and materials: cta was performed using -mdct from the aortic arch (aa) to the parietal region. seventy patients were divided into groups on the basis of cm ( mg/ml) administration protocol: group (n= ) received ml of cm with ml of saline fl ushing at ml/sec; group (n= ) received ml of cm in the same fashion. first, time to peak enhancement (ti) of the internal carotid artery (ica) at circle of willis (cw) was calculated by test bolus method. next, scan duration (sd) between aa and cw was calculated (collimation . mm; pitch . ; rotation time . sec). scan was started at [(ti+ )-sd] (sec) in group , and [(ti+ )-sd] (sec) in group . thirteen rois were placed from aa to above the cw. mean attenuation of carotid arteries (caas) and cerebral arteries (ceas) were quantitatively analyzed. venous contamination (vc), and vr and mip images were also visually analyzed. results: although there was a statistically signifi cant difference (p < . ) in mean attenuation of each artery between both groups, the attenuation of all arteries in group was over hu, and analysis of vc in group was better than that in group . visual analysis of caas showed no difference, and that of ceas in group was better than group . conclusion: a ml cm cta of the brain and neck may provide suffi cient attenuation and diagnostic performance. a vascular tree is known by mdct before gastrointestinal surgery h. funatsu, h. takano; chiba/jp learning objectives: in this exhibit, we illustrate the normal branching pattern of visceral arteries and their variants in the abdomen with use of volume rendering technique. background: multidetector-row computed tomography (mdct) has come to be recognized as a useful diagnostic tool for preoperative evaluation. for example, angiographic images can be easily acquired after administration of iv contrast media. there is a certain kind of vascular variant that can be a potential source of complication during laparoscopic-assisted surgery for its inherent property (e.g. limited view of the fi eld, loss of three-dimensional depth perception, limited surgical manipulation). therefore, preoperative vascular mapping in each anatomic site would help your colleague. imaging findings: replaced left hepatic artery arising from left gastric artery, common trunk of left gastric artery and common hepatic artery, tortuous course of splenic artery were all depicted and relevant to procedures of or complications after laparoscopic partial gastrectomy. resection of left gastric artery from which left hepatic artery branches can lead to liver dysfunction. whether ileocecal artery runs anterior to vein or not determines an approaching method for exposure of superior mesenteric vein during right hemicolectomy. delineating root of left colic artery would facilitate left colic artery preserving lymph node dissection during laparoscopic low anterior resection. conclusion: with recent widespread use of laparoscopic procedures, more detailed information about relevant anatomy is required. mdct providing d images could be an imaging method of choice for the purpose. the effect of cardiac function on aortic peak time and peak enhancement during ct angiography: a retrospective study s. sakai, t. okafuji, a. chishaki, h. yabuuchi, y. matsuo, t. kamitani, h. honda; fukuoka/jp (sakai@shs.kyushu-u.ac.jp) purpose: to investigate how cardiac function affects the magnitude and timing of aortic contrast enhancement during ct angiography (cta). methods and materials: twenty-nine patients ( men, women; mean age: . ± . years; mean weight: . ± . kg) underwent measurement of cardiac output within weeks of coronary cta. during coronary cta, after a test injection, ml of contrast medium was injected at ml/sec and scanning was initiated after a delay based on the previously determined contrast transit time. the cardiac output of each patient was measured by the thermodilution technique, and the cardiac index was calculated. attenuation of the descending aorta was measured at the workstation every sec with reference to the image acquisition time shown by dicom header information. then the aortic peak time and aortic peak enhancement of each patient were calculated. pearson's correlation coeffi cient analysis was used to investigate the relationships between the cardiac index and aortic peak time or aortic peak enhancement. the ranges of cardiac index, aortic peak time, and aortic peak enhancement were . to . (mean: . ± . ) l/min/m , to (mean: . ± . ) sec, and . to . (mean: . ± . ) hu, respectively. with an increase of the cardiac index, the aortic peak time decreased (r=- . , p < . ) and aortic peak enhancement also decreased (r=- . , p= . ). conclusion: the aortic peak time and peak enhancement during cta are closely related to cardiac function. the role of advanced vessel analysis software to evaluate aortic diameter in patients with ascending aorta dilation a. ferraris, f. caraffo, m. oggero, s. rossetti, a. secinaro, c. venturi, m. martina, g. gandini; torino/it (francesca.caraffo@libero.it) purpose: to evaluate the "vessel analysis" software accuracy and usefulness versus direct axial slice measurements to estimate preoperative maximum aortic diameter in patients with ascending aorta dilation. we performed preoperative angio-ct with -row mdct ge lightspeed in patients with ascending aorta dilation. four radiologists with different experience ( - yrs) revaluated ascending aorta maximum diameter with "advanced vessel analysis," an automatic system that is able to generate view true oblique cross sectional vascular images perpendicular to the vessel axis, and then evaluated the same patients with simple direct axial measures. then, we compared the results so obtained to test the interobserver variability with these measurement methods. results: the mean of the maximum aortic diameters obtained by advanced vessel analysis was . mm. the mean of the maximum aortic diameters obtained with direct axial measures was . mm. interobserver difference was . mm with the use of "vessel analysis" software and . mm with direct axial measure. the maximum difference between the radiologists with respect to the direct axial measurements was . mm, and while using vessel analysis it was . mm. conclusion: the routine use of "vessel analysis" software allows minimization of the interobserver bias, and increases the accuracy in the preoperative evaluation of ascending aorta dilatation. carotid artery wall thickness and stroke: evaluation by using multidetector-row ct angiography l. saba, g. caddeo, r. sanfi lippo, r. montisci, g. mallarini; cagliari/it purpose: the aim of this work is to determine if carotid artery wall thickness (cawt) evaluated by using multi-detector-row ct angiography (mdcta) is an effective parameter to consider as predictive of increased risk of stroke. in this retrospective study, we analyzed patients by using a multi-detector-row ct scanner. in each patient, we measured cawt and measurements were made with an internal digital caliper. we divided patients into groups: the fi rst group (group a) included patients without stroke (n = ) and the second group (group b) included patients with stroke (n = ), and we made a statistical analysis by using t-student test to asses the cawt difference in the groups. results: measurements of the distal common cawt varied from . to . mm. in group a, average cawt was . mm ( . sd) and in group b it was . mm ( . sd). cawt in group a patients showed statistical difference (p < . ) com-c b d e f a g pared to group b. by using mm as the threshold, we observed another statistical correlation (p < . ) for stroke: in fact, patients with ≥ mm cawt had stroke with an odds ratio . . in comparison with patients with cawt < mm. conclusion: results of our study suggest that an increased cawt is an indicator for risk stroke and this parameter can be used as risk factors besides other wellknown ones like diabetes, hypertension, smoking, dyslipidemia. purpose: to prospectively determine the feasibility of two different protocols in patients with peripheral arterial occlusive disease (paod) using the current generation of -detector row ct scanners. methods and materials: twenty patients with known paod underwent -cta (sensation cardiac, siemens). patients were randomly divided into two different groups (a, b) regardless of age or severity symptoms. group a was studied using a regular ct scan following the base rule of scan time=contrast material (cm) administration duration; thus, patients received ml of highly iodinated cm ( mgi/ml) at ml/s; scan time was s and a bolus trigger technique was employed at the level of the proximal abdominal aorta and the acquisition started soon after the attenuation reached hu. group b received ml of the same cm (independently of scan duration or patient characteristics) with bolus tracking positioned at the level of the infrarenal abdominal aorta; scanning started s after attenuation reached hu. peripheral arterial tree was divided into segments. quantitative and qualitative analysis was performed. results: in patients with fontaine ii or iii, analysis of attenuation values was signifi cantly (p < . ) different for the two groups. higher mean hu values and highest quality images were obtained with group b acquisition strategy. for group a, attenuation of distal arteries was weak in heavily diseased patients, resulting in poor image quality even for diagnosis. conclusion: -detector row ct angiography allows high spatial resolution angiographic assessment of patients with paod; cm administration strategy and scan acquisition protocol require fi ne adaptation to avoid run out the bolus. pitfalls in diagnosis of pulmonary embolism with ct angiography e. protopapa, a. gyftopoulos, p. filis; athens/gr learning objectives: . to demonstrate the causes of pulmonary embolism (pe) misdiagnosis with the use of ct angiography. . to become familiar with a range of pitfalls. . to highlight the radiologist's need to determine the quality of a ct pulmonary angiographic study. background: computed tomographic pulmonary angiography (cta) is the modality of choice at our institution for the evaluation of patients with suspected pulmonary embolism because of its high sensitivity. despite the high accuracy of this method, there are several pitfalls that cause indeterminate ct pulmonary angiography. these pitfalls may be a consequence of patient-related factors such as respiratory motion artifact, image noise and presence of pulmonary artery catheter. technical factors include mostly inappropriate window settings, partial volume artifact and stair-step artifact. furthermore, various anatomic and pathologic factors are responsible for the poor quality of the examination. the anatomic factors include partial volume averaging effect in lymph nodes and vascular bifurcation. finally, coexisting pathology can decrease the value of diagnosis such as mucus plug and tumor emboli. procedure details: the patients were examined using -detector row ct (ge). the examinations were performed with ml/sec injection rate of ml contrast agent and collimation x . mm with a pitch of . mm. conclusion: although cta is the standard at many institutions for pulmonary embolism diagnosis, there are several factors that reduce this ability. the radiologist is requested to evaluate the quality of the study and, if it is poor, he should identify which pulmonary vessels are rendered indeterminate and whether additional imaging is necessary. factors associated with vessel enhancement in ct pulmonary angiography and indirect ct venography h. arakawa, t. kohno, y. kaji, t. hiki; tochigi/jp (arakawa@dokkyomed.ac.jp) purpose: to determine the factors associated with contrast enhancement of pulmonary ct angiography (cta) and indirect ct venography (ctv). methods and materials: patients underwent cta using bolus-tracking technique, of which patients underwent subsequent ctv. we administered two different amounts of nonionic iodine contrast medium depending on the body weight of the patient: patients with body weight > kg undergoing both cta and ctv received mg i (group b), while other patients received mg i (group a). the enhancement of vessels was subjectively estimated by the four-point scale and densities were measured at the predetermined levels. multiple regression analyses were performed with density as the dependent variable, and age, sex, weight, contrast medium, scan delay and presence of embolism as independent variables. results: the mean scan delay of cta was seconds (sd: . ; range: - ). subjective estimate of enhancement quality in cta did not differ between the two groups (p = . ), while it was signifi cantly better in group b than in group a (p < . ) in ctv. multiple regression analyses revealed that body weight and age were the only signifi cant and consistent independent variables associated with enhancement of the pulmonary arteries. on the other hand, contrast medium, body weight and scan delay were the independent variables consistently associated with the enhancement of deep veins. conclusion: bolus-tracking technique showed relatively small variation in the scan delay time. age, body weight and contrast medium were the important factors associated with vessel enhancement in combined cta and ctv. purpose: to evaluate whether low-volume contrast material (cm) mdct angiography (cta) utilizing aortofemoral bolus transit time (taf) can provide suffi cient contrast enhancement. methods and materials: cta was performed using -mdct with . mm collimation. after surgical bypass graft of abdominal aortic aneurysms, patients were divided into two groups. in group (n= ), taf was acquired from time to peak aortic enhancement (ta) at l vertebra and time to arterial enhancement at femoral heads by twice-test bolus method. scan duration was arranged according to individual taf, and scan delay was sec after ta. a ml cm ( mgi/ml) with ml saline fl ush at . ml/sec was used for cta. in group (n= ), ta was calculated only at l vertebra. scan delay was sec after ta, and table speed was mm/sec. an ml cm was used for cta in the same fashion. mean aortofemoral attenuation and mean differentiation between maximum and minimum attenuation were quantitatively analyzed, and also cross-sectional, mip, and vr images were visually analyzed. results: although there was statistically signifi cant difference in mean aortofemoral attenuations ( . ± . hu in group vs. . ± . hu in group ), visual analysis showed no difference between both groups. it is interesting to note that mean differentiation between maximum and minimum attenuation was signifi cantly smaller in group than that in group ( . ± . hu vs. . ± . hu, p < . ). conclusion: low-volume cm cta can provide suffi cient aortofemoral contrast enhancement. visualization of the posterior gastric artery with ct angiography k. miyatake, k. nakatani, t. yamanishi, n. hamada, t. okabayashi, y. ogawa; nankoku/jp (jm-kanakana@kochi-u.ac.jp) purpose: the posterior artery (pga) is one of the important feeder arteries of the stomach. although the pga is unfamiliar with computed tomography (ct) imaging, lymphonode dissection in gastric surgery depends on how the pga branch and/or run. we evaluated the detectability of the pga with the -scanner multi-detector row ct angiography (cta). methods and materials: a total of preoperative patients [ men and women, - years (mean . years)] underwent ct angiography. the presence and feature of the pga was assessed by experienced readers using multi-planar reconstruction (mpr). the pga was detected in patients ( . %). in of the , the pga had branched from the splenic artery. in one of the , the pga had branched from the celiac artery. no signifi cant differences were seen between age or sex, and visualization of the pga. conclusion: cta depicts the pga in a high percentage in this study. preoperative information of anatomical feature of the pga can be helpful for planning the surgical strategy. b d e f a g intraindividual comparison among source images, mip and vri algorithms in willis' circle anatomy and diseases assessment. case series and literature review f. favano, a. saponaro, l. fortunelli, f. travaglini, d. volpe, a. stecco, a. carriero; novara/it (chiccait@hotmail.com) learning objectives: to compare the anatomic visualisation and disease assessment of willis' circle offered by source images (sis), volume-rendered images (vris) and maximum intensity projections (mips), and to describe the advantages and disadvantages of each algorithm by means of a case gallery and review of the literature. background: although the assessment of source images provides precise local information concerning vessel diameter, source and area, it is often diffi cult to appreciate their spatial relationships and mentally reconstruct their global morphology. mips and vris are based on post-processing algorithms developed in order to improve the rendering of the overall morphology and/or spatial relationships of anatomic structures, but in addition to their strengths, they have weaknesses that can lead to artefacts and misinterpretations. procedure details: mips and vris are the most widely used means of showing mr angiography data; d image displays of vascular anatomy frequently provide excellent information. but both types of reconstruction are associated with disadvantages, such as the misrepresentation of spatial relationships and failure to detect eccentrically located stenoses. a case series is shown to illustrate these aspects. conclusion: vessels with low-signal intensities that may be partially or completely imperceptible on post-processing images can be seen on individual source images. in order to improve detection, it is essential to integrate the information coming from sis, vris and mips. normal the aim of this study is to evaluate the accuracy of mdcta in the detection of endoleaks aetiology in patients who have undergone endovascular repair (evar) of abdominal aortic aneurysm (aaa). methods and materials: patients undergone evar for aaa. follow-up was performed using mdcta after , and months after the procedure and every months. patients with endoleaks detected at mdcta underwent to dsa to determine endoleaks aetiology. the results of the cta-based endoleak calssifi cation were compared to dsa. results: agreement between mdcta and dsa was observed in patients ( %). in patients mdcta classifi ed endoleaks as type while dsa as type ; in patient classifi ed as type at mdcta, dsa revealed type endoleak; one patient with type endoleak at dsa was incorrectly classifi ed as type at mdcta. conclusion: mdcta seems to be a feasible technique in the evaluation of endoleaks aetiology. however, selective angiogram with dsa remains the goldstandard to manage endoleaks. atherosclerotic carotid plaque quantifi cation with multidetector computed tomography angiography t. background: besides carotid stenosis degree, atherosclerotic carotid plaque morphology has shown to be predictive for stroke. therefore imaging modalities are challenged to provide not only the severity of stenosis but also information on plaque morphology. state-of-the-art multidetector computed tomography angiography (mdcta) can accurately grade stenosis degree. with a custom made software program, we are now able to assess plaque volume and plaque component volumes. procedure details: it will be shown how to perform mdcta of the carotid arteries with good image quality, low use of contrast material and reduced perivenous artifacts. it will be shown how plaque and plaque component volumes can be assessed. it will be shown how these plaque volumes can be used to assess stroke risk, and what future developments can be awaited. in vivo assessment of atherosclerotic plaque and plaque component volumes in carotid arteries is feasible. prospective longitudinal studies which examine the relationship between plaque volume, plaque component volumes, and outcome have the potential to establish mdcta-based plaque quantifi cation as a stroke risk predictor. demonstration the scanning parameters included a detector row confi guration of x . mm or x mm with retroreconstruction of . mm. after bolus injection of contrast medial materiel, arterial phase scans were obtained. multiplanar and curved planar reformation, parallel to the spinal cord, were evaluated and the detectability of the asa and the aka were analyzed. results: the asa was visualized on the scans of all the patients. the aka was visualized on the scans of patients ( %), its segmental origin ranged from t to t . analysis of hemodynamics in patient-specifi c stenotic carotid bifurcation using computational fl uid dynamics and mr angiography y.-j. xue, p.-y. gao, y. lin; beijing/cn (xueyunjing@ .com) purpose: to analyze fl ow pattern and hemodynamic variables in stenotic carotid bifurcation in vivo by combining computational fl uid dynamics (cfd) and mr angiography imaging. methods and materials: seven patients with carotid atherosclerosis underwent contrast-enhanced mr angiography of carotid bifurcation by siemens . t mr scanner. hemodynamic variables and fl ow patterns of the stenotic carotid bifurcation were calculated and visualized by combining vascular imaging postprocessing and cfd. results: as the extent of stenosis were commencing and aggravating, the stronger jets formed at the portion of narrowing and more prominent fl ow separation in the ica with regions of slow retrograde fl uid eddies in the lee of the stenosis. regions of elevated wall shear stress (wss) were predicted at the portion of stenosis and at the path of the downstream jet. areas of low wss were predicted on the leeward side of the stenosis, corresponding with the location of slowly recirculation turbulent fl ow. conclusion: cfd combined with mri can be used to simulate fl ow patterns and calculate hemodynamic variables in the stenotic carotid bifurcation as well as normal carotid bifurcation. the abnormal high wss may be relative to the rupture of vulnerable plaque. the secondary turbulent, recirculation fl ow associated with low wss regions on the downward of stenosis are likely to favor plaque development and thrombogenesis. a protocol for magnetic resonance renal angiography in suspected renovascular disease i. ahmad, p.s. lewis, a.h. choudhri; stockport/uk (abdul.choudhri@stockport-tr.nwest.nhs.uk) purpose: magnetic resonance renal angiography (mrra) is now thought the best non-invasive technique for assessing renovascular disease, with increasing demand putting pressure on our mr service, a limited resource. there being no consensus on indications for mrra, this study was performed to identify which patients would best benefi t from the procedure. methods and materials: provisional guidelines for requesting mrra were formulated, including: diastolic bp > at any age; peripheral vascular disease; abdominal bruit; sudden increase in bp; high serum urea and creatinine and/or low serum potassium; bp not adequately controlled despite medications. consecutive patients referred for mrra were reviewed retrospectively, and the results correlated with the indications and patient management. renin and aldosterone measurements and renal ultrasound scans were also considered, where available. results: there was % compliance with the provisional guidelines. % of studies were diagnostic, % being abnormal, with a change in management in %. the results correlated well with clinical suspicion and ultrasound fi ndings, but not with serum urea, creatinine or renin measurements. conclusion: a written referral protocol for mrra can achieve good compliance and best use of a limited resource, reducing unnecessary requests and aiding non-specialists in selecting appropriate patients. these indications are proposed: i. high bp and age < and ii. high bp and/or chronic renal failure (crf) with any of the following: audible vascular bruit; > . cm difference in bipolar renal length on ultrasound; unexplained pulmonary oedema; unexplained crf with other vascular disease; worsening of renal failure with ace inhibitor. hemodynamics hemodynamic variables at these carotid bifurcations were calculated and visualized by combining vascular imaging post-processing and cfd. results: a largest contiguous region of low velocity occurred at the carotid bulb. the eddy current and back fl ow was observed at bifurcation and outer part of proximal internal carotid and external carotid artery and the shapes of them changed with phase of cardiac cycle. the eddy current and back fl ow were signifi cant at middle of systolic phase and faded out quickly along downstream of internal carotid artery and external carotid artery. the wall shear stress map revealed a large region of low wall shear stress (wss) at carotid bulb and extended to the outer wall in the proximal end of internal carotid artery, the lowest value was below . pa. also there was a small region of low wss at the outer wall in the proximal end of external carotid artery. conclusion: cfd combined with vascular imaging can calculate and visualize the hemodynamic variables at carotid bifurcation in vivo. it is an interdisciplinary science of computer, radiology and hemodynamics and provides a new method of investigating the relationship of vascular geometry and fl ow condition with atherosclerotic pathological changes. bloodpool-enhanced mr angiography: optimization of scan protocols, evaluation and combination of conventional fi rst-pass with steady-state ultra-high spatial resolution imaging t. leiner, r.n. planken, m.w. de haan, j.m.a. van engelshoven; maastricht/nl (leiner@rad.unimaas.nl) learning objectives: to provide practical guidelines on how to perform blood poolenhanced high-quality fi rst-pass and ultra-high spatial resolution steady state mr angiography of abdominal and peripheral arteries using the latest technological developments, and how to evaluate such studies in order to maximize diagnostic yield. background: the recent introduction of the clinically approved blood pool agent vasovist enables steady state imaging of vasculature in addition to conventional fi rst-pass imaging. because of the increased distribution volume of the agent, there are major differences with regards to choice of optimal imaging parameters. procedure details: despite the much lower dose ( . mmol/kg vs. . mmol/ kg) and injection volume ( . vs . ml for a kg person), fi rst-pass imaging yields equivalent image quality at identical imaging parameters. ultra-high spatial resolution equilibrium-phase imaging on the other hand demands increase of tr, decrease of bandwidth and fl ip angle to maximize vessel-to-background contrast. images are best evaluated in the transverse plane as well as with curved multiplanar reformations. the major teaching points of this exhibit are: ) ultra-high spatial resolution steady state mr angiography of abdominal and run-off arteries is feasible in several minutes with voxel sizes in the order of - microns. ) when using ultra-high spatial resolution, acquisitions venous enhancement will no longer interfere with image evaluation and assessment of disease. ) because of the much longer intra-vascular residence time, blood pool agents enable imaging of additional arterial territories. learning objectives: . to illustrate the mr angiographic appearance of the different recanalization procedures used to treat ischemia of the lower extremities. . to review the complications following surgery including obstruction, stenosis and pseudoaneurysm formation. background: three-dimensional contrast-enhanced mr angiography represents a good alternative to catheter digital subtraction angiography (dsa) to assess peripheral artery graft patency. mr angiography is safer, faster, and less costly than dsa. postoperative graft surveillance is of particular importance, because fl ow impairment is the major cause of graft failure. it is important to detect early graft stenosis to improve the bypass patency rate. venous and expanded polytetrafl uoroethylene grafts are used to treat peripheral artery occlusion. autologous venous grafts have a primary and secondary graft patency superior to that of expanded polytetrafl uoroethylene grafts. imaging findings: mr angiography can identify accurately graft stenosis involving the proximal and distal anastomosis as well as the midportion of the graft course. aneurismal ectatic changes can also be assessed on mr angiography. metallic clip presence can represent a limitation on mr angiography; the susceptibility artifact produced by the clips can produce a misinterpretation of the images. source images should be evaluated to avoid misinterpretation of clip-induced susceptibility artifacts as stenosis. we present our experience with mr contrast-enhanced angiography for the evaluation of different types of vascular grafts used to treat peripheral arterial stenosis. we show the normal fi ndings, the complications and limitations we have found on mr images, using the dsa as a gold standard technique. color doppler sonography before, during and after endovenous saphenous laser ablation a. cina, s. venturino, c. di stasi, a. fiorentino, g. cina, l. bonomo; rome/it (acina@sirm.org) learning objectives: to describe the principles and technique of endovenous laser treatment of saphenous vein refl ux. to illustrate the color doppler us (cds) criteria for selecting patients suitable for the procedure. to teach how to perform cds during the procedure. to show cds fi ndings during follow-up and how to evaluate the outcome of the procedure. background: the procedure of endovenous laser ablation of the saphenous vein is simple and effective, with minimal side effects. cds is fundamental in selecting patients for the procedure, during the procedure and to verify the outcome of the treatment at the follow-up. procedure details: advantages and limits of the procedure. cds criteria for selecting and excluding patients. cds data required for the treatment. echo-guided puncture of the saphenous vein. checking the correct positioning of the laser probe. cds guide for the tumescent local anaesthesia. ruling out complications on the deep venous system. follow-up: how to evaluate the effectiveness of the treatment. tips and tricks of the procedure. conclusion: this exhibit will provide the knowledge necessary to perform cds before, during and after the endovenous treatment. the exhibit will also review anatomy, technique, cds inclusion and exclusion criteria for the treatment. temporal arteritis: avoidance of unnecessarily performed biopsies after color doppler us evaluation e. antypa, a. baltouka, a. parlamenti, m. skilakaki, d. ziaka, t. kratimenos, p. piperopoulos; athens/gr (baltoukamina@yahoo.com) purpose: the management of temporal arthritis is crucial, and the purpose of this study is to demonstrate the value of color doppler us (cdus) in the diagnosis of temporal arthritis and to permit the reduction of unnecessarily performed biopsies. methods and materials: cdus was performed in patients, mean age years, with clinical suggestion of active temporal arthritis. none of the patients was treated with cortical steroids previously. linear high-frequency transducers, - mhz, were used. the common temporal artery and its branches, frontal and parietal, were examined in all patients. the main sonographic criterion for a positive diagnosis was visualization of a periluminar hypoechoic halo and the suspicious areas were marked. biopsy was performed in all patients. additionally, in patients with positive cdus fi ndings of temporal arthritis, the biopsy was guided at the indicated suspicious sites. results: cdus fi ndings suspicious of temporal arthritis were reported in patients. in all of them, the biopsy results were positive for temporal arteritis.the biopsy results in the remaining patients were negative, as were the cdus fi ndings. the method of cdus evaluation of temporal arthritis, using a linear high-frequency transducer and assessing the characteristic sign of periluminal hypoechoic halo, leads to the direct diagnosis of temporal arthritis, and allows a proper medical approach to the disease. moreover, cdus guides the biopsy at the indicated areas and, additionally, contributes to avoid surgical biopsy in selected patients with typical sonographic fi ndings. the use of contrast-enhanced ultrasound in detecting type-ii endoleaks after endovascular abdominal aortic aneurysms repair (evar) a. drelich-zbroja, t. jargiello, a. drop, e. czekajska-chebab, m. szczerbo-trojanowska; lublin/pl (zbroanna@interia.pl) purpose: to assess the effi cacy of contrast-enhanced ultrasound in detecting type-ii endoleaks in the aneurysmal sac after evar. methods and materials: during the period - , standard and contrastenhanced ultrasound with the use of sonovue were performed in patients who underwent evar. ultrasound examinations and spiral ct were done months after evar. the evidence of endoleak type ii was evaluated. results: in conventional doppler study, type-ii endoleaks were diagnosed in patients, from lumbar arteries (la) and from inferior mesenteric artery (ima). contrast-enhanced ultrasound examinations revealed type-ii endoleaks in patients, from la and from ima, and showed different mechanisms of c b d e f a g endoleaks: complex type-ii endoleaks and simple endoleaks. all endoleaks were characterized by slow velocities with vmax from cm/s to cm/s. ct examinations detected type-ii endoleaks from ima in patients and confi rmed endoleaks from ima diagnosed with the use of sonovue and indicated additional endoleak from ima. ct examinations showed only type-ii endoleaks from la. there was more endoleak from la diagnosed with the use of sonovue, which was not detected during ct. conclusion: the use of ultrasound contrast agents increased the diagnostic effi cacy of doppler examinations for detecting type-ii endoleaks. this examination is comparable to ct value in detecting type-ii endoleaks, but contrast-enhanced ultrasound examinations additionally show the mechanism of endoleak and the direction and velocities of blood fl ow. purpose: insulinoma is a rare functional pancreatic neuroendocrine tumor, usually localized in the body and tail of the pancreas. diagnosis is highly diffi cult, and performed by computed tomography, magnetic resonance and selective angiography of the pancreatic arteries by digital subtraction angiography (dsa). the purpose of the study was to analyze the diagnostic assessment of pancreatic dsa, computed tomography and magnetic resonance in patients ( females, males; + years) with insulinoma. the tumors were localized in the pancreatic body in / patients ( . %), in the pancreatic tail in / patients ( . %) and in / patient ( . %) in the head of the pancreas. the diagnosis was confi rmed by pathohistology after the surgical treatment in all patients. the tumors were - mm in diameter and well vascularized. results: dsa detected insulinoma in / patients (sensitivity %). computed tomography detected insulinoma in / patients (sensitivity . %, p < . vs. dsa), whereas magnetic resonance detected tumors in / patients ( . %, p < . vs. dsa). in patients in whom dsa failed to detect insulinoma, the diagnosis was achieved by computed tomography or magnetic resonance. the potential causes for dsa's failure to detect insulinoma are poor vascularization of the tumor and presence of extra gasses in the bowel. conclusion: digital subtraction angiography has better sensitivity than computed tomography and magnetic resonance imaging. so, it has a major role in the detection of insulinoma. lower limb venography: the forgotten "gold standard" a. saini, n. fotiadis, p. goutzios, r. dourado, f. kazmi, r. salter, c. sandhu, t. sabharwal, a. adam; london/uk learning objectives: over the last ten years, dulpex ultrasound has become the primary modality used to assess lower limb venous disease. as a result, the use of contrast venography has declined and in some institutions is rarely performed. this pictorial review is based on the authors' experience and aims to review the indications, techniques, venous anatomy and pathology as demonstrated by lower limb contrast venography. background: contrast venography has long been considered the 'gold standard' in the assessment of lower limb veno-occlusive disease and can effectively demonstrate thrombus within the below knee veins. since duplex ultrasound has the advantages of being non-invasive and does not use ionising radiation, it is favoured by both clinicians and patients as the initial diagnostic test for deep vein thrombosis. radiologists in training no longer have the exposure previously available and may not be familiar with the techniques or the appearances of common pathology. procedure details: the indications, technique and radiological appearances of lower limb venography are illustrated. emphasis is placed on common anatomical variants that are often poorly recognised by routine duplex ultrasound. the use of venography in the assessment of venous malformations, venous tumour encasement and in the post-phlebitic limb are also discussed. conclusion: venography remains the 'gold standard' in the assessment of lower limb venous disease. however, since this method is no longer in frequent use, it is imperative that radiologists remain familiar with the current indications, technique and interpretation of the test. a novel delivery system for hand injection of carbon dioxide in digital subtraction angiography m. cherian, p. mehta, p. gupta, b. madhavram, s.r. jayesh, t. kalyanpur, v. ilayaraja, n. sekhar, s. hedgire, d. raja; coimbatore/ in (drprashg@gmail.com) learning objectives: to demonstrate the feasibility of a plastic bag injection system for a hand injection of carbon dioxide in digital subtraction angiography. background: iodinated contrast agents are routinely used in procedures to diagnose and treat peripheral vascular disease. these agents are associated with contrast-induced nephropathy and allergic reactions in some individuals. to overcome these problems, carbon dioxide angiography has been developed as an alternative to standard iodinated contrast angiography. conventionally available co injectors are expensive and require specialized cylinders which are not currently available in india. we developed a simple plastic bag delivery system to perform co angiography at our hospital. procedure details: the problems associated with carbon dioxide: ( ) co comes in large cylinders under high pressure and thus the pressure has to be reduced close to atmospheric pressure before it is injected. ( ) co is colorless and requires closed circuit to prevent contamination with air. a blood bag was used in the circuit to reduce the pressure equal to that of the atmosphere and co was aspirated through a three way stop cork into a ml syringe. angiography was then performed in the lower limb arteries of patients. digital subtraction angiography performed with a hand injection of carbon dioxide depicted the vessels in adequate detail in all the patients. we demonstrate a simple, safe and inexpensive system that delivers a known volume of co at atmospheric pressure and effectively prevents contamination with room air. mallard, and so on) were studied and systemized in chronological order. we describe the works of the authors who were pioneers in vascular imaging, and whose works were historical landmarks. we display the progress that has been made in vascular imaging from conventional angiography to modern mri angiography. c b d e f a g aneurysms in patients. this study included men and woman (mean age: years). one radiologist reviewed computed tomographic (ct) studies, arteriograms, magnetic resonance (mr) studies and one doppler sonography. features evaluated included aneurysm size, shape, and location; branch involvement; arterial wall calcifi cation; gas; and periaortic and associated fi ndings. results: aneurysms were located in the thoracic aorta (n= . %), thoracoabdominal aorta (n= %), infrarenal aorta (n= . %), iliac artery (n= . %), femoral artery (n= . %), tibial-peroneal arterial trunk (n= . %), and peripheral middle cerebral artery (n= . %). four patients had infected aortic aneurysms.ct revealed saccular (n= . %) and fusiform (n= . %) aneurysms. paraarterial soft-tissue mass, stranding, and/or fl uid were present in (n= . %) of aneurysms, and early periarterial edema with rapid aneurysm progression and development was present in ( %) patients with sequential studies. other fi ndings included psoas muscle abscess (n= . %), absence of calcifi cation in the aortic wall (n= %), and periaortic gas (n= %). angiography showed saccular aneurysms with lobulated contour in ( %). mr imaging showed saccular aneurysms. conclusion: saccular aneurysms with rapid expansion and adjacent mass, stranding, and/or fl uid in an unusual location are highly suspicious for an infected aneurysm. chronic mesenteric ischemia: imaging fi ndings s. jiménez, a.b. delgado, a. sánchez, y. revilla, a. martínez, e. garcía; learning objectives: to describe the imaging fi ndings of chronic mesenteric ischemia (cmi) on duplex ultrasonography (dus), and their correlation with computed tomography angiography (cta), magnetic resonance angiography (mra) and angiography. background: cmi is an unusual but important cause of abdominal pain and weight loss, resulting from occlusion or severe stenosis of at least two of the three main splachnic vessels. understanding abdominal visceral circulation, its variants and collateral pathways that develop in patients with visceral artery stenosis is key to recognize cmi. atherosclerosis is the main cause of cmi ( % cases), usually involving the ostium of celiac artery (ca), superior or inferior mesenteric artery (sma or ima). other rarer causes are nonatheromatous lesions (dysplastic lesions, thromboangitis obliterans, radiation-induced lesions, takayasu arteritis…). imaging findings: evidence of visceral artery occlusion with noninvasive imaging such as dus, cta or mra could suggest cmi, if other causes of abdominal pain have been confi dently ruled out. in dus a peak systolic velocity greater than cm/sec or end-diastolic velocity greater than cm/sec seems highly specifi c for signifi cant sma stenosis. vascular obstructions, stenosis, collateral pathways and changes in the bowel wall can be depicted on both cta and mra. if endovascular treatment is proposed, angiography remains the diagnostic gold standard. conclusion: dus, as the preferred noninvasive screening test for sma and ca stenosis, followed by cta, mra or angiography allow us to make the diagnosis of cmi, as well as a valuation of extension, severity and number of affected arteries. takayasu's arteritis: a multi-modality pictorial essay j.p. banerjee, v. prabhudesai; hamilton, on/ca (pjbanerjee@hotmail.com) learning objectives: to better appreciate the imaging characteristics of takayasu's arteritis based on various modalities and thereby improve detection and surveillance of disease activity. background: imaging characteristics play a critical role in the diagnosis of takayasu's arteritis given that both clinical presentation and serological markers are non specifi c. traditionally, angiographic studies have primarily been used to demonstrate the vascular effects of this disease. however, employing additional and/or alternative modalities provide a more complete understanding of takayasu's arteritis. our institution serves as a local referral base for rheumatologic conditions and the department of medical imaging is routinely consulted in cases of suspected vascultitis. we have selected a group of patients whose imaging best illustrates the salient features of this clinical entity. the benefi ts and shortfalls of angiography, ultrasonography, contrast enhanced ct and mri are reviewed and a pictorial essay is offered to illustrate various fi ndings using these modalities. imaging findings: while angiography is the traditional gold standard for investigation of vasculitides, ultrasonography provides a non invasive alternative with fewer side effects, albeit at the expense of lower predictive value and operator dependance. cross sectional imaging by means of ct and mri also offer non invasive visualization of luminal pathology with the additional benefi t of demonstrating changes within the wall. conclusion: although knowledge of angiographic fi ndings of takayasu's arteritis aid in the evaluation of this disease, familiarity with imaging characteristics of other modalities allow the radiologist to better assess patients and offer additional and less invasive imaging options. current radiological approach for the diagnosis and follow-up of takayasu arteritis a.y. goktay, a. gulcu, t. celik; izmir/tr (yigit.goktay@deu.edu.tr) learning objectives: to evaluate the combined use of doppler us, mri, mr angiography and dsa for the diagnosis and follow-up of takayasu arteritis. background: takayasu arteritis is characterized by granulomatous infl ammation of the arterial wall which eventually leads to stenosis, occlusion and sometimes aneurysm formation. classical diagnosis has been based on characteristic fi ndings of the aorta and its major branches at conventional angiography or dsa. however, current developments in the fi eld of cross-sectional imaging have increased the diagnostic capacity of radiological methods even in the early systemic phase without any luminal abnormality. we present the combined radiological approach for the patients with takayasu arteritis. procedure details: cervical, renal, abdominal and extremity arterial doppler us examinations were performed for obtaining direct and indirect information about arterial fl ow and vessel wall. thoracoabdominal mri and mr angiography studies were performed on a . t scanner with body coil. multiplanar t -weighted fat-suppressed, t -weighted black blood inversion recovery before and after administration of gd-dtpa and contrast enhanced d mr angiography sequences were obtained. image interpretations were performed after post-processing studies. all luminal fi ndings were compared with dsa results. during the follow-up, us and mri fi ndings about vessel wall thickening and contrast enhancement of arterial wall were also evaluated. if necessary, endovascular treatments were performed according to the activity of the disease. background: dvt is a common vascular disease requiring prompt diagnosis and treatment but clinical assessment is often unreliable. d-dimer testing and pre-test probability scoring are used as guides for selection of the most appropriate investigation. vascular imaging remains essential for diagnosis and b-mode and doppler us, mdct and mri play an important role in the work-up of the disease. procedure details: the authors discuss advantages and limitations of each method in the evaluation of dvt, illustrating thoroughly the spectrum of fi ndings at us, mdct and mri. technical principles are outlined as fundamental tools to optimise disease detection and avoid potential pitfalls. conclusion: b-mode and doppler us is a cost-effi cient and widely available technique for initial evaluation of suspected extremity dvt. mdct and mri allow visualisation of affected areas non-accessible to us imaging. mdct with shorter acquisition times, greater coverage and reduced scan width provides excellent resolution in depiction of the disease, and detection of eventual complications as pulmonary thromboembolism. imaging features of the congenital and acquired abnormalities of the svc and the pulmonary vasculature k. burney , h. young , p. mccoubrie , s. barnard , m. darby ; southampton/uk, bristol/uk (kburney@doctors.org.uk) learning objectives: to illustrate the spectrum of congenital and acquired abnormalities of the superior vena cava (svc). to present the congenital anomalies of the pulmonary veins and the associated anomalous drainage patterns seen. background: a wide range of clinical conditions can affect the svc. these include both congenital and acquired abnormalities. similarly, the pulmonary veins can be affected by a number of congenital anomalies, which can occasionally mimic other disorders and be associated with congenital heart disease. imaging findings: we retrospectively reviewed the imaging of patients with svc or pulmonary venous abnormalities treated in our hospital, and present a review of abnormalities as seen on various radiological investigations including ct, mri and plain fi lms. the congenital abnormalities of the svc highlighted include left-sided and double svc. acquired abnormalities including intra luminal defects caused by line-associated thrombus, svc stenosis secondary to multiple central line insertions or tumour invasion, extra luminal compression caused by mediastinal tumour and vascular aneurysms are demonstrated. partial anomalous pulmonary venous return (papvr) is a congenital abnormality in which one or more of the pulmonary veins are connected directly to the right atrium or to a systemic vein. we also present various patterns of papvr as seen on contrast-enhanced ct, as they may be associated with congenital heart disease. the development of the central systemic veins including the svc and pulmonary veins is a complex process subject to a number of variations. knowledge of some of the resulting variations can be of clinical importance. flow spectra were evaluated with doppler scan mode and fl ow parameters were calculated for the femoral, popliteal and calf arteries and veins. results: hit was proven by a positive platelet aggregation test in patients ( %), females and male, who suffered lower extremities thromboembolic complications. fifteen patients ( %) had arterial thrombosis, most prominent of the common femoral, superfi cial femoral and posterior/anterior tibial artery. six subjects ( %) had deep venous thrombosis, most prominent of the common femoral and superfi cial femoral vein. conclusion: our study confi rmed the remarkably high incidence of thromboembolic complications, mostly arterial, in critically ill patients with hit. the routine cdus is appropriate in these patients since if silent arterial or venous thrombosis is identi developmental dysplasia of the hip in children: can mri features predict the need for surgical oseotomy? n. chew, p. mitchell, i. goutos, s. evans, a. hulme, j. lee, j. healy; london/uk (drchew@doctors.net.uk) purpose: open or closed reduction is undertaken to facilitate normal hip growth in children with ddh. however, a proportion of children who undergo hip reduction fail to develop deep well-formed acetabuli. these children will need to undergo pelvic osteotomy to improve cover of the femoral head and thereby reduce risk of premature osteoarthritis. we ascertain if the presence of abnormalities on mri immediately after hip reduction can predict long term hip dysplasia, therefore, aiding surgical fore-planning and reducing need for follow-up radiographs. methods and materials: nineteen hips with ddh were followed up over years. all had initial reduction and post-reduction mri. mri fi ndings of hips where acetabular dysplasia resolved by age four were compared with the hips that underwent pelvic osteotomy for unresolving dysplasia. cartilage anlage shape, bony acetabular index, acetabular anteversion, lateral displacement due to panniculus, ligamentum teres and transverse ligament thickness, and whether the acetabular labrum was in a normal position or folded into the joint were were analysed and compared. the scans were analysed by two consultant musculoskeletal radiologists who were blinded to the outcome of each child. results: statistical analysis found none of the abnormalities on mri were predictive of persisting acetabular dysplasia in the older child. conclusion: although post reduction mri demonstrates anatomical abnormalities secondary to ddh, none of these were predictive of long term acetabular dysplasia. this suggests that the factors determining long term outcome are not visible on mri, but perhaps due to poor muscle dynamics or a biomolecular abnormality. radiological fi ndings in patients with stuewe-wiedemann syndrome surviving infancy r.d. langer, l. al-gazali, p. raupp; al ain/abu dhabi/ ae (rlanger@uaeu.ac.ae) learning objectives: to illustrate radiological fi ndings in the subgroup of patients with stuewe-wiedemann syndrome (sws), surviving the second year. background: sws is a rare skeletal dysplasia. mutations responsible have been recently identifi ed. the prevalence is high in the uae ( . / , birth). most sws patients die before the age of . out of sws patients, survived the second year. all came for regular orthopedic and pediatric checkups, or were admitted due to respiratory distress. patients received follow-up bone and chest radiographs; underwent cct. our fi ndings have been compared to few published data. imaging findings: all children showed congenital dwarfi sm with progressive bowing of the extremities and demineralization. three had metaphyseal enlargements with coarse trabeculae. three developed progressive (kypho)-scoliosis and one spontaneous fracture. three children showed fragmented epiphyses. epiphyseal fl attening occurred in patients. metacarpals and metatarsals were shortened and undertubulated. one patient developed an osteonecrosis of the talus. rips were broadened and osteoporotic with old fractures. all survivors repeatedly received chest radiographs due to aspirations, pulmonary infections, and pneumonias. two patients expired subsequently; they died from respiratory insuffi ciency. one girl developed a neurological defi cit due to left frontal infarction, which was caused by hypoxia. conclusion: while maroteaux reported a mean survival time of months, several cases surviving infancy have been published, and are under surveillance. sws survivors after the second year show progressive bowing of the extremities with osteoporosis, a tendency to fractures, metaphyseal abnormalities, and severe (kypho)-scoliosis. pulmonary infections are less frequent after the second year. conclusion: the image plates will tested more with the phantom and after that the results will be tested with clinical use. the experienced radiology will analyse the image quality. the results will be introduced. these fi rst tests showed that it is possible to optimise the radiation dose and image quality easily according to the dimondiii process. optimization of patient exposure dose in low-dose scanning for ct colonography by adjusting dose according to patient weight y. hirano, k. sasaki, h. matsuya, s. katsuki, k. sasaki; otaru city, purpose: reducing patient exposure dose is important in ct colonography. in a previous study (ecr ) , we studied laboratory models and found that scanning with an air sd value (standard deviation value in the acrylic part) of approximately or more results in poor visualization. air sd values vary according to patient size. in the present study, we investigated optimization of the patient exposure dose by adjusting the dose according to patient weight. methods and materials: patients were examined using a -row multidetector ct scanner and a d workstation. patient weight was measured before ct colonography. scanning was performed with an extremely low dose of mas ( patients) or mas ( patients), and the air sd values in the colon were determined in the upper abdomen and in the pelvic cavity. scan conditions were kv, . -mm scan slice thickness, and . -mm reconstruction slice thickness. results: a positive correlation was observed between patient weight and air sd values in the colon. the correlation coeffi cients were . and . in the upper abdomen and . and . in the pelvic cavity for extremely low-dose scanning at mas and mas, respectively. conclusion: our previous study (ecr ) showed that air sd values of approximately or more result in poor visualization, making it diffi cult to observe the tissue surface. the present study has shown that adjusting the dose according to patient weight is useful for optimizing the patient exposure dose in low-dose scanning while maintaining good visualization. how versatile is ct-aec? radiographic technique considering performance characteristics k.o. oosawa , y.m. muramatsu , s.t. terakawa , t.m. mito , s.n. nakahira , y.h. hamada , y.u. ueda , i.f. fujimura ; sakurai nara/jp, chiba/jp, osaka/jp (alfa-k @t-kadomatsu.net) purpose: ct automatic exposure control (ct-aec) is a new technique to optimize increasing exposure during ct examination. because different ct-aec systems use different operational principles, ct-aec cannot be expected to be effective when used thoughtlessly. the purpose of this study is to develop a radiographic technique that considers performance characteristics of different ct-aec systems, pursuing maximum dose reduction while ensuring image quality. methods and materials: two ct-aec systems from one manufacturer were investigated: ( ) somatom volume zoom with care dose, and ( ) sensation with care dose d (siemens, germany). the phantoms for evaluation are cone, elliptical, variable-xy and step phantoms (kyoto kagaku, tokyo). data was collected by changing abdominal ct scan parameters as appropriate. the data was converted to dicom images; image noise, tube current and absorbed dose (ctdiw) were obtained using a dedicated software program (bioarts, fukuoka). the relationship between tube current and image noise was compared for care dose and care dose d. dose reductions from % to % were obtained in both aec systems compared with doses obtained without aec. while dose reduction depends on phantom size in both systems, the dependence changes with dose correction curves in care dose d. the dependence of image noise on phantom shape is observed in care dose, but is not conspicuous in care dose d. conclusion: a tube current correction table considering phantom size and shape was developed from the results, allowing dose reduction and comparable image quality from the two systems. can the isolated distension of the colon be infl uenced by adequate preparation during virtual colonoscopy, or, if needed, can adequate small intestine distension also be achieved? e. turupoli, k. szeidl, l. fehér, Á. szilvássyné takács; budapest/hu (turupoli@freemail.hu) purpose: to develop a method by which the isolated distension of the colon can be achieved, or if the status of the small bowel is also questionable, to produce the distension of small bowel too. methods and materials: we performed virtual colonoscopies. the infl ation conclusion: sd is the appropriate sd setting level for ct-aec in abdominal ct examinations. usefulness and optimal noise (sd) of auto-ma: survey among radiology technologists using -slice mdct and esophageal cancer phantom study n. yanagawa, h. satou, t. kazama, t. iimori, k. shutou, s. okazumi, t. ochiai; chiba/jp (yanagawa@ho.chiba-u.ac.jp) purpose: image quality and radiation exposure are confl icting factors. recently, automatic determination of radiation dose (auto-ma) in ct scans has been developed. the purpose of this study was to determine optimal noise level at auto-ma. methods and materials: questionnaire was mailed to institutions that have -slice mdct. the questions were usage of auto-ma, and the setting of noise level when it was used. a basic study was performed with small and large phantoms. the small (s)-phantom was a low-contrast phantom and cm in diameter. the large (l)-phantom was made of the low-contrast phantom rolled with water-polymer absorber material. this was cm in diameter. the largest diameter of the lesions demonstrating more than two-third of their profi le was searched. results: fifty-one institutions answered the survey. in % institutions, auto-ma was used and the standard deviation (sd) of auto-ma set between and , but it was set constant in each institution. on phantom study when sd was set at , the largest profi le of lesions in l-phantom was mm, while that in s-phantom was . mm. when sd was set at , the largest profi le of lesions in l-phantom was . mm, while that in s-phantom was . mm. conclusion: although sd of auto-ma was set constant in many institutions, phantom study suggested different optimal sds depending on patients' body habitus. manual labeling of brain tissues on mr images -a method to assess the quality of brain tissue volumes by automatic segmentation in a large population based study: the age, gene/environment susceptibility (ages)-reykjavik study b. oskarsdottir , s. sigurdsson , l. purpose: automated segmentation of brain tissue on mr images is critical to accomplishing analyses of mr scans acquired in large population-based studies, but manually labeled tissue is needed to check the accuracy of the algorithms. here we describe a method for manual labeling of brain tissues on mr images and assess the reproducibility of the method. methods and materials: the brain tissues on the mr images were labeled using "borderline", a software drawing tool specially designed for the ages-reykjavik study. borderline uses a wacom pen tablet as a human interface device for drawing and labeling anatomical landmarks. the tablet comes with a computerized pen interface and a drawing board, allowing the user to label multiple rois or tissue classes based on a multi-modal set of registered brain images. intra-rater variability was assessed based on repeated measures from one observer on pre-defi ned slices of the brain for cerebrospinal fl uid (csf), gray matter (gm), white matter (wm) and white matter lesions (wml), based on the following mr sequences: d spgr t , fse pd/t , and flair t . the intra-rater variability was calculated for each tissue class and each slice location individually using kappa statistics describing spatial agreement (dice similarity coeffi cient). results: kappa agreement for all tissue classes and all slice locations was excellent (mean k= . ± . and mean k= . ± . , respectively). conclusion: a robust, highly reproducible method has been developed for manual labeling of brain tissues. an evaluation of computer-aided instruction courseware for mri physics d. koumarianos, e. mihalopoulou, l. costaridou, g. panayiotakis; patras/gr (dikoum@panafonet.gr) purpose: the evaluation of a computer-based instructional package designed to interactively teach mri concepts using media-rich animations. methods and materials: eighteen postgraduate students were prospectively, randomly assigned to receive instruction on the same mri topic from a textbook and a computer module. participants were evaluated by a multiple choice test weeks before the lectures, at the end of the lectures and by a retention test after month. they also completed questionnaires to rank their attitudes quantitatively and qualitatively toward the two instructional methods. mean test scores of the textbook and computer groups were compared by means of analysis of variance. results: the percentage of correct answers increased from . % on the pretest to . % on the posttest, and then decreased to . % on the retention test administered month after completion of the mri course. computer group students scored signifi cantly higher on their posttest (m= . , sd= . ) when compared with the textbook group (m= . , sd= . , p=. ), while they seem to appreciate multimedia modules more when compared to textbook students (p=. ). the textbook learning group was equally satisfi ed with their method of instruction in comparison to the computer group (p=. ). students' rationale for expanding the use of multimedia in physics education seemed to focus on issues concerning motivation, instructional capabilities and content. conclusion: interactive animations are a useful and effective aid for teaching mri principles. the study demonstrated that the inclusion of properly designed multimedia modules enhances conceptual understanding far more than traditional methods do. atlas of normal and variant abdominal arteries. d anatomy with channel multidetector-ct p. sedati, g. pelle, m. telesca, f. macrì, a. napoli, c. catalano, r. passariello; rome/it (psedati@hotmail.com) learning objectives: . to illustrate basic liver and renal vascular anatomy and its variation with multiplanar and d imaging using detector row ct. . to provide an atlas of normal and variant vascular d anatomy. . to illustrate the basic principle of multiplanar and d imaging using d workstation and to explain how to optimize image quality. background: multi-detector ct (mdct) is now a standard type of clinical ct scanner. appropriate post-processing of mdct images enables the effi cient gathering of much more information than by just evaluating thin source images. post-processing techniques are useful both in clinical situations and for educational purposes. however, incorrect use of these techniques may hide important information. procedure details: ) major vascular anomalies that involve the systemic arterial system of the abdomen are reviewed with emphasis on key imaging fi ndings and differential diagnostic features that allow for differentiation from other abnormalities. ) review most important post processing technique and how to avoid important error. ) understand which of such anatomical variants are related with specifi c clinical symptoms, syndromes or are important for a correct surgical planning. conclusion: recognition of abdominal vascular anomalies on imaging is important because several such variants may be associated with specifi c clinical symptoms, syndromes and other pathologic processes. major vascular anomalies that involve the systemic arterial systems of the abdomen are reviewed with emphasis on key imaging fi ndings and differential diagnostic features that allow for differentiation from other abnormalities. images were acquired in a multi-phase fashion: the arterial phase using bolus tracking technique (smart-prep), and the venous phase after a second delay, at . mm of collimation, . mm of reconstruction interval, and of pitch. the active bleeding sign (ab) was detected with mean attenuation values. images were reconstructed and rendered with mip and mpr algorithms. image evaluation was carried out by two experienced abdominal radiologists in a blinded-end fashion, and inter-observer agreement (cohen-test) was obtained. results: attenuation values ranged from to h.u. eighteen out of patients had abdominal hemorrhage, whereas the ab sign was detected in out of patients. it was secondary to spontaneous bleeding from an intrahepatic pseudoaneurysm (n= ), rupture of a splenic artery pseudoaneurym (n= ), rupture of a giant renal angiomiolypoma (n= ), bleeding from an aorto-duodenal fi stula (n= ), bleeding from gastric ulcer (n= ), and rupture of a hepatic hemangioma (n= ). almost perfect agreement was obtained between the two readers in the detection of the ab sign (k= . , ci= %). conclusion: mdct angiography and mpr reconstructions allowed satisfactory detection of active hemorrhage. the ab sign precisely localized the bleeding site, and therefore should be considered before therapeutic planning. advantages and disadvantages of ecg-gated multislice spiral ct (msct) in the study of the thoracic aorta c. sebastia, h. cuellar, s. quiroga, a. evangelista, r. boyé, a. alvarez; learning objectives: . to describe our protocol for studying the thoracic aorta with ecg-gated msct. .to demonstrate, with images and videos, the advantages of this technique for studying several thoracic aorta diseases. . to depict the pitfalls, artifacts and disadvantages of the ecg-gated technique for imaging the thoracic aorta. background: since january , we have performed an ecg-gated msct technique in patients with thoracic aortic disease ( aneurysms-pseudoaneurysms of the ascending aorta, type a acute aortic dissections, chronic aortic dissections, aortic coarctations, patent ductus arteriosus, postoperative ascending color doppler sonography before and after av haemodialysis fi stulas preparation a. cina, c. di stasi, s. venturino, e. muto, l. tazza, l. bonomo; rome/it (acina@sirm.org)learning objectives: purposes of this exhibit are: to describe how to perform a color doppler sonography (cds) examination before the creation of av fi stulas for hemodialysis and to show normal cds fi ndings and complications of av hemodialysis fi stulas. background: surgically created brescia-cimino arteriovenous fistulas and prosthetic loop grafts are common vascular accesses for hemodialysis. although angiography has been the traditional method of imaging, cds is now the standard technique employed before the fi stula creation and for evaluating dysfunctional hemodialysis access. procedure details: anatomy and surgical techniques -( ) cds methodology of study; ( ) cds qualitative and quantitative data necessary before the fi stula preparation; (a) normal fi ndings after fi stula preparation; (b) complications: feeding artery occlusion; anasthomotic stenosis; venous stenosis; venous/graft thrombosis; anasthomotic pseudoaneurisms; infections; radial steal. conclusion: in this exhibit, we describe the role of cds in selecting arteries and veins for the preparation of av fi stulas for hemodialysis and the sonographic fi ndings of the more frequent complications. a detailed description of cds examination protocol before and after the fi stula creation is reviewed. purpose: the renal resistive index (ri) measured by doppler us has a well known prognostic signifi cation in vascular nephropathies and an elevated ri is currently associated with the diagnosis of nephroangiosclerosis. its value is more controversed in parenchymal nephropathies or in renal transplanted patients. our study correlated the ri with renal intraparenchymal parameters: endarterial sclerosis (esc) and interstitial fi brosis (if). methods and materials: the ri of consecutive patients were measured by doppler us, just before renal biopsy. ri results were given as mean of measurements performed at upper, lower and middle poles. the biopsy was made for the diagnosis of nephropathy (n= ) or for decline of renal function of kidney allograft (n= ). a histomorphological analysis was performed, using an automated methodology to determine the if and esc index. these parameters were correlated with the calculated ri for each patient (mann-whitney test). other parameters were evaluated especially creatininemia (cr) and cockroft glomerular fi ltration rate (cgfr). results: for patients having a native kidney biopsy, an independent positive qualitative and quantitative correlation statistically signifi cant, could be made between ri and cr, decline in cgfr, and esc index. no relation was noted with the if index. correlations were not signifi cant for transplanted patients. conclusion: ri is an exclusive non invasive index to diagnose the vascular sclerosis in native kidney and an elevated ri is a marker of poor prognosis renal function evolution in patients having nephropathy and chronic renal failure. colour background: celiac-mesenteric insuffi ciency is characterised by a hyper-affl ux to the celiaco-mesenteric district that may manifest itself asymptomatically, by means of aspecifi c pictures characterised by post-prandial pain (angina abdominis), or by means of dramatic conditions such as intestinal infarction. the risk factors are obesity, dyslipidemia, cigarette smoking, and antomical malformations such as fi bromuscular dysplasia, a high origin of the celiac tripod or hypertrophy of the arcuate ligament. procedure details: the fi rst diagnostic step when evaluating non-acute celiacmesenteric insuffi ciency is colour doppler us, which allows us to localize the site of the stenoses and measure their severity (expressed as% stenosis). we show the technique of performing such an examination and describe the semeiotic principles underlying it and b-mode echography: the evaluation of the presence of plaque, post-stenotic dilatation, and the quantifi cation of the degree of stenosis by means of the assessment of direct and indirect signs; and the colour doppler effects and fl ow acceleration. conclusion: the exhibit will review the indications and techniques, and provide the tips and tricks, and a complete case gallery. helical background: b-fl ow sonography is a relatively new sonographic technique that directly depicts blood echoes in a gray-scale presentation. this technique utilizes digitally encoded us technology and allows simultaneous imaging of blood fl ow, vessel walls and neighbouring tissues. the main imaging parameters are few (sensitivity, background control, gain control, focus number and location) and easy to use. imaging findings: b-fl ow sonography has several advantages over color and power doppler sonography: the information from both tissue and blood fl ow is identifi ed in higher resolution and higher frame rates. angle dependency, overwriting of the vessel walls by the color overlay, aliasing and perivascular color artifacts are eliminated. major indications for b-fl ow and areas of research are as follows: evaluation of carotid artery lesions and stenoses; follow-up of carotid artery stents; evaluation of hemodialysis fi stula patency and complications; evaluation of pseudoaneurysms and guidance for therapy; lymph node characterization; and abdominal applications like the investigation of portal vein thrombosis, cavernous transformation of the portal vein and budd-chiari syndrome. the technique has also some limitations such as decreased sensitivity with increasing depth and inability to obtain signals from a structure located deep to a calcifi ed plaque. also, fl ow directions are more easily recognized by color doppler than by b-fl ow. conclusion: b-fl ow technique provides higher resolution and higher sensitivity to fl ow without doppler artifacts. further improvements in the technique may overcome limitations and expand its clinical applications. learning objectives: . give an overview of the anatomy of the jugular, subclavian and axillary veins. . explain the techniques of cannulation of these veins, based upon anatomical landmarks, and correlate them with ultrasound (us)-guided approaches. background: central line catheterization is a clinically useful tool, performed for invasive monitoring the hemodynamic, respiratory, and fl uid status of patients, as well as for delivery of drugs and nutritive solutions. classically, techniques based upon anatomical landmarks have been used, but that may fail if any vascular anatomic variant exists. moreover, these techniques may cause complications as pneumothorax and hemorrhage after arterial injury. procedure details: after giving an overview of the anatomy of neck and shoulder, with special attention on anatomical relationships of veins, we expose the different catheterization techniques based upon anatomical landmarks. jugular vein can be catheterized by anterior, medium or posterior approaches, and subclavian vein by infra or supraclavicular approaches. us-guided cannulation technique is correlated with each of these approaches. finally, advantages and disadvantages of both techniques are summarized. conclusion: based on current literature, us can play an important role in the guidance of cannulation of central lines, as it can detect anatomical variations and venous thrombosis prior to the catheterization. nevertheless, it may reduce complication rates and number of attempts during catheterization. morphologic and hemodynamic study of gastrocnemius medial vein with color duplex ultrasonography in chronic venous insuffi ciency s. jiménez, a.b. delgado, a. sánchez, p. martín, s. zubicoa, j. leal; madrid/es (sarajimenezarranz@gmail.com) purpose: to describe the morphologic changes and hemodynamics of the gastrocnemius vein (gv) in patients with chronic venous insuffi ciency (cvi) with color duplex ultrasound (cdus). the study was performed in lower limbs of patients. lower limbs presented clinical signs of cvi according ceap classifi cation and lower limbs were normal. we carried out an anatomical study of the gv and muscle, and provided hemodynamic information about the incompetent veins by demonstrating the presence of refl ux. results: in % of limbs, the gv showed no refl ux and connections with superfi cial varicose veins through may's perforating veins (re-entry veins). % had gv refl ux associated with superfi cial varicose veins, in % the refl ux was due to post-thrombosis syndrome, and in % the refl ux was interpreted due to primary incompetence (no superfi cial varicose veins and no evidence of deep venous thrombus). % presented mainly gv stasis (enlargement, slow fl ow and symptoms of pain), and % displayed asymptomatic dilatation. in %, the study was normal (no enlargement and no refl ux), and the remaining % showed gastrocnemius muscle atrophy with dysfunction of muscular pump. the gv mean diameters in the cvi group were larger than those of the non-cvi group ( . cm vs. . cm). we also measured the venous fl ow velocities and fl ow-volume after muscular systole in the different groups. conclusion: cdus is a non-invasive technique that allows anatomical and functional studies of the gv in patients with cvi. it is also useful for physiopathological classifi cation and pre-therapeutic evaluation. arterial and venous thromboembolic complications in heparin-induced thrombocytopenia (hit) patients: color doppler sonography evaluation a. balanika, m. theodorakopoulou, m. lignos, c. baltas, e. melissari, a. gouliamos, a. armaganidis; athens/gr (mpaltas@hotmail.com) purpose: heparin-induced thrombocytopenia (hit) is estimated to occur in - % of all patients receiving heparin. the purpose of this study was to investigate by color doppler ultrasonography (cdus) the incidence of thromboembolic complications in medically critical patients with hit. methods and materials: over a period of eighteen months, intensive care unit (icu) patients (aged - ) presented with thrombocytopenia were investigated for hit and underwent arterial and venous cdus examination of lower limbs. orthopedic, surgical and cardiosurgical patients were not included in the study. we evaluated advanced multi-modality imaging of therapeutic angiogenesis and arteriogenesis: experimental in-vivo applications k. katsanos, d. karnabatidis, a. diamantopoulos, g.c. kagadis, p. kraniotis, d. siablis; patras/ gr (katsanos@med.upatras.gr) learning objectives: to familiarise radiologists and research scientists with advanced cross-sectional and angiographic in-vivo imaging modalities for the study of experimentally induced therapeutic angiogenesis and arteriogenesis. background: therapeutic angiogenesis (new vessel growth) and arteriogenesis (collateral vessel enlargement) constitute the frontiers of cardiovascular research in the reversal of ischemic myocardial and peripheral arterial diseases. in-vivo vascular imaging allows the quantifi cation of the angiogenic process and is necessary for the reproducible morphological and functional investigation of novel proangiogenic agents. imaging findings: experimental models of hindlimb or myocardial ischemia generally involve surgical or endovascular occlusion of the femoral or coronary arteries in animals. after the endogenous angiogenic response comes at rest, exogenous proangiogenic growth factors are administered and the evolution of therapeutic angiogenesis and collateralization is followed-up. non-contrast and contrast-enhanced cross-sectional studies with computed tomography (ct) and magnetic resonance (mr) may depict variations in tissue vascularity and enhancement after administration of contrast media. multiplanar reformatting along with volume-rendered cta and/or mra images may accurately display the morphology and bridging points of collateral vessels with diameter > µm. moreover, dynamic image acquisitions during contrast administration and corresponding perfusion studies permit the functional assessment of the newly developed collateral vessels. finally, intra-arterial digital subtraction angiography delineates the newly formed vessels with great anatomic detail. recently developed post-processing computerised algorithms provide the capacity of segmentation, visualisation and quantifi cation of microvessels with diameters down to - µm. conclusion: modern applications of cross-sectional and angiographic vascular imaging with advanced post-processing and reformatting algorithms enable in-vivo morphological and functional experimental studies of therapeutic angiogenesis and arteriogenesis. imaging spectrum of the infectious and infl ammatory etiologies of aortitis r. suri, c.s. restrepo, k.n. chintapalli, s.r. prasad, d.w. postoak, b. toursakissian; san antonio, tx/us (suri@uthscsa.edu) learning objectives: . review the clinical spectrum of infectious and infl ammatory conditions of the aorta. . highlight the role of cross sectional imaging in the diagnosis and assessment of the extent of aortitis, thus helping in the management of these patients.background: infl ammatory/infectious conditions of the aorta and its major branches may present with nonspecifi c symptoms and are often missed clinically in the workup for fever of unknown origin (fuo). increased awareness of aortitis would facilitate appropriate management. imaging findings: . clinical signifi cance of aortic and major arterial infl ammatory conditions. . ct/mr/angiographic techniques and the role of image post-processing for dedicated evaluation of the aorta. . pictoral review of cross sectional imaging of a wide spectrum of aortitis due to vasculitidis (takayashu's arteritis, giant cell arteritis) and infection (granulomatous and other bacterial) involving the native aorta or after endograft or surgical repair. conclusion: increased awareness of aortitis and knowledge of the cross sectional imaging appearances helps to establish accurate diagnosis, which facilitates appropriate medical or surgical management. early diagnosis with ct and mr avoids life-threatening complications, thus, decreasing morbidity and mortality. a comprehensive pictorial review of anomalies of the superior and inferior vena cava e. sueyoshi, i. sakamoto, m. uetani; nagasaki/jp learning objectives: to provide a pictorial review of the embryology and anatomy of the superior and inferior vena cava. to show a detailed overview of cogenital and acquired diseases demonstrated by ct, mr, and/or angiography. to discuss the importance of careful analysis during the imaging interpretation. to discuss the prognosis of patients with these abnormalities. background: anomalies of superior and inferior vena cava are not rare. these abnormalities include congenital and acquired abnormalities associated with abnormal development, thrombosis, tumor, infl ammation, etc. procedure details: we provide a pictorial review of the embryology and anatomy of the superior and inferior vena cava. we show a detailed overview of congenital and acquired diseases demonstrated by ct, mr, and/or conventional angiography. we also discuss the importance of careful analysis during the imaging interpretation and the prognosis of patients with these abnormalities. conclusion: knowledge of this exhibit may be useful for the diagnosis and prediction of prognosis of patients with abnormality of the superior and inferior vena cava. interruption or congenital stenosis of the inferior vena cava z. koc, l. oguzkurt, s. ulusan; adana/tr (zaferkoc@superonline.com) purpose: to present the prevalence, clinical, and imaging fi ndings of interruption or congenital stenotic lesions of the inferior vena cava (ivc), associated malformations, and their clinical relevance. methods and materials: between march and march , patients who had undergone consecutive routine abdominal multidetector row computed tomography were analysed for interruption or stenotic lesion of the ivc. results: prevalence of interruption (n = ) or congenital stenosis (n = ) of the ivc occurred in ( . %) of patients. four patients with interruption and patients with congenital stenosis of the ivc were symptomatic with dvt (n = ), leg swelling (n = ), leg pain (n = ), lower extremity varices (n = ), hepatic vein thrombosis (n = ), and hematochezia (n = ). all four of the asymptomatic patients were from the interruption group, and these patients had interrupted ivc with well-developed azygos/hemiazygos continuation. eight symptomatic patients did not have a well-developed azygos/hemiazygos continuation, and drainage of lower extremity was mainly from collateral veins. additional fi ndings in symptomatic patients were abdominal venous collaterals (n = ), venous aneurysm (n = ), lower extremity varices (n = ), varicocele (n = ), and pelvic varices (n= ). conclusion: interruption or stenosis of the ivc are rare on routine abdominal ct examinations and may cause different clinical fi ndings depending on the variant drainage patterns or collaterals. interrupted ivc is commonly asymptomatic if associated with well-developed azygos/hemiazygos continuation, whereas commonly symptomatic if well-developed azygos/hemiazygos continuation is not present. key: cord- -n epxwn authors: nan title: ecr – final programme: scientific and educational exhibits date: journal: nan doi: . /s - - - sha: doc_id: cord_uid: n epxwn nan contrast enhanced ultrasonography (ceus) of pancreatic masses m. d'onofrio, s. vasori, u. rozzanigo, s. caffarri, n. faccioli, c. procacci; verona/it purpose: to evaluate the role of ceus in the study of solid and cystic masses of the pancreas. materials and methods: masses of the pancreas, found on conventional us, were studied with ceus, by using sonovue (bracco) on a sequoia (acuson). a dynamic observation from the early contrastographic phase (during arterial enhancement), to the late contrastographic phase (after venous enhancement) was possible. all the lesions were cytologically/histologically proved. the results were compared with those obtained at spiral ct and/or mri. seven distinct enhancement patterns were observed: ) rapid intense enhancement in the early contrastographic phases with microbubble entrapment in the late phase [ neuroendocrine tumors, metastases from hypervascular tumors, poorly differentiated carcinomas]; ) moderate enhancement in the early contrastographic phase, resulting hypoechoic in the late phase [ poorly differentiated carcinomas, acinar cell carcinoma, neuroendocrine tumors]; ) capsular enhancement in the earliest phases [ solid and papillary epithelial neoplasm; neuroendocrine tumor]; ) no enhancement [ ductal adenocarcinomas and neuroendocrine tumor]; ) progressive enhancement [ solid and papillary epithelial neoplasm]; ) "parenchymographic" enhancement [ inflammatory masses]; ) parietal nodules and septas enhancement [ cystic tumors] . results: ceus correctly characterized / ( %) solid pancreatic tumors. in particular all ( / ) the ductal adenocarcinomas were correctly diagnosed. small nodules and septas of pancreatic cystic tumors, not visible at conventional us, were detected at ceus. conclusions: ceus can demostrate macrocirculation and microcirculation of solid pancreatic masses and can improve the characterization of cystic pancreatic lesions. is dual-phase spiral ct adequate for the confirmation of resectability and preoperative staging of pancreatic carcinoma? s. mylona, l. thanos, a. pagonas, v. kalioras, s. lyra, n. batakis; athens/gr purpose: to present the value of dual-phase spiral ct for the confirmation of resectability and pre-operative staging of pancreatic carcinoma. materials and methods: in a period of years patients with pancreatic carcinoma underwent dual-phase spiral ct for preoperative staging. ct scans after iv administration of contrast material with an electronic injector were obtained in the arterial (scan delay = sec) and in the portal venous phase (scan delay = sec) under a protocol with a total volume of ml, flow rate ml/sec. we have correlated the ct findings with surgical-pathologo-anatomic findings. results: dual-phase spiral ct was positive for pancreatic carcinoma in patients ( . %). in patients it was false-positive ( . %). in ( . %) out of patients it showed hepatic metastases, in ( . %) out of patients it showed lymph node enlargement, in ( %) out of patients vascular invasion, and in ( . %) out of patients peritoneal metastases. the accuracy of the method was up to %. conclusion: dual-phase spiral ct is a safe, noninvasive, and accurate method to investigate pancreatic carcinoma and should be considered as the standard preoperative method for assessing lesion resectability. assessment of resectability of pancreatic head cancer with ct imaging g.g. karmazanovsky, v.a. kubyshkin, a.v. kotchatkov; moscow/ru purpose: to investigate the value of preoperative ct in assessment of resectability of pancreatic head cancer. methods and materials: eighty-nine patients ( males and females; mean age ) with pancreatic head adenocarcinoma were investigated with spiral ct with bolus intravenous contrast enhancement. all of the patients were operated on. whipple procedures were performed on patients and palliative operations were performed on patients. results: tumors of patients were considered unresectable. patients (group ) had tumors that were encircling superior mesenteric or portal veins ( pts), superior mesenteric ( pts) or hepatic arteries ( pts) completely. no fat layer was identifiable between the tumors and the vessels. patients (group ) had ct appearances of tumors that partially (less than / of the circumference and in less than mm) circumscribed the vessels. tumors of all group patients were not resectable with a negative margin. among group , four patients ( . %) had unresectable tumors; six patients ( . %) had tumors that were difficult to dissect from the vessels; patients ( . %) had no evidence of vascular involvement and in fact went through curative surgery. conclusion: the ct findings predicted correctly surgical findings in of unresectable tumors ( . %). when the tumor partially circumscribed the vessels ct was not to be relied upon in predicting whether or not the tumor was fixed against the vessels. contrast-specific ultrasound (cs-us) imaging of the spleen: a pictorial essay of traumatic and nontraumatic disorders a. nunziata , o. catalano , m. mattace raso , i. matarazzo , a. siani ; naples/it, pozzuoli/it learning objective: to illustrate the appearance of several splenic lesions as shown during real-time, contrast-specific, harmonic imaging. background: contrast-enhanced, low-mechanical index us is a new technique allowing continuous, real-time assessment of splenic abnormalities. in our institution we use the technology named contrast tuned imaging (esaote, italy) and we employ a second-generation, sulfur-exafluoride based, microbubble contrast agent (sonovue-bracco, italy). the contrast agent, at a volume of . or . ml, in injected through a peripheral vein and a g needle, using a three-way stopcock and a -ml normal saline flushing. imaging findings: a wide spectrum of splenic disorders is depicted: injury, spontaneous hematoma, abscess, capillary and cavernous hemangioma, lymphomatous infiltration, metastasis, splenomegaly, and accessory spleen. several potential pitfalls are also shown. conclusion: contrast-specific us is being used with increasing frequency in the evaluation of the spleen. this is a superficial organ, with an almost homogeneous echotexture and with a dense and persistent contrast-enhancement; these characteristics make the spleen an optimal organ to be studied with contrast-specific us. radiologists should be aware of the typical and atypical appearance of splenic disorders as shown at contrast-specific us imaging. the spleen: normal variants and pathologies (imaging review) s. vessal, a. anbarasu, s.b. rai, w. shatwell, r. ramachandra; birmingham/uk learning objectives: to familiarise with the normal anatomy of the spleen. to further demonstrate common variations and splenic pathologies encountered in clinical practice. background: the spleen is the largest single mass of lymphoid tissue seen in the body. we familiarise with its normal image appearance using ct, uss and mri. the pattern of contrast enhancement of the spleen during the arterial and venous phases in ct can mimic disease by forming pseudomasses. normal variants such as splenunculus, splenic clefts/lobulations, liver wrap-around, wandering spleen as well as congenital heterotaxic syndromes will be discussed. a spectrum of splenic pathologies are demonstrated and the list of differential diagnoses that should be considered when seeing splenomegaly, cystic lesions, solid lesions and splenic calcification. examples of splenic trauma -laceration, subcapsular and intraparencymal haematoma will be discussed and complications such as splenosis demonstrated. image findings: images of the spleen on plain radiography, ct, mri, uss and radionuclide imaging from our institution are demonstrated along with imaging protocols. conclusion: there are several normal variants of the spleen which should be readily recognised. congenital abnormalities of the spleen such as polysplenia are rare, this should not be misdiagnosed as splenosis. it is useful to assess the presence and extent of splenomegaly. further classification of parenchymal lesions into cystic or solid can be made. solid lesions can be further subclassified into those with calcification. this poster demonstrates some splenic pathologies, a clear list of differential diagnosis is essential in interpreting any splenic lesion. non-traumatic acute splenic lesions: role of ct f. garibaldi, y. hetmaniak, b. gallix, j.-m. bruel; montpellier/fr learning objectives: -to illustrate a pictorial review of various acute splenic pathologies of non traumatic origin. -to learn characteristic imaging features of spontaneous spleen rupture or splenic infarction. -understand the pivotal role of abdominal ct when acute splenic pathology is suspected. background: splenic pathology is rarely suspected in patients with acute pain of the left upper abdominal quadrant. ct imaging is a well established tool for splenic injury of traumatic origin but ct features of non traumatic acute splenic pathology are less known. the purpose of this exhibit is to review the main causes of non traumatic acute splenic lesions and to describe their specific ct patterns. b d e f a g procedures: material consisted of patients with acute non traumatic splenic pathology who underwent multiphase contrast enhanced ct examination of the abdomen. the medical report of these patients were reviewed. cases were categorized according to the presence of the main ct patterns we found: spontaneous rupture, ischemic lesion, abscess or pseudo cyst or complicated tumoral involvement. conclusion: helical ct, in association with patients history and biology results is accurate to characterize the severity and the causes of acute non traumatic splenic injury. the new ultrasound who-classification for diagnosis, staging and follow-up of patients with cystic echinococcosis (ce) w.p. hosch, g.w. kauffmann, t. junghanss; heidelberg/de learning objects: the new who-classification provides, for the first time, a standardized sonomorphological staging of echinococcal cysts. we demonstrate the clinical value of this classification with examples from our cohort of patients. specific signs supporting the diagnosis of ce, and criteria for assessing cyst viability are presented. this allows staging of cysts relevant for treatment decisions (surgery, percutaneous drainage (pair), albendazole or "watch&wait") and treatment monitoring. background: ultrasonography plays a central role for diagnosis and follow-up of abdominal ce due to problems regarding sensitivity and specificity of clinical symptoms and serological tests. this technique allows the staging of cysts with respect to the involution process (spontaneous and treatment induced). the treatment options of ce have broadened in recent years with percutaneous drainage (pair), medical treatment and "watch&wait" as preferable strategies over surgery for specific cyst stages. in a standardized classification has been published by who allowing inter-observer comparison of treatment decisions and follow-up. procedure details: patients with a follow-up of up to years have been seen in our referral centre for ce since . apart from patients with pulmonary lesions and patient with a spinal manifestation, all other patients had abdominal cysts ( hepatic, spleen, kidney, peritoneal). we evaluated the value of the who-classification for diagnosis, therapeutic decision making and follow-up. conclusion: on the basis of the who-classification ultrasonography is not only an excellent tool for the primary diagnosis of ce but also very valuable for clinical decision making and monitoring treatment response. the spectrum of manifestations of metastatic malignant melanoma c.s. ng, v. kundra, m.j. jacobson, j. szklaruk, d.g. bedi; houston, tx/us learning objectives: . to gain an appreciation of, and be alert in clinical practice to, the wide range of sites, both common and uncommon, of metastases from malignant melanoma, including the lymphatic, central nervous, and musculoskeletal systems, thorax, abdomen and pelvis. . to become familiar with the radiologic appearances of metastatic melanoma on ct, mr, and ultrasound. background: malignant melanoma is a tumor that is increasing in incidence throughout the world, with a widely varying prognosis and distinctly capricious behavior. if, and when, the tumor metastasizes it can spread in an expected manner; however, frequently both the timing and sites of dissemination can be entirely unpredictable. imaging findings: this exhibit will present the wide range of manifestations of metastatic melanoma throughout the body, including the lymphatic, central nervous, and musculoskeletal systems, chest, abdomen and pelvis, and soft tissues, as identified by the major cross-sectional modalities of ct, mr, and ultrasound. the hypervascular and hemorrhagic tendency of the tumor, and its typical mr signal characteristics, will be illustrated. the exhibit will demonstrate the typical sites of metastases, namely lymphatics, brain, lungs, and liver; but will also illustrate the wide spectrum of more unusual sites of dissemination, including meninges, pleura, pancreas, gallbladder, gastrointestinal tract, genitourinary tract, peritoneal cavity, skeletal muscle and bone. the illustrative examples will be correlated with the tnm staging system. conclusions: metastatic malignant melanoma has an extremely wide spectrum of manifestations. practicing radiologists should be alert to these manifestations. malignancies in the aids affected population other neoplasms such as cervical cancer, hodgkin's disease and others have been observed with an increased incidence, probably because of the longer survival of aids patients. the aim of our exhibit is to describe ct and mr features of aids related neoplasms. procedure details: we reviewed ctand mr findings of aids patients examined between - , amongst which demonstrated pathologically confirmed neoplasms. ct's were performed by using spiral (plus, plus , siemens, erlangen, germany), and multislice ct equipment (lightspeed ge medical systems, milwaukee, usa); mr examinations were performed by using a . unit (vision; siemens medical systems, erlangen, germany) . we demonstrated nhls, hodgkin's disease, ks, cervical cancers, leukaemias, testicular, larynx, lung, breast, esophagus, stomach, liver, kidney, and adrenal carcinomas, intrahepatic multinodular cholangiocarcinoma and stromal tumors of the gastrointestinal tract. / nhl showed extranodal involvement to the liver ( / ), brain ( / ), lung ( / ), pleura ( primary effusion lymphomas with lymphomatous cells in the pleural effusion and no identifiable tumor mass) and gastrointestinal tract ( / ). ks involved the gastrointestinal tract ( ), lung ( ), liver ( ), larynx ( ), muscle ( ) , adrenal gland ( ), spleen ( ), pancreas ( ) . conclusion: ct and mr proved useful in the evaluation of the variegate pathologic findings of aids related neoplasms. abdominal imaging of post transplant lymphoproliferative disorders (ptld) k. burney, i. lyburn, r. hopkins; cheltenham/uk learning objectives: this exhibit will review the pathogenesis, staging and abdominal imaging findings of post-transplant lymphoproliferative disorders (ptld) seen in cardiac, lung, renal and liver transplant organ recipients. background: post-transplant lymphoproliferative disorders (ptld) are a complication of immunosuppression in solid organ transplant recipients. we reviewed the imaging of patients with a histologically proven diagnosis of ptld treated at our sub-regional oncology unit over the past years. conclusion: ptld is estimated to occur in between - % of patients. clinical manifestations are variable ranging from focal disease with graft dysfunction to systemic illness. ptld may be unsuspected or more extensive than expected and imaging plays an important role in diagnosis, staging and follow-up. ct (and to a lesser extent us) is the imaging modality of choice. does clinical examination of polytrauma guide properly ct evaluation? a. kalai, y.k. maratos, t. loeb, o. clément, g. frija; paris/fr learning objectives: to know the new definition of polytrauma patient based on the risk factor. to know that a whole body scanner is indicated in polytrauma patient. to know the ct protocol in polytrauma. background: the evaluation of the polytrauma patient is still most of time based on regional ct oriented with the clinical finding. based on our experience in patients this exhibit purposes a systematic evaluation with whole body scanner. major findings and pitfalls are illustrated. procedure details: whole body scanner includes: axial head ct, cervical spine helical ct with sagittal and coronal recontructions, helical ct with contrast iv with an arterial phase on the thorax and portal phase an the abdomen and pelvis, sagittal reconstruction on the dorsolombar spine. the severity of the lesions after the clinical evaluation were compared to the iss (index severity score) after the whole-body scan. % of the patients had at least one missed lesion when compared to clinical assessment .the average iss of these patients was higher and there was a surmortality. conclusion: whole-body scanning is highly recommended for polytrauma victims in order to enable prompt and early treatment of lesions which might have been missed at the initial clinical evaluation. radiological exploration of the embalmed cadaver of eva peron c. gotta, a. buzzi; buenos aires/ar learning objectives: to exhibit for the first time a medical document of eva perón's embalmed cadaver. background: eva perón was juan domingo peron's wife (he was president in argentina between argentina between and argentina between , and between argentina between and . for her political and social action she is known worldwide. she died of a cervix cancer in . when she died, she weighed less than kg, so many people doubt that her embalmed cadaver (small and consumed) belonged to her. the cadaver was embalmed by dr pedro ara, professor of anatomy at the school of medicine of the university of cordoba. he was born in zaragoza, spain, and he was established in argentina in the decade of . professor ara carried out excellent work with eva peron's cadaver. contrary to the classical technique, eva peron's embalmed body conserves its viscera. imaging findings: when the régime was overthrown in eva peron's cadaver was deposited in the general confederation of work ("confederacion general del trabajo", cgt). the new authorities doubted of the authenticity of the cadaver. radiological exams were made by dr guido gotta (father of one of the authors), who confirmed that the body corresponded to a human being, and that there was evidence of neoplasia (abdominal nodules, bone metastasis). conclusions: besides its medical use, thanks to its capacity to examine the interior of bodies, since their discovery x-rays were used for other purposes. in this case, they were used to determine the authenticity of eva peron's embalmed cadaver. imaging of complications of drug abuse s. van background: the material is culled from our databank of the emergency department of our institution. the age of the patients in our series ranged between and -years-old. imaging findings: complications of drug abuse in the drug addict will be classified according to their pathogenic mechanism or by their way of administration. pathologically, complications are usually due to their vasoconstrictive and thrombogenic effect on different organs, including the brain (stroke), heart (myocardial ischemia), the gastro-intestinal system (ischemic colitis), the nose (nasal septum perforation due to cocaine snorting). a direct toxic effect of drug metabolites is another pathogenic mechanism resulting in tissue necrosis, as typically seen in liver cell necrosis due to ecstacy. the route of administration (intravenously, orally, inhalation or smoking) may also reflect the radiological presentation. local abscess formation, septic thrombophlebitis, septic pulmonary emboli or bloodborn infections result from intravenous access, whereas inhalation and smoking may result in pneumothorax, pneumomediastinum and epidural pneumatosis. indirect complications, such as an increased risk for traffic accidents can be attributed to the additive effect of a cocktail of drugs and/or alcohol. complications related to smuggling are due to accidental rupture of packed drugs in the gastrointestinal lumen. the radiologist should be aware of the possible causal relationship with drug abuse, especially when those complications are encountered in a young population. abdominal background: there is a broad spectrum of neurogenic tumors that involve the abdomen. in this exhibit, we will describe the variable radiologic findings of abdominal neurogenic tumors. this study included patients with abdominal neurogenic tumors which were confirmed histologically by surgical resection (n = ) or us guided biopsy (n = ). two radiologists reviewed radiologic findings retrospectively and correlated with pathologic results. imaging findings: we categorized them into groups by cell of origin; nerve sheath origin (schwannoma in , neurofibroma in , plexiform neurofibromatosis in , malignant peripheral nerve sheath tumor in ), paraganglionic cell origin (paraganglioma in , pheochromocytoma in ), and ganglion cell origin (ganglioneuroma in , ganglioneurofibroma in , ganglioneuroblastoma in , neuroblastoma in ). conclusion: although abdominal neurogenic tumors show a broad spectrum, some neurogenic tumors revealed characteristic radiologic findings and correlated well with pathologic findings. familiarity with various neurogenic tumors in the abdomen is helpful in the approach of the diagnosis. purpose: to illustrate the broad spectrum of imaging findings (ct, us, urography and barium contrast studies) of patients with proven abdominal tuberculosis. we review between january and july , the typical and atypical imaging findings of patients that had a final diagnosis of genitourinary ( ), adrenal ( ), bowel ( ), peritoneal ( ), and hepatosplenic ( ) tuberculosis. results: most patients had been at increased risk because of drug abuse, alcoholism, aids and steroid therapy. radiological findings included low density lymph nodes, splenomegaly, hepatomegaly, intrasplenic and intrahepatic masses, ascities, diffusely thickened and enhanced peritoneum, mottled low density masses in the omentum, pleural effusion, thickening of the bowel, adrenal enlargement, atrophy and calcification, fallopian tube fibrosis, uterine atrophy and adhesions, ureteral and bladder fibrosis, and different patterns of renal hydronephrosis and calcification. conclusion: patients with aids had more severe form of involvement than those who did not have aids. sonography was the only imaging modality to demostrate septations within the tuberculous ascites, but showed the fewest morphologic details in renal tuberculosis. ct is the imaging modality that best determined the extent of intrabdominal tuberculosis. recognition of these manifestations should help optimize the correct diagnosis and management of tuberculosis in order to obtain a favorable outcome, biopsy is mandatory in almost all cases. predictive to develop a predictive model for the presence of esophageal varices (ev) in patients with hepatic cirrhosis (hc). this model would limit the endoscopic screening to the group of patients with high risk of bleeding from ev. methods and materials: consecutive patients with hc were included in this prospective study ( men, women; mean age . ). physical and laboratory examinations, upper gastrointestinal endoscopy and doppler ultrasonography were recorded. patients were divided in two groups: ) no ev or small ev, ) medium or large ev. the distribution of clinical, biochemical, and doppler ultrasonographic variables were compared in each group. the u statistic of mann-whitney was performed for the quantitative variables, whereas the chi-square or the fisher's exact tests were used for the qualitative ones. variables were also included in a multivariate stepwise logistic regression model. a roc-analysis was performed. results: in the stepwise logistic regression, presence of medium or large ev was independently predicted by splenomegaly, decreased platelet count, hcv infection and a decrease of the maximum portal flow velocity (mpv). the discriminating ability of the prediction rule was high, with an area under the roc curve of . ( % ci: . - . ). conclusion: patients with hc should be screened by upper gastrointestinal endoscopy only if splenomegaly, low platelet count, infection by hcv and decreased mpv are present, since these parameters confidently predict the existence of medium or large ev. premier experience of multiphasic contrast material-enhanced dynamic study on . tesla magnetic resonance (mr) imaging t.-j. hsieh, g.-c. liu; kaohsiung/tw purpose: to evaluate the accuracy and sensitivity of a dynamic contrast material-enhanced three-dimensional ( d) volumetric breath-hold hepatic magnetic resonance (mr) imaging examination on a . tesla machine. methods and materials: . tesla mr imaging with serial multiphasic contrast material-enhanced dynamic study was performed in patients with hepatocellular carcinoma (hcc). all patients had pathologic comfirmation by fine needle biopsy and followed angiographies were performed in . months. each test result was interpreted independently by two radiologists. separate reading sessions were performed for images from the multi-phases. sensitivity and positive predictive values were calculated for each reading session. results: one hundred twenty-nine early-enhancing lesions were detected in the patients on the . tesla mr images. the followed angiographies showed hypervascular tumor stains. all the lesions showed in the mr images were identified in the angiographies. the breath-hold dynamic examination on . telsa showed a overall sensitivity of . %. conclusion: multiphasic contrast material-enhanced dynamic study on . tesla magnetic resonance (mr) imaging . tesla mr imaging is insensitive for the diagnosis of hccs. role the insulinomas are rare functional pancreatic neuroendocrine tumours. the most common clinical presentations include hypoglycaemia (< . mmol/l), confusion, and loss of consciousness. diagnosis is difficult, and performed by computed tomography, magnetic resonance or selective angiography of the pancreatic arteries by digital subtraction angiography (dsa). the aim of the study was to analyse head-to-head the diagnostic value of pancreatic dsa, computed tomography and magnetic resonance in patients ( female, male; ± years) with insulinoma. the diagnosis was established by pathohistology after the surgical treatment in all patients. the tumours were localised in the pancreatic body in / patients ( %), in the pancreatic tail in / patients ( %) and in / patients ( %) purpose: to estimate variants in the anatomic structure of the gallbladder, the biliary and pancreatic ducts and to develop a technique of research. material and methods: patients underwent complex mri using a . t unit. t w haste, t w turboflash, including fs, and mrcp (single-slice turbose and multi-slice haste in different orientations) were acquired. patients also examined with ercp. results: in % of patients the merger of the hepatic lobar bile ducts was extrahepatic. % revealed an additional right hepatic duct, more than half running into the common bile duct (cbd) low. the low fusion of the cystic duct and cbd was revealed in % of the patients, and its left arrangement in %. anomalies in the form of the gallbladder are revealed in % and additional pancreatic duct in % of patients. in % patients the main pancreatic duct and cbd had a common ampoule, in more than % of cases they enter the duodenum parallel, in % cases separately. it is expedient to study the mutual relationships of ducts, parenchyma and vessels with application of t -w haste. general submission about bile and pancreatic ducts and gallbladder allows receiving single-slice tur-bose. for better analysis of details of anatomic structure it is necessary to study of source images multi-slice haste in different orientations. the results of research especially are useful for planning of operative treatment. conclusions: complex mri, especially reception of t -w images and realisation of mrcp, is an excellent tool for revealing variants in anatomic structure of the gallbladder and ductal system. the clinical utility of diffusion imaging out of the central nervous system y. murakami , k. imoto , n. aito , t. sakamoto , m. yamasaki , a. furukawa , r. ito , k. murata ; kohka/jp, shiga/jp the clinical utility of diffusion imaging out of the central nervous system is not yet clear. the purpose of this prospective study is to determine the role and the clinical usefulness of diffusion-weighted mr imaging combined with conventional mr imaging for the detection of visceral disease without of the central nervous system. material and methods: one hundred and thirty-four cases who were referred to our hospital for the examination of visceral disease without the central nervous system (including cases with neoplasms and cases with inflammatory disease, upper abdomen; , pelvis; , other organ; ) were investigated. mr imaging ( . t) was performed using a diffusion-weighted single-shot spin-echo echoplanar sequence, t -weighted fast spin-echo sequence, and t -weighted spin-echo sequence. an experienced reviewer evaluated the diffusion-weighted mr images for the presence of a high-signal-intensity lesion and compared with other mr sequences. imaging findings were correlated with findings from histological specimen in patients and with findings from clinical follow-up examination in other patients. results: diffusion-weighted mr imaging depicted high signal intensity lesions, including cases with malignancy and five cases with inflammation, and a case of castleman's disease. in three patients with lymphomas, high signal intensity lesions reflected the activity of the disease process. there was no high signal intensity lesion in cases with eight adnexal diseases. conclusion: diffusion-weighted mr imaging out of the central nervous system may possibly be useful for the extent or the activity of malignant or inflammatory disease. evaluation of computed tomography for assessment in lipodystrophy syndrome j.a.g.s. gallego, f.m.a.i. ardoy, s.p.u. padilla, f.g.r. gutierrez; elche/es purpose: lipodystrophy syndrome (peripheral fat loss and/or visceral fat accumulation) is a main problem in hiv-patients treated with antiretroviral therapy. the diagnosis is based on physical examination and/or standardized questionaires so there is a need for quantitative diagnostic tools. the aim of this study is to evaluate computed tomography (ct) to measure fat distribution in hiv patients. methods and materials: hiv-patients ( men) were included. lipodystrophy was diagnosed clinically on . subcutaneous limb adipose tissue area and their percentage were measured by a single slice at mid thigh and mid arm by ct. the subcutaneous (sat), visceral (vat), and total (tat) abdominal adipose tissue as b d e f a g well as the vat/tat, sat/tat and vat/sat ratios were calculated by a single slice at umbilical level. results: vat/tat and vat/sat ratios were significantly greater in lipodystrophic than in non-lipodystrophic patients: . vs . , p < . and . vs . , p < . respectively in men. . vs . p < . and . vs . p < . in female patients. sat/tat and mid thigh fat tissue percentage were significantly lower in lipodystrophic patients: . vs . p < . and . vs . p < . respectively in men. . vs . p < . and . vs . p < . in female patients. no significant differences were found at mid arm. a vat/sat ratio > . for men and > . for women had a sensitivity of % and % respectively and a specificity of %, to diagnose lipodystrophy syndrome. conclusion: computed tomography may be a useful technique to quantify lipodystrophy in hiv-infected patients. withdrawn by authors ultrasonographic assessment of body fat distribution in type ii diabetes mellitus of insulin resistant type and its relation to anthropometric measurements n. previous studies have shown that in subjects with type ii diabetes mellitus of insulin resistant type there is a relation between cardiovascular diseases and obesity, insulin resistance and body fat distribution. in these patients body fat distribution assessed with dexa and antrophometric measurements were correlated with ultrasonographic fat assessments. materials and methods: subjects ( male and female with mean age of . ± . ) in whom type ii diabetes mellitus of insulin resistant type was diagnosed with homa (homeostasis model assessment) were enrolled in the study. their weights, heights, abdominal diameters, and gluteal diameters were recorded. body mass index (bmi, kg/m²) and the ratio of abdominal diameter to gluteal diameter (a/g) were calculated. subcutaneous (fatsc), preperitoneal (fatpp), and visceral (fatv) fat thicknesses were ultrasonographically assessed. results: there was a significant correlation between bmi and fatsc or fatv (p < . ); and between total fat ratio and fatsc and fatv (p < . and p < . , respectively). there was no relation between a/g and fatsc, fatpp and fatv. conclusion: ultrasonographically assessed subcutaneous and visceral fat thicknesses in type ii diabetes mellitus patients of insulin resistant type may be used as prognostic factors of cardiovascular diseases. withdrawn by authors c- mri of the upper abdomen using a new free-breathing navigator triggered t -weighted tse-sequence (pace-tse) c. klessen, p. asbach, r. kirsch, b. hamm, m. taupitz; berlin/de purpose: to evaluate image quality of a new free-breathing navigator triggered t -tse sequence (pace = prospective acquisition correction) for magnetic resonance imaging of the upper abdomen in comparison to a established standard breath-hold t -weighted sequence. materials and methods: prospective evaluation of consecutive patients with various pathologies referred to our clinic for mri of the upper abdomen. all patients were examined at . t (siemens magnetom quantum) using the following sequences: pace-tse (work-in-progress sequence, x matrix, fov mm, axial slice orientation, tr ms, te ms, turbo factor , slices, mm slice thickness, n = excitations), breath-hold haste sequence ( x matrix, axial slice orientation, tr ∞, te ms, slices, mm slice thickness, n = excitation). three independent abdominal mri experienced radiologists reviewed all images and evaluated motion artifacts, liver-spleen contrast, depiction of intrahepatic vessels, depiction of the pancreas and the adrenal glands and overall image quality on a -point scale. in addition, to directly evaluate the influence of the respiratory trigger technique, in patients the t -tse sequence was repeated with the respiratory trigger function switched off. results: mean examination time of the pace-tse was . minutes. the depiction of anatomical details and contrast was significantly better (p < . ) using the pace-tse sequence compared to the standard haste sequence. the pace-t -tse sequence has the potential to significantly im-prove recognition of anatomical details and contrast compared to standard breathhold haste imaging. reactive lymph node hyperplasia: a diagnostic problem in the staging of hodgkin's disease (hd) l. ilic-todoric, b. lukac; belgrade/yu purpose: therapeutic approach to hd requires determination of the disease extent to supra/infradiaphragmatic lymph nodes (ln) . a problem appears when ln are of borderline size or only slightly enlarged. should such a finding on ct be considered as reactive hyperplasia or a pathological finding? the purpose of this report is to solve this dilemma. methods and materials: infradiaphragmatic spiral ct scan was performed in patients with histologically confirmed supradiaphragmatic hd. bipedal lymphography represented the gold standard for final staging. taking reactive hyperplasia into consideration, we estimated and statistically analysed ct's ability to differentiate benign and malignant conditions, and its value for staging. results: lymphography showed infradiaphragmatic disease in % of patients, % of whom had enlarged ln, while in % ln were of normal size or smaller. of the total number of patients, reactive hyperplasia and lymphographically normal findings were found in % and % of patients, respectively. ct detected enlargement in % of patients, and in % of these this finding concurred with the lymphographic one. ct could neither detect affected normal/reduced ln, nor differentiate reactive from malignant hyperplasia. postlymphographic restaging of the disease showed that % of patients would be understaged and % overstaged on the basis of ct finding only. conclusion: reactive hyperplasia represents a risk of up/downstaging if staging relies on ct only. errors can be partially assigned to the inadequate interpretation of the ct findings, which cannot be taken for granted when ln are of borderline sizes. in such cases additional diagnostic procedures are necessary. purpose: to compare the diagnostic accuracy of mr (magnetic resonance) images with msct (multislice ct) for preoperative t-staging in patients suffering from cardiac cancer. materials and methods: mr and msct were performed in cases of cardiac cancer diagnosed by biopsy prior to operation. mr and msct scans were performed on two different days. mr sequences included fset w, fset w, fse t w with fat suppression and dynamic enhanced fspgr with fat suppression; msct was applied with dynamic triphasic contrast enhancement. all these findings were prospectively analyzed by two doctors separately and correlated with the surgery pathological findings. statistic work was performed with spss. results: according to histopathologic staging, the accuracy for t -staging detected with mr and msct were % and % respectively, % and % for t staging, % and % for t -staging, % and % for t -staging. compared with msct, dynamic enhanced and delayed mr with fat suppression was superior for revealing the involvement of esophagus and aorta, early stage of invasiveness and providing more evidence in t from t or t from t staging (p < . ). among these mr plain scan sequences, t w with fat suppression was outstanding in depicting the gross features of the tumor, presence of ulceration, and adjacent lymph node swelling. diagnostic accuracy determined by roc analysis was marginally higher with mr scan than with msct scan in t-staging of cardiac cancer. conclusion: mr is superior in t-staging of cardiac cancer and can be used to optimize the therapeutic strategy, thus avoiding unnecessary operation. multidetector ct and virtual endoscopy of the esophagus s. mazzeo, d. caramella, e. neri, p. giusti, c. cappelli, r. bertini, a. belcari, c. bartolozzi; pisa/it purpose: to assess the diagnostic capabilities of multidetector ct in various esophageal pathological conditions. methods and materials: thirty-three patients underwent a multidetector ct study after esophageal distension by means of effervescent powder administered after induction of hypotonia. all acquired images were post-processed with d and d software tools. the ct data was compared with the results of conventional radi-ology ( ), endoscopy ( ), or surgery ( ) . follow-up ranged between and months. results: esophageal distension in the upper and middle third was classified as "good" in / cases ( %); in the lower third, esophageal distension was "good" in / cases ( %). final diagnoses were: leiomyoma ( ), squamocellular carcinoma ( ), adenocarcinoma ( ), esophageal infiltration by thyroid cancer ( ), benign polyposis ( ), chronic esophagitis ( ), post-sclerotherapy stenosis ( ) , no abnormalities ( ). when good distension was achieved, the thickness of unaffected esophageal wall was < mm (range between . and . mm, mean . mm). pathological wall thickening was observed in / cases ( %) with values ranging between . and mm (mean . mm). spiral ct demonstrated true positive cases and true negative cases. there were false negative cases and false positive case. sensitivity was %, specificity %, diagnostic accuracy %, positive predictive value %, negative predictive value %. conclusions: evaluation of the esophagus with multidetector ct proved to be a promising and easy to use technique, allowing panoramic exploration, virtual endoluminal visualization, accurate longitudinal and axial evaluation, and simultaneous evaluation of t and n parameters. (ibd) . to describe the technique of barium tagged dark-lumen mrc. to outline the advantages, disadvantages and limits of the method. background: conventional colonoscopy (cc) is the most widely used method for the assessment of the extension and the activity of ibd. however, cc is an invasive technique and requires long-lasting bowel preparation. furthermore, not infrequently the examination of the entire colon and terminal ileum wouldn't be possible due to severe pain or fecal residue. these disadvantages are eliminated with barium tagged dark-lumen mrc which makes this examination more tolerable and acceptable by patients. imaging findings: ten patients who present with symptoms of ibd underwent cc first and subsequently mrc. for fecal tagging, barium sulphate-containing contrast agent is given with meals, beginning hours before the examination. for mrc the colon was filled with ml of diluted barium. after intravenous administration of . mmol/kg gd-dtpa, coronal t -weighted three-dimensional gradient-echo sequence is performed. additional fat-saturated axial two dimensional gradient-echo and coronal true-fisp sequences are obtained. colon segments are interpreted seperately (rectum, descending, transverse, ascending colon, caecum) when assesing the extent of the disease. bowel wall thickening and congestion of marginal vascularity are considered as signs of the disease. out of sixty segments, of them had colonoscopic correlation. of these in ( %) the extent of disease correlated with cc. non-correlation of findings of mrc and cc was detected in ( %) patients. conclusion: barium tagged dark lumen mrc can be used for the assesment of the extent of ibd. evaluation of ct gastric virtual endoscope (ve) findings: comparison with real gastric fiberscope (gf) lesions k. inamoto, k. kouzai, k. hamada; osaka/jp learning objectives: to check ve findings compared with gf lesions in cases. to learn about images of ve and to consider possibilities to use ve clinically. background: gf is an invasive examination for patients. if ve can be used for checking pathologies of gastric diseases it will be beneficial to detect malignant changes of the stomach in their early stage. procedure details: md-ct images were obtained on the same day as gf with somaton sensation , siemens, erlangen, germany. thin slice ct images with mm thickness were reconstructed to ve images by surface rendering and volume rendering with advantage workstation . _ . with volume analysis voxtool . . e, ge, milwaukee, wi.usa. results indicated that ve images succeeded in showing subtle alteration of mucosal folds. gastric cancer, polyp, ulcer, erosion and gastritis were clearly visualized. by comparison studies between ve and gf, a sensitivity . %, specificity . %, positive predictive value . %, negative predictive value . % and accuracy . % were calculated. conclusion: d md-ct examination of the stomach is noninvasive except for radiation exposure. it will be expected as a new technique of the stomach examinations. gastrointestinal stromal tumor: current concepts and imaging characteristics j.h. lee, k. kim, c. park, w. jeong, j. lee, e. kang, i. cha, h. seol; seoul/kr learning objects: to provide an in-depth review of gastrointestinal stromal tumors (gist's) with their epidemiology, histopathology, clinical manifestations and the most up-to-date therapy. to describe radiologic features of gist's. to discuss differential diagnosis of gist's throughout the abdomen. background: gastrointestinal stromal tumors (gist's) are unique neoplasms that occur throughout the gastrointestinal tract, mesentery, omentum, and retroperitoneum. they are the most common mesenchymal neoplasm of the gastroin-testinal tract and are defined by their expression of kit (cd ), a tyrosine kinase growth factor receptor. the expression of kit is important to distinguish gist's from other mesenchymal neoplasms such as leiomyomas, leiomyosarcomas, schwannomas, and neurofibromas and to determine the appropriateness of kit-inhibitor therapy. imaging features of gist's vary depending on tumor size and organ of origin. since most gist's arise within the muscle layer of the gastrointestinal tract, they most commonly have an exophytic growth pattern and manifest as dominant masses outside the organ of origin. procedure details: the purpose of this exhibit is to provide an in-depth review of gist's with their epidemiology, histopathology, clinical menifestation and differential diagnosis. this exhibit will also reflect our experience in the radiologic evaluation of patients with gist's, with emphasis on the typical findings present on small bowel series, ultrasonography and ct (including d images using multidetector ct). examples of unusual gist's and pathologic correlation as well as the most up-to-date therapy will be included. conclusion: after interacting with this exhibit the radiologist will have an enhanced understanding of gist's including histopathology and radiologic features. imaging of jejunal and ileal primary tumors with pathologic correlation b. rodríguez-vigil, m. lamas, t. berrocal, j. fernández, v. tarín, a. alvarez; madrid/es learning objectives: to illustrate the spectrum of usual and unusual primary neoplasms involving the jejunum and ileum. to evaluate the efficacy of barium studies, us, ct and mr imaging in the management of these tumors. to understand the radiologic findings on the basis of pathologic correlation. background: preoperative diagnosis of jejunal and ileal neoplasms can be a challenge for both clinicians and radiologists. symptoms are nonspecific and endoscopy is commonly unsatisfactory. since early diagnosis is crucial for prompt therapy, imaging plays an essential role. tumors develop in all histologic components of the small intestine including epithelial cells, lymphoid tissues, lymphatics, vessels, nerves, and muscle. imaging findings: we retrospectively reviewed the imaging findings of jejunal and ileal neoplasms from our digestive pathology database. findings were correlated with pathology in all cases. specific neoplasms addressed include benign (adenoma, leiomyoma, lipoma, familial polyposis, hemangioma, lymphangioma and fibroma); and malignant neoplasms (adenocarcinoma, carcinoid tumor, lymphoma, leiomyosarcoma, direct extension to the small bowel from extraintestinal tumors, and metastasic lesions). enteroclysis is the primary and most effective radiologic modality in the evaluation of these neoplasms. ct should be the complementary radiologic modality and used for staging. mri may help in specific cases. pitfalls, diagnostic difficulties and differential diagnoses are emphasised. conclusions: evaluation of patients with small bowel neoplasms frequently requires multiple imaging modalities for diagnosis and treatment planning. because of the characteristic imaging appearances of many of these tumors, this exhibit will help the radiologist in training to better understand and recognise jejunal and ileal neoplasms. imaging findings of sigmoid diverticulitis: a pictorial essay of anatomy, pathology, differential diagnosis and radiologic treatment options m.c. freund, j. bodner, e.m. gassner, m. rieger, a. gschwendtner, w.r. jaschke; innsbruck/at learning objectives: to understand the anatomy and pathology of sigmoid diverticula and of the mesosigmoid. to be familiar with the typical findings of different imaging modalities in sigmoid diverticulitis and its complications and differential diagnosis. to be familiar with percutaneous and endovascular radiologic treatment options including abcess drainage and embolization for diverticular bleeding. background: sigmoid diverticulosis and diverticulitis represents a commonly encountered disease in western countries. an exact diagnosis is a prerequisite for further therapy. imaging findings: different imaging modalities are proposed for detection of self-limiting or complicated sigmoid diverticulitis e.g. abdominal radiography, contrast enema, ultrasound and even catheter angiography. during the last years ct has evolved to be a primary diagnostic imaging modality in patients with left lower abdominal pain. this pictorial essay will demonstrate the relevant anatomy of the sigmoid, mesosigmoid, and vascular supply as well as the typical pathology of the diverticula and its inflammatory complications including diverticulitis, peridiverticulitis, perforation, contained abcess in the mesosigmoid or rarely free intraperitoneal perforation with peritonitis, as well as fistula formation, obstruc- the learning objectives: to depict the ct imaging spectrum of the faeces sign, which is a consequence of small bowel occlusion, and to illustrate its causes. background: abdominal ct scan has been shown to be the most valuable technique, in confirming the diagnosis of small bowel occlusion and to depict the site, level and cause of occlusion. very few studies have focused on the contents of the bowel. particulate faeces-like material mixed with gas bubbles within the lumen of a dilated small bowel loop is always a pathological condition. it is the result of a delayed intestinal transit. to access prevalence, characteristics of this ct sign, and differential diagnosis, we have reviewed ct scans of small bowel occlusion over a period of two years. imaging findings: our analysis suggests that the small bowel faeces sign is probably more frequent than the previous reported studies, in demonstrating cases of small bowel faeces sign mainly observed in the ileal loops, and pointing to the site of occlusion. faeces sign appeared as tubular gas bubbles mixed with particulate matter with no capsule in dilated segments of small bowel loop, due to adhesions, closed loop, and tumours (adenocarcinoma, carcinoid). differential diagnosis of two phytobezoars is also illustrated and discussed. conclusion: small bowel faeces sign may not be confused with colonic segments leading to a failure to recognize the exact level of obstruction. moreover, it represents a sentinel sign in determining the site of occlusion and consequently the cause of the obstruction. imaging appearances and predictors of disease response in metastatic gastrointestinal stromal tumours (gist) treated with imatinib s. cox, b. lanka, m.b. taylor; manchester/uk learning objectives: to evaluate changes in radiological appearances in patients with metastatic gist treated with imatinib. to highlight any specific imaging features that can be used to predict disease relapse. background: imatinib (glivec, sti- ) is a kit tyrosine-kinase inhibitor drug, recently developed and found to be effective in the treatment of metastatic gist. we reviewed the pre-and post-treatment imaging findings on ct in ten patients. the duration of treatment varied from two to forty one months. the pre-treatment, eight and sixteen weeks scans were reviewed, along with the scans at the time of any relapse. the sites of metastases, size of lesions and cystic change were assessed. imaging findings: metastases were present in the liver and peritoneum in seven patients each; mesentery and retroperitoneum in four and two patients respectively; splenic, renal and subcutaneous in one patient each. one patient had progressive disease at eight weeks. nine patients responded to treatment. the maximum reduction in size of the metastasis was at eight weeks. most metastases underwent cystic change with treatment, particularly in the liver and peritoneum. two patients are known to have relapsed at fourteen and fifteen months. in both cases, cystic metastases developed more solid components prior to disease progression as indicated by an increase in the tumour volume. conclusion: ninety percent of the patients responded to treatment. cystic change in the liver and peritoneal metastases correlates with disease response to imatinib. an increase in solid components may be a useful predictor of disease relapse. ct appearances of neoplasms of the small bowel as a cause of obstruction s. sadiq, d. markham; swansea/uk learning objectives: this poster presents a pictorial review of the ct appearances of primary and secondary tumours of the small bowel in patients presenting with obstruction, including neoplasms that are the lead point of an intussusception. background: patients presenting with small bowel obstruction in two district general hospitals over the last twelve months and who were subsequently investigated by ct were selected. the imaging features of those with a neoplastic aetiology were reviewed. image findings: the imaging reflects recent studies examining the incidence of primary small bowel tumours. adenocarcinoma, non-hodgkins lymphoma, carcinoid and leiomyosarcoma comprise the majority. secondary tumour deposits also lead to small bowel obstruction. we demonstrate those that metastasize intraperitoneally (such as ovarian carcinoma), haematogenously (such as melanoma), or by local tumour extension (such as liposarcoma and bladder carcinoma). conclusion: it is well established that ct is a valuable diagnostic procedure in patients with acute small bowel obstruction. it is not only useful in distinguishing obstruction from ileus, but frequently establishes the cause of obstruction. small bowel neoplasms are rare but have a high mortality since tumour-related symptoms occur late and are non-specific. endoscopy is not feasible in most cases, as enteroscopy is limited to specialist centres. small bowel contrast studies do not reach the high level of accuracy obtained in the evaluation of the upper and lower gastrointestinal tract. ct not only allows tumour detection, but demonstrates possible complications and offers the possibility of pre-operative staging in the acute or elective situation. ct in adult intussusception: radiologic-pathologic correlation c. triantopoulou, p. maniatis, i. siafas, n. giannakou, c. avgerinos, c. dervenis, j. papailiou; athens/gr learning objectives: review the ct characteristics of bowel intussusception in adults through a wide variety of cases. emphasize the ability of ct imaging in narrowing the diagnostic possibilities and defining the cause of intussusception. stress the need for familiarization with the different aspects of this rare entity. background: intussusception is a relatively common cause of intestinal obstruction in children but is a rare clinical entity in adults. however, there is a lead point in % of adult cases. cases of adult intussusception were retrospectively reviewed. all ct examinations were conducted on a spiral unit with administration of both oral and intravenous contrast agent, using slice thickness of - mm anda pitch of . site, level, cause and degree of obstruction as well as signs of threatened bowel viability were evaluated and correlated with surgical findings and pathology examination. imaging findings: cases of ileocolic intussusception and of ileoileal were revealed. in patients findings included: cases of polypoid lesions, malignant neoplasms, lipoma, inflammatory diseases and in adhesions due to preceding surgery. in the other three cases no underlying pathology was proven so they were characterized as idiopathic conditions. all neoplastic lesions were correctly depicted before surgery while in the case of lipoma a specific diagnosis was made. ct is a powerful tool in adult intussusception, providing valuable information regarding the involved enteric segments, the underlying pathology and possible local complications, thus assisting in preoperative planning. diagnosis of perforation of stomach or duodenum on multislice computed tomography j.-i. nishimura, t. ohkoshi, y. yamamoto, t. inoue; yokohama/jp learning objectives: a review to determine the variety and relative conspicuity of findings in patients with perforation of the stomach or duodenum. background: multislice computed tomography (ct) gives us detailed information as thin-slice sagittal, coronal, and -dimensional images rapidly. a small volume of free air can be detected, and the perforation holes were predicted in some cases. during a -year period patients with perforation of the stomach or duodenum underwent preoperative ct scans. there were men and women averaging . ± . ( to ) years old. all patients underwent to surgical treatment, and all sites of perforation were confirmed. imaging findings: levels of perforation were the antrum of stomach (n = ), body of stomach (n = ), duodenal bulb (n = ), and descending limb of duodenum (n = ). ct images showed local extraluminal gas near the perforation sites in patients ( %), local ascites near the perforation sites in patients ( %), edematous wall of perforation sites in patient ( %), dirty increased density in the fat tissue in patients ( %), and a perforation hole in patients ( %). diffuse extraluminal gas and ascites were showed in , and patients respectively. in of patients ( %), we could predict the level of perforation. conclusion: multislice ct is a valuable method in the diagnosis of perforation in stomach or duodenum. the diagnosis can be established rapidly with high sensitivity. defecographic imaging of anorectal sphincter dyssynergia syndromes: our experience in subjects a. nunziata , a. salzano , p. de feo , a. de rosa , f. de rosa , m. covello ; naples/it, frattamaggiore/it, napoli/it learning objective: anorectal sphincter dysfunction can be responsible for evacuation difficulties and constipation; in addition, pelvic floor disorders can be associated. by using defecography associated with videoproctography, the evacuation time and the sphincters' opening time can be assessed, obtaining further information about the physiopathology of rectal empting and anal sphincter function. the aim of this study is to have functional radiological parameters of anal activity to detect anorectal sphincter dyssynergia syndrome. background: on a consecutive series of patients suffering from constipation we assessed by defecography combined with videoproctography cases of sphincter dyssynergia syndrome ( males and females with mean age of years, range of - years). all patients underwent clinical examination and endoscopy; patients were investigated by anorectal manometry. imaging findings: in all patients defecography with videoproctography provided a sphinter opening delay > s (normal values: - s) and increased evacuation time > s (normal values: - s). manometry revealed anal hypertonia in cases. conclusion: defecography associated with videoproctography is an accurate, simple and non-invasive method to approach anosphincteral pathology, permtting study of this particular type of terminal constipation, which is difficult to demonstrate using other techniques. background: gist are rare mesenchymal tumors of the abdomen, for which an effective, molecular-targeted therapy with imatinib mesylate has been recently developed. imaging findings: pts with advanced gist ( / with liver lesions and / with peritoneal involvement) undergoing therapy with imatinib mesylate. all pts had a baseline mr, and then at , , , months during treatment. pts responsive to therapy ( / ) showed: a) tumor decrease in size (with an in-crease in tumor volume at months from treatment start in some cases ( %) due to necrosis or bleeding): b) hypointensity of the lesions on t w images (lesion was hyperintense in rare case due to bleeding) and hyperintensity of the lesions on t w images (correlating with the amount of degenerative tissue or necrosis): c) hypovascularization of the lesions on contrast-enhanced t w images in comparison to pre-treatment assessment, due to the presence of degenerative tissue or necrosis: e) evidence of peritoneal fluid in all pts at the first months, reabsorbed in the following months. conclusions: mri is useful to identify tumor response to imatinib mesylate in advanced gist as from the early months of therapy with the following indicators of treatment activity: a) size of lesions; b) signal intensity; c) vascularization; d) amount of degenerative tissue or necrosis; e) presence of peritoneal fluid. crohn's disease: spectrum of findings on helical contrast enhanced ct enterography a.j. madureira, r. cunha, p. varzim, f. magro, i. ramos; porto/pt learning objectives: to illustrate the spectrum of imaging findings of smallbowel crohn's disease at contrast enhanced spiral ct after oral hyperhydratation with isotonic solution (ct enterography). background: spiral ct has become one of the most valuable methods in the assessment of parietal inflammatory changes and extraluminal involvement in small-bowel crohn's disease. the accuracy of this technique depends on the presence of well distended bowel loops. procedure details: after oral hyperhydration with ml of isotonic polyethylene glycol electrolyte-balanced solution, contrast enhanced ct of the abdomen and pelvis was performed with a collimation of mm and mm, respectively. the following ct findings were evaluated: wall thickening, parietal contrast enhancement, extraparietal anomalies (lymph nodes, vessels and mesenteric fat), and presence of inflammatory complications (abscesses, fistulas). the spectrum of findings of small-bowel crohn's disease is thoroughly illustrated and discussed based on our experience with over patients. conclusion: this method provides important information about the extent and activity of small-bowel crohn's disease and its extraluminal involvement and is a potential alternative to small-bowel ct enteroclysis. bowel intussusception in adults: an imaging review h.d. roach, j.m. hanson, r. bagree, c. evans, a. yong; cardiff/uk learning objectives:to outline the mechanism and causes of intussusception in the adult population. to provide a review of the imaging findings in intussusception using several imaging modalities. background: bowel intussusception is more commonly associated with the paediatric population, but can occur in adults, affecting virtually any part of the gastrointestinal tract. in adults there is more often an underlying structural lesion, which acts as a lead point. imaging findings: bowel intussusception has a classical appearance on barium studies and cross-sectional imaging and occasionally a lead point can be identified. due to the underlying structural causes, surgery is more often required in adults than children, resulting in the availability of histopathologic specimens for correlation. however within the small bowel even in adults it has been shown that the majority of cases are self-limiting. in this exhibit, we review the imaging findings of intussusceptions affecting various sites in the gastrointestinal tract using different modalities. conclusion: bowel intussusception is less common in the adult population, but is often associated with underlying structural lesions. the imaging findings are reviewed here. can double contrast barium enema exams incidentally detect terminal ileum tumoral lesions? c. gotta, s. merola, e. sanabria, m. landi, s. ballester, c.a. dominguez; buenos aires/ar learning objectives: to describe a number of radiological signs, found in barium enema double contrast exams in patients, that are specific or suspicious of terminal ileum tumoral lesions. background: since there have been few reports about radiological signs in double contrast barium enema exams that can help in the diagnosis of terminal ileum pathology. some of them use glucagon to improve the reflux of contrast material through the ileo-cecal valve in order to allow the visualization of the reviewing the available literature, there are no reports which describe specific radiological signs on this matter. procedure details: a total of cases of tumoral terminal ileum pathology were found. all lesions were seen for the first time at the double contrast barium enema, and lately examined and characterized by the follow through or small bowel enema. in most of them abdominal computed tomography was performed. cases had histological confirmation based on surgical specimens. of the remaining cases, were lipomas with typical densitometric values diagnosed by computed tomography, thus these patients did not undergo surgery. the other lesions described as polipoid did not have histological confirmation as the patients refused surgical resection. conclusion: double contrast barium enema can detect the presence of terminal ileum tumoral pathology even when not yet clinically suspected. there are a few radiological signs which allow the radiologist to recognize and diagnose it. background: magnetic resonance is a powerful diagnostic tool for abdominal imaging, particularly for extra-visceral tissue depiction. newer pulse sequences, such as single shot fast spin echo (ssfse) and steady state free precession (ssfp) with a water solution infusion via naso-jejunal tube can accurately depict the bowel lumen in a fashion similar to conventional double contrast enema. furthermore d and d fast t weighted sequences with iv contrast administration allows the evaluation of wall involvement. imaging findings: findings are summarized into lumen abnormalities, wall involvement and extra-luminal alterations. corresponding dcsbe are shown and compared. signs of disease activity at mre plus conventional mri are stressed. contribution of different pulse sequences is evaluated. conclusions: mre plus conventional mri is feasible in the diagnosis, staging and follow-up of crohn's disease. subtle mucosal lesions are still poorly depicted, compared to dcsbe. extra-luminal involvement is superbly showed, particularly by new ssfp sequences. disease activity signs seem to be the added value of magnetic resonance in crohn's disease assessment. diagnosis and staging of colorectal carcinomas using multislice ct colonography (msctc): pictorial essay with pathologic correlation r. iannaccone, a. laghi, c. catalano, a. lamazza, f. mangiapane, s. trenna, d. marin, a. schillaci, r. passariello; rome/it learning objectives: to assess the role of msctc in the detection and staging of colorectal carcinoma. background: patients affected by colorectal carcinoma underwent colonoscopy and msctc on the same day. patients free of colonic lesions were included as a control group. ct parameters were: collimation, x mm; effective mas, - ; and kvp, . msct colonography was performed before (prone position) and after (supine position) intravenous administration of contrast material with a -sec delay-time. msctc images were interpreted by two radiologists on a workstation. the results of msct colonography were correlated with colonoscopy and with the results of the histopathologic examination performed on the resected surgical specimen. intra-operative ultrasonography was used as the reference standard for the presence of liver metastases. sensitivity and specificity for tumor detection and staging accuracy (according to the tnm classification) of msctc were calculated. imaging findings: surgery revealed carcinomas ( primary and synchronous lesions) in patients. colonoscopy failed to visualize the entire colon in patients due to obstructive neoplasms and missed all synchronous carcinomas. msctc provided a complete evaluation of the colon in all cases, correctly identified all primary and synchronous carcinomas ( / ; sensitivity, %), and yielded three false-positive diagnoses (specificity, . %). msctc also detected polyps ( true-positives and three false-positives). overall, msctc correcly staged of primary tumors (overall tnm staging accuracy, . %). conclusion: msctc can be proposed as a comprehensive diagnostic test for the pre-operative evaluation of patients with known, or strongly suspected, colorectal carcinoma. gastrointestinal to present the characteristic features of malignant gist and correlated these with histopathologic findings. background: in our pathologic database from to , we found patients with gist and retrospectively reviewed their radiologic findings. thirty one ct, four us, and four barium studies were included. imaging findings: involved organs were as follows; in the small bowel ( %), in the stomach ( %), five in the rectum ( %), two in the mesentry ( %) and one in the colon ( %). on histochemical analysis, eight were classified as benign ( %), six as borderline ( %) , and as malignant ( %). mean tumor size was . cm ( . cm- cm): benign (mean; . cm, range; . cm- cm): borderline (mean; cm, range; cm- . cm): malignant (mean; . cm, range; cm- cm). multiplicity was demonstrated in one benign and one malignant tumour. six cases showed microscopic metastasis to the surrounding lymph nodes without evidence on radiologic imaging. ct features were relatively smooth margination and homogeneous enhancement of smaller tumors. poor margination with surrounding infiltration, central necrosis or ulceration was seen in larger tumors. no evidence of intestinal obstruction, peritoneal seeding or ascites was demonstated. barium examination showed a well demarcated, smooth marginated tumor with normal overlying mucosa. some ulceration was seen in larger masses (bull's-eye sign). us features were welldemarcated homogeneous hypoechogenicity of small masses, hyperechoic foci of ulcerated masses. the characteristic radiologic findings of immunohistochemically kitpositive malignant gist were large tumor size, poor margination, central necrosis or ulceration. the clinical significance of each feature and differential points from benign gist or other conditions will be discussed. learning objectives: to illustrate ct findings of common and uncommon duodenal diseases with pathologic correlation. to demonstrate a comprehensive ct anatomy of the duodenum and adjacent organs. to describe the pitfalls on ct interpretation of duodenal diseases. background: the duodenum may be involved by secondary process as well as primary pathology because it is close to adjacent organs including the stomach, pancreas, liver, gallbladder, hepatic flexure of the colon, aorta, ivc, right kidney and adrenal. duodenal pathology can be overlooked on ct interpretation but understanding of ct anatomy of the duodenum and adjacent organs may be helpful in the diagnosis of various duodenal pathology. procedure details: helical ct during the portal phase with water as an oral contrast agent was performed for better detail of duodenal lesions. we reviewed ct findings with pathologic correlation in patients with various duodenal diseases. duodenal diseases were classified as follows; congenital (duplication, malrotation, diverticulum, and annular pancreas), trauma (intramural hematoma, iatrogenic perforation by endoscopy), inflammatory (perforated peptic ulcer, secondary process by pancreatitis or cholecystitis), primary neoplasms (lipoma, adenoma, adenocarcinoma, lymphoma, and gastrointestinal stromal tumors), secondary invasion of adjacent neoplasms (pancreas, stomach, colon, and gallbladder), bezoar, and postsurgical afferent-loop syndrome. conclusion: helical ct during the portal phase with water as an oral contrast agent provided a comprehensive view of the duodenum and adjacent organs. understanding of ct anatomy and the pitfalls on ct interpretation was helpful in the diagnosis of various duodenal diseases. to investigate utility of mr volumetry for resectable rectal cancer before and after preoperative concurrent chemoradiotherapy. methods: patients with respectable locally advanced rectal cancer underwent preoperative concurrent chemoradiotherapy. among them, patients ( men and women; median age years; range, - years) who had mri before, and month after concurrent chemoradiotherapy were enrolled into this study. radiation of gy/ fractions was delivered to the pelvis, followed by a . gy/ fractions boost to the primary tumor. chemotherapy was administered concurrently with radiotherapy and consisted of cycles of -fu ( mg/m / day) and leucovorin ( mg/m /day) for five days during the first and fifth weeks of radiotherapy. surgery was performed - weeks after the completion of chemoradiation. mr volumetric examinations for tumor volume before and after chemoradiotherapy were perfomed in workstation software using t -weighted axial images. results: according to dworak grade, grade was present in . % ( / ), grade in . % ( / ), grade and in . % ( / ), respectively. primary tumor downstaging occurred in . % ( / ). the mean tumor volume was . cm ( . - . cm ) in mr volumetry before chemoradiotherapy and . cm ( - . cm ) in after chemoradiotherapy. when the tumor volume reduction rate was correlated with the dworak grade, mean tumor volume reduction rate was . % ( . - %) in grade , . % ( - . %) in grade and . % ( . - %) in grade and . the tumor volume reduction rates demonstrated statistically significant differences among dworak grades. conclusion: in mr volumetric evaluation for rectal cancer before and after preoperative chemoradiotherapy, tumor volume reduction rate is well correlated with histologic reduction grade. functional the rectum was insufflated with air. we used t -weighted haste sequences at rest, squeeze and strain, in the axial and sagittal planes. we also performed a dynamic study using a t -weighted haste modified sequence, acquiring a single mid-sagittal slice, repeated every second for seconds, starting with the patient at rest then in squeezing and finally in straining. mr findings were compared with evacuation proctography, considered as gold standard. rectocele and pelvic floor descensus were graded either with the standard reference values, and with modified values obtained from normal volunteers. results: mri vs evacuation proctography identified / rectoceles, / anorectal junction descents, / rectal prolapses, and / diskinetic pubo-rectalis syndromes. mri detected additional findings in % of patients ( enteroceles, uterine descents, cystoceles, perianal pathologies-abscesses, anal fistulas). mri, using specific reference values provided % sensitivity, % accuracy, % npv for the anorectal junction descent, while using conventional values provided % sensitivity, % accuracy and % npv. conclusions: defeco-mri requires a short examination time, is well accepted and gives reliable information for the diagnosis of posterior pelvic disorders. specific reference values should be used to correct the bias of the supine position. correlation between mr findings and pathology in evaluation of the affected bowel wall in crohn's disease f. maccioni, m. colaiacomo, a. bruni, a. cocco, s. parlanti, f. siliquini, m. marini, a. marcheggiano; rome/it purpose: to correlate mr findings with the corresponding pathologic specimens obtained at the level of the pathologic wall in patients with crohn's disease (cd). method and materials: patients with known cd underwent mri after oral administration of a superparamagnetic contrast, using t -weighted plain and fatsuppressed haste sequences, and gd-enhanced t -weighted flash sequences on axial planes. degree and pattern of wall signal, wall thickness and abnormalities of perivisceral fat were evaluated. disease activity was evaluated using standard clinical scores. endoscopic or surgical pathologic specimens were obtained in all patients (gs) . mr findings were inter-correlated and correlated with pathologic findings (gs) either prospectively or retrospectively, with a sideby-side analysis of results. results: high wall gd-enhancement and high t wall signal were observed in patients with active disease and diffuse transmural inflammatory cells infiltrates at gs (n. ). in patients with active disease a layered pattern of gd-enhancement was observed, associated with either submucosal oedema or fibrosis at gs (n. ); in this group of patients, however, t -weighted images showed high or low wall signal in presence of oedema or fibrosis, respectively. in patients with non active disease poor gd-enhancement and low t wall signal were observed and preoperative evaluation of early gastric cancer for laparoscopic gastrectomy by d-ct angiography using -row multislice ct angiography s. kumano , h. miki , t. mochizuki ; onsen-gun/jp, ehime/jp purpose: the purpose of this study was to determine the efficacy of d-ct angiography ( d-cta) using -row multislice ct (msct) in the pre-operative simulation of laparoscopic gastrectomy for early gastric cancer. method and materials: twenty patients with early gastric cancer underwent ct examination using -row msct ( . -mm x ). ml/kg of mgi/ml contrast material was intravenously injected at a rate of ml/sec. timing for the arterial phase scan was determined by using a test bolus injection. portal phase scan was performed s after the start of bolus injection. for d-cta, ct images of . mm thickness were reconstructed at . mm intervals. with a computer workstation, d-cta was produced using volume rendering and maximum intensity projection techniques. results: d-cta demonstrated the left gastric artery (lga), right gastric artery (rga) and left gastric vein (lgv) in all cases. d-cta also demonstrated the lga arising from the celiac trunk in cases and from common hepatic artery (cha) in one case; the left hepatic artery (lha) from the lga in two cases; an accessory lga from lha in one case; and the rga from the proper hepatic artery in cases, from the cha in five cases, and from the lha in one case. regarding the venous system, d-cta demonstrated lgv flowing into portal vein in cases, splenic vein in cases, and the junction of portal and splenic veins in one case. conclusion: -row msct d-cta clearly demonstrated the vascular anatomy in all cases that is necessary for laparoscopic gastrectomy, and was thought to be useful for the preoperative simulation of laparoscopic gastrectomy. douglas pouch hernias: evaluation with entero-colpo-defecography m. estienne , m. moretti , m. valle , p. meinero , o. brunetti ; lavagna/it, santa margherita ligure/it purpose: to assess the usefulness of entero-colpo-defecography (ecd) in the evaluation of douglas pouch hernias and to improve the technique by a simple and non-invasive method. methods and materials: female patients (mean age: years) with clinical symptoms of obstructed defecation underwent ecd. our standard technique includes: ml of diluted barium suspension given orally at least ½ hours before examination; a small gauze opacified with iodamide placed into the vagina; rectal filling with ml of thick barium paste. static and spot lateral radiographs of the pelvis are obtained at rest, during squeeze and push, and during and after evacuation. if widening of the rectovaginal space (rvs) is observed during the dynamic phase, in the absence of an enterocele, a barium sigmoid enema is performed and further lateral films are obtained at maximum straining. results: widening of rvs was observed during ecd dynamic phase in of the patients ( %). thirteen of these patients had small bowel loops prolapsing into rvs (enterocele). for the three remaining patients, in which the widening of rvs could not be explained by enterocele, we performed a sigma barium enema demonstrating the presence of a sigmoidocele. we did not find a peritoneocele without bowel contents. conclusions: douglas pouch herniations may account for symptoms of obstructed defecation. defecography alone is not able to evaluate the hernia contents and peritoneography is an invasive technique. visualization of douglas pouch hernias is improved by the use of our ecd technique allowing a correct identification of enteroceles and sigmoidoceles. were prospectively studied by mdctc and compared with colonoscopy. all patients were referred to ct immediately after colonoscopy. ct was performed with x . mm, kv and mas in both supine and prone positions after colonic air insufflation. this method was well tolerated for all patients. independently, two experienced radiologists interpreted axial, sagittal and coronal images and d endoluminal reconstructions (virtual colonoscopy). in cases of disagreement, the diagnosis was established by consensus. sensitivity, specificity, predictive values and kappa test were analysed. both methods were compared with chi-squared test. results: in our series, the prevalence of colorectal polyps was %. when polyps were mm in size or greater mdctc had a % sensitivity, % specificity, % pvp and % pvn. the agreement between colonoscopy and mdct was observed in %. no statistical differences were found between these methods. conclusion: ct colonography is emerging as a potential alternative to conventional colonoscopy in the screening of colorectal cancer. row mdctc represents a reliable imaging method to detection of colorectal polyps with a high accuracy, particularly when the polyp size is mm or greater. this suggests an improvement over single slice ct. a. kalogera-fountzila, c. kouskouras, a. lefkopoulos, n. fotiadis, d. karanikolas, i. tsifountoudis, a.s. dimitriadis; thessaloniki/gr purpose: to prospectively evaluate the characteristic spiral ct features of intestinal ischemia and necrosis in patients with acute abdomen. materials and methods: twenty patients, aged - (median ), were examined in a three year period, using helical ct without oral contrast administration and after intravenous injection of contrast medium. the clinical manifestations consisted of acute abdomen and/ or sepsis in all patients. the diagnosis of bowel ischemia was confirmed with surgery, where colonic and/ or small bowel resection was performed in patients within hours. one patient with the presence of portal gas was found to be normal at surgery and one patient died before surgery and had a confirmatory autopsy. results: the causes of critical intestinal ischemia were diverse, including superior mesenteric artery thromboembolism in ( %) patients, inflammation in ( %), intussusception in ( %), volvulus in ( %), adhesions in ( %), hiv infection in ( %) and unknown etiology in ( %). spiral ct identified necrosis of colon and small bowel in ( %) patients, necrosis of small bowel only in ( %), and of colon in ( %). suggestive findings included intramural air in ( %) patients, thickening of the bowel wall in ( %), thinning in ( %), double or concentric ring sign in ( %) and bowel dilatation in ( %). presence of increased density of mesenteric fat was noted in ( %), mesenteric vein dilatation in ( %), free intraperitoneal air in ( %) and peritoneal fluid or blood in ( %). conclusion: spiral ct can accurately demonstrate signs of bowel ischemia and is often helpful in determining the primary cause of ischemia or necrosis. a comparison of single and multi row ct colonography in the detection of colorectal polyps p. vagli, e. neri, s. picchietti, g. naldini, m. rossi, c. bartolozzi; pisa/it purpose: to compare the diagnostic accuracy of single and multi row ct colonography (ctc) for detection of colorectal polyps. materials and methods: between and , seventy-two consecutive patients with a moderate to high risk of developing colorectal cancer underwent ctc followed by complete cc within hours. ctc was obtained by means of single row ct (n = ) and multi-row ct (n = ). sensitivity and specificity of single and multi-row ctc for detection of colorectal polyps was determined by means of lesion location in four colonic segments (cecum-ascending c-a, transverse t, descending d, sigmoid-rectum s-r). results: all colonic segments were completely visualised in each patient both by single and multi row ctc study. ctc identified polyps (< mm) in pa-tients (c-a n = , t n = , d n = , s-r n = ) , and polyps ( - mm) in patients (c-a n = , t n = , d n = , s-r n = ) . ctc generated false positives (fp) for polyps smaller than mm and fp for polyps - mm. false negatives (fn) were for polyps < mm, and for polyps - mm. sensitivity of single and multirow ctc for detecting polyps were % and % respectively for polyps < mm, and % and % for larger polyps - mm (p < . ). overall sensitivity and specificity of ctc for small polyps (< mm) was % and % respectively. overall sensitivity and specificity increases for larger polyps ( - mm) at % and % respectively. conclusion: multi-row ctc demonstrated a higher diagnostic accuracy than single-row ct in detection of colorectal polyps. paring the two ct techniques, considering patient discomfort and respiratory artifacts. results were compared with double-contrast small bowel enema and evaluated by two experienced radiologists. the integrated diagnosis showed negative patients, with signs suggestive for crohn's disease, with reflux ileitis, with ischemic ileitis and with non-specific ileitis. ct detected positive loops (sensitivity %, specificity %, diagnostic accuracy %); conventional radiology showed positive loops (sensitivity %, specificity %, diagnostic accuracy %). ct-enteroclysis false positives were due to poor bowel distention and false negatives to proximal bowel localization of disease; conventional study false negative cases were due to unseparable loops. mild respiratory artifacts were present in % ( of patients) of sdct examinations vs % ( of patients) of mdct examinations. conclusions: mdct-enteroclysis in comparison with sdct-enteroclysis reduces scanning time, respiratory artifacts and patient discomfort, allows a better spatial resolution, more evident on mpr, and improves pathological pattern representation. detection and staging of gastric lesions combining axial ct and virtual endoscopy images s. visconti, v. panebianco, m. celestre, t. celano, d. tancredi, f. iafrate, r. passariello; rome/it purposes: the aim of our study was to develop a virtual endoscopy examination protocol for the stomach after co distention, and to identify agc lesions according to borrmann's classification based on tumor morphology. methods and materials: virtual endoscopy of the stomach was performed in patients with gastric lesions. the stomach was distended with g of top effervescent granules used for double contrast upper gi studies (duogas, bracco), after intramuscular injection of mg of scopolamine butylbromide. all patients underwent a spiral ct volume zoom examination ( / / mm/ mm/ mm/ .l sec kv/mas/slice-coll./slice-width/feed-rot/rot.time). in cases spiral ct was repeated in a prone position because of a limited gastric distension by air. real time endoscopy images were reconstructed using a volume rendering technique with a dedicated workstation and specific software (vitrea . -vital images), and evaluated combined with axial images by two radiologists. one week later a fiberoptic gastroscopy was performed in all patients. results: image quality was graded as optimal in cases. in cases the stomach was not distended. virtual endoscopy correctly showed gastric lesions (ulcerative lesions n = , vegetating lesions n = , benign lesions n = ). we found a good correlation with surgical specimens in cases. the actual role of virtual gastroscopy combining axial ct and ve images is to evaluate the locoregional and distant extension (perigastric tumor involvement, distant metastasis) of tumors. it's potential roles are replacing barium studies and examining patients with surgical gastric exclusion. traumatic bowel perforation after blunt abdominal trauma: analysis of the ct findings according to the perforation site and the elapsed time since the trauma h. kim, h. shin, s. park, s. park, h. kim, w. bae, i. kim; cheonan/kr purpose: to evaluate the efficacy of ct in predicting the perforation site and the differential findings according to the elapsed time from the trauma in patients with bowel perforation after blunt abdominal trauma. methods and materials: abdominal ct's of patients with bowel perforation after blunt abdominal trauma confirmed by surgery were retrospectively analyzed without knowledge of the surgical results. the interval from the trauma to ct was to hours (mean, hours). the ct findings of traumatic bowel perforation including extraluminal air collection, segmental bowel wall thickening, localized inter-mesenteric fluid, bowel wall discontinuity, and mesenteric hematoma were analyzed. the predicted perforation sites were classified as: duodenum, jejunum, jejuno-ileal junction, ileum, and colon. based on the mean elapsed time ( hours), the patients were divided into the early lapse group (n = ) and the late lapse group (n = ), and the differential ct findings were analyzed. results: diagnostic accuracy of predicting the perforation site was: duodenum ( %), jejunum ( %), jejuno-ileal junction ( %), ileum ( %), and colon ( %). extraluminal air collection was more frequently seen in the late lapse group ( %) than in the early lapse group ( %) (p < . ), whereas other ct findings showed no statistically significant difference in the incidence. contrast-enhanced magnetic resonance imaging of the terminal ileum in children with crohn's disease p. paolantonio, a. laghi, o. borrelli, c. miglio, m. celestre, d. marin, s. cucchiara, r. passariello; rome/it introduction: to evaluate the diagnostic value of gadolinium enhanced mri with polyethylene glycol solution as oral contrast agent (ce-peg-mri) in revealing inflammation of the distal ileum in children with crohn's disease (cd) and in differentiating them from other inflammatory bowel diseases. subjects and methods: seventy-five consecutive paediatric patients referred for suspected cd underwent ileo-colonoscopy with biopsy and ce-peg-mri. the distal ileal mucosa was assessed by endoscopic and histological scores. the cd activity was measured by means of paediatric crohn's disease activity index (pcdai). results: active cd was diagnosed in cases, active ulcerative colitis (uc) in , spondyloarthropathy and indeterminate ileo-colitis in . in all cd patients ce-peg-mri showed a high concordance with endoscopy and histology. of the uc patients the ce-pegmri was negative in and showed mild parietal contrast enhancement of the terminal ileum in of the patients with backwash ileitis. among the group of spa patients, ce-peg-mri was negative in and revealed mild parietal contrast enhancement in . no increase in wall thickness in any of the uc and spa patients was demonstrated. sensitivity and specificity of ce-peg-mri were % and %, respectively. the test optimally correlated with endoscopic and histological scores (r: . ; r: . , respectively) as well as with the pcdai in the cd patient group (r: . ). conclusions: high correlation of ce-peg-mri with ileal endoscopy, histology and pcdai makes this test of great interest as a tool for monitoring the clinical course and the effect of therapy in cd patients. small bowel sonography in celiac disease after oral administration of sonographic contrast medium p. mirk, r. foschi, i. de vitis, l. guidi, a. vecchioli-scaldazza, p. marano; rome/it purpose: to assess the usefulness of sonography in celiac disease after small bowel loop filling by sonographic contrast medium. materials and methods: consecutive patients with clinical suspicion or diagnosis of celiac disease were prospectively examined by us before and after ( '- ') drinking of - ml of an isosmotic water solution of polyethilene glycol. patients had celiac disease (positive histology or aga or ema antibodies); patients had previous celiac disease but were clinically negative, or had other benign disorders, and were considered as normal. results: after contrast administration intestinal loops were better or slightly better shown in / and / patients ( . % and . %), or unchanged in / ( . %). among celiac patients, observed intestinal abnormalities were: segmental dyskinesia; transient intussusception; reduced number of jejunal folds; increased number of ileal folds; hypotonic dilated fluid-filled loops; increased intestinal motility. extra-intestinal abnormalities in celiac patients were: spleen size reduction; mesenteric lymphadenopathy; liver steatosis; free peritoneal fluid. celiac patients had no detactable abnormalities (false negatives); there were no false positives. overall accuracy was . % (sensitivity: . %; specificity: %; ppv %; npv . %) conclusions: small bowel filling by sonographic contrast medium improves us evaluation of wall thickness, mucosal fold pattern, and intestinal motility. transient intussusception was the single most diagnostic sign, whereas other features were less specific and of limited value unless found in combination. preoperative mri and transrectal us in the staging, and post-irradiation therapy restaging, of rectal cancer i. miucin-vukadinovic; sremska kamenica/yu purpose: the goal of the study was to determinate and compare the value of mri and transrectal us (trus) in the staging, and post-irradiation therapy restaging, of rectal cancer. this study was designed to evaluate the down-staging effect of preoperative radiation. method and materials: patients (range, - ) with biopsy-proven rectal can-cer underwent imaging using a . t scanner and transrectal us ( . or mhz transducer) before, and after radiation therapy ( gy, a daily fracton of gy, days a week).tumors were staged according to the tnm staging system. two observers independently scored the tumor stage. the standard of reference was histopathology (after surgical resection). results: all patients underwent radiotherapy before surgery for rectal carcinoma. before radiotherapy mr examination detected . % t (b ), . % t (b ), . % t n (c ) and . % t / n (c ) tumors. down-staging of one or more t stages occurred in . % with tumor regression in . %. the mri tumor stage agreed with the histological stage in % of patients. trus correctly staged % of lesions. t category was correctly restaged after preoperative radiation in only . %. conclusion: preoperative radiotherapy is becoming the standard of care for resectable, locally advanced adenocarcinoma of the rectum. mri and trus enable selection of appropriate patients for preoperative radiotherapy. preoperative trus can establish the depth of penetration of a tumor and showed less sensitivity for lymph node staging. mri showed better diagnostic accuracy (with tendency for overstaging) then trus for interpretation of complete pelvic status in the pre-and post-irradiation period. echographic efficacy evaluation of gastric ulcer treatment s. pimanau, n. mikhailava; vitebsk/by purpose: the objective of this study was to investigate the possibilities of noninvasive abdominal echography in efficacy evaluation of chronic peptic ulcer pharmacotherapy. method and materials: patients with gastric ulcers in the exacerbation phase were examined before the course of pharmacotherapy and after it. ultrasound investigation was carried out after administration of - ml deaerated liquid. on echography a chronic gastric ulcer was visualized in cases. in the acute exacerbation phase the peptic ulcer was deep, filled with echogenic contents, the ulcer edge being sharp and overhanging. periulcerous infiltration was hypoechogenic, - mm long, - mm thick, and its area made up about - mm . the peripheral edge of periulcerous infiltration seemed sharp. in the course of effective treatment both ulcer dimensions and periulcerous infiltration area reduced on echograms. periulcerous infiltration reduction speed made up about mm /day. the reparative process was also accompanied by ulcer flattening. in cicatrization the ulcer was not visualized on echograms, a hypoechogenic stripe - mm thick generally remaining. in the absence of reparation, the echographic picture of the ulcer and periulcerous infiltration didn't change essentially. parallel endoscopic study of the stomach revealed either coincidence with echographic findings of qualitative characteristics of the reparative process positive dynamics or its absence. in cases the results of ultrasound and endoscopic investigations didn't coincide; echograms showed slight infiltration with a central small echogenic area at the site of ulcer regarded as ulcer reparation, while endoscopy revealed a red scar. conclusion: thus, abdominal ultrasound investigation of the stomach enables reliable evaluation of gastric ulcer dynamics in the course of conservative treatment. comparison of multi-slice ct-colonography in ultra-low-dose technique with high resolution video-colonoscopy in the detection of colorectal polyps m. cohnen, c. vogt, k. andersen, a. saleh, a. beck, s. vom dahl, v. aurich, d. häussinger, u. moedder; düsseldorf/de purpose: to prospectively compare msct-colonography using an ultra-low-dose technique (uld-msctc) with high-resolution video-colonoscopy (hr-vc) as the standard technique for detection of colorectal cancer and polyps. patients and methods: patients underwent msct-colonography (uld-msctc) after standardized oral bowel cleansing immediately before video-colonoscopy (hr-vc). patients were scanned with an ultra-low-dose msctcolonography protocol ( mas, ctdiw eff: . mgy). after noise reduction using an mathematical algorithm by dedicated software, uld-msct-colonographic images were analyzed by a team of two readers in a blinded fashion and the results were compared with the results of hr-vc. results: lesions were detected by hr-vc in patients. sensitivities for detection of polyps < mm, - mm, and > mm in size were % ( of polyps), % ( of polyps) and % ( of polyps) respectively. all colorectal tumors ( of , %) were prospectively diagnosed. the sensitivity to detect flat lesions was % ( of flat lesions). the overall specificity was calculated at %. the calculated effective dose ranged between . and . msv. conclusions: uld-msctc has an excellent sensitivity and specificity for the detection of colorectal lesions > mm despite a significant reduction in radiation exposure. defecographic the pelvic floor in straining state descended an average of . cm from the inferior margin of the ischial tuberosity, its broad range of position from - . cm to . cm implying a wide variation of anorectal angle and perineal descent. mild degree rectocele with less than cm of depth was found in out of cases. rectal intussusception was noted in six and rectal incontinence was seen in one. formation of rectocele and intussusception during defecation was common in asymptomatic young volunteers. the wide range of defecographic measurements warrants the necessity of other complementary studies on anorectal function to improve the diagnostic accuracy. therefore, the interpretation of defecographic findings should be made with caution and should not be used as the sole criteria for selection of a treatment modality. right-side colonic diverticulitis: sonographic and ct findings (differential diagnosis) e. blanc, m.j. martínez, t. ripollés, m. agramunt, c. soto, r. pastor; valencia/es purpose: to describe the sonographic and ct features in right-side colonic diverticulitis and to differentiate this entity from other right-side acute abdominal conditions. methods and materials: patients with a final diagnosis of diverticulitis of the ascending colon or cecum were retrospectively reviewed. sonography was performed in all patients and ct in . the following findings were evaluated: the presence of an inflamed right colonic diverticulum, pericolonic infiltration, focal colonic wall thickening and the identification of a normal appendix. the diagnosis was confirmed by surgery, clinical course, or barium enema. results: sonography and ct showed pericolonic inflammation and focal colonic wall thickening in all cases. the inflamed diverticulum was seen with sonography and ct in ( %) and ( %) patients respectively. the normal appendix was identified with sonography in ( %) and with ct in ( %) cases. the initial diagnosis was: right-side colonic diverticulitis (n = ), acute appendicitis (n = ), perforated colonic carcinoma (n = ) and an inflammatory mass (n = ). conclusions: right-sided colonic diverticulitis is a condition that can clinically mimic other causes of right abdominal pain like acute appendicitis, perforated colonic carcinoma, salpingitis, ileocecal inflammatory pathology, epiploic appendicitis and omental infartion. in this series the most common sonographic and ct findings included the presence of a right colonic diverticulum with thickening of the adjacent pericolonic wall and pericolonic infiltration. both ultrasound and ct can be extremely useful in the early diagnosis of this entity avoiding unnecessary surgery procedures, in a primarily benign and self-limiting condition that can be treated conservatively. an accurate scanning technique for detecting recurrent rectal cancer: enhancement of early-phase dynamic helical ct j. tanaka, s. tsukuda, a. heshiki; iruma-gun/jp purpose: to evaluate the usefulness of dynamic enhancement of helical ct in the detection of local recurrence of resected rectal cancer. in patients with a history of curatively resected t or t rectal cancer, follow-up plain ct indicated that they had a loco-regional recurrent tumor; consequently, they underwent follow-up pelvic helical ct providing accurate early-phase contrast enhancement in the lower pelvic region. the patients were divided into four groups according to grade of contrast enhancement of the suspected mass-like lesion before and after contrast enhancement, and correlation between groups and results obtained by biopsy and/or surgery was assessed. if no correlation was found, patients were followed up for a period lasting from days to two years. as of june , results had been obtained for patients; and correlation between these results and grouping by contrast enhancement ratio was analyzed. results: all patients in the highest-grade group (n = ) had local recurrence. when only the highest-grade group was considered positive, there were no false positives and only one false negative. conclusion: our results suggest that early-phase contrast enhancement is useful for accurately detecting recurrent rectal cancer. this can be easily achieved using smartprep function, and should be used to distinguish recurrent tumors from post-surgical scar tissue, because these two tissue types do not exhibit similar enhancement patterns. staging of gastric carcinoma by mr imaging in vitro c. sato , s. naganawa , h. kumada , t. miura , t. ishigaki ; nagoya/jp, toyohashi/jp purpose: to evaluate the accuracy of cancerous invasion to gastric wall with magnetic resonance imaging in vitro. twelve specimens of gastric carcinoma were examined with a . t mr using a small loop surface coil. they were fixed in formalin within days prior to imaging. the field of view was mm, a matrix size was x , and the section thickness was mm. the t -and t -weighted images were obtained. two radiologists evaluated the mr images independently, and consensus was obtained if there were any discrepancies between the two. findings on mr images were compared with histopathologic findings. results: mr images depicted the normal gastric wall as consisting of the layers clearly. cancerous invasion was detected in of specimens with mucosal invasion, with submucosal invasion, with the invasion to muscularis propria, with subserosal invasion, and the rest that extended into the serosa. the mr imaging-determined grade correlated with the histopathologic findings for of tumors. the overall accuracy was . %. conclusion: mr imaging has an accurate diagnostic capabilities for the evaluation of the cancerous invasion to the gastric wall in vitro. the results of the present study may encourage the further development of an endoscopic surface coil. role to investigate the value of mri in the overall assessment of crohn's disease (disease activity, disease extension, complications). method and materials: consecutive patients with crohn's disease underwent mri in the context of a clinical evaluation including biochemistry, endoscopy, histology and radiology. all patients underwent mri after oral administration of a superparamagnetic contrast agent, using standard sequences (haste t weighted, with and without fat-suppression and gd-enhanced t -weighted flash). two independent radiologists evaluated mr images on printed films. disease length, presence of strictures, fistulae, abscesses, phlegmons and any other abdominal complication were evaluated at the level of each segment. gold standard (gs) for morphological assessment were: barium studies, ct or us, and surgery when performed. at the level of the affected segments bowel wall thickness, t wall gd-enhancement, t wall signal, t fibro-fatty proliferation signal were evaluated and graded ( - ) to assess disease activity. gs for disease activity were endoscopy, biological activity and cdai. results: mri detected % of overall disease length, % of fistulae, % of strictures; adhesions were overestimated. in % of patients mri showed complications requiring surgery ( hydronephrosis, abscesses, phlegmons, pancreatic duct stone, enterovesical fistula, ovarian involvements). the following mri findings were statistically correlated with the clinical and biological signs of active disease: bowel wall thickness (r = . ), wall gd-enhancement (r = . ), t wall signal (r = . ), t fibro-fatty proliferation signal (r = . ). learning objectives: to recognize usual and unusual radiologic findings of pseudomyxoma peritonei with pathologic correlation. background: pseudomyxoma peritonei is a rare neoplastic condition in which gelatinous intraperitoneal fluid collections associated with mucinous disseminated implants are observed. although a ruptured appendiceal mucocele is the most common cause, pathologies arising from other origins may cause this condition with various imaging manifestations. imaging findings: the usual imaging findings were of mucinous, fluid-like material spread over the peritoneal cavity with organ scalloping observed in the liver, splenic and mesenteric margins, with central displacement of small intestinal loops. within the material, cyst-like round structures may be observed and clarified by the septal enhancement on contrast-enhanced images. punctate, annular, or curvilinear calcifications may be disseminated. dropping appendiceal mucocele or a rare urachal tumor located in the female pelvis may simulate an ovarian tumor and be misdiagnosed as gynaecological disease. demonstration of the continuity to the cecum or urachus was the diagnostic clue. localized disease in the female pelvis may simulate ovarian carcinomatous peritonitis, and scalloping of the uterine margin may suggest this condition. because synchronous mucinous tumors of the ovary and the appendix may occur, careful observation to detect the slight irregularity of the omentum adjacent to the cecum is necessary to avoid overlooking an occult primary appendiceal lesion. conclusion: to recognize various imaging findings is important to make the correct preoperative diagnosis. in particular occult appendiceal lesions must not be overlooked. multiplanar observation on ct and mri was important to recognize the complex organic-pathologic relationships to identify the primary neoplasm. retroperitoneal cystic masses: ct findings d. yang, h. kim, j. kang, t. seo, h. kim, s. kim, j. kim; incheon/kr learning objectives: to illustrate the ct findings of the different types of retroperitoneal cystic masses. background: retroperitoneal cystic masses, which arise within the retroperitoneal space but outside the major organs of that compartment, are uncommon. however, the widespread use of computed tomography (ct) for evaluating abdominal and retroperitoneal diseases has increased the detection rate of retroperitoneal cystic lesions. in this exhibit, we conduct a literature review and present the ct findings of our own patients to illustrate the ct appearance of different types of retroperitoneal cystic masses. imaging findings: a variety of ct features were identified in various retroperitoneal cystic masses. the disease entities include cystic lymphangioma, retroperitoneal mucinous cystadenoma, müllerian cyst, cystic change of paraganglioma, epidermoid cyst, cystic teratoma, tailgut cyst, mucocele of appendix, perianal mucinous adenocarcinoma, cystic change of leiomyosarcoma after chemotherapy, pancreatic and nonpancreatic pseudocyst, lymphocele, urinoma, and hematoma. conclusion: knowledge of ct findings of various retroperitoneal cystic masses may be helpful for differential diagnosis. learning objective: our purpose is to describe the ct and mr findings of cystic dystrophy of the duodenal and gastric wall in heterotopic pancreas (cdhp) which allows an accurate diagnosis of this pathology usually associated with chronic pancreatitis. background: cystic dystrophy in heterotopic pancreas is characterized by the development of cysts in heterotopic pancreatic tissue localized in the duodenal or gastric wall. cyst formation is related to cystic dilatation of an anomalous duct bordered by pancreatic excretory epithelium, or to pseudocysts caused by pancreatitis of the heterotopic pancreas. we reviewed ct and mr findings in five patients with cystic dystrophy in heterotopic pancreas (cdhp). they underwent spiral ct (n = ) and mr/ cholangio-mr (n = ). diagnosis was confirmed by endoscopic us in all cases. three cases were pathologically proven after surgery. imaging findings: the ct and mri findings of cdhp consists of cysts, (normally multiple), located in the inner wall of the second part of the duodenum and less frequently in the stomach. the duodenal or gastric walls affected are thickened and inflammatory changes are observed around the cysts. signs of chronic pancreatitis are frequently seen. mr/ cholangio-mr shows high intensity lesions corresponding to the cysts. conclusion: cdhp presents some ct and mr features which permit an accurate and reliable diagnosis. when a cystic lesion is found in the duodenal or gastric wall cdhp should be included in the differential diagnosis with other cystic masses such tumors or abcesses. , and thanks to its favorable influence on serum glucose and lipid profiles, this technique is the preferred treatment for patients with severe type i diabetes mellitus and end-stage renal disease (simultaneous pancreatic-kidney transplantation) . therefore an understanding of the anatomic configuration and the spectrum of postsurgical complications is needed. imaging findings: we retrospectively reviewed computed tomographic scans (ct), ultrasounds (us) and doppler studies of patients who had undergone pancreatic transplantation using portal-enteric drainage in our hospital between january and july . we review the usefulness, limitations and potential pitfalls of ct and us. acute postoperative complications, including acute rejection, transplant pancreatitis, peripancreatic collections and abscess, pseudocysts, vascular complications (thrombosis, pseudoaneurysm) and exocrine leaks, are depicted. furthermore, ct-guided percutaneous biopsy and drainage is a safe and an alternative method for obtaining tissue from the transplanted pancreas with graft dysfuntion, and collections. conclusion: knowledge of normal anatomic configuration and the radiologic appearance of normal pancreatic transplant will allow proper interpretation and early treatment of the spectrum of portsurgical complications in this kind of pancreatic allograft. the more common current gastric bypass procedures include the roux-en-y procedure and bilio-pancreatic diversion with duodenal switch procedure. the more typical complications of these surgeries include anastomotic leaks and stenoses, both of which have been reported in the current literature. more atypical complications, however, have not been comprehensively demonstrated. imaging findings: gastric bypass/gastric stapling is a common surgical procedure at our institution. we have encountered several atypical complications, documented with flouroscopic studies using water soluble contrast. we offer five unusual complications which include the following: internal herniation through the small bowel mesentery, internal herniation through the transverse mesocolon, external herniation through the abdominal wall incision, enterocutaneous fistulas, roux-en-y configuration with anti-peristaltic inversion of the gastroenteric roux limb, and incorrect anastomosis of the roux limb with the excluded stomach (resulting in a roux-en-o configuration). conclusion: our findings expand those of the current literature to include the more infrequent complications of gastric bypass surgery. in the fluoroscopic evaluation of post-operative gastric bypass patients, a thorough understanding of expected post-operative bowel configuration is essential. in addition to assessing anatomical abnormalities, it is equally important to assess for abnormalities of motility. in this study, we performed a retrospective review of the medical records and imaging studies of patients with proven fmf, diagnosed between - . imaging findings: the commonest clinical manifestation were recurrent peritoneal attacks with abdominal pain ( . %) and fever ( . %). abdominal imaging findings included ileus (n = ), focal peritonitis (n = ), ascitis (n = ), splenomegaly (n = ), and hepatomegaly (n = ). one patient developed fatal peritoneal mesothelioma, and . % of patients developed amyloidosis with sonographic findings of renal parenchymal disease or cardiomyopathy. arthritis was second in frequency occurring in . % of patients. radiographs were normal (n = ) or showed joint effusion and soft tissue swelling (n = ) due to synovitis. two patients developed seronegative destructive arthropathy. pleuritis was encountered in . %. polyarteritis nodosa (pan) was present in patients, multiple sclerosis in one, and autoimmune hemolytic anemia in one patient. conclusion: fmf predominantly involves abdominal viscera but can affect other organs. the majority of patients have nonspecific imaging findings and the radiologic diagnosis is rarely considered. amyloidosis, mesothelioma, and destructive arthropathy are potential serious complications of fmf. polyarteritis nodosa, multiple sclerosis, and autoimmune hemolytic anemia are rare associations or coincidence with fmf. mucosal associated lymphoid tissue lymphomas: imaging evaluation with pathologic correlation d. voultsinou, t. gerukis, n. staurogianni, k. anastasiadou, a. anagnostopoulos, p. palladas; thessaloniki/gr learning objectives: to identify the radiological features of extra nodal non hodgkin malt lymphoma. to illustrate the spectrum of appearance of the disease in its various locations in the human body. to list the various imaging strategies. to discuss the differential diagnosis. background: mucosal associated lymphoid tissue (malt) lymphoma arises in extranodal mucosal lymphoid tissue and has only been recognized recently. it affects several extranodal structures such as the stomach, the lung, the eye and the salivary glands. it is generally low grade and has an indolent course, as it remains long confined to the initial site. in this exhibit we describe and illustrate the most common radiological patterns of malt lymphoma. imaging findings: we retrospectively reviewed clinical and radiographic records in cases with confirmed low-grade gastric malt lymphoma. the study group consisted of men and women (mean age years). the predisposing factors of malt lymphoma, number and location of lesions, and course of the disease were evaluated. we determined the most probable diagnosis on the basis of the radiologic findings and correlated them to pathologic and immunohistochemical findings of endoscopy, biopsy and bone marrow examination. out of patients presented with malt lymphoma of the stomach, in the parotid gland, in the lung, in the large intestine (sigmoid colon, rectum), in ileocecal valve and in the orbit rectal malt lymphoma coexisted in one patient, and parotid gland and lung lymphoma in patients. all patients were treated with chemotherapy. the disease resolved in patients. the correlation of imaging, endoscopic and pathologic findings significantly contributes to diagnosis and follow-up of malt lymphomas, early diagnosis of which results in complete regression. to describe a new approach to ct colonography for detecting colo-rectal polyps with multidetector row ct (mdct). to display the results and to present the benefits provided by this technique. background: virtual dissection‚ (gems) is an original application to display the entire inner surface of the colon without the need for navigation. the method consists of displaying the straightened and flattened colon using surface rendering. we performed virtual colonoscopies with a ge lightspeed mdct. the acquisition parameter and each step of the imaging procedure will be described. procedure details: all patients underwent ct colonography in both supine and prone positions, the following parameters were used: kvp; - mas; . mm collimation; . -mm reconstruction intervals and rotation time, . - . sec. the colon was assimilated to a cylinder manually defined. time to display the straightened and flattened colon using surface rendering was about minutes. normal aspect, polyps and artifacts were displayed. polyp detection was faster and easier with this method compared to axial images and the usual virtual endoscopy mode with forward and reverse viewing fly-through volume rendered movies. conclusion: this method makes it possible to stretch the colon virtually and to cut it along its axis similar to a real dissection on the pathologist's ( ) and luschka duct ( ). ce-mrcp succesfully revealed the origin of the leak in patients. conclusion: contrast enhanced mr cholangiography with iv mangafodipir trisodium can accurately diagnose the presence and location of bile duct leaks in patients who have undergone laparoscopic cholecystectomy. internal hernia of the anterior part of the abdomen: imaging in the multidetector-row ct era n. hongo, h. mori, s. matsumoto, y. okino, a. adachi, a. kaku; oita/jp purpose: internal hernia of the anterior part of the abdomen (ihapa) is difficult to diagnose preoperatively because of its rarity and lack of imaging landmarks. the purpose of this study is to clarify the ct features of ihapa by ct, especially with multi-detector row ct (mdct). methods and materials: the ct scans in patients with surgically confirmed ihapa through a transverse mesoclolon (n = ) or an omentum (n = ) were retrospectively reviewed; furthermore, the transverse mesocolic type was classified into intramesenteric type (n = ) and transmesenteric type (n = ). special attention was paid to the herniated sac-like appearance, hernial orifice, running course of the omental fat and transverse colon. results: the closed loop of the small bowel was observed in all cases. a sac-like appearance, enclosed by transverse colon was identified in both cases with intramesenteric type, but was not observed in other types of ihapa. fatty continuation between the hernial orifice and omentum was identified in two out of four cases with omental type of ihapa. furthermore, the transverse colon passed above to the hernial orifice in all cases with omental type, while this finding was not observed in any of the transverse mesocolic type. conclusion: the relationship between the hernial orifice and transverse colon, and sac-like appearance enclosed by transverse colon are the diagnostic key of ihapa on ct. particularly, mdct would become feasible to diagnose the ihapa preoperatively, even though it lacks of vascular landmarks. contrast enhanced mri using oral peg solution in the follow-up of patients with known crohn's disease m. scettro, a. grasso, f. monetti, g. rescinito, g. rollandi, c. neumaier; genoa/it purpose: aim of our study was to analyze, in the context of an extensive evaluation, crohn's disease activity index (cdai), and conventional enteroclysis, the value of mri to identify disease extension and complications in patients with known disease. material and methods: abdominal mri of patients in a period of months with a diagnosis of crohn's disease were analyzed by two experienced gastrointestinal radiologists, in consensus, looking for any intestinal and extra-intestinal abnormality. mri studies were performed on a . t (intera nt, philips) with a phased array coil. mri was performed using a polyethylene glycol (peg) solution b d e f a g as oral contrast agent to distend the small bowel (ce-peg-mri), using standard sequences (ss-tse t and tfe t with fat saturation after gd-dtpa and buscopan mg i.v.) . results: mr imaging had an overall sensitivity of % and a specificity of % for active disease. bowel wall enhancement (ratio of signal intensity of abnormal to normal bowel > . : ), bowel wall thickening greater than / mm and increased mesenteric vascularity were useful in identifying active disease. the experience shows that the method is complementary to conventional enteroclysis in the detection of superficial and transmural abnormalities in patients with crohn's disease. in addition, ce-peg-mri can provide excellent information concerning mesenteric involvement, disease activity, and complications of crohn's disease. finally mri may become a gold standard in the identification of recurrant disease. withdrawn by authors the number of x-ray based examinations (using a contrast medium) of the oesophagus, stomach, and large bowel, decreased by %, % and %, respectively. x-ray based examination of the small bowel and plain radiography of the abdomen remained unchanged. endoscopies of oesophagus / stomach and the large bowel increased by nearly %. x-ray based examination of the biliary tract almost disappeared with us, ercp and mrcp taking over. the annual collective effective dose for the all gi tract examinations was reduced by %, from . mansv in to . mansv in . the shift in modalities used for diagnostic imaging of the gastrointestinal tract from x-ray examination to us, endoscopies and mri resulted in a significant reduction in exposure to ionising radiation of patient, and need to be considered when discussing further development and structure of diagnostic imaging in general. perfusional enhanced ultrasound in the diagnostic evaluation of sicca syndrome g. argalia, d. salera, g. giuseppetti; ancona/it purpose: sicca syndrome is a relatively common disorder especially among older women. it may be caused by an autoimmune disorder like sjogren's syndrome (ss) or by several other illnesses. our purpose is to evaluate the diagnostic possibilities of contrast enhanced ultrasound in the characterization of sicca syndrome. we studied consecutive patients with sicca syndrome, affected by ss ( with primary sjogren's syndrome, with secondary sjogren's syndrome due to connetivitis) and patients with a sicca syndrome not related to ss. all patients were selected according to the european community study group diagnostic criteria for sjogren's syndrome (the gold-standard of the study) and underwent contrast enhanced ultrasound examination with timeintensity curve analysis obtained before and during saliva stimulus, salivary glands scintigraphy and labial gland biopsy. results: ss patients had an echo contrast enhancement before and during saliva stimulus significantly lower (p < . ) than the non ss ones. the patients with primary ss showed a significantly lower enhancement during saliva stimulus than the secondary ss patients (p < . ); no statistically different enhancement was seen in basic conditions (p = . ). in the study group ( subjects with sicca syndrome) the enhanced ultrasound showed a sensitivity of . %, a specificity of % and an accuracy of . % on the diagnosis of ss. our experience confirmed the good diagnostic accuracy of salivary glands scintigraphy and labial biopsy. the preliminary results show this method is useful in the functional study of parotid glands in the characterization of sicca syndrome. fusion imaging of d angiographies of arteries and veins around the stomach by multiphase fusion technique under a single-breath hold using row multidetector row ct: its usefulness for preoperative simulation and intraoperative navigation of laparoscopy-assisted gastrectomy m. matsuki, h. kani, i. narabayashi; takatsuki/jp purpose: gastric arteries and veins can vary between patients; therefore, it requires much time to ligate arteries, and veins can be damaged during regional lymph node excision under laparoscopy-assisted gastrectomy (lag). we evaluate the efficacy of fusion imaging of three-dimensional angiographies of arteries and veins around the stomach by the multiphase fusion technique under singlebreath hold using row multidetector row ct (mdct) in the preoperative simulation and intraoperative navigation of lag. methods and materials: contrast-enhanced ct scan using das mdct was performed on patients before lag. images at both arterial and venous phases were obtained under a single-breath hold. three-dimensional ct angiographies at the arterial and venous phases were reconstructed using the volume-rendering technique and then fused. ) the detectability of the left gastric artery (lga), right gastric artery (rga), left gastric coronary vein (lcv), right gastric vein (rgv) and helens' gastrocolic trunk (gct) on the multiphase fusion images was evaluated in comparison with the surgical findings. ) in intraoperative navigation, the clinical usefulness of multiphase fusion imaging was evaluated. results: . in nine of ten patients ( %), the multiphase fusion images could demonstrate clearly, simultaneously and three-dimensionally the lga, rga, lcv and gct without a respiratory gap. . we could arrange and rotate a multiphase fusion image to correspond to the operative view, which was very useful in the intraoperative navigation of lag. the multiphase fusion imaging is considered to be very useful in the preoperative simulation and intraoperative navigation of lag. three-dimensional endosonographic guidance of needle positioning in interstitial brachytherapy a.f. christensen, m.b. nielsen, s.a. engelholm; copenhagen/dk interstitial brachytherapy is used in the treatment of anal carcinoma, so far without image guidance during needle positioning.the aim of the study was to describe a procedure for optimizing needle positioning guided by three-dimensional ( -d) endosonography. twelve patients who received external radiation therapy for anal carcinoma were referred for interstitial brachytherapy under -d endosonographic guidance. the procedure was initiated by anal endosonography performed with a mhz rotating endoprobe. cross-sectional images of the anal sphincters were stored on a -d system during retraction of the endoprobe. afterwards, any projection could be reconstructed. from this scanning the optimal positioning of the needles was determined. the needles containing radioactive isotopes were inserted through holes in an externally fixated disc. repeated endosonography assured that optimal tumor coverage was obtained by adjusting the number, loading or position of the needles. in all patients endosonography was able to visualize the extent of the tumor and the position of each needle so that both the distance from needle tip to upper tumor border, as well as the distance from the anal orifice to the lower tumor border could be determined. in patients endosonography showed a, at least clock-positions larger circumferential tumor size than manual examination. this made an increase in number of needles necessary. in patients endosonography influenced the extent of loading of the needles. in patients endosonography led to a change in positioning of the needles. -d endosonography guidance of interstitial brachytherapy in anal carcinoma seems possible, which may influence the radiation coverage. to determine ct criteria that allows accurate classification of interstitial hernias. methods and materials: ct scans of patients with surgically proved spigelian hernia (n = ) or interparietal inguinal hernia (n = ) have been retrospectively reviewed. ct assessment included: ) assessment of the hernial sac (anatomic situation, extension, content) and ) assessment of the fascial defect (anatomic situation, relationship to the inferior epigastric vessels). results: in all cases (n = ), the hernial sac was located between the internal and external oblique muscles. the fascial defect was located at the spigelian aponeurosis, above the inferior epigastric vessels in the seven cases of spigelian hernia, and at the internal inguinal ring, lateral to the inferior epigastric vessels in the six cases of interparietal inguinal hernia. conclusion: assessing only the hernial sac does not allow accurate classification of interstitial hernias. diagnosis is established by precise analysis of the anatomic situation of the fascial defect. the role of magnetic resonance cholangiography in patients with biliaryenteric anastomosis y.a. akhmetov; almaty/kz purpose: the study was aimed at investigating the role of mr-cholangiography (mrc) in the examination of patients treated with biliary-enteric anastomosis. methods and materials: mrc was performed in patients ( female and male, mean age: . years) undergoing biliary-enteric anastomoses ( hepatico-jejunostomies and choledocho-duodenostomies). mrc was performed with a non-breath-hold d turbo spin echo sequence (tr = msec, te = msec, etl = ) with an acquisition time from min to min. patients subsequently underwent percutaneous transhepatic cholangiography (ptc) in order to confirm the mrc findings and to perform a therapeutical procedure. patients with choledochoduodenostomy were examined with ercp. the remaining patients, with no evident symptoms or signs of bile duct dilation, were examined during their surgical follow-up without the performance of any invasive procedure. the degree of bile duct dilation was correctly evaluated with good panomaric assessment of the ducts and site of anastomosis in all patients. both dilated and non-dilated bile ducts were well depicted. mrc correctly showed stenosis of anastomosis in of patients, - mm stones in of patients and bile ducts irregularities in of patients with cholangitis. conclusion: mrc is a safe, noninvasive technique in the study of biliary-enteric anastomoses and can be used to the screening of symptomatic patients. mrcp images may serve as a guide for planning of interventional procedures. cystic duct imaging using both magnetic resonance cholangiography (mrc) and d learning objectives: to describe the indications and diagnostic limits of each procedure, to present the steps taken to perform each procedure as well as the possible complications, and potential pitfalls. background: the early diagnosis of breast cancer is a challenge in breast imaging work-up. to detect malignancy in non-palpable breast lesions without unnecessary open biopsies, percutaneous biopsy of the suspect lesion should be undertaken. percutaneous breast biopsy can be performed under sonographic or x-ray guidance. whatever method is used, certain principles apply. exhibit details: the exhibit will be divided into subsections focusing on the indications and diagnostic limits of each procedure, the necessary equipment for each method and the steps taken to perform each procedure through sample cases. we will focus on practical issues such as needle size, site of entry, number of tissue probes that we need to take according to the lesion type. also the avoidance of complications, and other useful tips will be presented. a special reference will be made to the histological findings that require surgical excision and the potential pitfalls in case of false negative samples. we will also present a short time follow-up diagram for the histologically confirmed benign lesions. conclusions: whenever a non-palpable breast lesion is considered for biopsy, either x-ray or ultrasound guided procedures are performed. each method has its indications, advantages and disadvantages, and the examiner should be familiar with those factors for proper procedure selection. the use of carbon marking after stereotactic -gauge vacuum-assisted breast biopsy and during advanced breast results: eleven cases were considered fn ( %). a) four cases were found after -g core biopsies: two architectural distorsions initially diagnosed as radial scars proved to be malignant after surgery, and one case of microcalcifications, first diagnosed as adenosis, underwent month follow-up corresponding to a ductal carcinoma in situ. also a ductal carcinoma in situ was found inside a fibroadenoma (first diagnosed as fibroadenoma). b) also seven cases were found after vacuum-assisted biopsies, all of them microcalcifications that were confirmed in the radiograph of the specimen: five cases were initially diagnosed as atipical ductal hyperplasia and corresponded to four ductal carcinomas in situ, and one infiltrating ductal carcinoma; the remaining two cases were first reported as ductal ectasia and interstitial microcalcifications, becoming two ductal carcinomas in situ (one of them was diagnosed months later after core biopsy). the average diameter of the lesion was . mm. none of the lesions were removed completely. conclusion: results such as radial scar, atypical ductal hyperplasia, interstitial microcalcifications and ductal ectasia may occult a carcinoma after needle core biopsies. the percutaneous triple sample (fnac, core biopsy, and cylinder smears) in breast cancer diagnosis: results in patients i. vizcaino, v. torres, s. picó, e. blanc, c. soto, s. isarria; valencia/es purpose: to evaluate a combined method to sample tumoral tissue in breast cancer. a prospective study using at the same time fnac, core biopsy and cylinder smears was performed in patients. we used a g needle ( - passes) and a thin-wall g needle ( - cylinders, mm/ cm sized). smears of core biopsy cylinders were systematically prepared to cytological examination. the lesions were targeted using palpation, ultrasound, coordinates plate, and a stereotactic device depending on the lesion. all patients had breast cancer. the results were evaluated regarding the sensitivity to breast cancer diagnosis. the overall sensitivity of three-way diagnosis was % (the false negative case was a non-palpable dcis that showed necrosis in cylinder and no tumoral cells in both, fnac and cylinder smears). the sensitivity of fnac was the same as core biopsy: %. the sensitivity of cylinder smears was %. benign tissue in cylinders with malignant cells in cylinders smears was seen in cases ( dcis, necrotic medullar carcinoma, intracystic carcinoma and idc). fibrous tissue was found in the cylinders of these cases. the combination of fnac, core biopsy and cylinder smears show a high sensitivity to breast cancer diagnosis. cylinder smears must be obtained systematically in core biopsy in order to prevent the false negative results. weak cohesion of tumoral cells can explain this phenomenon. purpose: mammographic follow-up of patients after conservative treatment for breast cancer by screen-film mammography is difficult and sometimes impossible due to the post-radiation and surgical changes. digital mammography (dm), with post-processing tools, might facilitate the reading. the purpose of this presentation is to evaluate the accuracy of dm and to describe the post-therapeutic changes in these patients. materials and methods: dm (senograph d, gems®) was performed in patients and months after conservative treatment (surgery and radiotherapy) for breast cancer. mammograms were indepedently read by two senior radiologists. both radiologists performed screen-reading, using commercially available post processing tools (magnification, zoom, contrast inversion, thickness compensation). they evaluated the overall image quality. the following features were also analysed: breast density (according to birads classification), skin thickening, parenchymal changes with glandular oedema ( grades), scar and microcalcifications. results: all dm were considered as of diagnostic quality by both radiologists. importance of glandular oedema was correlated to breast density (birads , n = ; oedema , n = ), (birads , n = ; oedema , n = ). analysis of skin and dermal thickness was facilitated by the algorithm of thickness compensation. visibility of scars (n = ) and microcalcifications (birads , n = ; bi-rads - - , n = ) was improved by digital magnification and digital contrast variations. conclusion: digital mammography due to the post processing tools seems to facilitate dramatically reading of mammography in patients with previous conservative treatment for breast cancer, and helps to delineate post-therapeutic changes. the conclusions: it appears that the achievable image quality of a system not only depends on detector characteristics but also on available combinations of target, filter and tube voltage. therefore image quality comparisons show different results using optimized spectra for each digital system, compared to using the same spectrum for all systems. to show a short way to present breast mr dynamic imaging obtained using -mm isotropic d acquisition and single-voxel proton spectroscopy. background: during a standard breast mr exam, including a precontrast shorttau inversion recovery (stir) or fast spin-echo t -weighted fat-sat and a dynamic gd-enhanced d sequence, at least native and subtracted images are produced. moreover, maximum intensity projections (mips) of a subtracted phase and dynamic curves must be shown. if performed, proton spectra could be given with localizing images, too. procedure details: seventy breast mr exams were performed at our department as follows: -slice axial stir; t -weighted d gradient-echo coronal -mm partitions ( x -mm field-of-view; x matrix; -mm voxel) with . mmol/kg gd-chelate and -s time resolution ( postcontrast phases), giving native and subtracted for a total of images; single-voxel spinecho (te ms) proton spectroscopy. we present firstly an axial mip of the first subtracted sequence similar to cranio-caudal x-ray mammography (xm) views, two lateral mips similar to lateral degrees xm views, and a coronal mip. then, only selected images are presented: stir, precontrast t -weighted, and postcontrast subtracted images (morphology); percent enhancement-to-time curves for regions of interest (dynamics); proton spectra with/without choline peak at . - . ppm and lipids peaks (metabolism). representative cases will be shown in correlation xm, ultrasound, and pathologic proof. conclusion: breast mr high-resolution imaging and proton spectroscopy can be effectively summarized in no more than images ( x -in-one films), % of the acquired/subtracted images. mr guided interventional procedures in breast pathology management i. herraiz, l. concepción, j. ballesteros, a. fernández-moscoso, j. gallego, m. garcía-franco; alicante/es; presented by s. lopez-celanda; alicante/es learning objectives: to descibe mri-guided core biopsy of mri-suspected lesion, hook wire placement or clip marking for excisional biopsy of non-palpable, mri-only visualized lesions. procedure details: all procedures were performed on a . t philips gyroscan intera unit. standard ce breast mri imaging protocol included a dynamic volumetric t -weighted acquisition prior and after gd-dtpa injection employing a bilateral surface coil. localization was achieved either by employing a stereotatic device or by triangulation methodology with external markers with a flexible unilateral surface coil. imaging acquisition was tailored to each case. titanium clips (inrad®) or nitinol (somatex®). g titanium coaxial needles (somatex®) and g automatic biopsy gun were employed (tsk acecut®,). our series includes patients with mri suspected lesions. reevaluation of them with conventional methods (mammography and sonography) allowed location of half of them resulting finally in a total of mri-guided interventional procedures. this includes mri-guided core biopsies in lesions measuring - mm, mriguided presurgical hook wire localization and clip placements to assist location of a mri visible single lesion. pathologic evaluation resulted in cases of infiltrative ductal carcinoma and benign lesions. the only biopsy false negative result was in the smallest lesion ( mm). conclusions: all mri-suspected lesions must be reevaluated by conventional methods. in mri-only visible lesions we favor clip marking or hook wire location if size is smaller than mm. in lesions highly suspicious for malignancy additional clip marking during core biopsy procedure is recommended. background: accuracy of pre-treatment diagnosis of breast carcinoma extension is essential in order to plan the most effective therapeutic approach. extension of carcinomas can be difficult to interpret on d images, especially if their distribution is segmental or irregular. also, additional multifocal or multicentric foci can be problematic to localize in respect to the main tumour and the anatomy of the remaining breast. it is furthermore important for breast surgeons to apprehend the extent of the disease in radiological images in order to plan the surgical approach. procedure details: t -weighted flash d pre-and post-contrast images were obtained in patients diagnosed with breast cancer on core biopsy. analysis of images was done with a dedicated software for breast mri (asymedâ). parametric images for maximum enhancement speed, maximum enhancement, multiplanar and d reconstructions, speed of enhancement curves and enhancement curves are analysed in each patient. d images were viewed as video clips with a degree rotation around both breasts. maximum tumor diameter was measured in all images and distribution was reported following surgical anatomy. all shown cases have been histopathologically proven in respect to size and extension. conclusion: besides analysis of morphology and speed of enhancement curves, maximum enhancement speed parametric d images stand as a useful approach to tumor extension, giving additional information and an overall view of distribution of the disease in respect to breast anatomy. background: the rate of breast cancer recurrence is - % per year. follow-up of patients after conservative surgery includes a periodic clinical examination and a mammography every months during the first years and every year thereafter. post-treatment changes may mimic or obscure recurrent cancer. diagnostic problems are encountered with conventional imaging and fine-needle aspiration cytology. increased vascularity and vascular permeability occurs in recent scars and inflammation; however majority of scars months after surgery do not enhance significantly at mrm while all malignancies do. imaging findings: in our series all cases of proved recurrence showed over % maximum signal intensity enhancement at minute and plateau or washout dynamic curve at mrm. only two cases of scar showed more than % maximum signal intensity enhancement at minute and the curve in all benign cases was gradual. the quantitative data should be always correlated with the morphology of enhancement curve. irregular shape or margins and inhomogeneous enhancement proved to be important criteria for recurrence assessment. conclusion: mrm appears a valuable tool to differentiate post-treatment changes from recurrent carcinoma and to guide the pathological confirmation. its high negative predictive value may have an impact on follow-up of treated breasts. the correlations between enhancement parameters and histopathological findings were analyzed using stepwise multiple regression analysis, student's-t test and spearman moments correlation coefficients. results: significant correlations were determined between the presence of lymph node metastasis and tumor size (r = . , p < . ), contour characteristics (r = . , p < . ), and edge characteristics (r = . , p < . ). a highly significant correlation was found between histological grades and qualitative enhancement patterns (r = . , p < . ). statistically significant differences were found between the groups with and without lymph node metastasis regarding enhancement in the st minute (p < . ) and tic slope (p < . ). a significant difference was found between the histological grades i and iii regarding all quantitative enhancement parameters, whereas no difference was found between the grades i-ii, and ii-iii. conclusion: dce-mri helps to predict prognostic factors of breast cancer by revealing qualitative and quantitative enhancement features of the primary tumor. additional morphological factors further improve our ability to predict lymphatic metastasis. we measured the number of vessels, the major systolic velocity (ps), the end diastolic velocity (ed), the resistance index (ri) and the glosing index (pi) appearing in all the slices we took. we noted the maximum and minimum values of all the above parameters that appeared in the same mass in different slices and calculated the differences. results: for the benign tumors the mean values for the differences between the maximum and the minimum number of vessels was (diffves) . (p < . ), the diffps was . cm²/sec (p < . ), the diffed was . cm²/sec (p < . ), the diffri was . (p < , ) and diffpi was . reliability of us-diagnosis of metastatically affected regional lymph nodes in the presence of female breast cancer e. shevchenko, a. zubarev; moscow/ru purpose: analysis of false-positive and false-negative results of us in diagnosis of metastatic lymph nodes (l.n.) in breast cancer. materials and methods: patients with breast cancer (stages t n -t n ) were examined on hdi atl philips with morphological verification. patients ( . %) had metastatic deposition in regional l.n. results: precision of us-diagnosis of unchanged l.n. was equal to . , specificity - . %, sensitivity - . %. false-negative results were found in cases ( . %). in b-mode the oval shape remained unchanged in all cases, cortical layer and core were differentiated. thickness of cortex: . - . cm, node size: . x . cm- . x . cm. in cases blood flow was located in portal region, cases - longitudinal vessel in center of the l.n. sizes of the l.n. with micrometastases were up to . cm. we had false-positive results in patients ( . %). round shape was found in cases, oval -in , in patients l.n. joined together in irregularly shaped node. in cases there was uneven thickening of cortex in one pole of node with size fluctuation. differentiation of cortex and core was absent in cases and echogenity was diffusely lowered. subcapsular vessels were located in cases, aberrant vessels -in , distortion of central vessel -in , local absence of perfusion -in . false-positive cases corresponded to sinus-histiocytosis, hyperplasia of lymphoid tissue. conclusion: only use of the full complex of us-symptoms of metastatically affected l.n. lets us improve the precision of diagnosis. inter-and intraobserver agreement in breast ultrasonography: significance of internal echoes at image interpretation j. tsutsumi, k. shimamoto, m. ikeda, a. sawaki, h. satake; nagoya/jp purpose: to evaluate the significance of internal echoes among diagnostic us criteria for breast lesions. materials and methods: breast masses ( benign, malignant) were interpreted by radiologists and radiological technologists using a four-point rating scale, and the kappa statistics were employed for analying interobserver agreement. to assess reproducibility in judgments, double reading was done in cases, and a total of cases were interpreted for each observer. us criteria included shape, border, boundary echoes, internal echoes (homogeneity and echo level), posterior echoes, lateral shadow, gland surface, depth-width ratio (d/w) and total impression in differentiating benign from malignant lesions. to evaluate the significance of internal echoes at us image interpretation, us images were modified to make the internal echoes invisible by painting with black color using the adobe photoshop. : roc analysis showed a significant difference in diagnostic performance between the original us images and modified us images (p < . ). the kappa value of posterior echoes was highest whereas that of boundary echoes showed the lowest value in both the original and modified us images. inter-observer agreement in shape, border, and category in the original images was significantly higher than that in the modified images (p < . ). reproducibility in boundary echoes and gland surface was fair, and that in posterior echoes and the d/w was good. can a mammogram dictate to you the diagnosis? a review of characteristic mammographic findings a.n. chalazonitis , j. tzovara , t. vrakatselis ; athens/gr, ioannina/gr learning objectives: participants will obtain an approach to various mammographic patterns and improve their diagnostic skills in breast imaging. background: mammography is considered by far the single most important imaging modality for breast diseases. except from radiologists with vast experience, many other physicians without specific knowledge are unable to discriminate normal from abnormal findings in the mammograms. imaging findings: the main aim of this exhibit is to provide a pictorial review of characteristic radiological findings in different mammograms. various examples due to different causes are illustrated and mammographic findings, as well as differential and final diagnosis are also discussed. all cases have been selected by reviewing our hospital teaching files. conclusion: our exhibit will allow participants to challenge their skills in the detection of both normal and abnormal mammographic signs. breast imaging and histopathologic correlation of fibroadenomas in patients with transplanted kidney: different features from usual fibroadenoma e. son , e.-k. kim , k. oh ; sungnam/kr, seoul/kr learning objectives: to analyze the imaging and histopathologic features of fibroadenomas in kidney transplanted patients and to compare findings of fibroadenomas in kidney transplanted patients with those in a control group. background: from to , , patients underwent renal transplantation at our institute. all patients received immunosuppressive therapy with cyclosporin a and steroid after renal allograft. we examined ten female patients who were diagnosed with fibroadenomas during chemotherapy, and compared the data obtained with that of fibroadenomas in the normal population. procedure details: twenty-two fibroadenomas developed in ten patients. eight of the patients had multiple fibroadenomas and had bilateral fibroadenomas. the mean diameter of the fibroadenomas was . ± . cm. by mammography the lesions were spherical in shape and had a well circumscribed margin with a high density mass. none of the lesions showed calcification or spiculation. sonographic findings of the masses showed relatively high echogenecity with higher l/t ratios than benign masses, however, features of homogeneous internal echo and well circumscribed margin were consistent with benign. conclusion: the fibroadenomas that developed in patients with renal transplantation showed a tendency to be multiple, bilateral and larger than those in the control group. these fibroadenomas also exhibited a more rapid growth, a more spherical shape and an unusually high internal echo and higher l/t ratio than usual fibroadenomas. to present mammographic and ultrasonographic (us) findings in various types of reconstruction using autogenous myocutaneous flap after mastectomy or breast conserving operation. background: breast reconstruction is an integral part of a woman's breast cancer management and yields positive psychological benefits for the patient. autologous tissue reconstruction has gained in popularity in part owing to adverse publicity regarding prosthetic implant safety. it can alter breast anatomy and architecture drastically. in this exhibit, we describe mammographic and us findings in the various types of reconstruction using autogenous myocutaneous flap after mastectomy or breast conserving operation. procedure details: mammography and ultrasonography obtained in patients who had undergone reconstruction mammoplasty using the autogenous myocutaneous flap procedure were reviewed to facilitate recognition of both normal and abnormal postoperative appearances of the various types of reconstruction using autogenous myocutaneous flap after mastectomy or breast conserving operation. normal mammographic and us findings include predominance of fatty appearance, surgical clips, and surgical scars. abnormal mammographic and us findings include fat necrosis, calcifications, and locally recurrent carcinoma. us findings of fat necrosis were cystic, complex and solid appearing masses with circumscribed or ill-defined margins in peripheral portions of flap. us finding of locally recurrent carcinoma was ill-defined heterogeneous hypoechoic lesions in reconstructed breast, similar to those of primary breast cancer. conclusions: breast reconstruction using autogenous myocutaneous flap has increased in popularity with various methods. mammography and sonography facilitated excellent visualization of normal and abnormal findings of various reconstructed breasts using autogenous myocutaneous flap. extramammary pathology mimicking breast disease e. rabanal, r. rosell, j. salvia, r. garcia; sabadell/es learning objectives: to present the imaging findings in cases suspected initially of breast disease which turned out to have extramammary pathology. background: we reviewed our records for the last ten years. during that time, , mammary studies were performed. all cases with extramammary pathology were selected. they were classified into two broad categories: those which had abnormal physical findings (palpable mass or skin thickening) and those with abnormal findings in the mammogram (calcifications, nodules and thickened lymphatics). imaging findings: cases were classified as follows: microcalcifications secondary to filariasis. we will see more of these cases due to increased immigration. it's important to know this entity to make the correct diagnosis and avoid unnecessary examination or biopsy. uniform skin thickening and/or oedema, secondary to systemic disease (sclerodermia), congestive heart failure or lymphoedema. palpable skin nodules (infected sebaceous cysts), simulating mammary abscesses. chest wall disease: empyema necessitatis draining into the breast. extramammary (chest wall) lipomas and dercum's disease. neurofibromas in von recklinghausen's disease. the imaging findings of these processes will be reviewed and their salient features described in order to suggest the correct diagnosis. conclusion: it is important to know the features of extramammary disease in order to make the correct diagnosis, avoiding further examinations and unnecessary invasive procedures. the reality of microcalcifications in breast tissues shown by synchrotron radiation imaging j. okamoto, y. kanemaki, k. imamura, n. ehara, y. inada, i. maeda, k. miyamoto, y. nakajima, m. fukuda; kawasaki/jp purpose: the aim of this study was to approach the reality of microcalcifications of benign and malignant diseases using synchrotron radiation imaging, and to make a comparison with conventional x-ray images. materials and methods: surgical and biopsied specimens fixed in wax blocks were imaged using synchrotron radiation (sr), and conventional mammography unit (conv) as well. studied were patients ( benign, malignant). sr imaging was performed at spring- in japan in refraction-enhancement mode. conv images were evaluated visually using a magnifying glass. sr images were inspected on a monitor without magnification. morphology of microcalcification was categorized to groups: small round, amorphous (am), and pleomorphic (pl). results: , calcifications were observed in conv images and , calcifications in sr images. , of , ( %) were invisible in conv images. sr imaging revealed that great numbers of specks were recognized collectively as a single calcification in conv images, and of , calcifications in conv images were found to consist of multiple specks. the incidence was especially higher in am and pl types ( / and / , respectively). comparing malignant with benign diseases, there was a striking contrast in am-type calcifications; majority of am-type calcifications in malignant diseases were found as collectives of fine specks ( / ), to the contrary / in benign (p < . ). conclusion: synchrotron radiation imaging showed that majority of amorphous and pleomorphic type calcifications, especially of amorphous type of malignant diseases, in conventional images were essentially collectives of multiple specks. psychological perceptions of women due to mammographic follow-up b. barreau , r. gilles , s. tastet results: women answered the questionnaire. all women were satisfied with the mammography and the medical staff except that the mammography was painful in cases. for women, the period between mammographic follow-up was too long. in women, the quality of life was altered. communications of the experience to a relative was frequent ( / cases) but satisfactory in only cases. for women, medical information was considered relevant. the median of the scale of stress was ( - ). there is two pickaxes, one at , the second at . "low-stressed" women could have an avoidance coping. "high-stressed" women could use a helplessness-hopelessness coping strategy. conclusion: women reported relevant medical information and comprehension of the short follow-up -mammography. they were reassured by the medical care, but the evaluation of the scale of stress was high, probably due to the diagnosis. mammographic density changes in postmenopausal hormone therapy: effects of various agents using a new scoring system s. orguc, c. göktan, g.y. ovali; manisa/tr purpose: to evaluate the changes of mammographic breast density due to postmenopausal hormone replacement with various agents using a new scale and to compare the new scoring system with the classical methods. materials and methods: women who received hormone replacement therapy in celal bayar university hospital between - were examined with baseline and follow-up mammograms. the effects of various hormone regimens, selected according to the gynecological status, were evaluated by two radiologists. wolfe classification and a new scoring system were used to assess the change of mammographic density. the new scale divides each breast into ten wedge shaped slices on the cc positioned mammograms. change of density is scored according to the number of slices, which have an increase of density in comparison with the baseline mammograms. the results were statistically evaluated to compare the effects of various hormone regimens using a control group of patients who did not receive any hormonal therapy. statistical analysis was also carried out to determine the effect of using different scales. results: tibolone effected breast density is less than preparations containing oestrogen. degree of mammographic change differs depending on the scale used. the new scale is more sensitive in depicting changes of breast density. conclusion: preparations containing oestrogen effect the mammographic density more than tibolone regimens. the new scaling system is highly efficient and objective in determining the changes of breast density. to evaluate sensitivity and specificity of positron emission tomography (pet) and -f-fluorodeoxyglucose ( f-fdg) in breast cancer diagnosis and to assess tumor dissemination. materials and methods: patients were examined: without mammary disease, with fibrous cystic mastopathy, and with breast cancer, which was hystologically proven. pet-scans (ecat exact ) in "whole body" mode were performed min after intra-venous injection of - mbq f-fdg. the t/ nt ratio for radiopharmaceuticals was evaluated. results: in all patients with malignant tumors the t/nt ratio for pet- fdg was higher than . (m ± m = . ± . ). it was shown that pet has a high diagnostic accuracy in breast cancer detection with sensitivity % and specificity %. pet scanning in the "whole body" mode was allowed to assess dissemination of tumor process with high accuracy. pet f-fdg sensitivity was around . % to % in diagnosis of regional and distant metastases. it was related to metastases localisation. conclusion: pet with f-fdg has high diagnostic accuracy in diagnosis of breast carcinoma and staging of tumor extent. results women aged between - were invited in three rounds in the mentioned period of time. bilateral mammography with double projection was performed, and read in a double blind manner, according to the strict, prescribed methods. if needed, additional mammographic x-ray, us, fnab and core biopsy was performed. results: the acceptance rate was low, around . % ( women were screened during five years). we called back around % of the screened patients for additional x-ray examination ( . %) or for us ( . %). we performed fnab in % of all cases ( women). cases were proven benign. the overall rate of hystopathologicly verified invasive cancers per women were ( patients). we could detect an increasing rate of small cancers and better lymph node state by the time, because around % of the examined women were already screened by us before, during the -year-period. number of interval carcinomas was nine ( . %). conclusions: comparing to european standards our screening program was the same, but the acceptance rate was lover. the high non-acceptance rates can be explained mainly by the cross-screening possibilities of budapest, hungary and because the high risk population is not informed well enough. however, due to the mental hygenic program running in hungary, we could detect an increased number of inquisitive women. tubular carcinoma of the breast: clinical, mammographic and ultrasonographic findings f. zandrino , m. calabrese , l.e. bacigalupo , f. musante ; alessandria/it, genova/it purpose: tubular carcinoma is a well differentiated invasive adenocarcinoma, with a prevalence ranging from to % of all carcinomas of the breast. the purpose of this presentation is to analyse its clinical, mammographic, and ultrasonographic features, with histopathological correlation. materials and methods: in a retrospective review of consecutive histologically proven carcinomas of the breast, pure (tubular component of at least %) tubular carcinomas were found ( . %) in women (age ± yrs). results: three lesions were palpable. on mammography, five were not detectable; the remaining presented as nodules with spiculated ( lesions) or irregular ( ) margins, spiculated nodules with microcalcifications ( ), distorsion ( ), or asymmetric density ( ). on us, lesion was not detectable; the remaining presented as hypoechoic lesions with irregular ( ) or well defined ( ) borders. for tumours, diagnosis of carcinoma was made with cytology; in cases core biopsy: in the first a complex sclerosing lesion with atypical cells was suggested, in the second differential diagnosis between tubular carcinoma and sclerosing adenosis was proposed. lesion size was . ± . mm. only in patient were metastatic axillary nodes found. conclusion: in our series, tubular carcinoma presented mainly as a non-palpable, small-sized lesion, with non-specific mammographic patterns and a hypoechoic ultrasonographic appearance. lymph node metastases are rare, as previously reported in the literature. dose distribution in tangential irradiation for breast h. ohtani, s. usui, y. jincho; tokyo/jp purpose: skin injury, lung disease and conservation radiation therapy for breast is reported. in a previous investigation, local management and survival rates were reported on the face of treatment effect's records, but the real irradiation doesn't become clear. this report is to measure the dose distribution of the effect on the critical organ by tangential irradiation of the left breast. materials and methods: measurement was performed with a semiconductor detector. irradiation was performed with x-ray beams at degrees. irradiation field sizes were established × cm to investigate influence by field sizes. irradiation was done on the wedge of degrees. results: dose equivalent was accurately measured with semiconductor detectors. from the results, breasts, thyroid gland, heart, both lung fields, kidney, ovary, and uterine doses become clear. the dose distribution at tangential irradiation of left breast was measured. consequently, the breast in which a radiation injury tends to be encountered, lung field, and the dose of important internal organs could be obtained. the necessity to confirm the dose distribution in the body for tangential irradiation in breast preservation treatment, refers to a radiation injury, and this study estimates these doses. the to assess the influence of days of repetitive hyperbaric simulations on the form and structure of single-lumen silicone gel-filled implants. materials and methods: new implants from different manufacturers and removed implants were submitted for simulated dives in a hyperbaric chamber, with an average of dives a day and with a maximal depth of m. a standard x-ray and mri were performed before, after and days of repetitive diving, and days after the experiment. mri was performed using a . -t superconductive magnet (symphony-, siemensag, erlangen, germany) with a body and spine coil, and a gradient echo t -w sequence ( d flash), slice thickness mm. the prostheses were checked for bubble formation, volume changes, integrity and morphological appearance. results: there were no significant changes in form, nor in shell integrity. after days of repetitive diving, there were some tiny bubbles in the implants, confirmed by x-ray and mri. after days, there were significant bubbles in of the implants (increase in implant volume up to %); in the other there was a slight increase in number and volume of bubbles. there was no significant change in the bubbles days after the last dive. the significant bubble formation in some single-lumen silicone gelfilled implants after days of repetitive diving, raises concern about the influence of repetitive stress on the lifespan of implants in correlation with the number and depth of dives. resection of non-palpable breast cancer using d imaging created by multislice helical ct: a new interventional technique to design resection lines in breast preserving surgery k. oda, t. kubota, h. satake, a. sawaki, t. ishigaki, y. nimura; nagoya/jp purpose: we report a new method for an adequate segmental resection of nonpalpable breast cancer employing an interventional technique using three-dimensional images of contrast-enhanced ct. materials and methods: eight patients with non-palpable breast cancer (dcis , invasive carcinoma ) were included in this study. diagnosis of carcinoma was made by cytology, but the extent of the lesion could not be clearly shown by us. one hour before the operation, contrast-enhanced helical ct was performed using a toshiba aquilion (toshiba corp. tokyo) with the patient in the supine position, following the insertion of vats (video assisted thoracoscopic surgery) markers (hakko, japan) under us guidance. ct scan was performed seconds after the injection of contrast medium. the detector row configuration was x -mm. maximum intensity projection (mip) was performed on three-dimensional reconstruction ( d-ct). using three-dimensional images of ct, anatomical relationship of vats markers, nipple and carcinoma demonstrated as a well-enhanced focal-clumped lesion or segmental lesion was evaluated and lines of resection with to cm surgical margin were designed. curative resection was confirmed in x-ray films of resected specimens based on the relationship between the lesion and the vats markers in preoperative three-dimensional ct images. results: in all cases, adequate segmental resection with cancer free surgical margins was accomplished and the cosmetic results of the surgery were satisfactory. conclusion: three-dimensional images of contrast-enhanced ct with this interventional technique is a useful method to design resection lines for non-palpable mammary carcinomas. european breast screening performance: does case volume matter? h.j. scott , a.g. gale , d. wooding , d. walter ; derby/uk, augsburg/de purpose: u.k. breast screening radiologists typically read over , screening cases per annum, whereas in europe this figure is much lower as in many countries national breast screening programs are in their infancy. the performs scheme in the u.k. permits radiologists annual self-assessment of their filmreader skills. as part of the eu funded european breast cancer network a number of german radiologists have now read the current performs assessment set. we investigated whether real-life case volume affects reading performance by the comparison of matched groups of radiologists from these two countries. we analysed the data from current sets of difficult recent screening cases. for each case individuals identified which key mammographic features were present, whether the case was abnormal and should be recalled or not. for this analysis the participants were matched on age, gender, film-reading protocols and years of experience. assessment of case volume was elicited by questionnaire data. the radiologists were compared on several key performance measures; cancers detected, correct recall and correct return to screen, signal detection performance statistics and real-life screening practice. results: it was found that whilst the performance of the german radiologists on the current test sets was excellent (correct cancer detection rate > %) on average they performed less well than their uk counterparts. we argue that this is closely related to the volume of cases read per annum by individuals within each country, and theoretically their performance will be equivalent as their case volume increases. the cytogenetic method of dosimetric control for screening mammography v. demin, e. djomina; kiev/ua purpose: it is advisable to study a degree of risk due to the unfavourable consequences of irradiation of the breast with screening mammography in ukraine after the chernobyls disaster. the correlation of cytological (cytogenetic) and physical findings were accomplished. the test-tubes with donor human blood were placed on upper and lower surfaces of breast of tissue-equivalent aldersons phan-tom. the test-culture of lymphocytes of human peripheral blood were used for biological dosimetry. physical dosimetry are realised with the thermoluminescent system alnor. the chromosome aberrations are becoming + . % on the upper surface of breast (normal control level is %) on mammography in two projections (upper-lower and lateral), the fragments of chromosome type are %, radiation markers -dicentric chromosome are . %; equivalent dose is . %. conclusion: there is a risk of radiation induced genetic lesions in breast tissue after mammography. instability genome is a basic radiation carcinogenesis. this is very real for women in ukraine after the chernobyls disaster. efficiency of the multidetector row ct in the diagnosis of breast cancer and evaluation of intraductal spreading h. kani, m. matsuki, i. narabayashi; takatsuki/jp purpose: the purpose is to analyse the efficiencies of multidetector row ct (mdct) in the diagnosis of breast cancer and evaluation of intraductal spreading. materials and methods: pathologically diagnosed breast lesions from patients were examined by mdct. the lesions included the following: invasive carcinomas, noninvasive ductal carcinomas, fibroadenomas, papillomas and other benign lesions. non-contrast ct and contrast-enhanced ct scans at , and sec after the start of enhancement were performed using row mdct. the imaging was performed under the following conditions: . -sec gantry rotation speed, . helical pitch, mm slice thickness and reconstruction intervals of mm. the items examined were as follows: ) in time-enhancement patterns during four phases, the early enhancement and plateau patterns were defined as a malignant tumor and gradual enhancement pattern was defined as a benign lesion. its ability in the diagnosis of malignant tumor was evaluated in the comparison with histopathologic findings. ) the abnormal enhancement continuing to the tumor at sec after the start of enhancement was estimated as intraductal spreading of breast cancer. the detectability of intraductal spreading was evaluated by the comparison with histopathologic findings. results: . the sensitivity, specificity and accuracy of the diagnosis of malignant tumor were . %, . % and . %, respectively. . the sensitivity, specificity and accuracy of the detactability of intraductal spreading of breast cancer were . %, % and %, respectively. conclusion: mdct is very useful for the diagnosis and preoperative estimation of breast cancer. an exploratory study about mammographic practice (acr from bi-rads) three months after a medical continuing education on breast cancer b. barreau , s. tastet , m. deghaye , v. picot , i. brault , p. marelle , l. ceugnart , d. aucant , s. haber ; paris/fr, bordeaux/fr objectives: evaluation of practices, three months after a medical continuing education, when abnormalities acr (probably benign) are detected on mammography. materials and methods: a questionnaire ( items) about these practices was sent to radiologists three months after medical continuing education (may-december ) . the answers were analysed with chi-square test. results: radiologists completed the questionnaire; radiologists practiced breast screening; used the bi-rads classification; radiologists followed-up the abnormality with a short interval, made a biopsy and overclassed the image; radiologists asked for advice from other radiologists, from an expert, submitted to a multidisciplinary committe and asked for a second reading. a short interval-follow-up disturbed radiologists about an eventual unfavourable evolution of the abnormality and radiologists about legal problems; had difficulty in explaining to patients the short interval-followup. the median of the scale ( to ) of the radiologists perceived stress is . conclusion: these french radiologists have consistent practices with the bi-rads classification and the anaes recommendations. they may have difficulties in explaining the procedure to patients. the radiologist's ethic is based on the "primum non nocere". c b d e f a g histopathological perspective on the first german mammography screening project: a two year review g. gohla , u. sauer , p. hanisch , w. boecker , h. junkermann , u. bonk ; bremen/de, münster/de purpose: the aim of this investigation was to critically review the role of the histopathologist in a mammography screening project. materials and methods: the first model mammography screening project in germany has been running in bremen for the last two years. all women between and years of age have been offered mammography and any suspect findings were investigated by core biopsy. these cases were reviewed in the pathology dept. of the university münster and discussed at a weekly multidisciplinary meeting. lesions were classified using the point b classification scale as recommended by the european union. results: in the first two years of the screening project, a total of women had mammography. suspicious areas were detected and core biopsies were obtained from of these women. % were classified b (malignant) % of these cases were classified b , (regular breast tissue, benign) and % of these cases were classified b and b (atypia probably benign, suspicious of malignancy). in % of all cases there was agreement amongst the reviewing histopathologists, but in % there was no interobserver consensus. these disagreements centered on flat epithelial atypia, atypically hyperplasia and papillary lesions. the consensus amongst experienced breast histopathologists is satisfactory in clearcut cases, but it should be improved in less well classified lesions. these lesions are more likely to be seen in a screening situation and in core biopsies. in this area it is certainly advisable to cooperate closely with the clinician and radiologist. usefulness of multi-slice ct for nonpalpable breast lesions with microcalcifications: correlation with mammographic findings h. satake, a. sawaki, k. shimamoto, s. ishigaki, k. oda, t. imai, t. ishigaki; nagoya/jp purpose: to evaluate the usefulness of multi-slice ct for nonpalpable breast lesions with microcalcifications, compared with mammographic findings. materials and methods: cases with nonpalpable microcalcification of the breast recommended for biopsy on mmg. they included malignant lesions (ductal carcinoma in situ, n = ; ductal carcinoma in situ with microinvasion, n = ) and benign lesions (mastopathy, n = ; intraductal papilloma, n = ; other, n = ). on multi-slice ct images, the presence of focal or segmental enhancement in the region consistent with microcalfications was regarded as positive diagnosis for malignancy. all mammographic and ct findings were assessed with a consensus between two radiologists. results: cases of benign lesions pathologically were assessed as "suspicious malignant" on mmg, while, in three of them, focal or segmental enhancement appeared on multi-slice ct. although seven cases of breast cancer were assessed as "probably benign" on mmg, six cases acquired focal or segmental enhancement on ct. for cancer diagnosis, the sensitivity of mmg and multi-slice ct were . % and . %, specificity was . % and . %, and negative predict value were . % and . %, respectively. breast conservation surgery with simulation using d ct images was performed successfully in cases of breast cancer. the sensitivity and the negative predict value of multi-slice ct for nonpalpable breast microcalcifications were superior to those of mmg. when biopsy is recommended according to mmg, additional examination of multi-slice ct enables the indication for biopsy to be more optimized and is useful for planning the treatment. the value of magnetic resonance imaging in the assessment of adult patients with corrected transposition of the great arteries s. shine, e. kavanagh, c. we fully illustrate the morphology, contrast enhancement and mobility of myxomas in rare locations such as the right ventricle and unusual attachment to the tricuspid valve. background: although benign myxoma is the most common primary cardiac tumor ( %), it remains a rare finding with an incidence of . per million population per year in the western world. myxomas are found in the left ( %) or right ( %) atrium and seldom in the ventricles. these pedunculated tumors typically arise from the atrial septum near the fossa ovalis and much less frequently from the mitral valve. intracardiac obstruction and systemic emboli are the major complications. imaging findings: myxomas in an uncommon cardiac location should be differentiated from other primary (malignant) and secondary (thrombus; metastasis) cardiac tumors. mri allows visualization of the narrow pedicle, its attachment and the changing tumor shape and mobility during the cardiac cycle, unlike most malignant processes. in contrast to most thrombi, myxomas have low signal intensity on cine gradient-echo images and show contrast enhancement. the water-rich myxomatous stroma, fibrous stroma, calcifications and hemorrhage account for the heterogeneous t -weighted se images. increased interstitial space in the myxoid region and inflammatory zones enhance after intravenous gd-dpta on t -weighted se images. lobular tumor surface and higher volume increase the pre-and postoperative risk for systemic emboli. furthermore, the exact location on mri is most helpful in planning the surgical access. conclusion: myxomas in uncommon locations can be differentiated from other cardiac tumors by evaluating tumor morphology, mobility and enhancement. how to study with cmr a patient submitted to ross procedure: a step by step follow-up protocol r. ribes , a. luna , j. vida , p. caro ; cordoba/es, jaen/es, cadiz/es learning objectives: to describe an adequate protocol to study patients submitted to ross procedure with mr. to identify and quantify postsurgical complications in this group of patients with mri. b d e f a g background: ross procedure is widely accepted as one of the best methods for aortic valve replacement, especially in children and young adults. ultrasound is usually used in their follow-up, but tit offers a limited evaluation of the right outflow tract, being important to discard homograft stenosis. mri overcomes the limitations of ultrasound and may replace the number of digital subtraction angiograms traditionally performed in the follow-up of these patients. procedure details: we describe step by step our mr protocol, to study patients submitted tothe ross operation. examples of the mr features of common presentations and complications are shown from our series of patients. our protocol consists of the following steps: • black-blood coronal and transverse turbo spin echo t -weighted images. • cinemr gradient-echo sequences allow functional qualitative assessment of themotion of valves and chambers, the detection of either valvular regurgitation orstenosis, and areas of altered myocardial contractility or relaxation. we perform gre-cinemr sequences in left two chamber, right two chamber, fourchamber, short axis (at several levels from the apex to the base), left ventricular outflow tract, right ventricular outflow tract, and aortic rootviews. • phase contrast images are performed to obtain quantitative data about magnitude anddirection of blood flow through the right and left ventricular outflow tracts. conclusions: cmr allows an accurate evaluation of patients submitted to ross procedure and identification of the postsurgical complications. the causes of focal outpouching of the left ventricle are as follows: ) true aneurysm; a chronic complication of myocardial infarction, which contains the endocardium, epicardium, and thinned fibrous tissue replacing the myocardium, ) pseudoaneurysm; a consequence of rupture of the ventricular free wall due to acute infarction and confined by the pericardium, ) diverticulum; a congenital outpouching of ventricular wall including all of three layers, and ) hibernating myocardium due to chronic ischemia with paradoxical outpouching at systole. mr imaging is useful in differentiating these causes by using variable imaging sequences to evaluate the myocardial contractility, perfusion and viability. in this exhibit, we will show the usefulness of mr imaging to differentiate these pathologies using various mr imaging sequences. imaging methods and findings: cardiac mr imaging methods include; ) cine imaging for wall motion analysis, ) first pass myocardial perfusion imaging, and ) delayed enhancement imaging. images were obtained along the short axis and horizontal long axis of the heart. by analyzing the shape, contractility, motion, perfusion, and contrast enhancement, it is possible to differentiate the causes of the outpouching lesion of the left ventricle. conclusion: cardiac mr imaging is useful in differentiating various causes of focal outpouching of the left ventricle. features of cardiac disease demonstrated on ct pulmonary angiography s. conclusion: ctpa is an increasingly frequently used investigation for the detection of pulmonary embolism. most patients investigated have pathology other than pe as a cause of their symptoms. frequently information about the heart is yielded that provides important clues to determine the cause for the presenting symptoms and signs or reveals co-existing pathology. with this investigation being used more frequently in daily practise in many patients with unexplained breathlessness or chest pain it is important to have a clear understanding of the features of cardiac disease as seen on a ctpa. mri has been done twice - - days and - months after surgery. mri was performed with a . t mr imager using ecg-gated t -se (or t -tse), bright-blood gre-cine-technique and phase-contrast mri. results: pts (of ) had a positive dynamic study of heart chambers dimensions and volumes in early postoperative stage. in the area of prostheses signal of low intensity was defined in all the patients (artifacts). narrow flow of low signal intensity along the prostheses leaflets corresponded to normal function of prosthesis ( of valves). pts had signs of mechanical valve dysfunction ( mitral paravalvular leaks, -aortic prosthetic valve stenosis). mri data were in agreement with the results of echocardiography. mri was able to diagnose such postoperative complications as atelectasis ( ), mediastinal haematoma ( ), pleuritis ( ). conclusion: mri could give an objective information about heart morphology (chamber dimensions, hypertrophy degree) and mechanic valve functioning (normal and abnormal flow) in patients after surgery. it can be safely performed in patients with artificial heart valves. negative calcium scoring: can it rule out severe stenosis? p.m. carrascosa , c. capuñay , p. garcia merletti , p. johnson , s. chandra , r. pissinis , j. carrascosa ; buenos aires/ar, cleveland, oh/us objective: to determine the presence of stenosis greater than % (in at least one coronary vessel) proved by digital angiography (da) in patients with a negative calcium score and correlate findings with ct angiography. methods: patients were evaluated. cts were performed with a -row ct scanner. the calcium score was calculated according to the agatston method. a calcified plaque was defined as a lesion of at least two adjacent pixels with signal intensity above hu. the second enhanced acquisition was performed following the administration of ml of non-ionic contrast with x mm collimation and . mm slice increment. das were performed on a digital angiographer. meas- car car car cardiac diac diac diac diac urements were done by means of qca. stenosis was considered positive if it was greater or equal than %. results: there were patients with high grade calcium score. eleven had positive da for at least coronary artery and in cases the da did not show severe stenosis. there were patients with negative calcium scores (grade ), had negative da findings, and had positive da findings. in these patients, the contrast ct acquisition revealed that the cause of the stenosis was due to soft plaques. conclusion: high grade calcium scores predict severe stenosis. negative results do not exclude them. in this study the % of the patients had negative calcium scores but significant stenosis due to soft plaques. a contrast ct acquisition instead of the calcium score will be necessary to rule out all the severe stenosis. positron emission tomography and n-ammonia application to evaluate myocardial blood flow in the asymptomatic patients with coronary artery calcification d.v. ryzkhova, i.e. itskovich, l.a. tyutin, l.a. kofal; st. petersburg/ru the purpose of this study was to assess myocardial blood flow (mbf) in the asymptomatic patients with coronary artery calcification (cac). methods: symptom-free patients with cac were included in study. all of them hadn't any symptoms of cad (chest pain, severe arrhythmia, heart failure) and myocardial infarction history. the patients with significant myocardial hypertrophy weren't included. the myocardial blood flow at rest (mbf rest) and during dipyridamole test (mbf stress) was evaluated by n-ammonia dynamic pet ("ecat exact ", siemens). the coronary calcium score (ccs) was measured by msct coronaroangiography ("somatom volume zoom", siemens) using the agatston method. results: myocardial perfusion abnormalities during stress test were revealed in patients with cac, there were patients with silent ischemia ( st group). we observed normal myocardial perfusion at rest and during stress test in the remaining patients ( nd group). the mean values of total ccs were less than units and close between the both group ( . ± . units vs. . ± . units, p = ns). mbf-values at rest didn't differ between the both patients' groups ( . ± . ml/ g/min vs. . ± . ml/ g/min, p = ns). mbf stress mean values were significantly decreased in the st group ( . ± . ml/ g/ min vs. . ± . ml/ g/min, p < . ). the ccs less than units isn't a reliable marker of flow-unlimiting stenoses in asymptomatic patients.soft lipid-laden plaques is a cause of myocardial ischemia in symptom-free patients with cac and low ccs. these patients should undergo stress studies to detect silent ischemia. detection and assessment of myocardial inflammation and fibrosis by echo-densitometry and ce-mri in patients with mild and medium myocarditis: validation by wbc-mibi spect m. deryugin, i. itskovitch, v. soukhov, s. boytsov, a. svistov; st.petersburg/ru background: echo-densitometry and ce-mri are novel methods for assessment of inflammatory myocardial infiltration (imi) and myocardial fibrosis (mf). the purpose of the current study was to validate these methods in patients with mild/medium myocarditis using wbc-mibi spect. methods: ce-mri was performed in patients using t -weighted turboflash inversion recovery. inflammation was evidenced by use of threshold method (signal intensity > + . sd). left ventricle echo-densitometry performed in long-axis views from left parasternal border at es/ed with following percentage cyclic variation indexes (cvi) calculation. spect was performed - hrs p.i. of mbq mtc-wbc and min p.i. of mtc-mibi. results: all patients were divided into groups based on scintigraphic data: first group - patients with diffuse leukocytes uptake that considered as imi; in second group there were patients with local leukocytes uptake and abnormal mp (imi+mf); third group consisted of patients with only mf. control group patients (n = ) had normal mp and no leukocytes uptake. cvi was ± % in controls; . ± % in st ; - . ± % in nd and - ± % in rd group. ce-mri was able to detect imi in % of patients. regression analysis revealed good correlation between imi by ce-mri and by wbc-spect (r = . , p < . ). furthermore, good correlation was found between cvi and mtc-mibi uptake (r = . , p < . ) both for imi and mf detection. conclusion: ce-mri enables exact detection of imi as compared to wbc-spect. the results of videodensitometry studies demonstrated that different types of imi were associated with definite cvi percentage, while cvi became negative with mf appearance. one-year ct evaluation of pulmonary veins following percutaneous cryoablation in patients treated for atrial fibrillation b. ghaye , d. szapiro , c. background: pulmonary vein isolation (pvi), using radiofrequency energy, for treatment of atrial fibrillation (af) has been associated with complications including pulmonary vein (pv) stenosis or thrombosis. the purpose of this study was to prospectively evaluate the pv morphology following cryoablation. method: patients underwent percutaneous pvi in academic centers. contrast-enhanced, single-slice or multi-slice spiral ct ( - . mm thick slices) was obtained before, and months following pvi. all examinations were read blinded to the location(s) of ablation. pvs were evaluated quantitatively and qualitatively: the diameter at ostium and at cm from ostium were measured. the presence and location of luminal irregularity or thrombosis was also assessed. the aims of this study were comparison of the local myocardial contraction between the myocardium with de and without, and evaluation of myocardial de's prognostic significance in patients with congestive heart failure due to nonischaemic dcm. materials and methods: delayed enhanced mri and myocardial tagged images were taken in patients ( ± yrs, male) referred for congestive heart failure due to nonischaemic dilated cardiomyopathy, whose left ventricular (lv) end-diastolic volume index > ml/m and lv ejection fraction < %. the patients were followed for a mean of ± months. results: myocardial de was present in patients ( %). in these patients, the average amount of myocardial de was ± % of lv myocardium ( - % of lv). myocardial axial thickening was ± % in the segments with myocardial de, and ± % without (p = . ). myocardial circumferential shortening was ± % in the segments with myocardial de, and ± % in without (p = . electron beam ct (ebct) in the detection of abnormal myocardial contrast enhancement in patients with recent and chronic myocardial infarctions t. vesselova, v. sinitsyn, s. ternovoy; moscow/ru purpose: of the study was to determine the occurrence of low-density areas in the myocardium of the left ventricle (lv) in patients with myocardial infarction (mi) seen during non-invasive ebct coronary angiography. material and methods: patients ( . ± . years old) with ischemic heart disease and mi were included in the study. in patients with first myocardial infarction (mi) ebct was performed during first weeks after coronary event. in patients ebct was done months after an mi. ebct angiography and venticulography were done with imatron c- imager. results: low-density areas in lv myocadium were seen on ebct images in all patients with mi. in % of patients these findings were accompanied by myocardial thinning and in % cases intracavitary thrombi were present. in . % patients with transmural mi low-density myocardial regions were visualized on non-contrast images. in . % patients with mi subendocardial low-density zones were seen. results of ebct were in agreement with myocardial scintigraphy. characteristics of hypodense areas (hu values) in patients with recent and chronic mi were similar. calcifications and significant stenoses of coronary arteries were found in all patients with old mi, the mean (sd) agatston score was . ± . . in patients with subacute mi the mean agatston score was . ± . (ns). four patients from this group had coronary score = . conclusion: during ebct coronary angiography most of the low-density areas corresponded to sites of previous myocardial infarctions. some of these areas may correspond to hypo-perfused areas of ischemic, but viable myocardium. progression of coronary artery disease in relation to coronary stenosis morphology: quantitative coronary angiography analysis j. saponjski, m. ostojic, b. beleslin, v. vukcevic, m. nedeljkovic, s. stojkovic, a. dordjevic/dikic, i. nedeljkovic; belgrade/yu objective: the aim of this study was to analyze progression and regression of coronary stenosis in relation to stenosis morphology. the study group consisted of patients ( male, female; mean age ± years). coronary stenoses were analyzed by quantitative coronary arteriography including percent diameter stenosis (%ds) and changes in obstruction diameter between two arteriographies. according to the ambrose angiographic lesion morphology groups were identified: group i (n = )-simple concentric lesion morphology, group iia (n = ) -simple eccentric lesion morphology, group iib (n = ) -complex lesion morphology, and group iii (n = ) with complex and multiple coronary stenoses. the follow-up period between first and second arteriography were similar for all groups (i, ± months; iia, ± months; iib, ± months; iii, ± months; p = ns). results: progression of coronary artery disease was identified in %, %, % and % of lesions in ambrose groups i, iia, iib, and iii, respectively. on the contrary, regression of coronary stenosis was documented in %, %, % and % of lesions in groups i, iia, iib, and iii respectively. however, comparing the lesions with non-significant and significant stenosis (cut-off point % ds), progression of coronary stenosis was higher for the lesions with ds < % for all groups (except group iii where all the lesions were with ds > %), reaching statistical significance in group i (i, + . ± . vs - . ± . mm, p < . ; iia, . ± . vs . ± . mm, p = ns; . ± . vs . ± . mm, p = ns). conclusion: coronary lesion morphology of simple type was associated with lower rate of coronary stenosis progression. noninvasive the aim of this study was to assess coronary microcirculatory function in postmenopausal women. methods: we measured myocardial blood flow (mbf) with a n-ammonia pet scan at rest, during cold pressor testing (cpt) for an indirect measurement of endothelium-dependent vasomotion, and during dipyridamole hyperemia (endothelium-independent vasomotion) in postmenopausal women without coronary artery disease. young healthy women served as controls. results: rest-mbf and hyperemic-mbf did not differ between the young and the postmenopausal women (rest: . ± . vs. . ± ,. and dipyridamole: . ± . vs. . ± . ml/ g/min; ns). coronary flow reserve was similar between the two groups (the young women: . ± . , the postmenopausal women: . ± . ; ns). cpt induced a similar increase of rate-pressure product in the young and the postmenopausal women ( ± vs. ± beats/min/mmhg), cpt-mbf was significantly decreased in the postmenopausal women ( . ± . ml/ g/min) compared with the young women ( . ± . ml/ g/ min; p < . ). conclusion: pet with n-ammonia during cpt is a noninvasive imaging technique to detect mbf abnormalities, which associated with endothelial dysfunction in postmenopausal women. contrast-enhanced magnetic resonance imaging at true end-diastole to quantify reproducible transmural extent of myocardial hyper-enhancement y.-j. kim, b. choi, k. choe; seoul/kr purpose: to determine feasibility of contrast-enhanced mri (ce-mri) at true enddiastole (ed) free from limitation of time for inversion-recovery and trigger window for quantifying transmural extent of infarction. methods and materials: mri was performed in patients with myocardial infarction. cine imaging and ce-mri with same registered slices in short axis were performed. to allow true ed ce-mri, ecg synchronization should use two rrintervals for one acquisition of a segment of k-space by setting the heart rate to half that of the true heart rate. trigger delay time was adjusted to the rr-interval for imaging at ed and to the sum of rr-interval plus the time between r-wave and the end-systole (es) determined in cine images for imaging at es. results: wall thicknesses of the ed and the es ce-mri were greater than those of the ed and the es cine images ( . ± . mm > . ± . mm, . ± . mm > . ± . mm respectively). subendocardial hyperenhancement was detected in patients. among them, systolic wall thickening was observed with cine imaging in patients and the transmural extent of hyperenhancement measured on ed ce-mri decreased by - % on es ce-mri proportional to the degree of systolic thickening of the epicardially nonenhanced myocardium. transmural hyperenhancement in patients showed no difference in thickness between enddiastole and end-systole. conclusion: ce-mri at ed is constantly possible by using two rr-interval per acquisition of a segment of k-space and useful to avoid the variation in infart sizing with irreproducible cardiac phase other than end-systole in case of subendocardial infarction. comparison of computed tomography (ct) and magnetic resonance (mr) for screening of pulmonary veins (pvs) complications of cryotherapy for percutaneous ablation of atrial fibrillation (af) b. ghaye , d. szapiro , l.-m. rodriguez , c. timmermans , r.f. dondelinger ; liège/be, maastricht/nl purpose: to prospectively compare ct and mr for evaluation of potential complications, including stenosis or thrombosis of pvs, of cryoablation for af. methods and materials: patients underwent percutaneous cryo-ablation of af. cardiac spiral ct and mr were performed before the procedure, at hours, and at months following af cryo-ablation. ct was performed with spiral ct (pq , phillips, eindhoven, the netherlands) using mm thick slices reconstructed every mm, -s rotation time, ma and kv per rotation following iv peripheral injection of ml of % iodinated cm. mr was performed on a . t symphony va system (siemens, erlangen, germany) using a multi-slice t -weighted dark-blood turbo-spin-echo pulse sequence and bright-blood cine trufisp sequence. all ct and mr examinations were quantitatively and qualitatively read blinded to the location(s) of ablation. results: for ct, the mean diameters at la-pv junction and at cm from ostium were . ( . ( . - - ) . associated cardiac and extracardiac anomalies were evaluated on fetal echocardiography. postnatal diagnosis or autopsy were correlated with fetal echocardiography. results: in fetuses with right aortic arch, combined congenital cardiac diseases were as follows, tof ( ), vsd( ), and dorv with pulmonary stenosis ( ) . associated extracardiac anomalies were oligohydramnios( ), arthrygryposis( ), splenic cyst ( ), and shortening of long bones( ). on postnatal echocardiography, previously non-diagnosed vsd were found on two neonates and tga without vsd in one neonate. overall incidence of combined cardiac defects is about . %. conclusion: right aortic arch associates variable cardiac defects and extracardiac anomalies in about half of fetuses. prenatal diagnosis of right aortic arch must be followed further echocardiography and targeted fetal sonography for exact diagnosis. potential myocardial iron content evaluation by mr in β β β β β-thalassemia major patients treated by deferoxamine or deferipron m. galia, m. midiri, t. bartolotta, a. maggio, r. lagalla; palermo/it purpose: to evaluate the usefulness of mri to assess myocardial iron content in patients with β-thalassemia major treated by deferoxamine b mesylate (df) or deferiprone (l ) chelation therapy. method and materials: consecutive patients with β-thalassemia major ( treated by df and by l ) underwent, at enrollment and after one year treatment, heart mri ( . t unit) with an electrocardiogram-triggered gradient-echo t weighted sequence. liver mri was obtained at the same time in all patients. measurements of the heart to muscle signal intensity ratio (hsirs) were compared between the two groups and with laboratory parameters, liver iron concentration (lic) and liver to muscle signal intensity ratio (lsirs). results: hsirs were significantly increased in df (t = - . ; p = < . ) and l group (t = - . ; p = < . ) after one year treatment. no statistically significant difference in the values of hsirs was present between the two groups at the beginning (p = . ; t = . ) and after one year treatment (p = . ; t = . ). hsirs were inversely correlated to lic (r = . ; p = < . ) but not to ferritin levels (r = . ; p = . ). a positive correlation was found between the variation of hsirs and that of lsirs (r = . ; p = < . ), and a mild correlation (r = . ; p = < . ) was found between the γ-glutamyltransferase levels and the hsirs values. conclusion: mri is usefull to detect hsirs variations during iron chelation therapy. moreover it is non-invasive and easily repeatable. application of -iodine labelled -iodinepentadecanoic acid for detection of myocardial viability in patients with chd and resting regional lv dysfunction v. soukhov, i. savicheva, a. partsernyak, a. svistov; st.petersburg/ru purpose of this study was to assess -iodine labeled -iodinepentadecanoic acid ( i-pda) -synthetic radiolabeled free fatty acid with the potence for detection of myocardial viability. methods: patients ( male and female, mean age ± yrs) who had history of myocardial infarction and resting regional left ventricular dysfunction were examined. blood supply, regional myocardial oxidative metabolism and regional metabolic substrate utilization were assessed by spect at - and - min after i.v. injection of mbq with i-pda. echocardiography with low doses of dobutamine was used for measuring inotropic reserve. results: early i-pda spect demonstrated high specificity in diagnostics of perfusion defects (up to %). the delayed images showed foci of remaining higher activity in regions of ischemic, but viable myocardium. of a total of myocardial segments had abnormal resting wall motion. in of them no oxidative metabolism and inotropic reserve were detected, that indicated scarred myocardium. of them were considered to be viable as they demonstrated both oxidative metabolism and inotropic reserve. conclusion: i-pda as an agent for simultaneous perfusion and oxidative metabolism evaluation may be used for identifying myocardial viability. diagnostic value of this method in combination with low doses of dobutamine echocardiography even in the cases of severe myocardial metabolic damage is nearly equal to pet with fdg and should be applied for detection of viable myocardium. comparison of mri and nuclear medicine in detection and analysis of left ventricular infarction r.m. macmillan , t. vakhtangadze , m.r. rees ; philadelphia, pa/us, bristol/uk aims: to compare standard spect perfusion imaging with last contrast enhanced mri for the detection of infracted myocardium. materials and methods: patients ( female, male) from two centres with proven myocardial infarction by ecg, clinical and echo criteria underwent stress/ rest tc sestamibi gated spect scanning with a dual headed gamma camera and late contract enhanced mri on identical . tesla scanners in each centre using a protocol which imaged minutes after injection of . mmol/kg iv gadolinium. analysis of segments used a segment system, with a total of segments analysed in both imaging methods. results: segments demonstrated scars on mri and segments demonstrated scars on isotope imaging. comparison of isotope imaging to mri showed that segments who had scars on isotope scanning failed to show on mri whilst scars on mri were not demonstrated on nuclear imaging. the majority of these scars were small or sub-endocardial. in some cases these scars had islands of functioning myocardium within them. some scars seen as completely non perfused defects on nuclear imaging were demonstrated to be partial thickness scars on mri. there was no significant difference in the findings from each centre indicating reproducibility and transferability of technique and findings. mri was able to detect smaller scars than nuclear imaging and viable myocardium in proximity to scar tissue. prenatal diagnostics of obstructive heart lesions g. spanovic , i. jovanovic , v. parezanovic , a. zvezdin ; novi sad/yu, belgrade/yu purpose: aim of prenatal diagnostics of obstructive heart lesion is to make right decision about the way leading further pregnancy, and decision about the time, place and way of labor. sensitivity and sensibility of fetal echocardiography are very high -between and %. methods and materials: fetuses were examined in period of seven years. fetuses with the diagnosis of some obstructive lesions of the heart were investigated. control group was made of fetuses with normal echocardiograms divided into four groups according to gestational weeks. echocardiographic techniques used: m-mode, d and doppler techniques. results: examination were made between and weeks of gestation. all cardiac structures show linear growth with progression of pregnancy. both halfs of the fetal heart are the similar size. obstructive lesions of the left heart and lesions of the right heart were diagnosed. there is statistically significant difference in size of the left and right structures in fetuses with obstructive lesions according to each other and also the same structure of the normal fetal heart. conclusions: obstructive lesions of the left heart were diagnosed much more frequently ( %) than the obstructive lesions of the right heart ( %) in the examination material. left heart hypoplastic syndrome was dominated lesion- % of obstructive lesions of the left heart and % of all diagnosed obstructive lesions. difficult obstructive lesions are progressive, have poor prognosis and present one of the indications for abortion. background: encouraged by beautiful cardiac multislice ct (msct) images presented at radiology and cardiology meetings, and by the favorable preliminary reports on high diagnostic value, more and more radiologists consider starting up their own cardiac msct program. the quality of the examinations initially obtained then, however, often does not live up to the high expectations. procedure details: a common cause for insufficent image quality is the poor attention to detail during image acquisition. in fact cardiac msct depends on the skill and dedication of the ct-technician. as an international training center for cardiac msct, we have noticed some common mistakes likely made by less experienced operators. generally, the basic procedures issues tend to go wrong: e.g., positioning the patient, placing the ecg-electrodes, choosing appropriate filtering, applying basic cardiac anatomy and physiology knowledge, etc. we will provide a step-by-step "how-to" pictorial with tips and tricks for successful cardiac ct imaging, illustrated by many examples of "right and wrong". issues addressed include handling of patient and workflow, data acquisition, and standardized image post-processing. conclusion: a step by step approach to cardiac msct scanning prevents scan failure. tomographic imaging of sinus venosus defects with multidetector ct angiography (mdcta) and magnetic resonance imaging-angiography (mri-mra) j.c. hellinger, a. napoli, f. chan; stanford, ca/us learning objectives: . describe tomographic imaging techniques for assessment of sinus venosus defects (svd). . illustrate intra and extracardiac anomalies during mdcta and mri-mra for svd. background: svd with associated partial anomalous pulmonary venous return (papvr), accounts for - % of congenital heart anomalies. clinical presentation is nonspecific and thus, diagnosis relies on imaging. transesophageal echocardiography (tee) and digital subtraction angiography (dsa) have been established as standard for this purpose. however, both are invasive and not without risk. mdcta and mri-mra are alternative noninvasive means to image these patients. mri offers the additional benefit to assess shunt ratios with cine phase contrast (pc) sequences. in this exhibit, we highlight our experience with mdc-ta and mri-mra in exams having surgically proven svd-papvr. procedure details: five exams were performed on or channel mdct. contrast was injected at cc/sec, employing bolus trigger technique. two of the -mdct were retrospectively ecg-gated with . mm thickness. non-gated studies were acquired at . mm, with a pitch of . - . and rotation time of . - . seconds. sequences employed in the four mri-mra exams included ecggated t , balanced steady state free precession, pc, and d-spgr angiography. d post-processing employed volume rendering and maximum intensity projection techniques. conclusion: anatomic defect size and location; number of abnormal veins) and dynamic evaluation for svd-papvr corroborated tee, dsa, and/or surgical findings. we identified on all mdcta, a jet of contrast crossing the defect into the left atrium (ct shunt sign). our preliminary experience indicates tomographic imaging is a reliable noninvasive alternative to tee and dsa for assessment of svd-papvr. to sensitize radiologists to the application of reformatting and d-reconstuctions in cardiac ct which depict the coronary arteries in a manner consistent with standard catheter angiography in routine clinical practice. to demonstrate a step by step approach to acquistion, optimized reconstruction techniques, and read-out algorithms in the evaluation of the coronary vessels. background: recent advances in the temporal and spatial resolution of mdct have opened the door to the use of ct in routine cardiac diagnostics, which is evolving rapidly as a noninvasive method. ct coronary angiography has compared favorably with conventional catheter coronary examinations, however new reconstruction and visualization methods are continuously being developed and are often lacking in meeting the demands of the routine clinical setting. it is crucial that radiologists become attuned to the standard approach to the coronary angiogram used in clinical cardiology so that advantage is not lost in the competition to provide services. procedure details: in this educational module, we present a step by step assessment of coronary vessels based on d-reconstructions of isotropic mdct datasets with special consideration to projections and visualization techniques which correspond with the standards of clinical cardiology. optimization of time consuming d renderings of ecg triggered datasets as well as read-out algorithms are demonstrated in examples for normal coronary vessels in addition to representative cases of coronary artery pathology. the resulting effective temporal resolution is - msec (depending on heart rate and reconstruction algorithm). larger volumes can be studied with isotropic spatial resolution and higher temporal resolution. the capability to scan larger volumes increases the feasibility and the accuracy of this technique in the visualisation of coronary artery bypass grafts (cabg). the scan protocol to evaluate cabgs with -row msct is described. different types of conduits (arterial and/ or venous), artefacts (surgical clips) and distal anastomoses of the graft are illustrated with dsa correlation. furthermore, atherosclerotic graft's disease (stenoses and occlusion) as well as native coronary artery disease is displayed with dsa. conclusion: ecg-gated -row multislice ct coronary angiography with . s gantry rotation time provide improved image quality in the evaluation of cabg. significance objective: to compare the msct and pet results in studying the condition of myocardial blood supply and to decide advisability of using them together. materials and methods: patients with suspected diagnosis of coronary artery disease were examined by msct and pet. msct data was obtained using siemens volume zoom ct scanner. retrospectively ecg-gating image reconstruction was conducted. pet was performed on ecat-exact- (siemens) with n ammonia at rest and during pharmacological test with vasodilatators (adenosine, dipyridamole). results: the first group comprised ( . %) patients without stenoses in coronary arteries according to the results of msct. pet also didn't detect reduction in perfusion of myocardial ischemic genesis in these patients. the second group included ( . %) patients with low-grade (< %) stenosis of coronary arteries. in these patients pet at rest and during stress didn't reveal a reduction in perfusion of myocardium. invasive coronarography was not performed for the and groups. the third group included ( . %) patients with different grades of stenosis in coronary arteries, according to the msct. there was reduction in perfusion in the corresponding myocardial segments revealed during at rest and/ or stress-pet. there was invasive coronarography done for these patients, which confirmed the existence of stenosis. methods and materials: ten volunteers (m:f = : , mean age ) without ischemic heart disease and consecutive patients (m:f = : , mean age ) with ischemic chest pain underwent ct coronary angiography (sensation , siemens, germany). reconstruction was done around - ms from r peak and multiplanar reformation and volume rendering were included. myocardial bridge was determined by demonstration of tunneled segment dip into myocardium. invasive coronary angiography was performed in patients. results: twelve tunneled segments in lad were detected in two volunteers ( %) (n = ) and patients ( . %) (n = ). nine were located in middle lad ( in volunteers, in patients) and in distal lad (in patients). with to mm in length, to . mm in greatest depth. the cross-sectional areas of tunneled segments were % smaller than those of the just proximal and % smaller than those of just distal to the tunneled segments. calcification in lad was detected in volunteer and patients with myocardial bridge but not in tunneled segment itself. significant stenosis was detected in proximal lad of two patients and mild stenosis in one patient which were confirmed by invasive coronary angiography. five patients showed only myocardial bridging in lad without coronary arterial stenosis. conclusion: msct directly visualizes tunneled segment within myocardium and gives useful information about myocardial bridging and neighboring coronary arteries. multi-detector row ct for the assessment of atrial septal defect and pulmonary venous drainage in adults g. morgan-hughes, a. marshall, c. roobottom; plymouth/uk purpose: to evaluate retrospectively ecg-gated multi-detector row computed tomography (ct) for the full evaluation of secundum and sinus venosus atrial septal defects (asd), in adults, in comparison to trans-esophageal echocardiography (toe). materials and methods: twelve patients undergoing toe for further assessment of presumed asd, as a prelude to definitive treatment, also underwent retrospectively ecg-gated multi-detector row ct. the multi-detector ct scans were compared to toe for defect and pulmonary vein visualisation. secundum asd sizing; measurements, before possible device closure, were compared, and virtual angioscopy of the right atrium was evaluated for direct, three-dimensional defect visualisation. results: larger secundum asds (greater than . mm) were well visualised with multi-detector row ct, but smaller defects and sinus venosus defects were not. for maximal secundum defect size there was a mean difference between the techniques of . mm (limits of agreement minus . to plus . mm). overall there was moderate agreement for the defect and rim sizing measurements. pulmonary venous drainage was universally fully and correctly evaluated with multidetector ct, which compared favorably to toe. virtual angioscopic visualisation of secundum defects was possible in patients, but the images produced were considered of limited clinical value. conclusions: retrospectively ecg-gated multi-detector row ct offers alternative imaging of asd in adults, allowing visualisation of significant secundum defects, pulmonary venous drainage and defect sizing. further investigation, to establish the accuracy of defect and rim sizing measurements and to re-explore direct defect visualisation with advanced post-processing tools, is required. detection of necrotic myocardial segments using multi-slice computed tomography: comparison with nuclear medicine p. . mm slice width, . mm slice increment and ml of non-ionic contrast ( mgi/ml) administered with a delay scan of seconds. nm and cts datasets were reoriented perpendicular to the left ventricle long axis. segmental analysis was performed on segments within the short axis planes ( basal, mid-ventricular and apical segments). a positive nm finding was defined as a perfusion defect within a segment at both rest and stress. a positive ct finding was defined as a hypo-intensive region within a segment. statistical analysis was performed using a % confidence interval calculated by the exact binomial method. results: segments were evaluated on both nm and msct. nm detected necrotic segments whereas msct detected . there were true-positive, true-negative, false-positive and false-negatives findings. the sensitivity was . %, specificity . %, positive predictive value . % and negative predictive value . %. conclusion: msct showed high sensitivity and specificity for the detection of myocardial necrotic segments compared with nm. evaluation of myocardial bridging by multislice computed tomography p.m. carrascosa , c. capuñay , m. vembar , p. johnson , r. pissinis , j. carrascosa ; buenos aires/ar, cleveland, oh/us to determine the usefulness of multiphase reprocessing msct coronary angiography in the identification of myocardial bridging (mb) and the detection of related ischemia. methods: patients were studied. cts were performed in a -row ct scanner with x mm collimation, . mm slice increment and ml of non-ionic contrast. ten patients with mb diagnosed with msct were evaluated with nuclear medicine (nm). rest and stress studies were performed with mci technetium m sestamibi. segmental analysis were performed on segments within the short axis plane ( basal, mid-ventricular and apical) in both methods. positives nm findings were defined as a perfusion defect within a segment at both rest and stress. positives ct findings as hypo-intense region within a segment. results: all the mbs were placed in the lad. da detected cases, whereas msct only . the sensitivity was . % and the specificity . %. in cases the mb of the lad had greater diameter in the % phase and they were compressed in the % phase. six cases showed ischemia in the nm studies. there were true-negatives, true-positives and false-negatives findings. the sensitivity was . % and specificity %, positive predictive value was % and the negative predictive value was %. conclusion: msct can detect the presence of mb in coronary arteries. it is essential for this identification a multiphase reprocessing of the ct data and can also detect the presence of myocardial perfusion defects. to predict the local, gonadal, thyroidal and eye dose with and without different protection devices in retrospective-gated multi slice ct of the heart. material and methods: radiation dose was measured with an alderson phantom and a digital dose meter with and w/o an infradiaphragmatic lead drape, a cervical lead protection and an eye shield. measurements were done with the ionization chamber placed over the heart, uterus, thyroid gland and eyes. helical ct of the heart was performed with an aquilion msct (toshiba). the dose was determined with slice collimation and pitch between and . using constant voltages and current-time-products for retrospective gated ct. results: local dose over the heart ranged from to µsv. gonadal dose was determined with to µsv w/o lead protection and to µsv using a circular infradiaphragmatic lead drape, meaning a gonadal dose reduction of up to %. with use of protection devices the dose to the thyroids could be reduced by . % and % in terms of using an eye shield. conclusion: radiation causing gonadal dose in cardiac ct is predominantly extracorporal radiation and only in a lesser degree due to scatter radiation from inside the body. an effective dose reduction of % can be achieved by consequent use of a circular lead drape closely adapted to the inferior helical range. the use of organ adapted shields covering the thyroids or eyes mainly results in a decrease of the surface dose and is recommended as well for all patients receiving cardiac ct. images were acquired using a -row spiral ct scanner with . s gantry rotation time. in all patients detailed clinical, ecg, us and scintigrafic (when available) data were collected in order to identify the presence of mi. when a patient with mi was found, mdcta images were analyzed on both axial and multiplanar reconstruction in order to confirm the presence of an infarcted area. results: our study population included patients who previously underwent coronary percutaneous transluminal angioplasty (pta) and stent placement (a total number of stents) and patients with previous by-pass surgery. after clinical assessment, mi was found in patient ( septal, apical, anterior wall of left ventricle, infero-septal). mdct was able to detect the presence of mi in / cases ( . %), showing a regional hypoattenuated area and wall thinning. in all cases, localization and extention of ischemic area were perfectly correlated with clinical known data. in two patients with sub-endocardial involvement, mi could was not detectable with mdct. in one patient the presence of motion artefacts affected image quality and myocardial scar wasn't visualized. the presence of mi is usually well depicted with retrospective ecg gated mdct. mdct coronary angiography: optimization of the image reconstruction phase y. nagatani, r. takazakura, n. nitta, m. takahashi, k. murata; otsu/jp purpose: to investigate the relationship between the heart rate and the optimal image reconstruction phase in mdct coronary angiography. material and method: patients underwent cardiac mdct ( das) (aquilion , toshiba, japan) to obtain coronary angiography. scan data were subsequently reconstructed at different kinds of phases in ecg wave. these methods can be classified as follows according to the used wave in ecg; ).the center of the reconstruction phase is positioned at the peak of t-wave (method t-p), the end of t-wave (method t-e) and the midpoint of descending curve of t-wave (method tm). ).the end of the reconstruction phase is positioned at the peak of p-wave (method p). ).the center of the reconstruction phase is positioned using nterval (method r , , , , , ) . all patients were classified into groups according to their heart rates (hr) (group ; hr < (n = ), group ; < hr; < (n = ), group ; hr < (n = )). two radiologists assessed image quality in blind fashion and scored as follows ( :good, :fairly, : bad). bonferroni/dunn test was performed for statistical analysis. results: in group , significantly better image quality was achieved in method p, rr , rr than other methods. among them, highest image quality was obtained by method p. the best result was obtained by method p in group and tm in group . conclusion: optimal image reconstruction phase in mdct coronary angiography shifts from late diastolic phase to late systolic phase as heart rate increases. assessment of aorto-coronary bypass grafts patency by detector rows computed tomography g. two out of five tumors (right atrium lipoma and aortic valve fibroelastoma) were discovered in a routine msct study of coronary arteries and left ventricle myxoma in an elective coronarography. atypical left ventricle myxoma with mitral stenosis and epicardial cyst were primary visualized in transoesophageal echocardiography. results: both methods allows to evaluate tumors size, localization and structure. the biggest advantage of echocardiography was aknowledged possibility of evaluation of lesions mobility while the biggest advantage of msct was possibility of both d and d imaging in arbitrary planes using multiplanar reformations with evaluation of tumor relations towards adjacent tissues and simultaneous visualisation of coronary arteries. conclusions: msct and echocardiography (tte and tee) are complementary methods in diagnosis of primary cardiac tumors. usefulness of -slice multidetector row computed tomography (msct) in assessment of dilated cardiomyopathy s. hosoi, t. mochizuki, t. haraikawa, j. funada; ehime/jp purpose: the purpose of this study is to show the potential benefits of -slice msct for the diagnosis of dcm. we studied consecutive patients, including dcm, coronary artery disease (cad), and patients with non-cardiac disease as a normal control. dcm was diagnosed on the basis of the clinical data by cardiologists. the msct system used in this study was a lightspeed (ge medical systems) with available gantry rotation speeds of . sec. all cardiac images reconstructed were divided into phase data sets in a r-r interval on ecg. end-diastolic (ed) and end-systolic (es) phase could be visually extracted, and the lv wall thickness and volume was measured. moreover, the segmental lv wall motion was evaluated by the cardiac movie image which was reconstructed using the phase data. results: image quality of mdct were considered sufficient for this analysis. concerning about the rate of coronary artery stenosis, dcm group were significantly less than cad group (p < . ). in dcm group, both lv wall thickness of ed and es were smaller than other groups (p < . ). lv volume between dcm and cad group had no significant difference. lv wall motion in dcm group had a tendency to be diffusely hypokinetic. conclusion: using -slice msct, lv function and coronary artery stenosis was able to be evaluated and distinguished the features of dcm and cad. this study revealed a potential ability of mdct as a useful method for the diagnosis of dcm. background: a variety of pulmonary complications occur in bone marrow transplant (bmt) recipients and are a major cause of morbidity and death. imaging findings: hrct is useful in detection of pulmonary abnormalities, but these findings are generally non-specific. these complications, which reflect the immunologic status of the patients, occur in three phases. this pattern can be used to interpret ct scans. the neutropenic phase (up to weeks after bmt) is characterized by fungal infections, alveolar haemorrhage, pulmonary oedema, and drug reactions. at ct, fungal infections like angioinvasive aspergillosis appear as nodules surrounded by a halo of ground-glass attenuation; alveolar haemorrhage and drug reactions, as bilateral areas of ground-glass attenuation or consolidation. the second phase ( weeks to days after bmt) is dominated by cytomegalovirus pneumonia, which appears as multiple small nodules with areas of consolidation or ground-glass attenuation, and pneumocystis carinii pneumonia again mostly as ground-glass attenuation. the late phase (more than days after bmt) is characterized by bronchiolitis obliterans revealing bronchial dilatation and a mosaic pattern of attenuation, bronchiolitis obliterans with organizing pneumonia (boop), the ct findings usually being patchy consolidation or ground-glass attenuation and chronic graft-versus-host disease. conclusion: if ct findings are considered in relation to the time elapsed after bmt, diagnostic options can be narrowed sufficiently to enable accurate diagnosis. small pulmonary nodules: an easy approach to the differential diagnosis j. rimola, x. gallardo, e. castañer, j.m. mata, a.m. quiles, p. bermúdez; sabadell/es learning objectives: to know the anatomy of the secondary pulmonary lobule, which is essential to the interpretation of high-resolution ct (hrct). to learn an easy way to approach the differential diagnosis of small pulmonary nodules. background: a wide variety of pathologies may present with small pulmonary nodules, which are defined as rounded opacities smaller than cm in diameter. differences in appearance, distribution and attenuation of nodules provide useful clues for correct diagnosis. helical ct and hrct enable correct identification and characterization of small nodules. imaging findings: we illustrate different examples of multinodular lung diseases in an easy-to-understand way. a simple algorithm is used to help in the differential diagnosis. we classify nodules according to distribution (centrilobular, perilymphatic or random) and show the most representative cases of each pattern. we present a wide variety of entities, including: infections such as tuberculosis (endobronchial spread or miliary tb), nontuberculous mycobacteria, fungus; sarcoidosis; tumors (lymphangitic carcinoma, hematogenous metastases); silicosis and coal worker's pneumoconiosis; hypersensitivity pneumonitis; cryptogenic organizing pneumonia; histiocytosis; etc. conclusion: an easy way to assess multiple nodular opacities in the lung is useful to reach an accurate diagnosis. differential diagnosis of unilateral hyperlucent lung m. nishino , k. hayakawa , h. hatabu ; boston, ma/us, kyoto/jp learning objectives: to review differential diagnosis of unilateral hyperlucent lung, understand pathological mechanisms causing the findings, and to be familiar with the imaging findings and clinical manifestations characteristic in each condition. background: unilateral hyperlucent lung on chest radiograph is seen with various pathological conditions. the conditions include both acute and chronic processes, and thus need accurate and prompt diagnostic evaluation. the findings on chest radiograph can provide clues to differentiate various causes of this condition and help to achieve proper management. imaging findings: we present cases of unilateral hyperlucent lung, emphasizing specific imaging findings along with characteristic clinical manifestations. the cases include proximal interruption of pulmonary artery, pulmonary hypoplasia, swyer-james syndrome, congenital lobar emphysema, foreign body aspiration, and bochdalek hernia. findings on chest ct which can confirm or support the diagnosis are also reviewed and discussed. conclusion: familiarity with the characteristic imaging findings of unilateral hyperlucent lung is essential for radiologists to make accurate diagnosis for appropriate patient management. multislice ct of primary and multisystemic pulmonary vasculitis: a patternbased approach to differential diagnosis k. marten , m. prokop , p. schnyder , e.j. rummeny , c. engelke ; munich/de, utrecht/nl, lausanne/ch . clinical and radiologic features of these tumors are often indistinguishable from those of malignant tumors. however recognition and early diagnosis of these lesions may allow for conservative treatment and excellent patient outcome. the aim of this study is to illustrate the ct findings of variable benign tumors of tracheobronchial tree and correlate with the pathologic findings. imaging findings: this study included patients with benign tracheobronchial tumors which were confirmed histologically by surgical resection (n = ) or bronchoscopic biopsy (n = ). the tumors were classified the anatomic locations of the lesions into trachea (n = ), bronchus intermedius (n = ), lobar bronchus (n = ), and segmental bronchus (n = ). pathologic diagnoses were hamartoma (n = ), leiomyoma (n = ), lipoma (n = ), schwannoma (n = ), amyloidoma (n = ), inflammatory polyp (n = ), and bronchial adenoma (n = ). ct demonstrated all tumors confined in the tracheobronchial lumen. of bronchial tumors occluded the bronchial lumen completely, resulting in distal parenchymal collapse. to enhance the limitations of chest x-ray and axial chest ct slices in estimating the volume of pleural effusions. this interactive presentation will allow the reader to test himself, comparing his own subjective estimation to the real volume computed from d shaded surface displays (ssd). to outline the usefulness and ease of post-processing with spiral ct to obtain a true assessment of the pleural fluid volume. background: assessment of the volume of pleural effusions is very imprecise both on chest x-ray and axial chest ct slices. the amount of fluid may be required by clinicians for therapeutic purposes. d ssd of the effusion provides rapid computation of its volume. in this exhibit we will recall the physiopathologic mechanisms involving the preferential locations of pleural effusions. we will show pleural effusions of various volumes on chest ct along with the corresponding chest x-rays and the precise volume of the effusion computed from d reconstruction. procedure details: various cases of free or collected pleural effusions on spiral chest ct (ct twin and mx idt), are presented, including coronal and sagittal reformations. ct images stand along with the corresponding chest x-ray, obtained in the upright and supine position, and with the computed volume of the effusion using d reconstruction. conclusion: pleural volumetry is readily available using spiral ct data recontruction. it should be more often used, to assess the amount of fluid to withdraw with thoracocentesis, before drainage or for monitoring in intensive care unit patients. lung consolidations in various clinical entities: clinico-radiologic correlation presented in an interactive cd-rom in html format s. mylona, s. tandeles, l. thanos, s. lyra, p. ellinas, n. mpatakis; athens/gr learning objectives: to present lung consolidations as found in ct and plain radiographs in various clinical entities. to give a differential diagnosis based on clinical and radiologic features. background: radiologists often encounter lung consolidations in plain radiographs and lung ct. there is a broad spectrum of clinical entities, which either present as lung consolidations or involve lung consolidations. clinical information and radiologic features help to approach the right diagnosis. procedure details: cases are presented in a question and answer format using html resources in an interactive cd-rom. reference is made to proper diagnostic work up and to other relevant clinical information. histopathological confirmation is presented where it is needed. conclusion: radiologists must be trained to deal with patients presenting with lung consolidations using clinical and radiological features. hrct patterns of cardiogenic pulmonary edema e. chambrier, s. zafatayeff, y. badachi, p.a. grenier, c. beigelman-aubry; paris/fr learning objectives: to be familiar with typical and atypical hrct appearances of pulmonary edema based on patients. to emphasize the role of hrct in suggesting this diagnosis in the setting of acute dyspnea, especially if pulmonary embolism is suspected. background: pulmonary edema, a frequent cause of acute dyspnea, can be clinically difficult to detect. hrct is crucial in suggesting this diagnosis, particularly when pulmonary embolism is suspected. actually, bolus intravenous injection of iodinated contrast in case of pulmonary edema may worsen heart failure and lead to patient death. imaging findings: the hrct signs of pulmonary edema are usually divided into interstitial and alveolar patterns, and both can be associated. classic signs of interstitial edema, which accounts for % of cases, are peribronchial and peribronchovascular thickening, septal lines, ground glass opacity, pleural effusion, cardiac enlargement and pulmonary veins dilatation. alveolar edema is characterized by bilateral, patchy or coalescent areas of airspace consolidation, predominantly basal and perihilar. butterfly pattern is found in % of cases. atypical patterns are due to preexisting lung or heart disease, such as right upper lobe edema related to mitral regurgitation, or heterogeneous distribution of edema due to preexisting lesions of emphysema or constrictive bronchiolitis. highly selected cases will be used to illustrate typical and atypical patterns. the varied hrct appearances of cardiogenic pulmonary edema have to be recognized in order to delay the performance of angioct of pulmonary arteries if pulmonary embolism is suspected. smoking-related interstitial lung diseases: radiologic-pathologic correlation a. hidalgo, t. franquet, a. giménez, r. pineda, m. madrid; barcelona/es learning objectives: . to review the radiological findings of smoking related interstitial lung diseases and their pathologic correlations. . to provide some radiological clues for the correct diagnosis. background: interstitial lung disease (ild) represent a heterogeneous group of lung disorders of known or unknown cause. recently, it has been appreciated that cigarette smoking is related to the development of several ilds including desquamative interstitial pneumonia (dip), respiratory bronchiolitis-associated interstitial lung disease (ribld), pulmonary langerhans'cell histiocitosis (plch) and idiopathic pulmonary fibrosis (ipf). procedure details: we reviewed the plain radiograph, ct, and hrct findings of four intersitital lung disorders that have been linked to smoking. several examples of the radiological forms of srild and their differential diagnosis are provided. we will also show how the radiologists can get the diagnosis through some clinical and radiological clues. the link between several interstitial lung disease and smoking has been recently indicated. radiologists have to be aware of these entities and to suggest a diagnosis as accurate as possible by the knowledge of clinical context and the radiological features. the spectrum of ct appearances in pulmonary amyloidosis a. aylwin, p. gishen, a. nicholson, s. copley; london/uk learning objectives: to review the ct appearances of pulmonary amyloidosis. background: amyloidosis has three main histopathological subgroups, with typical imaging characteristics: ) tracheobronchial disease with plaques, nodules or circumferential thickening of the trachea or segmental airways; ) nodular parenchymal disease with single or multiple nodules demonstrating sharp lobulated margins, spiculated masses simulating tumours, and a rare form associated with sjögren's syndrome and lymphocytic interstitial pneumonitis (nodules and lung cysts); and ) diffuse alveolar septal disease showing ground glass opacification, interlobular septal thickening, and traction bronchiectasis on hrct. it is often possible to divide cases into localized amyloidosis with tracheobronchial deposition or nodular disease, or the systemic type with diffuse parenchymal disease or lymphadenopathy on the imaging findings, but cases demonstrating overlapping features are not uncommon. procedure details: the ct appearances of cases of biopsy-proven pulmonary amyloidosis will be demonstrated. the spectrum of ct appearances of pulmonary amyloidosis of both localised and systemic types will be demonstrated. the ct features of localized and systemic disease may overlap. thoracic conclusion: incidence and imaging features of these complications will be illustrated. paraquat poisoning of the lung: a study of patients with paraquat intoxication for years a. ichinose , k. kimura , m. tsuboi , h. saito , t. ishibashi , s. takahashi ; miyagi/jp, akita/jp learning objectives: to analyze patients who had taken paraquat intoxication and to compare those with % paraquat intoxication to those with % paraquat-diquat intoxication, especially with respect to the change of their chest x-rays and ct. background: paraquat is a widely used herbicide that has toxic effects on the lungs, liver, and kidneys. paraquat has been known to induce acute pulmonary fibrosis, causing progressive respiratory failure and death. in japan, % paraquatdiquat product has been used since , in place of % paraquat product,. however, there is no report that compares the influence these products have on the lung. procedure details: there were patients from whom chest x-rays were taken, and of those ( . %) had abnormal findings, which were composed of ground-grass patterns, reticulogranular patterns, pulmonary edemas, cardiomegalies and pulmonary congestions, pneumothoraxs, and mediastinal emphysema. pulmonary edema was found only in the patients with % paraquat intoxication; in all cases, the plasma paraquat concentration was much higher than others. all reticulogranular patterns were found a few days later, and those in the patients with % paraquat-diquat intoxication were potentially reversible. conclusion: % paraquat product has more influence on the lung than % paraquat-diquat product. pulmonary fibrosis caused by % paraquat-diquat product is potentially reversible. thoracic parenchymal abnormalities, enlarged lymph nodes, pleural effusion, and pleural thickening were evaluated. in patients who underwent surgical biopsy or autopsy, the ct-pathological correlation was performed with the actual specimens. imaging findings: on the ct scans, abnormal findings were seen in patients ( . %). the ct findings consisted of ground-glass attenuation (n = ), centrilobular nodules (n = ), thickening of bronchovascular bundles (n = ), and consolidation (n = ). these abnormalities were predominantly seen in the peripheral lung parenchyma (n = ). pathologically, these findings corresponded with atypical lymphocytes infiltration along the interstitium and the alveolar spaces. pleural effusion and enlarged lymph nodes were found in patients and patients, respectively. conclusion: the ct findings in patients with adult t-cell leukemia/lymphoma consisted mainly of ground-glass attenuation, centrilobular nodules, and thickening of the bronchovascular bundles in the peripheral lung. these ct findings, though non-specific, are considered as suggestive of thoracic involvement in patients with adult t-cell leukemia/lymphoma. high resolution ct imaging of the lung for patients with primary sjögren's syndrome c. lohrmann, m. uhl, k. warnatz, n. ghanem, e. kotter, o. schaefer, m. langer; freiburg/de purpose: to assess pulmonary abnormalities in patients with primary sjögren's syndrome using high-resolution computed tomography (hrct). the hrct scans of patients over a ten-year-period with diagnosis of primary sjögren's syndrome were retrospectively reviewed regarding the presence, extension and distribution of pathological findings. results: patients ( . %) showed pathological findings and in ( . %) the hrct scan was normal. a predominance of abnormalities in the lower lobes and subpleural areas was detected. bronchiectasis, thin-walled cysts and small pulmonary nodules in patients ( . %), ground-glass attenuation and emphysema in patients ( . %), interlobar-septal thickening in patients ( . %), honeycombing in patients ( . %), bronchial wall thickening and tree-in-bud pattern in patients ( . %), mosaic perfusion in patients ( . %), and architectural distorsion in patients ( . %). airspace consolidation, air trapping, large nodules ( - mm) and masses (> mm), mediastinal lymph node enlargement (> mm) and free pleural fluid were seen each in patient ( . %). in of patients ( %) with thin-walled cysts areas of ground-glass attenuation were detected. conclusion: hrct seems to be contributive to the characterization of the wide variety of lung abnormalities in primary sjögren's syndrome. airway disease alone or in association with the presence of varying degrees of interstitial disease represent the main findings in accordance with earlier reports. unexpectedly, almost half of the patients have thin-walled cysts on the hrct scans, which etiology is unclear but could be associated with areas of ground-glass attenuation indicating lymphocytic interstitial pneumonia. investigation of the bulky hilum: how accurate are radiologists at detecting hilar pathology on the chest radiograph? s. desigan, d. murray; london/uk purpose: to determine the accuracy of radiologists in detecting hilar pathology on chest radiographs. materials and methods: a retrospective study was performed, analysing the chest radiograph and computed tomography (ct) findings of patients, all of whom had initially been referred for thoracic ct as part of the investigation for a "bulky hilum" as detected on chest radiography. radiologists, comprising consultants and specialist registrar trainees who were blinded to the initial ct findings, were asked to assess the chest radiographs for the presence or absence of a hilar mass and their recommendations for clinical follow-up in each case were recorded. they were then scored for accuracy as compared to the thoracic ct results. the results showed marked variation between observers in the two groups. the participants had an accuracy of %, sensitivity of % and specificity of %. positive predictive values of registrars and consultants were % and % respectively. negative predictive values were % for registrars and % for consultants.the group as a whole detected only out of hilar masses confirmed by ct. the wide range of responses demonstrates the very subjective nature of interpretation of the lung hila on chest radiographs, and the difficulty involved in correctly identifying or excluding hilar masses on chest x-rays. one of the most useful aspects of this study has been to provide feedback to individuals for educational purposes and personal audit. b d e f a g m. paslawski, w. krupski, k. krzyzanowski, j. zlomaniec; lublin/pl purpose: the aim of the study is to evaluate the diagnostic value of hrct in revealing small bronchiectases and bronchiolectases in patients with previously diagnosed pneumoconiosis. the study comprises a group of patients, men and women, aged between and years, with pneumoconiosis in which hrct was performed. hrct was performed in all patients in the prone position, from the level of the apices to the level of the diaphragm. the collimation of the scans was mm, with cm intervals between sections. the hrct examinations were assessed retrospectively by two radiologists, and the presence and character of bronchiectases were noted. results: bronchiectases were seen in patients ( %). in of them the "signet-ring sign" and "tram track sign" were seen, with lack of normal tapering. bronchi were visible in peripheral lung areas, within cm from the parietal pleura in patients. patients had varicose bronchiectases with the typical "string of pearls" appearance. in patients, cystic bronchiectases were seen, presenting with the picture of "cluster of grapes". conclusions: bronchiectases is very often seen in patients with pneumoconiosis, especially in advanced stages. hrct is the modality of choice to diagnose the presence of small bronchiectases and bronchiolectases. typical hrct patterns include "signet-ring sign", "tram track sign", lack of normal tapering, and visible bronchi in peripheral lung areas, within cm from the parietal pleura. in varicose bronchiectases, the "string of pearls" appearance, and in cystic bronchiectasis, the "cluster of grapes" appearance are typical. introspective background: spns occur on in chest radiographs with % being due to lung cancer. conventional imaging is fairly effective in determining the nature of the spn, although - % remain indeterminate following ct scan. the spn will often have needle biopsy either via bronchoscopy or percutaneously which have a recognised complication rate of - %. depreotide is a tc- m labeled analogue of somatostatin with affinity to receptors types , and . various tumours including lung cancer, breast cancer, lymphoma and neuroendocrine tumours express these receptors. we undertook a retrospective review of one years' referrals for depreotide imaging comparing the results with subsequent biopsy or surgical histology where available. additionally we assessed if the referring clinical question had been answered. results: depreotide studies performed, with showing increased uptake within the spn. patients ( %) with positive studies had had a previous indeterminate lung biopsy thus enabling planning of further biopsy or wedge resection with frozen section. depreotide and histology agreed in all patients who had subsequent histology of the spn ( malignant, benign). further biopsy was avoided in out of patients with negative studies. specific answers were given to the clinical referring question in cases. conclusion: depreotide effectively determined the nature of the spns with ability to avoid biopsies in the % of patients with benign disease and to prompt further invasive investigation following an indeterminate biopsy. pleural invagination in progressive massive fibrosis (pmf) in silicosis and mixed dust pneumoconiosis h. arakawa, k. honma, h. shida, h. mori, y. saito; tochigi/jp purpose: invagination of the pleura often accompanies progressive massive fibrosis (pmf) in pneumoconiotic lung. to elucidate the relation between pmf and the pleura covering them, we conducted a retrospective study comparing ct and autopsy findings in silicosis and mixed dust pneumoconiosis (mdp). the study group was an autopsy series of consecutive patients with complicated silicosis or mdp. ct images were examined to determine the location, shape, composition and size of pmf, distance between the lesion and the covering pleura, presence of pleural thickening, a band-like structure between the lesion and pleura, and pleural effusion. autopsy data were reviewed for the presence of pleural thickening and invagination and were compared with the ct findings. results: we identified pmf lesions. pleural invagination was found in ( . %) pmf and was always associated with pathologically determined pleural thickening. ct images showed pleural thickening in ( . %) and invagination in ( . %) lesions. lesions were associated with ipsilateral pleural effusion (p < . ). statistical analysis revealed pleural invagination was associated with pleural thickening (p < . ) and proximity of the lesion to the pleura (p < . ) but not with radiographic profusion of pneumoconiotic opacities, or the shape, composition, size of pmf (p > . ). pmf were radiographically identical to rounded atelectasis. conclusions: fibrous thickening of the pleura and invagination into the adjacent pmf are not uncommon in advanced silicosis and mdp. some lesions resemble rounded atelectasis. ct is beneficial in assessing these pathologic features. imaging the aim of this teaching exhibit is to illustrate a spectrum of usual and unusual cystic diseases involving the lung, and to evaluate the efficacy of plain radiographs and computed tomography (ct) imaging in the diagnosis and management of these conditions, with emphasis in high resolution ct (hrct). we retrospectively reviewed the imaging findings of patients with diffuse cystic lesions involving the lung from our data base of thoracic pathology. a cystic lesion was defined as an air-containing, well-defined space, variable in size. the pertinent embryology and pathologic basis of the radiographic findings are discussed. pitfalls, diagnostic difficulties and differential diagnoses are emphasised. results: specific topics addressed include diffuse cystic diseases of the infancy (bronchopulmonary dysplasia, pulmonary interstitial emphysema, types i, ii, and iii congenital cystic adenomatoid malformation, chronic eosinophilic pneumonia, and pneumatoceles), and diffuse cystic diseases of the adulthood such as honeycomb lung (secondary pulmonary fibrosis), langerhans cell histiocytosis, pulmonary lymphangioleiomyomatosis, tuberous sclerosis, and lymphoid interstitial pneumonia. we also include pulmonary diseases simulating cysts such as congenital diaphragmatic hernias, diffuse bronchiectasis, and emphysema. conclusions: hrct is an adequate imaging modality to assess diffuse cystic disease of the lung, allowing an excellent visualisation of the cysts as well as other secondary findings (distribution, size, location, and wall thickness). because many of these disorders have characteristic imaging appearances, this exhibit will help practising radiologist to better understand, recognise and differentiate cystic diseases involving the lung. beware the normal chest x-ray in suspected lung cancer: a pictorial review of the potential pitfalls a.k. basu, k. jeyapalan, j. entwisle, r. bhatt; leicester/uk purpose: to demonstrate that a standard pa chest x-ray can be falsely reassuring in patients where there is a high index of clinical suspicion for lung cancer. we reviewed the patients with suspected lung cancer whose chest x-rays were radiologically normal and had further ct cross sectional imaging. emphasis was placed on the hidden review areas on a standard pa chest x-ray, e.g. the mediastinum, the apices, behind the diaphragm and behind the heart. we present a pictorial review of these hidden areas and illustrate the potential lesions not seen on a "normal" chest x-ray. results: ct can often demonstrate lesions not visible on chest x-ray. conclusion: a normal pa chest x-ray may be falsely reassuring in patients suspected of having lung cancer. therefore in patients with a high index of clinical suspicion a ct should be carried out despite the normal pa chest x-ray with careful review of the hidden review areas. should a chest radiograph be requested in all cases of febrile neutropenia admissions? a study in a university hospital a.v. acharya, a.k. burnett; cardiff/uk purpose: to evaluate the clinical utility of obtaining chest radiographs, in the absence of chest symptomatology, in patients admitted with acute neutropenic sepsis. methods: prospective study of in patients with febrile neutropenia admitted to the haematology ward was carried out in this university hospital over a period of months. symptoms & signs, chest x-ray findings and changes in management because of these findings were assessed in these patients. we also conducted a questionnaire survey of haematologists of south wales regarding obtaining chest radiographs in these patients. results: chest radiographs were obtained in . % of the patients at the time of diagnosis of febrile neutropenia but only . % of the patients had chest signs/ symptoms. if chest signs/symptoms were present, . % had abnormal chest x-rays and this influenced change in clinical management. in the group where chest signs/symptoms were absent, radiographs were normal and no change in management resulted from a chest radiograph. the survey of haematologists suggested that majority of them ( %) requested chest radiographs in acute neutropenic sepsis irrespective of presence or absence of chest signs or symptoms. in neutropenic patients with no chest signs/symptoms, a chest radiograph on admission is not likely to be abnormal and is unlikely to change the management. on the basis of our study we suggest that the chest radiographs in these patients in the absence of clinical signs or symptoms, are of little value. this would however not exclude the possibility that other imaging approaches would be of clinical value. low to evaluate the usefulness of low dose thin-section ct by multidetector-row ct (mdct) for lung cancer screening in both the determination of malignancy or benignancy and the differential diagnosis. methods and materials: cases with pathologically proved solitary pulmonary nodules, which sizes were less than cm in diameter, were entered into this study. after the routine full dose thin-section ct ( . mm collimation, fov cm, pitch : , kvp, -ma/rotation, . second/rotation, high-spatial frequency algorithm), additional two kinds of low dose helical thin-section ct ( . mm collimation, pitch : , -(in initial cases), -(all cases), -(in remaining cases) ma/rotation) were scanned using a mdct scanner (lightspeed qxi, ge, milwaukee, wi). using roc analysis, an observer performance study, in which three observers indicated the confidence level for the determination of malignancy or benignancy for each nodule, was done. in addition, three observers recorded the final diagnosis of each case. accuracies of the final diagnosis were compared by mcnemer's test. in the determination of malignancy or benignancy, there was no significant difference among these four kinds of thin-section ct (full dose, -, -, and -ma/rotation; mean az = . , . , . , and . , respectively). accuracy of the final diagnosis by low dose thin-section ct ( -, -, and -ma/ rotation; %, %, and %, respectively) was significantly lower than that of full dose thin-section ct ( %) (p < . ). conclusion: efficacy of low dose thin-section ct by mdct is comparative to that of full dose thin-section ct in determining whether small nodules are malignant or not. lung cancer screening using low-dose spiral ct: preliminary results in asymptomatic smokers s. giunta, m. crecco, f. facciolo, l. carpanese, v. cilenti, m. caterino, p. visca, m. mottolese; rome/it purpose: to evaluate the feasibility of lung cancer screening using low-dose spiral ct and to present initial baseline data from a non randomized screening trial using low-dose spiral ct. methods and materials: asymptomatic smoker volunteers, aged years or older who had smoked packs-year or more, underwent baseline low-dose multislice spiral ct (volume zoom siemens) of the chest without contrast material enhancement following the elcap protocol. annual repeat screening was performed on participants. lesions up to mm were deemed non suspicious and low-dose ct was repeated after months. results: at baseline, non calcified nodules were identified in participants. nodules were larger than mm. biopsy of lesions revealed nsclc in cases ( adenocarcinoma, squamous cell carcinoma, large cell carcinoma, adenoid cystic carcinoma). of these were stage i ( . %); stage ii ( %); stage iii ( %) and one stage iv ( . %). were benign lesions ( hamartomas, lymph node, fibrosis). in cases the pet was negative, in cases the nodules resolved after antibiotics; participants refused biopsy. conclusion: low-dose spiral ct seems to be a promising method for screening lung cancer. our preliminary cancer screening results with low-dose spiral ct, demonstrated a prevalence of asymptomatic cancers in . % of a smoking population including a high proportion of early tumor stages. pathological mismatched findings of specimens between ct guided biopsy and resection in noguchi's classifications of small peripheral lung adenocarcinoma s. yoshida, h. ue, s. itou, y. murata; nankoku/jp purpose: we sometimes experience mismatched pathological findings of specimens between preoperative ct guided biopsy and resection in the noguchi's classification of small peripheral lung adenocarcinoma. in this study we discuss the mismatched pathological findings in each case and explored the possibility of reducing the incidence of mismatch. we selected cases, in which preoperative ct guided biopsy and consecutive resection were performed. tumors were peripheral lung adenocarcinoma of cm or less in diameter. the final diagnosis by resected specimen of these cases were type b, type c and type f peripheral adenocarcinoma. we compared hrct findings of them to identify the ct density in each tumor. results: though the final pathological findings show type c tumors, the specimen by ct guided biopsy show only type a or b tumors. further more, though the final pathological findings show type f, not having a replacement growth pattern, the specimen also show type a or b, having a pure replacement growth pattern. conclusion: pathological mismatched findings between ct guided biopsy and resection were observed. additional ct image comparison between mediastinal and lung window settings gave us probable information about the tumors having replacement growth patterns or not. before performing ct guided biopsies, image recognition about the solid density helped us choose the most suitable biopsy site. with more thorough information derived from hrct and biopsy on the types of tumors patients have, physicians can offer patients more accurate prognosis. purpose: to analyze high-resolution ct (hrct) findings in asthmatics and control subjects, and to evaluate the relationship between hrct findings and pulmonary function tests in asthmatic subjects. to try to evaluate the correlation between the bronchial wall thickening (bwt) with pathologic findings and reflect the thickness of epithelial basement membrane on basis of the hrct findings. materials and methods: using hrct, the author analyzed the ratio of bwt, the frequency of bronchial dilatation, the extent of air trapping and centrilobular nodules. in addition, the author assessed hrct findings of asthmatic patients for correlation with pulmonary function tests and then obtained bronchoscopic biopsy at the second divisional branch of patient among the asthmatics. the author measured the thickness of the epithelial layer and basement membrane after h-e stain and then statistically compared with bwt on hrct. results: among the total asthmatics, bwt on hrct showed significant correlation with fev (p = . ) and tlc (p = . ). pefr (p = . ) shows significant correlation with the air trapping on hrct statistically. among the patient of asthmatics, bwt on hrct shows statistically significant correlation with basement membrane thickness on pathology, but not with epithelial layer thickness on pathology (p = . , r = . ). the ratio of bwt between asthmatics and control subjects are significantly different on hrct. the grade of bwt shows significant different fev and tlc statistically, and that of extent of air trapping reveal significant different pefr statistically. the bwt on hrct reflect the thickness of epithelial basement membrane. computer-aided diagnosis: a shape classification of pulmonary nodules imaged on high-resolution ct s. iwano, t. nakamura, t. ishigaki; nagoya/jp purpose: the purpose of this study was to decide whether the computer image analysis could classify shape of pulmonary nodules like radiologists. materials and methods: based on the high-resolution ct (hrct) findings, two radiologists classified pulmonary nodules ( - mm in diameter) into types of shape: round (n = ), lobulated (n = ), polygonal (n = ), tentacle (n = ), spiculated (n = ), ragged (n = ), and irregular (n = ). on the other hand, an image processing computer software extracted several quantitative measures of the shape of each nodule from dicom data of hrct images. to identify the contour of the pulmonary nodules, - hu was used as the predefined threshold values. these quantitative measures were contrasted to the classification by radiologists. results: as quantifiable features to characterize nodule shape, the circularity (= π*area/ perimeter ) and the second moment were suitable. the combination of the circularity and the second moment could classify round, tentacle, spiculated, ragged, and irregular nodules. however, it was difficult to separate lobulated from polygonal nodules. conclusion: computer image analysis of hrct could classify round, tentacle, spiculated, ragged, and irregular pulmonary nodules like radiologists. this method may be useful for the differentiation between malignant and benign nodules. hrct of the lungs in cystic fibrosis: more sensitive marker of cf lung disease than lft m. polakovic, h. kayserová, p. boruta; bratislava/sk purpose: our study was aimed at determining the usefulness of hrct in evaluating pathomorphological changes of lung parenchyma, the reversibility of these changes, and correlation of these changes to pulmonary function and mutations in cftr gene. two hrct examinations of the chest were performed on cf patients ( males, females) with lft (maximal interval: two weeks) in the period of to . follow-up studies were evaluated by a modified bhalla scoring system and compared with initial studies. lung function testing was performed on a mir spiro-bank, using ers (zapletal) predicted values. in group with df /df genotype ( pts) the first examination mean score reached . (rl)/ . (ll), second . (rl)/ . (ll). lung function tests were: first examination -fvc %, fev %, mef % and second one fvc %, fev %, mef %. for groups with df /other genotype ( pts) and other/other genotype ( pts) similar results were obtained. conclusion: hrct is a more sensitive method of evaluating pathologic process in lungs of cf patients than lft. lft is a more complex examination, and the results of pulmonary functions are modified by the physical status of the cf patient (nutrition, strength of muscle, acute exacerbation) and his/her ability to cooperate with spirometry (age). severe mutations of cftr gene in genotype are accompanied by an increasingly high hrct score in spite of therapy applied and stable lung functions. high resolution computed tomography in the diagnosis of bronchiolitis obliterans syndrome after lung transplantation a.e. berstad, t.m. aaløkken, a. kolbenstvedt, Ø. bjørtuft; oslo/no purpose: to evaluate the clinical value of high resolution computed tomography (hrct) of patients after lung transplantation. materials and methods: hrct with insp-and expiratory scans was performed in patients ( women, single-and double lung-, including two heartlung transplanted) who had survived for months or more. the median followup time was months (range to months). air trapping was evaluated on expiratory scans constructed from two short spiral scans in two levels with minimum intensity projection (minip)-reconstruction. the degree of air trapping was classified on a to scale according to the affected surface area. a score of or more was defined as significant air trapping. results: patients developed the bronchiolitis obliterans syndrome (bos) as defined by reduction of pulmonary function test results to less than % of the best postoperative values after a median time of months. of these had an air trapping score of or more. among patients without bos (n = ), patients showed significant air trapping. the sensitivity, specificity and accuracy of a score of or more in the diagnosis of bos were , and % respectively. bron-chiectasis developed more frequently in bos than in non-bos patients ( and %, respectively). conclusions: hrct, including expiratory scans with minip-reconstruction, or development of bronchiectasis was of limited accuracy in diagnosing bos after lung transplantation. hrct indices and pulmonary function tests in patients with chronic bronchial asthma c. kalogeropoulou, d. kalampoka, p. zampakis, i. tsota, k. spyropoulos, t. petsas; patras/gr purpose: to quantitatively evaluate the presence and extent of low attenuation areas on chest high-resolution ct (hrct) in patients with chronic bronchial asthma and correlate such findings with the pulmonary function tests (pft). we examined patients (m: and f: , age . ± . yrs) with chronic bronchial asthma. all patients underwent inspiratory and expiratory hrct as well as forced spirometry, maximum voluntary ventilation, somatic plethysmography and cardiopulmonary exercise test. hrct images were evaluated for the presence and distribution of low attenuation areas. objective quantification of low attenuation areas was obtained by determining the relative area of pixels representing lung tissue with a density below - hu (pixel index). the resulting pixel index was determined for a single slice at the upper middle and lower zone. results: pulmonary function parameters correlated well with pixel index during expiratory scan. there was significant correlation between the upper part of the lung and forced vital capacity (fvc),%fvc, forced expiratory volume in sec (fev ), maximum voluntary ventilation (mvv) and total lung capacity (tlc). the middle part of the lung correlated with fvc, fev , fef - and resistance. the lower part of the lung was also correlated with fev , fef - , residual volume (rv) and total resistance. pixel index during inspiratory hrct scans did not correlate with pulmonary function tests. conclusions: expiratory hrct in asthmatics correlates well with pulmonary functions, which suggests that in asthmatics substantial gas trapping may occur during expiration because of severe airway narrowing and/or airway closure. thoracic imaging during treatment with pergolide r. dore, a. gervasio, m. braschi, v. vespro, g. meloni, c. nascimbene; pavia/it purpose: pergolide is a dopaminergic agonist widely used in the treatment of parkinson's disease. toxicity has been described in the form of fibrosis, inflammation of the pleura, retroperitoneal fibrosis, constrictive pericarditis and inflammatory lung infiltrates. we analyzed thoracic abnormalities in patients who have been taking pergolide long term and the possible differential diagnosis. hospital, "s.matteo" irccs, a group of neurological patients treated with pergolide underwent chest ct, because of clinical and chest x-ray abnormalities. we scanned each patients before and after intravenous injection of contrast medium; the lung parenchyma was evaluated with high resolution algorithm; three patients with pulmonary opacities also underwent fnab. results: all patients had round atelectasis associated either with pleural plaques of vary entity or with atypical and reactive pleural effusion. the thickest pleural plaques were located in the costovertebral angles, followed by the diaphragmatic pleura without effusion. in all the cases the pleural plaques in the parietal side were definetly irregular, linear in the lung side. association with lung interstitial septal thickening was inconstant. conclusions: although our cases are few in number and need further validation, pleural involvement, either fibrotic or inflammatory, always seem to be associated with pulmonary abnormalities. ct pleural signs are non specific; differential diagnosis may include tumors, asbestos exposure and inflammatory disease; however the association with relevant lung round atelectasis is significant. these ct findings must be held in mind and thought to be due to toxicity in patients treated with pergolide. the chest radiological appearances of severe acute respiratory syndrome methods and materials: patients with sars confirmed clinically had serial chest plain films, of whom also underwent chest ct scans. the radiological appearances and evolution patterns of sars were analyzed retrospectively. based on the extent and duration of the lesions on the chest plain films, the patients were classified into three types: simple type (type i) in which the lesions were limited, progressive type (type ii) in which more than three lungs fields were involved, and prolonged type (type iii) in which the lesions remained for more than six weeks. the follow-up chest plain films and ct scans were analyzed comparatively in patients of this group discharged from the hospital after clinical cure. results: in cases, on the chest radiography, cases showed predominately pulmonary parenchymal lesions in the form of ground-glass opacity and consolidation, cases showed predominately interstitial infiltration and cases showed both parenchymal and interstitial lesions. the radiological appearances were nonspecific with good patient prognosis in type i (n = ), and the radiological appearances were relative specific with high patient fatality rate ( %) in type ii (n = ). all of the patients ( %) in type iii (n = ) had residual lesions. ct was superior to the chest plain film on detecting residual lesions. the radiological appearances of sars were relatively specific. the exact diagnosis of sars must combine radiological appearances with the clinical, epidemiological and laboratory findings. hrct to identify hrct features that indicated predisposition to potentially fatal asthma and to evaluate serial follow-up hrct scans of patients with nearfatal asthma (nfa). abnormalities of the large airways (bronchial wall thickness) and small airways (centrilobular thickening and air trapping) were measured semi-quantitatively on hrct scans of non-nfa, nfa, and control subjects. in addition, these abnormalities were re-evaluated after intensive and relatively long-term (> -month) treatment with inhaled steroids. results: centrilobular thickening was observed in % of mild asthma cases, in % of moderate to severe asthma cases, and in % of nfa cases. centrilobular thickening, but neither bronchial wall thickness nor the area of air trapping, was significantly increased in nfa, as compared with mild or moderate to severe asthma (p < . , respectively). in the non-nfa and nfa patients who underwent follow-up hrct scans, only bronchial wall thickness was decreased significantly in the nfa cases (p < . ), while bronchial wall thickness and centrilobular thickening were significantly decreased in the non-nfa cases. these small airway abnormalities were partially reversible in the both groups. residual centrilobular thickening after long-term steroid treatment was significantly higher in nfa than non-nfa patients. the results of our study indicate that extensive small airway abnormalities may be associated with nfa, and that these abnormalities are partially reversible after the successful control of asthma symptoms. a. kalogera-fountzila, a. haritanti-kouridou, a. lefkopoulos, g. sevas, a. tzinas, a. sarafopoulos, a.s. dimitriadis; thessaloniki/gr purpose: we prospectively studied aids and non-aids immunocompromised patients with lung infection in order to evaluate the hrct findings, to characterize the infection and seek for differences in appearance of pcp in the two groups. methods and materials: hiv positive patients were referred to the special infectious diseases unit and non-aids immunocompromised patients were referred to the oncology unit of our hospital with a diagnosis of clinically suspected pulmonary infection. all patients were evaluated with hrct ( . mm collimation, mm interval, kvp, mas, and -s scan time). all non-aids immunocompromised patients had bronchoalveolar lavage, sputum culture, or ct guided biopsy as well as did of the hiv-positive patients which revealed pcp. in the rest of the patients pcp was confirmed after successful anti-pcp treatment. the data were calculated using the chi square test. results: all patients in both groups had the typical findings of pcp, such as presence of ground glass appearance (patchy or diffuse), consolidation (focal or diffuse), bronchiectasis or bronchioloectasies, septal thickening, cysts and nodules. the incidence of consolidation, especially diffuse, was a significantly higher finding in non-aids patients (p = . ). on the contrary, presence of ground glass in a central/perihilar distribution (p = . ), septal thickening (p = . ) and bronchioloectasis (p = . ) was significantly higher in aids patients. conclusion: hrct findings of pcp in non-aids immunocompromised patients are more aggressive, with diffuse consolidation as the cardinal sign and are associated with a more advanced disease. primary and secondary lung malignancies treated with percutaneous radiofrequency ablation: to describe the important ct findings to evaluate for therapeutic efficacy on follow-up ct after rf ablation for the lung cancer. the study group included lung cancers and metastatic nodules in patients. all patients underwent follow-up helical ct examinations immediately, one month later, and then every three months after percutaneous rf ablation. two reviewers interpreted the ct findings with consensus. the serial changes in the enhancement pattern, size, peripheral groundglass opacity, and other findings in the treated area were assessed on the follow-up ct. sensitivity, specificity, and the positive predictive value for evaluating the complete ablation using enhancement pattern on immediate follow-up ct were determined using the chi-square test. in the completely ablated group (n = ), the ablated lesions demonstrated absolutely no contrast enhancement on follow-up ct and the mean percentage of ablated lesion size decreased at , , , , and months ( . %, . %, . %, and . %, respectively) compared with immediate follow-up ct. in the partially ablated group (n = ), the ablated lesions demonstrated varying patterns of enhancement and the mean percentage of ablated lesion size showed a gradual increase after the -month follow-up ct scans. enveloped ground glass opacity surrounding the tumor was seen in ( . %) of lesions on immediate follow-up ct. conclusion: of the ct findings of lung malignancy after rf therapy, the enhancement pattern and the change in size of the ablated lesion are the most important factors in determining whether complete ablation can be achieved. (ip) is an uncommon benign lesion characterized by an irregular growth of inflammatory cells. the purpose of this study was to evaluate ct findings of the thoracic inflammatory pseudotumor. methods and materials: chest ct findings of pathologically proven seven thoracic ip were reviewed retrospectively. mean age of the patients was years old ( - years). pre-and post-contrast enhancement ct were performed in all patients. location and contour with margin of the lesion, pattern of contrast enhancement, calcification in the lesion, lymphadenopathy, associated parenchymal or pleural lesion were reviewed. clinical findings of the patients were also evaluated. results: six were in the lung parenchyma (five in peripheral, one in central; four in upper lobe, two in lower lobe), and one was in the anterior mediastinum. average size of the lesions was . cm ( - cm). of the six parenchymal lesions, three revealed as ill-defined mass-like consolidation, two as well defined masses, and one as speculated mass. one mediastinal mass showed ill-defined margin. all lesions showed heterogeneous contrast enhancement. three had eccentric calcification. none had satellite nodule. four cases had adjacent pleural thickening or effusion. lymphadenopathy was noted in one patient. they complained of mild fever (n = ), hemoptysis (n = ), coughing (n = ), weight loss (n = ). four patients had past history of pulmonary tuberculosis. conclusion: thoracic ip showed variable ct findings. however, when dealing with a peripheral pulmonary mass with heterogeneous contrast enhancement without remarkable lymphadenopathy, the radiologists should always include ip among the entities of the differential diagnosis. early to highlight the potential benefit of including fdg-pet in an early lung cancer detection protocol. materials and methods: from september to october , asymptomatic smokers (mean age . years, sd . , mean tobacco consumption . pack-years) were studied with ldct. repeat short-term high-resolution ct follow-up was done for non-calcified pulmonary nodules (ncpn) < mm to exclude growth. ncpn mm or more were considered as potentially malignant and complementary fdg-pet scanning was recommended. biopsy was recommended for ncpn found to be positive on the fdg-pet. results: ncpn were found in ( %) asymptomatic subjects. the diameter of the largest ncpn was: mm or less in ( . %) participants, > -< mm in ( . %) and mm or more in ( %). subjects underwent fdg-pet exam ( positive, negative). among the fdg-pet positive ncpn were resected (lung cancer), underwent fine needle aspiration cytology (fnac) (non-specific / necrosis). the remaining subject refused further work-up. ct follow-up was decided for the other ncpn. results will be updated after inclusion of more participants. this ldsct based screening programme demonstrated a prevalence of lung cancers in a population of ( . %) asymptomatic subjects at high risk, all with surgical stage t n m . addition of fdg-pet to the protocol may reduce the number of invasive procedures for histologically benign nodules. technical aspects postprocessing procedures after mdct for airway and lung diseases a.-l. brun, c. beigelman-aubry, y. badachi, p.a. grenier; paris/fr learning objectives: to be familiar with the postprocessing procedures after multi-detector row ct (mdct) which can optimize the assessment of airway and lung disease. background: axial slices are considered as the gold standard for analysis of airways and lung diseases. since the era of mdct, excellent reformations, and d reconstructions have become available and frequently used in case of airway disease. infiltrative and cystic lung diseases may also benefit from these techniques, provided that they are optimally used. procedure details: all d and d reconstruction techniques available were retrospectively applied on mdct volume data set from patients with airway and/or lung disease, using various parameters. optimized multiplanar volumetric reconstruction and d ct bronchography are particularly well adapted for assessing tracheobronchial stenosis and bronchiectasis. maximum intensity projection is recommended for assessing small nodular and mosaic perfusion patterns. minimum intensity projection is helpful: ) to detect and assess ground glass opacity; ) to visualize the airways within any lung parenchymal lesions, helping guide selective bronchial aspiration and bronchoalveolar lavage; and ) to depict bronchial adenolectasia in patients with copd or bronchiectasis. virtual endoscopy is particularly helpful in depicting tiny nodulation of the tracheobronchial mucosa in granulomatous and malignant diseases. highly selected cases will be used to illustrate the most striking additional information provided by postprocessing techniques in airway disease, infectious lung disease, and diffuse infiltrative lung disease. postprocessing procedures in addition to axial slices allow an excellent assessment of tracheobronchial and parenchymatous diseases, particularly concerning their depiction, characterization and extent assessment. volume rendering: less-time consuming and accuracy technique in diagnosis of rib fractures e. chavarri, c. trinidad, e. guerra, g. fernandez, c. delgado, p. moreno de la santa; vigo/es learning objectives: to asses the useful of volume rendering d images (vr) in the evaluation of rib fractures using a -slice multidetector ct. to compare vr and conventional images in determining the number and location of fractures. to describe the advantages of vr over conventional images. background: multislice ct has improved the resolution in evaluation of traumatic patients because it permits thinner slices and multiplanar reconstructions with near isotropic voxel. however, the number of images to be evaluated is greater and the diagnosis of rib fractures remains difficult due to the obliquity of costal arches in the axial view. we evaluated chest ct examinations in patients with rib fractures. in this exhibit, we describe ct technique, reconstruction parameters and the advantages of vr over conventional images to ensure number and location of rib fractures. procedure details: a -slice multidetector ct was performed using the following parameters: mas, kv, x . mm collimation, during a single breath hold. images were reconstructed with mm thickness, % overlapping and soft tissue kernel filter (b ). two experimented radiologists analysed axial, multiplanar and vr images. the number of fractures, location and part of arch fractured (anterior, medium and posterior) was described. conclusion: volume rendering is more accurate than conventional images in determining the presence and location of rib fractures, particularly when arches are fractured in more than one site. also, it is a less time consuming technique with better diagnosis confidence. we recommend its use in a routine practice for chest-ct in traumatic patients. c b d e f a g volume rendering d bronchography imaging of the airways with multidetector row ct c. trinidad, g.c. fernandez, m. rodriguez-castilla, c. martinez, e. guerra, f. tardáguila; vigo/es learning objectives: to describe the technique of d volume rendering bronchography (vr-b) with multidetector row ct. to evaluate the usefulness of vr-b of the tracheobronchial tree in clinical practices comparing with axial and multiplanar reconstructions. background: multidetector row ct allows superior imaging resolution in axial and multiplanar images, and also contributes to advances in d-volume rendering that can now be feasible in clinical routine practice. in this exhibit, we will describe the ct technique and vr-b parameters to obtain good quality d images for visualization of central and small airways. in addition, we will evaluate the role of this technique in clinical practice and in different pathologies of the tracheobronchial tree. procedure details: patients with airways pathology due to different etiologies were prospectively studied with -row multidetector ct. images were acquired at end-inspiration during a single breath-hold with x . collimation detector and reconstructed with - mm collimation, . - mm increment (overlapping %) and soft tissue kernel filter (b ). vr-b images were showed using - to - uh window with, - to - uh window level, % opacity and unshaped. conclusion: good quality vr-b images are feasible in daily practice. in patients with benign stenosis of the central airways additional information in assessing length and degree is provided. this technique improves confidence diagnosis in extrinsic compression by malignancies. however, no additional benefit in the evaluation of endobronchial lesions and bronchiectasis is shown. clinical procedure details: all scans covered from the vocal cords to the mainstem bronchi. ct parameters included a slice thickness of mm, a reconstruction interval of mm, a pitch of . mm, and a table speed of mm per rotation. data were obtained during a single-breath-hold acquisition in a craniocaudal direction. twodimensional reformation images including multiplanar reconstructions (mpr), multiplanar volume reconstructions (mpvr), and three-dimensional reconstructions (external and internal rendering) were obtained at a workstation (vitrea ; vital imaging). the main applications of msct in airways disease as well as its limitations and pitfalls are emphasized. specific topics addressed include congenital airways anomalies (anomalous origin of bronchi, vascular rings, tracheomalacia, bronchopleural fistula), extrinsic airways compression, tracheal and bronchial wall infiltration (bronchogenic carcinoma, angiosarcoma), intraluminal airways masses (carcinoid tumor), inflammatory diseases and posttraumatic and iatrogenic airways injuries. conclusion: msct provides very high-quality image postprocessing (multiplanar and three-dimensional images), overcoming limitations inherent to sdct. additional benefits include preprocedural planning for bronchoscopy and surgery, and a more comprehensive spatial anatomy for both radiologists and referring physicians. ultrasound: guided aspiration of supraclavicular lymph nodes in patients with suspected lung cancer m. kumaran, r. benamore, r. vaidhyanath, j. entwisle; leicester/uk learning objectives: to illustrate the utility of ultrasound-guided supraclavicular lymph node aspiration in the cytological diagnosis of lung carcinoma. we describe our preliminary experience in patients over the last months. background: lung carcinoma is the leading cause of cancer death in the uk. histological diagnosis traditionally requires invasive techniques to obtain tissue, such as bronchoscopy, mediastinoscopy or image-guided lung biopsy. we have introduced this technique in patients who have at least n disease on staging ct. if positive, this helps both to stage the patient and provide a cytological diagnosis. it may prevent the need for more invasive techniques, such as percutaneous lung biopsy or mediastinoscopy. procedure details: all patients were scanned and nodes over mm in size were aspirated under ultrasound guidance, using a gauge green needle. a capillary "coring" technique was employed, without suction and aspiration. the samples were then expelled from the needle into cytospin fluid, for cytological examination. the procedure could be performed without local anaesthetic and as an out patient. of the patients examined, had significant lymphadenopathy. of these, had positive malignant cytology, although had indeterminate cell type. samples showed no evidence of malignancy and pet confirmed no evidence of supraclavicular nodal involvement in case. conclusion: this is a promising non-invasive technique in the staging and diagnosis of patients with lung cancer. simulated low radiation dose ct angiography of pulmonary arteries d. tack , v. de maertelaer , c. suess , p. muller , p. scillia , w. petit , p. gevenois ; baudour/be, brussels/be, forchheim/de, charleroi/be purpose: to compare standard dose and simulated low-dose ct angiography of pulmonary arteries (ctpa). raw data of ctpa acquired in consecutive patients with pulmonary emboli (pe) were included. ct acquisitions (volume zoom, siemens) were: x mm, kv, effective mas. from the native raw data, four sets of simulated raw data were generated with , , and effective mas, respectively. from each raw data set, ct slices were reconstructed with . mm thickness and . mm increment, and with a soft tissue kernel. three readers who were blinded to the patients names and to the simulated mas levels analyzed the ct series twice, in random order. pe in central pulmonary arteries (pa) and segmental pa were graded with a four-point scale. agreements (kappa statistics) and readers performances using mas as the gold standard were calculated. results: all pe seen at mas were depicted at all lower radiation dose levels. intraobserver agreements were independent from the radiation dose but strongly depended on the reader's experience. agreements were good for central pe but only moderate for peripheral pa branches. accuracy of low-and lower dose ctpa ranged from to %, and were independent from the radiation dose (p < . ) but not on the reader. conclusion: reducing the radiation dose during ctpa is feasible with high accuracy, and may have less influence on ctpa interpretation than may have changing the reader or repeating a reading. receiver operator characteristic analysis of observer performance in virtual bronchoscopy p. maniatis, c. triantopoulou, h. labrakis, k. malagari, i. tsalafoutas, i. siafas, j. papailiou, d. kelekis; athens/gr purpose: to evaluate the observer performance with the combined interpretation on a workstation of vb, axial, coronal and sagittal images against hard-copy films of thin section ct in low grade bronchial abnormalities using receiver operating characteristic (roc) curves. patients and methods: bronchial sections in patients were evaluated in a prospective observer study using spiral ct data. exclusion criteria included occlusions, high-grade bronchial stenoses (> %) and tracheal lesions. all patients underwent a spiral ct acquisition with mm collimation. two reconstruction intervals were used: mm for virtual bronchoscopy and mm for thin section ct. both examinations were reviewed by two independent radiologists. the findings were correlated with those of flexible bronchoscopy and the statistical analysis was done with receiver operating characteristic curves. results: a total of lesions were identified by flexible bronchoscopy. areas under curves for virtual bronchoscopy and multiplanar reconstructions were . and . for the two observers respectively, while areas . and . were provided from thin axial ct images (by the two observers respectively). these results differed at statistical significant level (p < . for the first observer and p < . for the second observer). the combination of multiplanar reconstructions and virtual bronchoscopy in simultaneous viewing on a workstation is particularly useful for the evaluation of low grade bronchial abnormalities at statistical significant level when compared to thin section axial ct images alone. b d e f a g optimization of voltage combination for chest radiography in a new dualenergy subtraction system n. bandai , h. tagashira , m. yoshimoto , t. kiriyama , t. maruyama ; onsen-gun/jp, matsuyama/jp the new dual-energy subtraction system allows the fast ( millisecond) acquisition of two, high and low voltage images using csi:tl amorphous silicon flat-panel technology. the purpose of this study was to determine the best combination of the voltage for the soft tissue of the chest radiography. the dual-energy subtraction imaging increases the sensitivity and specificity of the pulmonary nodule detection in the chest radiography by reducing the contrast of overlying the bone structures. the range of the high voltage is from kvp to kvp and the low voltage is from kvp to kvp, respectively. the physical factor such as contrast, density and graininess and the anatomical factor such as visibility of the vessel were evaluated by five radiologists using the normalized-rank approach. all rank orders were transformed to the distance scale by the statistical method. the ranking in the low voltage was better in the order corresponding to kvp, kvp and kvp (p < . ). the ranking in the high voltage showed better in the order corresponding to kvp, kvp, kvp and kvp. there were significant differences (p < . ) except the distance scale between kvp and kvp. the best combination for the soft tissue of the chest in a new dualenergy subtraction system was kvp (high voltage) and kvp (low voltage). spiral low-dose ct of the chest: a "one-stop-shop" modality for early detection of the leading causes of death g. bastarrika, o. cosín, j.c. pueyo, Á. alonso, d. cano, j.j. zulueta; pamplona/es purpose: spiral low-dose ct (ldct) can identify very small lung cancers in high-risk individuals. the purpose of this study is to assess feasibility of quantifying coronary calcium using non ecg-gated ldct exams performed in individuals participating in an early lung cancer detection programme (elcdp). a comparative study was performed in asymptomatic smokers included in an elcdp ( male, female; mean age . years; sd . ). subjects consecutively underwent a ldct of the chest and an ecg-gated cardiac ct with a four-row msct scanner (volume zoom, siemens, erlangen, germany). standard parameters were employed: ldct: kv, mas, mm slice, mm coll., mm table feed, . mm rec. interval; ecg-gated cardiac ct: kv, mas, mm slice, . mm coll., . mm table feed, . mm rec. interval. retrospective reconstruction using the raw data from the ldct was performed reproducing the specific ecg-gated ct parameters. intraclass correlation coefficient (icc), paired-sample t-test and bland and altman plot were employed for the statistical analysis. the paired sample t-test showed there was not a systematic bias in the measures of calcium (p = . ). the icc for the overall calcium score and for the different main coronary arteries showed and excellent agreement (overall icc . , % ci . - . ). conclusion: a clear correlation when evaluating quantification of coronary calcium with both ct techniques is observed. a single ldct exam may be useful for early detection of leading causes of death: lung cancer and coronary artery disease. dual energy in digital chest x-ray: material and methods: patients scheduled to undergo routine chest ld-msct were examined either without ( mas, kv, . mm slice width fused to mm effective width, spiral acquisition, n = ) or with ecg-triggering ( mas, . mm slice width, axial incremental acquisition, n = , age-, sex-and bmi-matched) on a philips mx -row msct scanner. three independent radiologists scored axial slices at four different levels (carina, apical, mid-cardiac, basal), using a four-point scale for discrimination of pulmonary structures in the hilar region, the lung core and the subpleural region. mediastinal structures were scored on a three point scale. scores were compared using wilcoxon's test. results: for the more experienced ct radiologist, delineation of pulmonary structures did not improve significantly with ecg-triggering (p = . ), while improvement in the delineation of mediastinal structures was highly significant (p = . ). for the less experienced ct radiologist, there were no significant differences between ld-mscts with and without ecg-triggering for either pulmonary or mediastinal structures (p = . resp. p = . ). although not formally evaluated in this study, both radiologists reported a higher quality of sagittal and coronal mprs from non-triggered data due to lower susceptibility to breathing artifact. conclusion: results indicate that ecg-triggering improves delineation of moving structures (heart, mediastinum) in ld-msct of the chest. ecg-triggering improves delineation of pulmonary structures only in paracardial lung tissue. results: time-distance curves of the breathing-cycle using mri correlated highly significantly with spirometry (p < . ). vc calculated by the model was similar to vc measured in spirometry ( . l vs . l). tvc correlated highly significant with spirometry (p < . ). vertical parameters had a more profound influence on tvc change than horizontal parameters. conclusions: dynamic mri is a simple non-invasive method to evaluate local chest wall motion and respiratory mechanics. it widens the repertoire of tools for lung examination with a high temporal resolution. influence the aim of this study was to investigate influence of reconstruction filters on image quality in ct chest exams. methods: patients were examined with standard chest scanning protocol. after scanning, images were reconstructed with smoothing filter. both set of images were filmed under the same conditions. in blinded assessment, three radiologists independently rated films for overall image quality and chest anatomic details ( -unacceptable, -substandard, -acceptable, -above average, and -superior). for all exams and reconstruction filters image noise were measured in relation to the descending thoracic aorta. results: for all three readers overall image quality was higher for standard filter. image quality for standard protocol was . and for images reconstructed with smoothing filter . . average image noise for images reconstructed with standard filter was . and for images reconstructed with smoothing filter the noise was . . all three radiologists rated greater chest anatomic details for standard protocol images. for both protocols the best-rated detail was that of the trachea and main bronchi ( . standard, . smoothing), and the worst was that of the esophagus ( . standard, . smoothing). the greatest difference between rates of the two protocols was for paratracheal tissue ( . standard, . smoothing) and the smallest for carina and lymph node area ( . standard, . smoothing). conclusion: standard filter is better in visualization of all anatomic detail in general chest exams including mediastinal structure and lymph node area. greater image noise for image reconstructed with standard filters does not influence visualization of anatomic detail. usefulness new quality assurance systems for the evaluation of detectability of lung nodules on the digital chest radiograph y. fujiwara, k. higashimura, h. kimura, h. itoh; fukui/jp purpose: the goal of this study is to develop a new quality assurance system for evaluating detectability of lung nodule of the digital chest radiograph. method and materials: first, we made an oval shaped phantom, which simulated lung tissue such as muscle, fat, and pulmonary field. then several nodules with variable ct values were inserted into the center of the phantom. second, we took images of the phantom using ct and digital radiography (dr) with a flat panel detector.the contrast of the nodules relative to the pulmonary field were measured both on chest ct and dr. the relationship between contrast from ct and dr was analyzed in regression using rd order polynomial. finally, the same analysis was also performed on nodules from clinical cases with lung cancer (n = ), and clinical data was fitted into the same polynomial line. results: all nodules with the ct value less than in the difference between nodules and lung field could not be detected on dr. the relationship between the contrast from ct and dr in clinical cases was also regressed with the same rd order polynomial line from the phantom data. the current result is very useful for the evaluation of the detectability on chest dr. when one want to check it using variable nodules with known ct values, if the contrast of the nodules on dr is not regressed on above line, the assurance of dr might be problematic and/or dr system may need to be reconditioned. b d e f a g pulmonary thromboembolism: acute versus chronic (pictorial review) a. oikonomou , c.j. dennie , j.m. seely , f.r. matzinger , f.d. rubens , p.k. prassopoulos ; alexandroupolis/gr, ottawa, on/ca learning objectives: to present the spectrum of imaging findings that allow the differentiation of acute pulmonary embolism (ape) from chronic thromboembolic pulmonary artery hypertension (cteph) based on chest radiography and helical computed tomography (ct). background: patients with a prompt diagnosis of ape may recover completely following anticoagulation therapy. in a minority, pulmonary emboli do not completely resolve leading to organization, artery obstruction and ultimately to cteph. although the evolution process of ape to cteph has not been fully elucidated, the distinction of the two entities is critical since the treatment of ape is conservative, while cteph warrants pulmonary thromboendarterectomy. imaging findings: radiographic findings of ape are nonspecific and include atelectasis, peripheral consolidation and pleural effusion. localized lung oligemia with associated dilatation of a central artery is extremely rare. right ventricular and central pulmonary enlargement, patchy oligemia and peripheral scars may be seen in cteph. the cardinal signs of ape on ct angiography are central or completely occluding arterial filling defects, which may be associated with peripheral airspace disease and pleural effusion. eccentric filling defects adherent to the vessel wall, irregular intimal thickening, abrupt vessel narrowing or tortuosity are features of cteph. dilatation of central arteries, abrupt vessel cut-off and peripheral scars are more common in cteph than in ape but arterial webs, bands and mural calcifications are only observed in cteph. if arterial findings suggestive of cteph are present, the addition of mosaic oligemia on hrct is pathognomonic of cteph. conclusion: ct allows differentiation of ape from cteph. pulmonary hypertension: ct of the chest in pulmonary veno-occlusive disease a. resten, s. maître, m. humbert, f. capron, g. simonneau, d. musset; clamart/fr purpose: pulmonary veno-occlusive disease is a rare cause of pulmonary hypertension and often difficult to distinguish from severe primary pulmonary hypertension. unfortunately, medical treatment of the primary pulmonary hypertension by prostacyclin (pgi ) can be fatal in veno-occlusive disease and an early pre-therapeutic diagnosis of this uncommon condition is critical. so, the aim of the study was to evaluate ct of the chest as a non invasive approach of this disease. we reviewed cross-referenced records from to in our departments of radiology and pathology and identified patients with an initial pre-therapeutic ct and a pathologically confirmed pulmonary venoocclusive disease. ct scans were compared with the ct scans of consecutive patients with a pathologically confirmed primary pulmonary hypertension. results: ground glass opacities were significantly more frequent in pulmonary veno-occlusive disease (p = . ), abundant, with a random repartition, and a preferentially centrilobular distribution (p = . ). sub-pleural septal lines, and adenopathy were also significantly more frequent (p < . ). the association of these three findings appeared to be quite pathognomonic of pulmonary venoocclusive disease as the cause of pulmonary hypertension (specificity = %) with a % sensitivity. conclusion: on the initial pre-therapeutic chest ct, association of ground glass opacities (particularly with a centrilobular distribution), septal lines, and adenopathy are indicative of pulmonary veno-occlusive disease in patients displaying pulmonary hypertension. caution must be taken before initiating vasodilatator therapy in the presence of such radiological abnormalities. . x . mm ) was performed during and after a single injection of . mmol/kg body weight of gadomer. image data was compared to pre-embolism gd-dtpa-enhanced mri and post-embolism thin-section multi-slice ct (n = ). snr measurements were performed in pulmonary arteries and lung. results: one animal died after induction of pe. in all other animals, perfusion mri and mra could be acquired after single injection of gadomer. at perfusion mri, pe could be detected by typical wedge-shaped perfusion defects. while the visualization of central pe at mra correlated well with ct, peripheral pe were only visualized by ct. gadomer achieved a higher peak snr of the lungs compared to gd-dtpa ( ± vs. ± ). conclusion: contrast-enhanced d perfusion mri and mra allow the assessment of pe using a single injection of the blood pool contrast agent gadomer. c b d e f a g detection of pulmonary emboli with thin slice ( mm) maximum intensity projection reconstructions of multi-detector ct pulmonary angiography s.k. venkatesh, s. wang, p. goh; singapore/sg purpose: to compare thin-slice ( -mm) maximum intensity projection (mip) reconstructions with mm axial scans for detection of acute pulmonary emboli. materials and methods: multi-detector ct pulmonary angiography ( x mm, . pitch; . sec) was performed in patients. from each raw data set, axial mm and mm scans were reconstructed. thin-slice ( mm) mips in axial, coronal and rotational planes were reconstructed from mm axial data using a d workstation. the data sets were reviewed for evidence of embolus on a per vessel basis by radiologists with discrepancies resolved by consensus. emboli demonstrated on the axial mm images were taken as standard for comparison. results: pulmonary emboli were detected in vessels (mean of . emboli per patient) with . % in subsegmental arteries. the thin-slice mip images demonstrated more emboli as compared to axial mm images. axial and rotational mm mip images detected most of the emboli ( . % and %). significant advantage of axial and rotational mm mips over axial mm images was seen at subsegmental artery level ( . % and . % versus . %) (p < . ). among the mips, axial mips detected the most number of emboli in upper and middle lobes, whereas the rotational mip detected slightly higher emboli in the lower lobes. conclusions: thin slice mips are superior to axial mm for pulmonary embolus detection. the advantage of mips is most significant at the level of subsegmental artery level and beyond. we recommend routine use of axial mm mips in the detection of pulmonary embolus. primitive angiosarcomas of the pulmonary arteries: difficulties in ct diagnosis r. dore, m. mantelli, v. vespro, d. savulescu, g. digiulio; pavia/it purpose: primitive angiosarcomas of the pulmonary arteries are very uncommon tumors. the radiologist should consider them in the differential diagnosis with thromboembolic disease, in patients with clinical suspicion of pulmonary embolism, as early surgical treatment may be beneficial. between and , at our hospital, "s.matteo" irccs, we identified three cases of primitive angiosarcomas of the pulmonary arteries, subsequently confirmed at surgical examination, on chest cts of patients with clinical suspicion of thromboembolism. we used a single-slice spiral ct scanner ( sec., - mm collimation), with iv contrast injection at high flow rate. both pulmonary parenchyma and vasculature were evaluated, along with the enhancement pattern of the endoluminal lesions. results: in all cases, the left main pulmonary artery was affected (the distal segment in one case and proximal segments in two). in one patient, the right main pulmonary artery was also involved. all the vascular lesions were occlusive, without anterograde flow and extravasal diffusion. in two patients, contrast enhancement of the endoluminal mass was better detected in the delayed scan. in one patient, contrast enhancement had a periferical distribution. in all the patients, there were no parenchymal signs of thromboembolic disease. conclusions: primitive angiosarcomas of the pulmonary arteries are associated with occlusion of the main pulmonary artery and lack of parenchymal signs. as the differential diagnosis between massive thromboembolic disease and primitive angiosarcoma may be difficult with monophasic ct scan, the evaluation of the contrast enhancement of intraarterial lesion in the delayed phase becomes fundamental. purpose: to demonstrate the imaging features of chronic thromboembolic pulmonary hypertension (ctph) on chest ct scans and to evaluate the correlation between the extent of mosaic pattern of lung attenuation and hemodynamic measurements. methods and materials: chest ct scans of patients with ctph were reviewed to assess vascular and parenchymal changes. in all patients diagnosis was confirmed by surgery. the diameter of the main pulmonary artery (pa) and the ratio of the diameters of the main pulmonary artery to the ascending aorta (rpa) were correlated with mean pulmorary artery pressure and pulmonary vascular resistance. mosaic attenuation was quantitated by adding the number of abnormal lobes (including lingula, score - ). this score was correlated with the hemodynamic measurements. results were analysed by regression analysis and spearman's correlation. results: thrombi were observed in the central pulmonary arteries in % of cases. in all ct scans a mosaic pattern of lung attenuation was found. scars related to the pleural surface were identified in % of cases, bronchial artery collaterals in %. ct scans showed dilated pa in % and rpa ≥ in %. mean pulmonary artery pressure correlated more strongly with rpa than with diameter of pa. the score of mosaic attenuation showed a strong correlation with pulmonary vascular resistance (r = . ; p < . ). to be able to recall the most common ct and mr intrathoracic manifestations in patients with breast cancer. . to be able to describe the radiologic features of this entity. . to be able to recall helpful clues for narrowing the differential diagnosis and appropriately directing patient management decisions. background: breast cancer is a common cancer in women and is second only to lung cancer as a cause of cancer-related deaths in women. the thorax is a common site of metastasic disease and complications related to surgery, chemotherapy, radiotherapy and autologous bone marrow transplantation. imaging findings: the purpose of this exhibit is to review the ct and mr findings of the various intrathoracic manifestations occurring in patients with breast cancer. these include complications related to direct extension of tumor, to metastatic spread, and complications secondary to treatment. the complications can be divided into those that affect the chest wall (chest wall invasion, chest wall metastases, axillary and internal mammary lymphadenopathy, local recurrence, postradiotherapy sternal and costal tumors, surgical complications), mediastinal and hilar manifestations (lymphadenopathy, abscess formation, lymphatic obstruction), pulmonary manifestations (lymphangitic carcinomatosis, pulmonary metastases, endobronchial metastases, neoplastic emboli, lung infections related to immunosuppressive therapy, obliterative bronchiolitis post bone marrow transplantation) and pleural manifestations (pleural effusion, pleural metastases). conclusions: knowledge of the full spectrum of radiologic manifestations of the thoracic complications of breast cancer is useful in diagnosis and in preventing diagnostic errors. bronchogenic cysts: range of radiological appearances f. almolani, p.m. logan; dublin/ie learning objective: to review and illustrate the range of plain film, ct and mri appearances of bronchogenic cysts. background: bronchogenic cysts are one of the congenital cystic lesions in the chest. it has variable appearances on imaging and overlapping features with other mediastinal lesions. it is often identified incidentally. imaging findings: we reviewed the imaging on proven bronchogenic cysts. plain radiographs and ct images were available for all cases. mri images were available in cases. most of bronchogenic cysts have a classic mediastinal location and well defined margin on plain films, with homogeneous low density appearance on ct. however they can be found within the lung parenchyma, be cystic or cavitary, have thick walls and be seen to expand. on mri, fluid levels can be demonstrated. occasionally, they can be multiple or co-exist with significant unrelated pathology. conclusion: bronchogenic cysts have a wide range of imaging appearances and familiarization with these appearances is essential for appropriate inclusion of the diagnosis within a list of differential diagnoses. imaging appearances of mediastinal cystic lesions s.p. prabhu, k. burney, p. goddard; bristol/uk learning objectives: to illustrate the radiological appearances of various mediastinal cystic lesions using various imaging modalities. background: cysts of the mediastinum constitute a small but important diagnostic group, representing to % of all primary mediastinal tumors. mediastinal cysts can be classified based on their aetiology, and include bronchogenic, oesophageal duplication cysts of foregut origin, mesothelial derived pericardial and pleural cysts, cystic thymic lesions, and other miscellaneous cysts. neuroenteric cysts may develop by abnormal septation of the embryogenic germ cell layer, which closely associate with the vertebral column. in addition, mesothelial cysts, including pericardial and pleural cysts, and thymic cysts also occur in the mediastinum, as well as other rare cysts. imaging findings: characteristic location and internal architecture of different mediastinal cystic lesions are used to aid the clinician in formulating a diagnostic plan. plain chest radiographs can identify mediastinal cysts in a large proportion of cases. ct usually reveals well-circumscribed rounded masses of water density or a little higher and is useful in delineating the size, shape, and extent of the mediastinal masses. characteristic fluid signal on mri performed in selected patients differentiates the benign cystic lesion from solid mediastinal masses. mri has therefore succeeded in providing valuable pre-operative specific diagnostic confirmation in regard to mediastinal cysts in selected cases. in this pictorial review, we review the radiological appearances on plain radiographs and cross-sectional imaging for the entire spectrum of cystic lesions of the mediastinum. non-infectious radiographic manifestations of bone marrow transplantation: a pictorial review d. beckett, j. oliff; birmingham/uk learning objectives: to illustrate the radiological manifestations following stem cell transplantation for haematological malignancy. to outline the incidence, clinical presentation and role of imaging within this patient sub-group. background: bone marrow transplantation (bmt) is a critical therapeutic intervention for a variety of pathological conditions. the complications of bmt include chemotherapy and radiation toxicity, graft versus host disease, recurrent malignancy and miscellaneous conditions. complications of allogenic bmt manifest in a variety of clinical settings affecting all organ systems. plain radiography, contrast enhanced studies, sonography, ct, mri and interventional techniques are essential in diagnosing these complications and evaluating their response to therapy. imaging findings: pulmonary manifestations include drug and radiation toxicity, bronchiolitis obliterans, bronchiolitis obliterans organizing pneumonia, lymphocytic interstitial pneumonitis and diffuse alveolar haemorrhage. gastrointestinal presentation with veno-occlusive disease, typhlitis and pneumatosis intestinalis are also reviewed, as are central nervous, musculoskeletal and cardiovascular system manifestations. the spectrum of imaging findings following bmt is diverse. a firm understanding of the clinical presentations and incidence in combination with typical radiological findings is essential in the successful management of this patient sub-group. thoracic manifestations of chronic renal failure a.m. barnacle, p.g. gishen, s.j. copley; london/uk learning objectives: to review the radiological spectrum of thoracic manifestations of chronic renal failure, including the more unusual imaging appearances. background: the effects of chronic uraemia are evident in a multitude of organ systems, including the pulmonary, cardiovascular and musculoskeletal systems. imaging findings: the poster illustrates common thoracic manifestations such as pulmonary oedema and uraemic pericarditis. more unusual manifestations of chronic renal failure such as metastatic pulmonary calcification, renal osteodystrophy, amyloidosis and peritoneal dialysis fluid collection within the mediastinum are highlighted. plain radiographic and ct imaging findings of both these common and more unusual pulmonary manifestations are reviewed. the study illustrates the diversity of thoracic manifestations encountered in chronic renal failure patients and the less well recognised sequelae that should not be overlooked when imaging such patients. background: while the availability of bone marrow transplantation is improving and increasing numbers of adults and children are undergoing the procedure for the treatment of a wide variety of malignant tumours and haematological disorders, it remains a procedure which carries with it a very significant complication risk. despite prophylactic therapy, patients remain at particularly high risk for bacterial, viral and fungal infection in the post-procedure time period. infectious complications are diagnosed and monitored using plain radiography, ultrasound, ct, mri, image-guided biopsy and less often, nuclear medicine. other commonly encountered complications requiring radiological investigation include hepatobiliary complications, veno-occlusive complications and graft-versus-host disease. imaging findings: this educational exhibit demonstrates the radiological appearances of the spectrum of common and unusual complications encountered by patients who have undergone bone marrow transplantation, as depicted using a wide variety of imaging modalities. conclusion: while bone marrow transplantation is a life saving procedure it still retains a high degree of morbidity and unfortunately a wide range of complications can arise following the procedure. the role of the radiologist in using a number of imaging modalities to accurately diagnose and follow these complications remains an important one. air-space pattern lung metastasis l. herraiz, a. cima fernandez, s. dieguez, m. grande, m. sanchez nistal; madrid/es learning objectives: to identify and describe the imaging findings on air-space pattern in lung metastasis. background: lepidic pattern growth in lung metastasis is an uncommon manifestation of disseminated malignancies, mainly described in gastrointestinal adenocarcinomas. on ct, differentiation from other lung diseases as multifocal pneumonia, bronchiolitis obliterans organizing pneumonia (boop) and brochioloalveolar carcinoma (bac) may be difficult, and diagnosis of bac cannot be made with confidence if a primitive extrapulmonay adenocarcinoma has not been ruled out. imaging findings: we reviewed x-ray films and ct studies of patients with proven air-space pattern lung metastasis. metastasis was classified as air-space disease when it showed one or more of the following ct findings: air-space nodules, including cavitating and pseudocavitating nodules; parenchymal consolidation containing air bronchogram and focal or diffuse ground-glass opacities. the primary tumors were colorectal adenocarcinoma in patients; pancreatic adenocarcinoma in ; adenocarcinoma of the ampulla of vater in and infiltrating duct breast carcinoma in . in patient the diagnosis of pulmonary disease preceded the discovery of primary malignancy and was synchronous in other patients. cavitating nodules were seen in patients; parenchymal consolidation in ; ground-glass opacities were seen in ; pseudocavitated nodules in other patients; solid nodules in ; nodules with air bronchogram in two; mass with air bronchogram in and lymphangitic carcinomatosis in patient. conclusions: air-space pattern is an uncommon manifestation of lung metastasis. differentiation from boop, multifocal pneumonia and bronchioloalveolar carcinoma can be difficult because this can be the onset of the disease. imaging of chest wall disorders j. lee, k.-n. lee, s. kim, j. lee, m. roh; busan/kr purpose: to illustrate the radiologic features of a wide spectrum of chest wall disorders according to anatomic location. we have retrospectively reviewed the radiologic findings of patients with chest wall lesions pathologically proven by biopsy or surgery between january and july . we excluded cases of pleural effusion or thickening, chest wall invasion by lung cancer or mediastinal malignant tumor, and secondary metastatic lesions. all patients had plain films and spiral ct scan with intravenous contrast enhancement. several patients underwent supplementary mr with gadolinium enhancement. results: pleural lesions include empyema, tuberculous empyema, empyema neccessitatis, localized fibrous tumor of pleura, malignant mesenchymal cell tu-mor, malignant mesothelioma, pleuroblastoma, fibrosarcoma, angiosarcoma and asbestos-related pleural plaques. muscle and subcutaneous fat are involved in poland's syndrome, inflammation, abscess, tuberculous abscess, empyema neccessitatis, post-operative hematoma, epidermal cyst, intramuscular hemangioma, elastofibroma dorsi, pectoralis muscle fibromatosis, neurofibromatosis, malignant schwannoma, muscle involving nhl, subcutaneous t-cell lymphoma and extraskeletal ewing's sarcoma. rib lesions include chronic inflammation, osteochondroma, enchondroma, eosinophilic granuloma, and plasmacytoma. sternal lesions include chronic inflammation and pigeon breast. a case of chondrosarcoma of the t vertebral body is also included. a wide of spectrum of disease processes affect the chest wall. the ct and mr imaging has enabled precise localization and differential diagnosis of chest wall lesions. therefore, familiarity with these radiologic features will make accurate diagnosis possible and and allow for optimal patient treatment. standardized in all patients ml contrast-agent was injected with a flow-rate of . ml/sec, scan delay was sec. results: in ( %) of patients chest injuries were detected. the following posttraumatic thoracic injuries were revealed: in patients ( %) emphysema, in ( %) hematoma of chest wall; in patients ( . %) fracture of the thoracic spine, ( . %) fractures of the ribs, ( . %) of clavicle, ( . %) of sternum, ( . %) of scapula; ( %) patients had a pneumothorax, ( . %) a hematothorax, ( . %) a tension pneumothorax; patients ( . %) had a lung contusion, ( . %) a lung laceration; patients ( %) had a pneumomediastinum; ( . %) a rupture of thoracic aorta; ( . %) rupture of a supraaortal ar tery and ( . %) a rupture of diaphragm. no injuries of tracheobronchial system, esophagus or the heart were detected. conclusion: a standardized msct examination protocol represents the preferred screening method in the evaluation of patients who have sustained chest trauma. purpose:to find out important ct findings for the prediction of prognosis of thymoma with a survival analysis. materials and methods: patients with thymoma, who underwent surgical resection, were retrospectively analyzed. clinical data were collected from chart review. preoperative plain and contrast enhanced ct was performed in all patients. two independent chest radiologists evaluated ct images paying special attention to diameter, contour, shape, cystic or necrotic portion, calcification, mediastinal fat obliteration, invasion of adjacent mediastinal structure, thickening of adjacent pleura, infiltration of adjacent lung, infiltration of adjacent chest wall, pleural effusion, pericardial effusion, mediastinal lymphadenopathy, enhancement pattern, and degree of enhancement. kaplan-meier survival curves were generated. influence on survival for each ct finding was analyzed by logrank test. results: cystic or necrotic portion, calcification, mediastinal fat obliteration, invasion of adjacent mediastinal structure, thickening of adjacent pleura, infiltration of adjacent lung, infiltration of adjacent chest wall, pleural effusion, pericardial effusion, mediastinal lymphadenopathy, homogeneous enhancement pattern and high degree of enhancement were seen in %, %, %, %, %, %, %, %, %, %, % and % of patients respectively. the ct finding that were most predictive of survival was calcification (logrank test: p = . ). cystic or necrotic portion (p = . ), infiltration of adjacent chest wall (p = . ), and pleural effusion (p = . ) were independent predictors of long-term survival. there were no differences in survival for the other findings. conclusion: calcification, cystic or necrotic portion, infiltration of adjacent chest wall, or pleural effusion on ct suggest poor prognosis of thymoma. b d e f a g low attenuation splenic lesions found at chest ct: differential diagnosis and investigation a.k. choudhary, e.l. senior, n.j. screaton; cambridge/uk learning objectives: . to illustrate the causes of low attenuation splenic lesions. . to discuss clinical and imaging features which aid diagnosis in patients with known or suspected malignancy. background: abnormalities of the spleen are commonly encountered during ct of the thorax and abdomen in patients with suspected thoracic disease, posing diagnostic difficulty particularly in patients with otherwise operable malignancy. we present a pictorial review of low attenuation splenic lesions in patients with suspected thoracic disease. the most common causes are benign (including pseudocysts caused by trauma, infection or infarction), infections (mycobacterial, fungal, hydatid), sarcoidosis, haemangiomata, and lymphangiomatosis. malignant causes include lymphoma and metastases (lung, breast, melanoma, stomach, liver, colon). in patients with known malignancy, splenic metastases are rare in the absence of widespread metastatic disease. although the morphological pattern on ct may suggest malignancy (multiplicity of lesions, irregular margins, enhancement and splenomegaly), other imaging studies may be complementary. on ultrasound focal anechoic lesions are typical of benign cysts while multifocal or diffuse solid lesions are suggestive of malignancy. on mri heterogeneous lesion signal is suggestive of malignancy. in cases where morphological imaging is non-specific, fdg-pet may play an important role. the accuracy of splenic biopsy in indeterminate lesions approaches % but significant complications occur in . %. conclusion: isolated low attenuation splenic lesions must not be considered synonymous with metastases even in patients with known cancer. awareness of the differential diagnosis and further imaging permit accurate diagnosis and management. evaluation . whole-body msct scan were performed using the following protocol: ) native head and neck: mm slice thickness, um mode, reconstruction . mm; ) administration of - ml nonionic contrast media using automatic injector at flow rate of ml/sec and smart prep feature; ) thorax, abdomen and pelvis scan: . mm slice thickness, us mode, reconstruction . mm; ) scan time under minute; ) images were used for mpr and d-vr. results: in management of polytrauma patients, time is of the essence. in high-risk patients who were selected for msct examination following injuries were found: cranial (sub and epidural hematoma, contusion, fracture etc); thoracic (hematothorax, lung contusion, pneumothorax etc); abdominal (contusion and hematoma of parenchymal organ, retroperitoneal bleeding); aortic (rupture, dissection, periaortal hematoma); fractures (mostly ribs - [ %] and pelvis - [ %]) conclusion: in our hospital msct represents the major diagnostic tool in the management of high-risk polytrauma patients, reducing time spent outside of emergency unit. it is a fast and reliable method for diagnosis of skeletal trauma, parenchymal organs and aortic injuries. the radiologist becomes important member of the trauma team in management of acute polytrauma patients. learning objectives: to illustrate the fundamentals of digital imaging, the basic operations of image display and manipulation, the principles of image compression and filtering. backgound: radiological scanners generate digital images and image interpretation is performed using dedicated workstations. the knowledge of digital imaging, image compression and filtering is crucial to understand the new technologies and the post processing operations. procedure details: the structure of a digital image, the encoding algorithm, the operations for image display and manipulation, and the compression algorithms are described. a phantom and clinical cases are used to show the influence of these aspects on the quality and information of the images. conclusion: several aspects affect the information and the quality of digital images. the basic criteria for assessing image quality are defined. web-based radiology-teaching library for board examination of radiologists with object-oriented database system n. we have developed a web-based radiology-teaching library for a board examination of radiologists in japan. this library receives imaging cases from all of japan via the internet. the web-based radiology-teaching library is developed with an object-oriented database, and it is readily available with a simple operation to radiologists. the submission process makes full use of the internet. the reviewers, who are expert radiologists, carefully review the submitted cases. when the reviewed case is sent back to the submitter with the reviewers' comments, the submitter should correct their text and images according to the reviewers' comments in order to obtain the reviewers' approval. the computer assists these processes automatically, and it enables submitters and reviewers to do collaborative work in registering cases without temporal or spatial restriction. finally, approved cases can be registered to our library. results: up to august , our radiology-teaching library has collected imaging cases in all subspecialties. in these cases, cases have been registered. in august , the board examination of radiologists in japan has been performed with selected cases from this library in all subspecialties. conclusion: our library is readily available to radiologists who do not have much computer knowledge. our web-based radiology-teaching library will be useful for the education of all radiologists. pacs: ergonomic considerations c.l. arnoldus, c.j. zylak, m. flynn; detroit, mi/us learning objectives: ergonomic issues associated with picture archivial and communication systems (pacs) should be addressed during the early phase of incorporation in the radiology department. this reviews how a large tertiary care teaching hospital addressed these issues. background: existing computer and alternator workstations in the radiology department were observed for six months. the radiologists were surveyed on workstation issues related to space, noise, lighting, and repetitive motion. a pacs ergonomic work group consisting of radiologists, physicists, and administrators accepted the task of addressing these issues and recommending solutions. procedure details: on non-ergonomic workstations, repetitive strain occurred. of the forty-one radiologists on staff, four who used computer workstations extensively had elbow and shoulder tendinitis from extended periods of reach while manipulating images with the mouse. carpal tunnel symptoms, neck strain from periods of flexion or extension, and eye fatigue were also experienced. alternators placed near monitors reflected light and ghost images on monitor screens. eye level evaluation of films was not possible with fixed monitor height. crowded workstations and alternators were observed. based on the findings, adjustable workstations with articulating keyboards, mousing surfaces with gel wrist rests, flat screen liquid crystal display (lcd) monitors, and multi-adjustable posture support chairs were evaluated. placement of view boxes and ambient lighting issues were addressed. adjustable height workstations for small group consultation and conferencing will be strategically located. voice amplification is being considered. conclusion: ergonomic issues should be identified early before pacs transition to allow a workplace design to maximize workflow and minimize repetitive strain. withdrawn by authors in any single patient we use the same position during each scan to get proper images coregistration. during body scans patients were instructed to breath freely, but not deeply, and not to move. we used a dedicated system for image fusion that combines volumetric information from pet, ct and mri to get proper coregistration in all cases. conclusion: metabolic and anatomical information can be combined precisely to asses anatomic locations of lesions and artifacts with proper coregistration obtained with separate scanners using dedicated software. background: current limitations with regard to medical image quality control and consistency have been discussed previously. we have recently suggested proposals to several american industrial and scientific bodies aimed to improve image quality performance criteria for both clinical and diagnostic images. although some regional and national guidelines and regulations exist, practical universal standards have not yet been achieved. procedure details: this exhibit shows how international radiology and technical societies, regulatory groups, and standards agencies may collaborate in order to improve medical image quality performance and standards, including but not limited to ( ) performance criteria for softcopy and hardcopy, ( ) extending communication and control standards for the performance of output devices, and ( ) initiation and support for research into the relationship between display physical metrics and diagnostic performance, to assess clinical consequences of variations in image quality metrics, and to define what constitutes image quality from a diagnostic perspective. the exhibit has presented some initial steps that will improve the consistency and reproducibility of medical images in electronic imaging systems. the international medical community has an opportunity to build upon the work of many regional and national efforts in a collaborative effort to improve medical image quality with anticipated benefits to patient care, medical practitioners, and the medical industry. b d e f a g modeling and simulation of the blood flow using multi-slice ct: application of computational fluid dynamics s. yamamoto , s. hamada , t. johkoh , s. murai , s. yoneyama , s. maruyama , n. tomiyama , m. komizu , h. nakamura ; osaka/jp, tokyo/jp learning objectives: to understand the prediction based medicine model using computer fluid dynamics (cfd). to support the informed consent of the patient using four-dimensional display. to describe the technical procedure of ct scanning for blood flow analysis. background: aortic aneurysms or dissecting aneurysms are serious and lifethreatening conditions that requires early diagnosis and prompt surgical treatment. it is difficult to directly measure the blood flow and pressure without invasive examination. computer simulation is one of the solutions for non-invasive diagnosis, or for comparison of pre-and post-operative measurement of the blood flow and pressure. in this exhibit we will describe the application of cfd based on four-dimensional vessel reconstructions from multi-slice ct data. procedure details: the volume data ( . - mm slice thickness) was acquired from half-second multi-slice ct (aquilion, toshiba, tokyo, japan). segmented vessels were converted surface display by marchine cubes method. input parameters of blood were applied as an ideal incompressible fluid. steady and transient analysis of cfd was performed using commercially available software (acusolve, acusim software, mountain view, ca) by a finite element method. original program modules for image processing of both vector and medical (di-com) data was implemented on a commercially available workstation (amira . , tgs, san diego, ca). variable dynamic display of both steam line of blood and blood pressure was superimposed on the three-dimensional ct data (multi planer reformat, maximum intensity projection and volume rendering etc) conclusion: modeling and simulation applications to the blood flow could enable us to build rapid prototypes of the models for quick visual validations. using remote asp and internet- for integrating digital radiological images with a regionalinformation system in a new population-based purchasing system for public healthcare provision o. barbero , j. guanyabens , c. rúbies , j. fernández , j. maideu , i. cerdà ; sabadell/es, vic/es to learn about the improvements in health care management due to the implementation of several integrated his/ris and pacs in a regional area.to learn how new technologies like java, internet , asp and remote image archival can be used to improve health care management and provision. background: a pilot project to evaluate the possibilities of digital radiology in the improvement of health care is underway within the framework of the catalan health service's strategic plan to establish a system in the county of osona(*), not far from barcelona (spain). the sharing of information forms the backbone of the project, the aim being to enable all authorized healthcare personnel to have -hour-a-day access to all digital information and images from examinations performed in all healthcare centers in the county, whether private or public. procedure details: for the evaluation and analysis: . improvements brought about in healthcare services; . organizational impact; . cost-benefit analysis; . elements to take into account for the system's implementation and extension. from the technological point of view: . remote asp archive; . high-speed internet- links; . information systems integration based on web, java, xml and dicom. the analysis and evaluation of the results of this innovative project and health care provision strategy will be presented in ecr. (*) the health care ministry will pay a fixed amount of money per person and per year to all the health care providers of the area in exchange for public health care services. a new parameter enhancing breast cancer detection in computer aided diagnosis of x-ray mammograms k. murase , n. tanki , m. iinuma , h. kubota , m. nagao ; osaka/jp, matsuyama/jp purpose: to introduce a new parameter enhancing breast cancer detection in computer aided diagnosis (cad) of x-ray mammograms. we used the database of mammograms generated by japan society of radiological technology. this includes patients with benign masses and patients with malignant masses. the age ranged from to years ( . ± . years). the new parameter called -dimensional fractal dimension ( d-fd) was obtained from the slope of the graph with the logarithm of the cutoff value on the horizontal axis and that of the number of pixels with a gray level above the cutoff value on the vertical axis. in addition to d-fd, the conventional image features such as eccentricity (e) and curvature (c) were extracted. the conventional fractal dimension (c-fd) was also calculated using the boxcounting method. the artificial neural networks were used as a classification algorithm, and a receiver operating characteristic (roc) curve and the area under the roc curve (az) were calculated to evaluate the diagnostic accuracy in the task of differentiating between benign and malignant masses. results: when using e, c, c-fd and age as inputs, the az value was . ± . . on the other hand, when d-fd was added to inputs in addition to the above parameters, the az value was significantly improved to be . ± . . the d-fd is a new parameter which can enhance breast cancer detection in cad of mammograms, because it is effective for discriminating between benign and malignant masses. web computed radiography: a solution for x-ray examinations in africa d. soft tissue tumor distributed decision support system m. robles, l. marti-bonmati, j. garcía-gómez, c. vidal; valencia/es purpose: to provide distributed decision support services in soft tissue tumor (stt) to assist the radiologist. previous studies have shown the capability of pattern recognition techniques to classify between benign/malignant character and different histological groups. methods and materials: radiologist access to the stt distributed decision support services is achieved using a graphical interface, with four windows that offers the main system functionalities areas: . access to local or distributed stt registers that contain the features to study. new data can be imported from microsoft access formatted files or other databases. . statistical analysis that provides the graphical representation and reports of statistical and evaluation information like probability distributions per class, correlation studies, roc curves. . graphical representation of stt registers provides graphical representation of stt features from the protocol, using pca-transformation, or feature selection. . automatic classification access to stt classifiers distributed web-services, developed with pattern recognition technology. results: a location independent and multi-platform system has been developed to provided decision support services for radiologists dealing with stt diagnosis. the system architecture considers the access from hospitals using local or distributed data and connections to clinical decision support servers. the nodes maintenance and upgrade are automatically controlled by the architecture. conclusion: this system helps radiologists with novel and powerful methods in stt diagnosis and characterization. it provides access to distributed data, statistical analysis, graphical representation and pattern recognition classification. grid technology will incorporate more facility, security and powered communications to the stt distributed decision support services. integration of broadband teleradiology into picture archiving and communication system (pacs) y. zhao, k. chen, z. yao, d. wu, z. pan, b. guo; shanghai/cn purpose: the availability of broadband wide-area networks (wans) facilitates a range of new applications in healthcare. teleradiology is increasingly integrated into picture archiving and communication system (pacs). this paper introduces a broadband telemedicine system for transmitting interactive audio and video signals, and high-quality medical images directly acquired from a hospital-wide pacs. methods: a high-performance telemedicine system was developed over the existing metropolitan broadband multimedia network in shanghai to exploit the possibilities offered by internet protocol (ip) over synchronous digital hierarchy (sdh) technology to support real-time tele-consultation for medical imaging. a trial session was held with two channels of fiber-optic connection transmitting real-time duplex audio/video signals and high-quality dicom images between rui jin hospital and shanghai international convention center, kilometers apart. the system enabled direct retrieval of dicom images from the pacs, and allowed to use interactive telediagnosis tools for image visualization and processing. results: during the teleradiology session, dicom images archived at the pacs were readily accessed without any loss of information. a number of functionalities of visualization software were utilized and tested, combined with real-time videoconference session. the system was proven robust, efficient and providing for high performance. conclusion: the broadband telemedicine system under study has given us a useful insight about the potential of applying broadband technology in healthcare, especially the performance of videoconferences with telediagnosis of radiological images. with the close integration of teleradiology into a hospital-wide pacs, it yields sufficient sound and image quality for remote educational and clinical collaboration. performance assessment of a wavelet contrast enhancement method in dense parenchyma based on simulated lesions s. skiadopoulos, l. costaridou, p. sakellaropoulos, c. kalogeropoulou, e. likaki, g. panayiotakis; patras/gr purpose: evaluation of an adaptive wavelet-based contrast enhancement method in dense parenchyma based on simulated radiopaque lesions. methods and materials: sixty normal mammographic images of dense breasts were selected from the ddsm database. simulated radiopaque lesions of known image characteristics, such as low contrast ( . %- %) and unsharp contour ( %- %), were generated and superimposed in dense breast areas. this resulted in a case sample that is difficult to achieve and verify with real lesions. all images with simulated lesions were processed by the wavelet-based method. evaluation was carried out by an observer performance comparative study between the wavelet-processed images and original ones. the sample was presented to three experienced radiologists, classifying each simulated lesion with respect to contour type, using a five-point rating scale. a binormal roc curve was individually fitted to the scores of each observer with a maximum-likelihood procedure and the area under the roc curve (a z ) as well as the % confidence interval were calculated, for each technique. results: combining observers' responses, the a z values are . and . and their corresponding confidence intervals are ( . , . ) and ( . , ) for wavelet method and original one, respectively. this difference in a z values is statistically significant (students' t-test, p < . ), indicating the effectiveness of the wavelet method. conclusion: improved contour characterization of low contrast simulated lesions sample is achieved with the use of the wavelet-based contrast enhancement method. use of simulated lesions sample servers for verification purposes, required to assess the performance of various digital image post-processing techniques. estimating the arterial compliance in early stages of atherosclerosis: evaluation of a new index on the curve-fitted doppler sonograms n. erdogan, s. kara, f. dirgenali, m. okandan; kayseri/tr purpose: to develop a computational method to define a new index to estimate the arterial compliance in early stages of atherosclerosis. the doppler data was obtained from a nonstenotic arterial site (carotid artery) in patients with femoropopliteal atherosclerosis (n = ) and healthy volunteers (n = ) using the audio output of a commercial color doppler ultrasound unit. the signals were transferred to a personal computer and two dimensional sonograms were plotted by fast fourier transformation. smoothing and curve-fitting operation is performed on the sonograms. a moving average method was used for smoothing and interpolant-cubic spline was processed to make curve-fitting. the time interval between the first transmitted peak (t ) and the second compliance peak (t ) in the arterial waveform was evaluated as a new index. our preliminary data showed no significant difference between healthy subjects and the patients with regard to the acceleration, resistivity and pulsatility indices, although a significant difference exists for the new index ( . ± . msec for patients vs. . ± . msec for healthy people). the proposed new index on the the curve-fitted fast fourier transformation sonograms seems to be promising in assessing the cardiovascular risk by detecting the degree of compliance in atherosclerotic vessel walls before the overt clinical symptoms develop. however, its efficacy and prognostic implications need to be confirmed by large scale studies. the contribution of virtual endoscopy (ve), in the imaging of the upper airways and tracheobronchial tree a. morichovitou, a. manolitsas, s. stratilati, i. tsitouridis; thessaloniki/gr purpose: the purpose of our study is to demonstrate the contribution of virtual endoscopy in the imaging of the upper airways and tracheobronchial tree. we studied cases, ( male and female, aged to years old, mean yrs), with tracheobronchial diseases. the virtual endoscopy images were compared with those of actual endoscopy in patients. the examinations were performed using a picker pq spiral ct scanner and a picker voxel q visualization workstation. thickness: mm, pitch: . , overlap: % ( mm). results: ct virtual endoscopy depicted the anatomical structure of nasopharynx, larynx, trachea, and main bronchi in all patients as the actual endoscopy. the results show that virtual endoscopy can study the tracheobronchial tree as far as the segmental bronchi, and sometimes the subsegmental bronchi (in patients). in addition, it can evaluate the extraluminal location of the lesions. lesions in patients were shown by virtual endoscopy ( occlusions, stenosis, compressions) and in patients the examinations were negative. the findings were always in agreement with those of the actual endoscopy and surgical findings. we studied the results of the two methods and describe the advantages and disadvantages of each of them. conclusion: virtual endoscopy can be used in the primary evaluation of the patient before actual endoscopy is performed. it can be used for preparing, guiding and controlling actual endoscopy or in the postoperative follow-up when immediate biopsy is not necessary. pancreatic duct imaging using the curved thin-slab minimum intensity projection method t. ogura , t. ikari , t. tachikawa , a. kamei , k. takano , s. asahara , n. fujita , m. shimizu ; maebashi/jp, tokyo/jp purpose: the recent wide use of curved mpr was applied for pancreatic duct imaging, but curved mpr requires a great deal of skill for the trace of narrowed and tortuous pancreatic duct. mis-tracing on pancreatic duct has led to various artificial images such as false pancreatic stenosis. so novel curved thin-slab minimum intensity projection methods have been employed to obtain correct pancreatic duct image. the purpose of this study is to explain the protocol, reconstruction method, and describe the potential advantages and various problems of this method in the diagnosis of pancreatic diseases. materials and methods: pancreatic duct image was reconstructed from three dimensional volume data using multidetector-row ct (qx/i, gems) scans. axial images were taken with . -mm collimation, a table speed of . mm/rot and . mm image reconstruction intervals. image processing was performed with the virtual place (m.i.lab). results: this method was successful in depicting a wide range of tortuous pancreatic ducts. also the narrowed pancreatic duct is easily visualized, and even branch ducts. the characteristic of this method is that we can easily make a pancreatic duct image quickly and with little dependence on expert technique. in abdominal studies, this method enabled the visualization of the narrow, bending pancreatic duct, reducing false pancreatic stenosis, and also could be applied for screening examination for anomalous union of pancreaticbiliary ductal system in the future. evaluation of the optimal scanning protocol for ct virtual endoscopy using a -slice scanner w. wojciechowski , w. de wever , a. urbanik , g. marchal , r. chrzan , j. kozub ; krakow/pl, leuven/be purpose: the objective of this study was evaluation of optimal scanning protocol for ct virtual endoscopy using a -slice scanner in a phantom study. methods and materials: using the mdct scanner somatom sensation (siemens, germany), ct-images of a phantom were performed, with diferent combinations of slice-thickness ( . , , , , mm), pitch ( . , , . ), slice-collimation ( x . and x . ) and reconstruction increment ( % and %). the phantom consists of simulated round lesions of different size (diameter between and mm) placed into a thin-walled plastic tube of -cm diameter. quantitative analysis was assessed by evaluation of changes in size and shape of the lesions and calculation of sensitivities. qualitative analysis was perfomed by evaluation of lesion's blurring of stairstep artifacts and rippling artifacts. results: overall sensitivity was % with slice thickness . , and mm and not dependent on pitch. the smallest lesions (diameter mm) were not detected with slice-thickness of and mm. image quality of endoluminal images was graded as optimal for slice-thickness . mm and mm. there was no statistical significant difference in quality using a different pitch in these images. however mild rippling artifacts were documented together with an increase in pitch value. conclusion: slice-collimation and slice-thickness are the most important parameters in selection of on optimal scan-protocol for ve: slice-collimation of x . and slice-thickness of mm seem to be optimal. pitch and increment are less important, although values of and % seem to be optimal. selection of optimal parameters is also depended on lesion size. automatic methods and materials: fully automatic and manual methods were developed and compared using in vivo studies. this tool allowed automatic determination of a region of interest (roi) with background correction. by means of this technique, a roi was set, corrections performed and calculation of different parameters (flow, stroke volume and velocity) and flow curves made. this tool was designed using matlab . (mathwork, inc, natick, usa) with a friendly graphical user interface. comparisons were performed by means of intraclass correlations (icc). this model was validated in patients, men and women, age range: - years-old. mr examinations were performed on a . -t system (gyroscan nt intera, the netherlands) with a phase contrast sequence. image parameters were as follow x matrix; fov, mm; mm slice thickness; tr msec, te , excitations, flip angle ° and cardiac phases with use of peripheral retrospective gating. the automatic method performed significantly better than the manual analysis, icc of . - . and . - . , respectively. at the same time partial volume effect caused by inclusion of stationary tissue was corrected. conclusion: automatic setting of roi flow measurements at the cerebral aqueduct is feasible with an adequate reproducibility. it makes the measurements independent of the radiologist, generalizing the calculus of flow parameters. virtual duodenoscopy on the basis of high-resolution mrcp data for the simulation of ercp procedures t. yamagishi , k.h. höhne , k. abe ; tokyo/jp, hamburg/de purpose: ercp has been regarded as one of the most difficult endoscopic procedures for a trainee because of a high possibility of technical failures. therefore, it is considered useful to prepare a rehearsal of ercp. we present a virtual duodenoscopy for practical ercp simulation. the hr-mrcp data sets are imported into the voxel-man program (institute of medical informatics, university hospital hamburg-eppendorf, germany). an interpolated movie of the duodenal inner surface is computed by tracing where the endoscopic tip goes through to the duodenal papilla following the actual ercp procedure. three orthogonal radiological planes of the source mrcp are integrated into the movies, which are showing the conic extent of the endoscopic viewing field. the usefulness of making a prior simulation for a successful ercp was evaluated. the post-processed endoscopic view is precise and realistic enough to execute a practical simulation of ercp, following the actual procedures step by step, e.g., which angle and position of the endoscopic tip is best for the cannula insertion into the common bile duct. the movie created can indicate an ideal approach to the duodenal orifice in exactly the same way performed by ercp experts. the radiological planes are useful as external images like x-ray fluoroscopy. a practical simulation of ercp can be performed by a combination of hr-mrcp data and the voxel-man interactive visualization program. the presented method can provide useful information prior to actual ercp. to review the physics of the interaction between the us beam, the "bubble" and the corresponding us image of the liver and portal system. to estimate the degree of portal hypertension through better visualization of collateral pathways using usca. background: a short historical review of the evolution of usca is followed by a detailed presentation of the physics and technology of recent usca. the interaction between the "bubbles" and the us beam is explained with analytical drawings and real-time us videos. procedure details: the technique and the protocol of the hemodynamic examination of the hepatic veins and the portal system are explained. a detailed anatomical review of the portal venous system is presented with special attention to the main collateral pathways present in cases of portal hypertension. the findings of imaging methods (us, ct, mr) as well as endoscopic methods are presented and their limitations are underlined. new non-invasive hemodynamic us imaging of the main collateral pathways (gastric and esophageal varices, splenorenal, splenogastric, retroperitoneal anastomoses, recanalization of the paraumbilical vein) are described and presented in images and videos after administration of second generation usca. c b d e f a g the benefits as well as the limitations of usca, including those caused by artifacts, are thoroughly discussed so that an unbiased conclusion on new diagnostic possibilities in the study of the portal hypertension can be drawn. clinical impact of liver specific contrast agents in liver imaging a. ba-ssalamah, m. uffmann, s. mehrain, s. schweighofer, w. schima; vienna/at learning objectives: to illustrate the usefulness of liver specific contrast agents in identifying morphological and functional features of focal liver lesions. to educate radiologists about new mr liver specific contrast agents and mr imaging techniques. to demonstrate the value of the combined use of liver specific and non liver specific contrast agents as a problem solving tool. background: liver specific contrast agents used in combination with non-specific gadolinium chelates may serve as a problem solving tool in the diagnosis of focal liver lesions. hepatic focal lesions with atypical imaging appearances usually need further assessment, namely biopsy, particularly in patients with history of malignant disease. liver specific contrast agents offer new opportunities for liver imaging and provide information about the functional and morphological features of focal liver lesion. currently a variety of contrast agents, subdivided in different categories are available for clinical use in mri of the liver. procedure details: in this exhibition, we describe the use of reticuloendothelial system-specific iron oxide particulate agents, hepatocyte-selective agents, nonspecific gadolinum chelates and the combined use of these contrast agents for a large variety of liver diseases.we distinguish between specific imaging characteristics for various liver diseases and nonspecific imaging characteristics that may be found in both malignant and benign focal liver diseases. the combined use of liver specific and non liver specific contrast agents is a valuable tool for the diagnostic work up of special focal liver lesions and may replace the invasive biopsy in the vast majority of cases. doppler rescue: a review of the use of ultrasound microbubble contrast agents in the visualisation of the large vessels k. satchithananda, m.e.k. sellars, s.m. ryan, p.s. sidhu; london/uk learning objectives: understanding of the types of ultrasound contrast agents available and nature of enhancement. understand when these agents could be used to improve diagnostic images and cost effectiveness. an appreciation of the clincial appearances of "doppler rescue" in different areas of vascular imaging. background: ultrasound (us) assessment of the vascular system remains an accurate imaging modality despite the advancement of magnetic resonance angiography. us allows real-time, multi-planar and safe assessment of the vasculature which is convenient to both operator and patient. limitations of us, es-pecially in the vascular system are well documented. full diagnostic doppler assessment is not always possible for a variety of reasons. color doppler assessment greatly improves vascular imaging and recent technical advances have further improved the capabilities of doppler us. a further important development is the introduction of microbubble contrast, which allows previously non-diagnostic studies to become interpretable and avoids further imaging: termed "doppler rescue". image findings: the use of microbubble contrast will be illustrated in the cerebral circulation using trans-cranial us, the extra-cranial carotid system, the liver vasculature, renal artery and the peripheral arterial system. conclusion: both color doppler enhancement and low mechanical index b-mode non-linear imaging will be demonstrated. one learning objectives: initial work-up of trauma patients is time-critical. diagnostic demands require different examination techniques including unenhanced and several contrast enhanced scans for musculoskeletal, angiographic and parenchymal diagnosis. -channel mdr-ct overcomes previous technical limitations, which used to require thickening of slices or segmenting for whole body coverage. we therefore developed a multi-phase contrast protocol allowing acquisition of musculoskeletal, angiographic and parenchymal organ information in a single scan. ct technique and contrast protocol, advantages and limitations of this procedure are described and illustrated. procedure details: consecutive trauma patients were examined on a channel mdr-ct (philips, mx idt). after exclusion of cerebral hemorrhage application of iodine contrast media ( mg iodine/ml, imeron , altana, germany) was started with a bolus of ml at a flow of . ml/sec, followed by a pause of sec. subsequently, a second ml contrast bolus ( . ml/sec) is followed by a saline chaser. the ct-scan is initiated with a delay of sec using a collimation of x . mm, slice thickness of mm and an increment of mm. results: this protocol provides excellent diagnostic image quality covering all issues of trauma work-up. within a table time of less then minutes all relevant pathologies were assessed as proved by further clinical follow-up. all fractures including two petrosal ones were detected. parenchymal pathology included lacerations of liver, spleen, and kidneys. all arterial and venous hemorrhages were diagnosed without the need of additional diagnostic work-up. intravenous, oral and, rectal contrast media for abdominal spiral ct examinations: when to use, how much, how fast, and when to scan a.n. chalazonitis , j. tzovara ; athens/gr, ioannina/gr leaning objectives: to optimise the choice of contrast media initiation parameters for abdominal single slice spiral ct examinations, tailored to each specific organ and to the most common clinical conditions. background: introduction of multi-slice spiral ct permitted greater flexibility in abdominal examinations. however single slice spiral ct still remains a powerful tool in routine imaging practice. procedure details: the aim of this exhibit is to describe lesion or organ behaviour before and/or after contrast material initiation in order to help the participant to understand why, when and how these agents should be administrated for optimal abdominal single slice spiral ct evaluation. contrast volume, flow rate and scan delay before initiation, are discussed. the influence of patient weight and circulatory parameters such as cardiac output and inflow obstructions on contrast enhancement will be also analysed. special techniques in order to achieve optimum gi opacification will be also discussed. purpose: to compare hepatic signal intensity change using superparamagnetic iron oxide (spio)-enhanced mr imaging with scintigraphy using technetium- mgalactosyl human serum albmin ( mtc-gsa) and a visual grading score, in patients with hepatic dysfunction. methods and materials: forty-six patients with hepatic dysfunction who underwent spio-enhanced mr imaging and scintigraphy with mtc-gsa were examined prospectively. in terms of clinical cirrhosis severity, patients were classified into four group; patients were classified as non-cirrhotic, were classified as group a, as group b, and as group c (child-pugh classification). on mr imaging, t -fast field echo (t -ffe) images were obtained before and after the administration of spio. to assess the effect of spio, post contrast relative reduction in signal-to noise ratio (reduction-snr) was calculated. the findings of mtc-gsa-scintigraphy were classified into types according to visual grading score. the clinical cirrhosis severity, reduction-snr, and visual grading score were analyzed with nonparametric methods. the clinical cirrhosis severity was positively correlated with visual grading score (spearman rank test, p < . ). there were significant differences between the clinical cirrhosis severity and the reduction-snr on t -ffe and between the visual grading score and the reduction-snr (kruskall-wallis test, p < . , all comparisons). the index of blood clearance (hh ) was positively correlated and the receptor index (lhl ) was negatively correlated with the reduction-snr on t -ffe (spearman rank test, p < . , all comparisons). conclusion: to evaluate the reduction-snr on spio-mr imaging is helpful in predicting not only kupffer cell function but also hepatic function as assessed by mtc-gsa-scintigraphy. are efficient contrast agents available for use with ultra-high field mr imaging? r.n. muller, p.a. rinck, l. vanderelst, a. roch; mons/be purpose: molecular mr imaging requires specific markers exhibiting high relaxivities at ultra-high fields ( - tesla). although there are theories on the design of optimal paramagnetic centers, actual relaxivities are still below expectations. methods and materials: measurements of relaxivites s - mm - ) to establish nuclear magnetic relaxation dispersion profiles of existing and possible future contrast agents were performed on two field cycling relaxometers and on a . t mr research machine. results: at high field, r and r of small gadolinium complexes are low and decrease; high-field relaxivities can be increased through reduction of molecular motion. to some extent, it is possible to increase the r of small dysprosium complexes. nmrd profiles of superparamagnetic particles reveal a high r /r ratio at ultra-high fields. however, one particle of nm contains around , iron ions, whereas one macromolecular complex contains one or a few gadolinium ions. assuming equivalent relaxivites, the gd complex should carry approximately , ions to present, per molecule, the same relaxivity as the magnetic particle which leads to a molecular weight increase of , . conclusion: for small complexes of dy, r can be modestly increased at high fields. both r and r of gd complexes can be enhanced at high fields by an increase of the molecular size, however, only r keeps increasing. superparamagnetic particles seem clearly more efficient. this fact will be of paramount importance in the context of molecular imaging. they will act as negative agents. results: the contrast ratios of rat abdominal aorta and portal vein on the first to fifth contrast imaging were higher for nms than those for gd-dtpa with every injection doses. the peak contrast ratios of aorta and portal vein for nms were . - . and . - . times as high as those for gd-dtpa. the renal excretion of nms was as fast as gd-dtpa. conclusion: nms showed stronger contrast enhancement for the rat vascular system, especially the portal vein and provided mr angiograms of higher image quality when compared with gd-dtpa at the same injection dose. d-fspgr imaging was performed before and after , , , , min. delineation of popliteal lymph node (pln) and lymph duct (ld) (extremity region, iliac, para aorti, thoracic duct) was examined.on the evaluation of ld, visual evaluation ("good visualization": ++, "visualization": +, "poor visualization": ±, "no visualization": -) was carried out. on pln, snr was calculated as follows: snr = si (pln)/sd (noise). results: in gd-dtpa ( , , ), gd-eob ( , ) and gd-bopta ( , , ), grading of ld from lower extremity region to para-aortic region was "good visualization" or "visualization". in gd-dtpa ( ), grade of ld from lower extremity region to para-aortic region was "poor visualization". on the other hand, using gd-eob ( ), gd-bopta ( ), we could see ld from lower extremity region to iliac region.we found only ld of lower extremity region in gd-dtpa-dea ( , ).these grades were "good visualization" or "visualization". each concentration besides gd-dtpa ( ), contrast enhancement of plns were very well. the pln almost showed peak value after enhancement for most cases ( / ) in five minutes. we saw pln very well after enhancement minutes later, and, at the time of gd-dtpa ( ), gd-eob-dtpa ( , ), gd-bopta ( , , ), gd-dtpa-doa ( , ), snr value was more than . conclusion: using hepatobiliary agents and extracellular agent we were able to do good mr lymphography. optimized iv contrast administration protocols for diagnostic pet/ct imaging t. beyer, g. antoch, s. rosenbaum, l. freudenberg, t. fehlings, j. stattaus; essen/de purpose: we compared different iv-contrast injection protocols for pet/ct-exams (dual-slice) to assess their efficacy in avoiding high-density artifacts on ct and subsequent false positives on corrected pet. methods: four groups of pet/ct-referrals ( mbq fdg at min pi) each were investigated with/-out iodinated contrast ( mg/ml) application: (a) without, (b) multi-phase / ml ( / . ml - ) cranio-caudally with s delay, (c) / / ml ( / / . mls - ) cranio-caudally with s delay, and (d) / ml ( / . mls - ) caudo-cranially with s delay. ct-based attenuation correction (ac) of the pet was applied routinely. ct image quality (iq) was graded (very good), (good), or (insufficient) by three radiologists. image quality and artifacts were reported for head/neck, thorax, and abdomen. two nuclear medicine physicians reviewed the ac-pet images for potential artifacts from iv-contrast without knowledge of the ct, and reported lesion-to-background (l/b) values for potentially related uptake on pet. all reviewers were blinded to the contrast protocol and patient names. results: average ct iq was poorest ( . ) for protocol a across all regions, but improved to . (b), . (c), and . (d). high-density (> hu) ct artifacts were introduced only in the upper thorax in % (b) and % (c) of the patients. mean l/b in corresponding artificial lesions was . and . , respectively, thus resembling false positives. protocol d resulted in artifact-free images. pet/ct iq increased in the presence of iv-contrast agents. highdensity artifacts from bolus injection may lead to false positives on ac-pet. the artifacts can be avoided by alternative contrast administration protocols (e.g. d). contrast enhanced ultrasound in the evaluation of hepatic metastases treated using radiofrequency ablation: hours, and months follow-up assessment g.a. vorkas, i.a. chryssogonidis, c.a. papadopoulos, e. syndouka, k. lytras, l. grassos; thessaloniki/gr purpose: this study evaluates the importance of periodic follow-ups in the assessment of hepatic metastases treated with radiofrequency ablation (rf) using contrast-enhanced sonography. materials and methods: hepatic metastases in selected patients were included in our study. all lesions were studied with ce-us using real-time, continuous scanning with esaote esatune equipment with the cnti software, enabling non-destructive imaging at low mi, following intravenous bolus administration of . ml of a second-generation agent (sonovue-bracco). the enhancement patterns of lesions were assessed during the arterial, portal and late phases. the examination was conducted pre-ablation, hours, month and months after thermoablation. purpose: an up-to-date study showed that for high-risk patients the nonionic, dimeric radiographic contrast medium (rcm) iodixanol had less nephrotoxicity than the nonionic, monomeric rcm. the lower incidence of secondary effects is often attributed to the lower osmolality of the dimeric rcm. to compare the effect of dimeric iotrolan to monomeric iohexol and iomeprol independently of their osmolality, we have modelled the vascular activity of the rcm. in an organ bath, isolated segments of porcine renal arteries, uncontracted or precontracted by micromol/l phenylephrine, were incubated with increasing concentrations of iotrolan- , iohexol- , iomeprol- and mannitol solution iso-osmolal to the rcm. results: expressed in terms of concentration of iodine in the buffer as well as in terms of concentration of the rcm-molecule in the buffer, iotrolan induced a significantly lower relaxation than the monomeric rcm (p < . ). there was no significant difference between the two monomeric rcms iohexol- and iomeprol- (p > . ). the iso-osmolal formulation iotrolan- induced a smaller relaxation than the iso-osmolal formulation of iomeprol- (p < . ). precontracted segments were strongly relaxed by all the rcms as compared to mannitol (p < . ). iotrolan had no significant effect on the basal tone of the vessel whereas iohexol and iomeprol induced a small relaxation effect. conclusion: independently of its osmolality and dilution effect, dimeric iotrolan causes less relaxation of isolated, precontracted segments of porcine renal arteries than monomeric iohexol and iomeprol. this effect can be attributed to the different biological properties of the monomeric and dimeric rcm-molecules. ultrasound contrast agent in the study of traumatic splenic rupture g. caruso , g. salvaggio , g. bellissima , v. ricotta , g. ascenti , r. lagalla ; palermo/it, messina/it purpose: to evaluate the role of ultrasound contrast agent (uca) in the identification of traumatic splenic lesion. materials and methods: from may to july , consecutive patients were admitted to the emergency department for blunt abdominal trauma. ultrasound examinations were performed with an atl-hdi machine with a - mhz convex trasducer capable of fundamental and harmonic imaging. patients were studied before and after uca ( . ml of sonovue®). multi-detector computed tomography was used as the gold standard. all examinations were performed within hours. results: ninety seconds after uca administration, homogeneous contrast enhancement of the whole of the splenic parenchyma was observed in patients. in four patients, no contrast enhancement was observed in a subcapsular splenic area: inferior splenic pole (n = ) and mid-portion of the spleen (n = ). multidetector ct performed in the portal venous phase confirmed traumatic splenic rupture in four patients, and showed an unremarkable spleen in the remaining patients. conclusion: ultrasound after sonovue administration is useful in showing traumatic splenic rupture. contrast-enhanced, wide-band phase-inversion harmonic power doppler imaging of hepatocellular carcinoma j.r. janica; bialystok/pl purpose: to determine whether examination of hepatocellular carcinoma by wideband, pulse inversion sonography offers excellent accuracy in depiction of specific characteristics of these pathologies. b d e f a g eighteen patients were examined. the presence of hcc was confirmed by ultrasound-guided biopsy or surgical resection. all patients, prior to enhanced sonography, had undergone b-mode gray scale sonography, color doppler, and power doppler examinations. after injection of . g of levovist intravenously, analysis of contrast agent arrival was performed by wide-band, pulse inversion power doppler sonography. the b-mode gray scale sonography, color and power doppler sonography were non-specific for hcc in cases in our examination. however, based on the wide-band, phase inversion power doppler sonography findings, all patients with hcc were diagnosed. all typical anatomical features of hcc as chaotic appearance with irregular paths, breaks in calibre and arteriovenous shunts were clearly visible. in cases, computed tomography had failed to disclose pathology while pulse inversion sonographic images were completely suggestive, which was later finally confirmed by histologic examination. conclusions: our data demonstrates the usefulness of wide-band, phase inversion power doppler sonography in the diagnosis of hepatocellular carcinoma by visualizing all characteristic anatomical details. characterization of small liver lesions with contrast enhanced harmonic sonography (ceus) in patients with chronic liver disease p. cabassa, r. taranto human comparative study on zinc and copper excretion via urine after administration of magnetic resonance imaging contrast agents j. kimura, t. ishiguchi, j. matsuda, a. nakamura, s. kamei, k. ohno, k. murata; aichi/jp purpose: to evaluate the in vivo kinetic stability of magnetic resonance (mr) imaging contrast agents, excretion of zinc and copper via urine were studied for three gadolinium (gd) chelate complexes. methods and materials: urine samples were taken before, three hours, and six hours after intravenous administration of gd-dtpa-bma, gd-dtpa, and gd-dota at . mmol/kg to each of five patients who underwent contrast-enhanced mr imaging. five patients who had non-contrast mr imaging were evaluated as controls. urine was assayed for quantitative analysis of zinc and copper using atomic absorption analysis. results: gd-dtpa-bma caused the highest increase in zinc excretion among the three agents, ± µg at hours and ± µg at to hours. gd-dota did not cause a significant increase in zinc excretion, ± µg at hours and ± µg at to hours. gd-dtpa caused moderate increase in zinc excretion, ± µg at hours and ± µg at to hours. excretion of copper did not show a significant difference between the three agents. the difference in zinc excretion among the mr contrast agents reflects in vivo transmetallation of the gd chelate complexes and correlates with the respective stability of the contrast agent. gd-dota was found to be the most kinetically inert among the three agents tested. effect of contrast material pushed with saline solution using a dual injector on enhancement of abdominal aorta, portal vein, and liver parenchyma in multidetector row ct of the liver f. tatsugami low-high and high-low biphasic injection forms in ct examinations of the upper abdomen l. martí-bonmatí, e. tobarra, e. arana, s. costa; valencia/es purpose: our objective was to analyze the influence of different biphasic injection rate protocols in abdominal ct. a double-blind, randomized, parallel group study was designed and conducted in patients without differences regarding gender, age and weight. all of them were studied with the same ct helical protocol. patients were randomly distributed into three groups: a) monophasic ( ml at . ml/s); b) low-high biphasic ( ml, the first ml at a rate of ml/s and the other at . ml/s); and c) high-low biphasic ( ml, the first ml at a rate of . ml/s and the other at ml/s). all the patients were injected, through an antebrachial route, with mg i/ml non-ionic contrast media. all ct scans were obtained at the portal phase with a fixed delay time of seconds. contrast enhancement was evaluated by attenuation coefficients measurements at liver, inferior cava and portal veins, renal cortex, superior aorta and aortic bifurcation. results: the biphasic protocols obtained statistically higher enhancement at the aortic bifurcation (anova, p = . ). however, there was no other statistically significant difference (anova, p > . ) among the three protocols at the different levels. although non-significative, enhancements following monophasic protocol were always higher than those obtained with biphasic protocols, with the exception of aortic bifurcation. conclusion: monophasic injection of contrast agents on helical ct of the upper abdomen gives higher enhancement of parenchymal and venous structures. no significant difference was observed between low-high and high-low biphasic protocols. quantitative analysis showed a statistically significant difference between si of myometrium on plain and sinerem-enhanced mr images assessed by means of t-test. c/n between lesion and normal myometrium significantly increased following sinerem administration. in four patients sinerem-enhanced images provided additional information leading to more accurate t staging. conclusions: intravenous injection of sinerem provides a significant decrease of si of normal myometrium with higher c/n between neoplastic lesion and normal myometrium. sinerem-enhanced mri provides better evaluation of myometrial neoplastic invasion increasing the conspicuity of neoplastic lesions in patients with endometrial and cervical carcinoma. further studies are necessary in order to realize the physiologic mechanism of myometrial uptake of sinerem. purpose: verification of radiological methods with histology has always been difficult due to poor correlation of slice thickness, orientation and confinement to two dimensions. a method for a quantitative three-dimensional reslicing of histological sections is introduced (patent pending epa . ) permitting exact matching of slice geometry. this will enable proper correlation with radiological data. hacatras tumor (mouse) were examined by acquiring dynamic t -weighted mr images and mr microangiography. the tumors were subsequently serially sectioned ( ìm slice thickness) and vessels stained with immuno-fluorescence markers. slices were digitally captured with a microscope, assembled in the sectioning plane and co-registered in the vertical axis. a ray-tracing algorithm performed three-dimensional visualization allowing the virtual re-slicing of the histological sections to create thick-slices ( . mm) in accordance with mri slice geometry. thick-slices were processed as parameter-maps of marker volume density, giving information beyond the area density signal of immuno-fluorescence images. results: d-reconstructions of immuno-fluorescence images displayed diffuse angioarchitecture which is typical for malignant tumors. resliced images revealed the exact architecture of vessel structures seen on mra. also, large single vessels could be clearly delineated on reconstructions. parameter maps of vessel density in virtual thick slices matched well with mr-parameter maps. the quantitative d approach to histology essentially improves correlation of histological and radiological data due to proper matching of slice geometry. as this new method can be used with any histological stain, it provides a tool for verification of new molecular imaging techniques by means of histology. monitoring a human fibrosarcoma (ht ) was implanted in nude mice and grown up to a size of - mm. tumor bearing animals were intravenously injected with a vascular targeting agent (vta) inducing selective thrombosis of tumor neovasculature (treatment group) or saline (controls) respectively. mri ( . t) was performed using an ultrasmall superparamagnetic iron oxide agent (uspio, shu c, schering®) hours after initiation of treatment. iron oxide-induced change in r * (∆r *) was measured using a t w dual echo-epi sequence. ∆r * values of tumor tissue were calibrated by ∆r * of muscle for determination of the vascular volume fraction (vvf). parametric ∆r *-maps were calculated for visualization of tumor perfusion patterns. correlative immunhistochemistry was performed for assessment of the treatment effects in both groups. results: ∆r *-maps revealed a clear reduction of tumor perfusion in treated animals compared to controls. anti-angiogenic tumor treatment resulted in an approximate % decrease of iron oxide induced susceptibility effects. vvf was significantly reduced after injection of the thrombogenic peptide ( the in vivo detection of arthritis by autofluorescence using an antigen-induced arthritis (aia) model was investigated. material and methods: for autofluorescence investigations of joints, a mobile fluorescence-detector was designed consisting of a lens/mirror system attached to a conventional spectrofluorometer and of optimized fiber optic cables leading to and from the site of investigation. measurements were performed in arthritic and healthy mice. aia-and healthy mice were used for histological examinations. results: at the exudative stage (day ) of aia, a decrease of fluorescence signal intensities (arbitrary units, a.u.) for excitation wavelengths of nm (emission at λ = - nm; mean signal intensity . ± . a.u.) and excitation at nm (emission at λ = - nm; mean signal intensity . ± . a.u) were observed. signals increased on day (maximum of cellular infiltration; mean signal intensity . ± . for λ exc = nm and . ± . for λ exc = nm). chronic inflammation (day and ) led to a signal decrease again. signal intensities of nad(p)h differed significantly (p ≤ . ) from controls at days and . conclusion: arthritis influences autofluorescence signals in-vivo. the detected excitation/emission pairs can be assigned to collagen/elastin and nad(p)h. autofluorescence of nad(p)h can be a helpful tool for detecting arthritis noninvasive and in real-time. postpartum uterus: what is normal? what is pathological? evaluation with ultrasound and ct i. escape, j. martinez, f. bastart, l. ortega, c. solduga; barcelona/es learning objectives: to know the normal findings, mean diameters and evolutive changes in postpartum uterus and uterine cavity, in early, middle and late puerperium with ultrasound and ct. to differentiate them from pathological conditions. background: the majority of postpartum patients undergo an unremarkable clinical course. a small percentage of patients develop serious complications in the abdomen and pelvis. endometritis, the most common cause of fever in the postpartum period, complicates - % of vaginal deliveries and up to % of cesarean sections. post partum hemorrhage is most often caused by uterine atony and retained products of conception, and complicates - % of vaginal deliveries. imaging findings: in early puerperium, uterus is most often retroverted and empty with fluid and debris in the cervical area. intrauterine cavity increases on days - post partum with fluid and debris in the whole cavity and it may be normal to see an intracavitary echogenic mass. ap diameter of the uterus diminishes progressively in - weeks. endometrial gas is occasionaly visualized after normal vaginal delivery in the immediate puerperium and disappears within - weeks. it can be difficult to differentiate from endometritis, which can progress to pelvic inflamatory disease. endometrial stripe decreases during puerperium; if it remains thickened, complications such as retained products of conception or hypotonic uterus may be suspected. doppler us can be useful for differentiating between them. we describe these features with ultrasound and ct. conclusion: it is important to recognize normal postpartum uteral findings in order to differentiate them from pathological conditions. pelvic floor dysfunction: interest of mr imaging of ortheses and prostheses j. villeval , m. de graef , r. guillon , c. courtieu , a. maubon , j. rouanet ; montpellier/fr, limoges/fr learning objectives: to display the mri appearance in static and dynamic conditions of intra-vaginal device and post surgical procedures used for the treatment of pelvic floor dysfunction. background: we retrospectively analysed mr exams performed before and after surgical treatment and mr exams without and with intra vaginal device of patients with pelvic floor dysfunction: urinary incontinence (tension-free vaginal tape n = , artificial urinary sphincter n = , intra vaginal device n = ) and pelvic prolapse (intra vaginal device n = , promontofixation n = , prosthetic b d e f a g plaques permacol and polypropylène in recto-vaginal and uretro-vaginal wall n = ). mri consisted of t turbo spin echo, t turbo spin echo and dynamic single shot sequences. imaging findings: we will show the mri appearances of the devices in static and dynamic conditions. prosthetic plaques and tension-free vaginal tape appear as low signal intensity structures which are difficult to visualize compared to promontofixation, artificial urinary sphincter and intra vaginal device. mr imaging represents a good functional post operative evaluation for prosthetic plaques and intra-vaginal device in pelvic prolapse with dynamic studies especially in cases of suboptimal post treatment outcome. conclusion: a radiologist involved in pelvic mri should be aware of the various surgical treatments of pelvic floor dysfunction in order to avoid misinterpretation and evaluate their functional results. mri allows detection of complications for a better collaboration between radiologist and pelvic floor surgeon. pathologies of the uterine endometrial cavity: usual and unusual manifestations and pitfalls on magnetic resonance imaging m. takeuchi background: the endometrial cavity may demonstrate a spectrum of imaging manifestations ranging from normal, to that of a reactive, inflammatory, and benign and malignant neoplastic cause. imaging findings: thickened endometrium or endometrial mass included benign endometrial hyperplasia or polyps, endometrial carcinomas or carcinosarcomas, and gestational trophoblastic diseases. hyperintensity similar to the endometrium suggested rather benign hyperplastic lesions. hyperplasia or polyps associated with adjuvant tamoxifen therapy tended to be large masses with cystic changes and prominent stromal proliferation. myometrial thinning suggested malignancy but was occasionally overestimated because of the fragility of the myometrium with adenomyosis. submucosal leiomyoma with edematous change may mimic endometrial mass, and demonstration of the continuity to the myometrium was the clue to its myometrial origin. uterine sarcomas may involve endometrial cavity, and endometrial stromal sarcomas often showed endometrial masses with characteristic myometrial invasion. adenomyomatous endometrial polyp may simulate endometrial stromal sarcoma due to arborescent smooth muscle components which resemble the preserved bundles of myometrium within the tumor on t -weighted images. fluid collection in the cavity was well visualized on mri to distinguish between hydro-, pyo-, and hematometra. conclusion: to recognize various imaging findings of the uterine endometrial cavity; it is important to make a correct preoperative diagnosis to avoid unnecessary or excessive surgical intervention and to preserve the fertility of the patients. learning objectives: to demonstrate wide variations of the fluid collection in the female pelvis with pathophysiologic correlation and evaluate the diagnostic clues to the differential diagnosis. background: there are various situations with fluid collection in the female pelvis. although physiologic ascites is often observed in the reproductive era, other pathophysiologic fluid collection with both benign and malignant conditions may occur. imaging findings: mucinous ascites with organ scalloping in pseudomyxoma peritonei is characteristic. hemorrhagic ascites, which shows high attenuation on computed tomography (ct) and is well visualized on magnetic resonance imaging (mri) may be observed with malignant tumors, adnexal torsion or ruptured endometriosis. lactate detection on magnetic resonance spectroscopy (mrs) may suggest its malignant condition. non-neoplastic diseases such as ovarian hyperstimulation syndrome, pelvic inflammatory diseases, endometriosis, adnexal torsion and massive ovarian edema may cause accompanying fluid collection with adnexal enlargement. benign tumors may cause ascites, such as meigs' and pseudo-meigs' syndrome, and malignant tumors may cause carcinomatous peritonitis with fluid collection. ascites in postmenopausal woman is an unnatural finding and may suggest adhesion due to old inflammation or surgical procedure, or existence of hidden neoplastic disease. ascites in a tumor-bearing woman may suggest an advanced stage of disease with occult tumor implants. localized fluid collection like peritoneal retention cyst is observed in adhesive pelvis after surgery, inflammation or endometriosis with characteristic contour shape. conclusion: to evaluate the nature or biochemical components of ascitic fluid by mri and mrs may be helpful for the differential diagnosis. recurrent ovarian cancer: patterns and spectrum of imaging findings m. moon, s. kim, j. cho, y. lee; seoul/kr learning objectives: to illustrate the spectrum of imaging findings of the recurrent ovarian cancer. background: ovarian cancer is the most common cause of death among the gynecological malignancies. the treatment of ovarian cancer has traditionally been initial surgical staging and cytoreduction, followed by adjuvant chemotherapy. then, a second look operation is performed to reassess the tumor status after first line chemotherapy. once pathological complete response is defined, the management of ovarian cancer depends on non-invasive methods such as serology and cross sectional imaging. on the follow-up evaluation, identifying patients with minimal recurrent disease is important as it provides the best chance for complete clinical response and long-term survival following second-line chemotherapy. imaging findings: recurrent ovarian cancer usually manifests as local recurrence, peritoneal seeding and nodal recurrence. vaginal stump recurrence is the most common manifestation of the local recurrence. peritoneal seeding presents as ascites, peritoneal enhancement, peritoneal nodularity, and/or mesenteric infiltration on cross sectional imaging. nodal recurrence is most commonly seen in the external iliac group, which is not the presumed site based upon anatomic studies. although hematogenous dissemination is less frequently seen in the recurrent ovarian cancer, hepatic or pleuropulmonary involvement is a relatively common manifestation of hematogenous spread. the unusual manifestations of hematogenous dissemination include metastases in the extrahepatic abdominal solid organs, bone, central nervous system, and abdominal wall involving subcutaneous fat or muscle. conclusion: familiarity with the patterns and spectrum of imaging findings of recurrent ovarian cancer will facilitate accurate diagnosis and prompt treatment. ing of cervical carcinoma. the particular advantages of mri over ct include its multiplanar imaging capability and its superior depiction of soft tissue planes. accurate staging of cervical carcinoma at presentation is essential from the point of view of prognosis and also for management planning, as patients who present with stage iia or lower grade carcinoma proceed to surgery, and those with higher grade tumours are treated primarily with radiotherapy. recurrent disease is also best depicted using mri. patients can present with or develop a wide variety of complications as a result of their tumour and mri can be of particular advantage in the investigation of local complications. imaging findings: this educational exhibit illustrates the mr imaging findings of cervical carcinoma of all grades. we also demonstrate the mr imaging features of a wide variety of local and distant complications, including local invasion, fistula formation, small bowel obstruction and obstructive hydronephrosis. conclusion: mri is the imaging modality of choice for the diagnosis and staging of primary cervical carcinoma. it is also of benefit for the investigation of disease related complications and for the investigation of recurrent disease. the most common is serous papillary carcinoma. these tumors can show totally solid appearance, but mainly solid mass with some cystic portions is more common. they have unique imaging findings especially on mr in that papillary masses with branching pattern are frequently accompanied by peritoneal seeding masses. serous surface papillary carcinoma of the ovary, a distinct subtype of these tumors, is mainly located on the surface of the ovary. sometimes normal ovaries can be found inside papillary masses on mr, which is a very unique and striking appearance. brenner tumor and endometrioid carcinoma are another subtypes of epithelial tumors that can show solid appearance. extensive calcifications can be found in some solid brenner tumors. endometrioid carcinomas are sometimes accompanied by endometrial pathologies including endometrial carcinoma. conclusion: knowing these characteristics can help make correct diagnosis on ct and mr, especially differential diagnosis with metastatic tumors. wide spectrum of uterine leiomyomas mr imaging: radiologic and pathologic correlation h.k. kim; seoul/kr learning objective: to provide an in-depth review of uterine leiomyomas with their epidemiology, histopathology, clinical manifestations and the most up-todate therapy. to describe radiologic feature of usual and unusual appearance of uterine leiomyomas on mr image and histopathologic correlation. to discuss differential diagnosis of uterine leiomyomas from gynecologic and non-gynecologic disorder. background: leiomyomas are the most common uterine neoplasm and are composed of smooth muscle with varying amounts of fibrous connective tissue. imaging features of uterine leiomyomas vary depending on tumor size, location, degeneration and other histologic findings, and specific types of unusual leiomyomas. uterine leiomyomas are classified as submucosal, intramural or subserosal. the common types of degeneration are hyaline (> % of cases), cystic, myxoid, red and hemorrhage. degenerated leiomyomas have variable appearances on t -weighted and contrast-enhanced images. specific types of unusual leiomyomas include lipoleiomyoma and myxoid leiomyoma, which have characteristic mr findings enough to differentiate from other gynecologic and nongynecologic disease. the differential diagnosis of leiomyomas includes adenomyosis, solid adnexal mass, focal myometrial contraction, and uterine leiomyosarcoma. the purpose of this exhibit is to provide in-depth review of epidemiology, histopatholoy, clinical manifestations and differential diagnosis. this exihibit will also reflect our experience in radiologic evaluation of patients with leiomyomas, with emphasis on the typical and atypical findings on pelvic mri. examples of unusual uterine leiomyomas, pathologic correlation as well as the most up-to-date therapy will be included. after interacting with this exhibit the radiologist will have enhanced understanding of uterine leiomyomas including histopathology and radiologic features. experience of mri in women with suspected and known endometriosis: a pictorial review r. benamore, l. grosvenor, a. liddicoat; leicestershire/uk learning objectives: review of imaging features in women with endometriosis since introduction of a . t magnetic resonance (mr) scanner. women were referred when they did not wish to undergo laparoscopy or where surgical intervention and visualisation was difficult. background: endometriosis affects women during the reproductive years between and , with an estimated prevalence of - %. presentation range from pain (symptoms and severity do not correlate) to asymptomatic (diagnosed during infertility investigations). endometriosis (functional glands and stroma outside normal endometrium) is characterised by deposits, endometriomas (cysts) and adhesions, commonly ovarian but is documented to involve any site within the peritoneum and extraperitoneum. mr is noninvasive with high sensitivity and specificity, small foci appearing hyperintense on t and variable signal on t weighted images. endometriomas (> cm) appear hyperintense on t and hypointensity on t , with hyperintense foci on t dependant on age of haemorrhage. fat saturation sequences are essential to improve lesion conspicuity on t . we reviewed all women referred for investigation of suspected endometriosis, and for evaluation of disease extent and sites (notably recto-vaginal pouch) in known cases of endometriosis. procedure details: sequences used were axial t , sagittal t , axial oblique fat saturation (tirm) and narrow section coronal t imaging. mr identified endometriosis involving ovaries, bilateral thick walled and unilateral endometriotic cysts, extra-ovarian disease within peritoneum and soft tissue. fibroids and simple ovarian cysts were common, with evidence of concurrent endometriosis. conclusion: mr detected small foci of endometriosis outside of the ovaries. there was a high incidence of other gynaecological pathologies allowing early review and treatment. d transvaginal sonography in uterine leiomyomas with hysteroscopic and pathomorphological correlation v. gazhonova, k. sokolskaya, t. kurganskaya, a. zubarev; moscow/ru purpose: to determine the possibilities of d transvaginal (tv) sonography in preoperative assessment of uterine leiomyomas and to correlate the findings with hysteroscopic, laparoscopic and macroscopic data. method and materials: women with symptomatic uterine leiomyomas were evaluated before myomectomy and hysterectomy. multiplanar images of the uterus were created in d tvs. preoperative location of the leiomyomas, and interactions with uterine cavity, cervix and iliac vessels were assessed in each case. us results were compared with hysteroscopy in pts, laparoscopy in , open surgery in and pathomorphology data in pts. results: surgical management was changed after d tvs examination in cases. d coronal images allowed better location of the submucous and centripetal leiomyomas especially in multiple closely lying fibromyomas. d tvs results correlated with hysteroscopy in % ( / ) of cases vs. % ( / ). d power doppler tvs provided precise evaluation of the pedunculated submucous and subserous leiomyomas thus enabling adequate myomectomy. in comparison to macroscopic data of the uterus, d tvs were superior to d tvs in differentiation of the type of leiomyomas in % vs. % of cases, and in assessment of the interactions with the cervix in % vs. %. multiplanar reconstruction of the coronal planes on d tvs improved determination of the uterine cavity interactions with large subserous-interstitial leiomyomas before laparoscopic myomectomy. conclusion: d tvs is a useful complement to d tvs in preoperative assessment of leiomyomas. accurate evaluation of the leiomyomas on d mpr can decrease the possibilities of intraoperative hemorrhage and uterine trauma. b d e f a g treatment of the symptomatic large and multiple uterine fibroids by uterine artery embolization s. speca, a.m. costantini, c. di stasi, g. tropeano, v. summaria, p. marano; rome/it purpose: to evaluate the potential usefulness of uterine artery embolization as an alternative to traditional surgery (hysterectomy or myomectomy) for the treatment of symptomatic large or multiple fibroids. material and methods: premenopausal women, aged - years (mean age . ), who presented with menorrhagia, pelvic pain, and/or mass-related symptoms due to large (< or = cm) or multiple fibroids (> or = cm) and were unwilling to undergo surgery or had an increased surgical risk, underwent bilateral uterine artery embolization. before embolization all pts underwent to a complete clinical examination, a basal fsh and estradiol dosage, a vaginal and ureteral tampon, a papanicolau test, a trans abdominal and trans vaginal ultrasonography and color doppler flowmetry. for embolization we used polyvinyl alcool particles, embosphere or spongostan. detailed clinical and ultrasound follow-up were obtained at regular intervals ( - months). the procedure was technically successful in / patients. a mean clinical follow-up of months for pain, mass-related symptoms and menorrhagia was done. % of the patients treated reported a marked to complete symptomatic improvement. only patient experienced no changes in her symptoms. nobody had immediate or late complications. a median reduction of % in the uterine volume and a median decrease of % in the dominant fibroid volume were observed in patients who had follow-up ultrasounds for up to months. conclusions: in our experience artery uterine embolization may provide an important therapeutic alternative for women with symptomatic large or multiple fibroids who desire to avoid surgery. how to conduct quantitative evaluation of uterine neoplasms using gddynamic contrast-enhanced mri k. hayasaka, y. tanaka materials and methods: women with histopathologically proved cervical carcinoma underwent preoperative t -weighted fast spin-echo, dynamic imaging using gradient-echo and postcontrast t -weighted spin-echo mr imaging with a phased-array surface coil. the axial plans in each sequence were reviewed at separate sessions by three radiologists blind to the histopathologic data. results: for the conspicuity of tumor, dynamic and t -weighted images showed high detectability more than postcontrast t -weighted images. most appropriate enhancing time in dynamic study was seconds. in assessing parametrial invasion, the accuracy of t -weighted, dynamic and contrast-enhanced t -weighted mr imaging was . %, . % and %, respectively; no statistically significant difference was observed. conclusion: dynamic imaging is useful in assessing tumor visualization, and the most adequate enhancing time in dynamic study is seconds. but in diagnosis of parametrial invasion, the addition of dynamic mr images does not improve the accuracy compared with t -weighted images alone. ( ), on clinically progressive disease ( ) or patient death ( ). patients had undergone previous surgery ( radical hysterectomy, trachelectomy). patients had non-surgical treatment (chemo and/or radiotherapy). a recurrent mass was identified in patients (mean size cm, . - cm). on t w, the recurrence was hyperintense in %. in the post-surgical group, the recurrence was in the vaginal stump in patients ( %) with parametrial involvement in ( %). in the non-surgical group, the recurrence was in the cervix in patients ( %) with involvement of vagina in % and uterus in %. uterosacral ligament and/ or pelvic sidewall involvement was present in patients ( %). bladder invasion was suspected in % and rectal in %. nodal enlargement was seen in %. bone metastases were present in patients while had dxt changes ( sacral insufficiency fractures). recurrence in the pelvic muscles was also seen. conclusion: recurrent disease in patients with cervical carcinoma usually involves the cervix or vagina, however can present with varied manifestations. knowledge of the site and pattern of disease recurrence can help in early and accurate detection of recurrence. hysterosalpingography: is still useful in the diagnosis of peritubal pathology? s. deftereos, j. manavis, g. alexiadis, g. kafetzis, p. prassopoulos; alexandroupolis/gr purpose: to reevaluate the role of hysterosalpingography in the diagnosis of adhesions related to infertility and in patients managment. materials and method: consecutive patients with more than two years infertility underwent hysterosalpingography (hsg), followed by laparoscopy. patients with infertility related to uterine abnormality were not included. diagnosis of peritubal adhesions was based on the presense of the following six imaging findings: convoluted tubes, vertical tubes, loculation of contrast medium in peritoneum, halo effect, ampullary dilatation or fixed laterodeviation of the uterus. results: in total, tubes were delinated. no abnormality was detected in tubes on both hsg and laparoscopy. laparoscopy disclosed adhesions in tubes. diagnosis of adhesions was made in tubes ( correct, false positive), when the presence of one abnormal sign on hsg was considered as criterion; and in , when two or more signs are present ( correct, false positive). ten live births five to eight months after hysterosalpingography occured. conclusions: accurate diagnosis of adhesions on hsg requires the presence of at least two abnormal signs. the six-month interval between hsg and laparoscopy might be shortened when adhesive peritubal involvement is radiologically suspected. laparoscopy is less indicated when no abnormality is detected on hsg. withdrawn to illustrate ct-urographic patterns of neoplasia of the collecting system. background: conventional excretory urography and conventional computed tomography (ct) were considered the standard techniques used to examine patients with urinary tract neoplasia. multi-detector row ct offers high speed of acquisition and high resolution images, allowing axial and d urographic acquisitions. imaging findings: pts with transitional cell carcinomas were analysed. all patients underwent unenhanced and post-contrast ct axial scans, followed by a urographic acquisition in the excretory phase ( mm collimation, . mm reconstruction interval). d reconstructions of excretory phase images were created with on an independent workstation using a mip algorithm. neoplastic lesions were visualised as solid papillomas in / cases, as wall thickening of the collecting system in / cases and as solid tissue in the renal sinus in / case. lesions were more evident on the source axial images of the excretory phase urographic acquisition. in the post-contrast images, the lesions resulted quite vascularized. urinary tract dilation was evaluated in / patients. dilation was better evaluated on the d mip ct-urographic images in the case of normal renal excretory function and on the source axial images of urographic acquisition in the case of functionally excluded kidneys. conclusion: ct-urographic axial and d images combined with conventional ct imaging allowed good evaluation of urinary tract neoplasia. the more frequent pattern was the wall thickening of the collecting system ( % cases), associated to urinary tract dilation ( % cases). renal background: lc is a minimally invasive surgical technique for patients with small renal masses; mr provides an effective tool for imaging follow-up of renal lesions treated with lc. methods and materials: pts with renal masses underwent renal lc. all patients underwent follow-up mri hrs after surgery, and at , , and months. mr examinations were performed using gre t w, tse t w and ce fs-gre t w sequences. two radiologists reviewed mr images for i) signal intensity, ii) size, iii) vascularization, and iv) perinephric changes after treatment. imaging findings: a) t w images showed isointense cryolesions, and cryolesions isointense to renal parenchyma with hypo-or hyper-intense foci. on t w images all cryolesions were hypo-intense with iso-or hyper-intense foci; b) hrs after treatment all cryolesions were more than cm larger than the original masses; cryolesions decreased in size of an average of % at month, % at , % at , and % at months; c) ce-fs-gre t w images showed complete ischemia of cryolesions in cases; d) cases showed a perinephric haematoma at , and months. the more significant mr pattern in the follow-up of renal lesions treated with lc were the decrease in size of the cryolesions over time and the complete ischemia of the cryolesions. ( ), benign obstruction ( ), not obstructed ( ) and transplanted kidneys ( ). procedure details: we used ultrasound-guidance in cases and ct-fluoroscopy-guidance in cases. the technique was standard seldinger. most patients received -or f. nephrostomy catheters. we had access failures, usually in patients with nondilated systems. we encountered major complications (bleeding and two big urinomas) and only minor complications. catheter dislodgement was relatively frequent ( cases). conclusion: urinary diversion at renal level is necessary in the following clinical situations: as short-term palliation in a terminal case, as a temporary measure prior to definitive diversion, to relieve obstruction where immediate surgical intervention is not feasible and for prolonged drainage where surgical intervention is not indicated. since its first description in , percutaneous nephrostomy has developed into a technique that is now routinely used for a wide range of clinical applications. imaging of angiomyolipoma focused on the clinical issues k.-s. cho, y. jung, s. kim, j. kim; seoul/kr learning objectives: to discuss the role and findings of us, ct and mri in the detection and diagnosis of angiomyolipoma. to discuss the complication of angiomyolipoma and confusion in differentiation from other malignant neoplasm. to discuss the clinical issues of angiomyolipoma including the natural history concerning growth, efficacy of biopsy for diagnosis, and association with tuberous sclerosis. background: angiomyolipoma is the most common benign neoplasm of the kidney and consists of mature adipose tissue, smooth muscle and thick-walled blood vessels derived from perivascular epithelioid cells. although most angiomyolipomas are asymptomatic and cause no problem, some cases raise important clinical issues. ( ) angiomyolipomas may be complicated by risk of hemorrhage and cause confusion in differentiation from malignant neoplasm when they contain minimal amount of fat. ( ) angiomyolipomas are often related with the stigmata of tuberous sclerosis. ( ) the natural history of this benign neoplasm has been controversial, with regard to growth on follow-up images. ( ) the efficacy of biopsy for diagnosis is controversial when image findings are indeterminate. procedure details: in this illustration, we evaluate the role and findings of ultrasonography, computed tomography and magnetic resonance imaging in the detection and diagnosis of angiomyolipoma. discussion will be focused on the important clinical issues. conclusion: multi-detector row ct is the most accurate diagnostic modality for evaluation of angiomyolipoma especially in cases with minimal amount of fat in tumor or associated with complication. mr can differentiate minimal fat angiomyolipoma from small renal cell carcinoma. characterization to understand how to further characterize incidentally detected renal masses found on ct by using the appropriate modality with optimal techniques. backgrounds: due to advances in ct technology and its wide spread use for imaging a variety of abdominal conditions, small renal masses are being incidentally detected more frequently on ct. since at least half of renal cell cancers are detected incidentally by imaging, the cost and time for further imaging of small renal masses may increase. in addition, some renal cell cancers may be cystic and it is important to have a strategy for dealing with cystic renal lesions that do not meet the ct criteria for simple cysts. imaging findings: we will discuss and show a variety of small incidental renal masses detected on unenhanced and single phase contrast-enhanced ct. topics discussed will include the following: ct criteria for distinguishing lesions that do not need further imaging for characterization from lesions that require further imaging for characterization; technical considerations affecting imaging findings; updated bosniak classification for cystic lesions; pitfalls in interpretation; and an algorithmic approach for "indeterminate" masses by using ultrasound, dedicated renal ct, mri, or percutaneous biopsy. the majority of small renal masses incidentally found on ct can be characterized or managed through an appropriate diagnostic pathway. color-duplex imaging (cdi) and magnetic resonance angiography (mra) in reno-vascular disease l. olivetti , g. rozzi , p. pecchini , p. ravani , l. grazioli , e. botturi , i. laparoscopic cryoablation of small renal cell carcinoma: medium term outcome. g. cardone, p. mangili, a. cestari, g. balconi; milan/it purpose: to determine safety and efficacy of laparoscopic cryoablation in the management of small renal cell carcinoma and to assess its medium term outcome. methods and materials: patients underwent laparoscopic cryoablation of tumors between july and june . all treatments were delivered under laparoscopic us guidance. patients were followed up clinically, biochemically and by mr imaging hrs after surgery, and subsequently at , , , , and months. results: hrs after treatment all cryolesions were more than cm larger than the original masses; cryolesions decreased in size by an average of % at month, % at , % at and % at months following cryoablation. early post-procedure mr images showed complete ischemia of all cryolesions. follow-up (mean months) revealed no evidence of recurrence in / patients. one patient showed local recurrence at months, one patient demonstrated an metachronous nodule in the same kidney at months and another patient showed a pancreatic metastatic nodule at months. no significant rise in creatinine was noted post-procedurally. after surgery, retroperitoneal effusion was found in all cases; / cases showed an intralesional haematoma, / cases showed low signal intensity foci due to haemostatic material and / cases showed a perilesional haematoma at and month follow-up. conclusions: our medium term experience suggests that laparoscopic cryoablation is a safe, well tolerated and minimally invasive therapy for small renal cell carcinoma, and mr is an effective imaging technique in the follow-up of renal lesions treated with laparoscopic cryoablation. results: echographic findings postbiopsy were normal, or with loss of corticomedullary differentiation, enlargement and gross edema. clinical indication in transplanted kidneys was deranged renal function, and in native kidneys, nephrotic syndrome. acute rejection was the most frequent diagnosis in transplanted, and focal glomerulosclerosis in non transplanted kidneys. we observed cases ( % of all procedures) of postbiopsy complications ( haematomas, perirenal collections, decreased vascularization, arterio-venous fistulaes and deranged renal function), but none of them were significant. of them ( . %) were in native kidneys, and the remaining cases ( . %) were in renal allografts. we show an alternative way to perform the procedure in order to minimize patient risks and maximize results. we conclude that complications may be more frequent in renal allografts than in native kidneys. the complex preoperative assessment of patients with renal masses with complex mri-study i. platitsyn, e. zaytseva, a. zubarev, v.v. gazhonova; moscow/ru purpose: to study possibilities of complex mri-study in patients with renal masses in preoperative planning of renal surgery. material and methods: patients with renal masses detected by us were evaluated with complex mri-study. complex mri-study included mri before and after ce, d ce-mra and d ce-mru using fast d mra gre sequence were performed with . t system (magnetom harmony, siemens). dsa was used as diagnostic correlation as a gold standard. the obtained mr-data were compared with the results of surgical operation and histopathology. the renal tumors were identified with mri-study in patients; patients had cystic lesions. hypervascular masses were found in patients, hypovascular masses in patients. in one cases of cystic lesion detected with mri-study the patient had hypovascular cysto-solid masses. next, renal vascular variants were revealed: unilateral ara were detected with d mra in cases, with dsa in cases; bilateral ara -in and cases (consequently); triple unilateral ara -in and cases (consequently); multiple ara -in ( arteries) and ( arteries) cases (consequently); the sensitivity of d ce-mra was %. d ce-mru provided high-quality images of the urinary tract in all cases. mrstudy showed an almost complete correlation with results of operative treatment, histopathology and dsa. conclusion: complex mri-study allows noninvasive preoperative assessment of renal tumors localization, morphology and vascularisation, renal arterial system, renal parenchyma, urinary tract and perirenal region. it is valuable for planning of renal surgery. in all cases, the d free-breathing sequence was superior to the breathhold rare sequences in terms of spatial resolution, with equivalent contrast, and without significant motion artifacts. as a result, the level and length of stenoses were always better demonstrated with the d sequence than with the breathhold rare sequences. mip reconstructions allowed analysis of the entire urinary tract with different projections. the duration of the d sequence ( minutes) was comparable to the overall duration of the rare sequence, which requires several slice positioning to explore the entire urinary tract. less t -weighted sequences (haste and trufisp) were superior to d sequences to analyse the cause of obstruction, as they visualised the ureteric wall and the adjacent structures. the d turbo spin echo sequence is robust and especially useful in case of tortuous ureters. this sequence has now replaced the rare sequences in our protocol. haste and trufisp sequences remain useful to analyse the ureteric wall and the adjacent structures. prenatal ultrasonographic findings of multicystic dysplastic kidney: emphasis on cyst distribution m. moon, j. cho, m. song, y. lee; seoul/kr purpose: we retrospectively analyzed multicystic dysplastic kidneys to evaluate the prenatal sonographic characteristics, emphasizing the distribution of cysts. a total of cases was included in this study. the sonographic assessment included the site of the involved kidney, the size of the multicystic dysplastic and the contralateral normal kidney, the distribution of cysts, and associated anomalies. according to the distribution of cysts, multicystic dysplastic kidneys were categorized as subcapsular and random distribution, and interobserver agreement was determined using cross table analysis. the largest longitudinal diameters of the multicystic and the contralateral normal kidney were measured and data were plotted on the normal reference chart. results: multicystic dysplastic kidney was left sided in . %, right sided in . % and bilateral in . %. subcapsular distribution of cysts was observed in . % (n = ) for radiologist , . % (n = ) for radiologist . interobserver agreement was excellent (k = . ). the longitudinal diameter of the multicystic dysplastic kidney was above the % in % and that of the contralateral normal kidney was normal in %. there were major anomalies in cases and fetal karyotyping was offered in cases including cases with associated major anomalies. the results were always normal. conclusion: subcapsular distribution of cysts in multicystic dysplastic kidney is more common than random distribution, so the distribution of cysts may be helpful in the prenatal diagnosis of multicystic dysplastic kidney. tubular extraction rate of mag in patients with impaired renal function s. beatovic, e. jakšic, r. han; belgrade/yu purpose: to analyze whether clearance of mercaptoacetyltriglycine (mag ), which is equal to its tubular extraction rate (ter) could serve as a sensitive parameter of renal function impairment. methods and materials: investigation was carried out in patients, who were divided into nine groups, according to the diagnosis and the degree of renal failure. dynamic renal scintigtraphy was performed minutes after i.v. injection of - mbq of mag . ter was determined by single-sample, volume distribution method using the standard solution of labeled mag . results: results of ter were correlated with blood urea nitrogen (bun), serum creatinine (cr) and creatinine clearance (ccr). significant linear correlation between ter and ccr was found (r = . ; p < . ). correlation between ter/ bun and ter/cr was exponential (r = - . and r = - . , respectively; p < . ). conclusion: analysis of our results show that ter is a more sensitive parameter than ccr, cr and bun, especially in mildly deteriorated function. in advanced renal failure, the sensitivity of ter is similar to the sensitivity of bun and cr. daily we found some significant correlation between pulsatility indices (pi), resistance indices (ri) and renal volume (trv), with creatinine blood level (cr) in the patients with normal evolution, if we correlated the parameters using -day data. there was significant correlation between ri and cr in patients with nf ( days, p = . ). in the patients with atn there was significant correlation between trv and cr ( days, p = . ). significant correlation between trv and cr was found in rd evolution ( days, p = . ) and between pi and cr ( days, p = . ) in patients with rejection. these results confirm the findings obtained by dissection in five cadavers. the analysis of ct scans of retro-extraperitoneal pelvic processes demonstrates the inferior extension of the renal fasciae to the pelvis. these fascial planes serve as pathway for the spread of retro-extraperitoneal processes from the abdomen to the pelvis and vice versa. one can so explain, for example, the occurrence of an abcess in the prevesical space in case of sigmoid diverticulitis. to investigate the effect of alpha-blockers on prostatic blood flow and by means of power doppler image quantification. materials and methods: patients suffering from lower urinary tract symptoms (luts) were treated with alpha-blocker for weeks. transrectal power doppler ultrasound (trpdus) of the periurethral prostate as well as comparative cystometry were performed before and after therapy. for trpdus an acuson sequoia (acuson, mountainview, usa) fitted with a high frequency transrectal probe (ec -c ) was used at standardized machine settings. color pixel density (cpd) was calculated with computer assistance from transrectal power doppler images using scion image image analysis software. cpd and standard urodynamic parameters were recorded in each run at filling volumes of ml, ml and maximum cystometric capacity. in presence of nacl, mean cpd rose by % at ml and by % at full distension, whereas with kcl filling, mean cpd rose by % at ml and by % at full bladder capacity. after therapy, mean cpd was significantly increased at empty bladder by % compared to mean cpd before therapy. during nacl filling, mean cpd rose by % at ml and by % at full distension, while in the presence of kc , mean cpd rose by % at ml and by % at full bladder capacity. conclusions: using trpdus and cpd, relative changes of periurethral prostatic blood flow could be quantified. alpha-blocker lead to a significant increase of prostatic blood flow. these results may explain the therapeutic effects of alphablockers on luts. superselective results: using grey-scale trus, prostate tumors were hypoechoic before treatment. using d pd trus, tumors ( %) were hypervascular before treatment. during treatment the tumors' echogenicity increased gradually, focal fibrosis was detected; the degree of vascularity decreased gradually. in months the fibrosis was not revealed in ( . %) tumors and the hypervascularity was revealed in ( . %) patients that correlated with negative clinical response to hormonal treatment in patients. conclusion: d trus is an informative method in the assessment of the response to hormonal treatment of pc. methods: seven patients with adenocarcinoma of the prostate were scanned supine on a . t system. prior to imrt and during the -week treatment course, mm transverse, coronal and sagital haste-t -weighted images of the pelvis were acquired weekly. the bladder and rectal volumes, position of the prostatic margins, and center of prostate (cop) relative to the bony pelvis were measured. results: all pre-treatment positions were within a . mm range from the ontreatment mean position in each patient. the cop variability in the ap, cc and ml directions were . , . and . mm, respectively. the largest prostatic margin variability was . (posterior) and . mm (cranial and caudal). beyond a rectal volume of . , a strong correlation was found between rectal volume and anterior cop movement (p = - . ). a weak correlation (p = - . ) was found between bladder volume and cranial cop movement. beyond . ml, the mean variability of the cranial and caudal margins increased up to . mm, between and ml . mm, and above ml . mm. the pre-treatment prostate positions were representative of ontreatment positions. a . mm ctv expansion in any direction was sufficient to ascertain % coverage of the ctv within the ptv, assuming a rectal volume < . ml (rectal suppository) and bladder volume around ml (voiding followed by drinking ml of water to keep small bowel away from treatment field). local results: there was no significant difference between the number and severity of complications in the group with local anesthesia compared to the group without anesthesia. there were no significant side effects caused by the infusion of the anesthesic drug. however the infusion of the drug may cause a degradation of the trus image. air bubbles are sometimes infused with the drug causing a "fuzzy" image, which results in a degree of difficulty in guiding the needle. a thorough trus examination of the prostate prior to the anesthesia helps the radiologist in planning the biopsies in advance and thus guiding the needle to the appropriate area, even through a "fuzzy" image. conclusion: us-guided local anesthesia, before trus biopsy, is useful for assuring patient cooperation during this often painful procedure and essential if trus findings call for a large (more than ) number of biopsies. conclusion: conventional mr images combined with pyelo-urographic techniques allowed a good evaluation of urinary tract neoplasia. more frequent patterns were solid papillomas or wall thickening of the collecting system ( % cases), associated with collecting system dilatation ( % cases). there is a "difficult zone" located - cm below the iliac vessels. examination with mild compression is used to solve this problem. color doppler sonography is valuable to distinguish the ureter from vessels. conclusion: abdominal sonography is a cheap and informative method in the diagnosis of ureteral disorders and may replace traditional technologies. trauma of the urinary system: spectrum of findings at helical ct a.j. madureira, c. tavares, l. melao, i. ramos; porto/pt learning objectives: to review and illustrate the spectrum of imaging findings associated with blunt and penetrating trauma to the urinary system on helical ct. to discuss the importance of an appropriate technique and the major pitfalls encountered. background: injury of the urinary system is a common complication of major abdominal trauma. helical ct is a powerful imaging modality in the evaluation of patients with suspected injuries of the adrenal gland, kidney, ureter and bladder. the renal injury ct classification system is valuable and clinically important as it serves as a guide for patient management. procedure details: the authors present a comprehensive review of the imaging findings in common and rare traumatic lesions of the adrenal gland, kidney, ureter and bladder based on the experience of a level trauma center. the indications for helical ct are discussed and a special emphasis is placed in the use of an appropriate technique and discussion of the major pitfalls that may be encountered. conclusion: helical ct is a useful modality in the diagnosis, grading and followup of patients with trauma to the urinary system. helical ct protocols should be optimized and adapted to the clinical situation in question. characterization learning objectives: this poster will present the anatomical waxes dedicated to urogenital anatomy which are displayed at the museum "la specola" of florence. background: teaching gross human anatomy is traditionally based on demonstration and study of the different organs and systems directly on corpses. however, availability of specimens for this purpose can be difficult for a variety of problems and, at present, anatomical models made of plastic material and electronic files are used in most schools of medicine. these problems have been always present in the history of medicine. to overcome this, in , a special laboratory was established at the "imperial regio museo di fisica e storia naturale" of florence to create a collection of anatomical waxes, copied from anatomic dissections, to enable three-dimensional anatomic studies with schematic drawings and captions indicating anatomical details. imaging findings: from to , the laboratory prepared a large number of models, and the collection in florence consists of about pieces. in the collection there are over preparations, showing the complete urogenital system in the male and the female. special models have been created to demon-strate sectional anatomy, the internal structures of the kidney, the relationships of the prostate with the bladder base and the seminal vesicles, the penis, the vagina and the uterine cavity. many waxes depict the gravid uterus and the foetus, with its vasculature and its relations with placental vessels. conclusion: this allows the collection to be considered as the first d "textbook" of anatomy in medical history. characterisation of adnexal masses with magnetic resonance imaging a. saini; london/uk learning objectives and background: the accurate assessment of adnexal masses remains a challenge. to determine key differentiating features of adnexal masses, we retrospectively reviewed the magnetic resonance (mr) characteristics in patients and correlated their appearances with the findings at histopathology. imaging findings: benign solid lesions were characterised by fat, haemorrhage or fibrous components. mature teratomas (n = ) possessed high fat content. haemorrhage was a predominant feature of endometriomas (n = ) but also seen in some malignant tumours. fibromas (n = ), cystadenofibromas (n = ), benign brenner tumours (n = ) and fibrothecomas (n = ) that have a similar fibrous component shared a distinctive short t relaxation. benign cystic lesions comprised serous or mucinous cystadenomas (n = ), were recognised as thin walled uni-or multilocular cysts. borderline (n = ) and malignant epithelial tumours (n = ) were predominantly cystic and distinguished by papillary projections and the secondary features of malignancy, such as ascites, rather than their tissue signal intensity. malignant solid primary ovarian masses were less common. clear cell carcinomas (n = ) were recognised by a predominantly solid mass with more modest cystic elements. granulosa cell tumours (n = ) had variable amounts of cystic change and intratumoural haemorrhage. immature teratomas (n = ) contained circumscribed foci of variable signal-intensities. inflammatory masses (n = ) also presented as complex adnexal cysts. in these cases, the clinical history and examination was key in making the diagnosis. the ability to manipulate tissue contrast with mr imaging makes it an invaluable tool in the assessment of complex adnexal masses enabling characterisation and identification of features associated with less common pathology. to discuss the imaging features so that when this tumor is encountered the diagnosis may be considered. to correlate the pathologic characteristics with the imaging findings. to discuss the key elements to be included in the differential diagnosis and to provide examples of them. background: urachal adenocarcinoma is an extremely rare malignant neoplasm that develops from embryonic remnants and has a variable clinical course. clinical, pathologic and imaging findings were retrospectively evaluated for patients with urachal adenocarcinoma referred from centers. imaging studies (ct, n = ; mri, n = ) were reviewed for morphologic features, such as tumor size, homogeneity, margins and degree of enhancement. imaging findings: the mean tumor size was . cm. the tumors were heterogeneous in / patients, with irregular margins in / , calcifications in / and strongly enhanced in / . all tumors extended anteriorly from the bladder dome; endoscopy was normal in all cases. enlarged lymph nodes were visible in / patients. histologically proven invasion of the bladder dome was detected in / patients and invasion of the anterior abdominal wall in . d reconstructions in the sagittal plane (n = ) evoked a urachal mass and assessed its relationship with the urinary bladder, umbilicus and rectus muscles. all tumors were resected. conclusion: multimodality imaging is essential to obtain an early and accurate diagnosis of urachal adenocarcinoma. multiplanar ct and mr give the best assessment of the extent of tumor invasion. reduction of ionising radiation exposure to patients due to new imaging technology for medical diagnostics of the urinary tract: a retrospective study covering years in a norwegian referral hospital a. nyquist , i. børretzen , h. olerud , b. bjørnarå , t. gudmundsen ; drammen/no, oslo/no purpose: to examine possible changes in ionising radiation doses to patients (collective effective dose) undergoing diagnostic imaging procedures of the urinary tract over the last years in view of shift in modalities from conventional x-ray examination to ultrasonography (us). retrospective study of all patient files for the period from to . the number of plain radiographs, intravenous pyelography (ivp), ultrasonography (us), computer tomography (ct) and magnetic resonance imaging (mri) examinations were registered. for each type of examination the mean effective radiation dose were obtained from the norwegian radiation protection authority (nrpa) as published in . the number of plain radiographs of the lower abdomen covering the urinary tract increased by approximately %, ivps were reduced by %, and ct examination decreased by %. mri examinations did not play any significant role in examining the urinary tract. us of the urinary tract increased from in to in . this shift in modalities from totally x-ray based procedures, to nearly exclusively us often supplemented with one plain radiograph, caused a decrease in the annual collective effective dose for this group of patients with % from . mansv in to mansv in . the shift in modalities used for diagnostic imaging of the urinary tract from conventional x-ray to almost exclusive use of us, resulted in a significant reduction in exposure to ionising radiation of patients, and need to be considered when discussing further development and structure of diagnostic imaging. comparison of the adrenal vein sampling value between primary aldosteronoma and nonfunctioning adrenal adenoma: evaluation with receiver operating characteristic ( , voiding cystourethrography, urethroscopy and biopsy. combined retrograde and voiding sug with saline and echocontrast media levovist® were used in pts with urethral obliteration and chronic suprapubic catheters. the transperineal or transrectal ultrasound was performed to evaluate anterior and posterior urethra respectively. the images obtained allowed detailed morphology assessment of the urethra at different levels. results: compared with rug, the sug more accurately measured stricture length and diameter that was confirmed by measurements at optical urethrotomy ( pts) and urethroplasty ( pts). the introduction of contrast agents enhanced the visibility of the flow in the most strictured segment (less than . mm), which was diagnosed by rug as urethral obliteration in pts. the ce sug accurately diagnosed diverticula ( ), false passages ( ), which were confirmed by urethroscopy in all pts. conclusion: our preliminary results show, that the combined retrograde and the voiding power doppler sonourethrography with ultrasound contrast media might be an effective support in diagnostics and in the planning of treatment of patients with complex strictures and urethral obliteration. ce sug is an informative method in the differential diagnostics of patients with urethral obliteration and complex strictures. differentiation of adrenal adenomas from metastases with unenhanced ct using a scoring system h. gufler , g. eichner , a. results: attenuation values on unenhanced ct were significantly lower for adenomas than for metastases ( . ± hu versus . ± . hu, p < . ). the combined score parameter including all ct criteria showed the largest area under the roc curve. the highest predictive power suggested by the model was calculated with a cut-off point at . for benign lesions with a sensitivity of . and a specificity of . . at . points the scoring system yielded a sensitivity of . % and a specificity of . %. conclusion: compared to densitometry alone, diagnostic accuracy in the differentiation between adrenal adenomas and metastases is improved by including all ct criteria in the evaluation. the presented scoring system is simple but efficient and easy to use in the clinical routine. eswl of the unusually located stones in pediatric patients z. siric, m. radovanovic, a. slavkovic; nis/yu aim: to show the possibilities of lithotripsy in the treatment of bladder and urethral stones in pediatric patients. in a twelve year period, we treated pediatric patients, aged from months to years, by eswl. in children, stones were located in the urinary bladder, and in the urethra in another . all of them were male patients; we decided to use eswl instead of invasive methods of treatment. eswl procedures were performed under general anesthesia in and under sedo-analgesia in patient. during treatment, the patients were placed in the prone position (patients with bladder stones) or in a modified supine position (perineal approach for urethral stones). an average shock waves were applied per patient with a maximal energy of . kv. average duration of treatment was minutes. results: successful fragmentation was achieved during the first session in patients. in patient with a urethral stone, the fragmentation was not satisfactory and the treatment was repeated days later. complete elimination of stone fragments was achieved during the first days in the patients with successful first treatment, but was not achieved at all in the patient with repeated treatment. cystoscopy was performed and the stone was found within a urethral diverticulum. there were no complications in our patient group. conclusion: eswl in our experience seems to be useful as a non-invasive method in the treatment of stones with in unusual locations. it could be recommended in male patients without anatomical variations of bladder and urethra. methods: this is a retrospective study of helical ct of patients that showed iliopsoas abnormalities ( neoplasms, abscesses, hematomas, cases of atrophy and of calcifications). the study group included men and women, - years old (mean years). all studies were obtained over a -year period. final diagnosis were correlated with different ct features to determine findings that could be used to differentiate these abnormalities. these included enlargement of the iliopsoas muscle, irregular margins and fat infiltration, attenuation of the lesion, calcification, bone fracture and associated adenopathy. result: psoas pathology is more frequent in men (p < . ). low attenuation and heterogeneity are the most reliable ct features of iliopsoas abscesses (p < . ). the sensitivity and specificity of low attenuation for the diagnosis of abscesses are % and % respectively. the specificity of heterogeneity for the diagnosis of abscesses is %. bone fracture is useful for the diagnosis of hematoma (p < . ). bone fracture is % sensitive and % specific for diagnosis of hematoma. conclusions: low attenuation, heterogeneity and bone fracture are helical computed tomography features useful for differentiating iliopsoas pathology. results: all masses were classified correctly by both analysis. the mean percentage of signal intensity on subtraction images were ± (means ± sd) and nonadenomas ± (means ± sd), respectively. the difference between two groups was statistically significant (t test, p = . ). our results show that chemical shift subtraction imaging is an objective technique that allows the adrenal adenomas to be differentiated from the other tumors. the objectivity of the technique may help the unexperienced radiologists to improve their interpretation. patient ( %) had uretheral dilatation. the mru visualized the dilatation and determined the obstruction level in cases ( %). the excretory urography detected uretheral dilatation and determined the obstruction level in cases ( %). the mru detects with great accuracy the dilatation and also, obstruction level in patients with obstructive uropathy and could be used as an alternative to excretory urography in specific cases. oro objective: many congenital dysplasias of the osseous labyrinth have been identified. differentiation of these dysplasias is essential for patient management. the purpose of this study is to describe the imaging findings which can be found in anomaly of the inner ear. we retrospectively reviewed imaging findings of children with congenital sensory neural hearing loss ( male, female, mean age . years, age range - years) who had ct (n = ) and mr imaging (n = ). ct was performed on a ge hispeed/i scanner (general electric medical systems, milwaukee, wis, usa). . mm thick direct coronal axial sections were obtained with bone algorithms. mr was performed on a ge signa mr/i with temporal t fse thin section mm scan and routine brain axial, coronal, flair, fse t , se t , coronal fse t , sagittal se t weighted images. results: there were cochlear aplasia with large vestibule (n = ), cochlear hypoplasia (n = ), mondini malformation with large vestibular aqueducts (n = ), mondini dysplasia with large vestibule (n = ), large vestibular aqueduct and endolymphatic sac (n = ), small internal auditory canal (n = ) and large vestibule (n = ). four cases were involved unilaterally. seven cases had combined deformities. five cases had cochlear implant. conclusions: both ct and mr can be used to look at inner ear malformations, but often both techniques are complementary. ct is preferred when associated middle or external ear malformations must be excluded. mri is preferred when subtle changes in the membranous labyrinth or abnormalities of the nerves in the internal auditory canal must be visualized. purpose: benign paroxysmal positional vertigo (bppv) is probably the most common cause of vertigo and the most common peripher vestibular disorder. bppv has been postulated to be the result of freely floating debris of degenerative otoconia in the endolymph of a semicircular canal (sc), canalolithiasis or debris that becomes adherent to the cupula of the semicircular canal. the key in determining the diagnosis of bppv is still examination performing positioning manovers and the use of frenzel glasses. differential diagnosis can be difficult. the aim of this study was therefore to provide a new diagnostic approach by d-nmr technique. our special interest has been if there was a structural change in the sc or the cupula, which could be identified in patients with incurable vertigo compared to those with self-limited disease. methods and materials: we investigated normal and bppv subjects using a . t ge mri with d data set: tr , te , mm slices, x matrix, x fov, . nex. results: all bppv patients had pathological filling defect of the sc before therapy which must be considered as an anomaly canalolithiasis. we postulate there must be structural changes in its lumen which makes the endothelium adhesive which is recognizable in hr- d-mr as a filling defect. conclusion: a significant improvement in quality of high-resolution mri of the inner ear using ciss could be obtained at . t despite potential drawbacks. to obtain at . t, the same snr would require approximately double measuring time, optionally increasing the risk for an accidental head movement which may prove detrimental at high resolution. ( ), dysplasia of the vestibule with or without abnormality of the lateral scc ( ), mondini-deformation ( ), cochlear dysplasia and absence of cochlear nerve ( ) and dysplasia of the modiolus ( ). one patient showed labyrinth hemorrhage at the time of mri. ten cases presented typical clinical features of a progressive hearing loss. in patients a constantly moderate or profound sensorineural hearing loss was present since early childhood. one patient was deaf. one patient suffered from a pendred syndrome. conclusion: a large vestibular aqueduct is a common finding in patients with suspected inner ear malformation. nevertheless, especially in isolated lva, it is sometimes missed in routine work. even if there is no therapy, an early diagnosis is needed to explain to the patient, the cause of hearing loss, the prognosis and behaviour which can possibly delay progression. color digital radiography density measurements in differentiation of periapical granulomas and radicular cysts i.k. rozylo-kalinowska; lublin/pl purpose: the differentiation of periapical granulomas and radicular cysts is crucial for decision on conservative or surgical treatment and therefore influences the success and long-term results of the treatment. although radiograms are a valuable diagnostic tool, relying solely on the evaluation of these images may lead to mistakes in the choice of treatment. the aim of the study was determination of possibile applications of digital radiography density measurements in differentiation of periapical granulomas and radicular cysts of inflammatory origin. the material consisted of digital periapical radiograms obtained using digora, rvg and dixi digital radiography systems in patients aged to , divided into two groups: granulomas and radicular cysts. by means of digora . software, maximum and minimum densities were measured along a line and the difference between these densities was calculated. the largest dimensions of the lesions were measured both perpendicular and parallel to the root canal axis. results: the differences between the results for granulomas and cysts were statistically significant. when the difference of densities exceeded . , the lesion was a cyst and when it was below . , a granuloma was diagnosed. combined application of two criteria, namely the calculated difference between densities and the largest dimension, increased diagnostic possibilities of radiological differentiation of granulomas and radicular cysts. conclusion: it was proved that to some extent it was possible to differentiate granulomas and radicular cysts by means of digital radiography software. ameloblastomas d e f a g x-rays, ct and mri. the use of d-ct and dentascan proved especially helpful in determining tumor dimensions. histological examination of the lesions showed that were of the follicular type, presented as mural ameloblastomas, were squamous type, plexiform and was a malignant ameloblastoma. results: in patient the extension of disease was proven inoperable. in patients various types of mandibulectomies along with immediate reconstruction were performed. in cases of mural ameloblastomas local excision only was performed, whereas in patients the mandibular defect was reconstructed with a titanium plate. conclusion: in large monolocular lesions treatment can be conservative surgery, whereas in large multilocular lesions radical surgical treatment that includes segmental ostectomies with immediate reconstruction of either vascularized or autogenous bone grafting is the treatment of choice and produces the best post operative results. the interpretation of the d reconstruction images and the dentascan are of great importance when such an operation is decided upon. differential growth in vestibular schwannoma g.c. bockeler, v. nandapalan, t. lesser, h. lewis-jones; liverpool/uk purpose: mri plays a pivotal role in the management of patients with vestibular schwannoma (vs), yet there are no universally agreed guidelines on the use of this expensive investigation. this study analyses the site, size and morphology of vs referred for possible intervention. where clinically a wait-and-watch approach was chosen, growth of vs was determined on subsequent imaging. methods and material: mr images of patients with unilateral vs referred to a tertiary centre were classified according to the site of vs with respect to the internal acoustic canal. a variety of measurements were obtained to determine the most sensitive method of measurement. growth was expressed as absolute and relative change in the direction of the largest increase in size. results: vs showed growth in % of patients, % remained static and % regressed. growth was most frequent in vs with an intra-and extracanalicular component whereas purely intracanalicular vs showed no growth. the initial size did not predict growth. growth rates were largest in predominantly extracanalicular vs. conclusion: our findings confirm previous findings of infrequent and smaller growth in purely intracanalicular vs and more frequent and larger growth in predominantly extracanalicular vs. an incremental delay in follow-up imaging of the former vs appears justifiable in the absence of new symptoms. conversely most vs require close monitoring as even small changes in size may lead to symptoms necessitating invasive treatment. sonographic sialadenitis/sialolithiasis: ultrasound is accurate in the assessment of acute and chronic inflammation and abscess formation. it has replaced sialography in many centres for evaluating suspected stone disease and duct dilatation. granulomatous disease: sarcoidosis and sjögren's syndrome may both involve the submandibular glands. ultrasound is able to delineate the phases of disease progression in sjögren's and is also used in lymphoma surveillance in these patients. other lesions of the submandibular space: including adenopathy, cystic hygroma, brachial cleft cyst, ranula and lipoma may mimic submandibular gland lesions and are readily identified sonographically. conclusion: ultrasound represents a safe, widely available and accurate means of assessing the submandibular space and is able to delineate and characterize lesions. ultrasound can be used to guide aspiration or biopsy and reduce the need for surgical excision. ultrasound-guided core biopsy of the parotid gland: results of patients k.k. lewis , m. williams , d.c. howlett , g. manjaly , a.b. moody , n. violaris ; eastbourne/uk, brighton/uk purpose: to evaluate the role of ultrasound-guided biopsy in the management of palpable parotid lesions. materials and methods: one hundred patients were included in this prospective study over a -year period. initial ultrasound examination was performed using a - mhz high frequency transducer. guided biopsies were taken under local anaesthesia (single operator) with a spring loaded variable throw ( mm/ mm) biopsy gun using or g needles with an average of passes per patient. results: in patients, biopsy revealed benign neoplasms, malignant lesions (including primary and secondary lesions as well as lymphomas) and other pathologies including sarcoidosis, tuberculosis, reactive lymphadenopathy, sjogren's and actinomycosis. only lymphoma patients needed surgery for further histological grading. diagnostic accuracy was % for benign versus malignant pathology in the patients who underwent subsequent surgery. there was % correlation between biopsy and operative histology with only two non-correlates. these involved misdiagnosis of squamous cell carcinoma and mucoepidermoid carcinoma. these would have required further histochemical staining for differentiation. surgery was avoided in forty-six patients after biopsy diagnosis. there were no immediate complications of biopsy. conclusion: ultrasound guided biopsy gives % benign versus malignant pathological differentiation. it also has % correlation with operative histology. correct pre-operative diagnosis influences the decision to undertake conservative or radical surgery and unnecessary surgery can be avoided. a core of tissue allows histopathological analysis where assessment of tissue architecture, tumour grading and immunochemical staining is possible. this is invaluable for accurate diagnosis. contrast enhancement of the cochlear aqueduct in mr imaging: its frequency and clinical significance t. nakamura , s. naganawa , h. fukatsu , y. sakurai , i. aoki , a. ninomiya , t. nakashima , t. ishigaki ; nagoya/jp, tochigi/jp purpose: there have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance (mr) imaging. the purpose of the present study was to evaluate the frequency and significance of this finding. methods and materials: thirty-one patients ( men and women; age range - years) with otologic symptoms (sudden sensorineural hearing loss, vertigo or tinnitus) were examined using contrast-enhanced imaging on a . t mr scanner. the normal ear served as the control. two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. result: forty-eight of ears ( . %) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors or a highriding jugular bulb. in addition, no gender or age-related differences were noted. conculusion: contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. the results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion. high-resolution mr imaging of basaliomas of the facial soft tissue with a microscopy coil h. gufler, c. zörb, w.s. rau; giessen/de purpose: to correlate the tumor extension measured on high-resolution mr images with histology. patients and methods: five patients with basaliomas of the facial soft tissue were examined before surgery with high-resolution mri using a . tesla system with a mm microscopy coil. axial t -and t -weighted tse images were obtained from all patients before gd-dtpa application and additional axial and/ or sagittal t -weighted sequences with and without fat suppression after cm application (fov mm, matrix x , slice thickness . mm, acquisition time - minutes). qualitative analysis of mr images was performed by two radiologists who measured the extension of the tumor and decided whether bone erosion or infiltration of the orbit or of the nasal cartilage was present. results: t -weighted unenhanced axial images proved to be the most useful sequences in predicting the extension of the basaliomas. for the evaluation of b d e f a g orbital invasion, additional sagittal t -weighted unenhanced images were helpful. the extension of the lesions correlated well with the results on histology. in one case, however, nasal cartilage infiltration was not correctly diagnosed on the basis of high resolution mr. conclusion: high-resolution mr imaging using a microscopy coil is a promising method to predict the exact extension of basaliomas of the facial soft tissue. three orbit mri of the superior oblique muscles to measure the asymmetry in patients with iv nerve paresis m.a. eleta, f. shokida, f. seclen, j. gabriel, c. zanchez, f.a. eleta; buenos aires/ar purpose: to evaluate the section of the superior oblique muscles (so) in patients with unilateral congenital or acquired pareses to detect asymmetry and the relationship between the degree of vertical deviation and mri measurements. method and materials: from march to september , patients underwent orbits mri. seventeen patients had unilateral so muscle paresis: congenital and acquired. fifteen patients had normal so. the area of the superior oblique muscle in the section of maximun width was obtained in primary gaze position, supra and infraversion. asymmetry of the superior oblique muscles was defined arbitrarily as the difference between both so in the same patient and the measurement was compared with the values obtained in the normal group of patients. results: mean maximal difference was . ± . mm (p < . ) between the healthy and paretic eye. in the normal group of patients it was . ± . mm (p < . ). eleven out of the patients with congenital paresis showed asymmetry of the superior oblique ( . %). asymmetry determination of the superior oblique muscles disclosed . % sensitivity and % specificity. the relationship between vertical deviation and the maximal difference between the section of the normal versus the paretic eye was p > . . conclusion: imaging of the superior oblique muscles in patients with congenital iv nerve paresis showed significant asymmetry in the section area with regard to the contralateral muscle. however, no correlation was found between the degree of vertical deviation and interocular asymmetry. high resolution gray scale and color doppler imaging was performed in more than patients using a high frequency linear array transducer. various planes of imaging of the eye correlating with drawings of normal anatomy are shown. views are used to illustrate the complex anatomical relationships. an overview of the normal anatomy and pathologic conditions is presented with clinical correlation. results: evaluation with high resolution gray-scale and color doppler ultrasound can often determine diagnosis without further imaging procedures. us is sometimes insufficient to evaluating a deep structures of the orbit. paradigmatic us images from different pathologic entities of the eye (for instance: intraocular foreign bodies, haematoma, cataract, vitreal pathology and ablation of the retina etc.) are shown. conclusion: adequate knowledge of the anatomy of the eye and orbit is needed to correctly limit the differential diagnostic possibility of pathology of the eye and orbit. us is an available method for an accurate diagnosis of the eye with ct, and preferably mr, being reserved for cases which require additional information about deep structure, or those with in which there is discrepancy between the sonographic and clinical diagnosis. nasopharyngeal angiofibroma: the role of angiography in diagnosis and treatment a. szymanska, r. pietura, a. drelich-zbroja, m. szymanski, m. szczerbo-trojanowska; lublin/pl background: nasopharyngeal angiofibroma (na) is a rare, benign, unencapsulated tumour affecting adolescent males. surgery and radiotherapy are main treatment modalities. we evaluated typical angiography findings of na, its role in defining tumour blood supply and treatment planning. material and methods: forty patients with jna ( males and females aged to ) underwent angiography. we assessed tumour vascular composition, its location in relation to the maxillary artery (ma), feeding vessels and feasibility of preoperative embolization. relationship between stage of tumour, presence of intracranial extension and internal carotid artery (ica) blood supply were statistically evaluated. results: on angiograms, all tumours presented intensive inhomogenous blush. . % of tumours were supplied by ma, % by ascending pharyngeal and . % by the facial artery. in % of tumours, feeding vessels originated from the ica and in ( . %) case from the vertebral artery. the relationship between ica blood supply and tumour stage was statistically significant. ica blood supply had no correlation with the presence of tumour intracranial extension. two patients with abundant ica supply were disqualified from surgery and underwent irradiation. in patients with previous external carotid atery ligation, preoperative embolization of vascular recurrent tumour was not feasible. in % of cases ma was displaced by tumour lateral extension. conclusions: angiography shows typical features of na (nasopharyngeal, highly vascular tumour supplied by ma), confirms diagnosis of this tumour and enables preoperative embolization. analysis of tumour blood supply is useful in determining best therapeutic approach. angiography visualises displaced ma, which helps the surgeon identify and ligate it during tumour removal. is an increased capsular width a reliable indirect indicator of temporomandibular joint effusion? f. tognini , d. manfredini , v. zampa , g. tognini , m. bosco ; pisa/it, parma/it purpose: to establish the most accurate cut-off value of ultrasonographic (us) capsular width which consents to discriminate between temporomandibular joints (tmj) with and without magnetic resonance (mr) effusion. the study group consisted of patients who sought treatment for temporomandibular disorders (tmd). all the tmjs (n = ) were evaluated in order to detect the presence of effusion by means of us and mr. ultrasonographic examination allowed measurement of the capsular width, in the sagittal-oblique scans, as the distance between the hyperechoic lines representing condylar surface and the glenoid fossa. after capsular width was measured, roc curve analysis was performed to establish the most accurate cut-off value to discriminate between joints with and without mr effusion. results: diagnostic accuracy of us to predict mr evidence of tmj effusion was good (area under the roc curve = . ). us sensitivity was high for values lower than the cut-off value of . mm (true positive rate (tpr) = . %; false positive rate (fpr) = . %), while specificity was high for values higher than the cut-off value of . mm (tpr = . %; fpr = . %). conclusion: ultrasonography proved to be accurate in detecting the presence of effusion in the temporomandibular joint. analysis of receiver operating characteristic curve seems to reveal that the critical area of capsular width indicating effusion is that around the value of mm. patients were referred for ct angiography of carotid arteries in our institution. of these patients, were found to have carotid body tumors and were included in the study. all tumors were confirmed with several imaging modalities (us, msct, mr, digital subtraction angiography and somatostatin scintigraphy) and with histologic examination performed on the resected surgical specimen. imaging findings: the us (including power-and color-doppler scanning), msct angiography, mr angiography, digital subtraction angiography and somatostatin scintigraphy findings of carotid body tumors were reviewed. tumors were unilateral in eight cases and bilateral in the remaining two patients. all lesions were well-defined (ranging in size from . to . cm) and located within the carotid bifurcation, causing splaying of the carotid branches. all tumors were highly vascularized (mainly by branches of the external carotid artery) and no sign of malignancy was identified. after pre-operative embolization, all lesions were surgically removed with no complications and were confirmed to be carotid body tumors at histology. the diagnostic possibility of a carotid body tumor has to be considered when a solid mass is detected within the carotid bifurcation. imaging studies are essential to differentiate carotid body tumors from other masses of the neck (lymphadenopathy, tumors, cysts, etc). imaging background: evaluation of cervical spaces is an important procedure for patients with cervical pathology because it assesses the prognosis of the patients and helps to select adequate treatment. ultrasound, computed tomography and magnetic resonance play an important role in the imaging diagnosis of this area. however, before examination of pathology, a clear understanding of the anatomy of cervical spaces is essential. the neck is divided into eight regions, enabling the radiologist to examine all areas of the neck in a systematic way in order not to miss a lesion. procedure details: we have reviewed all the normal studies of the neck that were performed during the last year using at least one of the three techniques. we selected the most illustrated cases to describe the anatomy of the cervical spaces. the neck is a complex anatomic area. this education exhibit helps the radiologist to have a better knowledge of imaging of the cervical spaces. preoperatively, the thyroid nodules were assesed in terms of number, compressibility, texture, complexity, margins, volume, vascularity, interactions with great vessels and the presence of thyroid, parathyroid and cervical lymph nodes. d usa multiplanar reconstructions (mpr) reslicing thyroid nodules for virtual surgery were created. us results were compared with intra-operative findings and final pathomorphology. results: fifty-three patients had operations ( lobectomies, thyreoidectomies including with lympadenectomies and thyroid resections). six cancers, adenomas, colloid nodules, goiters and with thyroiditis were found. demonstration of the nodules in three orthogonal planes by d usa and assessment of the nodule's character and vascularity helped to change surgical management in cases; in cases post puncture morphological diagnosis and in cases operation was rejected. d usa was superior to conventional d in differential diagnosis of thyroid nodules. the preliminary decision to perform a lobectomy or a total thyroidectomy was based on variety of factors, many of which were delineated by detailed ultrasound examination. preoperative evaluation of thyroid vascular anatomy and mpr of the nodules were of value for changing surgical management for thyroid resections and in rejecting the necessity of operation. conclusions: d usa is a useful complement to conventional ultrasound that allows precise preoperative evaluation of thyroid nodules which influences surgical management. the value of mr imaging and mr angiography in the differential diagnosis of carotid space tumors p. virtual laryngoscopy: comparison with fiberoptic laryngoscopical findings z. celej , a. wygoda , c. przeorek , w. przeorek , j. baron , a. siemianowicz ; gliwice/pl, katowice/pl purpose: to evaluate the concordance between virtual and direct laryngoscopy in the estimation of laryngeal carcinoma staging. material and methods: multislice ct and direct laryngoscopy were used to examine patients with laryngeal carcinoma. ct data were obtained on a sixteen row detector ( . mm slice thickness, pitch factor ) during free breathing and "e" phonation both before and after contrast enhancement. the patients were examined before radiotherapy and surgical treatment. postprocessing was performed using multiplanar rendering (mpr) and virtual laryngoscopy (vl) as a surface rendering algorithm with boundary density of - ,- and - hu. all ct examination results (mpr and vl) were compared with fiberoscopy. virtual images created at boundary density of - hu revealed better concordance to direct laryngoscopy. every case of laryngeal carcinoma, even plain infiltration at t stage, was correctly diagnosed by virtual endoscopy. the disorder of vocal cord function was better demonstrated in fiberoscopy. virtual laryngoscopy is complementary to fiberoptic endoscopy and should be combined with axial slices and mpr images for the estimation of laryngeal carcinoma staging. ultrasound characteristics and histopathologic correlation in primary thyroid carcinomas c. to describe the technique and problems related to spect/ pet/ct/us image fusion in the neck region and to demonstrate the clinical relevance of the information gained by multimodality imaging on a series of patients with neck tumors, lymph node metastasis, graves disease and chronic ent inflammations. background: small tumors or subtle changes in inflammatory diseases cannot be detected in only one imaging series. multimodality imaging allows for a combination of functional and anatomical information in one dataset and therefore gives more detailed informations on distinct changes. procedure details: for reproducible immobilization of the patient, an individual mold of the patient's head, neck and shoulder was produced using the bodyfix vacuum device (medical intelligence, schwabmünchen, germany). up to modality-specific markers were reproducibly attached to the skin and to the mold. the data-sets were transferred to the treon stealthstation navigation system (medtronic inc.) and image fusion was performed based on the markers and anatomical landmarks. image fusion allowed precise correlation of suspicious tracer-enhancements to tumorous contrast-enhanced nodules on the ct images. in patients with graves disease and ent inflammations focal disease in homogeneous tissues was uncovered due to increased tracer uptake. us images were used for screening and to depict vascularisation. the presented method aids in the detection of tumors and lymph node metastasis in the neck area, influencing the surgical strategy in most patients. in patients with graves disease and chronic inflammations the real amount of inflammation can be determined. lemierre's syndrome (necrobacillosis): the imaging findings s. powell, m. powell, d. bakshi, j. evans; liverpool/uk learning objectives: the purpose of our poster is to demonstrate the imaging findings in the rare and interesting lemierre's syndrome (necrobacillosis), to heighten clinincal suspicion and therefore allow more rapid diagnosis. background: lemierre's syndrome is the triad of pharyngitis, internal jugular vein thrombosis and pulmonary infection. the causative organism is fusobacterium necrophorum. this is a commonly fatal disease requiring both the radiologist and clinician to keep an index of suspicion. the diagnostic findings include pharyngitis with direct local invasion into the lateral pharyngeal space and thrombophlebitis of the internal jugular vein. metastatic infection is common and the usual site is pulmonary ( %). imaging findings: the imaging findings include pharyngitis with direct spread of infection into the lateral pharyngeal spaces. internal jugular vein thrombosis and pulmonary infiltration leading to cavitation are the next most common findings.other findings include pleural effusions, spinal and brain abscesses, septic arthritis and ivc thrombosis. a variety of imaging modalities are employed to assess the patient with disseminated fusobacterial infection. conclusion: our poster aims to provide a comprehensive collection of imaging findings in lemierre's syndrome. lymph node staging in head and neck cancer: a pictorial review s. connolly, h. lewis-jones, r. hanlon; liverpool/uk learning objective: the purpose of this poster is to describe and show the anatomical location of the lymph node levels as described by the american joint committee on cancer. it will also cover some of the difficult diagnostic areas involved in reporting head and neck staging images. background: as a radiological department attached to a large head and neck unit, we have wide experience of head and neck cancer. the extent and level of cervical node involvement is probably the most important prognostic factor for patients with a primary squamous cell carcinoma. node level has also been shown to be a highly significant predictor of survival. procedure details: using anatomical drawings and cross sectional images of pathology that we have encountered in our department, we will show examples of nodes in the described levels. the pictorial review will include examples of normal reactive nodes as well as typical examples of extracapsular spread, squamous cell cancer metastatic nodes and lymphoma. we will also depict some of the more unusual cases we have experienced, such as histologically proven recurrent metastatic nodes, which on imaging grounds appeared benign and cystic, along with some examples of intraparotid nodal disease. the pictorial review will allow greater understanding of the staging process of head and neck cancer and its implication on patient prognosis and survival. ten patients with squamous cell carcinoma of the neck (t - , n - ) planned for primary radiochemotherapy were examined at several time points in the course of the weeks therapy (before, after beginning, and at and weeks). the examinations were performed with aplio us-system (toshiba) with . mhz broadband transducer. pd and adf (either d and d) were applied pre and post application of ultrasound contrast agent (intravenous bolus of . ml sonovue). the methods were compared by visual assessment. results: both ce adf and pd are sufficient to depict blood supply. while pd delivers better b-mode information, adf allows continuous examination due to the lower mi thus giving more time to acquire d data set and determining signal intensity time curve after one bolus application of contrast. adf showed less artifacts concerning blooming and cluttering in number and extent in almost all cases. in cases, we were able to demonstrate a perfusion after weeks of therapy but in it was only possible using ce techniques. conclusion: although pd delivers more b-mode information adf is the method of choice since it has the same sensitivity for detecting blood vessels but allows continuous examination and is less susceptible for artifacts. conclusion: percutaneous islet cell transplantation appears to be a simple and clinical promising radiological intervention and an alternative to surgical pancreas transplantation in patients with type diabetes refractory to insulin therapy. imaging findings and procedure details: diagnostic imaging and interventional minimally invasive percutaneous procedures in disk diseases are reviewed through an interactive hypertext-based teaching file with images and movie demonstrations. ct, mr imaging and discogram findings in disk pathology will be described including degenerative disk diseases, spondylosis, disk herniations, traumatic disk diseases, septic diskitis, and postoperative disk diseases. techniques, indications, contraindications, complications and results of percutaneous minimally invasive procedures of intervertebral disk diseases will be described and illustrated. these procedures include percutaneous periradicular and epidural steroids injection, percutaneous diskogram, diskal biopsy and drainage, percutaneous radiofrequency and laser nucleotomy. conclusion: for disk disease with appropriate indications, minimally invasive interventional radiologic procedures are able to relieve pain and to minimize the risk of disability. colonic stents in acute malignant colorectal obstruction: cases p. bermudez bencerrey, j. falco fages, j. perendreu sans, j. fortuño andrés, m. alcantara moral, d. gil bello; sabadell/es learning objectives: to illustrate our experience with colonic stents in the treatment of acute obstruction from colorectal cancer. to describe the results and complications of the procedure based on a series of patients. background: colorectal cancer is an important health problem with a high morbidity and mortality rate. between - % of patients with colon cancer present with acute obstruction. % of acute obstructions are in the left colon and rectum, and only % of left sided carcinoma colonic obstructions can be treated with intraoperative lavage and subtotal colectomy. the rest of the patients need a temporary or, more probably, permanent colostomy with an important impact on quality of life. in this exhibit we will describe the use of colonic stents as a temporary treatment prior to elective surgery of left sided colon and rectal cancer and as a palliative treatment in the unresectable colon cancer. between july and august , patients with acute colonic obstruction were treated with colonic stents in our department. the procedure, indications, contraindications, and the results are described and illustrated. procedure details: plain abdominal radiography and abdominal ct was performed to all patients prior to the procedure. two different types of colon stents were used: enteral wallstent (boston scientific) and hanarostent (mitech co., ltd.) conclusion: clinical resolution of the obstruction was achieved in %. anastomosis was successfully performed in % of the patients undergoing surgery. major complications developed in % ( perforations, obstructions and migrations). palliative treatment was effective in all cases. saline injection of solid tumours prior to radiofrequency ablation: our experience a.m. camenzuli, a. attard, j.c. evans; liverpool/uk learning objectives: . to outline the procedure we have adopted to instil saline into the tumour. . to describe the appearances of complete necrosis on the inital, early and late follow-up scans. . to describe the complications and patterns of recurrence of tumours after radiofrequency ablation. background: the injection of saline to potentiate the effects of radiofrequency ablation in solid organ tumours in experimental models is well described in the literature. we have injected saline prior to ablation into primary hepatocellular carcinomas, colorectal metastases to the liver and primary renal cell carcinomas. procedure and iimaging details: using either ultrasound guidance or ct and under general anaesthesia, we lace the tumour with ml of % saline via a coaxial needle. a radioablation probe is then placed along the needle -the latter is then removed prior to applying the rf pulse. we routinely ablate the track along which the probe has travelled to avoid seeding. routine follow-up with a dual phase abdominal ct scan is done at month and months. the appearances of ablated tumours, recurrences and complications are reviewed in this presentation. conclusion: saline infiltration is a safe and effective way of potentiating radiofrequency ablation of solid tumours in the liver and kidneys. percutaneous background: renal abscess is a collection of purulent material confined to the renal parenchyma. it is often life threatening leading to septicemia and is difficult to manage only with the use of antibiotics especially in immuno-compromised patients. ct is currently the most accurate modality in detecting and following renal abscesses. treatment with ct-guided percutaneous drainage and appropriate antibiotics can be very useful. in a period of two years we treated patients with renal abscesses. we demonstrate the technique and discuss the indications and complications of ct-guided percutaneous drainage of renal abscesses. the procedure is performed with the patient in prone position under local anesthesia supplemented with minimal sedation. initially a gauge chiba needle is passed into the renal abscess under ct guidance. on confirmation of an abscess we use a pigtail trocar catheter of to f for the drainage. conclusion: ct-guided percutaneous drainage is an effective and well-tolerated method for the therapeutic management of renal abscesses. the imaging features and percutaneous drainage of mediastinal abscesses secondary to oropharyngeal infection s. sadiq, s. owen, r. evans; swansea/uk learning objectives: oropharyngeal infection, such as dental abscess and acute pharyngitis, are recognised but rare causes of mediastinal abscess formation. we highlight the use of multimodality imaging and percutaneous image guided drainage. the hospital records of four such patients, including casenotes, microbiology data and imaging were reviewed. the clinical courses were followed in order to identify the causative pathogen and illustrate the imaging features and subsequent radiological interventional management. the patients presented over a two-year period. the age range of these patients was sixteen to forty seven. the primary aetiology in three patients was a dental abscess. the fourth patient had an acute pharyngitis. image findings: a combination of ultrasound (us), computed tomography (ct) and magnetic resonance imaging (mri) of the neck and thorax was used to define the anatomical compartments involved. radiological placement of an fpigtail catheter using us or ct avoided a major surgical procedure in all patients. the common pathogen isolated was streptococcus viridens. patients were treated with the appropriate antibiotics and all made an uneventful recovery. conclusion: an understanding of the anatomical spaces of the neck and their communication with the mediastinum is demonstrated and we recommend that in this condition, which has a high mortality when managed surgically, interventional radiology is an effective treatment option with a low complication rate. complications occurring after drainage are not uncommon and add to the morbidity of the procedure. the authors display their experience in handling complications (remedial procedures with appropriate images) that occurred in patients with malignant biliary obstruction, in whom ptbd and/or stenting was performed over a -year-period. the authors will also list precautions to be observed to prevent such complications. procedure details: severe hemorrhage was treated by catheter repositioning, angiographic embolization of pseudoaneurysm and coil embolization of a portal vein branch rent via a ptbd tract. cholangitis and bilomas required placement of additional drainage catheters. a migrated plastic stent was repositioned with vascular snare. a ring biliary catheter that broke during procedure, the proximal part lying in peritoneal cavity, was removed by image guided forceps, followed by replacement. blocked plastic stents were removed endoscopically or via the percutaneous route by canulation with a guidewire followed by replacement. ring biliary catheter and additional stents plastic/metallic stents were used for blocked metallic stents. pericatheter leaks responded to flushing, wire passage or larger catheter exchange. conclusion: it is important to be aware of complications that occur during ptbd and stenting, and how to deal with them before embarking on a full time biliary decompression program. intellectual property: development and protection c. cook , m. rees ; weston-super-mare/uk, bristol/uk learning objective: to discuss the different methods of intellectual property (ip) protection. to review the methods of interventional radiology device product development. background: there are many ways of protecting intellectual property. we discuss each of these in turn. we discuss the differences between the methods used in the united states and the european union. we also discuss the methods of product development. details: trademark, copyright, patents are all reviewed. we discuss the need for patent attorneys and specialist ip management units. we describe the different types and levels of protection available. we also discuss specific means by which an idea can be developed, then protected. we look at the methods available to link with development companies, leading to manufacture. all the principles are specifically discussed with respect to the development of a interventional radiological device. there are numerous ways of protecting ip, and we describe each of these in turn. in addition we look at the means of developing and ultimately manufacturing a radiological interventional device. purpose: ethanol injection (pei) and radiofrequency (rf) are the percutaneous radical therapies most frequently employed in europe to treat liver tumors in non surgical patients. we present our experience in these techniques over the last years at the hospital clinic in barcelona. since multisession pei was applied in patients with hepatocellular carcinoma (hcc) (uninodular ≤ cm or multinodular ≤ cm). rf was performed in patients since : hcc, metastasis and others. ct and us (with contrast agents in the later years) were used for efficacy assessment. results: pei: initial complete response (cr) = . %. extra and intratumoral recurrence = and %. one, and year survival rates in child a patients = , and % and in child b patients = , and % (mean follow-up = months). rf: cr in hcc patients = %. extra and intratumoral recurrence = and %. one, and years survival rates = , and % (mean follow-up = months). in patients with metastasis cr = %, with a recurrence rate = % (mean follow-up = months). major complications, that includes hemoperitoneum, liver abscess, needle-tract seeding and cardiovascular death are . % in pei and . % in rf. conclusion: pei and rf are effective local curative methods in liver tumors, with more frequent major complications in the rf group. and excellent ( - ). the efficacy was also evaluated with the days until the patients unable to move started to walk again after pvp. results: pvp was technically successful in all patients with three cases of minimal complications. the mean vas score for patients was . before pvp compared with . after the procedure. on the degree of improvement, the groups of ineffective, poor, effective and excellent consisted of . , . , . and . % of patients, respectively. patients ( . %) could walk the next day after pvp and the mean value until ambulation was . days. conclusion: pvp is a safe and effective treatment for relieving severe pain of osteoporotic vertebral compression fractures, leading to avoid various complications associated with prolonged immobilization in aged patients. effect of vessel size on creation of pulmonary radiofrequency lesions in sheep: assessment of the "heat sink" effect k. steinke , k.s. haghighi , k.k. hazratwala , d.l. morris ; basle/ch, sydney/au purpose: to evaluate the effect of vessel size on radiofrequency lesion creation in the lung with respect to potential for perfusion-mediated heat sink effect and for vascular and bronchial injury. methodology: radiofrequency lesions targeted to tissue encompassing a variety of vessels were created in vivo in the lung of cross-bred sheep. the access was either open after thoracotomy along the th intercostal space, or percutaneous. acute, subacute and chronic changes have been investigated, with immediate, hours and days sacrifice of the sheep post ablation. macroscopic and histopathologic analysis of the vessels and bronchi was performed. the degree of vascular and bronchial injury and viability of perivascular pneumocytes were recorded. results: heat sink effect, macroscopically indicated by invagination of the lung tissue between the vessel and the radiofrequency lesion, was not observed in vessels with a diameter less than mm. half of the vessels mm or smaller were thrombosed, while the arteries of the same size looked to be patent. macroscopically no vessel wall injury could be detected. all vessels mm and above showed a certain extent of invagination, no clots were visible. occasionally within the bronchial lumen small amounts of dark solid material was seen, macroscopically believed to be consolidated blood-tinged sputum. the histopathological results are expected soon. conclusion: as already shown for liver vessels, lung vessels seem to also have a perfusion-related heat sink effect, consistently seen in vessels above mm in diameter. peritoneal seeding of hepatocellular carcinoma after radiofrequency ablation: post-rf bleeding was detected in cases. two of these patients had hepatic arterial embolization performed due to severe bleeding. in terms of seeding pattern, massive perihepatic and ometal masses were seen in cases and multiple small peritoneal nodules were noted in a further cases. other cases showed small single mesenteric mass and gastrohepatic ligament thickening. the rate of peritoneal tumor seeding after rf ablation of hcc was . %. the capsular attachment, tumor bulging and post-rf bleeding seems to be risk factor of peritoneal seeding after rf ablation of hcc. r. marcello, l. broglia, m. castellana, g. gasparini, m. castrucci; rome/it purpose: the aim of our study was the evaluation of the spio contrast-enhanced mr pattern of malignant focal liver lesions treated with percutaneous radiofrequency ablation. methods and materials: focal liver lesions were evaluated with magnetic resonance ( . tesla philips, the netherlands), with spio (resovist schering, germany) contrast media after rf percutaneous ablation. lesions ranged in size from . cm. to . cm. mr examination sequences protocol was as follows: tfe t w and ffe dynamic study before contrast media injection and after and sec spio iv administration; tse t w and spir tse t w before contrast media injection and after - min after spio injection. all patients underwent mr imaging evaluation after days, days and months the procedure was carried out. the signal intensity appearance was examined in order to identify size, signs of absence, residual or recurrence of neoplastic tissue. the gold-standard was clinical and ct imaging follow-up. results: spio enhanced sequences were superior in conspicuity, presence or absence and residual or recurrence of tumoral tissue. in % of lesions a homogeneous pattern was observed within the lesion with a hyperintense peripheral rim; in % of cases inhomogeneity of lesions was observed in examinations performed at days. residual tumor was depicted at days examination as presence of hyperintense foci localized within the treated area. in this preliminary study spio appeared to be an efficacious contrast agent for detection and follow-up of percutaneous rf ablated focal hepatic lesions, especially on t w and the sec t w dynamic mr study. radiofrequency ablation of hepatic dome lesions g. papaioannou, l. thanos, a. nikita, e. alexopoulou, d. loggitsi, d.a. kelekis; athens/gr purpose: to present the additional difficulties and technical peculiarities of radiofrequency ablation (rf) for hepatic dome lesions. materials and methods: patients with focal subphrenic hepatic lesions ( hccs, metastases) underwent percutaneous ct-guided rf ablation. electrodes with or active tips were advanced under ct-guidance. although technically difficult due to the great needle angulation and penetration of a long hepatic portion, transhepatic route was followed in all cases. transpulmonary penetration was considered high-risk due to the large diameter of the electrode. results: all patients experienced mild discomfort during the procedure. three complications were noted: small subcapsular hematomas and pleural effusion, which were treated conservatively. % of the hccs and . % of the metastatic lesions showed signs of complete necrosis immediately post procedure. residual non-necrotic tumour was present in cases and repetition of the procedure was required. tumour recurrence was demonstrated in patients ( . %) on -year follow-up control and was treated with a new session of rf ablation. overall, rf sessions were performed. conclusion: hepatic dome lesions can be treated successfully with rf ablation. careful planning and technical skill are required due to their location. results: no treatment complications were noted. the patients recovered well post injection. ct performed in both children after three months showed ossification of the lytic lesions, allowing the cervical braces to be removed. conclusions: to our knowledge no prior experience in endosteal cervical steroid injection has been reported. these two cases confirm the improvement of osteolytic lesions in children with lch after treatment with endosteal infusion of steroids. stabilisation of the cervical spine was particularly beneficial, as the children were no longer in pain and removed the need for cervical braces three months after the treatment. the influence of radiofrequency ablation on hepatic vessels in porcine liver k. satoh, k. nakamura, m. hamuro, y. sakai, n. nishida, y. inoue, r. yamada; osaka/jp purpose: the objective of this study was to clarify the influence of radiofrequency ablation on hepatic blood vessels. hepatic rfa was performed on swine (mean body weight: kg). the livers were removed either immediately following ablation, week or weeks after ablation. the patency of vessel was determined by ct, and the extent of endothelial disorder with diameter less than . mm was determined histopathologicaly. the portal vein patency rate of immediately, or weeks after rfa were: . ± . %, . ± . % (less than . mm), . ± . %, . ± . % ( . mm and more). hepatic vein patency rate were: . ± . %, . ± . % (less than . mm), . ± . %, . ± . % ( . mm and more). the patency rate was higher for larger vessel diameters. the patency rate of the portal and hepatic veins with diameters less than . mm was found to decrease with time. at weeks after ablation, the patency rate for vessels with diameters of . mm and over were significantly higher (p < . ) compared to those of diameters less than . mm. endothelialization were found in patent vessels from week to weeks after ablation. conclusion: endothelization was confirmed from week to weeks after rfa in patent vessels. blood vessels with diameters of . mm and over maintain high patency even after rfa. it is therefore possible to maintain blood flow in the distal area of hepatic parenchyma following ablation for hepatic tumors, thus rfa has a limited impact on hepatic function. in three cases, a successful second trial after an initial failure was performed. the procedure was performed by means of a transhepatic (n = ) or a transperitonea l (n = ) access route. during procedure, the seldinger technique was used (transhepatic approach, n = , transperitoneal approach, n = ) in patients, while in the remaining patients the procedure were performed using a trocar technique with a transperitoneal approach. chiba needles ( g, mdtech, denmark, n = ), jelco needles ( g, johnson & johnson, usa, n = ) and secalon catheters ( g, ohmeda, uk, n = ) were used for initial puncture of gb. only minor complications such as abdominal pain (n = ), hemorrhage (n = ), referred pain (n = ) occurred in cases ( %). abdominal pain is more frequent in transhepatic approach ( %) than in transperitoneal approach ( %), but not statistically significant (p = . ). overall complication rate is lower in transperitoneal approach ( %) than in transhepatic approach ( %)(p = . ). according to puncture needle, there is no significant difference in complication rate between the chiba needle ( %) and the g needle (jelco needle and secalon catheter, %). conclusion: percutaneous cholecystostomy has proved to be safe and effective treatment for patients with acute cholecystitis. t.v. bartolotta, t. angileri, m. midiri, f. sorrentino, g. sparacia, a. carcione; palermo/it purpose: to evaluate the ct role in treatment of lumbosciatalgia through chemonucleolysis with oxygen-ozone (o -o ) mixture with periradicular and periganglionic technique. materials and methods: from january to june , patients ( women, men; age range: - years) with lumbosciatalgia, underwent intradiscal, periradicular and periganglionic treatment with o -o mixture, corticosteroids and anaesthetics. the analysis of the results was made by visual analogue scale (vas) day before treatment (t ) and, respectively, weeks (t ), months (t ), months (t ) later. all the procedure was performed in a step-wise fashion and controlled by ct scans: from positioning the needle in the centre of the nucleus polposus to mixture administration within the nucleus and in periradicular and periganglionic sites. results: in / ( . %) patients a partial remission of the complaints just after the first treatment (vas at t ) was observed; vas was at t and at the last evaluation, six months later (t ), it was . in / ( . %) patients vas was at t and another treatment was performed, with an improvement of vas at t and t respectively of and in / cases. the remaining / patients did not show any improvement even after the second treatment and vas ranged from to at t . conclusions: chemonucleolysis with o -o mixture with periradicular and periganglionic technique under ct guidance is a reliable and competitive method in treatment of lumbosciatalgia. multiple in patients with malignant biliary obstruction of the hilum and unavailable bilateral access, drainage of biliary tree was obtained with one percutaneous access through which multiple stent deployment was performed with a cross-positioning technique. the first self-expandable endoprosthesis was positioned in the common bile duct. thereafter a balloon catheter was inserted along a previously introduced guide wire to dilate the mesh of the stent. after having removed the catheter, a second stent was implanted through the dilated wall of the first stent, across the hilum. overall stents have been cross-implanted. in patients stents have been inserted, in patient stents, in another patient cross-positioning of stents was required. results: no relevant complications have occurred. patient survival and stent patency rates were comparable with those of multiple-access stenting technique. the procedure is generally more protracted implying an increased radiation exposure for both the patient and the operator. conclusion: biliary stenting with one percutaneous access and cross-positioning technique is a useful procedure in all cases in which bilateral access in not possible. it reduces the risks connected to multiple passages of liver parenchyma though at the expense of a longer time of exposure for both the patient and the radiologist. results: in ( %) patients pain relief was complete within one to two days after injection. one ( %) patient with multilevel hemangioma failed to respond. we did not observe any complications. conclusion: percutaneous vertebroplasty is a promising therapy for patients with painful vertebral hemangiomas. this method is effective, with low risk of complications, and may be appliciable to asymptomatic cases as a preventive treatment. percutaneous a retrospective analysis was performed of percutaneous nephrostomies in patients ( male, female; age range: days- years). twenty patients had bilateral nephrostomies and patients were recatheterized. the procedures were performed with sonographic and fluoroscopic guidance under sedation or general anesthesia. the catheters ( . - fr) were placed either with a seldinger technique or an accustick introduction system. results: percutaneous nephrostmy catheters were placed due to up junction obstruction in patients, uv junction obstruction in patients, posterior urethral valve in patients, neurogenic bladder in patients, congenital anomalies in patients, trauma in patients, stones in patients, tumor in patient and renal insufficiency in patients. pyonephrosis was detected in patients. nine dislodged catheters were replaced percutaneously. all procedures were carried out successfully. no procedure related mortality was seen. one patient arrested right after the procedure because of methemoglobinemia due to local anesthetic and treated with methylene blue. no other major complications were detected. catheter dislodgement and infection were detected in and patients, respectively. duration of catheterization was between and days. all the catheters were removed after medical, surgical or percutaneous treatments. conclusion: image guided percutaneous nephrostomy in pediatric population is a safe and effective procedure with low mortality, morbidity and high success rates. percutaneous ct-guided facet screw fixation in lumbar spines: technical aspect h.y. kang, s.h. lee; seoul korea/kr purpose: to report our experience of the technique of percutaneous ct-guided facet screw fixation of cases in lumbar spines. the ct gantry has an angle tilt limitation of approximately . degrees, but the z-axis (coronal) angle of facet joints is about - degrees. thus under local anesthesia, positioning was head first, prone with cephalad elevation of upper body to compensate for the facet angle. after selecting the route of the procedure, the guide wire and fixed screws were inserted, after measurement of the size of fitting screw. this procedure was performed in patients, with combination of anterior lumbar interbody fusion (alif, patients) and cases of discitis ( patients). results: all procedures of facet screw fixation with alif were performed successfully, there were no definite malpositioning of screw or segmental instability on postoperative images at one month follow-up. in cases of discitis, the procedure were performed also successfully, but with more slightly decreased disc height on image at one month follow-up. the controlateral translaminar facet screw fixations were performed at the levels of l - and l - , and ipsilateral transfacet screw fixations were done at l -s level. conclusion: percutaneous ct-guided facet screw fixation in lumbar spines was a safe and reliable procedure for a method of spinal fusion. minimally invasive management of benign biliary diseases a. doros, v. weszelits, a. peter, a. nemeth; budapest/hu purpose: report our experience in treating percutaneously benign biliary strictures, fistulas, post-operative leakages, residual stones/sludge, bilomas and abscesses. in the last five years, patients ( women, men, - years) with benign biliary diseases were referred to our interventional radiology unit. twenty patients underwent laparoscopic or open cholecystectomy, six had residual stones, three had biliary fistulas. twenty patients had hepatico-or duodeno-jejunostomy stenoses, four had cholangitis-induced liver abscesses, and three had chronic pancreatitis. results: forty percutaneous biliary interventions were performed with good longterm results. strictures were dilated times. six metallic stents were placed into three patients. two plastic stents were placed in one patient with a rendez-vous maneuver. two fistulas were treated with drainage and glue. five stones were removed percutaneously with balloons or dormia baskets. one patient with chronic pancreatitis was treated with a metallic stent. another patient underwent insertion of three metallic stents for intrahepatic stenosis. of the four abscesses, two were surgically and one was percutaneously drained. one patient had two small abscesses treated with iv antibiotics. conclusions: percutaneous management is useful in selected benign biliary diseases. dilatation, stone extraction, and abscess drainage can be performed successfully. in difficult cases combined surgical, endoscopic and percutaneous approach must be chosen. role of aspiration-lavage in the treatment of abscesses in the gallbladder bed after laparoscopic cholecystectomy a.b. stoian, z.a. sparchez, r. badea; cluj napoca/ro purpose: the evaluation of the efficacy of ultrasound guided aspiration followed by lavage with antibiotics in the treatment of gallbladder bed abscesses after laparoscopic cholecystectomy. materials and method: patients with gallbladder bed abscesses were treated percutaneously between - . the abscesses were located in gallbladder bed with extension into subhepatic area % ( / ). the volume of aspirated pus was - ml (average ml). the first step of the treatment was the abscess puncture by a transhepatic % ( / ) or another approach % ( / ) using an g needle ( . mm). after pus aspiration, the cavity was washed - times with a metronidazol + ampicillin solution, the amount of antibiotics once injected being half the amount of the aspirated pus. oral or iv antibiotics (corresponding to antibiogram) were administrated for - days. in the case of fluid reaccumulation the treatment was repeated. background: ptpe is a reliable tool to induce liver regeneration of the nonembolized lobe. this facilitates extended right resection in e.g. klatskin tumor, hcc or liver metasases. between and we performed ptpe. in three cases we noted a failure in regeneration of segment ii + iii but a growth of segment iv after right lobe embolization. in portal vein ligations which regularly spare segment iv the regenerative outcome was significantly reduced compared to ptpe including segment iv. procedure details: in / patients we use a subxiphoidal access to puncture the left portal vein under us-guidance, otherwise a transhepatic right intercostal access. via f guiding catheters a . f microcatheter is placed in each segmental branch in order to apply - ml histoacryl-lipiodol solution in total. segment iv branches are difficult to reach because of the configuration of the rex recessus anatomy. since the left lateral segments lie adjacent, the emolization of segment iv is critical and has to be performed with the utmost care to prevent spill over of embolzation material. conclusion: segment iv turnes out to be the key for optimal portal vein embolization results. although bearing the risk of embolization material displacement to segment ii and iii the better results clearly suggest application of this technique. . palliation of duodenal obstruction via trans-oral route (n = ) and trans-gastric route (n = ). procedural details and results: for group and , and the trans-oral route in group , the technique is essentially an extension to the well established technique of oesophageal stenting of malignancy (except longer wires and catheters are used when more distal stenting is required). as more distal lesions are tackled, the intrinsic difficulty of manipulating long wires and catheters increases and gives way to the more direct transgastric route approach of group . this is also an extension to the well established technique of radiological insertion of gastrostomy using t-bar fixation. failure of insertion occurred in patients in the duodenal obstruction group via the trans-oral route. there were no immediate or delayed complications and no re-interventions were required. five patients ( %) returned to normal diet, patients managed semi-solid diet ( %) and patients ( %) had no significant improvement post stent insertion respectively. the mean survival for groups ( ) and ( ) (i.e. primary carcinoma) was days (range to days). conclusion: radiological placement of gastroduodenal stents is effective for palliation of upper gi malignancies. impact of multi-detector-row-ct ( x) prior to angiographic intervention m.s. juchems, s. pauls, h.j. brambs, a.j. aschoff; ulm/de learning objectives: to demonstrate the additional impact of contrast enhanced multi-detector-row-ct angiography (mdr-cta) compared to digital subtraction angiography (dsa) for planning of angiographic intervention. backround: in selected cases a pre-interventional cta can be useful to facilitate angiographic intervention. we selected four patients with different disease entities (pulmonary av malformation; bleeding caused by hepatic aneurysmosis and from renal pseudoaneurysm after partial renal resection; hepatocellular carcinoma (hcc) prior to transarterial chemoembolization (tace) with aberrant arteries) from our collective who underwent cta prior to angiographic intervention. procedure details: all ct scans were performed using a channel multi-detector-row-ct (philips mx idt). both multiplanar reconstructions (mpr) and slab maximum intensity projections (slab mip) were performed. after cta, patients underwent angiographic intervention (coil embolisation in the first three, tace in the last case). mdr-cta can demonstrate the exact extent and localize multiple vascular malformations, as demonstrated in the first case. in addition, mdr-cta can not only find the cause of hemorrhage but also demonstrate the exact localization of the specific vascular pathology ( nd and rd case). these findings facilitate the intervention, resulting in decreased in three children, a renal artery stenosis between and % due to fibromuscular dysplasia was discovered. in two of these three, the stenosis was unilateral and in one bilateral. in the remaining child, a long stenosis of unknown etiology was discovered. procedure details: in all patients, ptra was performed after having exactly defined the morphology and the hemodynamics of the renal artery stenoses. in three children we have achieved very good. results: ptra was successful resulting in an increased diameter of the arterial lumen. ptra was repeated and unsuccessful in one child with a severe stenosis and an emphasised "recoil" phenomenon. autotransplantation was therefore performed. reference is made to current controversies on this issue. background: endoluminal repair is an acceptable treatment modality for abdominal aneurysms. implant selection is based on the aneurysm's neck anatomy, resulting in two main implant groups; those fixed above the level of the renal arteries, and those fixed below this level. each group presents advantages and disadvantages that should be considered in the selection process. type i endoleaks are the most common complications derived from implant selection. procedure details: in order to select the implant, the patient should undergo a contrast-enhanced abdominal ct scan with coronal reconstructions to image in detail the abdominal aorta, and measure the size of the aneurysm, the distance from the renal arteries to the upper border of the aneurysm, and several other measurements needed. alternatives are abdominal aortic dsa and mra. the two main features that will determine the fixation site are the neck's shape and distance. sealing is always infrarenal. suprarenal devices provide better fixation, although some series report small renal parenchyma infarcts, due to emboli. infrarenal devices are easier to handle, provide for small corrections one placed, but cannot be placed in tortuous necks. conclusions: two main implant groups are used in endoluminal abdominal aneurysm repair, the suprarenal and infrarenal fixation devices. proper patient selection is needed to decide which device is to be used, in order to minimize post-procedural complications. in-vivo transcatheter implantation of a new aortic stent-valve for the temporary relief of acute aortic insufficiency m. hashimoto , t. kaminou , p. haage , y. ohuchi , k. nakamura , k. sugiura , y. noishiki , r.w. günther , t. ogawa ; yonago/jp, aachen/de, yokohama/jp purpose: acute aortic regurgitation is a life-threatening condition, particularly when associated with type a aortic dissection or aortic ectasia. the aim of this animal study was the evaluation of a novel temporary stent-valve as a potential temporizing measure to prevent progression to sudden death until conventional surgical repair can be performed. an umbrella-shaped highly porous polyester mesh valve was placed in the subcoronary portion with the attached metallic stent fixed in the ascending aorta. the prosthesis (stent-valve) was implanted in pigs via the right carotid artery through an fr introducer. the efficacy of the valve was assessed by aortography, pressure measurement and electrocardiography. hour after the implantation, the animals were killed and the stent-valve was subjected to macroscopic examination. results: a severe peri-prosthetic leak and cardiac arrest due to the deep implantation of the stent-valve were seen in case. although, a few premature ventricular complexes were seen in and slight blood stagnation in the valsalva sinus was seen in two, excellent performance of the mesh valve was demonstrated in of cases. there was no significant thrombus formation inside the umbrella valve. the presented new temporary stent-valve shows promise for possible future clinical application. further studies are necessary to assess valve thrombogenicity and coronary flow. percutaneous ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) with hepatic posttransplantation biliary complications who required treatment with interventional radiology techniques. were pediatric patients and were adults. diagnostic percutaneous transhepatic cholangiography (ptc) was performed in all patients, followed by placement of an internal-external biliary drain in the same procedure. in patients presenting with stenosis in the area of the anastomosis, dilatation with balloon angioplasty was also carried out. in patients with biliary calculi, lithotomy was performed followed by expulsion of the calculi to the digestive tract. one patient presented with a massive biliary leak that did not respond to percutaneous drainage and required implantation of a metal prosthesis. results: the transhepatic approach was used for the diagnostic study, for locating the cause of the complication and to carry out the therapeutic maneuvers required for its resolution. in the patients studied, the initial outcome of percutaneous treatment was satisfactory ( % technical success) and in of them ( %) it was the definitive therapeutic measure. among the remaining patients, underwent surgical re-anastomosis and re-transplantation. drainage placement was beneficial in all patients, allowing elective surgical treatment once the infectious-obstructive complication was resolved. conclusion: interventional radiology plays an important role in the therapeutic management of hepatic post-transplantation biliary complications. ptc allows precise early diagnosis of the complication. the interventional technique reduces the need for reoperation, thereby reducing associated morbidity and mortality. a comparative study of transjugular intrahepatic portosystemic shunt and transcatheter sclerotherapy for gastric varices t. ninoi , k. nakamura , n. nishida , y. sakai , t. kitayama , m. hamuro , r. yamada , y. inoue , t. kaminou ; osaka/jp, yonago/jp purpose: the rupture of gastric varices (gv) is a serious complication in patients with portal hypertension. transjugular intrahepatic portosystemic shunt (tips) and transcatheter sclerotherapy (ts) are effective treatments of gv. the effects on the portal pressure completely differ in tips and ts. however, to our knowledge, no comparative study of the two treatments for gv has been reported. the purpose of this study was to compare tips with ts on gv bleeding and survival. materials and methods: a total of cirrhotic patients with gv underwent endovascular treatment. of the patients, without hepatocellular caricinoma were enrolled in this study; patients were treated by tips, and patients by ts. gv bleeding and survival rates were compared between the tips and ts groups. multivariate analysis was used to identify the prognostic factors for gv bleeding and survival. results: the cumulative gv bleeding rate at year was % in the tips group, and % in the ts group (p < . ). the prognostic factor associated with gv bleeding was the treatment method. the cumulative survival rates at , , and years, were %, %, and %, in the tips group, and %, %, and %, in the ts group, respectively (p < . ). the prognostic factors for survival were the treatment method and the child-pugh classification. conclusion: ts may be more useful for gv than tips in consideration of gv bleeding and survival. results: tpsae was technically feasible in all patients without procedure-related complications. despite significant higher injury grade ( . vs ), higher rate of active contrast extravasation ( % vs %) and higher amount of hemoperitone-um on ct, secondary bleeding rate requiring splenectomy was lower in the tp-sae group ( . % vs %). conclusion: tpsae is a feasible and safe procedure in the treatment of splenic injury. tpsae allows a non-operative management despite a selection of severe splenic injuries with one of the lowest reported secondary splenectomy rates. recanalization of acute vertebro-basilar occlusion by a coronary waterjet thrombectomy device t.e. mayer, g.f. hamann, h. brueckmann; munich/de purpose: with a death rate of more than %, vertebrobasilar thromboembolism still remains a dangerous disease. this high rate can be mainly attributed to the overall failure of recanalization of %, depending on the extensiveness of the clot. this is especially in multisegmental occlusions, where the recanalization rate is very low and mortality is about %. we investigated the feasibility of using a coronary mechanical device based on the bernoulli effect (angiojet) for rapid recanalization. methods: ten patients with acute vertebrobasilar occlusion were included in the pilot study. inclusion depended on the presence of multisegmental intracranial ( patients) or any extracranial occlusions and coma lasting no more than hours. local intra-arterial fibrinolysis had failed in two patients before the angiojet was used, and thrombolysis was administered to two patients afterwards (rt-pa). five patients underwent additional intracranial balloon or stent angioplasty, and five received platelet inhibition by tirofiban. results: treament was primarily done with the angiojet and succeeded in complete recanalization in % of the patients ( % of the vessel segments). addition of fibrinolysis resulted in success in % of patients and segments. three hemorrhages were associated with additional thrombolysis, tirofiban, or both. seventy percent of the patients survived, and % had moderate to excellent outcome. the use of the coronary angiojet in the vertebrobasilar system is feasible. a success rate of % recanalization was achieved in a pilot study. compared to historical data of multisegmental thrombosis, the death rate was cut in half and good neurological outcomes increased. experience of transradial and transulnar abdominal angiography and intervention t. sato, m. kajikawa; hiroshima/jp purpose: in coronary angiography and angioplasty, transradial and transulnar approach has currently been accepted as an alternative catheterization method to transfemoral or transbrachial approach. the purpose of this study was to report practical and clinical applicability of these methods in abdominal angiography and intervention. methods and materials: between february and august , abdominal examinations were tried transradially or transulnarly in cases. cases were for liver or gall bladder tumor, cases were for other abdominal tumors, cases were due to gastrointestinal bleeding, cases were for renal or superior mesenteric arterial thrombosis and case was for ulcerative colitis. examinations were with further intervention. cases were examined twice, cases were examined times, case was examined times, cases were examined times, case were examined times and cases were examined times during this period, transradially. results: radial puncture was failed in examinations ( . %) and changed to brachial puncture. in cases with weak radial pulsation, ulnar puncture was tried. in cases of hepatocellurar carcinoma, superselective catheterization was also available and transarterial chemoembolization was done. in cases of abdominal branch aneurysm, successful coil embolization was done in cases and a femoral approach was needed on another occasion for complete embolization in one case. no puncture site hematoma was seen. radial arterial stenosis was found in cases at the next examination. no cerebrovascular problems were noted. conclusion: transradial and transulnar approach are alternative catheterization methods even in abdominal angiography and intervention. pre-and post-operative ct scans before discharge, at , , months and biannually thereafter were performed; pla and pima were evaluated in each followup scan and the number of pla was counted.these data were correlated with the frequency of el-ii. pre-and postoperative volumes of the aneurysmal sacs were measured from ct data. results: median follow-up was months (range - months).in total ct scans were performed and analyzed. six months after stent-graft implantation pima and/or at least pla were seen in patients ( . %); patients ( . % of the study cohort) had an el-ii. no el-ii was seen in patients without pla/ pima. three groups were identified and compared: patients without pla/pima/ el-ii and patients with pla/pima with/without el-ii. a tendency to minor mean volume loss in patients with pla/pima and a significant trend to volume increase in patients with el-ii in later follow-ups was seen. conclusion: there is a high incidence of pla/pima in patients after evr. persistent lumbar and inferior mesenteric artery perfusion is associated with significantly higher el-ii rates after evr of aaa. significant differences in volume changes in later follow-ups were seen between patients with or without el-ii. chemoembolization of hepatocellular carcinoma in candidates for orthotopic liver transplantation: histopathologic findings s. terraz, p. majno, l. rubbia, p.-a. schneider, c.d. becker; geneva/ch purpose: to evaluate the effects of selective transarterial chemoembolization (s-tace) in patients with suspected hepatocellular carcinoma (hcc) before orthotopic liver transplantation (olt). materials and methods: candidates for olt, with viral or alcoholic cirrhosis and a total of nodules suspected to be hcc ( - nodules of . - . cm), underwent s-tace with doxorubicine/lipiodol in - sessions. catheter position was segmental or subsegmental in % and unilobar in %. particles were added unless complete stasis was observed. the delay between s-tace and olt was ( - ) days. histologic findings of the explanted livers was correlated with all clinical, biologic and radiologic parameters. results: based on the final diagnosis, nodules were hcc, five were regenerative nodules and one was focal nodular hyperplasia. we observed total or neartotal necrosis (> %) in ( . %) hcc nodules and no dissemination was present. twenty-three hcc ( . %) nodules were partially necrotic; in of these, capsular and/or vascular invasion were present. one patient developed a pseudoaneurysm at the puncture site; no other complication was observed. conclusion: s-tace leads to complete necrosis in the majority of hcc nodules. olt candidates with a long waiting period should be followed by repeated imaging studies, in order to be able to prevent tumor regrowth or spread by repeating s-tace when necessary. kasabach merritt syndrome: treatment with transarterial embolization k.s. malagari, d. antonopoulos, d. loggitsi, d. danassi, a. rigopoulou, a. sissopoulos, a. nikita, g. papaioannou, d. kelekis; athens/gr aim: kasabach merritt syndrome is a rare life threatening condition characterized by consumption coagulopathy, most often associated with liver hemangiomas. we report on the value of transarterial embolization in the treatment of this condition. material and methods: two patients are included in the study (mean age yrs, range - ). both were women. kasabach merrit was the first manifestation of the liver lesion in one patient and a complication of a known cavernous liver hemangioma in the second. hct values were % and %, plt , and , / mm , fibrinogen and mg/dl respectively. spiral ct of the liver showed typical hemangiomas with a lace-like enhancing pattern (mean diameters and cm respectively). patients were infused with platelets, fresh plasma, cryoprecipitates, aprotinin and antithrombin prior to embolization. one patient required also units of packed red blood cells. selective hepatic angiography was performed prior to embolization, followed by superselective injection of the feeding vessel(s). microspheres of - microns were injected under fluoroscopic guidance until cessation of flow. the procedure was uneventful in both patients. partial restoration of plt cell count was observed from the following day and within a week fibrinogen levels and plt levels were completely restored in one patient and partially to the other. conclusions: transarterial embolization may be life saving in kasabach merritt since it can safely control coagulation abnormalities and allows planning for more definitive treatment including surgical resection or liver transplantation for non operable hemangiomas. in vivo characteristics of microspheres injected into the hepatic arteries of rabbits: angiographic and microscopic comparison of embosphere and beadblock m. takahashi, y. saida; tsukuba/jp purpose: the authors presently utilize non-resorbable microspheres (ms) for the transarterial embolization (tae) of hepatocellular carcinoma (hcc). to correlate their clinical features and in vivo characteristics, two different types of industrially-produced ms, injected into the hepatic arteries of rabbits, were microscopically compared. eight japanese-white rabbits were divided into four groups. hepatic arteries were selectively catheterized by the femoral approach. in each group, lipiodol, embosphere ( - and - µ) or beadblock ( - µ) were injected. ms were prepared as a ml suspension with contrast material, in which ml ms were contained. animals were sacrificed immediately after the injection. the liver was excised with ligation of all major vessels. sections were made in the radiate plane along with hepatic arteries. results: lipiodol spread into the hepatic sinusoid and reached the central veins. they were found also in the peribiliary plexus (pbp). ms reached maximally glisson's sheath but was not found around the pbp nor the sinusoids. embosphere occluded the artery after an injection of some milliliters. microscopically they were often clustered and compressed but their spherical shape was maintained. smaller embosphere penetrated deeper than larger one. beadblock once occluded the artery with a smaller amount of suspension than embosphere. after a few minutes, however, the arterial flow resumed and additional injections were possible. microscopically they formed casts and tend to reach deeper tissue than embosphere of the same size. conclusion: embosphere is elastic but robust, while beadblock is plastic, forming casts in the vessel. these characteristics explain much of their features at the time of injection. the at another patient hours after the implantation the rupture of common femoral artery aneurysm was stated. there were also observed certain post-hospitalization complications which included: a) clotting of stent-graft leg in cases b) leak type i which demanded implantation of additional element of stent-graft in one case c) small leaks type i in cases and type ii in cases which did not demand any further intervention-the type ii leaks were observed in cases months after the operation d) the increase of parietal circular thrombus inside the main part of the stent-graft in two cases e) complaints connected with the internal iliac artery occlusion were declared by patients. the catheter has four microsurgical blades that cut directly into the stenotic plaque during inflation. recently they were proposed for the use in peripheral arterial system using a balloon diameter raging from up to . mm. material and methods: seven consecutive patients (mean age years) were treated with cutting balloon pta (cb-pta) from june until september . all of them had severe multiple, calcified stenosis of the femoro-popliteal artery, maximum cm in length, never treated before. all patients had important associated risk factors such as insulin-dependent diabetes mellitus, hyperlipoproteinemia and smoking. results: cb-pta was technically successful in all patients, with lumen diameter improvement at least of % or residual stenosis less than %; moreover we never observed major dissection of the intimal plaque and we never required stent placement. conclusion: cb-pta in lower limb calcified stenoses is a promising technique that seems to be superior to pta alone, without requiring stenting in femoropopliteal arteries. aneurysm diameter in all patients were > cm (average diameter were . cm, range, . - . cm). the mean follow-up was months. average hospital stay after the intervention was - days. results: the stent-grafts were successfully deployed in all patients. control spiral ct hours after the procedure revealed endoleak in patients ( . %). spiral ct follow-up on th day following the intervention showed that in patients endoleak spontaneously stopped and in one patient small endoleak was seen, but it also stopped within a month following the intervention. in two patients ( . %) acute thrombosis of iliac graft extensions was diagnosed a month after the intervention. in both cases successful endovascular thrombolysis was performed with good clinical outcome. in one patient ( %), progression of atherosclerotic disease resulted in migration of the stent-graft two years after the placement of the graft. reintervention was done with successful deployment of additional aortic extension of the stent-graft. average reduction of aneurysm diameter was . mm (range, - mm). conclusion: endovascular treatment of aaa with talent stent-graft is a safe and effective procedure. in patients with well defined indication it is safe alternative to open surgery procedure. direct thrombin injection for non-femoral pseudoaneurysms r. corso, m. solcia, m. castoldi, r. vercelli, m. intotero, a. rampoldi; milan/it purpose: percutaneous thrombin injection under sonographic guidance has been shown to be an effective and well tolerated treatment for a iatrogenic femoral pseudoaneurysms. for these reasons some authors suggest thrombin injection as alternative treatment also in other body districts. we illustrate our experience, techniques and results in the ablation of pseudoaneurysms of different etiologies and locations whit direct thrombin injection. materials and methods: from june we treated six patients, age range - years, affected with pseudoaneurysms developed after iatrogenic trauma in three patients (arising from radial, posterior tibial and thoraco-acromial arteries), post-pancreatitis (splenic and superior mesenteric arteries) in two patients and in one patient after spontaneous rupture of renal angiomyolipoma in tuberous sclerosis. two patients were anticoagulated. the diameter of pseudoaneurysms varied between . - . cm. after disinfection of the entry site, we slowly injected bovine thrombin ( u/ml of solution) percutaneously under ultrasound guidance in four cases, while in two cases we injected directly the thrombin in the pseudoaneurysm cavity with a fluoroscopically guided endovascular angiographic catheter. results: all interventions were successful and showed no immediate or late complications. doses of thrombin needed varied between - units ( . - ml of solution). a complete thrombosis of the pseudoaneurysm sac was accomplished within minutes of thrombin injection. no recurrence was seen at the follow-up. conclusion: in selected cases, direct thrombin injection may be useful in treating non-femoral pseudoaneurysms resulting in rapid and persistent occlusion. in our limited experience it represents a safe and effective minimally invasive technique and an alternative to surgical repair. the purpose: bronchopulmonary sequestration is a combined lung and vascular anomaly witch is usually surgically treated. in those cases witch the anomaly is mostly vascular, coil embolization is a safe alternative to surgery. method and materials: coil embolization of intrapulmonary sequestration was performed in three adult patients, two of them admitted with hemoptysis and the third one with low left thoracic pain and fever. the initial diagnosis was made by ct and confirmed with angiography. we embolised the feeding arteries using coils (from to mm, cook). angiography after embolization indicated almost complete occlusion and all patients were discharged the next day. results: there were no immediate nor long term complications. follow-up ct was performed six months and one year later, at witch time there was complete occlusion of the anomalous artery. all patients are asymptomatic at present. conclusion: arterial embolization of intrapulmonary sequestration with a predominant vascular component, is a less invasive method of occluding the anomalous artery in selected patients and is a safe alternative method to surgery. emergency endovascular repair of ruptured hepatic artery pseudoaneurysm with coronary stent-graft: two cases a. park; pusan/kr purpose: to report two cases of successful emergent endovascular treatment of ruptured pseudoaneurysm from the hepatic artery using balloon expandable coronary stent-grafts. materials and methods: case . a -year-old male underwent whipple's operation for a cholangiocarcinoma in the distal common bile duct, but his postoperative course was complicated by serious blood loss from a ruptured pseudoaneurysm in the common hepatic artery. using premounted coronary stent-grafts (jostent, jomed, germany), the neck of the aneurysm was completely excluded. case . a -year-old male underwent surgical treatment of a klatskin's tumor and hepaticojejunostomy. four weeks later, an episode of gastrointestinal bleeding prompted celiac angiography. active bleeding from a small pseudoaneurysm in the right hepatic artery was controlled with endovascular deployment of a premounted coronary stent-graft (jostent, jomed, germany). the final angiogram demostrated a total exclusion of the aneurysm with preservation of the arterial lumen. results: transcatheter embolization using a variety of embolizing materials has been considered the treatment of choice for true or false hepatic artery aneurysms. however stent exclusion of the hepatic artery bleeding in an emergent situation has been reported only in few cases. for patients with a compromised blood supply due to portal vein occlusion or exclusion of important collateral pathways by surgical operation, a stent-graft may become the procedure of choice. in emergent situations of hepatic artery bleeding, endovascular implantation of a stent-graft may be an alternative procedure to transcatheter embolization or surgical repair. materials and biomaterials for interventional radiology t. hasebe , a. shimada , t. suzuki , y. matsuoka , h. yoshimura , s. kuribayashi ; tokyo/jp, sagamihara/jp, hiyoshi/jp learning objectives: . to describe the most often used interventional devices (id) benefiting from the recent intensive research activity to improve their functionality or their biocompatibility. . to provide an update on the current status of new materials and biomaterials available in the field of vascular and non-vascular interventional radiology, including our original experimental data . to discuss the importance and the safety issues related to the use of biomaterials and coating materials concerning id. background: in the past decade, interventional radiology has allowed percutaneous access devices and therapeutic implants to be more reliable and effectively used due to the availabiliity of new materials. currently, there are several passive or active stent coatings commercially available with good results in preliminary studies. these materials more often result from industrial research and less frequently from medical research. procedure details: in this paper, we discuss biomaterials currently available for use, together with new biomaterials for the vascular or non-vascular id, such as, for example, the drug-eluting stents, coils for embolization, and biliary/ureteral catheters or stents. finally, we discuss the future of biomaterial use in interventional radiology with the original data in our laboratory (e.g., antithrombogenic and biocompatible stent coating: diamond-like carbon). conclusion: biocompatible issues are very critical for id in order to coexist with living tissue without causing harm. considering the recent advances in new materials with biological effects, we believe the biomaterials will soon constitute a new core of interventional radiology. the radiologists should establish new research domains and complete new and effective products. clinical usefulness of a unified multidetector-ct we can always generate a control image during intervention without repositioning the patient. we have performed highly integrated imaging diagnosis and interventional therapy with this system in more than patients. procedure details: angiography assisted multidetector-ct was performed for the diagnosis and the target therapy of hepatic, pancreatic, adrenal and renal tumors and uterine myomas. in addition, multidetector-ct assisted angiography and interventional therapy was performed for vascular recanalization, such as aortic and peripheral vascular stent therapy; for endovascular treatment of aneurysms and for percutaneous therapy of varices, with a variety of three-dimensional reformatting techniques. we also performed several interventional procedures, such as percutaneous biopsy, biliary and abscess drainage, with this system. conclusion: we introduce our highly integrated intervetional ct system with technical merits to clinical use. background: ct is the imaging method of choice to evaluate hemodynamically stable patients with significant blunt abdominopelvic trauma. contrast enhancement is essential for the diagnosis of many visceral injuries in these patients. it has been demonstrated that contrast-enhanced ct is valuable in the detection of active extravasation of contrast material. the detection of contrast extravasation is critical because it indicates an ongoing, potentially life-threatening hemorrhage. imaging findings: the purpose of this exhibit is to review our experience with active contrast extravasation in patients with blunt trauma to the abdomen and pelvis. findings of contrast-enhanced ct are correlated with those of conventional angiography. the role of angiography and transarterial embolization in patients with active extravasation on contrast-enhanced ct will be discussed. conclusion: contrast extravasation on ct can be used to localize anatomic sites of hemorrhage and to guide immediate angiographic or surgical intervention in patients with abdominopelvic trauma. state-of-the-art ct enables a more detection of contrast extravasation than is possible with conventional and single detector helical ct. for the presented in vitro study, peas (mean diameter . mm) were embedded within a gel-phantom in order to simulate small target lesions. positional data of the patient and of the needle guide mounted to the robot arm were acquired via an optical tracking system (ndi polaris). a preliminary ct calibration procedure allowed assignation of d coordinates to each d pixel of the particular ct scan for fast and accurate intervention planning. the best needle trajectory was defined graphically by simply selecting skin entry point and target point -appropriate position and angulation of the robotic arm were calculated and sent to the robot controller. after confirmation of the planning, the robot moved to the start position using different modes of motion. the coaxial biopsy was performed manually using a -gauge puncture needle, combined with an -gauge biopsy needle and an automated biopsy device. the complete intervention could be monitored and documented by means of superimposed information on the actual ct scan. to prove efficacy of biopsy the length of the harvested specimen, as well as the distance between actual needle tract and centre of the lesion was measured. results: biopsy specimens were successfully obtained from all targets with only one needle pass necessary. radial distance between needle trajectory and centre of the target was surpassing clinical requirements. conclusions: robotic assisted biopsies with high accuracy were feasible using ct guidance. a new laser guidance device for ultrasound guided percutaneous biopsy a.e. samir, j. koukounaras, p. u, a. moorhouse, m. brooks; melbourne/au introduction: ultrasound guided needle placement is usually performed by inserting a needle along a path in the plane of the ultrasound beam. this permits visualisation of the needle in "real time", allowing accurate needle placement. a novel laser guidance device that facilitates needle placement during ultrasound guided biopsy is presented. methods: a laser module was constructed by mounting a laser diode in a nylon tube. a lens was used to transform the pencil laser beam into a linear alignment beam. the laser module was mounted on an ultrasound probe using a customdesigned clip that consisted of two polycarbonate half shells. the linear laser beam was calibrated to be coplanar to the ultrasound beam. no probe modifications were necessary. fourteen biopsy operators performed eight free hand and eight laser guided biopsies each of capsicum-stuffed olives suspended in gelatine phantoms. endpoints measured were: ( ) time to biopsy, ( ) sample quality and ( ) perceived usefulness. the laser beam was visible on the surface of needles ranging from to gauge in size. when the needle was inserted colinear to the laser beam it was visible on the ultrasound image. a significant difference in procedure time or sample quality was not observed. however, % of operators stated that laser guidance had a positive effect on the procedure, and % said that they would use it in the future. conclusion: a probe-mounted laser guidance device is perceived to facilitate accurate ultrasound guided needle insertion by the majority of operators in a pilot study. planning of the intervention is on basis of ct-imaging data sets acquired immediately before an intervention. spatial relation between imaging space and targeting device is either established by using of an optical tracker system or via robot registration based on a ct data set. after graphically selection of the target point and manual pre-positioning of the device, correct needle angulation will be set automatically by the system. during the intervention, the robot kinematic holds the needle guide in a defined position/ orientation to the patient's body -needle insertion will be performed manually by the physician. results: the developed system is easy-to-use and does not interfere to the clinical work-flow. system accuracy and clinical relevance currently is being tested in a series of in vitro tests. the designed and realized prototype of a modular automated needle guide allows positioning of a biopsy needle based on an intra-operatively planning with good cost/benefit ratio. effect of radiotherapy and ischemia on rat liver z. vigvary, p. kupcsulik, a. szijartó, o. hahn; budapest/hu aim: the aim is to create a model of a liver resection combined with intraoperative irradiation for micrometastases. this combined ischemic-reperfusion and irradiation injury of the liver has not yet been investigated. methods: normothermic segmental liver ischemia were created on - g male wistar rats. rats were divided into four groups for , , and minutes of ischemia. hepatic microcirculation was studied by laser doppler flowmeter. histological alterations were followed. i, ii, iv lobes were exposed to , and gy of cs- ã-radiation. alp, alt, ast, ldh, bilirubin and tnf-á tests were performed. results: reperfusion was assesed by post-ischemic flux plato maximum (pm), by area under the curve (rt) and by the time to maximum flux level (rmi). flowmetery showed a nonlinear fashion of reperfusion according to ischemic period. after and minutes ischemia the rate of the reperfusion is almost the same. minutes of ischemia represents an intermediate lesion in term of recovery. after minutes, minirapid deterioration of flux (below % of control) was observed. survival is rather determined by the length of the ischemic period, than the irradiation dose. low dose irradiation ( gy) with short-term ischemia ( min) did not result in increased liver enzymes and resulted only in minimal histological changes. the group of gy irradiation with normotherm, short-term ischemia seems to be tolerable for the tumor-free liver. conclusion: liver toleratse irradiation injury suprisingly well and preconditioning promotes restitution of liver circulation after ischemic injury. purpose: the aim of the study was to assess radiation exposure to the radiologist incurred with ct fluoroscopy. the spectrum of indications and radiation exposures for the radiologist were assessed for an -month period. scatter exposures were measured with and without radiation protection devices: without and with placement of a lead drape on the patient, with and without use of thin rubber radiation protection gloves. in addition, scatter radiation was determined for a combination of lead drape and radiation protection gloves. results: there is a wide variety for the use of ct fluoroscopy ranging from diagnostic biopsy procedures to therapeutic interventions such as radiofrequency ablation of liver metastases and ct fluoroscopy-guided osteosynthesis of fractures. scatter exposure rates to the hand of the radiologist ranged from to micro sv per case without use of a lead drape and radiation protection gloves. the lead drape reduced the scatter exposure to the hand of the radiologist by percent. radiation protection gloves reduced scatter radiation by percent. the combination of both radiation protection devices was most effective in decreasing the dose by percent. conclusion: ct fluoroscopy is a useful targeting method with a wide variety for interventional procedures. however, significant radiation exposures may occur. therefore, the radiologists should be aware of different techniques of ct fluoroscopy guidance and the methods to reduce scatter radiation. purpose: workforce planning, deskilling scenarios and risk containment are generating a need for interventional training processes remote from patients. fixed models lack ultimate realism, and animal models lack pathology with political problems in the uk. virtual environments for interventional needle puncture training require accurate haptics, based on force relationships between tools and tissues, and visualization. to achieve this demands advancements in tissue segmentation, assignment of tissue properties and generation of synthetic images from abnormal patient anatomy and pathology. these challenges require wideranging expertise and will probably take over a decade to achieve fully. no existing simulator model covers interventional radiological needle access procedures (eg: targeted biopsy, nephrostomy, biliary and abscess drainage). thus a substantive collaboration is essential to develop appropriate virtual training environments. internet search highlighted key development areas and, together with conventional networking, relevant departments and individuals were located with major involvement in medical simulations. results: the craive collaboration was established and comprised interventional radiologists, computer scientists, physicists, clinical engineers and psychologists. the key challenges of interventional procedures have driven specific proposals for accurate representation of haptics, from measured in vivo forces, within imaging-derived, immersive, simulated environments. conclusion: achieving effective simulator modeling for training and rehearsal requires research advances and further development in the underlying technologies. while currently beyond the scope of any research group or individual company, a substantive new collaboration, craive, aims to develop interventional radiological simulator models, initially based on a spectrum of interventional needle access procedures. and % (on low dose mode) reduction. image quality measurements were consistently superior ( % higher resolution in fluoroscopy and % in dsa) with significantly more low contrast iodine targets and moving wires detected and a larger dynamic range or working thickness range. the results of our first clinical investigations give further evidence for superior image quality. conclusions: on all modes, dose monitoring and image quality of the digital flat panel system compared favorably to the conventional image intensifier system. the results of our first clinical investigations on image quality based on our routine daily practice will be presented. differential diagnosis of femoral head bone marrow edema pattern i. kalaitzoglou , p. papadopoulou , a.s. dimitriadis ; thessaloniki/gr, kavala/gr learning objectives: to present the imaging features which help in the differential diagnosis of the femoral head "bone marrow edema pattern". background: bone marrow edema of the femoral head is a non-specific mri finding associated with various painful conditions of the hip like osteonecrosis, idiopathic transient osteoporosis, transient bone marrow edema syndrome, migratory osteoporosis and stress fracture. a total number of approximately hip mri examinations were performed in three different diagnostic centers from january to july . bone marrow edema was present in cases. procedure details: mri units used ranged from . to . tesla and the examination protocols included t se and t fse fat-sat or stir axial and coronal images, while sagittal images and contrast administration were reserved for specific cases. patients with typical findings leading to the diagnosis of osteonecrosis or fracture were excluded. the remaining patients had non-specific bone marrow edema of the femoral head which was demonstrated as diffuse, ill defined, low signal intensity on t w images, high on t w and stir images, and extended to the femoral neck region. in half of the patients follow -up examinations were also available. we selected and present the imaging criteria, at presentation and follow -up, which can lead to an early specific diagnosis. conclusion: bone marrow edema of the hip has to be correctly interpreted in order to avoid overtreatment in transient and self-limiting conditions. the presence of subtle subchondral lesions and the temporal evolution are usually key to diagnosis. periosteal reactions: the spectrum of radiological appearances with histopathologic correlation i. pinilla, d. bernabéu, c. martín-hervás, a. alvarez, a. bravo, f. lópez-barea; madrid/es learning objectives: the aim of this exhibit is to illustrate the spectrum of imaging features of periosteal reactions with plain radiography, computed tomography (ct) and magnetic resonance imaging (mri) with emphasis in pathologic correlation. imaging findings: patients with histologically proved diagnosis of benign and malignant lesions in our institution between january and december were identified from the pathology data base. imaging findings with plain radiography, ct and mri were retrospectively reviewed and correlated with key pathologic features. the various patterns of periosteal reaction are arranged into the following categories: continuous (smooth, lobulated, and ridged shells, solid, single lamella, laminated or "onion skin", and parallel spiculated or "hair on end" reactions), interrupted (buttres, codman triangle, lamellated, and spiculated reactions), and complex (divergent spiculated or "sunburst", and combined reactions). the most representative cases of each form of periosteal reaction are displayed. specific topics addressed include benign and borderline bone tumors (osteoid osteoma, osteoblastoma, periosteal chondroma, aneurysmal bone cyst, giant cell tumor, langerhans cell histiocytosis, and adamantinoma), primary malignant bone tumors (osteosarcoma, chondrosarcoma, ewing's sarcoma and non-hodgkin's lymphoma), skeletal metastases, and non-neoplastic conditions such as osteomyelitis and myositis ossificans. the changes in the periosteum are common and important imaging features of bone diseases. recognizing and understanding the different radiological patterns and underlying histopathologic changes help the radiologist to narrow the differential diagnosis. this teaching exhibit gives an overview of the wide spectrum of radiological appearances of periosteal reactions together with histopathologic correlation. in mr images, spin-echo (se) t -weighted images (t -wi) and t -wi were obtained and gd-dtpa contrast enhanced images were obtained in cases. in these cases, the location, the radiographic findings, signal and enhanced pattern on mri were analyzed. imaging findings: in cases, the tumor located in epiphysis ( . %), in cases in apophysis ( . %), in cases in apo-metaphysis ( . %), in cases in epimetaphysis ( . %). in all cases, the tumor was depicted as radiolucent area and in cases, the sclerotic margin was recognized. in all cases, the tumor was revealed as iso-intensity comparing with surrounding muscle on t -wi. on t wi, in cases, the tumor revealed as iso-intensity with bone marrow and in the other cases, it revealed as low intensity. on t -wi, in cases, high intensity area was included which corresponds to the cystic degeneration. in all cases, the tumor was moderately enhanced on contrast enhanced t -wi. in cases, t -t -prolonged lesion which is considered to be the reactive inflammatory change were shown in the bone marrow around the tumor. conclusion: to analyze the image characteristics of chondroblastoma is important to approach the exact diagnosis of bone tumor. chondrosarcomas background: parosteal osteosarcomas represent only - % of all osteosarcomas, and have better prognosis than the classical osteosarcoma.they are frequently low-grade tumors, which may rarely dedifferentiate into high grade sarcomas. imaging findings: mr images performed on - . t mr system of histologically proven cases of parosteal osteosarcoma were retrospectively analyzed for the bones involved, location and the relationship between the signal intensity and the grade of the tumor.there were females and males. ages ranged from to (mean . ). most commonly affected bone was femur, on its distal end, posterior aspect ( ). histological grading was described as follows:grade i: hypocellular stroma with subtle atypia; grade ii: mild increase in stromal cellularity and more prominent cytologic atypia, grade iii: marked pleomorphism with high cytologic atypia and mitotic rate, also called dedifferentiated type. regarding the described grading above, of our cases were grade i (low), were grade ii (intermediate) and were grade iii (high). on mri, all of the parosteal osteosarcoma cases were of hypointense signal intensity on t -weighted images and were hyperintense on t -weighted images with no exception. on gadoliniumenhanced images, heterogeneous contrast enhancement was observed. conclusion: in our study, mri signal intensity was the same in all of the cases; hypointense on t -weighted images and hyperintense on t -weighted images; regardless of the grade of the tumor. giant cell tumor of knee: imaging findings of the most common site v. zampa, s. giusti, c. spinelli, s. ortori, c. bartolozzi; pisa/it learning objectves: . to describe imaging findings useful for an effective diagnosis . to discuss the main differential diagnosis with giant cell tumor (gct) of knee. background: gct is a relatively common skeletal tumor. it is a benign but locally aggressive and destructive lesion composed of primitive histiocytes and large, multinucleated giant cells. the most frequent symptom is pain, local swelling, limited range of motion and pathologic fracture ( %). location of gct and age of patients suggest the diagnosis. it usually affects long tubular bones and, in particular around the knee, the most common site is distal femoral and proximal tibia ( and % of all tgc). the main differential diagnoses include osteosarcoma (teleangectatic or fibrogenic), malignant fibrous istiocytoma, chondromyxoid fibroma and aneurysmal bone cysts. treatment of choice is surgical resection but recurrence is frequent. imaging findings: on radiography gct appears as an eccentric and geographic bone lysis, associated with a narrow zone of transition and lacking surrounding sclerosis. ct is superior to conventional radiography in outlining the extent of the tumor and in demonstrating cortical invasion but mr is currently the best imaging modality in determining extra-osseous extent, articular surface involvement and tumor recurrence with optimal definition of either osseous sclerosis or pseudocapsule. the signal characteristics of the lesion on the different mr sequences will be described to find out if they can help in differential diagnosis. conclusion: radiologic appearances of gct is important in allowing prospective diagnosis, guiding therapy, and facilitating early detection of recurrence. superscans: a pictorial review s.a. o'keeffe, t. geoghegan, w.c. torreggiani; dublin/ie learning objectives: the objective of this poster presentation is to pictorially describe the causes, findings and interpretative pathways of patients undergoing radionuclide bone scintigraphy resulting in a superscan. background: a superscan is a radionuclide bone scan which demonstrates markedly increased, homogenous skeletal radioisotope uptake relative to soft tissues and is usually associated with absent or faint renal images. a retrospective analysis of all whole body radionuclide bone scans performed over a fiveyear period was performed to identify the presence of superscans. analysis was based on review of reports identified on a computerised radiology information system (ris). images were reviewed in association with other relevant imaging and in select cases, with laboratory data and clinical notes. a variety of cases were then selected for this pictorial review. imaging findings: a total of whole body bone scans were performed in our institution in the last five years. superscans were selected for inclusion in this pictorial review. the vast majority of superscans identified were related to metastatic disease of which prostate cancer dominated. superscans were also identified secondary to hyperparathroidism, metabolic bone disease including osteomalacia and pagets disease. conclusions: in this pictorial review, we describe the patho-physiological pathways resulting in the appearances of a superscan. in addition, we pictorially demonstrate a variety of causes resulting in superscan. finally, interpretative pathways of analysis and helpful signs are suggested. usefulness of d reformations in the assesment of spondylolisthesis and spondylolisis of the lumbar spine e. vilar bonacasa, p. sanchez santos, j. torres nuez, g. martinez sanz; teruel/es learning objectives: to obtain images that provide a full and direct view of the pars interarticularis in order to determine the isthmal affectation in lumbar spondylolisthesis. background: nine patients with spondylolisthesis of the lumbar spine among sent to our department for ct study during the last year were performed a volumetric acquisition from l or l to s instead of the conventional axial scanning. later, a d image was obtained and modified in the work station, to achieve a view of the pars interarticularis from the vertebral canal. procedure details: using this method, we obtained images wich allowed us to asses the isthmal affectation in a direct way in all patients. moreover, it permits the study of the repercussion of vertebral bodies slide over the vertebral canal and the intervertebral foramina. conclusion: convencional ct has some limitations to determine exactly the type and degree of isthmal affectation in spondylolisthesis as well as its repercussion on intervertebral foramina. helical ct, using volumetric acquisition with three-dimensional reformations can resolve those limitations. morphology in these cases, the improvement of the skeletal pain were scored in five-levels by patients' interview from = marked improved to = worse and the duration of the symptom's improvement was monitored. results: a total of taes (mean . times) were performed. all procedures were technically successful. skeletal pain was relieved in patients ( %) between = slightly and = markedly improvement. in of patients with malignant lesions, the duration of pain relief ranged from one to months (mean months). no serious complications were observed except for a case with transient neurogenic bladder. conclusion: tae using sap-ms was a safe and effective treatment for the pain control with long duration of unresectable bone tumor. bone marrow edema at mri: diagnostic clue to the underlying cause of knee pain a. blanco, m. martinez, e. parlorio, m.a. corral, s. torres; murcia/es purpose: bone marrow edema (bme) is usually associated with traumatic injuries of the knee but there are other conditions, often unsuspected, that can cause this pattern. our purpose was to evaluate the patterns of distribution of bme in patients with knee pain and try to correlate them with their possible underlying cause. we retrospectively reviewed mri examinations of patients referred for knee pain, with or without history of trauma, during a month period. the examinations were performed in a . t unit using our standard protocol which included fluid-sensitive sequences. in some cases intravenous gadolinium was used. results: patients ( . %) showed bme with variable distribution, resulting from: acute trauma ( ), stress fracture ( ), degenerative disease ( ), spontaneous osteonecrosis ( ) and osteochondritis dissecans ( ) of the femoral condyle, soft-tissue infection ( ), excesive lateral pressure syndrome ( ), iliotibial-band friction syndrome ( ), transient bme ( ), tumor ( ), and nonspecific ( ). in many cases associated with trauma, the distribution of edema allowed to explain the mechanism of injury and predict with accuracy the soft-tissue abnormalities that may be present. conclusion: bme patterns at mri can help to establish the possible cause of knee pain. when there is a history of acute trauma, edema shows typical features that can give the clue to a possible mechanism of injury. on the other hand, if clinical data is not clear, the distribution of edema can orientate to other unsuspected pathologic conditions. appropriate recognition is necessary for an accurate diagnostic and therapeutic orientation. percutaneous percutaneous thermoablations was performed with radionics cool tip rf generator system by using probes with or cm unprotected tip applied for minutes in the center of the lesion. the procedure consisted of localizing the osteoid osteoma on ct imaging and positioning within the lesion a kirschner wire, rigged on a hand-drill device. once the nidus was engaged we proceeded to exchange the thread of kirschner for a rf probe and emit the radio waves. results: at a mean follow-up of months the treatment has been considered effective in % of the cases. in four patients pain has subsequently recurred; one of these cases has been treated for a second time with success. in two cases procedural complications of minor degree, represented by limited cutaneous burns have occurred. conclusion: in our experience ct-guided percutaneous radiofrequency treatment of osteoid osteoma proved to be effective in % of the cases. deprived of severe complications it may represent an uncomplicated, minimally invasive, rapidly effective procedure, alternative to the surgical treatment. order to obtain the load-to-fracture, the specimens were tested destructively at side impact. results: in the standard regions of interest, correlations between fracture load and bmd (bmc) ranged from r = . to r = . , p < . (r = . to . , p < . ). for the newly defined roi in the upper neck of the proximal femur, significantly higher correlations between bmd, bmc and fracture load (r = . and . , respectively; p < . ) were obtained. only a weak statistical relationship between fracture load and fnal was found (r = . , p < . ). normalization of fracture load with respect to fnal of the specimens did not significantly improve results. the mechanical competence of the hip highly depends on the bmd and bmc of the proximal femur. of all the regions of interest analysed in this study a newly defined roi in the upper neck showed the strongest correlation with fracture load. under in-vitro conditions, only a weak association between mechanical strength and fnal was observed. or secondary (n = ) diagnostics were analysed visually. the final diagnosis based on histology, imaging and follow-up. results: histologically the primary lesions were es (n = ), pnet (n = ) and osteomyelitis (n = ). the sensitivity and specificity of fdg-pet for disease (presence of et, and/or its metastases) were and % respectively. fdg-pet and/ or other imaging modalities detected altogether focal lesions. sensitivity and specificity regarding focal lesions were and %. this lower sensitivity is due to small lesions. wbs detected all primary bone lesions present at wbs investigation, but only of bone metastases in four patients, while fdg-pet detected both the primaries and metastases. conclusion: fdg-pet investigation is a valuable method in case of et-s. concerning the detection of bone metastases of et-s fdg-pet is superior to wbs, while for the depiction of small lesions mainly represented by pulmonary metastases fdg-pet is less sensitive than helical ct. the determination of the role of whole body fdg-pet in the diagnostic algorithm needs further investigations. the role of an optimized mr protocol in the detection of osteomyelitis neighbouring metallic bone implants g. michailidis , n. economopoulos , c. kontopoulou , s. argentos , n.l. kelekis ; piraeus/gr, athens/gr purpose: osteomyelitis presents as a complication in a percentage of patients after metallic bone-implant placement. early and accurate detection is crucial for proper treatment. conventional mr images are usually severely degraded from intense artifacts, rendering interpretation often impossible. we report our results using an optimized mr imaging protocol in detecting foci of osteomyelitis near metallic bone implants. materials and methods: during the last year we examined patients ( men and women, age range - ) with metallic bone implants and clinical suspicion of osteomyelitis. the mr protocol consisted of t -weighted stir and single shot turbo spin echo sequences. for t and t contrast-enhanced images we employed turbo spin echo sequences with slice thickness of mm, echo train length > , minimum echo spacing and minimum te. diagnosis of osteomyelitis was based on the detection of one or more of the following findings: subperiosteal fluid, bone sequestrum, fistula and abscess. results: all mr examinations were of diagnostic quality with minimal artifacts present. in patients one or more of the above mentioned findings were present and were diagnosed with osteomyelitis. in the remaining patients no findings suggestive of osteomyelitis were observed. confirmation was obtained by followup and clinical outcome. conclusion: with the use of an optimized scanning protocol mri may overcome its limitations caused by metallic artifacts and is able to detect foci of osteomyelitis in patients with metallic bone implants. primary methods and materials: patients were included, aged to years old. flat bones (pelvis = , sternum = ) were involved as well as metaphysis of tibia (n = ) and femur (n = ). pathologic diagnosis was obtained in all cases. results: in long bones, tumor originated from the medulla, excentered and metaphyseal in location. in all cases, agressive patterns were present such as osteolysis, cortical break and tumoral extension in surrounding soft tissues, lack of peritumoral reactional osteocondensation. periosteal reaction was present in one case. no calcification was noted. on mr imaging, tumors demonstrated intermediate signal intensity on the t -weighted images with heterogeneous enhancement following gadolinium injection. pathological findings included smooth muscle cells with interlacing fascicles of spindle cells, without osteoid production or cartilagineous matrix. despite adequate surgical resection, metatastatic diseases appeared in cases. conclusion: primary leiomyosarcoma of bone is a rare tumor which must be included in the diagnostic possibilities in case of agressive purely osteolytic lesion. results: patients included females and males (aged from to years) with pain in extremities. osteogenic sarcoma was diagnosed in patients, ewing sarcoma - , chondrosarcoma - , bone lymphoma - . in cases on plain film bone damage wasn't detected. on bone scintigraphy, the majority of lesions showed greater than mild uptake, in cases showed no uptake. at mr imaging isointense or low t w signal and increased t w signal was present in all cases. specific cellular constituents (e.g. fibrous, chondroid, blastic or teleangiectatic components), can modify signal characteristics. lesions that are primarily blastic, and, therefore, sclerotic on plain film radiographs, demonstrate low signal intensity on both t -and t -weighted sequences. edema characterized by indistinct margins, is a poor indicator of malignancy. conclusion: study shows that there is overlap in the radiological appearances of primary malignant bone tumors especially in the early stages. magnetic resonance imaging is shown to be a useful and sensitive modality in the detection and evaluation of bone tumors. mr imaging accurately assesses soft tissue and synovial involvement, as well as marrow infiltration, which may be radiographically silent. in patients with extremity pain mr imaging is necessary and mri data wasn't correlated with conventional radiology. all of them were underwent lateral flexion-extension radiography and lumbar mr imaging. differences of interspinous distances at flexion-extension radiography were analyzed at upper, lower, and spondylolisthetic segments. the mr features of the interspinous ligament were divided into groups according to their signal intensities: group , with inflammatory type presented as high signal intensity at t -weighted image and low signal intensity at t -weighted image, and group , fibrotic or fatty type. the incidence of the interspinous ligament with the inflammatory type was analyzed on the spondylolytic segment and the upper and lower segment without spondylolysis, respectively. results: spondylolysis at l , l and l levels were , and , respectively. of patients, the inflammatory type of the interspinous ligament was ( %) on the spondylolisthetic segment and ( %) on the upper segment without spondylolysis (p < . ). the mean difference of interspinous distance on the spondylolisthetic segment and the upper segment were . mm and . mm, respectively (p < . ). in patients of isthmic spondylolisthesis, the upper segment without spondylolysis showed more inflammatory type of the interspinous ligament on mr imaging than spondylolisthetic segment probably due to interspinous hypermobility. advantages of multislice ct in the diagnosis of traumatic osseous disease c. remaining cases, to assess the articular surface involvement and the real extension of the fracture. the isotropic mpr reconstructions carried out with the multislice ct scanners allow us to scan the patient in only one position, usually the axial plane, saving time and using less radiation dose. the mpr reformats takes an important role in the final diagnosis of many cases. the consideration of positioning in radiography for the waist of the scaphoid bone fractures s. matsubara; hiroshima/jp purpose: the most common type of scaphoid bone fracture is the transverse fracture of the waist (central / ). however, traditional positioning in radiography frequently fails to visualize bone fracture line. this may be caused by the fact that x-rays cannot be irradiated perpendicularly onto the scaphoid long axis. in this study, we searched optimal limb position for visualizing the waist of the scaphoid bone. method: in volunteers, the scaphoid bone was taken in the ulnoradial direction at °ulnar deviation (group a) and ° ulnar deviation with the fist clenched (group b). images measured the angle between the cassette plane and long axis of the scaphoid (c-s) and the angle between the cassette plane and the volar tilt (c-v). result: the c-s angle in group a was . ± . ° and in group b was . ± . °. the c-v angle was . ± . °. we devised new positioning that lift distal side of forearm upward at about ° in group a, at about ° in group b. these positioning make the long axis parallel to the cassette plane. especially, the later view was able to visualize the ulna-scaphoid joint more clearly without overlap of radius and scaphoid bones as compared to traditional method. conclusion: in fractures of the scaphoid, in which early diagnosis is critical, optimization of first-choice x-ray imaging is a key factor, and an additional image involving a ° scaphoid waist view will be useful. background: mri imaging is a very powerful tool in the evaluation of the acl, with higher sensitivity than the clinical examination of the knee. some of its lesions are well known and easily identifiable, but others require careful interpretation and familiarity with the spectrum of acl pathology. over knee mri examinations performed in three different diagnostic centers from january to july were reviewed retrospectively. acl lesions were found in approximately knees. procedure details: mri units ranged from . to . tesla, and various imaging protocols were used, with t and t coronal and sagittal images obtained in all cases. traumatic tears were the most common lesions identified. tears were classified as acute or chronic, complete or partial. we illustrate and discuss the primary and secondary findings of acl tears, as well as the imaging criteria in the evaluation of the postoperative acl. we also present fractures of the anterior tibial spine with acl avulsion, acl ganglion cysts and mucoid degeneration, which are less commonly seen. in the examination of the acl pathology the radiologist should evaluate multiple signs and be aware of some less common pathologies in order to effectively contribute to the clinical management. ultrasound and x-ray findings in painful shoulder involvement in rheumatoid arthritis l. rutkauskiene; vilnius/lt learning objectives: to illustrate and compare conventional x-ray and ultrasonography diagnostical possibilities of painful shoulder in ra. background: up to percent of rheumatoid patients have shoulder pain. a rational decision on the treatment of shoulder disease in rheumatoid arthritis depends on an accurate assessment of its cause and the extent of rheumatoid involvement. imaging details: a group of ra patients, who reported a pain in the arm and/ or limitation of the active movement, were examined first with conventional anterioposterior and obligue -outlet -view with - angulation x-ray of both shoulders. the most common findings were: joint space narrowing, erosions, subchondral cysts, irregularities of greater tuberosity, deformity and flattening, superior migration of humeral head, erosions in acromioclavicular joint, sometimes soft tissues swelling. ultrasonography study was performed with a . results: clinical signs and symptoms (pain and swelling) due to foot involvement were present in ( %) of the patients while frequency of involvement was ( %) with mr imaging assessment. the most common involved anatomical region was the hindfoot ( %) following by midfoot ( %) and ankle ( %). the mr imaging findings were bone erosions, achilles tendinitis, para-articular enthesophyte, joint effusion, plantar fasciitis, joint space narrowing, subchondral sclerosis, soft tissue edema, bone marrow edema, enthesopathy of the achilles attachment, plantar fascia attachment, and plantar ligament, subchondral edema, retrocalcaneal bursitis, subchondral cysts, subchondral fissures, and bone ankylosis. conclusion: mr imaging may detect bone, soft tissue, cartilage, tendon, and joint abnormalities in as patients, even if as patients did not have clinical signs and symptoms of foot involvement. this imaging modality may be of importance especially early diagnosis of inflammatory changes in the foot. additionally, familiarity of the typical mr appearances of foot involvement in as patients may be helpful in narrowing the wide differential diagnosis of spondyloarthropathies. mr handle meniscal tear using the following criteria: a) bow tie sign; b) double posterior cruciate ligament sign; c) coronal truncation sign; and d) displacement of the free meniscal fragment. results: in / cases a bucket-handle meniscal tear was identified. in of these latter an infero-medial displacement of a free fragment of the medial meniscus was identified. in all cases a lesion of the posterior horn involving the inferior articular surface was observed on axial plane. on coronal plane was observed the truncated triangle aspect of the peripheral, not displaced, meniscal portion. on all planes the displaced free meniscal fragment was identifiable as a little hypointense formation, medially to proximal tibial extremity, inferiorly to meniscal plane and deep to tibial collateral ligament. in all cases diagnosis was confirmed by arthroscopy. conclusions: mri allowed the detection of the infero-medial displacement of a free meniscal fragment thus helping the arthroscopic approach. high-resolution mri of ulnotriquetral ligament injury and its anatomical variations with a microscopy coil t. ueno , h. yoshioka , t. tanaka , y. kujiraoka , m. shindou , k. ooyama , y. saida ; tsukuba-shi, ibaraki/jp, boston, ma/us purpose: to demonstrate ulnotriquetral ligament (utl) injury and its anatomical variations using a microscopy coil. materials and methods: patients ( males and females with age ranging - year-old), who suffered ulnar side wrist pain and suspected triangular fibrocartilage complex injuries, were investigated in . t mri system with a microscopic coil ( -mm in diameter). axial and coronal t *-weighted images, sagittal and coronal proton density-weighted images, coronal stir images were obtained with a -mm fov and a - . mm of slice thickness for all patients. result: utl was identified in patients and its injuries were found in patients. regarding anatomical variations, in proximal side, utl always connected to volar radiocarpal ligament and disc proper. however, there were many variations of the attachment to triquetrum bone. in patients, bands attached to triquetrum at different site: one attached to the distal aspect of triquetrum, and another attached to a notch which was found at volar aspect of triquetrum. in patients, one attached to proximal side of the notch. patients showed separate utl bands. conclusion: high-resolution mri with a microscopy coil is a promising method to demonstrate utl injury. it would be useful to know normal anatomical variations for understanding the mechanism of utl injury. pictorial review of diagnostic imaging techniques in hip arthroplasty follow-up j. rimola, p. melloni, r. valls, p. bermúdez, d. gil, a. massuet; sabadell/es objective: to evaluate the spectrum of findings for plain-film radiography and other imaging techniques in patients with early or late complications of hip prostheses. we describe the usefulness of each imaging technique in follow-up. background: over the last years more than hip replacements have been performed in our hospital annually. all patients are followed up immediately after surgery, at months and then yearly or when necessary, using plain films and sometimes sonography (us) and/or computerized tomography (ct). us and ct are used to confirm or rule out osteointegration of the prosthesis and complications such as periprosthetic abscess and/or hematoma. imaging findings: we analyzed radiological features of the normal and pathological evolution of hip prostheses. we describe early complications (affecting . % of patients), such as infection, cement extrusion, and periprosthetic fracture, as well as late complications (affecting . % of patients), including aseptic loosening, osteolytic lesions, heterotopic calcifications, migration of the acetabular component, femoral diaphysis fracture, and dislocation of the prosthesis. conclusion: plain films are essential for evaluation and detection of hip arthroplasties. us is usually used to guide percutaneous aspiration of soft tissue. ct enables correct assessment of osteointegration of hip prostheses. results: with wrist arthroscopy as the standard of reference, average sensitivity and specificity of non-enhanced mri, for tears of the tfcc were . and . respectively and . / . / for arthroscopy. conclusion: mr imaging-plays a major role in evaluation and management of traumatic wrist injuries, improves clinicians diagnostic accuracy and reduces the need for arthroscopy. these preliminary results illustrate the ability of mri to assess the integrity of the tfcc and suggests its use as the first imaging method following plain radiography in the evaluation of patients with chronic posttraumatic pain on the ulnar side of the wrist. wrist arthroscopy is a more valuable technique in determining the location, size, and extent of ligament injuries within the wrist. high patients ( women, men; mean age: years) referred from e.r. for a suspect traumatic dislocation of the a-c joint. all patients underwent plain x-ray examination (conventional projections integrated by "outlet" view and stress projections) and hrus scan (longitudinal and axial scan planes of interested ligaments) of both the interested and contralateral a-c joint. ultrasonographic criteria of lesion were considered the absent recognition of the ligament and strong echostructural inhomogeneity a-c joint. measures of a-c and coraco-clavicular (c-c) distances were drawn by means of both methods. dislocation's degree was defined according with rockwood's classification. results: in / cases of indirect trauma, diastasis of the a-c joint ( - mm), was observed, whereas c-c joint was not involved and c-c ligaments were normal. in / patients with direct trauma, distracting lesion of the a-c ligament was observed in cases, and involvement of both a-c and c-c ligaments with diastase of both joints was observed in the remaining cases. a complete correspondence of the two methods was observed. conclusion: hrus enables early anatomical-structural changes detection and lesion's degrees assessment in acute traumatic lesions of the a-c joint, and could be considered more than complementary to x-ray exam in the emergency clinical setting, mantainig its role in the follow-up. ligaments and ac joint soft-tissue morphology, acromioclavicular distance and coracoclavicular distance were evaluated. sonographic findings were correlated with the results of conventional radiographic examination, which was performed in all cases with anteroposterior projections, taken with and without weights, and with "outlet" projection. sonographically, all patients presented lesion of ac ligament with high amount of sero-hemorrhagic fluid inside and outside the joint. in / patients, which had indirect trauma, we observed ac joint dislocation with ac ligament lesion that was not associated to involvement of cc joint and ligament. in / patients, which had direct trauma, we observed lesions of ac and cc legaments with associated joints dislocations. conclusions: ultrasonography, if performed with appropriate technique and adequate transducer, is accurate in the evaluation of acute traumatic ac joint lesion and dislocation, integrating and correlating well with the informations offered by conventional radiography. study of the mr imaging of the posterolateral structures of the normal knee c. yu, k. li; beijing/cn puropse: through the study of the mri appearance and localization of the posterolateral structures (pls), to provide a practicable method for intactly displaying them. methods: thirty tibial bone specimens were observed to establish the bony landmark for localizing the knee. in cadaver knees, the angles between lateral tibial plateau and the long axis of the individual structure of pls were measured. then we can determine the scan methods of the oblique mr images based on above results. the routine and oblique scans of t wi were performed in normal knees. the display effect and appearance of the pls were observed in mri. the lateral tibial plateau is a stable bony landmark for measuring and localizing of the knee. in the pls, the fibular collateral ligament can be intactly displayed on ° posterior coronal oblique images in cases ( %). the popliteus can be better seen on either ° posterior coronal oblique in cases ( %) or ° medial sagittal oblique planes in cases ( %). the popliteofibular ligament can be intactly appreciated on both ° posterior coronal oblique in cases ( %) and ° lateral sagittal oblique images in cases ( %). although the arcuate ligament and the fabellofibular ligament can occasionally be seen on routine and oblique images, their presence rate is low. the oblique mr imaging can intactly display the main structures of pls, and can be an useful tool in diagnosing these structures' injuries. patients are also asked for the presence of their prolonged physical activity in their life. results: patients had type ii, patients had type i and of them showed type iii patellar shapes, out of . patients had patella alta whereas all others stayed in normal range as patellar position. in patients' case no other abnormalities were seen apart from the signs of iliotibial band friction syndrome and three of them had shown type iii patellar shape. conclusions: no apparent correlation was found between iliotibial band friction syndrome and patellar position. as it is much more rare in the normal population wiberg type iii patella showed considerably high prevalance in our study. shoulder to assess by mri the potential benefit and efficacy of selective meniscectomy combined with radiofrequency ablation in cystic degeneration of the lateral meniscus treatment. materials and methods: sixty-one patients entered this study. patients underwent arthroscopic selective meniscectomy and patients underwent arthroscopic selective meniscectomy and radiofrequency treatment (arthocare, sunnyvale, ca) of the meniscal remnant. all of them were submitted three months later to mri and clinical evaluation. in case mri examination was performed before and after the surgical treatment. mri examination was performed using a dedicated . t (artoscan esaote italy) and a . t superconductive unit (ge signa horizon usa) employing se t -w, se t -w and ge t -w sequences on axial and longitudinal scan planes. in case arthro-rm was also performed. clinical evaluation included physical examination and questionnaire. results: clinical evaluation did not show statistically significant discordance between the two groups. mri follow-up after months demonstrated a very clear decrease of the degenerative spots inside the meniscal remnant in the group with combined treatment respect to the group treated only with selective meniscectomy. conclusion: in conclusion our experience considers mri the method of choice in the evaluation of post surgical treatment of degenerative cystic diseases of the lateral meniscus of the knee. high-resolution ultrasonography of the extrinsic carpal ligaments: examination technique and performance d.v. guntern, n. favarger, p. schnyder, n.h. theumann; lausanne/ch purpose: to develop an examination technique to visualize the extrinsic carpal ligaments by ultrasonography and to assess the performance of high resolution ultrasonography in the visualization of different parts of these ligaments. the extrinsic carpal ligaments of wrists of healthy volunteers were examined with a mhz linear array transducer by two muskuloskeletal radiologists in consensus. an examination technique was developed for each extrinsic carpal ligament (radioscaphocapitate, radiolunotriquetral, palmar scaphotriquetral, dorsal scaphotriquetral, palmar ulnotriquetral, dorsal ulnotriquetral, dorsal radiotriquetral and radial collateral ligaments). delineation of the proximal attachment, the body and the distal attachment of each ligament was evaluated as good, poor or absent. results: with a profound knowledge of the anatomy, especially of the osseous landmarks, an easy and fast examination of the extrinsic carpal ligaments by high resolution ultrasound is possible. the more superficial ligaments such as the dorsal scaphotriquetral and the dorsal radiotriquetral ligaments are well visualized by high resolution ultrasound whereas ligaments in a deeper position, such as the proximal and distal insertion of the palmar scaphotriquetral and the distal insertion of the radioscaphocapitate are less well visualized. high resolution ultrasonography is an accurate method to visualize the extrinsic ligaments of the wrist. direct mr arthrography of the glenohumeral joint with capsular distension using a posterior approach r. drescher, j. ludwig, f. rubenthaler, o. köster, g. schmid; bochum/de purpose: evaluation of the clinical use of direct mr arthrography of the glenohumeral joint with maximum distension of the joint capsule in patients with glenohumeral instability using a posterior approach. patients and methods: direct mr arthrography of the shoulder joint was performed on a . t system in patients ( women, men, mean age years). right and left shoulders were evaluated. all patients had anterior or bidirectional instability ( posttraumatic, constitutional). using a fluoroscopically guided posterior approach, ml iopamidol m and ml . % mepivacaine were injected, followed by a % dilution of dimeglumine gadopentetate in . % sodium chloride until full capsular stretching was achieved. mr sequences were t -weighted spin-echo axial and oblique-coronal, fat-saturated t d axial and oblique-coronal, and axial t flash- d. results: arthrography was possible in all patients. the total amount of intraarticularly injected fluid was - ml (mean ml). no complications occurred. mr imaging showed significant capsule distention in patients ( %) and ventral capsule defects in patients ( %). labral lesions ( anterior, posterior), bicipital tendon lesions ( complete, partial ruptures) and partial ruptures of the rotator cuff were noted. patients underwent surgery. regarding labral lesions, sensitivity of mri was . %, specificity was %, and diagnostic accuracy was . % compared with surgical results. conclusions: glenohumeral direct mr arthrography allows accurate detection of labral and tendinous lesions. maximum capsular distension allowed preoperative evaluation of capsular laxity as a source of shoulder instability. anterior talofibular ligament injury: evaluation with mr imaging j. ishida , j. yoshigi , h. okizuka , k. ooae , m. takao , t. yoshizako , k. izaki , n. uchida , h. kitagaki ; izumo/jp, himeji/jp purpose: inversion stress is most frequent injury of all ankles. atfl is the weakest of lateral collateral ligaments and first to rapture. the purpose of this study is to evaluate the usefulness of high-resolution mri for diagnosis of atfl disruption divided into acute and chronic phase. method and materials: patients suspected atfl disruption underwent mri ( . t). cases were in acute phase (< days) and cases were in chronic phase (> month). axial spin-echo (se) t -wi (tr/te = / , fov cm, mm/ . mm, x , nex,) and axial fast se t -wi (tr/te = / , etl , fov cm, mm/ . mm, x , nex,) were obtained with an extremity coil. atfl disruption was diagnosed when either finding is positive:discontinuity, irregularity, non-visualization of aftl, and high signal intensity lesion in atfl on t -wi. results: arthroscopy confirmed atfl disruption in cases in acute phase and b d e f a g cases in chronic cases. in acute phase, sensitivity was %, specificity was %, and accuracy was %. only false negative was seen. in chronic phase, sensitivity was %, specificity was %, and accuracy was %. / was false negative. conclusion: in acute phase, mri was accurate for evaluation of aftl disruption. however, in chronic phase, mri was less accurate because granulomatous tissue after disruption cannot be detected with mri. ct arthrography of the shoulder a. gligorievski, z. temelkovski; skopje/mk purpose: to present ct arthrography (cta) as a new method in our practice in order to point out its advantages and to compare the results with conventional arthrography and mr arthrography. we describe the technique of the examination in detail, performed at the institute of radiology in cooperation with an orthopaedic surgeon and radiologist that form the diagnostic-therapy team. cta performed with patients, aged to , men and women. conventional arthrography was performed in and mra in patients. results: patients presented with lesion of the glenoid labrum, with rotator cuff lesion, with a frozen shoulder, with a hill-sachs lesion, with biceps brachi tendon subluxation and case with slap lesion. we report our first experiences and the results gained are compared to similar recent studies as well as to the conventional radiologic techniques. cta is a method of choice in case of frozen shoulder and glenohumeral instability, but mra is better in case of rotator cuff lesion. we can conclude that cta is a sophisticated method of extreme diagnostic value in the evaluation of the humeral joint especially in case of glenohumeral instability. the invasiveness of the method is small, no complications have been noticed and compared to mr it is significantly cheaper and more available for the medical centers equipped with a ct scanner. mr imaging of the metatarsophalangeal joint with standard mr imaging: evaluation of six patients with clinical suspicion of plantar plate disruption p. hauser; lausanne/ch purpose: to report the mr imaging findings of painful injured metatarsophalangeal joints (mtpj) in case of clinical suspicion of plantar plate (pp) tear. a series of patients with clinical suspicion of pp rupture of first (mtpj ) or second (mtpj ) ray underwent mr studies with . tesla units with use of an extremity coil. the patients lay on their back with the ankle in plantar flexion and the toes in extended position. the standard mr imaging protocol performed in all specimens consisted of t weighted spin echo sequences in sagittal and coronal plan and t fse fat satured sequences in sagittal, coronal and transverse plan. the examinations were interpreted separately by two musculoskeletal radiologists assessing whether or not a pp rupture and associated lesions were present. after the imaging study all the patients underwent surgical revision in a mean delay of one month. results: tears of the pp were visualized in cases, degenerative lesions of the pp were visualized in two cases and two other cases showed no lesion. the mr imaging results concerning pp rupture although allowed depiction of several associated lesions including injuries of the extensor hood, the collateral ligament complex, ostechondral lesions and joint deformities. conclusion: although surgical treatment is generally the rule for hallux valgus deformities, surgical repair is also often required in cases of traumatic injuries of the mtp joints. the force of accord between radiologists and surgical observation of pp ruptures is good. mrt monitoring of autologous hyaline cartilage grafts c. müller, e. grönewäller, c.d. claussen, f. schick; tübingen/de purpose: seven different mr sequences were compared to localize cartilage defects in knee and to evaluate the stage of maturation of the hyaline cartilage graft. methods: mrt was performed in patients aged - years with autologous transplantation of a hyaline cartilage tissue graft after a knee trauma. examination dates were: before transplantation to localize the defect, and weeks, , and months after transplantation to control the morphology and the maturation of the autologous graft. standard t -and proton-density weighted turbo spin echo (tse) sequences, t -weighted spin echo (se) sequences, gradient echo (gre) sequences with and without magnetization transfer (mt) pulses as well as experimental diffusion weighted gre sequences (psif) were used. results: for depiction of the graft short time after surgery t -weighted tsesequences showed the best results, to identify potential secondary damages before transplantation pd weighted sequences were superior. and months after transplantation spoiled d-gre-sequences displayed the graft in high spatial resolution. from the diffusion measurements no statistically significant discrimination between cartilage and graft was obtained at any time, whereas, different images from gre-sequences with and without mt pulse provided high contrast between cartilage and surrounding tissue. the quantification of the mt effect showed an assimilation of the graft to the original cartilage within months. conclusion: mrt should be performed before every transplantation because cartilage defects and secondary damages can be detected clearly. after transplantation mrt can easily identify the graft and detect hypertrophy or debonding in early stage. quantitative macroradiographic study with fractal signature analysis measures bone loss in the rheumatoid arthritis hand l. disini , m. foster , j. buckland-wright ; london/uk, loughborough/uk purpose: fractal signature analysis (fsa), a computerised method of textural analysis, permits the separate measurement of changes in vertical and horizontal trabeculae based on the fractal dimension over a range of trabecular widths (fractal signature). we determined whether the fsa of high definition macroradiographs (x magnification) quantified differences in trabecular organisation at sites of osteopenia and erosion formation in the rheumatoid arthritis (ra) hand. methods: sixty-seven ra patients had macroradiographs of the left hand. the distal radius was scored and grouped from very mild (ra ) to moderate (ra ) disease. macroradiographs were digitised and fsa of horizontal and vertical trabecular organisation were measured in the radius at sites of osteopenia, erosion formation and a mid-shaft site. the fractal signatures were compared to healthy non-arthritic subjects using the t-test. results: compared to the non-arthritics, fsa at the distal radius in groups ra to ra measured a significant reduction (p < . ) in fractal signature at the osteopenic and mid-shaft sites, affecting small to large sized vertical trabeculae, and at the erosion site, involving small and medium sized horizontal and vertical trabeculae. the reduction was smallest in ra and greatest in ra . conclusion: fsa quantified the trabecular bone loss in the distal radius of ra patients of increasing radiographic severity based on a proportional reduction in fractal signature. disease related bone loss involved varying trabecular widths with vertical trabeculae at the osteopenic site and both vertical and horizontal trabeculae at the erosion site. potentially, fsa can distinguish changes consequent to bone-mediated ra drug treatment. the results: the value of d ct reconstructions in external projections was the highest in revealing of the osteophytes of anterior margins of vertebral bodies; the anterior osteophytes were found in ( . %) patients on d ct images. the d ct reconstructions cut off in sagittal plane along the spinous process were the best imaging modality in evaluation of the osteophytes of the posterior margin of the vertebral body, which were seen in cases ( %) and in evaluation of narrowing of the intervertebral foramens ( cases - %). conclusions: d ct reconstructions are valuable in determining the localization and the extent of the cervical spine osteophytes. they are the imaging modality of choice in assessment of the degenerative narrowing of the intervertebral foramens. d ct reconstructions should be the integral part of ct examination of patients with the neck pain. purpose: the aim of our study was to determine the incidence of jspa in croatian population in the last years in relation to other rheumatic diseases and the presence of hla -b in children with jspa. as the cause of jspa is still unknown, the strong association with hla -b suggests genetically determined mechanism. methods and materials: the patients from to years of age diagnosed during the period - at department of paediatric rheumatology, university hospital zagreb following strict criteria of european spondyloarthropathy study group. we identified newly diagnosed patients with rheumatic disease using hospital and outpatient records. results: were identified as having jspa ( . %) amongst , patients with rheumatic disorders. sex ratio was females against males, mean age of . years. patients had undifferentiated spondyloarthropathy ( . %), patients had reiter's syndrome ( . %), had arthritis of inflammatory bowel disease, i.e. crohn's ( . %), two patients had psoriatic arthritis ( . %), and two had ankylosing spondylitis ( . %). ocular complications were present in patients ( . %), enthesitis in ( . %), sacroileitis in ( . %) and peripheral arthritis in all patients ( %), diagnosed radiologicaly. hla -b was present in patients ( . %). conclusion: our epidemiological study showed similar incidence of jspa among other rheumatic diseases in childhood and adolescents ( . %) compared to results of american, canadian and british studies in which this incidence is . - . %. however, the presence of hla -b antigen is lower ( . %). postprocessing optimization of computed tomography data of acetabular fractures v. moschenko, t. shamova, a. sklyarenko, i. bobkova; kharkov/ua purpose: to study diagnostic opportunities of postprocessing programs -multiplanar (mpr) and d shaded surface display (ssd) reconstruction of ct data on acetabular fractures. methods and materials: patients aged - with acetabular fractures in various terms since the moment of trauma (from days to months) were examined. plain radiographs and ct with the subsequent application of programs mpr and ssd were conducted. the acetabular fractures classification by judet -letournel was used. results: use of postprocessing programs allowed in ( . %) cases to specify a type of fracture and character of deformation of acetabulum, therefore in ( . %) -the originally prospective conservative treatment was replaced by operative. considering complexity of choice certain reformations mpr and ssd for analysis and documenting of views, we used standard projections: for mpr - ) along anterior column, ) along posterior column, ) along both columns; for ssd - ) anteroposterior view of the pelvis; ) direct projection (lateral view) of the acetabulum; ) obturator oblique view of the pelvis; ) iliac oblique view of the pelvis. in ( . %) cases use of only these projections was enough to establish the type of acetabular fracture. conclusion: use of mpr and ssd in ct data postprocessing allows establishing the type of acetabular fractures that defines a choice of treatment tactics. our standard protocol of mpr and ssd reduces analysis time of research results and creates conditions for uniform perception of injuries by all participants of diagnostic process. conclusion: routine x-ray projections prove insufficient to establish a diagnosis in / th of the cases. confusion is caused by overlaying of fracture edges and pelvic bone in the direction of x-ray beams. the latter makes hardly visible the small posterior fragment, too. therefore, ct scanning is required for the diagnostic protocol of displaced femoral head fractures. is learning objectives: to describe us and mr imaging findings of nerve infiltration by extrinsic masses, including lipomas, hemangiomas, non-hodgkin lymphomas and ganglion cysts. to learn to differentiate between these pathologic conditions. to emphasize the role of us and mr imaging in the management of these lesions to further delineate the nature and extent of the process. background: in addition to peripheral nerve sheath tumors (e.g. neurofibromas, schwannomas and malignant peripheral nerve sheath tumors), there are softtissue masses, such as hemangiomas, lymphomas and ganglion cysts, which do not originate from the nerve itself but may occasionally infold among the nerve fascicles and expand into the neural tissue. the intraneural growth of these masses is rare, may cause nerve dysfunction and local symptoms and should not be confused as the more common nerve sheath tumors. imaging findings: - mhz us and . t mr imaging findings for a series of eight retrospectively collected cases of masses infiltrating nerves are illustrated with emphasis about the different pathogenetic mechanisms of intraneural infiltration. hemangiomas involved the median and ulnar nerves, ganglion cysts the peroneal nerve, non-hodgkin lymphomas the sciatic and median nerves. correlation of imaging findings with gross surgical views is provided in / cases. conclusion: high-resolution us and mr imaging can detect nerve infiltration by extrinsic masses. knowledge and recognition of the characteristic imaging features can aid in the proper diagnosis and treatment of these lesions. mri of lipomatous soft tissue tumors: radiologic pathologic correlation m. pilavaki, d. chourmouzi, g. boulogianni, a. drevelegas; thessaloniki/gr purpose: to study the mr imaging findings for each type of lipomatous soft tissue tumors and to correlate them with the pathological findings. we studied retrospectively the mr examinations of patients with histological proven lipomatous soft tissue tumors. the histological types of the tumors were: lipomas, fibrolipoma, lipoblastoma, lipomatosis and liposarcomas ( well-differentiated, myxoid, and mixed type) t -, t -, and fat-suppressed and t -weighted images after administration of gadopentetate dimeglumine were obtained. the signal intensity on different sequences, the internal characteristics, the presence of septa and other nonadipose component, revealed on the mr images and the degree of contrast enhancement of septa and nonadipose component were evaluated. results: from the group of benign lipomatous lesions lesions were without a recognizable nonadipose component. lesions had thin septa without contrast enhancement. in case of fibrolipoma areas of nonadipose component correlated with fibrous tissue. in the group of well-differentiated liposarcomas had thin septa and thick septa with mild contrast enhancement. the remaining liposarcomas had thick septa with of them having a nodular and globular non-fatty component with enhancement after the administration of paramagnetic agent. conclusion: statistically significant imaging features favoring a diagnosis of liposarcoma included the presence of thick septa, enhancement of septa and the presence of nodular or patchy nonadipose components. imaging features suggesting benignancy included thin septa with no enhancement relative to muscle and no recognizable nonadipose component. guidelines for diagnosis of soft tissue lipomatous masses (stlm) g. chave, d. ranchere-vince, p. meeus, p. thiesse; lyon/fr learning objectives: to clarify the steps of pretreatment diagnostic procedures in case of soft tissue lipomatous masses (stlm). to describe the mri findings for lipomas and liposarcomas. to develop the principles of percutaneous biopsy. background: differential diagnosis between lipomas and liposarcomas, especially atypical lipomas is not always easy. despite similarities, differential diagnosis can be reliably established employing image parameters. nevertheless, the staging process of stlm culminates in biopsies, allowing to manage the proper treatment. biopsies can be performed percutaneously using imaging guidance. an open biopsy with the resection of the entire mass is disputed when the stlm is composed essentially of fat on mri imaging to avoid the misdiagnosis of benign lipoma. each procedure must be carefully planned: an inadequate biopsy may fail to allow proper diagnosis, have a negative impact on survival, and ultimately necessitate an amputation to accomplish adequate margins of resection. procedure details: after the description of characteristics and different histological subtypes of lipomas and liposarcomas, we will describe the mri findings for each diagnosis, according to a review of the litterature by illustrating with mri imaging of patients followed in our center. we will develop the principles of percutaneous biopsies according to litterature and our experience. conclusion: accurate diagnosis of stlm is based on three factors: clinical presentation, radiological features and pathologic evaluation. the importance of careful planning and performance of biopsies cannot be overemphasized because errors may have a negative impact on survival and impede proper diagnosis. high background: clinical assessment of extensor tendon injuries is not straightforward because of the peculiar anatomy of these tendons made of several interconnecting layers and different attachment sites in the fingers. the development of very high-frequency "footprint" transducers has improved the ability of us to scan the extensor tendon complex in the fingers, allowing accurate depiction of the central and lateral slips of the extensor tendon, and the sagittal and lateral bands of the extensor hood. imaging findings: paradigmatic - mhz and - mhz us images from a series of retrospectively collected cases with a variety of extensor tendon injuries in the fingers are illustrated, including partial and complete rupture of the central slip (boutonnière deformity), tears of the lateral slip, avulsion injury of the terminal tendon (mallet finger), injury of the sagittal band over the metacarpophalangeal joint with tendon instability (boxer knuckle). dynamic us is essential to diagnose injuries of the extensor hood mechanism. correlations of us findings with schematic drawings and the results from . t mr imaging are also provided. conclusion: high-resolution us is promising for evaluating the extensor tendons complex in the fingers. it can identify and characterize a variety of abnormalities. by providing unique information on these tendons, us has potential for major impact on treatment planning. high-resolution us of tenosynovitis in the wrist and hand a. picotti , l.e. bacigalupo , r. podestà , g. succio , f. pugliese , s. bianchi , c. martinoli ; siena/it, genoa/it, geneva/ch learning objectives: to describe the spectrum of tenosynovitis of flexor and extensor tendons in the wrist and hand by means of high-resolution us. to correlate us findings with clinical features and mr imaging. to emphasize the role of us in the management of these lesions to further delineate the nature and extent of the process. background: tenosynovitis of wrist and hand tendons are common and account for a high percentage of orthopaedic consultations. they can be related to local causes, particularly overuse due to sport or occupational activities or may be the result of systemic musculoskeletal disorders. imaging findings: paradigmatic - mhz and - mhz us images from a series of retrospectively collected cases with a variety of tenosynovitis in the wrist and hand are illustrated with emphasis on the pathogenetic mechanism of tendon disease, including de quervain disease, intersection syndrome, extensor pollicis longus, extensor carpi ulnaris, flexor carpi radialis and flexor digitorum tenosynovitis. the main findings in infectious and hypertrophic tenosynovitis are also described and a spectrum of unusual causes producing them is reported, including foreign bodies and conflict with fracture residuals and osteosynthesis material. conclusion: due to its widespread availability, low cost and high spatial resolution, high-resolution us is an excellent tool for investigating a variety of tenosynovitis of the wrist and hand. background: the patients with inflammatory myopathies (inclusion-body myositis (ibm) = , polymyositis (pm) = and dermatomyositis (dm) = ) underwent whole-body mr muscle screening examination. mr examination is performed at six different levels: neck, shoulder, abdomen, pelvic girdle, and upper and lower leg. t -and t -weighted images with and without fat suppression were performed for each level. signal intensity of muscles, volume and the symmetry of involvement were quantified in individual muscles on each side. imaging findings: ibm, dm and pm are rare diseases with clinical and histopathological similarities. ibm usually does not respond to immunosuppressive therapy. therefore, it is necessary to distinguish these entities correctly. ibm is characterized by more frequent fatty infiltration, atrophy, inflammation, a distal predominance, and anterior group involvement. the finding of selective involvement of the medial gastrocnemius and of the vasti with sparing of rectus femoris is typical for sporadic ibm. the selective involvement of flexor digitorum profundus is also highly suggestive for ibm. t , t and fat-sat images contain different but complimentary information. pm and dm predominantly affect muscle groups of the shoulder girdle and the thighs. a newly introduced mr technique provides an excellent overview of all diseased muscles in the body. moreover, it helps us to distinguish ibm from other iims. mri may help establish the diagnosis, suggest appropriate sites for biopsy, and enable assessment of disease progress or regression over time. background: elastofibroma dorsi is a rare, typically slow-growing, often bilateral, para-neoplastic formation. it's composed by fibro-elastic and adipose tissue and is selectively localized along the postero-lateral side of thoracic wall, under the scapula. the certain diagnosis is cyto-histological. mri was the hitherto elective diagnosis. all cases of elastofibroma in our series were studied with us; some of them also with ct and mri; in a retrospective analysis us allowed to suspect presence of elastofibroma in all patients: of them underwent surgery that confirmed the diagnosis. procedure details: in our series the us examination, performed with . - mhz linear probe, showed solid masses, sometimes in both sides, with badly visible margins, hypoechoic with inside hyperechoic stripes, obliquous from the transducer plan. conclusions: in all cases us and clinical findings allowed the diagnosis of elastofibroma dorsi. the mri, performed in patients that underwent surgery, confirmed the us findings. the remaining patients are undergoing follow-up with us. so, us findings, within site, slow growth and possible presence of bilateral masses, allow the diagnosis of elastofibroma dorsi, avoiding costly mri. a comparison between ultrasound, echo-color-doppler, and mri in the evaluation of achilles enthesopathy in psoriasis: preliminary results f. maggi, f. di gregorio, c. de simone, c. pagliarello, m. politi; rome/it purpose: psoriasis is often associated with achilles enthesopathy. this study compares the efficacy of ultrasound, echo-color-doppler and mri in the evaluation of early signs of achilles enthesopathy in psoriatic patients. methods and materials: consecutive psoriatic patients, men, women, mean age years (age range - ), mean pasi score , entered the study. all patients underwent sonography of the achilles tendon and peritendinous structures with aplio (toshiba) equipped with a linear multifrequence ( - mhz) transducer; the study was completed with color-doppler analysis. an mri study, before and after gadolinium, was then performed using e-scan xq (esaote), . tesla superconducting magnet. axial and sagittal t and t weighted, sagittal ge and stir sequences were obtained. after gadolinium, axial and sagittal t weighted sequences were obtained. results: the more frequent us findings were microcalcifications inside the achilles tendon ( % of cases) and signs of bursitis ( %), while uncommon there were degenerative lesions and signs of peritendinitis. completion with echo-color-doppler did not add significant data to us study. mri imaging showed degenerative lesions and peritendinitis as well as us, but was not able to identify any microcalcification. all the alterations were identified in the basal study; administration of gadolinium did not allow any additional pathological finding. conclusion: our preliminary results show that mri, especially with low magnetic field, is not sensitive compared to us in detecting early changes of achilles enthesopathy in psoriatic patients, while echo-color-doppler and enhanced mri sequences had limited utility in diagnostic imaging of early stages of this pathology. characterization high resolution us and mri in the evaluation of plantar fibromatosis i. gallesio, s. parodi, r. pastorino, d. schettini, m. falchi, e. silvestri, g. garlaschi; genoa/it purpose: plantar fibromatosis is a benign fibroproliferative disorder of the plantar fascia clinically presenting subcutaneous nodules in the foot sole. this study aimed to evaluate the application potential of us and mri performance in detection of these lesions. material and method: patient with palpable nodules suspected plantar fibromatosis were evaluated. the us examination was performed by means of a high resolution transducer through tranverse and longitudinal scans along with evaluation of intra-nodular vascularization by power-doppler. mri was performed by means of a . t unit with axial and sagittal planes. t weighted mri images after administration of iv contrast medium were acquired from two patients. results: nodules were, overall, detected, most of them located in the medial plantar fascia. all nodules were oval-shaped, hypoechoic at us and hypointense at mri. considering number and size of nodules, us and mri overlapped (were strikingly similar). moreover, nodules showed hypervascularization at power-doppler, confirmed at mri with paramagnetic contrast medium. this pattern might suggest a different pathoanatomical condition of these lesions, as hypervascularization is a sign of an early stage lesion, featuring a large fibrovascular proliferation. no correlation was found between vascularization degree and symptoms the latter resulting from the neurovascular structures disorder. conclusions: us associated with power-doppler is the first choice method in the evaluation of plantar fibromatosis, able to detect number, size and activity pattern of nodules, leading to a pre-surgery diagnosis. in severe plantar fibromatosis mr is to be considered a complementary method in evaluation of the extent. purpose: conventional mri is a well-accepted technique in evaluating soft tissue tumors. however it is not specific in differentiating benign and malignant lesions. in this study the differential value of the dynamic contrast enhanced mri (dce-mri) was investigated. methods and materials: turbo flash dce-mri was performed on subjects ( - yrs) with soft tissue tumors. enhancement in the st min (e ), nd min (e ), maximum enhancement (emax), and time-signal intensity curve (tic) slopes were calculated. discriminant analyses were performed to reveal parametric differences of the benign and malignant lesions. results: histopathological diagnosis of benign (n = ) tumors were hemangioma (n = ), neurogenic tumor (n = ) lipoma (n = ) and desmoid (n = ), whereas malignant lesions (n = ) were classified as liposarcoma (n = ), osteosarcoma with soft tissue component (n = ), malignant fibrous histiocytoma (n = ), synovial sarcoma (n = ) and giant cell tumor (n = ). for malignant lesions mean values for e , e and emax were %, %, and %, respectively. mean tic slope was . . for benign lesions the above mentioned values were %, %, %, and . , respectively. anova based discriminant analysis was correctly classified % of the lesions to benign and malignant groups using e , % of the lesions using e or emax, and % of the lesions using tic slope. the combination of the above mentioned parameters had resulted a % accuracy (p < . ). conclusion: dce-mri parameters are the surrogate markers of tumoral microcirculation and tissue perfusion. these parameters may be used as key factors when deciding proper treatment alternatives and to reveal malignant transformations. the relation of flexor retinaculum laxity with age, gender, and hand dominance t. altinok, h.m. karakas; malatya/tr purpose: carpal tunnel syndrome (cts) is an entrapment neuropathy involving the median nerve within its fibroosseous tunnel at the wrist. one of the main radiologic parameters in diagnosing cts is the palmar displacement (pd) of the flexor retinaculum in this study, possible physiologic factors that may affect the palmar displacement and decrease the sensitivity of this criterion were investigated. materials and methods: normal wrists of male and female with ages between and (mean: . ; sd: . ) were ultrasonographically investigated with - mhz linear transducer. pd values obtained were correlated with with age, gender, and hand dominance was analyzed. results: there was no significant difference between different genders and between dominant and non-dominant hands regarding palmar displacement. when considering all subjects this parameter was varied between . and . mm (mean: . ; sd: . ). palmar displacement exhibited a very strong correlation with age (p < . ; r = . and r = . , for dominant and non-dominant hand, respectively). when considering all subjects, linear regression between both factors was found to be . (p < . ). the sensitivity of pd in diagnosing carpal tunnel syndrome was variously reported to be lower than other radiologic criteria. we have found this relative insensitivity to be originated from the age dependent laxity. the cut-off value of . mm given in the relevant literature must therefore be considered normal for the paients older than years of age. the use of the normalization data presented may help to improve the sensitivity of the palmar displacement. vascular soft tissue tumor discrimination with mr image findings by pattern recognition techniques c. vidal, j. garcía-gómez, l. marti-bonmati, m. robles; valencia/es purpose: to discriminate within soft tissue tumors (stt) those with a vascular origin from other histological groups by using pattern recognition techniques with mr image findings. a total of consecutive patient with confirmed musculoskeletal stt from different european centres were examined with mr. t and t -weighted fat-suppression or stir images were obtained in all subjects. the recorded variables were: age, clinical presentation, localization, size, shape, mr signal intensity, margins, homogeneity, edema, t -hyperintense tracts, mul-tiplicity, target appearance, muscular atrophy, intratumoral hemorrhage, calcification, intratumoral fat, fibrosis, fascial relationship, bone alterations, vessels. the k-nearest neighbour (knn), support vector machine (svm) and decision trees (dt) were used to classify vascular from cystic, fatty, nervous, synovial and fibrous origin. the sample was splitted with % of cases used as test. results: efficacy of vascular in front of each histological group using knn was high (nervous . , cystic . , fibrous . , fatty . and synovial). vascular vs. all other stt gave an efficiency of . with dt, . with svm and . with knn. conclusion: discrimination of vascular from nervous and cystic origin was easier than from fatty, synovial and fibrous stt. however, the overall values were very high. the computer assisted diagnosis in the discrimination of the vascular histological group from the others in stt diagnosis is possible by using pattern recognition techniques. spring ligament chronic injury on mr imaging a. iovane, m. midiri, m. galia, t. bartolotta, r. lagalla; palermo/it purpose: to evaluate the usefulness of mr to depict spring ligament (sl) and to visualize its chronic abnormalities even when associated to injury of the posterior tibial tendon (ptt). materials and methods: mr images from patients ( female and male; age range - years), with clinical suspect of injury of the ptt, were retrospectively examined for sl normal appearance and abnormalities. all exams were performed by a . t mr using t weighted spin-echo and t weighted fast spinecho sequences on the axial plane. asymptomatic control patients ( female and male; age range - years), were examined in the same interval time using t weighted spin-echo and t weighted fast spin-echo sequences on an oblique plane ( °), parallel to sl. we evaluated if sl was totally or partially visualized, sl thickness and signal intensity. results: in all control patients sl was completely visualized, - mm thick and homogenously hypointense. / patients had injury of ptt. among these patients sl was visualized in its medial portion in patients of which had chronic abnormalities of ls. at standard mr examination was not possible to visualize the inferior portion of sl in almost all patients. conclusions: mr seems to be an important diagnostic technique to evaluate sl abnormalities. the high association of sl lesions with ptt injury has to be known and considered when studying patients with proved advanced ptt injury in order to plan correctly the mr study to sl whole examination. primitive muscular hydatidosis: a pictural review of cases a. konan, h. rajhi, n. mnif, m. karray, m. zlitni, r. hamza; tunis/tn purpose: soft tissue involvement by hydatid disease remains unusual even in endemic areas. in this report our aims are to review the imaging findings of muscular hydatidosis and underline possible peculiarity. we review retrospectively patients ( men, women) who underwent surgery for primitive muscular hydatid disease. imaging technique used included ultrasonography (n = ), ct scan (n = ) and magnetic resonance imaging (n = ). results: ultrasonography found multiple anechoic and hypoechoic cystic lesions (n = ), necrozing tumor-like lesion (n = ). ct scan showed evidence of multivesicular cysts in all cases. mri showed typical liquid lesions (n = ), heterogenous signal due to scraps (n = ) and evaluate accurately the extent of involvement. conclusion: in our experience multivesicular cysts is the main lesion showed in primitive hydatidosis soft tissue. ultrasound is still in routine relevant to detect muscular hydatidosis; ct scan and mri confirme the diagnosis and are helpful to demonstrate the relation between cysts and adjacent structures and evaluate extent of involvement before surgical management. results: mri showed degenerative signs. in % disc enhancement was peripheral, parallel to the end plates.the disk enhancement was at l -l in % and l -s in %. it was found in % of end plates inflammation and in % of fatty changes. it was found in % of stage ii and iiia normal or earlier degenerative stages, % of stage iiib and % of iv stage latter degenerative stages. biopsies were performed avoiding disc infection. of the mri of patients with ankylosing spondylitis showed large contrast enhancement parallel to the end plates without end plates inflammation. mri of operated patients showed linear uptake parallel to end plates associated with enhancement in the posterior part of operated disc. mri of patient with infectious spondylitis showed central disk enhancement with end plates inflammation in % and vertebral abscess in %. conclusion: disc enhancement parallel to end plate is a disc degenerative sign in operated and non-operated disc. it may be present in inflammatory conditions as ankylosing spondylitis. central disk enhancement appears to be an infection sign. effectiveness of us-guided core needle biopsy in the diagnosis of musculoskeletal lesions i. lecumberri, j.l. del cura, o. gorriño, i. lópez, a. legorburu, d. grande; bilbao/es purpose: to evaluate effectiveness and accuracy of ultrasound (us) guided core needle biopsy in musculoskeletal lesions. material and methods: us guided core needle biopsies were performed in patients with musculoskeletal lesions imaged by us. all lesions were tumors on us exam, except two that appeared as ill-defined alterations in soft tissues. twelve were arising from or involving bone. location of the lesions was axial in and in extremities in . results of core biopsy were correlated with the final diagnosis, that was based on the exam of surgical specimen in patients who were operated on, and in clinical course in the rest. results: no complications occurred. core biopsy was considered diagnostic in cases. fifty-two lesions were finally diagnosed as malignant and were benign. in cases final diagnosis was different from that of core biopsy. two lesions with non-diagnostic result were finally diagnosed as malignant and another one as benign. five lesions, benign in core biopsy, were diagnosed as a different benign entity after surgery. three lesions, considered benign after core biopsy, were finally diagnosed as malignant. us-guided core needle biopsy achieved % sensibility, % specificity, % positive predictive value and % negative predictive value to detect malignancy in musculoskeletal lesions. in us-visible musculoskeletal lesions, us-guided core biopsy can establish a diagnosis with great accuracy and frequently can avoid other explorations. thus, it should be considered a stable technique in the management of musculoskeletal pathology. extra-abdominal desmoid tumours in the post-partum period: diagnosis and staging with ultrasonography and mri l. dogliotti , m. bazzocchi , n. gandolfo , f. pugliese , f. prefumo , g. serafini ; pietra ligure/it, genoa/it purpose: the extra-abdominal desmoid tumour (eadt) is a rare disease more common in young females. this study describes the ultrasonographic features of eadts, and compares them with mri in the diagnosis and staging of the disease. a total of lesions of the anterior abdominal wall and perineum have been assessed with ultrasonography and mri. six of them were subsequently diagnosed as eadts at histology. of these, were located in the anterior abdominal wall and one, the largest, was embedded within the perineal muscles. all patients were female and reported being pregnant in the year preceding the diagnosis. three had delivered by caesarean section. the ultrasound examination were performed with a - mhz multifrequency transducer. mri imaging employed tse-t w sequences with and without gadolinium, and tse-t w sequences with and without fat suppression. results: in the cases of eadt ultrasonography showed solid homogeneous masses, slightly hypoechogenic compared to the adjacent fibromuscular structures. in the anterior abdominal wall cases, the margins were clearly identified on a transversal plane but spiculated and irregular along the longitudinal plane in out cases. the large perineal lesion (diameter cm) appeared dyshomogenous, but margins were regular and clearly identifiable. at color doppler exami-nation, all lesions showed a rich vascularisation. mri confirmed the fibrous nature of the lesions and helped in the differential diagnosis with endometriosis. conclusion: eadts appear as solid, homogeneous, clearly delimited lesion at ultrasonography. mri is useful for excluding endometriosis in case of dyshomogeneous lesions. retrospective analysis of ultrasound guided core biopsy in the diagnosis of soft tissue masses f.j. perks, i. beggs; edinburgh/uk purpose: to assess the accuracy of ultrasound guided core biopsy of soft tissue masses. we reviewed soft tissue biopsies in consecutive patients. diagnoses were compared to the post excision diagnosis in patients. all core biopsies were performed by the same radiologist using ultrasound guidance. biopsies were performed as outpatient procedures. results: biopsies repeated. ( %) biopsies diagnostic of a wide range of benign and malignant disease. of ( %) biopsies accurately representative of post excision histology. biopsies diagnosed disease that did not warrant excision. false negative biopsies when sampling liposarcoma, lymphoma, chondrosarcoma and metastasis. overall sensitivity and specificity was . % and % respectively. there were no complications. the purpose of this exhibit is to describe the imaging features of sapho in adults. this retrospective study included patients ( women, men). all imaging procedures, radiographs, ct, mri and scintigraphy, were reviewed. background: sapho (acronym for synovitis, acne, pustulosis, hyperostosis and osteitis) is a syndrome of obscure cause, commonly considered to represent a seronegative spondylarthropathy, affecting especially young adults and children and leading to osteoarticular and skin manifestations. osteosclerosis, cortical thickening, enlargement of bone, arthritis are the predominent radiologic pattern, but periostitis and soft tissue swelling also may be seen and these findings can simulate osteomyelitis, sarcoma, lymphoma. imaging findings: of the patients, topographic localizations were the upper anterior chest wall ( %), spine ( %), periphral bones and joints ( %), pelvis ( %), mandible ( . %). the main radiologic findings correlated with hyperostosis, osteitis and synovitis. the radiologist plays a major role in the diagnosis: this exibit reviews the radiologic appearance of this syndrome and illustrates difficulties in differential diagnosis. erdheim-chester disease: detection and staging with multimodality imaging a. miquel , e. dion , c. graef , y. menu , p. grenier , j.-d. laredo ; le kremlin-bicêtre/fr, paris/fr learning objectives: to illustrate the clinical, radiological and histological spectrum of findings in erdheim-chester disease. to be able to recognise the disease in a patient with elementary symptoms. to describe the imaging modalities that are necessary for a precise staging of the disease. background: erdheim-chester disease is a multisystemic histiocytosis associated with characteristic skeletal abnormalities. bone (bone pain), skin (xanthomas), orbits (exophthalmos), pituitary gland (diabetes insipitus), retroperitoneum (hydronephrosis) and lungs may be affected by the disease. the relashionship of the disease with langerhans cell histiocytosis is still unclear. seventeen patients with erdheim-chester disease were evaluated between and , using conventional x-rays, us, ct, bone scintigraphy and mri. radiological-pathological correlations were available in cases. imaging findings: osteosclerosis of long bones in lower limbs is the most common feature ( / cases) and should be a trigger for the diagnosis. mri demonstrates replacement of the high signal of the bone marrow by a decreased signal on t and t -weighted images. atypical osseous manifestations include involvement of ribs, skull and pelvis; focal lytic lesions are seldom encountered ( / ). visceral involvement may affect pituitary gland, orbits, pericardium, lungs, kidneys and retroperitoneum. pathologic study shows accumulation of lipid-laden histiocytes and fibrosis. conclusion: bone lesions are rather specific and should suggest the diagnosis of erdheim-chester disease. detection of visceral involvement, sometimes asymptomatic, requires imaging of brain, lung and retroperitoneum. histological analysis is necessary to assess the diagnosis and differentiate the disease from other cases of histiocytosis, especially langerhans cell histiocytosis. the learning objective: we aim to highlight the manifestations of myeloma using referrals from such specialities as haematology, orthopaedics and general medicine. the classical appearances of myeloma are presented with aids to enable the radiologist confirm the diagnosis and differentiate from other pathologies of similar appearance. background: multiple myeloma is the commonest primary malignant neoplasm and therefore as pathology the radiologist should be mindful of its many appearances. imaging findings: through a pictorial review we show not only the classical appearances of myelomatosis on plain film and bone scans but we also present its' appearance on ct scan and mri. the limitations and benefits of each modality are discussed. furthermore we highlight the recent findings which show that not only is mri better at staging multiple myeloma but compared to the dated "durie and salmon" criteria it negates the need for repeat blood and urine samples. conclusion: multiple myeloma may not always present with classical appearances and therefore it is paramount that a radiologist be aware of some of the unusual forms. through an assortment of imaging modalities we present not only the characteristic appearance but also atypical varieties. vertebral development: normal and abnormal aspects-interactive a. marinescu, a. pavel, h.c. ionescu, g. iana; bucharest/ro learning objectives: the program is conceived as an interactive lesson for those who wants to easy understand the vertebral development and also the pathology of an inadequate development. it is addressed to any radiologist in training. background: the vertebral development consists in three stages: mesenchymal, cartilaginous and bony. during this development appear many centers of the future vertebrae (mesenchymal, chondrifications and ossifications centers).o:p> procedure details: using a graphic presentation (originally and schematically) of the vertebrae for any stage and a color convention (the mesenchimal stage is represented in orange, the cartilaginous stage in blue and the third -the bony stage in pink); you can follow all the steps of the vertebral development. the program is interactive, meaning that you can follow the graphic presentation of the steps of the vertebral development, but also: • if you want to know more about the elements on the graphics, you can use the left button of the mouse clicking on the red sign. • before "details" and you will get the information and explanations. then, you can come back to the slide with the marks ü "details". • you can see, for each type of pathology which can occur in different steps of vertebral development, a graphic presentation and radiography (you press the left button of the mouse on the red sign before "pathology". conclusion: all the radiology trainees in our department have been satisfied with the program, instead of reading some arid pages for this topic. nevoid background: nevoid basal cell carcinoma syndrome (nbccs) is a rare autosomal dominant inherited disorder with complete penetrance but variable expressivity. although many radiologists are familiar with typical findings (e.g. major criteria) of this disease there are also findings that are only rarely demonstrable (e.g. minor criteria). imaging findings: we present nbccs-findings of patients. they include numerous pathologies such as multiple cutaneous basal cell carcinomas, odontogenic jaw cysts, ectopic calcifications of the falx cerebri as well as palmar or plantar pits. characteristic images of the patients faces as well as bifid or fused ribs, vertebral anomalies, bridging of the sella turcica, flame shaped pseudocysts of the hands, lymphomesenteric cysts as well as increased frequency of tumors particularly medulloblastomas and ovarian fibromas that are also very important to recognise will be shown. the radiological findings are specific for this disease and may confirm the diagnosis in combination with the clinical presentation. furthermore early diagnosis as well as periodical follow-up examinations is very important since the nevi after puberty turn out to be aggressive. imaging with pathological correlation of sacral and presacral lesions s.a. o'keeffe, t. geoghegan, w.c. torreggiani; dublin/ie learning objectives: the objective of this poster presentation is to pictorially review the imaging of a series of patients with sacral and presacral lesions and to correlate these with pathology. background: presacral tumours are extremely rare accounting for less than in , hospital admissions. there are many pathological causes as this is an anatomical area of embryologic fusion. a review of reports on the radiology information system (ris) was undertaken to identify those patients who had pre- in this pictorial review, we describe the anatomical contents of the presacral space and correlate this with the possible pathological causes of a lesion in this area. in addition, the imaging and pathology of a selection of sacral and presacral tumours is presented and methods of analysis of imaging are suggested. diagnosis background: chordomas are very rare tumors, for which standard medical therapies are lacking. following detection of pdgf-r expression in tumor samples, it was decided to treat some patients with advanced chordoma with imatinib mesylate on an individual basis. these patients were treated at the istituto nazionale tumori, milano, italy, as from august . imaging findings: five pts with advanced disease ( with sacral, one with clivus chordomas) undergoing imatinib mesylate were evaluated with mri at baseline, and then every months. four pts showed hints of tumor response. these were: i) minor and slow decrease in size in the pt with the longest follow-up, following a transient initial increase in size, which was seen in all pts; ii) hypodensity of lesions on t w images and hyperintensity on t w images; iii) hypovasculature of lesions on contrast-enhanced t w images in comparison to baseline assessment. conclusion: actual responsiveness of chordomas to molecular-targeted therapy with imatinib mesylate is left to be determined. however, preliminary observations suggest that mri may be useful to assess tumor response. signs of response may be subtle, likely depending on changes in tumor tissue rather than (or before) decrease in size. groin pain in athletes: mri findings f. idoate saralegui; pamplona/es learning objectives: this exhibit reviews the rmi findings in athletes with groin pain. background: groin pain is a common complaint in athletes, particularly prevalent among soccer players. this condition is frequently multifactorial, and the differential diagnosis can cover a rather broad area of entities, mainly involving adductor muscle and tendinous group, pubic bone even inguinal hernia. between january and august , athletes with groin pain were examined at our institution. the mri findings of the possible causes of groin pain in athletes are described and illustrated. imaging findings: the examinations were performed in a tesla imaging system (magnetom impact expert, siemens) with a surface coil. t -weighted spin echo and t -weighted fat suppressed turbo spin echo images were obtained in axial plane; stir a t -weighted turbo spin echo sequences were performed in coronal plane. the pathological findings observed were: osteitis pubis, stress fracture of pubic bone, muscle tears (adductor, obturator, rectus abdominis, pectineus, iliopsoas, gracilis and rectus femoris groups), abdomino fascial abnormalities, inguinal hernia, bursitis and inflammation conditions of the spermatic cord. conclusion: mri depicts adequately the numerous pathologic entities related to groin pain in athletes. infection background: prosthetic, graft or catheter infection, irrespective of location, invariably equates with a poor outcome. modern aseptic technique, in addition to the use of antibiotic-coated prostheses, have dramatically reduced the incidence of such infection. aggressive antibiotic suppression is effective in fewer than % of cases, the remainder requiring removal of the infected prosthesis, with associated morbidity, and occasionally, mortality. clinical signs and symptoms are frequently non-specific, including lethargy, pyrexia and anorexia. it is for this reason that quite often the task of locating a causative factor relies upon the expertise of the radiologist. imaging: using a pictorial review we depict the numerous pitfalls in the radiological diagnosis of prosthetic and endovascular graft infections. in addition, a guide to radiological imaging of less frequently encountered infections, such as those of breast and penile prostheses, ventriculo-peritoneal shunts, intra-ocular lens, cardiac pacemakers and valves, will be provided. the limitations and benefits of conventional radiography, digital subtraction angiography, computed tomography, ultrasound, magnetic resonance imaging and radio-isotope scintigraphy with respect to the site of infection will be explored in turn. the radiological diagnosis of infection of synthetic materials is notoriously difficult. the use of these materials for therapeutic, cosmetic and palliative purposes is ever-increasing. it is therefore of vital importance that the radiologist be aware of the advantages and disadvantages of available imaging modalities in arriving at a confident, swift diagnosis. a new method for radio frequency of lumbar disc in treatment of chronic low back pain n. azulay , m. forgerit , a. moumouh , e. alava , p. vandermarq , j.-p. tasu ; poitiers/fr, niort/fr, barcelona/es purpose: treatment of chronic low back pains remains a challenge for physicians. recently, radio-frequency heating of inter vertebral disc has been proposed, as an alternative to surgery. we propose here a new method of discal radiofrequency in which heated water is used to spread the thermal energy. materials and methods: seventeen patients were included prospectively according to the criteria used in previous intra discal radiofrequency studies. the catheter is placed in the nucleus and heated water is used as thermal conductor to burn the annulus nociceptors. intra discal pressure and impedance measurements were used to control the energy delivered during the procedure. clinical results were evaluated by the oswestry score. the treatment was scored as a success with at least a % pain reduction on global perceived effect on oswestry score. the global oswestry before treatment was . points and points b d e f a g after corresponding to a . % improvement. on the patients, were successfully treated ( %). we have shown that injection of heated water is sufficient to spread thermal energy to the anular nociceptor. this method is technically more simple than previous techniques using anular needle, avoiding navigation of the catheter through the anulus. ultra low dose ct in navigated closed reduction and percutaneous screw fixation of pelvic ring fractures h.g. staedele, r. huegli, s. meckel, a.l. jacob, h. roser, p. messmer, j. roth; basle/ch purpose: to reduce radiation doses in image-guided pelvic closed reduction and percutaneous fixation crpf without compromising guidance quality and procedural outcome. prospective study including patients with pelvic ring fractures treated with ct-guided crpf. patients received screws which were navigated over guide pins. imaging modality used was a single slice scanner (general electric, usa). tube current was reduced by % with every step starting with routinely used scan parameters for diagnostic and interventional procedures ( ma). if the image quality was good the next control scan was performed with % reduction of ma again. results: patients with fractures underwent crpf. were males, females, with a mean age of years (range . - . ). dose reduction was possible in all patients in to steps ending up in ma (n = ), ma (n = ) and ma (n = ) respectively. ma is the lowest current provided by the ct. number of misplaced screws was . number of additional correction of guide pin was . number of fallbacks to the next dose level was . conclusion: by lowering scan doses no relevant morphological information needed for safe guidance of instruments and implants was lost. scan protocols can be changed to lower ma values without compromising the safety of crpf. immediate procedural outcome was not affected. withdrawn by authors pelvic painful syndrome in athletes: diagnostic imaging evaluation l. zugaro, f. iannessi, a. catalucci, a. barile, c. masciocchi; l'aquila/it purpose: to describe the imaging features of the anterior and posterior painful syndrome in athletes. materials and methods: athletes ( males, female) suffering from pelvic pain (groin pain = and hamstring syndrome = ) underwent mri after plain film and ultrasound preliminary evaluation. in patients ct evaluation was also performed. mr examination was performed using a . t unit (ge medical system). proton density, t weighted and t weighted sequences on axial and coronal planes were employed. in one case mri was also obtained after surgical treatment. in all cases mri demonstrated pathological findings: anterior painful syndromes were related to osteitis pubis, bursitis, inguinal hernia, post-traumatic muscular lesions and stress fractures. hamstring syndrome was related to insertional pathology of hamstring tendons, inflammation disease of regional bursae and fibrotic changes of fatty tissue surrounding the ischial tuberosity. conclusion: anterior and posterior pubic painful syndromes are painful conditions often affecting athletes. mri provides a correct evaluation of these syndromes enabling an adequate therapy. the value of qualitative and semiquantitative ultrasonographic findings in the differential diagnosis of superficial lymph node enlargements o.o. okten , n. tuncbilek , h.m. karakas ; edirne/tr, malatya/tr purpose: the value of the gray-scale (gsusg), color doppler (dusg), and power doppler (pdusg) ultrasonography in the differential diagnosis of superficial lymph node enlargements were evaluated. the study group was consisted of males and females ( - yrs old, mean age . yrs) in whom physical examination had revealed superficial lymph node enlargement(s). all patients were investigated with power doppler usg (sonoline elegra advanced, siemens, germany) using . mhz linear transducer. longitudinal/transverse dimensions (l/t), edge characteristics and hilar echogenecity of lymph nodes were evaluated with gsusg. pulsatility (pi) and resistivity (ri) indexes were calculated using cdusg. vascular pattern described as hilar or non-hilar were determined by pdusg. above parameters were analyzed to determine their differential diagnostic values using anova based discriminant analysis. results: when clinical data and histopathological findings were combined, subjects were diagnosed as lymphoma, and cases were classified as lymphadenitis. multiple comparison analysis of qualitative gsusg and pdusg features consisting of edge characteristics, hilar echogenecity and vascular pattern was able to differentiate lypmhomatous lymph nodes and lymphadenitis with % accuracy (p < . ). in contrary, semiquantitative features (ri, pi and l/t) were not able to classify lymph nodes ( % accuracy, p < . ). conclusion: semiquantitative rdus parameters are not valuable in the differential diagnosis of superficial lymph node pathologies. qualitative usg and pdusg features, on the other hand, may be used as an alternative work-up to cytological studies in patients in whom diagnostic surgical procedures cannot be performed. modern imaging in langerhans cell histiocytosis a. geoffray, k. oudjhane, l. lau, s. weitzmann; toronto, on/ca purpose: to review imaging features of pediatric langerhans cell histiocytosis (lch) with particular attention to cross-sectional imaging and aggressive cases. we reviewed retrospectively the imaging database of all the cases treated in our institution for lch during a years period (january to december ). there were patients, boys, girls, with an age range of weeks to years. results: patients had no imaging anomalies and were excluded. among the with anomalies, had a solitary bone lesion (skull , orbit , spine , iliac , long bones ), had multiple bone lesions associated with other organ involvement in (lung , liver and spleen , thymus ), patients had no bone lesions ( cervical adenopathy, abdominal involvement, abdominal and lung, pituitary gland, middle ears), patient had lch associated with neuroblastoma, and presented with lymphadenopathy, mediastinal and sacrococcygeal masses. imaging modalities were conventional radiography in %, nuclear scans %, ct %, mr %, us %. conclusion: lch in children is characterized by a wide spectrum of organ involvement. cross sectional imaging is useful in assessing the diagnosis and managing the most aggressive cases. can calcaneal spur help in the evaluation of a painful heel? n. sabir, s. demirlenk, b. yagci, n. karabulut; denizli/tr purpose: to determine the value of presence of calcaneal spur in evaluating painful heels. materials and methods: heels of female and male patients with a mean age of . ± . years and mean body mass index (bmi) of . ± . complaining of bilateral (n = ) and unilateral (n = ) heel pain were studied. lateral radiographs of the symptomatic and asymptomatic heels were obtained to assess presence of calcaneal spur. mr imaging of the symptomatic heels was performed using . t superconductive system. the images were taken and reviewed for presence of plantar fasciitis (pf). heel pad thickness was also measured. results: calcaneal spur was seen in of ( %) symptomatic and in of ( . %) of asymptomatic heels. mr has revealed pf in of ( . %) painful heels and calcaneal spur was present in of the cases with pf. calcaneal spur was significantly correlated with weight (p < . ), bmi (p < . ), age (p = . ), heel pain duration (p = . ) and pf (p < . ). no correlation was seen between calcaneal spur and both height and heel fat pad. conclusion: although calcaneal spur is not the cause of pain, it may provide an objective assessment of the changes due to chronic repeatitive trauma to plantar fascia secondary to obesity or age. on the other hand foot radiography should be part of the initial diagnostic methods as it helps in excluding different causes of heel pain. purpose: the positive areas in scintigraphy of sentinel lymph nodes are sometimes difficult to be anatomically identified. we have examined the usefulness of bone scintigraphy performed together with lymphoscintigraphy for identification of the anatomical positions of the positive area in lymphoscintigraphy. materials and methods: sixteen patients, cases of malignant melanoma and cases of squamous cell carcinoma were examined by lymphoscintigraphy. nine patients, cases of malignant melanoma and cases of squamous cell carcinoma, were examined by bone scintigraphy together with lymphoscintigraphy. the patients were divided into three groups. in the first group, lymphoscintigraphy was performed alone. in the second group, the patients were first injected intravenously with tc- mhmdp or tc- mmdp and then lymphoscintigraphy was performed after intradermal administration of tc- m sulphur colloid. three hours after injection of tc- mhmdp or tc- mmdp, bone scintigraphy were taken. in the third group, lymphoscintigraphy was performed minutes after bone scintigraphy. result: anatomical identification of the positive areas in lymphoscintigraphy was difficult when used alone, whereas their identification became easier when used together with bone scintigraphy. when bone scintigraphy was performed after lymphoscintigraphy, evaluation of lesions in the bones near the original focus was sometimes not easy. however, evaluation of lymphoscintigraphy was not affected by prior performance of bone scintigraphy. conclusion: identification of the anatomical positions of the positive areas in lymphoscintigraphy was easier when used together with bone scintigraphy than in lymphoscintigraphy alone. in cases of the joint use, lymphoscintigraphy should be operated after bone scintigraphy. ultrasonographic detection of iatrogenic foreign bodies in an in vitro study i.k. rozylo-kalinowska, l. barczewski, e. szczepanik, r. lenard; lublin/pl purpose: sometimes foreign bodies being parts of surgical appliances remain in soft tissues as a result of iatrogenic faults. their presence is dectected clinically or radiologically, when the objects are radiopaque. nevertheless, radiolucent or faintly radiopaque objects often are a diagnostic challenge as their presence is difficult to diagnose on the basis of conventional radiograms. the purpose of the study was application of ultrasonography for detection of radiolucent and faintly radiopaque foreign bodies in an in vitro model. examples of radiolucent and poorly radiopaque foreign bodies such as plastic fragments of syringes, intravenous catheter, different cotton and gauze swabs, were embedded in containers filled with gelatine, which served as a model of soft tissues as well as played the role of a stand-off pad. the ultrasound scanning was performed by means of atl hdi machine with a high-frequency broadband linear transducer. results. there was determined the possibility of detection of various types of foreign bodies. there were described ultrasonographic image patterns of different objects. image findings: all types of used materials were well visible and hyperechoic in ultrasound image. plastic objects caused appearance of reverberation artifacts. the swabs produced characteristic patterns of internal structure. variations in ultrasonographic image patterns of foreign bodies studied in vitro allowed differentiation of various types of the examined materials. conclusion: ultrasonography may become a useful, widely available and costeffective tool in detection and localisation of foreign bodies of iatrogenic origin that otherwise remain undetected. spectrum of mr findings of herniation pit of the femoral neck m. ferrer, r. dominguez, m. romera, e. castella, x. merino, l. casas; barcelona/es background and purpose: herniation pit of the femoral neck has been considered a normal variant. this lesion is located in the superior aspect of the femoral neck, below the anterior cortex of the femur. the aim of this study was to describe the spectrum of magnetic resonance imaging (mri) findings associated with herniation pit of the femoral neck. material and methods: we retrospectively reviewed the mr studies in patients with hip pain performed in our hospital over the last years. a total of patients presented herniation pit. the features analyzed included: type of herniation pit (unilateral/bilateral), iliofemoral ligament thickening and asymmetry, iliopsoas muscle/femoral head relationship, acetabular coverage angle, cervicodiaphisary angle, femoral anteversion angle, and associated imaging findings (synovitis). results: in patients with hip pain and herniation pit, the following data were found: no other apparent cause of the pain ( %), iliofemoral ligament thickening ( %), decreased acetabular coverage angle ( %), altered cervicodiaphisary angle ( %). the elevated incidence of alterations in acetabular coverage and cervicodiaphisary angle in herniation pit, together with other alterations in stabilizing elements, lead us to suggest that, rather than a separate entity, herniation pit can be considered a component of the spectrum of adult hip dysplasia. b d e f a g high resolution ultrasound of the peripheral nerves of the lower limb: technique of examination and normal us appearance x. montet , s. bianchi , c. martinoli , j. fasel ; geneva/ch, genoa/it objective: to present the basic normal us appearance of peripheral nerves evaluated in vitro and in vivo. to describe the examination technique, the normal us findings and the main anatomic variations of the nerves of the lower limb. materials and methods: us images were obtained with commercially available equipment utilizing two linear probes ( - , - mhz). the normal us appearance of a peripheral nerve was evaluated by in vitro examination a human sciatic nerve. sonograms were then obtained in normal volunteers and correlated with mri and images from anatomic textbook. results: the in vitro us appearance of the a normal peripheral nerve correlates well with the internal nerve structure. fascicles appear as hypoechoic bundles embedded within the hyperechoic connective tissue. the normal anatomy of the sciatic, peroneal, tibial nerve is first briefly described. then for each nerve the scanning technique is presented with emphasis on patient position, probe orientation and dynamic maneuvers. to improve the understanding of us images, correlative drawings showing the adjacent anatomic structures and diagrams showing the position of the probe are presented. high frequency transducers allow a detailed analysis of even smaller peripheral nerves. we present a practical manner to realize a us examination of the nerves of the upper extremity as well as us images of normal nerves and of their main anatomic variants. withdrawn by authors radiologic and sonographic examinations in patients with heterotopic ossifications j. nagy; budapest/hu purpose: to evaluate the diagnostic capability of radiologic and ultrasonographic examinations in patients (pts) with heterotopic ossifications (ho). during the last four years we have examined pts ( women, men; age: / - / years) in case of the clinical suspicion of ho. dynamic conventional radiologic and ultrasonographic ( . mhz linear transducer) examinations were performed. results: in the background of ho, spinal cord injury ( pts, %), brain injury ( pts, %), limb damage ( pts, %), orthopedic surgery ( pts, %) or limb amputation ( pts, %) were found. the most frequent localizations of ho were as follows: one side ( pts) or on either of the sides of the hip ( pts), elbow ( pts), knee ( pts), hip + knee ( pts) or rare localizations (around the femoral stump) ( pts). more than one localization was found in half of the pts. when the clinical suspicion of ho was not proved by radiology, dynamic ultrasonographic examinations were positive in each cases ( pts, %). conclusions: ( ) ho can occur in more than one localization after cns or limb injuries, ( ) the most frequent localization was around one or both hip joints, ( ) sonographic examinations showed earlier positivity compared to conventional radiology, ( ) rare localizations of the ho can induce differential diagnostic problems in clinical practice. ultrasonographic experiences of spine-related lesions in patients with back pain: correlation with mri w. jin; incheon/kr purpose: multiple paraspinal lesions or spine-related lesions have been overlooked on transabdominal ultrasonograhic examination. therefore, we correlated transabdominal ultrasonographic findings with mri findings in spine-related lesions. materials and methods: patients were underwent transabdominal ultrasonographic examinations for routine check prior to surgery. they were men and women aged to (average, ) years. all patients also were checked with mri. in transabdominal ultrasonographic examination, compression of abdominal wall and inner contents were done. after this, we observed closely the contour of body, the height of body, disc height, and paraspinal lesion. results: in patients, there were ) compression fractures or burst fractures; patients, ) spondylitis; patients, ) bone tumorous condition; patients, ) abscess formations in paraspinal muscle; patients, ) ankylosing spondylitis; patient, and ) disc herniation; patients. in these patients, transabdominal ultrasonographic findings were relatively correlated with mr findings, but lesions in posterior and middle elements of spine could not be evaluated with transabdominal ultrasonographic approach. conclusion: despite of many limitations of transabdominal ultrasonographic examination for detection of spine and paraspinal lesion, when spine and paraspinal structures or lesion are visible on transabdominal ultrasonography, ultrasonography suggested to be a screening method in patients with back pain. in particular, ultrasonography was superior to mri in detecting the minimal change of anterior disc, prediscal space, or anterior longitudinal ligament of spine. creation of a radiological musculoskeletal database (db) for statistic referrement, differential-diagnosis and didactic use (stuart project) s. trupiani, e. baldan, r. stramare, c. saccavini, l. bacarini, g. feltrin; padua/it purpose: to create a radiological db, with normal and pathologic cases, to be used for statistic endings, differential-diagnosis and for consultation. the db is available to everyone who as investigation or consultation needs or else for cases submission; for this reason is necessary to follow some fixed criteria unless the case is not accepted. the submission modalities have a starting schedule that contains: patient's anagraphic data, documentation source, sequence of technical-methodological procedures used, a description of every semeiological aspect contained in every single image, gamuts criteria-based diagnosis and final diagnosis. the cases are resumed by acr code. the definitive diagnosis, that contain a synthesis of anatomical-clinical and diagnostic aspects about the pathology observed, is open to critical observations by everyone that is consulting the db. every db consulter is able to introduce his opinion in a special window. the case report ends with a bibliographic correlation that contains the latest literature articles about the argument. the db contents can be utilized as a cases archive for clinical research (for this aspect, very important is the acr code), or as a support in the diagnostic report making, or as a didactical archive. moreover the db users can exchange their opinions, modify or add informations for every case by the web. ment was present in cases ( . %) and discal involvement was present in case ( . %). patients had soft tissue involvement and abscess was present in patients. all cases showed vertebral and discal enhancement. patients showed diffuse involvement of vertebral corpus and patients showed endplate involvement. cases showed both vertebral corpus and endplate involvement. intervertebral space narrowing was present in cases, height loss in vertebral body was observed in cases and cases showed end plate deformities. we detected epidural extension in cases, posterior longitudinal ligament (pll) elevation in , spinal cord compression in and root compression in cases. conclusion: spondylodiscitis is a rare complication of brucellosis and it can cause permanent neurologic deficits and spinal deformities. mri is a very sensitive and non invasive imaging technique which must be firstly preferred for the early diagnosis of spondylodiscitis. imaging findings: a total of aneurysms in patients were evaluated. all were proved at surgery. five small aneurysms were not depicted at d-cta-ssd (three were less than mm, two were less than mm). but only three small aneurysms were missed in d-cta-vrt (two were less than mm, one was less than mm). in ( %) of the patients, d-cta-vrt gave additional informations: orientation (n = ), defining exact neck anatomy (n = ), incorporation of vessels into aneurysm (n = ), lobulation (n = ), and blebs of aneurysms (n = ). conclusion: d-cta-vrt is superior to d-cta-ssd in the detection of very small aneurysms and evaluation of complex anatomy of intracranial aneurysms. gadolinium enhanced ultra-fast mra: a primary diagnostic tool in the recognition and follow-up of dural sinus thrombosis s. gaudino, t. tartaglione, f. molinari, v. valentini, c. colosimo; rome/it dural sinus thromboses (dst) are not extremely rare, they still account for % of ictus in young adults. they need an accurate diagnosis at the onset of symptoms, and during the follow-up, to reduce the risks related to prolonged thrombolytic therapy. digital subtraction angiography (dsa) and, in the last years, phase contrast mr angiography (pc mra) with conventional mr sequences have become the methods of choice for dst diagnosis. our purpose was to evaluate the usefulness of gadolinium-enhanced ultrafast mra (ge-uf mra), routinely employed in supra-aortic vessel evaluation, in the diagnosis and follow-up of dst. materials and methods: we retrospectively evaluated patients with diagnosis of dst, studied using . t magnet, conventional se, tse and ge-uf mra sequences. we could compare ge-uf mra images with dsa in patients and pc mra in patients. results: in all dsa controlled patients, we found a complete agreement between ge-uf mra and dsa concerning location and extent of dst. in all patients with both ge-uf and pc mra, the overall dst diagnosis was identical, even if the diagnosis of minimal dural sinus involvement was easily and definitively assessed with uf-ge mra, which allows a superior diagnosis confidence. conclusions: our preliminary experience suggests that ge-uf mra is a very fast modality, is easily obtained and analyzed and has a superior diagnostic confidence compared to pc mra. in our opinion ge-uf mra should be proposed as the primary diagnostic tool in the recognition and follow-up of dst. imaging imaging appearances: the images were obtained using unenhanced ct and routine mri sequences for brain imaging (ie sagittal t , axial t and coronal proton density weighted sequences). fat suppression sequences were sometimes used for further clarification. the characteristic ct and mri appearances of intracranial fat and the anatomical location of the lesion allow the provision of a narrow differential diagnosis using routine imaging protocols. this facilitates decisions on the need for further imaging modalities. background: vascular dementia represents a very heterogeneous diagnostic category. utilizing the ninds-airen criteria and a centralized imaging rater to determine eligibility for enrollment in recent large-scale clinical trials testing new treatments for vascular dementia has provided increased consistency in the diagnosis of vad. the diagnostic criteria for probable vascular dementia include the development of dementia temporally related to stroke with neuroimaging confirmation. the criteria include a table listing brain imaging lesions associated with vascular dementia. in this study, patients have been screened for the presence of cerebro-vascular disease using brain ct or mri. imaging findings: the wide spectrum of neuroradiological features that are associated with vad may result from cerebral small-vessel disease with extensive leukoencephalopathy or lacunes (basal ganglia or frontal white matter), or may be the consequence of single strategically located infarcts or multiple infarcts in large-vessel territories. it may also be the consequence of global cerebral hypoperfusion, intracerebral hemorrhage or other mechanisms such as genetically determined arteriopathies. conclusion: neuroimaging is required for confirmation of cerebrovascular disease in vad and provides information about the topography and severity of vascular lesions. neuroimaging may also assist with the differential diagnosis of dementia associated with normal pressure hydrocephalus, chronic subdural hematoma, arteriovenous malformation or tumoral diseases. imaging spectrum of cerebral complications after cardiac surgery e. testempassi, g. katsou, v. vantali, m. kolios, d. exarchos, d. chondros; athens/gr learning objectives: to present a systematic approach to imaging findings of cerebral complications caused by cardiac surgery. to review and understand the mechanisms and pathophysiology of cerebral involvement after cardiac surgery. background: a wide spectrum of neurologic complications may occur after cardiac surgery, such as motor, sensory or visual disturbances, stupor or depression of consciousness. the role of imaging in differentiating a variety of conditions that may cause the above neurologic symptoms is very important. morphology and patterns of cerebral lesions also enables an assessment of the pathophysiology and hemodynamics of brain complications after cardiac surgery. we retrospectively reviewed the brain ct images of symptomatic patients, who previously had cardiac surgery performed. imaging findings: a variety of common and uncommon findings on ct and mr images of neurologic complications after cardiac surgery are illustrated. acute infarctions involving a vascular territory, hemorrhagic infarctions, multiple infarctions, watershed infarctions, bilateral infarctions, braistem and cerebellar infarctions, uncal herniation, brain edema and inflammatory processes are depicted. preoperative cerebral ct or mr images are helpful in diagnosing new lesions in patients with old infarctions, lacuna or ischemic leucoencephalopathy. the radiologist must be familiar with the imaging appearance of complications that affect the brain after cardiac surgery. imaging findings of an ethmoidal dural arteriovenous fistula with venous drainage in the vein of galen v.t. skiadas, a. prasouli, p. mitseas, g. kottas, s. laxanis; athens/gr learning objectives: to illustrate the mri, mra and angiographic findings of an ethmoidal dural arteriovenous fistula (avf) in the anterior cranial fossa. background: ethmoidal avfs are rare vascular anomalies. only cases have been presented since , when they were first described by lepoire. they can be either congenital or acquired lesions. ethmoidal arteries are the main feeding vessels. the vast majority drain to the superior sagittal sinus and to the cavernous sinus. the presenting symptom is intracranial hemorrhage, mostly subarachnoid or intracerebral. their propensity for hemorrhage justifies immediate surgical removal of the lesion. imaging findings: an mri scan was performed demonstrating an abnormal region of signal void, suggesting a vascular anomaly involving the base of the left frontal lobe. for further evaluation, the patient underwent an mra examination. a vascular linear lesion, probably a vein, at the base of the left frontal lobe and enlargement mainly of the left, as well as of the right ocular artery was discovered. a digital subtraction angiography (dsa) was performed and an edaf on the left ciribriform plate supplied by bilateral ethmoidal arteries was revealed. it drained via a dilated abnormal vein to the left vein of galen. so far, only one other case has ever been reported with venous drainage to the vein of galen. conclusion: specific mri and mra imaging findings should arouse the suspicion of an edaf and dsa can effectively demonstrate the nidus of the lesion, as well as the feeding and draining vessels and confirm the diagnosis. functional based on the hypothesis of focal cortical inhibition, low-frequency transcranial magnetic stimulation (tms) was used, resulting in a slight reduction of hallucinations in some patients. in this case study, functional magnetic resonance imaging was employed to image blood oxygenation level dependent (bold) effect changes in the temporal lobes under tms-therapy. methods: in a curative attempt, a -year old schizophrenic patient (dsm-iv) with medication resistent acoustic hallucinations was treated with low-frequency tms (fstim = hz) over a four week period. fmri was performed in a . t clinical scanner using the standard head coil and a ge-epi sequence. the tmseffects were detected based on the event related bold-fmri of auditory hallucination and auditory hallucinations rating scale. fmri was performed prior to and after the tms series to visualize possible cortical activation changes in the stimulated area. data analyses were performed with spm (http:// fil.ion.ucl.ac.uk.spm). results: after the third week, the patient presented a reduced frequency of acoustic hallucinations of approx. %, while the loudness of the hallucinations remained unchanged over the weeks of stimulation. fmri demonstrated a bold effect activation reduction after tms in speech related areas, which exceeded the local stimulation area. discussion: fmri data revealed an activation reduction in temporal and temporo-parietal areas after tms corresponding to the clinical recovery. the combination of tms and functional imaging is promising, allowing an insight into neuro-biological mechanisms during tms intervention, which may help to improve treatment success. went immediate hyperbaric oxygen (hbo) therapy and the initial result was excellent. he was discharged with subtle weakness in the right lower extremity. the second woman didn't undergo hbo therapy and was discharged with left hemiparesis. imaging findings: mr imaging with diffusion-weighted images (dwis) and adc maps were performed at admission. the first man showed high signal intensities bilaterally of the perirolandic cortex and occipital cortex on t -weighted images (t wis) and dwis. these areas showed dark signal intensities on adc maps, suggesting cytotoxic edema. the second woman showed high signal intensities bilaterally of the perirolandic cortex, bilateral globus pallidus and left occipital periventricular white matter on t wis and dwis. these areas also showed dark signal intensities on adc maps. conclusion: mr imaging findings are similar to co poisoning in that cytotoxic edema involves the globus pallidus bilaterally. but we experienced some different mr imaging finding to co poisoning in that cytotoxic edema involves the perirolandic area bilaterally, which can be seen in profound perinatal asphyxia in term infants. computed tomography angiography ( volumic acquisition of the brain with multislice detector ct at arterial phase is analyzed systematically with d maximum intensity projection (mip). in most cases, volume rendering reconstructions are also performed. all patients with negative cta have a conventional cerebral angiography to visualize entire intracranial circulation. cta and conventional cerebral angiography are performed by senior neuroradiologists. imaging findings: multislice detector cta explores all the locations of intracranial aneurysms. cta is a quick and reliable technique for the detection and therapy planning of intracranial aneurysms. rarely, cta depicts arteriovenous malformations. in some cases, hemorrhage suggests cerebral venous thrombosis that is also diagnosed on cta. we present selected cases emphasizing the utility and the limits of the technique. conclusion: cta is a non invasive, reliable tool to explore patients with non traumatic intracranial hemorrhage. the use of cerebral cta by expert neuroradiologists allows a significant reduction of the number of emergency diagnostic angiography required. brain activations during bi-script reading in chinese: a direct comparison of alphabetic and non-alphabetic reading using functional magnetic resonance imaging (fmri) y. li , x. feng , y. chen , w. tang ; shanghai/cn, oxford/uk learning objectives: a direct comparison between reading alphabetic and nonalphabetic scripts was done using fmri during bi-scripts reading of chinese characters and its alphabetic sound symbols known as pin yin. background: six mandarin speakers and skilled readers of chinese participated in this study. all the subjects were right handed. experiments were performed on ge mri scanner at the huashang hospital. sixteen slices covering the whole brain were collected with blood oxygenation level dependent (bold) sequence. the anatomical images were obtained in the transverse plane during the same scan session with d fspgr sequence after the functional measurements. the four types of stimuli were distributed equally in two main conditions i.e. chinese and pinyin. in each condition, half stimuli were words and half were non-words. data analysis was carried out using feat, the fmrib easy analysis tool, an extension of medx. imaging findings: the activations in the right inferior frontal gyrus, the left fusiform gyrus, the bilateral cuneus and the bilateral superior frontal gyrus were stronger for chinese character reading than for pinyin reading. the activations in the bilateral supramarginal gyus, the bilateral superior parietal gyrus and the bilateral middle frontal gyrus, however, were stronger for pinyin reading than for chinese character reading. different parts of the middle temporal gyrus were also activated for reading these two scripts. the low hemispheric lateralisation for both chinese character and pinyin reading indicate an important role for both hemispheres in reading. conclusion: fmri is one of the best methods of illustrating difference of brain activations during alphabetic and non-alphabetic reading. mri of the brain in inherited neurometabolic disorders: a pictorial review s.p. prabhu, s.a. barnard, n. stoodley, s.a. renowden; bristol/uk learning objectives: to illustrate typical mri appearances of the brain of patients with inborn errors of metabolism and toxic inherited white matter disease. a simple algorithm to unravel the possible cause of imaging findings is incorporated as part of this presentation. background: the diagnosis of a neurometabolic disease is usually suggested by clinical history and physical findings and is confirmed by appropriate special studies, which may include neuroradiological investigations. when the patient is referred with a nonspecific diagnosis, such as delayed development, the aim is to suggest the possibility of a neurometabolic disorder and initiate further evaluation including possible therapy and genetic counselling. on occasion, routine neuroradiological studies may incidentally produce results suggestive of a neurometabolic disorder. imaging findings: disorders including glutaric aciduria, pyruvate dehydrogenase deficiency, leigh's encephalopathy, maple syrup urine disease, methylmalonic aciduria, adrenoleukodystrophy, metachromatic leukodystrophy, krabbe's leukodystrophy and pelizaeus-merzbacher disease are illustrated. a pattern approach based on which part of the brain is affected is used to provide an aid to the diagnosis. conclusion: magnetic resonance imaging plays an important role in the identification, localisation and characterisation of underlying white matter abnormalities in affected patients and is also extensively used to monitor the natural progression of such disorders and the response to therapy. background: to compare d-dsa with d-dsa and d multi-detector ct angiography (cta) with vrt in the detection and evaluation of intracranial aneurysms. imaging findings: a total of aneurysms were evaluated. seven very small aneurysms (diameter less than mm) and two small aneurysms (less than mm) that were not depicted at conventional d-dsa and d-cta-vrt were depicted at d-dsa and all were proved at surgery. in ( %) of the patients, d-dsa gave additional informations: orientation (n = ), defining exact neck anatomy (n = ), incorporation of vessels into aneurysm (n = ), lobulation (n = ) and blebs of aneurysms (n = ). conclusion: d-dsa is superior to d-dsa and d cta-vrt in the detection of very small aneurysms and evaluation of complex anatomy of intracranial aneurysms. low background: dwi is a useful diagnostic tool that improves our background understanding to pathology. the b-value choice has a significant repercussion on signal-to-noise ratio, dwi contrast and t shine-through phenomenon. we have created a straightforward animated microsoft power point presentation showing diffusion physical principles and its imaging consequences. the dwi studies from normal subjects and patients (including brain tumours, encephalitis, demyelinating and cerebrovascular diseases) were further analyzed. all studies were b d e f a g carried out with three different b-value ( , , s/m ). exponential images and apparent diffusion coefficient (adc) maps were subsequently computed. in normal individuals, the signal and adc in the hemispheric white matter, basal ganglia and brain cortex were measured. lesions' signal with different bvalues, and their contrast rate on computed maps, were subjectively compared. imaging findings: when we visualised some acute lesions, higher b-values improved contrast compared with lower b-values. other lesions, like tumours, showed mixed dwi intensities and their contrast also improved with high b-value images. exponential and adc maps were useful for discarding t shine-through effects, moreover with low b-values, but contrast rate was significantly dismissed. conclusion: high b-value dwi provides a better contrast and a reduced t shinethrough phenomenon but it does not display more lesions than low b-value dwi. as computed maps add useful information to that provided by dwi, it seems that the b-value choice depends on each group preferences. utility of mr spectroscopy, diffusion and perfusion mr imaging in the evaluation of brain lesions in aids patients l. . diffusion weighted imaging were performed using a diffusion gradient of sec/mm applied in three axis planes. mr perfusion was performed using tr ms and te ms, following bolus infusion of intravenous contrast material, obtaining relative cerebral blood volume maps (rcbv). to determine metabolites a mr spectroscopy (mrs) was performed with single-voxel press- sequence. we classified the brain lesions in two majors groups: one with brain lesions that cause mass effect (n = ) and the other with infiltrating white matter lesions (n = ). three patients did not have any lesion. mass effect lesions could be inflammatory/infectious diseases: toxoplasmosis (n = ), tuberculosis (n = ), cryptococcosis (n = ) and neoplasic lesions: lymphoma (n = ). as infiltrating white matter lesions, we included progressive multifocal leukoencephalopathy (n = ), hiv encephalopathy (n = ), cmv infection (n = ) and hsv infection (n = ). brain infarct (n = ) is an important condition in aids patients and is more prevalent than in the general population. the mrs, diffusion and perfusion mri have been shown to be extremely useful in characterizing and making the correct diagnosis of brain lesions in aids patients. "string-knot shape" enhancement: a presenting feature of cerebral sparganosis in mri c. shuguang; shanghai/cn learning objectives: to describe the mri character of cerebral sparganosis. background: the cases of cerebral sparganosis have shown a trend of increased frequency with the change of eating habits, especially eating under-cooked products of snake or frog. there is sparse literature available which illustrates nonspecific findings of cerebral sparganosis in mri including nodular lesions, white matter degenerations or haemorrhages. mr imaging of six patients with cerebral sparganosis were reviewed retrospectively in our exhibit. imaging findings: all six cases of cerebral sparganosis showed a single lesion. the location of lesions were superficial with three in the parietal lobe, one in the frontal lobe, one in the temporal lobe and one in the posterior part of brain stem. five lesions were irregular in shape and about cm diameter with moderate hypointensity on t wi and hyperintensity on t wi. a presenting feature of the parasitic granuloma was a "string-knot shape" enhancement, which was demonstrated in cases. one case showed a cystic lesion with peripheral enhancement. there was slight hyperintensity surrounding the nodular lesions which corresponded to edema. no white matter degenerations or hemorrhages were revealed which had been described by previous studies. diagnosis of sparganosis was made on the basis of characteristic enhancement in mri for cases and one was diagnosed as parasitic infectious disease. during surgery, live larvas of sparganum were successfully removed in five cases with "string-knot shape" enhancement lesions. in the case with a cystic lesion, only fragments of worm body were obtained. conclusion: "string-knot shape" enhancement is a characteristic mri finding which has a high value in diagnosis of cerebral sparganosis. cystic lesions of the brain: a pictorial essay with mr imaging s. cakirer, m. basak, e. serin, i. ince, m. birinci; istanbul/tr learning objectives: to illustrate the spectrum of intracranial cystic lesions. to clarify the underlying reasons for specific mr appearances. to define the role of additional mr sequences for differential diagnosis of cystic lesions with similar appearances. background: intracranial cystic lesions are common in radiological practice. the differential diagnosis of intracranial cystic lesions includes a wide spectrum of diseases and is much easier with the use of standard and advanced mr imaging techniques including diffusion and perfusion-weighted studies and mr spectroscopy. between january and august , patients with intracranial cystic lesions were studied in our institute. mr imaging characteristics of the lesions, the underlying reasons for the specific mr appearances and the role of additional mr sequences for the differential diagnosis were defined following the categorization of the lesions. imaging findings: intracranial cystic lesions can be categorized into five groups. they include cystic components of primary and secondary neoplasms (glioblastoma multiforme, pilocytic astrocytoma, pleomorphic xanthroastrocytoma, ependymoma, ganglioglioma, central neurocytoma, hemangioblastoma, macroadenoma, craniopharyngioma, metastases), benign developmental cysts (arachnoid cyst, colloid cyst, epidermoid cyst, dermoid cyst, pineal cyst, rathke cleft cyst, choroid plexus cyst), post-infectious and inflammatory cysts (abscess, parasitic cysts including cystisercosis and hydatid cyst, multiple sclerosis, adem), post-traumatic or post-infarct cysts (porencephalic cyst, encephalomalacic cyst, leptomeningeal cyst) and normal variant cysts (enlarged tumefactive perivascular spaces, cavum septum pellucidum, cavum vergae). the underlying reasons for mr appearances of cystic lesions, role of additional sequences for their diagnosis and differential diagnoses between lesions with similar appearances have been evaluated. cta was performed on a single-slice spiral ct scanner (hispeed lxi, ge) with slice thickness mm, reconstruction interval . mm and pitch . an area from base of the skull to above the clinoid processes was covered. a non-ionic contrast medium was injected in cubital vein ( mgi/ml, ml/ s, ml) and scanning started after delay of - s. corresponding d image reconstructions (maximum intensity projection (mip) and volume rendering (vr)) were produced at accompanying workstation (aw . , ge). conclusion: intracranial aneurysms were visualized in of patients, but only were further evaluated. although intra-arterial dsa is still regarded as "gold standard" in diagnostic evaluation of the sah, cta can serve as guidance for intervention. proton mr spectroscopy of the brain: patterns and pitfalls in diagnosis of brain tumors c.c.t. lim, h. parmar, h. yin, v.g.e. chua; singapore/sg learning objectives: to review typical spectral patterns of brain tumours and non-neoplastic lesions and to understand the potential mimics and pitfalls in using proton magnetic resonance spectroscopy (mrs). background: mrs provides metabolic information that is independent of conventional mr imaging. mrs has been applied to distinguish brain tumors from other diseases and is available on many clinical scanners. post-processing of single-voxel and multi-voxel studies may be presented either as metabolic spectra or parametric maps in the latter. imaging findings: in brain tumours, there is elevation of choline (a marker of cell membrane turnover) and decreased n-acetyl aspartate (a neuronal marker) and creatine (an energy substance). lactate and mobile lipids are sometimes present. conversely, non-neoplastic lesions typically do not show increased choline. lactate is sometimes detected in ischemia, abscess and demyelination. toxoplasmosis and tuberculomas typically show a dominant lipid peak. bacterial breakdown products including acetate, alanine and succinate are detected in abscesses. occasionally, increased cellular infiltrates and reactive astrogliosis may result in elevated choline levels, mimicking tumour. conclusion: with increasing clinical application of mrs, radiologists should be familiar with common spectral patterns of brain disease as well as the potential pitfalls in interpretation. decreased signal intensity on t -weighted mri in the basal ganglia in patients with white matter disorders p. arguis, s. capurro, j. berenguer, t. pujol, m. olondo, j.m. mercader; barcelona/es learning objectives: to describe some aspects of brain iron metabolism which can be studied by mri. to learn how decreased signal intensity on t -w images in the basal ganglia can be seen in several white matter disorders. background: the iron is taken up by capillary endothelial cells in basal ganglia and then is transported axonally to projection sites where it is used in local metabolism, there the iron is stored in oligodendroglia cells. interruption of normal axonal transportation of iron caused by white matter abnormality might lead to increased accumulation of iron at the basal ganglia since it could still be taken up but not be transported. it is generally accepted that there is a correlation between the accumulation of iron in the extrapyramidal system and the degree of hypointensity observed at this site on t -weighted images. imaging findings: low signal intensity on t -w images were observed in the basal ganglia in patients with different white matter disorders (congenital, multiple sclerosis, postradiation toxicity, ischemia, aids-related and tumoral). mr studies were performed with a . t scanner. conclusion: decreased signal intensity on t -w images in the basal ganglia can be seen in several white matter disorders. typical background: wernicke encephalopathy (we) is a severe neurologic disorder caused by thiamine deficiency related to malnutrition or malabsorption of b vitamin that occurs mainly, but not exclusively, in alcoholic patients. we reviewed the risk factors as well as the usual and unusual clinico-radiological features including two cases in non-alcoholic patients (one with gastroesophageal reflux and other with pyloric stenosis secondary to biliogastric reflux). a third of patients with acute we present with the classic clinical triad: opthalmoplegia, ataxia and confusion. other initial manifestations are hypothermia, hypotension, coma, nutritional polyneuropathy, cardiovascular involvement. early diagnosis is crucial because of non-specific clinical findings, a high mortality rate but a possible complete recovery with immediate thiamine replacement. imaging findings: typical mr findings include symmetrical signal changes in medial thalami, tectum and periaqueductal region. in the acute stage, enhancement after contrast injection may be visible in these regions as well as in the mamillary bodies, but at chronic stages atrophy is the main finding. atypical features described include signal changes in the cerebellum, dentate nuclei, pons, red nuclei, basal ganglia and central and precentral sulci. massive haemorrhages are rare whereas microscopic foci are frequent. differential diagnosis includes de/dysmyelinating disorders, infarctions and creutzfeldt-jakob variant but symmetrical distribution of findings rules out most of them. conclusion: we is a reversible, severe disorder and a high index of suspicion is recommended to diagnose it, even in non-alcoholic patients. to determine whether functional mr imaging sequences (diffusion tensor, tractography, perfusion, spectroscopy, blood oxygenation level dependent-bold), can help add new information to the pre-surgery approach to brain tumors. to determine the efficiency and efficacy of these news tools in evaluating brain tumors. during the period of months, mr exams of patients with brain tumors ( men, women; mean age . years) were performed in a . t clinical scanner (siemens, germany) , using mr clinical standard protocol and functional sequences (diffusion tensor imaging, perfusion, spectroscopy and bold sequence). all the patients had their histopathology diagnosis confirmed by brain biopsy and surgery; glioblastoma multiforme (n = ), anaplastic astrocytoma (n = ), low grade glioma (n = ), gliomatosis cerebri (n = ) and metastases (n = ). high grade glioma and metastases had hyperperfusion, high picks of choline and low n-acetylaspartate (naa). low grade glioma and gliomatosis cerebri had low relative cerebral blood volume, low naa, high choline and myoinositol. diffusion tensor imaging showed alterations of the main tracts within and nearest the high grade tumors. low grade tumors had main tracts dislocated but not interrupted. the white mater tract were preserved in gliomatosis cerebri. bold sequence identified the sensory-motor and language activating areas. mr imaging has been used to evaluate brain tumors. with new neuroimaging advanced tools, we can do this analysis in a more accurate and precise way and it takes less time than it was thought to. it is a huge contribution to the evaluation and management of patients, providing a type of diagnosis close to histopathology diagnosis. individual approach to recanalization treatment of acute ischemic brain contrast-enhanced mra were obtained three to five days after the insult. we retrospectively reviewed the mr findings and clinical courses of patients with anterior circulation territorial infarction. those with ica and mca lesions were divided into six and five groups respectively, according to the level and mechanism of the occlusion. pwi findings can be another factor in the management planning. here, we will present representative cases of each group and discuss the management with thorough consideration of various factors, such as pattern and type of arterial occlusion, the extent of dwi/pwi mismatch, the duration of the ischemia, age of the patient, the severity of neurologic deficits, or use of other anticoagulants, etc. we believe that mr imaging is very helpful in the evaluation and management planning of patients with hyperacute stroke. the treatment should be individualized to enhance the effectiveness and safety of the various treatment modalities. similarities and differences in functional connectivity of the prefrontal cortex: task in episodic memory (em), task-and item-related processes have been postulated to contribute to asymmetries in cortical involvement with the prefrontal cortex (pfc) being of particular interest. this study demonstrates task-and itemrelated differences in functional connectivity of pfc in verbal vs non-verbal em. methods and materials: twelve healthy volunteers performed visual non-verbal (line drawings of known objects) and verbal (abstract words) em tasks undergoing o- -butanol-pet to measure regional cerebral blood flow. using correlation analyses, functional connectivity of item-related (verbal vs non-verbal) processes during episodic encoding and retrieval was assessed. results: across all tasks/items we observed strong prefrontal interactions regarding the dorsolateral (dl) and frontopolar (fp) pfc. during encoding we found bilateral but left dominant pfc interactions with any material, right dlpfc showed no interactions during the abstract word condition. during retrieval of pictures we found an increase of right fppfc interactions and a symmetrical increase of dlpfc interactions. during retrieval of abstract words we observed an increase of left fppfc interactions, while right dlpfc showed no interactions. memory performance was higher for pictures vs words. conclusion: firstly, our results support the idea of a common bilateral pfc involvement across different stimuli and mnemonic operations. secondly, item-related processes point to a left lateralized pfc involvement for words and a bilateral pfc involvement for pictures. these data support the "dual coding" hypothesis, introduced by paivio (paivio, ; paivio ) , postulating a double (verbal and non-verbal) processing pathway for pictoral stimuli, hence a supplementary mnemonic strategy to increase memory performance. perfusion weighted dynamic susceptibility ( method: fifteen patients with unilateral - % carotid artery stenosis were studied with dsa and perfusion-weighted dynamic susceptibility (dsc) mri and were compared to age/sex matched controls. regional cerebral blood volume (rcbv) and mean transit time (mtt) values were calculated in the middle cerebral artery (mca) and borderzone (bz) territories. all patients underwent tea within one week from mri and were re-examined one month after surgery. results: there was no significant difference in rcbv and mtt values between the hemispheres in the symptomatic patients. there was a significant difference in mtt values in the borderzones between patients and controls. after tea we found a decrease of mtt of both hemispheres in bz territories while the remaining hemodynamic parameters persisted unchanged. the decrease in mtt values after tea lead these values to be similar to those of normal subjects. the results of our study suggest that there is an adequate compensation of unilateral stenosis when it is less than %. a hemodynamic compensation mechanism between the two hemispheres, particularly for the distal border zone territories that tend to have a slower mtt with respect to the control subjects before tea, and the restoring of mtt values in the bz after surgery, seems to be demonstrated as well. parkinson's disease: pre-and post-apomorphine perfusion evaluation with dynamic susceptibility contrast (dsc) mri f. gaudiello, s. marziali, a. ludovici, e. ferone, r. floris, g. simonetti; rome/it purpose: our aim was to study whether dsc-mri perfusion method may detect an altered pattern of regional cerebral blood flow (rcbf) in parkinson's disease (pd) patients in comparison to normal subjects and whether this altered pattern may be normalised by apomorphine. material and methods: twenty subjects affected by idiopathic pd according with the brain bank criteria were enrolled for this study. nineteen normal subjects were included as controls. ten of them performed a retest procedure. pd patients, after at least days of therapy withdrawal, were submitted to perfusion dsc-mri. sixteen of them were retested after apomorphine injection at least hours. relative regional blood flow was evaluated by using regions of interest (roi) of pixels manually placed in different region of basal ganglia. results: pd patients showed a significant inter-hemispheric asymmetry due to a higher perfusion in the more affected side (< . ), while normal subjects did not. pd exhibited an abnormal "asymmetry index" in the measured nuclei. dsc-mri performed after subcutaneous apomorphine injection did not show any significant asymmetry in pd patients. retest in normal subjects did not show any significant variation. conclusion: dsc-mri of basal ganglia confirms the asymmetry observed in pet studies of pd, suggesting this method as a promising technique in neurodegenerative diseases. b d e f a g steeper (r = . , p < . ) comparing to wm (r = . , p < . ) and almost negatively linear. conclusion: our study shows that ageing effects on metabolite concentrations are more pronounced in the gm regions of the brain. determination of absolute metabolite concentrations, rather than use of ratios only, is essential for characterizing age-related changes in brain metabolites. diagnosis of cerebral vascular malformations with ct angiography in patients with subarachnoid hemorrhage s. stathopoulou , c. kokkinis , n. makris , a. petinelli , k. vassiou , m. vlychou , p.j. papadaki , g.m. zavras , j.b. fezoulidis ; athens/gr, larissa/gr purpose: to evaluate the diagnostic accuracy of spiral ct angiography in patients with subarachnoid hemorrhage due to vascular malformations. methods and material: one hundred and fifty-eight patients suffering from subarachnoid hemorrhage (sah) underwent ct angiography (cta) as well as intraarterial digital subtraction angiography (ia-dsa). cta was performed using spiral ct with ml of intravenous contrast at ml/sec, after a delay of sec. slice thickness . mm and a reconstruction index of . was used. axial slices and multi-planar reformatting (mpr), maximum intensity projection (mip) and d surface shaded display (ssd) reconstructions were reviewed. ia-dsa followed in all patients. there was comparative study between two methods. results: twelve cases of vascular malformations were diagnosed by cta and these comprised arteriovenous malformations and venous angiomas. in cases, the cause of sah was vascular malformation and in cases was an incidental finding. in comparison with ia-dsa, cta missed only a small dural arteriovenous malformation but diagnosed a small venous angioma missed by ia-dsa. these two malformations appeared without hemorrhage. conclusion: cta is a useful non-invasive method in detection of cerebral vascular malformations causing sah, with similar results to ia-dsa. even though ia-dsa offers more anatomical detail in the evaluation of supplying and draining vessels, cta can be a useful diagnostic tool as the tridimensional aspect offers additional information in the therapeutic planning of these vascular malformations. material and methods: ct angiography (cta) was performed using spiral ct with ml of intravenous contrast at ml/sec, after a delay of sec. a slice thickness of . mm and a reconstruction index of . were used. axial slices and multi-planar reformatting (mpr), maximum intensity projection (mip) and surface shaded display (ssd) reconstructions were studied to evaluate aneurysm characteristics. then the image data was analyzed using volumetric d rendering technique to succeed endoscoping imaging. this technique extracts ct numbers in the boundary region between the vessel wall and contrast media within the vascular lumen. results: forty cases of cerebral aneurysms were detected by cta. with the technique of ct virtual angioscopy, we assured an excellent visualization of the inner contours of the vessels including the neck and the dome of the aneurysm (fly through). also d morphology of the internal structure of the aneurysm was demonstrated (fly around). the size of the sac (true lumen) and the neck were exactly estimated. blood vessels flowing into and out of aneurysms were visualized. in patients with ruptured aneurysms that were operated, virtual angioscopy showed the site of rupture, wich was confirmated by operation. conclusion: virtual angioscopy following spiral cta is a very useful technique supplementary to cta in non-invasive evaluation of cerebral aneurysms and selection of the most appropriate therapeutic modality. serial mri in adult-onset rasmussen's encephalitis reveals two main radiographic and clinical variants n. danchaivijitr, r. nicholas, t. smith, i. hart; liverpool/uk purpose: rasmussen's encephalitis (re) is a rare autoimmune disorder that classically affects one cerebral hemisphere. it is characterized by intractable epilepsy with progressive neurological deterioration and usually presents in childhood. adult onset re was believed to have a more benign clinical course and imaging features are less well described. here, we characterize the mri brain findings of a series of adult onset re patients and correlate with the clinical progression. we retrospectively reviewed the serial mri brain scans of patients with pathologically confirmed adult onset re ( scans in total). five patients had complete series of annual mri studies from their onset. clinical data including neurological signs, cognitive deficits and functional disability were recorded prospectively. results: we recognized patterns of imaging findings; patients had focal increase signal on t w in subcortical white matter of the temporal lobe. later, these were followed by ipsilateral hemispheric atrophy. these patients had a rapidly progressive clinical course in which neurological deficits occurred within months after onset. the second group ( patients) had initial focal cortical atrophy followed later by diffuse atrophy of affected hemisphere without evidence of high signal changes. in addition, bilateral involvement and caudate atrophy were more frequent than childhood variant. conclusion: adult re can be difficult to diagnose because the early mri findings can be subtle and physicians may be unaware of the possible presentation of one hemisphere atrophy without inflammation. pattern of initial mri features may help to predict clinical course of the disease. radiofrequency neurotomy for the treatment of headache associated with the third occipital nerve g.b. marshall, c. siwak, b. frizzell; calgary, ab/ca purpose: to assess the efficacy of a fluoroscopically-guided neurotomy technique in patients with cervicogenic headache associated with the third occipital nerve. methods: retrospective analysis of patients ( women and men) who underwent third occipital neurotomy for cervicogenic headache. these patients had failed conservative treatment and were selected based on response to facet joint injection and medial branch block. neurotomy procedures were completed by two radiologists. a chart review of pre-and post-procedural pain levels was undertaken in addition to follow-up patient interview to determine whether they had improvement in their activities of daily living and recreation. results: all patients reported a reduction in the frequency of their headaches. pain levels reported on a visual analog scale dropped from a pre-procedural mean of . / to a post-procedural mean of . / . the mean duration of pain relief was . months, with of the patients describing ongoing relief of symptoms. all patients reported restoration of activities of daily living, albeit for varying lengths of time. no significant complications were encountered. this radiofrequency neurotomy technique may be a useful means of providing symptomatic relief from cervicogenic headache associated with the third occipital nerve. the study justifies proceeding to prospective evaluation of the technique. functional magnetic resonance imaging (fmri) study of memory functions in elderly and young healthy controls and alzheimer's disease (ad) patients a. urbanik, m. binder, b. sobiecka, j. kozub, m. kuniecki; krakow/pl purpose: the aim of the study was to assess differences in the neural correlates of nonverbal memory functions in pathological and normal ageing. methods: thirty-six volunteers were examined in a . t mr scanner. three groups of twelve subjects were examined: young and elderly healthy controls, and patients with probable ad diagnosis. subjects were required to memorize complex geometrical figures. after the scanning session, they were all asked to redraw these figures. their performance was scored. image data were analysed with spm statistical package. results: both control groups copied drawings more accurately than the ad group. in all groups, the most prominent differences were seen in frontal regions and the occipital lobes, extending to the temporal. for each group this pattern was dissimilar. for the ad group moderate activation in the occipital lobe was observed, but no activation in frontal lobes. in turn, the elderly group revealed quite weak activation in occipital lobes and strong bilateral activation in the frontal lobes. finally, in the young adults group there was very prominent activation in occipital lobes, as well as in the frontal lobes, with apparent left-hemispheric dominance. we have succeeded in revealing differential patterns of brain activation in the studied groups during nonverbal memory encoding. our results suggest that a successful encoding requires an involvement of frontal lobes, that are probably responsible for the strategic aspects of memory functions. as was shown in the elderly control group, frontal lobes can compensate for the deteriorated visual memory which is known to decline over time. the special features of cerebral hemodynamics were studied in patients with chiari malformation (cm) with the help of magnetic resonance angiography (mra) and transcranial dopplerography (tcd). mra data analysis ( ) revealed the frequent presence of vertebrobasilar system (vbs) maldevelopment and embryonic type of circle of willis. tcd data analysis ( ) discovered vertebrobasilar insufficiency and bilateral blood flow increase in the intracranial part of the internal carotid arteries giving evidence of the compensated blood flow from the carotid system to the vbs. % of patients with cm and communicating hydrocephalus had tcd signs of intracranial hypertension. the most significant changes in cerebral hemodynamics were found in patients with marked pathology and older than years. conclusions: . changes of cerebral hemodynamics in patients with chiari malformation are conditioned by a complex of various causes; vertebrobasilar system underdevelopment, extravasal compression of the vbs arteries, rombencephalon hernia (cm) compensated blood flow from internal carotid system to vbs and the presence of intracranial hypertension. . the role of vascular factors in pathogenesis of the clinical signs of chiari malformation is confirmed. acute disorders of cerebral ischemic circulation in vbs and syncopal conditions were mainly found in patients with the nd / rd degree chiari malformation above years of age, that correlates with the greatest changes of cerebral hemodynamics by transcranial dopplerography findings. routine mr imaging in parkinsonian syndromes m. cosottini, r. ceravolo, g. lazzarotti, u. bonuccelli, m. michelassi, c. bartolozzi; pisa/it purpose: to assess the usefulness of routine mri in the differential diagnosis of parkinsonian syndromes such as multiple system atrophy type p or c (msa p and msa c), supranuclear palsy (psp), and corticobasal degeneration (cbd) from idiopathic parkinson disease (pd). we retrospectively evaluated patients with extrapyramidal signs and symptoms that had been followed for five years until a definitive clinical diagnosis. ninety five patients had pd, msa p, msa c, psp, cbd. mr examinations were obtained with . and . t equipment in cases and cases, respectively. axial dp-t and sagittal t -weighted images were evaluated considering the most frequently abnormal findings reported in parkinsonian syndromes. pd mr examination was supposed to be normal. results: using the reported radiological criteria, imaging by mri revealed a sensitivity and specificity of % and % in psp, % and % in msa p, % and % in msa c, % and % in cbd. a correct diagnosis of atypical parkinsonian syndrome was made in % of patients with extrapyramidal signs and symptoms. conclusions: several features on brain mr imaging may improve the diagnosis of atypical parkinsonian syndromes and pd in a substantial proportion of patients. brain with done by pc mra and the intracranial circle was evaluated with d tof mra. dsa was then performed to confirm the grading of stenosis and to depict the presence of collateral intracranial compensatory circles. patients were divided into two groups on the basis of the presence (group ) or absence (group ) of a regional or hemispheric perfusion defect detectable at visual inspection of mtt map. results: in group (six patients) there was a prolonged mtt, a reduced cbf and an increased cbv in two cases. a poor depiction of mca with mra and a significant reduction of mbf in the mca homolateral to ica stenosis ( ml/ min), as well as an angiographic impaired willisian compensation with a recruitment of vessels arising from the external carotid artery and from superficial collateral supply was detected in group . conclusions: pwi reveals oligemic abnormalities in only some patients with ica stenosis. increased mtt and reduced cbf are associated with an impaired willisian collateral supply. probably, bolus dispersion may influence the pwi-detected oligemia in ica stenosis. specificity results: statistical differences were found between the dementias group (ad and vd) and the non-demented group (depression and mci). the ratio choline/ creatine (cho/cr), myoinositol/creatine (mi/cr) and n-acetylaspartate/creatine (naa/cr) showed differences between the studied pathologies, only in ppgm, without significant differences in rtl. naa/mi and mi/cr distinguished between ad and the other pathologies, in ppgm, with the best area under the roc curve for naa/mi, showing the higher sensitivity ( %) and specificity ( %) for the diagnosis of the ad. conclusion: h mrs is a non-invasive tool for the study of ci, showing biochemical information to differentiate ad, vd, depression and mci. the metabolical alterations observed contribute to the differential diagnosis with a high sensitivity and specificity in pathologies with ci, in particular for the diagnosis of ad. value of transcranial doppler (tcd) measurements and "hyperdense middle cerebral artery" sign on ct for acute ischemic stroke prognosis y.t. efendiev, l.b. khalilova; baku/az methods: ct examination was carried out on the first day of stroke for patients (age range to ), who had ischemic infarcts in the middle cerebral artery (mca) territory and repeated on the rd , th and th days. "hyperdense middle cerebral artery" sign reflecting active intraluminal thrombosis was found in patients. the same patients had tcd on the st day. results: symmetric blood flow velocity (bfv) in both mcas was revealed in % of the patients. in this group, clinical course was rather auspicious in more than % of patients. infarcts area in these patents had limited, cortical ( %) and subcortical ( %) localization. no lethal outcome was noted. asymmetric blood flow with decreased mca bfv by more than % on the affected side was noted in % of the patients. in this group, the infarctions had cortico-subcortical localization on final ct. the clinical course was more severe and complicated than in the first group.one lethal case occurred. in %, tcd demonstrated signs of hyperperfusion of hemodynamics with increased of mca bfv by more than %, on the affected side, combined with high peripheral resistance index. infarcts had mainly deep basal location, and lethal cases occurred. later ct detected hemorrhagic transformation of necrotic area ( cases, %). conclusion: "hyperdense middle cerebral artery" sign on ct is significant for early diagnosis of stroke, whereas the tcd measurements in mca is important to predict the clinical course and possible impairment at the early stage of the disease. b d e f a g imaging of brain parenchymal and leptomeningeal metastases from lung cancer: significance of contrast enhancement mri m.p.i.m. jakimovska, t. markoski, m. grunevski, s. jakimovska, s. jovanoska; skopje/mk purpose: to estimate significance of iv application of paramagnetic contrast in mr imaging in diagnosis of parenchymal brain metastases, especially leptomeningeal carcinomatosis seeding from lung cancer. next purpose is to compare sensitivity between ct and mr imaging. material and methods: thirty-six patients with lung cancer were evaluated radiographicaly to determine the present of metastases in cns. we used ct as a screening tool and mr after i.v. application of gddtpa. results: our series with patients included or % with non small-cell lung cancer and patients or % with small-cell lung cancer. three patients ( %) of with small-cell lung cancer had occult metastatic disease to the brain. eight patients ( %) of with non small-cell lung cancer had metastatic disease to the brain parenchyma. in this series, leptomeningeal metastases were not found. ct scans were performed in all patients, mri was performed in cases, some with i.v. application of gddtpa, and in patients brain metastatic disease was found. post contrast mr imaging presents leptomeningeal carcinomatosis as thin linear enhancement along the cortical surface, which follows the gyral pattern of the cortex. conclusion: all patients with lung cancer have to be investigated for brain metastases because of a great percentage (about %) of occult metastatic disease. contrast enhanced mr of the brain is a superior method compared to ct because of excellent contrast resolution, is safer and has multiplaner abilities. to demonstrate meningeal seeding, contrast enhanced mri is the modality of choice. evaluation of the uselfulness of high b-value diffusion-weighted mr imaging in patients with acute cerebral infarction h. hirota , e. shimosegawa , k. takahashi , m. mineta , t. yamada , w. yamamoto , k. nagasawa , h. sato , t. aburano ; asahikawa/jp, akita/jp, iowa, ia/us purpose: we occasionally encounter cases without distinct abnormal findings on conventional diffusion-weighted mr imaging despite there being obvious clinical findings of acute cerebral infarction. our purpose was to evaluate positive predictive value of high b-value diffusion-weighted mr imaging in subjects with acute cerebral infarction. we prospectively assessed subjects with acute cerebral infarction within hours from the onset. all examinations were performed with . t unit using single-shot echo planar diffusion-weighed mr imaging at three different b values of , and s/mm . seven days later from the onset, we re-examined the subjects with t weighted image for confirming the final diagnosis. four experienced neuroradiologists assessed each diffusionweighted images for the presence of cerebral infarction and then compared the findings of each images with those of t weighted images. we divided the findings of each diffusion-weighted images into five categories by location of abnormal signal intensities and calculated true positive rate in each categories. purpose: arterial visualization of intracranial d-cta is difficult in the area of the skull base. this is due to the close proximity of the internal carotid artery and skull base and the fact that they both have almost the same ct values. accordingly, subtraction artifacts due to misregistration are unavoidable using the conventional subtraction method. even a slight difference of the start position in data between pre-and post-contrast ct may lead to the production of considerable artifacts. nowadays, subtraction of two sets of volume data has become possible on a workstation. we assessed whether this technique was useful in intracranial d-cta. methods and materials: subtraction was performed in both phantom and patients and the accuracy was tested. results: precise measurement was shown to be possible in the phantom experiment. following this, several clinical cases were applied. conclusion: subtraction is effective due to being almost free of misregistration. does an interpolated high resolution matrix improve the detection of brain hyperintensities on flair images in multiple sclerosis? f. sardanelli, a. fausto, g. spadaccini, b. cotticelli; milan/it purpose: to test whether an interpolated high resolution matrix improves the detection of brain hyperintensities on flair images in multiple sclerosis (ms). materials and methods: seven ms patients ( male, females, - years old, median ) underwent brain mr at . t using a fast-flair para-axial sequence (tr/te/ti = / / ms; fov mm; no-gap -mm slices; matrix x ; pixel size = . x . mm; time ' "). the sequence was repeated changing only from the standard matrix to an interpolated matrix with a pixel size of . x . mm. the two sequences were read on a remote console in a random blinded fashion, using a one-in-one format and free windowing, grading them as certain (c) or probable (p); for confluent plaques, only the lesions with more than half the contour detectable were counted. wilcoxon test was used. results: a total of hyperintensities (c/p = / ) with and of ( / ) with were counted. they ranged in total - (median = ) with and - ( ) with ; c hyperintensities - ( ) and - ( ); p hyperintensities - ( ) and - ( ), respectively. data were similar in / patients; in the remaining patient (female, years old) total hyperintensities were ( ) and ( ), with a c/p of / and / , respectively. in spite of this outlier, no significant overall difference was found between and for total, c, and p hyperintensities (p > . ). conclusion: interpolated matrices do not significantly improve the detection of brain hyperintensities on flair images in ms. a method for reducing radiation exposure in cerebral perfusion study using multi-detector row ct t. nanjo , k. murase , y. sugawara , m. hirata , t. mochizuki ; osaka/jp, onsen-gun/jp purpose: radiation exposure during ct perfusion study is a serious problem. the purpose of this study was to devise a method for reducing radiation exposure in cerebral perfusion studies using multi-detector row ct. methods and materials: nine patients ( males and females; mean age . years) participated in this study. following a standard protocol for ct perfusion study, continuous (cine) scans ( . - . sec/rotation x sec) consisted of four -mm-thick contiguous slices performed after an injection of iodinated contrast material ( - ml) using a multi-detector row ct scanner (light speed qx/i, ge). new image data were generated by thinning out the original images thus acquired. the thinned-out images were interpolated by linear or cubic interpolation. the functional images of perfusion parameters such as cerebral blood flow (cbf), cerebral blood volume (cbv) and mean transit time (mtt) were generated from these images by applying deconvolution analysis based on singular value decomposition pixel by pixel. we calculated the correlation coefficients between the perfusion parameters obtained from original and thinned-out images for regions of interest in the grey and white matter. results: when using continuous images with a scan time of . - . sec and the thinned-out images with a scan interval of . - . sec, the radiation exposure could be reduced to . - . %, with the correlation coefficients of cbf, cbv and mtt being kept greater than . . conclusion: this method can reduce radiation exposure while keeping the accuracy of perfusion parameters equivalent to that obtained from original images. dynamic scanning. the data acquisition conditions (analysis algorithm, analysis matrix, contrast medium injection rate, image reconstruction algorithm and exposure dose) were optimized while maintaining high quantitative analysis capabilities. cerebral blood flow was then measured in volunteers in their s, in their s, in their s, in their s, in their s, and in their s. none of the subjects had cerebral blood flow disorders. results: the use of optimized data acquisition conditions provided high reproducibility while permitting the exposure dose to be reduced by % or more. a decrease in cerebral blood flow with advancing age was confirmed in ct dynamic perfusion studies. the use of optimal data acquisition conditions allows the exposure dose to be reduced and provides high reproducibility while permitting acceptable quantitative cerebral blood flow analysis. this has made it possible to determine age-specific normal values for cerebral blood flow in dynamic ct perfusion examinations. it is expected that dynamic ct perfusion analysis will prove clinically useful for the assessment of diffuse cerebrovascular diseases and chronic-stage blood flow disorders, as well as for the diagnosis of acute-stage cerebral infarction. diffusion weighted imaging (dwi) epi on low field mr system ( . t): comparison with . t and preliminary report on clinical use in brain ischemia p. purpose: this study assessed the diagnostic value of low field dwi in brain stroke. the secondary goal was to compare apparent diffusion coefficient (adc) values obtained in high and low systems. methods: dwi were performed in groups of volunteers, on . t and . t systems. dw images at b = and mm /s were recorded. adc values from regions of interest (roi) were compared. forty patients with acute symptoms of cns stroke were examined by ct and mr, - h after symptoms onset. dwi-epi images were obtained. follow-up mr weeks later were set as a reference. results: statistical analysis showed significant differences of adc values dependent on roi location within the brain hemisphere. there was no difference between right and left hemisphere. adc values for low and high field systems were similar. in patients, ischemic lesions were found in the first examination. follow-up confirmed infarcts. four patients out of with negative dwi revealed infarction in follow-up mr. sensitivity, specificity, and diagnostic accuracy were . %, %, and %, respectively. conclusions: low field systems are capable of diffusion weighted imaging. for the same b value, adc values at . t and . t are similar. in clinical practice dwi on low field mr systems can be used as a fast and reliable tool for detection of acute ischemic lesions in the brain. advantages of a d multislab t turbo spin echo magnetic resonance (tse mr) sequence for high resolution brain imaging b. it is feasible to scan the whole brain with t contrast in mm³ isotropic resolution with high snr and cnr using a multislab d tse sequence. postoperative multidetector-row ct angiography ( ( ), hemimegalencephaly( ), bilateral perisylvian syndrome( ), lissencephaly( ) and focal cortical dysplasia( ). all were the subject of conventional brain mr imaging studies using the mp-rage (magnetization-prepared rapid gradient-echo) sequence and the resulting -d data sets were processed on a commercially available workstation. abnormal gyral configurations were reviewed. results: abnormal gyral patterns were seen of patients. the configuration and orientation of affected gyri were clearly evaluated in the brain surface-rendering image. in two cases of the schizencephaly (involved the frontal lobe), there were wheel shaped broad gyral pattern of the superior, middle, and inferior frontal lobes. in two cases of the hemimegalencephaly, there were thick gyral pattern and enlarged ipsilateral brain. in two cases of the lissencephaly, the frontoparietal cortex was not delineated and showed a markedly thick and smooth gyral pattern. in two cases of the bilateral perisylvian syndrome, there were opened insular cortex and a thickened gyral pattern. in the focal cortical dysplasia, there were irregular serrated or thick and enlarged gyri. in patients with cerebral cortical dysplasia, brain surface-rendering mr imaging detects a detail gyral pattern and involvement site of abnormal gyri. it can create difficulties in the differential diagnosis and can therefore cause problems in choosing the appropriate therapy. this is especially true in cases with alzheimer's versus lewy-body disease ((dlb), which require different therapeutical approach. we applied h-mrs to assist the diagnostic process and to look for specific differences in the metabolic content of the brain tissue in these two entities. methods: h-mrswas performed using . t scanner in t -weighted images in orthogonal planes in elderly subjects with consensus criteria dlb (n = ), nincds-adrda ad (n = ), and normal control subjects (n = ). h-mrs was performed with single-voxel (svs) technique using steam sequence (tr ms, te ms). voxel was positioned in the temporal, occipital lobe and centrum semiovale. results: in both alzheimer's and lewy-body group, h-mrs showed changes in the metabolite pattern in all voxel locations, with the most distinct expression within temporal lobes. naa and creatine peaks were lowered in both patients groups, comparing to the controls. in spectra of lewy-body patients myoinosytol peak remained unchanged as opposite to the alzheimer's where it was increased. conclusions: h-mrs can be an additional, very important tool in dementia studies and differential diagnosis of this group of diseases. in dlb patients h-mrs is feasible but there are difficulties in scanning patients in the later stages of the illness due to tremor and the degree of brain atrophy. the activation tasks consisted of left finger movement, sensory stimulation, listening to comprehension (for sensory language area), word generation (for motor language area) and working memory. the reference function was boxcar waveform. activation maps were thresholded at uncorrected p = . . the thresholded activation maps were placed into talarach's space. results: cerebellar activation was observed in the motor, the word generation and the working memory tasks. in the hot sensory and listening comprehension tasks, there was not any visible activation in the cerebellum. left and right posterior cerebellar (declive) activation was observed in the left motor task. ipsilateral cerebellar activation was more prominent than contralateral cerebellar activation during the left motor task. left posterior cerebellar (declive) activation was observed in the working memory task. left posterior cerebellar (declive) and both anterior cerebellar (culmen) activations were noted in the word generation task. conclusion: cerebellar activation was observed in the afferent actions of the brain including motor, motor language and working memory tasks. there was no activation of the cerebellum in the efferent action of the brain including sensory and sensory language tasks. the cerebellum is involved in a variety of functional tasks including motor, word generation and working memory. the brain smell centres: comparison of localisation and activation in male and female subjects using functional mr imaging (fmri) m.d. marchwicka-wasiak, b. goraj; lodz/pl the study was conducted in order to determine and to compare the location and activation of smell brain centres in females and males brains using olfactory nerve-mediated (geraniol) and combined olfactory and trigeminal nervemediated (patchouli) stimulants. methods: ten normal volunteers (five women and five men), right-handed, nonsmokers, without any cns diseases were examined to determine the activated cortex areas during stimulation by geraniol and patchouli. mr brain scans were obtained using a . t clinical scanner, with the head-neck coil. the imaging was performed in each subject using se and epi sequences with a blood-oxygenlevel-dependent (bold) effect. the individual inhaled odorized air during the seconds period and alternating room air over the same period. the mean pixel intensity of activated images was substracted from the mean pixel intensity of preactivated images. results: the olfactory system-mediated stimuli (geraniol) evoked bilateral activation of female brain smell centres compared to right hemisphere centre activation in male brains. the exposure to the olfactory and trigeminal nerve-mediated stimuli (patchouli) showed more activated regions in both sexes than to the olfactory nerve-mediated stimuli. conclusion: fmri proved to be a useful method to compare the location and activation of male and female brain smell centres. we compared the group of psp patients with that of control subjects and found a highly significant difference in antero-posterior midbrain diameters (mann-whitney test: p < . ), absolute midbrain volumes (p < . ) and naa/ cr ratios (p < . ), as well as a significant difference in total intracranial volume-normalized midbrain volumes (p < . ). we also found out a significant correlation between naa/cr ratios and antero-posterior midbrain diameters in psp patients (spearman's rank correlation test: rs = . , p < . ). the aim of this study was to compare the diagnostic accuracy of t fast spin echo (t fse), fluid attenuated inversion recovery (flair) and inversion recovery (ir), in evaluating hippocampal sclerosis and to determine a costeffective protocol for this disease process. in this prospective study, patients (aged months- years) with drug-resistant temporal lobe epilepsy (based on clinical symptomatology and electroencephalographic (eeg) registrations) were evaluated by mri with a . tesla unit. the protocol consists of axial t and pd/t se, and flair, t fse and ir in a coronal plain perpendicular to the long axis of the hippocampus. whenever necessary, we applied t + gd se in axial and coronal planes. films were interpreted by two experienced neuroradiologists. sequences were statistically analyzed in pairs using wilcoxon sign ranks test. results: there were patients ( . %) with mr and eeg findings suggestive of hippocampal sclerosis. eight of them underwent therapeutic surgery and there was histopathologic confirmation of the diagnosis. flair detected hyperintensity of the hippocampus in / ( %) and was much more sensitive than t fse ( / p = . ) and pd/t ( / p = . ). reduced hippocampal size ( / ), atrophy of hippocampus ( / ) and enlarged temporal horn ( / ) were better detected with ir than t ( / p = . ). conclusion: a mr protocol using thin coronal sections angled perpendicular to the hippocampus with flair and ir sequences is cost-effective for mesial temporal sclerosis because it is highly sensitive, inexpensive, quick and easily applicable in most units. reversibility of the brain white matter changes in adults with late diagnosed and treated phenylketonuria m. gizewska, l. cyrylowski, d. koziarska, p. nowacki, a. walecka, m. walczak; szczecin/pl purpose: phenylketonuria (pku) is an autosomal recessive disorder related to absent or reduced activity of phenylalanine hydroxylase what leads to increased plasma phenylalanine (phe) concentration. because screening the whole newborn population for pku in poland began in the late s, many pku adults have been diagnosed and treated very late. patterns and extent of the brain white matter changes in these patients is described. in this paper, late diagnosed and treated adults with pku, including males and females, is presented. the mean age at diagnosis was . y (range - ). microcephaly was present in , seizures in , aggressive behavior in ; all but one had speech difficulties, including total mutism in . mri of the head was performed on . t unit with fse and flair sequences without contrast medium administration. results: mri of the head detected white matter changes, hyperintense on t weighted images, in all but one patients. all but one of them had changes in parietal and/or occipital regions. the treatment with low-phe has been introduced in with improvement in all of them. the follow-up mri were performed after mean . months, revealing decreased severity of the white matter changes in all, from mean (according to cleary's scale) on the initial mri to . on the follow-up. our results indicate the possibility of white matter changes reversibility in late diagnosed and treated pku adults. conclusion: dwi is thought to be useful in the diagnosis of cns infections. in our experience, dwi may allow the differentiation of brain abscess from necrotic or cystic brain tumor. dwi is also a useful tool to differentiate subdural and epidural empyemas. detection . coronal views were performed for flair imaging, and coronal and axial views for dp and t -weighted imaging. images were reviewed by two seniors radiologists in consensus for localisation of the signal abnormalities. results: lesions of the olfactory system were observed in patients ( %). signal abnormalities were localised in the temporal lobe in cases ( % with cases of unilateral lesions and cases of bilateral lesions) and in the orbito frontal cortex in cases ( % with cases of bilateral lesions and cases of unilateral lesions). with flair, dp, and t weighted imaging, lesions was detected respectively in %, % and %. olfactory bulb signal abnormalities were diagnosed in cases ( % with cases of unilateral lesions and cases of bilateral lesions). for this localization, the accuracy of flair, dp and t sequences was respectively %, %, %. in post-traumatic anosmia, coronal flair and coronal pd imaging is required to detect respectively signal abnormalities in the parenchyma and in the olfactory bulbs. t weighting imaging seems to be inferior. cerebral hydatid disease: ct and mr imaging findings y. bükte, s. kemaloglu, h. nazaroglu, a. uyar, c. akgül, m. simsek; diyarbakir/tr purpose: cerebral hydatid disease is very rare, representing only % of all cerebral space occupying lesions, even in the countries where the disease is endemic. the aim of this study was to describe the discriminative computed tomography (ct) and magnetic resonance (mr) imaging features of cerebral hydatid disease. we retrospectively reviewed the imaging findings of patients with pathologically confirmed cerebral hydatid disease over a period of years ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) . among these patients, there were cases of echinococ-b d e f a g cus granulosis and case of echinococcus multilocularis (alveolaris). they were male ( . %) and female patients ( . %), ages ranging from to years with an average age of . years. results: common ct and mr imaging findings of e. granulosis lesions were well-defined, smooth thin-walled, round or spherical, homogeneous cystic lesions with no contrast enhancement, no calcification and no surrounding edema. the lesion seen in e. multilocularis showed a well-defined multiseptated mass consisting of solid and cystic components with calcifications of solid portions. cystic lesions with surrounding hyperintense area of perifocal edema, complete and incomplete rim of contrast enhancement were seen in two patients and were labeled as complicated and infected cysts. conclusion: although the cystic cerebral hydatid disease could be equally well demonstrated on ct and mr examinations, ct is superior in detecting calcification of the cyst, when present. mr is better in demonstrating cyst capsule, detecting multiplicity and defining the anatomic relationship of the lesion with the adjacent structures and helps in surgical planning. ct it may be used to identify regional differences within a patient. qualitatively, single scan cbv maps were noisier than maps using the dynamic method. conclusion: cbv estimates from a single contrast-enhanced scan may identify abnormal areas. however, differentiation between normal and abnormal regions is not as pronounced as when using quantitative, dynamic methods. virtual endoscopic imaging of cerebral ct angiography (veccta) in selecting patients for neurosurgical intervention or endovascular treatment r. prpic-vuckovic, m. rados, m. batinica, j. papa, m. seronja-kuhar; zagreb/hr purpose: to assess the usefulness of virtual endoscopic cerebral ct angiography data analysis in patients with aneurysm rupture before making a decision between neurosurgical intervention or endovascular treatment. materials and methods: during a one-year period, mscta was performed in patients after a conventional ct proven subarachnoid hemorrhage. images were acquired using msct lightspeed ultra, ge. helical data acquisition followed after rapid i.v. administration of contrast material ( . ml/sec), with - sec delay. data was postprocessed on ge advantage workstation ultra v . using reconstruction protocols mip (maximum intensity projection), ssd (shaded surface display), vr (volume rendering) and ve (virtual endoscopy). results: detailed analysis of aneurysmal neck, dome, vessel of origin and surrounding vascular or bone structures was acquired by ssd, mip or by high-accuracy vr protocol. modified surface rendering and ve protocol were used for endoscopic mode viewing to visualize neck shape, accessibility from the parent vessel, presence of thrombotic clots or calcifications inside the aneurysm and vessel of origin, as well as to define orifices of branches arising from the dome. conclusion: accurate characterization of morphology of the aneurysm, especially depiction of orifices and aneurysmal neck are essential for choice between neurosurgical intervention or endovascular treatment. when endovascular treatment is an option, it is useful to know angulation between parent vessel and neck and real volume of aneurysmal dome for proper estimation of coil size and shape. vr and ve imaging of the aneurysmal sack and surrounding anatomy may provide additional useful information for endovascular treatment or neurosurgical intervention. we have demonstrated the existence of non-monoexponential diffusion in the human csc that can be approximated by fast and slow diffusion components. our results are within the limits of human brain and full dti data for the rat spinal cord. the aim of this study is to review the embryology and the development of this structure. to describe the normal ct and mr appearances and to show the neuroradiological findings of pathology that can effect the craniocervical junction. background: the craniocervical junction is an anatomical crossroads with characteristic pathologic entities, mainly malformative and traumatic in origin. we illustrate the normal anatomy of the craniocervical junction and a wide spectrum of pathological conditions involving this structure through a selection of cases from a retrospective review of the ct, mr and plain-film examinations carried out in our centre over the last five years. imaging findings: normal anatomy and a wide spectrum of pathologies affecting the craniocervical junction are illustrated by ct and mr examinations. we group the findings according to etiology: malformation, trauma, infection, inflammatory and tumor, placing emphasis on the radiological features and the differential diagnosis. conclusion: ct depicts the bony structures of the craniocervical junction superbly while mri shows the neurological components better, enabling excellent characterization of lesions and recognition of all potential types of disorders that need to be recognized by general as well as neuroradiologists. the spectrum of t hyperintensities of the sellar region f. with the introduction of high field strength it is expected to overcome the limited signal to noise ratio and subsequently decreased spatial resolution in routinely used standard field strength . - . tesla mr scanners. this would have clinical impact in the preoperative work up of patients with sellar processes. imaging findings: in this exhibit we present a large variety of sellar diseases using tesla mr imaging with emphasis on detection of microadenomas and visualization of anatomic structures. furthermore, the differentiation between infiltration or just compression of the medial wall of the cavernous sinus in case of macroadenoma is illustrated. the excellent visualization of normal anatomy and tumor topography makes this technique a very valuable tool for planning neurosurgical operations. cns manifestations following stem cell transplantation: a pictorial review d. beckett, a. banerjee, j. oliff; birmingham/uk learning objectives: to illustrate the spectrum of radiological manifestations in the central nervous system and head and neck following stem cell transplantation for haematological malignancy. to outline the advantages and limits of plain film radiography, cross-sectional imaging, interventional radiology and radionuclide imaging. background: bone marrow transplantation (bmt) is a critical therapeutic intervention for a variety of pathological conditions. the complications of bmt include chemotherapy and radiation toxicity, graft versus host disease, recurrent malignancy, infection and miscellaneous conditions. complications of allogenic bmt manifest in a variety of clinical settings. the neurological system is commonly affected. in this presentation we will review the incidence, clinical presentation and the radiographic findings of cns involvement following stem cell transplantation. plain radiography, contrast material enhanced studies, sonography, ct, mri and interventional techniques are essential in diagnosing these complications and evaluating their response to therapy. imaging findings: findings may be broadly classified into either infective, cerebrovascular or treatment induced. common infective manifestations include human herpes virus , invasive mucormycosis and central nervous system tuberculosis. classical image findings of haemorrhage and infarction are seen in addition to graft versus host disease cerebrovascular angiitis. infarcts, diffuse white matter disease and cortical atrophy are seen following total body irradiation. the imaging findings of posterior leukoencephalopathy in cyclosporin toxicity is illustrated. the spectrum of imaging findings in the central nervous system is diverse. a firm understanding of the clinical presentations and incidence in combination with typical radiological findings is essential in the successful management of this patient sub-group. b d e f a g background: diffusion weighted imaging has been widely used in stroke patients to detect early acute cerebral infarction and find out ischemic penumbra. however, we often unexpectedly encounter restricted diffusion on dwi of nonvascular origin mimicking hyperacute or acute infarction in clinical practice.we reviewed nonvascular diseases with restricted diffusion on dwi for past three years by retrospective selection. imaging findings: the characteristic findings mimicking hyperacute or acute infarction are high signal intensity and low apparent diffusion coefficient values, mainly distributed in the white matter and incompatible with arterial territory with no stenoocclusive lesion on mr angiography or conventional angiography, and are reversible. these findings may increase possibility of nonvascular diseases such as infection, inflammation (viral or bacterial encephalitis), hemorrhage, leukodystrophy, toxic (anti-cancer drugs, co poisoning), metabolic origin and tumors. conclusion: we present various diseases, under certain clinical settings, and systematically discuss the mechanism of restricted diffusion in a limited number of specific diseases. background: in patients with vitamin b deficiency, symptoms related to the spinal cord may often help to find the diagnosis. however, in patients with atypical symptoms mri shows typical findings often diagnostic for scd. beneath a general discussion, we present cases of scd in whom mri findings were leading to the diagnosis of b -deficiency. patient presented with tingling in her extremities. neurologic examination showed a subacute loss of proprioception and profound loss of vibration sense. vitamin b serum levels were normal. t w-mri showed increased signal in the posterior columns of the spinal cord. dwi showed disturbance of diffusion in the same location. patient , who practiced a vegan alimentation, was admitted with incomplete paraplegia with signs of spasticity. vibration sense and proprioception were impaired as well. mri revealed the typical findings of severely increased signal within the posterior columns of the spinal cord. both patients presented in very early stages of the disease. in summary, the mri findings showed typical signal hyperintensities in t w images in the posterior columns of the cervical and/or thoracic myelon-segments. conclusion: even in patients with subtle atypical symptoms, mri with its typical findings often allows the diagnosis of scd even in the rare case of normal levels of vitamin b . fiber tracking and tensor metrics in diffusion tensor mr imaging c.c.t. lim, h. yin, m. xu, f. hui; singapore/sg learning objectives: to review anatomical patterns and distribution of white matter tracts in the brain and to understand the potential uses of diffusion tensor imaging (dti), including pathological disruption and destruction of fiber tracts. background: dti is a new mr imaging technique that non-invasively visualizes white matter fiber tracts and may have potential to assess demyelination and other brain disorders. using single shot echo planar imaging (tr - /te - ms, mm section thickness, b value - s/mm in - non-collinear directions at . and t) and offline post-processing of diffusion tensor metrics (fractional anisotropy, mean diffusivity and principal eigenvector) and fiber connectivity images (using fast marching tractography) could be studied. imaging findings: in normal patients, the fractional anisotropy (fa) maps clearly visualized white matter tracts as areas of high fa compared to gray matter. the corticospinal tracts, corpus callosum and optic radiations could be consistently identified. abnormalities such as brain neoplasm, cerebral infarction and multiple sclerosis lesions showed decreased fractional anisotropy and elevated mean diffusivity. principal eigenvector maps of water diffusion showed deviation in the direction of the white matter tracts surrounding benign brain neoplasms and malformations. conclusion: quantitative in vivo information on water diffusivity, degree of directionality and directional vector in space, that are not available on conventional mr imaging, can be measured in dti studies. with a potential new clinical application of dti, radiologists should be familiar with anatomy and pathology of the white matter fiber tracts. neuroimaging of background: multiple gliomas are rare findings with variable incidence ( . to %). they can by classified according to: a) time of presentation as early = synchronous (at initial diagnosis) or late = metachronous (diagnosed during the treatment); b) the imaging characteristics as multicentric (arise independently in different sites, there is absence of macroscopic connections or way of dissemination) or multifocal (they spread from primary tumor to other areas in the brain, with evidence of routes of dissemination). we reviewed documentations of patients with diagnosis of glial tumor who grade iii-iv who underwent surgery between january and december . in all patients radiological and histological diagnosis was performed and cases were established as multiple glioma. imaging fingings: most of the patients had one bigger lesion and or smaller ones. the lesions were usually hyperintense on t -weighted images and hypoor isointense on t wi with strong postcontrast enhancement. most of them had moderate edema. we recognized multicentric and multifocal gliomas, were synchronous and one metachronous. conclusion: multiple gliomas are often radiologically reported as metastasis, sometimes as lymphomas or infectious diseases. the differential diagnosis of multiple masses in the brain is very important for therapeutic consequences and multiple glioma should considered because of suggested increasing frequency of this entity. if strong postcontrast enhancement and moderate edema around the lesions are observed, this diagnosis should be suggested. role background: gks is a method of treatment allowing the delivery of a conformal radiation dose to a stereotactically defined target. the significant development of interest in the role of gks as an alternative or adjunct to the neurosurgical management of many brain disorders, requires accurate and reliable methods of acquisition of image modalities for the stereotactic planning. imaging and procedures: between december and august , we treated patients for a large variety of indications (metastases %, vascular malformations %, trigeminal neuralgia %, pituitary adenoma %, primary brain tumor %, other tumors %, vestibular schwannoma %, meningioma %, other functional < %). all patients had an mri combined with ct in stereotactic conditions. some patients also benefited from stereotactic dsa (n = ) or pet (n = ). in all cases, mr was used to delineate a target before radiosurgery. ct was always used as a control for mr distorsion. dsa was used in combination with angiomr for all arteriovenous malformations. when the tumor was ill-defined, we anticipated some limitation of target definition (infiltrative lesions, recurrence of metastases, pituitary adenomas) and also used stereotactic pet. we present a pictorial review illustrating the role of neuroimaging for appropriate targeting in gks. these images are also critical for the evaluation of the potential risks and complications. the complementary information provided by the combination of various imaging modalities allows appropriate and accurate delineation of a target volume before stereotactic irradiation. to familiarize non-greek radiologists with the definition of greek eponyms and to emphasize on those terms and words that have been derived from greek mythology. background: medical eponyms serve as mnemonics, add color to medical writing and are useful shorthands in medical communications. a long catalogue with the most representative greek medical terms is listed. the exact definition and meaning of each word is explained and a short narrative of the relative myth is presented for the neuroanatomical terms which gained their name from greek mythology. conclusion: accurate knowledge of the meaning of these words will help the radiologist to remember the terms and make their learning fun. preoperative to present the potential of diffusion tensor imaging (dti) and colored coded fractional anisotropy (fa) maps in identifying the anatomy of white matter tracts for pre-operative planning. materials and methods: dti data were acquired using dw-se-epi sequences and a . t mr-unit, with the following parameters: tr - , - slices, mm slice thickness, . mm intersclice gap, x matrix and gradients encoding in directions, b- sec/mm . data were acquired in normal subjects and patients with brain tumors, avm's or seizure foci being considered for surgery. fa images and corresponding colored coded maps were generated. also, fse t or flair images were acquired in identical locations for comparative use. results: major white matter tracts (intrahemispheric, interhemispheric, and brain stem) were readily visualized, including the following: superior longitudinal fasciculuus, superior fronto-occipital fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, corpus callosum, cingulum, optic radiations, anterior commissure, corona radiata, internal capsule, pyramidal tracts, medial lemniscus, medial longitudinal fasciculus, cerebellar peduncles and gracile and cuneate fasciculi. the spatial relationships of these tracts and resectable lesions were analysed, with particular attention to the risk of a postoperative deficit. all results were correlated with the pre-and post-operative deficits. conclusion: white matter anatomy can now be imaged using dti/fa and access to pre-operative eloquent white matter mapping has great potential to improve the outcomes of neuro-surgical candidates. the future management of neuro-surgical patients will be impacted by future refinements and developments of this technique. to present a retrospective analysis of our experience in the endovascular coil trapping for ruptured vertebral artery (va) dissecting aneurysms. materials and methods: we treated patients who presented with acute subarachnoid hemorrhage due to rupture of a vertebral artery dissecting aneurysm. embolization of the entire segment of the dissected site with detachable platinum coils (internal trapping) was performed in all patients. in one patient with posterior inferior cerebellar artery (pica)-involved va dissecting aneurysm, internal trapping of the aneurysm followed by occipital artery-pica bypass was performed by a neurosurgeon. results: coil embolization was successful in all patients. there were no procedure-related complications. there was no sign of infarction in the pica territory in all patients. there was no recurrent bleeding or ischemic symptoms during the follow-up periods. follow-up angiography showed complete occlusion of the aneurysm without recurrence in all patients. conclusion: endovascular coil embolization is a safe and highly effective treatment of ruptured va dissecting aneurysms. high-grade stenoses of the carotid artery were treated with stent implantation. dw mr imaging of the brain was performed a day before and after the endovascular treatment. all patients underwent neurological examination before and after the procedure. results: dw mr images showed a total of new hyperintense lesions in ( %) of the procedures performed. eight lesions were ipsilateral to the treated vessel and lesions, in patients, were contralateral. these patients with contralateral lesions also had new ipsilateral lesions. the lesions were located in parietal lobe (n = ), periventricular (n = ), occipital lobe (n = ), frontal lobe (n = ) and corona radiata (n = ). all lesions measured < mm in diameter. none of the patients had neurological symptoms. results: angiographic occlusion was complete in ( %) and ( %) aneurysms in groups a and b, respectively. mean percentage of volumic occlusion in these groups was . and . %, respectively. perioperative morbidity and mortality rates were and %, respectively in group a, and were respectively similar in group b. no significant difference between the two groups was observed. however, percentage of volumic occlusion correlated with sac-to-neck ratio smaller than . (p = . ) and with sac size (p = . ), except when or more threedimensional coils per aneurysms were used (p = . ). the better the percentage of volumic occlusion, the better the percentage of angiographic occlusion (p = . ). percentage of volumic occlusion was an independent predictor of angiographic complete occlusion (p = . ). wfns grade was an independent predictor of perioperative mortality (p = . ). the use of three-dimensional coils improved the coil-packing and angiographic and volumic occlusion of aneurysms with a neck greater than mm at the time of treatment, provided the sac-to-neck ratio was . or greater and the largest number of three-dimensional coils were positioned first. minimum apparent diffusion coefficient: a quantitative parameter for prediction of malignancy of gliomas preoperatively x. yun; sendai/jp introduction: in gliomas, choline signal (cho) correlates with total membrane metabolism, apparent diffusion coefficient (adc) inversely with cell density, cho*meanadc with each cell's metabolism. we examined which parameter is the most reliable in prediction of malignancy of gliomas. methods: twenty-three pathologically proven glioblastomas (gbm) and anaplastic gliomas (ag) were retrospectively evaluated with preoperative mri with mr spectroscopy (mrs) and dwi. ki index was counted to evaluate pathological malignancy. to evaluate clinical malignancy, we selected cases in which at least enhancing lesions were removed and classified into progressed and stable groups. the minimum adc (madc) of gbm was shown to be significantly lower than ag (p = . ). the highest value of madc in gbm was . , and the lowest in ag was . . using this threshold, subjects were divided into groups; a: gbm with madc < . (n = ); b:gbm and ag with . < madc < . (n = ), c: ag with madc < . (n = ). six cases in group a were classified as progression ( pathologically proven recurrence, two dissemination) and all cases in group c were stable. six cases in group b showed progres-sion ( recurrence, dissemination). fisher test showed significance (p = . ). in group b, the madc of progressive gbms was significantly lower than stable gbms (p = . ). the ncho and ncho*meanadc showed no difference between gbm and ag (p = . , p = . ). inverse correlation was found between ki and madc (p = . ), no correlation was found between ki and ncho (p = . ) and meanadc*ncho (p = . ). the madc suggestive of cell density was the most reliable in prediction of malignancy of gliomas preoperatively. usefulness methods: forty-one cases of skull base lesions ( meningiomas; petroclival, clinoidal, olfactory, in foramen magnum, spheno-petro-clival, in the planum sphenoidale, in posterior pyramid and in pca; acoustic schwannomas, epidermoids, pituitary adenomas, craniopharyngiomas, posterior fossa aneurysms, trigeminal schwannoma, dermoid and juvenile angiofibroma) have been evaluated. data was collected, fused, integrated and reconstructed by a dedicated stealthstation system for neuronavigation. ct images were acquired on axial non-overlapping slices, - mm thick; mri images were obtained with . t device, same field of view and thickness. results: neuronavigation was possible in all cases and was successfully applied in pre-operative planning and during surgical procedures. we calculated some data to check the efficacy of the method, having a mean fiducial error of . mm and an accuracy value at cm of depth . mm. discussion and conclusion: imaging fusion for pre and intra-operative neuronavigation provided, in all cases, great advantages in the choice of the best approach, placing of bone flap, early identification of deep normal or distorted anatomic or pathologic structures and their eventual encasement or involvement by the pathologic primary process, correct definition of tumor boundaries and meningeal implant and relationship with functional areas. neuronavigation appeared ideal for skull base meningiomas making surgical maneouvres safer, more effective and less invasive. a study of mr diffusion changes in normal appearing white matter (nawm) of patients with relapsing remitting multiple sclerosis (ms) f. gaudiello, s. marziali, a. ludovici, e. ferone, r. floris, g. simonetti; rome/it background and purpose: the aim of our study was to monitor water diffusion changes over time in nawm of patients with relapsing-remitting ms and to monitor water diffusion changes in patients with different disability status (edss) and with different clinical status (poussè). methods: we selected subjects who had completed a month follow-up. the mr scans were obtained at baseline, at months and at months. two regions of interest (roi) were placed in each hemisphere in the nawm in each mr study and the apparent diffusion coefficient (adc) value were calculated in patients and in healthy controls. results: tadc in nawm in patients was significantly higher then in controls (controls mean tadc ± sd = . ± . mm /sec x - ; patients mean tadc ± sd = . ± . mm /sec x - ; p < . ). in nawm in patients with higher edss, tadc was significantly higher then in patients with lower edss (patients with higher edss: mean tadc ± sd = . ± . mm /sec x - ; patients with lower edss: mean tadc ± sd = . ± . mm /sec x - ; p < . ). tadc in nawm in patients with poussè was significantly higher then in patients without poussè (patients with poussè mean tadc ± sd = . ± . mm /sec x - ; patients without poussè mean tadc ± sd = . ± . mm /sec x - ; p < . ). purpose: evaluation of uveal melanoma imaging characteristics in ultrasound, computed tomography and magnetic resonance imaging and correlation of those findings suggestive of melanoma. material and methods: eleven patients ( men, women, age - years) with possible diagnosis of uveal melanoma were evaluated. the patients underwent ophthalmoscopic and ultrasonographic examination followed by ct and mr examination. ct imaging was performed with mm axial pre-and post-contrast and coronal post-contrast sections. axial and coronal mm t and t images were obtained, followed by post-contrast t images in axial and coronal direction. additional t fat-sat post contrast images were also obtained depending on the relative position of the melanoma in order to evaluate possible extra-orbital extension. results: of the melanomas, six were located in the left globe, ranging from mm to mm in size and most commonly on the lateral wall. the tumors appeared as hyperechoic lesions on us with a reflectivity range of - %, suggestive of melanoma. retinal detachment was detected in four patients. on ct images the melanomas appeared as homogenous slightly enhancing lesions, while in two patients, the tumor was less obvious due to the retinal detachment. on mr images the tumors appeared as homogenous hyperintense lesions on t wi in five patients. characteristic signal void on t wi due to melanin deposition was noted in three patients. conclusion: ultrasonography appears to be a valuable tool in tissue differentiation of uveal melanoma although magnetic resonance, and to a lesser degree, computed tomography are more specific in evaluating the extra-orbital extension. purpose: gadobenate dimeglumine (gd-bopta: t relaxivity in blood = . mmol - s - ) was evaluated to determine whether the high relaxivity offers advantages over other agents for cns imaging. methods: preliminary studies evaluated gd-bopta at cumulative doses up to . mmol/kg to ascertain the optimal dose for mri of cerebral metastases. two phase iii controlled trials were conducted to compare gd-bopta at cumulative doses up to . mmol/kg with gadodiamide (gd-dtpa-bma) at cumulative dose up to . mmol/kg. two intra-individual, blinded, fully randomized comparative studies were conducted in patients with cerebral gliomas or metastases to determine differences in quantitative (tumor contrast, cnr ratios) and qualitative (lesion contrast, delineation, internal morphology, structure) enhancement parameters versus gadopentetate dimeglumine (gd-dtpa) and gadoteric acid (gd-dota) at a dose of . mmol/kg. in patients with metastases a dose of . mmol/kg gd-bopta proved sufficient for most situations while a cumulative . mmol/kg dose provided additional information in certain cases. comparative studies revealed that . mmol/ kg gd-bopta offers improved performance compared to . mmol/kg gd-dtpa-bma and that cumulative . mmol/kg gd-bopta is equivalent to cumulative . mmol/kg gd-dtpa-bma. the intra-individual comparative studies revealed superior qualitative enhancement performance for gd-bopta compared to both gd-dtpa and gd-dota for all evaluations. the subjective assessments were confirmed by the objective measurements of signal intensity and cnr which were significantly higher for gd-bopta (p < . ). discussion: gd-bopta is a safe and valuable contrast agent for the assessment of cns neoplasms offering statistically significant advantages over gd-dtpa, gd-dota and gd-dtpa-bma for brain lesion enhancement. the in cases the examinations were performed before the treatment, in patients as an assessment of drug treatment. in cases the efficacy of stereotactic effect (se) was assessed on the suitable target structures. results: a metabolism decrease (md) in the right caudate head (ch) was noted in two patients before drug treatment. in two patients hypermetabolism was observed in the anterior cingulate (ac). follow-up examinations revealed a md in the ac and an metabolism increase (mi) in the right ch in these patients. in one case an mi in both dorsal thalami (dt) was observed. a md in both dt before drug treatment was seen in two cases. a bilateral mi was noted in dt by followup examinations in these patients. in all cases of se, it revealed a md in suitable structures. in cases, a md was observed in ac and both the ch. in two cases, a md was seen in the ac, in a bilateral md in the dt. changes of glucose metabolic rate were associated with severity of clinical manifestations in all cases. this data proves participation of limbicostriatal system in forming aod. our results demonstrate the possibility to use f-fdg pet for aod diagnosis and estimation of treatment efficiency. b d e f a g magneting resonance imaging in patients with intractable partial seizures: a preoperative assessment a. lefkopoulos, a. kalogera-fountzila, c. kouskouras, n. fotiadis, g. spanos, e. papadopoulou, a.s. dimitriadis; thessaloniki/gr purpose: the aim of this study was to assess the prevalence of detected structural abnormalities in medically intractable epilepsy, especially those who are amenable to a surgical therapy, and also to evaluate the sensitivity of different dedicated mr sequences. materials and methods: one hundred and twenty patients (aged months- years) with medically intractable partial seizures underwent an mri examination in a . t unit, with t and pd/t se in an axial plane and fluid attenuated inversion recovery (flair), t fse and inversion recovery (ir) in a plane perpendicular to the long axis of the hippocampus. whenever necessary, we applied t se + gd dtpa in axial and coronal planes. results: seventy-nine of the patients had a pathological scan ( . %). abnormalities were hippocampal sclerosis (hs) in patients ( %), cerebral tumors in patients ( %), vascular malformations in patients ( . %), cortical infarcts in patients ( . %), cerebral infections in patients ( . %) and patients with developmental disorders ( cortical dysplasias, pachygyrias, polymicrogyrias, subcortical heterotopias and patient with tuberous sclerosis). all patients with cerebral tumors and eight patients with hs were operated and there was a pathologic confirmation of the diagnosis. patients with vascular malformation underwent a therapeutic embolization. flair had higher sensitivity in detecting hippocampal sclerosis and cerebral infarcts while ir was particularly useful in detecting developmental disorders. conclusions: mr imaging, with an epilepsy dedicated protocol, plays a cardinal role in locating and characterizing anatomic epileptogenic foci in patients with refractory epilepsy and helps in defining the type of treatment. the purpose: the aim of this study was to evaluate the possibilities of combined pet/ct imaging in detecting glioblastomas and in estimation of efficiency of their surgical treatment and radiotherapy. materials and methods: seven patients ( men, women, age between - years) with biopsy-proven glioblastomas were scanned before and/or after treatment by pet/ct (biograph, siemens). a dose of to mbq fluorine- fluorodeoxyglucose (fdg) was administered for each pet scan with an acquisition time of minutes for bed and interactive reconstruction. acquisition time for ct was seconds, bringing the total acquisition of combined pet/ct study to minutes. results: three patients with high-grade astrocytomas demonstrated hypometabolic fdg nodules without contrast enhancement at ct scan before surgery. two patients showed nodules with hypermetabolism of fdg (suv - ) and intensive enhancement of contrast medium due to the recurrence of tumor after combined therapy. in one patient, after radiation therapy, the region of treatment had decreased uptake of fdg and increased enhancement of contrast medium at ct because of radionecrosis. conclusion: it was confirmed that combined pet/ct study could effectively determine whether a lesion was malignant and provide evidence of tumor recurrence. the collection of prominent medullary (white matter) veins appears like a "medusa head" on mr angiographic images and gadolinium-enhanced d-tof sequences; this sign is considered pathognomonic. conclusion: mri is of great value in the accurate identification and morphologic specification of vascular abnormalities. traditionally, these cases required invasive diagnostic imaging. va correct identification is very important because this anomaly is asymptomatic but the ablation can induce venous infarctions. abdominal imaging findings: gastrointestinal tract (gi), hepatobiliary system and the pancreas are involved in cf. the gi complications include obstructive (distal intestinal obstruction syndrome, intussusceptions, fibrosing colonopathy, post surgical adhesions) and non-obstructive conditions (pneumotosis intestinalis, gastroesophageal reflux, duodenitis, and rectal prolapse). liver pathology includes steatosis, cirrhosis, and portal hypertension. the pathological mechanism of cirrhosis may be due to obstruction of the biliary ductules with thickened secretions and secondary inflammation producing fibrosis. biliary tract abnormalities include gallstones, micro gallbladder, and sludge. excessive loss of faecal bile acids due to pancreatic insufficiency is associated with increased lithogenicity of the bile. the pancreatic abnormalities include fat infiltration, fibrosis, atrophy and occasionally cysts and calcification. the primary problem is the plugging of the intralobular ductules by inspissated viscid mucus. conclusion: abdominal symptoms in patients with cf may be due to the various causes related to cf or may be due to coincidental pathology e.g. appendicitis, renal disease. the radiologist should keep an open mind and not restrict his thought process only to the conditions related to cf. neck masses in infants and children: a pictorial review j.r.a. turkington, a. paterson, l.e. sweeney, g. thornbury; belfast/uk learning objectives: this poster presents a pictorial review of pediatric neck masses and their imaging features. particular emphasis is applied to the anatomical site of the mass to aid in differential diagnosis. background: infants and children with neck masses frequently present to the radiologist for further evaluation. the most common aetiologies include congenital lesions and their complications, lymphadenopathy and malignant masses. the role of the radiologist is to differentiate between these conditions using im-aging modalities such as ultrasound and colour doppler, ct and mri. where appropriate, the radiologist will also stage lesions for management purposes, and aid in guiding aspiration or biopsy. imaging findings: the radiological appearance of congenital lesions such as thyroglossal duct cysts, branchial cleft cysts, cystic hygromas, haemangiomas, dermoid cysts and sternomastoid "tumours" are discussed. cervical lymphadenitis and abscesses, and neoplastic masses such as neurogenic tumours, rhabdomyosarcoma, neuroblastoma and lymphoma are also described. lastly, lesions of the thyroid and salivary glands are evaluated. it must be emphasised that the radiological findings should always be interpreted in conjunction with the patient's age, the clinical history and the findings on physical examination. conclusion: neck masses are common in children and a frequent cause of attendance at a&e departments. identifying the anatomical site and radiological appearance aids the differential diagnosis. conclusion: a typical osteoarticular lesion in a typical site can alert you to the diagnosis of sapho, but an unusual site or a primary presentation with no skin lesions will make diagnosis harder or there may be misdiagnosis. children may be seen in a number of specialties, which can lead to unnecessary delays in diagnosis and possible incorrect treatments. this makes the radiologist pivotal in the diagnosis of sapho, although the differential diagnosis should always be considered. to demonstrate the problems which can be caused when trauma x-ray films are incorrectly marked when using the red dot system. background: many radiographs are returned to accident and emergency departments without formal radiological reports, and the red dot system, whereby radiographers attach a red dot to radiographs which they suspect to be showing a fracture, is a widely practised system, used throughout the national health service. it is acknowledged that whilst this system can be beneficial to accident and emergency departments it is not without its problems. procedure findings: our poster examines the problems which can arise in children where normal variants are often highlighted as "fractures" by radiographers. most of the common misinterpretations occur in the appendicular skeleton, e.g. normal variants of epiphyseal ossification or accessory epiphyses, especially of the metacarpal and metatarsal bones. other common "errors" include the pisiform, or os trigonum and accessory ossification centres for the medial and lateral malleoli. in the axial skeleton, vascular markings in the skull, facial bone sutures and end plate ossification centres for the vertebral bodies are some of the commoner areas of concern. conclusion: issues are raised for both accident and emergency departments and for radiology departments if these "errors" are not minimised, including patient complaints of over-diagnosis and potentially unnecessary treatment and follow-up visits. the radiology of pediatric extracorporeal membrane oxygenation: normal appearances and complications a.m. barnacle, m.p. hiorns; london/uk learning objectives: to demonstrate the normal appearances of the pediatric chest during extracorporeal membrane oxygenation (ecmo). the spectrum of radiological abnormalities arising from the complications of ecmo is illustrated, including cannula position and anticoagulation complications. background: ecmo is a means of cardiopulmonary bypass therapy used in patients with cardiorespiratory failure who are unresponsive to conventional intensive care interventions. there is a range of indications for ecmo therapy in the pediatric population, which include congenital diaphragmatic hernia and cardiac disease. there are a number of complications associated with the use of ecmo, many of which are related to the high levels of anticoagulation required during therapy. radiological assessment prior to the commencement of treatment and sequential imaging during therapy are mandatory, and appropriate imaging protocols are discussed. imaging findings: the normal radiological appearances of the chest during ecmo therapy are demonstrated, including the correct positions of both va and vv ecmo cannulae. several technical points are highlighted, to avoid the misinterpretation of certain radiographic appearances. the radiological manifestations of a wide range of complications are illustrated. these include intracranial haemorrhage and extra-axial collection, haemothorax, peritoneal collections and vascular complications. inappropriate cannula positions are also reviewed. the radiologist must be familiar with both the normal and abnormal imaging appearances during ecmo therapy and should be aware of the range of potential complications. the importance of sequential imaging is highlighted and appropriate imaging protocols discussed. acute disseminated encephalomyelitis or multiple sclerosis: what tips the balance? s. avula, a. ghatak, n. wright, r. appleton; liverpool/uk learning objectives: to identify the imaging features and clinical parameters which help to distinguish between acute disseminated encephalomyelitis (adem) and multiple sclerosis (ms) in children. background: both adem and ms are disseminated inflammatory disorders affecting the central nervous system. distinction between the two is difficult, especially at the initial presentation when the prognosis and risk of relapse is an important issue. this exhibit will highlight the salient distinguishing features stated in the literature and illustrate cases of adem and ms which presented over a three year period. procedure details: literature review of childhood adem and ms was carried out and a retrospective review of cases presenting over a three year period with a subsequent diagnosis of adem or ms was performed. there is a considerable overlap between the imaging and clinical features of adem and ms. though there are a few features that predominate in either condition, the temporal progression of the disease with presence of new lesions with or without relapse of symptoms as noted in ms, is the most important factor in distinguishing the two. mri in assessment of fetal renal anomalies j.l. hughes, w. jan; london/uk introduction: in patients with renal anomalies causing severe oligohydramnios, the lack of fluid around the fetus significantly degrades the ultrasound image, making assessment of the fetal abdomen difficult. the presence of renal anomalies has great postnatal significance and successful antenatal counselling depends on the availability of the most complete information. the advent of fast mr sequences has allowed the acquisition of high signal to noise ratio images of the fetus even in the absence of amniotic fluid. we discuss the technique of mr of the fetal renal tract. we describe the normal appearances fetal kidneys on mr and present data on illustrative cases where mr provided additional information over and above a detailed ultrasound examination. methods: t w single-shot rapid acquisition with relaxation enhancement (rare) and t w d fast low angle shot (flash) were obtained of the fetal kidneys in the three orthogonal planes. all images were acquired without fetal sedation with the mother in the supine position within minutes. comparison ultrasound and mr images are presented. results: mri is able to diagnose and assess a variety of renal anomalies such as renal aplasia, dysplastic renal tissue, polycystic kidney disease, congenital hydronephrosis, and ectopic renal tissue. conclusions: fetal mr offers further information over ultrasound examination and hence allows appropriate ante-natal counselling. pediatric urethral anomalies a. sharma, s. maroo; glasgow/uk imaging evaluation of neonatal cystic pelvic masses v.v.t. mascarenhas, a. duarte, l. lobo, j. fonseca-santos; lisbon/pt learning objectives: to describe imaging features of cystic pelvic masses (cpm) in the newborn. to outline main differential diagnosic pitfalls. to emphasise the role of imaging evaluation in treatment and follow-up orientation. background: neonatal cpm are among the most common abdominal masses in the neonate and usually first suspected during fetal ultrasonography. a more precise diagnosis in the neonatal period is essential to an adequate orientation in treatment and follow-up. on this regard, imaging evaluation, particularly us and mri as the main techniques, undertake a pivotal role. we describe diagnostic imaging features, differential diagnosis limitations and a systematic diagnostic approach to cpm among selected cases in our department. imaging findings: we reviewed the referred cases based on sex, location, relation to adjacent anatomic structures and morphological features. main diagnostic entities considered were pre-sacral (sacrococcygeal teratoma and myelomeningocele) and non pre-sacral masses (genitourinary related namely hydrocolpos, ovarian cyst, bladder diverticulum; digestive tract related e.g. duplication cyst; others, particularly lymphangioma). morphological imaging findings according to their uni-or multilocularity, simple or complex components and the presence of specific findings were considered. ultrasound was the first and sometimes the only imaging modality performed. selected cases were further evaluated with other imaging modalities such as conventional contrast studies (e.g. cystography) or mri. conclusion: although there is a wide range of entities presenting as a cpm in the neonate, a systematic imaging approach allows a more precise diagnosis or at least a considerable narrowing of diagnostic possibilities in the majority of cases, which is essential for therapeutic orientation. normal sonographic appearance of kidneys and adrenals in neonates and young infants: unique distinctive features m. vakaki, g. pitsoulakis, h. manoli, c. koumanidou; athens/gr learning objectives: to familiarize residents in radiology or pediatric radiology with the sonographic characteristics of neonatal and infantile kidneys and adrenals. backround: the kidneys are the most commonly sonographically examined abdominal organs during the first months of life. the adrenals, due to their position adjacent to kidneys, are almost always clearly visualized during the renal sonogram. their sonographic appearance is quite different from that in older children and adults and often causes misleading incorrect diagnoses. imaging findings: examples of various normal sonographic findings of the kidneys and adrenals in neonates and young infants are presented and embryologically, anatomically or functionally explained. they include the hyperechogenicity of the renal cortex, the "enlarged" hypoechoic pyramids, the fetal lobulation, the inter-renicular septum, the transient neonatal renal medullary hyperechogenicity, the papillary projections in the pyelocalyceal system, the renal pyelectasis, the large and hyperemic neonatal adrenals and even more. these sonographic interpretations are often misdiagnosed as abnormal conditions, which are also provided. conclusion: this exhibit will allow an interesting way for young radiologists and pediatric radiologists to learn the common, but also the rare sonographic appearances of neonatal and infantile kidneys and adrenals. this knowledge is essential in order to prevent misdiagnoses and needless further investigation. background: difficulties with blind corticosteroid injection of the subtalar joint are commonly encountered in children with jra. ultrasound (us) guidance can make the puncture more accurate by directly showing the needle tip within the joint. procedure details: twelve consecutive patients with jia who had clinical signs of active arthritis and intraarticular fluid or synovial proliferation in the subtalar joint detected at us received either a blinded injection (n = ) or a us-guided (n = ) injection with free-hand technique using high resolution ( - mhz) us. patients were assessed at hours, months and months of follow-up to compare the level of clinical response and the frequency of complications between the two treatment groups. conclusion: although significant improvement was documented in both groups of patients with respect to baseline, those injected under us-guidance had a lower clinical dysfunction score at hrs and months follow-up. no major complications were noted. our preliminary results indicate that intraarticular corticosteroid injection of the subtalar joint in children with jia is more accurate and successful when performed under us guidance. background: doppler sonography is a well-established technique to evaluate a number of pediatric abdominal conditions, but the field of diagnostic applications is now on the brink of major changes. many contrast-specific modalities have been developed in recent years by academic researchers, ultrasound scanner manufacturers, and pharmaceutical companies. our aim is to update the diagnostic value of conventional doppler modalities, and to analyse potentially useful applications and indications for the more recently developed techniques. imaging findings: specific entities will be used to illustrate clinical principles that can be applied to multiple clinical situations. topics addressed include: vascular patency (arterial or venous thrombosis or stenosis, biliary atresia, liver and bowel transplantation, and surgical shunts); anomalous vessels and tubular structures (dilation of the biliary tree vs. blood vessels, pulmonary sequestration, varicocele); and evaluation of hyperemic and ischemic lesions (appendicitis, intussusception, pyelonephritis, orchitis / testicular torsion). conclusion: b-mode sonography, as well as doppler techniques, have a key role in pediatric diagnosis for several reasons (non-invasivity, lack of ionizing radiation, sonographic access is better than in adults, no need for anesthesia or sedation). understanding the physical principles that govern doppler imaging is essential for its successful clinical application. symptomatic cases: n = . mean onsd right eye = . mm (sd = . ), mean onsd left eye = . mm (sd = . ). a wilcoxon signed ranks test showed no significant difference between these results. using the largest reading for each eye when well and symptomatic: mean asymptomatic onsd = . mm (sd = . , n = ), mean symptomatic onsd = mm (sd = . , n = ). a wilcoxon signed ranks test showed a significant difference in these results (p = . ). conclusion: onsd increases in acutely raised icp. our results suggest that children with spina bifida and shunted hydrocephalus cannot be assumed to have onsd within the normal range even when clinically well. in the long term we aim to compile new onsd reference ranges for children with shunted hydrocephalus. withdrawn by authors hyperechoic foci in the kidney: an incidental sonographic finding in neonates and infants m.a. pourbagher, a. pourbagher, f. tiker, z. koc, e.a. niron; adana/tr purpose: the purpose of this study was to determine the incidence and significance of non-shadowing hyperechoic foci in the kidney and to evaluate metabolic disturbances in these patients. in a period of years abdominal ultrasonography (us) was performed as a screening procedure in neonates and infants. a followup us was performed in of ( female and males) patients with hyperechoic foci in the kidney approximately - months after the initial examination. all patients underwent metabolic evaluation, including serum electrolyte measurement and -hour urine collection. results: non-shadowing hyperechoic foci were detected in ( %) patients ( kidneys). the size of foci were - mm (mean mm). the foci were located in the lower pole calix in %, upper pole calix in % and middle zone calix in % kidneys. sixty kidneys had single, had and had or more foci. at - months follow-up the clearance for foci was %. size and site of foci has no relation with foci clearance. urinalysis showed elevated urinary calcium in and hematuria in patients. in patients foci were passed without intervention, and uric acid was the dominant foci composition in both patients. serum electrolyte measurement were normal in all patients. the incidence of hyperechoic foci in our study was %. that is usually discovered incidentally during sonography of the abdomen and generally resolve spontaneously. follow-up of the patients is advocated with us and urinalysis. germinal matrix morphology in antenatal ventricular dilatation k.m. koprivsek , t. vanderheyden , s. counsell , j. allsop , a. stonebrige-foster , s. kumar , n. fisk , m.a. rutherford ; sremska kamenica/yu, london/uk purpose: the germinal matrix (gm), a densely cellular zone lining the lateral ventricles, and give rise to the developing cortex. the mri appearance of gm during fetal development has been well-documented, but data about gm morphology in pathological conditions is sparse. antenatal ventricular dilation (vd) is associated with significant neurological morbidity. we used antenatal magnetic resonance imaging (mri) to measure the gm in fetuses with and without vd. methods: retrospective analyses were conducted of fetal mr images acquired over a -year period, using fast t weighted sequences. in fetuses (normal ventricles in , vd in cases), we evaluated the signal characteristics and the maximum germinal matrix diameter (gmd) at three sites: the anterior and posterior ventricular horns and the caudothalamic notch (ctn). between-group comparisons of gmd in normal and fetuses with vd were made using a students t-test. results: gm had the same low signal intensity regardless of ga and/or ventricular volume. none of the infants with vd had evidence of gm haemorrhage. the mean gmd in controls showed a linear decrease with brain maturation. in fetuses up to weeks of ga with normal ventricles the gmd was greatest at the ctn. the similar pattern of changes in gmd was measured in vd group, where the mean gmd at the tcn were slightly, but not significantly lower then in controls (t = . : p > ( . )). conclusion: gm diameter decreased with increasing gestational age. we did not detect any significant difference in gm morphology in the group of fetuses with antenatal vd. contrast enhanced color doppler ultrasonography in diagnosis of scrotal lesions in children u. zaleska-dorobisz, e. czapiga, k. moron; wroclaw/pl purpose: to investigate the usefulness of ultrasound with contrast agent levovist-schering (usca) for the detection scrotal lesions in children. between - , boys with scrotal masses were examinated. mean age was . years and ranged from - . diagnostic assessment included in all cases conventional us, color doppler and power doopler before and after the adminstration of contrast agent keeping the same methodology in every examined patient. focal testicular lesions (cystic and solid tumor) and extratesticular structures were documented regarding size, localization, range, vascularity and ultrasound diagnosis. in testicular tumors, the degree of tumor vascularity was subjectively graded from to iv. the ultrasound diagnoses were compared to the final diagnoses based on clinical tests, surgical and histological examination. results: testicular and extratesticular tumors showed more enhancement than adjacent testicular parenchyma, seen between to s (mean s) and to s (mean s) after injection. the duration of enhancement was to s (mean s). cross sections and adjacent vessels were only seen in: teratoma, embryonal carcinoma and yolk sac tumor. conclusions: usca is an important and significant aid in the diagnosis of scrotal diseases, in the assessmentof of degree of vascular change and is predictive of malignancy. mr features of the preterm children with athetotic cerebral palsy k. hayakawa, t. kanda, y. yamori; kyoto/jp purpose: the recent development of the neonatal intensive care medicine has caused not only a dramatic decrease in the incidence of kernicterus, but also marked improvement in the survival of premature babies. consequently, the incidence of pure athetotic cerebral palsy has decreased, whereas the incidence of spastic cerebral palsy associated with athetosis, termed mixed cerebral palsy, has increased. the purpose of this study is to evaluate the brain mr features of this condition and to assess the frequency of basal ganglia injury. the subjects consisted of boys and six girls diagnosed with mixed cerebral palsy. their gestational age range from to weeks (average = weeks) and the birth weight ranged from g to g (average = g). mr brain scans were assessed with particular attention to the basal ganglia. imaging of pancreatic disorders in pediatric patients y. herrero, t. berrocal, c. prieto, j. fernández, m. parrón, r.r. lemos; madrid/es purpose: the aim of this teaching exhibit is to illustrate a wide spectrum of usual and unusual disorders involving the pancreas in children, and to evaluate the efficacy of ultrasound (us), duplex and color doppler sonography, endoscopic retrograde cholangiopancreatography (ercp), computed tomography (ct) and magnetic resonance (mr) imaging in the diagnosis and management of these conditions. methods and materials: the imaging findings of patients with disorders involving the pancreas were reviewed from our database of pediatric pancreatic pathology. ultrasound was performed in all cases, while ct, and mri were performed in all tumors and whenever us and doppler images were not conclusive. ercp was used to study the pancreatic ducts. the embryologic and pathologic bases of the imaging findings are discussed in appropriate cases. the key findings at each imaging modality are shown and compared with the underlying pathologic features when available. pitfalls, diagnostic difficulties and differential diagnoses are emphasized. results: specific topics addressed include congenital anomalies (pancreas divisum, annular pancreas, ectopic pancreas, pancreatic cysts, cystic fibrosis, shwachman-diamond syndrome, von hippel-lindau syndrome, and nesidioblastosis); acute and chronic pancreatitis; pancreatic cyst and pseudocysts; primary neoplasms (insulinoma, cystadenoma, and papillary cystic carcinoma); metastasis of burkitt lymphoma; and miscellaneous (hemochromatosis, cushing's disease, steroid and cytostatic therapy, and parenteral nutrition). conclusion: evaluation of patients with pancreatic disorders frequently requires multiple imaging modalities for diagnosis and planning surgical correction. because many of these disorders have characteristic imaging appearances, this exhibit will help practicing radiologist to better understand and recognize pathologic processes affecting the pancreas. imaging congenital vertebral disorders in pediatric patients m. fernández -velilla, t. berrocal, a. royo, a. fernández, j. gutierrez, n. gómez-león; madrid/es purpose: to illustrate a wide spectrum of usual, unusual and exceptional congenital anomalies involving the vertebrae, and to evaluate the efficacy of plain radiographs, computed tomography (ct) and magnetic resonance (mr) imaging in the management of these conditions. methods and materials: we retrospectively reviewed the imaging findings of patients with congenital abnormalities involving the vertebrae from our database of spinal pathology. abnormalities were divided into isolated vertebral anomalies and anomalies associated with systemic diseases or syndromes. plain radiographs were performed in all patients. ct or mr were performed whenever plain radiographs were inconclusive. the embryology and pathologic basis of the radiographic findings are discussed. pitfalls, diagnostic difficulties and differential diagnoses are emphasized. results: specific topics addressed include anomalies in number (vertebral agenesis, sacral agenesis, omovertebral bone); anomalies in size and shape (vertebral and sacral hypoplasia, hemivertebra, occipitalization of c , os odontoideum, lumbarization, sacralization); anomalies of fusion (blocked vertebra, klippel-feil abnormality, spina bifida, butterfly vertebra, coronal cleft vertebra); anomalies of alignment (spondylolisthesis, spondilolysis, scoliosis); neural arch defects (absence of the pedicle and lamina); caudal spinal anomalies with anorectal and urogenital malformations (terminal mielocystocele, caudal regression syndrome, vacter association, oeis complex, currarino triad); and skeletal dysplasias (achondroplasia, thanatophoric dwarfism, chondrodysplasia punctata, spondyloepiphyseal dysplasia, and mucopolysaccharidoses). conclusion: evaluation of patients with vertebral abnormalities frequently requires multiple imaging modalities for diagnosis and planning treatment. because many of these disorders have characteristic imaging appearances, this exhibit will help trainee radiologist to better understand and recognize pathologic processes affecting the vertebral spine. defecography in chronically constipated children a.d. yang, m.-t. cheng, k. lee; changhua/tw purpose: to evaluate the defecographic findings in children suffering from chronic constipation. between may to august , we performed a prospective study of children ( boys, girls) with an age range of - years old who fit the criteria for chronic constipation in our institution. defecography was performed using flouroscopy with radiographs were taken during different phases of defecation; the whole study was video recorded. results: of the children studied ( ) children were found to have abnormal defecographic findings: partial relaxation to non-relaxation of the puborectalis muscle on defecation was found in patients; anterior rectocele in , posterior rectocele in , rectal intussusception in , mucosal prolapse in , rectal prolapse in ; sigmoidoceles in : grade i ( ), grade ii ( ), grade iii ( ). conclusion: . the defecographic findings that are seen in adults could also be found in children. . defecographic evaluation could be a potentially valuable and simple radiologic study which could be used in the evaluation of children suffering from chronic constipation. evaluation of the usefulness of d ct reconstructions of multifragmented fractures in children m. wozniak, e. dybiec, p. wieczorek; lublin/pl purpose: the aim of the study was the evaluation of the usefulness of d ct reconstructions in the imaging of post-traumatic alterations of the bones in children. the analysis was based on three dimensional ct reconstructions of the fractured bones. there were cases of extensive, complex bone fractures, when evaluation based on conventional radiographs was insufficient. all examinations were performed on a shimadzu sct tx scanner. surface and volume rendering were employed in the processing. the results of the study show that d reconstructions allow very precise evaluation of post-traumatic alterations, especially in the bones of complex anatomical structures. they enable the imaging of small fracture fissures invisible on conventional radiographs and ct. in the cases of bone indentations d reconstructions allow very detailed evaluation of the depth of indented fragments, their displacement and rotation. results: ct examinations were performed over the nine month study period. examinations using tube current of more than % greater than protocol were noted. these reduced from % of examinations prior to the introduction of the protocol to % following its introduction. reductions were most noticeable in helical examinations of thorax, abdomen and pelvis. conclusion: weight related protocols reduce the tube current used and thus the radiation dose in a large percentage of paediatric ct examinations. this has proved to be an effective method of reducing dose both in this study and in previous studies. bone sarcomas as a second malignancy in children c. renal dysplasia and intrarenal reflux in boys with posterior urethral valves: high resolution sonographic findings m. vakaki, g. pitsoulakis, h. manoli, c. koumanidou; athens/gr purpose: voiding cystourethrography (vcug) is considered the gold standard for the diagnosis of the posterior urethral valves (puv) and the accompanying vesicoureteral reflux (vur) in boys. however, its contribution to the characterization of intrarenal pathology, which is considered to be of great prognostic value, is minimal. it is only with recently introduced high resolution ultrasonographic equipment that details of disturbed renal architecture can be visualized. materials and methods: infant boys with puv, aged day to months were examined sonographically with - mhz convex and - mhz linear transducers. the presence of puv was confirmed with vcug in all cases. results: apart from the classic sonographic findings of puv, which were also demonstrated, findings specific to the kidney included: a) bilaterally increased renal parenchymal echogenicity and loss of corticomedullary differentiation ( / ), which with b) small cortical cysts ( / ) imply renal dysplastic lesions, c) increased medullary echogenicity, cupping of dilated calyces, which is attributed to intrarenal reflux ( / ), d) hypoechoic lines pointing towards rounded calyces, corresponding to the pelvotubular backflow of urine ( / ), e) small subcapsular urinomas ( / ), f) urinoma and urine ascites ( / ) and g) intrarenal abscesses ( / ) and fungal balls in the collecting system ( / ), due to post-surgical candidiasis of the urinary tract. conclusion: ultrasonography with high-resolution transducers is able to visualize underlying renal pathology and to image the parenchymal architecture, contributing not only to the diagnosis but also to the definition of the prognosis in boys with puv. meningiomas within the vertebral column are even rarer. we present the imaging characteristics of meningiomas ( intracranial and intracanal) in girls and boys, aged . - years (mean age . years). these meningiomas were diagnosed during year period ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) . none of the studied children had previously been treated with radiotherapy. both children with vertebral meningioma suffered from neurofibromatosis. the imaging studies included brain ct ( / ) and mr of the brain ( / ) and vertebral column ( / ) before and after intravenous administration of gd-dtpa. the histologic examination after the surgical tumor resection showed meningioma of the transitional type in children and co-existing malignant elements in the th child. following tumor resection, children were free of symptoms and no other treatment was required. in contrast, the patient with the meningioma with malignant elements was treated with chemotherapy and radiotherapy, after subtotal tumor resection. conclusion: imaging of meningiomas (intracranial and intracanal) provides essential information for surgical planning, demonstrating the extraparenchymal nature of the neoplasm, its location, its dimensions, possible calcifications, as well as its effects on adjacent anatomic structures. rare hepatic vascular anomalies in pediatric patients z. harkanyi, g. balazs, g. tasnadi; budapest/hu purpose: to present a selection of rare cases of hepatic vascular anomalies in pediatric patients. us, helical ct and mr were used in the diagnosis and in the follow-up of these lesions. various venous anomalies were detected including intrahepatic arterio-portal and porto-hepatic shunts. a case of porto-caval shunt was also identified. the most frequent anomaly was portal cavernoma due to portal vein thrombosis. one case of caval web has been followed up for years. another case of budd-chiari syndrome has been followed up for two years. several cases of hepatic and portal vein anatomic variations are also documented. d and color doppler us was used as the first line examination in the diagnosis and follow-up different congenital hepatic vascular anomalies. helical ct, cta and, more recently, mra has been used for further analysis of these lesions. conclusions: us is still the first method for the evaluation of the pediatric liver and the hepatic vessels. color doppler is the modality of choice for functional evaluation of the vascular anomalies and is also useful in the follow-up of the patients. contrast-enhanced mra and cta is helpful in selected cases to demonstrate the extent of the lesions and other associated anomalies, such as development of systemic collaterals. acute [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] , (n = ) children with septic sacroiliitis and/or acute osteomyelitis of the pelvic bones were imaged by our radiology department. other laboratory tests were already performed and in ( / ) young patients, material from needle aspiration had been sent for cytological examination. the imaging initial approach included plain film study and triple-phase tc radiophosphate scan. in addition, ( / ) patients underwent mri examination and ( / ) children had ct. the laboratory results confirmed the diagnosis of osteomyelitis and/or that of septic sacroiliitis. the retrospective study of the imaging examination results indicated the superiority of scintigraphy and of mri in the diagnosis of these entities. plain film radiographic signs of disease were observed only in patients ( / ) though the bone scintiscan was positive in all patients ( / ). the ct examination was positive in young patients ( / ) while mri's sensitivity was % ( / ). at the end of therapy all patients recovered completely. conclusion: a bone scan is warranted in every case of clinically suspected osteomyelitis and/or septic sacroiliitis in which the radiographs are unrevealing. however, mri is a useful adjunct in the evaluation of the bone edema, the detection and localization of abscess and in the demonstration of the soft tissue extent of the infectious process. the results: hrct showed that / of the cases had bronchiectasis, with cystic fibrosis as the underlying cause in cases. cases had bronchiolitis obliterans and cases had macleod's syndrome. cases with aspiration pneumonia had gastroesophageal reflux, and a intrabrochial foreign body was detected in one case. one case had bronchopulmonary dysplasia, and had tb lymphadenitis compressing bronchi. chest radiography revealed findings of bronchiectasis only in of the cases. hyperaeration was detected in the chest radiographs of only cases out of , whose hrct revealed air trapping. hrct showed peribronchial thickening in cases, however, chest radiography showed the same finding in patients. hrct made it possible to observe linear densities caused by linear atelectasis / scars in cases. hrct showed the underlying pathology and consequent pulmonary lesions in out of cases, and linear densities in . conclusion: hrct has a significant role in detecting the underlying abnormalities and consequent lesions in children with recurrent pulmonary infections. compared to chest radiography, hrct gives much more information. analysis of doppler signals: application for detection of fetal movements a. kribeche, s. benderbous, m. berson, d. kouame, l. pourcelot; tours/fr the objective is to develop and validate a new doppler ultrasound system allowing the imaging of fetal movements in real time. we describe the prototype of new ultra-sound sensors and present the results obtained in pregnant women. the apparatus enabling us to acquire the signals coming from fetal activity consists of ultrasonic sensors, a doppler module and a computer provided with a chart of acquisition of the signals. after suitable recording and signal processing, fetal heart rhythm (fhr) and the fetal breathing movements (fbm) are extracted. study of the doppler signals after fast fourier transform enables us to characterize the fetal movements in term of the amplitude, displacement and frequency. estimate of displacement is obtained by calculating the phase of the signal resulting from the analytical filtering of the doppler signal and to separate the direction from the doppler signals. results: twenty recordings were carried out on four women in their last quarter of pregnancy. during the last quarter of pregnancy, the fhr is approximately beats.min - . however, the fhr that we detected is about beats.min - . we are thus in the presence of the fetal heart rhythm. conclusion: this is the first time that parameters giving the fetal movements are extracted. as a first approach, the fft gives satisfactory results. assesment of skeletal age with hand and wrist sonography: could a standardised method replace radiography? s. megremis, g. cavallo, m. michalakou, e. kehagias, n. segkos, e. agianniotakis, e. sfakianaki; iraklion/gr purpose: to investigate the capability of hand and wrist sonography in skeletal age assessment, and to propose a technique that could be commonly used. materials and methods: forty-two children, aged months to years, underwent a left hand radiograph for skeletal evaluation. they were also sonographically examined on the same hand, with focus on distal epiphyses of radius and ulna, carpal ossification centers, adductor sesamoid bones of metacarpophalangeal joint of the wrist and the cartilage of the third's finger distal phalange. scanning and measurements were obtained in both transverse and longitudinal planes, and the images were digitally recorded for further evaluation. results: all areas of interest were identified both in the left hand radiograph as well as in the sonographic examination, for each individual. furthermore by dorsal and palmar scanning of the carpal ossification centers, accurate mapping and measurements were feasible. gaining experience, and developing a common procedure, we were able to progressively minimize most technical difficulties. conclusion: hand and wrist sonography promises an accurate, safe and cost effective assessment of skeletal age. detailed knowledge of hand and wrist anatomy, and familiarization with a standardized method, as the one we propose, in acquiring and interpreting images is indispensable. in addition, the designation of sonographic charts for the evaluation of skeletal age could be possible in the future. the role of hepatobiliary scintigraphy in the differential diagnosis of neonatal hepatitis, intrahepatic cholestasis, and biliary atresia e. palócz, t. györke, k. bártfai, l. balogh, l. szönyi, i. máttyus, É. kis, t. verebély, e.k. makó; budapest/hu purpose: biliary atresia (ba), intrahepatic cholestasis (ihc) and neonatal hepatitis (nh) are the main causes of neonatal direct hyperbilirubinaemia (ndh). the distinction of ba needing early surgical intervention from nh and ihc syndromes is essential, but difficult. the impact of hepatobiliary scintigraphy (hsc) in the differential diagnosis of ndh was evaluated. methods and materials: hscs of patients (age: days- months) with ndh were included in our retrospective study of a five years period. after administration of . mbq/kg (min.: mbq) mtc-brida serial abdominal images were performed up to hours. the scintigraphic diagnoses (sd) of ba, ihc, nh and indeterminate (ind) were defined based on visual scoring of liver uptake, intrahepatic radiopharmaceutical transport and bowel activity. sds were compared with clinical diagnoses (cd), which were based on laboratory, histological or operative findings and/or clinical follow-up. results: the cds were: ba, ihc, and nh. the sds were: ba, ihc, nh, ind were correct in and false in cases, while the cd in the ind cases was ba. regarding the shortage of bowel activity as a basis for sd of ba the sensitivity and specificity of hsc in the diagnosis of biliary atresia were and % respectively. conclusion: our results suggest that hepatobiliary scintigraphy is a useful tool in distinguishing ba requiring urgent surgical intervention from other kinds of pathologic conditions causing ndh, but that it is unreliable in further narrowing of the differential diagnosis. various radiologic findings of wilms' tumor y.-w. kim , w. kim , i.-o. kim , k. yeon ; busan/kr, seoul/kr purpose: wilms' tumor is the most common pediatric renal mass. although it usually manifests as a solid intrarenal mass with a pseudocapsule and distortion of the renal parenchyma and collecting system, some atypical radiologic findings may produce diagnostic confusion. the purpose of our exhibit is to illustrate various radiologic findings of wilms' tumor. we retrospectively reviewed radiologic findings of cases, which were pathologically proven from to (the age of patients; between months and years). results: this exhibit includes: ) typical intrarenal wilms' tumor (n = ), ) wilms' tumor with vascular invasion (n = ; renal vein , ivc , right atrium ), ) wilms' tumor with perirenal extension (n = ; psoas & ln , perirenal hematoma , subcapsular hematoma ), ) wilms' tumor with extension into the urinary tract (n = ; renal pelvis , ureter & bladder ), ) wilms' tumor with metastasis (n = ; lung , bone , pleura , mediastinum , scrotum ), ) bilateral wilms' tumor (n = ), ) wilms' tumor in a horseshoe kidney (n = ), ) atypical wilms' tumor (teratoid wilms'; n = , cystic wilms'; n = , extrarenal wilms'; n = , intrapelvic wilms'; n = ). the knowledge of these various radiologic findings of wilms' tumor can be helpful in the diagnosis and management of the tumor. extracorporeal shock wave lithotripsy monotherapy for pediatric urinary tract calculi z. siric, a. slavkovic, m. radovanovic, m. mrvic; nis/yu purpose: to show the safety and efficacy of extracorporeal shock wave lithotripsy (eswl) for the urolithiasis in the pediatric age group and to evaluate the complications encountered after the treatment. material and methods: children (age range months to years) with stones underwent eswl. kub were taken on the day after treatment. if stonefree status was achieved, the patient was followed with ultrasonography and urinalysis every six months. if fragments < mm were present, follow-up was repeated every months. results: stone size ranged from . to . cm. kidneys, ureters and bladers underwent eswl sessions. retreatment was required in % patients. the mean number of sessions per child was . . mean fluoroscopy time per session was . min. the overall success rate was %, but the stone -free status was achieved in % of children. the composition of the stones were struvite and calcium oxalate in the majority of the patients. auxiliary procedures (jj stents) were used in % children. transient hematuria, ecchymoses and colic p p p p pedia edia edia edia ediatric tric tric tric tric were the complications encountered after treatment in % of children. perirenal haematoma was identified in one patient. ( %) children developed obstruction and required nephrostomy. conclusions: eswl is non-invasive procedure suitable for stones in all locations in the pediatric patients. it may be the first-line treatment for all pediatric urinary tract calculi, although the long-term effects of lithotripsy on the kidney are unknown. imaging to meckel's diverticulum (n: ), small bowel tumour (n: ), duplication enteric cyst (n: ), postoperative (n: ) and bowel wall hemorrhage (as in henoch-schonlein purpura (n: ). the enema failed to reduce the intussusception in all cases. all children underwent definitive surgery rather than inappropriate treatment by attempted radiological reduction. conclusion: abdominal sonography is the most efficient examination for the diagnosis of intestinal intussusception. various pathological lead points in intussusception can now be defined by ultrasound. secondary intussusception treatment is surgical. diagnostic value of diffusion weighted mr imaging in pediatric cerebral neurological diseases y. oksuzler, h. cakmakci, s. kurul, m. oksuzler, e. dirik; izmir/tr purpose: to detect the diagnostic value of diffusion weighted (dw) magnetic resonance (mr) imaging in different diseases involving the cerebral white and gray matter and to compare the diffusion properties with age matched normal children. conventional and dw mr imaging was performed in children with neurologic disorders, and normal control subjects. neurological disorders included neurodegenerative brain diseases (n: ), anoxic encephalopathy (n: ), acute disseminated encephalomyelitis (adem) (n: ), encephalitis (n: ), subacute sclerosing panencephalitis (sspe)(n: ). apparent diffusion coefficients (adc) were measured from the brain lesions and normal appearing white and gray matter areas in study group. normal appearing areas were also measured in the control group. results: adc values obtained from the normal subjects were similar to values described in the literature. adc values of study groups were significantly different from the control subjects. adc values for the neurodegenerative disease group, anoxic encephalopathy group, adem group, encephalitis, sspe group, were respectively between . x - - . x - cm /s, . x - - . x - cm /s, . x - - . x - cm /s, . x - - . x - , . x - - . x - cm /s. conclusion: although this study is limited due to population size and disease heterogeneity dw mri provides useful and complementary information regarding the degree of involvement in different pediatric neurological disorders. clinical presentation and mri findings in non-accidental trauma in children under two years of age p.c. sundgren , m. petrou , j. jennings , j. ksar , j. smythe , b. foerster , p. maly , p. eldevik ; ann arbor, mi/us, lund/se purpose: to describe the clinical presentation and illustrate the mri findings in suspected non-accidental brain trauma in children under two years of age. we reviewed the hospital charts and the mr reports of patients examined due to clinical suspicion of non-accidental brain trauma. we noted the clinical presentation and the mri findings in each case. both the radiological diagnoses and the final diagnoses were extracted and compared, and the impact of the mri examination on the clinical course of the patient was evaluated. results: subdural hematoma was the most common finding seen in of the patients, petechial hemorrhages and brain edema was other common findings in these patients. discussion/conclusion: non-accidental brain trauma is not uncommon and in most cases ct of the brain is the method of evaluation. mri is only performed in a limited number of cases, for example, when dating the abnormalities is crucial, and to evaluate for additional findings of axonal shearing injury. examples of this will be illustrated. congenital hip dysplasia: mri after reduction of the femoral head e. svedström; turku/fi purpose: in the treatment of developmental dysplasia of the hip, maintenance of the correct position of the reduced femoral head is very important. many modalities such as conventional x-ray images, tomography, ct and us have been used in the evaluation of the femoral head position after reduction. these techniques either use ionizating radiation or require an experienced examiner. they might even be subject to technical limitations or sometimes be inaccurate. this poster describes the use of mri in the assessment of femoral head position after closed or open reduction. mri studies with an open-configured . t mr-imager were performed on four children. some of these children ( - months of age) were studied multiple times during the follow-up. no sedation was used. coronal and axial sequences were used. position of the femoral head, appearance of the limbus and formation of the pseudoacetabulum were noted. results: all mri studies were successfully performed without any sedation. the plaster did not reduce image quality in any of the studied hips. in four still-dislocated hips mri showed correct diagnosis. in two of these hips an inverted limbus could correctly demonstrated. conclusions: accurate diagnosis is very important after reduction of the femoral head. these children commonly require multiple imaging studies during followup. therefore, mri and us, which do not use ionizating radiation, are the preferred modalities. after reduction, mri findings are easily reproduced and are accurate. even other findings like inverted limbus in interposition and formation of pseudoacetabulum can be demonstrated. b d e f a g practical experience with the application of the "digital addendum of the european protocol for quality assurance in mammography" h. bosmans , f. rogge , a.-k. carton , k. young , r. van engen , m. thijssen , g. marchal ; leuven/be, guildford/uk, nijmegen/nl learning objectives: to teach different aspects of the digital addendum (da) to the european protocol for quality control in mammography: • the purpose of the tests as described in the document. • the test methods. • the applicability of the test methods and the discussion of the first measurement results. background: digital mammography is a new imaging modality for mammographic applications. in order to assure sufficiently high quality standards, new test protocols had to be developed. a group of european medical physicists has cooperated under the coordination of the european breast cancer network and euref. the first publication is expected for october . the (pre-released) version (aug. ), work in progress, has been evaluated on different full field digital mammography (ffdm) systems and is the basis of the present teaching session. procedure details: following systems were included: senographe d (ge), senoscan (fischer), ma (fuji), ac (fuji), embrace cr (agfa) and embrace dr (agfa). the tests as described in the protocol included direct performance tests, contrast detail analysis, patient dose measurements and physical measurements such as mtf and dqe. for these last measurements, acceptable and achievable levels have not yet been defined. the help of a service engineer was necessary in most systems to get access to raw data. the tests as proposed in the protocol could then be performed. contrast detail analysis is the most critical part and should be automated to reduce interobserver variability. patient doses were comparable or lower than doses in conventional mammography. the acquisition of mtf and dqe requires a further standardization of the method. the digital addendum in its current phase was applicable to all systems tested so far. practical experience is growing and will add to the applicability and value of the document. anisotropic resolution in helical cone-beam ct reconstruction d. heuscher , s. utrup , f. noo ; highland heights, oh/us, salt lake city, ut/us learning objectives: to describe how the different aspects of helical cone-beam reconstruction affect spatial resolution in all three dimensions. to demonstrate that depending on the radial and angular position of a voxel, this resolution can be anisotropic. to describe appropriate filtering and interpolation steps that can be taken to reduce these effects. background: a number of methods have been described recently that provide either exact or near-exact reconstructions of helical cone-beam scan data. in this exhibit, we will describe key aspects of the implementation of these reconstruction algorithms that affect spatial resolution. we will show how the anisotropy of in-plane resolution can be related to the corresponding effect in single-slice d reconstructions. alternative filtering and interpolation steps will be suggested. procedure details: fwhm slice-sensitivity profile and in-plane resolution measurements were performed on helical reconstructions of a phantom consisting of seventeen . mm diameter spherical beads located at , , and mm radii. the scans used an mx -idt x . mm detector configuration with a . pitch factor. single-slice d reconstructions were performed on the same phantom using both fan and parallel convolution-backprojection algorithms to produce comparative in-plane measurements. alternative hi-order interpolation and voxel-dependent filters were investigated to produce nearly isotropic resolution. conclusion: significant spatial variation in resolution can be observed in exact or near-exact helical cone-beam reconstructions. a more uniform and isotropic result can be achieved by using hi-order interpolation to produce parallel projection data along with longitudinal voxel-dependent filtering. comparison in pet/ct studies iv contrast agents increased the suv of the mediastinum to . ( . ) and the liver to . ( . ). these increases in suv were coincident with changes in ct density from hu to hu (mediastinum) and from hu to hu (liver). suv values in the colon wall seem unaffected by positive oral contrast compared to pet: . ( . ) vs . ( . ). conclusions: physiologic suv from pet/ct appear somewhat higher than suv from standard pet when the ct is acquired with standard volumes of iv contrast media. adventures in non medical radiography a.a. alhajeri, d. mckenna, b. tuohy, c. roche, p. mccarthy; galway/ie learning objectives: to demonstrate the non-radiological use of familiar imaging modalities and show how far we have come since the first x-rays of mrs. roentgen's hand. background: today, x-rays technology has a wide application and is presently in use in fields as diverse as engineering, art, forensic pathology and security. procedure details: through a pictorial review we show how x-rays have a role in non-medical applications. we demonstrate how law enforcement agencies have adapted x-ray technology to screen luggage at airports, sometimes even using ct. furthermore newer technology in use in europe has been developed, termed "back scatter", which makes possible the detection of illegal immigrants and contraband material concealed within trucks. the characterisation of the bony skeleton with the aid of x-rays is not only helpful in identification but sometimes can also indicate to the forensic pathologist the mode of death. industrial engineers are able to evaluate the integrity of a structure with the aid of x-rays. examples include the examination of airplane engines and pipes for hairline fractures, unidentifiable to the unaided eye. in the art world, x-rays have been used to detect forgeries and even to create original art works. conclusions: this poster reaffirms the benefits of different imaging modalities showing how technology developed for medical imaging has been adapted for use in non-medical areas. radiation-induced temporary hair loss after cerebral perfusion studies with multi-detector ct y. imanishi, a. fukui, h. niimi, s. nakaji, k. nozaki, y. furuya, m. uzura, s. hashizume, y. nakajima; kawasaki/jp learning objectives: learning presence of complications by a cumulative or multiplier effect of radiation exposure from multiple diagnostic techniques. background: as various imaging technologies become increasingly advanced, they make it possible to get various kinds of information and large amount of imaging data. in some imaging technologies, the radiation dose increases with the ability to obtain better images or more detailed information. imaging findings: we encountered cases of temporary bandage-shaped hair loss, which was caused by perfusion studies of the head by multi-detector computed tomography (mdct) for evaluation of blood flow in the brain. in all of the , digital subtraction angiography of the head was performed within a period of the ct perfusion studies. this suggested the possibility that radiation exposure from angiography performed in serial examinations, combined with the perfusion studies effectiveness of a new dual-energy subtraction system using csi:tl amorphous silicon flat-panel technology h. tagashira, n. bandai, m. yoshimoto, y. yasuhara; ehime/jp learning objectives: to describe the theory of the new dual-energy subtraction system. to demonstrate the system with chest radiology cases. background: lung cancer is the current leading cause of cancer death and continues to be increasing. chest radiography has been shown to have relatively low sensitivity and specificity for the detection of the pulmonary nodules. this new dual-energy subtraction system allows the fast ( millisecond) acquisition of two, high and low voltage images and provides soft tissue and bone structure image of the chest with relatively low dose. procedure details: the radiologists' performance for reporting chest radiographs was evaluated by use of receiver operating characteristic (roc) analysis. the performance of radiologists was improved significantly when the dual-energy subtraction image was used (p < . ). conclusion: diagnostic accuracy will be improved by using this dual-energy subtraction system. longitudinal filters for uniform cone-beam resolution d. heuscher, s. utrup; highland heights, oh/us purpose: this presentation demonstrates the non-uniform longitudinal resolution inherent in today's cone-beam reconstructions and how, through the appropriate use of longitudinal filtering, improvements in image quality can be achieved. simulations and scans for acquisition geometries of or more detector rows were evaluated. a circular half-scan (hs) and a helical scan (pitch factor . ) were performed on an mx idt using a x. mm detector configuration. a phantom consisting of steel beads was used to measure longitudinal resolution at angles and radii. simulations were performed using the same phantom geometry, including a x. mm helical scan. a voxel-dependent filter was used to achieve uniform longitudinal resolution and compared to projectionbased filtering. both real and simulated thorax phantoms were used to evaluate the effects on image quality. results: resolution measurements demonstrate an angular variation in longitudinal resolution for large-pitch helical and circular hs cone-beam scans. the fwhm ssp measurements varied by over % and % at and mm radii respectively. reconstructions with projection-based filters did not reduce this variation. similar results were observed for helical scans with the larger cone angle ( x . mm detectors), wherein the resolution pattern varied at half the frequency along the longitudinal direction. applying voxel-dependent longitudinal filtration achieved uniform resolution, demonstrating improved image quality in both real and simulated scans. conclusion: there is an inherent non-uniformity of longitudinal resolution for cone-beam scans, particularly for large-pitch helical and circular half-scans. uniform resolution can be achieved using voxel-dependent filters. potential of phase contrast in x-ray imaging p. monnin , r. meuli , j. hoszowska , j.-f. valley , f.r. verdun ; lausanne/ch, grenoble/fr purpose: one of the limitations of conventional radiology is that small or weakly absorbing structures cannot be detected on images. coherent properties of an x-ray beam produce phase contrast images where a change of the refraction index of tissues translates into an edge enhancement phenomena on the images that allows the detection of weakly contrasted structures. this study shows the feasibility of implementing the in-line holography principle with an aim to imaging very small structures. material and methods: phase-contrast images were obtained using synchrotron radiations at esrf (grenoble, france). images of to micrometer nylon wires, immersed in different media, were recorded with a ccd camera ( . micrometers pixel size) in different imaging conditions. images were compared with the results obtained by means of fresnel diffraction theory. the coherent x-ray beam and the defocusing distance between the structures to be imaged and the detector produced phase contrast images of the wires. the comparison of the recorded images with the predicted image formation from the fresnel diffraction theory revealed the performance of this technique in terms of sensitivity, geometrical and energy requirements. images of a biological sample (i.e. pork kidney, cam's) were also produced where very fine low contrast structures, unnoticed in pure absorption contrast, appeared. the potential of the technique in neo-vascular process imaging will also be discussed. the potential of in-line holography techniques to improve image contrast of biological tissues has been demonstrated. experimental the aim of the present study was to evaluate y al o :ce (yag:ce) phosphor for radiographic and mammographic imaging. yag:ce, which has never been previously used in diagnostic radiology, emits green light with very short decay time ( ns). it is expected to match the spectral sensitivities of most photodetectors. radiographic test screens of various coating thickness ( - mg/cm ) were prepared in laboratory employing yag:ce phosphor in powder form with . µm median grain size. luminescence emission efficiency (emitted light over x-ray exposure) and light emission spectrum were experimentally evaluated as a function of x-ray tube voltage employing both tungsten and molybdenum target x-ray tubes. in addition, the spectral compatibility of yag:ce emission spectrum with orthochromatic films, photocathodes, ccd arrays and amorphous silicon photodiodes, used in both conventional and digital radiography, was determined. results were compared with other phosphor materials (gd -o- s:tb, csi:tl) currently employed in medical imaging. results: maximum yag:ce emission efficiency was observed for mg/cm screen at - kv using tungsten target x-ray tube. emission spectra peaked at nm. the spectral compatibility with amorphous silicon photodiodes ( . ) and ccds ( . ) was found to be very high, better than the corresponding compatibility of csi:tl, as mostly used in digital radiography detectors currently. conclusion: considering the yag:ce performance, its short emission decay time and its spectral compatibility with amorphous silicon detectors and ccds, this phosphor material is appropriate for use with digital radiography detectors. b d e f a g reduction of eddy current artifacts in echo planar diffusion tensor imaging with a stimulated echo preparation g. steidle, f. schick; tübingen/de purpose: diffusion-tensor-imaging (dti) using se-epi in tissue with short t values, such as kidney or skeletal muscle, suffers from a poor snr for higher bvalues. using a stimulated-echo diffusion preparation, sufficiently high b-values can be obtained by increasing the mixing time (tm) rather than te. a diffusionweighted stimulated-echo epi sequence is proposed which minimizes the influence of eddy currents (ec) without any increase in the minimum te or acquisition time. methods and materials: assuming a monoexponential decay for the ec with time constant λ, gradient pulses can be implemented within the tm interval such that eddy current effects proportional to exp (-λ x t) will vanish. in-vivo dti measurements were performed in human calf musculature on a . t siemens sonata unit. measurement parameters were te = ms, tm = ms, tr = ms, b = resp. s/mm , matrix x , fov mm, nex = , slice thickness mm. diffusion weighting was applied in six directions in order to calculate the diffusion tensor. results: diffusion images were acquired with and without ec correction. images without ec correction showed obvious scaling and shearing distorsions whereas in images obtained with ec correction no significant distorsions were observed. conclusion: diffusion-weighted mr imaging using epi is very sensitive to image distorsions caused by eddy currents. inserting additional gradient waveforms in a stimulated-echo epi sequence drastically reduces these artifacts and allows a calculation of the diffusion tensor in various tissues with low t /t ratios without significant misregistration. rf-induced artifacts due to aneurysm clips in mrt at . t u.a. lauer, h. graf, f. schick, c.d. claussen; tübingen/de purpose: metallic implants such as aneurysm clips may cause enlarged artifacts at higher magnetic field strengths, not only due to susceptibility effects. aneurysm clips made of ti-alloy were investigated with special respect to mr-imaging results and possible rf-induced artifacts. materials and methods: aneurysm clips were measured in gd-dtpa doped water at . t and . t with adapted se-sequences. additionally, two models made of copper were investigated at . t. to separate rf induced effects, the transmitter voltage was bisected stepwise to verify the rf-induced deviation of the local flip angle near to the implant. this was also done with d-tse sequences. results: in comparison to . t, more pronounced hyperintense zones were found at . t. they were independent of the exchange of phase-and frequency-encoding direction (swap) and became more pronounced at reduced transmitter voltage. comparative investigation of two cu-models and one selected ti clip at reduced transmitter voltage revealed rf induced effects depending on inductive and capacitive structures of the clip. conclusion: metallic implants have to be considered carefully at . t due to the electrical conductivity. rf-induced artifacts can appear not only for longish objects but also on smaller devices. in the case of aneurysm clips, a slight rfinduced effect could be detected. potential patient endangering due to a local enhancement of the secific absorption rate (sar) can be estimated as negligible. optimum is currently recommended as a consistent image display function. however, while the cielab function is still in use in europe, comparative evaluation of these two functions for optimum display function has not yet been reported. the purpose of the present study was to identify which of gsdf and cielab is the optimum display function for thoracic ct imaging by means of visual contrast analysis (vci), i.e. the ratio of luminance contrast to ct value contrast. methods and materials: monochromatic m lcd monitor and photometer of luminance calibration tool kit (data ray corp, westminster, usa) were used. the luminance contrast of this monitor was measured by a photometer displaying gsdf and cielab. luminance change and digital driving level (ddl) that corresponded to ct value (hu) were tabulated. ct value was represented by window setting of thoracic ct imaging, i.e. for mediastinum (ww: ~ , wl: ) and lung (ww: ~ , wl:- ) using gsdf and cielab. the ratio of luminance contrast to ct value contrast was calculated as visual contrast index (vci). the vci of gsdf and cielab was evaluated using t-test. result: using t-test, vic of cielab was significantly higher than that of gsdf in window setting of thoracic ct imaging (p < . ). based on visual contrast index analysis, cielab was more useful than gsdf as a monitor display function of thoracic ct imaging. we suggest that cielab is the optimum monitor display function of thoracic ct imaging because it intrinsically has excellent luminance contrast characteristics. follow-up of patients subjected to high skin radiation dose as a consequence of repeated interventional cardiology procedures r. padovani, g. bernardi, e. quai, m. signor, h. toh; udine/it purpose: as part of a quality assurance program, to retrospectively evaluate cumulative skin dose (csd) received by patients subjected to repeated interventional coronary procedures and to detect radiation induced skin injuries in patients who have received the highest dose. materials and methods: from april to february , cardiac procedures, coronary angiography (ca) and percutaneous transluminal coronary angioplasty (ptca) have been performed on patients. mean dap was . gycm . patients with a cumulative dose-area product (dap) higher than gycm have been extracted. they were patients ( . %), female and male, mean age years, who underwent a mean number of . procedures resulting in a mean cumulative dap of gycm and a maximum value of gycm . from dap, csd has been estimated adopting . and . - cm - as conversion factors for ca and ptca, respectively. clinical follow-up has been performed adopting the lent-soma methodology and scale. results: the highest csd estimated was . gy and only patients ( %) exceed a skin dose of gy. no skin injuries were detected at clinical follow-up. these results allow to estimate a frequency for skin injuries of less than . - in patients undergoing repeated cardiac procedures. the results of this study implies that the frequency of skin injuries may be very low when a quality assurance programme, including regular patient dose monitoring, periodic evaluation of procedure protocol, quality control of equipment and operator training, is established. ultrasound purpose: ultrasound is the most frequently used diagnostic imaging modality. the main problem of ultrasound, however, is interobserver variability. the intention of the development of ultrasound computer tomography was to increase the reliability of ultrasound imaging and to supply standardized images similar to other cross section imaging procedures. methods and materials: instead of a manually-controlled linear transducer array, we used ultrasound computer tomography (usct) to image a volume directly. a few thousand ultrasound transducers were arranged in a cylindrical array around a tank containing the object to be examined coupled by water. every single transducer was small enough to emit an almost spherical sound wave. while one transducer was transmitting all other transducers worked as receivers simultaneously. afterwards a different transducer emitted the next pulse. for volume reconstruction each transmitted, scattered and reflected signal was used. in an experimental set-up a phantom containing nylon filaments, straws, and a cadaveric forearm were investigated. results: nylon filaments with a diameter of . mm were visualized. the skin and soft tissue of the cadaveric forearm were clearly detectable but the bone structures could not be delineated sufficiently. usct supplied reproducible image sequences. conclusion: usct promises to supply standardized high quality three-dimensional images without ultrasound shadowing artifacts and without interobserver variability. furthermore, the tissue is not deformed, in principle offering multimodal image fusion with other cross section imaging modalities. prior to clinical set up extended development especially of large transducer element tubes and improvement of software is necessary. multicentre assessment of a complexity index for ptca procedure a. peterzol , e. quai , r. padovani , g. bernardi , j. kotre , a. dowling ; udine/it, newcastle/uk, dublin/ie purpose: multicentre assessment of a procedure-severity-based complexity index (ci) for the introduction of reference levels (rls) in percutaneous transluminal coronary angioplasties (ptca) as a function of procedure complexity. materials and methods: , and ptcas performed at three different centres were investigated. multiple linear stepwise regression analysis, including clinical, anatomic, and technical factors, was performed in order to obtain fluoroscopy time (ft) predictors. based on the regression coefficients of the emerging model a scoring system was defined, and a ci was obtained by adding up the single scores for each individual procedure. since a good correlation (r = . ; p < . ) was found between the dose-area product (dap) and the resulting ci, the latter was used to classify dose values into three groups. ci groups were determined by means of an anova test: different sets of groups were explored until the matrix of pairwise comparison probabilities reached a minimum value (p < . ). the resulting dap and ft third quartiles corresponding to each ci group are suggested as preliminary rls in ptca as a function of procedure complexity. results: ptca preliminary rls: (i) for dap values: , and gycm , and (ii) for ft: , and min, respectively for the three ci groups: low, medium and high complex procedures. the possibility to introduce rls as a function of procedure complexity, as confirmed by this multicentre study, can improve the process of patient dose optimisation in interventional cardiology. investigation of the radiation detection properties of lu sio :ce and gd o s scintillators for applications in medical imaging d. nikolopoulos, p. liaparinos, d. margetis, d. linardatos, p. mellisaropoulos, k. kourkoutas, g. panayiotakis, d. cavouras, i. kandarakis; athens/gr purpose: the aim of this study was to use monte marlo techniques to examine the detection efficiency of three ce-doped fast emitting scintillators, yap (yalo : ce), lso (lu sio :ce) and gos (gd o s:pr, ce, f) when used with photon energies and coating thicknesses employed in medical imaging. a general monte carlo code has been generated for tracking photons in the energy range covering all medical imaging applications (diagnostic radiology, nuclear medicine). simulated scintillator materials were selected to be in blocks and arrays of dimensions equal to those usually employed in medical imaging. the results for the yap scintillator, showed that the fraction of the incident photon energy which was totally absorbed decreases very rapidly for energies higher than kev (e.g. from % at kev to % at kev for . mm coating thickness). lso was better than yap, its absorption efficiency being significantly higher (p < . ) at - kev (mammography), - kev (x-ray imaging), kev (gamma ray imaging) and at kev (positron imaging). gos was also found to exhibit significant detection efficiency in the whole energy range examined (e.g. from % at kev to % at kev for . mm coating thickness), however its applications are limited due to its longer decay time. conclusion: lso was found to be of adequate efficiency for most imaging applications, while yap could be considered most suitable for x-ray mammography applications. analyses of physiological kinetic functions in dynamic chest radiography by the use of time series spectroscopy y. tsuchiya , y. kodera , m. tsuchiya , a. fukui , s. itou , y. machida ; shizuoka/jp, nagoya/jp purpose: the purpose of this study was to distinguish between movement of diaphragm and heart wall, and to evaluate the kinetic function of these structures in dynamic chest radiography with computer aided diagnoses. we obtained a dynamic chest radiograph of one healthy volunteer during respiration to assess the distinction between structures and another radiograph of a patient during a left ventriculogram to evaluate heartbeat calculation using an image intensifier system. we performed fft and band pass filter processing to obtain an intensity curve of the spectrum of dynamic chest radiography and detected the "change-point" of the phase by using characteristic analysis. fifty-five kinds of band pass filters were used to compare "detection rate of change-point", "matching rate of heartbeat" and "heartbeat error". results: movement of diaphragm and heart wall could be extracted selectively by the use of an extreme low pass filter ( . ~ . cycle/mm) and middle frequency pass filter ( . ~ . cycle/mm). we obtained % of matching rate, when detection rate was % with these two kinds of filters. there was correlation significantly between them (r = . , p < . ). improvement of detection rate decreased heartbeat error. but there was no significant difference between them by the non-repeated measures anova (p = . ). conclusion: our method was effective in analysing the dynamic chest radiograph in order to evaluate precise kinetic function, when suitable filters were used. therefore it is expected to apply for computer-aided diagnoses. reduction of ionising radiation exposure in patients as a consequence of new imaging technology for medical diagnostics of the spine: a retrospective study covering years in a norwegian referral hospital a. nyquist , h. olerud , b. bjørnarå , l. borgen , t. gudmundsen ; drammen/no, oslo/no purpose: to examine possible changes in ionising radiation doses to patients (collective effective dose) undergoing diagnostic imaging procedures for spinal problems over the last years in view of the shift in modalities from conventional x-ray examination and myelography to computed tomography (ct) and later on to magnetic resonance imaging (mri). retrospective study of all patient files for the period from to . the main modality groups for each of the three parts of the spine (cervical, thoracal, lumbar) were: conventional radiographs, myelography, ct, and mri. for each type of examination the mean effective radiation dose were obtained from the norwegian radiation protection authority (nrpa) as published in . the number of conventional x-ray examinations performed was nearly unchanged. use of myelography reduced by %, %, and % for the cervical, thoracal and lumbar regions, respectively. ct usage increased steadily, remained nearly unchanged, and was reduced by nearly % for the cervical, thoracal, and lumbar regions, respectively. the annual collective effective dose from examinations the spine was reduced by % in our hospital from . mansv in to . mansv in . the shift in modalities from conventional x-ray and myelography to ct and mri resulted in a significant reduction in patient exposure to ionising radiation. the results may be explained by our intended policy to select mri insted of ct whenever possible, and is an overture to the discussion of the further development and structure of diagnostic imaging in general, and for the spine in particular. dose evaluation for clinical proton beam with standard dosimetry h. ohtani , t. hiraoka , h. saitoh , t. irifune , t. katoh ; tokyo/jp, chiba/jp purpose: the standard dosimetry was revised on august in japan; it had calling standard dosimetry of absorbed dose in external beam radiotherapy (standard dosimetry ). the purpose of standard dosimetry are the establishment of traceability for dose of radiotherapy and quality assurance / quality control, according as we measure the dose of high-energy radiation using the standardized international method. we explained the dosimetry of absorbed dose with the standard dosimetry for proton beams and the depth dose was measured with the reference ionization chamber and the parallel plate ionization chamber. the maximum energy of the proton beam used in this study was mev. electric separation induced radicals were calibrated for squarer field of × cm with some ionization chambers. the absorbed dose to water calibration factor is obtained by the reference ionization chamber calibrated co gamma rays. the remainder range in water calibrated the beam quality conversion factor for proton beam. using these coefficients, the absorbed dose was calibrated. the absorbed dose used the parallel plate ionization chamber was relatively decided by the results for the reference ionization chamber. conclusion: the absorbed dose for proton beam was calibrated at each depth. dosimetry in water was recommended on the standard dosimetry . however, it is difficult that we have the waterproof dosimeter. we suggested that the method and problem for proton dosimetry using the standard dosimetry . b d e f a g kinetic analysis of the temporomandibular joint with computer-aided detection system n. bandai , s. sanada , k. ueki , s. funabasama , s. tsuduki , y. otani , t. matsui ; onsen-gun/jp, kanazawa/jp, otsu/jp purpose: the purpose of this study was to develop a method of kinetic radiography and a computer-aided detection (cad) system for quantitative evaluation of the temporomandibular joint (tmj). methods and materials: dynamic images of the tmj were obtained from one healthy volunteer by digital fluoroscopy in the lateral view on the right and left sides. the accumulated image subtraction technique extracted the condyle in each image. a sequential similarity detection algorithm (ssda) was employed to trace the movement path and the velocity of the condyle. results: there were no significant differences between by manual and computer analysis. the shape of the path of the right condyle was smoother than that of the left condyle. the size of the maximum vertical and horizontal movements of the condyle were . ± . mm and . ± . mm, respectively. the velocity of the movement of the condyle was higher in the area close to the articular eminence than in any other area during the opening and closing of the mouth. conclusion: our cad system will contribute to the kinetic analysis of the tmj for screening, follow-up study, and informed consent, providing speed, quantitation, and cost-effectiveness. assessment of fetal dose in x-ray examinations of pregnant patients a.j. servomaa , a. kettunen ; helsinki/fi, oulu/fi purpose: when a pregnant woman undergoes examination of the lower abdomen or pelvic area, the fetus is directly irradiated. determination of the absorbed dose to the fetus is therefore of interest as a basis for risk estimates. in finland, the practice with regard to both estimation of the dose to the fetus and recording of the examination in patient records varies considerably. the fetal dose calculated by means of various dose calculation methods are compared and the results presented. methods and materials: using the "fetdose" and "pcxmc" programs, the normalized fetal dose was calculated for abdominal and pelvic examinations of various radiation qualities, esd and conceptus depths. the doses obtained were compared against those reported in the literature. the calculated nuds (normalized uterus doses) obtained for various parameters by means of various calculation methods agree, with reasonable accuracy. the nud occurring in a pelvic ap examination ( kv, mmal filtration, fsd cm) is about . for a gestational age of - weeks and for a fetal depth of cm. the dose to the ovaries differs slightly from the dose occurring to the uterus during the same examination. detailed data about the nuds in various common radiography examinations are presented. the results of calculations obtained with different programs show the same nud with reasonable accuracy. normalized fetal doses and radiation risks corresponding to the european esd recommendations in conventional radiography examinations may help the radiological staff to assess the significance of the exposure to the fetus. withdrawn by authors quality advances via noise reduction in laser imaging t.r. lindquist; oakdale, mn/us purpose: noise sources in medical imaging and printing can limit diagnostic accuracy but are often not assessed quantitatively. a method is described for objectively quantifying noise by means of a film digitizer and analysis software. a second method, based on human perception of simulated nodules on films with varying amounts of noise, is also described. in the first method, a film digitizer scans a print of a constant gray level image. the scanned digital image file is then processed by software that: ( ) extracts and averages density data from narrow horizontal and vertical strips, and ( ) performs one-dimensional fast fourier transform (fft) processing to yield a noise power spectrum (nps) for each horizontal or vertical strip. in the second method, a computer program is used to synthesize a test image with very low contrast dots ("nodules") superimposed on a gradually changing background. in timed experiments, prints of these images are placed on a light box, and an observer is asked to mark the locations where the dots are believed to be present, after which the true and false positives are counted. results: prints were made on a variety of medical imagers, using film with a variety of quality levels. prints made with the latest laser imager and film yielded lower measured noise and higher perception scores than prints made with prior technology. conclusion: measurable progress has been made in reducing the noise level of medical imaging printers. this is further demonstrated by improved perception of subtle details. estimation of maximum skin dose and average lung dose in coronary angiography procedures a. karambatsakidou, p. tornvall, n. saleh, p.-o. löfberg, a. fransson; stockholm/se purpose: a comparison of phantom and patient based techniques to estimate the maximum skin dose (mesd) and average lung dose from coronary angiography procedure is described. conversion factors for the dose to the skin and lung, normalized to the dose-area-product (dap), have previously been obtained from measurements using an alderson phantom. in this study, measurements on patients using slow radiographic film and diodes were used in combination with the software winods to evaluate the impact of different operators, and of variations in patient size, on these factors. the transmission ion chamber integrated into the angiographic unit was used to measure dap. the conversion factor for mesd from the phantom simulation was reported as . msv/gycm . the corresponding value for measurements on patients in this study was . ± . msv/gycm ( sd; patients). no significant difference in conversion factor between the operators was found. the lung dose varied with the body mass index (bmi). in slightly overweight patients (bmi: - ), the lung dose was about % lower than in normal sized patients (bmi: - ) for the same dap-value, while for overweight patients (bmi > ) this difference increased to %. conclusion: measurements on phantoms and on patients yield similar conversion factors for mesd in coronary angiography procedures. the bmi-value seems to be a robust indicator of the variation in dose to internal organs from such procedures. with film/diode measurements, the differences in techniques (geometry; projections) between operators can be easily verified, and as such be integrated into the training of new angiography operators. radiation doses in a newly installed flat-panel digital system in interventional cardiology department v. tsapaki, s. kottou, n. kollaros, p. dafnomili, v. neofotistou; athens/gr purpose:the purpose of the study was to investigate the radiation doses of the newly installed flat-panel fluoroscopy (fpf) system in an interventional cardiology (ic) department and to examine possible methods of technique optimization regarding the new digital system. materials and methods: fifty coronary angiographies (cas) and percutaneous transluminal coronary angioplasties (ptcas) were investigated. patient data were: sex, age, weight, height, dose area product (dap), fluoroscopy time (t) and total number of frames (f). further more, dose rates in all fluoroscopic and cine modes were measured. image quality was assessed using a dedicated test tool. results: median values of dap, t and f were: . gycm , . min and in ca and . gycm , . min, in ptca. our results are comparable with those found in the recent literature. regarding the technical characteristics of the digital system, the high contrast resolution (hcr) is not affected by fluoroscopic mode, whereas low contrast resolution (lcr) is slightly decreased in the lowest mode. the results of the study concerning the fpf system lead to the conclusion that the lowest fluoroscopic mode and the lowest frame rate should be used routinely for dose optimization and that the new digital technology has comparable radiation dose to the conventional technology. purpose: an earlier study using the mte scanner enabled us to register in vivo wave-like activity of the skin electrical landscape (sel), which is supposedly macroscopic manifestation of intercellular communication. the present study of the chaotic sel activity was done to try to find out distinctive dynamic features between melanoma and adjacent tissues. methods and materials: mte is a new functional, non-invasive digital imaging modality, which enables dynamic visualization of the skin and underlying tissues in terms of spectral electroimpedance and electropotential parameters, with high spatial and temporal resolution (~ . mm). non-thermal mm-emf ( min) and weak mf (< . t) were used as test influences. initial and induced sel dynamics have been graphically and statistically analyzed. specifically, the throughimage-sequence analysis resulted in detailed dispersion maps of the scan-area. the sels of (i) healthy and allergic subjects, and (ii) those with cutaneous melanoma were investigated. results: primary melanoma manifested not only as a sharp electro-abnormality, but also as a distinctly stable/hyposensitive zone (sigma = . - . %) in all measurement parameters.this hyposensitive zone(s) was surrounded by islet areas of marked hypersensitivity (sigma is up to %). dispersion range of the more distant environment had intermediate values. in cases of allergy, strongly pronounced dependence of the mm-emf response upon time of investigation was observed at the same subject, i.e.: from sharply marked reactions at the stage of sensitization to practically indistinguishable ones during remission. in healthy subjects, in most cases, significant trigger reversible changes of histograms were registered in response to both tests. intracranial elastance analysis using mri in normal-pressure hydrocephalus t. miyati , m. mase , m. onoguchi , h. kasai , m. hara , k. yamada , y. shibamoto , s. matsunaga , t. kasuga ; kanazawa/jp, nagoya/jp purpose: in order to assess the state and dynamics of the intracranial system in normal-pressure hydrocephalus (nph), intracranial elastance (ice) was measured with magnetic resonance imaging (mri). the ice index, which is the ratio of pressure to volume change, was obtained with alperin's method; intracranial volume and pressure changes during the cardiac cycle were calculated from the net transcranial blood and cerebrospinal fluid (csf) flow measured with phase-contrast (pc) cine mri. ice indices were determined in patients (n = ) with nph, brain atrophy or asymptomatic ventricular dilation (vd), and in healthy volunteers (control group; n = ). concurrently, a time constant of the integral of the csf response function, which represents the intracranial mechanical property was determined with pc cine mri. the changes in ice indices were also analyzed after intravenous injection of acetazolamide. these values were then compared with the volume-pressure response (vpr) during the shunt operations. results: the ice index in the nph group was significantly higher than in the control or vd group, but no difference was found between the control and vd groups. the ice index increased in all groups after an acetazolamide injection because of an increase in cerebral blood volume. there were significant correlations between the ice index and the time constant. a positive correlation was noted between the ice index and the vpr. conclusion: ice analysis measured by pc cine mri makes it possible to noninvasively obtain a detailed assessment of intracranial state and dynamics in the nph and to assist in diagnosis of the nph. quantification of magnetization transfer by sampling the transient signal using mt-prepared single-shot epi g. helms , g.e. hagberg , c.d. claussen , f. schick ; tübingen/de, rome/it purpose: using trains of mt-pulse and epi readout, the transition to steady state can be measured with higher accuracy than the steady state. a novel quantification method based on sampling transitions at different repetition periods (pr) is introduced. gaussian mt-pulses of . ms duration and flip angle of degrees were repetitively applied at khz offset at pr = , , , , ms. an axial slice through the centrum semiovale of the brain was measured by single-shot se-epi ( ms te, mm thickness, cm fov, x matrix). in brain tissue, the signal dependence was described by analogy to progressive partial saturation, where the direct saturation is increased by pr-dependent mtcontribution proportional to macromolecular content and differential saturation. macromolecular content, kinetic and relaxation parameters and the saturation were estimated by a global non-linear least-square fit of the signal equation for rois in cortical grey matter (gm) and central white matter (wm). results: the macromolecular content was ( . ± . )% in wm and ( . ± . )% in gm, the apparent relaxation rates ( . ± . ) /s and ( . ± . ) /s. the apparent transfer rates were ( . ± . ) /s and ( . ± . ) /s. macromolecular saturation of a single mt-pulse was ( . ± . )% in wm and ( . ± . ) in gm; the direct effect on water less than %. signal correction for csf contributions was necessary. conclusion: quantitative mt-mapping of the whole brain may become feasible in vivo at higher field strengths by means of permutation of the slice order. b d e f a g the concept of radiography in health sciences: a concept analysis s. sorppanen , a. servomaa ; oulu/fi, helsinki/fi learning objectives: to clarify the content and uses of the concept of radiography in health sciences and to compare it to the concept of radiography in physics and technology. background: in the field of radiography, theoretical research related to concepts has so far being rare. nevertheless, the concept development is an important part in constructing theories and clarifying the identity of a discipline. in finland, the discipline of radiography started in at the university of oulu, and since then it has offered radiographers academic education in their own field. for being able to build its own knowledge base and theories to be used in developing the profession and education of radiographer, and for being able to stand for its position as an independent academic discipline, the young discipline of radiography needs systematic conceptual clarification and development. procedure details: the concept of radiography was analysed using so-called evolutionary method of concept analysis (presented by rodgers). the contents and uses of the concept were studied by determining the concept's characteristics and by observing these characteristics in the cross-disciplinary comparison. the data consisted of literature and internet pages, and were analysed using deductive-inductive content analysis. conclusion: the concept of "radiography" in health sciences can be determined as "dual, dynamic, social and situation-related expertise of radiographers in the use of radiation, which is based on a versatile synthesis". it seems to be wide and complex in nature, and radiographer-centered. the content and the use of the concept varies according to the discipline. measurement of distribution of horizontal dose amount to chest x-ray by gafchromic film k. nishikiori , m. miyazawa , a. otonashi ; habikino/jp, itabashiku/jp, suita/jp learning objectives: to illustrate horizontal dose distributions of human diagnostic level in the chest phantom by gafchromic film and glass dosimeters. to point out the characteristics of horizontal dose distributions by materials in ten shots and in fluoroscopy. background: in general, we use an ionization chamber dosimeter or tld to measure dose distribution of diagnostic level. however tld can not indicate horizontal and consecutive dose distributions, because it has only scattered dose data. consequently, we used gafchromic film to obtain a horizontal consecutive dose distribution of human diagnostic level. imaging findings: . first, we placed a gafchromic film and glass dosimeters in the specific place of the chest phantom. then we irradiated the chest phantom with diagnostic level x-rays. the dose distribution which was acquired by the film and glass dosimeters was then analyzed. . next, we examined the result of fluoroscopy. . the results of the first method were compared with the result of the fluoroscopy and the difference between the distributions in (gafchromic film and glass dosimeters) and (fluoroscopy) examined. the characteristic dose distributions of the incidence dose in diagnostic level were confirmed by both horizontal dose distributions. . horizontal dose distribution which was specific and consecutive data could be obtained from the gafchromic film. . horizontal dose distribution which was specific and scattered data could be acquired by glass dosimeters. we obtained almost the same as results in fluoroscopy. horizontal dose distribution of fluoroscopy showed a sharp reduction on the subcutaneous tissue of the chest phantom. barium enemas: are radiographers up to it? p. vora, a. chapman; leeds/uk aim: to determine the types and rates of complications encountered by radiographers when performing double contrast barium enemas. a similar complication rate to those encountered by radiologists will reassure those who have adopted this new skill mix and encourage its further development whereas an increase in complications may point to areas where radiographer training needs to be improved. materials and methods: questionnaires were posted to radiographers who had in the last years attended one of the biannual leeds barium enema training courses. results: of questionnaires posted ( . %) were returned completed. approximately, , barium enema examinations had been performed. radiographers reported complications, including intraperitoneal and extraperitoneal perforations. there were five deaths (mortality rate - in , ). the five deaths included two of the twenty-four ( %) perforations, two of the forty-five ( %) cardiac events and one cva that occurred during an examination. conclusions: radiographers have been regularly performing dcbes for almost a decade. the mortality rate for radiographer performed double contrast barium enemas is similar to that reported for radiologists. a slightly higher than expected rate of perforation is noted in this study and so this is an area where radiographer training should be targeted. the level and incidence of the fear in patients subjected to radiological examinations e. czekajska-chehab, m. makara-studzinska, a. koczynasz, i. nowak, a. drop; lublin/pl purpose: analysis of incidence and intensity of fear in patients subjected to diagnostic procedures. methods: an anonymous survey concerning the occurrence and level of fear connected with radiological examinations was conducted among individuals: patients attending for various contrast examinations and women before mammography, using the questionnaire prepared by the authors. the level of fear was evaluated according to the adopted scale in relation to the obtainable maximum values. results: out of individuals ( %) reported their fears before planned radiological examinations. the frequency of fear was extremely high for mammography ( %) and lower for contrast procedures ( %). the strongest fear was associated with the uncertainty of diagnosis and length of waiting for results ( - %). the fears of patients before contrast examinations were mostly related to results and harmful effects of radiation. the fears concerning allergic reactions were reported by almost a half of patients before ct, urography and barium enema. in patients before contrast procedures the highest fear level was related to the uncertainty of results ( - %). the lower level ( %) was associated only with urography. the fears about the examination itself, allergic reactions or harmful effects of radiation showed similar intensity ( - %), irrespective of the kind of examination. conclusions: fears before radiological examinations are common and concern over a half of patients subjected to contrast procedures and almost all of those before mammography. the most common causes of fear include: uncertainty about diagnosis, exposure to harmful effects of radiation and length of waiting for results. audit of adequacy of inpatient ct requests: implications and consequences w. chooi, p. heath, m.j. bull; sheffield/uk purpose: vetting of ct requests ensure that the examination is justified in accordance to local guidelines and also allow the radiologist to select the most appropriate ct protocol. however the provision of poor clinical information severely limits this step. this audit aims to determine the prevalence of inadequate clinical details in ct request forms and also identify trends that result in poor referring technique. methods and materials: for a two week period all inpatient electronically generated ct request were prospectively monitored. outpatient & out-of-hour requests were excluded. results: out of a total of requests, were successfully audited ( %). the types of examinations included ct head ( %), abdomen ( %), thorax ( %), abdomen and thorax ( %), and musculoskeletal ( %). problems were encountered with requests ( %). the most common problem encountered was that of inadequate or misleading information (n = ). others issues included better alternative examination (n = ), undisclosed renal impairment (n = ), failed examinations due to agitated patients (n = ), ward cancellations (n = ), requests without contact details (n = ), and wrong ward details (n = ). as a result of these requests were not performed. the majority of these requests are completed by junior doctors. conclusion: vetting of ct requests is an essential first step towards a successful ct examination. the provision of inadequate clinical information is prevalent and junior doctors require closer supervision when completing ct requests. to determinate whether use of high iodine concentration contrast medium offers more complete information. diagnosis and follow-up of aortic dissection with multislice computed tomography y. herrero, m. martí, j. echeveste, m. fernández-velilla, g. garzón, n. gómez-león; madrid/es purpose: to assess the utility of multislice computed tomography (msct) in the diagnosis and follow-up of aortic dissection. materials and methods: seventy-one patients referred to rule out aortic dissection underwent msct following a standardised protocol. the volume of interest was the entire aortoiliac system, ml of non-ionic iodinated contrast were administered at a flow rate of ml/sec. a collimation of mm, table speed of mm per rotation, pitch of and reconstruction interval of mm were used. multiplanar (mpr) and three-dimensional reconstructions (external rendering) were obtained in a workstation (vitrea ; vital images plymouth, minn). aortic dissection was diagnosed when an intimal flap separating the true and false lumen was observed. patients diagnosed with aortic dissection underwent an endovascular repair (stentgraft placement). follow-up ct examinations after endovascular repair were acquired with the same msct protocol, after performing a basal nonenhaced study. complete closure of the entry site, and both stent-graft and visceral arterial branches patency were considered as adequate stent-graft function signs. results: nine of the patients were diagnosed with aortic dissection (six acute and three chronic dissections), two of which involved the ascending aorta and seven the descending thoracic aorta. follow-up demonstrated in all cases a residual abdominal aortic dissection with progressive decrease in size of the false lumen. conclusion: msct determined the exact anatomy of the dissection flap, the location of the entry and reentry sites, and the major branch vessels that were supplied by the true lumen. endovascular stent-graft placement for treatment of thoracic aortic aneurysms m. fernández -velilla, g. garzón, i. acitores, f. ibáñez, l. riera; madrid/es learning objectives: to assess the safety and efficacy of endovascular stentgraft placement for repairing descending thoracic aortic aneurysms in high-risk patients. to analyse the major associated complications. to show our experience in the management of these patients over a six-year period. background: by helping patients avoid open surgery, endovascular aneurysm repair minimises the perioperative derangement of pulmonary, renal, cardiac, and gastrointestinal function. the greatest potential benefit is in high-risk patients who have large aneurysms and who are poorly suited to any of the current alternatives. procedure details: endovascular aneurysm repair was performed in highrisk patients who could not undergo conventional repair. the feasibility of endovascular treatment and the prosthesis' size was determined based on preoperative spiral ct and intraoperative angiography findings. stent-grafts were surgically inserted through exposed femoral arteries with fluoroscopic guidance. the anaesthetic technique was either epidural or general. endovascular grafts were constructed with gianturco stents and polytetrafluoruroethylene (ptfe) graft. stent-grafts were placed in disecting, atherosclerotic, five traumatic, and one post-coarctation descending thoracic aortic aneurysm. % of them were chronic. we analysed the results obtained in both stable patients, in which an elective treatment was performed of sacular, fusiform, traumatic and chronic dissection aneurysms, and in emergency patients (intramural bruise, penetrating ulcer, and aortic dissection). conclusion: endovascular treatment of thoracic aortic aneurysms offers considerable benefits. long-term follow-up is needed to ascertain the durability of the procedure especially in dissecting aneurysms. an interdisciplinary and experienced team is needed to manage endovascular and surgical treatment. radiologic appearances of thoracic outlet syndrome: evaluated by pat optimized d contrast enhanced mr angiography and intraarterial dsa Ö. Özsarlak, o. d'archambeau, f. delrue, p.m. parizel; antwerp/be learning objectives: thoracic outlet syndrome: pat optimized contrast enhanced (ce) mra and intraarterial digital subtraction angiography. background: seventeen patients clinically suspected of having a vascular thoracic outlet syndrome were retrospectively reviewed. the patient population consists of women, and men with an age range between and . in eight patients, ce-mra was performed in . t mr system. gre flash d mr angiography with care bolus technique was used with a pat acceleration factor of two. the remaining nine patients were examined by intraarterial, and intravenous dsa of the upper extremity. all examinations, including mra were performed both in neutral and in adson positions with abduction of arms. imaging findings: none of the patients showed abnormality during neutral position. examinations repeated during adson position revealed subclavian artery lesions in patients: occlusions, high-grade stenoses, and mild-grade stenoses. in patients, the lesion was located on the left side, in patients on the right side, and remaining patients' lesions were bilateral. conclusion: a review of the functional anatomy, clinical symptoms, ce-mra and dsa findings are presented with illustrative cases. the advantages of patoptimized ce-mra are highlighted. mri evaluation of patients with peripheral vascular malformations g. calabrese, g. falda, g. lucchini, a. cazzulani; garbagnate milanese/it learning objectives: to define a mri protocol to study patients with angiodysplasia in order to evaluate soft tissues and bone involvement and to demontrate the appearance of the vascular malformations. background: imaging studies must show all the abnormal vessels and provide information on the degree of surrounding tissue involvement. in this exibit we describe the mri findings in patients with angiodysplasia of the lower or upper limbs. procedure details: t weighted fse sequences and t weighted fe sequences in the sagital and coronal planes were acquired. a sagital t fse sequence b d e f a g with echos and fat-saturation was used to demonstrate vessels with slow flow. dsa and dsv were performed to proceed to embolization or operation. t images gave good morphological demonstration of muscle involvement. on t fe images the presence of small vessels within the subcutaneous fat or within the bones was easily shown. images acquired with the echos t sequence were processed with the m.i.p. function to show the abnormal vessels; this sequence was especially useful in the venous malformations and in some cases the draining veins were also identified. conclusion: mri is the technique of choice to demonstrate the anatomic extent of the lesions and their relationship to the adjacent soft tissues. even if mra is improving from the technical point of view, still it remains quite complex and time consuming. in our protocol a simple t sequence showed to be a good method to demonstrate abnormal vessel with slow flow. occlusion background: thrombosis of the ivc and its tributaries is most commonly associated with malignancy, resulting from direct invasion by carcinoma of the kidney, liver or adrenal gland. thrombosis of the ivc secondary to benign causes is less common. predisposing factors include pregnancy, connective tissues disorders and coagulation abnormalities. recognition of caval thrombosis on ultrasound may be difficult. however, depiction of the ivc on both contrast-enhanced computerised tomography and mri is more accurate. although non-contrast mri is useful for demonstrating ivc occlusion, contrast-enhanced mr venography offers the opportunity for rapid evaluation in a single breath-hold. imaging findings: the normal appearance of the ivc as demonstrated by mri is illustrated, along with examples of ivc occlusion associated with both benign and malignant pathology. simple rules for differentiating bland versus tumour thrombus are presented and illustrated. a method for optimising the timing of data acquisition for ce-mra is presented. the merits of "indirect" versus "direct" ivc mr venography are also discussed. finally, artefacts that may mimic ivc thrombus are described. conclusion: mri/mra accurately evaluates the ivc. the multiplanar imaging capabilities, lack of ionising radiation, coupled with the added benefit gained from the use of intravenous gadolinium based contrast agents in mra, makes mri the modality of choice in evaluating patients with suspected ivc occlusion. the swollen leg: the various etiology and its ct venography findings w. jun, w. lee, j. chung, j. park; seoul/kr learning objectives: to illustrate the various causes of swollen legs. to recognize the characteristic imaging findings of various causes of swollen legs. to evaluate the accuracy of ct venography in the differential diagnosis of the etiology in patients with swollen legs. background: the swollen leg is a common clinical problem that complicates many medial and surgical disorders. clinical applications of computed tomography (ct) venography have increased with the improved technology of multidetector ct systems. ct venography showed the diagnosis of dvt and other soft tissue disease in patients with swollen leg. for the past two years, ct angiography of lower limbs was performed in patient (age - years) with swollen legs. the various causes and imaging findings of swollen legs are described and illustrated. imaging findings: the characteristic imaging findings of acute deep vein thrombosis (dvt) are a definite intraluminal filling defect, venous distension and muscle compartment enlargement. findings of chronic dvt are small, thick-walled, poorly enhancing veins and presence of collaterals. findings of lymphedema are skin thickening, subcutaneous tissue thickening, fat infiltration: lines parallel to skin and perpendicular to skin. findings of cellulitis including necrotizing fasciitis, are fascial thickening, fat infiltration, focal fluid collection, soft -tissue gas and muscle involvement. conclusion: ct venography showed promise for the diagnosis of dvt and other soft tissue disease in patients with swollen legs. ct venography is the modality of choice when clinical and other imaging findings are indeterminate. the aorta revisited: spectrum of findings on helical ct a.j. madureira, j.p. jesus, j. loureiro, i. ramos; porto/pt learning objectives: to review the imaging findings of the anatomical variants and disease processes that may affect the aorta from the aortic valve to the bifurcation. to describe the pitfalls that may be encountered. background: helical ct is a frequently used method in the evaluation of diseases affecting the aorta. it provides invaluable information in the assessment of acute aortic syndromes and is often employed in diagnosis and follow-up of dissection, aneurysm and bypass surgery. procedure details: the imaging findings of the diseases that may affect the aorta are presented based on the experience of our tertiary care hospital and level trauma center. the anatomical variations of the aortic arch vessels, acute aortic syndromes, aneurysmal disease and aortic bypass surgery are discussed and illustrated thoroughly. conclusion: helical ct is a firstline imaging method in the evaluation of aortic disease due to it's widespread availability, good spatial resolution and speed. learning objectives: to illustrate the mr findings that differentiate severe carotid artery stenosis with a tiny residual distal lumen from patients with total carotid artery occlusion. background: due to the small but substantial stroke risk in patients undergoing digital subtraction angiography, contrast enhanced magnetic resonance angiography (m.r.a.) has become the standard for evaluation of carotid occlusive disease in many centres. m.r.a. is highly accurate in differentiating significant stenosis ( %- %) that requires carotid endarterectomy, from insignificant (< %) disease. m.r.a. is also highly accurate in differentiating severe stenosis from occlusion. however, demonstration of a string sign depends on careful interrogation of the source images as the residual patent lumen may not be visualised on standard maximum intensity projections. given the clinical importance of differentiating between these two groups, we present and contrast the imaging findings of patients with significant carotid stenosis and those with total carotid artery occlusion. imaging findings: we describe the varied findings in both patients with total carotid artery occlusion and those with severe stenosis. we present a simple algorithm for rapid evaluation of patients referred for differentiation of severe stenosis from occlusion. background: anomalies of ivc and renal veins occur with a prevalence of . % to . %, and are easily identified on ct, frequently incidentally. if unidentified, they can be misinterpreted as pathology (adenomegaly, retroperitoneal masses, normal venous structures and/or collaterals during acquired obstruction) or can lead to morbidity during radiologic and surgical procedures (positioning ivc filters, varicocoele sclerotherapy, renal venous sampling, shunt placement for portal hypertension, liver or kidney transplantation, ivc ligation for thromboembolic disease, abdominal aortic aneurysm repair). we describe the ct findings in cases of anomalies of the ivc and the lrv. imaging findings: female and male patients, aged - years, were studied. we found anomalies of the suprarenal segment (interrupted ivc with azygos continuation), anomalies of the renal segment ( circumaortic lrv, retroarotic lrv), and anomalies of the infrarrenal segment ( retrocaval ureter, transposition of the ivc, and duplications of the ivc). one patient with agenesis of the ivc with azygos continuation had profound venous thrombosis, and another had bronchiectasis. in any other case the anomaly was responsible for the patient's symptoms. results: mean size of the ascending aorta in these patients at initial presentation was . cm (range . to . cm). dissection of the ascending aorta occurred in %. median size of ascending aorta at time of dissection was . cm. all patients underwent surgery for their aneurysms. the postoperative mortality was . %. we have compared the two groups of marfan's syndrome patients whom had dissections: with an aortic-root diameter from . to . cm ( %) and with an aortic-root diameter from . to . cm ( %). there is correlation between the aortic-root diameter and the probability of aortic dissection. analysis to isolate risk factors for dissection revealed that size larger than . cm increased the probability by %. the incidence of dissection increased with aneurysm size and the radiological criteria for surgical intervention in marfan's syndrome are aneurysm diameter of . cm. maximal information about size and dissection of aneurysms in marfan's syndrome patients are obtained from analysis of angiography data. an evaluation of internal carotid artery and cerebral blood flow volume using color duplex sonography in patients with vertebral artery hypoplasia m. acar, b. degirmenci, a. yucel, r. albayrak; afyon/tr purpose: vertebral artery hypoplasia (vah) may be defined as va flow volume below ~ to ml/min using color duplex sonography. the aim of this study was to evaluate the effect of va hypoplasia on internal carotid artery (ica) flow volume and cerebral blood flow (cbf) volume. materials and methods: in this study, patients with va hypoplasia and control subjects with normal va flow volume were enrolled. the patients and control subjects were - years of age. the ica and va flow volumes were determined by using color duplex sonography. cerebral blood flow volume was calculated as sum of flow volumes in the ica and va of both sides. the ica and cbf volumes of patients with va hypoplasia were compared with control group flow volumes. results: in va hypoplasia and control group, there were no significant differences between ica flow volumes of right and left sides ( ± versus ± ml/ min; p = . on the right side, ± versus ± ml/min; p = . on the left side) or sum of flow volumes of both ica ( ± versus ± ml/ min; p = . ). however cbf volume tended to be lower in patients with va hypoplasia than control group. conclusion: evaluation of cbf using color duplex sonography is noninvasive and easily applicable to all patients and provides valuable diagnostic data. to the best of our knowledge, this is the first study demonstrating lower sbfv and normal ica flow volume in patients with va hypoplasia. the floating layer: a new sonographic sign of ruptured abdominal aortic aneurysm a. nunziata , o. catalano , m. mattace raso , f. sandomenico , a. siani ; naples/it, pozzuoli/it purpose: in patients with ruptured abdominal aortic aneurysm we have occasionally seen a floating layer, similar to the intimal flap recognizable in patients with aortic dissection but slightly thicker. we reviewed our series to assess the overall prevalence, specificity and diagnostic significance of this finding. materials and methods: in a year period (from january to december ) we have evaluated with us, consecutive patients with abdominal aortic aneurysm (larger axial diameter of the aorta > mm). twenty-nine aneurysms were proven to be ruptured (sonographic and/or ct diagnosis) and were surgically confirmed. the remaining patients were not symptomatic and were proven to have a non-ruptured aneurysm at follow-up. results: a floating membrane was found in out of patients with ruptured aneurysm ( %) and in none of the subjects with non-ruptured aneurysm. the image appeared as a thick layer floating within the aneurysm lumen, clearly detached from a more or less eccentrically placed luminal thrombosis (present in all cases), with a paradoxical movement unrelated to overall vessel pulsation. the floating layer is an uncommon but specific sonographic sign of abdominal aortic aneurysm rupture. recognizing this findings should lead to prompt surgical treatment, without need for further imaging (contrast-enhanced ct). color duplex measurement of cerebral blood flow volume in patients with polycystic ovary syndrome m. acar, a.s. cevrioglu, b. degirmenci, a. yucel, r. albayrak, m. yilmzer; afyon/tr purpose: polycystic ovary syndrome (pcos), one of the commonest endocrinopathies in the human, is known to be associated with risk factors for cerebrovascular disease. we want to determined whether there is a change in cerebral blood flow volume in pcos. we reported women with pcos and healthy women with similar body mass index (bmi). both groups of women were aged to years. we detected internal carotid (ica) and vertebral artery (va) flow volume using color duplex sonography. cerebral blood flow (cbf) volume was determined as the sum of flow volumes of internal carotid and vertebral arteries of both sides. results: there were no significant differences between patients with pcos and control group in cbf volume or the bilateral sum of flow volumes in the ica and va. but bilateral mean velocity of va was significantly lower in patients with pcos compared to control group. correlation between age of patients and mean velocity of va and ica were assessed with pearson correlation analysis. in control group, mean velocity of va and ica was inversely correlated with age (r = . , p = . versus r = . , p = . ). however no correlation was found for patients with pcos. conclusion: this is the first study demonstrating normal cbf volume using duplex sonography in pcos. it is known that the increased risk factors for cerebrovascular disease does not increase stroke mortality in pcos. normal cbf volume and absence of decrease in va and ica mean velocity by aging may be protective mechanisms. thoracic aortic calcification in the elderly g.s. karlsdottir, t. aspelund, s. sigurdsson, g. eiriksdottir, l. launer, t. harris, v. gudnason, r. detrano; kopavogur/is purpose: though demographic associates of coronary and abdominal aortic calcification in elderly persons are known, similar information about the thoracic aorta is not available. we developed a protocol for scanning the thoracic aorta from the aortic bulb to the descending aorta at the level of the cardiac apex. methods and materials: computed tomographic images were acquired with a siemens sensation scanner, using sequential mode and prospective ecg gating. the ct images were processed using calcium scoring software for coronary arteries, which is modified in order to label areas and quantify calcium in the thoracic aorta. the thoracic aorta is divided into three segments: arch, ascending, and descending. these segments are labeled and calcium within them quantified and results expressed in agatston scores. results: agatston scores were acquired from individuals ( men, women) with an age range of - (mean ) years. there was a % increase ( %ci: %- %) in the total agatston score for every years of age for men, and % ( %ci: %- %) for women. there was no significant difference between men and women in the age group - and, men in the age group + had significantly lower scores than women. conclusion: a robust method for quantifying calcium in the thoracic aorta has been established. age and gender distributions of thoracic aortic calcification in the elderly show strong age dependance for both genders but significantly stronger for women than for men. b d e f a g materials and methods: ct scans of fourty patients (mean age years, female: previous aortic repair (n = ), atherosclerosis (n = ), trauma (n = ), other (n = )) with aortic or supraaortic emergency were reviewed for aortic rupture (ar), aortic or supraaortic fistula (af), covered aortic perforation (cap) with transection (at), dissection (ad), or ruptured ulcer (rau), and rapid aortic aneurysm expansion (raae). morphological findings were correlated by dsa, surgery or post-mortem. results: there were ar, af ( tracheobronchial, oesophageal, duodenal), cap ( at, ad, rau) and raae. cta was diagnostic in all cases except five af: four were diagnosed by dsa, one at post-mortem. in cases, cta correctly determined the decision of patient management. one separate vertebral artery origin was missed. two patients died before surgery. patients underwent emergency repair ( surgical, endovascular); two were observed. five thoracic af were treated by endovascular repair, two by surgery, one infradiaphragmatic af by surgery. conclusion: cta is valuable for diagnosing aortic and supraaortic emergencies and determining their treatment. however, in suspected af complementation by dsa is usually required. low materials and methods: seventy-five patients with peripheral arterial disease, divided into three groups of , underwent mdcta. mdcta scanning protocol was: collimation x . mm, thickness mm, gantry rotation time . s, kv , delay time s. the only variable among the three groups was mas, respectively , and , with a resultant ctdiw of . , and . mgy. all patients underwent dsa within hours from cta. the volume of contrast medium ( . gi/ kg of iomeprol mgi/ml), injected at . ml/s, was flushed with ml of saline. d real time interaction approach on a dedicated workstation was performed in all cases, with different reconstructions algorithms. image quality and degree of stenosis were independently evaluated by blinded readers. results: regarding image quality no significant difference was found among three protocols. slight artefacts related to beam hardening were present in the pelvis with the lower mas protocol without impairment of diagnostic quality. interobserver agreement was substantial to almost perfect in all cases. the sensitivity, specificity and accuracy resulted of , and %, independent of the mas value. conclusions: low-dose mdcta provides qualitatively acceptable images. it also appears accurate in the assessment of patients with peripheral arterial disease providing results comparable to higher dose protocols. image noise on native lowest dose protocol can be reduced or eliminated by thickening mip or mpr images. diseases had lymphadema, ( . %) had superficial venous thrombosis, ( . %) had popliteal vein or artery aneurysm. nine ( . %) limbs had pseudoaneurysms ( femoral and located at the tibial-peroneal trunk), ( . %) had avf ( detected to be femoral and at the level of the external iliac artery). four ( . %) had either abscess, or enlarged lymph nodes in the groin, compressing the veins, and ( . %) had some kind of musculoskeletal problem (muscular tear). conclusion: complete venous evaluation with duplex imaging can be very helpful in the determination of the underlying cause of leg swelling. dvt is the commonest. sonographic assessment of intima-media thickness (imt) and plaque morphology of the carotid system: a comparative study a.a. kotis , p. brestas , l. guindaglia , g. chatzakis , k. papanastasiou ; rhodes/gr, athens/gr purpose: to investigate the potential association of increase in imt with carotid artery disease extension, plaque morphology and formation of carotid bifurcation stenosis. materials and methods: patients females and males referred for color duplex ultrasound were included. risk factors for cerebrovascular disease were recorded. measurements of common carotid (cca) imt adjacent to the bulb and carotid bifurcation plaque characterization and classification were realized. coefficients of variation and k-statistics were used for assessment of variability in imt measurements and plaque characterization respectively. controversy cases underwent shu a contrast agent injection. results: significantly higher imt values were measured a) in men than in women (p < . ) b) on the left side compared with the right (p < . ). mean imt measurements showed positive linear relationship with age. we identified plaques in of carotid bulbs and stenosis (> %) in of them. echogenic us plaque appearance ( / ) predominated in comparison with echolucent ( / ) and relationship of lumen stenosis with the presence of echolucent plaques (p < . ) was found. multiple regression model revealed significantly higher imt values in patients with plaques at any side (p = . ), with more evident difference in those with stenosis (p < . ). the magnitude of plaques correlated significantly with imt. there was no relationship between plaque echogenity and imt (p > . ). we realize the existence of correlation between increase in imt in cca and extent of carotid bifurcation atherosclerotic disease. color doppler ultrasonography is accurate and reproducible for assessment of imt and detection of carotid plaque morphology and evolution. to emphasize the role of mr angiography in the evaluation of renovascular disease, and to discuss the performances, advantages and limitations of different mr angiography techniques. materials and methods: more than mr angiograms of renal arteries were reviewed for the presence of any anatomic variations, the number of renal arteries, the presence of renal artery stenosis, occlusion, or other arterial diseases together with the limitations, artifacts and pitfalls of the technique. more than examinations were performed after applying parallel acquisition technique with acceleration factors up to , using a -channel phased array body coil. influence of pat on slice thickness, image matrix, total examination time, and image quality are discussed. results: phase contrast acquisitions are extremely helpful in evaluating flow patterns in the renal arteries, and offer unique information about the flow velocity patterns. pat using sense reconstruction algorithm leads faster d mra acquisitions. this results in, not only shortening the examination time, but also shortening the breath-hold time, and providing better image quality due to decreased motion artifacts. pat-optimized d contrast enhanced mr angiography is unique among noninvasive imaging modalities in that it offers a comprehensive d evaluation of renal anatomy, and renal vascular territories in a very short acquisition time. the main challenge in the evaluation of renovascular hypertension is the detection of hemodynamically significant renal artery stenosis. a combination of different techniques (phase contrast and contrast-enhanced mra) yields the best results, comprising both morphologic and functional information. possibilities results: pathologic changes in the visceral arteries were revealed in cases, including findings with various grades of stenosis of the coeliac trunk, with stenosis of the sma, -occlusion of the splanchnic arteries. causes of visceral ischemia were: atherosclerosis (the main cause), found in patients, aorto-arteriitis -in , coarctation of abdominal aorta -in , extravasal compression-in . high correlation between conventional angiography and ce-mra was determined in patients. the functional phase-contrast mra was done in patients with stenoses of small and middle degree; it gave an opportunity to acquire information on flow parameters and to elaborate the grade of stenotic changes. the ce-mra with pc-mra gives a chance to determine the grade of stenosis with high accuracy, visualize colateral vessels, to get information on flow parameters in damaged splanchnic arteries. b d e f a g imaging findings: all degrees of local vascular damage were seen. various imaging modalities may be employed in characterising such lesions, including ct, mri and conventional angiography and venography. an addict may injure any vessel during injection and the superficially placed femoral vessels are particularly susceptible to damage. septic vascular complication is common. arterial injury resulting in haematoma formation, arterial dissection and thrombosis, arteriovenous fistula and mycotic aneurysm formation is shown. a case of torrential haemorrhage from a ruptured pseudo-aneurysm treated with coil embolisation is demonstrated. deleterious effects secondary to the injected substance, including distal ischaemia and tissue necrosis, are demonstrated. venous thrombosis is common and can be shown by multiple imaging modalities. infected venous pseudo-aneurysms with secondary septic embolisation may occur. conclusion: it is important for radiologists to become familiar with the appearance of vascular complications occurring in the setting of injection drug use. early imaging to define disease extent and possible complication is important in this difficult patient group. carotid intima-media thickness ( the aim of the study was to investigate the probable association of atherosclerotic disease with endothelial cell adhesion molecule icam- , vcam- and e-selectin levels. carotid imt was measured by high resolution ultrasonography of the common carotid arteries in predialysis patients with esrd, patients on chronic haemodialysis (hd) and controls. compared with controls, esrd and hd patients had increased imt (p < . and p < . respectively), as well as serum icam- (p < . and p < . respectively) and vcam- (p < . and p < . respectively) levels. imt was correlated with age in controls, esrd and hd patients (p = . , p = . and p = . respectively). no correlation was found between imt and other cardiovascular (cv) risk factors such as gender, lipid levels, mean arterial blood pressure, ca x p products or hd duration in hd patients. in univariate analyses, imt was correlated with history of cv events, logcrp and icam- both in esrd (p = . , p = . and p = . respectively) and hd patients (p = . , p = . and p = . respectively). moreover, compared with patients with normal imt, esrd and hd patients with increased imt (> . mm) had increased icam- (p = . and p = . respectively). multivariate analyses showed that icam- was a strong independent correlate of imt values both in esrd and hd patients (p = . and p = . respectively). vcam- and e-selectin levels failed to be a significant contributor to imt. in conclusion, chronic uraemia is associated with advanced atherosclerosis. in patients with esrd, both on conservative treatment and on hd, icam- levels are potentially a useful surrogate marker of the extent of atherosclerosis. evaluation of tumor microvessels using monochromatic x-ray after administration of angiogenesis inhibitor t. yamashita, s. imai, n. maehara, a. yamamoto, m. kobatake, y. kajihara; kurashiki/jp purpose: to quantitatively evaluate changes in tumor microvessels using synchrotron radiation in vivo after fr- administration as an angiogenesis inhibitor. the fr- agent (using propylene glycol as a solvent) was continuously infused subcutaneously to rabbits with vx carcinoma implantation at auricles. the rabbits were divided into six groups: control- and control- received only propylene glycol for three or seven days, fr- - and fr- - received mg/day/kg of fr- for three or seven days, fr- - and fr- - received mg/day/kg for three or seven days. microangiograms using a synchrotron radiation system were obtained to evaluate the tumor microvessels and tumor size. results: compared to control- group, fr-x- groups showed no significant tumor size difference (fr: diameter = . ± . mm, volume = . ± . mm , control- : . ± . mm, . ± . mm ), but microangiologically fewer vessels were observed. fr-x- groups presented significant difference (fr: diameter = . ± . mm, volume = . ± . mm , control- : . ± . mm, . ± . mm ), and many irregular vessels, findings similar to control- . there was no significant difference in tumor size and microangiographic findings between fr- -x and fr- -x. conclusion: our study demonstrates the application of new technique to examine antiangiogenic effects in vivo. the growth of the vx carcinoma were sup-pressed remarkably in the fr- -day-groups, and the microangiographic findings were similar to those of control- . the synchrotron radiation microangiogram is a useful tool to evaluate antiangiogenic agent. early atherosclerotic changes in hiv positive patients treated with protease inhibitors m. cristofaro, n. petrosillo, l. rovighi, c. bibbolino; rome/it purpose: antiretroviral therapies with protease inhibitors (pi) produce derangement of lipid metabolism with possible occurrence of early atherosclerotic changes. aim of this study is to evaluate onset of early atherosclerotic changes of epiaortic vessels in hiv positive patients, treated with pi. purpose: hematoporphyrin (hp) accumulates in arteriosclerosis selectively and shows specific fluorescence spectrum change in accordance with the stages of the sclerosis, and this fact is under discussion as to its availability to diagnosis and therapy. we paid our attention to the fact that hp accumulates in the interface of swollen collagen type iv and lipid. we assumed such a model of atheroma, and we examined the possibility of a photodynamic therapy for arteriosclerosis using collagen type iv and phosphatidyl choline liposome. material and method: we added hp to collagen type iv, then the liposome containing cholesterol to the mixture, and examined the agglutination state of the protein-lipid complex. afterwards, we irradiated that complex with led pulse of nm for one hour, and examined scattered spectroscopy, interference spectroscopy using nm semiconductor laser and high sensitivity ccd in order to observe the hp and the agglutination state of complex, and, then, analyzed the alteration of protein-lipid complex in terms of fourier analysis. result: hp gave influence to the various state of assembly of protein-lipid complex. in addition, protein-lipid integration state was changed by the irradiation of light pulse and the change of scattered light that signifies the state of dispersion was observed. conclusion: this study suggested that the molecule composition of the proteinlipid complex in the plaque was changed by the irradiation of light pulse after the addition of hp, and that the photo stimulation could contribute to the decomposition of the cumulated lipid and the stabilization of plaque. depiction of arterial branches in the abdomen using multidetector-row ct n. terayama , o. matsui , k. ueda , t. kobayashi contrast medium ( mgi) was administered intravenously at a rate of ml/sec. parameters of data acquisition were as follows: a slice thickness of . mm, reconstruction intervals of . mm, a pitch of . , and fov of cm. axial images were transferred to advantage workstation . (ge medical systems) and multi-projection volume reconstruction (mpvr) images were obtained. if the origin of each arterial branch and the route until the target organ was depicted, we regarded that the branch was visible. results: coeliac, superior and inferior mesenteric, renal, intercostal, lumbar, right and left hepatic, and anterior and posterior pancreaticoduodenal arteries were visible in all cases. cystic, right gastric and dorsal pancreatic arteries were visible in cases ( %), in cases ( %) and in cases ( %), respectively testicular arteries were visible in cases ( %), and in cases ( %), respectively. conclusion: reformation images of mdct can visualize thin arterial branches in the abdomen experimental lung injury prior to the ct examinations. in addition, segmental and subsegmental pulmonary embolism was artificially induced in four healthy pigs. scanning was performed using a -slice msct protocol using contour finding and adaptive thresholding, both plain and enhanced ct volumes were separated into lung parenchyma, vascular structures and airways. the high contrast information was used to locally match and align sub-volumes. the matched parenchymal volumes were low pass filtered, subtracted and normalized to the enhancement level in a major vessel. results: scanning was successfully performed during a total ~ s scanning time in all pigs. post-processing was technically feasible, even in underlying experimental lung injury. in pe, filling defects corresponded to areas of decreased enhancement. conclusion: it is expected that this imaging technique will increase the sensitivity and specificity of msct determination of arterial input function for measurement of brain perfusion index with tc- m compounds using a solid-state gamma camera y. uenishi, k. murase, m. nagayoshi, m. kawamata, m. takasawa, n. oku, a. takahashi, j. hatazawa; osaka/jp purpose: cerebral blood flow (cbf) can be non-invasively quantified using the brain perfusion index (bpi) determined from radionuclide angiography (ra). for measurement of bpi, accurate determination of arterial input function (aif) is necessary. we have developed a method for the automatic extraction of aif using fuzzy clustering and a solid-state gamma camera (digirad). methods and materials: ra was performed using tc- m hmpao for sec with a digirad placed on the heart and a -head spect (spect h). for comparison, the data were also acquired using a conventional gamma camera (rc- i). the aifs were obtained using fuzzy clustering (aif a ) and manual drawing of a region of interest (roi) (aif m ) from the region of aortic arch. the rois were also drawn over the left and right cerebral hemispheres. the bpi values were calculated using spectral analysis (bpi a : bpi obtained using aif a , bpi m : bpi using aif m ). the deadtimes of digirad and rc- i were measured using the reference source method. results: the mean and sd of bpi m became larger with increasing roi size, while the bpi a was almost constant regardless of roi size. the sd of bpi a was smaller than that of bpi m . the deadtime of digirad ( . ± . µsec) was much less than that of rc- i ( . ± . µsec). furthermore, the deadtime of digirad was almost constant regardless of the volume of phantoms, while that of rc- i increased with increasing volume. the proposed method appears promising for calculation of the bpi, because it allows automatic and objective determination of aif. spectroscopic imaging of radiation-induced effects in the brain after brachytherapy g. bajzik , j. julow , i. repa ; kaposvar/hu, budapest/hu purpose: the effect of brachytherapy, characterized by rapid dose fall off from the radiation source, is different compared to external radiation. we used proton mr spectroscopic imaging to investigate brain tissue response to brachytherapy. methods and materials: twenty glioma patients treated with surgery and/or brachytherapy were studied with mr imaging (t weighted images and post contrast t weighted images) and d proton mr spectroscopy (tr: ms, te: ms, voxel size . cm ). brachytherapy resulted in central necrotic zone, surrounded by an enhancing rim (demarcation zone) and an outer edematous zone on mr images. in each patient sample, spectra of the three zones and the normal appearing white matter were analyzed. results: in demarcation zone, choline/creatine (cho/crea) ratio ( . ± . vs. . ± . , p = . , two-tailed unpaired student's test) and choline/n-acetylaspartate (cho/naa) ratio ( . ± . vs. . ± . , p = . ) was increased compared to normal white matter. in edematous zone cho/crea ratio was increased ( . ± . vs. . ± . , p = . ), cho/naa ratio was not different ( . ± . vs. . ± . , p = . ) compared to normal white matter. in demarcation zone we found elevated cho/crea ratio ( . ± . vs . ± . , p = . ) and cho/naa ratio ( . ± . vs . ± . , p = . ) compared to edematous zone. in the central necrotic zone we could only detect lipid and/or lactate peaks. conclusions: mr spectroscopy demonstrates significant spectral differences in the brain following brachytherapy. tumor recurrence can be suspected in cases where focal choline accumulation is detected. does ct-perfusion imaging based on parametric deconvolution permit prediction of infarct volume in acute stroke? g. bohner , a. förschler , c. zimmer , r. klingebiel ; berlin/de, leipzig/de objectives: suitability of quantitative ct-perfusion (ctp) imaging for assessing the early as well as final infarct volume in acute stroke patients. material and methods: twenty-two patients with acute cerebral ischemia underwent ctp on admission. parameter maps of cerebral blood perfusion (cbp), cerebral blood volume (cbv) and mean transit time (mtt) were generated using a parametric deconvolution algorithm. additional diffusion weighted imaging (dwi) was performed in seven cases. volume of diffusion abnormality was compared with the infarct volumes as assessed by two blinded neuroradiologists for each of the perfusion maps. in addition, final infarct volumes were determined on the basis of follow-up studies. results: mean volumes of ischemia as assessed by cbp, cbv and mtt were . , . and . ml respectively. amongst the patients in whom dwi was performed, six showed perfusions deficits in all perfusion images. in one patient, who had no dwi abnormality, perfusion deficits only were found on cbp and mtt images. mean volume of dwi changes was . ml. the most significant correlation was found between the extent of cbv reduction and dwi infarct volume (r = . , p < . ). mean final infarct volume was . ml for all patients. cbv reduction showed the best correlation (r = . , p < . ) with final infarct volume. conclusion: our findings suggest that cbv maps based on the ctp technique applied in this study permit prediction of infarct volume in early stroke, so ctp would deliver information about the ischemic penumbra. hepatic encephalopathy in alcoholic and non-alcoholic subjects: correlation of magnetization transfer ratio, apparent diffusion coefficient and critical flicker frequency m. cohnen, g. kircheis, h.-j. wittsack, f. miese, f. wenserski, a. saleh, d. häussinger, u. moedder; düsseldorf/de purpose: to correlate quantitative changes of water content in brain parenchyma using magnetization transfer imaging (mti) with different stages of hepatic encephalopathy (he). materials and methods: forty-three patients with hepatic encephalopathy and age-matched control subjects underwent mr imaging ( . t vision, siemens) including mti, mr-spectroscopy (mrs) and diffusion weighted imaging (dwi). liver cirrhosis was due to alcohol in patients whereas non-alcoholic disease was found in . patients underwent assessment of critical flicker frequency (cff) as test for he with a frequency under hz considered pathologic. magnetiza-tion transfer ratios (mtr) and apparent diffusion coefficient (adc) values were determined in basal ganglia, posterior white matter and pons using roi-measurements. single-voxel mrs was performed using a steam sequence (te = ms, tr = . s) assessing basal ganglia and posterior white matter. results: mrs showed typical findings with decreased myo-inositol combined with increased glutamine/glutamate with increasing degree of he indicated by a reduced cff. compared to controls, mtr showed a significant decrease both in the basal ganglia as well as in the posterior white matter. in alcoholic subjects, this was independent from the degree of he, whereas in posthepatitic cirrhosis a correlation was found. a non-significant increase in adc was noted with a decrease of cff in both groups. conclusion: the results may indicate an increase of free protons in the brain parenchyma of patients with he possibly supporting the hypothesis of a lowgrade cerebral edema. the differences between alcoholic and non-alcoholic subjects may hint at a general brain damage due to alcohol independent of hepatic failure. assessment of cerebral blood flow values obtained from dynamic perfusion computed tomography: a comparison with positron emission tomography h. yokote, k. nakayama, t. okamura, n. tsuyuguchi, k. kitamura, n. ozawa, s. minamikawa, t. tashiro, y. inoue; osaka/jp purpose: among imaging modalities measuring regional cerebral blood flow (cbf), dynamic perfusion computed tomography (ct) studies are easy to perform and readily available without specialized equipment. however, quantitative studies comparing perfusion ct with positron emission tomography (pet) have been few. we assessed the correlation of cbf values obtained from perfusion ct and pet. methods and materials: eleven patients with various cerebrovascular diseases underwent perfusion ct and pet. the perfusion ct studies were performed with a four-channel multi-detector row ct scanner. four contiguous -mm ct sections were cine-scanned during a ml bolus of intravenous contrast medium at a rate of ml/s, with a total acquisition time of s. cbf maps were obtained from perfusion ct data by central volume principle and deconvolution method. on cbf maps of both perfusion ct and pet, multiple regions of interest (roi) were drawn independently, including frontal, temporal, parieto-occipital territories, caudate nucleus, thalamus and white matter in both hemispheres. rois were visually matched by agreement of three radiologists. mean cbf values of multiple rois with both ct and pet were compared through linear regression analysis. results: correlation coefficients for individual analysis ranged from . to . , overall . . linear regression analysis showed moderate correlation between perfusion ct and pet values (slope = . , intercept = . ). conclusions: our study has shown moderate correlation of cbf values between perfusion ct and pet. despite the various alterations of cerebral blood flow in our cases, perfusion ct studies were validated to be an easy-to-perform imaging technique to assess cbf values. ageing of the cerebrum: assesment with quantitative proton mr spectroscopy j. ostojic, r. semnic, d. kozic, d. bogdanovic, m. prvulovic; sremska kamenica/yu introduction: aging is recognized to originate from a diversity of mechanisms that blur the limits between normal and pathologic processes. the purpose of this study was to determine the early effect of normal aging on the regional distribution of brain metabolite concentrations, including n-acetylaspartate (naa), choline (cho) and creatine (cr). methods: seventy nine volunteers, ages to years, were examined by localized single-voxel proton mr spectroscopy at . t using press sequence.voxels x x cm were placed in the middle white matter (wm) of the centrum semiovale in the left hemisphere and in the occipital gray matter (gm) of posterior parietal lobes. the ratio of naa/cho were calculated, as well as absolute concentrations of naa, cr and cho.quantification was performed using method of external standard. results: absolute concentrations (mm/kg) of cho increased with age both in wm (r = . , p < . ) and in gm (r = . , p < . ). cr concentrations were much higher in gm than in wm and significantly higher in the old than young subjets (r = . , p < . ). the change of wm cr with age failed to meet p < . criteria. naa concentration was higher in gm than in wm and did not differ between young and old subjects. the age dependency of gm naa/cho ratio was technical inadequacies of plain films in an emergency department b. rajashanker, f. jabeen, r.w. whitehouse; manchester/uk purpose: . to assess the diagnostic quality of radiographs performed in the emergency department in a major referral hospital. . to determine the type and number of inadequacy encountered most often. materials and methods: two specialist registrars (trainees) in radiology, reviewed plain films performed in a busy emergency department. films were examined for inadequacies, which impair the diagnostic quality of the examination. despite artefacts or exposure problems, if a reasonable diagnostic conclusion could be made, the film was considered to be adequate. if a film was found to be inadequate, clinical details (that could have contributed to the poor quality) were looked at, and taken into consideration. artefacts obscuring the area of interest, inadequate collimation, incomplete examinations and improper exposure factors were considered as inadequate. the number and the type of inadequacy, the type of examination were noted. results: . the study showed that about % of the total films performed were inadequate. there are no national figures we could find to compare our results with to evaluate the performances on our emergency department. . the type of inadequacy encountered most often was the presence of jewellery obscuring the area of interest ( %), followed by artefacts caused by clothing ( %). chest radiograph was the most frequently encountered inadequate examinations ( %). conclusion: national guidelines regarding target quality radiographs that need to be achieved in institutions need to be published. the inadequacies were pointed out for better performance in future. drug courier pays a high price for easy money b. szabó, z. mocsári, s.o. farkas, p. magyar, Á. takács, k. karlinger, e.k. makó; budapest/hu purpose: the aim of this study is to show the most common methods for examining drug couriers and their results. method: native abdomen ct scans and native abdomen x-rays and us examination were performed on probably positive patients. in the year until now we examined patients. four positive cases were found. one of them after the ct examination died in the hospital, because leakage of a capsule. conclusion: swallowers before traveling swallow - cm long, cm diameter capsules, which they hope to retrieve after traveling. stuffers insert drug filled corpus alienums into the rectum or vagina. the danger of this type of drug smuggling is the braking or bursting of the capsules, leading to potential fatal drug overdose. steps to european union from europe: reforms of education of hungarian radiographers a. maléta, z. mocsári, s.o. farkas, Á. mester, k. karlinger, e.k. makó; budapest/hu purpose: the aim of this presentation is to show a short summary of the education of hungarian radiographers currently and in the future. method: assessment based on the bologna contract new education system with the cooperation between the society of hungarian radiographers and hungarian ministry of education according to the european directives. results: the base of the modular education system is already laid down. the construction and edition of the new scientific books and the preparation of the teachers and professors has already commenced. conclusion: since the hungarian educational system of radiographers has a history of nearly ninety years we need to use the lessonst of the past into the new system. since the result of the reforms requires a long time, well-organized feedback mechanisms is needed to ensure the effectiveness of the reforms. origin of military radiology: first use of x-rays in ottoman empire a. tunaci, n. yildirim, y.i. ulman, e. yekeler, h. genchellac, m. tunaci, g. acunas; istanbul/tr x-ray usage as a diagnostic device was realized in turkey first time at the military medical school in by esad feyzi, who was an intern and physics assistant. this new invention attracted attention so much that dr. salih and rifat osman also joined him and they started to work in a small unit, where they practiced radiographic examination.the following year, yildiz portable military hospital was reserved for wounded patients from the battlefield of the ottoman-greek war. this mobile hospital, which was activated in , was exported from germany and comprised duquer system pavilions that were reassembled within hours. they took away the x-ray equipment from the military medical school to yildiz and began to produce images of bullet and shrapnel pieces from the patients sent from the battlefield. kuttner and nasse from german red cross came to istanbul in . they were surprised to see that this new invention was already being used there. on the greek side english physicians used two x-ray devices that were transferred from england to pire harbour on may . therefore the ottoman-greek war took its place in medical literature as the first war that radiographic images were taken, first by the turkish and soon after by german and english physicians. references stated that english physicians took x-ray images of wounded greek soldiers and there is no record about greek physicians taking part in this work. turkish physicians continued to work on radiographic images during the war which they had started shortly after the discovery of x-rays. to demonstrate how to perform a numeric flow simulation in patient-specific vessels based on isotropic ctdatasets. to illustrate the possibilities of this promising tool on clinical cases. background: cfd was introduced recently to investigate the behaviour of blood flow. different studies determined cfd as a valuable method to demonstrate the flow and pressure. most studies use simplified standard models for the simulations. this exhibit explains methodological aspects of cfd and how numeric flow simulations are performed in patient-specific vessels based on high-resoloution ct datasets. possible applications of cfd in the cardiovascular field are discussed. procedure details: isotropic ct-angiography data are used to segment the vessels. after generation of a surface mesh using the marching cube algorithm, the model is transferred into a volume mesh and the different entities and walls were defined. specific parameters as velocity at the inlet boundary, flow parameters, and material specific parameters have to be assigned in a next step.the simulation itself provides detailed information about flow-behaviour and pressure. this helps to identify possible zones for development of artherosclerosis or, especially in aneurysms, locations for a possible rupture. furthermore, blood flow can be quantified and e.g. effects of stent-graft implantations or the benefit of a coronary bypass can be demonstrated. conclusion: cfd in combination with patient-specific patient-data is a promising method to visualise flow-effects. in the near future cfd will also gain increased importance for pre-interventional planning of vascular procedures. background: evaluation of the central veins is easily achieved with contrastenhanced mr angiography. "indirect" ce-mrv, a technique where the veins are evaluated during the "venous" phase has been largely replaced by "direct" ce-mrv, a technique whereby dilute contrast agent is injected into the upper extremity veins and imaging is performed during the first-pass. imaging findings: in order to overcome t *-induced susceptibility-effect commercial strength contrast-agent is diluted with saline. in our institution we use a % solution ( cc of contrast agent in cc saline). - cc of contrast is injected over the duration of the breath-hold scan (tr/te/flip msec/ msec/ deg, matrix x , fov - mm x - mm. - slices, mm interpolated to mm). mask subtraction of a pre-contrast scan is performed. the spectrum of findings in normal and diseased veins is illustrated. examples of thrombosis, stenosis and occlusion of the central veins will be illustrated. common pit-falls and artefacts will also be emphasised. conclusion: "direct" ce-mrv is an effective modality for evaluating the central veins. a simple robust method is presented, along with examples of the appearance in normal and pathological states. multidetector row ct angiography of the lower extremities for the assessment of traumatic vascular injury e.e. williamson, j.c. hellinger, a. napoli, g.d. rubin, d. fleischmann; stanford, ca/us learning objectives: . to describe the ct angiographic (cta) technique used in the evaluation of traumatic lower extremity (le) vascular injury. . to illustrate the spectrum of vascular and nonvascular pathology found during le-cta in the setting of trauma. background: digital subtraction angiography (dsa) has long been considered the imaging standard for traumatic vascular injury. cta is a more readily available, noninvasive imaging alternative which is less expensive, less resource intensive and can be used to assess bone and soft tissue injuries without the need for additional imaging tests. in this exhibit we highlight our experience with cta in trauma patients.procedure details: all examinations were acquired using or -channel multidetector-row ct (mdct). contrast media was administered at - cc/sec using bolus-tracking technique. thin section images were obtained from one vascular segment above the level of trauma through to the foot with collimation of . and pitch of . - . . table feed and gantry rotation speed were adjusted to optimize scan duration to match the peripheral delivery of iv contrast. all studies were reformatted in -dimensions using volume rendering, maximum intensity projection and curved planar reformation techniques. conclusion: the spectrum of direct vascular injuries included large and small vessel occlusions, pseudoaneursyms, active extravasation, and vasospasm. nonvascular pathology with indirect effects on the vascular system included complex fractures, open soft tissue wounds, hematomas, and joint effusions. ct angiography of the extremities is a promising technique in the evaluation of traumatic le arterial injury with the ability to assess nonvascular injuries without the need for additional studies. there is a wide range of imaging techniques available for mrv evaluation of the central chest veins, including conventional non-contrast time of flight imaging and contrast enhanced methods such as the newer vespa (venous enhanced subtracted peak arterial) sequences. imaging findings: examples of common central venous pathologies will be illustrated from our database of over patients, who underwent mr at . t using various sequences including non contrast time-of-flight, and post gadolinium true fisp, t -weighted vibe and d flash sequences. typical scan parameters included matrix x , fov - x - mm, - slices, mm interpolated to mm. common pathologies demonstrated included thrombo-embolic disease, central venous obstruction due to local tumour extension, congenital and acquired venous stenoses, av fistulas and infected venous pseudo-aneurysms. conclusion: mrv is a robust, highly accurate and non-invasive technique for assessment of central venous pathology. accuracy of automated centerline approximation algorithms for lower extremity vessels in a cta phantom a. la cruz , m. straka , a. köchl , m. Šrámek , e. gröller , d. fleischmann ; vienna/at, stanford, ca/us purpose: the accurate determination of the central vessel axis is a prerequisite for automated visualization (curved planar reformation) and quantitation. the purpose of this work was to assess the accuracy of different algorithms for automated centerline detection in a phantom simulating the peripheral arterial tree. materials and methods: six algorithms were used to determine the centerline of a synthetic peripheral arterial vessel (aorto-to-pedal arteries, diameter - . mm) dataset ( x x , voxel size . x . x . mm). they are ray-casting/ thresholding (rct), ray-casting/maximum gradient (rcmg), block matching (bm), fitting to ellipse (fe), center of gravity (cog), and randomized hough transform (rht). gaussian noise with a sigma: , and was used to observe the accuracy of the method under noise influence. the accuracy of automatic centerline determination was quantified by measuring the error-distance between the derived centerlines, and the known centerline course of the synthetic dataset. results: bm demonstrated unacceptable performance in large vessels (> mm) when the shift used was less than voxels. rcmg demonstrated a greater error (mean of the error . mm) in large diameter (> mm) vessels than in small diameter (< mm) vessels (mean of the error . mm). because rht and fe use canny edge detector preprocessing, both are sensitive to noise. cog and rct keep the mean of the error-distance significantly smaller ( . mm and . mm respectively) than all other algorithms. conclusion: cog and rct algorithms provide the most efficient centerline approximation over a wide range of vessel diameters. detection of the adamkiewicz artery by subtraction magnetic resonance angiography h. hyodoh, r. shirase, h. akiba, m. tamakawa, k. hyodoh, k. aratani, n. kawaharada, k. morishita, m. hareyama; sapporo/jp purpose: to assess the ability of magnetic resonance angiography (mra) to depict the adamkiewicz artery. materials and methods: fifty-one patients with thoracoabdominal disease underwent mra of the bypass graft region. subtraction maximum intensity projection (mip) images and cine-mode displays were produced to identify the adamkiewicz artery, its side of origin and branching level, and the drainage vein. for statistical analysis, signal intensity ratio (snr) and contrast noise ratio (cnr) were also calculated. results: in ( . %) of the patients, at least one adamkiewicz artery was seen to arise from an intercostal artery. two adamkiewicz arteries were identified in ( . %) of the patients. spinal drainage veins were visualized in ( . %) of the patients, a single drainage vein in of the ( . % of the total patient group) and two drainage veins in the remaining ( . % of the total patient group). in of the patients, both the adamkiewicz artery and the drainage vein were detected during the early phase. conclusion: subtraction mra depicts the adamkiewicz artery in a high percentage of patients. -row multislice computed tomography of pulmonary veins: assessment before and after cryothermal energy ablation r. maksimovic , f. cademartiri , m. scholten , l. jordaens , p.m.t. pattynama ; belgrade/yu, rotterdam/nl purpose: electrical isolation of the pulmonary veins (pvs) with radiofrequency ablation in treatment of patients with paroxysmal atrial fibrillation is associated with pv stenosis. cryothermal ablation (ca) is a new promising method in treatment of these patients. although initial experience of ca showed no associated pv stenosis, results at follow-up have not been reported. the aim of the study was to assess pvs for the presence of stenosis three months after ca by contrast enhanced angiography on -row detectors multislice computed tomography (msct). materials and methods: twenty four patients (mean age . ± . years, males) with symptomatic atrial fibrillation underwent ca in pvs. all patients underwent complete clinical work-up, electrophysiological study, ultrasonography and msct angiography before ca. msct pulmonary angiography was performed three months after the procedure to evaluate ostium and the proximal mm of all pvs. results: dimensions of the treated pvs remained unchanged: the coronal ostial diameter was . ± . preprocedural vs. . ± . mm at follow-up, p < . , ratio of coronal and axial diameter . ± . vs. . ± . , p < . , respectively and the coronal diameter of the proximal mm from the ostium . ± . mm vs. . ± . mm, p < . , respectively. conclusions: ca of pvs in atrial fibrillation has not been associated with stenosis at the orifice and proximal mm of the pvs after three months follow-up. msct pulmonary venography is a reliable, noninvasive method for assessment of pvs in a three-dimensional manner prior to ablative treatment and during the follow-up period. magnetic resonance venography without contrast media for patients with lower extremity varicose veins j. koizumi , m. wada , t. horie , e. kimura , i. muro , k. myojin , t. niibori , y. imai ; isehara/jp, wako/jp purpose: to compare three different sequences of magnetic resonance (mr) venography without contrast media for patients with varicose veins below the knee. materials and methods: for patients with lower extremity varicose veins, mr-venography using time-of-flight (tof), fat suppressed t -weighted turbo spin echo (tse) and balanced turbo field echo (btfe) were compared.the original images on . tesla gyroscan (philips) were transferred to a workstation (m quadra, ziosoft inc.) and d images were reconstructed using maximum intensity projection (mip), multiplaner reformation (mpr), and volume rendering (vr) techniques. for analysis, the veins were divided into superficial, deep venous systems, perforating and varicose veins, and were evaluated using three points scale by a radiologist and a surgeon.results: superficial, deep venous systems and perforating veins were best visualized on btfe (p < . ), while varicose veins were equally visualized on tse and btfe. tof provided poor visibility except in popliteal veins. coexisting arterial system seen on btfe could be discriminated from the deep venous system especially on axial reconstructed images. the varicose veins connected with the superficial venous systems and perforating veins on the surface of the muscle were easily recognized on vr only using btfe. conclusions: mr-venography using btfe displays the best images of the whole venous system in patients with varicose veins below the knee. magnetic resonance angiography in potential live renal donors: a joint radiological and surgical audit a. mizzi, g. roditi, m. subramaniam; glasgow/uk purpose: to assess the impact of joint surgical and radiological audit on the accuracy of mra reports in the evaluation of potential live renal donors. materials and methods: we analysed the case records of live renal donors who underwent gadolinium enhanced mra as part of pre-operative evaluation to assess renal vasculature between august and july . in cases of discrepancy between mra reports and surgical findings, studies were retrieved to the mri workstation and subjected to detailed joint clinical and radiological review. scan quality was assessed and sources of discrepancy were identified. results: there were donors, men and women. reported mra findings were fully confirmed at surgery in of cases. these scans were not analysed further. in donors, the findings at surgery were discrepant with the radiological reports. there were cases of "missed" early branches and cases of "missed" accessory arteries. in the first year of audit there were discrepant cases out of ( %), all of which were radiological reporting errors. the number of discrepant cases in the second year dropped to out of cases ( %). neither of these was a radiological reporting error. there was one "missed" early renal artery branch in the third year of audit, which was visualised on mra review. conclusion: the accuracy of preoperative mra in potential live renal donors is high. radiological reporting of mra examinations is improved through careful clinical feedback, audit and interdisciplinary co-operation. d contrast-enhanced mr portography to scan the entire volume of upper abdomen with maximal spatial resolution using parallel acquisition techniques: preliminary experience d. horák, m. herman, j. bucil, j. klein, j. nekula; olomouc/cz purpose: to assess the feasibility and to evaluate the benefit of a d contrastenhanced (ce) mr portography (mrp) covering the entire volume of upper abdomen with maximal spatial resolution using grappa (generalized autocalibrating partially parallel acqusitions). materials and methods: patients were examined before or after surgical creation of porto-systemic shunt. t -weighted d angiographic sequence with d centric reordering optimized using a grappa factor of was performed at a . t scanner (siemens symphony maestro class) in three phases after administration of - ml of . -molar or ml of -molar gadolinium-dtpa followed by ml saline solution into the canula in antecubital vein. anatomical postcontrast t -weighted d spoiled gre with fat saturation was added. parameters of hires d-ce-mra sequence: in-plane resolution = . x . mm, number of partitions = , slice = . mm, partial-fourier = / , fov = , tr/ te/fa = . / . / , ta = sec. results: large evaluated volume hires mrp sequence is suitable for detailed postprocessing (subvolume mips) in any plane, imaging borderline vessels like recanalized umbilical vein or retroperitoneal collaterals, usually best seen in portal phase. robust protocol can be very easily adapted for uncooperative patients covering the same evaluated volume. functional information (flow direction) can be added with phase contrast mra flow quantification sequence. conclusion: our preliminary results show that the application of grappa allows to capture the whole portal vascular system without missing any important collateral with high spatial resolution in cooperative patients and with sufficient spatial resolution in non-cooperative ones. it's possible to image the flow in surgically placed porto-systemic shunts. gadobenate dimeglumine (multihance®) in contrast-enhanced mr angiography m. kirchin , r. la ferla , m. daprà , g. pirovano , a. spinazzi ; milan/it, princeton, nj/us purpose: gadobenate dimeglumine (gd-bopta) has high t relaxivity in blood (r = . °mm- s - ) compared to other gadolinium agents. this review is aimed at defining the usefulness of gd-bopta for ce-mra. methods: preliminary intraindividual, crossover studies were conducted in healthy volunteers to compare gd-bopta and gd-dtpa at the same dose and injection rate for mra of the abdominal aorta and run-off vasculature. subsequently, phase ii multicenter trials were performed in the renal/abdominal arteries (n = patients), the pelvic arteries (n = patients) and the carotid arteries (n = patients) to establish the optimum dose of gd-bopta for ce-mra. standard unenhanced and contrast-enhanced sequences were employed and images were evaluated by independent, off-site blinded radiologists on the basis of segmental and overall diagnostic quality scores per patient and dose. the crossover studies demonstrated significantly greater signal intensity enhancement after gd-bopta compared to gd-dtpa both in the abdominal aorta and run-off vasculature. the phase ii studies revealed dose-related trends for the contrast-enhanced images in each territory and good correlation between readers. the greatest increase in diagnostic quality from unenhanced mra to ce-mra occurred at . mmol/kg bw while a higher dose of . mmol/kg bw provided little or no additional benefit. ce-mra led to an increased number of patients with lesions detected and increased reviewer confidence for lesion characterization. conclusions: ce-mra with gd-bopta is more efficacious than unenhanced mra and appears superior to ce-mra with conventional gadolinium chelates. the optimum dose for ce-mra of vascular disease is indicated to be . mmol/ kg bw. influence of ct scanner and observer on volume measurement: five glass phantoms filled with diluted contrast material underwent one single-detector row ct (sdct) and two multi-detector row ct (mdct) examinations. for each ct scanner the clinical protocol for ct angiography of the abdominal aorta was used. in a first step the resulting volumes were measured using a special software with automatic outline detection without need of manual segmentation and thus without intra-and interobserver variability to evaluate differences between the ct scanners. in a second step the volumes were measured by three observers using a standard software for manual outline detection to assess inter-and intraobserver variability. results: there was no statistically significant difference between the ct scanners with the corresponding standard protocols (p = . ). inter-and intraobserver variability was . and . ml and lead to significant difference in volume measurement between the observers (p = . ). conclusion: volume measurement does not seem to be influenced by the used ct scanner. the interobserver variability is significant, but slight. consequently, changes of the volume of abdominal aortic aneurysms in follow-up ct angiography after endovascular repair can be considered as true change and not as scanner related. -slice multi-detector ct angiography in the assessment of stenoocclusive disease of the carotid artery bifurcation and vertebral artery origin s. lee, h. roh, h. byun; seoul/kr purpose: to determine the accuracy of -slice multi-detector ct angiography ( -mdcta) in the assessment of steno-occlusive disease of the carotid artery bifurcation and vertebral artery origin. materials and methods: in patients, carotid arteries and vertebral arteries were evaluated with -mdcta and conventional digital subtraction angi-ography (dsa). standardized -mdcta acquired from the circle of willis to the aortic arch. -mdcta data were displayed with maximum intensity projection (mip) for carotid and vertebral arteries and with volume rendering (vr) for carotid artery. the percent diameter stenoses of the carotid artery bifurcation and vertebral artery origin were measured separately on mip, and/or vr ct images and dsa. the carotid stenosis was graded as no, mild (< %), moderate ( - %), severe (> %), and occlusion with nascet criteria. the vertebral artery stenosis was also assessed with the same five-grade scale. the results of -mdcta were correlated with the gold standard of dsa. results: all carotid and vertebral arteries were assessable on mip and/or vr ct images. correlation between stenosis measured with -mdcta and that measured with dsa were good (pearson correlation: on carotid mip images, c = . , < . ; on carotid vr images, c = . , < . ; on vertebral origin mip images, c = . , < . ). the aggrement rate of stenosis grading between -mdcta and dsa was also high ( . % on carotid mip; . % on carotid vr images; . % on vertebral origin mip images). conclusion: -mdcta has a high accuracy for the evaluation of carotid and vertebral artery stenosis and provides multiplanar information preoperatively. does high iodine concentration contrast agent improve arterial enhancement in mdct angiography of the run off vessels? comparison of three different iodine concentration contrast agents f. venditti, c. catalano, m. francone, f. fraioli, a. napoli, v. votta, r. passariello; rome/it purpose: to evaluate whether a high iodine concentration contrast agent may determine a greater arterial contrast enhancement in the visualization of aortoiliac and peripheral vessels. materials and methods: sixty-six patients, randomly divided into two groups, a and b, were studied with a multi detector-row ct (mdct) scanner. both groups were divided in three subgroups (a = , a = and a = mgi/ml; b = , b = and b = mgi/ml) in which different iodine concentrations were injected. in group a variable flow rates were used. in group b the flow rate was kept constant at . ml/s. quantitative and qualitative analyses were performed at predefined fixed vascular segments. results: in both groups a greater density value was achieved using the high concentration contrast agent, in particular at the level of the superficial femoral artery for subgroup a and at the level of the popliteal artery in subgroup b . for all vascular segments the best enhancement was visualized for group b . no statistical significant differences were achieved between the two different groups in the visualization of sub-popliteal vessels. conclusion: our study demonstrates that the use of a high iodine concentration contrast agent increases arterial enhancement of the peripheral arterial tree using mdct scanner. multidetector ct angiography in arterial occlusive disease of the lower extremities: a step forward in vascular diagnostic procedures? m. maggi, s. alborino, e. paci; ancona/it purpose: multidetector computer tomography (mdct) angiography is a new available technique for studying arterial disease of the lower limbs. in this study we report our experience with mdct angiography in evaluating atherosclerotic lesions of peripheral arteries. materials and methods: patients ( / male/female, age ± , in and in rutherford category) were investigated by mdct between april and march , patients underwent digital subtraction angiography (dsa) of the lower extremities within days from mdct angiography. we used a - channels ge medical system ct-scanner, needle-cannula, flow rate ml/ sec, ml iodinated contrast medium / mgi/ml, bolus tracking program (smart prep). mip and volume rendering reformations were used. dsa and mdct angiograms were blindly evaluated by two vascular radiologists according to the following parameters: stenosis (lumen reduction - %), occlusion (> %), absence of lesion (< %) in arterial segments, for each patient. therapeutical implications of mdct angiography were also evaluated. results: concordance between mdct angiography and dsa was . % in detecting and . % in excluding lesions, . % in defining stenosis and . % for occlusions. in / patients percutaneous approach was modified according to ct images. conclusions: mdct angiography could be considered as the first step in diagnostic procedures of peripheral arterial disease and could also modify therapeutical strategy and vascular radiologist's performance. further studies are needed value of long-term routine ultrasound assessment of hemodialysis fistulae in comparison with clinical parameters a. wojciechowski, m. golebiowski, m. grzeszczyk, w. kania; warsaw/pl purpose: the aim of the study was to correlate the results of clinical and ultrasonographic long term follow-up of hemodialysis fistulae. the utility of routine ultrasound examination was discussed. materials and methods: patients underwent doppler ultrasound evaluation of dialysis fistulae. patients were randomly assigned for evaluation. in addition routine tests for blood cell count, hematocrit, kt/v, urr and blood pressure in the venous line were available in all patients. all patients had native fistulae. a single unit (atl ultramark hdi) was used for ultrasound examinations. results: results of laboratory and clinical parameters were abnormal in almost % of patients. low levels of hematocrit (< %) were observed in . %, albumin (< . g/l) in . %, elevated pressure in venous line (> mmhg) in . %. abnormal kt/v (< . ) and urr (< %) in . and . % respectively. us revealed: pseudoanerysms in . % of patients, hematomas adjacent to the fistula . %, arterial steal syndrome in . %, stenosis in . % and mural thrombi in . %. in . % of patients brachial artery blood flow was less than ml/min and in % of cases dialysis fistula flow was greater than ml/min. conclusion: only . % patients had no abnormal either clinical, morphological nor flow parameters. . % of patients had abnormal clinical and us morphological parameters. colour doppler ultrasound is more sensitive than clinical or laboratory methods in detection of hemodialysis fistula dysfunction. it is strongly recommended to start regular ultrasound examinations of all dialysed patients. material and methods: patients with brescia-cimino-shunts were examined by independent examiners with i. a. dsa and vascular ultrasound. all patients had a shunt-volume of less than ml/min., an angiographical stenosis of the anastomosis of at least % or changes of the venous portion of the shunt were examined. studies were performed with the aid of a multifrequency ultrasound probe ( - mhz, logic , , ge) using b-mode, color coded duplex (ccd) and b-flow, first of all in the brightness modification. results: in the group of anastomotic stenosis measurements of intrastenotic diameter gave for i. a. dsa values of (average: . mm), for b-mode (average: . mm), for ccd (average: . mm), for brightness mode of b-flow (average: . mm) and for b-flow with b-mode information values of (average: . mm). the best agreement with dsa was achieved by brightness mode of b-flow. while in b-flow in cases of anastomotic lesion or venous stenotic lesions, hypoechogenic vessel wall alterations were detected, they were not seen in b-mode in any case and not reliably in ccd due to blooming artifacts. in cases of venous aneurysm and vascular elongation a flow detection free of artifacts was only demonstrated by b-flow. conclusion: ultrasound b-flow detects anastomotic stenosis of hemodialysis fistula better than other ultrasound modes. the visualization of hypoechogenic vessel wall alterations and the degree of stenosis is also better appreciated by this mode. ultrasonographic assessment of internal mammary artery in the screening of radiotherapy induced coronary artery disease n. tuncbilek , o.o. okten , h.m. karakas ; edirne/tr, malatya/tr purpose: radiotherapeutically treated breast carcinoma patients are prone to the development of iatrogenic fibrosis and plaque formation in coronary vasculature. in this group of patients, early changes in the diameter and the flow characteristics of internal mammary artery, hypothesised as the surrogate markers of the coronary artery disease, were ultrasonographically (usg) investigated. the study group was consisted of breast cancer patients with ages between and (mean age . yrs) and age-matched control subjects. all patients were radiotherapeutically treated to month ago. internal mammary arteries were ultrasonographically investigated with . mhz linear transducer in longitudinal planes. diameters of the arteries were measured in m-mode; resistivity indices (ri), pulsatility indices (pi), peak systolic and end diastolic values were measured with color doppler usg. mean values of the above mentioned parameters were statistically compared among patient and subject groups. results: mean diameter of the internal mammary arteries were found to be . mm in patients and . mm in control subjects. there was a statistically significant difference between two groups regarding the stated parameter (p < . ). in contrary, the difference of ri, pi, peak systolic and end diastolic values were not statistically significant in two groups studied. conclusion: shortly after radiotherapy the diameter of the internal mammary artery significantly decreases but its flow spectrum does not change. ultrasonographically performed simple diametric measurements may be used as rapid and noninvasive screening tests to predict the development of coronary artery disease. assessment and follow-up of endovascular repair of aortic aneurysm with multislice computed tomography m. fernández -velilla, m. martí, y. herrero, j. echeveste, g. garzón, n. gómez-león; madrid/es purpose: to evaluate the usefulness of multislice computed tomography (msct) after placement of endovascular stent-grafts for treatment of aortic aneurysms. matrials and methods: seventy-six patients underwent msct angiography following treatment of thoracic or abdominal aortoiliac aneurysm with endoluminal stent-grafts. msct was performed from the supracoeliac aorta to the femoral artery bifurcation in patients with aneurysm affecting the abdominal aorta (n = ), and from the thoracic inlet to the femoral bifurcation in patients with thoracic aneurysm (n = ). the standardized protocol consisted of a nonenhanced ct ( mm collimation, pitch of , reconstruction interval of mm, table speed of mm per rotation and a single-breath-hold acquisition), followed by a contrast-enhanced ct. all images were postprocessed in a workstation (vitrea ; vital images, plymouth, minn). the image postprocessing included multiplanar reformats, mip, shaded-surface display, and volume rendering. the studies were assessed for stenosis, thrombosis, perigraft leakage, migration, angulation of graft, and enlarging sac size without visible endoleak (endotension). follow-up ct was performed prior to discharge and at six and twelve months after intervention. results: after stent-graft placement in the patients, ct demonstrated graft permeability in ( %), perigraft leaks in ( %), angulation of the graft in ( %) and endotension in ( . %). conclusion: msct was able to study the entire aorta with a maximal and homogeneus opacification. the msct technique allowed fast scanning, great anatomic coverage during a single breath hold, few motion artefacts, and high spatial resolution in the longitudinal plane, improving the diagnostic accuracy of the examinations. evaluation of vertebral artery using color duplex sonography: comparison of vertebral artery velocity and flow volume measurements for diagnosis of vertebrobasilar insufficiency m. acar, b. degirmenci, a. yucel, r. albayrak; afyon/tr purpose: the aim of this study was to compare the measurements of vertebral artery (va) flow velocity and flow volume for diagnosis of vertebrobasilar insufficiency. matrials and methods: we examined patients referred for evaluation of vertebrobasilar insufficiency. net va flow volume and mean systolic flow velocity were determined by using color duplex sonography. we grouped the patients into three: group consisted of patients with severely damped va flow volume (< ml/min), group moderately damped ( - ml/min) and group , normal (> ml/min). the mean systolic flow velocities in each group were compared by one-way anova. results: damped va flow volume was determined in of patients, of these patients had severely damped, had moderately damped, had normal va flow volume. mean va systolic flow velocities of group , and were ± , ± and ± cm/sec, respectively. mean va systolic flow velocity in group was significantly lower than that of group (p = . ). however there were no significant differences between va systolic flow velocities in group and group (p = . ). conclusion: according to our findings, measurement of va velocity is enough for diagnosis of vertebrobasilar insufficiency in patients with severely damped va flow volume but may not always be helpful in differentiation of moderately damped flow volume from normal. therefore we conclude that for the diagnosis of vertebrobasilar insufficiency, measurement of volume in addition to velocity is necessary in detection of moderately damped va flow volumes. rotational angiography of femoropopliteal arteries after percutaneous transluminal angioplasty (pta): preliminary results f. pozzi-mucelli, m. belgrano, g. tona, r. pozzi-mucelli; trieste/it purpose: to report our experience in rotational angiography (ra) after pta of the femoropopliteal arteries and to compare this modality to standard anteroposterior (ap) projection. materials and methods: forty patients underwent pta of the femoropopliteal arteries in the last months. twentysix were stenoses (lenght: - cm) and occlusions (lenght: - ). in all cases pta was successful and the result was checked with ap projection and with an ra acquisition. the procedure were performed on the philips integris allura system providing the ra tool. results: ra after pta was successful in all cases. in % of cases there was no difference between the static ap projection and ra, whereas in % the static acquisition, compared to ra, underestimated the degree of residual stenosis by - %. in about % of these cases a disagreement on the presence and extent of subintimal flaps between static and rotational acquisition was identified. in another % of cases there was substantial agreement on the residual stenosis but not on the pta-induced dissection which was always better identified on ra. conclusions: ra allowed optimal evaluation of all cases improving the information on the conventional technique based on one or two projections. in our experience this information modified our therapeutic approach leading to repeated balloon angioplasty or stenting in % of cases. all the diagnosis were confirmed by digital angiography or surgical treatment. in the first group (endoluminal repair), the complications were: a) periprosthetic hematoma (n = ); b) neointinal hyperplasia (n = ); c) partial stent-graft thrombosis (n = ); d) total stent-graft thrombosis of an iliac branch (n = ); e) endoleak type ii (n = ); f) endoleak type iii (n = ), separation of the stents' components (n = ). in the second group (surgical repair) we observed: a) periprosthetic infections (n = ); b) supraprosthetic aneurysm (n = ); c) pseudoaneurysm (n = ); d) aortoenteric fistula (n = ). conclusion: cta is accurate, fast and minimally invasive imaging method in the evaluation of complications after abdominal aortic aneurism repair. interobserver agreement in the ct evaluation of carotid artery stenosis p.m. carrascosa , f. meli , c. capuñay , t. sampere , e. martin lopez , d. smith , s. chandra , j. carrascosa ; buenos aires/ar, cleveland, oh/us objective: to determine the usefulness of ct angiography (cta) in the detection and quantification of carotid stenosis in comparison with da. materials and methods: thirty-eight carotid arteries were evaluated in patients with transient ischemic attacks. ctas were performed with a helical ct scanner (pq ; picker). images were evaluated by two radiologists, who were blinded to the percentage of stenosis determined by da. the stenosis were considered positive if they were ≥ %. different methods of stenosis quantification (nascet(n), esct (e) and area quantification (a)) were performed on the same vessel to determine the sensitivity and specificity of each one in comparison with da. interobserver variability of the three methods was evaluated. statistical analysis: kappa coefficient was performed to determine the interobserver variability. results: observer : sensitivity: n: %, e: % and a: % and specificity: %, . % and . % for each method, respectively. observer = sensitivity: n: %, e: % and a: % and specificity: %, . % and % for each method, respectively. kappa: . , and . for n, e and a respectively. conclusion: cta showed high s and sp in the carotid stenosis quantification, specially with the nascet method. emergency multislice ct angiography (mscta) in patients with suspected aortic dissection r. stern padovan, m. lusic, b. oberman, k. potocki; zagreb/hr purpose: the purpose of the study was to evaluate positive msct-angiography findings in patients with spontaneus-nontraumatic aortic dissection. mscta is a noninvasive, time-saving radiological procedure for patients with aortic dissection because they need prompt and accurate diagnosis and treatment. aortic dissection is defined as a separation of the inner aortic wall layers. it is divided by stanford classification into type a that involves the ascendent aorta and type b involves distal to the origin of the left subclavian artery. materials and methods: mscta was performed in patients ( ( . %) female and ( . %) male age - ) with clinically suspected aortic dissection over a period of months on lightspeed ultra slices, ge. slice thickness was . mm with % overlap of reformatted images. we injected - ml of nonionic contrast material at a flow rate of ml/sec with smart prep feature. mip and mpr were usually used. results: aortic dissection was found in ( . %) patients. ( . %) had acute aortic dissection and ( . %) chronic type. acute aortic dissection stanford type a was found in ( %) and type b in ( %). in patients we did not find aortic dissection but other ct findings could explain the symptoms: aa, rupture of aa, mesenteric ischemia, pericardial effusion. conclusion: mscta is noninvasive, rapid and relatively comfortable radiological procedure for patients with suspected acute aortic dissection in cardiovascular emergency. this technique enables correct and detailed diagnostic information and obviates catheter aortography. diagnosis of aortic and supraaortic emergency with ct angiography: how does aortic morphology influence the choice of treatment? c. engelke , k. marten , a. chavan , j.f. reidy , a.-m. belli , e.j. rummeny ; munich/de, hannover/de, london/uk objective: ct angiography (cta) is the imaging method of choice for diagnosis of aortic and supraaortic emergency. in this retrospective evaluation of patients with aortic or supraaortic emergency undergoing intial cta at four european centres diagnosis and determination of treatment are reviewed. the assessment of diagnostic value of vmax, vmin, pi, ri measurements in the diagnosis of coeliac trunk stenosis before and after levovist injection -roc curves analysis a. drelich-zbroja, t. jargiello, w. krzyzanowski, p. kurczab, m. szczerbo-trojanowska; lublin/pl purpose: to assess the diagnostic value of vmax, vmin, pi, ri measurements in the diagnosis of coeliac trunk stenosis before and after levovist injection. in patients doppler examination of coeliac trunk before and after levovist injection was performed measuring vmax, vmin, pi, ri. in conventional doppler and after levovist administration stenoses were diagnosed. number of diagnosed stenoses in relation to number of normal coeliac trunks was representative enough to perform the statistical analysis using roc curves. results: . the areas under curves (aucs) for vmax, vmin, pi, ri, before and after levovist. a. before levovist: aucvmax = . *, aucvmin = . *, aucpi = . ns , aucri = . ns . a. after levovist: aucvmax = . *, aucvmin = . *, aucpi = . ns , aucri = . ns . *p < . when compared with auc = . ; ns-not significant when compared with auc = . . the comparison of aucs for vmax and vmin before and after levovist. aucvmax after levovist -aucvmax before levovist = . ns , aucvmin after levovist -aucvmin before levovist = . ns , aucvmax before levovist -aucvmin before levovist = . *, aucvmax after levovist -aucvmin after levovist = . *. *p < . ; ns-difference not significant conclusions: only vmax and vmin are useful in the diagnosis of coeliac trunk stenosis. the diagnostic value of vmax is significantly higher than diagnostic value of vmin. the use of levovist has no an effect on diagnostic value of vmax and vmin. the effect of body mass index on the ultrasonographic measurements of the portal venous system n. tuncbilek , o.o. okten , s. guldiken , h.m. karakas ; edirne/tr, malatya/tr purpose: the effect of body mass index (bmi) on portal venous diameter and pulsatility index was investigated. the study group consisted of obese and control subjects with normal bmi. inferior vena cava (vci) and portal vein (pv) diameters and their pulsatility indices (pi) were prospectively evaluated with . mhz convex transducer. diametric measurements were employed in m-mode imaging. the difference between obese and normal subjects regarding above mentioned parameters and their correlations with pi are investigated. results: bmi varies between . and . kg/m in control, and between . and . kg/m in obese subjects. in control subjects, mean pi is . for pv and . for vci. in obese patients, these values are . and . , respectively. pi for pv significantly differs between two groups (p < . ) whereas vascular diameters for vci and pv, and pi for vci are not statistically different. in both groups there is a negative correlation between pi and bmi (for control subjects: r = - . , p < . ; for obese subjects r = - . , p < . ). conclusion: pi of the portal venous system is regarded as the surrogate marker of right cardiac function. however factors such as inspiratory and expiratory intraabdominal pressure changes are known to affect this parameter. when considering pi as a marker of right cardiac function, attention must be paid to the relation of pi and bmi, proved by this study to be one of these factors. significance of patent pyloric branch in hepatic arterial infusion chemotherapy s. yoshioka, y. yasuhara, t. murakami, s. kumano, t. mochizuki; ehime/jp purpose: to investigate the clinical significance of the patent pyloric branches after right gastric artery (rga) embolization for arterial infusion chemotherapy. materials and methods: sixty-six patients who received catheter placement in the hepatic artery for arterial infusion chemotherapy were retrospectively recruited from the pool of clinical records between and . two interventional radiologists reviewed the digital subtraction angiographies (dsas) and clinical records of these patients. they assessed the following items by consensus: ) location of the rga, ) frequency of the patent pyloric branchs after coil embolizaton of the rga, ) outcome of arterial infusion chemotherapy through the catheter. results: the location of the rga could be determined in patients. rga-coil embolization was performed in patients. in patients, fine pyloric branchs were patent after embolization. they were too fine to be embolized by the catheter technique. in of these patients, the catheter was successfully placed to avoid the drug infusion into the pyloric branch. the clinical outcome of the other patients were as follows: one patient received the arterial infusion chemotherapy without any complication. one patient experienced transient abdominal pain in the course of arterial infusion chemotherapy. two patients received replacement of the catheter because of abdominal complication. the last patient received surgical ligation of the rga because of reopening of the rga. conclusion: the frequency of abdominal complication in arterial infusion chemotherapy was not negligible in the cases with patent pyloric branchs after rga embolization. erdheim-chester disease: imaging features c. graef, e. dion, p. cluzel, r. renard-penna, j. haroche, b. wechsler, c. beigelman-aubry, p.a. grenier; paris/fr learning objectives: to be familiar with the radiologic features of erdheim-chester disease, a rare form of non-langerhans cell histiocytosis of unknown etiology. background: the disease is characterized by tissue infiltration with lipid-laden foamy histiocytes, polymorphic granuloma of inflammatory cells and collagen fibrosis. the patients have a mosaic of infiltrative involvement of various organs. bone involvement is almost always present but often clinically asymptomatic. the prognosis depends on the severity of cardiovascular, renal or cerebral involvement. imaging features of histologically proven cases were reviewed. imaging features: radiological bone involvement was present in all cases, characterized by bilateral and symmetrical spongy bone densification, cortical thickening and periostosis of long bones from the metaphysis to the diaphysis associated with scintigraphic tracer uptake. renal and perirenal involvement seen on ct scans consisted of bilateral and symmetrical perirenal tissue infiltration (hairy kidney) (n = ), extended to the adrenal fossae, the renal sinuses, and the proximal ureters. cardiovascular involvement consisted in ) thoracic and abdominal circumferential periaortic tissue infiltration (coated aorta) with extension to the coronary, supraaortic and pulmonary arteries, and abdominal branches, ) stenosis of renal or mesenteric arteries (n = ), ) involvement of pericardium (n = ) and myocardial mass (n = ). tissue infiltration involved pituitary in one case and orbits in another one. conclusion: a diagnosis of erdheim-chester disease should be considered in patients who demonstrate bilateral and symmetric densification of the long bones with increased uptake on scintigraphy in association with perirenal fat infiltration and/or a periaortic fibrosis. human nk- cells were labeled with ferumoxides and ferucarbotran using simple incubation, lipofection and electroporation techniques. incubation times were varied from - hours and added contrast agent concentrations were varied from - microgram fe/ cells. pellets of labeled cells and non-labeled controls were evaluated by mr imaging. the cellular iron oxide uptake was proven by prussian blue stains and spectrometry as a standard of reference. in addition, cell viability was tested with the trypan blue exclusion test. differences between labeled cells and non-labeled controls were tested for significance using the t-test. results: nk- cells could be labeled with ferucarbotran and ferumoxides by lipofection and electroporation, but not simple incubation. lipofection had to be performed for h, but resulted in only minor, not significant impairment of cell viablility ( - %) compared to controls ( - %), while electroporation caused cell labeling within seconds, but reduced the viablility of the cells significantly ( - %), thereby necessitating additional cell culture time for cell recovery. the intracellular iron oxide uptake was proven histologically and quantified by spectrometry. ferucarbotran and ferumoxides-labeled cells could be depicted by a significant signal decline on t *weighted mr images. conclusion: human nk- cells can be labeled with ferucarbotran and ferumoxides by lipofection and electroporation. optimized labeling techniques allow a subsequent cell depiction with a standard . t mr scanner. which temporal frame rate is necessary in quantitative dynamic ³he-mri? c. heussel , a. dahmen , f. lehmann , m. salerno , k.k. gast , h.-u. kauczor , j.p.i. mugler , e.e. de lange , w. schreiber ; mainz/de, charlottesville, va/us purpose: dynamic ³he-mri permits regional analysis of distribution ventilatory kinetics. dedicated post-processing offers image-based lung function parameters. sliding window reconstruction of interleaved-spiral acquisitions provides high temporal rates, but do functional parameter values depend on the temporal frame rate? methods and material: single-slice coronal dynamic ³he-mri was acquired continuously for s during free respiration. image reconstruction was performed using sliding window technique with . ms data sampling-time (repetition-time ms). post-processing was performed using a self-written software with linear motion correction for calculation of: rise time (tr, interval of lung-signal from % to % of peak signal), delay- time (td , interval of trachea-signal % and lung-signal %), amplitude (peak lung-signal), and peak flow (pf, maximum signal slope). analysis was done for rois using a temporal resolution of ms, ms, and ms ( nd , th , and th image). this study included exemplary patients (asbestosis, x asthma, copd) so far. results: post-processing of the data-sets lasted to mins at an actual pc ( . ghz p , gb ram). tr ranged from to ms (median ms), td ranged from to ms (median ms), amplitude ranged from to a.u. (median a.u.), pf ranged from to a.u. (median a.u.). no relevant difference was detected in the evaluation of different temporal frame rates for all patients or within an individual patient. conclusion: since these preliminary data suggest a limited effect of high temporal frame rates, improvement of spatial rather than temporal resolution might be the emphasis in the future. to determine the compensatory mechanisms involved in recovery of motor function following resection of the supplementary motor area (sma) and their relation to the clinical characteristics of recovery. subjects and methods: thirteen patients referred for surgery of low-grade gliomas located in the sma were compared to nine healthy controls using fmri before and after surgery during self-paced movements of both hands, successively. activation within regions of interest (rois) (primary sensorimotor cortex (smc), premotor cortex (pmc), sma) were compared and tested for correlation with anatomical characteristics of the tumor and resection, and clinical data. interaction analysis between rois was performed using partial correlation. results: tumor growth induced preoperative underactivity in the adjacent sma and overactivity in the opposite sma. postoperative recovery was associated with recruitment of the lateral premotor cortex in the healthy hemisphere. in the affected hemisphere, pre-and postoperative correlations between sma, pmc and smc were decreased. in the healthy hemisphere, postoperative correlations between pmc and sma or smc were increased. shortened onset and duration of recovery was associated with preoperative changes in sma activation. conclusions: these findings suggest that tumors induced a dysfunction in activation and connectivity of the ipsilateral sma, which was partially compensated by a recruitment of the sma in the healthy hemisphere. this preoperative remodeling of sma activity did not prevent the occurrence of the postoperative deficit but was associated with shortened recovery. sma resection was compensated by the recruitment of an ipsilateral premotor circuitry. the use of internet filters to build a radiology education and teaching resource p. davison, j. revell, m.r. rees; bristol/uk purpose: to develop a resource for radiology undergraduate and postgraduate education from a series of research projects dealing with internet filter aided search. supported by a research and education grant from the ear. materials and methods: two independent research projects into internet search were examined for their application to radiology education and these methods were compared to conventional image search protocols. this experience was translated into constructive advice for undergraduate students undertaking special study modules in radiology. the two internet filters developed were designed to improve accuracy of text search and to improve the search results from image search enquiries in radiology and medical subjects. a second iteration of the image search filter was developed to produce a web crawler that selected images from previously carried out text searches. the text and image based filters were tested with other search engines over a preset number of criteria. results: both the text based search facility and the image based facility showed advantages when compared to conventional search methods. the image search facility was successful in handling medical searches compared to common search engines and the web-crawler was efficient at producing a large number of images from selected sites. these methods were used to develop medical students skills in the use of the internet and has been used in the construction of radiology image based special study projects. conclusion: web based filter programmes and education in search techniques can result in improving the efficiency of internet based material for radiology education. single breath-hold subtraction: novel approach to diagnosing pulmonary embolism by multi-slice ct (work-in-progress) j.e. wildberger , a.h. mahnken , h. ditt , m.u. niethammer , e. spüntrup , e. klotz , r.w. günther ; aachen/de, forchheim/de purpose: in the work-up of pulmonary embolism (pe), ct allows for direct visualization of emboli. in addition, perfusion defects permit direct assessment of the extent of pe, using color-coded lung densitometry. this new image processing technique has been deployed for a -slice multi-slice ct (msct) system. for further improvement, a subtraction technique within a single breath-hold will be mandatory. materials and methods: three healthy pigs underwent lung lavage to induce c- assessment of the angioarchitecture and hemodynamic characteristics of cerebral avms by contrast enhanced static and non enhanced dynamic mr angiography m. essig; heidelberg/de purpose: the aim was to improve the definition of the angioarchitectural components of the avm based on a dynamic mra (dmra) and a high resolution d multi-bolus and multi-phasic contrast-enhanced mra (ce-mra). both techniques will be compared with d-tof-mra and transfemoral high resolution plain film angiography performed for treatment planning. materials and methods: dmra will be performed by tracking a blood bolus through a vessel structure using the spin labeling technique star (signal targeting with alternating radiofrequency sequences). time-resolved ce-mra will be acquired with an ultrashort d fast low-angle shot (flash) sequence (tr/te . / . msec) using asymmetric k-space sampling in readout, phase-encoding, and partition directions. results: all used sequences were successful in the assessment of patients' cerebral avms. the integration of acquired images into the treatment planning protocol was possible for all modalities. the different avm compartments, feeding arteries, avm nidus, and draining veins were detected easily and best on the dmra. the method also allowed to hemodynamically assess the malformations: small avms generally showed shorter shunt times, however, a short shunt-time was associated with a higher risk of bleeding. ce-mra also proved to be superior than tof-mra in the assessment of the angioarchitecture, however, the time resolution of the dynamic varient was too slow to achieve a substantial hemodynamic characterisation. discussion: dmra and ce-mra are better suited than tof-mra to assess avm angioarchitecture. the differentiation of different compartments of the malformation and the hemodynamic assessment is best seen with dmra. diagnostic investigations in relation to determination of paramagnetic centres and free radicals in the model of testicular tumor metastases m. kekelidze, f. todua; tbilisi/ge purpose: to assess the possible connections between diagnostic imaging (spiral ct, mri) of retroperitoneal metastases of testicular tumor and the detection of paramagnetic centres and free radicals in the resected lymph node tissue after retroperitoneal lymph node dissection (rplnd). materials and methods: patients with stage i morphologically confirmed nonseminomatous testicular tumors were subjected to rplnd. diagnostic imaging included abdominal spiral ct with iv contrast and mri. specific tumor markers (afp, cgt) were detected. highly sensitive ( - spin/gas) electron paramagnetic resonance (epr) of resected lymph node tissue was performed to detect the presence of paramagnetic centres and free radicals (fe + , mn + , n ) signals. ct or mri scans were judged as positive or negative for rp metastases on the basis of size, contrast enhancement criteria and compared with morphological and epr data. results: in patients estimated as n on ct and mri the increased signals of free radicals were revealed in tissues. among patients (n ) with resected lymph node tissue, showed low signals of fe + mn + n and material (morphologically confirmed as metastatic) high signals of free radicals, while the increased presence of paramagnetic centers were not detected in these tissues. spiral ct and conventional mri fail to detect micrometastases in cases. there exists real correlation (p < . ) between the increased signals of free radicals (fe + , mn + , n ) and low stage metastatic lesions of rp lymph nodes, which can reflect the connection between particular molecular events and malignant degeneration. diagnostic accuracy of gadolinium-enhanced mr-angiography vs. contrastenhanced helical ct in the diagnosis of pulmonary embolism in the presence of lung infiltrate: an animal study t. franquet, s.e. kalloger, a. oikonomou, s.l. macdonald, e.m. baile, r.j. mayo; barcelona/es purpose: to compare gadolinium-enhanced mr angiography with contrast-enhanced spiral ct for the detection of small pulmonary emboli in pigs with and without pneumonia. materials and methods: ten female juvenile pigs were anaesthetized, intubated and ventilated. sub-segmental sized pulmonary emboli were introduced by injecting . mm methacrylate beads into the external jugular vein. lung infiltrates were simulated by intra-bronchial injection of human plasma. animals were imaged in the supine position at suspended inspiration with cm h peep. contrast media was injected via brachial vein. dual gradient (twinspeed) . t mr images were acquired using dimensional spoiled gradient-echo time of flight sequence; tr . msec, te . msec, * flip angle, mm section thickness, cm fov, x matrix, one average. two mra sets, pulmonary arterial and venous, were acquired in seconds. contrast enhancement was provided by ml of gd dimeglumine followed by ml of normal saline, injected at ml/sec. non-contrast and contrast enhanced ct images were obtained using an track spiral ct; . mm detector aperture, ml contrast at ml/sec. subtraction perfusion images were calculated by subtracting contrast enhanced from non-contrast ct images. after imaging the pig was euthanized and a methacrylate cast of the pulmonary vasculature was obtained and used as a "goldstandard". cta, cta with subtraction perfusion images and mr images were independently interpreted by two observers in a blinded fashion. results: no significant difference (p > . ) was seen between cta, cta with subtraction perfusion images and mr for mean sensitivity ( %, % and %) or mean specificity ( %, % and %), respectively. no significant difference (p > . ) was seen in sensitivity or specificity between pigs with and without infiltrates. a prospective power analysis based upon this preliminary data indicates that the addition of two more readers (n = ) would yield significant differences (p£ . ) between cta and cta with subtraction perfusion images compared to mra for sensitivity and specificity. conclusion: preliminary results indicate that cta and cta with subtraction perfusion images provide improved detection of sub-segmental sized pe in comparison to gadolinium-enhanced mra.