key: cord-0034114-gf32a6f1
authors: nan
title: B scientific sessions (SS)
date: 2002
journal: Eur Radiol
DOI: 10.1007/s00330-002-0002-9
sha: 61c5be62d6dfcce0a2590a9249c471617b7c7735
doc_id: 34114
cord_uid: gf32a6f1

nan

This icon indicates a pre-selected scientific paper to be judged by the subcommittee chairmen. The final winners of the best paper within one topic will be announced at the closing ceremony and presented with a diploma and their prize (€ 1500.-) In (a)symptomatic high-grade internal carotid artery (ICA) stenosis, ultrasound and digital subtraction angiography (DSA) are the established techniques for grading ICA stenosis; contrast-enhanced magnetic resonance angiography (CEMRA) is replacing DSA. Aim of this study was to evaluate the diagnostic accuracy of CEMRA in studying the carotid arteries and to compare CEMRA with DSA findings. Two MRA protocols, differing in acquisition voxel size, were used to assess whether intravoxel dephasing effects could modify diagnostic accuracy of CEMRA. 34 patients were studied: 20 (group 1) underwent a CEMRA protocol with an acquisition voxel size of 1.07 mm 3 and 14 (group 2) with a voxel of 0.40 mm 3 . DSA was perfomed in all patients. Morphology and degree of stenosis were evaluated, and a qualitative analysis comparing CEMRA and DSA findings was obtained. Diagnostic accuracy and correlation with DSA results for ICA stenosis were calculated in all patients and, separately, in the two groups. CEMRA diagnostic accuracy and agreement with DSA were respectively 94 % and k = 0.84; no significant difference was found among the two groups. Qualitative analysis revealed a better correlation between CEMRA and DSA images in group 2 than in group 1. These data suggest that CEMRA could be a powerful tool for the non-invasive evaluation of atherosclerosis of neck vessels. Stenosis overestimation of CEMRA is confirmed; reduction of voxel size, decreasing the dephasing intravoxel effect, allows to minimize it, with a better correlation of CEMRA and DSA findings; yet, no diagnostic gain is obtained in the patients' classification according to NASCET criteria.

MRI perfusion changes in unilateral symptomatic internal carotid artery stenosis: Evaluation of middle cerebral artery and border territories F. Gaudiello, G. Manenti, F. Garaci, R. Floris, A. Bozzao, G. Simonetti; Rome/IT Background and Purpose: To determine, with dynamic susceptibility contrast Magnetic Resonance Imaging (DSC-MRI), the hemodynamic changes occurring in patients with unilateral internal carotid artery stenosis (ICAS). Methods: 15 patients with symptomatic unilateral ICAS (over 70 % by NASCET criteria) as assessed by digital subtraction angiography and 15 age and sex matched control subjects underwent DSC-MRI. On a separate workstation rCBV and rMTT were calculated on the basis of signal decay rate during the passage of Gadolinium bolus through the sampled. Middle cerebral artery (MCA) and distal border territories (MCA to posterior and anterior circulation) were evaluated in all patients.

Results: Patients with unilateral ICAS did not showed statistically significant hemodynamic changes (rCBV and rMTT) between the two hemisphere both considering MCA and border territories. Comparing patients and controls statistically significant differences were found only for rMTT values in the border territories (increased, p = 0.005).

Conclusions: DSC-MRI is a valuable tool for measurement of hemodynamic changes in the presence of carotid disease with hemodynamic impairment. Based on our data no significant perfusion changes occurs between the two hemispheres in patients unilateral symptomatic ICAS. This indicates compensatory mechanisms between the two hemispheres in the cerebro-vascular reserve distribution. Only rMTT values changes (increased) in the border territories (of both hemispheres) differentiate patients with ICAS from normal controls.

Correlation of Doppler-and duplex ultrasonography based grading of unilateral internal carotid artery stenosis and blood volume flow quantification in brain supplying arteries using 2D cine phase-contrast MR imaging K.W. Neff, A.K. Kilian, S. Meairs, A. Schwartz, C. Düber; Mannheim/DE Purpose: Correlation of unilateral internal carotid artery (ICA) stenosis grading based on Doppler-and Duplex ultrasonography and the hemodynamic changes in brain supplying arteries. Methods and materials: 72 patients with unilateral ICA stenosis at the level of the bifurcation between 50 % and 98 % and 15 age-matched normal controls were examined using a 2D cine phase-contrast MR technique. Blood volume flow was measured in both ICAs and the basilar artery (BA). The ultrasonography based grading of stenosis was compared to the changes in blood flow in the stenosed ICA and to the changes in the contralateral ICA and the BA. Results: ICA stenoses greater 70 % were hemodynamically relevant. With increasing stenosis, a decrease of blood volume flow in the ipsilateral ICA was determined with a high linear correlation of r = 0.86. Normal controls showed a blood volume flow in an ICA of 256.8 ± 29.1 ml/min. In patients with 70 % stenosis a mean blood volume flow of 229.1 ± 32.2 ml/min; with 80 % stenosis 165.1 ± 52.3 ml/min and patients with 90 % stenosis a reduction of mean blood flow in the stenosed ICA to 80.4 ± 25.1 ml/min. With decreasing blood flow in the stenotic ICA an increasing blood volume flow in the contralateral ICA was found. In patients with unilateral ICA stenosis greater than 85 % a significant increase in BA blood flow was documented.

The comparison of ultrasonography based grading of unilateral ICA stenosis and blood volume flow determination in patients with hemodynamically relevant ICA stenoses demonstrates a high correlation between increase of stenosis, decrease of ipsilateral blood flow and collateralization of brain supplying circulation.

Doppler ultrasound, multidetector CT and Gd-MRA in the assessment of carotid artery stenosis E. Ferone, C. Pistolese, S. Fabiano, R. Floris, A. Spinelli, A. Bozzao, G. Simonetti; Rome/IT Aim of the study was to prospectively compare gadolinium-enhanced magnetic resonance (MR) angiography, computed tomographic angiography with multidetector capabilities (MD-CTA) and Doppler Ultrasound for use in detecting atheromatous stenosis and plaque morphology at the carotid bifurcation. Conventional angiography was available in all cases; surgical specimens were also available in many cases.

Methods and materials: 42 carotid arteries (in 21 patients) were analyzed by using MD-CT, enhanced MR angiography, and DSA. The following features were analyzed: degree of stenosis on the basis of North American Symptomatic Carotid Endarterectomy Trial criteria, luminal surface and presence of ulcers. Results: There was significant correlation between MD-CTA, enhanced MR angiography, and Doppler for degree of stenosis. With enhanced MR angiography and CT angiography, degree of stenosis was underestimated in two of 44 cases (1 mild and 1 moderate). No case of overestimation with enhanced MRA and MD-CTA was found. Severe internal carotid artery stenoses were detected with high sensitivity and specificity: 100 % and 100 %, respectively, with CT angiography; 96 % and 100 %, respectively, with enhanced MR angiography. Luminal surface irregularities were most frequently seen at MD-CTA as demonstrated by surgical specimens.

Conclusion: There was a significant correlation between MD-CTA, enhanced MR angiography and DSA in evaluation of carotid artery stenosis. CTA was however slightly better than MRA in detecting surface alterations.

Fucan, a natural polysaccharide from algal origin, inhibits intimal hyperplasia after stent implantation in normocholesterolemic rabbits We tested the hypothesis that fucan, a sulfated polysaccharide inhibitor of SMCs proliferation in vitro, may reduce intimal hyperplasia in vivo. We performed a pharmacokinetic study on a rat model and a restenosis study on a rabbit model.

A single dose of fluorescent fucan and heparin were administered to 10 rats and serum and urine were collected over time. Serum and urine concentration and pharmacokinetic parameters were calculated. Ten normocholesterolemic rabbits were treated with daily intramuscular injection of fucan (5 animals) or saline (5 animals) after stent implantation in both iliac arteries. Fourteen days after injury animals were sacrified and histomorphometric analyses were performed. Blood samples were systematically collected. Results: Fucan exhibited high plasma levels and a prolonged half-life (7 h 30 min) compared to heparin (1 h) after intravenous and intramuscular administration. Fucan reduced intimal hyperplasia by approximately 60 % after stent implantation in rabbits (1.79 ± 0.4 vs 0.73 ± 0.2 mm 2 , p < 0.005). Intimal hyperplasia inhibited was associated with a better longitudinal organization of cells layers. No toxic effect was noted in treated animals. Blood samples showed no anticoagulant activity. Conclusion: Fucan, a natural polysaccharide of algal origin, reduces markedly intimal hyperplasia in a rabbit restenosis model without anticoagulant activity. Methods: Endovascular treatment was performed in 39 patients with 42 aneurysms presenting with an unruptured aneurysm either of the anterior (n = 31) or posterior circulation (n = 11). 8 patients had a previous SAH from another aneurysm and 10 had neurological symptoms due to the aneurysm. In 21 patients the aneurysm was an incidental finding. Aneurysm size was small in 18 (25 mm). Occlusion rates was divided into complete (100 %), subtotal (95 -99 %) and incomplete (< 95 %). Results: Endovascular treatment was technically feasable in 38/42 aneurysms. Complete or nearly complete occlusion was achieved in 34/38 aneurysms. In four aneurysms of the ICA only incomplete obliteration could be achieved. Procedural complications included one case of thrombembolic vessel occlusion with narrowing of the parent artery due to coil protrusion, resulting in anterior cerebral infarction. With the exception of one patient with a mild deficit, all had a good recovery according to the Glasgow Outcome Scale, resulting in a morbidity of 2.4 % and a mortality of 0 %. Conclusion: Endovascular treatment in patients with unruptured aneurysms is an effective alternative with low morbidity and mortality and should be considered the first option for treatment. 

We designed three chains of calcium made from small cortical chicken bone fragments. Before the fragments were fixed with glue onto tape, volume measurements using water displacement and mass measurements using a precise balance (Mettlar H35AR) were performed. During open-heart surgery the chains then were sutured to the pig heart (n = 4) covering the coronary bed of each major epicardial artery as LAD, CX, and RCA in order to simulate real coronary motion. In each pig we performed a series of prospectively gated sequential and retrospectively gated half-scan and multisector helical scans (Lightspeed Plus, GEMS, Milwaukee, WI) using a range of scanning parameters (mA, kV, slice thickness).

We evaluated the Agatston score as well as the volume and a mass score for each chain and each pig. Results were compared to water displacement volume measurements and balance mass measurements. The cortical bone frag-Purpose: Electron Beam Computer Tomography (EBCT) and Multislice Computer Tomography (MSCT) are used to evaluate the amount of sclerotic plaque in coronary arteries in clinical practice. To investigate the potential of both CT techniques to identify calcified coronary lesions, we compared the results of EBCT and MSCT with intravascular ultrasound (IVUS) and histology. Methods: Five human autopsy coronary arteries were fixed in a saline perfused bath with vessel side branches and sutures defined as landmarks: a total of 81 vessel cross sections (VCS) were randomly assigned to undergo all 4 investigative steps. IVUS was performed with an automated pull back system (0.5 mm/s). Vessels were scanned with EBCT (Imatron, 3 mm slice thickness, 3 mm increment) followed by MSCT (Siemens Plus 4 Volume Zoom, 4 × 1 mm spiral mode, 3 mm slice thickness Purpose: To evaluate the reliability of Ca-score measurements of identical multislice CT (MSCT)-derived raw data obtained by the traditional Agatston method and a volume score using different software systems. Methods and materials: 22 asymptomatic patients with known or suspected coronary heart disease were scanned on a multidetector CT system (Somatom Volume Zoom, Siemens) with retrospectively ECG-gated 4-slice spiral scanning. Data was acquired with a 4 × 2.5 mm collimation. Continuous volume data sets were reconstructed in the enddiastolic phase with 3 mm slice thickness. For each patient reconstructions without (3 mm non-incremental -ni) and with a 50 % overlap (1.5 mm incremental -i) were performed. Two observers independently performed calcium-scoring using the Agatston (AS)-and volume-score (VS) on two software systems, the Calcium-Scoring (Siemens) and the AccuImage-Scoring-System. Replicated Ca-scoring was performed by each observer. The data was categorized into score groups 0; 1 -10; 11 -100; 101 -400; > 400. Results: Intra-and interobserver reliability was 0.94 -1.0 for both scoring methods (AS i/ni and VS i/ni). When Ca-scoring measurements were repeated on different scoring software systems, the kappa statistics were found to be 0.75 for AS i, 0.69 for AS ni, 0.75 for VS i, and 0.75 for VS ni, resulting in different risk stratifications in up to 14 % of the patients. Conclusion: Intra-and interobserver agreement was excellent using the same software. The two different softwares do not yield the same calcium quantities. There were significant differences with regard to interobserver reliability, resulting in different risk stratifications. The interpretation of calcium quantities should acknowledge which type of software was used.

Thirteen patients with heterozygous FH (mean ± SD; age 17.9 ± 3.4 a) and 13 controls were studied. Endothelium-dependent, flow-mediated dilation (FMD) and endothelium-independent, nitroglycerin-induced dilation (NMD) were assessed in the brachial artery using high-resolution ultrasound. In addition, FH patients were evaluated for coronary calcium using ECG triggered Multidetector CT. Results: FMD was significantly reduced in heterozygous FH patients compared to controls (10.7 ± 5.3 % vs. 17.3 ± 4.6 %; p = 0.002). In contrast, NMD values were similar in both study groups (17.7 ± 6.5 % vs. 21.0 ± 6.3 %; p = 0.22). On multiple stepwise regression analysis, a significant correlation was found between FMD and total cholesterol (r = −0.68; p = 0.0003) as well as between FMD and vessel size (r = −0.43; p = 0.01). Calcifications of the aortic root or the major epicardial coronary arteries were not detected. Conclusions: Endothelial dysfunction is present in the brachial artery of heterozygous FH already in the second and third decade of life without evidence of calcification of the aortic root and the coronary artery tree and is independently related to total cholesterol. Thus, altered vascular function precedes morphological evidence in the course of atherosclerosis. Therefore at this early age endothelial function testing seems to be more appropriate to evaluate FH patients developing atherosclerosis and to assess the short-term effects of therapeutic interventions.

The association between electron-beam CT detected coronary calcification and MRI detected cerebral white matter lesions J.C. de Groot 1 , R. Vliegenthart 1 , J.C.M. Witteman 2 , M.M.B. Breteler 2 , A. Hofman 2 , M. Oudkerk 1 ; 1 Groningen/NL, 2 Rotterdam/NL Purpose: Coronary calcification is associated with angiographically detected coronary artery disease. Cardiovascular risk factors are associated with cerebral white matter lesions (WML), which in turn play a role in cognitive decline. We investigated whether coronary calcification is associated with WML. Materials and methods: Participants were recruited from a population-based study of elderly patients aged 60 -90 years. During 1995 -96, cerebral MRI (1.5 T) scans of 554 subjects (response 63 %) were obtained on which the severity of deep subcortical WML (SCWML) and periventricular WML (PVWML) was estimated using a semi-quantitative scale. During 1998 -2000 thoracal electron-beam CT scans were obtained and coronary calcium scores (according to Agatston) are available for 221 of these subjects. WML was dichotomised in severe (upper quintile) versus mild to moderate (other quintiles) and the calcium score was dichotomised in severe (upper tertile) versus mild to moderate (other tertiles) for additional analyses. Results: Mean age was 72.3 years (50 % women). Mean severity of SCWML was 1.2 (range 0 -15.9) and of PVWML 2.2 (range 0 -9). Median calcium score was 125.3 (interquartile range 19.5 -501.4). Subjects with higher calcium scores had more SCWML (rho = 0.15, p = 0.02) and tended to have more PVWML (rho = 0.12, p = 0.08). When adjusted for age and sex, severe calcium scores were associated with the presence of severe SCWML (OR = 2.3, p = 0.05) but not with severe PVWML (OR = 1.8, p = 0.19). Conclusion: Preliminary analyses show that coronary calcification is associated with cerebral SCWML and as such may be indicative for a generalised vascular disease process.

Coronary calcification detected by electron-beam computed tomography is associated with mortality R. Vliegenthart 1, 2 , H.-H.S. Oei 2 , A. Hofman 2 , J.C.M. Witteman 2 , M. Oudkerk 1 ; 1 Groningen/NL, 2 Rotterdam/NL Purpose: Coronary calcification is closely related to the amount of coronary atherosclerosis, but its predictive value for cardiovascular disease and mortality has not been well established. We studied the association between coronary calcification and mortality in the population-based Rotterdam Coronary Calcification Study. Materials and methods: From 1997 -2000, Rotterdam Study participants were invited for electron-beam CT scanning to detect coronary calcification. Calcifications were quantified according to Agatston's method. Calcium scores of 2013 scanned subjects (46 % men, mean age (standard deviation, SD), 71 (5.7) years) were used in the analyses. The rate ratios of mortality between categories of the calcium score were calculated. Results: 40 % of men had a calcium score above 500, while 24 % had a calcium score above 1000. Corresponding percentages for women were 17 and 4, respectively. During a mean follow-up period (SD) of 2.4 (0.7) years, 80 subjects died (51 men, 29 women). The age-adjusted relative risk for death was 3.6 (95 % confidence interval (CI), 1.4 -9.4) for men with a calcium score above 500 compared to men with a calcium score of 0 -100 (reference category). Men with a calcium score above 1000 had a 4.5 times increased risk (95 % CI, 1.7 -11.9) compared to the reference category. In women, the relative risks were 2.3 (95 % CI, 1.0 -5.6) for calcium scores above 500, and 2.8 (95 % CI, 0.9 -8.3) for calcium scores above 1000, compared to the reference category. Conclusion: The amount of coronary calcification detected by electron-beam CT is predictive for all-cause mortality. Methods and materials: 20 consecutive patients (11 men and 9 women; mean age 64 years) with surgically treated mitral valve disease underwent preoperative contrast-enhanced, retrospectively ECG-gated MDCT. Two readers assessed visibility of the mitral valve annulus, mitral valve leaflets, tendinous cords, and papillary muscles using a four-point grading scale. Abnormal findings of the mitral valve, such as thickening of the mitral valve leaflets, presence of mitral annulus calcification (MAC) and calcification of the valvular leaflets, were compared to preoperative echocardiography and intraoperative findings. Results: Visibility of mitral valve annulus and mitral valve leaflets were good or excellent (grade 2 and 3) in 15 patients (75 %), and in 19 patients (95 %) for papillary muscles; visibility of tendinous cords was inferior. MDCT yielded a 95 -100 % agreement with echocardiography and surgery with regard to thickening of mitral valve leaflets and presence of calcification of the mitral valve annulus and mitral valve leaflets. Conclusion: Retrospectively ECG-gated MDCT allows good to excellent visualization of anatomical details of the mitral valve and its apparatus except for tendinous cords, and demonstrates high agreement between echocardiography and surgery with regard to the diagnosis of mitral valve abnormalities. With increasing experience a diagnostic niche may open up for preoperative assessment of mitral valve pathology using MDCT, especially for patients for whom echocardiography is of limited use, e.g., for patients with suspected perivalvular abscess. Conventional parathyroidectomy is a difficult operation and unsuccessful in 5 % to 10 % of cases. To improve the efficacy, preoperative (MIBI) SPECT scintigraphy and intraoperative radio-guided localization of parathyroid adenomas with γ probe and a quick PTH assay were used. Methods: Forty patients with the diagnosis of primery hyperparathyroidism were studied with (MIBI) SPECT scintigraphy. We combined the preoperative administration with the intraoperative γ probe examination to identify the exact localization of parathyroid adenomas. The intact parathyroid hormone was measured by IRMA method (SCHERING CIS bio international). Results: In all cases parathyroidectomy was performed successfully and the preoperative localization was always confirmed. After five minutes parathyroidectomy PTH concentrations decreased more than 55 % compared with the highest preexcision value. At follow-up, serum calcium and PTH levels were normal in all patients.

In hyperparathyroidism, the combined use of preoperative imaging MIBI-SPECT and intraoperative γ probe examinations improved the success rate of parathyroidectomy. The most helpful use of quick PTH in patients is its ability to give the surgeon quantitative assurance that all the hyper functioning parathyroid tissue has been removed.

3D ultrasound technology for the calculation of thyroid volume and the evaluation of benign cystic, nodular disease V. Osti, L. Cova, L. Solbiati, M. Tonolini, D. Della Chiesa; Busto Arsizio/IT Purpose: To assess whether three dimensional sonography (3D-US) can permit reliable and easily calculated volumes of the thyroid and nodules. Methods and materials: 24 patients, aged 33 -67, underwent 3D-US of the thyroid gland. Ten patients had prior hemithyroid resection for multinodular disease and presented with goitre relapse. After examination, all had surgical resection. The surgical specimen volume at pathology was compared with the volumes calculated using 3D-US. The remaining 14 patients had either single or multiple, cystic nodules. Following 3D-US, these nodules underwent percutaneous needle aspiration of the fluid content with measurement of the aspirated volume prior to ethanol injection. US examinations were performed using linear, 10 MHz probes (Voluson 530D and 730D, Kretztechnik, Austria). Volume acquisitions were automatically achieved by transverse scans, with the addition of coronal oscillations of the transducer crystals. Subsequently, both automatic [N = 9] and/or manual [N = 15] 3D reconstructions were performed, including volume calculations, for either the entire gland [N = 10] or the nodules [N = 14] . Results: Comparison between surgical specimen volumes and in-vivo volumes calculated by 3D-US demonstrated a restricted margin of error of 6 % for automatic reconstruction, and 4 % for manual reconstruction. The quantitative assessment of the fluid aspirated from cystic nodules was identical to the 3D-US calculation (margin of error < 1 %). Conclusions: 3D-US allows easy and accurate estimation of the volume of the thyroid gland and of nodular, cystic thyroid lesions. These measurements will undoubtedly provide both surgeons and interventional radiologists additional potentially useful information prior to procedures.

Role of color-Doppler sonography in Graves' disease diagnosis and follow-up after 131 I therapy V. Summaria, A. Costantini, V. Rufini, M. Garganese, G. Maresca, S. Speca; Rome/IT Purpose: To assess the usefulness of CDS in evaluating activity of Graves' disease and the response to 131 I therapy.

Methods and materials: Several CDS patterns: thyroid volume (TV), parenchymal hypoechogenicity (PH), parenchymal vascularity (PV), peak systolic velocity (PSV) in inferior thyroid arteries (ITA), were evaluated in 51 patients with Graves' disease divided in 4 groups: 13 pts at first diagnosis; 12 pts during antithyroid drug treatment; 11 euthyroid pts after withdrawl of therapy; 15 pts who relapsed into hyperthyroidism. All pts in the latter group underwent radioiodine therapy (RT) and CDS was performed 1, 3, 6 months after RT. 13 healthy subject were included as control group. Results: All 40 pts with hyperthyroidism showed an increase of TV, PV and PSV in ITA, compared with patients in remission and with control subjects. In pts within group 2, CDS values were lower, but not significantly different from those in group 1. PH was found in 40/51 pts, without a statistically significant difference between pts with hyperthyroidism and pts in remission. In pts within group 4, a significant decrease (p < 0.1) of TV and PSV mean values in ITA was observed in 11/15; the others pts, with residual signs of hyperthyroidism underwent further RT. Materials and methods: Forty two patients with 57 nodules were prospectively enrolled in this study. The nodules were studied in a transverse plane with conventional high frequency B-mode imaging and with sono-CT (ATL HDI 5000, L12-5 linear probe). The data were transferred on a PC (HDI Lab). After selecting two comparable images in both modes, three parameters of quantification were measured using region of interest: the difference of contrast between the nodule and the adjacent thyroid (dB), the slope of the transition between the nodule and the adjacent tissue (dB/cm). The nodule heterogeneity was evaluated as the standard deviation of the mean signal intensity normalized with the mean signal intensity (linear units).

The contrast between the nodule and the adjacent thyroid was systematically greater with sono-CT (mean 4.3 dB). The transition slope was higher with sono-CT. The average difference between the sono-CT slope and the conventional B-mode slope was 5.2 dB/cm. The heterogeneity index was superior in 83 % of cases with this modality. However, sono-CT imaging exhibited a blurring artifact when the probe was moved too fast, despite the use of a unique focal zone. Conclusion: The objective evaluation using appropriate quantification technique showed a significant improvement in the visibility of thyroid nodules with both sono-CT when compared to conventional B-mode imaging when the linear probe was moved very slowly. Pre-biopsy investigations included scintigraphy and thyroglobulin levels. Then we examined the US characteristics of the nodule (low reflectivity, irregular margins, thick-irregular halo, intranodular blood flow pattern, hypervascularity, invasion of vessels and adjacent structures, vessel encasement). In 25 patients the nodule was solitary and not palpable and in 20 patients the disease was multinodular with a nodule having characteristics suspicious for malignancy. We performed US guided FNA biopsy using 21 G needle. We used negative pressure on the syringe to obtain material through the needle. It is important to allow the pressure to equalize before removing the needle. The cytological specimen obtained was examined by cytopathologist. A post biopsy US was performed to exclude complications.

The following results were obtained: follicular ca (n = 1), papillary ca (n = 1), undiferentiated ca (n = 1), Hashimoto thyroiditis (n = 6), colloid and bening follicular cells (n = 7), blood (n = 5), nodular hyperplasia (n = 22), colloid and activated lymphocytes (n = 1), colloid and histiocytes (n = 1). Conclusion: US guided FNA is safe, fast and low cost method to determine the nature of thyroid nodules and exclude malignancy.

Papillary stenosis: Differential diagnosis with MR-cholangiography using a cholecystokinetic drug M. Di Girolamo 1 , L. Azzarri 2 , R. Di Nardo 1 , C. Rende 1 , G. Brughitta 2 , V. David 1 ; 1 Rome/IT, 2 Grottaferrata/IT Purpose: To differentiate with MR-cholangiography (MRCP) inflammatory papillitis from functional papillary stenosis, using a cholecystokinetic drug. Methods and materials: 17 patients with papillary stenosis diagnosed with ERCP underwent MRCP before and 30 minutes after i.v. injection of Ceruletide (Takus, Farmitalia, Italy) . This drug stimulates the activity of the gallbladder and promotes the relaxation of Oddi's sphincter. MRCP was performed by using 3-D non-breathholding, fat-suppressed Turbo SE sequence (TR: 3000 ms; TE: 700 ms; N.Ex.: 4; ETL: 128; Matrix: 128 × 256; Acq. time: 5 min 12 s) on coronal planes with 0.5 T superconductive magnet (Gyroscan T5 III, Philips Medical System). The 3D coronal images were post-processed with MIP algorithm. Results: In 13 patients MRCP diagnosed fibrotic papillary stenosis while in 4 patients detected functional papillary stenosis that in 3 cases was confirmed by ERCP with manometry. The diagnosis was based on the evaluation of the MBD calibre after drug administration: a partial reduction of the calibre is typical of functional papillary stenosis while the persistence of the same calibre allows the diagnosis of fibrotic papillary stenosis. MRCP could also exclude choledocholithiasis whose clinical symptoms can simulate papillary stenosis. Conclusions: It is possible to differentiate with MRCP between fibrotic and functional papillary stenosis, without performing invasive procedures like ERCP with manometry. This differential diagnosis is very important: in fact, fibrotic stenosis should be treated with sphinterectomy while functional papillary stenosis does not need any particular treatment. Methods and materials: 52 patients (25 women, 27 men) with confirmed PSC were examined with MRI at 1.5 T comprising: T1-weighted spoiled gradient echo (SGE), T2-weighted fat-suppressed turbo spin echo, HASTE, and serial postgadolinium T1-weighted SGE sequences without and with fat-suppression. Two radiologists reviewed retrospectively all images independently and in a consensus reading. The evaluations comprised: the imaging pattern of the liver parenchyma; the presence and grade of intrahepatic biliary ductal dilatation; the presence of areas of parenchymal atrophy or abnormal signal and/or gadolinium enhancement. Results: A "diffuse pattern" of liver cirrhosis was observed in 17 of 52 patients (33 %). A "large macronodular pattern" (regenerative nodules ≥ 3 cm) was observed in 28 of 52 patients (54 %) with nodules showing low signal on T1-and T2-weighted images and low gadolinium enhancement. Intrahepatic biliary ductal dilatation was observed in 44 of 52 patients (85 %) with a "general distribution" in 18 patients (35 %) and a "segmental distribution" in 26 patients (50 %). Peripheral wedgeshaped areas of abnormal parenchyma showing atrophy were observed in 24 patients (46 %) and without atrophy in 18 patients (35 %). The signal intensity on T1-/T2-weighted images was usually low/high. Gadolinium enhancement was typically late in areas with atrophy and early in areas without atrophy. Conclusion: The spectrum of MRI appearances of PSC is diverse and comprises distinct patterns. Large regenerative nodules are a frequent finding and may help to establish the diagnosis. 

For 17 months, 7 patients were diagnosed to have incomplete pancreas divisum on ERCP and six of them underwent MRCP after secretin stimulation. The maximal diameter and length of pancreatic duct (ventral, dorsal, and main duct) and the angle between the main pancreatic duct (MPD) and the communicating channel (CC) were measured on ERCP. Morphologic changes of the pancreatic duct, the presence of santorinicele, the shape of CC, and associated bile duct anomaly were analyzed on ERCP and MRCP. Results: ERCP showed dominant dorsal duct and foreshortened ventral duct with a small communication between the two ducts. The mean caliber of dorsal, ventral, and main duct was 3.8 mm, 4.2 mm, and 4.2 mm, respectively. The angle between the MPD and the CC was acute in 3 patients, right angle in 2, and obtuse in 2. The CC was classified into short (n = 5) and long (n = 2) types. The morphologic features of pancreaticobiliary duct included: santorinicele in 2, beaded appearance of pancreatic duct in 5, pancreaticoliths in 3, and bile duct anomaly in 1. MRCP successfully demonstrated the presence of the CC and associated morphologic features of the pancreaticobiliary duct in all 6 patients. Purpose: Since evaluation of bile ducts in MRCP can be complicated by other fluid filled structures as pancreatic or bile duct cysts superimposing the region of interest and the clinical relevance of a dilated bile duct regarding functional stenosis may be unclear we investigated the hepatobiliary contrast medium Gd-BOPTA as a positive contrast enhancer for intra-and extrahepatic bile ducts in MRI. Material and methods: 34 patients were investigated on a 1.5 T scanner (Magnetom Vision, Siemens, Erlangen) using unenhanced T1 an T2 w breathhold sequences as well as 2D-and 3D-MRCP. To evaluate contrasted biliary structures 60 to 90 min after CM administration (Gd-BOPTA, 0.05 µmol/kg bodyweight) a 3D GRE sequence as well as T1w axial images were applied. Results: In the majority of the patients (28/30) bile duct structures could be delineated by the MRCP sequence. However the identification of the common bile duct in the region of the pancreatic head was not possible in 6 patients. In 7 patients following pancreatitis or cholelithiasis a dilatation of the common bile duct was observed with unclear functional relevance, in 4 patients following resection of the pancreatic head the anastomosis of the common bile duct could not be displayed in detail in MRCP. CE MRCP was able to delineate the bile duct in 8 of the 10 unclear cases, functional relevance of dilatation could be evaluated in 4 of 7 patients. Conclusion: In unclear cases Gd-BOPTA can be helpful for a better delineation and functional evaluation of bile duct structures.

Follow-up of suspected pancreatic intraductal papillary mucinous tumours (IPMT) of collateral branches: Preliminary results G.M. Carbognin, A. Guarise, E. Dalla Chiara, N. Pagnotta, C. Procacci; Verona/IT Purpose: To verify the evolution of suspected collateral branches IPMT assessed as benign at the first imaging control. Methods and materials: 14 patients with a presumptive diagnosis of benign branch duct IPMT formulated by ERCP (#6) and/or MRCP (#10). Diagnosis on the basis of the following criteria: (1) no previous pancreatitis; (2) one/multiple cystic lesion/ s, homogeneous liquid content, thin wall, no parietal proliferation; (3) Maximum diameter of the lesion < 3 cm; (4) Normal main pancreatic duct (MPD). The patients were submitted to MRCP follow-up every 6 months. Two observers reviewed all the MRCP examinations. Results: Mean duration of the follow-up: 10.5 months (range: 3 -28 months). 12/14 (86 %) lesions with the requisite for benignity reported in literature, did not show any morpho-structural modification during the follow-up. In 1 case the lesion manifested rapid growth after 3 months, along with what seemed to be a small parietal nodule. At intervention, it was a retention cyst in a mild focal pancreatitis. In the other case, multiple apparently benign lesions were present, which demonstrated slight growth over 13 months of follow-up. Nevertheless, the patient was submitted to strict MRCP monitoring, since a total pancreasectomy would have been warranted.

Conclusion: Among those considered, lesions of different nature could be present. However, the evolution of all these lesion, when the sign of malignancy are absent, is so slow to justify the follow-up in the elderly, in the presence of high surgical risk or whenever the multiplicity of the lesions would require a largely demolitive intervention. Results: MRT and MRCP were false positive in a patient with a benign stricture due to an inflammatory pseudotumor and false negative in two patients (suspected granulation tissue after prior surgery and contrast enhancement of the wall of the bile duct after interventional therapy). Except for one false negative patient MRCP revealed stenosis of central bile ducts in all patients. In 15 patients a well demarcated mass was seen while 12 patients revealed circumferential tumor spread along the bile ducts. Most lesions appeared hyperintense on T2-weighted images (n = 22) and hypointense on unenhanced T1-weighted images in all cases. Contrast enhancement was either lower (n = 21) or higher (n = 7) than normal liver parenchyma. T2-weighted images and gadolinium-enhanced fat-suppressed T1weighted images showed best lesion conspicuity and tumor margins in 12 and 13 patients respectively. Combined ERCP, US and CT suggested hilar cholangiocarcinoma in 21/28 (75 %) patients.

MRT with MRCP appears to be the most sensitive imaging modality for detection of hilar cholangiocarcinomas and may replace US, CT and ERCP in the evaluation of suspected malignant bile duct obstruction.

Information supported by MRCP: consistency and repeatability T. Gorycki, B. Bobek-Billewicz, M. Studniarek, P. Jagodzinski, K. Grabska; Gdansk/PL Purpose: To compare decisions of radiologists watching MRCP images in order to find the strongest features on MIP reconstructions which characterise biliary strictures. Materials and methods: MRCP MIP reconstructions (0.5 T Gyroscan NT) from 80 cases of biliary stricture had undergone estimation by three independent observers who performed linear measurements on MRCP images concerning morphology of the biliary stricture including stricture length, proximal ductal dillatation and distance from stricture to hepatic ducts junction. Last of the measurements has introduced information about stricture localisation along the biliary tree. Measurements were compared in two stages: between two observers as well as counting their mean values against third observer. The analysis included change, consistency and repeatability values with relative repeatability coefficient (RRC). Results: Repeatability counted with RRC presented values from 3.7 % to 12.12 %, consistency did not exceed 1.52 mm when stricture length or proximal biliary dilatation were measured and 2.5 mm when stricture was localised along biliary duct. Conclusion: MRCP MIP reconstructions are valuable and easily understood images in radiologists' every day practice when morphology and localisation of biliary stricture is discussed. The most reliable conditions seem to be stricture length and stricture localisation.

Assessment of the role of translabial perineal ultrasonography (TPUS) to evaluate urinary stress incontinence in females C. Roy, D. Pfleger sr., E. Castel sr., H. Lang sr., C. Saussine sr.; Strasbourg/FR Purpose: Assess the usefulness of translabial perineal ultrasonography (TPUS) in the evaluation of the two mechanisms (Hypermobility of Bladder Neck and Intrinsic Sphincter Deficiency) of Urinary Stress Incontinence (USI). Method/materials: 52 women (mean age: 58.7) underwent US with translabial perineal approach (7.5 MHz transvaginal probe) located on the perineal floor, behind urethral meatus. Examinations performed in sagittal and coronal, in decubitus and standing positions, at rest, and during pelvic floor contraction and straining. Bladder was filled with 200 -300 ml of urine. Morphology of the bladder neck (funneled) was evaluated to diagnose ISD. To evaluate HBN, position and displacements of bladder neck was evaluated calculating the distance using inferior border of the symphysis pubis as reference according an orthogonal system, in sagittal plane. The diagnosis of HBN was based on a displacement up to 1.5 cm. Correlation was made with clinical evaluation and urodynamic testing results. Results: Among 35 patients with the clinical diagnosis of HBN, TPUS confirmed a displacement and depicted in 8 cases an additional ISD in front of funneling of bladder neck at rest and straining. Among 17 patients with diagnosis of ISD; US confirmed an abnormal bladder neck. An association with bladder neck hypermobility was found in 10 cases of this group. For the diagnosis of cystocele (20 cases), correlations were excellent, but without additional findings for TPUS. Conclusions: TPUS is easy to perform and no time consuming. It provides a perfect assessment of bladder neck during static and dynamic studies. It allows the diagnosis of associated mixed types of USI with a better classification of these disorders.

Dynamic fast MRI of pelvic floor dysfunction in females using a T2-w turbo spin echo technique: Value of knee flexion lateral position in comparison with conventional supine position C. Roy, F. Mayer sr., J. Pfeiffer sr., E. Castel sr., C. Saussine sr.; Strasbourg/FR Purpose: Evaluate organs displacements due to patient position by using a knee flexion lateral versus supine position and its role in the quantification of abnormalities. Materials and method: 55 women symptomatic for pelvic floor descent and 27 asymptomatic were explored with dynamic sagittal MRI (1.0 T) using a T2w TSE sequence (TR/eTE: 13950/100 ms) at rest, pelvic floor contraction, maximal straining and two series: supine and lateral position with knee flexion. Distances from bladder base, cervix and anorectal junction perpendicular to the pubococcygeal line were measured in the sagittal plane. In symptomatic patients, correlations with clinical evaluation and colpocystorectography was performed. Results: At rest and contraction, there was no significant difference. During straining; for asymptomatic patients mean descent differences of bladder base, cervix and anorectal junction between the two positions were 1.5 cm (± 0.5), 1.8 cm (± 1), 2 cm (± 0.9), respectively and for symptomatic patients 4.8 cm (± 1), 4.5 cm (± 0.8) and 6 cm (± 1), respectively. The lateral position revealed 5 rectoceles and 10 additional cystoceles with 4 enteroceles associated to rectal prolapse. The highest displacements in lateral position were better correlated with clinical findings. Conclusion: Dynamic MRI in lateral position is easy to perform, is more reliable to assess pelvic floor prolaps and to detect associated defects of other compartments.

Role of translabial perineal ultrasonography in females after surgical treatment of urinary stress incontinence by tension vaginal tape (TVT): A prospective study C. Roy, D. Pfleger sr., E. Castel sr., H. Lang sr., C. Saussine sr.; Strasbourg/FR Purpose: The efficiency of TVT unknown. To assess the morphologic and dynamic modifications of bladder neck in order to better understanding its action. Method/materials: 41 females (mean age: 58.7) underwent translabial perineal US (7.5 MHz transvaginal probe located on the perineal floor behind urethral meatus) in sagittal, decubitus and standing positions, at rest, during pelvic floor contraction and straining, before and after surgery. Bladder was filled with 200 -300 ml. Position, morphology, and displacements of bladder neck were calculated using inferior border of the symphysis pubis as reference according to an orthogonal system. Correlation was made with clinical findings and urodynamic results. Results: TVT was always perfectly seen as linear hyperechoic structure; against lower third (31), middle lower third junction (8) and upper third (2) of urethra, respectively. Before surgery, 15 cases had funneling of bladder neck in addition to hypermobile bladder base. After surgery, all bladder necks were closed, located at rest above the inferior portion of symphysis. In decubitus position, displacements before and after TVT were 30 -7 mm (m = 18.2 ± 1.2) and 45 -9 mm (m = 20.6 ± 0.5) at pelvic floor contraction and straining respectively. In standing position, they were 10 -5 mm (m = 7.2 ± 0.7) and 18 -3 mm (m = 8.2 ± 0.6) respectively. Among 5 cases of dysuria, TVT was located against the middle (3) or upper part (2) with angulation. Conclusions: TVT procedure limit excessive movement of bladder neck. It must be located against the lower third of urethra. US examination is reliable to detect malpositions. 

In 20 patients with symptomatic uterine fibroids ceMRA (Symphony-Siemens; 1.5 T) of the pelvic and uterine vessels combined with conventional MR imaging was performed. We used a breath-hold 3D FLASH ceMRA (TR/TE 3.6/1.3, FA 25°) and injected gadolinium (0.1 mmol/kg b.w.) at a rate of 3.0 ml/s. Clinical value of the arterial and venous ceMRA for the planning of the UAE was evaluated. After the MR-imaging biphasic UAE was performed. The selective and superselective DSA sequences were compared with a vessel by vessel technique with the ceMRA. Results: All ceMRA were technically successful and all topographically relevant segmental/subsegmental arteries could be evaluated. The common iliac, external iliac, internal iliac and uterine artery could be identified in all cases. The vascular 3D information of MRA provides additional information for the planning of the intervention and the superselective catheter placement. The arterial ceMRA phase allowed an exact demarcation of the hypervascular fibroids in 19 patients, thus defining the primary access site for the intervention. The venous phase did not provide an additional diagnostic information. The time for the interventions and the radiation could be reduced by using the diagnostic information of ceMRA in 18 of the patients.

CeMRA combined with MRI of the pelvis appears to be an important diagnostic tool for analysing the volume and location of the fibriod and planning of the vascular access.

withdrawn by author B-0117 11:25 Clinical stage I carcinoma of the uterine cervix: Value of preoperative MR imaging in assessing parametrial invasion S. Sironi; Milan/IT Purpose: The purpose of this prospective study was to assess the efficacy of different MR imaging techniques in the evaluation of parametrial tumour invasion in patients with early stage cervical cancer. Methods and materials: 73 consecutive patients, clinically considered to have stage 1B tumour (confined to the cervix), underwent MR imaging studies at 1 T, according to the following protocol: fast spin-echo (FSE) T2-weighted, gadoliniumenhanced SE Tl-weighted, and fat-suppressed gadolinium-enhanced SE Tlweighted sequences. Images obtained with each sequence were evaluated for parametrial invasion with the use of histopathological findings as the standard of reference.

Results: In the assessment of tumour infiltration into the parametrium, with FSE T2-weighted images accuracy was 83 %, with SE Tl-weighted gadolinium-enhanced images was 65 %, and with SE Tl-weighted gadolinium-enhanced fat-suppressed images was 72 %. The difference between the accuracy rate achieved with FSE T2-weighted images, and those obtained with the other two MR sequences was statistically significant (P < 0.05). The high negative predictive value (95 %) for the exclusion of parametrial tumour invasion was the principal contributor to the staging accuracy obtained with FSE T2-weighted imaging. Conclusion: Unenhanced FSE T2-weighted imaging is a reliable method in determining the degree of tumour invasion in patients with early stage cervical cancer. Our data suggest that contrast-enhanced sequences, even with the use of fat suppression technique, have a limited value in the assessment of tumour extension. Methods and materials: MRI of the pelvis was performed 24 h after i.v infusion of USPIO (2.6 mg Fe/kg b.w.) in 9 patients (mean age 48 years) with gynecologic tumours (6 cervical, 2 endometrial carcinomas, 1 malignant mixed mullerian tumour) who were scheduled for surgery. Axial T1w SE, T2w FSE (FatSat), FSPGR, sagittal and oblique T2w FSE sequences were acquired on a 1.5 T system. Next to the primary tumour, lymph nodes were staged prospectively using newly established criteria and results correlated with histology. Results: MRI correctly diagnosed the primary tumour as stage I in 7 cases and stage II in 1 case respectively. In 1 case preoperative diagnosis of stage IV led to a change in the therapeutic approach and chemotherapy was given. In this case, multiple malignant iliac nodes were demonstrated. No surgical proof was available. 58/62 of the lymph nodes detected on MRI, in which a histological correlation was available, were correctly staged (accuracy 94 %). 1 node was false positive; 3 micrometastasis < 5 mm were missed. Conclusion: According to our preliminary results, USPIO-enhanced MRI of the pelvis has the potential to become an important tool for preoperative assessment of uterine tumours.

The prognostic significance of high-resolution CT morphology compared to a histological diagnosis in usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia ( In idiopathic pulmonary fibrosis (IPF) both histological and CT features are known to predict outcome. The aim of this study was to compare the prognostic significance of the histological diagnosis (UIP vs NSIP) and CT findings. Materials and methods: 53 biopsy proven cases of UIP and NSIP were diagnosed by consensus by two histopathologists. The HRCTs were scored semiquantitatively by 4 observers with regard to the proportion of ground glass opacity to reticulation (1 = predominantly ground glass, 2 = mixed ground glass and reticulation, 3 = predominantly reticulation). In addition the exact proportion of ground glass opacity was recorded. Results: 32/53 cases were classified as UIP and of the 21/53 classified as NSIP 5/21 were cellular and 16/21 fibrotic. At follow up (median 33 months) there were 22/53 deaths. Both an increasing extent of ground glass opacity and a lower semiquantitative CT score were associated with a better outcome (p = 0.02, p = 0.01 respectively). The histological diagnosis of NSIP was also associated with lower mortality (p = 0.05). On bivariate analysis HRCT provided the more powerful prognostic information. Conclusion: In terms of prognosis HRCT features in IPF provide much information with little added value from the histological diagnosis.

Correlation between histologic features and CT morphology in idiopathic pulmonary fibrosis (IPF) S.M. Ellis 1 , S.R. Desai 1 , D.M. Hansell 1 , A.G. Nicholson 1 , T.V. Colby 2 , R.M. du Bois 1 , A.U. Wells 1 ; 1 London/GB, 2 Scottsdale, AZ/US Purpose: There is increasing evidence that the profusion of fibroblastic foci seen at histology in IPF is predictive of mortality. The aim was to determine whether high-resolution CT appearances correlate with prognostically important histological features.

The HRCT scans of 34 histologically confirmed cases of IPF were scored by two observers according to the proportion of macro (≥ 4 mm) and microcystic (< 4 mm) honeycombing, fine reticulation and ground glass opacity. Their relationships to histological scores of fibroblastic foci and macrophages were examined.

Results: There was a positive correlation between the proportion of combined HRCT score of macro and microcystic honeycombing and the number of fibroblastic foci on histology (p = 0.04). A further positive correlation was found between the extent of ground glass opacity and the macrophage score (p < 0.01). There was no correlation between any histological feature and the extent of fine reticulation on HRCT.

Purpose: To describe the radiological (thin section CT) findings correlated to activity and remission in ANCA associated pulmonary-renal small vessel vasculitis (SVV) Material and methods: We used retrospective analysis of 37 CTs, 27 in disease activity (8 first manifestations, 19 relapses) 10 im remission of 17 patients with pulmorenal syndrome (9 Wegener, 4 microscopic polyangiitis-MPA, 3 Churg-Strauss-syndrome, 1 idiopathic crescentic glomerulonephritis following the Chapel Hill classification) 7 women, 10 men, median 65.5 years (34 -84). The diagnosis was established by clinical presentation (cough, dyspnoea, hemoptysis and/or fever associated with significant hematuria or progressive renal failure), ANCA titers (11 c-ANCA, 5 p-ANCA, 1 ANCA negative) and renal biopsy in all patients. Results: Pulmonary involvement defined by pathological CT occured in all patients. Nodules with (n = 4) or without (n = 2) cavitation, ground glass opacity (n = 5), air space consolidation with (n = 6) or without (n = 9) cavitation and interstitial septal thickening (n = 4) were detected. Local interstitial infiltration and nodules in WGs, diffuse interstitial alveolar infiltration in MPA and CSS, neither lower versus upper lungfield involvement nor side preverence were evident. Radiological course of pulmonary involvement was the best indicator for therapeutic success after immunosuppression, occured earlier compared to renal symptoms and was a stronger indicator in first manifestations then in relapses for disease activity. Conclusion: Thin section CT as the most sensitive radiological examination detects and classifies efficiently the extent of pulmonary involvement of SVV, most likely air space consolidation and ground glass opacity, it proves to be the most efficient therapeutic monitor indicating remission.

Traction bronchioloectasis on HRCT in simple pneumoconiosis D. Ryu; Kangnung/KR Objective: Traction bronchioloectasis and focal pericicatrical emphysema in p type pneumoconiosis have been well known in pathologic report. However, traction bronchioloectasis, earlier finding of p type pneumoconiosis has not been yet radiologically reported. Therefore, we describe traction bronchioloectasis on HRCT in p type pneumoconiosis and assess its incidence among small rounded opacities (p, q, r).

We retrospectively analyzed the HRCT scans of 11 patients that showed small rounded opacity less than 1 centimeter. The study group had a history of occupational exposure to dust and was comprised of all men, 47 -67 years old (mean age 60). Type p, q, r rounded opacity consisted of 5, 2, 4 patients respectively. Two radiologists assessed with consensus whether traction bronchioloectasis was present or not, and its incidence at three levels (aortic arch, carina, and between carina and diaphragm). The degree of traction bronchioloectasis was classified as follows: Score 1: 1 -5 traction bronchioloectasis were visible at each scan level; Score 2: 5 -10 traction bronchioloectasis; Score 3: Over 10 traction bronchioloectasis. The total score was the sum of three level score. Result: All patients showed traction bronchioloectasis. The degree of traction bronchioloectasis decreased with increase of nodule size; p type 6.8; q type 4; r type 2.3. Conclusion: Traction bronchioloectasis is an early finding of pneumoconiosis with centrilobular dot or branching structure on HRCT. Such findings could be helpful to differentiate pneumoconiosis from other diseases showing centrilobular nodule.

Viewing efficiency of soft-copy reading of high-resolution CT of the lungs S.M. Ellis, X. Hu, L. Dempere-Marco, G.-Z. Yang, D.M. Hansell; London/GB Purpose: Soft-copy CT reading is increasingly common and offers the radiologist a choice of many viewing formats. Using eye-tracking data we have assessed the efficiency of reading high-resolution CT of the lungs comparing two fundamentally different viewing formats.

The eye movements of 2 experienced radiologists viewing HRCT's demonstrating diffuse lung disease (n = 6), airways disease (n = 6) or normal appearances (n = 4) displayed on a single monitor were recorded. The time taken to view each case, the number and duration of fixation points, the number of movements between sections and the proportion of these leading to fixation were calculated. The viewing formats used were 4 sections displayed simultaneously (2 × 2) and single sections displayed at full screen size (stack mode). Sections in both formats were viewable by sequential scrolling. Results: The number, duration of fixation points, and the number of movements between sections were greater in the 2 × 2 mode (p = 0.03, p = 0.05 and p < 0.001 respectively. However, the proportion of movements between sections leading to a fixation point was greater in stack mode (p < 0.001). There was no significant difference in the overall time taken on each case.

The viewing efficiency of soft copy reading of lung HRCT is greater with sections presented in a 2 × 2 format compared to a stack mode, despite the tendency towards non-fixation movement between sections in the 2 × 2 format. The group of most severe cases (parasitemia > 5 %, presence of complication) included 53 pts (19 %). Radiographic pulmonary examination was performed in 200 pts. Results: Pulmonary radiographic changes were founded in 23 pts (43 %) with severe malaria. 21 pts (91 %) had solitary or multiple pulmonary infiltration. One patient had hospital acquired pulmonary infection during artificial ventilation, while noncardiac pulmonary oedema with fatal outcome was noted in one patient. The therapy in this group of patients was based on quinine/arthemeter parentally. In 40 pts (81 %) tetracycline, erythromycin or clindamycin was added as second antimalarial drug. All pts who suffered from pulmonary complications received also various antibiotics parenteral (ampicilin/ceftriaxon/cefotaxim/imipenem, ciprofloxacin, aminoglycoside, vankomcin) according to severity of pulmonary changes, bacteriological findings (blood, sputum) and up to date therapetutical recommendations. Conclusion: Severe malaria is often connected with pulmonary manifestations, which implies prolonged course of healing and even fatal outcome (noncardiac pulmonary oedema).

The value of post-contrast FLAIR in the detection of brain metastasis A. Patsalides, J.A. Butman, N. Patronas; Bethesda, MD/US In this study we assessed the value of post-contrast FLAIR in the detection of brain metastasis. Brain MRI studies were performed in 160 patients with melanoma and renal cell carcinoma. Fluid attenuation inversion recovery (FLAIR) and T1-weighted (T1-W) scans were obtained before and after contrast administration in each patient. Each of these techniques was evaluated blindly by two radiologists who diagnosed the presence of metastatic tumors by consensus agreement. Follow up studies were available in patients with positive studies and the temporal changes of the lesions were used to confirm the diagnosis.

cases. At one month the mean serum creatinine level had decreased from 359 ± 138 mmol/l to 298 ± 87 mmol/l, blood pressure was reduced in all the patients from 160/82 ± 24/14 mmHg to 145/80 ± 16/10 mmHg and drug therapy was reduced from 3.3 ± 1.3 drugs to 2.4 ± 1.5 drugs. Results were maintained at 3 months.

Conclusions: In cases of renal impairment, renal PTRA/S using gadolinium chelates as radiographic contrast agents can be performed using standard digital subtraction angiography (DSA) equipment. Gd-DOTA (0.3 mmol/kg) can be administered intra-arterially without any effect on renal function up to a total volume of 45 ml.

Carotid artery stent implantation with cerebral protection: Multicenter experience of 320 procedures F. Castriota 1 , B. Reimers 2 , N. Corvaja 3 , R. Manetti 1 , C. Cernetti 2 , C. Di Mario 3 , P. Pascotto 2 , A. Cremonesi 1 , A. Colombo 3 ; 1 Cotignola/IT, 2 Mirano/IT, 3 Milan/IT Background: Distal embolization of debris during percutaneous carotid artery stenting may result in neurological deficit. Methods/results: 320 consecutive procedures (308 patients) of elective carotid stent implantation with cerebral protection performed in 3 different centers were included in a prospective registry. Cerebral protection was performed using filter devices (80.6 % of procedures), occlusive distal balloons (17.2 %), and endoluminal clamping of the common and external carotid artery (2.2 %). All lesions were > 70 % diameter stenoses (mean 82 ± 8 %). Mean age of the patients was 67 ± 11 years, 83 % were males, and 58.7 % of patients had had a previous stroke or transient ischemic attack. In 313 procedures (97.8 %) it was possible to position a protection device. In 9 of 55 procedures using distal balloon protection, this was not tolerated by the patient (2.8 %). In 317 procedures (99.1 %) a stent was successfully placed. Neurological complications during the procedure, in-hospital and during 30 days of follow-up, occurred in 6 patients (1.9 %). These were 1 major stroke (0.3 %; amaurosis of ipsilateral eye), 3 minor strokes (0.9 %), and 2 transient ischemic attacks (0.6 %). Protection device related complications, all without neurological symptoms, occurred in 8 procedures (2.4 %). These were 7 distal dissections (3 required additional stents and 1 lead to occlusion of the internal carotid artery) and 1 filter entrapment requiring surgical removal. Major adverse cardiac events during the 30 days of follow-up occurred in 2 patients (0.6 %). Conclusions: Routine use of cerebral protection during carotid artery stenting appears feasible. In this study the incidence of neurological complications was low.

Fresh DWI lesions after stenting of the internal carotid artery V. Moeller; Homburg a. d. Saar/DE Purpose: Our aim was to reveal the number of thrombembotic events after stenting of the carotid artery. Methods: 38 patients underwent stenting of the carotid artery. Afterwards patients were neurologically examined and underwent MR imaging. Stenting was performed without protective devices. Systemic anticoagulation was started three days in advance. In 10 cases predilatation of the stenotic vessel was performed.

Results: 40 stents were succesfully placed. 4 patients developed neurological deficits, 1 had a minor stroke, 3 a transient ischemic attack. Retrospectively anticoagulation was found to be insufficient in one of these cases. 3 months after the intervention none of the patients had developed neurological deficits. Diffusion weighted MR imaging detected fresh lesions in 16 patients. The medium degree of stenosis was 88.2 %, this being significantly higher than the 82.7 % among those without new lesions on DWI. Furthermore the mean age of the first group was

Thromboembolic events -a challenge in interventional neuroradiology I.Q. Grunwald, V. Möller, W. Reith; Homburg a. d. Saar/DE Purpose: Thromboembolic events are the most frequent complication in the endovascular treatment of intracranial aneurysms with GDCs. At the moment diffusion-weighted imaging is the most sensitive method for their early detection.

Our aim was to evaluate the number of ischemic events by using diffusion-weighted MRI.

Method: Before and within 48 hours of endovascular treatment with GDCs 13 patients with 15 asymptomatic aneurysms were studied with diffusion-weighted images. During positioning of the coils and for another 2 days the patients were heparinised. A neurological examination took place before and after coiling as well as on discharge.

Results: Occlusion of the aneurysm was achieved in all cases. DWI showed small, fresh hyperintense areas in 6 cases. They were all located in the vascular territory of the aneurysm and have to be seen as intervention-related. None of the patients had clinical symptoms. Occurance of thromboembolic events did not correlate with the number of coils used. Conclusion: Regarding the frequency of thromboembolic events, even though they are mostly silent, DWI monitoring should follow intervention. We assume that the thrombembolic lesions are due to embolic fragments that migrate from the aneurysm as well as due to ischemic events of other origin (vasospasm, arteriosclerosis). Therefore we think that in the endovascular treatment of asymptomatic aneurysms systemic anticoagulation should be performed. Purpose: For most of the pregnant women who underwent an obstetric flow study using color doppler imaging, we calculated low velocity values from the foetal middle cerebral artery in comparison to literature. The aim of this study was two-fold: to define the normal flow values of the foetal and maternal arterial systems and to compare the results with the literature. Methods and materials: 124 healthy pregnant women of various gestational age who underwent a color doppler examination were studied after having an uncomplicated pregnancy and labour. Pulsatility index (PI), resistance index (RI), peak systolic/end diastolic ratio (S/D ratio) values were calculated for the foetal aorta (fA), foetal middle cerebral artery (fMCA), umblical artery on the maternal (mUA) and foetal (fUA) side and the maternal uterine artery (UTA). The results were compared with the published literature. Results: 20 to forty week pregnancies were divided into 10 different groups, each group represented a period of 2 weeks of gestational age. For each group, the studied parameters were defined and presented in a diagram. Flowmetric values are helpful in defining the existing or potential abnormalities in the foetus. The published literature was used to compare patient flowmetric study results. In our study, we found significant differences for fMCA and UA values compared with the published data. To study the relationship of uterine artery impedance measured as pulsatility index (PI) and resistance index (RI) on the outcome of in vitro fertilization -embryo transfer cycles. Methods: 55 women in the age group between 25 -42 a were studied on the day of embryo transfer by performing tranvaginal color Doppler sonography. Uterine artery pulsatiliy index, resistance index and endometrial thickness were calculated. Subsequently pregnancy rates were calculated. Results: The pregnancy rate was 35 % in patients with a pulsatility index 2.45 ± 0.54 and resistance index 0.85 ± 0.04. In patients with a pulsatility index higher than 3.00 and resistance index higher than 0.91 the pregnancy rate decreased significantly to 15 %. Purpose: In addition to histologic evaluation of the effect of antiangiogenic treatment with anti-VEGF receptor antibodies, a functional investigation of tumour vascularisation was performed using contrast enhanced, intermittent power doppler sonography in tumour bearing nude mice.

Methods and materials: 10 thymus-aplastic nude mice with HaCaT-ras-tumours were examined weekly for 4 weeks after i.v.-bolus injection of Levovist with intermittent power doppler sonography. This further developed method allowed statements about the quantification of blood flow and volume by varying the time delay between doppler imaging sequences to be made. Besides other vascularisation parameters like time of arrival, slope of the curve, maximum and plateau phase of the colour pixel density (PCD) and mean colour value were measured. Five mice were treated with a VEGF-receptor antibody during the examination period. Results: While without contrast agent nearly no blood flow was visible, the tumours showed clearly visible enhancment of doppler signal after injection of Levovist. Tumours without therapy showed an increase in PCD signals during the tumourgrowing phase. Mice with antiangiogenic treatment showed a signal decrease in the first monitoring examination, even in growing tumours. There was a limitation of doppler signals to the periphery of the HaCaT-ras-tumours whilst untreated tumours showed a homogenous enhancement except in necrotic areas that were found in later phases. Conclusion: Contrast enhanced sonography enables vascularisation measurements of HaCaT-ras-tumours and the monitoring of antiangiogenic therapy. Therapeutic effects could be visualized before a macroscopic change of tumour size was observed. Furthermore intermittent doppler sonography enables objective perfusion parameters in ultrasound. 

We prospectively examined the VA origin with CDS using a 4 -8 MHz endovaginal transducer in 244 VAs in 122 consecutive subjects referred for evaluation of carotid and vertebral arteries. We also evaluated VA origins of the same subjects using a 5 -8 linear transducer and compared the visualization rates of both transducers. The criteria for visualization of VA origin was identification of origin of an artery arising from the subclavian artery and entering the transverse foramen at the C6 level. Angle-corrected peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) were determined. Angiography was available for comparison in 40 VAs of 20 subjects. Results: Two aplastic right VAs of 2 subjects were excluded. The VA origin was visualized in 241 (99.6 %) of 242 VAs (120 right and 121 left VAs) with the endovaginal transducer and 161 (66.5 %) of 242 VAs (97 right and 64 left VAs) with the linear transducer. PSV, EDV, and RI of 241 VAs were 61.9 ± 29.6 cm/s, 15.3 ± 9.9 cm/s, and 0.75 ± 0.08 (mean ± SD), respectively. Angiography revealed stenosis (> 50 %) of the VA origin in 2 VAs (PSV > 150 cm/s at CDS) and normal patency in 38 VAs. In the only one of 242 VAs missed at CDS with the endovaginal transducer, the VA was shown to arise directly from the aorta at angiography. Conclusion: CDS with an endovaginal transducer was a very useful and efficient method to visualize the VA origin.

Doppler sonography of sympathetic vasomotor response in patients with diabetic foot syndrome A. Hlawatsch 1 , J. Bauer 1 , V. Kuhl 1 , S. Mink 2 , M. Eicke 1 ; 1 Mainz/DE, 2 Heilbronn/DE Purpose: Neurophysiological assessment of the peripheral autonomic system is limited. Continuous wave doppler sonography of the radial artery can be used to measure the sympathetic vasomotor response (SVR).

We studied 25 patients (mean age 63 a) with diabetic foot syndrome. The data from 4 MHz CW doppler sonography before and after sympathetic stimulation by coughing (leading to a temporary disappearance of diastolic flow) were compared with normal controls. Correlation was made with nerve conduction studies and the extent of radiologically visible media sclerosis.

Results: Under baseline conditions, the mean flow velocity was similar in diabetics and controls, but the resistance index (RI) was significantly higher in diabetics (1.1 vs. 0.8). After coughing no significant difference in the RI or the duration of the response was noticed between patients and controls, but the onset of the response was significantly delayed in the study group (2.1 vs. 1.5 s). No correlation was found with nerve conduction studies and radiologic results. Conclusion: Radial artery SVR is an independent and sensitive marker for autonomic function.

14:00 -15:30 Room I Interventional Radiology

Liver tumor ablation -Metastases Purpose: To evaluate in vitro and in vivo the use of MR-guided interstitial thermotherapy with RFITT in bipolar technique and to compare electrodes with active and non-active tips. Material and methods: A newly designed internally cooled RF probe (∅ 3 mm) was used. Both electrodes were 18 mm in length, the inserted insulator between both electrodes was 8 mm in length. For cooling, distilled water was used at flow rates between 40 and 130 ml/min and the power was between 40 and 70 W. Three patients with a liver metastases were treated under local anesthesia. In vitro studies were done to compare electrodes with an active tip with electrodes with a nonactive tip. During MR measurements the RF generator was switched off. Results: MRI allowed a reliable visualization of the electrodes and the insulator in between. The experiments documented that a RF power of 40 W with an irrigation rate of 40 ml/min results in the largest possible area of coagulative necrosis with a diameter of 34 mm × 46 mm. The treatment of the patients was performed without any complications. The advantage of the active tip is that subcapsular lesions can also be treated using this bipolar RF technique with the active tip as the distal electrode. Conclusion: MR-guided RFITT using a internally cooled, irrigated bipolar RF electrode results in a coagulative necrosis which is comparable to those of MR-guided laser induced thermotherapy (LITT) . With the active tip as the distal electrode subcapsular lesions can also be treated with the bipolar system. To determine the value of multiplanar and 3D post-processing techniques for guidance of the ablative probe to an optimal position before radiofrequency treatment of liver lesions. Methods and materials: 21 patients with malignant hepatic tumors (HCC n = 6, Metastases n = 15) underwent radiofrequency ablation. Following conventional CTguided (Siemens Volume Zoom©, Biopsy Mode) positioning of the ablative device, its position was re-evaluated using multiplanar (MPR) and volume rendering 3Dreformations. The position of the ablative device was characterized qualitatively based on the following scale: Central -probe is localized within the central 20 % of the tumor; marginal -probe is lateralized towards the periphery of the tumor; outside -probe-position outside of the tumor. Suboptimal positioning was corrected following initial ablative therapy to assure complete ablation of the tumor and imaging was repeated. Results: Multiplanar and 3D renderings proved superior over imaging in the axial plane in determining the position of an ablative device within liver tumors (p = 0.008). In 9 out of 21 patients the probe position was considered to be central on axial images whereas multiplanar and 3D renderings only revealed marginal probe localisation. Axial, multiplanar and 3D renderings yielded identical results in the remaining 12 patients. Comparing multiplanar and 3D reformative techniques, no significant difference was shown in determining the ablative device position. Conclusion: MPR and 3D renderings aid in optimising the probe position for ablative therapy in a substantial number of patients. As a correct probe position is crucial for the success of an ablation procedure, these viewing techniques should be implemented without delay.

Clinical diagnosis was always underestimated at initial presentation. Imaging modalities were requested for cerebral ischemic attack (2/3), cephalalgia, photophobia and tinnitus (1/3). Initial imaging diagnosis was delayed (> 3 days) in all cases, as patients were referred for brain evaluation and carotid artery disease. Follow up clinical and imaging examination demonstrated: a death (N = 1) serious brain damage (N = 1), complete recovery after antiobiotherapy and anticoagulotherapy (N = 1). Conclusion: Delayed diagnosis of septic thrombosis of the lateral sinus is probably related to its non-specific clinical symptoms. Therefore, in patients with an history of diabetes immunodepression or of infection of the face or of the temporal bone, a careful examination of the skull base should be performed to determine the permability of the brain venous sinuses, the status of the mastoid cell pneumatization of the temporal and occipital bones and the normality of the related fatty spaces. Objective: Conventional or digital 2D dacrocystography and CT dacocystography is usually carried out after the catheterization of a lacrimal canaliculus. We tried to evaluate the quality of opacification on CT scans after simple instillation of contrast medium, without any catheterization. Patients and methods: 39 patients (78 nasolacrimal ducts) were explored for lacrimal pathways obstruction by CT scans after instillation of diluted water soluble contrast medium instillation. A complementary CT acquisition after catheterization was performed when the first ones did not show any opacification. Results: CT dacrocystography after instillation is a well tolerated and safe technique. In our study, it allowed detection all pathologic lacrimal canals; 7 normal lacrimal pathways (after catheterization) were not opacified after instillation (false positives). The sensitivity of the method was 100 %, its specificity 84 %. Conclusion: CT dacrocystography after ocular instillation is an easy, physiologic and sensitive method to evaluate lacrimal obstruction. We propose it as the first step test, the catheterization being used only when there is total absence of opacification after instillation. Results: Inflamatory causes are responsIble of lacrimal duct obstruction. We found no post-traumatic lesions, dacryolithiasis or nasolacrimal neoplasms. DCG evaluated lacrimal ducts and the nasal meatus. DCT was performed only in patients with simple intubation or endoscopic dacryocystorinostomy to exclude all postsurgical complications of the surrounding nasolacrimal duct tissues or an inflammatory process of paranasal sinuses. Discussion and conclusion: DCG and DCT have almost the same sensitivity and specificity in a morphological study of nasolacrimal ducts. Crystallin dosage is 0.04 to 0.2 mSv in DCG and 1.8 to 2.6 mSv in DCT. DCT with 3D reconstruction gives good spatial and anatomic details (orbital, etmoidal and nasal bone). DCG is always the gold standard in the imaging of the lacrimal ducts, but we propose DCT to check possible post-surgical complications. Purpose: POAG is an ocular disease based on a progressive optic neuropathy, visual-field defects and elevated intraocular pressure. Our purpose was to compare with Color Doppler the blood flow of the main orbital arteries of normal, atherosclerotic and glaucomatous subjects. Methods and materials: We evaluated with Color Doppler (ATL HDI 5000) the blood flow of Ophthalmic Artery (OA), Central Retinal Artery (CRA), nasal and temporal Short Posterior Ciliary Artery (SPCA). Peak systolic velocity, end diastolic velocity and Resistive Index (RI) of each artery were considered. We examined 3 group of patients: 30 normal subjects (group A), 30 patients (> 50 years) with positive risk factors for atherosclerosis (smoking, hypertension) (group B) and 30 patients affected by POAG (group C). Inclusion criteria in group C were: IOP > 21 mmHg, visus > 5/10, pseudoexfoliatio presence. Results: All the arteries of group B showed higher RI than group A, with low end diastolic velocities. SPCA (0.87 ± 3.3) and CRA (0.85 ± 2.6) of group C showed significantly higher RI than group A, but no significant RI differences were found in OA of group C (0.76 ± 4.2) and group A (0.77 ± 2.7). Conclusion: Normal, atherosclerotic and glaucomatous subjects can be distinguished by Color Doppler evaluation of the blood flow of the main orbital arteries. Orbital Color Doppler can be useful in the diagnosis of POAG and in the monitoring of these patients.

Which parameter should be used for rapid assessment of extraocular muscle enlargement in patients with Graves' ophthalmopathy? Z. Szücs-Farkas, J. Toth, L. Galuska, E. Balazs, E.V. Nagy; Debrecen/HU Purpose: To find the most accurate, easy-to-measure parameter that can be used as a substitute for extraocular muscle volume assessment in patients with Graves' ophthalmopathy. Subjects and methods: 70 orbits of 35 patients were examined in a conventional 1 T MR scanner and the rectus muscles evaluated. The diameter at the largest extent of the muscle belly, as well as the long and the short diameters and the cross sectional areas in a preselected coronal scan were measured for each muscle and compared with the corresponding muscle volume measured on contiguous T1w transverse slices. Results: The measured coronal area correlated well with the volume of the superior (r = 0.694) and inferior (r = 0.783) recti. The largest transverse diameter showed strong correlation with the volume of the lateral (r = 0.868) and medial (r = 0.869) recti. For the latter muscle, the coronal area also exhibited a high correlation with the volume (r = 0.838). Coronal cross-sectional areas can be well estimated by measuring both the short and long coronal muscle diameters (r values were between 0.914 and 0.966). p was less than 0.0001 for every above mentioned correlations. Conclusions: In Graves' ophthalmopathy, the volume of three of the rectus muscles seems to be well estimated by measuring their cross sectional area on a single coronal slice, while the largest transverse diameter of the lateral rectus is suitable for the same purpose. Purpose: A prospective study was performed to determine the accuracy of unenhanced, enhanced and early delayed (15') enhanced CT densitometry in differentiating adenomas from non adenomas and to evaluate the usefulness of absolute and relative percentage of washout. Methods and materials: 37 oncology patients with 44 undetermined adrenal masses were all studied by unenhanced, enhanced and 15 minutes delayed enhanced helical CT scans. Attenuation values of all adrenal masses on each type of scan was measured by mean of a region of interest and then used to calculate absolute and relative percentage wash-out. Proof of diagnosis was CT and/or MR follow-up (6 -36 months) in 31 patients; percutaneous CT guided biopsy in 5 patients; surgery in 1 patient. Results: On unenhanced CT scans, with attenuation threshold of 18 HU, specificity and sensitivity for the diagnosis of adenoma were 100 % and 93 % respectively. On 15 minutes delayed CT scans, with an attenuation threshold of 38 HU, specificity and sensitivity for the diagnosis of adenoma were 100 % and 90 % respectively. Moreover, all adrenal masses were correctly characterised as benign or malignant on delayed scans with a relative percentage washout of 35 % and an absolute percentage washout threshold of 50 %. Conclusion: Unenhanced and early delayed enhanced CT attenuation values can characterise an adrenal mass as a benign adenoma with high specificity and acceptable sensitivity. The percentage change in washout of contrast media can be a useful adjunct to absolute CT attenuation values in differentiation of adrenal adenomas and nonadenomas.

CT adrenocortical carcinomas and pheochromocytomas: Assessment of wash-out at delayed contrast-enhanced P.I. Reittner 1 , M. Korobkin 2 , P. Wehrschütz 1 , K.W. Preidler 1 , D.H. Szolar 1 ; 1 Graz/AT, 2 Ann Arbor, MI/US Purpose: To measure the changes in washout of contrast material on contrast medium-enhanced computed tomographic (CT) scans in patients with adrenocortical carcinomas and pheochromocytomas. Materials and methods: Fifteen patients with proven adrenocortical carcinomas and 17 patients with pheochromocytomas underwent helical CT. Unenhanced CT was followed by enhanced CT at 60 seconds and 10 minutes. 121 adrenal masses (74 adenomas and 47 metastases, respectively) in 108 patients served as reference data. Results: The adrenocortical carcinomas and pheochromocytomas enhanced significantly lesser than the adenomas at 60 seconds (P < 0.001). At 10 minutes, both the absolute and relative percentage loss of enhancement were significantly greater for the adenomas than for the adrenocortical carcinomas and pheochromocytomas (P < 0.001), respectively. Delayed-enhanced CT at 10 minutes (sensitivity, 92 %; specificity, 95 %) was more accurate for differentiation of adenomas and adrenocortical carcinomas and pheochromocytomas than unenhanced CT (sensitivity, 82 %; specificity, 95 %) Conclusion: Adrenocortical carcinomas and pheochromocytomas exhibit similar wash-out than do adrenal metastases, but significantly lesser than do adrenal adenomas. The percentage change in washout of contrast material is a useful adjunct to absolute CT attenuation values in differentiation of adrenal adenomas and adrenocortical carcinomas and pheochromocytomas.

Incidence of malignancy in complex cystic renal masses (Bosniak category III): Should biopsy precede surgery? M.G. Harisinghani, K. Jhaveri, D.A. Gervais, P.F. Hahn, J. Varghese, P.R. Mueller; Boston, MA/US Purpose: We sought to determine the incidence of malignancy and to assess a possible role for image guided biopsy of this category of renal masses Materials & methods: Of the 397 renal biopsies performed at our institution between 1991 and 2000; a total of 28 patients with 28 category III lesions, were identified for analysis. There were 18 men and 10 women with age range from 40 to 70. The incidence of malignancy, based on surgical pathology or imaging follow up, and percentage of lesions proceeding to surgery, among these 28 lesions, was determined. The surgical results were correlated to the biopsy findings Results: Of the 28 biopsied category III lesions, 17 were malignant (16 renal cell carcinoma, 1 lymphoma) and 11 were benign (4 hemorrhagic cyst, 1 oncocytoma, 3 inflammatory cysts, 2 adenomas, 1 focal glomerulosclerosis). Seventeen of the 28 (60.7 %) lesions (16 renal cell carcinoma, 1 inflammatory cyst) had surgical resection following the biopsy. All lesions proceeding to surgery had pathological diagnosis identical to the pecutaneous image guided biopsy results. Non-surgical patients had radiological follow up for minimum 1 year Conclusion: The incidence of malignancy in Bosniak category III is 60.7 % (95 % confidence interval). Presurgical renal biopsy and radiological follow up is useful in identifying non-malignant lesions in this category, thus avoiding unnecessary surgery in up to 39 % of patients Method and materials: Prospective analysis of 25 patients with histopathologicaly proved RCC included enhanced MDCT studies in arterial and corticomedullary phase (detector configuration: 4 × 1 mm, RT 0.5). We compared 3 reconstruction protocols (slice width/reconstruction interval: 1.25/0.7 mm, 3/1.5 mm, 5/2.5 mm). In addition, multiplanar reconstructions (MPR) in 5, 3 and 1.25 mm coronal planes were assessed. Finally, low-dose CT urography (delay 10 min) with MPR reconstructions was performed in the excretory phase. Image data of all reconstructions were analysed for the size of the lesion, TNM staging, morphological, and enhancement characteristics by two radiologists. Histopathological data were used to determine the efficacy of the different CT reconstruction protocols. Results: Different reconstruction protocols (5, 3 and 1.25 mm) have no influence on the evaluation of tumour size and T-staging. However, assessment of lymph node size was improved in 12 % of the patients by using thinner slice width and 1.25 mm MPR reconstruction. Vertical tumour size and V. cava infiltration was more precisely assessed by evaluation of MPR-than axial reconstructions. In all patients CT-urography demonstrated sufficient opacification of the collecting system. Conclusion: Axial reconstruction protocols are equally suited for the T-staging of RCC. A MDCT protocol using additionally 1.25 mm MPR reconstructions and lowdose CT urography appears effective as a "one-stop" protocol for a proper staging of RCC and eliminates further investigations such as IV urography.

B-0178 14:40 0.59 (95 % CI: 0.22 -0.95) for the N-stage. The average tumour size was 5.2 cm. All accessory arteries and veins were correctly described. The renal pelvis was opacified in 94 %, the proximal ureter in 89 %, and the distal ureter in 77 %. Distant metastases were found in 2 cases and 3 patients showed tumour extending into the renal vein. Conclusion: Isotropic multislice CT of the kidneys with a modified injection protocol provides good correlation with pathological tumour stage, allowing CTA and CT-urography calculation from the same dataset and, thus, may represent a universal imaging technique in renal cancer staging.

Histopathological correlated, staging of renal carcinomas by multislice CT and high performance MRI P.J. Hallscheidt, S.O. Schoenberg, G. Riedasch; Heidelberg/DE Aim: To evaluate the accuracy of multislice-computed tomography (CT) and magnetic resonance imaging (MRI) in staging renal carcinoma and planning of nephron sparing surgery. Material and methods: In a prospective study 58 renal carcinomas were preoperatively examined for tumour staging by multislice CT and MR imaging and correlated with histopathological staging. Triphasic CT imaging was performed with a Siemens Volume Zoom with a reconstructed slice thickness of 1 mm. 3D and coronal reconstructions were used to improve planning of the surgery. In MR imaging (Siemens Vision) additional to the transversal T1-weighted GE sequence with and without GDTPA, and a transversal T2 weighted respiration triggered TSE, a coronal T1-weighted GE sequence with GDTPA and fat saturation were acquired. In addition a multi phase 3D angio after GDTPA injection was performed.

Results: In early stage renal carcinoma CT and MR imaging provide similar staging accuracies. In all cases multi slice CT allowed us to identify all renal masses, especially in multifocal renal cell carcinomas. Accessory arteries could be identified in all cases, too. Multiphase MRI allows detection and differentiation of renal masses, especially in caval infiltration. Conclusion: Multislice CT and 3D reconstruction integrate essential information from angiography, venography, urography and 2D CT in a single imaging modality.

In Multislice CT all tumours in multifocal renal cell carcinoma were detected. In advanced renal carcinoma MRI was superior to CT imaging, especially in diagnosing tumour thrombus. Consequently the extent of tumour thrombus may be assessed by MRI which therefore may replace conventional cavography.

Small renal masses: Value of contrast-enhanced colour Doppler imaging A. Klauser, G. Janetschek, G. Helweg, R. Peschel, L. Pallwein, D. zur Nedden, F. Frauscher; Innsbruck/AT Purpose: We assessed the value of a microbubble based ultrasound (US) contrast agent for blood vessel enhancement in colour Doppler imaging (CDI) of small renal masses. Methods and materials: 51 patients with "indeterminate" small renal masses (< 3 cm in diameter) underwent prospective CDI before and after intravenous administration of the contrast agent Levovist® (Schering AG, Berlin, Germany). The degree of tumour vascularity was subjectively graded from 0 to IV (indicating an increasing vessel count) and the peak systolic velocity (PSV) was measured. CDI findings were compared with those obtained at histopathological examination. Results: Intra-and/or peri-tumour vessels were detected in 26 lesions (51 %) by unenhanced CDI and in 48 lesions (94 %) by enhanced CDI. The detection of vascularity was increased by contrast administration (p = 0.006, McNemar test). Higher grades of tumour vascularity (grade III and IV) were found more often in malignant renal masses (p < 0.01). PSVs higher than 80 cm/s were found only in malignant lesions. Based upon receiver operating characteristic analysis, enhanced CDI (Az = 0.789) is more accurate than unenhanced CDI (Az = 0.576) for differentiating benign from malignant renal masses (p < 0.004). Conclusions: Enhanced CDI is superior to unenhanced CDI in the detection of tumour vascularity, and in the discrimination between benign and malignant small renal masses.

Assessment of renal masses with contrast enhanced sonography using pulse inversion imaging and FSO69 J.-M. Correas 1 , M. Claudon 2 , A. Lesavre 1 , A. Méjean 1 , L. Bridal 1 , O. Hélénon 1 ; 1 Paris/FR, 2 Nancy/FR Purpose: To evaluate the efficacy of contrast-enhanced sonography of renal masses using a FSO69 (Optison®, Mallinckrodt, USA), with quantification of the signal intensity. Materials and methods: 24 renal masses were studied with pulse inversion imaging (PII) at baseline and following a bolus injection of FSO69 (1, 2, 3 and 4 ml, randomised dose, 6 patients per dosage group, ATL HDI5000, C5-2 probe). Cineloops were transferred to a PC for quantification with HDI Lab. The cortical and solid mass enhancement was calculated as the difference between the signal intensity of a region of interest located upon the normal cortex and the mass before and after injection (dB). The final diagnosis was obtained by CT, MRI and/or surgery (adenocarcinomas 16, complex cysts 5; hamartomas 3). Results: Cortical enhancement was correlated with the dose (r = 0.98) and was consistently greater when the mechanical index was lower than 0.4. The detection of normal and atypical cysts was improved and was correlated with CT and MRI features. Renal mass delineation was improved except when the enhanced mass signals matched with the normal surrounding cortex (2 cases). The visibility of the necrosis within the lesion was comparable to the CT and MR appearance. The peak enhancement was: 9.6 dB ± 4.0 dB for the cancers, 5.8 dB ± 3.5 dB for the hamartomas and 0.8 dB ± 0.5 dB for the complex renal cysts. Conclusion: PII of renal masses following FSO69 injection improved the detection and the characterization of renal masses, particularly in small tumours and complex cysts. Purpose: Combined inhibition of the synthesis of nitric oxide and prostacycline predisposes rats to renal injury from radiographic contrast media (RCM). The reliability of these pharmacological manipulations was investigated. Methods and materials: Adult male SD rats were injected with L-NAME (10 mg/kg), indomethacin (10 mg/kg) and RCM (or normal saline) 15 minutes apart. Serum creatinine (Cr) was measured prior to and post these pharmacological insults.

Results: A significant increase in serum Cr (from 54.66 ± 8.39 to 171.96 ± 24.49 µmol/l and from 80.95 ± 6.73 to 204.76 ± 16.73 µmol/l, n = 5/group) was observed 24 hours after injection of 6 ml and 8 ml of high osmolar RCM diatrizoate respectively. The increase in serum Cr recovered spontaneously 7 days after the injection. No significant change in renal function was observed in the control group receiving 8 ml/kg of normal saline (n = 5) or after injection of 4 ml of diatrizoate (n = 5). The increase in serum Cr observed with 6 ml of diatrizoate was significantly higher (p < 0.01) in comparison to the rise induced by equivolume of the low osmolar iopromide (serum Cr was 68.47 ± 8.39 µmol/l pre contrast and 143.59 ± 32.03 µmol/l 24 hours post contrast, n = 5). The calcium channel blocker diltiazem (10 mg/kg i.p., 30 min prior to contrast injection) prevented the rise in serum Cr observed with 6 ml of diatrizoate. The protective effect was less with lower doses of diltiazem. Conclusion: The used animal model is reliable and capable of reproducing previously established observations. The protective effect of a calcium channel blocker has also been shown. Purpose: Aim of the study was to evaluate the efficacy of gadobutrol as contrast agent for diagnostic chest and abdominal CT compared to iodinated contrast media in a porcine animal model. Methods: In 7 pigs spiral CTs of the chest and abdomen were performed using 2 ml/kg BW gadobutrol (Gadovist, Schering, Germany) given by single intravenous injection (Siemens Somatom Plus 4; slice: 5 mm, table feed: 7.5 mm, reconstruction increment: 5 mm). One week later the same animals were examined under the same protocol using iopromide (Ultravist 300; Schering, Germany; 2 ml/kg BW). In 3 additional animals serial CTs were performed using gadobutrol on day 1 and iopromide on day 7 to detect contrast media kinetics, peak enhancement and time enhancement-product in important vascular regions and parenchymal organs. Peak enhancement (net increase compared with native baselines) were measured in Houndsfield units (HU) in defined Regions of interest. Additionally, diagnostic quality and accuracy of the CTs were evaluated on a two-step scale by three independent blinded investigators. Results: In vivo, the mean peak enhancement 0, 5, 10, 30, 60 and 120 seconds in the abdominal aorta after injection of 2 ml/kg BW gadobutrol and iopromide was 40, 200, 224, 261, 118, 95 HU and 41, 232, 298, 152, 143 , 123 HU respectively. All CTs using gadobutrol were classified as diagnostic with excellent differentiation of vascular and parenchymal structures. Conclusion: Computed tomography with 1 mol gadobutrol resulted in an excellent contrast peak enhancement. Computed tomography using gadobutrol is feasible and a possible alternative to iodinated contrast material.

Use of artificial neural networks in predicting adverse drug reactions in patients receiving contrast media E. Grossi 1 , M. Buscema 2 , A. Seeberg 3 ; 1 Milan/IT, 2 Rome/IT, 3 Constance/IT Neural Networks (ANNs) are mathematical algorithms tools are able to determine the existence of subtle correlations between series of data and a particular outcome, and once "trained", can predict output data on the basis of the input data. Although neural networks have been applied in various areas of medical research, they have not been previously applied to the prediction of adverse events to contrast media. Materials and methods: ANNs (provided by Semeion Research Centre, Rome, Italy) were used to predict adverse events occurring in over 600 patients receiving Iomeprol 300 (300 mg I/ml) within a large observational clinical study performed by Bracco-Byk Gulden in 6 German radiological centres. The database consisted of 76 independent variables obtained from the case report forms. During an optimising process based either on linearity criteria or specific evolutionary algorithms, just 9 independent variables resulted as best predictors of the prognostic target. The sample size was divided into two random subsamples: the training one (the only one containing the dependent variable) and the testing one.

In the testing phase The overall prediction accuracy ranged from 91.6 to 95.6 %. These values were reproducible along ten consecutive experiments with independent networks of the same type trained in different random subsamples.

These results indicate that neural-network analysis can be used to predict adverse effects of contrast media within a given class.

MR imaging of atherosclerotic plaque with new ultrasmall particles of iron oxide (7228) compared to Sinerem® in hyperlipidemic rabbits C.U. Herborn 1 , T.C. Lauenstein 1 , F.M. Vogt 1 , C. Corot 2 , J.F. Debatin 1 , S.G. Rühm 1 ; 1 Essen/DE, 2 Aulnay-sous-Bois/FR Purpose: To evaluate a new USPIO compound 7228, compared to Sinerem® (both Guerbet, France) as a marker of macrophage activity in atherosclerotic plaques. Materials and methods: Experiments were conducted on 4 heritable hyperlipidemic rabbits aged 4 -6 months. Imaging was performed on a whole body scanner using the transmit/receive head coil. After initial 3D MR angiography of the thoracic aorta with conventional paramagnetic contrast agent (Gd-DOTA), animals were injected once with either 7228 (n = 2) or Sinerem® (n = 2) at equal doses. 3D MR angiography was repeated daily over 5 days. On day 6 the rabbits were euthanized for histopathologic evaluation of the aorta. Results: 3D MRAs with Gd-DOTA revealed no abnormal findings in any of the animals (n = 4). Luminal signal intensity at different days was comparable between both compounds with no significant differences regarding the time-evolution of T2* effects. Susceptibility effects within the aortic wall became evident on day 2 in both groups reaching the maximum after 4 days. These changes were more pronounced in the 7228 group without amounting to a statistical significance. Histopathology proved slightly increased Fe uptake in macrophages of atherosclerotic plaques of the two rabbits injected with 7228 compared to those who received Sinerem®. Conclusion: Both USPIO agents cause susceptibility effects within atherosclerotic plaques detectable by 3D GRE sequences. Since phagocytosis of 7228 seems to be superior to Sinerem® it can be assumed that lower doses of this compound are suited to allow better visualization of active plaque in atherosclerotic disease.

A.R. Rudisch 1 , C. Kremser 1 , W. Judmaier 1 , H. Zunterer 1 , J. Griebel 2 , A. De Vries 1 , W.R. Jaschke 1 ; 1 Innsbruck/AT, 2 Neuherberg/DE Aim: This study aimed to compare perfusion-index-values (Pi) of Gadolinum-DTPA (Gd-DTPA) obtained in malignant tumors with Pi's of normal tissue (muscle). Material and method: Perfusion data were obtained in histological proven primary rectal carcinoma and in left sided gluteus maximus muscles (N = 23). Perfusion data were obtained by Magnetic Resonance Imaging (MRI) measurements using a specially ultrafast T1-mapping sequence in a 1.5 T whole body scanner. T1-maps were acquired in intervals of 14 s or 120 s before, during and after constant rate infusion of Gd-DTPA. In order to investigate the relevance of spatial heterogeneities of microcirculation in tumors and muscles, relative frequency distributions of Pi's were computed with equal class intervals of 0.021 ml/min/g.

Not only the mean Pi but also the relative fraction of Pi £ 0.126 ml/min/g between tumor tissue (0.093 ml/min/g ± 0.021; 89.1 %; ±12.1) and muscle tissue (0.037 ml/min/g ± 0.012; 99.8 %; ±0.6) was statistically significantly different (both p < 0.001, Mann-Whitney-U-Test). Discussion: Our results cAN offer additional information about higher nurtrients supply, e.g. chemotherapeutic agents, to tumor tissue than to muscle tissue caused by high Pi's and a higher relative fraction of high intratumoral Pi's. The presentation was supported in part by grants from Schering, Germany and Austria.

Can necrosis avid-MR-imaging with metalloporphyrins differentiate between stunned and infarcted myocardium: Results of an experimental study in dogs P. Reimer 1 , J. Bankert 1 , C. Bremer 2 , K.-U. Jürgens 2 , T. Filler 2 , T. Weber 2 , B. Tombach 2 ; 1 Karlsruhe/DE, 2 Münster/DE Purpose: To investigate whether stunned myocardium may be differentiated from infarcted myocardium by metalloporphyrin-enhanced-MRI. Materials and methods: 10 open-chest anesthetized dogs underwent reversible (15 min; n = 5) and permanent (n = 5) pneumatic occlusion of the left anterior artery (LAD) to induce myocardial stunning and myocardial infarction, respectively. MRI was performed at 1.5 T obtaining ECG-triggered short and long axis T1-w TSE at baseline and every 30 min following injection of Gadophrin-2 (50 µmol/kg bw) up to 6 hours. Postmortem, needle biopsies were taken from the LAD-perfused and a remote area. Ex vivo, MRI (T1-w TSE) and TTC staining were performed.

Results: Gadophrin-2 enhancement was slightly higher in stunned myocardium than in remote regions but significantly higher than in infarcted areas when measured in the long axis. All regions showed highest signal intensity 30 min following injection followed by a decrease over time.

Conclusion: Gadophrin-2 enhanced MRI may serve as an additional tool besides functional measurements such as tagging or perfusion to differentiate stunned from infarcted myocardium.

Assessment of angiogenic tumor burden by susceptibility MRI using long circulating iron oxide nanoparticles C. Bremer 1 , M. Mustafa 1 , A. Bogdanov jr. 2 , V. Ntziachristos 2 , A. Petrovsky 2 , R. Weissleder 2 ; 1 Münster/DE, 2 Boston, MA/US Purpose: To evaluate iron-oxide enhanced MRI for the assessment of the angiogenic burden of various tumors Methods and materials: A variety of tumors (9L-gliosarcoma, DU4475-breast cancer, HT1080-fibrosarcoma and EOMA-hemangioendothelioma) with various angiogenic potential were implanted into nude mice. Tumors were imaged at 1.5 T using a PD-w GE sequence before and after i.v. injection of magnetic iron oxides nanoparticles (MION). ∆-R2* maps were calculated for all tumors and the relative tumoral blood volume was determined by ROI-analysis. Tumors were stained for CD31 for quantification of the microvessel density (MVD). Moreover, VEGF expression was analyzed for each cell line by Western Blotting and ELISA. A subset of animals was injected with a Tc-labeld intravascular tracer for measuring the blood volume distribution in vivo.

Results: Blood volume maps generated by MRI revealed a significantly higher tumoral blood for EOMA-(6.6 ± 0.9 %) and HT1080-(5.5 ± 0.8 %) compared to DU4475-(3.1 ± 0.4 %) and 9L-tumors (2.1 ± 0.3 %). MVD correlated well with the MR-data with EOMA-and HT1080-tumors revealing a higher MVD (150 ± 13 and 81 ± 5 counts per field) compared to DU4475-and 9L-tumors (43 ± 3 and 39 ± 2 counts per field). Moreover, MRI data closely correlated with Tc-blood volume maps and the VEGF expression patterns Conclusions: MRI with long circulating iron oxides can be utilized to assess tumoral angiogenesis. Since iron oxide based particles are widely available, this technique can be readily adapted for clinical use. 1999) . A 3-month clinical follow-up was obtained in all patients who were not anticoagulated. Results: For a longer mean z-axis coverage (Group 1: 152 mm; Group 2: 110 mm; p < 0.001), the mean duration of data acquisition was shorter with MSCT (Group 1: 17 s; Group 2: 21 s; p < 0.0001). Examinations devoid of respiratory and cardiac motion artifacts were more frequent in Group 1 than in Group 2 (p < 0.001). In the absence of significant difference in the quality of vascular enhancement, the porportion of examinations interpretable down to the subsegmental arteries was higher in Group 1 (57.5 %) than in Group 2 (13 %) (p < 0.0001). The benefits of MSCT were more marked for patients with underlying respiratory disease and did not lead to a higher detection rate of peripheral PE. The negative predictive value of SSCT and MSCT were 100 % and 99 %. Conclusions: Improvement in image quality on MSCT scans accounts for the improved diagnostic accuracy of SCTA, especially for patients with impaired respiratory function.

Incidental detection of pulmonary emboli on routine multislice CT of the chest C. Ciccotosto, M.L. Storto, F. Guido, A. Di Credico, A. Guidotti, L. Bonomo; Chieti/IT Purpose: To determine the prevalence of pulmonary embolism (PE) incidentally detected on routine multislice CT (MSCT) scans of the chest and to assess the influence of window width and level on PE detection. Methods and materials: Between January 1 and August 31, 2001, 542 routine contrast-enhanced CT scans of the chest were performed in 485 patients using a MSCT scanner (4 × 1 mm or 4 × 2.5 mm collimation; 5 mm slice width). CT angiographic studies performed for suspected PE or evaluation of the thoracic aorta were excluded. CT scans were retrospectively reviewed by 2 chest radiologists for the presence and site of pulmonary emboli using a cine-view mode on a dedicated workstation and 2 different widow settings: W = 400 HU, L = 40 HU (standard) and W = 600 -700 HU, L = 100 -150 HU (wide). Results: Unsuspected PE was present in 21/485 (4.3 %) patients, with an inpatient prevalence of 4.7 % (18/386) and outpatient prevalence of 3 % (3/99). Most patients (15/21; 71.4 %) with unsuspected PE had cancer. The proximal extent of PE involved the main pulmonary artery in 5 patients, a lobar artery in 10, a segmental or subsegmental artery in 6. Use of a wide window setting allowed detection of PE in 2 more patients than did the standard one.

Unsuspected PE was found in as many as 4.3 % of patients undergoing a routine study of the chest with MSCT, with a higher prevalence among patients with malignancy. The use of a wide window setting is recommended when interpreting routine MSCT of the chest in order to improve unsuspected PE detection.

Low kVp settings improve contrast enhancement and reduce radiation exposure in spiral CT of pulmonary emboli C. Weidekamm, M. Prokop, C.J. Herold; Vienna/AT Purpose: Higher contrast of iodinated contrast material at low kVp settings may be used to compensate for increased image noise at lower exposure dose. We evaluated this concept for spiral CT of patients with suspected acute pulmonary embolism.

We compared a standard protocol using 140 kVp, 175 mAs (CTDI vol = 12.4 mGy) to a protocol using 100 kVp and 125 mAs (CTDI vol = 3.8 mGy). We evaluated two groups of 25 consecutive patients, for whom identical scan parameters (3 mm collimation, 5 mm feed, 2 mm increment) and contrast injection protocols were used (140 ml, 3 ml/s, 20 s start delay). We measured the enhancement of the pulmonary artery in an ROI at the level of the pulmonary trunk. For the enhancement of small arteries, we measured the maximum CT number in peripheral pulmonary arteries at the level of the aortic arch and at the lung bases. We determined the percentage of segmental and subsegmental arteries with sufficient quality for PE evaluation. To test the influence of observer experience on the accuracy of CT venography (CTV) for diagnosis of acute deep thrombosis (DVT) and to identify potential sources of misinterpretation. Methods and materials: 64 patients with clinical suspect of pulmonary embolism (PE) underwent combined CT pulmonary angiography and CTV, using a multislice CT scanner. CTV was performed in the caudo-cranial direction, 3 minutes after administration of 140 ml of contrast material (300 mg I/ml). Scan parameters were: 4 × 2.5 mm collimation, 5 mm slice width, and 5 mm reconstruction increment. CTVs were analyzed independently and in a blinded fashion for the presence of acute DVT by three readers: (a) an experienced radiologist in body CT, but without experience with CT imaging of PE; (b) a fellow in CT; (c) a third-year resident without any formal experience with CT imaging of PE. CT scans were scored on a 4-point confidence scale and different causes of interpretation errors were analyzed. The gold standard was lower extremity sonography. Results: Interobserver agreement was moderately good (k = 0.60; 95 % confidence interval), whereas interobserver disagreement occurred in 5 (9 %) cases. The two observers with CT experience were more accurate than the less experienced one (p < 0.02) who made a higher number of false-positive diagnoses. The most frequent causes of misinterpretation were chronic thrombosis and arterial thrombosis. No clear differences were found among the 3 readers for the error type. Conclusion: CTV in addition to CTPA is a relatively accurate method for evaluation of DVT. CT diagnosis of acute DVT improves with general CT experience. Conclusions: A pre-therapeutic HR-CT should always be done before medical treatment by epoprostenol. If poorly defined nodular opacities, septal lines, pericardial effusion, pleural effusion, and adenopathies are found, the pre-therapeutic strategy should be discussed again, in order to prevent patients from the risk of a paradoxical aggravation under medical treatment by epoprostenol.

Purpose: Surgical repair of ventral hernias has been changed during the last years. This is due to new biomaterials as expanded polytetrafluoroethylene soft tissue patch (ePTFE), which lets a transabdominal preperitoneal technique. This laparoscopic hernioplasty has a lower morbidity and recurrence rate, whereas it needs an accurate follow-up to assess complications which require readmission.

In this prospective study we considered eight patients who underwent a laparoscopic repair of ventral hernia with an ePTFE mesh between March 2000 and June 2000 at our institution. In all cases CT of the abdomen was performed after 30 days to evaluate the position of the mesh which is visualised as an higher density bandlike structure. Results: In one patient after 30 days ct scan showed a fluid collection; one patient became syntomatic after 50 days and a new CT scan was performed with IV contrast medium which showed an infected fluid collection whith enhancing. Conclusion: CT scan is a useful technique to assess post-operative complication of laparoscopic repair of ventral hernias, such as sieromas, abscess, hematomas, bowel obstructions and recurrences and is a great advantage to an accurate follow-up evaluation. Methods: Patients admitted with acute abdominal pain for which no immediate surgical intervention or CT was indicated, were randomised to "early CT" (within 24 hours of admission) or to follow "standard practice". Diagnoses and confidences (on a 5-point scale) were documented by surgeons on admission and again after 24 hours. The admission, 24 hour, and final diagnoses (established at surgery and/or 6 months follow-up) were assessed by two reviewers for changes (to more serious, or less serious conditions, or "no change"). Results: 55 patients were randomised to "early CT" and 63 to "standard practice". Early CT reduced the length of hospital stay by 1.1 days, but this reduction did not reach statistical significance (p = 0.17). Only 50 % (59/118) of admission diagnoses proved to be correct on follow-up, improving to 75 % (89/118) after 24 hours (both independent of the randomisation arm). Although early CT was not associated with a significant change in diagnostic confidence at 24 hours, comparison with the final diagnosis revealed that early CT missed significantly fewer serious diagnoses (p = 0.006). There were 7 in-patient deaths, all in the "standard practice" arm. Conclusions: CT undertaken early during an admission for acute abdominal pain may have favourable effects on length of hospital stay and mortality, and it is able to identify unforeseen diagnoses and complications, particularly those of a potentially serious nature. Objective: To correlate isolated blunt spleen, and liver injury in children with presence and amount of free-fluid on CT scan. Methods: 134 paediatric patients (range 3 months to 17 years) with isolated solid organ injury (liver or spleen) was confirmed with enhanced CT scan and graded according to the ASST guidelines. The presence, location and amount of free-fluid was recorded. Free-fluid was quantified as 0 = no fluid, 1 = small amount, 2 = moderate, 3 = large for each of the 3 anatomic areas. Results: 134 paediatric patients with an isolated spleen (n = 66) or liver (n = 68) injury from blunt trauma were identified. Free-fluid was noted in 101 injuries overall (75 %), more commonly with spleen (82 %) than liver (69 %) injuries. As injury grade increased, so did the frequency of free-fluid (grade 1 50 % to grade 5 100 %) and the total volume of free-fluid in the three quadrants (grade 1 0.75 to grade 5 5.6). The total volume of free-fluid was greater for splenic injuries (3.1) than liver injuries (1.7). The pelvis was the most common location for free-fluid (liver 53 %, spleen 71 %) and had the greatest mean amount of free-fluid (liver 0.9, spleen 1.5) of the 3 anatomic areas evaluated.

(1) There is a direct correlation between the severity of the isolated injury and the frequency and amount of associated free-fluid.

(2) The pelvis was the most common location to detect free-fluid and had the greatest estimated volume.

Whole body spiral CT in trauma patients -part I: Assessment of cervical, thoracic and abdominal soft tissue and organ injuries T. Albrecht, J. von Schlippenbach, K.-J. Wolf; Berlin/DE Purpose: To assess the accuracy of standardized "whole body" spiral CT in the initial work-up of cervical, thoracic and abdominal soft tissue and organ injuries in trauma patients. Method: 46 patients with potentially life-threatening injuries underwent a spiral CT of the neck (unenhanced; 3/5/3), the chest, abdomen and pelvis (150 ml contrast agent, 5/7.5/5) immediately after resuscitation. The CT findings were compared with the final diagnoses at discharge or death. In 22 patients abdominal sonography and CT were also compared.

The final diagnoses were: cervical haematoma (n = 1), haemothorax (n = 15), pneumothorax (n = 11), pulmonary contusion (n = 12), mediastinal haematoma (n = 4), aortic dissection (n = 1), retroperitoneal haematoma (n = 6), renal haematoma/laceration (n = 4), hepatic haematoma (n = 3), splenic haematoma/rupture (n = 3), mesenteric laceration (n = 1), and isolated intraperitoneal haemorrhage (n = 2). Spiral CT showed all these injuries with the exception of a delayed splenic rupture. In the 22 patients with sonography available, ultrasound missed 2 hepatic, 1 splenic and 1 renal injury. Furthermore sonography produced two false positive findings: 1 haemopericardium and 1 renal contusion. Conclusion: The initial standardized "whole body" CT used provided fast, comprehensive and accurate diagnosis of cervical, thoracic and abdominal soft tissue injuries in trauma patients. It is superior to sonography in assessing abdominal injuries. It should be preferred over a targeted approach with selective CT of certain body areas according to sonography results and the clinical situation since it is time efficient and often reveals unsuspected injuries. Part II: B-0898 (SS 1810a)

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Single-phase helical CT protocol in the evaluation of patients with suspicion of pancreatic carcinoma M. Imbriaco, L. Camera, M. Romano, P. Mainenti, E. Soscia, A. Puzziello, M. Salvatore; Naples/IT Purpose: To evaluate the diagnostic accuracy of single-phase (SP) helical CT in the detection and assessment of resectability of patients with suspicion of pancreatic carcinoma (PC). Methods and materials: 78 (mean age: 62 ± 11 years) patients with a suspicious PC were studied. Unenhanced scan was followed by one set of scans (5 mm beam collimation, 3 mm reconstruction intervals, pitch 1.0, 120 kV, 220 -240 mA) in the caudo-cranial direction, from the inferior hepatic margin to the diaphragm, with a scan delay of 50 s after I.V. contrast administration. Results: A final histopathological diagnosis based on surgical findings was obtained in 57 patients, in the remaining 21 fine needle aspiration biopsy followed by 2 years clinical follow up showed no evidence of malignancy. Final diagnosis was PC in 52 cases and chronic pancreatitis in 26. Of the 52 tumors, 8 patients had surgically resectable disease and 44 were unresectable. SP helical CT showed a diagnostic accuracy for assessment of tumor detection of 93 % with sensitivity and specificity of 94 % and 92 % and positive and negative predictive value of 96 % and 89 %, respectively. The overall accuracy of SP helical CT to determine resectability or unresectability of PC was 92 %. Conclusion: SP helical CT is an effective technique for the detection and assessment of resectability of patients with suspicion of PC. Due to the lower radiation burden and to the lower cost a SP of acquisition in a caudo-cranial fashion might be considered the protocol of choice when evaluating patients with suspicion of PC.

Secretin assisted CT of the pancreas: Is it of benefit for pancreatic tumour staging or diagnosis? S.M. Lyon, T. Fotheringham, P. O'Sullivan, M.F. Given, M.J. Lee; Dublin/IE Purpose: To determine the effect of secretin assisted CT on contrast material delivery to the pancreas. Methods: 31 patients (mean age 70; range 47 -88) were enrolled. Triple phase helical CT of the pancreas was performed on successive days. Unenhanced and enhanced CT in the pancreatic phase and PV phase was performed without (day 1)and with (day 2) secretin (100 IU) given at t = 0 s (n = 10), t = 60 s (n = 5), t = 120 s (n = 5), t = 180 s (n = 4), t = 240 s (n = 4), t = 300 s (n = 3). Percent enhancement of the pancreas and PV system was calculated using ROI's obtained from studies with and without secretin. Two radiologists scored the images using a five point scale for: pancreas/tumour contrast, PV, SMV and duodenal mucosal enhancement. Results: Overall mean pancreatic enhancement was 125 % without secretin and 132 % with secretin. No significant difference in pancreatic enhancement was noted when secretin was given at t = 0, t = 60 s, and t = 300 s. However, significantly increased pancreatic enhancement was noted (secretin vs no secretin) at t = 120 s (12 %), t = 180 s (66 %) and t = 240 s (30 %) (p < 0.05). PV/SMV enhancement was significantly increased in the pancreatic phase in all secretin studies (p < 0.05). Qualitatively scores for pancreas/tumour contrast, PV/SMV and duodenal mucosal enhancement were all increased on secretin studies. Conclusion: Secretin administration increases pancreatic enhancement which aids tumour identification. Early enhancement of duodenal mucosa and PV/SMV is helpful for staging. For optimal results secretin should be given 2 -4 minutes before IV contrast administration. Further patients are being recruited and study completion is estimated for November 2001.

High resolution multislice spiral CT in pancreatic cancer: Preoperative detection and assessment of resectability F. Fraioli, C. Catalano, F. Pediconi, A. Laghi, A. Napoli, S. Vagnarelli, M. Danti, R. Passariello; Rome/IT Purpose: To prospectively evaluate multislice CT (MSCT) in the preoperative diagnosis and assessment of resectability in patients with clinical suspicion of pancreatic carcinoma. Material and methods: 26 patients referred for suspected pancreatic carcinoma underwent MSCT. Immediately prior to the examination, patients were given 300 -500 ml of tap water; i.v. scopolamine (20 mg/ml) was administered to reduce intestinal peristalsis. Unenhanced volume was first acquired, followed by the postcontrast acquisitions, during arterial and portal venous phases. The post-contrast volumes were acquired afeter injection of 140 ml of non ionic c.a. at 4 ml/s. Images were evaluated using a real time interactive 3D approach by two observers, in terms of lesion identification and conspicuity, infiltration of peripancreatic fat, vascular involvement of major peripancreatic arterial and venous vessels, adenopathies and liver metastases. Results: Pancreatic carcinomas were identified in 22 of the 26 referred patients; in 4 cases no abnormalities were detected. Tumors were located in the head in 13 cases, the isthmus in 3 cases and in the tail in 6 cases. Peripancreatic spread was seen in 12 cases. Vascular involvement was identified in 10 cases. Adenopathies were present in 14 cases, while liver metastases in 6 patients. 3D real time interaction with multiplanar reformations appeared particularly useful in the evaluation of vascular involvement and above all in the detection of liver metastases. Conclusion: High resolution MSCT with multiplanar reformations is a very accurate technique in the identification and staging of patients with suspected pancreatic carcinoma. To develop, test, and evaluate an automatic brain contour segmentation technique for multispectral MRI data of the human brain based on radial basis functions (RBF) neural networks. Methods and materials: 17 healthy male volunteers (aged 23 -32 years) were examined employing a standardized MRI sequence protocol (T1w MP-RAGE, T2w/ PDw SE, IR, anatomically correct image registration) on a 1.5 T system. Automatic brain tissue classification was performed by a 3-layer feed-forward RBF neural network: Image data were transformed to a 33-dimensional feature space with 3 spatial and 30 gray level coordinates of each voxel and its neighborhood. For comparison, manual interactive brain contour tracing was performed by two neuroradiologists on each data set. Five data sets served as training data. The procedure was tested on the remaining 12 data sets. Contingency tables were calculated w.r.t. results of human interactive contour tracing and compared to interobserver variability of manual segmentation. Results: Computation time for automatic brain segmentation was 31 ± 2 min on a Sun UltraSparc workstation. MRI acquisition time was 27.5 min for the sequence protocol. Manual processing time for interactive contour tracing of the training data was 110 ± 14 min. The ratio of voxels classified differently in manual and automatic segmentation was 2.5 ± 1.2 %. This is comparable with the interobserver variability for manual brain segmentation (2.4 ± 1.0 %). Conclusion: Automatic tissue classification by RBF neural networks is a powerful method for brain segmentation from extracerebral anatomical structures. Although comparable w.r.t. segmentation quality, the RBF approach is considerably less time-consuming than manual contour tracing by human operators. Purpose: For medical applications in the field of Computer Assisted Surgery it is essential to complement human visual systems. In order to develop new ultrasound based minimally invasive therapy systems in the head and neck region we combine both MR and 3D ultrasound data. Materials and methods: MR and ultrasound datasets from the head and neck region were prealigned manually and filtered using adaptive filtering techniques. The prealigned data were matched for the first time using our biomechanical model based on a linear elasticity model recently developed for nonrigid registration of MR datasets of the brain. In order to reduce the computational effort this model uses as input parameters a sparse deformation field estimated from the images as well as predefined homogeneous tissue parameters. Results: MR acquisition technique leads to rigid nondeformed datasets. Ultrasound techniques offer resolution capacity of higher quality specially for soft tissue diagnostics and therapy. But ultrasound volume datasets show distorted and deformed anatomical structures. In order to prealign the data all images need to be resampled using both global affine transformation and interpolation. After being carefully prealigned an edge enhancement was carried out using adaptive filter techniques. It is shown in some cases of the neck region, that it is possible to match both data types using a linear elasticity model.

The resulting images show clearly that the method can be used with slightly deformed ultrasound data. Up to now the model is limited to high quality image data with a highly optimized data acquisition.

Using MRI and CT data with the NASA virtual GloveboX; a simulation system for life science experiments aboard the ISS S. Wildermuth 1 , J. Smith 2 , C. Bruyns 2 , N. Teodorovic 1 , R. Boyle 2 , P.R. Hilfiker 1 ; 1 Zürich/CH, 2 Moffett Field, CA/US Purpose: The International Space Station will provide an orbiting research facility for addressing fundamental questions on the long-term effects of microgravity on living systems. Many of these life science experiments will require the use of the Space Station Glovebox Facility, a contained reach-in environment where astronauts will handle animals and collect biological samples. To aid in this endeavor, virtual environment technologies are being developed to assist astronauts in training and performing complex experiments in the Space Station Glovebox. This "Virtual GloveboX" (VGX) is designed to integrate ultra-high resolution imaging technology and force-feedback devices with highfidelity graphics and real-time computer simulation engines to provide a realistic immersive environment. Here, we describe the prototype VGX system and its initial simulation environment using CT and MRI datas. Material, methods, and results: The Virtual Glovebox was designed and developed for three main applications: engineering evaluation of operational efficiencies for glovebox equipment, experimental design for on-orbit life animal research and simulation for training astronauts to perform biological experiments in space. Different animal models are built based Multidetector-CT (MDCT) and MRI datasets. We present high resolution MDCT data to reconstruct anatomy of small animals and represent them as deformable objects within a linear mass-spring simulation system.

The VGX combines elements of aerospace flight simulator technologies with new imaging techniques (high resolution CT and MRI datasets) and medical simulation systems to provide a versatile, state-of-the-art virtual environment for training astronauts in biology research tasks.

Development of the function of the high speed virtualized bronchoscopy system and it's medical significance H. Natori 1 , M. Mori 1 , H. Takabatake 1 , K. Mori 2 , J. Toriwaki 2 ; 1 Sapporo/JP, 2 Nagoya/JP Purpose: We previously developed the virtualized bronchoscopy system which enables us to do intrabronchial high speed free navigation with special functions for clinical application and education in the medical school. We report the medical significance of the developed system. Materials and methods: Chest helical CT data were stored with DICOM format. On the ONYX2 (Silicon Graphics Inc), bronchial air space was extracted and three dimensionally reconstructed with surface rendering. This bronchial tree was used

A C D E F 154 as the virtual environment of this system. External view of the bronchial tree with the view point marker and its trace, CT image at the view point, intrabronchial view for navigation were displayed on the CRT. The system had the anatomical database of the bronchial tree for automatic display of the bronchial name and for the bronchial name quiz. The system had interactive artificial cough as a sonic alert against wall irritation by the virtualized bronchoscope. Results: Even faster speed than real bronchoscopy was obtained for navigation conducted by the mouse. The system enables navigation into the peripheral bronchus for example B1bi. Navigation into the peripheral intrabronchial space was possible beyond the narrowing portion. The system displayed proper bronchial names. Its accuracy was dependent on the spatial resolution of thin slice CT data. Conclusion: A high speed virtualized bronchoscopy system with special feature based on the CT data was developed. This system is useful for anatomical education for students, training to get their bronchoscopic skill for residents, and for preliminary examination simulator of real bronchoscopy.

Concept of a CT based orthopaedic simulation enviroment for movement analysis and osteotomy planning T.C. Mamisch 1 , J. Kordelle 2 , P. Everett 3 , M. Das 3 , F.A. Jolesz 3 , R. Kikinis 3 , R.M.M. Seibel 1 ; 1 Mülheim a. d. Ruhr/DE, 2 Gießen/DE, 3 Boston, MA/US Purpose: The goal of the presented study was to investigate the relation between the proximal femur and the orientation of the epiphysis, to determine if the acetabular development is influenced by the femoral neck orientation, and to simulate reorientating osteotomy. Material/methods: Three-dimensional reconstructed models based on CT data sets of 22 patients SCFE were reviewed. Measurement of the hip joint geometry was performed by using a newly developed interactive software to determine projected angles. A phantom scan was performed to validate the accuracy of the tool. A computer program for simulation of movement based on cartilage filtering techniques and osteotomy developed by the authors, served for study execution. Results: We found a significant positive correlation between the femur version and the version of the femoral epiphysis. Furthermore, there was a highly significant positive interdependence between the shaft-neck-angle and the shaft-epiphysis-angle. There was no correlation between the epiphyseal orientation and the anteversion and inclination of the acetabulum. Conclusion: The study of the hip geometry demonstrates a significant correlation between the femoral orientation and the epiphyseal alignment. In response to these results, we suggest that there is an interrelation between the development of the proximal femur and the epiphyseal growth plate, wich influences the planning of reorientating osteotomy Purpose: In addition to tumour size, the therapeutic effect after neo-adjuvant chemotherapy is histopathologically described by regressive changes. The aim of this study was to evaluate whether regressive changes affect the accuracy of preoperative MRI tumour measurement.

In an ongoing study initial and preoperative MRI was performed in 31 patients with advanced breast cancer. Beside T-1w FLASH 3D pre-and post contrast MRI, a fast TurboFLASH sequence was used for the dynamic examination. The time-intensity curves were parameterised by a pharmacokinetic two compartment model and colour-mapped. In consideration of the conventional MRI, tumour diameters were measured using the colour-mapped images and compared with the histologically determined tumour size. Regarding sclerosis, cytopathic effects and invasive residuals the histological regression was classified between 0 and 4. Results: In 12 cases without regressive changes (grade 0), the correlation (Spearman rank test) between MRI and histopathological tumour measurement was 0.88 (p < 0.0002). In 17 patients with regressive changes grade 1 -3 the correlation was 0.48 (p < 0.0538), without any tendency for systematic over-or underestimation (p = 0.32). Compared to tumours without regressive changes, those with grade 1 -3 were associated with a distinct decrease of pharmacokinetic parameters (Amplitude and distribution constant rate) derived from time-intensity curves (p < 0.037 resp. p < 0.034). In two cases without residual tumour (grade 4), a complete response was observed by MRI. Conclusion: Histological regression of breast tumours after neo-adjuvant chemotherapy leads to an inaccuracy of preoperative MRI tumour measurement. In addition to the lost tumour continuity the decrease of contrast uptake complicates the demarcation of residual tumour. (axial T1 3D FFE, axial and sagittal T2*  FFE, axial and sagittal T2 TSE) . Two experienced radiologists analysed the lymph nodes regarding size, morphology, and signal intensity before and after Sinerem®. The results were compared with histopathologic findings. Results: A total of 123 lymph nodes were detected equally by pre and post-Sinerem® MRI. 200 lymph nodes were diagnosed by histology. A node-by-node correlation between MRI findings and histology could be achieved in 93 lymph nodes. 10/93 lymph nodes were true positive, 75/93 true negative, 3/93 false negative, 5/93 false positive. Sinerem®-enhanced MRI revealed a node-by-node sensitivity, specificity, and accuracy of 77 %, 94 %, and 91 %, respectively. However, in the overall lymph node assessment for each patient Sinerem®-enhanced MRI did not miss any lymph node metastases. Conclusion: Sinerem®-enhanced MRI is an accurate method in the assessment of lymph node metastases in patients with breast carcinomas and is superior to plain MRI.

In our institute we performed 297 breast MRI examinations for different clinical queries. We used a 3D-dynamic contrast-enhanced FSPGR sequence and a 1.5 T MR unit. Before the examination patients underwent a careful clinical-anamnestic evaluation; in fertile women MRI was carried out between 7 th and 22 th day of menstrual cycle; previous MRX and/or US examinations were reviewed; patients were recommended for the highest compliance in order to reduce motion and breathing artefacts. Results: Among 106 cases with an histological equivalent we observed 20 false results. The 6 false negative cases were performed before the 10 th day of menstrual cycle (2 in situ carcinomas, 2 small fibroadenomas, 2 sclerotic adenosis). False positive results were 14: 6 due to a hormonal therapy recently suspended or still active, 4 due to the presence of the so-called UBOS (Unidentified Bright Breast Objects), 4 in which examination was performed after the 18 th day of menstrual cycle.

In literature breast MRI diagnostic accuracy varies from 65 and 90 %. This large variability is mostly due to pitfalls in cases selection and examination timing. We recommend an optimal examination timing (10 th -16 th day of the menstrual cycle); a 6 months interval after hormone or radiotherapy. Purpose: This study was designed to investigate the relationship between greater tuberosity irregularities, subacromial space, age and rotator cuff tears in the subacromial impingement syndrome. Methods and materials: Sonographic examination of 67 symtomatic shoulders (age range of patients from 33 to 79 years) were performed. The rotator cuff, greater tuberosities and subacromial space were evaluated. Full and partial thickness rotator cuff were given equal significance. Supraspinatus degeneration was graded according to the Neer classification. The sonographic finding of tears was confirmed surgically. A student's t test, and logistic regression analysis were used to analyze the data. Results: Sonography showed the greater tuberosity to be irregular in 78 % of 47 shoulders with a rotator cuff tear and in 75 % of 20 shoulders with supraspinatus degeneration. The thickness of supraspinatus outlet ranged from 8.5 mm to 2 mm in shoulders with rotator cuff tear and from 9 mm to 3.7 mm in shoulders with supraspinatus degeneration. Subacromial space: with tihckness < 6 mm was found in 70 % of rotator cuff tears and a thickness > 6 mm was found in 60 % with supraspinatus degeneration. Statistical significance was detected (p < 0.001) for the association of greater tuberosity irregularity and rotator cuff tear and for the association of subacromial space thickness < 6 mm and rotator cuff tear. Patients and methods: The study population comprises 109 randomly selected patients suffering from rheumatoid arthritis. A radiograph of the left hand was acquired for each patient and subjected to a new automated method for estimating bone mineral density (BMD) from a plain hand radiograph using the Pronosco X-Posure System™. This system digitizes a radiograph with a scanner and derives subsequently a BMD, a metacarpal index (MCI) and a porosity index (PI) from automated radiogrammetrical measurements of the three middle metacarpal bones. The severity of the decease was graded by two radiologists using the Larsen score. A third radiologist reviewed the incongruent scored cases.

Results: The X-posure system was capable of providing a BMD estimate in all 109 cases. Mean value of BMD decreased from 0.55 ± 0.08 (Score 1)g/cm 2 to 0.44 ± 0.11 (Score 5) g/cm 2 . Mean MCI-values decreased from 0.44 ± 0.08 to 0.33 ± 0.10. No significant change of PI was observed. Correlation of BMD, MCI, PI and severity score was -0.44, p < 0.05; -0.40, p < 0.05 and -0.07, n.s., respectively. Conclusion: The new densitometric system based on radiogrammetry seems to be able to detect differences of bone mineralization depending on the severity of rheumatoid arthritis. With suitable normative data, the new technology may be able to reduce additional radiation exposure in the future, especially in patients receiving a radiograph of the hand for e.g. diagnostic purposes. and normal subjects (n = 48) with equal mean age and sex ratios underwent electron-beam CT of the thoracic spine. Images were acquired using the single slice mode (slice thickness 1.5 mm, scan time 0.1 s, matrix number 512 × 512, field of view 34 cm). For bone density analysis, cortical, transitional, and medullary zones were semi-automatically segmented on four consecutive images of the vertebral bodies. Averaged histograms were acquired according to zones and proportions of five density intervals (A: 55, D: > 130, E: -1024-1024) were measured by custom-made software. Firstly, the feasibility of this method was evaluated by comparing normal and osteoporotic groups. Secondly, verification was performed by measuring the "coefficient of variance". Thirdly, the feasibility was compared with quantitative CT using intervals C and E in medullary zone, since the interval E in medullary zone was used on quantitative CT. Results: In the medullary zone, intervals A-D showed significant differences between osteoporotic and normal subjects, while analysis of whole density measurements (interval E) could not reveal a significant difference between both groups. Intra-and inter-observer errors of intervals C-E were lower than 5 % in all zones.

In the normal subject group, inter-subject variability of interval C was exclusively lower than 5 %. Therefore, interval C in all zones became the region for the histographic bone density analysis method. Conclusion: Bone density analysis using histographic intervals was feasible to diagnose osteoporosis and superior to quantitative CT. Purpose: Micro-CT may offer a worthwhile opportunity to analyse so called patterned injuries in bone. In the field of forensic science, it has not been possible until now to non-destructively document such damages to bone. Materials and methods: Based on a real murder case, porcine pelvic bones were experimentally stabbed with multiple knives. Afterwards these bone samples were examined with a micro-CT system developed at the IMP Erlangen. This cone beam scanner can achieve an isotropic resolution from 10 to 100 µm for sample diameters from 1 to 40 mm. Resolution in the specific bone samples is 30 to 75 µm depending on the sample size. So far analysis has been performed by visual inspection of double oblique slices of the reconstructed volume to optimally display the plane cut by the knife using Impact View (VAMP GmbH, Erlangen, Germany). Additionally the stabbing wounds were quantitatively evaluated by measuring distances and angles. Results: The micro-CT datasets of the injured bone samples were used to obtain those 2D slices that optimally showed the stabbing wounds inside. Based on the measured distances and angles it was easily possible to uniquely identify the size and shape of the injury-causing knife in straight stabs.

In the field of forensic pathology Micro-CT provides a new and advantageous tool for the non-destructive examination and analysis of patterned tool marks in bones. By using the micro-CT technology new horizons are opened for matching a possible injury-causing instrument against the patterned lesion in the bone. 

A bone defect (diameter 6 mm) was generated in the calvaria of 12 adult rats in general anaesthesia. This defect was filled with a threedimensional extracellular matrix gel inoculated with osteoblasts, marked with lipophilic tracer components, latter to proof viability. Implants were covered by Gore-Tex patches. The cells phenotype was determined by antibody staining. MS-CT examinations were performed 24 hours, 2, 4, 6, 8 and 10 weeks after implantation in short anaesthesia using a Siemens Somatom Volume Zoom unit (Siemens, Erlangen, Germany). Acquisition parameters were: collimation 2 × 0.5 mm, tube current 40 to 80 mAs at 80 to 120 kV, reconstructed slice thickness/increment 0.5/ 0.3 mm. Thin sagittal multiplanar reformations (slice thickness 0.5 mm, overlapping 0.5 mm) out of coronar acquisition were performed. The rats were sacrificed, the implants histologically examined, and correlated with CT findings with respect of defect size and ossification. Results: In all cases there was an absolute correlation between CT-findings and histological findings concerning the size of the defect and the presence of mineralised bone matrix. Conclusion: MS-CT is a very sensitive and specific diagnostic tool for this and similar studies. With respect to refinement and reduction of animal experiments following the directive 86/609/EEC of the council of the European Union MS-CT allows tremendous reduction of the number of animals to be sacrificed (in this study two-thirds).

3D-navigation with an infrared-based camera system for biopsies using spiral-CT datasets -initial preclinical results C.R. Krestan, S. Grampp, P.L. Peloschek, M. Pretterklieber, C. Czerny, H. Imhof; Vienna/AT Purpose: To assess the accuracy and feasibility of biopsies with a novel 3D-navigation system (CT-Sightline: Philips Medical System, Best, Netherlands) which is based on spiral-CT datasets. Methods: This navigation system uses an infrared based camera, which can track the biopsy needle and the patient position by infrared light reflected from mounted passive spheres. The spiral CT dataset (Philips, Secura Tomoscan 7000) gained during the procedure can be linked with the position of the instruments and the patient position. We used needle-marked water melons for biopsy purposes. After scanning the object, target and entry point are located by the physician. The accuracy of the simulated biopsies with 14 and 16 G standard coaxial biopsy systems was determined by a target scan. The table position of the target scan and the gantry tilt are given by the navigation system. Results: We performed 18 biopsies (targeting of needle-tip) using water melons. The mean distance between the biopsy needle tip and the target needle tip was 5.3 ± 3.6 mm (range: 0.8 -9.2 mm). The average time for the procedure after set-up of the navigation-system was 15 minutes on average. Conclusions: Our preliminary results suggest that this navigation system allows accurate targeting of biopsy needles at defined regions of interests within a reasonable procedure time. The advantage of this system is the potentially safer and more accurate positioning of the biopsy needle at different targets. Further studies and clinical evaluation will determine the value of this system in performing minimally invasive procedures. To explore the novel application of a methodology known engineering as pq diagrams to characterise the evolution of ischaemic stroke. Methods: Five acute stroke patients were imaged with diffusion tensor imaging (DTI) at presentation, 1 week and 3 months on a 3 T magnet using a previously described DTI data acquisition scheme. Each dataset was then processed on a voxel-by-voxel basis, and each tensor was decomposed on into its p (isotropic) and q (anisotropic) components. When p and q are taken as axes of a Cartesian plane, the evolution of tissue (e.g. due to pathology) can be visualized as characteristic trajectories or signatures in this plane. In this study, p, q, and the standard indexes relative anisotropy (RA) and fractional anisotropy (FA), were computed for the lesion (L) and contralateral control (C) regions, for each patient at each time point. Results: All patients showed the same characteristic trajectories consisting of: an acute (pL < pC, qL < qC), subacute (pL ≈ pC, qL < pC), and chronic (pL > pC, qL < qC) stages. Percentage acute changes in q, RA and FA for the five studies were: ∆q = 51 %, 69 %, 50 %, 51 %, 0 %. ∆RA = 3 %, 44 %, 14 %, −6 %, −110 %. ∆FA = 2 %, 35 %, 14 %, −5 %, −89 %. Conclusion: RA and FA are less sensitive than p and q to detect diffusion changes associated with early ischaemia. In particular, q seems to be the most sensitive parameter to detect early loss of anisotropy in tissue; pq diagrams provide a powerful analytical and visualization tool to investigate the evolution of stroke.

Advances in diffusion imaging using sensitivity encoding (SENSE) R. Bammer 1 , F. Fazekas 2 , M. Auer 2 , S.L. Keeling 2 , M. Augustin 2 , R.W. Prokesch 1 , M.E. Moseley 1 ; 1 Stanford, CA/US, 2 Graz/AT Purpose: Diffusion-weighted single-shot EPI (sshEPI) is currently one of the most important tools for the diagnostic assessment of stroke patients, however it suffers from well known artifacts. SENSitivity Encoding (SENSE) was employed to greatly enhance the quality of diffusion-weighted echo-planar imaging (EPI) in stroke imaging and for diffusion tensor imaging (DTI). Methods and materials: Eight healthy volunteers and a consecutive series of stroke patients (n = 8) were examined with diffusion-weighted SENSE-sshEPI using different reduction factors (1.0 < R < 3.0). Moreover, in eight volunteers the potential of SENSE to improve DTI was investigated. DTI scans were carried out with regular (42 × 128; R = 2.0) and high resolution acquisition matrices (42 × 256; R = 2.0). To further improve the image quality, new reconstruction and co-registration algorithms were applied. Results: Derived maps of the trace of the diffusion tensor and of fractional anisotropy were of high quality. Measured direction-dependent diffusion-coefficients and isotropic diffusion values were comparable to previous findings but showed less fluctuation. Overall, the geometric distortions were substantially removed and the resolution enhancement was remarkable. All patient examinations were diagnostic and of better quality than conventional sshEPI. The efficient use of thrombolysis requires robust algorithms for patient selection in acute stroke. Intracranial vessel status and properties of brain tissue perfusion are predictive of cerebral ischemia. We present first clinical results using a multimodal multislice CT concept. Material and methods: Sixteen patients (age 34 to 90 years) with suspected cerebral ischemia and onset of symptoms within 6 hours (mean 2.6 h) were included in this prospective study. We performed noncontrast CT (NCCT) followed by perfusion CT (PCT) and CT angiography (CTA). At the level of basal ganglia PCT data were acquired using a 4 × 5 mm collimation after injection of 40 ml of CM (flow 8 ml/s). Two consecutive slices of 10 mm slice thickness were reconstructed. Cerebral perfusion maps (CBF, CBV, TTP) were calculated using CTP software. The size of the ultimate cerebral infarction was measured by follow-up CT or MRI. Results: In nine patients significant perfusion deficits were noted in one (n = 1) or both (n = 8) slices. Four patients with normal PCT showed small supra-or infratentorial infarctions outside the section levels. No false-negative PCT results were seen. CTA revealed major vessel occlusion in five patients. NCCT showed early signs of infarction only in three individuals. Conclusion: PCT improves the sensitivity for the detection of cerebral ischemia in the section levels compared to NCCT and can estimate the ultimate size of infarction. CTA might localize the underlying pathomorphology. The presented multimodal CT concept is an accurate and reliable method for the assessment of acute stroke.

The preliminary study of CT perfusion imaging in TIAs K. Li, J. Lu, X. Du; Beijing/CN Purpose: To evaluate the application of CT perfusion imaging on transient ischemic attacks (TIAs). Methods: Conventional CT and CT perfusion imaging were performed on a group of TIAs and control group of normal adults. Cerebral blood flow, cerebral blood volume, and time to peak enhancement were measured within specific regions of the brain on CT perfusion imaging. Quantitative analysis was used for these images and comparative analysis was performed on these two groups to evaluate the differences on perfusion images between TIA patients and control group. Results: A gradient of perfusion between the gray matter and the white matter was shown on the CT perfusion images of normal adults and TIA patients. Persisting abnormal perfusion changes of decreased cerebral blood flow were found on about 86 % CT perfusion images of TIA patients. Abnormalities were detected on time-to-peak images of all TIA patients with diffuse or regional prolonged time to peak enhancement. Conclusions: Perfusion CT can provide valuable hemodynamic information and depict abnormalities of perfusion in the patients with TIAs.

Prognostic value of admission perfusion CT in acute stroke patients: Comparison with admission MR M. Wintermark, J.-P. Thiran, P. Maeder, S. Binaghi, P. Schnyder, R. Meuli; Lausanne/CH Purpose: Comparison between perfusion-CT and DWI-/PWI-MR in acute stroke patients at the time of their emergency evaluation Methods and material: 13 acute stroke patients underwent perfusion-CT and DWI-/PWI-MR on admission. 9 were treated with thrombolytic agents. The size of infarct and ischemic lesion (infarct + penumbra) on the admission perfusion-CT was compared to that of the MR abnormalities on the ADC map and on the relative cerebral blood volume (rCBV), cerebral blood flow (rCBF), time-to-peak (rTTP) and mean transit time (rMTT) maps extracted from PWI studies.

The most significant correlations were found between the infarct size on the admission perfusion-CT and the abnormality size on the admission ADC map (r = 0.971; p < 0.001) and between the size of the ischemic lesion (infarct + penumbra) on the admission perfusion-CT and the abnormality size on the rMTT map calculated from admission PWI-MR (r = 0.930; p < 0.001). Information provided by both imaging techniques about cerebral infarct and total ischemia (infarct + penumbra) are similar, with slopes of 0.910 and 0.925, respectively. Conclusion: Perfusion-CT and DWI-/PWI-MR are equivalent in the identification of cerebral penumbra in acute stroke patients and in their selection for thrombolytic therapy. Perfusion-CT takes advantage from its availability and from its feasibility in acute stroke patients, as part of their admission imaging survey.

A novel CT brain perfusion algorithm for improved measurement of low flow regions: Clinical results A.J. Cook II. 1 , S. Pohlman 2 , S. Lin 2 , P.C. Johnson 2 , A. Cook 1 ; 1 Ravenna, OH/US, 2 Highland Heights, OH/US Purpose: Accurate quantitative measurements of CT perfusion studies will make a significant impact on patient care. Low flow regions, associated with minimal contrast enhancement and poor signal to noise ratios, are susceptible to difficulties using traditional perfusion calculations. We propose a novel signal enhancement algorithm for analysis of low flow regions. Methods: 30 CT brain perfusion cases were acquired. A low flow improvement technique, which works by clustering similar tissue types, was applied to each case. Gray matter and white matter regions were manually segmented. For quantitative measurements, perfusion values and ratios were calculated for each region before and after the low signal correction. For qualitative evaluations, four radiologists reviewed the corrected and uncorrected images.

The corrected images were found to be visually superior to the uncorrected images, particularly in terms of reduced noise and improved distinction between gray and white matter. Perfusion values for the corrected images (gray matter: 75.9 ml/100 g/min, white matter: 29.1 ml/100 g/min) were closer to physiological norms than uncorrected images (gray matter: 84.0 ml/100 g/min, white matter: 46.7 ml/100 g/min). The gray/white matter ratio, typically reported in the literature to be approximately 3:1, improved from 1.9:1 for the uncorrected images to 2.8:1 for the corrected images. Regions with no blood flow, such as the ventricles, were also more accurately depicted on the corrected images. Conclusion: Initial results using our approach for low signal enhancement is very promising and could potentially provide more accurate quantitative measurements using CT perfusion. To evaluate the effect of dose reduction on diagnostic performance, using a digital chest imaging system in which amorphous selenium serves as the X-ray detector. Material and methods: 247 patients were examined with the selenium system. Three sets of images were made in each patient: one set with a standard X-ray dose, one set with 55 % of the standard dose, and one set with 35 % of the standard dose. All 741 images were read by two radiologists. The diagnostic value of each set of images for detection of pulmonary, mediastinal and pleural pathology was analyzed with receiver operating characteristic (ROC) methodology, using computed tomography (CT) as the reference standard. We also assessed the effect of the sex, height and weight of the patients on the diagnostic performance of the readers. 

A C D E F 166 Conclusion: We found no statistically significant difference between the radiologists' performance in detecting abnormalities with standard X-ray dose images, and the performance with images made with 55 % and 35 % of the standard dose. Sex, height and the weight of patients had no influence on diagnostic performance.

withdrawn by author B-0259 10:40

Flat panel X-ray detector: Reduced radiation exposure for the detection of simulated interstitial lung disease, nodules and catheters U. Rapp-Bernhardt, T.M. Bernhardt; Münster/DE Purpose: Evaluation of a flat panel detector (FD) using amorphous silicon with respect to detection of simulated interstitial lung disease, nodules and catheters and reduction of radiation exposure compared with an asymmetric screen-film system. Materials and methods: An experimental model was used to determine the detection of reticular, micronodular, linear, ground glass patterns, nodules and catheters which were superimposed over an anthropomorphic chest phantom. 19200 observation fields were evaluated using the FD with the simulated speed of 400, 600 and 1600 and compared with the asymmetric screen-film system with the speed of 400. Five radiologists performed receiver operating characteristics (ROC) for a five-level confidence scale.

The areas under the ROC-curves showed no statistically significant differences between the two detector systems at the same speed with respect to the detection of all simulated lesions (p > 0.05). The FD with a digital speed of 800 yielded in decreased diagnostic performance compared with the asymmetric screen-film system, however, these results were not statistically significant (p > 0.05). Using the FD with a digital speed of 1600 lead to statistically inferior results in the detection of catheters and nodules over obscured lung (mediastinum) as well as micronodular lesion over lucent lung (p < 0.05). Conclusion: These results suggest that a dose reduction up to the digital speed of 800 is possible for FD.

Image quality of computed radiography and flat panel detector radiography: Evaluation of simulated subtle lung abnormalities H. Tagashira, K. Arakawa, M. Yoshimoto, J. Ikezoe; Shigenobu/JP Purpose: To evaluate the image quality of computed chest radiography (CR) and flat panel detector radiography (FPD) for diagnosing subtle lung abnormalities. Materials and methods: We studied the differences of observer performance among computed radiography (new type computed radiography (FCR 5501D, pixel size 100 µm, dual side (front and back) read out by laser beam of imaging plate) and flat panel detector radiography (indirect type with screen, Canon CXDI-11, pixel size 160 µm). Simulated nodule, ground-glass opacity and reticular shadow were made of acrylic resin, sand ground down and softened gauze with urographin (contrast material), respectively. A simulated abnormality was placed on the back of the thorax of each volunteer (n = 50) in order to overlap the right or left lung parenchyma and each volunteer was examined with three different modalities with the same exposure condition. So, total of 200 unilateral lungs were obtained, and of these 200 unilateral lungs, 100 lungs had one of the simulated abnormalities, and the remaining 100 lungs were normal. Five chest radiologists evaluated these 200 unilateral lungs with ROC analysis with continuous confident scale. The area under the ROC curve (Az) was used to evaluate the results. Results: For all simulated abnormalities, dual read-out type CR (FCR 5501D) showed the best result (Az = 0.820), followed by FPD (Az = 0.780). However, in case of reticular simulated abnormalities, FPD showed the best result, followed by dual read-out type CR. Conclusion: Dual read-out type CR and FPD showed extremely high image quality.

First experiences with a detector-based dual energy system for thorax radiography J. Ricke, F. Fischbach, U. Teichgraeber, T. Freund, R. Felix; Berlin/DE Purpose: To assess the influence of dose on the image quality of subtracted soft tissue and bone images generated by a dual energy system based on a flat panel detector. Materials and methods: 88 patients were randomized in 2 groups. One group received a dual energy examination at a XQi revolution (GE Medical Systems, USA) with an intended approximative speed pair of 400/1000 for high and low energy shot, the other group with an intended approximative speed pair of 200/ 500. For data analysis, subgroups were specified according to additional dose measurements at the detector. Image quality indicators were noise, residual bone structures, motion artefacts of pulmonary vessels, heart and aorta, display of retrocardiac ribs or other bone structures, display of lung apex or retrocardiac lung. Image review was performed blinded by two experienced Radiologists in consensus applying a rating score of 1 to 5. Linear regression and chi square tests were performed for statistical analysis. Results: Overall image impression was rated good with no significant improvement of image quality with increasing dose. However, a trend for decreased noise in soft tissue and bone images was noted with higher dosage as well as increasing residual bone structures. Conclusion: Increased dose did not improve image quality significantly. Dual energy thorax imaging at a flat panel detector proved potential as a future routine application.

Digital bedside chest radiography with and without antiscatter grid: Impact on image quality and display of low contrast details M. Uffmann, K.S. Exter, I.M. Nöbauer-Huhmann, C. Balassy, J. Sailer, C.J. Herold, C. Schaefer-Prokop; Vienna/AT Purpose: Use of an antiscatter grid also for bedside chest radiographs improves image quality however at the expense of increased dose requirements. Image processing in digital radiography offers the option for optimising detail contrast. Purpose of the following study was a) to test whether contrast enhancing processing compensates for increased scatter radiation if no grid is used and b) whether further dose reduction is feasible. Materials and methods: Routine chest films with storage phosphor plates (ST Vn, Fuji) were performed on 24 ICU patients on 3 consecutive days using an antiscatter grid and an acquisition dose approximating 250 speed system, without grid and an optimised image processing, and without grid and additional dose reduction of one third. All images were overlaid by a 9 element matrix with small fragments of various catheter types (n = 120). 4 readers evaluated the hardcopies for the presence of catheter fragments and diagnostic image quality. Results: Areas under the ROC curve for the detection of catheter fragments were statistically equivalent for all images irrespective of the use of a grid or reduction of acquisition dose (0.92, 0.93 and 0.93, resp.). Visualisation of lung parenchyma and monitoring lines was rated comparable for all 3 image types. Visualisation of mediastinal and retrocardiac areas, however, was rated significantly poorer in images obtained without grid and reduced dose. Conclusion: Digital bedside chest radiographs can be obtained without an antiscatter grid by using optimised image processing. However, further dose reduction results in significant loss of image quality in high absorption areas.

Detection of simulated chest lesions using soft-copy reading: Comparison of an amorphous silicon flat-panel detector system and a storage phosphor system J. Goo, J.-G. Im, J. Kim, M. Chung, J. Seo, H. Kim; Seoul/KR Purpose: To compare observer performance using soft-copy images produced by an amorphous silicon flat-panel detector system and a storage phosphor system for the detection of simulated chest lesions. Materials and methods: To test the diagnostic performance of these two systems, we used four types of simulated lesions (nodules, micronodules, lines, and reticular opacities) that were superimposed over an anthropomorphic chest phantom. Digital chest radiographs were acquired by amorphous silicon flat-panel detector radiography (3K matrix, 12 bits) and by storage phosphor radiography (4K matrix, 10 bits). Six board-certified radiologists evaluated soft-copy images on a high-resolution video monitor (2560 × 2048 × 8 bit). A total of 14400 observations were analyzed in terms of receiver operating characteristics (ROC). Results: Averaged performance in terms of the detection of nodules was significantly better (p < 0.05) on the flat-panel detector system than on the storage phosphor system (area below ROC curve [Az] values: 0.93 ± 0.015 and 0.85 ± 0.033). For micronodules, lines, and reticular opacities, no significant detection differences in averaged performance were found between the flat-panel detector and storage phosphor system (Az values: micronodules, 0.86 ± 0.020 and 0.76 ± 0.049; lines, 0.85 ± 0.031 and 0.75 ± 0.051; reticular opacities, 0.96 ± 0.015 and 0.92 ± 0.022).

In the evaluation of soft-copy images, the amorphous silicon detector system appears to be superior to the storage phosphor system for the detection of pulmonary nodules. 

The total realistic examination time in multi-slice-CT is 5 min 28 s faster than in single-slice-CT. Due to shorter scanning time a reengineering of preparation and post-processing phase enables to increase the number examinations per day with multi-slice CT. Process simulation showed to be superior to CPM/PERT due to higher flexibility and ability to consider cycle overlap and determine cycle times.

Evaluation of a new patient transfer board (PTB) for diagnostic ER-/ICUpatient-management in diagnostic CT T. Schroeder, S. Ruchholtz, S.G. Rühm, S. Heistrüvers, H. Kuehl, J.F. Debatin; Essen/DE Purpose: MultiSlice CT has vastly reduced scan times. Rather than data collection, patient transfer and positioning has thus become the rate limiting step particularly for polytraumatized ER-and ICU-patients. To speed transfer to and positioning onto the CT table, we developed a patient transfer board (PTB) enabling the "en-bloc"-transfer of patient and life-support equipment.

The PTB was assessed on 20 acute trauma-patients and 50 ICU-patients. Patients were placed on the PTB directly in the ER/ICU before transfer to the CT room. Transfer-times between patient arrival in the ER and completing of the radiological diagnostic procedures (ER-patients) and the in-roomtimes in the CT (ER-and ICU-patients) were measured by stop-watch and compared to those determined in matched populations (40 acute trauma, 100 ICU) examined without the PTB. Results: The PTB enabled the "en-bloc transfer of ER-/ICU-patients and support equipment". The handling of the PTB was easy, and intuitive. The PTB had no adverse effect on image quality. Transit-times between arrival of trauma patients in the ER and completing the radiological diagnostic procedures including CT were reduced from 39 to 31 minutes (213 %, p < 0.05). The in-room-times in the CT (ER-and ICU-patients) were reduced from 14 to 9 minutes (36 4 %, p < 0.05). The PTB was well accepted by the medical staff. Conclusion: The PTB is a simple device capable of vastly shortening patient transfer and positioning times onto CT-tables. The PTB accelerates the diagnostic management of ER-and ICU-patients and hence increases CT patient throughput. 

Iliocaval thrombi were simulated using clotted bovine blood. Four experimental set-ups were performed with 10 interventions each. Thrombus particles and distribution were measured in the effluent. Mechanical thrombectomy (MT) was performed using the PTD alone. Secondly, a newly developed vena cava filter was inserted before and removed immediately after the intervention without manipulation within the filter. In a third procedure, the filter was filled with thrombus and closed without any fragmentation. Finally, the filter was completely filled with thrombus material and MT was performed within the filter using the PTD. Results: Running the PTD in the flow circuit led to a maceration of 67.9 % of clots into particles below 500 µm. In the second set-up, additional placement of the filter safely prevented embolization of particles above 500 µm. Closing the filled filter within the flow circuit macerated 75.2 %, while additional MT within the occluded filter led to a dissolution of 90.4 % of the initial clot weight.

The PTD proved as an effective and safe device for clot fragmentation in this experimental set-up. The use of a cava filter is mandatory to prevent embolization of thrombus fragments. Even large clot burdens can be further macerated easily by the PTD within the filter basket before removal. Clinical evaluation of these two devices in iliocaval thrombosis is promising.

Cost effectiveness assessment of port devices chemotherapy implant in 200 M0 breast cancer patients: Radiological versus surgical placement evaluation P.Y.R. Marcy sr. 1 , C. Bailet 1 , N. Magne 1 , E. Chamorey 1 , J.C. Machiavello 1 , J.C. Gallard 2 ; 1 Nice/FR, 2 Caen/FR Purpose: To report the feasibility and cost effectiveness of two venous chemotherapy port implantation techniques in 200 M0-breast cancer patients. Material and methods: Radiological venous arm port (R) and surgical subclavian (S) implantation techniques were retrospectively evaluated in an homogeneous set of 200 M0 breast cancer patients treated with adjuvant/neoadjuvant chemotherapy. Mean age was 55.7 a [55.5 a, n = 100 (R); 55.9 a, n = 100 (S)] and the F/M sex ratio was 1.0. Initial feasibility was evaluated for both techniques. Procedure related direct costs and outcome were respectively evaluated. Results: Initial technical failures rates (R/S) were 4 % and 9 %. Mean implant duration time was 168/222 days, the overall complication rate (R/S) was 9 %/13 % (CHI2 test p = 0.5) (0.24 -0.4/1000 patient-days). Mean implant duration time without any complication or death was 193 d vs 233 d. Median number of chemotherapy courses was 6 (R = S). 6 %/7 % of the devices had to be removed prematurely. Complications included device-related sepsis (n = 2 vs 5), skin dehiscence (n = 3), deep venous thrombosis (n = 1 vs 4), catheter occlusion (n = 1 vs 0) and fissuration migration (n = 1.1 vs 0.0) of the catheter. Direct costs (R/S) were respectively 230.8 vs 219.1 • . Conclusion: Both techniques are successful and safe, with a 5 % higher relative cost for R placement. Both are indicated for breast cancer adjuvant chemotherapy.

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Balloon angioplasty and stenting of subclavian and brachiocephalic benign venous obstruction B. Guadagni, M. Cariati, G. Cittadini, G. De Caro, C. Ferro; Genova/IT Purpose: Report our clinical experience of the treatment with balloon angioplasty and/or stent placement of subclavian or brachiocephalic benign venous stenosis or obstruction in patients undergoing hemodialysis. Materials and methods: Among 27 patients with subclavian (n = 13) or brachiocephalic (n = 15) venous stenosis or obstructions, 10 were treated with PTA alone and 17 with PTA and stent placement. Technical success and primary and assisted primary patency rates were calculated. Results: Technical success was 100 %. The ten patients treated with PTA alone had good immediate results. Primary patency rates at 6 months, 1 year and 2 years were respectively 90 %, 80 % and 80 %. Two patients required additional procedures with repeated PTA and stent placement (Wallstent) with an assisted patency rate of 100 % at 2 years. 24 Wallstents were inserted immediately after failed angioplasty in 17 patients because of early restenosis and unsuitablility for angioplasty. Primary patency rates at 6 months, 1 year and 2 years were respectively 76 % (13/17), 61 % (8/13) and 70 % (7/10). Eight patients required multiple reinterventions for restenosis or thrombosis with additional angioplasty and/or stent placement. Assisted patency rates at 6 months, 1 year and 2 years were respectively 100 % (17/17), 92 % (12/13) and 80 % (8/10). Conclusion: Endovascular treatment of subclavian and brachiocephalic benign venous stenosis or obstructions with PTA alone and/or stent placement can provide prolonged use of a hemodialysis access site. Close clinical surveillance and multiple reinterventions are usually necessary to maintain stent patency. Follow-up was available in 19 patients over 20 months. In this period 11/19 patients (57.9 %) had another treatment: PTA of intra stent stenosis in 23 cases; stenting of restenosis after PTA in 4 cases; positioning of a second stent in 2 cases. Results: In total we performed 62 procedures, with a full technical success in 59 (95.1 %), 2 (3.2 %) were technically unsuccessful and 1 complication ocurred (1.7 %): rupture of the treated vein. Primary patency rates were 82 % at 3 months, 53 % at 6, 17.6 % at 12 and 5.8 % at 24 months. Secondary patency rates were 100 % at 3 months, 55.5 % at 6, 33.3 % at 12 and 22.2 % at 24 months. Conclusion: Interventional procedures allow treatment of stenoses with a high grade of technical success but the high incidence of restenosis requires continuous monitoring and frequent re-intervention to maintain the functionality of the hemodialysis vascular access.

Mechanical thrombectomy to preserve vital venous access in patients with subclavian vein thrombosis P.M. Vos, H.J. Baarslag, J.A. Reekers; Amsterdam/NL Purpose: Deep venous thrombosis is one of the most important catheter related complications in patients with central venous lines. Preservation of venous access may be vital for these patients. Feasibility of percutaneous mechanical thrombectomy of subclavian vein thrombosis in patients with central venous lines was evaluated. Materials and methods: 7 patients (3 male; 4 female) with a mean age of 50 years were included. All patients had central venous catheters in the thrombosed subclavian vein. Catheters were placed for chemotherapy 5, nutrition 1 and dialysis 1. Before the procedure venography was performed to evaluate the level and extent of the thrombosis. If there was extensive thrombosis with extension in the brachial veins, patients were not included. Mechanical thrombosuction was performed using a 6 or 7 french hydrolyser catheter (Cordis J&J, 700 psi, 5 ml/s).

Prior to the procedure 5000 U of Heparin was given intravenously. All patients were treated with anti-coagulants after treatment. Re-establishing flow with or without wall adherent thrombus was defined as a clinical success. Results: In 5 cases, percutaneous mechanical thrombectomy was successful. In these 5 patients the central venous line could be preserved. In 2 patients re-canalization of the subclavian vein thrombosis could not be established due to wellorganized (longstanding) thrombus clots. In one patient with a clinical success, reocclusion occurred 2 months after the procedure. Conclusions: Percutaneous mechanical thrombectomy of subclavian vein thrombosis in patients with central venous lines is feasible if the thrombosis is acute and not too extensive.

Factors that influence the results of percutaneous transluminal angioplasty for hemodialysis access dysfunction K. Maeda, A. Furukawa, M. Yamasaki, M. Onishi, K. Furuichi, T. Nagata, S. Aoki, M. Takahashi, K. Murata; Otsu Shiga/JP Purpose: To evaluate factors that influence the initial success rate and long-term results of percutaneous transluminal angioplasty (PTA) for hemodialysis access dysfunction. Methods and materials: A total of 81 PTA procedures were performed in hemodialysis shunts with stenosis (61 procedures) or occlusion (20 procedures) in 47 patients between 1997 and 2001. Initial success rates were compared between patients with stenosis and occlusion. In cases where initial success was obtained, cumulative rates of shunt-patency (CRP) were evaluated to assess whether the following three factors may influence the long-term results; length of stenosis (≤ 3.5 cm vs > 3.5 cm), length of patent period of the primary shunt (≤ 12 months vs > 12 months) and diameter of the balloon used for angioplasty (≤ 4 mm vs > 4 mm). Results: Overall initial success rate was 87.7 % (Stenosis: 98.4 % vs occlusion: 55.0 %). Overall CRP at 3, 6, and 12 months were 81.5 %, 54.9 %, and 44.4 %, respectively. CRP was significantly higher in patients with shorter stenosis compared to patients with longer stenosis (93.8 %, 72.1 %, and 63.1 % vs 70.8 %, 37.1 %, and 20.6 %, respectively, p < 0.01). CRP was significantly higher in patients with longer patent period of the primary shunt compared to patients with a shorter period (83.7 %, 67.8 %, and 63.8 % vs 81.4 %, 36.9 %, 21.5 %, respectively, p < 0.01). Conclusion: PTA is technically highly successful in patients with shunt stenosis (not occlusion) and a better prognosis is expected in patients with shorter stenosis and patients with a longer patent period of the primary shunt.

Long-term follow-up of vena cava filters: Clinical and radiological findings S.C.A. Herber 1 , T. Knodel 1 , J. Schneider 1 , C. Düber 2 , M. Thelen 1 , M.B. Pitton 1 ; 1 Mainz/DE, 2 Mannheim/DE Purpose: To evaluate the clinical efficacy, mechanical stability and safety of vena cava filters (VCF) in patients for prophylaxis of pulmonary embolism. Material and methods: Retrospective analysis of 80 patients undergoing VCF for thrombosis (DVT) in 9/80 and pulmonary embolism (PE) in 71/80 patients. 3 filtertypes were inserted (73 LGM; 8 Antheor; 1 Cook Tulip) using a femoral approach in 66/80 and a jugular approach in 14/80 patients. Follow up included ultrasound, conventional X-ray and CT-scans. Results: No periinterventional complications occured. 71/80 patients were anticoagulated (51/80 marcumar, 20/80 heparin). Mean follow-up was 40.9 months (range 14 -113 months). 54 patients are still alive. Mean survival was 28 months (range 8 -40 months). 26 patients died (tumour progression n = 16, others n = 10). There was no evidence of further PE, but 3 DVT recurred during long-term follow-up. In 68/80 cases correct filter deployment was achieved including a suprarenal position (n = 3). Technical problems with filter deployment occured in 12 of 80: incomplete opening (n = 8), non-opening of filters (n = 2), filters tilted > 15° (n = 2). Follow up demonstrated significant filter migration in 28/80 with a mean migration of 19 mm (range 7 -48 mm), 7/28 within 30 days and 20/28 showed late filter dislocations (> 12 months). Fractures of filter struts occured in 4 cases (2 LGM, 2 Antheor) and perforation of struts through the venous wall occured in 2 (Antheor). Conclusion: VCF has a low periprocedural complication rate but significant migration, some filter fractures and strut perforations were seen. Due to the low incidence of re-thrombosis under anticoaglation, VCF is restricted to very selected cases. Patients and methods: 117 patients underwent percutaneous implantation of a SNF from 1993 through to 1999. Patient reports were retrospectively analysed for complications during and after implantation and deep venous thrombosis and PE before and after implantation. Helical-CT with contrast media and plain abdominal radiography were performed on 35 patients, helical-CT alone on 2 patients. We checked the position and configuration of the SNF and looked for perforation of the filter legs through the wall of the inferior vena cava (IVC). The IVC and deep pelvic veins were analysed for patency. Results: During implantation 10/117 (9 %) patients had minor complications, major complications were reported in 0.9 % (1/117). Pulmonary re-embolism was documented in 9/117 (7.7 %) patients. There was no significant increase in thrombosis of the deep pelvic veins or the IVC after implantation. 1/35 (2.9 %) examined patients showed a single strut fracture of the SNF. Tilting more than 15° was seen in 7/37 (19 %) patients. Dislocation of the SNF more than 10 mm occurred in 1/35 (2.9 %) patients and perforation through the wall of the IVC in all 37 patients. We found no occlusion of the IVC.

The SNF is easy and safe to implant. In our investigation, complication rates during and after implantation were low. The SNF effectively prevents PE. (June 1999 to September 2001 . The estimated period of protection against pulmonary embolism was less than 15 days. Before insertion, color duplex sonography was performed in all patients. All filters were implanted and retrieved through a femoral approach. The position and condition of the filters was assessed immediately and 4 days after insertion.

Results: There were no placement complications in any patient. No clinical manifestations of pulmonary embolism occurred during the filtration period or during removal. Implantation time was 7 to 12 days (mean 9 days). There were no filter thrombosis at the time of retrieval in 8 patients. One patient required reinsertion of a Gunther temporary vena cava filter 8 days after the first insertion because thrombus was captured. In two patients, permanent filtration was subsequently requested, in one due to an ongoing contraindication to anticoagulation whilst in the other due to sizable clot captured in the Gunther temporary filter. One other patient died of causes unrelated to the procedure. There were no complications of retrieval. No damage was detected at the insertion site. Clinical and imaging follow up of the patients did not demonstrate any pathology. Conclusions: Gunther temporary vena cava filters are easy and safe to use and effective in protecting against pulmonary embolism in high risk patients.

TIPS creation using self-expandable stent-graft covered with ePTFE (Viatorr): First experience and short-term follow-up V. Chovanec, A. Krajina, M. Lojik, J. Raupach, P. Hulek; Hradec Kralove/CZ Purpose: To evaluate technical success of TIPS dedicated stent-graft implantation and short-term patency. Materials and methods: Between February and September 2001, 13 patients (7 female, 6 male) aged 16 -76 years with end stage liver disease underwent TIPS procedure. Liver cirrhosis was due to alcohol abuse (6/13), hepatitis (2/13), liver fibrosis (1/13), unknown cause (3/13) and mixed etiology (1/13; patient with hepatitis C and Wilson disease). The shunt was created using ePTFE covered selfexpandable nitinol stent-graft (Viatorr, W.L. Gore), which was placed from the portal vein to the ostium of the hepatic vein. The 2 cm non-covered part of the stentgraft was placed into the portal vein branch which remained patent. TIPS procedure was done using a standard technique and with antibiotic prophylaxis. The TIPS patency was assessed by Doppler US at discharge and then at 1 and every 3 months. The follow-up period ranged from 1 to 7 months (mean 4 months).

Results: All TIPS were technically successful with a significant decrease in the portosystemic gradient (from 18.4 mmHg to 7.9 mmHg) without clinical complications and all were fully patent. In one patient (7.7 %) two stent-grafts had to be Results: Due to technical failures 2 patients were excluded from the evaluation. In the remaining 100 patients the exam rendered diagnostic image quality from the carotid arteries to the tibial vessels (3000 segments). Apart from the clinically suspected PVD, additional clinical relevant disease was found in 21 %. 16 patients had a renal artery narrowing, in 13 patients a carotid arterial stenosis was detected, and 2 patients showed an AAA. Conclusion: Noninvasiveness, three-dimensionality, extended coverage and high contrast conspicuity are the characteristics of the applied whole body 3D MRA approach allowing for a quick, risk-free, and comprehensive evaluation of the arterial system in patients with atherosclerosis. The impact of cardiovascular and colorectal disease processes can be diminished if recognized and treated at an early stage or pre-stage. Inherent noninvasiveness and lack of harmful side effects make MRI ideal for preventive imaging. The goal of this study was to assess the impact of a screening MR examination, encompassing depiction of the brain, the arterial system, the heart and the colon. Materials and methods: 28 healthy subjects (mean age 53.3 a, range: 39 -76 a) were evaluated. Using a high performance MR system (Siemens Sonata) equipped with a rolling table platform (AngioSURF), MRI of the brain (T1w, T2w and TOF sequences), whole-body MR-angiography (five contiguous 3D GRE acquisitions), cardiac MRI (TrueFisp cine and IR-Turbo FLASH) and eventually MR-colonography (3D GRE imaging following administration of a water enema) were performed. Paramagnetic contrast was administered i.v. prior to MR-angiography and for MRcolonography. All examinations were evaluated by two experienced radiologists.

Results: The compound MR examination was well tolerated by all 28 patients. Mean examination time amounted to 61 (± 6) minutes. A total of 14 unsuspected pathologies were detected: colorectal polyps (4), cerebral aneurysms (1), aortic aneurysm (2), stenosis of renal arteries (1), stenosis of femoral arteries (2), reduced myocardial EF (2) and mitral regurgitation (2). Conclusion: Multi-organ screening with MRI within a short time is possible. A considerable number of disease pre-conditions requiring subsequent treatment were identified. Further work will be required to determine the true value of such an approach.

The use of diluted contrast media in equipment with CO2 software T. Moreno Sánchez, E. Lopez Jimenez; Huelva/ES Objective: To determine the cost-effectiveness and efficiency of angiography of the abdominal aorta and lower extremities using diluted contrast media and CO2 postprocessing software for obtaining diagnostic images. Subjects and methods: Forty patients with peripheral vascular disease were evaluated by CO2 software-digital substraction angiography with diluted iodinated contrast material (Ioversol 240, diluted at 30 %). Results: Diluted contrast was well tolerated by all patients with no complaints despite the severity of the vascular disease. Good image quality was achieved for the aorta and iliofemoral arteries in all cases. The popliteal artery and distal tree images were of good quality in 35 patients. For the remaining five, it was necessary to use pure contrast along with the CO2 software. Conclusion: Contrast diluted angiography with CO2 software can be used as an alternative to pure iodinated contrast material for obtaining arteriograms of the abdominal aorta and lower limbs. The diagnostic quality is equivalent to that obtained with conventional methods. The lower dose of contrast reduces the risk of adverse reactions, increases the cost-effectiveness of the procedure and is more comfortable for the patients. The use of the CO2 software produces good quality diagnostic arteriographic images with more comfort for patients, less secondary effects and less cost. The time for completing the study is similar to the conventional one and less time consuming than CO2 lower extremities angiography. Material and methods: CDUV was performed using manual injection and digital substraction angiography in 40 consecutive patients (77 upper limbs). Images were read on a 1K high brillance digital workstation. The international anatomic nomenclature was used to divide the superficial venous network into 16 segments per limb. Two senior radiologists independently assessed the patency of all segments according to the following grading: absent or non-opacified (grade 1), poor quality (grade 2), small calibre (grade 3), good quality (grade 4). In the case of discrepancy, a consensus was reached by reviewing the images. The kappa-test was used to assess the inter-observer correlation in each of the 16 different venous segments. Results: Overall, grade 1 was seen in 24 %, grade 2 in 13 %, grade 3 in 12 % and grade 4 in 51 %. Mean κ was 0.72 (p < 0.05) for the right side and 0.71 (p < 0.05) for the left side. The worst correlation (k = 0.55) was obtained for veins at the elbow level. Conclusion: CDUV allows satisfactory imaging of the upper limb venous network with good agreement between the observers. Special attention must be paid to obtain good images at the elbow level.

Intraarterial digital subtraction angiography with carbon dioxide and nonionic gadodiamide in incomplete renal failure H.-P. Dinkel, H. Hoppe, I. Baumgartner; Berne/CH Purpose: To evaluate the benefit of gadolinium for intraarterial use in diagnostic and therapeutic angiography in patients with incomplete renal failure. Methods: 17 patients with planned peripheral or renal vascular interventions (1 iliac, 10 femoral, 3 renal, 3 transplanted kidneys) and renal insufficiency underwent digital subtraction angiography with intraarterial administration of gadolinium (1 gadolinium-DTPA, 16 gadodiamide). Gadolinium was used selectively after peripheral catheter placement, usually as an adjunct to carbon dioxide (CO2) if the quality of CO2-angiography (n = 14) was insufficient to assess the distal run-off vessels or did not sufficiently characterize stenotic lesions.

In 16 of 17 cases gadolinium yielded good or satisfactory results that were superior to those of CO2-angiography in each case. This applied to the calf and femoropopliteal region in patients with femoropopliteal occlusions, but at times also to the aorto-iliac vessels and the renal arteries. Mean serum creatinine level after angiography (295 µmol/l) was not significantly different from the initial level (279 µmol/l), p > 0.37. Conclusion: Gadolinium is a viable alternative contrast agent in digital subtraction angiography and percutaneous transluminal angioplasty (PTA). It enhances the diagnostic evaluation of stenoses and run-off vessel. Non-ionic gadodiamide is preferable to hyperosmolar gadolinium-DTPA. For economical reasons and since the maximal applicable dose of gadolinium is currently restricted to 0.4 mmol/kg bodyweight (40 -80 ml) its combined use with CO2-angiography is recommended.

Evaluation of the aorto-iliac and renal arteries: Intraindividual comparison of 3D MR angiography and MDCT angiography J.K. Willmann, P.R. Hilfiker, T. Pfammatter, J.E. Roos, B. Marincek, D. Weishaupt; Zürich/CH Purpose: To compare contrast-enhanced 3D MR angiography (MRA) and multidetector row spiral CT angiography (CTA) in the assessment of the aorto-iliac and renal arteries, using digital subtraction angiography (DSA) as the standard of reference. Methods and materials: DSA, MRA and CTA were performed in 39 consecutive patients with suspected occlusive arterial disease. Two readers assessed all MRA and CTA data sets independently; a third reader evaluated the DSA images. All reviewers were unaware of the results of the other imaging modalities. For data analysis, the arterial system was divided into 16 segments, and a 4-point grading system was applied to assess arterial luminal stenosis. Time for post-processing and reading times of MRA and CTA data sets were noted. Results: For readers 1/2 sensitivities of CTA were 80 %/83 % and specificities 96 %/96 %; MRA had sensitivities of 91 %/92 % and specificities of 97 %/96 % for detection of hemodynamically significant stenosis (> 50 %). Interobserver agreements for both MRA and CTA were good (kappa = 0.74 and 0.67). Intermodality agreement between CTA and MRA for readers 1/2 were 0.73/0.70. Post-processing of CTA data sets was significantly more time consuming (mean 15 minutes) compared to post-processing of MRA data sets (mean 4 minutes) (p < 0.001). Similarly, reading time for evaluation of CTA was longer than reading time of MRA (4 versus 2 minutes). Conclusion: Both MRA and CTA demonstrate a similar diagnostic performance compared to DSA in the assessment of occlusive disease of the aorto-iliac and renal arteries. Due to shorter post-processing and reading times, MRA seems to be more suited to clinical routine.

Correlation of spatial resolution in multislice CT and angiography in kidneys P.J. Hallscheidt, C.C. Cardenas, J. Boese; Heidelberg/DE Aim: The aim of this study was to evaluate the maximum spatial resolution of multislice CT in comparison to digital subtracted angiography. Material and methods: 15 kidneys were catheterised with a 4 french straight catheter and under went mulitslice-CT in an early arterial phase with a reconstructed slice thickness of 0.2 mm. The data were evaluated in MIP and 3D reconstruction and the resolution was compared to conventional DSA angiography, which was performed after the CT scan. Results: In reconstruced multislice CT with isotropic voxels all segmental and subsegmental arteries could be delineated. The reconstructed CT data allowed similar spatial resolution to DSA, but additionally the segmental anatomy could be evaluated. Discussion: Reconstructed multislice CT gives similar spatial resolution, with delineation of subsegmental arterial branches, as angiography. But the 3D data allows additionally the delineation of the segmental anatomy which is essential for the planning of nephron sparing surgery. 

Material and methods: 51 patients with a clinical or ultrasound suspicion of renal artery stenosis were examined with MSCTA after a bolus injection of 100 ml of non-ionic c.a. at 4 ml/s. In most cases the renal artery study was part of a run off examination for patients with peripheral arteriopathy. A fixed time delay of 25 to 28 (in presence of abdominal aortic aneurysm) seconds was used in all cases. Images were interpreted by 3 blinded radiologists either on axial or reconstructed images. In all patients DSA was performed within 72 hours and considered the gold standard. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the assessment of degree of stenosis and evaluation of supernumerary arteries were calculated. Results: We evaluated 123 renal arteries. MSCTA provided good to excellent diagnostic quality in all cases; all 21 supernumerary arteries were correctly demonstrated. Regarding the degree of stenosis the values of sensitivity, specificity, PPV and NPV were respectively 100 %, 95 %, 100 % and 92.6 %. CTA was superior to DSA in the delineation of calcification. In 4 cases with ostial calcified plaque the stenosis, moderate at DSA, was overestimated with MSCTA and considered severe.

Multislice spiral CTA provides excellent arterial delineation in patients with suspected renal artery stenosis. The limited amount of contrast agent used lends itself to use in patients with partially impaired renal function. To evaluate the utility of MRI for the assessment of angiodysplasia compared to conventional duplex US, venography and arteriography. Methods and materials: 14 patients (9 male, 5 female; age range, 10 -64 years) with clinically diagnosed angiodyplastic abnormalities of the extremities were examined on a 1.5 T whole body scanner (Magnetom Sonata, SIEMENS, Germany). Based on a localizer sequence axial/coronal T1-, heavily T2-weighted (STIR) as well as axial T1-weighted sequences post contrast were acquired to determine the extent and type of the arteriovenous malformation. In addition dynamic contrastenhanced (0.2 mmol/kg Gd-BOPTA, Multihance, BRACCO, Italy) 3D gradient echo sequences were collected. A board certificated radiologist as well as an angiologist analysed the MR data sets for lesion depiction, determination of extent and involvement of neighbouring structures as well as characterisation of the malformation. Results were compared to findings from duplex US, conventional venography and intraarterial arteriography. Results: All MR examination were of diagnostic quality. A total of 16 arteriovenous malformations (venous malformation: n = 11, arteriovenous fistulae (AVF): n = 2, posttraumatic AVF: n = 3) were depicted. The STIR sequence was helpful in the determination of the extent of the vascular malformation which was often underestimated by 3D MRA alone, whereas dynamic 3D MRA was mandatory for the classification of the lesion. These findings correlated well with the combination of conventional venography (n = 11) and Duplex-US (n = 16).

Conclusion: MRI appears to be valuable in the assessment of angiodysplastic lesions of the extremities. The protocol should combine dynamic contrast-enhanced 3D GRE-sequences with heavily T2-w (STIR) sequences. Material and methods: All procedures were done on a multislice-spiral-CT (Siemens Somatom Plus 4VZ) using a standardized CT-fluoroscopy technique. Robot assisted punctures were executed using a remote-controlled robotic system (UnitedRobotSystems, Evolution1) with unrestricted flexibility of movement. Interventions performed were either punctures of contrast-media filled capsules, placed in a soft-tissue-phantom, or interventions within the spinal column of human bodies, such as vertebroplasty or discography. Evaluation parameters were accuracy and application of the system, access to the patient and procedure time for the intervention.

Results: Using robotic assistance high accuracy was achieved for all interventions. Each lesion within the soft tissue phantom was punctured precisely (20/20). Interventions on the spine (10) and the intervertebral discs (8) were performed without significant deviation from the approach determined initially. Though application of the system was simple, free access to the patient was often aggravated by the scanner and robotic design. A marked learning curve was observed, thus leading to a significant reduction in intervention time in the course of all procedures (40 %) Conclusion: A robotic system may be useful for CT-interventions in the spine, significantly reducing the radiation dose to the radiologist. As examination time is still markedly increased and patient access remains difficult, the system configuration has to be further optimized for the clinical setting. Purpose: Percutaneous vertebroplasty is used to strengthen the pathologic vertebral body and reduce pain in some diseases involving the spine. The purpose of this study was to evaluate segment stability and clinical status in patients who received vertebroplasty after radiofrequency ablation of spinal tumors. Methods and materials: 23 vertebroplasties with polymethylmethacrylate were performed in 14 patients who had been treated with radiofrequency ablation of inter-or paravertebral tumors in the thoracic and/or lumbar spine. Vertebroplasty was indicated due to presence or imminent tumor related vertebral fractures and presence of imminent neurological deficits. Operations were carried out under CT/ fluoroscopy guidance under local anesthesia and on an out-patient basis. At follow-up, preoperative MR images were compared with follow-up MR-images in addition to clinical examination. Follow up ranged from 3 to 12 months. Results: At follow-up, MR images of treated vertebral bodies showed no signs of sintering or refracture. Clinical examination showed improved mobility of the spine in 13 patients (92.9 %). In none of these patients was the presence or progression of neurological deficits diagnosed. 1 patient (7.1 %) was restricted in motion due to a new tumor in another segment. No intra-or postoperative complications were reported.

Our results indicate that image-guided percutaneous vertebroplasty seems to be a safe and effective, minimally invasive method to stabilize pathologic vertebral bodies in patients who have received radiofrequency ablation of spinal tumors. Purpose: Frequent complications of osteoporosis are fractures, especially in the vertebral bodies of the thoracic and lumbar spine. The purpose of this study was to ask whether percutaneous CT-/fluoroscopy-guided vertebroplasty can cause pain reduction in patients with fractured osteoporotic vertebral bodies. Methods and materials: 25 verebroplasties were performed on 17 patients with osteoporotic vertebral body fractures. Patients suffered from superior or inferior endplate fractures, combined end plate fractures without loss of height and combined end plate fractures with loss of height. Inclusion criteria were new osteoporotic vertebral body fractures with acute pain as well as older fractures with persistent pain. Exclusion criteria were fractures causing a narrowing of the spinal canal and neurological deficits, tumors, cement allergy and haemorrhagic diathesis. The procedure was carried out on an outpatient basis under local anesthesia and was performed under combined CT/fluoroscopy-guidance. Follow up examinations were carried out after an average of 2 days and after 3 months. Pain was assessed with the help of a visual analogue scale. Results: At the time of the first follow up, patients reported on an average relative pain reduction of 29.9 %. After 3 months the patients obtained an average of 33.4 % relative pain reduction according to the visual analogue scale. Conclusion: CT/Fluorscopy-guided percutaneous vertebroplasty of osteoporotic vertebral body fractures is a gentle, effective and minimally invasive method to reduce symptomatic pain in the affected region. It can be carried out on an outpatient basis under local anesthesia, which results in direct mobilization and rehabilitation.

Steroid injection in sciatica due to lumbar disk herniation: Technical aspects and clinical results (80 patients) D. Krause, F. Cognet, M. Dranssart, D. Ben Salem, S. Chapuy, J. Lerais, J. Cercueil, J. Couaillier; Dijon/FR Purpose: To assess the feasibility and efficiency of foraminal or intracanalar steroid injections in cases of sciatica due to disk herniation. Materials and methods: Between January 1999 and January 2001, 80 patients presenting with typical sciatica, resisting usual medical treatment (four weeks), underwent a prospective protocol of pain treatment. A percutaneous approach was performed using CT guidance under local anesthesia. In foraminal lateral herniation (25 %), the 22 G needle tip was positioned through the soft tissues. In intracanalar herniations (75 %), the needle tip was advanced directly into contact with the posterior part of the root, through the ligamentum flavum (homo-lateral or contra-lateral approach in case of a narrowing lumbar tendency). In all cases the steroid injection (Dexamethasone acetate 20 mg) was rigorously epidural.

The procedure was possible in all cases, without any complications or side effects. The analysis of the results was based on a multi-factorial analysis: analogue visual scale for pain intensity measurement; family G.P questioning; professional activity recovery; stopping medical treatment. The mean follow-up was more than nine months. Good or excellent clinical results were observed in 70 % of cases, poor results (without surgical intervention) in 20 % of cases and failures in 10 %. Conclusion: This less aggressive and non expensive technique, performed under very precise CT guidance, is particularly adapted to ambulatory patients with encouraging results.

Effect of CT-guided lumbar facet joint infiltration on lower back pain R. Knapp, A. Glück, J. Lukasser; Kufstein/AT Purpose: CT-guided lumbar facet joint infiltration is a valuable tool in treating lower back pain. The duration and quality of pain relief is evaluated. Methods and materials: 60 patients suffering from lower back pain caused by osteoarthritis of the facet joints underwent CT-guided lumbar facet joint infiltration with bupivacain and hydrocortisone. Only one facet at one lumbar level was treated. Evaluation of pain relief and change in medical treatment over a period of one year was performed with a questionaire. Results: 58 patients (97 %) felt a complete relief of pain after a mean time interval of 5.2 days after the infiltration. After one year 19 patients (32 %) remained free of pain. 16 patients (27 %) improved markedly or reported rarely any pain, whereas in 25 patients (42 %) the pain recurred to the same extent as before the infiltration. The pain free interval after infiltration was a mean of 110 days. Before infiltration 55 of the patients (92 %) took one or more different oral analgesic drugs. One year after infiltration 28 patients (51 %) still needed analgesics. In 25 patients (45 %) who took two or more different drugs before treatment this was reduced to 5 patients (9 %) after one year. No adverse effects of the infiltration were seen during the study interval. Conclusion: CT-guided lumbar facet joint infiltration is a save and effective treatment for patients with lower back pain caused by osteoarthritis of the facet joints. Purpose: Offical recommendations for obtaining informed consent for operative or IR procedures are that the patient is consented by the operator. The purpose of the study was to identify the proportion of European interventional radiologists who conform to these guidelines. Materials and method: A questionnaire was designed and consisted of thirteen questions on current working practice and opinions on informed consent. The questionnaire was distributed to 786 European interventional radiologists who were members of Irish or British Societies of Interventional Radiologists and members of CIRSE. The anonymous replies were then entered into a database and analysed. Results: 254 (32.3 %) questionnaires were returned. Institutions were classified as academic (56.7 %), 40.5 % non-academic (40.5 %) and private (40.5 %). 83.5 % of responders do not use specific consent forms and 61 % have patient information leaflets for procedures. Although 72.8 % of radiologists consent patients for some procedures, junior medical staff (house officers or senior house officers) consent patients in 58 % of replies. Over half (56.3 %) did not feel that their current policy was adequate. Comments from responders indicated that there is insufficient time for radiologists to consent all patients. Suggestions to improve current local policies included radiology outpatient clinics and radiology nurses visiting patients on the wards or in outpatient clinics. Conclusion: Only 24.8 % of European interventional radiologists follow current guidelines for obtaining informed consent. The causes identified were resource limitations and in particular constraints on time.

Optimizing material management in interventional radiology departments Methods and materials: After compilation of a comprehensive stock list of all disposable materials necessary for interventional radiology an ABC-analysis was performed with focus on high quality and high volume materials (A-articles). Based on ordering frequency, all A-articles were subjected to XYZ analysis, which is based on predicting the probability of requirement of the article. On this basis capital binding costs were considered with an annual interest rate of 8 % assumed.

Results: Current inventory control reveals an annual capital binding for all articles of $ 250000 mainly due to A-articles, which accounted alone for $ 200000. If articles are bought in a just-in-time (JIT) mode instead of mid term, stock costs could be reduced by $ 130000, thus storage time is shortened and capital binding is reduced and $ 10000 can be saved. With a stock turnover of the remaining material of 9 months, which matches our experience, JIT-buying of articles can lead to an additional cost reduction of $ 5000. Altogether $ 15000 could be saved, which means a relative cost reduction in stock of 6 %. Besides this, there are lower costs for renting space and expiration dates of articles can better be controlled. 

Late improvement of regional myocardial wall motion in the area of infarction after acute PTCA in a 6-month follow-up study using delayed contrast enhanced magnetic resonance imaging: Is "bright" really "dead"? Purpose: Acute recanalization in myocardial infarctions (MI) has shown to be of benefit with respect to global myocardial function and prognosis. The aim of our follow-up study was to investigate late effects of acute coronary angioplasty (PTCA) on regional wall motion after the subacute phase of MI. Patients and methods: 17 patients underwent MR imaging at 1.5 T after acute PTCA in the subacute phase of MI and a second time 6 months later. Corresponding short axis slices encompassing the left ventricle (LV) were acquired with standard Cine and delayed contrast-enhanced Magnetic Resonance Imaging (ceMRI). Target parameters were the percentual size of infarction (PSI (%)) and percentual wall thickening (PWT (%)) in the infarct area (IA) and the remote area (RA). Results: PSI was similar in the subacute phase and at 6 month's follow-up (22.2 and 21.9 %, respectively; n.s.). PWT improved significantly in IA (21.9 and 37.9 %, p < 0.05) in contrast to RA (46.4 and 38.4 %; n.s.), whereas global myocardial function did not change significantly. This late improvement was only observed in transmural MI. Patients with subendocardial myocardial infarction did not show any further improvement. Conclusion: PWT improved in IA after acute PTCA even after the subacute stage of transmural MI in this 6-month follow-up study. This phenomenon could be explained by a prolonged stunning in transmural infarctions and contradicts the hypothesis that "bright" in delayed ceMRI represents nonviable tissue in all cases. Contrast-enhanced (ce) MR can clearly depict definitive necrotic areas after myocardial infarction: The high resolution of MRI permits discrimination of subendocardial versus transmural infarction. Follow-up with cine MRI allows documentation of functional recovery of both subgroups. Methods: 30 Patients (26 males, mean age 56 years) underwent emergency PTCA ± stent for AMI. MR controls were done on day 1, 3, 7 and 28 after AMI using a 1.5 T unit (Siemens, Sonata) with the following protocol: (1) multiple TrueFISP (TR 3.2 ms, TE 1.6 ms) along the short axis to assess LV volumes and wall motion abnormalities; (2) 3D inversion recovery sequence (TR to RR, TE 1.64 ms) 10 -15 min after administration of Gd-DTPA to visualise infarcted myocardium ("late enhancement"). Results: 12 patients showed transmural infarction in late enhancement. All of these patients had wall motion abnormalities in the same segments which persisted over the observation period of 28 days. 21 patients had myocardial segments with non-transmural enhancement in late enhancement. Improvement of the wall motion abnormality was shown in 11/21 patients. The transmural group showed a decrease of EF (0 -7 %) and the non-transmural group an increase (0 -4 %).

Conclusions: Transmural infarction with late enhancement has a worse functional outcome in the involved myocardial segment and the entire ventricle than nontransmural infarction. Longer observation periods than 28 days may be required for monitoring the outcome of non-transmural infarction.

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Combined first-pass and delayed contrast enhanced MRI in the assessment of myocardial viability after acute infarction L. Natale 1 , A. Meduri 1, 2 , A. Lombardo 1 , A. Giordano 1 , R.M. Razmi 2 , P. Marano 1 ; 1 Rome/IT, 2 Birmingham, AL/US Purpose: To define the role of MRI in the assessment of myocardial viability we compared MRI, rest 99 Tc SESTAMIBI SPECT and Dobutamine Echocardiography (DE). Methods and materials: 18 consecutive patients with first AMI (63.9 a, 16 anterior, 2 inferior, 8 primary PTCA, 4 thrombolysis) underwent MRI, SPECT and DE within the first week after onset of symptoms. MRI was performed with a 1.5 T scanner (GE Signa Horizon Echospeed); short axis single slice first pass (iv 10 ml Gd-DTPA, 3 ml/s) and multi-slice delayed T1 imaging were performed. Using a 16 segments LV model, both segmental analysis and percent infarct area were analyzed. Segments were classified as: (1) normal first-pass, absent or delayed hyperenhancement; (2) hypoenhancement at first-pass, delayed hyperenhancement; (3) hypoenhancement both at first-pass and delayed imaging. In delayed images, segments out of first-pass slice were classified at delayed imaging as normal, hyperenhanced and hypoenhanced. Patterns 2 and 3 and patterns hyper-and hypo-were considered non viable. Results: Segmental analysis results were poor, particularly if compared with DE (sensitivity 70 %, specificity 78 %); infarct area analysis (at least 2 viable segments) was better (vs DE and SPECT respectively: sensitivity 76 % and 72 %, specificity 83 % and 88 %). Conclusions: Patterns 1 and 3 respectively identify viable and non viable tissue. Pattern 2 or delayed hyperenhancement is less specific as 25 % viability was demonstrated at DE and/or SPECT. First pass plus delayed imaging are superior to delayed imaging alone (sensitivity and specificity with DE and SPECT respectively 76 % vs 72 %, 84 % vs 78 %, p > 0.05), but multislice first pass is mandatory.

Comparison of Magnevist™ and Gadophrin-3 for the assessment of acute and chronic myocardial infarction J. Barkhausen 1 , W. Ebert 2 , C. Heyer 2 , J.F. Debatin 1 , H.J. Weinmann 2 ; 1 Essen/DE, 2 Berlin/DE Purpose: To investigate whether the area of hyperenhancement using extracellular contrast agents is larger compared to the region demarcated by a necrosisspecific contrast agent. Methods and materials: 15 rabbits underwent thoracotomy and permanent occlusion of a branch of the left coronary artery. Two animals died prior to imaging, 8 animals were examined 48 hours following occlusion and 5 animals were imaged six weeks following induction of the infarction. All animals received 50 mmol/kg of a necrosis-specific contrast agent (Gadophrin-3, Schering, Berlin/Germany) 24 hours prior to the MR examination. Continuous short axis views were collected on a 1.5 T MR scanner using an ECG-triggered IR-turboFLASH sequence. Imaging was repeated 10 minutes after additional injection of 100 mmol/kg of Magnevist (Schering, Berlin/Germany). The area of hyperenhancement demarcated following Gadophrin-3 injection was compared with hyperenhancement seen on Gadophrin-3 plus Magnevist enhanced images and with TTC staining. Results: In animals with acute myocardial infarction hyperenhancement was detected in 27 slices. The mean difference in the size of hyperenhancement seen on the two different in-vivo MR scans was −1.8 ± 6.0 mm 2 (p > 0.05). Both measurements showed excellent agreement with TTC-staining. Chronic infarctions showed no enhancement following Gadophrin-3 injection, whereas application of Magnevist resulted in hyperenhancement. Conclusion: In acute myocardial infarction the area of hyperenhancement following Gd-DTPA application does not exceed the area of hyperenhancement seen on Gadophrin-3 enhanced images. The combination of Gadophrin-3 and Magnevist can distinguish acute and chronic infarction because chronic myocardial infarctions do not enhance with Gadophrin-3.

Multi-slice first pass myocardial perfusion imaging: First results comparing saturation recovery (SR) trueFISP 2D und SR turboFLASH 2D pulse sequences S. Miller 1 , M. Fenchel 1 , O. Simonetti 2 , U. Kramer 1 , U. Helber 1 , N.I. Stauder 1 , J. Finn 2 , C.D. Claussen 1 ; 1 Tübingen/DE, 2 Chicago, IL/US Purpose: To compare two different pulse sequence techniques for multi-slice first pass myocardial perfusion imaging.

Methods: Using 1.5 T (Magnetom Sonata, Siemens, Erlangen) 14 patients and 6 volunteers were examined using both SR trueFISP 2D and SR TurboFLASH 2D pulse sequences. T1-weighting was enhanced applying a 90° saturation recovery preparation pulse. Sequence parameters were TR 2.4 ms, TE 1.2 ms for TrueFISP 2D and TR 1.8 ms, TE 0.8 ms for TurboFLASH imaging with a 280 -300 mm field of view and 80 × 128 matrix. Contrast injection was standardized to 5 ml (5 ml/s flow rate) resulting in a dose of 0.025 -0.035 mmol Gd-DTPA/kg per injection. Data evaluation included signal intensity (SI) over time analysis and determination of baseline and peak signal and contrast to noise ratios (S/N, C/N). An automated post-processing software (ARGUS, Siemens) was used to derive perfusion parameters SImax, slope, time to peak and area under curve. Results: With diastolic ECG-triggering 2 -4 slices/RR-interval were acquired. Values of S/N baseline were comparable (TrueFISP 5.2 ± 2.4, TurboFLASH 4.5 ± 2.4, p > 0.3), but superior results of S/N SImax (9.2 ± 5.4 vs. 6.1 ± 2.6, p < 0.006) and C/N (4.0 ± 2.1 vs. 1.6 ± 1.1, p < 0.0001) could be obtained with trueFISP. Additionally, analyzing individual myocardial segments, absolute and dynamic ranges of slope and area under curve were 2 -9 fold higher (slope 3.8 ± 2.2, area under curve 4.5 ± 2.2, p < 0.0001) using SR trueFISP compared to SR TurboFLASH imaging. Conclusion: Superior results for multi-slice first pass perfusion imaging can be obtained using SR trueFISP 2D imaging compared to SR TurboFLASH 2D.

Myocardial perfusion assessment with dynamic P792 enhanced MRI compared to 99 Tc-sestamibi-SPECT: phase II European multicenter trial J. Bremerich 1 , M. Friedrich 2 , B. Wintersperger 3 , F. Brunotte 4 , J. Piek 5 , N. Al Saadi 2 , T. Schindler 1 , S. Friedrich 2 , M.F. Reiser 3 ; 1 Basle/CH, 2 Berlin/DE, 3 Munich/DE, 4 Dijon/FR, 5 Amsterdam/NL Purpose: To compare MRI enhanced with the new rapid clearance blood pool agent (RCBPA) P792 with the gold standard 99 Tc-Sestamibi-SPECT for the assessment of myocardial perfusion. Materials and methods: By September 2001 40 patients with subacute myocardial infarction were included in 5 European centers. Dynamic first pass and delayed equilibrium phase MR images were acquired after injection of 0.0065 or 0.013 mmol/kg P792 (Guerbet, France) at injection rates of 2 ml/s or 4 ml/s. MR was conducted at 1.5 T with phased array coils. MR images were acquired in the short axis during first pass of P792 with a dynamic Saturation Recovery TurboFlash sequence (Magnetom Vision/Symphony; Siemens, Germany or CVI; General Electrics, USA). Subsequently equilibrium phase Inversion Recovery MRI were acquired 5 and 10 min after contrast injection to assess late enhancement. ∆SI and SI-upslope were calculated. Results were compared with 99 Tc-Sestamibi SPECT as Gold Standard. Results: P792 was well tolerated by all patients. With 0.013 mmol/kg infarction was readily detected on dynamic first pass MR images as hypointense areas. With 0.0065 mmol/kg infarction was not visible in all patients on dynamic images, but upslope and delta SI were attenuated. Location and extent correlated well with 99 Tc-Sestamibi-SPECT. Infarction was also visible on Inversion Recovery MR images.

The results from this study exhibit the potential interest of a new Gadolinium based intravascular contrast agent in assessing qualitatively and quantitatively hypoperfused myocardium on P792 enhanced MR images during first pass and equilibrium phase. This study was supported by Guerbet, France.

Quantitative first-pass myocardial perfusion MRI in patients with coronary artery disease after successful revascularization V. Gramovitch, V.E. Sinitsyn, M. Gordin, O. Stukalova, E. Noeva, S.K. Ternovoy, E. Chazov; Moscow/RU Purpose: To determine the potential value of quantitative myocardial perfusion MRI in the assessment of successful coronary intervention. Method and materials: We studied 9 pts (9 men, age 49 ± 10 years, weight 80 ± 9.7 kg) with 1 -3 vessel CAD and normal left ventricular (LV) function before and after (2 nd day to 1 month) coronary intervention. All pts underwent either PTCA (7/9, stent 6/7) or CABG (2/9). MRI was performed using a 1.0 T Siemens Magnetom scanner with snapshot-FLASH sequence. Perfusion was assessed by injecting the contrast agent Gd-DTPA-BMA (Omniscan, Nycomed Amersham) via the antecubital vein before (1 st bolus 8 ml) and after dipyridamole (0.56 mg/kg, 2 nd Gd bolus 12 ml). Myocardial and blood SI were converted to concentration of Gd according to the in vitro calibration curve and fitted by one-compartment model by

Saturday B A C D E F 175 the use of a custom written program. Eleven normal and 11 segments supplied by stenotic coronary arteries (³ 50 % diameter stenosis) with successful intervention afterwards (residual stenosis < 50 %) were included in the final analysis. Results: Myocardial blood flow was similar in normal and "stenotic" segments at base line (1.21 ± 0.49 and 1.28 ± 0.37 ml/min/g of tissue) but significantly lower in "stenotic" segments during hyperemia (1.44 ± 0.57 vs. 2.52 ± 0.94 ml/min/g, p < 0.05). Coronary vasodilator reserve (the ratio of flow during hyperemia to flow at base line) was significantly lower in "stenotic" segments than in normal (1.2 ± 0.36 vs. 2.1 ± 0.75, p < 0.05) and normalized completely after successful revascularization (3.1 ± 1.45). Conclusion: Quantitative MR perfusion assessment may be useful for the follow-up of patients with CAD after coronary intervention.

Myocardial perfusion in the human heart: Quantitative assessment using a spin-labeling technique at 2 T F. Fidler, C.M. Wacker, P.M. Jakob, W.R. Bauer, A. Haase; Würzburg/DE Purpose: The aim of this study was to determine myocardial perfusion of the human heart using a spin-labeling technique without exogenous contrast agent. Method and materials: An ECG-gated fast saturation recovery FLASH sequence was implemented using a 2 T scanner (Bruker) with a homebuilt quadrature surface coil for signal reception. T1 measurements were performed after global and slice-selective saturation under resting conditions and adenosine-induced stress. Exams were obtained breathing room air (air) and pure oxygen (oxy). 10 ECGtriggered enddiastolic midventricular short axis views were acquired in a single breathhold of about 15 s in 9 healthy volunteers. Results: Myocardial perfusion was calculated as P = 2.5 ± 0.7 ml/g/min (rest, air), 4.8 ± 1.1 ml/g/min (stress, air) and 1.6 ± 0.6 ml/g/min (rest, oxy). T1 of LV (RV) blood was 1700 ± 100 ms (1600 ± 120 ms) (air) and 1440 ± 45 ms (1560 ± 150 ms) (oxy).

The presented spin-labeling method is a robust alternative for quantitative perfusion evaluation and allows repeated measurements without contrast agents. Oxygen induced changes of T1 (myocardium and blood) are detectable and may therefore become important in patients with coronary artery disease. Purpose: In small larynx tumors (T1, T2) the presence of spread is crucial in determining adequate surgical or laser-surgical treatment. Therefore, the purpose of the study was to determine sensitivity and specificity of preoperative multi-slice helical CT (MSCT) for the infiltration of various glottic laryngeal structures. Material/methods: 30 patients with suspected laryngeal cancer were investigated on a MSCT scanner (Siemens plus 4 Volume Zoom) with 4 × 1 mm collimation, 0.5 seconds rotation time in a single breathhold. Multiplanar reconstructions (MPR) in sagittal and coronal planes were reconstructed in all patients and rated in consensus. All findings regarding tumor spread into the glottic fat, crossing the anterior commissure, infiltration of the arytenoids and the extension along the vocal cords were compared to surgery and histology.

The sensitivity and specificity of MSCT regarding the infiltration of the glottic region were 93 %, 85 %. Regarding infiltration of the anterior commissure sensitivity and specificity were 85 %, 94 %, respectively; regarding the infiltration of the anterior part of the vocal cords 89 % and 92 %, and regarding the infiltration of the arytenoids 83 % and 96 %, respectively. Sagittal MPRs were especially helpful regarding the surfaces of the arytenoids and the anterior commissure, and coronal MPRs were most helpful in the evaluation of the vocal cords. The detection of spread of supraglottic laryngeal tumors is crucial in determining best treatment, as the preoperative assessment decides to what extend surgical therapy can be offered. Thus, the purpose of the study was to determine sensitivity and specificity of multislice helical CT (MSCT) for the identification of infiltration of supraglottic laryngeal structures. Material/methods: Investigations on a MSCT scanner were performed in 30 patients with suspected supraglottic laryngeal cancer, with two entire acquisitions; one in breathhold and one in phonation. Multiplanar reconstruction's (MPR 3 mm thickness) in sagittal and coronal plane were reconstructed in all patients. The findings were separately evaluated regarding tumor spread into the pre-epiglottic fat, the anterior commissure, the laryngeal and the superficial side of the epiglottis and the piriform sinus, and were compared to surgery and histology. Results: Regarding infiltration of the piriform sinus sensitivity and specificity were 86 % and 96 %, regarding the infiltration of the laryngeal side and the superficial side of the epiglottis 100 % and 93 %, and regarding the anterior commissure 85 % and 94 %, respectively. The cumulative sensitivity and specificity of MSCT regarding the infiltration of the entire supraglottic region were 89 % and 95 %, respectively. While the MPRs were felt to be of general benefit, sagittal MPRs were especially helpful regarding both surfaces of the epiglottis, and coronal MPRs were mot helpful in the evaluation of the piriforme sinuses.

The extend of supraglottic laryngeal tumor spread can be depicted with high accuracy using MSCT.

Referred pain in oropharynx carcinoma: A clinical symptom finds its anatomical correlate in MRI H.C. Thoeny, K.T. Beer, R.H. Greiner, P. Vock; Berne/CH Purpose: Is there a correlation between MRI and the prognostic symptom of referred pain to the ear in patients with oropharynx carcinoma? Method/materials: Irritation in the region innervated by the glossopharyngeal nerve can be transmitted as pain to the ear due to connections between the glossopharyngeal nerve and the tympanic nerve. In a prospective study 36 consecutive patients, median age 59 (range, 41 -76 years) with oropharynx carcinoma underwent MRI before radical radiotherapy. 21 patients had referred pain to the ear, 15 did not. The protocol included axial PD/T2-weighted TSE sequences, axial, coronal, and sagittal T1-weighted SE sequences before and/or after contrast medium administration. Examinations were performed on two 1.5 T MRIs (Magnetom Vision, Siemens, or Signa, GE). Two independent, blinded radiologists analyzed the MRI studies for alterations of anatomical structures (effacement, signal alteration, or contrast medium enhancement) of the oropharynx and adjacent regions. A twosided 2 test was used to compare variables. Results: Patients with referred pain to the ear showed significantly more alterations of the following structures innervated by the glossopharyngeal nerve: palatoglossus (p < 0.002), stylo-(p < 0.006) and palatopharyngeus (p < 0.004), and constrictor pharyngis (p < 0.04) muscles; hard palate (p < 0.005), tonsil (p < 0.002), pre-epiglottic space (p < 0.03), and posterior soft palate (p < 0.003). No difference could be observed for structures innervated by different cranial nerves. Conclusions: Alterations of structures innervated by the glosso-pharyngeal nerve showed a significant association with referred pain to the ear in patients with oropharynx carcinoma. The symptom of reflex-otalgia has, therefore, an anatomical correlate in MRI.

Virtual laryngoscopy with multislice CT enables grading of upper airway stenosis H. Hoppe, H.C. Thöny, H.-P. Dinkel, P. Zbären, P. Vock; Berne/CH Purpose: To compare the efficiency of noninvasive virtual laryngoscopy in depicting and grading upper airway stenosis with multislice CT versus fiberoptic laryngoscopy. Methods and materials: Multislice CT and fiberoptic laryngoscopy were used to examine 116 upper airway sections (supraglottis, glottis, subglottis, trachea) from 29 patients (n = 19 malignant upper airway pathology, n = 5 benign upper airway pathology, n = 5 control group without upper airway pathology). CT data were obtained on a Toshiba Asteion multislice CT in 4 × 1 mm collimation, pitch 5.5/4 and 1 mm reconstruction interval. Postprocessing was performed using surface ren-

A C D E F 176 dering and multiplanar reformats (MPR). CT images were independently interpreted by two radiologists. Fiberoptic laryngoscopy was the gold standard of reference. Results: Virtual laryngoscopy and MPR accurately demonstrated upper airway stenosis caused by intraluminal tumor growth. There was a close correlation (r = 0.94) between virtual laryngoscopic and fiberoptic laryngoscopic grading of stenosis. Virtual laryngoscopy was limited in the differentiation of mucus and appositional tissue folds from tumor, which was more reliable with MPR and axial CT slices. Furthermore, subtle mucosal irregularity could not be defined. Conclusion: Virtual laryngosopy with multislice CT enables high-resolution endoluminal imaging of the upper airways with a short scan time despite thin collimation, but should be combined with axial CT-slices and MPR readings. Virtual laryngoscopy was especially useful for evaluation of subglottic and tracheal stenosis, which may be difficult to assess with fiberoptic laryngoscopy. It is a reliable non-invasive method for the assessment of upper airway stenosis as a complement for fiberoptic laryngoscopy. Purpose: To evaluate the potential of MR-guided laser-induced thermotherapy using a high power irrigated laser application system for the treatment of recurrent head and neck tumors. Materials and methods: 27 recurrent tumors in the head and neck tumors (recurrent squamous cell carcinoma n = 24, recurrent pleomorphic adenoma n = 3) were treated using MR-guided laser-induced thermotherapy and a newly developed irrigated power application system which allows power settings 6 times higher than the conventional system. A total of 53 laser applications were performed using 37 laser applicators. MR thermometry was performed using a temperature sensitive T1-weighted gradient echo sequence for monitoring thermal induced changes in signal intensity. Follow up studies were performed using plain and contrast enhanced MR. Results: All procedures could be performed under local anesthesia. Laser applicators with an active length of 2 or 3 cm were used with 24 or 36 W respectively (12 W/cm active length of the laser applicator). The application time was between 4 and 15 minutes. All lesions showed a very rapid heat distribution. We were able to induce coagulative necrosis in all patients. Clinical relevant improvement of clinical symptoms was observed in 24 lesions. The treatment of 3 lesions resulted in no improvement of clinical symptoms. Conclusion: MR-guided LITT using a high power irrigated laser application system proved to be an reliable and effective method to treat recurrent tumors in the head and neck region. MR-thermometry allowed monitoring of laser induced temperature changes during LITT.

Fat suppressed T1 sequences in the evaluation of "T" factor in carcinoma of the tongue S. Cappabianca, A. Barberi, L. Pasqualetto, G. Colella, R. Grassi; Naples/IT Purpose: Comparison between SE T1, DP and T2 sequences and T1 fat-suppression sequences in staging of lingual carcinoma Methods: 47 patients with lingual carcinoma underwent MRI exam using a 1 T superconducting scanner. In all cases SE sequences DP-T2w were obtained; T1w and T1w with selective fat suppression before and after intravenous administration of Gd-DTPA were also acquired. Two different groups of radiologists evaluated independently the DP-T2 and T1 sequences, and the DP-T2 and T1-FS sequences, in order to define the extension of the neoplasm ("T" factor). MRI findings were compared with pathological staining. Results: DP-T2 and T1: Tumour not detectable n = 3; T1 n = 4, T2 n = 6, T3 n = 20, T4 n = 12. DP-T2, T1 and T1-FS: Tumour not detectable n = 2; T1 n = 5, T2 n = 6, T3 n = 23, T4 n = 9. Surgery/Pathology: Tumour not detectable n = 0; T1 n = 8, T2 n = 7, T3 n = 20, T4 n = 10. DP-T2w and T1w sequences diagnostic accuracy 93.3 %; DP-T2w, T1w T1-FS sequences diagnostic accuracy 95.5 %. Conclusion: Our data suggests that in the local staging of lingual carcinoma the use of SE-T1 sequences with selective fat suppression can improve diagnostic accuracy of MRI in evaluation of tumour volume.

withdrawn by author

Ultrasonographic detection of iatrogenic accessory nerve palsy P. Kovacs, G. Bodner, A. Gardetto, H. Piza-Katzer, W.R. Jaschke; Innsbruck/AT Purpose: To report the ultrasonographic findings of 4 cases of iatrogenic accessory nerve palsy after lymph node biopsy and neck dissection and to demonstrate feasibility of ultrasonography (US) in detecting the accessory nerve in three cadaveric specimens. Methods and materials: 4 patients (range 42 -65 years) presented with neck and shoulder pain after surgical intervention in the neck region (2 after lymph node biopsy, 2 after neck dissection). US was performed with a linear broad-band transducer (5 -12 MHz) working on a HDI 5000 (ATL). In 3 fresh cadavers the accessory nerve was detected by means of US and marked with blue ink. Following, the accessory nerve was exposed carefully. Results: In the right lateral cervical region of two patients, who underwent lymph node biopsy, we found a hypoechoic mass, in which a tubular structure ended. We suspected a cut accessory nerve. In two patients with unilateral neck dissection US revealed a tubular structure ending in a hypoechoic scar measuring 3 cm in length. In all cases the trapezius muscle showed hyperechoic texture, suggestive of muscular atrophy. US findings were confirmed by electroneurographic testing and surgical nerve inspection. On US the accessory nerve appears a small tubular structure (diameter 0.7 mm) lying just under the superficial layer of cervical fascia. In all specimens the nerve was correctly marked by means of US showing blue stained accessory nerves after dissection. Conclusions: The capability of high resolution US allows detection of the normal accessory nerve and of iatrogenic accessory nerve palsy. 

Saturday

Materials and methods: To date, 5 small (< 3 cm) and 5 large (> 3 cm) solid renal tumours and 2 cystic complex renal masses (< 3 cm) were evaluated by ultrasound (US), Color Doppler (CD) and PIHI. PIHI was performed after Levovist injection by high MI (1.0 -1.2) intermittent manual triggered stimulation every 10 -15 seconds, during vascular (20 -60 seconds) and late phase (60 -120 seconds). Helical CT pattern and/or histologic findings were considered as the reference procedures. Results: Reference procedures classified 3 small solid tumours and 5 large solid tumours as renal adenocarcinomas, 2 small solid tumours as angyomiolipomas and 2 cystic complex renal masses as cystic papillary tumours. Small solid renal adenocarcinomas were hypoechoic (n = 2) or hyperechoic (n = 1) on US with a basket arterial pattern on CD. Large solid adenocarcinomas appeared inhomogeneous with no vascular pattern, while angiomyolipomas appeared hyperechoic with peripheral venous flows. Cystic complex renal masses revealed thick septa and a peripheral solid portions on US with a basket arterial pattern on CD. On PIHI small solid renal adenocarcinomas appeared hyperechoic on vascular phase and isoechoic (n = 2) or hypoechoic (n = 1) on late phase. Large renal adenocarcinomas revealed increased conspicutiy of necrotic intratumoural zones and inhomogeneous enhancement. Renal angiomyolipomas revealed dot-like enhancement. Cystic renal adenocarcinomas revealed peripheral enhancement limited on septa or solid portion. 

During a 6-month period, variable renal masses including renal cell carcinoma (n = 10), transitional cell carcinoma (n = 2), acute pyelonephritis (n = 3), angiomyolipoma (n = 1), and traumatic renal contusion (n = 1) were evaluated with CHA US (LogiQ 700 Expert Series; GE Medical Systems) using microbubble contrast agent. US images were obtained before contrast administration and with a bolus injection of 4 g of microbubble contrast agent (300 mg/ml of Levovist; Schering) in every 10 -15 s for 5 min. The contrast enhancement patterns of variable renal masses were assessed. Result: 10 renal cell carcinomas showed more enhancement than adjacent renal parenchyma was seen between 16 to 57 s (mean, 30 s) and 51 to 252 s (mean, 82 s) after injection. The duration of enhancement was 13 to 208 s (mean, 80 s). One angiomyolipoma showed heterogeneous enhancement from 27 s to 84 s. All transitional cell carcinomas showed no definite enhancement. Three acute pyelonephritis and one traumatic renal contusion showed focal perfusion defects that were not apparent on pre-contrast scan. Conclusion: CHA US with microbubble contrast agent is an effective US technique in the evaluation of both tumour vascularity and renal perfusion abnormality.

withdrawn by author (5). All patients were followed-up clinically, biochemically and by CT both early (< 7 days) and at 6 monthly intervals. Results: One patient demonstrated a minor internal injury to the psoas muscle. No significant rise in creatinine was noted post-procedurally in 7/8 patients (mean rise: 3.6 µmol/l; range −8.1 to 19.8 µmol/l). One patient with Von Hippel-Lindau syndrome had 4 tumours treated in a single kidney. There has been a gradual post-treatment rise in creatinine, from 130 to 233 µmol/l. Early post-procedural CT demonstrated complete tumour necrosis in 9/11 tumours. Two tumours (3.0 and 5.5 cm) required additional CT-guided treatments of residual crescents of viable tumour. Follow-up (mean 7.4 months, 82 patient months, range 1 -17 months) revealed no evidence of local or distant recurrence. Conclusions: Early experience suggests RFA is a safe, well-tolerated, and minimally invasive therapy for renal cell carcinoma. In the era of nephron-sparing surgery RFA may have a role in the management of small problematic RCC. 

Drug-induced MR-pyelography in the evaluation of renal collecting system malformations, tumours, renal calculi and obstructed renal ureters M. Di Girolamo 1 , A. Grossi 1 , A. Roncacci 1 , R. Di Nardo 1 , L. Azzarri 2 , V. David 1 ; 1 Rome/IT, 2 Grottaferrata/IT Purpose: Drug-induced MR-pyelography (DiMRP) is a diagnostic technique for the evaluation of obstructed and non-obstructed renal collecting systems.

A C D E F 178 Method and materials: 10 normal volunteers and 135 patients underwent DiMRP. The examination was performed with a 3-D non-breath-holding fat-suppressed TurboSE sequence (TR: 3000 ms; TE: 700 ms; N.Ex.: 6; ETL: 128; Acq.Time: 9 min) on coronal planes. These acquisitions were post-processed with a MIP algorithm. To obtain maximum filling of the collecting system, the diuresis was pharmacologically induced by administering i.v. 250 ml of saline solution together with 20 mg i.v. of furosemide. One MR acquisition was performed 10 minutes after diuresis induction. 5 normal volunteers and 115 patients had undergone IVU and ascending pyelography was performed in 15 cases. Results: We always obtained an excellent anatomical evaluation of the renal collecting system that was considered comparable to that obtained with IVU. It was always possible to study the renal collecting system malformations, even in patients with known contraindication for i.v. administration of contrast media. Renal calculi larger than 2 mm were always identified by the analysis of 3D coronal scans. DiMRP is particularly important for the detection of ureteral stones. 24 patients had non-functioning kidneys on IVU: in 23 cases with obstructive uropathy the site of the obstruction was determined and using conventional MRI, abdominal plain radiograph and urinary cytology, the cause was always determined. Conclusions: DiMRP is recommended for patients with contraindications for i.v. administration of contrast agents; in non-functioning kidneys is considered the best diagnostic imaging modality to perform after US, especially in case of ureteral obstruction.

Filling defect artefacts in magnetic resonance urography G. Girish, W.K. Chooi, S.K. Morcos; Sheffield/GB Purpose: (1) assessing the prevalence of filling defect artefacts (FDA) in magnetic resonance urography (MRU). (2) Presenting the characteristic features of FDA, that can differentiate them from true filling defects (TFD). Method/materials: MRU's of 45 patients with neurogenic bladder dysfunction were reviewed to assess the prevalence of filling defects within the pelvicalycyal system (PCS) and ureter. Heavily T2 weighted fast spin echo techniques with fat saturation were used. These included axial images 5 mm (thick)/2 mm (gap), slab images (75 mm thick) of retroperitoneum and volume coronal imaging of kidneys and retroperitoneum with 3D and maximum intensity projections. Dilatation of pelvicalyceal system as well as features of filling defects (central, eccentric, complete) were graded. Clinical course and plain films were reviewed to determine significance of filling defects. Results: Filling defects were present in 27 pts (60 %). Prevalence of filling defect artefacts amounts to 22/45 (49 %) and that of true filling defects was 11 %. The following are the characteristic features of FDA that differentiate them from true filling defects: (1) Vast majority of FDA occurred in axial T2 weighted images and very rarely in slab and maximum intensity projection images. (2) FDA's were usually small, centrally placed (94 %) and noted mostly in pelvicalyceal system (41.8 %) and the upper third of the ureter (39.5 %). (3) True filling defects were bigger in size and seen in two or more image sequences. Conclusions: (1) Awareness of these artefacts will avoid misinterpretation and prevent further unnecessary investigations or interventions.

(2) When in doubt, correlation is suggested with other MRI sequences, plain abdomen radiograph and clinical presentation. Purpose: Differentiation of healthy kidneys from those with haemodynamically significant stenosis or those with renoparenchymal disease. Methods and materials: In 79 kidneys with suspected renal artery stenosis (confirmed stenosis n = 38, no stenosis found n = 41) or parenchymal disease (n = 30) renal flow and perfusion measurements as well as MR angiography were performed. Flow measurements were done using an ECG gated cine phase FLASH sequence, perfusion was measured using an arterial spin labeling FAIR sequence. Contrast enhanced MR angiography was done with a fast 3D GRE sequence in a single breath hold. Data was compared to that from 31 healthy volunteer kidneys and correlated to serum creatinin levels. Results: Substantial differences in mean renal artery flow and perfusion were found in kidneys with renal artery stenosis or parenchymal disease compared to healthy kidneys. In addition perfusion measurements showed significant agreement to 99 Tc renal scintigraphy. Using the discriminant analysis we were able to achieve a specificity of 79 % and a sensitivity of 90 % in terms of separating healthy kidneys from those with either vascular, parenchymal or combined disease. On the contrary, renal volume measurements did not show any significant differences.

The combination of MR angiography, flow measurements and MR perfusion measurements offers a comprehensive way for assessment of both renovascular and renoparenchymal disease. It offers a non invasive way to separate normal individuals from either those with haemodynamically significant stenosis or those with underlying renoparenchymal damage.

Functional imaging of the kidneys using pure O2 inhalation R.A. Jones, N. Grenier, M. Ries, C.T.W. Moonen; Bordeaux/FR Purpose: Because of its paramagnetic effects, pure O2 reduces the T1 of lungs. Our purpose was to investigate the intra-renal signal intensity changes induced by the dissolved molecular oxygen in blood. Materials and methods: Nine volunteers were imaged while breathing normal atmosphere and pure O2 alternatively with an inversion prepared, segmented, half Fourier TSE sequence for T1 measurement and a multiple echo gradient echo sequence for T2* measurement. ROI were positioned on the cortex, the medulla, the liver and the spleen. Subtraction and cross-correlation images were also obtained after dynamic T1w acquisitions during three successive phases (air-O2air) Results: The only significant intrarenal change was the reduction of T1 within cortex while O2 breathing (882 ± 59 ms vs 829 ± 70 ms, p = 0.0001) and a reduction of T1 within the spleen. Neither significant change of T1 within the medulla and the liver nor significant change of T2*, in all organs, were observed. The effect was not related to flow because no change was noted between selective and nonselective inversion pulses.

The observed T1 change induced by pure O2 within the cortex is related to the high arterial blood volume without O2 consumption. The absence of change within the medulla is probably related to the high O2 consumption and shunting effect. is to distinguish it from other entities for prognostic and management purposes. It is the unusual cases of LCH that often create a particular diagnostic dilemma. However, careful analysis of the radiographs including the site of involvement and behavior, coupled with a detailed demographic and clinical history, can be suggestive of the diagnosis. Methods and materials: 542 consultation cases, including 730 skeletal sites, submitted to the Armed Forces Institute of Pathology, were analyzed for unusual manifestations of LCH. Five unusual manifestations were evaluated including cortical involvement, disease at birth, presence of fluid levels, circumferential "pencilling", and involvement of the mandibular inferior cortex. Results: Unusual demographics included 46 non-Caucasian cases. Unusual sites of involvement were the epiphysis (2), apophysis (1), cervical spine (13), posterior elements of the spine (8), soft tissues (2), cortical involvement (6), and atypical locations (sternum, middle and distal phalanx). Unusual manifestations included crossing the physis (1), crossing calvarial sutures (6), fluid levels (2), erosion of the inferior mandibular cortex (1), transforming from sclerotic to lytic (2), brain invasion (1), circumferential "pencilling" (5), sequestrum in noncalvarial sites (2), unusual size of a lesion (1), and bone expansion (4). These unusual appearances may mimic other diseases including Paget disease, fibrous dysplasia, Ewing sarcoma, coxa vara, and metaphysitis. Conclusion: Recognition of the spectrum of unusual manifestations of LCH is helpful in allowing distinction from other differential diagnoses. 

The imaging of 6 patients (4 female, 2 male; age range 13 -55 a, mean age 24.8 a) with biopsy-proved subperiosteal aneurysmal bone cyst was reviewed. Radiologic studies inculuded radiographs (n = 6), CT (n = 2), and MR images (n = 6). Evaluation included patient demographics, lesion location and size, radiographic features, and intrinsic characteristics on CT and MR images. Review of histologic specimens was carried out by an experienced musculoskeletal pathologist. Results: All lesions were located at the surface of long tubular bones (femur 3, tibia 2, humerus 1); three involved the diaphysis, two the dia-/metaphysis, and one exclusively the metaphysis. Lesion size ranged from 2.5 to 6 cm in maximum diameter. Radiographs and CT images always showed a superficial bone defect, which on radiographs demonstrated irregular margins in four cases. All lesions caused an interrupted periosteal reaction (shell 3, trabeculated shell 1, Codman angle 2). MR images always showed a multicystic appearance with hypointense rim, contrast-enhancing cyst walls, and fluid levels. Edema of adjacent soft tissues was present in all cases. Conclusion: Aneurysmal bone cysts in a subperiosteal location can demonstrate an aggressive radiographic appearance. MR imaging appears to be most valuable in differential diagnosis, since it can demonstrate typical morphological features of the underlying process.

Rib sonography: Can we obtain more information than with conventional radiologic studies? S.H. Paik, M. Chung, Y. Yoon, J.-G. Im, J. Ahn; Seoul/KR Purpose: We performed this study to evaluate whether high-resolution ultrasonography can give more information concerning rib lesions than plain radiography or bone scintigraphy. Method: We selected 20 patients with high uptake rib lesion on bone scintigraphy. Plain radiography and rib ultrasonography were performed on these patients. Ultrasonography was performed using linear 12.5 MHz transducer. We analyzed cortical disruption, mass, callus formation, hematoma, deformity and bone destruction by rib ultrasonography. We considered radiologic findings and clinical information in the diagnosis. Purpose: Innovative therapeutic protocols of musculoskeletal tumors include neoadjuvant and antiangiogenic approaches. Functional tumor imaging including dynamic contrast enhanced (DCE) MRI and FDG-PET seem to be capable techniques to evaluate ongoing response during therapy. Aim of this study is to assess the clinical utility of DCE-MRI in such cases. Materials and methods: Within a therapeutic phase I protocol, DCE-MRI was included as a surrogate marker to assess the tumor prior and during therapy. After neoadjuvant treatment, surgical resection was performed with histological correlation as well as detailed micro-array analysis. MRI was performed on a 1.5 T clinical system using optimized fast 3D gradient echo sequences. Standard Gd-chelates were given at 0.1 mmol/kg bw and the studies post processed using a PC based environment facilitating quantification and visualization.

Results: DCE-MRI could be performed and quantified in all cases. The enhancement patterns observed revealed a wide variability with areas of high uptake and rapid washout correlating to active tumor areas and regions of contrast agent trapping seen in less vascularized, necrotic areas. Areas with decreased enhancement correlate with response to therapy. In more than 1/3 of the cases, active tumor areas were only detected by functional imaging, not seen otherwise and confirmed histologically. Conclusion: Functional Imaging is an essential tool to assess ongoing therapy in musculoskeletal tumors, it is robust and can be used as surrogate marker in therapeutic trials.

Whole body MR imaging with a rolling We assessed a single whole-body MRI examination for detection and staging of metastases and compared the results with findings of nuclear bone scintigraphy and CT examination. Materials and methods: 37 patients with known primary malignancies were included in this study. Patients were examined on a MR system (Siemens Sonata) equipped with a rolling table platform (BodySURF) allowing the swift movement of the patient through the magnet bore as well as through a phased array surface coil. T1w 3D VIBE data sets were collected in five stations following the intravenous application of paramagnetic contrast covering the body from skull to the knees. The chest and abdomen were imaged with T2 HASTE and T1 FLASH before contrast. Mean examination time amounted to 15 (± 3) minutes. MRI findings were compared to results obtained with skeletal bone scintigraphy and CT-scans of the abdomen and chest. Results: All pulmonary and hepatic metastases > 6 mm detected by CT were identified by whole-body MRI. Skeletal scintigraphy detected bone metastases in nineteen patients. In eighteen patients MRI confirmed these lesions. In one patients presenting with bone metastases in the ribs MRI failed to reveal the osseous lesions, whereas in four other patients MRI detected bone metastases missed by scintigraphy and eventually confirmed by biopsy. Conclusion: VIBE whole-body MRI screening for metastases correlated well with CT and scintigraphy. Use of the rolling table platform provides the basis for a comprehensive whole-body exam in merely 15 minutes.

Early therapeutic evaluation of bone metastases from breast cancer: Histopathology, MR imaging and CT I. Ciray, G.K.O. Åström, H. Lindman, H. Nordgren, J. Bergh, H.K. Ahlström; Uppsala/SE Purpose: Evaluation of early therapeutic changes in breast cancer bone metastases using various parameters of MRI, CT and histopathology. Materials and methods: 20 metastatic bone lesions in 17 breast cancer patients were examined with MRI and CT, and were subsequently biopsied under CT-guidance before initiation of chemotherapy and 6 courses later (median). The changes in size and signal intensity (SI) on T1-weighted and long TE inversion-recovery turbo-spin-echo (long TE IR-TSE) MR sequences and in density on CT were measured. The histopathological changes in the amount of tumor and fat cells, in the density of fibrosis and in the trabecular bone were evaluated. Results: The amount of tumor cells was decreased in 16 (responding) and was increased in 4 lesions (progressive). SI could not be measured in one responding lesion. There was no change in the tumor size and SI on T1-weighted sequence in 8 of 15 responding lesions. There was an increase in SI on long TE IR-TSE sequence of 11 of 15 responding lesions. Two progressive lesions remained unchanged, one increased in size and the other in SI on T1-weighted sequence with no alteration on long TE IR-TSE sequence. Density increased in 12 of 16 responding lesions and in 3 of the 4 progressive lesions on CT images. Conclusion: An increase in SI in metastatic lesions on long TE IR-TSE sequence may indicate an early therapeutic response while a T1-weighted sequence is of limited value. An increased density on CT can be measured in both responding and progressive lesions.

Belgian soft tissue neoplasm registry (BSTNR) J.L. Gielen, P.M. Parizel, A.M.A. De Schepper; Antwerp/BE Introduction and objectives: Based on epidemiological data from the USA, the total number of new cases of malignant soft tissue tumors in Belgium is estimated at 200 per year. This low incidence and the overmedicalization with numerous university hospitals and large general hospitals with MR-equipment available limits the number of cases seen in each hospital and per year and hampers the gaining of expertise in this field. To cope with these disadvantages, the department of radiology of the University Hospital of Antwerp in cooperation with all MR centers (47) in Belgium created a Belgian Soft Tissue Neoplasm Registry ("BSTNR"), starting the registration on January 1, 2001. Material and methods: Internationally accepted standard procedures are used in the development of the electronic database in order to guarantee future and systematic availability of the data. A clinical and statistical indexing of biomedical imaging and image-related information based on the attributes of image acquisition procedures and on the diagnostic image obeservations is applied. In this way, an electronic image data selection by image related, acquisition related as well as disease related criteria will be possible. Results: Until now 330 cases of soft tissue tumor sent by the cooperating centers have been registered.

The BSTNR achieves 3 objectives: (1) to provide the referring radiologist with a second opinion about diagnosis and differential diagnosis within 48 hours;

(2) to create a digital archive at the disposal of national or foreign researchers;

(3) to obtain epidemiological information about the prevalence of STT in Belgium. The vascularity in malignant lesions was significantly greater than in benign (benign: 0.96 m%CDA, malignant: 5.88 m%CDA, P < 0.001). Vascular heterogeneity (SD%CDA) showed similar results, albeit less significant (P < 0.01). There was a monotonic linear relationship between m%CDA and SD%CDA with increasing tumor grade. Best separation was achieved between benign, intermediate and high grade (P < 0.001). There was a clear correlation between increasing tumor grade and higher vascularity (m%CDA). Separation between benign and low grade was possible, but less significant (P < 0.08). This correlates to histopathology, where vascular markers are low -similar to benign -for this group. Conclusions: QPD shows the potential to differentiate benign from malignant softtissue tumors. It can measure increasing vascularity and vascular heterogeneity and reliably predict higher-grade malignancy. QPD therefore is a promising new non-invasive method both diagnostically and prognostically. After Gd administration there was no significant enhancement of the nodules. Our findings were then confirmed in all cases with the exception of one patient in whom arthroscopy did not find the lesion as it was located outside the synovial membrane.

Conclusion: MR provides a good and detailed evaluation of the different recesses of the knee and demonstrates high diagnostic accuracy in the evaluation of PVNS enabling lesion characterization. To verify the benefits introduced by a new CR system for digital mammography, using a dual-side reader and transparent imaging plates. Methods and materials: Two kinds of breast phantom have been used to compare the performance of two different CR systems employed in digital mammography. They are the high resolution imaging plate HR-V coupled with the FCR 5000-R reading unit and the last Fuji CR system including transparent IPs and a dual-side reader. This detects also the laser-stimulated light propagating toward the back of the plate, which was previously removed from the HR-V plates. Consequently, the detection efficiency and the signal-to-noise ratio are increased, resulting in a better image quality. Phantom images have been taken for different values of entrance dose. The images produced by the two CR systems have been scored by three expert observers and the results compared in terms of both contrast-detail curves and detail visibility.

The benefits of the new CR system are emphasized by the contrastdetail curves and the CIRS phantom scoring. The new system permits a dose reduction of about 30 %. The spatial resolution is heavily better and exceeds 7 lp/mm for the new system, while is slightly lower than 5 lp/mm for the previous. The contrast-detail analysis shows a gain of 13 % in disk size and 6 % in contrast.

Saturday Purpose: Dry and conventional laser printers have become an equipment for producing images from digital mammography. Purpose of our study was to compare image quality of a dry versus a conventional laser imager for digital mammography. Materials and methods: Two view mammograms of 80 patients with different breast composition (pattern I -IV) and mammograms of 44 patients with pathologic lesions were printed on a conventional wet laser imager (Agfa ScopixLR 5200) and a dry laser imager (Kodak DryView LaserImager 8600). All examinations were performed on a full field digital system (Senographe 2000D, GE). Two radiologists independently scored images side by side on the following aspects: delimitation of the skin, subcutis, musculature, glandular tissue, fat, and calcification. Each comparative aspect was rated by using a five-level scale. In case of a breast lesion (masses n = 22, calcifications n = 22) lesions characteristics and resulting BIRADS-classification were assessed. Additionally, artefacts were noted.

Objective comparison was performed in accordance to instructions of the producers.

Results: A total of 248 digital mammograms were assessed. Breast parenchyma of different composition and pathologic lesions were equally displayed by dry and conventional laser imagers. Dry laser images showed significantly more artefacts at the film surface (73.6 % vs. 22.6 %, p < 0.001). However, these artefacts did not influence image interpretation. Conclusion: Compared to a conventional wet laser imager, a dry laser imager is capable of producing images of equal quality. The dry laser imager offers advantages with regard to handling, installation, maintenance, and environmental criteria.

Full-field digital mammography and patient dose reduction G. Gennaro, C. di Maggio, E. Bellan; Padova/IT Purpose: To estimate the dose reduction factor allowed by the full-field digital mammography. Methods and materials: Exposure parameters and breast characteristics have been collected from 300 screen-film (GE Senographe DMR) and 300 digital mammograms (GE Senographe 2000D) randomly distributed. From the track/filter combination, kV and mAs values and breast thickness we estimated the entrance skin dose by using the IPEM (Institute of Physics and Engineering in Medicine) data.

Results: Data analysis shows a mean dose reduction of 32 % for the digital system. It is mainly due to the larger dynamic range of the digital detector, which permits the use of Rh/Rh combination in almost 60 % of considered cases without image quality degradation. In screen/film the Mo track was needed in most cases, while the Rh/Rh choice was convenient only for 20 %. Moreover, by analysing data as a function of breast thickness, the digital system shows an extra dose reduction for each track/filter combination due to its higher quantum efficiency compared with the screen/film system. Conclusion: The digital system delivers an entrance skin dose 30 % lower than the screen-film system.

A quality control phantom for full field digital mammography: First experience P. Baldelli 1 , C. di Maggio 2 , M. Gambaccini 1 , G. Gennaro 2 , D. Giannopoulou 1 , A. Taibi 1 ; 1 Ferrara/IT, 2 Padova/IT Purpose: To verify the usefulness of a simple phantom to monitor some quality control parameters in full field digital mammography. Methods and materials: A phantom has been developed for periodic quality control measurements on a full field digital mammography system GE Senographe 2000D). The phantom allowed us to verify the detector linearity, uniformity, contrast and spatial resolution and the reproducibility and stability of both the detector and the automatic exposure control system (AOP). The system stability was daily controlled by using four different exposure settings. The raw images have been used for data analysis.

Results have shown that the presented phantom is able to give information on the detector characteristics and can detect any problem related to the system stability. The collected data have verified that the detector response is linear with a high correlation degree, for both the Mo/Mo and Rh/Rh combinations. The non-uniformity was lower than a few percent. The detector response variability was lower than 1 % when manual exposure is employed while the fluctuation in the AOP choices was less than 5 % for the three available settings (STD, CNT and DOSE).

The phantom used was found useful to check the key detector performance parameters and the system stability. It is fast and easy to use, as required for a quality control.

Full-field digital mammography -comparison of hardcopy versus softcopy reading S. Obenauer, S. Luftner-Nagel, K.-P. Hermann, U. Fischer, E. Grabbe; Göttingen/DE Purpose: To evaluate the feasibility of using a mammography workstation for the interpretation of digital mammography images in comparison to the results of hardcopy reading. Materials: Mammograms performed on a digital full-field mammography system (Senographe 2000D, GE) of 50 patients were evaluated as softcopies and hardcopies by 2 readers. 19 of the 50 patients had histologically proven carcinomas, the remainder showed no malignancies after a follow-up of 2 years. The softcopies were displayed on a 2.5 × 2k monitor, the hardcopies were printed on a laser printer (Scopix, Agfa). The mammograms were evaluated with respect to image quality, artefacts, presence of masses and microcalcifications. All detected lesions were categorized according to the BI-RADS classification. The time for this evaluation was written down. Post-processing in softcopy evaluation (windowing and levelling, zooming, inversion) and additional views like spot views in both methods were also timed. Results: Diagnostic accuracy of the classification of the malignant lesions according to the BI-RADS categories showed no significant differences between soft-and hardcopy. More time was needed for the evaluation of softcopies than for hardcopies. Additional views were recommended in hardcopy more often than in softcopy evaluation (26 versus 21 for reader 1, 20 versus 18 for reader 2). Postprocessing was used in 9 cases by reader 1 and in all cases by reader 2.

The evaluation of softcopies needs more time than those of hardcopies, especially when post-processing is performed. However, it seems that softcopy reading reduces the need of additional views without change of diagnostic accuracy.

Full-field digital mammography (FFDM): Intrapatient comparison of direct magnification versus monitor zooming U. Fischer, F. Baum, S. Obenauer, S. Luftner-Nagel, D. von Heyden, E. Grabbe; Göttingen/DE Purpose: Our goal was to compare digital magnification mammograms with images zoomed from the digital contact mammogram in patients with microcalcifications. Materials and methods: 55 patients with 57 microcalcification clusters were evaluated with a FFDM system (Senographe 2000D, GE). In addition to a digital contact mammogram, a digital magnification mammogram (factor 1.8) and two images zoomed from contact mammogram with magnification factors of 1.8 and 5 -8 were obtained in each patient. The image quality (1 = perfect to 5 = inadequate) and the characterisation of microcalcifications (BI-RADS™ 2 -5) were evaluated by 4 readers. The results were compared to histopathologic findings in 35 patients (37 lesions) and follow-up in 20 patients. 

In patients with mammographic microcalcifications, monitor zooming of the digital contact mammogram is equivalent to direct magnification FFDM. Therefore, monitor zooming allows a reduction of the radiation exposure and an optimization of the work-flow.

B A C D E F 182

Full-field digital mammography -comparison of different exposure protocols S. Obenauer, K.-P. Hermann, E. Grabbe; Göttingen/DE Purpose: To evaluate the potential of radiation dose reduction in full-field digital mammography (FFDM) compared to screen-film mammography (SFM). Materials and methods: FFDM was performed by using an amorphous silicon detector with a cesium iodide scintillator layer (Senographe 2000 D, GE). SFM was performed by using a state-of-the-art system (Senographe DMR, GE) combined with a dedicated screen-film. An anthropomorphic breast phantom with superimposed egg shell fragments (50 -200 µm) was used to evaluate the detectability of microcalcifications. Contact mammograms and magnification views (m = 1.8) performed with both the digital and the screen-film system were compared. Images were exposed automatically (AEC mode) by using a Molybdenum/ Molybdenum (Mo/Mo) anode-filter-combination, 28 kVp and 63 mAs (protocol A, dose ~100 %). Dose reduction in digital mammography was achieved by using protocol B with Mo/Rh and 31 kVp (dose ~60 %) and protocol C with Rh/Rh and 32 kVp (dose ~40 %). The detectability of microcalcifications was assessed by 3 well-experienced readers with a confidence level ranging from 1 to 5. A receiver operating characteristic (ROC) analysis was performed. Results: In protocol A the area under the ROC-curve (Az) for contact views performed by the screen-film system was 0.63 and for those performed with the FFDM system 0.68. For the conventional and digital magnification views Az was 0.70 and 0.79, respectively. For the protocol B/C the Az value reached 0.74/0.65 for the contact views, and 0.81/0.77 for magnification views.

Conclusions: Compared to screen-film mammography the digital mammography system allows an equivalent detection rate of microcalcifications at a slightly lower radiation exposure.

Comparison between analogue and digital reading performance in screening mammography A.A.J. Roelofs 1 , S. van Woudenberg 1 , J.H.C.L. Hendriks 1 , A. Boedicker 2 , C.J.G. Evertsz 2 , N. Karssemeijer 1 ; 1 Nijmegen/NL, 2 Bremen/DE Purpose: To investigate the use of a digital reading station for screening mammography and to compare results with analogue reading. Materials and methods: 500 cases, 125 screen-detected cancers, 125 interval cancers, and 250 non-cancers, were collected from the Dutch breast cancer screening program. For each patient, mammograms from two prior screening rounds were collected in addition to diagnostic mammograms. Diagnostic mammograms and pathology reports were used to establish ground truth. All mammograms were digitised and processed by a CAD system (R2 Imagechecker, Los Altos, CA). Experienced screening radiologists participated in a study in which each of them read one film the two prior screening mammograms of all 500 cases in randomised order and blinded to the detection results. The readers were asked to annotate potential abnormalities, and estimate the likelihood of malignancy of each finding they reported. A subset of 100 cases with visible cancers on the prior mammograms and 175 non-cancers were randomly selected. This subset was reread on a dedicated workstation we are developing for screening mammography, by a subset of 5 radiologists 1.5 years after their first reading. The workstation was has two highresolution monitors (BARCO). Results were evaluated using ROC analysis and compared to the results obtained with analogue reading. Results: No significant difference in screening performance between analogue and digital reading was found, provided CAD was available for microcalcification detection. Conclusion: Using a dedicated reading station for mammography, soft-copy reading of digital mammograms in screening is possible without loss of quality.

Management through PACS and digital telemammography A. Grueva, M. Mahesh; Baltimore, MD/US Purpose: Digital telemammography (DTMg) is rapidly developing into a mature technology due to advances in digital image acquisition, database design and communications infrastructure. Current film-screen mammography has a number of inherent limitations, which can be overcome effectively with DTMg. Since acquisition display and storage can be optimized independently, screening sensitivity is increased.

The initial goal was to provide DTMg in a screening environment with radiologist teleconsultation. Technical issues in planning the establishment of DTMg screening infrastructure include network design, image compression, archiving, and special viewing station. Displays, picture archiving and communications systems (PACS), image storage and processing architecture are examined, all at a concrete functional level of DTMg. A component-based approach to software development is described and is validated for each of the abstract system requirements for future breast screening computing environments and information management. Research approach is telediagnosis, teleconsultation, and telemanagement. Results: The implementation of this architecture is described and analysed from image and clinical data. Workstations and comprehensive database development is the most difficult and expensive technology for teleimaging and information management. Full-field DTMg with technical components, study protocols, and preliminary results of a study are analysed. Conclusion: The study shows the DTMg system to be successful in fulfilling the goals, DTMg is also considered in the general context of an integrated regional health telematics network, emphasizing its role and its interaction with other information and networking services for decision treatment strategies. DTMg standard needs to be further evaluated for quality of telemammography and for cost effectiveness. Material & methods: Seventeen subjects affected by drug resistant cryptogenic partial epilepsy underwent long-term computer assisted video-EEG monitoring and DSC MRI in the same day. MRI data were compared with EEG findings, and accuracy of perfusional MRI was analyzed considering the spiking rate and the type of epilepsy. Results: DSC MRI showed a relevant asymmetry in a region compared to the contralateral areas in 8 (47 %) out in 17 patients, suggesting the presence of a relative focal hyperperfusional pattern. This area corresponded to the epileptogenic focus or to the hemisphere involved. In the genesis of epileptic discharges in 7 (77.7 %) out of 9 patients showing a higher spiking rate (HSR) Conversely, all patients with a low spiking rate (LSR group) did not show significant asymmetry indexes in perfusional pattern. Moreover we found that DSC-MRI seems to be very sensitive for detection of epileptogenic focus in patients affected by temporal lobe epilepsy (TLE). In 5 (83.3 %) of 6 HSR-TLE patients DSC-MRI showed a relative hyperperfusion region concordant with EEG focus or hemisphere involved in the genesis of epileptic discharges. Conclusion: Perfusional MRI is a noninvasive procedure that provides useful additional information to better localize the epileptogenic zone, when the interictal epileptiform activity is sufficiently elevated. 

Saturday

Materials and methods: Eleven patients (6 females, 5 males), affected by intractable epilepsy were included. Brain lesions were: 4 mesial sclerosis, 3 brain tumors, 2 cortical gliosis, 1 encephalomalacia, 1 cortical displasia. MRI studies were performed on a 1.5 T scanner. fMRI volumes were acquired according to a block paradigm of 6 alternating (rest-task) phases, including 10 scans for each phase. BOLD contrast images were obtained by echo-planar FID sequences (FoV = 250, TR = 0.8 ms, TE = 54 ms, thickness 3 mm). High resolution MPRAGE sequence, covering the whole head, served as basis for the integration of anatomical, MEG and fMRI data. Magnetic field recordings were performed using a whole head MEG system, equipped with 165 integrated SQUID magnetometers.

The location of magnetic field source during intercritical activity identified by MEG was found to be in close proximity to the lesion in 6 cases. A displacement of the source with respect to the lesion was found in two cases. In three cases MEG was not able to reliably locate a source. Functional markers (sensory areas identified by MEG and motor areas identified by fMRI) where in accordance with the known cortical organization. Conclusion: These preliminary results are encouraging toward the use of morphological MRI, fMRI and MEG in the identification of the functional areas within the affected region.

Quantitative 1 H MRS investigations of the regional and age dependences of metabolite content in the human brain V.A. Rogozhyn, Z.Z. Rozhkova; Kiev/UA Purpose: The aim of our work is a quantitative study of the age and regional dependences of cerebral metabolism using primary spectral parameters of main metabolites. Materials and methods: 65 healthy volunteers (age range 25 -75) were examined by 1.5 T Magnetom Vision (SIEMENS). Spectra were obtained in two locations of each brain hemisphere: in the occiput (gray matter), and in the forehead (white matter). All spectra were recorded with the STEAM sequence: TR/TE 1365/ 135; 1500/270, 20 ms; VOI = 2 × 2 × 2 cm 3 . Results: For the normal brains the peak areas of 1 H MRS signals from N-acetylaspartic acid (NAA), total creatine (Cr) and choline (Cho) were obtained. We define the metabolite concentration as the ratio of the peak area to the sum of all the peak areas. We have found a "fine structure" of the average metabolite concentrations which depends on the relative values of peak areas. To describe this fine structure we introduce the triad T* = {A, B, C}, where A, B, and C are the unequal peak areas of the signals from NAA, Cr and Cho, respectively. We believe that each of the three peak areas takes three values: 1, 2 and 3, to represent symbolically six possible spectral configurations: T = {1*, 2*, 1/4, 6*}. The triads 1* = {3, 2, 1} and 2* = {3, 1, 2}denote the most frequent configurations in the spectra. Metabolic variations with age are especially noticeable in the left forehead for them.

We have built spatial maps of the age dependences of metabolite content in the normal brain. Our results serve as the background for the description of brain pathologies.

MRS data for the quantitative description of the brain metabolism in patients with brain tumors V.A. Rogozhyn, Z.Z. Rozhkova; Kiev/UA Purpose: The aim of our study is to propose the quantitative indicators of metabolic changes in the human brain and brain pathologies. Methods and materials: 72 patients with gliomas (of various grades of anaplasty) or meningiomas, together with 65 healthy volunteers were examined using a 1.5 T Magnetom Vision (SIEMENS). All spectra were recorded in 4 brain locations with the STEAM sequence: TR/TE 1365/135; 1500/270, 20 ms, VOI = 2 × 2 × 2 cm 3 .

The peak brain areas of 1 H MRS signals from N-acetylaspartic acid (NAA), total creatine (Cr) and choline (Cho) were obtained for all subjects. We introduce the metabolite concentration as the ratio of the peak area to the sum of all the peak areas. We describe the metabolic state of the brain in each VOI by the triad T* = {A, B, C}, where A, B and C are the unequal peak areas of the signals from NAA, Cr and Cho, respectively. Each of the areas takes three values: 1, 2 and 3, to give six symbolic spectral configurations: 1* = {3, 2, 1}, 2* = {3, 1, 2}, 3* = {2, 3, 1}, 4* = {1, 2, 3}, 5* = {2, 1, 3} and 6* = {1, 3, 2}. The frequency of appearing each of the triads in spectra depends on the brain state. The triads 1* and 2* denote the most frequent configurations in the spectra. And the triads 5* and 6* we observed only in the pathological brains: both in the tumor location and in the intact tissue.

We give a quantitative classification of the brain state by creating spatial triad maps. This essentially amplifies MRI examinations of patients with brain pathologies.

Proton MR spectroscopic imaging and FDG-PET in irradiated glial brain tumors H.-P.W. Schlemmer 1 , M.P. Lichy 1 , M. Henze 1 , P. Bachert 1 , S. Sammet 1 , A.A. Maudsley 2 , J. Debus 1 , G. van Kaick 1 ; 1 Heidelberg/DE, 2 San Francisco, CA/US Purpose: To assess the clinical utility of proton MR spectroscopic imaging ( 1 H MRSI) for evaluating suspicious brain lesions after radiotherapy of glial brain tumors. Methods and materials: In this ongoing study 17 patients with irradiated gliomas (WHO grade 2, n = 12; grade 3, n = 4; grade 4, n = 1) were examined by 1 H MRSI and positron emission tomography with [ 18 F]-2-fluoro-2-deoxy-D-glucose (FDG-PET) to evaluate suspicious brain lesions. The MR protocol included multiplanar T2w turbo spin echo MRI, 1 H MRSI (PRESS, TR/TE 1500/135 ms; spatial resolution 8.75 × 8.75 × 15.0 mm 3 ), and pre-and post contrast T1w-spin echo MRI. Relative signal intensity ratios of choline-containing compounds (Cho), total creatine (Cr), and N-acetyl-aspartate (NAA) were determined both in lesions and in contralateral normal tissue using the program SiTools. FDG-standard uptake values of the lesions were obtained from PET examinations and were related to normal gray (SUVgr) and white matter (SUVwm). Lesions were classified as neoplastic (P) and non-neoplastic (nP) based on MRI follow-up or biopsy. Results: Significantly enhanced intensity ratios Cho/Cr and Cho/NAA were observed in P compared to nP (p = 0.05 for both ratios) and compared to the contralateral normal tissue (p = 0.01 and p = 0.00003, respectively). In all patients Cho/NAA and Cho/Cr correlated with FDG-standard uptake values, e.g., Cho/Cr and SUVwm: r = 0.58, p = 0.01. Conclusion: Parameters from 1 H MRSI are helpful for differentiating neoplastic from non-neoplastic lesions after brain tumor radiotherapy. Moreover, the correlation with glucose metabolism indicates that MRS parameters may also indicate tumor grade.

Proton magnetic resonance spectroscopy ( 1 H MRS) of brain meningiomas at long echo time C. Majós, J. Alonso, C. Arús, C. Aguilera, M. Serrallonga, J.J. Acebes, J. Cabiol, J. Gili; Barcelona/ES Purpose: To assess the utility of 1 H MRS in the categorization of meningioma with especial emphasis in their differentiation with respect to other brain tumors. Methods and materials: Single voxel "in vivo" 1 H MRS at an echo time of 136 ms was carried out in 37 patients with meningioma. A data-set of 93 spectroscopic exams of brain tumors acquired under identical conditions was used for comparison. This data-set included 15 low-grade astrocytomas, 14 anaplastic astrocytomas, 30 glioblastomas and 34 metastases. Fitted area of seven resonances of interest (lipids at 1.30 ppm, Lact at 1.35 ppm, Ala at 1.45 ppm, NAc at 2.02 ppm, Glx at 2.35 ppm, Cr at 3.03 ppm and Cho at 3.20 ppm) was calculated. We searched for the resonances that better discriminated meningioma from every other tumor type. An empirical algorithm for bilateral discrimination between meningioma and the other tumors was produced on the basis of these findings. The performance of the algorithm was assessed by means of the leave-one-out method. Results: High Ala, low or absent lipids, high Glx, low Cr and high Cho were found to be the most characteristic trends of meningioma. When applied in pair-wise discrimination with the other tumors, these findings produced 91 % successful classification outputs, 7 % unsuccessful and 2 % "unclassifiable". Conclusion: Single voxel 1 H MRS provides biochemical information from meningioma that can be satisfactorily applied in its categorization. According to our results, high Ala, Glx and Cho, as well as low lipids and Cr are characteristic spectroscopic signatures of meningioma. 

A C D E F 184 Materials and methods: 22 patients who underwent supratentorial cortical/subcortical infarction were studied, 3 months after the onset of clinical symptoms of ischemic stroke The MR studies were performed on 1.5 T system. The results of spectra approximation (presented as metabolite ratios: NAA/CR, NAA/SUM, Chol/Cr, Chol/NAA, Lac/NAA, Lac/SUM, Lip/NAA and Lip/SUM were subjected to statistical analysis. MR spectra were recorded from a tissue adjacent to area of infarction and normal appearing brain region: contra and ipsilateral internal capsule. Spectra from stroke patients were compared with control group from 32 healthy volunteers recorded with the same techniques. Results: The statistical analysis revealed significant differences between data obtained from the various regions in the patients who had undergone ischemic stroke and between the infarcted and control groups. Proton MR spectroscopy detects changes in cerebral metabolites levels also in apparently normal regions. In contralateral brain regions, as well as in the internal capsule we have noticed significant reduction in choline, creatine and NAA; we found correlation between clinical outcome and MRI/MRS findings. Conclusions: Proton MRS is a very useful tool for evaluating major changes in cerebral metabolite levels in infarcted patients. Our preliminary results of H MRS, MRI and clinical data support the idea that metabolic leasions distant from the infarcted tissue can be responsible for clinical course and have predictive value.

Fingerprinting of the etiological agent in brain abscesses using proton MR spectroscopy M. Garg jr., R.K. Gupta, M. Hussain, K.N. Prasad, S. Chawla, R. Kumar, N. Hussain; Lucknow/IN Purpose: In vivo proton MR spectroscopy data was analyzed from 70 cases of proven brain abscess(s) to look for the possible metabolites that may act as marker for the specific group of bacteria. Methods and materials: Data from 70 patianets with proven brain abscess by pus aspiration, bacterial culture, and histopathology of the wall were analyzed to look for spectral pattern relationship with the bacterial culture. In vivo data was obtained using single voxel STEAM (TE = 20 ms) and SE (TE = 135 ms) sequences. Results: The in vivo spectra show the following 4 patterns:

• Abscesses in 4 patients showing only lipids (1.33 ppm, 0.9 ppm) and without amino acids (0.9 ppm) and showed M. tuberculosis on smear and culture. • Abscesses in 16 patients showing succinate (2.4 ppm) and/or acetate (1.92 ppm), along with lipid/lactate (1.33 ppm) and amino acids (0.9 ppm) and showed anaerobic bacterial growth namely Peptococci, Peptostreptococci, and Bacteroides. • Abscesses in 20 patients showing only lipid + lactate (1.33 ppm) and amino acids (0.9 ppm). Orgainsms seen on culture in these were either aerobes (Pseudomonas, Nocardia) or facultative anaerobes (Staphylococcus, Proteus, and Escherichia coli). Two patients with this pattern also showed anaerobic bacterial growth (Peptostreptococci). • Abscesses in the remaining 30 patients were found sterile on culture. These patients were on treatment with broad spectrum antibiotics at the time of spectroscopy and show lipid + lactate (1.33 ppm) and amino acids (0.9 ppm) only. Conclusion: Our data suggests that it may be possible to group the brain abscesses on the basis of metabolite pattern seen in vivo and may be of value in improved management of these cases.

Subclinical cerebellar neuropathy as a result of chemotherapy in proton magnetic resonance spectroscopy B. Ciszkowska-Lyson, L. Krolicki, A. Janowicz-Zebrowska, A. Teska, E. Tacikowska, M. Krzakowski, S. Budrewicz; Warsaw/PL Purpose: Of our study was to evaluate the central neurotoxicity of chemotherapy using MRI and MRS, in patients with lung cancer who were treated with cisplatin and vinca alkaloids. We expected to find a reduction in N-acetylaspartate, as a result of the neurotoxicity of chemotherapy. Methods: 31 patients aged 42 to 73 years underwent before and after chemotherapy: clinical examination; MRI of the brain, MRS (PRESS, TR 1500 ms, TE 80 ms) VOI of 8 ml localized in centrum semiovale (CS) and hemisphere of cerebellum. Each patient's NAA/Cr and Cho/Cr ratios have been analyzed statistically. Analysis was carried out separately for CS and cerebellum.

None of the patients demonstrated clinical manifestation of CNS neurotoxicity. MRI did not reveal any abnormalities caused by chemotherapy. Analysis of NAA/Cr and Cho/Cr ratios in CS did not show significant differences before and after chemotherapy. Analysis of the cerebellar spectra showed significant decrease of NAA/Cr ratio (p < 0.05) and time dependent decrease of Cho/Cr ratio (p < 0.05) after chemotherapy. Analysis of Pearson's correlation showed very strong linear relationship between NAA/Cr and Cho/Cr ratios (p < 0.001), both at CS and cerebellum. Conclusion: Decreased NAA/Cr ratio can indicate the neuronal loss caused by chemotherapy. Decreasing Cho/Cr ratio could be associated with damage of myelin. The MRS results suggest presence of subclinical selective cerebellar neuropathy caused by chemotherapy. The MRS revealed different reaction to chemotherapy at CS and cerebellum. These initial results indicate that proton MR spectroscopy is a potentially useful modality for detecting early stage of the CNS neurotoxicity caused by chemotherapy. The liver and splenic parenchyma were surveyed and evaluated before and after embolization with plain helical CT, including volumetry of the liver and spleen. Results: DSA examinations revealed a dilated splenic artery (n = 18) or gastroduodenal artery (n = 4) combined with slightly decreased perfusion of the hepatic arteries, while immediately after successful embolization normal perfusion of the hepatic arteries was noted. Volumetric measurements before and after embolization showed no significant changes in liver parenchyma (6 % -10 %, mean, 6 %), and an alteration in spleen volume (11 % -27 %, mean, 16 %) in comparison with initial measurements. Clinical follow-up examinations revealed a normalization of the previously elevated hepatic enzymes and a normalization of the liver function tests after successful embolization. Complications were observed in 4 patients (infarction of the spleen).

The preliminary results reveal that in liver transplant candidates with splenohepatic and gastroduodenal steal syndrome, successful embolization of the splenic artery results in a improvement in organ perfusion with normalization of function tests. were noted after 11 sessions (5.9 %). The number of sessions of TACE, pancreatic location of primary tumour, extent of hepatic involvement and use of TACE as a first line non-surgical treatment were significant for response rates in an univariate as well as a multivariate analysis. When survival from date of TACE was considered, previous resection of primary and number of TACE sessions were significant on univariate and multivariate analysis, while location of primary, histopathological grading and extent of hepatic involvement were significant only on univariate analysis.

The digestive location of the primary tumor appears to be the strongest positive prognostic indicator for both response to TACE and survival. Use of at least 2 TACE sessions per patient is recommended. Poor prognostic indicators are presence of extra-hepatic lesions (nonresected primary and/or extra-hepatic metastases), poor histological differentiation of the tumor and more than 60 % involvement of liver. (2), kidney (2), spleen (1), brain (1). Mostly there was an asymptomatic clinical course postprocedure. In six cases there were serious complications (3 × pneumonia, 1 × renal failure, 1 × cholecystitis) which resolved after two weeks. Without evidence of displacement of lipiodol, there was one renal failure, one abscess of the liver and one case of hepatic encephalopathy. Post-embolization syndrome (PES) with abdominal pain, nausea and vomiting, subfebrile temperature and pleural effusion was seen in 59 % (41/69) for a period of a few days. No rupture of an embolized HCC and no reflux embolization was observed.

Conclusions: Unexpected displacement of embolisation material is not seldom, but mostly clinically inapparent. In cases with complications, symptomatic therapy is sufficient and successful. The frequent postembolization syndrome is transient and can be easily managed.

Transcatheter arterial chemoembolization (TACE) as a first line treatment for liver metastasis from digestive neuroendocrine tumors A.J. Roche, B.V. Girish, V. Kuoch, T. de Baère, E. Baudin, M. Ducreux; Villejuif/FR Purpose: To report the outcome in patients who underwent TACE as a first line non-surgical treatment Methods and material: From Jan. 1990 to Dec. 2000 fourteen patients with progressive unresectable liver metastases from digestive neuroendocrine tumor were treated with TACE (mean of 3.6 sessions) before any non-surgical treatment (somatostatin analogue, chemotherapy or interferon). Liver involvement was less than 50 % in 11 patients. The size of the largest lesion ranged from 1.5 to 10 cm. The number of lesions was more than 10 in 8 patients. Ten patients presented with carcinoid symptoms. TACE was performed with Doxorubicin emulsified in Lipiodol® and gelatin sponge particles. Results: A symptomatic response relating to flushes and/or diarrhea was complete in 7/10 cases and partial in 2/10. An objective morphologic response was noted in 12/14 cases. One patient developed transient renal failure and hypertension after the first TACE. There was no procedure-related mortality in the series. The 5 and 10-year survival from diagnosis was respectively 83 % and 56 %. Six patients were alive at the end of the study after 27 to 100 months from first TACE and 38 to 142 months from diagnosis. Three of them were successfully palliated for 55, 69 and 100 months with only TACE as treatment (they received 9, 3 and 8 sessions respectively).

The control rate of carcinoid syndrome with TACE is comparable to somatostatin analogues. Long term clinical, as well as morphological palliation, is possible in unresectable liver metastases from digestive neuroendocrine tumors with a few sessions of TACE as early and exclusive treatment. Material and methods: 220 TACE in 54 consecutive patients with HCC. Sequential TACE (interval: 6 weeks) was performed using a suspension of 10 mg mitomycin C and 10 ml iodized oil (lipiodol). Follow-up included pre-and post-interventional CT scans and laboratory measurements (liver-function parameters; AFP). The number of lesions and tumour size were investigated using spiral CT. Results: Mean follow up was 17 months (range 6 to 50). 35 patients are still alive (mean survival 23 months, range 7 -50 months). 152 lesions were detected on the initial CT scans. Size of individual lesions was < 20 mm (I), 21 -50 mm (II), and > 50 mm (III) in 42.8 %, 38.2 % and 19 %. Over all median change of tumour size was -8.2 % (range -61 % to +82 %). Median change depending on the initial lesion size was -7.7 % (I), -9.5 % (II), and -3.8 % (III). Stable disease was noted in 33/54 patients. 10/54 patients had significant tumour regression and liver transplantation was successfully performed. Tumour progression was noted in 14 patients with multilocular HCC and tumours > 50 mm. Complications occurred in 3 patients, pancreatitis in one and dissection of the hepatic artery in two. There were no periinterventional deaths. Conclusion: Sequential TACE in primary HCC is an effective therapy in patients with small tumours. Because of tumour size control and avoidance of new tumour lesions, TACE is a promising method to bridge the time to liver transplantation or to change patients into a transplantable condition.

Hybrid MRI: Transarterial chemoembolization of liver metastases using interactive MR guidance T.J. Vogl, J.O. Balzer, S. Zangos; Frankfurt a. Main/DE Purpose: To evaluate the effectiveness of MR guided transar terial chemoembolization (TACE) of liver metastases by employment of a hybrid MRI system.

In a newly built suite with fully interactive high field (1.5 T) MRI and C-arm angiography units, elective TACE was performed in 30 patients. An interactive table was positioned between the MRI and angiographic unit, and allowed repositioning of the patient on a carbonfibre-plate within 20 seconds. Arterial access was successfully achieved by employment of the DSA-unit and a MR compatible angiography catheter was superselectively positioned in the tumor feeding artery. The patient was then positioned in the MR unit and Gd-enhanced dynamic MRI (TurboFLASH) via the catheter revealed the regional perfusion and verified the correct catheter position prior to TACE. Results: In 14/30 patients immediate embolization of the tumor bearing liver segments was performed. In 14 patients repositioning of the catheter and in 2 patients a change of vascular access was necessary. Therapy monitoring using MRI therefore resulted in the repositioning of the catheter tip in 53 % of the embolization maneouvers. DSA control immediately after TACE revealed successful TACE of the appropriate liver segments. Conclusion: The presented hybrid system optimizes complex TACE procedures in patients with liver metastasis. MRI guidance enables the exact identification of the tumor bearing liver segments and correct catheter placement.

Uterine artery embolisation for symptomatic fibroids: Results in 400 women W.J. Walker, J.-P.J. Pelage; Guildford/GB Purpose: To evaluate the mid-term efficacy, adverse events and complications of uterine artery embolisation (UAE) in women with symptomatic fibroids. To assess reduction in uterine and dominant fibroid volumes using ultrasound imaging and magnetic resonance imaging (MRI). Methods and materials: Four hundred women were treated between December 1996 and February 2001. Indications for treatment were menorrhagia, menstrual pain, abdominal swelling or urinary frequency. Imaging was performed before embolisation and at regular intervals thereafter. Clinical evaluation was made at regular intervals after embolisation to assess patient outcome.

Results: Bilateral UAE was achieved in 395 women whereas 5 women had a unilateral procedure. With a mean clinical follow-up of 16.7 months, menstrual bleeding was improved in 84 % of women and menstrual pain was improved in 79 %. The mean changes in uterine and dominant fibroid volumes were 55 and 73 % using ultrasound (performed at an average of 9.7 months after embolisation) and 53 and 64 % with MRI (performed at an average of 6.4 months). Three (1 %) infective complications requiring emergency hysterectomy occured. 23 (6 %) patients had clinical failure or recurrence and nine (2 %) had a hysterectomy. 26 (7 %) of women had permanent amenorrhea after embolisation including 4 patients under the age of 45. Thirteen pregnancies occurred. 97 % of women were pleased with the outcome. Conclusion: Uterine artery embolisation is associated with a high clinical success rate and good fibroid volume reduction. Infective complications requiring hysterectomy and amenorrhea under the age of 45 are rare but major complications.

Embolization of bleeding arteries from pelvic trauma N.-E. Klow 1 , A. Riise 2 , M. Brekke 1 , O. Roise 1 ; 1 Oslo/NO, 2 Fredrikstad/NO Purpose: To study the effects of arterial embolization after pelvic trauma in hemodynamically unstable patients. Material and methods: From 1994 to 2000, 17 patients were included, three women and 14 men, mean age 35 years (from 16 to 72 years). All patients were admitted with trauma to the pelvis, but freqently multiorgan trauma was present. The pelvic fractures were bilateral in five, a sacral fracture was present in seven and diastasis of the symphysis pubis in seven. Over the 24 hours immediately before embolization the need for whole blood transfusion was 18 ± 17 units (range 2 -64). Results: All 17 patients were successfully embolized. Fourteen had embolization of one internal iliac artery (IIA), one both IIA and a lumbar spinal artery, one a lumbar spinal artery, and one a superficial femoral artery branch. In 15 patients coils were used exclusively, in one gelfoam and in one coils and gelfoam were combined. The total need for blood transfusion after the embolization was 0.8 ± 1.0 units (range 0 -3). Three patients died during the hospital stay, and no deaths were related to the procedure or rebleeding from the pelvic arteries. Conclusion: Embolization of arteries bleeding from traumatic injuries of the pelvis is a life saving procedure with a high procedural success rate. The procedure can be done on call, in hemodynamically unstable patients, and should probably be performed in an early stage of bleeding.

Intraarterial chemotherapy of malignant pelvic tumors under tourniquet occlusion of the femoral vessels P.D. Niggemann 1 , S. Murata 2 , H. Tajima 2 , Y. Okajima 2 , K. Ichikawa 2 , H. Kawamata 2 , T. Kumazaki 2 ; 1 Aachen/DE, 2 Tokyo/JP Purpose: To evaluate the possible benefit of intraarterial chemotherapy in malignant pelvic tumors under tourniquet occlusion of the femoral vessels. Methods and materials: The difference in contrast enhancement of 55 regions in 23 malignant pelvic tumors was evaluated with and without tourniquet occlusion of the femoral vessels. In nine patients (Group A) two CT scans of the pelvis, one and five minutes after starting an intraarterial contrast medium injection under tourniquet occlusion, were performed and then two CT scans after injection of the same dose without tourniquet occlusion were performed. In the remaining 13 patients (Group B), the study was done in the opposite order. Results: In Group A, a mean change of the contrast enhancement of all tumors was 0.6 Hounsfield units (HU) after one minute and −3 HU after five minutes. In Group B, a mean change in contrast enhancement of 2.1 and 0.8 HU at one and five minutes respectively was observed. In patients with prostate tumor, the results were 5.2 and 3.9 HU respectively in patients from Group A and 14.1 and 10.2 HU in patients from Group B. The average of both groups together showed an increase of 8.9 and 6.5 Hounsfield units respectively. Conclusion: An increase in the contrast enhancement of malignant pelvic tumors due to tourniquet occlusion of the femoral vessels has been observed only in patients with prostate cancer after one and five minutes. Therefore intraarterial chemotherapy under tourniquet occlusion of the femoral vessels only seems to yield a benefit in poorly vascularized tumors. Purpose: To establish a high resolution MRI (HR-MRI) protocol for precise and repeated non-invasive analysis of selected atherosclerotic vessel segments in vivo and to compare the results with intravascular ultrasound (IVUS). Materials and methods: 7 patients with atherosclerotic disease of the superficial femoral artery were examined on a Magnetom Vision, Siemens using axial T1-w, fat-saturated contrast enhanced T1-w, T2-w and 3D-TOF sequences. Contrast enhanced MRA was used to display the detailed vasculature for precise orientation. Maximum matrix size was 320 × 512, minimum voxel size 0.49 × 0.49 × 2.0 mm. IVUS (3.5 F, 40 MHz) images were recorded with a standardized motorized pullback system (pullback speed 1.0 mm/s). Parameters analysed were minimum and maximum luminal diameter and cross sectional lumen area. Vessel wall calcification was determined by 900 steps. Results: 123/123 segments were available for comparison between HR-MRI and IVUS. Intra-and interobserver repeatability for exact assignment of vessel segments was high (r = 0.92, r = 0.87). There was a good correlation for luminal parameters (correlation coefficients ranging from 0.82 to 0.98 depending on the plaque burden). No correlation was found for cross sectional vessel area. Calcification could be classified with a sensitivity of 91 %, a specificity of 93 %. Accuracy was 93 %. Conclusion: Our HR-MRI protocol is highly accurate for non-invasive assessment of atherosclerotic lesions in human femoral arteries. The results are comparable with IVUS as known reference standard in vivo. Purpose: To evaluate ultrasonography as a method of characterizing plaque surface configuration and plaque internal structure in comparison to in vitro angioscopy and pathological specimens.

The carotid plaque specimens of 15 patients were examined by in vitro angioscopy and histopathological examination after carotid endarterectomy (CEA) in a comparative study with preoperative ultrasonography. Colorcoded ultrasonography was obtained with a 7.5 MHz linear transducer (Logic 500, GE). Transverse and longitudinal sections were recorded from the bifurcation area as well as from the proximal internal carotid artery. The plaque surface was characterized as smooth if the plaque surface did not show any disruptions. Further, the echogenic structure was recorded by grey scale analysis. After CEA the inner surface of the plaque was visualized by a 1.4 mm angioscope. The results were compared with histopathological findings. Results: Peak flow velocity (mean: 2.77 m/s, range 1.76 -4.24 m/s) demonstrated a > 60 % stenosis in all cases. The median of gray scale analysis (GSM) was 55 with a high correlation between both investigations (P < 0.01; r = 0.954). In comparison to pathological findings there was a correct detection of plaque surface in 86.6 %. Pathological classification of plaque composition revealed no correlation to computer-assisted analysis (P = 3.85; r = -2.63). Conclusion: Detection of an ulcerated plaque surface by ultrasonography is difficult with a wider degree of variation when compared with direct visualisation of the surface and pathological examination. Computer-assisted analysis of the morphology provides a high interobserver correlation, however, there was no correlation between the GSM and histological findings in this series.

Common carotid artery intima-media thickness (CCA-IMT) and carotid plaque echogenicity: Correlation with cardiovascular risk factors in patients with acute ischemic stroke G. Terzis, A. Chrysanthopoulou, G. Gioldasis, A. Kalogeropoulos, C. Paschalis, J.A. Dimopoulos; Patras/GR Purpose: To correlate the CCA-IMT and the echogenicity of the carotid plaques with the main cardiovascular risk factors in patients with acute ischemic stroke. Methods and materials: 535 consecutive patients (male 344, female 191, mean age 67.6 years) with acute ischemic stroke were studied with B-mode and Color Doppler ultrasonography during May 1999 to July 2001. CCA-IMT was evaluated and four types of plaques were defined by their echostructure. Type I: uniformly echolucent, type II: predominantly echolucent, type III: predominantly echogenic and type IV: uniformly echogenic. Cardioembolic and undetermined strokes were excluded. All patients were evaluated for a history of smoking, hypertension, diabetes or hypercholesterolemia.

Smoking, hypertension and diabetes were all significantly associated with an increased CCA-IMT (p < 0.01 for all subgroup comparisons). Hypercholesterolemia had no significant effect (p = 0.67). Smoking was associated with an increased CCA-IMT (P = 0.0032) independently of other risk factors. Hypertension was significantly associated with diabetes (p = 0.0033) as a risk factor. Smoking, hypertension and diabetes had no significant effect on the type of the plaque (p = 0.374, p = 0.607, and p = 0.636 respectively). Hypercholesterolemia was significantly associated with type I plaques (p < 0.05). A trend for advanced echogenicity was observed among smokers (p >> 0.1).

Smoking, hypertension and diabetes but not hypercholesterolemia were significantly associated with an increased CCA-IMT in patients with acute ischemic stroke. Smoking, hypertension and diabetes were not associated with a specific type of plaque, but hypercholesterolemia was clearly associated with type I plaques.

High-resolution MR of carotid atheroma: A non-invasive tool for assessing plaque morphology and potential risk? J.H. Gillard 1 , M.T. Gaskarth 1 , M.J. Graves 1 , R.A. Coulden 1 , H. Wilson 1 , N.M. Antoun 1 , M. Goddard 2 , P.J. Kirkpatrick 1 ; 1 Cambridge/GB, 2 Papworth/GB Purpose: Whereas current imaging techniques provide excellent structural information including the quantification of vascular stenosis, they provide no information of the degree of functional plaque stability. Risk of rupture is more closely related to plaque composition and macrophage content than size. Thus angiographic appearances are an inaccurate predictor of risk; even large atherosclerotic lesions may not produce a significant stenosis at angiography. We aimed to use highresolution MR to evaluate plaque morphology in patients being evaluated for carotid endarterectomy.

Methods: Blood-suppressed fast spin echo imaging was performed using a dedicated surface coil (T1, T2, proton density, and chemical shift selective fat suppression; spatial resolution 0.24 × 0.24. × 3 mm) in 29 patients with symptomatic carotid disease. Gadolinium-enhanced elliptic centric MRA was also performed and compared with conventional digitally subtracted angiography (DSA). Histopathological examination was carried out on 4 specimens. Results: 37 plaques were identified, 15 of which were eccentric, extending outside the limit of the "normal" vessel wall. There was no significant difference in the degree of stenosis (using NASCET criteria) assessed with DSA and Gd-enhanced MRA (p = 0.11). High-resolution axial MR measurements, however, demonstrated more severe stenoses than was apparent from 4 projection DSA (mean difference 11 ± 13 %, p < 0.005). MR correctly identified plaque constituents (fibrin, lipid and focal hemorrhage). Conclusion: High-resolution carotid MR appears to be a useful tool in evaluating plaque morphology and effectively assesses plaque volume and degree of arterial narrowing. It may be an effective tool in evaluating plaque risk and the effects of pharmaceutical interventions. 

In 18 patients with bTM (mean age 25.8 ± 7.6 year, 55.5 % male, mean hemoglobin 10.2 ± 1 g×dl -1 , mean serum ferritin 2396 ± 1754 ng×ml -1 , 44 % on optimal chelation therapy) without cardiac disease or diabetes mellitus and 18 healthy control subjects, flow-mediated dilatation (FMD) was measured as a percentage change of the post-ischemic right brachial artery (BA) diameter. Endothelial-independent, nitroglycerin-induced vasodilatation (NID) and CCA IMT were also assessed.

The study groups were matched for age, gender, body surface area, blood pressure and smoking habits. Serum cholesterol levels were lower in the patient group (102 ± 39 versus 178 ± 30 mg⋅dl −1 , p = 0.001). The brachial artery diameter was 4.07 ± 0.66 mm in patients and 4.06 ± 0.52 mm in healthy subjects. Post-ischemic increase in the brachial artery blood flow was 555 ± 383 % (p < 0.01) for patients and 1072 ± 6.61 % for healthy subjects. FMD was 5.97 ± 2.3 %(p < 0.001) for patients and 10.44 ± 44 % for healthy subjects. NID was 14.86 ± 6.22 % for patients and 16.66 ± 4.23 % for healthy subjects. CCA IMT was 0.539 ± 0.078 mm for patients and 0.453 ± 0.072 mm for healthy subjects. FMD and thickness of the carotid arterial wall did not correlate with serum ferritin levels.

Conclusions: In patients with thalassemia major, endothelial function of conduit arteries is impaired and CCA IMT is increased. Our findings suggest a proatherosclerotic milieu with reduced bioavailability of nitric oxide, probably due to the iron-induced, high oxidative stress in these patients.

Functional imaging of the aortic wall by ECG-gated multislice-CT: An ex vivo experiment M.-K. Ganten 1 , J. Boese 1 , D. Leitermann 2 ; 1 Heidelberg/DE, 2 Prague/CZ Purpose: ECG-gated multislice-CT (MSCT) allow imaging with increased temporal resolution. The aim of this study was to evaluate the possiblity of obtaining functional information determining aortic-wall-elasticity in an ex-vivo experiment. Elasticity is a piece of clinically relevant information not yet widely accessible.

Methods & materials: 16 samples of porcine aortas were examined ex-vivo. To imitate physiologic circulation an artificial heart phantom emitting an ECG signal was used to perfuse the samples with pulsatile flow and varying pressures. Aortic wall elasticity can be determined by dividing the relative change in vessel area by the corresponding pressure change. As a reference, the wall distension was measured using an optical system with high temporal and spatial accuracy. ECG-gated CT images were acquired with a standard CT-angiography protocol applying specially developed reconstruction algorithms. This allowed us to obtain images with improved temporal resolution of about 100 ms. The aortic cross-section was determined from the images by manual segmentation. The accuracy of the crosssectional changes measurements was evaluated by comparison between the optical and the CT data. Results: Determination of aortic wall elasticity was possible in all samples. Elasticity, expressed as mean compliance, was 1.4 × 10 −5 /Pa. Precision of the manually determined values was in the order of 10 % compared to a precision of about 1 % for the reference optical method. Cross-section changes obtained from the CT images were in line with the error bounds obtained from the optical measurements. Conclusion: Our study shows that aortic wall elasticity determination using ECGgated CT is feasible. This allows functional information about the aortic wall to be obtained. Patient studies are required to investigate the in-vivo applicability.

Detection of atherosclerotic plaque using gadofluorine enhanced magnetic resonance imaging J. Barkhausen 1 , W. Ebert 2 , C. Heyer 2 , J.F. Debatin 1 , H.J. Weinmann 2 ; 1 Essen/DE, 2 Berlin/DE Purpose: To visualize atherosclerotic plaques independent of luminal narrowing using T1-w contrast enhanced MRI. Methods and material: 5 Watanabe heritable hyperlipidemic rabbits (9 -18 months) and 5 age-matched controls (White Newseeland) underwent magnetic resonance imaging of the aortic arch using a 1.5 T MR system (Magnetom Symphony, Siemens AG, Erlangen, Germany) before and 48 h after injection of 100 mmol Gadofluorine (Schering AG, Berlin, Germany). A HASTE sequence (TR 700 ms, TE 60 ms) and a T1-weighted inversion recovery turboFLASH sequence (TR 300 ms, TE 4 ms, TI 120 ms) were used for data acquisition. Immediately following the MR examination the animals were sacrificed and the aorta was stained with Sudan. Ex vivo imaging of the stained aortic specimens was performed. Additionally, the gadolinium concentration in plaques and normal aortic wall was measured by means of inductively coupled plasma atomic emission spectrometry. Results: Plain MR imaging revealed no plaques in the aortic arch in either animal group. Enhancement occurred in the aortic wall of all WHHL rabbits but not in the vessel wall of the control group. Sudan staining demonstrated multiple plaques in the aortic arch of the WHHL rabbits and using ex vivo imaging the area of hyperenhancement matched the area of plaques stained with Sudan. The gadolium concentration was 51 ± 21 nmol/g for normal aortic wall in the control group and 531 ± 144 nmol/g for plaques. Conclusions: Gadofluorine enhances atherosclerotic plaques thereby permitting the detection of plaque independent of luminal narrowing.

Vessel wall MRI of the descending aorta: Comparison with transesophageal ultrasound N. Abolmaali, M. Langenfeld, C. Schick, R. Kraforst, V. Schächinger, T.J. Vogl; Frankfurt a. Main/DE Purpose: To evaluate the validity of high-resolution contrast-enhanced MRI of the aortic wall and to prove comparability of plaque morphology detected by transesophageal ultrasound (TEUS). Is there additional information in MRI? Methods and materials: We performed MRI in five patients (median age: 62 years) in whom aortic wall thickening and plaques of varying morphologies were detected by TEUS. After sequence optimisation in cadaver studies, all MR-examinations were performed with a 1.5 T scanner (Magnetom Symphony Quantum, Siemens) with the cp-spine surface coil (supine position) using ECG-triggered T1weighted TSE-Sequences with dark-blood-preparation and fat-suppression before and after iv-administration of 0.1 mmol/kg BW Gadolinium-DTPA (GD). Slice thickness was 5 mm, in-plane-resolution using a 256 2 Matrix was 0.5 × 0.5 mm 2 . The heart-frequency dependent acquisition time for 10 slices was 10 -14 minutes. ROI-measurements of the aortic wall before and after contrast enhancement were performed and MRI was correlated with the TEUS findings.

Results: Thickened wall segments and plaques of the descending aorta detected by TEUS were visualized by MRI. Different morphologies with evidence of fatty deposits were detected. Unaffected aortic wall revealed two layers and signal isointensity compared to striated musculature. After iv-administration of GD most parts of the aortic wall did not enhance (< 6 %) while wall thickening and plaques showed considerable enhancement (22 -59 %) solely of the inner layer of the aortic wall. Conclusion: High-resolution MRI of the aortic wall provides similar morphologic information as TEUS does. Additionally the distinct enhancement of the inner aortic layer may correspond to an inflammatory process of the vessel wall. , metastases (n = 11, mainly colorectal), carcinoid (n = 5) and two benign liver tumours. 3 patients were excluded from follow-up. Results: Mean survival for all patients was 15.2 months, with an adjusted mean survival of 16 months for HCCs and 15.2 months for metastases. There were three major and five minor post-procedural complications but no deaths. An average of 57 % of tumour was ablated as assessed by per-procedural thermal mapping, with an average of 49.4 % of tumour ablated assessed by pre and post ablation gadolinium-enhanced MRIs. Average tumour size was unchanged after ablation.

In patients with multiple liver tumours ablated tumours grew significantly less than untreated tumours over the same time period (108 % compared to 196 % growth over an average follow up period of 5.8 months). Conclusions: MR guided laser thermal ablation of primary and secondary liver tumours is safe and feasible and produces a better survival in patients with HCC than would be expected in untreated patients, as well as a mean survival in patients with metastases at least equal to the longest median survival in untreated patients. Percentage viable tumour was decreased by a mean of 49.4 % per LTA session.

Contrast enhanced harmonic sonography (CEUS) used in the interventional room (IR) during radiofrequency (RF) ablation treatments: How to save time and reduce patients' discomfort L. Solbiati, T. Ierace, M. Tonolini, L. Cova, V. Osti, P. Marelli; Busto Arsizio (VA)/IT Purpose: To evaluate usefulness of CEUS performed during RF ablation procedures to assess the therapeutic result prior to ending the treatment session. Materials/methods: 61 patients with 1 -5 HCC in liver cirrhosis (42 patients) or 1 -4 metastases from colorectal (10), breast (3), gastric (2) and endocrine (4) cancers underwent single session percutaneous RF ablation with cool-tip electrodes, under general anesthesia, in the IR. Before and 5 -10 minutes after ending each treatment session, continuous mode, low mechanical index, CEUS with a second generation contrast agent (SonoVue, Bracco) was performed. A total of 86 lesions were examined. When, residual enhancement was detected within treated tumors, a second targeted electrode insertion was carried out. When complete tumor avascularity was demonstrated, general anesthesia was terminated. Contrast-enhanced helical CT (CECT) was performed in all cases 2 -15 days after ablation. Results: In 67/86 (77.9 %) lesions no post-ablation residual enhancement was found with CEUS. Subsequent CT showed unablated portions of tumors in 8/67 (11.9 %) lesions (all larger than 5 cm) and complete necrosis in the remaining 59

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In 19/86 tumors in 17 patients, CEUS showed either single or multiple intralesional areas of residual enhancement in arterial and/or portal phase, 1 -2.5 cm in size. All these likely viable portions were immediately targeted with 1 -2 electrode insertions, until no residual areas were demonstrated. On subsequent CECT, only in 2/19 (10.5 %) of these tumors, 1 -1.5 cm residual areas were found requiring new RF treatment. To prove the hypothesis that T1W thermal mapping is reliable and achievable in MR guided laser tumour ablation.

Methods & materials: 110 MR guided Laser thermal ablations (LTA) of liver, kidney and uterine tumours were studied. After laser fibre placement, near real-time grey and colour scale thermal maps are produced. Previous work showed T1 signal is inversely proportional to temperature below 55°C (the point of irreversible tissue necrosis). Measurements included: (i) percentage (%) of cases in which the thermal map provided sufficient information to control the procedure (ii) ability of grey and colour scale maps to demonstrate size (centimeteres) and conspicuity (10 point scale) of thermal lesions (iii) factors causing thermal mapping failure. Results: (i) Thermal mapping was successful in 84 % uterine, 74 % hepatic, and 20 % renal ablations. (ii) For hepatic/uterine tumours, size and conspicuity of thermal lesions were significantly greater on the colour than grey scale mapping. For uterine ablations, mean lesion size was 3.1 cm (colour) and 2.5 cm (grey, p = 0.001, paired Student's t-test), while mean conspicuity was 7.3 (colour) and 1.7 (grey, p = 0.001). For liver ablations mean lesion size was 3.1 cm (colour) and 1.7 cm (grey, p = 0.001) while conspicuity was 7.5 (colour) versus 3.7 (grey, p = 0.001).

(iii) Patient movement (n = 24), fibre charring (n = 2), magnetic field distortion & reconstruction errors (n = 2) caused mapping failure.

In hepatic & uterine thermal maps the colour scale produced significantly greater sized lesions with significantly greater conspicuity than the grey scale. T1W signal thermal mapping was reliable and successfully achieved in 73.7 % of procedures.

The most important challenge on the follow-up of radiofrequency treated hypovascular liver metastases: The differentiation of coagulative necrosis from viable tumor. Is there a role for contrast enhanced sonography? L. Solbiati, M. Tonolini, L. Cova, D. Della Chiesa, V. Osti; Busto Arsizio/IT Purpose: To assess if contrast enhanced harmonic sonography (CEUS) can be useful for the differentiation of radiofrequency-induced coagulative necrosis from viable hypovascular liver metastases. Materials and methods: 29 metachronous colorectal liver metastases (mean size 2.7 cm) in 9 patients treated 2 -9 months beforehand with RF ablation and systemic or intraarterial chemotherapy underwent conventional US and continuous mode, low mechanical index, CEUS with a second generation contrast agent (SonoVue, Bracco) due to suspicion of local recurrence. Triphasic contrast-enhanced helical CT (in all cases) and FNAB (10 cases) were performed to confirm recurrence. Results: Usind CEUS in arterial and very early portal phases, 25/29 metastases showed intense, predominantly peripheral enhancement. In full portal phase, complete disappearance of the enhancement was observed, with homogeneously hypoechoic appearance. The same arterial CT demonstrated enhancement, although less evident than with CEUS, in only 10 of these 25 metastases (40 %). US-guided FNAB was performed in at least one metastasis for each patient, with diagnosis of viable adenocarcinoma cells. In the remaining 4/29 lesions no enhancement was found with either CEUS or CT and FNAB (in 2/4 nodules) did not yield viable tumoral cells.

Conclusions: Differentiation of coagulative necrosis from unablated or recurring hypovascular tumor is a diagnostic challenge. CEUS demonstrates marked arterial enhancement of the viable tumor portions, better and with higher sensitivity than with CT. This finding could represent a quick and valuable tool for post-ablation follow-up. Such arterial enhancement (more intense than that observed before ablation) raises a suspicion of more active neovascularity in uncompletely ablated tumors There was no effect on survival by tumor size, number of tumor nodes or the grading. However, the survival of 50 % of the patients with a Child C cirrhosis or with AFP levels > 1000 ng was less than 6 months with nobody living longer than 36 months. In patients with Child A cirrhosis and/or normal AFP levels the mean survival was 14 and 17 months, resp. 10 % of these patients lived more than 60 months. Conclusion: TACE is an effective therapy that may prolong the patients survival in patients with non-resectable HCC. However, Child class in cirrhotic patients and elevation of AFP levels have to be considered as prognostic factors for a life extending TACE therapy. Purpose: To evaluate a neoadjuvant treatment protocol for large sized liver metastases performing repeated transarterial chemoembolization (TACE) and LITT (laser induced thermotherapy) in patients with unresectable liver tumours initially unsuited for LITT Material and methods: 519 patients with different malignant liver tumours were evaluated between January 1999 and September 2001. TACE was performed with 50 mg/m 2 mitomycin C, 10 ml/m 2 lipiodol and microspheres. The tumour volume was measured by MR-imaging. Lipiodol retention and perfusion of the tumours were evaluated by CT and angiography. After response to TACE and reducing the tumor size 106 patients (16 patients with HCC, 59 patients with metastases of colorectal cancer, 17 patients with metastases of breast cancer and 14 patients with metastases of different primary cancer) could be treated with MR-guided LITT 4 to 6 weeks post embolization. These patients received 2 to 6 (mean: 3.6) TACE before LITT. Results: Repeated TACE enabled a significant reduction in tumour size and/or tumour perfusion in 106 patients, forming the basis for the performance of MRguided LITT procedure for a complete ablation of the tumour. In 178 tumors lesions 203 laser interventions archived a complete tumour ablation. The initial tumour volume pre-LITT presented with a mean of 30.1 ml, the resulting necroses was 73.4 ml. The local tumour recurrence rate was 7 % in the 6 month control, the rate of side effects 11 %. Conclusion: Repeated TACE alteres the size and structure of primary unresectable liver metastases and expands the indication for MR-guided LITT. 

Results: TACE treatment were performed successful in 99.9 %. Only in 2 cases sondage of celiac trunk and performing TACE was not possible. During the TACE procedure in 12 cases an occlusion of the A. hepatica was evidenced with good collateral arteries, so that TACE could performed. In one case perforation of A. hepatica propria resulted in a small subhepatic bleeding. No therapy associated mortality was observed. Only minimal side effects like pain (53.8 %), nausea (30.8 %), vomiting (20.5 %), fever (43.6 %) and apokamnosis (82.1 %) were associated with the TACE, which could be managed by oral medication easily. In 15 patients aszites was documented after TACE treatment. In 6 patients intrahepatic abscess cavities were evidenced and treated with percutaneus drainages. Conclusion: TACE in liver tumors proved to be a safe oncologic treatment in an outpatient setting. Side effects must be treated fast to reduce failure.

Extrahepatic recurrences after radiofrequency ablation treatment of hepatocellular carcinoma: Spectrum of imaging findings M. Tonolini, L. Solbiati, T. Ierace, V. Kirn, P. Marelli; Busto Arsizio/IT Purpose: To describe diagnostic aspects and particularly CT findings of extrahepatic relapses observed after treatment of hepatocellular carcinoma. Materials and methods: During a six-year span, 226 patients (aged 32 -88 years) with chronic hepatitis or cirrhosis were diagnosed with hepatocellular carcinoma confined to the liver and treated percutaneously with radiofrequency (RF) ablation. A total of 313 treatment sessions were performed. Post-therapeutic follow-up is based upon serum alpha-fetoprotein levels and CT examination. Results: Mean duration of follow-up was 17 months. After successful treatment, actuarial probability of neoplastic relapse is 30.7 % after 1 year and 58.5 % after 2 years. 88 patients had recurrence of hepatocellular carcinoma after a variable time interval (mean 7.3 months). Extrahepatic neoplastic relapse was observed in 14 patients, half of these without active hepatic disease. Distribution of extrahepatic sites of recurrence was as follows: abdominal lymph nodes (6 cases), bone (3), peritoneum (2), adrenal (2), lung (1). Five patients (2.2 %) had a second primary extrahepatic neoplasm. Conclusion: Extrahepatic hepatocellular carcinoma is considered rare and occurring in advanced stages, but may represent a modality of post-treatment relapse. The distinctive hypervascularity of this tumor histology may be observed in adenopathy and adrenal metastases. Second primary neoplasms should be considered in the differential diagnosis of lesions observed during follow-up.

Radio-frequency (RF) ablation of liver tumors: Postprocedural appearances on multiphasic spiral CT P. Cabassa, L. Romanini, D. Guidetti, F. Simeone, A. Maggi, L. Grazioli; Brescia/IT Purpose: To describe the spectrum of CT findings of liver malignancies treated with RF. Materials and methods: 40 histologically proven malignant liver lesion (35 HCC, 5 methastasis, size range 1.6 -7.5 cm) in 37 patients (26 male, age range 44 -82 years) were treated with RF (using either internally-cooled electrode or Le Veen needle electrode). Multiphasic spiral CT at 1, 4, 6, 12 months (and every 6 months after 1 year) was performed for follow-up. Spiral CT included unenhanced and enhanced arterial and portal venous phase images. Absence of contrast enhancment within the lesion was considered as complete ablation. The location (local intrahepatic, remote intrahepatic) and morphology of tumor recurrence were rewiewed. Any other findings (perilesional hyperemia, THAD etc) were recorded. Results: Complete necrosis was described in 31 lesions (77.5 %) at 1 month, partial necrosis in the remaining 9 lesions (22.5 %). Local tumor recurrences (persistence) appeared in three patterns: nodular, halo or gross enlargement. 4/31 lesions (12.9 %) tumor-free at 1 month showed tumor persistence at 4 months. Analysis of these cases showed that residual disease was probably masquerade by perilesional hyperemia, a common finding at 1 month. Any lesion considered complete ablated at 6 month didn't show tumor recurrence in the following controls. 15 cases showed remote intrahepatic recurrence. Pseudolesions as THAD or a-v fistula were common findings expecially in early controls. The median follow-up was 13 months (range 6 -34 months). Conclusion: Knowledge of any CT findings after RF ablation is important but correlation with timing of follow-up is mandatory to avoid misdiagnosis.

CT-guided aspiration and drainage of suppurative residual cavities after hydatidectomy A.I. Ikramov, N.M. Djouraeva; Tashkent/UZ Purpose: To evaluate the efficacy of CT controlled intervention procedures in infected residual cavities after hydatidectomy. Material and methods: CT-guided drainage was conducted on 62 patients with infected residual cavities after hydatidectomy. Age varied between 14 and 76 years (mean 39.6). Size of cavities ranged from 4.5 cm up to 12 cm. 76.3 % of cavities were located in the right lobe. In homogenous low density collections (+10 ± 18 HU) with thin walls an FNA procedure was used to allow aspiration. In other cases (37) with high density collections (+25 ± 30 HU) we performed percutaneous drainage with 9 -18 F pigtail catheters. In 12 cases when cavity sizes were more than 10 cm we performed drainage via two catheters. Results: In 93.5 % of patients CT-guided interventions allowed us to achieve a full recovery. Repeated aspirations (from 2 up to 5) were conducted in 12 cases. One complication occurred (partial lung collapse). In 4 cases with ineffective drainage surgical conversion was needed. Conclusion: CT-guided drainage procedures can be an effective method of treating suppurative residual cavities after hydatidectomy and may be an alternative to surgical treatment. In none of the patients was contrast material administered for MRI. 90 patients also underwent cardiac catheterization within two months after MRI examination. All patients were examined with percutaneous echocardiography. The results were compared to the anatomical situs and functional parameters. Patients with abnormal coronary arteries were excluded from this study. Results: In 70 of 90 patients (77 %) cardiac catheterisation and MRI examinations provided results which led to the same clinical decisions. Discordance between the two methods occurred in the assessment of pulmonary stenosis, in the evaluation of spongy myocardium, and straddling of mitral or tricuspid valves. Overall there was no significant difference between MRI and cardiac catheterisation in the pre-and postoperative evaluation of congenital heart disease (CHD). Conclusion: MRI can be more beneficial in difficult patients especially with complex postoperative situs. Cardiac catheterisation should only be performed when MRI is questionable. Percutaneous echocardiography still remains the first diagnostic tool in the evaluation of CHD. 

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Methods: 29 patients with an established echocardiographic diagnosis of tricuspid valve insufficiency grade II or grade III and planned combined reconstruction of tricuspid and mitral valve were prospectively included and examined with MRI. Sequences included continuous short axis truefisp cine sequences of the whole heart for volumetry of atria and ventricles, phase contrast (PC) through-plane flow measurement and cine sequences for assessment of valvular function. Patients were randomized and treated either by DEVEGA annuloplasty or by carpentier ring implantation. In 12 patients, postoperative results were obtained 2 -3 months after surgery. Results: 21 of 29 patients examined had an absolute arrythmia, thus impairing diagnostic quality especially for flow measurements. Atrial volumetry in these cases showed no discernible contraction, and through plane flow measurement in the valvular plane showed no A-wave. In all patients, the degree of insufficiency was established with PC-flow correlated with 4 chamber view cine sequences and echocardiographic findings. In the follow-up-studies, no significant differences between the surgical treatment groups could be detected. Conclusion: Cardiac MRI with PC-flow measurement and cine sequences seemed to be well suited for evaluation of atrial function and valvular morphology and function before combined valvular reconstruction. Atrial volumetry is less useful than valvular flow measurement. Cine sequences in the valvular plane allowed for sizing of the valvular ring. Purpose: Severe pulmonary regurgitation late after total correction for tetralogy of Fallot leads to progressive right ventricular dilatation and an increased incidence of severe arrhythmias and sudden death. MRI was used to assess the effect of PVR on RV function and PR. Materials and methods: 26 Adult patients who underwent pulmonary valve replacement in our institution between 1998 and 2001 were studied. Mean age at initial repair was 5.5 ± 3.6 years and mean duration of follow-up was 30.0 ± 8.9 years. Cardiac MRI was performed 6.2 ± 3.7 months before and 7.7 ± 2.3 months after PVR. Pulmonary regurgitation (PR), RV end-diastolic volume (RVEDV), Right ventricular end-systolic (RVESV) and RV ejection fraction (RVEF) were measured. Results: Preoperative PR was 45 % (range from 25 to 64 %). After PVR, 20 out of 26 patients (77 %) showed no residual PR. RVEDV decreased from 305 ml ± 87 ml to 210 ml ± 62 ml (p < 0.01) and RVESV decreased from 181 ± 67 ml to 121 ± 58 ml (p < 0.01 Purpose: Retrospectively ECG-gated 3D volume data from Multislice spiral CT (MSCT) coronary angiography enables image reconstruction in diastolic and systolic phase of the cardiac cycle. Thus, the objectives of our study were to determine LV ejection-fraction (LV-EF) from MSCT data set and to compare the results to Cine Magnetic Resonace Imaging (MRI). Materials and methods: 28 patients (60.6 ± 8.5 a) with coronary artery disease (CAD) underwent MSCT coronary angiography (Somatom Volume Zoom, Siemens AG; 4 × 1 mm slice thickness, 120 kV, 300 mA; 140 ml nonionic CM, flow 3 ml/s). An additional Cine MR study was performed at a 1.5 T MR unit (breath-hold FLASH 2D sequence, TR 80 ms, TE 4.8 ms, flip angle 20°, slice thickness 6 mm). From MSCT data set retrospectively ECG-gated axial images were reconstructed in systolic and diastolic phase (ACV reconstruction algorithm). Enddiastolic and endsystolic LV volumes were determined from multiplanar reformations (slice thickness 6 mm) in short-axis image orientation (3D volumetry) to assess LV-EF. Cine MRI data was analyzed by using the implemented ARGUS™ software in shortaxis image orientation.

Multiplanar reformations from MSCT data set allowed good delineation of endocardial and epicardial contours. Systolic reformations showed slight motion artifacts in patients with a heart rate above 75 b.p.m. Enddiastolic (r = 0.92), endsystolic (r = 0.90) LV-volumetry and LV-EF determination (r = 0.90) from MSCT data set demonstrated good correlation to Cine MRI. Conclusion: In patients evaluated for CAD, retrospectively ECG-gated 3D volume data set from MSCT angiography provides LV volumetric and functional data in good correlation to Cine Magnetic Resonance Imaging. After intravenous administration of contrast media (120 ml, 370 mg/ml iodine, flow 3 ml/s) scanning was initiated by bolus tracking and performed using a ECG-gated protocol at 40 mAs and 120 kV, collimation of 4 × 4.0 mm, pitch of 1.2:4 and 0.5 s rotation time. The raw data was reconstructed with 50 % reconstruction pitch every 10 % of the R-R interval. Images were transferred to external workstations for diagnostic interpretation of the chest (Easy-Vision, Philips) as well as the cardiac data (Alato-View, Toshiba). Studies were evaluated with regard to image quality. Left ventricular function parameters were calculated and were compared with echocardiographic measurements using Pearson's correlation coefficient and Student's t-test for paired samples. Results: Diagnostic interpretation of the images was feasible in all patients without recognizable reduction in image quality. The radiation dose of the modified protocol did not exceed the exposure of a routine chest CT. Retrospective reconstruction of diastolic and systolic cardiac images succeeded in all patients, only minor motion artifacts occurred in 9 cases due to cardiac arrhythmia. Comparison between MSCT and echocardiographic measurements revealed no significant differences in the mean values of the function parameters (p < 0.05 in all cases) and a good correlation between both modalities: diastolic/systolic wall thickness r = 0.88/ 0.84; diastolic/systolic diameter r = 0.91/0.86 and EF r = 0.82. Conclusion: Using a modified protocol for routine chest scanning, MSCT allows a reliable, fast calculation of heart size and function without additional radiation exposure.

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Value and reproducibility of multidetector-row CT in the assessment of cardiac function C. Herzog, A. Mehtap, N. Abolmaali, J.O. Balzer, S. Schaller, T.J. Vogl; Frankfurt a. Main/DE Objective: To explore the value and accuracy of multislice-cardiac-CT in the assessment of functional cardiac parameters. Materials and methods: 23 patients prospectively underwent multislice-CT (SiemensPlus4VZ, Germany) and invasive angiocardiography. Using retrospective ECG-gating scanning parameters were 4 × 1 mm collimation, pitch 1.5 and 500 ms rotation time. Based on a proportional reconstruction algorithm two datasets were obtained from the endsystolic, endiastolic phase respectively. Effective slice thickness amounted to 2 mm, increment to 1 mm. Measurements were performed in 10 mm thick slices cut orthogonal to the short axis of the heart. Functional parameters determined were endiastolic (EDV) and endsystolic ventricular volume (ESV), segmental wall thickening and ejection fraction (EF). All measurements were performed using a MRI-proved evaluation software (ARGUS 2.3 WIP, Siemens, Germany). Invasive angiocardiography served as a reference measuring method using centerline analysis for functional evaluations. Results: Concerning evaluation of the ejection fraction, the Wilcoxon test for matched pairs did not reveal significant differences between the two methods (Tukey confidence interval: p = 0.95). However CA tended to overestimate EF by 4.5 %. The limits of agreement between CT and CA in EF were ±24.2 %. Significantly higher differences between both methods were found for EDV rather than for ESV, again values being overestimated by CA. The best correlations for EDV, ESV and EF were obtained in patients with DCM. Hypokinetic wall areas were detected with a sensitivity of 87.5 % (21/24), hyperkinetic regions with 92.6 % sensitivity (25/27). Conclusion: Multislice-cardiac-CT provides precise evaluation of functional parameters such as ejection fraction, wall thickening or endiastolic and endsystolic volume. To evaluate left ventricular volumes and systolic function using multirowdetector spiral computed tomography (MDCT) with retrospective ECG gated biphasic data reconstruction in comparison to left ventriculography (LVG). Methods and materials: 25 patients underwent routine MDCT coronary angiography using retrospective ECG-gating. Dedicated algorithms allowed for a temporal resolution of 250 ms. Contrast enhancement was provided by administration of 120 ml of Iopromid. To assess LV volumes and systolic cardiac function biphasic reconstruction at end-diastole (ED) and end-systole (ES) was performed. Data reconstruction timing was based on the ECG trace with placing the ED window at −100 ms before the R-wave and the ES window to cover the T-wave. Short axis views were reconstructed from ED and ES data sets and the Simpson rule used for calculation of ED volumes (EDV), ES volumes (ESV), stroke volumes (SV) and ejection fractions (EF). Data were compared to results of LVG. Results: EDV (R = 0.59) and SV (R = 0.56) showed good correlation with LVG, whereas ESV (R = 0.88) and EF (R = 0.82) showed very good correlation. MDCT significantly overestimated EDV (MD: 22 ± 36 ml; P = 0.0045) and ESV (MD: 39 ± 22 ml; P < 0.0001) whereas SV (MD: −17 ± 27 ml; P = 0.008) and EF (MD: − 17 ± 9 %; P < 0.0001) were significantly underestimated. MDCT intraobserver variability ranged between 4 % and 6 %. Conclusion: ECG orientated biphasic reconstruction of coronary MDCT data sets allow for estimation of LV volumes and systolic function without the need for additional scanning. However, with current possible temporal resolution cardiac volumes are consistently higher in MDCT and therefore SV and EF are underestimated in comparison to ventriculography.

R. Rienmüller, G. Reiter, U. Reiter, N. Gagarina, A. Ryabikin, B. Schröttner; Graz/AT Purpose: Comparison of left ventricular volumes and muscle mass studied by electron beam tomography (EBT) and magnetic resonance (MR) evaluated by a geometry-based model as well as 3D methods in patients with suspected or known coronary heart disease. Materials and methods: 40 patients were studied by EBT (ECG gated, multislice mode, 50 ms exposure time, intravenous contrast agent application) in long axis view and by MRI (1.5 T field strength, 40 mT/m gradients, cine-TrueFISP) in 4 chamber view. Enddiastolic (EDV) and endsystolic (ESV) volumes as well as left ventricular muscle masses (LVMM) were evaluated by a single-plane ellipsoid model. In addition MRI short axis scans were performed in 23 patients to use Simpson rule (ARGUS software) to determine the above parameters. Results: Correlation between EBT and MRI ellipsoid model is r = 0.87 (95 %-confidence interval is 0.76 to 0.93) for EDV, r = 0.92 (0.85 to 0.96) for ESV and r = 0.82 (0.68 to 0.90) for LVMM. Correlation between EBT and MRI Simpson approach is r = 0.92 (0.81 to 0.96) for EDV, r = 0.93 (0.83 to 0.97) for ESV and r = 0.79 (0.55 to 0.91) for LVMM, respectively. Relative standard deviations of the differences of single paired measurements varied in the range of 15 % to 25 %. Conclusion: Both EBT and MR methods may be used to determine left ventricular volumes and mass. The differences of standard deviations implicate the need to determine ranges of normal values for all evaluation approaches in clinical routine. Background: Several tumor-host biological factors seem to be valuable predictors for the prognosis of patients with squamous cell carcinoma (SCC) of the head and neck, such as the peritumoral lymphocytic infiltration (PLI) or a sharp tumor border. In particular, significant associations have been reported between the presence of PLI and the absence of cervical adenopathy. Preoperative biopsy specimens are often insufficient for an evaluation of these criteria. Therefore, this study was performed to examine whether an elevation of peritumoral CT-values correlates with the presence of PLI. Moreover, correlations with present cervical adenopathy were obtained to check whether an elevation of peritumoral CT-values can be regarded valuable in predicting a prognosis. Methods: In total, 45 patients with primarily resected SCC were involved (pT1 = 8, pT2 = 13, pT3 = 9, pT4 = 15); 28 patients were pN-positive. All tumors were histopathologically analyzed regarding the presence of PLI and a sharp or infiltrating tumor border. Based on standardized CT examinations, repeated ROI-based density measurements were obtained in vital parts of the tumor boundary. Statistics were performed to find dependencies between PLI, pattern of tumor invasion, cervical adenopathy, T classification, and CT densities. Results: Our results show that an elevated peritumoral CT-density is a highly specific and sensitive sign for the presence of PLI. Moreover, there were significant statistical correlations of present PLI and elevated peritumoral CT-values with absent regional lymph node metastases.

Our results show that the evaluation of peritumoral CT-values appears to be a valuable prognostic co-factor, useful in the majority of patients (especially in patients without clinically detectable cervical metastases).

Clinical trial of the accuracy of a freehand and sensorless three-dimensional power Doppler ultrasound system measuring the diameters, volumes and vascularity of malignant primaries of the neck M. Keberle, M. Jenett, D. Hahn; Würzburg/DE Purpose: The diameters, volumes, and vascularity of malignant primaries of the neck have substantial impact on staging and prognosis. The purpose of this study was to determine the accuracy of a novel freehand and sensorless three-dimensional power Doppler ultrasound (3D PDUS)technique in the assessment of these parameters.

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Method: 24 patients with squamous cell carcinomas of the neck underwent conventional ultrasound in B-and power Doppler-mode (US), 3D PDUS, and computed tomography (CT). Diameters (sagittal, longitudinal, and transverse) and volumes of the tumors were correlated with hand-segmentated CT images, and tumor vascularity with US. Results: 3D PDUS and CT were highly correlated regarding diameters and volumes (correlation coefficients r = 0.98/P < 0.001 and r = 0.98/P < 0.001, respectively). 3D PDUS and US highly correlated regarding vascularity (r = 0.92/P < 0.001). Conclusion: Although 3D PDUS is based on a freehand and sensorless data acquisition, it appears to be as accurate as CT or US for measurements of diameters, volumes, and vascularity of neck malignancies. In spite of the excellent results it has to be noted that this technique requires a lot of training and its general use has to be employed with caution.

Prognostic significance of the revised tnm staging 1998 in patients with locally advanced nasopharyngeal carcinoma (NCP) A. Kalogera-Fountzila, C. Kouskouras, N. Fotiadis, E. Vakali, G. Sevas, C. Christoforidis, L. Papadopoulou, A.S. Dimitriadis; Thessaloniki/GR Purpose: To evaluate the prognostic significance of specific anatomical structure involvement related to the revised TNM staging (1998) in patients with locally advanced NPC. Materials and methods: CT images of 132 patients, who were treated in our hospital with radiation or chemotherapy and radiation, were retrospectively reviewed. We analyzed, the CT scans performed prior and after the completion of treatment.

Results: There were 99 men and 33 women (median age 54 a). Histology was undifferentiated carcinoma in 104 patients and SCC in 28. The paranasopharyngeal space was found to be involved very commonly (98 %). Degree 1 (d1) of paranasopharyngeal extension included 27 % of the patients, d2 39 %, and d3 32 %. The incidence of osteolysis was 33 % (clivus 20 %, foramen rotundum 5 %). Cavernous sinus involvement was present in 15 % and carotid sheath in 38 %. Retropharyngeal nodes were found in 42 % of the patients. T2b (65 %) and T4 (20 %) as well as N1 (29 %) and N2 (50 %) were more frequent. After the completion of treatment 81 patients demonstrated complete response. After a median follow up of 79 months 31 complete responders have relapsed. Median time to progression for all patients was 37 months and the median survival 55 months. Cox univariate analysis revealed, age, T1, T2, paranasopharyngeal extension and cavernous sinus involvement, as significant prognostic factors for survival.

The revision of TNM staging, in our study, was useful in the prognosis of NPC. The degree of extension of the tumor into the paranasopharyngeal space has to be considered in future TNM staging revisions.

The prognostic value of MRI in nasopharyngeal carcinoma S.S.A. Lingawi, Y.F. Ragab, M. Mansour; Jeddah/SA Purpose: To evaluate the role of MRI in the prediction of nasopharyngeal carcinoma (NPC) response to radiotherapy. Material and methods: 52 NPC patients had MRI before and after radiotherapy to the local disease and to the nodal involvement. The MRI assessed the size, site, signal intensity, enhancement pattern and extension of the regional disease in 25 anatomical sites. Radiotherapy was delivered using X-rays of 4 -6 MV Linac. Purpose: Head and neck tumors show considerable variation in perfusion pattern and biological behavior as well as response to chemoradiation. The high frequent acquisition of multislice CT data after a contrast medium bolus allows quantification of tumor perfusion. The aim of this study was to assess therapy-induced changes of tumor perfusion early after initiation of treatment. Methods and materials: Dynamic MSCT was performed in 22 patients with histologically proven head and neck cancer before and 3 weeks after initiation of chemoradiation. After bolus injection of 80 ml contrast medium, two 10 mm-sections through the largest tumor region were scanned for 40 s (Siemens SOMATOM Volume Zoom). The arterial input function was derived from the largest arterial vessel in the field of view. Perfusion values were calculated using graphical analysis and displayed as parametric color coded images. Standardized circular regions of interest were drawn on the area displaying highest perfusion. The tumor area was determined by the product of the maximum perpendicular diameters. Results: At baseline, all tumor lesions were visible in parametric images by enhanced perfusion values (0.474 ml/min/ml ± 0.212), however the perfusion pattern was very inhomogeneous. The tumor area was 1007 mm 2 ± 736. Three weeks after initiation of chemoradiation, tumor perfusion increased to 0.493 ml/min/ml ± 0.214, whereas tumor area decreased to 734 mm 2 ± 960. There was no correlation between perfusion and tumor size changes (r = 0.185).

These results indicate that chemoradiation induces significant changes of tumor perfusion. Standardized assessment is possible by perfusion MSCT.

Evaluation of radiation response with dynamic gadolinium-enhanced MRI for head and neck cancer: Correlation of hemodynamic changes with pathology N. Tomura, K. Omachi, K. Kato, S. Takahashi, I. Sakuma, K. Sato, J. Watarai, M. Sageshima; Akita/JP Purpose: To assess the diagnostic value of dynamic gadolinium-enhanced MR imaging in the evaluation of response to radiation therapy for head and neck cancer, and to correlate hemodynamic changes after radiation therapy with pathology. Methods and materials: MR imaging was prospectively performed before and after radiation therapy in 26 patients with various head and neck cancers. A dynamic Gd-enhanced study was performed using a fast SPGR sequence. The maximum slope of increase (MSI) on the time-intensity curve was displayed as a colorcoded image. Ratios were obtained for peak time of enhancement (TPR) and intensity of maximum enhancement (MER), as well as the MSI (MSIR) between the

A C D E F 194 tumor and normal muscles. TPR, MER, and MSIR after therapy were compared with those before therapy. Pathologic specimens after radiation therapy were acquired in 23 patients. Histological grading of radiation changes was divided into grades I -IV. TPR, MER, and MSIR after therapy were compared with histological grades. Results: A significant difference (p < 0.05) was observed in MSIR before and after therapy. Although only 4 of 19 patients with grade II (viable tumor cells present) or III (only non-viable tumor cells) showed a MSIR < 2.5, all patients with grade IV (no tumor cells) showed a MSIR < 2.5. Conclusion: MSI quantitatively reflects the treatment response of radiation therapy for head and neck cancer. Color-coded MSI display is feasible for depicting hemodynamic changes following radiation therapy.

Scintigraphic prediction of resistance to radiation and chemotherapy in patients with head and neck tumors K. Sato, N. Tomura, O. Watanabe, K. Sasaki, J. Watarai; Akita/JP Purpose: 99 Tc-sestamibi (MIBI) SPECT was compared with 201 TlCl SPECT for prediction of multidrug resistance and radioresistance in patients with head and neck tumors. Materials and methods: Eighteen patients (age range: 48 -76 a, mean 63 a) with tumors in the head and neck region (larynx in 6, oropharynx in 5, hypopharynx in 5, oral cavity in 1, maxillary sinus in 1) were evaluated with dual-isotope SPECT imaging using 99 Tc-MIBI (600 MBq) and 201 TlCl (111 MBq) at 15 (early) and 120 (delayed) minutes after the injection. Quantitatively, tumor-to-background (T/B) ratio of tracer uptake was calculated in the early and delayed phases of each tracer, and retention index was calculated as follows: [(delayed ratio − early ratio)/early ratio] × 100 (%). Using radiation and chemotherapy concurrently, the patients were classified into partial remission (PR) and no change (NC) groups. The relationship between therapeutic response and tracer uptake was analyzed. The detectability of resistance to radiation and chemotherapy was examined. Results: The delayed ratio for 99 Tc-MIBI in the NC group was significantly lower (p < 0.05) than that in the PR group. There was no significant correlation between T/B ratio and tumor response using 201 TlCl. There were no significant differences in the early ratio and the retention index with respect to the tumor response in both 201 TlCl and 99 Tc-MIBI SPECT images. Conclusion: 99 Tc-MIBI SPECT may be more effective than 201 Tl SPECT for prediction of multidrug resistance and radioresistance in patients with head and neck tumors. 

Purpose: To evaluate the need for doubling the effective mAs in obese patients when performing low dose multi-row detector CT (LDMRDCT) for the assessment of ureteric lithiasis. Materials and methods: 106 consecutive patients with known body mass index (BMI), and clinical suspicion of renal colic were referred for a LDMRDCT with the Volume Zoom (Siemens) and 120 kV, 30 mAs, 4 × 2.5 mm collimation, 0.5 s/rotation, pitch of 1.5. A second acquisition limited to the region with artefacts, using the same parameters but 60 mAs, was obtained if necessary. Slice thickness and increment were of 3 and 2 mm respectively. Workstation based assessments of ureteric lithiasis were later performed by 3 radiologists who were unaware of the final results, and compared all clinical, surgical and radiological results available. Effective dose was computer simulated and correlated with BMI.

Results: Intra and interobserver agreements were greater than 0.88. The prevalence of ureteric lithiasis was 36 % and the accuracy of LDMRDCT ranged from 95 to 98 %. Effective doses for males and females were 1.2 and 1.9 mSv respectively at 30 mAs and 0.5 and 0.8 mSv respectively in 20 patients with focused acquisitions at 60 mAs. A BMI of 35 was found to be a threshold over which all patients needed 60 mAs. Conclusions: LDMRDCT with 30 mAs in patients with normal weight and with 60 mAs in those with BMI greater than 35 is an accurate method for assessment of ureteric lithiasis, resulting in a dose similar to a 3 film IVU. MDCT was used with 4 × 1.0 mm collimation, 100 mAs, and 120 kV (CTDI = 11.4 mGy). We compared 3 reconstruction protocols (slicewidth/reconstruction interval: 1.5/0.7 mm, 3/1.5 mm, 5/2.5 mm). In addition, multiplanar reconstructions (MPR) in coronal plane were performed. 3 experienced readers analyzed each scan. Presence, number, size of calculi and additional findings not associated with urinary stone disease were evaluated. Results: MDCT was positive for calculi in 107 cases independent of axial reconstruction protocols. Coronal MPR's were helpful in evaluation of the precise stone location, although on 5 mm MPR's significantly less calculi were depicted. There was also no significant difference between performed protocols in evaluation of additional findings. Conclusion: Axial reconstruction protocols (1.5/0.7 mm, 3/1.5 mm, 5/2.5 mm) are equally suited in the diagnosis of urinary stone disease. Coronal MPR's are helpful in the evaluation of precise stone location, however very small calculi may be missed on 5 mm coronal reconstructions. Purpose: This study investigates the possibility of using combined blood oxygen level dependent (BOLD) imaging and diffusion weighted imaging to detect pathological changes in renal tissue induced by chronic renal hyper-filtration.

The apparent diffusion coefficient (ADC) and the T2*value within the four inner compartments of the kidneys of 17 rats with diabetes mellitus were compared with the results obtained from a control group of 16 rats. Furthermore, the influence of the hyper-filtration on the blood-oxygen saturation was evaluated by comparing the T2*-values before and after the active tubular transport was reduced by injecting furosemide. Results: All compartments of the diabetic kidney showed significantly (p < 0.05) lower T2*-values compared to the control group. In particular, the very low values in the outer stripe of the outer medulla (T2*-normal: 69.4 ± 10.9 ms; T2*-diabetic: 51.4 ± 13.9 ms) indicated either hypoxia due to hyper-filtration or renal blood volume changes. Diffusion imaging of the same area showed significantly lower ADC values (ADC-normal: 1.45 ± 0.26; ADC-oedema: 1.19 ± 0.25 [10 -9 m 2 /s]) that correlated with pathological findings on biopsy.

Conclusions: BOLD-contrast imaging appears to be able to depict tissue that is at risk of suffering from ischemia by revealing information about the balance between tubular workload and delivery of oxygen and may thus reflect a measure of the reserve capacity. The diffusion measurements reveal complimentary information -ADC imaging is not sensitive to the current energy metabolism but reflects the pathological changes within the tissue. Therefore ADC-measurement might be a sensitive indicator of the severity of the induced ischemic lesions.

Virtual endoscopy of moderate or non dilated renal pelvis and calices with unenhanced 3D T2-weighted static fluid MR urography: A prospective study C. Roy, C. Vasilescu sr., L. Solair sr., C. Tuchmann sr., C. Saussine sr., D. Jacqmin sr.; Strasbourg/FR Purpose: To assess the accuracy and usefulness of virtual endoscopy (VE) by MR to study moderate dilated renal cavities. Method/materials: 33 patients, having excretory tumours (n = 18), calculi (n = 11), and extrinsic compressions (n = 4) underwent MRU (1 T Philips) using T2 3D TSE (TR/eTE: 1800/500 ms, ETL: 130, 80 slices, slice thickness: 0.6 mm, 256 × 256, FOV: 240, TA: 4 min 21 s. VE were reconstructed using volume rendering and were interpreted (MIP reconstructions, sources images) by two radiologists. Correlation was made with conventional endoscopy/pathological findings. Results: Mean operator time was 20 min. Endoluminal masses (up to 3 mm) were depicted by source images and VE, but missed by MIP in 5 cases (2 tumours, 3 stones). Morphologic assessment (smooth or irregular surface, position, number, surface extension) was more pertinent on VE than on sources images. Blood clots (3 cases) were misdiagnosed as tumoural polyps. A smooth surface with abrupt margins was present for all stones and in 8 cases of tumoural process. An irregular surface was only present in tumoural processes. VE images did not allow evidence of intramural extension of the tumour. Assessment of surface alone did not allow to differentiate between a calculus from a smooth polyp. Conclusions: VE is easily feasible in moderate or non dilated renal cavities. It permits precise location and number of filling defects with delineation of the surface extension. It is not really time consuming and it seems to be a promising modality for optimal visualization of pelvo-caliceal pathology. In 2 patients the process progressed to abscess formation. Retracted cortical scars in 9 patients reflected the healing phase. The IVU was normal in 16 of 18 patients with early lesions showing minimal delay of contrast excretion in the collecting system in 2 patients. Conclusions: Early cortico-medullary and nephrographic phase spiral CTs are highly sensitive in detection of compromised parenchyma in the pyramids indicating papillary necrosis and thereby allow treatment at a time when the disease process is still reversible. Methods/materials: We minimize patient dose by adapting the tube current to anatomy in two ways: a local projection angle dependent tube current modulation that minimizes the current for projections of low attenuation is combined with a global tube current control that adapts the tube current 360° mean level to the anatomic level. Our method uses the projections currently scanned to "foresee" the behavior while scanning the next 180° segment. Based on user-defined image quality parameters (selected by choosing the desired reconstruction kernel and the image noise standard deviation in HU) the tube current curve is computed. The approach has been tested in simulations and phantom measurements on a Somatom Volume Zoom scanner (Siemens, Forchheim, Germany). To further reduce the projection noise we have implemented a raw data-based MAF approach. It locally smoothes the projection values of highest attenuation. MAF is utilized as a preprocessing step during image reconstruction; the algorithms are implemented on the Syngo Explorer workstation (VAMP, Moehrendorf, Germany). Results: MAF reduces image noise by up to 50 % and thereby allows for respective dose reduction. The combination of AEC and MAF allows to secure this reduction and to increase it further. Conclusions/discussion: The combination of AEC and MAF allows to greatly reduce patient dose for a given image quality over complete anatomical ranges. The user simply specifies the desired image quality instead of setting the "mAs-value" or other parameters.

Spiral imaging properties of a 16-slice CT-system T.G. Flohr, K. Stierstorfer, H. Bruder, J. Simon, S. Schaller; Forchheim/DE Purpose: The spiral imaging properties of a newly introduced 16-slice CT system (Siemens, Forchheim, Germany) are evaluated.

The 16-slice CT system provides a novel image reconstruction technique for multislice spiral CT (Adaptive Multiple Plane Reconstruction AMPR) which takes into account the cone-angle of the measurement rays and allows for a free selection of the spiral pitch. For a given collimation (e.g. 16 × 0.75 mm), a variety of different spiral slice widths is available. We measured spiral slice sensitivity profiles, image noise in a centered 20 cm water phantom and dose (CTDI 100) as a function of the spiral pitch in the range 8 to 24. In our definition, the spiral pitch is the Purpose: Aim of our study was to establish a complete analytical description of noise and resolution in X-ray Computed Tomography (CT) and to predict trends for patient dose with respect to future developements in CT technology.

We performed various simulations to validate the analytical predictions of pixel noise dependency on sampling distance in parallel beam geometry and the convolution filter. Further, we measured image noise and high contrast resolution on a clinical CT scanner (Siemens SOMATOM Volume Zoom), thereby operating with all available scan modes. Data sets were reconstructed with several convolution filters. Results: Noise variance at the center of a typical 20 cm water phantom varies with the inverse third power of the sampling distance. The tests with measured data showed that the convolution filter influences noise and resolution directly with variance depending linearly on the total area under the squared modulation transfer function (MTF). Based on the measurements we were able to derive noise equivalent quanta for the CT scanner under examination. Conclusion: Due to the interdependence of noise and resolution, which is an intrinsic property of tomographic reconstruction from projections, it can be predicted that the dose necessary for constant noise level and unchanged object size will increase by a factor of x 3/2 when the resolution element is reduced by 1/x. This has direct implications for future CT systems that employ flat panel detectors with sampling distances down to 0.1 mm, thereby yielding a tenfold improved resolution compared to today's high-end CT scanners. Method and materials: 50 patients with head and neck tumours were scanned using a multislice CT scanner (SOMATOM Volume Zoom, Siemens Medical Solutions, Germany) with a high resolution protocol. Reconstruction was performed using dedicated reconstruction software (ImpactIR, VAMP GmbH, Germany) with the standard algorithm and the MAF approach. We measured the noise for 6 anatomical regions at the level of the humeral heads. Image quality, image noise and the diagnostic value comparing the standard reconstructions to the multidimensional adaptively filtered images was rated.

Results: The use of MAF significantly improves image quality by reducing noise levels and by removing noise structures in the images. Noise is reduced by 39 % on average, depending on the patient shape and the anatomical regions. The overall image quality is rated significantly better with MAF in comparison to the standard reconstruction without any loss of image sharpness. Especially the visualization of the cervicothoracic junction is drastically improved for all examinations, whereas the image quality of the upper neck is unchanged. The differentiation of anatomical and patholocical structures is enhanced in particular in the upper mediastinum and in the supraclavicular regions.

The reduction of image noise, the improvement of image quality and the high diagnostic accuracy achieved with MAF without any loss of image sharpness offers new perspectives to reduce patient dose. The reduction in patient exposure and image quality and noise were evaluated. To assess the noise, the standard deviation of the density of the trachea and the aorta were used. For the image quality a three point scale: worse -equivalentbetter.

The mean dose reduction in the modulated scans was about 29 % (p < 0.001). In the area of the shoulder it was about 35 %, of the thorax and abdomen about 25 % and of the pelvis about 29 %. The noise of the images in the modulated scans was between 17 % (p = 0.01) at the level of the trachea bifurcation and 15 % (p = 0.06) at the level of the aorta bifurcation higher compared to the standard scans. With attenuation-based on-line modulation of tube current in 21 cases the diagnostic image quality was assessed as equivalent to the images using the standard protocoll. In 3 cases the image quality was worse.

The use of attenuation-based online modulation of tube current allows a substantial dose reduction without a diagnostic relevant decrease in image quality.

Characterizing coronary artery motion using multi-slice CT M. Vembar 1 , D.J. Heuscher 1 , D.E. Smith 1 , D.D. Matthews 1 , S. Chandra 1 , M. Garcia 2 ; 1 Highland Heights, OH/US, 2 Cleveland, OH/US Purpose: 3D motion of proximal regions of the coronary arteries during the cardiac cycle were measured from image data obtained from multi-slice computed tomography to identify cardiac phases for optimal coronary imaging and to provide a realistic model for cardiac simulation. Methods and materials: Spiral ECG-gated contrast-enhanced 1 mm retrospectively reconstructed scans were performed on patients with heart rates ranging from 49 to 75 bpm using four-slice CT (Marconi Mx8000) at a temporal resolution of 250 ms. Using landmarks along the proximal regions of the coronary arteries (left main and anterior descending (LM and LAD), right coronary artery (RCA) and left circumflex (LCX)), we obtained estimates of 3D position and velocity of these arteries during a cardiac cycle. Identifying phases with minimum velocity, we correlated the image quality in these regions with the estimates obtained. Results: Motion characteristics varied depending on the artery, with the highest degree of motion being observed for RCA. The points at which the lowest velocities occurred correlated well with the images in which the arteries could be best viewed. Though more than one minimum was observed within a heart cycle for all arteries, the most consistent image quality was observed at 70 -85 % of the cardiac cycle.

We were able to estimate the 3D motion of the three major coronary arteries. By identifying the phase in the cardiac cycle with lowest velocity, imaging of each coronary artery can be optimized. Using these estimates in characterizing cardiac motion also provides realistic simulation models for future cardiac CT applications.

and T2-weighted (HASTE) sequences in coronal (5 mm) and axial (4 mm) plane, followed by a coronal gadolinium-enhanced-acquisition with fat saturation (FLASH 2D In accordance to the RECIST criteria for evaluation of tumor response, target lesions were analyzed. T2 weighted, native and dynamic enhanced T1 MRI were acquired. Shape and character were described. Size was taken as the clinical gold-standard for response criteria progression, stable disease or regress. 3 groups of patients were compared: response (n = 19); stable (n = 6); progression (n = 3). Signal-to-noise (SNR) measurements in T1 and T2 were obtained and correlated with size. Results: Preliminary results show that STI-571 changes morphological characters of the target lesions dramatically. In the response group decreasing lesions correlate with SNR in dynamic T1 MRI (r = 0.78; p < 0.01) but not in T2 (r = −0.13).

In the progression group MRI shows no significant correlation between size and dynamic T1 (r = 0.43) but in T2 images (r = 0.99; p < 0.01). These findings are concordant to the morphological change from solid to cystic or necrotic lesions.

The information of MRI in the early follow-up is helpful to individualise the management of patients in a timely way and to keep patients with increasing, but morphologic-changing tumor leasions in the study protocol. 

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Material and methods: A prospective, randomized and double-blind trial was conducted in 50 patients randomly distributed into 2 groups: the control group (received only an oral solution) and a treated group (received the oral solution plus a subcutaneous injection of 20 mg of butylscopolamine 10 minutes before the MR examination). Breath hold T1W GRE images were obtained. Quantitative image analysis was performed of the signal intensity of the liver and in background air anterior and lateral to the patient. A qualitative analysis of the subjective image quality was also done, and the adverse reactions were registered. Results: The groups were homogeneous regarding age, sex and weight distribution. No significant differences in the signal intensity of the liver and in the incoherent noise measurements were found between both groups. Gastrointestinal noise was statistically lower for the butylscopolamine group compared to the control group. There was also a statistical difference in the image quality between groups: optimal studies were only found in the butylscopolamine group. Regading adverse events, there was non-significant differences between groups. To define the spiral CT findings in patients with superior mesenteric vein (SMV) thrombosis and to compare these with surgical findings. Material and method: Abdominal CT examination of 12 patients with partial or total SMV thrombosis were retrospectively reviewed by two radiologists. The level of the thrombus, patency of portal vein and intestinal findings were noted. These findings compared with the surgical findings in patients who were operated following SMV thrombosis. Results: In 10 of the 12 patients (83.3 %) there was complete thrombosis of SMV and 2 patients (16.7 %) thrombus was partial and non-occlusive. In one patient with complete SMV thrombosis, air was observed within SMV and portal vein. Portal vein was totally thrombosed in 8 patients (66.7 %), partially thrombosed in 2 patients (16.7 %) and patent in 2 patients (16.7 %). All 10 patients with complete thrombosis SMV were operated and SMV thrombosis was confirmed in these patients. Small bowel resection was performed in 9 patients and sigmoid colon resection was performed in 1 patient. Ischemic changes in small bowel could be detected preoperatively in 8 of the 9 patients who had small bowel resection. Colonic wall thickening was observed in 5 patients including the patient with sigmoid resection. Colonic ischemia was not confirmed by surgical findings in other 4 patients. Conclusion: Spiral CT can reliably demonstrate the presence, level and extent of the SMV thrombus. Spiral CT can also detect ischemic changes in the intestine and especially small bowel findings correlate well with the surgical findings. To determine whether ultrasound-guided delineation of the tumour bed after breast conserving surgery can improve the accuracy of conventional electron boost planning. Methods and materials: 20 patients underwent post-operative radiotherapy plus electron boost following wide local excision for breast cancer, were selected at random. Conventional boost planning was undertaken using clinical examination, surgical details and pre-operative imaging, and a standard boost field recorded. Next ultrasound was used to delineate the tumour bed and an optimum boost field calculated using parameters including cavity size measured by ultrasound, 10 mm margin and 5 mm error margin. The standard and optimum fields were compared and potential areas of under and over-treatment of the standard field calculated.

Clinically acceptable values for these were set at 0 % of optimum boost area for under-treatment and 300 % of optimum area for over-treatment. 

The DMNI visualisation and sampling management include galactography (Ggr), MR and ultrasound Ggr, Fiber-ductendoscopy to investigate patients with intraductal abnormality. Using ductal lavage (DL) and saline retrieval we tested material collected from breast ducts cells by methylationspecific PCR (MSP) methylated alleles of Cyclin D2, RAR-, and Twist genes detected in fluid from mammary ducts or endoscopically visualized DCIS. Northern blot analysis was performed for expression in Epithelial Cells. Results: We were successful in intraductal cannulation, endoscopies and molecular testing, resulting in 96 % diagnostic accuracy. High-risk subjects were enrolled in two groups of a previous history of breast cancer and, a Gail Index score m 1.7 or BRCA 1/BRCA 2 positive status. Of 502 eligible subjects suspicious/malignant cells were detected in 2 8 % (36/502). A comprehensive database created from imaging, interventions and molecular study protocols explored current pathology management. MR, ultrasonography Dgr, and ductoscopy revealed papillomas but no high-grade intraductal lesions correlated with the lavage cytology. Immunohistochemistry, histology grading, and the relevance of diagnostic certainty were considered.

The DMNI is feasible for early breast cancer conservation and prevention. Evaluation of cellular samples for tumour biology and molecular imaging are the strongest predictors of the outcome. Diagnosis, risk assessment, and prognosis emphasise the indicators for breast DCIS, DMNI and for survival rates.

Preoperative assessment of axillary lymph node involvement in breast cancer by ultrasound R. Wenke, L. Sanders, A. Grosse, I. Schreer; Kiel/DE Purpose: To assess the sensitivity of ultrasonographic axillary lymph node detection and accuracy of different sonographic signs of malignancy in correlation with histopathological examination. Material and methods: We examined 61 patients with preoperative histologically proven breast cancer. In 34 patients conventional axillary dissection was performed, 27 patients underwent excision of sentinel lymph node (s). Clinical examination was performed independently. Sonographic criteria included lymph node size, form, shape, presence or absence of hilar reflex, echogeneity, cortical rim thickening and vascularisation. Results: Ultrasonography detected 0 -7 lymph nodes (mean 2.66) were detected in Level 1 and 0 -2 (mean 0.5) in Level 2. Histologically 2 -29 (mean 12.07) were detected in Level 1 and 0 -9 (mean 3.01) in Level 2. In 20 patients (31.74 %) axillary lymph node metastasis was detected histopathologically. Sonographically suspicious lymph nodes were inferred in 23/61 (36.5 %) patients. In 4 cases (20 %) lymph node metastasis was missed, including one case of micrometastasis. Clinical examination revealed only 9/20 (45 %) axillary metastases. Sensitivity of ultrasonography was therefore 80 %, specificity 82.9 %, positive predictive value 69.5 % and negative predictive value 89.5 %.

A satisfying prediction of axillary lymph node involvement can be achieved by means of ultrasonography. The lack of detection of micrometastases and of lymph nodes smaller than 5 mm is still a problem. The false positive rate (7) could possibly be decreased by an optimised combination of morphologic aspects. With a negative predictive value of 89.5 % ultrasonography can be a powerful tool in pre-selection for SLN biopsy and the necessary follow-up of these patients. .5 G needle with appendant coil was used. After the procedure the distance from the coil artefact to the lesion was measured in two planes (sagittal, transverse). All lesions have been histologically proven by excisional biopsy 12 to 72 hours after the MR-guided localisation. Results: Localisation and excision of the lesion was successful in all cases. Each MR-guided procedure lasted 45 -150 minutes (mean 66 min). 20 % (11/55) of the lesions were malignant. In most cases (75 %, 41/55) the coil was placed immediately adjacent to the lesion. The coil was placed up to 10 mm and 11 -15 mm (mean distance 1.8 mm, range 0 -15, SD 3.5) away from the lesion in 20 % (11/55) and 6 % (3/55) of cases respectively. Conclusion: MR-guided localisation of only MR-detectable breast lesions with an embolisation coil system is easy to perform and results in a high precision. The coils are hocked into the tissue and detectable by specimen X-ray. The aim of our study was to investigate the feasibility and potential of cryosurgery in the therapy of breast cancer. Materials and methods: 21 patients (60.5 ± 9.4 a) with histologically proven breast cancers underwent cryotherapy. After ultrasound-guided placement of the cryo probe in the tumour, two freeze/thaw cycles with a duration of 7 and 5 minutes respectively were carried out. The diameters of the occurring iceballs were measured sonographically. The patients were operated within 1 to 5 days later. The operation specimens were evaluated histologically.

The maximum diameters of the iceballs were between 21 and 31.8 mm.

The surface of the iceballs was well definable in ultrasound. 6 tumours with a diameter below 16 mm and one tumour with a diameter of 19 mm did not show rests of invasive cancer after treatment. 3 of them had DCIS in the surroundings. Subtotal necrosis was observed in 14 tumours which had a diameter of 16 mm or greater. Conclusion: After these first cases cryotherapy seems to be promising in the treatment of small breast cancers. The low detection rate of surrounding DCIScomponents in pre-interventional MRI of breast cancer results in remaining DCIS after cryotherapy. In larger breast cancers two or more cryo probes should be used to achieve larger iceballs. Purpose: To examine the effectiveness of a potential minimal-invasive method for the elimination of breast tumours by magnetic heating. Methods: A human adenocarcinoma (MX-1 cells) was implanted into 16 SCID mice. After intratumoral application of iron oxides (7 ± 3 mg per 350 mm 3 tumour tissue; average particle diameter: 10 nm), mice were exposed to an AC magnetic field (4 min; amplitude: 6.5 kA/m, frequency: 400 kHz). 4 controls did not receive an iron oxide application. Temperatures at the tumour and rectum were monitored and quantified as total heat doses (THD = temperature × time). DNA damages were investigated using the comet assay (percentage of DNA in the tail). A calibration curve between temperature and DNA damage was determined. Results: Intratumoural temperatures ranged from 59°C to 96°C (THD from 105 to 315°C × min), the percentage of the total cellular DNA in the tail was of 67 ± 23 %. In controls, no significant temperature elevation was observed and only 8 ± 2 % of the DNA was found in the comets tail. In vivo and in vitro experiments showed a temperature threshold for cell destruction of 55°C.

Conclusions: Reliable tumour cell destruction is possible by magnetic heating. Methods and materials: MR images of the EUROSPIN-TO4 phantom were obtained using standard 2D SE, 2D TSE, 2D-spoiled GRE and 3D MPR sequence types and evaluation of spatial and high contrast resolution was performed. All images were transferred to a standard PC workstation utilizing a DICOM protocol. These images were then converted to the four most commonly used image file formats on the web: TIFF, JPEG, GIF and PNG. A total number of 136 images using different file formats and compression ratios were evaluated. Image Quality

A C D E F 206 (IQ) was evaluated by consensus by three reviewers utilizing a 5 point grading scale (1: poor, 2: moderate, 3: good, 4: very good, 5: excellent). Image Size to Image Quality ratio's (IS/IQ) were also calculated for all images. Results: Minimal IS/IQ was obtained when working with low compression (20 -30 %) JPEG images and moderate to high compression (60 -80 %)PNG images. High compression JPEG images showed severe image distortion while maintaining acceptable spatial resolution. This problem was not encountered in PNG images. IS/IQ was quite satisfactory on GIF images. TIFF images were of excellent quality but with larger image sizes. The optimum compression levels were tested on routine brain and abdominal MR examinations with results comparable to phantom measurements. Conclusion: The study determined the acceptable compression levels for JPEG and PNG MRI images used for educational purposes on the web. The newly introduced PNG format offers high image quality with acceptable file sizes. • checking about 1000 homepages of international radiological institutes, • inquiries to EUFORA -a popular mailing list, • asking about 100 medical students and residents in Radiology. The 100 favorite on-line teaching programs in Radiology were evaluated by representatives of the target group -100 students and 10 residents in Radiologyaccording to user friendliness, didactic, interactivity, content and layout. Results: We created an on-line list (RadList) of categorized and evaluated on-line teaching files in Radiology, ranked according to user friendliness, didactic, interactivity, content and layout. Conclusion: RadList (http://www.radlist.uni-erlangen.de/) is a useful on-line tool for students and residents in Radiology to find their way within thousands of Internet teaching files in Radiology. RadList will be updated regularly.

Open connectivity and interoperability of web based medical teaching file servers using XML-based Web services T. Schaaf, J. Hohmann, K.-J. Wolf; Berlin/DE Purpose: Support of automated access to dynamic webbased medical teachingfile-servers. The connectivity and system interaction should be realized with the help of consistent methods based on common standardized concepts and protocols. Methods and materials: By using SOAP (Simple Object Access Protocol) as the fundamental information exchange protocol in cross-language and cross-platform communication, the herewith provided WebServices offers a consistent application interface to dynamic generated data of our medical teaching-file-server. SOAP is an standardized (http://www.w3.org/TR/SOAP) and XML-based (Extensible Markup Language; http://www.xml.org) protocol consisting a framework for describing the exchanged messages and their processing, rules for expressing instances of application-defined datatypes and definitions for representing remote procedure calls and remote responses. We have extend our multimedia teachingfile-server, built with no-cost common software components, with an PHP-based (PHP: Hypertext Preprocessor; http://www.php.net) SOAP-adaptor and could thereby offer the dynamic medical teaching-knowledge encapsulated in a medical WebService. Since SOAP could be combined with existent common transport protocols such as HTTP (Hyper Text Transfer Protocol), our WebService is seamless internet accessible. Results: The PHP-based SOAP-adaptor handles the application-driven XML-defined messages addressing the server-stored procedures for accessing the medical teaching-file-data via the inter-/intranet. Thus this application interface addresses the same database functions used by the beside existent human-computer-interface, our WebService provides the same programmed security issues. Conclusion: The SOAP-ready extension of our multimedia dynamic webbased medical teaching-file-server supports the application layer interoperability through a consistent XML-based interface. Thereby the provided medical knowledge could be easily accessed and integrated in decentralized, webbased knowledge-and workflow application frameworks in healthcare environments.

Building up a teaching system out of the radiological workflow A. Schroeter 1, 2 , K. Annacker 1, 2 , T. Geisbe 1 , M. Kroll 1, 2 , J. Martin 1 , J. Holstein 1 , D.H.W. Groenemeyer 1 , H.G. Lipinski 2 ; 1 Bochum/DE, 2 Dortmund/DE Purpose: The aim is the development of a radiological teaching system, whose contents of the learning contexts are inferred directly from the radiological work routine. This system pulls DICOM images, DICOM Presentation States and findings out of the RIS and PACS to transfer them to an HTML learning text whitin an embedded DICOM viewer. Methods and materials: A radiologist will select a few images and send them to the teaching system together with the finding and Presentation States. A learning text will then be extracted out of the finding. This text will be converted to an HTML page with an embedded Java-based DICOM viewer to visualize the medical images. Within the HTML text, buttons will provide a context-referred view of the images via DICOM Presentation States. So all that radilogists will have to do, is to perhaps correct some text phrases or the layout. Results: The result is a teaching system with its contents pulled out of the normal radiological workflow making it possible to transfer DICOM images, Presentation States and findings to interactive learning texts. DICOM images can be freely manipulated and Presentation States can be applied to achieve a context-referred view of medical images. Conclusion: The efficiency of learning can be increased by being as close as possible to the real-life diagnostics and by making the images available for free manipulation. Building up a learning case is quite easy because image data and views on these images already exist.

Webbased knowledge transfer in a radiology department for scientific and educational purposes J. Hohmann, T. Schaaf, K.-J. Wolf; Berlin/DE Purpose: To implement a basic system which allows: (1) scientific chats and interactive lectures, (2) live broadcast of scientific events, (3) access to teaching-files and examples in a medical image database. Materials and methods: (1) The HyperChatSuite by FH Software (www.fhsoftware.net) is Freeware and allows common and private chat rooms as well.

(2) For evaluation purposes of the live broadcasting the no-cost RealSystem Server Basic (www.realnetworks.com) was installed which allows up to 25 concurrent users the access to the delivered data stream. RealSytem servers supports up to 45 media types and different operating systems. (3) Part of the teleteaching/-learning system is an access to teaching files and the medical database (introduced on ECR 2000). The medical database consists of Open Source components (MySQL, www.mysql.com; Apache, www.apache.org; PHP, www.php.net) and is in use since last year. Results: (1) We conceptualised a lecture together with scientific groups in the USA regarding the principles of digital imaging. After performing initial testlectures this lecture will be held next term at our radiology departement. (2) The Benjamin Franklin Contest 2001 was availaible as our first live broadcasted videostream of about 4 hours. (3) Due to the flexible structure of the former medical image database the added functionalities with teaching files consisting of multi-media-data were easily achieved. Conclusion: Since the parts of the system fullfills our expectations in first trials we now have to get more experience during next term or year to find out about the advantages and disadvantages and to yield the necessary changes.

Current concepts in digital conference communication in radiology M.V. Knopp, H. von Tengg-Kobligk, F.L. Giesel, P.L. Choyke; Bethesda, MD/US Purpose: Clinical conference of cases as well as group conference with clinician or research partners is one of the bases of radiological interaction in academia and hospitals. While PACS and all the advances in telecommunication have changed tremendously our work, these concepts have not been embraced sufficiently in conference communication.

Our group based in a major academic and research institution investigated the different capabilities available such as telephone (ISDN) based systems Picturetel, direct satellite links and web based approaches. The different systems were assessed using objective criteria such as speed, costs, image resolution etc. and subjective criteria using a questionnaire. Results: Many radiologists feel at unease using digital conferencing mostly due to lack of experience. After training, it was readily used and a code of conduct was helpful for training purposes. While image quality and speed is still superior with commercial systems, innovative uses of web based applications with concurrent B-0439 09:35

Improving the workflow with central scheduling: Introducing a "Rad Call Center" P. Gocke, A.P. Bruckmann, J.F. Debatin; Essen/DE Purpose: To improve the workflow in a radiological department with central scheduling, by introducing a radiological call center (RCC) Method/materials: With a separate module of our RIS (Radiological Information System) we were able to introduce a central electronic scheduling. Appointment schemes were created for all work places, time table-based or list-based. One central telephone number was assigned to the newly etablished Radiological Call Center. Rules were created for scheduling, and staff were trained by a telephone and marketing coach. Results: With central electronic scheduling, the task of scheduling is removed from every workplace and focused on one center with specially trained staff. This center is an efficient tool offering flexible workload balancing. Information about daily workload is available for every employee. Especially helpful in workflow optimization was the introduction of 'virtual work places' were patients can be scheduled for urgent investigations and directed to the next available appointment. Conclusions: Central scheduling by a Radiological Call Center improves workflow and enables a department to (re)direct patient flow and balance work load. Inherent advantages were optimis ation of investigation strategies and avoidance of double/unnecessary investigations. Acceptance of referrers is good (only one central telephone number!), especially when offering add-ons like a radiological advice service.

Work flow analysis using process simulation in a routine ultrasound division C. Gillessen, U.K.M. Teichgräber, J. Ricke; Berlin/DE Purpose: (I) To evaluate a routine ultrasound workflow by means of project graph technique (PGT) and process simulation (PS) and identify ways to redesign and improve it. (II) To evaluate PGT and PS for significance and feasibility in workflow management.

A workflow analysis of a routine ultrasound division was performed by:

1. Observation and definition of work steps to perform an ultrasound examination. 2. Time measurements of 500 activities using a software tool for parallel work step measurement. 3. Designing a project graph. 4. PGT: Calculation of operational measures. PS: Generating operational measures by applying process simulation on network plan.

5. Identification of reasons for delay. 6. Process redesign and re-evaluation. Results: Average realistic examination time for abdominal ultrasound was 44 min 52 s. Average simulated examination cycle time with 3 ultrasound devices, 3 examiners and 2 technicians was 10 min 42 s. By increasing personnel, average cycle time was reduced but average personnel slack time increased. Major structural work flow deficits were not identified under given circumstances. Replacing paper and film work associated activities with activities as expected with an electronic archive reduced total work effort by 16 %. Major advantages of simulation over NPT were the ability to consider cycle overlap and to calculate cycle times. Conclusions: (I) Under given circumstances, the observed work flow showed high efficiency. Major effort reduction by the introduction of an electronic report and image archive is predicted. (II) Process simulation is superior to PGT in evaluating workflows and anticipation of the effect of variations.

Is speech recognition the best reporting method for any case? P. Gocke, C. Hogh, E.R. Gizewski, J.F. Debatin; Essen/DE Purpose: To decide in which cases speech recognition is the best method for reporting, and in which cases other existing methods should be preferred Method/materials: In our department, 'instant reporting' is performed by residents typing preliminary reports into a RIS (Radiological Information System) based reporting module using a special MS WinWord 2000 environment. Additionally, we have reporting stations equipped with a state-of-the-art speech recognition system (latest Dragon Naturally Speaking Professional with Radiological Dictionary).

To compare both methods, the residents hand-stopped the time needed for generating the first, preliminary report for three different types of investigations: CT, skeleton and chest X-ray. Results were discussed and tips were delivered for developing efficient auto-texts and macros. Results: For CT, speech recognition was faster (4 min 49 s ± 1 min 44 s) than typing (5 min 10 s ± 1 min 32 s). For chest X-rays, there was no significant difference (speech recognition: 1 min 58 s ± 46 s, typing: 2 min 5 s ± 1 min 6 s). For skeleton X-rays, typing was faster (1 min 35 s ± 44 s) than speech recognition (2 min 4 s ± 58 s). Conclusions: In many cases, speech recognition is an adequate technique for radiological reporting, but especially in cases of short and standardizable reports an autotext-and macro-based reporting technique is faster and more convenient.

Long-term experience with speech recognition of more than 240000 dictations T. Ybinger, W. Kumpan, F. Karnel; Vienna/AT Purpose: X-ray departments are increasingly under pressure to reduce costs and save time. This paper presents the experience of many years of using speech recognition to optime our services.

The Kaiser-Franz-Josef-Spital in Vienna is a 720-bed hospital which specializes in oncology and infectious diseases. A speech recognition system for producing reports was integrated into our RIS early in 1998. Since then the system has proved itself by completing more then 240000 dictations. We also investigated the efficiency increase achieved by using the system and its influence on our work processes. Results: Speech recognition is used to transcribe more than 98 % of our reports. We have been able to reduce the turnaround time for our reports by 35 % to an average of 8 hours. Despite a high number of trainee doctors, 95 % of all reports are signed within 24 hours. Our secretaries save approximately 40 % transcription time, and we have become more flexible in the use of typists. The average recognition rate is around 95 %, with some doctors clearly achieving even better results. However, of even greater importance to the workflow is an optimal integration into our RIS.

A C D E F 208 Conclusion: Speech recognition has fully established itself in our hospital and is routinely used for practically all dictated reports. This has considerably increased the productivity of our typists and clearly reduced the turnaround time of reports. We are convinced that speech recognition will soon make its entry as state-of-theart technology in numerous other institutes. When the bladder was filled of contrast-material-enhanced urine, the patient in supine position was asked to urinate. During the micturition T1-weighted spoiled 3D-gradient-echo acquisitions on sagittal plane were performed (Acq.Time: 12 s). These acquisitions were post-processed with MIP algorithm. 15 patients performed retrograde and micturating conventional cystourethrography in the month preceding MRI. One patient was unable to perform the exam because of the inability to urinate in the supine position. Results: We always obtained perfect evaluation of the male urethra with voiding MR-cystourethrography. The visualization of the urethra with MIP reconstructed images was considered comparable to that obtained with conventional cystourethrography. The analysis of 3D sagittal scans allowed a better evaluation of the urethral strictures in comparison with conventional cystourethrography. We detected 10 cases of bladder neck obstruction, 12 cases of urethral stricture and 3 case of benign prostatic hypertrophy Conclusions: Voiding MR-cystourethrography demonstrates the morphology of the bladder neck and urethra during the micturition and can a substitute for standard retrograde and micturating cystourethrogram, avoiding radiation exposure to the gonads. Patients underwent combined MRI and 3D-MR spectroscopic imaging (MRSI) of the prostate after up to (n = 16) or more than (n = 20) 16 weeks of HT. Pretherapeutic PSA levels (11.8 ± 10.1 vs. 14.2 ± 10.0 ng/ml) and Gleason sums (6.2 ± 1.2 vs. 6.4 ± 1.0) did not differ significantly. Posttherapeutic PSA was dichotomised as being up to or more than 0.20 ng/ml. HT of more than 16 weeks was significantly associated with PSA up to 0.20 ng/ml (15/20 vs. 3/16 patients, p = 0.002, chi square test) and loss of citrate from the peripheral zone of the prostate (15/20 vs. 5/16 patients, p = 0.022). PSA exceeding 0.20 ng/ml was associated with prevalence of citrate (12/18 vs. 4/18, p = 0.020).

Citrate was detected at MRSI in 4 patients with PSA under 0.20 ng/ml, including 3 of 4 patients on monotherapy with LHRH agonists for more than 16 weeks.

In conclusion, this study finds an association between PSA decrease and loss of citrate from the peripheral zone of the prostate in patients on HT for locally confined PCA. There is a hint of dissociation of PSA loss and detectable citrate in patients on longer-term LHRH agonist monotherapy that warrants more extensive analysis.

Longitudinal follow-up with combined MRI and 3D-MR spectroscopic imaging of patients on hormone therapy for locally confined prostate cancer U.G. 

Functional assessment in non radicular low back pain patients with an ultrasound-based 3D-topometry-system (ZEBRIS®) and radiographic motion analysis of the lumbar spine correlated with the results of a self administered health status questionaire A. Petrovitch, S.O.R. Pfleiderer, T.U. Schreiber, W.A. Kaiser; Jena/DE Purpose: Non-radicular low back pain (LBP) is a leading cause for compensation in industrialised countries with high socioeconomic impact. In the past it was mostly described by structural deficiencies, but not by disturbance of functional spinal segments or the instantaneous axis of rotation. Methods: 45 out-patients (age 22 -85 a; 22 males, 23 females) with suspected vertebral instability were included. General health and orthopedic status was evaluated at admittance. Health status was evaluated using the self-administered SF-36 questionnaire, which includes eight scales of functional health. A self administered pain score was evaluated using the visual pain analogue scale (VAS). The motion of the lumbar spine was analysed in lateral and AP projections using radiographs and in all three main axis of rotation with the topometric motion analysis system. Results: Compared to norm-based population scores for Europe and North America, values are reduced below one standard deviation in almost all items using the SF-36-questionaire. The items body pain and physical function are decreased by two standard deviations (SD) and role physical has a score reduced by more than three SD. Where heavy pain was reported, the correlation between disturbed physical and mental scores was high (r = 0.8950; p < 0.001), but no correlation to radiographic spondylolisthesis could be observed. Conversely, a good correlation between reduced physical score (SF-36), pain and disturbed instantaneous axis of rotation was observed in 3D-topometry (r = 0.6820, p < 0.01).

Conclusions: This study supports a new concept in functional assessments of non-radicular LBP using ultrasound-based 3D-motion analysis. 

Spinal pM MSCT-studies of 45 consecutive patients, assessed for non-radicular, multisegmental cervical and/or lumbar pain syndromes by myelography and pM MS-CT were reviewed for additional information when compared to the myelographic findings alone by two neuroradiologists. All pM MSCT studies had been performed on a four-slice CT scanner using the following parameters: slice thickness of 1 mm, reconstruction increment of 0.7 mm, field-of-view 15 (cervical)/20 (lumbar) cm. Subsequently data postprocessing to multi-and curviplanar reconstructions was performed. In addition, the radiation exposure was assessed by calculating the effective dose values. Results: MSCT yielded additional diagnostic information, termed as clinically significant in 60 % of the studies. Due to the resulting voxel size of about 0.4 × 0.4 × 0.8 mm multiplanar imaging of the spinal pathology in all planes with excellent image quality was possible. Typical image artefacts at the cervico-thoracic junction as well as due to metallic implants were significantly reduced. The effective dose amounted to 2.8 mSv (cervical spine) and 6.2 mSv (lumbar spine). Conclusion: PM spinal MS-CT is a useful tool in assessing multisegmental spinal pathology in patients in whom MR imaging is either contraindicated or not compatible with the clinical findings. In terms of radiation exposure, careful restriction of the scan area to the clinically relevant segments seems to be more important than the type of helical CT, i.e. single-vs. multi-slice. Results: There were five women and one men, mean age of 66 years. A diabetes mellitus was present in half cases. Mean delay between vertebral collapse and the infectious syndrome was 12 days. Staphylococcus aureus, E coli, Salmonella enteritidis, were the identified pathogens. Bone biopsy isolated the pathogen in two third of cases, and was the sole positive sample in one third of cases. A thoracic vertebra was involved in three cases, a lumbar one in three cases. Lysis of the spongious bone associated with a soft tissue mass thicker than 8 mm was observed in five cases. Two patients died from consequences of the disease. Conclusion: We want to highligh a seemingly unusual entity to avoid a radiological diagnostic pitfall.

Calcified cervical intervertebral disc in children -radiological findings V. Jevtic; Ljubljana/SI Purpose: To describe radiographic, CT and MRI features in a relatively rare entity of unknown etiology, calcified intervertebral disc in children (CIDC). Material & methods: 12 patients (7 males, 5 females, mean age 9 years) with clinical signs of limited movements, stiff neck, torticollis and pain were radiologically investigated. The patients were imaged using radiography, functional radiographic examination, CT and MRI. Plain films, CT and MRI were analysed in a qualitative fashion. Results: Radiography demonstrated a calcified nucleus pulposus which was flattened, oval or round. In 10 patients more than one disc space was calcified. Additional radiographic findings included widening or narrowing of the disc space and moderate flattening of the vertebral bodies. In 6 cases functional abnormalities were revealed at the level of disc calcifications. CT clearly demonstrated hyperdense disc calcifications with posterior disc protrusion in 4 cases and extrusion into the epidural space in one patient. Calcifications were shown as signal void areas by MRI. There were also discrete signal intensity changes of bone marrow below the endplates. Conclusion: CIDC may be diagnosed using plain radiography, CT or MRI. The advantage of CT examination is in exact demonstration of clinically important protrusion or extrusion of the calcified nucleus pulposus.

Sacroiliitis in children with spondylarthropathy: Use of dynamic MR imaging to detect the therapeutic efficacy of intraarticular corticosteroid injection T. Fischer, B. Hamm, M. Bollow; Berlin/DE Purpose: Our aim was to prospectively study the therapeutic efficacy of CT-guided intraarticular corticosteroid instillation of inflamed sacroiliac joints (SIJs) in children with juvenile Spondylarthropathy (SpA) and to evaluate the role of MRI as a procedure for establishing the indication and the therapeutic follow-up. Method/materials: A total of 69 CT-guided corticosteriod injections of the SIJs were performed in 42 children with inflammatory back pain (IBP): 27 bilateral, 15 unilateral. Forty milligrams of a crystalline longacting corticoid was instilled in each inflamed joint. All 42 patients underwent continuous clinical follow-up at 10 week intervals after corticosteroid injection to a maximum of 18 months. Intensity of back pain before and after the intervention was graded on an visual analogue scale from 0 (no pain) to 10 (very severe pain). Dynamic contrast-enhanced (Gd-DTPA, 0.1 mmol/kg body weight) MRI with quantitative determination of contrast enhancement was performed in all patients before the intervention and 8 ± 4 months after therapy. Results: 37 of the 42 study patients (88.1 %) showed a statistically significant abatement of subjective back pain from 8.4 ± 1.4 to 3.3 ± 2.2 (p < 0.05) at 1.5 ± 1.0 weeks after therapy, and this improvement lasted for 12 ± 6 months. The percentage contrast enhancement at dynamic MRI showed a reduction from 110.5 ± 52.3 % before to 53.4 ± 38.1 % after intervention (p < 0.01). Conclusions: Dynamic MRI proved to be a reliable non-invasive tool for the assessment of inflammatory activity of sacroiliitis and the response to the therapy in patients with juvenile SpA.

Congenital lesions of the lumbar spine: CT depiction and significance D. Passomenos, G. Mantzikopoulos, G. Giannikouris, I. Staikidou, C. Pikoulas, S. Ispanopoulou, C. Dayiada; Athens/GR Purpose: Congenital lesions of the bony skeleton are not uncommonly detected incidentally by plain films. Moreover, posterior elements due to their complex anatomy and orientation are poorly visualized on plain films. In acute trauma setting, in order to exclude a fracture, further investigation without the problems of superimposition is needed.

We retrospectively evaluated the files of 873 patients examined to our Diagnostic Department over a period of 9 months. Patients ranged in age from 12 to 44 a. Most of them presented with a history of minor recent trauma or had a vague intermittent back pain. Cases of spinal cord lesions in association with bone dysplasias were excluded from the study. Plain films were mostly suggestive of congenital lesions but further investigation with CT to ascertain the diagnosis was requested. Scans consisted of consecutive 3 mm cuts through the questioned area of the spine. Obtained scans were imaged at softtissue and bone windows. Sagittal and coronal reformatted images were also obtained.

We could locate a total of 18 cases of unilateral spondylolysis, butterfly vertebra, posterior limbus vertebra, hypoplastic or absent facets associated with hypoplastic arch, spina bifida and pseudo-arthrosis of transverse process. The lesions were mostly located at L5 -S1 level. Purpose: To describe characteristics on MR imaging of radiation osteitis of the pelvis in patients who had received radiation therapy for gynaecological tumours. Material and methods: 9 women (mean age: 67.5 years) with gynaecological tumours who developed radiation osteitis where examined with radiography, computed tomography and magnetic resonance imaging (MRI). On a 1.5 T system we used plain T1-and T2-weighted sequences and contrast enhanced T1-weighted

A C D E F 212 sequences with and without fat saturation. MRI was performed at different distances between the end of radiation therapy and developing pain. MR Images where correlated with the results of clinical examinations. Results: Depending on the time from radiation therapy, radiation osteitis showed different signal intensities. The acquired images suggest that signal changes in T2 weighted images as well as the different enhancement behaviour of radiation osteitis might be dependent on the time from radiation therapy. Best visualisation of regions with even low contrast enhancement was achieved with fat-saturated sequences. Computed tomography showed increased density in the affected regions corresponding to osteosclerosis. In all cases at least one iliosacral joint was affected with different topographies in sacral and iliac bone. Conclusion: MRI is helpful in detecting and characterizing ORN and eases the demarcation from secondary manifestations of the known malignancy. Changes in signal intensity, based on histopatholocical tissue changes, might make a chronological classification possible. The purpose of this on going study is to evaluate the usefulness of whole body MRI in the diagnosis of the inflammatory myopathy seen in polymyositis and to assess the disease extent in affected patients. Materials and methods: Eight patients with laboratory, muscle biopsy and electromyographic evidence of probable or definite polymyositis were referred for imaging. An additional patient was referred for MR to identify a potential site for muscle biopsy. 16 Coronal turbo STIR images were taken in each of three or four body regions (TR/TE/TI; 2400/40/160 ms). Acquisition time per region was 3 minutes 30 seconds, with a total scan time of approximately 30 minutes. Results: Mean patient age was 43.5 years (32 to 57 years). One patient with "probable" polymyositis by conventional criteria had a normal scan. One patient with polymyositis had inflammation in a myofascial distribution in the gluteal region. Two patients had florid symmetrical myopathy involving proximal upper and lower limb girdle muscles, psoas, intercostal muscles and neck flexors and extensors. In addition, mild involvement of the calf muscles was also seen. Three patients had more patchy asymmetrical muscle involvement, but also demonstrated involvement of psoas, intercostal and neck muscles. Conclusion: Whole body MRI gives a much more extensive assessment of muscle involvement in Polymyositis than the conventional MR protocols used to image these conditions. Extensive muscle involvement of psoas, intercostal, neck and distal limb muscle groups were diagnosed. These muscle groups are not imaged on standard sequence protocols. The posterior half of the lateral tibial plateau and the lateral half of the medial femoral condyle were statistically more frequently involved than their corresponding halves (p < 0.0001 for both parameters). The bare area of the medial, but not of the lateral tibial plateau is more frequently involved than the meniscus-covered area (p < 0.0001). The meniscuscovered area of the lateral tibial plateau was more frequently involved than that of the medial tibial plateau (p < 0.0001). Results: MRI allowed a good identification of the sites of osteochondral cylinder remotion ("donor" sites) and of the treated lesion sites at the 5 month MRI. Small ferromagnetic particles artifacts due to surgical instruments were often present, with limitation of diagnostic value, in particular the "gap" regions between cylinders and health tissue were not individuated. Only the oldest two patients showed mild inflammatory signs (intraarticular fluid collection, synovial hypertrophy) at the 5 and 10 month MRI. No case of donor site degeneration was seen at the 5 and 10 month MRI. In all cases, the sites of treated lesions showed regularity of subchondral bone and the fillling-repair of donor sites at the 10 month MRI. Evaluation of the chondral portion was very difficult due to artifacts. Conclusions: MRI allows a good evaluation of knee chondral implant healing, especially of the subchondral bone repair and seems to be a good diagnostic tool, avoiding invasive examination. Results: Based on the statistical analysis of the ultrasonographic measurements, diagrams and tables were created. The study of these data concluded that:

• Articular cartilage thickness is the same in both knees.

• Articular cartilage of the knee is thicker in boys.

• Cartilage thickness reduces with age.

• The rate of diminution is higher during the first six years of age and lower after the age of six years. • There is negative linear correlation between cartilage thickness and somatometric parameters. • Body height is the somatometric parameter that has the strongest correlation with articular cartilage thickness. Conclusion: Equations, diagrams and tables of normal articular cartilage thickness of femoral condyles in children, measured with ultrasonography, represent a precise method for cartilage growth estimation. These equations, diagrams and tables afford an objective way to compare normal articular cartilage thickness with the thickness noted in various pathologic conditions affecting articular cartilage in children.

Opportunities for the use of high frequency ultrasound (10 -13 MHz) in the diagnosis of degenerative-dystrophic changes of the knee joint N. Lordkipanidze, D. Tatishvili, M. Lortkipanidze; Tbilisi/GE The purpose of study was to define diagnostic criteria for degenerative-dystrophic damage to the knee joint according to the stage of disease using high frequency ultrasound.

The investigations were performed on the "SIEMENS SONOLINE Elegra" ultrasound system using SieScape panoramic imaging with a 7.5 -13 MHz frequency linear transducer. A group of 956 patients, 10 -75 years of age, with complaints of knee joint pain were included in this study. 738 patients were diagnosed as having knee joint degenerative-dystrophic changes. The early stage is characterized by a normal or decreased hyaline cartilage thickness of the femoral condyle. Ultrasound studies detected increased echogenity of the cartilage surface, existence of freely floating 0.4 -0.6 mm crystals in the joint cavity and suprapatellar synovial bursa. The same type of crystals, in addition to insignificant synovitis, were found in sportsmen and dancers who exercised vigorously. In the case of difficulties in examining the lateral patellar and medial inferiorlongitudinal surface the existence of crystals was revealed during its maximum displacement from the condyles of the femur. In severe cases, examination revealed marginal joint osteophytes, margin skipping of cartilage surface, discontinuous contour of the femoral condylar bony surface, narrowing or complete disappearance of joint space and the existence of hypertrophic synovial membrane and villi and Baker's cysts. As a result, Pan Zoom mode is used to detect joint crystals, to study in details the structure of hyaline cartilage, fluid and to identify their minimal changes, which helps to diagnose degenerative-dystrophic changes of the knee joint. Multislice spiral CT (Somatom Plus 4 Volume Zoom, Siemens, Germany) examination was performed after standard oral colonoscopy preparation and colonic distension with room air. Images were obtained using 2.5 mm slice collimation; 3.0 mm slice thickness; 1.0 mm reconstruction interval; 17.5 mm/s table speed; kVp, 140; and mAs 10. Supine and prone acquisitions were obtained in all patients. Dose exposure was calculated. Images were directly reviewed on a dedicated workstation by two experienced gastrointestinal radiologists using a software with volume-rendering capabilities (Vitrea 2.2, Vital Images, USA). Conventional colonoscopy was performed on the same day in all patients and represented the standard of reference. Results: All colorectal cancers were correctly identified at CT colonography (9/9, sensitivity 100 %). CT colonography also detected 12 of 14 polyps (sensitivity, 85.7 %). Both false-negative findings were represented by lesions smaller than 5 mm. Dose exposure (CTDI) never exceeded 1.37 mGy for each scan. Conclusion: Although studies on larger series are certainly needed, our preliminary experience demonstrates that ultra-low-dose scanning is a feasible and accurate option for multislice CT colonography. This technique allows to scan the patient in both supine and prone positions with a radiation exposure lower than that of a double contrast barium enema, which is of paramount importance to introduce this imaging modality in screening programs. Results: Of 264 cancers diagnosed in this cohort, 260 were detected by CT colonography. 3 were missed in our early experience with single slice spiral CT. 2 were flat cancers < 5 mm thick. 1 was a polypoid tumour hidden by residue in a poorly prepared patient. This was obvious on a repeat study with adequate preparation. One recently missed cancer was in a co-existent acute diverticulitis and was described as suspicious for malignancy only. There were 18 false positive diagnoses of cancer. All but 2 were cases of diverticulitis or IBD. In only 2 cases was no lesion found at laparotomy or repeated colonoscopy. 2.5 % of patients failed to complete their preparation or did not attend for scanning. This was no different to other complex CT examinations. 7 % of studies were sub-optimal (poor preparation, no IV access, could not lie prone etc). Only 1 patient could not be scanned. Conclusion: CT colonography is remarkably robust with a sensitivity of 98.5 % and a specificity of 98.4 % for the detection of colorectal cancer.

Is 1 mm collimation (effective slice width 1.25 mm) essential for multislice CT colonography? A.R. Gillams, V. Munikrishnan, W.R. Lees; London/GB Purpose: Whilst the finest collimation possible with adequate signal to noise may seem desirable, fine collimation results in increased radiation dose and generates very large data sets. This increases expense, slows down analysis and 3D reconstruction times. We studied the impact of 1.25, 2.5 and 5 mm slice width on polyp detection and cancer staging. Methods and materials: 55 symptomatic patients, 22 male, referred for CT colography ± virtual colonoscopy underwent multislice CT following standard bowel prep, bowel paralysis and rectal air insufflation. Scans were performed with 1 mm collimation, effective slice width 1.25 mm, pitch 5, 0.5 s rotation time following IV contrast. Retrospective reconstructions were performed at 1.25 mm, 3 mm and 5 mm. 1.5 and 2.5 mm overlap was used for the 3 and 5 mm data sets respectively. Scans were analysed for the presence of lesions and any cancers detected staged. All patients had colonoscopic correlation and where cancer was detected the resected specimen was also included in the analysis. Results: There were 23 cancers and 25 polyps. Finer sections aided separate detection of small nodes but this did not impact staging. Overall there was no difference in cancer staging between the three data sets. There was no difference in the number of polyps detected on the 1.25 and 3 mm data sets. Small polyps were smeared out on the 5 mm data sets. Conclusion: 2.5 mm slice width appears to be adequate for multislice colography. Previous studies have shown no beneficial effect of using IV glucagons as a spasmolytic for CT colonography. Studies of barium enema examinations, however, have shown that Buscopan may be a more potent spasmolytic in the colon compared with glucagon. The use of Buscopan in CT colonography has not been tested to date. The aim of this study was to assess the effect of IV Buscopan on colonic distention and polyp detection when used as a muscle relaxant in CT colonography Methods: 70 patients undergoing CT colonography were randomized to receive iv Buscopan or no muscle relaxant prior to air insufflation and scanning. Patients were scanned in both supine and prone positions using a multislice helical CT acquisition. For the purposes of reporting, the colon was subdivided into 6 different segments, yielding a total of 12 colonic segments per patient. The degree of luminal distention of each segment was scored on a scale from 1 to 4. The accuracy of CT colonography for polyp detection was based on findings at subsequent conventional colonoscopy.

Results: There was no significant difference in the degree of colonic distention achieved between the group receiving iv Buscopan and those who did not. The addition of prone scanning was found to be the single most important factor in ensuring adequate visualization of the entire colon.

There is no evidence to support the routine use of IV Buscopan in CT colonography. MR was performed on a 1.5 T scanner by using gadolinium as a rectal enema. The 3D data set was post-processed on a workstation to obtain VDC and SSD images. 2 radiologists with knowledge of the colonoscopic findings compared coronal and rotated views. They were compared by consensus in terms of the visualization of the mass lesions and normal colonic segments. Technical visibility and interpretation accuracy of the colonic lesions were rated on a score.

Coronal VDC was regarded superior to SSD for assessment in 11 of 17 patients, equal to SSD in 5 and worse than SSD in 1 case. Rotation of VDC and SSD improved the assessement of the colon. Rotated VDC was regarded superior to SSD in 4, equal in 11 and worse than SSD in in 2 of 17 cases. All mass lesions above 10 mm were equally well depicted with the VDC mode compared to SSD Conclusions: VDC and SSD are useful as a first step and possibly online analysis tools and could possibly allow for an earlier finishing of the MR exam in case of poitive findings. VDC appears to be superior to SSD in excluding colorectal mass lesions At the slice position with the visually largest lymph node extension in plain sequences, dynamic MRI was performed using a TurboFLASH starting withj a bolus injection of 0.1 mmol/kg b.w. Gd-DTPA. Results: In a retrospective evaluation, lymph node staging using the contrast enhanced endorectal and body-coil MRI studies was based on the following criteria: stage N0 designated failure to identify nodal structures with a diameter larger than 3 mm in the imaging volume including the perirectal space and the pelvic structures, and stage N1 designated visualization of four or less nodes larger than 3 mm in diameter. In our series eleven patients (n = 11) had histopathologically proven lymph node stage N1; all other patients (n = 12) were stage N0. We were able to depict the enlarged and involved lymph nodes in eight of eleven patients with stage N1. We staged correctly nine of twelve patients with stage N0 (sensitivity of 85 % and specificity of 72 %). Conclusions: High-resolution contrast endorectal MRI was excellent for depicting perirectal nodes larger than 3 mm in diameter. Further studies are necessary to assess the architecture, geometry, and contrast-enhancement characteristics of lymph nodes to improve higher specificity. To investigate systemic and regional LV functional parameters including myocardial wall thickening in patients with symptomatic coronary artery disease and CABG.

Methods/materials: On a 1.5 T Magnetom Vision (Siemens) 40 patients with angiographically proven CAD underwent prospective evaluation of ejection fraction (EF) and regional myocardial function in 320 myocardial segments by cine MRI (FLASH-2D, TR = 11 ms, TE = 4.8 ms, flip 25°) at rest. Consensus reading by two observers was used for the analysis of myocardial function. A phase-contrast FLASH-2D sequence (pixel 0.98 × 0.98, venc 250 cm/s) was applied for flow measurements in the ascending aorta in order to derive functional parameters such as LV ejection time frame (Ät) and cardiac index. Patients were re-examined 6 months after surgery. Results: Clinical symptoms improved in 35 of 40 patients after CABG. In patients with significantly reduced EF (n = 10) an improvement from 38.4 ± 10.3 % to 49.8 ± 15.3 % (p < 0.05) was found postoperatively. After CABG surgery functional improvement was observed in 45 of 53 myocardial segments (X of Y patients) with severe hypokinesia (p < 0.03); mean increase of cardiac index was 15 % (from 2.26 -0.5 l/min/m to 2.65 -0.41 l/min/m, p < 0.02), mean decrease of ∆t was 10 % in patients with functional myocardial recovery (p < 0.05).

In general, clinical improvement can be found 6 months after CABG surgery and corresponds to improvement of systemic and regional LV function. Patients with persistent symptoms still presented with pathological findings. Therefore, MRI can be used as a tool to follow-up symptomatic patients after CABG. 

The following effective doses (male/female) were calculated for the different calcium scoring modalities: Sequential MSCT prospectively ECG-triggered (3 mSv/3.7 mSv), spiral MSCT retrospectively triggered (3 to 5.2 mSv/3.6 to 6.2 mSv), EBT (1.0 mSv/1.4 mSv). Effective doses associated with CT coronary angiography were: spiral MSCT retrospectively triggered (6.7 to 10.9 mSv/8.1 to 13 mSv), EBT (1.5 mSv/1.8 mSv). Highest organ doses in all examinations were found for the female breast followed by the lungs and the oesophagus. Conclusion: Up to a 7-fold higher radiation dose is obtained in MSCT compared with EBCT in coronary artery examinations. The high radiation exposure inherent in cardiac MSCT warrants careful analysis of the underlying clinical indication.

Bolus optimisation in multi-slice CT of the coronary arteries and assessment of diagnostic accuracy in comparison with cardiac catheter T.F. Jakobs, C.R. Becker, R. Brüning, A. Knez, C. Thilo, M.F. Reiser; Munich/DE Objective: To determine optimal contrast concentrations and injection rates for detecting coronary stenoses with multi-slice CT (MSCT) angiography. Materials and methods: 60 patients, 4 groups of 15 patients, underwent MSCT (Somatom VolumeZoom, Siemens) with different contrast protocols: (A) 300 mg iodine/ml at 2.5 ml/s; (B) 300 mg/ml at 3.5 ml/s; (C) 400 mg/ml at 2.5 ml/s; (D) 400 mg/ml at 3.5 ml/s (Byk Gulden, Konstanz, Germany). Assessment of location and degree of coronary stenoses was compared with cardiac catheter. Results: The faster injection rates resulted in higher enhancement compared with the lower injection rates at both iodine concentrations (210.9 ± 34.2 HU (A) versus 366.6 ± 84.2 HU (D)). Diagnoses of significant stenoses obtained by MSCT were confirmed by coronary angiography in 37 out of 43 patients (86 %). Among those with false negative results there were 3 patients in whom MSCT failed to determine significant stenoses in the coronary arteries. The diagnostic findings as described in MSCT were not consistent with angiography with regard to localisation and degree of stenoses: In 42 % of cases, the degree of the most severe stenosis was identical in MSCT and cardiac catheter. Conclusion: Superior coronary enhancement was achieved with higher iodine concentrations and flow rates. However, MSCT with any contrast protocol was unable to achieve the diagnostic level of coronary angiography in assessing location and degree of significant coronary stenoses. Therefore further improvement of spatial and temporal resolution in MSCT-technique is required.

Coronary artery by-pass grafts: Evaluation by retrospectively ECG-gated multislice spiral CT R. Marano, M. Zimarino, M.L. Storto, R.L. Patea, N. Maddestra, L. Bonomo; Chieti/IT Purpose: To assess the potential value of Multislice Spiral CT (MSCT) using retrospective ECG-gating in patients who had undergone coronary artery by-pass grafting (CABG).

Retrospectively ECG-gated MSCT was performed in 61 asymptomatic patients (144 grafts) 147 ± 86 months after cardiac surgery. Scanning parameters were: 4 × 2.5 mm collimation, 3 mm slice width, and 1.5 mm reconstruction increment. Images were reconstructed during end diastole with an absolute or relative delay before the next R-wave and volume rendered images were obtained to display the grafts. Visualization of the proximal, middle and distal segments of each graft was assessed. The presence of artifacts was recorded. Results: 59 left internal mammary artery (LIMA) to left anterior descending artery (LAD) and 85 non-LIMA grafts were studied. 3 non-LIMA grafts were shown to be occluded. The entire LIMA to LAD and non-LIMA grafts could be visualized free of artifacts in 39/59 (66.1 %) and 19/82 (23.2 %) cases, respectively (p < 0.001). The most frequent causes of incomplete visualization were the presence of surgical clips (21.3 %) and motion artifacts (35.5 %) impairing distal anastomosis evaluation. Conclusion: ECG-gated MSCT is a promising imaging technique for non-invasive evaluation of CABG, allowing a complete assessment of LIMA to LAD grafts. Current limitations are artifacts from surgical clips and irregular heart rates.

Isotropic sub-millimeter volume scanning of the heart with ECG-gated multislice spiral CT: First experience T. 

We investigated the performance of a new multislice CT system with simultaneous acquisition of up to 16 slices and sub-mm collimation (Siemens, Forchheim, Germany) for ECG-gated cardiac imaging. ECG gated spiral data were acquired at pitch 3.5 -4 (pitch -feed/rot divided by one collimated slice width), providing continuous image data with up to 110 ms temporal resolution. Spatial resolution, image quality and artifacts were evaluated with a simulation study of an anthropomorphic heart phantom for 0.8 mm, 1.0 mm and 1.5 mm slice width. The results were confirmed by scans of coronary specimens. Scan times and radiation exposure for coronary CTA protocols were evaluated. First clinical results are presented. Results: With the investigated CT system a 120 mm heart volume can be covered in less then 20 s with sub-mm slices. Sub-mm slice width allows for improved assessment of non-calcified coronary wall changes, heavy calcifications and instent lumen. Radiation exposure for coronary CTAs with sub-mm slice width is about 7 mSv (male), which can be considerably reduced by ECG-gated dose modulation.

A 16-slice platform can cover the heart with ECG-gated spiral acquisition with sub-mm slices within short breath-hold times. Increased scan speed and isotropic resolution with voxel size >> 0.5 mm allow for substantially improved coronary imaging. 

A C D E F 218 Results: Biexponential relaxation was more pronounced in "black hole" lesions and homogeneous enhancing plaques while DWM, NAWM and hypointense lesions presented biexponential behavior with a lower frequency. Non-enhancing isointense lesions and normal white matter didn't reveal any biexponentional behavior. Linear regression between monoexponential T2 relaxation time and MTR measurements demonstrated excellent correlation for DWM, very good correlation for "black hole" lesions, good correlation for isointense lesions, moderate correlation for hypointense lesions and non-significant correlation for homogeneous enhancing plaques, NAWM and NWM. Conclusion: Biexponential behavior is more evident on plaques with high degree of demyelination and homogeneous enhancing lesions when using conventional sequences with long first echo time. A strong correlation between MTR and T2 values in regions where either inflammation or demyelination is present was found while when both pathological conditions coexist this linear relation is destroyed. Method and materials: MRI of 24 pediatric patients affected with definite MS (13 male and 11 female; mean age 15) and 20 with ADEM (7 male and 13 female; mean age 12) were retrospectively evaluated to identify differences in the morphology, location and post-contrast behavior of the demyelinating lesions at the onset of the disease. Clinical and laboratory data were not used. Plain T2 and T1weighted sequences were always available, FLAIR in only 30 % of more recent cases; i.v. contrast injection was done in 18 ADEM and 21 MS patients. Results: Lesions in ADEM patients were multiple in all but 1 case and in 16/19 cases were more then 3; 10/20 cases infratentorial region was involved; gray matter involvement was present in 10/20 and thalamus was the most common involved (6/20); corpus callosum was involved in 2/20 cases; contrast enhancement was present in 16/18 cases; a "lumpy-bumpy" effect was never remarkable. Conclusion and discussion: Differentiation of MS and ADEM has an high prognostic significance. Clinical and laboratory data may often overlap between the two demyelinating disorders. Even though single MRI findings can be non specific, the global evaluation of each patient leads to a differential diagnosis in more then 90 % of cases. Results: MRI of the brain revealed no abnormality in the 7 patients who had lower plasma FA levels both in the last 5 years and on the day of MRI (mean 474.0 and 510.9 mmol/l respectively). However, the 3 patients who had demyelination changes detected on MRI had average plasma FA levels in the last 5 years and on the day of MRI of 768.6 and 1026.0 mmol/l respectively. No difference of IQ between both subgroups were observed. Conclusion: The low number of patients within the study group precludes evaluation of the statistical significance of the detected differences, but a trend toward correlation between a degree of metabolic compensation of the disease and a presence of brain lesions can be observed; no correlation was detected between the lesions and a degree of mental development.

Intracranial tuberculosis: MRI evaluation and 1 year follow up I. Tsitouridis, M. Emmanouilidou, S. Chondromatidou, F. Goutsaridou, S. Stratilati, P. Papapostolou, A. Morichovitou; Thessaloniki/GR Purpose: To present our experience in the MRI diagnosis and follow up of patients with intracranial tuberculosis. Materials and methods: 27 patients with intracranial tuberculosis were evaluated by MRI. The examinations were performed on a 1 T, Siemens Expert plus scanner, using conventional SE T1WI and T2WI. All the patients were conservatively treated and underwent clinical and MRI examinations every two months for a year. Results: 14 patients revealed basal leptomeningeal dissemination and meningeal enhacement and 4 of them also had a tuberculous abscess in this area. 7 patients had disseminated parenchymal tuberculosis and 3 of them had also and meningeal enhancement. One case had tuberculomas and aspergillomas closed together and this patient had a biopsy in the left parietal lobe. The other 5 patients also revealed spinal subarachnoid dissemination. There was no correlation between the MRI findings and the clinical status at the early stages of he disease. Conclusion: We believe that MRI alone or in combination with the other clinical data clearly can detect and characterize this group of patients.

Differentiation of tuberculous from non-tuberculous meningitis using magnetization transfer MR imaging: A prospective study P. Kamra, R.K. Gupta, S. Pradhan, K.N. Prasad, R. Kumar, S. Chawla, S. Jha; Lucknow/IN Purpose: Infectious meningitis presents similar features on MR imaging regardless of etiology. The purpose of this study was to characterize meningitis of different etiology using MT imaging. Methods and materials: One hundred patients with meningitis on post-contrast MT imaging -65 tuberculous, 9 with viral, 9 with fungal, and 17 with pyogenic meningitis -were studied. The visibility of the meninges on pre-contrast MT imaging in different etiologic groups was studied and percentage difference between the mean signal intensity (SI) of the meninges and the mean SI of the surrounding T2 normal brain parenchyma was calculated. The MT ratio was also calculated from the thickened meninges in tuberculous meningitis. The MT ratio could not be calculated in other etiologic groups due to difficulty in the placement of pixel due to thin nature of the meninges and their location in the cerebral sulci. Results: Thickened meninges appeared hyperintense relative to surrounding brain parenchyma in the cisterns on pre-contrast MT-SE images in all 65 patients with tuberculous meningitis. Meninges were not visible on pre-contrast MT images in the non-tuberculous group. The percentage difference in the mean SI of the meninges and the surrounding brain parenchyma was significantly higher (P < 0.05) in the tuberculous group (21.21 % ± 1.98) compared to that in the non-tuberculous group (5.55 % ± 1.01 viral, 3.76 % ± 2.39 fungal, 6.18 % ± 2.18 pyogenic) and explains this difference in visibility.

The visibility of meninges on pre-contrast MT-SE imaging is specific for tuberculous meningitis, and helps in its differentiation from other non-tuberculous meningitis. Purpose: Septo-optic dysplasia is a variable condition, characterized by developmental anomalies of midline structures, the optical pathways, and the hypothalamus/pituitary system. While visual and hormonal disturbances are well known in these patients, neurological and mental development has not yet been related to the morphological findings. Patients and methods: 22 children, 12 female, 10 male, aged between 0 -13 years at first presentation underwent MRI (0.5 -1.5 T superconducting systems, T1w and T2w sequences in 3 section planes, slice thickness 1.5 -5 mm. In 19 patients behavioural abnormalities and school performance could be analyzed with age appropriate tests. Results: MRI abnoralities consisted of a completely or partially missing septum pellucidum in 14 cases, anomalies of other midline structures (corpus callosum, fornix, other commisures) in 12, 3/14 MR scans revealed hypoplastic optical structures. Anomalies of the hypothalamius/pituitary system were seen in 10, hemisperic lesions (mainly schizencephalic clefts) or infratentorial abnormalities occured in 10, and pathological formation of the hippocampus in 7/15 scans. Marked devel- The purpose of this presentation is to report on the prevalence of cerebrovascular complications in children with AIDS and investigate whether the mode of HIV infection plays a role in the development of this complication. 508 children (ages, 4 months to 17 years) with AIDS were periodically evaluated with pre-contrast CT scans. Further evaluation with MRI was perfomed for patients with either focal neurologic deficits or CT findings other than diffuse atrophy. In five patients MR angiograms and in one conventional angiography were also performed. Eleven children were found to have vascular lesions. Only one had focal neurologic symptoms at the time of diagnosis. Six children were found to have 25 aneurysms. A seventh child had a surgical clip at the site a previously treated anerysm. Eight patients were found to have 27 infarctions. In four of the patients with infarctions, fysiform aneurysms of the cerebral arteries were also identified. Nine of the 11 patients in our study were infected by transplacental route or during blood transfusion in prematurely born infants. In this group of patients the diagnosis of cerebrovascular disease was made earlier (mean, 8.2 years) compared to the two patients that were infected later in life (mean, 14.9 years). There is increased prevalence of cerebrovascular disease in children infected by HIV. The risk is greater if the exposure to the virus took place prior to the 40 th week of gestation. This finding suggests that the immature vessels of the fetuses or the prematurely born children are more vulnerable.

A quantitative study of MR imaging in vascular dementia L. Wang; Beijing/CN Purpose: To identify the neuroimaging determinants which could predict the occurrence of the vascular dementia (VaD).

The findings of cranial MRI were compared in 30 VaD patients and 30 stroke without dementia (SWD) patients by means of quantitative measurement of some indexes. The indexes of measurement included the cerebral white matter lesion (WML) area, the cerebral infarct area, the ratio of ventricle-to-brain (VBR) and the ratio between the areas of the corpus callosum and supratentorial brain in the midsagittal plane. Discriminant analysis was used to search for the indexes which could contribute significantly to distinguishing the two groups. Results: Small cerebral vessel disease and multi-infarct were two major basal diseases of VaD in this series. The WML areas, the left cortical infarct and VBR were significantly higher and the corpus collsum areas was significantly lower in the VaD group than the SWD group. The indexes that could significantly discriminate the two groups was: callosal atrophy, ventricle-to-brain ratio, white matter lesions area, left cortical infarct area, left parietal infarct area, total cortical infarct area. Conclusions: Callosal atrophy, lateral ventricle enlargement and extensive WML are important predictors of incidence of dementia in the small vessel disease; however, left cortical infarct, especially left parietal infarct, is important predictor of incidence of dementia in the multi-infarct group.

Biological markers of Alzheimer's disease: Diagnostic imaging and oxidative stress D. Lupoi, R. Squitti, A. Orlacchio; Rome/IT Purpose: A bulk of evidence indicates that oxidative stress mediated by redox transition metals plays a central role in the neurodegeneration of Alzheimer's disease (AD). Iron and copper are strongly concentrated within neuritic plaques and represents the hallmark of the AD brain. Recent studies indicate that peripheral markers of oxidative stress in AD patients could be informative about the pathophysiology of this brain condition and suggested that elevated copper in serum may represent a peripheral marker for AD. We report a pilot study examining the relation between copper and oxidative parameters in serum and the lesions present in the AD brain.

We performed retrospective subjective qualitative and quantitative analysis of the MR brain images of 53 subjects affected by AD and 30 without AD (healthy control group). On imaging, we noted the degree of atrophy and amount vascular lesions in both patients and controls and correlated these with oxidative stress parameters.

The preliminary results indicate that oxidative stress, with higher copper levels, are related to atrophy of temporal lobe. Vascular lesions and global atrophy do not correlate with copper and peroxides in serum. Our evidence sustains copper as peripheral marker in AD to help in the early diagnosis. To determine whether diffusion weighted MRI (DWI) contributes to the differential diagnosis of patients with Parkinson's disease (PD) and the parkinsonian variants of multiple system atrophy (MSA-P) and progressive supranuclear palsy (PSP) Methods and materials: Conventional dual-echo fast spin echo and DWI scans were obtained from 12 MSA-P, 13 PD, and 10 PSP patients matched for age and disease duration. DWI was performed using echoplanar imaging with diffusionsensitizing gradients switched in slice direction and three different b-values (30, 300, 1100). Regional apparent diffusion coefficients (rADC) were determined in different brain regions including basal ganglia and pons. Results: Using the Kruskal Wallis test and post hoc testing with the Mann Whitney U test, significant differences in rADCs of the putamen (0.85 vs. 0.71 s/mm 2 ; p < 0.001) and the caudate nucleus (0.81 vs. 0.72 s/mm 2 ; p = 0.007) were detected between patients with MSA-P and PD. Between PSP and PD patients, significant differences in rADCs were revealed in the putamen (0.87 vs 0.71 s/mm 2 ; p = 0.008) and in the globus pallidus (0.72 vs 0.65 s/mm 2 ; p = 0.006). No significant differences in rADCs were obtained between patients with MSA-P and PSP. Conclusion: The significant higher rADCs in patients with MSA-P (putamen, caudate nucleus) and PSP (putamen, globus pallidus) compared to patients with PD may reflect a more advanced alteration of the CNS tissue integrity due to neuronal loss and gliosis leading to increased random movement of water molecules.

Metabolic impairment of the brain in patients with apallic syndrome S. Mirzaei, C. Stepan, P. Knoll, H. Köhn, H. Binder; Vienna/AT Purpose: A reliable assessment of prognosis in acute/persistent vegetative state following cerebral anoxia is mandatory for clinical decisions concerning extended intensive care procedures.

We evaluated five patients with apallic syndrome with [ 18 F]-2-deoxy-D-glucose (FDG) positron-emission-tomography (PET). PET images of the head were performed using a Siemens ECAT-ART Scanner (CTI, Knoxville). Two 137 Cs point sources were applied for attenuation correction and OSEMalgorithm for iterative reconstruction. Regional cerebral metabolism in 12 cortical and subcortical regions was determined and compared to a normal control group.

The global cerebral metabolism of glucose was markedly reduced in all patients. So far, a follow-up PET scan of the brain in one patient without clinical amelioration showed further decrease of cerebral glucose metabolism.

In accordance with limited reports in the literature these results suggest that the extent of metabolic impairment may play an important role in order to assess the probability of clinical recovery from severe anoxic brain injury. Methods and materials: A pioneer instance of a fully digital radiology department has been implemented at Shanghai First Hospital since Aug. 2000, which has been composed of a DICOM compliance PACS and a chinese RIS developed inhouse. Two phases were implemented for whole setup procedures. Results: In initial phase started in Oct.99, CT, MRI, RF, DSA and a film digitizer connected to a central archiving system which involved a 300 GByte RAID and a round about 3 TByte DVD jukebox, simultaneously a chinese RIS was installed to implement the computerized management for routine workflow; Full implementation of digital department was completed with three new modalities, a DR, a Digital Mammography and a Digital Radiofluoroscopy installed in Aug. 2000, which realized full electronically archiving of images and initiated a filmless procedure. Central and distributed image store management and auto-routing procedure employed to reduce network traffic and improved processing response of the system. Soft copy image diagnosis and the computerized management of imaging workflow elevate workflow efficiency and improve patients passthrough obviously. The Chinese version RIS, which was developed based on the workflow and routine manage model of typical radiology department of China, has successfully transferred traditional film-based management into a revolutionary efficient and reliable digital management. Conclusion: Phases approach is a perfect way to achieve the fully digital radiology department in China and a specifically RIS would play an important bridge role in a complex medical information system environment.

Possible pitfalls in the digitalisation of the radiologic image archive P.M.A. van Ooijen, M. Oudkerk; Groningen/NL Purpose: With the increase in the amount of data produced at radiology departments, the importance of digitalisation of the radiologic image archive also increases. When planning a Picture Archiving and Communiations System (PACS), an overview of the possible pitfalls is crucial to judge the quality of the implementation plan. We present such an overview based on our experience with the digitalisation of a radiology department in the Netherlands. Methods and materials: According to our experience, seven pitfalls are present when implementing a PACS: (1) System acceptation by the radiologist;

(2) Emphasis on storage instead of retrieval performance; (3) Reduction of data transfer capacity; (4) Undersized digital storage capacity; (5) Unpredictable radiologic workflow; (6) Functionality archive media; (7) Pseudo DICOM 3.0 solutions. Results: For a successful PACS, all pitfalls described above have to be eliminated. To achieve this, the Everything On-Line (EOL) principle was developed based on the ground rule that all images have to be available to the radiologist fast at every workstation at all times (emphasis on retrieval). The EOL PACS is a, WindowsNT™ based, full DICOM solution with a large (last months to years) RAID-5 on-line archive (fast, standardized, scalable) and a large DVD-R on-line backup storage (non-erasable, standardize, scalable), eliminating dependency on workflow management, pre-fetching or auto-routing and increasing the ease of acceptation by radiologists. Conclusion: A large number of pitfalls are present when digitising a radiologic image archive but with careful planning and by putting certain demands on the manufacturer, these pitfalls can be eliminated. 

This new technique is based on a regular 15″ TFT-Flatscreen monitor equipped with a special filter system. This configuration allows the display of objects from 8 different angles with a shift of one degree in between. Of these 8 perspectives only two reach the eyes of a viewer at one time. Different viewers in front of the screen obtain different perspectives resulting in a stereoscopic view for all viewers in front of the monitor. To demonstrate 3D data sets, we use a 69″ plasma display equipped with the "Stereo Viewing" panel. The stereoscopic view is used for still images and for movies, e.g. AVI files. The described system was evaluated over a period of 6 months. Results: Panel-based Stereo Viewing is possible. Without the addition of cumbersome and costly glasses, the technique can be used to provide a 3D rendition of complex 3D MRI-and CT-data sets for large audiences. The system proved easy to use and was widely accepted by referring physicians as a tool for rapid data assessment. A selection of cases will be presented in this presentation. Conclusion: "Stereo Viewing" without glasses proved to be feasible and became widely accepted at our department, especially for demonstration purposes.

Accessing 2D Purpose: Accessing medical images everywhere and everytime on mobile hardware is very important for both routine diagnostic and research. Therefore, we developed an application for mobile devices, which are increasingly present like pencils. Methods and materials: Java Mobile-Informations-Device-Profile (MIDP) was selected for development. For data-transfer the http network protocol is used. The image data is available in the DICOM file standard. There is no need of special filepreparation before file access. Stereoscopic images were generated with our previously developed medical interactive stereo-3D visualisation tool. Results: Java was used because of the growing range of java-enabled hardware like mobile phones, personal-digital-assistants and tablet-pcs. The MID-Profile was created especially for limited devices. Our reference application is running on 16 bit color Palm-Organizers. Image files can be accessed through wireless or wired connections. Once the data is retrieved from a server, the images can be viewed, edited and saved. It is also possible to list and edit the Dicom tags and make additional comments. Precalculated 3D-data (e.g. from CT-datasets) based on chromatek visualisation can be displayed stereoscopic on color devices. Summary: The goals of a mobile implementation is not the replacement of medical desktop workstations, but enlargement. The implementation includes methods for intelligent interaction and reduction of drawbacks of limited devices. Because of using distributed standards and the standalone implementation, the application can easily be integrated into medical systems. 

Creating HIS-based quality mangement: The Nottwil experience H. Hawighorst, T. Mayer; Nottwil/CH The Swiss Paraplegic Center was founded in 1990 and is a modern level I trauma center for patients with all type of spine injuries. In this presentation we will discuss our road to success and the difficulties lying ahead to fully integrate a knowledgebased quality management to our institution. PACS was installed in 1998 and is productive with HIS and RIS as a knowledge based information system since the end of 1999. Radiological images and reports are distributed within the hospital by a WebServer based Intranet technology.

For management purposes the model of EFQM (European Foundation for Quality Management) was choosen at the end of 1999 and aims at Total Quality Management. Although the PACS sytem is running quite well there are still problems to be solved. In the EFQM model "processes" are the essential element. We adopted from the EFQM matrix an audit matrix with 90 quality steps. The result of the first quality selfassessment has shown that knowledge-based quality has to be transparent and understandable to employees and has to be "lived" and continuously "taught".

To increase and assure widespread access and acceptance of quality management we bring Intranet technology-based information together with continuous education of employee. However, trained people with skills in modern technology and quality mangement are warranted in this type of modern infrastructure.

New approach to picture communication in an outpatient environment F.X.J. Fruehwald, E. Steiner, M. Obermayer; St. Pölten/AT Purpose: While PACS inside hospitals is a widely used technology nowadays, the situation is much different outside hospitals. A new approach offers picture communication to the medical community outside hospitals. While hospitals solutions are "islands" with little communication to the outside world, the new system supports communication between all providers of medical services Materials and methods: Application provided PACS allows storage of image data in a professionally organised server farm. Patients are provided with a chipcard containing the name, a unique serial number and a PIN. All doctors authorised by the patient can access the server and load down all images they want using secured lines. Results: Technological requirements and guaranty of privacy of medical data are described. The system has been implemented in a part of Austria. Some 50 physicians up to now take part in this project. Only normal amateur PC equipment is needed on the physician's side, ADSL is recommended for download of DICOM images; for use of JPEG images ISDN standard would be sufficient. Global access of the server is possible. Conclusion: A combination of application provided PACS and a plastic card with a chip can transfer all advantages of hospital PACS into the extra hospital world. As storage costs and costs for telephone lines go down it is to be expected that this internet based system will replace traditional image communication per hardcopy and mail shortly. Purpose: Magnetic resonance imaging (MRI) is limited by artifacts and image distortion in vessels after stenting. With a rigid active magnetic resonance imaging stent (AMRIS) the stent lumen can be illuminated without causing artifacts, however, the use is limited due to the need for surgical placement. A new balloonexpandable stent design enables catheter implantation of the AMRIS. The purpose of this study was to evaluate the imaging properties of this stent in a rabbit model using MR angiography (MRA) and flow measurements.

The AMRIS was expanded with a balloon catheter in the abdominal aorta of five rabbits. Flow measurements and MRA before and after injection of an iron-oxide-based blood pool contrast agent were performed at 1.5 T.

Signal-to-noise ratios (SNR) were calculated within and outside the stent lumen. Results: Placement of the expandable stent was feasible in all animals. SNR outside as compared to within the stent increased significantly (p < 0.05) from 5.0 to 23.2 for plain, from 19.5 to 30.7 for contrast-enhanced MRA, and from 5.8 to 13.9 for magnitude images of the flow measurements. Flow volume curves within and distal to the stent were comparable. Conclusion: MR imaging after interventional placement of the expandable AMRIS is capable of illuminating the inner stent lumen. Thus, follow-up after stent placement is feasible and it appears to be a useful tool for clinical follow-up and basic research on vessel alteration after stent placement. 

We retrospectively studied 37 procedures of mechanical thrombectomy of PTFE dialysis access grafts with the AT-PTD performed in our vascular department. 28 dialysis accesses in 26 patients were included (nine had a double procedure). The delay between thrombosis and percutaneous thrombectomy was less than 48 hours. Duration of the procedure, immediate technical results, primary patency and complication rates were analysed.

The mean duration of the procedure was 137 minutes. A venous stenosis was associated with thrombosis in 90 % of cases. The technical success was 89.2 %. 31 % of successfully declotted access grafts presented with early recurrent thrombosis less than 3 months after the procedure: 45.5 % of them presented with residual stenosis at the end of the initial procedure and 45.5 % with residual clots. In this group, the mean primary patency was 30.5 days. Three major and 4 minor complications were observed. Conclusion: Thrombectomy of dialysis access graft with the AT-PTD is a safe and effective technique. The mean patency rate is superior to pulse-spray and the complication rate is lower. Moreover, the procedure seems to be faster to perform than other techniques. Results: Indications for PTA were ulceration in 40 limbs, rest pain in 26 limbs, gangrene in 4 limbs and bilateral intermittent claudication in a patient requiring total knee replacements. 24 limbs underwent one procedure, 12 underwent two and 8 underwent three. Technical success was achieved in 67/72 (93 %), partial success in 4/72 (5.6 %) with 1 failure to achieve any improvement (1.4 %). 30 day mortality was 1/40 (2.5 %) from bronchopneumonia 17 days post BKPTA. Mean/ median follow up was 24 months (range 0 -48). Clinical improvement (ulcer healing, reduced or absent pain) was seen in 34 patients (77 %). Expected major and minor amputations were 2 (9 %) and 3 (14 %). There were no major complications requiring further radiological/surgical interventions or increased hospital stay. There was 1 minor groin haematoma. Conclusion: BKPTA is a safe, worthwhile procedure in carefully selected patients, although repeat procedures were required in almost half of the limbs treated. Following appropriate inflow procedures we consider PTA as a first line treatment for patients with distal critical ischaemia. (3) after previous SFA angioplasty, underwent PTA with adjuvant PDT using 60 mg/kg of the photosensitiser 5-aminolaevulinic acid and 635 nm light at 50 J/cm 2 to PTA site. At 6 months of follow up all patients were asymptomatic with no restenosis and no arterial complications. Because of previous restenosis/re-occlusion these patients would be at a high risk of this complication again.

Results: These patients have now been followed up for 26 ± 3 months. Patients were reviewed clinically and were offered Duplex examination. Six of the 7 patients remained asymptomatic. One patient has had repeat angioplasty. A further patient had mild, unlimiting claudication. Three of the 4 patients who had duplex showed no restenosis. The 4 th patient (the only currently symptomatic one) had a significant stenosis (PSVR = 3.7). There were no arterial complications such as aneurysm formation or occlusion at the treated sites. Conclusions: PDT as an adjunct to PTA is a safe and feasible procedure and appears effective in the long term. We have now started a randomised control trial to assess its potential for the treatment of restenosis. Purpose: To present statistical data from a registry including patients after angioplasty or stenting of atheromatous peripheral lesions (essentially renal and lower limb arteries). Methods and materials: Angioplasty with or without stenting of an atheromatous peripheral lesion was the criteria for inclusion: 729 patients were included (540 men, mean-age 59.9 years) between May 1998 and Dec. 1999, in 10 centers. Cardiovascular risk factors, symptoms and atheromatous localization were analyzed with a descriptive method; the population with renal disease was compared with the one with lower limb disease. Results: Smoking (78.5 %), hypertension (58.7 %), and hypercholesterolemia (50.9 %) were the most frequent risk-factors. Men were more frequently smokers than women (92.7 % and 37.8 % respectively). Lower limb arteriopathy was more frequent in men than in women (80.9 % and 44.4 % respectively). Vasculo-renal disease was more frequent in women than in men (46 % and 20.4 % respectively).

Smoking was much more frequent in the group with lower limb arteriopathy (90.3 %) than in the group with vasculo-renal disease (53.3 %).

Conclusion: This registry gives access to statistical data about a population of atheromatous patients treated for peripheral localization. Long-term follow-up will allow us to evaluate the changes in the profiles of the patients and the morbidity and mortality in this population. Results: All lesions with a maximum diameter of 5 cm were treated with a safety margin of 5 -10 mm around the lesion. Lesions with a close relationship to the liver capsule, the gall bladder and major vessels were treated. In patients treated with LITT for liver metastases from breast cancer the mean survival was 3.6 years (95 % CI 3.0 -4.2 years, median 3.5 years) after the first LITT treatment and 4.6 years after the diagnosis of metastases, which was treated with LITT (95 % confidence interval 3.9 -5.9 years, median survival 4.5 years , partial necrosis in the remaining 8 lesions (23.5 %); two of these tumors were > 5 cm. Patients had no major complications except one hemorrage that required transfusion but resolved spontaneously. Transient pain, nausea and fever were common minor symptoms that resolved within 2 -3 days. The median follow-up was 12 months. Conclusion: RF ablation with the Le Veen probe is a safe, well tolerated and effective procedure for the treatment of unresectable liver tumors.

Enhanced gray scale ultrasonography with Levovist and C 3 -Mode of hepatocellular carcinoma treated with interstitial laser photocoagulation L. Tarantino 1 , A. Giorgio 2 , G. de Stefano 2 , F. Esposito 2 ; 1 Torre del Greco/IT, 2 Naples/IT Purpose: To evaluate C 3 -Mode enhanced ultrasonography of hepatocellular carcinoma (HCC) treated with interstitial laser photocoagulation (ILP). Method/materials: 8 patients with a single HCC (2.0 -5.5 cm) treated with ILP underwent helical CT and were also studied with C 3 -Mode™ (ESAOTE BIOMEDICA, Genoa, Italy) and an i.v. microbubbles contrast agent (Levovist, Shering, Berlin, Germany). After injection of Levovist (4 g; 300 mg/ml), C 3 -Mode™ scans were recorded at the times 20 s, 40 s, 60 s, 2 min, and 3 min. The results of C 3 -Mode™ were compared with CT. Results: After injection of Levovist, C 3 -Mode™ showed homogeneous enhancement (hyperechogenicity) of liver parenchyma at 20 s, 40 s, 60 s, 2 min, and 3 min. In 6 patients, with complete necrosis of HCC at CT, the lesions did not show any intralesional enhancement during C 3 -Mode™ examination (complete agreement with CT). In one nodule, with enhancing intratumoral areas suggestive of viable tumor at CT, C 3 -Mode™ showed hyperechogenicity in the same corresponding areas (agreement with CT). In the remaining patient, CT showed complete necrosis of the nodule. Howewer, enhanced spots along the inferomedial margin of the lesion suggested parenchymal infiltration left untreated by ILP. C 3 -Mode™ did not show enhancement in that area and a biopsy did not show malignancy. No relapse has been observed after 8 months. Follow-up of the patient is in progress. Results: All patients tolerated the procedure well under local anesthesia. The total procedure time was 90 minutes. All complications observed were minor and no further treatment was necessary. Online MR thermometry allowed exact visualization of the extension of laser-induced changes and their relationship to the neighboring anatomy. Lesions up to 2 cm in diameter could be efficiently treated with a single laser application; larger lesions were treated with dual, triple and quadruple simultaneous applications. In 97.5 % we achieved complete necrosis of the tumor and a 5 mm safety margin, resulting in complete destruction of the tumor without local recurrence. Mean survival after the first laser treatment was 3.4 years (95 % confidence interval (CI) 2.5 -4.2 years) and 4.4 years (95 % CI: 3.6 -5.2 years) after the time of diagnoses of the HCC. Conclusion: In hepatic involvement with oligonodular hepatocellular carcinoma, LITT appears to be an effective therapeutic procedure. Results: Before treatment, intratumoral arterial-phase enhancement followed by a hypoechoic appearance in the portal venous and delayed phases was demonstrated by contrast US in 38 (90 %) of 42 HCCs. After RF, all the 32 (84 %) of the 38 HCCs that were found to be necrotic at spiral CT, failed to enhance using contrast US. By contrast, in the six HCCs with residual viable tumor at spiral CT, intratumoral areas of persistent enhancement -corresponding to the enhancing areas at spiral CT -were identified using contrast US. These six nodules were retreated with RF, targeting residual tumor with contrast US guidance. Conclusion: Contrast-enhanced US, performed using C3-mode imaging, shows promise in assessing the therapeutic effect of RF thermal ablation in HCC. Purpose: Cytokine-based gene therapy has been shown to be highly efficient in stimulating an immune response leading to tumor rejection in transplanted tumors. Woodchucks infected with woodchuck-hepatitis virus (WHV) develop orthotopic hepatocellular carcinomas (HCC). The purpose of this study was to evaluate the efficacy of MR-guided injection of a therapeutic Adenovirus vector into HCCs of woodchucks and to monitor the course of the tumor non-invasively using MRI.

For MR imaging five woodchucks with known hepatocellular carcinomas were anesthesized using ketamine and xylazine. The animals were examined using standardized sequences on a 1.5 T whole-body scanner. Under MR-guidance either AdIL-12/B7.1 or a control adenovirus were injected into selected tumor nodules. The animals underwent axial MR examinations of the liver immediately as well as 2, 4, 7 and 10 weeks following application of the therapeutic agent. Finally all animals were sacrificed and the liver was referred to histopathology.

Results: MRI of all animals was feasible. Injection of AdIL-12/B7.1 caused a reduction of the tumor nodule volume in all animals. In contrast, tumor areas injected with the control vector showed increased tumor size. Histopathologic examination of liver sections revealed necrosis and inflammatory infiltration in tumor nodules injected with AdIL-12/B7.1 whereas typical features of neoplastic hepatic cells were found in areas injected with the control vector. Conclusion: Objective monitoring of gene therapy strategies in vivo by means of high resolution MR imaging in small animals is possible.

Purpose: Paediatric diagnostic examinations in Ireland are currently under investigation, such that recommendations may be made for greater optimisation of practice. Methods and materials: A questionnaire survey established which Irish hospitals perform paediatric examinations. Dose measurement, using a combination of TLD and DAP monitoring, is being conducted in a sample of these. In line with European recommendations, diagnostic reference levels are being established for examinations with high effective dose. An evaluation panel is using image assessment criteria derived from those of the European Commission to assign objective image quality scores. Correlation of dose and image quality allows proposals for optimal techniques for paediatric examinations. Results: There is a wide spectrum of paediatric practise nation-wide, in terms of caseload, equipment used, and technique applied. This has significant impact on the range of patient dose for similar investigations, and on the diagnostic quality of the images produced. Comprehensive analysis of image quality is difficult, and in paediatrics, is complicated by the fact that essential image details depend heavily on the clinical situation. An absolute image quality measure such that the lowest achievable dose for an examination may be specified is being sought.

The formulation of a non-biased, representative sample of hospitals is fundamental to the validity of any dosimetric survey, but particularly one concerned with the establishment of national reference doses. Optimisation demands that image quality is evaluated in clinical radiographs -in paediatrics this requires consideration of the clinical context of the request. Does an absolute image quality measure exist? Purpose: To investigate in a controlled patient study the potential of online tube current modulation in subsecond multi-slice spiral CT (MSCT) examinations of children to reduce dose without loss in image quality. Method/materials: Dose can be reduced for non-circular patient cross-sections without an increase in noise if tube current is reduced at those angular positions where the patient diameter and, consequently, attenuation is small. We investigated a pre-release product version of an online control for the tube current integrated in a SOMATOM VZ with improved technical performance. We evaluated image quality, noise and dose reduction for examinations with online tube current modulation in 50 MSCT of the thorax and the abdomen. We evaluated mAs for tube current modulation and compared to the mAs in standard protocols. Image quality was rated as very good, good and poor in a consensus by three radiologists. Noise was assessed in comparison to a control group and by phantom measurements. Results: Dose was reduced typically by 20 to 37 %, depending on the patient geometry and anatomical region (thorax 25 to 29 %, abdomen 20 to 37 %). In general, no loss of image quality was observed. Measured noise did not change significantly. In some cases the noise pattern was improved. Online tube current modulation is now used as a standard in multi-slice spiral CT at our institution. Conclusions: Dose in multi-slice spiral CT examinations of children can be reduced substantially in routine examinations by online tube current modulation without a loss of image quality.

Purpose: Malformations of the corpus callosum (CC) may occur in many different syndromes. Various forms have been observed with different degrees of structural abnormality. The purpose of this study is to review characteristic signs of callosal abnormality and try to find a correlation with the degree of clinical disability. Material and methods: MRI examinations were performed in patients with developmental delay. Imaging included T1 and T2-weighted sequences in all cases. All patients had a thorough neuropaediatric clinical examination. The MRI images were evaluated regarding the degree of callosal hypoplasia, presence of a fornix and hippocampus, hydrocephalus and concomitant further abnormalities. Results: Seven different forms of malformation of the corpus callosum were encountered. In particular the development of the fornix and hippocampus differed significantly as did the amount of clinical disability. As a hippocampal commissure is a prerequisite of normal hippocampal development, the size of the temporal lobes depended on the degree of this midline abnormality. Patients without hippocampi were all severely disabled.

The clinical disability of the patients presented here differed significantly, which may in part be due to the different extent of the midline cerebral malformation. The relevance of the concomitant aplasia of the limbic system has not been addressed in detail before in the literature. Purpose: To evaluate the role of CT and CT angiography in the diagnosis and treatment of pulmonary cystic and adenomatoid malformations in the newborn and young children. Methods and materials: Nine children aged between 2 days and 5 months with respiratory failure and cystic pulmonary malformations underwent conventional CT and CT angiography. Lung abnormalities were present on all the chest radiographs prior to CT. The abnormalities had varying appearances; 2 resembled pneumonia, 3 appeared as a mass and 4 as cysts. The CT acquisition protocol included sequential scanning with a 5 mm scan thickness and scan interval, which was followed by high resolution CT in all cases and CT angiography in two. All CT studies were performed under general anaesthesia. The final diagnosis was based on the surgical data and morphologic examination of resected lung tissue in all patients. Results: Morphologic investigation revealed different types of cystic adenomatoid malformation in 6 cases and persistent interstitial emphysema in association with other hallmarks of bronchopulmonary dysplasia in 3 cases. The following types of congenital cystic adenomatoid malformation were found: type I (4), type II (1), type III (1), and the CT data was in close relationship to the morphologic findings. In 3 cases CT showed the presence solitary or multiply lung cysts. Conclusion: CT is a useful diagnostic tool for precise estimation of the extent and differential diagnosis of cystic pulmonary malformations in the newborn and young child with respiratory failure. CT angiography can provide important diagnostic information in the preoperative investigation of pulmonary and mediastinal vessels in these cases. 

We analysed 97 AUBMT (46 boys, age 11.5 a; 51 girls, age 11.2 a), 35 (36 %) died and 83 ALBMT (33 girls, age 12 a; 50 boys, age 16 a), 29 (34.9 %) died. At least one plain radiograph and one CT were obtained before ALBMT and AUBMT respectively. Results: Only 13 CT examinations in clinically complicated cases were peformed after ALBMT. Pathological findings were found in 6/83 (7.2 %). 3/6 (50 %) later died because of infections. Inflammatory pneumonia occured in 3 cases, mycotic infection in 2 cases and pneumonitis after chemotherapy was found in one case. Graft versus host disease was the cause of death in 3/97 cases. 655 CT examinations of patients were performed after AUBMT, mostly to exclude lung metastases and to follow up mediastinal lymph nodes. In 4/7 patients with respiratory symptoms parenchymal changes were found. We diagnosed 1 pneumonitis after chemotherapy, inflamatory pneumonia in 2 cases and mycotic infection in 2 cases. Two patients had clinical symptoms with a negative CT. Only 1/7 (12.5 %) died due to respiratory complications. Conclusion: Different imaging strategies for AUBMT and ALBMT were used. The therapy of pulmonary complications is more complex with ALBMT, but there are frequently diagnosed with plain films. CT is used more frequently after AUBMT in which pulmonary infections are rare and less serious. CT has a decisive role in BMT patients.

Chrispin-Norman-score and Bhalla-score of patients with cystic fibrosis: Results: CN-scores varied between 2 and 24 in Rx and MR. The mean CN-score was 12.6 ± 6.4 in Rx and 12.8 ± 6.2 in MR. The CN-score was higher in Rx in 10 patients and higher in MR in 15 patients. In 30.6 % the difference between the two scores was 0, in 88.9 % the difference was smaller than or equaled 2. High correlation was found between scoring with Rx and MR with minor restrictions in differentiation of nodules and rings on MR. Bhalla-scoring was possible in MR-imaging. Conclusion: CN-scoring and Bhalla-scoring of CF is possible with fast low-field MR. Since scoring differences between Rx and MR are not higher than interobserver differences in Rx scoring, further research is strongly suggested to reduce radiation exposure in the long term follow-up of patients with CF, especially in children with minor pulmonary involvement.

True-FISP lung MRI at 0.2 T in pediatric oncology patients presenting with FUO G. Schultz, C. Laub, W. Kenn, A. Trusen, J. Kühl, D. Hahn; Würzburg/DE Purpose: To compare conventional chest X-ray and MRI in pediatric patients with a diagnosed cancer suffering from fever of unknown origin (FUO). Materials and methods: 13 patients (aged 3 -22 years, mean age 8 years) had 21 chest X-rays and underwent MRI in a 0.2 T MRI unit (Siemens Magnetom Open) using a phased array surface coil. The images were acquired in coronal and sagittal planes. For the MR investigation a TRUFI-sequence (TR = 6 ms, TE = 3 ms, matrix 256, slice thickness 20 -40 mm) was used with an acquisition time for 10 slices of 20 s. Results: Although breathhold-sequences were not possible in all cases, it was possible to evaluate all investigations. With regard to pulmonary infiltration coincident findings were achieved in 15/21 cases. 2 out of 6 infiltrations could only be detected on the MR images and the extent of infiltration was better evaluated in 4 cases. Additional MRI-findings such as sinusitis, pericardial effusion and hepatosplenomegaly were detected. Conclusions: True-FISP lung MRI was found to be more sensitive than the conventional chest radiograph. Additional important clinical information was also obtained with MRI. underwent duplex Ultrasound and Digital Subtraction Angiography, followed by percutaneous treatment. Duplex US was performed via trans-lumbar approach: RI derived from the interlobular arteries was obtained. Pre-procedural mean ± SD values of RI and referral cut off values were calculated. Patients were classified as cured/improved or not improved according to blood pressure values and changes in antihypertensive drugs before and after treatment. Results: Pre-procedure, mean ± SD RI values were different (p = 0.001) for atherosclerotic (0.63 ± 0.11) and fibrodysplastic (0.56 ± 0.10) stenoses, with no difference between cured/improved and not improved patients (0.59 ± 0.10 vs. 0.64 ± 0.12); no difference (ANOVA p = 0.5) was found for medical therapy. In cured/ improved atherosclerotic patients (41/58, 70 %), RI was < 0.65 in 28 (57 % 

SonoVue enhanced US measurement of altered renal haemodynamics in patients with liver metastases E. Leen, J. MacQuarrie, W.G. Angerson, P. Horgan; Glasgow/GB Purpose: To assess SonoVue enhanced Ultrasound in the measurement of renal haemodynamics in patients with liver metastases. Materials and methods: 10 healthy volunteers and 10 patients with proven liver metastases were studied; non-linear ultrasound imaging (M.I: 0.15 -0.20) of each kidney was performed continuously in a sagittal plane before and after bolus intravenous injection of 2 ml contrast medium (SonoVue, Bracco, Milan). There was a minimum of 10 minutes delay between the examinations of either kidney to allow for contrast clearance from the previous injection. Digital data acquisition over a period of 60 seconds was subsequently recorded for quantification analysis. Timeintensity curves were derived from regions of interests placed over the kidneys. The contrast arrival times (AT), peak amplitude (PA), time to peak (TP) & gradient (G) of the steepest portion of the curves for each kidney were measured. Results: There was no significant difference in all the parameters between the contra-lateral kidneys for both controls and patients with liver metastases. There was no significant difference in the PA, AT and TP indices between controls and metastases. In contrast the gradient values were significantly raised in those patients with liver metastases (metastases vs controls: 1.59 ± 0.47 vs 0.40 ± 0.22, p < 0.01); there was clear separation of the gradient values between the two groups. To study diagnostic possibilities of 3D-VUSA in evaluation of main renal vessels. Materials and methods: 71 consecutive patients were referred to 3D-VUSA for assessment of major renal vessels: aortic aneurysm (5 pts), renal tumors (16 pts), suspicion of RAS (22 pts), suspicion of UPJ obstruction (28 pts). 3D-VUSA was performed on Sonoline Elegra (Siemens) version 6.0 with Power Doppler and a special 3D program. Postprocessing was performed using volume rendering data to obtain angiogramm-like virtual images. Verification was made by conventional angiography (51 pts) and surgery (20 pts).

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Results: 3D-VUSA revealed 17/22 unilateral accessory RA, 2/3 bilateral accessory RA (sensitivity 75 %, specificity 95 %). UPJ obstruction was diagnosed by 3D VUSA in 12 cases and was confirmed by conventional angiography and operation in 11 cases (sensitivity 81 %, specificity 71 %). RAS was revealed in 4/22 patients referred to 3D-US study (sensitivity 50 %, specificity 62 %). 3D-VUSA diagnosed 3 infrarenal aortic aneurysms. In the cases of renal tumors 3D-VUSA helped to delineate normal and abnormal renal vasculature, thus providing necessary information for nephron-sparing surgery. Conclusion: 3D-VUSA is a useful, noninvasive new promising method for evaluation of main renal vessels. We suggested it especially in children and young adults, in patients with renal failure, allergy to iodinated contrast agents, or fear of ionizing radiation or arterial catheterization.

High resolution 3D MR-angiography in renal arteries using sense This was related by measurement to the umbilicus and ASIS. Results: On CT, the median (interquartile range) of the distances between the umbilicus and the AB, from the ASIS to the AB and from the umbilicus to the IV were −9.0 (28.8), 48 (16) and −24.9 (32) mm respectively. The mean angle of the umbilicus from the AB was 21.6° (range 14 -34°). On US, the mean distance from the IEA to the midline was 36.2 mm (10 -48) and from the IEA to the ASIS was 100 mm (80 -140).

The relationship between the level of the ASIS and AB/IV is more consistent than the position of the umbilicus. Primary-port trocar insertion at an angle of 34° and secondary-port insertion 15 mm from the midline is recommended.

Renal cyst ablation using mixture of n-butyl cyanoacrylate and iodized oil in patients with autosomal dominant polycystic kidney disease: A preliminary report J. Kim 1 , S. Kim 1 , M. Moon 1 , H. Lee 1 , J. Sim 2 , S. Kim 1 , C. Ahn 1 ; 1 Seoul/KR, 2 Koyang/KR Purpose: To assess the feasibility and effectiveness of renal cyst ablation using n-butyl cynoacrylate (NBCA) in patients with autosomal dominant polycystic kidney disease (ADPKD). Materials and methods: During the past 14 months, 50 renal cysts in 14 patients were treated with percutaneous needle aspiration and intracystic injection of 1:2 mixture of NBCA and iodised oil. Clinical follow-up was done in all 14 patients for the period of 1 -12 months. Subjective symptoms, blood pressure, and serum creatinine level before and after the procedure were compared. CT follow-up was done in 31 cysts in eight patients for the period of 3 -12 months. The procedure was considered successful at follow-up CT when the diameter of the cyst decreased more than 50 % after the procedure as compared to that before the procedure. Results: After NBCA therapy, symptom was improved in 12 of 14 patients (86 %) and cyst was disappeared or decreased more than 50 % in diameter after the procedure in 25 of 31 cysts (81 %). There were no significant changes in blood pressure and serum creatinine level after the procedure. There was no significant complication related to the procedure in any of the patients. Conclusion: Percutaneous needle aspiration with intracystic injection of mixture of NBCA and iodised oil appears to be feasible and may be an effective modality in ablating renal cysts in patients with ADPKD. Purpose: Stimulated acoustic emission effect shows marked lesional difference in uptake of the microbubble Levovist in its liver specific phase. Benign lesions showed high uptake, malignancies appeared as defects. A multicenter trial using a novel non-linear mode (ADI, Acuson, Mountain View) offering greater sensitivity and spatial resolution. Methods and materials: 67 patients with focal liver lesions characterised either by biopsy or serial/multimodality imaging have been studied. Diagnoses were: metastases n = 34, hepatocellular carcinoma (HCC) n = 10; haemangioma n = 8 and benign non-haemangiomatous lesions (BNHL) n = 15, comprising focal nodular hyperplasia FNH; n = 5, focal fatty sparing n = 4, focal fat 1, adenoma n = 3, regenerating nodule: RGN n = 2. ADI imaging of the lesion was performed without interval scanning after a delay of 5 minutes from bolus injection of Levovist (2.5 g). Liver-lesional uptake differences (LLUD: as %) were compared using a visual analogue score. Comparisons were made using non-parametric comparisons (Kruskal-Wallis ANOVA; Mann-Whitney 2-column comparisons with Bonferroni corrections). Results: Highly significant differences (p ≥ 50 %), while fat/fatty sparing, RGN and FNH showed minimal differences (< 10 %). HCCs (mean liver-lesion difference 67 %, range 0 -100 %) and haemangiomas (average 45 %, range 7 -80 %) showed overlap features. Intergroup comparisons showed significant differences between BNHL and all other lesion types and between metastases and haemangiomas.

Conclusion: This simple test shows marked differences between lesion types. It is a very useful test for fatty change, FNH and RGN. Non-haemangiomatous lesions can be separated from metastases with particularly high accuracy. The present of high-uptake of Levovist at 5 minutes is strong evidence for benignity.

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Contrast-enhancement patterns of hepatic lesions at C3-mode intermittent US imaging D. Cioni, R.A. Lencioni, F. Donati, L. Crocetti, M. Perri, C. Franchini, C. Bartolozzi; Pisa/IT Purpose: To describe contrast enhancement patterns of focal hepatic lesions at C3-mode intermittent US imaging. Materials and methods: A series of 99 hepatic lesions in 66 patients were examined. US examination was performed by using C3-mode intermittent imaging (Technos, Esaote Biomedica) with 1.4 mechanical index after bolus injection of 2.5 g Levovist (Schering AG) at the concentration of 400 mg/ml. US images were acquired in arterial (15 -25 s), portal in-flow (40 -55 s), full portal (70 -85 s), and delayed (180 -200 s) phases. Findings at contrast US studies were correlated lesion-by-lesion with those at spiral CT or dynamic MRI. Results: Four distinct enhancement patterns were observed: (1) rapid enhancement in arterial phase, followed by either isoechoic (5/5 focal nodular hyperplasia, 1/1 hepatocellular adenoma, 1/6 haemangioma) or hypoechoic appearance (38/38 hepatocellular carcinomas) in portal-venous and delayed phases; (2) peripheral globular enhancement in arterial phase, with centripetal fill-in in portal-venous and delayed phases (5/6 haemangiomas); (3) rimlike enhancement in arterial phase, followed by hypoechoic appearance in portal-venous and delayed phases (9/25 metastases); and (4) no enhancement in arterial phase followed by either isoechoic (13/13 macroregenerative nodules) or hypoechoic appeareance (16/25 metastases) in portal-venous and delayed phases. The enhancement patterns shown at contrast US correlated with spiral CT or dynamic MRI findings in 80 of 88 lesions (90 %). Conclusion: C3-mode intermittent US imaging is an accurate tool to evaluate the contrast enhancement patterns of focal hepatic lesions. Findings correlate well with those at spiral CT or dynamic MRI.

Clinical study of a 3D virtual sonographic system to be used for remote diagnosis D. Jeanbourquin 1 , T. Le Bivic 1 , R. Larrue 2 , P. Pineau 2 , J.-C. Provost 2 ; 1 Clamart/FR, 2 Paris/FR Objectives: VirtualProbe system (IôDP, Paris, France) allows to acquire sonographic images simultaneously with spatial position of the probe, in order to rebuilt exact 3D sonographic volumes. The system allows to rescan through the 3D volume in order to perform a complete but asynchronous sonographic examination. One possible application would be military medicine, because the expert is not present at the time and on the site where diagnosis has to be done. The objective was to evaluate the ability of the system to be used for remote medical diagnosis.

The examinations from 40 patients were done on non moving organs, mainly on cervical and abdominal areas. Examinations using conventional method were performed and later on compared to those realized using VirtualProbe. All examinations were done by qualified radiologists. The image quality of the 2 methods were scored from 1 to 5 (poor to very good). Moreover, the ability of the system to allow proper diagnosis was recorded. Results: There was no difference between methods in image quality. For VirtualProbe, diagnosis was adjudicated as "possible" in 33 cases (82.5 %), "possible with some difficulties" in 5 cases (12.5 %) and "not possible" in 2 cases (5 %) due to technical problems (electromagnetic interferences and patient with polypnea leading to the impossibility to do acquisition). Conclusion: VirtualProbe system is a powerful tool that would provide a significant improvement in remote medical diagnosis using ultrasonography.

Differentiation of neoplastic portal vein thrombus from vascular thrombus in cirrhotic patients using harmonic sonography and second generation contrast agents M. Tonolini, V. Osti, L. Solbiati, P. Marelli, V. Kirn; Busto Arsizio/IT Purpose: Assessment of neoplastic nature of intraportal thrombus is of crucial importance for staging and therapeutic choice in patients with hepatocellular carcinoma (HCC). We sought to assess the utility of grey-scale harmonic sonography using second generation contrast agents for differentiating between neoplastic and bland portal venous thrombus. Materials and methods: 85 cirrhotic patients with solitary or multifocal HCC were evaluated for potential RF ablation therapy with triphasic helical CT, B-mode and color Doppler US. Contrast enhanced ultrasonography (CEUS) was performed using low mechanical index (0.1 -0.2) and a second-generation contrast agent (SonoVue, Bracco). Liver parenchyma and main portal branches were examined over arterial, portal, and delayed phases. Results: In 10 patients (11.8 %) conventional US and helical CT identified thrombus within the portal trunk or main branches. Arterial enhancement was depicted by CT in 7/10 (70 %) cases suggesting malignant nature. Unenhanced color Doppler detected arterial-type flow signals within the thrombus in 3 of 10 cases (30 %). With CEUS, 8/10 (80 %) thrombus showed rapid and inhomogeneous enhancement in the arterial phase (p < 0.05, compared to unenhanced US). In the portal phase, the enhancement of these 8 thrombi decreased in proportion to the respective HCCs, as contrast filled the patent portions of the vessel. In the remaining 2 cases, no arterial enhancement was detected and no malignant cells were found by US-guided fine-needle aspiration biopsy. Conclusions: Our study suggests that continuous-mode, contrast-enhanced harmonic sonography may serve as an easy and highly reliable modality for the characterization of portal thrombus in cirrhotic patients.

Specificity of contrast-enhanced harmonic sonography for characterization of solid, incidentally detected focal liver lesions L. Solbiati, M. Tonolini, L. Cova, D. Della Chiesa, V. Kirn; Busto Arsizio/IT Purpose: To assess the use of contrast-enhanced harmonic sonography (CEUS) in the differential diagnosis of incidentally detected focal liver abnormalities. Methods and materials: 460 patients underwent abdominal US for clinical questions unrelated to the liver. None of the patients had chronic hepatitis/cirrhosis nor history of malignancy. Solid focal lesions were found in 49 patients (8.75 %). Lesions with characteristic features of hemangioma were excluded. Low mechanical index, continuous-mode CEUS was performed using a second-generation contrast agent (SonoVue, Bracco). Final diagnosis was established by means of helical CT, dynamic MRI and/or FNAB. Results: In 14/14 focal nodular hyperplasias (FNH) and 13/13 atypical hemangiomas the typical enhancement pattern was detected. In 6 patients presenting multiple hyperechoic lesions, CEUS showed enhancement analogous to that of the surrounding liver in all vascular phases, suggesting the diagnosis of focal fatty changes, subsequently confirmed with CT and FNAB. In four patients with poorly enhancing lesions, CEUS did not provide diagnostic findings and FNAB was necessary to diagnose fibrotic hemangioma (1 patient), multiple tubercolous granulomas (1) and disseminated metastases form unknown origin (2). Conclusions: For the characterization of most incidentally detected and sonographically indeterminate benign lesions (FNH, atypical hemangioma, focal fatty change) CEUS (through the assessment of the enhancement behaviour over the different vascular phases) showed specificity equal to that of helical CT. CEUS will probably alleviate the need for further investigation with helical CT studies and aspiration biopsies.

O. Catalano 1 , A. Nunziata 2 , F. Sandomenico 1 , A. Siani 1 ; 1 Pozzuoli/IT, 2 Naples/IT Purpose: To evaluate if CE-PD is helpful in the differential diagnosis of focal hepatic lesions detected by grey-scale ultrasound. Methods and materials: In a 1-year period 98 consecutive patients where found to have previously unknown, non-cystic lesions on ultrasound examination (51 subjects showed 1 lesion, 29 2 -5 lesions, and 18 > 5 lesions). These lesions were evaluated with Levovist-enhanced PD and were fitted into 9 categories (hepatocellular carcinoma, cholangiocellular carcinoma, adenoma, focal nodular hyperplasia, angioma, metastasis, dysplasic nodule, abscess, other). Diagnostic confidence level was graded subjectively from 1 (possible) to 4 (certain). Categorisation and diagnostic confidence scoring were repeated after CE-PD study. Eight cases without confirmation were excluded. Results: Addiction of CE-PD study resulted in a change of category for 5 patients (5.6 %), all with a single lesion; this modification proved correct in all of them. Excluding 48 subjects with a maximal scoring (level 4), there were 16 patients with increased confidence after CE-PD study, 2 with decreased confidence, and 24 with unmodified confidence after CE-PD; score change was never greater than 1 level. In the two most commonly encountered issues, suspected nodule in chronic liver disease and angioma vs. hypovascular metastasis, CE-PD imaging was rarely useful. Conclusion: CE-PD increased the characterisation accuracy of ultrasound only in selected cases while it is not cost-effective if employed routinely. These patients can usually be predicted on a clinical-sonographic basis allowing selective CE-PD imaging to be performed. Purpose: To define and quantify acoustic parameters in order to characterize liver histopathologic findings in patients presenting with chronic hepatitis type C using a commercially available ultrasound system. Materials and methods: 78 patients with a chronic hepatitis type C were prospectively enrolled. Cineloops from the liver and the spleen were acquired using an ATL HDI 5000 unit (ATL-Philips, WA, USA). Raw data were transferred to a PC for quantification with HDI Lab, a software that eliminates the effects of the nonlinear B-mode map. Two parameters were calculated using a linear time gain compensation: the liver and spleen attenuation coefficients (respectively LAC and SAC), and the signals of a region-of-interest (ROI) located at 6 cm depth (mean and SD, linear units). All results were correlated to the results of the liver biopsy (Knodell and Metavir score). Results: LAC was higher than the SAC in all cases. LAC and the normalized AC (LAC − SAC) was significantly higher in cases of cirrhosis (p < 0.01). The signal intensity from the ROI was not correlated to the histological findings. The standard deviation increased in cases of cirrhosis due to the heterogeneity of the echostructure. Conclusion: Quantitative ultrasonography is feasible in routine practice and can improve the stadification of cirrhosis due to chronic hepatitis type C.

Evaluation of reformatted image quality using a new 3D imaging tool for ultrasound multiplanar reconstruction M.J. O'Neill, S.I. Lee, J.F. Simeone, P. Mattos, J. Haase, P.R. Mueller; Boston, MA/US Purpose: VirtualProbe® (IôDP, Paris) is ultrasound acquisition and post processing software that uses an electromagnetic field to acquire positional data, allowing retrospective multiplanar 3D rescanning through a volume of tissue. The aim of this study was to compare image quality of the 2D movie clips used for volume rendering and the 3D reformatted images to that of conventional 2D images. Methods and materials: 30 patients referred for exams of the kidney (9) and abdomen (21) were enrolled. Each patient had a conventional ultrasound exam, followed by the VirtualProbe. The static images, 2D movie clips, and 3D reformatted images were then graded by 2 radiologists on a 5 point scale (1 = best quality and 5 = worst). The difference between either the 2D clips or 3D reformats and the static images for right and left (28) kidney (58) liver (21), pancreas (21), CBD (21), spleen (20), gallbladder (18), and bladder (9) , for the static images, 2D clips, and 3D reformats. There was no significant difference in image quality for 2D movie clips or 3D reformats when compared to standard images. Ratings when compared to the static images yielded p values ranging from 0.4 to 1.0 and 0.1 to 1.0 for 2D clips and 3D reformats.

There is no significant difference in image quality between static ultrasound images, 2D movie clips, and reformatted multiplanar reconstructions when using the VirtualProbe® post processing software. 

PIm 3 minutes after iv injection of Levovist (2 g, 300 mg/ml). PIm examinations were analysed in consensus by two radiologists who assessed the number of lesions, the conspicuity of lesions on a scale 1 -4, and the smallest lesion diameter in comparison with baseline US. CT studies were performed using a multidetector CT scanner with 130 cm 3 of a non ionic contrast agent (400 mg I/ml) at a flow rate of 4 ml/s. Scans were acquired at 35 scan delay for the hepatic arterial phase, 70 s scan delay for the portal venous phase and 120 s for the delayed phase, with a collimation of 4 × 2.5 mm and a slice thickness of 3 mm. All CT scans were evaluated in consensus by two experienced radiologists blinded to the results of US analysis. Results: PIm improved the conspicuity and the detection of lesions in comparison to baseline US (43 % increase) and to MSCT (13 % increase). In comparison with MSCT, the number of lesions detected with PIm increased from 60 to 69; the improved detection rate was limited to lesions less than 5 mm in diameter and to non-cirrhotic patients.

Conclusions: Pulse inversion mode may depict more lesions than MSCT although patients with very inhomogeneous liver parenchyma can represent a limit. 

Performance of a digital flat-panel detector system in the detection of subtle rib fractures: A comparison with a conventional screen-film system and a phosphor-storage system at different levels of exposure K. Ludwig, C. Schuelke, H. Lenzen, T.M. Bernhardt, S. Diederich, D. Wormanns, P. Brinckmann, W.L. Heindel; Münster/DE Purpose: To compare a digital flat-panel detector in the detection of subtle rib fractures with conventional screen-film radiography and phosphor-storage radiography at different levels of exposure. Method/materials: Subtle fractures were created in 100 of 200 porcine rib specimens. Specimens were mounted into a basin filled with water to obtain absorption and scatter radiation conditions comparable to a human chest. Imaging was performed using a flat-panel detector system, screen-film system and phosphor-storage system. Exposure settings comparable to clinical imaging were applied (77 kVp, S = 400). Additional imaging was performed with both digital imaging modalities at lower exposure doses: With the flat-panel detector images were acquired at exposure doses corresponding to speed-class 800, 1600 and 6400, with the phosphorstorage system to 800 and 1600. For each image the presence/absence of a rib fracture was assessed independently by three radiologists according to a five level confidence scale. ROC-analysis was performed for a total of 5200 observations (600 for each imaging modality/exposure level). Multivariate analysis was used to compare AUCs. Introduction: New digital imaging techniques offer the ability to adjust the radiation dose required to answer the clinical question. Irrespective of the type of imaging technique, the lowest dose compatible with the required image quality should be used. Material and methods: A comparative study was performed with three units for storage phosphor and a flat detector unit. Image quality was evaluated by a contrast detail radiography phantom (Nuclear Associates: Digirad). This was completed by further studies using phantoms containing anatomical structures. Clinical images and doses were also evaluated by 5 European centres for radiology and medical physics that co-operate within the DIMOND-3 EC project. Results: The images of the Digirad Phantom demonstrate differences in the image quality of storage phospor systems, but flat panel detector technology showed far the highest image quality. For the flat panel detector radiation dose can be decreased significantly in comparison to storage phosphor systems. Using flat panel detectors all examinations can be performed with a maximum of halve the dose compared to storage phosphor systems, operated at a 400 speed class. Further dose reduction by a factor of 4 is possible for specific examinations. Conclusion: Dose mangement with new digital imaging techniques can decrease radiation dose to the patient significantly. In a broad range dose and image quality can be optimized and adapted to the clinical question.

Performance of a digital flat-panel detector system in the detection of simulated rheumatoid erosions: A comparison with a conventional screenfilm system, a mammography-system and a phosphor-storage system at different levels of exposure K. Ludwig, A. Henschel, H. Lenzen, T.M. Bernhardt, D. Wormanns, W.L. Heindel; Münster/DE Purpose: To compare a flat-panel detector system in the detection of simulated rheumatoid erosions with a screen-film system, mammography system and phosphor-storage system at different levels of exposure. Method/materials: 320 artificial lesions (diameter 0.5 -1.2 mm, depth 1.5 mm) simulating erosions were created in 640 predefined regions in the MCP-and PIPjoints of 20 monkey paw specimens. Specimens were enclosed in containers with water for absorption/scatter conditions comparable to a human hand;Imaging was performed at 44 kVp using a digital flat-panel detector system with exposure-doses corresponding to speed-class (S) 25, 100, 200, 400, 800, 1600, 3200 system, a phosphor-storage-system at (S) 200, 400, 800, 1600, a speed-class 200 screenfilm system and a mammography system. Three radiologists independently evaluated each region for the presence/absence of a lesion according to a five level confidence scale. ROC-analysis was performed for 16.224 observations (1248 for each imaging modality/exposure dose). Multivariate analysis was used to compare AUCs. 

In erosive lesions the flat-panel system is superior to conventional screen-film radiography and phosphor-storage radiography at clinical exposure settings. It offers the same diagnostic performance with a lower exposure.

Reference levels during interventional cardiology procedures: The European DIMOND experience V. Neofotistou; Athens/GR Purpose: To present the European DIMOND approach in defining Reference Levels (RLs) for radiation doses delivered to patients during Interventional Cardiology (IC) procedures, namely Coronary Angiography (CA) and Percutaneous Transluminal Coronary Angioplasty (PTCA). RLs have been suggested by the Council Directive of the European Community 97/43/Euratom as a means of optimising diagnostic exposures. Method: During the DIMOND (Digital Imaging: Measures for Optimising Radiological Information Content and Dose) european research program patients' doses during IC procedures were measured. This was done in terms of dose-area product (DAP), fluoroscopy time and total number of radiographic exposures. Values were obtained in three participating European hospitals, using previously checked X-ray equipment and according to a commonly agreed protocol. Moreover, a DAP trigger level has been defined in order to prevent skin injuries since IC techniques are known to be associated with high radiation doses and thus deterministic effects may be observed. Results: RLs for DAP equals 60 Gycm 2 and 100 Gycm 2 , for fluoroscopy time 6.5 min and 20 min and for number of frames 1000 and 1400 for CA and PTCA respectively. DAP trigger level for cardiac procedures, which should alert the fluoroscopist for probable skin injury, equals 300 Gycm 2 .

The proposed values, which should be considered only as interim RLs, take no account of the complexity of particular case or patient's physical characteristics DIMOND RLs are being updated with patient doses measurements taken in seven European countries and with degrees of tolerances assigned to complexity of procedure as well as the patient's size.

Optimized spectrum in direct digital mammography W.J.H. Veldkamp, N. Karssemeijer, R.E. van Engen; Nijmegen/NL Purpose: The objective is to find the optimum target-filter and kilovoltage for varying simulated breast thicknesses when using a flat panel full field digital mammography detector (GE Senograph 2000D).

We use the CDMAM phantom that was developed at our institute. This phantom consists of a matrix of squared cells with dots of varying size and contrast. Each cell contains two dots, one in the center and one in a Scientific Sessions Sunday B A C D E F 233 randomly selected corner. A computer program was used for automatic readout of the phantom recordings. The program uses the ideal observer model for detecting the dots. Image quality is expressed by the contrast detail curve relating object size and contrast at some fixed detection threshold. To cover a range of exposure conditions and breast thicknesses a total of 288 recordings were evaluated. The glandular dose was kept constant for each simulated breast thickness while spectrum parameters were varied. Results: Results showed that for 7 cm perspex the Rh-Rh target-filter combination gave superior image quality compared to Mo-Rh and Mo-Mo. For 3 and 5 cm perspex the different target filter combinations gave comparable image quality.

The results suggest that in full field digital mammography a Rh-Rh target-filter combination can be used for the whole range of breast thicknesses.

An investigation of the observer variability in reading a contrast detail test object in digital mammography P. . Images were printed on high resolution printers. A CDMAM contrast detail phantom 3.2 (Nijmegen, The Netherlands) was placed on top of 4 cm of polymethyl methacryllate. Images were read by a group of experienced observers within the DIMOND III EC project. Optimal viewing conditions in respect of viewing box brightness and ambient light level were used. Image scores were analysed using a computer program which incorporated the rules for interpreting images. Results and discussion: Contrast-detail curves and image quality factors could be calculated for the different observers and images. Observer variability was compared with theoretical predictions and some readings from conventional mammography images. Image quality factors were low, meaning that low contrast differences and small objects could be distinguished. The variability of the readings was large, but tolerances were similar in all observers. Therefore, we propose to also acquire typical CDMAM images from digital mammography systems as part of an acceptance testing programme.

First clinical experience of a digital slot-scanning-area detector for mammography T. Francke 1 , J. Egerström 2 , M. Eklund 2 , L. Ericsson 2 , T. Kristoffersson 2 , V. Peskov 1 , J. Rantanen 2 , S. Sokolov 1 , P. Svedenhag 2 , S. Thunberg 2 , C. Ullberg 2 , N. Weber 2 ; 1 Stockholm/SE, 2 Danderyd/SE Purpose: To compare image quality and dose for a novel digital slot-scanning area detector vs. conventional analogue film-screen images.

The design of the detector, photon counting and small detector width of 50 mm, results in a very high image quality (high resolution and high contrast) at a low dose. The avalanche gaseous photon counting technique, allows for virtually scatter free and noise free images, resulting in very high signalto-noise ratio. This new detector has been mounted on a commercially available mammographic unit (Mammomat 3000, Siemens). The digital images taken with the instrument are compared to analogue film images, where the beam quality (kVp and anode/filter combination) as well as projections has been kept the same to allow a true comparison. Results: A full field mammographic digital detector, 19 × 24 cm, based on a slotscanning-area technique with photon counting gaseous detectors has been evaluated. The performance of the detector has been studied and compared to analogue film-screen system by imaging phantoms, breast specimens and patients. The results are very promising, compared to conventional film-screen images, regarding image quality and a significant dose reduction. Conclusions: Noise-free photon counting is a promising method for digital X-ray imaging, improving image quality as well as significant reducing the glandular dose to the patient.

First considerations regarding an acceptance protocol for full field digital mammography equipment: Validation in a multicenter setting F. Rogge 1 , A.-K. Carton 1 , H. Bosmans 1 , E. Vano 2 , P. Torbica 3 , A. Crevecoeur 4 , Y. Palmers 5 , K. Faulkner 6 , G. Marchal 1 ; 1 Leuven/BE, 2 Madrid/ES, 3 Innsbruck/AT, 4 Liège/BE, 5 Genk/BE, 6 Newcastle upon Tyne/GB Purpose: The introduction of full field digital mammography equipment requires the development of acceptance testing protocols. We have reviewed the current European protocol for quality control in (conventional) mammography within the DIMOND-3 EC project and we propose a similar series of tests for digital systems. Methods and materials: Following tests had to be redefined: the assessment of the focal spot size, different tests of the automatic exposure control and tests of the detector including the grid. Image quality was evaluated via phantom exposures and DQE measurements. The protocols were tested on 3 digital Senographe DMR systems (GE) and on 1 digital Fuji detector. Results and conclusion: All the tests included in the revised acceptance protocol may be completed in under 4 hours. The performance of the three systems was very stable. The doses for standard exposures were variable between the different sites. This has an impact on image quality. Since the dose setting for a digital detector is a parameter of the X-ray system only (independent of any filmscreen combination) that can be freely adjusted in the different centers, we propose to use a quite strict guidance regarding the standard dose settings. A difficult practical problem is the transfer of data in order to perform some evaluations offline. Further cooperation with the manufacturer may be needed to make this type of testing feasible for hospital medical physicists.

Interventional Radiology Purpose: Percutaneous CT guided biopsy is an accurate and safe procedure to evaluate indeterminate adrenal masses in oncologic patients. We sought to assess the clinical outcome in patients with negative percutaneous needle biopsies of focal adrenal lesions Materials and methods: Retrospective analysis of 225 oncologic patients (F:M, 138:87; age range 33 -87 years, mean age 66 years) who had undergone CT guided FNA biopsies of an adrenal mass over a 5-year period were reviewed. The incidence of negative (for tumor) biopsy results were identified and assessed for subsequent evaluation of the biopsied lesion in these patients Results: Of the 225 biopsies, 41 (18 %) were negative for neoplasm. The primary neoplasm in these 41 patients included 32 lung cancers, 1 bladder, 1 prostate, 5 breast and 2 renal malignancies with the size of the adrenal lesion ranging from 2.8 -5 cm. Of these 41 biopsies negative for tumor; 10 were identified as adenomas and the rest showed benign adrenal cortical cells or hyperplasia on cytopathology and histopathology. An experienced pathologist interpreted all specimens as sufficient for diagnosis. Repeat biopsies were obtained in 13/41 (31 %) patients; whereas 2/41 (5 %) had the adrenal glands analyzed on post mortem examination. None of these 15 repeat evaluations yielded tumor Conclusions: A negative or normal pathology result in a CT guided percutaneous adrenal biopsy can be regarded as a true negative evaluation in oncologic patients with no necessity to repeat the biopsy. 

A C D E F 234 Materials and methods: In 54 patients (32 liver tumors and 22 different abdominal tumors) MR-guided biopsies or punctures were performed with a low field MRI (0.2 T, Magnetom Open, Siemens). For guidance of the needles, T1-weighted FLASH sequences (TR/TE 100/9; 70°) were performed in all patients and an additional FISP-Rotated-Keyhole-sequence (TR/TE 18/8; 90°) was also used. After positioning of the needle tip in the tumor, 82 biopsy specimens were acquired with 14 -16 G cutting needles (Somatex®) during the interventional procedures. The visibility of the needles, the tumors and the abdominal vessels were evaluated. Results: All interventional treatments were performed without vascular or organ injury. Adequate specimens for histological interpretation were obtained in 47 cases (87.0 %). In 3 patients (5.6 %) the biopsy result was non-specific and in 4 patients (7.4 %) the lesion was missed. T1-weighted FLASH images were useful for confirming needle-tip placement during the biopsies or punctures. The use of free slice orientation facilitated the interventional procedure. The organs, tumors and vessels were easily determined. The FISP sequence resulted in equal or inferior results. Conclusion: MR-guided abdominal interventions can be performed with acceptable safety and accuracy with low field systems. Lesion and needle visibility are significantly affected by user-defined parameters which must be considered during procedure planning. Materials and methods: Over 4.3 years, 1120 biopsies were carried out under CT-fluoroscopic control (Philips AVEU and Toshiba Aquilion) in the lung (33.6 %), mediastinum (6.6 %), abdomen (26.6 %), pelvis (7.5 %), retroperitoneum (11.8 %) and varia (14 %). In 867 cases, the obtained material was sent to pathology. 88 % (761) provided material for cytology, 48 % (413) for histology. A pathologist was on-site and decided, by means of a quick staining procedure, whether further tissue removal was necessary. The primary tumour was known in 403 cases. The number of punctures, unsuccessful biopsies, positive and negative results (classified according to biopsying examiner and location), differences between histology and cytology and complications were analysed. Results: On average, 1.6 punctures were performed to complete the procedure. 2 tissue samples for cytology were obtained in 181 cases (21 %). The overall sensitivity for cytology and histology was 97 % and 96 %, respectively; 93 % and 97 % with known primary; 99 % and 95 % with unknown primary. In 83 (0.1 %) and 26 (0.03 %) of cases, no diagnostic material was obtained with cytology and histology, respectively, although the on-site pathologist assumed that sufficient material was present. Benign lesions were found in 163 cases (18.8 %), 45 biopsies were unsuccessful (5.2 %). One less experienced examiner yielded only 61 % sensitivity. Overall, complications occurred in 43 patients (5 %). Conclusions: CT-fluoroscopy-guided biopsy represents a safe and reliable technique with a high sensitivity for malignancy and minimal difference between cytology and histology. The examiners experience plays a decisive role in the diagnostic outcome. 

The device used (Pin Point*) is integrated into a Multisclice CT (Mx8000, *Marconi Medical Systems). It uses a laser assisted proprietary articulated arm technology and displays corresponding multiplanar CT images as the computer assisted arm is manipulated along the patient's body. The system includes an intuitive virtual planning tool that allows simulation of the best instrument path from the entry point to the target area. 50 biopsies of masses in 50 patients were carried out. All biopsies were obtained using an 18 or 20 gauge high speed tru-cut biopsy gun. Masses biopsied included lung (25), lymph nodes (8), bone (10) and pelvis (7). An average of 2.5 passes was performed. Results: Using this system interventions could be confidently planned and safely carried out even in difficult or risky areas in all 50 cases. However, due to respiratory motion there are some limitations, particularly with lung lesions. Mean proce-dure time was 8 min ± 10 min. In 95 % of the cases biopsies were diagnostic. After central lung biopsy 1 of 4 patients with pneumothorax required a chest drainage. 2 cases with haemoptysis resolved with conservative treatment. Conclusion: The evaluated simulation and virtual planning system is safe, quick and convenient for CT-guided biopsies with some limitations due to respiratory motion. It may also become a useful tool for additional CT-guided therapeutic procedures.

Evaluation of age-related risk profiles for pneumothorax in CT-guided percutaneous thoracic biopsies B. Rapprich 1 , T. Werba 1 , R. Tomczak 2 , N. Rilinger 1 ; 1 Offenbach a. Main/DE, 2 Bad Friedrichshall/DE Purpose: In studies of patients undergoing percutaneous thoracic biopsies, the risk for pneumothorax has varied from 2 -61 %. Our aim was to develop a risk profile for pneumothorax based on the severity of pneumothoraces and in correlation with age and the presence of emphysema. Methods and materials: We retrospectively investigated outcomes of 133 patients with CT-guided thoracic biopsies using an 18 G coaxial cutting-needle with a high-speed-automatic system (biopty Bard). Pneumothorax was graded as: I minimal, local; II < 1 cm; III > 1 cm; IV chest tube required. Emphysema was graded as: I discrete; II moderate; III extensive. Results: 97.7 % of the biopsies in 133 patients were successful. The diagnostic sensitivity was 94 % and the incidence of pneumothorax was 30.1 % (grade I: 17.3 %; II: 5.3 %; III: 3.8 %; IV: 3.8 %). For younger patients the risk of severe pneumothorax (Grade III or IV) increased linearly. The degree of emphysema did not correlate with the incidence of pneumothorax. Conclusion: The pneumothorax risk for elderly patients decreases in transthoracal CT guided automated high-speed cutting-needle biopsies. The incidence of severe, clinically relevant pneumothoraces increases linearly in younger patients. The linear correlation is caused by morphological and functional linear changes due to the regular aging of the lung. No correlation with pathological emphysema was found. Purpose: The aim of this study was to examine the feasibility of percutaneous drainage of abdominal fluid collections using a MRI-compatible drainage system. Material and methods: In 6 patients drainage procedures were performed with MRI-compatible drainage systems (Somatex®) for the interventional treatment of abdominal fluid collections). For all procedures a low field MR-system (0.2 T, Siemens) was used. The punctures were controlled using T1-weighted FLASH sequences (TR/TE 100/9; 70°) and a FISP-Rotated-Keyhole-sequence (TR/TE 18/8; 90°). After positioning of the catheter in the fluid collection, the topographic details were controlled with intracavitary injection of an aqueous gadolinium solution (dilution 1:200). Results: All drainage catheters were successfully placed into the fluid collections under MR-guidance. The catheter position was easily visualized with the T1weighted FLASH sequences. Using the FISP sequences the visibility of the catheters was good or moderate and also useful for MR-guidance. No procedure-related complications occurred. The mean time needed for the drainage procedure was 30 min ± 15 min. The fluid collections were drained for a mean of 12 days. The topic of the study presented here is the evaluation of the feasibility and acceptance of repeated ultrasound-guided lymph node puncture for vaccination.

We performed 548 ultrasound-guided punctures of inguinal lymph nodes in 58 patients with proven malignant melanoma and biopsy confirmed metastases of the disease. We delivered a suspension containing antigen pulsed dentritic cells, under ultrasound view, directly into the lymph node's paracortical area. To visualize the procedure we used a high-resolution computed ultrasound system (Sequoia 512) with a 13 MHz linear array probe. The tip of a 20 G needle was placed into the paracortical area of the node, and application of the suspension was performed under ultrasound view. Results: Normal-sized, morphologically unsuspicious lymph nodes were found in every patient during every procedure. Major side effects were not observed; we merely noticed fever in 1 patient, painful swelling of the punctured lymph node in 3 patients, and newly occurring vitiligo in 10 patients. The immunological results of our therapy are still under evaluation. Conclusion: Ultrasound-guided intranodal vaccination is a reliable and reproducible technique to deliver antigen-pulsed dentritic cells into peripheral lymph nodes. The method is well accepted by patients. It could lead to changes in the therapeutical options of both malignant and infectious diseases.

Slowly-heparin-releasing drainage catheter: In vivo and in vitro assessment of clog-resistant effect J. Han, K. Lee, B.-I. Choi, C. Yoon, Y. Byun, H. Moon; Seoul/KR Purpose: Clogging of catheter is frequently encountered during various drainage procedures. We evaluated the effectiveness of a novel clog-resistant drainage catheter.

We have recently developed slowly-heparin-releasing catheter by coating standard drainage catheter with the blend of amphiphilic heparin-derivative (heparin-deoxycholic acid) and polyurethane. In vitro fibrin formation test was performed by dipping heparin-coated catheter and non-coated catheter (as control) into fresh plasma for 60 minutes, and the results were interpreted using scanning electron microscopy. For in vivo assessment, eight pairs of coated and control catheters (8 French) were inserted into the peritoneal cavity in normal New Zealand White rabbits (n = 8). Applying a basic principle in flow dynamics (resistance = pressure/flow rate), intra-catheter pressure was measured at the plateau (Pmax) during saline infusion in constant rate (0.1 ml/s) and Pmax was followed up for 14 days to estimate the changes in effective caliber. Results: On in vitro assessment, no fibrin formation was observed in heparincoated catheter compared to strong reaction in control catheter. On in vivo assessment, decrease in mean effective caliber was 1.7 % vs. 7.5 % (coated vs. control) at 3 rd day (p = 0.14, paired t test), 4.8 % vs. 12.5 % at 7 th day (p = 0.059), 6.5 % vs. Palermo/IT Purpose: Hepatic artery stenosis and thrombosis are common complications in liver transplant patients. Digital subtraction angiography (DSA) has served as the gold standard to make this diagnosis. More recently, three dimensional helical computed tomographic arteriography (3D CTA) with maximum intensity projection and shaded surface display techniques has been compared with DSA. The purpose of this study is to determine if 3D CTA with volume rendering technique is a useful and accurate tool in the detection of vascular complications after liver transplantation. Methods: 35 consecutive liver transplant patients underwent 3D CTA with volume rendering technique. The standard of reference was DSA for 20 patients and imaging and clinical follow-up for 15 patients. Two blinded reviewers evaluated the axial and 3D CTA images in consensus. Results: 3D CTA with volume rendering technique detected 10 hepatic artery stenoses, six hepatic artery thromboses, two hepatic artery pseudoaneurysms, two splenic artery aneurysms, two portal vein stenoses, and four redundant hepatic arteries. In one case CT detected a moderate hepatic artery stenosis, while conventional angiography showed a normal artery. The sensitivity of CT for detecting vascular lesions was 100 %, specificity 89 % (8 of 9), accuracy 95 % (19 of 20), positive predictive value of 92 % (11 of 12), and negative predictive value of 100 % (8 of 8). Conclusions: 3D CTA is a useful and accurate noninvasive technique for detection of vascular complications in liver transplant patients.

Evaluation of an "all-in-one" multidetector-CT protocol for potential living liver donors T. Schroeder, M. Malagó, S. Heistrüvers, S. Nadalin, J. Stattaus, J.F. Debatin, S.G. Rühm; Essen/DE Purpose: To evaluate an "all-in-one" multidetector-CT-approach for evaluation of potential living related liver donors. Materials & methods: 21 consecutive potential living donors of the right lobe of the liver (mean age 32 years) underwent three-phase, dual-enhancement multidetector-CT imaging to delineate biliary, vascular and parenchymal morphology. For display of the biliary system the first CT-image set was collected 25 minutes following the infusion of 100 ml of a biliary contrast agent (Biliscopin). Subsequently CT (slice thickness/collimation 1 mm, pitch 4 mm, table-speed 12 mm/s) was performed for display of the arterial as well as the portal and hepatic venous systems, following automated injection of 140 ml of an iodinated contrast agent (Imeron 350). Analysis was based on source images and multiplanar reformats. The hepatic parenchyma was assessed for the presence of pathologies and volumetry was based on the venous data set. Results: All potential donors tolerated the exam well. The 'in-room' time for the exam ranged between 7 and 12 minutes. One hemangioma and one adenoma were identified. Total liver volumes ranged between 1040 and 1716 ml. The underlying biliary and vascular anatomy was displayed at least to the second intrahepatic branch in all cases. Anatomic variations were observed involving the biliary system (n = 16), the arterial system (n = 13), the portal system (n = 5) and the venous system (n = 6). Conclusion: The outlined approach proved efficient and robust. All relevant pre-op data for potential living related liver donation was collected in one single diagnostic step.

Ischemic-type biliary lesions following liver transplantation: Evaluation with MR cholangiography P. Boraschi, R. Gigoni, L. Urbani, E. Neri, F. Filipponi, C. Bartolozzi, F. Falaschi; Pisa/IT Purpose: To assess the diagnostic value of MR cholangiography (MRC) when evaluating ischemic-type biliary lesions (ITBL) in the follow-up of liver transplant patients.

We retrospectively reviewed MR imaging and MRC of sixteen liver transplanted patients (13 men, 3 women) with ischemic changes of the biliary tree. The MR examinations were performed on a 1.5 T unit (Signa, GE Medical System) with high performance gradients. After the acquisition of axial T1w and T2w sequences, MRC involved a coronal, non breath-hold, respiratorytriggered, fat-suppressed, two-dimensional, thin-slab, heavily T2w fast spin-echo sequence, and a coronal breath-hold, thick-slab, single-shot T2w sequence. Ten patients underwent either surgical reconstruction of the biliary system (n = 4) or liver retransplantation (n = 6); the pathologic specimens were employed as standard of reference. The final diagnosis was obtained through direct cholangiography in the remaining cases. Without knowledge of the surgical, pathological and cholangiographic findings two experienced observers evaluated in conference the MR images to determine the presence of biliary tract abnormalities. Results: MRC demonstrated strictures involving the hepatic bifurcation and extrahepatic pre-anastomotic bile duct with concomitant thickening of the biliary wall in 13 patients; sludge or stones were present in 7 out of these patients. In the other 3 cases with circumscript extrahepatic lesion, MRC clearly showed intraductal sludge and/or biliary tract dilation above the non-anastomotic stricture, but direct cholangiography was more precise in determining the length of the stricture and grading the stenosis. 

We retrospectively reviewed Doppler US images of the HV in 113 consecutive patients who underwent LRLT. Doppler US was performed between 1 and 25 times (mean, 5.2 times) during 1 -433 days after LRLT. Nineteen patients who were excluded for analysis of HV stenosis from various causes (early postoperative death, etc). Patients who had more than 10 mmHg of pressure gradient between the HV and the inferior vena cava during the procedure of HV stenting were considered to have significant HV stenosis. The control group included patients with no evidence of HV stenosis at least 3 months after LRLT. Spectral Doppler US findings between the two groups were compared. Results: Five patients (4.4 %) had significant HV stenosis, and three of them showed persistent monophasic waves on Doppler US whereas two patients showed monophasic waves on most of US examinations and a biphasic or a triphasic waves on 6-and 9-day follow-up. In control group (n = 89), 52 patients with persistent tri-or biphasic waves and 35 with mixed monophasic wave with tri-or biphasic wave according to the follow-up period of US examinations, and 2 showed persistent monophasic waves. Conclusion: Persistent monophasic waves on Doppler US in the hepatic vein is a suggestive, but not a specific finding to be significant HV stenosis after LRLT. Persistent triphasic waves on Doppler US can confidently exclude significant stenosis.

3D CT angiography using multidetector row helical CT in the preoperative assessment of arterial supply to the liver G. Brancatelli 1, 2 , M.P. Federle 1 , V. Kapoor 1 , D.A. Geller 1 , J.J. Fung 1 ; 1 Pittsburgh, PA/US, 2 Palermo/IT Purpose: To evaluate the usefulness of CT angiography (CTA) with 3D reconstruction to detect the arterial supply to the liver using a multidetector row helical CT. Methods and materials: Eighteen patients had CTA. Of these, 17 had surgical correlation, including 9 who also underwent conventional arteriography. The remaining patient had conventional arteriography only. Images were reviewed in cine mode on a PACS station with 3D volume rendered images. Axial CT sections and volume rendered images were prospectively reviewed by two blinded readers jointly. Results: All studies were technically satisfactory. CT angiographic findings were confirmed at surgery in 17/17 (100 %) patients (classical arterial anatomy, n = 11; replaced left hepatic artery (LHA) off the left gastric artery (LGA), replaced right hepatic artery (RHA) off the superior mesenteric artery (SMA) and accessory LHA to segment IV off the common hepatic artery (CHA), n = 1; replaced LHA off the LGA, n = 1; replaced CHA off the aorta, n = 1; replaced LHA off the LGA and replaced RHA off the SMA, n = 1; RHA, LHA and gastroduodenal artery off common hepatic as a trifurcation, n = 1; RHA off the coeliac trunk, accessory LHA to segment IV off the CHA, n = 1). Findings at CTA and conventional arteriography were concordant in 8/9 patients. In the single discordant case CTA depicted a RHA off the celiac trunk and an accessory LHA to segment IV off the CHA, but did not identify a LHA off the LGA. Conclusion: CTA is valuable in detecting the arterial supply to the liver allowing for precise surgical plannning. There are a number of sonographic features of posterior tibial tendinosis (PTT). One of these is an increase in posterior tibial tendon calibre. The aim of this study is to compare the posterior tibial tendon calibre in patients with PTT against a group of normal subjects by ultrasound. Methods: Patients with PTT were referred by the orthopaedic department for assessment of the posterior tibial tendon. Healthy asymtomatic volunteers were taken as normal subjects. The posterior tibial tendon was examined by high frequency ultrasound (at least 7.5 MHz, usually 10 -12 MHz). The cross-sectional area was measured at three points along each tendon whilst keeping the probe at a right angle to the course of the tendon as it runs behind and under the medial malleolus and then forward on to its insertion at the navicular bone. The reference points were behind the medial malleolus, below the medial maleolus and just proximal to the tendon insertion. Results: Over a four year period, 44 patients with uni-or bilateral PTT were examined. The tendon calibre was compared with measurements obtained from 100 normal subjects from which the mean and standard deviation values were determined. It was shown that the vast majority of those with symptomatic PTT had values greater than 2 standard deviations above the mean normal value at each reference level. Conclusion: Patients with posterior tibial tendinosis demonstrate an appreciably larger tendon calibre than normal subjects. This is a very helpful sign in the diagnosis of posterior tibial tendinosis.

Kinematic ankle MRI with a low field MRI system G. Dazzi, E. Silvestri, A. Iozzelli, F. Magnaguagno, G. Garlaschi; Genova/IT Purpose: To test the usefulness of kinematic ankle MRI performed with low field MRI equipment. Methods/materials: From January 1999 until February 2000 we examined 150 ankles using a 0.2 T MR system (ARTOSCAN, ESAOTE). 25/150 patients (n = 4 synovial anterior impingement, n = 6 osseous posterior impingement, n = 15 lateral ankle sprains) underwent kinematic evaluation. We obtained the adequate range of motion by moving the chair with the foot in a fixed position, so that the leg passes from a semiflexed to the fully extended position. In this way, the ankle moves from 90° dorsiflexed to 135° plantarflexed position. Kinematic examinations were performed on sagittal and/or axial planes using HSE T1w sequences. Results: We didn not identify significative findings in all cases of synovial anterior impingement. On the other hand, kinematic exams allowed a better evaluation of all patients with osseous posterior impingement. We directly visualized peroneal tendon instability in 3/15 cases of lateral ankle sprains. Conclusions: Kinematic ankle MRI, performed with a low field unit, is a simple and quick technique in the study of some ankle pathologies. In particular, it seems to be very useful to evaluate the biomechanical alterations of osseous posterior impingement and to demonstrate the presence of peroneal tendon instability which is often unrecognized and misdiagnosed. Purpose: The aim of this work was to assess MRI diagnostic accuracy in detecting pathological conditions which lead to tibio-talar joint (TTJ) impingement, using arthroscopy as the gold-standard. Method and materials: 21 patients (aged 19 -35 years) clinically complaining of ankle unsteadiness and swelling entered this study; 20 out of 21 patients referred to a history of ankle sprain. MRI examination was performed with both a 1.5 T whole-body (TSE T2-w and SE T1-w sequences) and a 0.2 T dedicated system (SE T1 and T2-w sequences). In 12 cases i.v contrast material was administered followed by SE T1-w sequences with fat saturation pulse. All the patients underwent arthroscopy. Results: MRI examination revealed the presence of TTJ synovial impingement in 9 patients and in only 4 of them the presence of contrast enhancement revealed acute inflammatory stage; arthroscopy always detected a thickened synovial lining. In 3 patients MRI examination showed the presence of tibio-peroneal tendon injury associated with synovial hypertrophy ("meniscoid syndrome"); in 1 of these cases contrast enhancement was evident. In 6 patients MRI examination documented the presence of a bony impingement due to talus and tibial osteophyte; in these cases arthroscopy confirmed MRI diagnosis. Three patients had a completely negative MRI examination, one of them showing a meniscoid syndrome on arthroscopy.

Conclusion: Because of a good correspondence with arthroscopic findings we may consider MRI very accurate in the diagnosis of different pathological conditions causing TTJ impingement. MRI is also able to detect extra-capsular causes of impingement. 

Forty patients affected by tibio-talar pain and swelling were submitted to plain films and to MRI using dedicated and whole body MRI units. In 21 of them history of a previous inversion ankle sprain was present. In five cases intra-articular injection of paramagnetic contrast media (5 -10 ml of contrast medium obtained from the dilution of 0.6 ml of Gd-DTPA in 250 ml of saline) was performed. CT scanning was performed in nine cases. All patients underwent surgery.

In 36 of the 40 cases arthroscopy confirmed the MRI findings. 25 examples of chondral disease were discovered by MRI with differing degrees of severity (6 low, 11 mild, 8 severe grade). In 3 of 6 low grade conditions, arthroscopy could not reveal the damage of the deepest aspect of the cartilage and subchondral drilling was performed on the basis of MRI findings. In nine patients arthroscopy confirmed CT and MRI evidence of osteochondritis dessicans. In the other 4 cases MRI and arthroscopy could not reveal any pathological condition. Conclusion: On the basis of our experience, MR has to be considered the gold standard in the study of TTJ cartilage allowing evaluation of its full thickness and of the subchondral bone. Subjects and methods: 63 patients with recurrent lateral derangement of the ankle were studied with CT and MRI. CT was performed with coronal acquisitions using a conventional equipment. MRI was performed with a superconductive scanner, and coronal and sagittal T1 and T2*w images. In 24 cases (selected group) no signs of alteration of both internal and external collateral ligaments were demonstrable. In these patient analysis of the angle between long axis of the tibia and major axis of subtalar joint (TS angle) was calculated and the appearance of the articular space of subtalar joint was also evaluated. Analogous measurement was done in a control group of asymptomatic patients Results: In 13 cases TS angle appeared acute; in 7 of them MRI demonstrated partial synostosis/synchondrosis of the subtalar joint. In 7 cases TS angle appeared highly obtuse and no signs of synchondrosis/synostosis were identifiable. In 4 cases no signs of alteration of the subtalar joint were demonstrable both at CT and MRI. To analyse the normal MR anatomy of the intermetatarsal space, with emphasis in the description of the intermetatarsal bursae and neurovascular bundles, using MR imaging, MR bursography, as well anatomic and histologic correlation in cadavers.

High resolution MR imaging of 32 intermetatarsal spaces derived from fresh human cadaveric feet was performed. The 4 intermetatarsal bursae were injected, and MR imaging were performed. T1-weighted and fat saturated T1-weighted spin echo sequences were performed in the 3 orthogonal planes. The intermetatarsal space anatomy was analysed. Histologic examinations were performed.

The intermetatarsal spaces were located in the forefoot, between two metatarsal heads, below and above the deep transverse metatarsal ligament (DTML) that divided them in two levels. The superior levels contained the synovial bursa, the interosseous muscles and tendons, and the collateral ligament complexes of the metatarsophalangeal joints, while the inferior levels contained lumbrical muscles and neurovascular bundles. One case presented a Morton's neuroma. MR bursography improved the visualization of the structures of the superior level. The bursae extended distal to the DTML in the second and third spaces close to the neurovascular bundles and did not extend beyond the DTML in the first and fourth spaces. Objective: Plantar fibromatosis is an uncommon benign condition manifested by proliferation of fibrous tissue within the plantar fascia. As opposed to plantar fasciitis which affects the calcaneal insertion, plantar fibromatosis affects the mid-to forefoot region of the plantar fascia. Methods: Over a four year period, 10 patients (8 females; 2 males, average age 54.8 years) with clinically suspected plantar fibromatosis were examined by ultrasound 13 MHz (Siemens Sonoline) or 12 -5 MHz (ATL HDI 5000) linear array transducers.

Results: Plantarfibromatosis was seen as a discrete fusiform-shaped nodular thickening of the plantar fascia removed from the calcaneal insertion. Of the 12 patients examined, 8 (66 %) had unilateral disease while 4 (33 %) had bilateral disease. Of the 16 affected feet, a single site of fibromatosis was present in 9 (56 %) feet with two or more sites in 7 (44 %) feet. Of the 25 discrete foci of fibromatosis, 22 (88 %) were hypoechoic to the plantar fascia and 3 (12 %) were isoechoic. The fascial margin was well-defined in 12 (48 %) and ill-defined in 13 (52 %). 2 of the 25 lesions (8 %) showed mild internal vascularity. No correlation was found between the ultrasound appearances and the chronicity of patients symptoms. 15 (60 %) of lesions were located in the midfoot while 10 (40 %) were located at the forefoot. 17 (68 %) were located medially in the fascia while 8 (32 %) were located centrally. Conclusion: This is the first reported series detailing the ultrasound appearances of plantar fibromatosis. While the ultrasound appearances are variable, they are still characteristic enough to allow a specific diagnosis in all cases. Purpose: Spontaneous involution of lumbar disc herniation in patients treated with conservative therapy is reported in up to 70 % of cases. The aim of our study was to evaluate any eventually predictive signs on MR imaging of disc herniation involution. Methods and material: 65 patients, affected by 72 lumbar disc herniations, entered a perspective study. MRI examinations were performed on 1.5 T magnet, using sagittal and axial T1w SE sequences before and after contrast administration, and FSE T2w ones on the same scan planes. Patient age, sex and level and size of disk herniation, clinical onset interval, type of herniation, T2-w signal intensity and pattern of contrast enhancement had been registered. All the patients, conservatively treated, underwent clinical and MRI follow-up after 6 months: disc herniation size and contrast-enhancement variations were re-evaluated. Results: MRI follow-up showed herniation regression in 66 % cases. Extruded disk with high signal intensity on T2w sequences regressed in 83 % of cases. The same percentage of regression was registered in enhancing cases. Free fragments disappeared in all cases. Rest in bed for at least 15 days resulted to be a significant factor for a favorable evolution of acute disk herniation. No relationship was found with side, size, level. Conclusion: MRI features seems to have a significant meaning in assessing spontaneous tendency on herniation involution, thus furnishing additional prognostic value.

The role or MRI and MRA in diagnoses of cervical spondilotic myelopathy V.P. Marchuk 1 , A. Chernenko 2 ; 1 Vitebsk/BY, 2 Minsk/BY Purpose: There are three important pathophysiologic factors in the development of cervical spondylotic myelopathy (CSM): static and dynamic mechanical spinal cord compression, spinal cord ischemia. This study was performed to analyze the role of combination MRI and MRA in patients with CSM. Materials and methods: 121 pts were examined on a 1.0 T Picker Vista unit -18 healthy subjects, 50 pts had signs of discogenic radiculopathy and neuroreflected disorders (I), 53 pts had signs of cervical spondylotic myelopathy (II). MRA was carried out in coronal projection, oriented perpendicular to the direction of blood flow of RA (TR/TE 40/12.5, 256 matrix, 2DFT ToF, MAST, overlap 0.5 mm). MR investigation included standard protocol.

The difference in groups were mainly obtained in the evaluation of the number of radicular arteries branches (RA) -more than 3 branches were visualized (+) or were not visualized (-); and spine cord compression (C) -present (+) or absent (-). Combination (RA+ C-) for healthy group displayed in 100 %, for I group in 52.8 %, II group in 16.73 %. Combination (RA-C+) for I group 11.1 %, for II group 40.47 %.

The spinal cord damage and CSM arising from inadequate blood passage in RA branches and spine compression were increased twofold in cases of combination (RA− C+). The MR technique allows these complications to be revealed simultaneously and serves as a basis for appropriate treatment. Material & methods: 20 patients who suffered from radiation myelopathy were examined by MR. Patients underwent radiotherapy with total dose of 40 -44 Gy and irradiation was performed in two series, with one month time interval between them. Radiotherapy was performed in patients with bronchial carcinoma (14 patients) and malignant lymphoma (6 patients). Examinations were performed on 1.5 T MR imager using a surface coil. The protocol included T1w and T2w sagittal images, T1w and T2w axial images and images after application of Gd DTPA. Results: Clinical signs of radiation myelopathy appeared 6 -18 months after radiotherapy. Symptoms included weakness of lower limbs and paresthesia. MR examination revealed abnormally decreased signal on T1W images, increased signal on T2W images, focal contrast enhancement and spinal cord enlargement. Cord enlargement was detected in 19 patients while in 1 patient spinal cord atrophy was found. Radiation-induced abnormal high signal intensity was presented in cervical and thoracal vertebral bodies due to fatty replacement of bone marrow with sharp boundary corresponding to the radiation field. Conclusion: MR is easy, safe and valuable imaging method in diagnosis and differential diagnosis of radiation myelopathy. Then we performed contrast-enhanced sagittal T1-weighted scans after i.v. administration of Gadolinium-DTPA (Magnevist, Schering, Germany). When we recognized these features with MRI, the exam was completed with axial scans using the same sequences. All the patients underwent lumbar puncture within 2 days of the MR examination. Results: In 10 patients MRI was positive. We detected diffuse sheet-like infiltration of the arachnoid membrane or neoplastic coating of the conus and cauda equina to nodular deposition throughout the subarachnoid space. The most sensitive acquisition was the contrast-enhanced SE T1-weighted sequence. Only 7 patients out of 10 had a positive lumbar puncture. In the follow-up during therapy, MRI was considered more accurate in the evaluation of the pathological evolution of leptomeningeal involvement by hematopoietic neoplasms. Conclusions: In our limited experience, MRI was more sensitive in the detection of spinal epidural and leptomeningeal involvement by hemopoietic tumors. In patients with strong clinical suspicion of this involvement and negative lumbar puncture, MRI should be performed. Purpose: Knowledge of the exact site and localisation of a CSF fistula is important for planning surgical procedures and to prevent further complications. The purpose of this prospective study was to establish and to evaluate GD-DTPA enhanced MR cisternography in the detection of rhinobasal CSF fistulae in patients with suspected CSF rhinorrhea. Materials and methods: 10 patients with suspected CSF rhinorrhea were examined. Clinical diagnoses were: 7 severe head/brain trauma, 1 meningocele, 1 hydrocephalus and 1 chronic sinusitis. MR cisternography included the following investigation steps: acquisition of non enhanced fat suppressed T1-weighted SE scans of the skull base and the paranasal sinuses, lumbar puncture with administration of 1 ml GD-DTPA solute with 4 ml NaCl and performance of MR cisternography with the same fat suppressed T1-weighted sequences as used initially.

In 5 patients GD-DTPA enhanced MR cisternography detected a CSF fistulae (2 sphenoidal and 3 ethmoidal). While 4 of these depicted leaks were confirmed surgically and sealed. In one case the CSF fistula closed spontaneously. In another case, CSF leakage after severe head injury was highly suspected clinically, but ceased prior to MR cisternography, which was unable to detect the temporary fistula. In the remaining 4 patients with serous rhinorrhea MR cisternography did not provide any evidence for CSF fistulae. Intrathecal GD-DTPA injection was well tolerated. Conclusions: MR cisternography after intrathecal administration of GD-DTPA is a safe, promising and minimally invasive method for detection of CSF fistulae. This MR investigation provides excellent depiction of CSF spaces and pinpoints CSF fistulae. The description of the complex 3D shape of the ventricular system is an important aspect for the typisation of the ventriculomegaly. Materials and methods: PD and T2W 3D datasets were used for the segmentation of ventricular system. Using the volume and surface data's a size independent shape descriptor number (Edginess) was created. Edginess number of 8 atrophic, 10 Alzheimer and 7 NPH patient's was compared 44 normal subjects database. Results: Upon statistical analysis the data for the control patient group showed a significant difference from those for the Alzheimer's group (p < 0.003) and for the NPH group (p < 0.003), but no significant difference from the atrophy group. With respect to the atrophy group a significant difference was ascertained both from the Alzheimer's group (p < 0.002) and from the NPH group (p < 0.000). Significant difference was also ascertained between the Alzheimer's group and the NPH group (p < 0.001). Discriminate analysis enables 100 % reliability to be achieved in distinguishing the NPH group.

Conclusion: Size-independent shape description provides the opportunity for the objective monitoring of hydrocephalus cases, with particular respect to those occurring in developing children. It also enables ventricular shape changes developing in individual hydrocephalus cases to be differentiated. A substantial aspect the procedure creates a new possibility in differential diagnostics for the determination and type classification of every condition involving ventriculomegaly. Aim of the study was to examine the effect of three different types of meal on the function of proximal stomach in alcoholic cirrhotic patients by ultrasound.

The proximal stomach of 12 normal volunteers and 15 alcoholic cirrhotic patients were examined by ultrasound. Each subject received on consecutive days 500 ml meat soup, or 500 ml of two different semisolid meals: yogurt with potato flakes or sour cream with potato flakes, the latter contained 12 % fat. The proximal sagittal area and the frontal diameter were measured fasting and 5, 10, 15, 20, 30, and 120 min. after a meal and my multiplication of these two parameters approximate volume (aV) was calculated. Relaxation of the proximal stomach was characterized by the ratio of fasting aVf to the actual aV at different time points. Results: Compared with healthy controls, aV/aVf was significantly decreased (p < 0.05) after liquid and semisolid meal in cirrhotic patients (2.9 ± 0.3 vs. 5.3 ± 0.7 after liquid and 3 ± 0.3; 6.5 ± 1.5 after semisolid meal), while difference of this value was not observed after semisolid fatty meal between cirrhotic and healthy patients. 

The abdominal CT scans of 42 patients were retrospectively reviewed by 3 radiologists. Eighteen patients had surgically proven internal hernias (2 paraduodenal, 16 transmesenteric, case group) while 24 had no evidence of internal hernia at surgery (comparison group). Images were reviewed in a random and blinded fashion. Individual and group performance was evaluated by ROC analysis, and inter-observer agreement was measured by Cronbach's coefficient alpha. Individual CT signs relevant as predictors of transmesenteric hernia were identified by logistic regression and ranked by their odds ratio and p-values.

The 2 paraduodenal hernias were diagnosed by all 3 readers. CT signs of paradoudenal hernias include: a sac-like mass of small bowel, encapsulation of small bowel, mass effect on the posterior wall of the stomach, left displacement of the main mesenteric trunk and mesenteric vessel abnormalities. We found poor inter-observer agreement in diagnosing transmesenteric hernia in the case group, but good to excellent interobserver agreement for some of the CT findings predictors of transmesenteric hernia, with a Cronbach's coefficient alpha value ³ 0.8. Logistic regression analysis suggests that clustering of small bowel loops, en-gorgement, stretching and crowding of the mesenteric vessels, right displacement of the main mesenteric trunk, and small bowel obstruction manifested as bowel dilatation with a transition point are associated with transmesenteric hernia. Conclusion: CT may allow a diagnosis of internal hernia, although this diagnosis remains difficult, especially of transmesenteric hernia.

Provoked gastro-intestinal bleeding with tissue plasminogen activator -a useful diagnostic tool in patients with occult lower GI bleeding J.M. Ryan, S. Dumbleton, T. Smith; Durham, NC/US Purpose: The purpose of this study was to assess the efficacy and safety of provocative mesenteric angiography with tPA, heparin and tolazoline in patients with occult lower gastrointestinal bleeding. Materials: 17 provocative bleeding studies were performed on 16 patients for occult LGI bleeding including 9 women and 7 men, aged 44 -79 years. All patients had previous negative endoscopic and negative angiographic studies. To provoke bleeding we used a combination of intravenous heparin (range 3000 -10000 units), intra-arterial tolazoline (range 25 -100 mg) and intra-arterial tPA (range 10 -50 mg, mean 20.3 mg).

Results: 17 studies were performed in 16 patients leading to bleeding in 6 patients (37.5 %). 2 vascular abnormalities were diagnosed which did not bleed during provocation -an abnormality was identified in 8 of 16 patients (50 %). There were no procedural complications encountered. Of 6 patients in whom bleeding was successfully provoked, 4 bleeds occurred in the large bowel, and 2 in the small bowel. 3 patients had embolization at the time of provoked bleeding. 5 of these 6 patients required no further therapy for lower gastrointestinal bleeding. 10 patients (including 2 with vascular abnormality) did not bleed during the provoked study with tPA. Of 8 patients with normal study 5 patients rebled during followup. Conclusion: Intraarterial provocative mesenteric angiography with heparin, vasodilator, and tPA identified the site of bleeding in 37.5 % of patients in our study group, and contributed to treatment in 50 %. This small study indicates that the procedure appears to be safe. 

Monday B

Methods and materials: CT films of 10 cases with internal hernia including 4 cases with paraduodenal hernia, 3 cases with transmesenteric hernia, 2 cases with transomental hernia and 1 case with foramen of Winslow hernia were retrospectively reviewed. Surgical proof was obtained in all cases and strangulation was found in 5 of the cases. Results: Prevalent CT findings found in internal hernia were cluster of small-bowel loops, crowding of mesenteric vessels, engorgement of the mesenteric vessels, evidence of small bowel obstruction, and closed loop. Saclike mass was a helpful CT finding to diagnose internal hernia having hernia sac. Mesenteric edema, bowel wall thickening, and ascites were frequently observed in cases with strangulation. In paraduodenal hernia, herniated bowel loops showed a sac like mass and were found posterior to either ascending or descending mesocolon. In a subtype of paraduodenal hernia and foramen of Winslow hernia, herniated loops were found in the lessor sac. In transmesenteric and transomental hernias, herniated bowel loops were found lying adjacent to the abdominal wall displacing the colon centrally.

Conclusions: CT may allow the diagnosis of internal hernia based on the shape and anatomical location of the herniated bowel loops. The presence of strangulation can be assessed by the CT features of the bowel wall and mesentery.

Cross sectional imaging findings of juxtapapillary duodenal diverticulum C. Balci, A. Akinci, E. Akun, C. Duran; Istanbul/TR Objective: The purpose of this study was to evaluate the CT and MR imaging features of juxtapapillary diverticulum, correlating with ERCP, duodenoscopy.

We retrospectively evaluated CT (n = 6) and/or MRI (n = 11) examinations of 12 patients who were diagnosed juxtapapillary diverticulum on ERCP (n = 10) or endoscopy (n = 2) examinations as correlative diagnostic examination. MRI was performed in a 1.5 T scanner, CT was performed with helical technique using thin sections. CT (n = 5) and/or MRI (n = 9) were primary imaging modalities in 10 patients. Size, location of the diverticula and imaging findings of associated biliopancreatic disease were assessed. Results: Diverticula were missed initially in three patients on CT (n = 1) and/or on MRI (n = 3). Size of the diverticula ranged between 1 -3 cm. Imaging findings of the juxtapapillary diverticulum was characterized as outpouching of the duodenal wall towards pancreatic head (n = 5). On 5 patients papillary relation to diverticular wall was evaluated on MRI. On CT, layering of oral contrast with air level was characteristic imaging feature. On MRI T2-weighted true FISP and HASTE techniques demonstrated the air fluid level with hyperintense fluid and signal void air level above. Associated imaging findings as dilated CBD (n = 5), cholecystitis (n = 2) cholecystolithiasis (n = 2), chronic pancreatitis (n = 6) and were visualized on both imaging modalities. Conclusion: With a better recognition of juxtapapillary diverticulum on CT and MRI, initial cause of biliopancreatic disease symptoms in patients with juxtapapillary diverticulum can be depicted by these modalities.

Results of screening ultrasound diagnosis of gastric and colonic cancer S. Pimanov, A. Sikora, C. Vergasova, N. Lud; Vitebsk/BY Purpose: The problem of colonic cancer (CC) and gastric cancer (GC) diagnosis remains a difficult issue. A number of screening programs for CC diagnosis based on faecal occult blood tests and endoscopy are well-known. The objective of this study was to determine the possibilities of screening ultrasound examination for gastric cancer and colonic cancer. Patients and methods: 29467 patients aged 25 -87 with various diseases were examined for CC and GC diagnosis. Screening ultrasound examination for CC and GC was performed in all the patients of the hospital and ambulance station who were examined by conventional abdominal sonography. CC and GC had not been suspected before the examination. Revealing of concentric hypoechogenic thickening of the stomach and bowel wall with increased central reflection (i.e. non-specific "pseudokidney symptom") was defined as a pathological criterion. Bowel and stomach sonography lasted for about 3 minutes. Results: The ultrasound examination resulted in revealing 54 cases of CC and 18 cases of GC. Almost all patients with tumours were operated and in all cases the diagnosis was confirmed histologically. According TNM classification most of these patients had T2 -T3 stages of cancer. False negative results were analyzed using regional cancer register. Conclusion: It seems quite possible to diagnose actively colonic and gastric cancer by means of screening ultrasound examinations. The aim of our study was to develop an examination protocol for Esophagus Virtual Endoscopy, that in association to axial CT images allowed to evaluate malignant stenosis and diverticuli. Methods and materials: Virtual endoscopy of the esophagus was performed in 29 patients with esophageal wall pathology. Esophageal distention was obtained by oral administration of effervescent granules and intramuscolar injection of 20 mg of scopolamine butylbromide. In all patients, Spiral CT Volume Zoom examination (120/80/1 mm/1 mm/8 mm/0.5 s kV/mAs/slice coll./slice width/feed per rot/rot. time) of the thorax and upper abdomen was performed within a single breath-hold, before and after i.v. administration of contrast media. Real time endoscopy images were reconstructed using volume-rendering techniques with a dedicated workstation and specific software (Vitrea 2.2, Vital Images). Conventional esophageal endoscopy was performed in all cases and an additional bronchoscopy was executed. Results: 5 diverticuli and 24 endoluminal stenotic lesions were founded. Most of them were localized in the middle or lower thoracic esophagus and were displaied as a discontinuity of esophageal lumen. 3D CT imaging associated to axial images depicts esophageal tumoral extension, other mediastinal air filled structures, the gastroesophageal junction and shows the presence of diverticuli complications. Conclusions: Our protocol achieves excellent distention of the lumen both proximal and distal to the stenosis and allows a correct differentiation between malignant stenosis and tumor located into diverticular task. This technique allows to obtain additional informations in the stenosis that do not permitt the passage of an endoscope and comparing to barium studies excludes the risk of aspiration of contrast agent. In 15 patients with positive EGR, HP was negative, while both were negative in one patient. There was highly significant difference between the HP and EGR findings (p < 0.01), meaning that statistically there was no dependence between HP and EGR. In all 52 patients, HP finding did not correlate with index values (r = 0.181, p > 0.05). Index of EGR in patients with positive HP was C = 16.7 ± 11.5 %, while in those with negative HP were X = 25.3 ± 9.8 %. There were significant differences (P < 0.05) in the values of index in relation to the presence of HP, meaning that it was lower in the patients with positive HP finding. However, when only patients with pathologic values of EGR were considered (EGR > 10 %), there were no significant differences (p > 0.05) in the values of index in relation to the presence (n = 19, X = 27.7 ± 9.6 %) or absence (n = 15, X = 27.0 ± 7.15 %) of HP. Conclusion: There was no relationship between the presence of HP and EGR. Birmingham, AL/US, 2 Rome/IT Introduction: Cardiovascular MRI (CMRI)can accurately assess LV systolic function. Diastolic function assessment involves complex methodologies such as phase contrast imaging or myocardial tagging. Our purpose was to define diastolic dysfunction (DD) with a routine CMRI approach. Methods: Using a 1.5 T system (GE Signa CV/i; GE Medical Systems, Milwaukee, WI), LV volumes and mass were calculated on cine short axis sequences in 19 patients, 8 with risk factors for DD (LVH, hypertension, coronary disease, etc) and 11 (control group) without risk factors. Post-processing was performed with MASS analysis package (MEDIS, Leiden, the Netherlands) Studied variables were ventricular relaxation rate, LV mass index, EF, and end diastolic volume index. Results: Diastolic relaxation rate was calculated from a linear regression line fitted to the rate of LV volume change and was normalized using the body mass index. EF and LV mass index were calculated. Using binary linear regression analysis, diastolic relaxation rate predicted patients with risk factors for DD with a 2 of 9.8 (P < 0.005), whereas LV mass index predicted DD with a 2 of 5.6 (P < 0.05). EF and end diastolic volumes were not significantly different between groups. Normalized diastolic relaxation rate distinguished the two groups with 79 % accuracy, cardiac mass index with 74 %, and the combination of the two with 95 %, with 2 of 18 (P < 0.0001). Conclusions: Diastolic relaxation rate and LV mass index can be used to evaluate LV diastolic function as a component of every CMRI study, using a simple cine sequence, without additional time or complex techniques not widely available.

Clinical usefulness of high dose dobutamine stress MRI for the detection and cardiac tagging for the detection of myocardial ischemia D.Y. Kuijpers, K.Y. Ho; Groningen/NL Purpose: To evaluate the clinical value of high dose dobutamine stress MRI (DSMRI) for the detection of myocardial ischaemia by wall motion analysis using myocardial tagging. Patients and methods: A consecutive group of 159 patients with known or suspected coronary artery disease, who stopped their anti-anginal medication 4 days before the examination, were examined with a cine breathhold using a standard 16 segment short axis model. Seven patients could not tolerate the examination.

Patients were examined at rest and during increasing doses of dobutamine stress at 6-minute intervals up to 40 µg/kg/min. Cine images were acquired during breathholds at 3 short axis levels, including myocardial tagging. The data were evaluated for the presence of ischaemia, which was defined as a new wall motion abnormality (hypokinesia, akinesia, dyskinesia) in at least 2 segments at 2 different levels. MR images were interpreted during the examination by two 2 experienced investigators. Two datasets were not interpretable. Results: Average examination-time was 52 minutes without major complications. 54 patients who showed signs of ischemia, were examined with coronary angiography within 2 weeks. 51 patients showed significant coronary artery disease of whom 49 needed revascularisation. Three patients showed false-positive MRI results, while sensitivity for 50 % luminal narrowing was 94 %. In the 86 patients without ischaemia on MRI, the cardiovascular occurence-free survival rate was 98 % (average follow-up period was 10 months). Conclusion: High dose DSMRI using myocardial tagging is a safe and clinically useful method for the detection of myocardial ischaemia. Aim of this study was to investigate the capability of MR imaging as a noninvasive tool to follow up ventricular and valvular function, perivalvular flow and myocardial remodeling in patients after AVR. Methods: On a 1.5 T MR system 15 patients with aortic stenosis and 20 healthy volunteers were examined. Cardiac output (CO), ejection fraction (EF), enddiastolic volume (EDV) and LV ejection time frame as a parameter of contractility (∆tLV) were determined using a velocity encoded 2D FLASH technique (TR 24 ms, TE 5 ms) and Cine sequence (TR 100 ms, TReff. 10 ms, TE 4.8 ms, flip 25°, temporal resolution 50 ms). Hemodynamic parameters and end-diastolic myocardial wall thickness (EMWT) were determined 1 ± 0.5 days pre/7 ± 2 days and 10 ± 3 months after implantation of a St. Jude Medical prostheses. Invasive measurements (Fick principle/thermodilution) and Echocardiography served as reference standard. Intra-and interobserver variability of two observers were calculated for MR measurements.

Results: For CO a good correlation with invasive measurements was found using phase velocity mapping (r = 0.66, p < 0.0007). LV parameters normalized late postoperatively (∆t = 158 ± 20 ms/98 ± 20 ms, EDMT = 18 ± 3 mm/11 ± 3 mm, pre/ 10 ± 3 months surgery, p < 0.001). Differences between normal volunteers and patients were detected on a high level of significance (normal ∆t = 102 ± 24 ms, EMWT = 9 ± 3 mm, p < 0.0001). For MR flow measurements interobserver variability was 2.5 ± 2.7 %, intraobserver variability was 1.7 ± 1.6 %.

In patients with suspected postoperative complications after AVR cardiac MRI should be applied prior to hospitalization and invasive diagnostic procedures.

Cardiac systolic rotation and contraction before and after valve replacement for aortic stenosis -a magnetic resonance myocardial tagging study J.J.W. Sandstede 1 , T. Johnson 1 , M. Beer 1 , K. Harre 1 , T. Pabst 1 , W. Kenn 1 , W. Völker 1 , S. Neubauer 2 , D. Hahn 1 ; 1 Würzburg/DE, 2 Oxford/GB Purpose: Aortic stenosis leads to derangement of cardiac function and contraction mode due to chronic pressure overload that is relieved after surgical valve replacement (SVR). This study aimed to determine the changes in left ventricular (LV) systolic wall function before and after SVR using MR tagging, compared to age-matched healthy volunteers.

Monday B A C D E F 249 Materials and methods: 12 patients with aortic stenosis were examined with an ECG-triggered 2D tagging sequence at 1.5 T before and 12 months after SVR. LV function and mass were determined by cine MRI. Cardiac rotation at the apical, mid-ventricular, and basal level and overall torsion were evaluated. 8 healthy volunteers within the same age group served as a control. Results: Before surgery, all patients showed a significant increase of apical rotation and overall LV torsion, basal rotation was not significantly different compared to volunteers. Apical rotation and torsion were negatively correlated with LV mass and end-diastolic volume. One year after surgery, basal rotation was reduced compared to controls. In comparison to pre-operative values, apical rotation also decreased but was still elevated, and this resulted in a normalization of LV torsion. Conclusion: Pressure overload before surgery is associated with an increase of systolic LV wringing motion, possibly serving as a compensatory mechanism. This mechanism declines with increasing LV hypertrophy and dilatation. SVR for aortic stenosis leads to normalization of LV torsion one year after surgery. Patients and methods: Global and regional function was determined by cine MRI in 30 patients 3 weeks after anterior MI. At the same time, 31 P-spectra were obtained from infarcted as well as non-infarcted adjacent myocardium using a 3D-CSI technique (voxel size 25 ml each). PCr/ATP ratios and signal to noise ratios (SNR) were determined using AMARES. 6 months after revascularization MRI and MRS were repeated. Gold standard for viability was recovery of regional function after revascularization. Healthy volunteers served as control group. Results: Two groups of patients (15/15; wall motion recovery versus persisting wall motion abnormalities) were formed according to follow-up MRI. At study entry patients with non-viable segments had significant reductions of PCr/ATP-ratios in non-infarcted and infarcted myocardium due to a significant reduction of PCr SNR, whereas patients with viable segments showed that only in the infarcted areas (p < 0.05 each). No significant differences were detected concerning morphologic or functional parameters between both groups. Control examination 6 months after revascularization revealed significant increases of energy metabolism and cardiac function for patients with viable myocardium (p < 0.05). Conclusions: Restoration of regional oxygen supply by revascularization therapy is connected with improvement of metabolism and function in patients with viable segments, whereas irreversible damage of infarcted tissue is connected with continuous depression of energy metabolism.

Time course of 23 Na signal intensity after myocardial infarction in humans J.J.W. Sandstede 1 , H. Hillenbrand 1 , M. Beer 1 , T. Pabst 1 , W. Machann 1 , W. Völker 1 , W.R. Bauer 1 , S. Neubauer 2 , D. Hahn 1 ; 1 Würzburg/DE, 2 Oxford/GB Purpose: Elevated sodium (Na) content in myocardial infarction (MI) can be imaged by increased Na signal intensity ( 23 Na SI). Experimental studies described the temporal changes of myocardial Na content post-myocardial infarction. Aim of our study was to determine the time course of 23 Na SI after MI in humans. Materials and methods: 13 patients were examined 14 ± 3 days and 3 months after MI, 7 patients underwent an additional examination 4 ± 1 days after MI. Double angulated short axis 23 Na images of the heart were obtained in prone position using a 23 Na surface coil and an ECG-triggered 3D-FLASH-sequence with 32 acquisitions. Wall motion abnormalities were detected by cine MRI. 23 Na SI of MI was expressed as percentual increase compared with the entire circumference of noninfarcted myocardium. Results: All patients showed an area of elevated 23 Na signal intensity correlating with wall motion abnormalities. 23 Na SI remained elevated between day 4 and day 14 in the 7 patients that were examined twice in the early stage after MI. All patients revealed a decrease of 23 Na SI until 3 months after MI. Conclusion: 23 Na SI is elevated in acute MI and throughout infarct healing but decreases until 3 months after MI. This is in concordance with experimental studies, these studies showed the highest Na content at day 1 with a decrease until day 90. Correlation of 23 Na SI and myocardial viability in humans has to be determined in future studies. P-SLOOP-MRS. 15 healthy volunteers were included in the study. Results: Compared to matched volunteers, a significant decrease of absolute PCr concentration was observed in patients with MS (p < 0.05), whereas ATP concentrations showed no significant changes. Functional analysis by MRI depicted depressed left ventricular (LV) EF in 3 patients. For MS patients with mitoxantrone treatment, an association between cumulative dose and EF could be detected (r = 0.59; p = 0.0189). However, EF, LV ESV and LV ESV were not statistically significant between the two groups of patients. MRS detected no association for ratios or absolute values and cumulative mitoxantrone dosage.

The reduction in cardiac high-energy phosphates as well as LV EF in some patients points to a subclinical involvement of the heart in MS. Treatment with a putative cardiotoxic drug like mitoxantrone seems, however, not to aggravate a possible pre-existing heart disease within the examined cumulative dose range up to 100 mg/m 2 .

Absolute concentrations of cardiac high-energy metabolites -relation to clinical severity M. Beer 1 , H. Köstler 1 , J.J.W. Sandstede 1 , K. Harre 1 , S. Neubauer 2 , D. Hahn 1 ; 1 Würzburg/DE, 2 Oxford/GB Purpose: Cardiac high-energy metabolism is impaired in failing human myocardium, and this may contribute to contractile dysfunction. Current technical improvements of cardiac MR-Spectroscopy (MRS) allow for absolute quantification. We tested the correlation between clinical severity and metabolite concentrations. Patients and methods: Patients with hypertrophic (aortic valve stenosis, AVD) and dilated cardiomyopathy (DCM) were studied (10 each). Patients were graded according to NYHA; LV volumes, mass and EF were determined by cine MRI. 31 Pspectra were obtained using a 3D-CSI technique. PCr/ATP ratios and absolute values (mmol/kg) were determined using AMARES and SLOOP. Healthy agematched volunteers served as control group. Results: For NYHA classes 0 (VOL), II (7 AVD, 1 DCM) and III (3 AVD, 9 DCM), PCr concentrations were 8.48 ± 1.42, 6.78 ± 1.11, and 4.23 ± 1.01, ATP levels 5.93 ± 0.85, 5.03 ± 0.81, and 3.58 ± 0.64; and PCr/ATP ratios were 1.59 ± 0.28, 1.36 ± 0.22, and 1.21 ± 0.30. PCr absolute concentrations showed the highest, ATP intermediate and PCr/ATP ratios lowest correlations with clinical and functional variables. Conclusions: Absolute concentrations seem to be more representative of the extent of energetic derangement in heart failure than established PCr/ATP ratios. Material and methods: High resolution MR imaging was performed on a 1.5 T unit (Symphony Quantum, Siemens) using T1-and STIR T2-weighted sequences via a dedicated wrist coil (total acquisition time 8 min) a mean of 6.5 days after initial radiographs in 50 patients with clinical suspicion of wrist fractures and normal plain or indistinct radiographs. Initial radiographs were evaluated independently by two senior radiologists without knowledge of the MRI findings. The resulting change in therapeutic strategy was clinically evaluated. Results: In 29/52 wrists MRI findings resulted in a change of diagnosis. There were false positive diagnoses on plain radiographs in 23 cases (46 %) and false negative diagnoses in 6 cases. MRI allowed to detect additional injuries of soft tissue in 19 cases (38 %). In 19/52 wrists the period of immobilization could be shortened or ended. In 11/52 it needed to be prolonged and in 3/52 a surgical intervention was necessary. In 19 wrists MRI had no therapeutic consequence. Correspondingly, after MRI examination the period of being unable to work was reduced in 15/50, prolonged in 7/50 and was not changed in 28/50 patients. Axial images were not helpful regarding diagnostic accuracy. Conclusion: MRI of the wrist is recommended on the day of trauma if there is clinical suspicion and normal plain radiographs. Accurate diagnosis by MRI examination on the day of trauma may reduce economic costs due to shortened immobilization time.

MRI evaluation of the wrist using dynamic studies M. Mastantuono, E. Bassetti, G. Simonelli, L. Di Giorgio, R. Passariello; Rome/IT Purpose: In some painful syndromes of the wrist the conventional MRI imaging is not satisfactorily for diagnosis. We describe a new dynamic MRI method, that is accurate and easy to repeat, for the study of carpal instability and wrist pain. Materials and methods: We performed a dynamic study of the carpus in 27 healthy volunteers and on 38 selected patients which we chose from a group of 232 previously studied by static MRI wrist examination. We used a dedicated magnet (Artoscan, E-Scan 0.2 T) that has revealed itself to be particularly useful for dynamic acquisitions. We standardized a technique of image acquisitions at different degrees of flexion both on the coronal plane in ulnar-radial deviation and in sagittal for palmar-dorsi-flexion. We used SE and GE sequences obtaining sagittal and coronal scans with a slice thickness of 2 -3 mm. Results: The dynamic study is superior in the evaluation of carpal instability and in the assesment of capsular and ligamentous lesions if compared to standard MRI examinations. The kinematic evaluation of the images acquired in the different positions of movement allowed to document the pathologic articular kinetics. Conclusions: In our experience the MR kinematic study provided information that permitted differentiation of the possible mechanisms responsible for chronic wrist pain. Kinematic MRI is a simple and low time-consuming method of study that permits an accurate assessment of carpal instability, easily demonstrating articular biomechanical alterations that may be difficult to diagnose on static conventional MR examination.

In 23 patients we assessed direct MR-arthrography in comparison to multiportal wrist arthroscopy for the evaluation of extrinsic and intrinsic ligaments, the TFCC. we used a 1.5 T MR system (Magnetom). After fluoroscopic-guided direct wrist arthrography into the mid-carpal and radiocarpal joint with a solution of Ultravist and Magnevist (1:200) we applied following sequences: (1) T1 TSE (TR 500 ms, TE 20 ms) 3 mm slice-thickness, coronal and sagittal plane, matrix 512, FOV 120 mm. (2) 3D FLASH (TR 24 ms, TE 11 ms, flip angle 50°) 1.5 mm slice-thickness, coronal and sagittal plane, matrix 256, FOV 120 mm. Between 1 and 14 weeks after MR-arthrography, all patients underwent diagnostic multiportal arthroscopy. For the evaluation of the scapholunate ligament and the lunotriquetral ligament we subdivided lesions in partial defects and complete tears. The MR-sign of a partial-ligament defect was the passage of Gadolinium-contrast agent between the mid-carpal joint and the radiocarpal joint, but with intact ligament structures palmar or volar to the defect visible. Complete TFCC-defects, recognized by passage of contrast-agent into the distal ulnoradial joint, were classified according to Palmer. Results: For complete defects there was a high correlation between MR-arthrography and diagnostic multiportal arthroscopy (Sen: 91.7 %, Spez: 97.9 %, PPV: 78.6 %, NPV: 96.2 %). For partial defects the correlation was moderate (75.0 %; 98.0 %; 85.7 %; 94.8 %). Conclusion: For the evaluation of complete defects of the intrinsic and extrinsic ligaments, the TFCC MR-arthrography and multiportal arthrography have nearly the same diagnostic power. For evaluation of partial defects arthroscopy is superior to MR-arthrography. 

After undergoing arthrography with a mixture of 1:200 diluted contrast medium (Gadolinium-DTPA: Imeprol) injected radiocarpally and midcarpally under fluoroscopic control, 65 patient suffering from ulnar-sided wrist pain were examined with a 1.5 T MR scanner. Using computer-aided "navigator"technique, the 3D data sets were converted into a virtual arthroscopy. All these patiens underwent a conventional arthroscopy within 24 hours. Imaging results were compared with the virtual findings. Results: In 57 of the 65 cases virtual arthroscopy could be performed adequately, whereas in 8/65 the procedure was not successful due to excessive narrowing of the ulnocarpal compartment or artefacts caused by patients movement. Among To determine morphologic changes of the median nerve in median nerve entrapment syndrome after surgical decompression using high resolution ultrasonography and to correlate with the clinical outcome. Materials and methods: 25 carpal tunnels of patients (18 women, 7 men, mean age 66.7 years) with documented median nerve entrapment were examined with high resolution sonography before and at least 3 months after surgical decompression. A subgroup of 10 subjects was scanned before and after 3 months following surgery. We evaluated nerve AP diameter, the flexor carpi retinaculum, postoperative scar tissue and correlation with clinical outcome. Results: 3 or more months after decompression the mean nerve diameter in the proximal canal is reduced from 2.46 mm to 2.09 (p = 0.05), in the distal canal from 2.32 to 1.98 (p = 0.0005). There was no significant difference in the subgroup examined within 3 months after decompression and in the relation proximal to distal nerve diameter pre-and postoperatively. The flexor retinaculum could be depicted clearly in all scans. The existence and extent of scar tissue and reduction of nerve diameter were found unreliable parameters regarding outcome. Conclusion: Analysed at least 3 months after surgical decompression the AP diameter of the median nerve is significantly smaller compared to preoperative values. This diameter reduction, however, as well as existence and extent of scar tissue does not always correlate with clinical outcome. The relation between nerve diameter in the proximal and distal canal does not seem to be a helpful parameter in the diagnosis of median nerve entrapment.

Ultrasonography of hand joints in rheumatoid arthritis Y. Khodjibekova, T. Zasteba; Tashkent/UZ Purpose: The aim of this investigation was to study typical sonographic signs of hand joints lesion in rheumatoid arthritis. Materials and methods: 67 patients aged 20 to 55 years (15 males, 52 females) with rheumatoid arthritis affecting hand joints were investigated. The control group comprised 10 healthy individuals. In all patients diagnosis was established by clinical, laboratory and radiographic examinations. Results: Soft tissues, bone contours, ligaments, joint-forming surfaces, joint space and synovium were visualized on hand joints sonograms. The first stage of the disease was characterized by soft tissue thickening, increase of ligaments echogenity, effusion and increase of joint space. At the second stage of the disease soft tissues thickness decrease, slight increase of their echogenity, periosteum thickening, joint-forming surfaces destruction, narrowing of joint space to

A C D E F 252 0.1 -0.2 cm were revealed on sonograms. At the third stage of the disease soft tissues were not visualized, bone contours were well-defined and deformed, periosteum was thickened, joint-forming surfaces were indistinguishable. Conclusion: Sonography is effective method for the diagnosis of hand joints lesion in rheumatoid arthritis, particularly in its early stages.

Preliminary experience with "extended field of view" (EFV) ultrasonography in musculoskeletal disorders E. Santacroce, C. Avanzino, G. Dazzi, L. Raimondi, E. Silvestri; Genova/IT Purpose: To evaluate the usefulness of EFV ultrasonography in the study of musculoskeletal system. Materials and methods: Forty subjects with musculoskeletal disorders were submitted to an EFV ultrasound examination after a routine US evaluation. 20 shoulders with anterior-superior impingement, 4 wrists with carpal tunnel syndrome, 2 wrists with De Quervain's disease, 8 ankles with Achilles tendonitis and 8 patients with post-traumatic muscle injuries were considered. An ATL HDI 5000 system equipped with a broadband 7 -14 MHz transducer with EFV software was used. Results: The EFV evaluation improved the muscular and tendon anatomy demonstration and correctly showed the pathologic process extension in all cases.

The larger field of view of this technique allowed more precise anatomic definition of muscles, tendons and peripheral nerves but did not provide further diagnostic information. Not easy images acquisition, evaluation of small structures and convex bone surfaces are the main limits to this technique. Purpose: This study was performed to establish the value of breathhold MR imaging in the diagnosis of acute appendicitis. Materials and methods: Over a 14-month period 138 consecutive patients, clinically suspected of having appendicitis all underwent an US study and a subsequent MRI. The MRI images were obtained with breathhold coronal and axial fast spin-echo T1, T2, and T2 fat suppression sequences with 5 mm thick slices. MRI images were evaluated prospectively. Appendiceal diameter, signs of periappendicitis, abscesses, fecaliths, free fluid, mesenteric lymphnodes, paralytic ileus, or the existence of an alternative diagnosis was noted. Also the total duration of the MRI study was noted. MRI findings were correlated with surgical pathology in 62 patients and clinical follow-up in 76 patients.

The MRI findings of 63 patients were interpreted as positive for appendicitis (62 true positive, 1 false positive). MRI findings showed no signs of appendicitis in 76 (true negative in all) and showed an alternative diagnosis in 36. Sensitivity and specificity for detecting acute appendicitis were 100 % and 98 %. The median total duration of the MRI study was 15 min. Conclusion: Fast spin echo T1, T2 and T2-fat-suppression breathhold MRI imaging for the evaluation of patients with suspected appendicitis achieved a high accuracy in the detection or exclusion of appendicitis or an alternative diagnosis. The use of short imaging sequences minimized the impact on the routine MRI program. In selected cases MRI is a reliable, safe and quick tool that can be implemented in a community hospital.

Helical CT diagnosis of closed-loop obstruction and strangulation: How and when M. Scaglione, F. Pinto, A. Pinto, F. Lassandro, N. Renda, E. De Lutio, S. Romano, L. Romano; Naples/IT Purpose: Definite confirmation or exclusion closed-loop obtruction (CLO) is one of the most difficult tasks the radiologist has to face in the clinical practice. The aim of this presentation is to focus on the impact of helical CT in the diagnosis of CLO and strangulation. Materials and methods: 120 cases of surgical proven CLO diagnosed by helical CT were retrospectively reviewed. Helical CT scans were performed after administration IV contrast material (120 ml, 50 s scan delay, 2.5 -3 ml/s rate), with initial 10 × 10 mm collimation and repeated 5 × 5 mm over the region of interest. The state-of-art CT signs were considered for the diagnosis. Results: Serrated beaks with poor or no contrast enhancement of the bowel walls, ascites or engorgement of the mesenteric vasculature are CT signs allowed the diagnosis of CLO complicated by strangulation in 26/120 cases. U or C-sharped of dilated loops, radial distribution of the mesenteric vessels, beaks and whirls suggested CLO in 94/120 cases, but did not help differentiate from strangulation in 17 cases.

Conclusions: CLO is a dynamic entity which may regress or need laparotomy depending on the time and degree of rotation of the incarcerated loops. CT is a reliable imaging modality able to differentiate CLO from strangulation, which is rarely simple and obvious. Detection of ischemic changes in the bowel walls and/or attached mesentery on CT scans imply strangulation highlighting the need for laparotomy; if only signs of CLO are detected, the existence and/or development of strangulation cannot be predicted. Results: A diagnosis of strangulation was made in 30 patients at surgery. In the patients whose CT findings were mesenteric haziness and decreased conspicuousness of the mesenteric vessels with normal enhancement of the affected small bowel, diagnosis of viable ischemia was made at surgery. CT findings predicting strangulation were poor contrast enhancement of the bowel wall, haziness of mesentery, diffuse engorgement of mesenteric vessels and ascites. (p < 0.05). Among these findings, poor contrast enhancement of bowel wall was the most significant one.

In the patients with small bowel obstruction, poor contrast enhancement of the bowel wall, haziness of mesentery, diffuse engorgement of mesenteric vessels and ascites were useful CT findings for detecting and predicting strangulation. Purpose: The aim of the study was to define the role of high resolution Ultrasound in establishing the imaging diagnosis of the right iliac fossa pain syndrome (RIFPS).

The retrospective study has included 25 patients, which were admitted in The Emergency Room presenting the clinical picture of acute RIFPS. Paraclinic investigations were: abdominal high resolution US, blood and urinary testes. We compared the diagnosis emitted ultrasonographically with the one established by the surgeons in the theatre following the intervention. Results: Ultrasound examination has showed: 10 patients with inflammatory changes suggesting acute appendicitis (with a thickening of the appendic's wall greater than 6 mm and free peri-cecal liquid collection; mild small bowel loops distension with reduced motility at the right iliac fossa in 4 patients; 1 patient with suggestive terminal ileitis and mesenteric adenitis; 7 women with gynecological abnormalities (4 with big right ovarian cyst and 3 with ectopic right pregnancy) and Douglas free of fluid collections; 3 patient with ureteral impacted stone and dilatation of the right ureter. Conclusions: Ultrasound examination used in Emergency rooms offers reliable differential diagnosis data between inflammatory ceco-appendicular disease and renal or gynecological disfunction. The high resolution US diagnosis has a high sensitivity and specificity concerning the gynecological abnormalities. The diagnosis of acute appendicitis requires a carreful and several "in dynamic" examination. The diagnosis of acute appendicitis is not in most of the cases exclusively done by US, it necessitates very often a correlation with the clinical examination and laboratory tests.

Helical computed tomography diagnosis of gastrointestinal perforation in the elderly patient A. Pinto, F. Pinto, M. Scaglione, F. Lassandro, E. de Lutio di Castelguidone, L. Romano; Naples/IT Purpose: To determine the diagnostic value of helical CT in a consecutive series of elderly patients referred with clinically suspected gastrointestinal perforation. Methods and materials: Our series includes 48 consecutive elderly patients (mean age: 69 years old) presenting with acute abdominal symptoms suggestive of gastrointestinal perforation. All the patients were prospectively submitted to abdominal CT evaluation. As revealed on helical CT, the presence of free air was considered diagnostic of gastrointestinal perforation. Other CT findings considered indirect of perforation were: intraperitoneal free fluid, thickening of bowel wall, streaky density within the mesentery, the "dirty fat" sign, and focal collection of extraluminal fecal matter. Results: At surgery, the following sites of perforation were found: duodenum (38.8 %); stomach (30.6 %); ileum (8.1 %); sigmoid colon (8.1 %); rectum (6.1 %); jejunum (4 %); appendix (2 %), and trasverse colon (2 %). In our series, helical CT demonstrated the presence of free air in 95.9 % of cases, intraperitoneal free fluid in 81.6 %, and thickening of bowel wall in 48.9 %. Streaky density within the mesentery was found in 1 patient. Conclusion: CT is a reliable and accurate imaging method for assessing gastrointestinal perforation by providing excellent contrast resolution to depict presence of even small amounts of free air in the abdomen. This is particularly helpful when elderly patients series are concerned. 

A C D E F 254 Materials and methods: 63 female patients with disorders of defecation-and/or micturition were examined. Video-fluoroscopy was performed in a sitting position. The urinary bladder was filled with water-soluble contrast media. Rectum and vagina were contrasted with bariumsulfate. Dynamic-MRI was performed with a 1.0 T scanner (Magnetom Expert, Siemens Erlangen) using an T2 weighted gradient echo sequence ("true fisp"). Patients were asked to present with full urinary bladder at the time of examination. Rectum and vagina were filled with ultrasound-gel. Results: In 28 patients we found a anterior rectocele with a anterior extent between 3 and 11 cm in video-fluoroscopy. MRI failed to visualise rectoceles in 4 cases. In 9 cases rectoceles lead to a displacement of the urethra thus causing a voiding deficiency of the urinary bladder. These findings could be depicted better in MRI. 12 patients presented a cystocele shown by both modalities. In another 4 cases a enterocele could be detected. Conclusions: MRI is inferior to video-fluoroscopy for the detection and the estimation of the degree of anterior rectoceles. However MRI is superior in assessment of the severity of displacement of the urinary bladder and the urethra. The extent of pelvic descent could more accurately be assessed by MRI. Due to the capability of MRI of direct visualisation of the pelvic contents it is superior in demonstration of enteroceles. In 1997, the gradual implementation of the nation-wide mammographic breast cancer screening in the Netherlands was completed. Since then, 625000 screening examinations are being performed annually in the agegroup 50 -75 years, at an interval of two years. The medical performance of the various disciplines in the regional screening centres is assessed by means of regular site visits. At these site visits, first, the overall screening outcomes are evaluated. Subsequently, screening and diagnostic mammograms of interval and screen-detected St. II cancer cases are reviewed. Results: Despite the small size of the country, notable regional variations e.g. in the relative frequency of small tumours (T1) are observed, ranging from 21 % to 35 % at a national average of 27 %. From a not blinded review of > 2000 interval cancers, we found that in about half of the previous screening mammograms in some way abnormal signs were notable. In one fourth of the cases, with a range from 17 % to 40 %, significant lesions were found, that should have been referred for further examination. Conclusion: This large regional variation in outcomes prompted us to carry out the so-called national optimisation study. The objective is to learn in what aspects screening performance may improve as to the earlier detection of relevant lesions. These aspects include; (1) double reading;

(2) contribution of additional craniocaudal views; and (3) recall criteria for further assessment.

The role of individual MCs shape and cluster shape in the interpretation of mammograms I. Leichter 1 , R. Lederman 1 , P. Bamberger 1 , B. Novak 1 , S. Fields 1 , S.S. Buchbinder 2 ; 1 Jerusalem/IL, 2 Bronx, NY/US Purpose: To evaluate the diagnostic role of computer extracted features reflecting the cluster shape compared to features reflecting the shape of individual microcalcifications, identified mammographically. Material and methods: 286 cases of clustered MC's with proven pathology were obtained from three university hospitals and reviewed by experienced mammographers. Quantitative features characterizing the finding were extracted by a CAD system following digitization at 42 µm resolution. The shape factor and number of neighbors, according to Delaunay and Gabriel methods, were com-puted for each MC together with the eccentricity of the cluster. While shape is related to the individual MCs, the average number of neighbors and eccentricity reflect the cluster geometry. Stepwise Discriminant Analysis (SDA) determined the significance of the extracted features in predicting malignancy. The performance of a classifier based on these features was evaluated by ROC analysis. Results: SDA assigned variability of shape the highest predictive power followed by average number of neighbors (Delaunay) and average shape but excluded cluster eccentricity and number of neighbors (Gabriel) from the model. A classification scheme assigned the variability of shape a weighting factor, about 2.4 times greater than that assigned to the number of neighbors and average shape. A scheme based on these three features yielded a ROC curve with an Az of 0.88, indicating a PPV of 77 % for 95 % sensitivity. Conclusion: The variability of shape of individual MCs was found to have a higher impact in differentiating benign from malignant clusters than the average shape or features characterizing the cluster geometry. The efficacy of the independent double reading of mammograms with consensus has been established, but the observer variability between the readers must be supervised to determine the homogeneity of radiological criteria. Objective: The k index has been proposed as a method to calculate the interobserver agreement that was not due to hazard. We use the k index regarding the classification of mammographic findings in the assessment of mammographic categories (weighted k). 

Status of nuclear medicine in breast cancer imaging, staging and therapy E. Piperkova 1 , A. Grueva 2 , S. Sergieva 1 ; 1 Sofia/BG, 2 Baltimore, MD/US Purpose: Accurate staging in breast cancer depicting and averaging primary lesions, multifocal and spread of the disease and lymph nodes imaging by Nuclear Medicine (NM) effects surgery and treatment plans. Current status, diagnostic importance, priorities and limitations of SPET and PET modalities are analysed using different tumourtropic agents. Materials and methods: Evaluation of primary lesions, detection of regional and systematic metastatic disease and the assessment of treatment response are discussed through SPET using 99 Tc-MIBI or 99 Tc-antiCEA and PET using FES or FDG for two patients' groups in four trials targeted categories. In addition localisation of "hot spots" and tumour margins in radiodense breasts are introduced. MRM showed a significantly higher sensitivity, but its specificity was significantly lower than SMM. In the subgroup of lesions equal or greater than 0 mm (n = 97) the figure of the sensitivity was higher (93.2 %), than the overall sensitivity of SMM. Using receiver operating characteristic (ROC) analysis, between XMM and the combination of XMM and MRM we found no significant improvement, but the combination of XMM and SMM yielded a significantly higher diagnostic accuracy than XMM alone. Conclusion: Both MRM and SMM have adjunct value to XMM. MRM is to be preferred when high sensitivity and spatial resolution is essential, while SMM is recommended as a complementary method in lesions larger than 1 cm. Tc-MIBI. The one, measured in ipsilateral and/or contralateral area divided the count density, measured within a region of interest. This value represents coefficient of tracer uptake (in SUV). Differences between count densities in early and delayed images reflected the washout of the tracer from the tumour and thus sensitivity to chemotherapy. MR-mammography included assessment of T1 and T2 weighted images with the use of FLASH-mode and Gd-enhancement.

Results: Statistically significant correlation coefficients (T/NT) were observed for evaluated regions of increased uptake of radiopharmaceuticals in primary lesions: MIBI > 1.67 ± 0.21, FDG > 1.69 ± 0.25. These data were concordant with MR findings of primary breast tumours. In all cases p < 0.001. Regional lymph nodes involvement in scintigraphy was assumed in cases of axillary region uptake > 1.36 ± 0.29 for PET and > 1.33 ± 0.28. Parasternal lymph nodes were only detected FDG-PET in 15 pts. Washout coefficients calculated using 99 Tc-MIBI data stipulated for chemotherapy choice in 32 consecutive pts. Conclusion: MRI-mammography, mammoscintigraphy and FDG-PET correlate in assessment of primary BC. The best tools for the staging and adequate planning of radiation and/or chemotherapy are mammoscintigraphy and FDG-PET.

Contrast enhanced digital mammography: Phantom experiment and first clinical results C. Marx 1 , M. Facius 1 , S. Muller 2 , A. Rick 2 , K. Benali 2 , W.A. Kaiser 1 ; 1 Jena/DE, 2 Buc/FR Purpose: We evaluated on phantoms the capability of a full field digital mammography (FFDM) system to show lesion contrast enhancement after intravenous injection of iodine. Acquisitions on patients have begun to validate the potential of this new application as an alternative to Contrast Enhanced MRI of the breast. Method/materials: Using appropriate phantoms, we simulated the iodine diffusion in vessels and lesions to evaluate the threshold of detection of contrast uptake on FFDM images (Senographe 2000D, GE Medical Systems). The injections consisted of 1 -3 cm 3 of 2 ml Hexabrix 160 diluted in 60 ml of water, and were washed out using water. Sequences of 5 -7 images were acquired on FFDM (45 -49 kV, Mo/Cu) and were analysed to quantify contrast uptakes. Clinical use of Contrast Enhanced Digital Mammography (CEDM) requires the uptake contrast to be visible for iodine concentration between 0.12 mg/cm 2 and 1.8 mg/cm 2 . Results: Detection thresholds, with and without structured noise, were 0.50 mg/cm 2 and 0.25 mg/cm 2 respectively. Breast thickness has a low impact on uptake detection. Spatial and temporal analysis showed delayed marginal contrast uptake and slow increase of contrast in the background. Initial results on patients have demonstrated contrast uptake in malignant lesions. The shape of the uptake curves is influenced by the thickness of the breast under compression (4 -5 daN). Conclusions: Given these initial results, Contrast Enhanced Digital Mammography may be a fast and less expensive alternative to MRI for breast lesion characterisation. MRI studies were performed at 1.5 T using a modified volumetric interpolated breathhold examination (VIBE) sequence before and after administration of gadolinium. All images were evaluated prospectively regarding lesion detection and characterization. MRI findings were correlated with final diagnoses. Retrospective grading (scores 1 -4 for "poor" -"excellent") was performed for: (1) general image quality and presence of artifacts (rated "negligible" -"severe"); (2) imaging quality of detected pulmonary lesions (conspicuity and contrast on pre-and postgadolinium images)

Results: 23 solid pulmonary lesions, 25 infiltrates and segmental atelectases, and 1 cyst were detected and prospectively correctly diagnosed. Sizes ranged from 0.3 -10 cm. The mean grading scores for overall image quality and presence of artifacts were 3.3 (SD 0.7) and 1.8 (SD 0.7), respectively. Conspicuity and contrast of pulmonary lesions received mean scores between 3.0 and 3.8 (SD 0. We observed a lower peak intensity of emphysematous regions. In 22 subjects with distractedly hypo-perfusion a hyper-perfused region was detected and this occurrence was interpreted as pulmonary circulation re-distribution. Discussion: The low specificity was due to three positive cases observed in the control group. These perfusion defects were very well defined and there was total agreement between the three radiologists. In our experience, MR perfusion might be an effective alternative to perfusion scintigraphy in patients with pulmonary emphysema. 

After an informed consensus, 20 non-smoker subjects, without any present or past pulmonary pathologies, were studied by means of an ultra-fast gradient echo sequence after a Gd-DTPA intravenous administration. The acquisitions were performed in coronal and sagittal planes, in supine and prone position, in breath holding. An ulterior acquisition was performed in only five cases immediately after 2 -3 minutes of physical exercise. Results: All the examinations, reviewed according to a visual score by three independent observers, resulted fairly interpretable. The I/T curves, obtained in postprocessing evaluation, have the same trend in all cases and are correlated to the lung physiological criteria: the positional changes of the examined subjects confirm the gravity dependence of perfusion; the study performed immediately after physical exercise showed a reduction in the perfusion of the whole lung due to a transitory massive shift of blood mass from visceral to muscular compartment.

The extremely short acquisition and post-processing time coupled with a simple feasibility, the ability to detect physiological perfusional changes, and the minimal invasiveness indicates a potential clinical use of MR in the evaluation of pulmonary perfusion defects. Tl myocardial scintigraphy. Results: Echocardiography was normal in 20 cases, including 2 patients with cardiac-symptomatic sarcoidosis. MR images were normal only in cardiac-asymptomatic stage I or Lofgren syndrome patients (n = 4). Multiple organ cardiac-asymptomatic sarcoidosis (n = 17) displayed similar MR abnormalities to those observed in patients with cardiac symptoms (n = 5). Focal myocardial thickness and/or intramyocardial increased signal on T2-weighted and/or intramyocardial increased signal on gadolinium-DTPA-enhanced T1-weighted images, representing granulomatous inflammation, were correlated with segmental perfusion defects on the thallium scan. Available MR follow-up in 11 patients showed regression of gadolinium-DTPA uptake after corticosteroid therapy while progression was recorded in 2 patients without treatment. Conclusion: MR imaging enables valuable detection and localisation of cardiac sarcoidosis. The occurrence of subclinical lesions in multiple organ sarcoidosis may legitimise the use of MR as a screening method to identify early patients requiring careful review and treatment.

Detection of regional wall motion abnormalities: Tissue Doppler echocardiography in comparison with magnetic resonance imaging D.E. Kivelitz, A.C. Borges, G. Baumann, B. Hamm; Berlin/DE Purpose: Echocardiography when combined with spectral and color flow Doppler is well established as a safe, non-invasive, and versatile diagnostic modality for evaluation of left ventricular global and regional function. Tissue velocity imaging is a new technique that measures myocardial motion by tracking myocardial velocities with color Doppler myocardial imaging principles. The purpose of this study was to compare this new tool with magnetic resonance imaging. Methods and materials: 30 patients with wall motion abnormalities underwent echocardiography (Harmonic Mode-Octave) in comparison with Tissue Tracking (VivedFiVe, GE, Vingmed Ultrasound, Horten Norway, equiped with the EchoPac software package) which allows real-time acquisition of color Doppler images and on-line as well as off-line analysis of time-velocities-integrals (Tracking). Magnetic resonance imaging (Magnetom Vision, Siemens, Erlangen, Germany) was performed using Stripe Tagging. For regional wall motion analysis we used the 16 segment model. Results: In 29/30 patients we analysed quantitative data from Tagging and Tracking. The concordance was 85 % and the best results were in septal, posterior and apical regions. Conclusion: Tissue tracking, compared with magnetic resonance imaging, is a reliable method for on-line quantification of global and regional systolic function of the left ventricle.

Fast assessment of abnormal valve function using MRI A. Meduri 1, 2 , R.M. Razmi 2 , V.K. Rathi 2 , L. Natale 1 , G.M. Pohost 2 ; 1 Rome/IT, 2 Birmingham, AL/US Background: Valvular diseases can be rapidly assessed by Fast Cine (FC) MRI. Signal void is related to the TE and determines the severity. A short TE may impair assessment and detection of valvular lesions. We hypothesize that a lower receiver bandwidth, a longer TE, increases sensitivity and accuracy. Methods: A total of 30 pts and 59 valves were evaluated with the predefined bandwidth of 31.2 kHz (TE = 4.7 ± 0.2 ms) and with the narrower bandwidth of 15.6 kHz (TE of 7.1 ± 0.4 ms). Length, area and maximum width of signal void associated with every diseased valve were calculated. Each area was graded as mild, moderate or severe and compared with echocardiography. Results: Lowering the bandwidth significantly increases signal void area (117 ± 124 vs. 71 ± 78 pixel, p < 0.0001), length (21 ± 15 vs. 16 ± 12 p < 0.001) and the width (5.8 ± 5.2 vs. 4.4 ± 4.0, p < 0.001), graded as mild, moderate, or severe for each TE. Longer TE increases the severity graded in 22/49 (44.9 %) valves with signal void and diagnosed one abnormal valve not detected with the shorter TE. In the 23 cases compared with echocardiography, the longer TE showed a significantly better correlation (contingency coefficient 0.708, R = 0.657). Conclusion: Lowering the bandwidth allows longer TEs, giving better correlation with echocardiography. We conclude that a short TE leads to underestimation of the severity of the valvular lesion. Accordingly, a longer TE should be used routinely in every comprehensive cardiac MRI study.

Three-dimensional blood flow in the heart: Evaluation with MRI G. Reiter, U. Reiter, R. Rienmüller; Graz/AT Purpose: Evaluate a method of 3-dimensional determination of the intercardiac flow for early recognition of flow based cardiac dysfunction using magnetic resonance imaging (MRI). Materials and methods: Using flow quantification via phase contrast methods (TR = 33 ms, TE = 6.5 ms, flip angle 30°, Slice thickness 8 mm, pixel size 2.25 mm × 1.64 mm and Matrix 140 × 256) of MRI (1.5 T field strength, 40 mT/m gradients) we measured and reconstructed discretized time-dependent 3-dimensional velocity fields of blood flow within the different intracardiac regions. At any time of the cardiac cycle calculated velocity fields were projected onto a corresponding cine-TrueFISP image (e.g. 4-chamber view). The protocol was designed on healthy volunteers. Results: As result of reconstruction and projection we obtained a time series of TrueFISP images where in-plane velocities were displayed by vectors proportional to the in-plane velocity and through-plane velocities were color encoded. Images can be displayed picture by picture as well as in cine mode.

The presented method appears robust and sensitive in the 3-dimensional evaluation of the normal blood flow and promising to observe changes as possible causes of ventricle wall dysfunction.

Benchmarking non-rigid registration techniques for the quantitative analysis of myocardial function in tagged-MR imaging C. Petitjean 1 , N. Rougon 1 , P. Cluzel 2 , F. Preteux 1 , P.A. Grenier 2 ; 1 Evry/FR, 2 Paris/FR Purpose: In the framework of quantitative analysis of myocardial function our purpose was to assess the relevance of non-rigid registration techniques for estimating dense displacement fields and functional parameters from tagged-MRI sequences of the heart without performing tag extraction.

The study was conducted on 2D tagged-MR sequences under short axis incidence using various gradient echo/tagging sequences including FISP/DANTE and bFFE/SPAMM. Pixel-based, non-rigid registration techniques which deliver dense displacement fields over the whole image domain by establishing pointwise correspondences without requiring preliminary segmentation of heart walls nor tagging pattern have been evaluated. State-of-the-art methods have been tested for major registration criteria: (i) "demon" algorithms using an optical flow constraint with prior elastic smoothing; (ii) fluid registration methods governed by deformation laws from fluid mechanics; (iii) informational techniques maximising entropic measurements between successive images. In each case deformation modelling has been addressed by comparing functional measurements derived from non-parametric and parametric motion estimates. Using hierarchical solvers for handling large deformations has also been investigated. Results: Demon and mutual information maximisation techniques allow accurate derivation of dense maps of functional parameters including deformation tensor eigenelements, local contraction/dilation and circumferential/radial strains. Moreover, informational approaches are insensitive to tag fade out. B-spline modelling offers a good trade-off between measurement accuracy and modelling compactness. Multiresolution processing allows us to account for large deformations. Conclusions: Following this assessment stage, novel non-rigid registration techniques are have now been developed that incorporate local image geometry information to constrain and accelerate the matching process.

Evaluation of palliative procedures in functional singular ventricle with MRI F. Weiss, C.R. Habermann, C. Lilje, K. Sasse, J. Weil, G.B. Adam; Hamburg/DE Purpose: To determine the value of MRI in the postoperative evaluation of singular ventricle compared to echocardiography and cardiac catheterisation. Methods/material: 19 patients (range: 4 month to 16 years) with functional singular ventricle who had undergone palliative corrective operations. 5 patients were treated without separation of circulation to improve pulmonary perfusion with Blalock-Taussig-Shunts. 13 patients had cavopulmonary shunts, 10 of them total cavopulmonary anastomosis, 3 only partial separation with bidirectional Glenn-Anastomosis. 1 patient was treated with a central shunt. The results were compared to percutaneous echocardiography, cardiac catheterisation and operation reports regarding postoperative morphologic changes. Detectability of thombotic material in the low-flow-system was evaluated. Conclusions: 3D-rotational angiography allows for a more exact depiction of anatomical details important in planning surgical and interventional therapy of intracranial aneurysms than DSA. RA also identified more aneurysms.

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Incidence of old intracranial microbleeds in patients with acute intracranial hemorrhage M. Alemany, R. Raininko, A. Stenborg, A. Terent; Uppsala/SE

Purpose: Previous publications have demonstrated, using blood sensitive T2*weighted (w) sequences, the presence of incidental foci of signal loss which have been confirmed histopathologically to represent hemosiderin deposition from earlier bleeds. Their clinical significance is still debated. Our purpose was to evaluate the occurrence of old microbleeds in patients having acute intracranial hemorrhages and correlate these findings with clinical data. Methods and material: We studied 26 patients (mean age 65 years) with acute intracranial hemorrhages. 23 patients had spontaneous bleeds, 1 appeared after subclavian dilatation and 2 after coronary and lung thrombolysis, respectively. Axial spin echo T1-w and T2-w, FLAIR and gradient echo T2*-w images were obtained using a 1.5 T system. Results: Besides the acute hemorrhages, evidence of prior bleeds were found in 13/26 patients (50 %). 18/26 patients were hypertensive and 8/26 were normotensive. 10 of the 18 hypertensive patients (56 %) and 3 of the 8 normotensive ones (37 %) had evidence of old bleeds. Other clinical data were also investigated (diabetes, abuse of alcohol or tobacco, anticoagulant treatment, etc) but no clear correlation with intracranial microbleeds was found. Only the T2*-w sequences were able to detect these lesions.

Our results support the hypothesis of a correlation between hypertension and old intracranial microbleeds. The microbleeds may be the sign of a microangiopathy that could give a increased tendency for intraparenchymal bleeding. The detection of old microbleeds is, thus, of diagnostic importance. They may also help to predict risk for spontaneous rebleeding or bleeding complications after anticoagulant therapy.

Multislice angio-CT in the evaluation of cerebral aneurysms M. Wintermark, M. Chalaron, P. Maeder, A. Uske, P. Schnyder, R. Meuli, S. Binaghi; Lausanne/CH Purpose: Evaluation of the accuracy of multislice angio-CT in the detection of cerebral aneurysms, by comparison with conventional cerebral angiography Methods and material: 50 consecutive patients, who successively underwent multislice cerebral angio-CT (1.25 mm-thick slice reconstructed every 1 mm, pitch 0.75, 140 kVP, 200 mA, timing determined with a bolus test) and conventional cerebral angiography, were prospectively identified in our department between July 1999 and August 2001. Both examinations were reviewed independantly by two neuroradiologists, who were blinded to their initial interpretation and who did not perform the cerebral angiography. Angio-CT axial slices were reviewed, as well as 2D MIP and 3D SSD reconstructions. Angio-CT and angiography data analysis was performed separately, but according the same systematic interpretation strategy. Results: 49 cerebral aneurysms were diagnosed. Sensitivity, specificity and accuracy of multislice angio-CT in the detection of cerebral aneurysms were 95 %, 100 % and 96 %, respectively. The impact of aneurysm location was determined. The ability of multislice angio-CT in the characterization of cerebral aneurysms was evaluated: size (slope 1.138, r = 0.79, p < 0.001), orientation (accuracy 91.2 %), thrombosis, calcification, origin of arteries, apical teat. Conclusion: Multislice angio-CT of the Willis circle is a worthy tool in the detection and characterization of cerebral aneurysms. Its ability to detect aneurysm partial thrombosis is higher than that of conventional cerebral angiography. Angio-CT allows for efficient planning of cerebral angiography and affords useful information in the determination of the therapeutical strategy. 

Monday B A C D E F 259 Methods and materials: In a blinded, prospective study 50 patients with acute subarachnoid haemorrhage underwent both CTA and DSA. Spiral CT with 3D reconstruction was performed. 120 ml of intravenous contrast was administered at 4 ml/s. Collimation of 1 mm. with a pitch of 2, and a reconstruction index of 0.5 was used. There were 32 females and 18 males entered into the study. The CTA images were separately reviewed by two Consultant Neuroradiologists, who were blinded to the DSA findings. The CT angiograms were assessed for aneurysm size and location, in addition to adjacent vascular anatomy. The results were compared with DSA. Results: From the initial group of 50 patients with SAH, no aneurysm was evident on either CTA or DSA in eleven. Of the remaining 39 patients, 51 aneurysms of varying types were diagnosed. CTA accurately diagnosed 48 of these (sensitivity 94 %). Of the 3 intracranial aneurysms missed on CTA all of these were under 3 mm in size. Specificity of CTA is 98 %. Conclusion: CTA would appear to be a safe and relatively reliable alternative to DSA in the management of acutely ruptured intra-cranial aneurysms. Other advantages include speed, cost and its non-invasive nature. In addition it may be of benefit in the follow-up of known aneurysms. In view of these results we have since modified our protocol to improve sensitivity further. Purpose: To evaluate the blood flow dynamics in patients with arterio-venous malformations (AVMs) before and after radio-therapy treatment. Patients and methods: Two different MR imaging techniques were used in a total of 25 patients. A non enhanced dynamic MRA based on a blood bolus tagging technique and a new contrast enhanced projection MRA (fluoroscopic MRA/ MRDSA) based on a fast FLASH sequence were used to assess the angioarchitecture of the malformation as well as the hemodynamics, mainly based on a calculated shunt-time between feeding arteries and draining veins. The conventional TOF-MRA and conventional DSA served as an internal standard. MRDSA was performed with a bolus injection of 0.1 mmol/kg BW of Gadodiamide (Omniscan®, Nycomed-Amersham) at an infusion rate of 3 cm 3 /s and a time resolution of 400 ms per projection. Images were assessed in regard to vessel detection and demarcation as well as the hemodynamic aspects of the malformation. Results: Both techniques were able to assess the angioarchitecture of the AVM in all patients. The arterial feeder, the AVM nidus and the venous drainage pattern could be clearly delineated. The time resolution of the non enhanced tagging technique was substantial better enabling a more precise assessment of the hemodynamics.

Discussion: MRDSA and dynamic non enhanced MRA are able to assess both the AVM angioarchitecture and the AVM hemodynamics non invasively. The techniques are easy to implement and can be used for treatment planning. Hemodynamic changes due to therapy (embolisation or radiosurgery) can be monitored.

The role of transcranial Doppler sonography (TCD), and somatosensory evoked potentials (SEP), in the detection of vasospasm after subarachnoid hemorrhage A. Fatourou, C. Constantoyannis, E. Solomou, P.A. Dimopoulos; Patras/GR Purpose: To evaluate the correlation between blood flow velocity (BFV) and vasospasm in patients suffering from subarachnoid hemorrhage (SH). To detect any relationship between conduction time of somatosensory evoked potentials and vasospasm in the same group of patients. To assess the simultaneous use of TCD and SEP in the detection of vasospasm. Materials/methods: In our study, we included 105 patients with subarachnoid hemmorhage (SH), diagnosed with CT. Six of them also underwent a lumbar spine puncture (LSP). All of them had Digital Subtracted Angiography (DSA), for aneurysm localisation. The follow-up was performed using TCD and SEP.

The diagnosis of SH, in 99 patients was made with CT, and in the rest of them (6 patients), was made with LSP. DSA revealed an aneurysm in 85 patients, whilst there were no remarkable findings in 17 patients. The latter were reviewed again and an aneurysm was detected in one more patient. Vasospasm appeared in 27 patients, whose BFV in the middle cerebral artery was 160.8 cm/s, and central conduction time (CCT), was 6.05 ms. The remaining 78 patients without vasospasm, had BFV 95.37 cm/s and CCT 5.81 ms. Conclusion: Statistical analysis showed that the prediction of vasospasm, with the correlation of the two modalities TCD and SEP, allowed a proper successful classification in 93.3 %. Using two additional parameters, the Fisher classification, and the classification Hunt-Hess, the percentage of proper successful classification did not change significantly.

Clinical and neuropsychological outcomes in 35 patients presenting with a ruptured anterior communicating aneurysm: Mid term follow-up B. Jean, K. Martin, M. Gely-Nargeot, A. Bonafé; Montpellier/FR Purpose: Rupture of an anterior communicating aneurysm (AcomA) is associated with substantial cognitive and psychopathological dysfunction, disability in psychosocial activities and daily living. We report the clinical and neuropsychological outcome of 35 patients treated by embolization of an AcomA; subgroup of our base of 61 Acom Aneurysm. Material and method: From September 1998 to May 2001 we treated 61 ruptured AcomA by coil embolization. At admission age, aneurysm description, initial clinical WFNS score, Fisher grade were collected. At discharge occlusion rate, Glasgow outcome scale (GOS) and complications were reported. We followed patients at 6 months, and 1 year with clinical evaluation and an angiographic control. Out of 61 patients, we submitted 35 patients to an extensive range of tests: comprehensive batteries of neuropsychological and psychopathological tests, daily living scales. Cognitive outcome was evaluated using global rating scale (Mattis), and assessment for attention, executive functions, explicit, implicit memory and psychiatric associated disorders. Results: We treated 61 patients using GDC coils. Technical and clinical results are provided. We report our technical complications and complications due to SAH evolution (symptomatic vasospasm, acute hydrocephalus). 35 patients were submitted to the battery of neuropsychological tests. The patient's performances were characterized by neuropsychological deficits, especially impairments in learning and explicit long term memory, associated with functional frontal dysfunction. Conclusion: Aneurysm morphological characteristics and occlusion rate do not influence early clinical evolution in ruptured aneurysm. Patients submitted to a battery of neuropsychological tests showed neuropsychological deficits and frontal dysfunction on mid term follow-up. Purpose: Although preoperative embolization of meningioma is a helpful procedure to minimize bleeding and to facilitate resection, some meningiomas showing lack of vascularity are not suitable for embolization. The DSA itself would therefore be an unnecessary procedure. The goal of our study was to predict poorly vascularized meningiomas using time resolved MRA (TR-MRA). Materials and methods: TR-MRAs were performed on a 1.5 T whole-body unit (Vision, Siemens, Erlangen, Germany) in 18 patients with meningioma using a snapshot FLASH optimized for 2D projection (TR/TE 4.2/1.5 ms, slab thickness 45 mm). A standard dose of Gd-DTPA was injected with an automatic injector (volume 15 ml at 3 ml/s). Coronally directed TR-MRA was obtained using single slice, 3 frames/s during 34 seconds without time-interval. TR-MRA, DSA and embolization were done at the same day when possible. Signal intensity (SI) of meningiomas in TR-MRA was graded as 0 if no SI is detected. Faint SI was graded as +, good SI as ++, and dense SI as +++. Grades of SI on TR-MRA of meningiomas and possibility of embolization were analyzed using X 2 -test. Results: In 18 meningiomas, 7 graded as +++, 5 as ++, 3 as +, and 3 as 0 in TR-MRA. Embolization was done in all graded as +++ and ++. However, embolization could not be performed on grade + and 0 due to lack of vascularity from external carotid artery (p = 0.000). Conclusion: TR-MRA is an useful study to avoid unnecessary DSA in cases of meningiomas with lack of vascularity which would not be candidates for embolization. Purpose: Traditionally estimation of pancreatic exocrine function has been invasive e.g. duodenal intubation or non-specific. Secretin MRCP can be used to calculate exocrine flow rates. We compared 29 patients with normal pancreatic morphology and 28 patients with chronic pancreatitis. Materials and methods: Following baseline SSFSE, 0.1 ml/kg IV Secretin was administered and the acquisition repeated every 2 minutes for 7 minutes. The receiver gain was held constant. Flow rate = change in total signal intensity over time divided by the signal intensity of a voxel containing 100 % water. Breath-hold axial T1W images and spiral CT were also performed as part of their work-up. 29 patients had a normal pancreas on CT and ERCP, 28 had chronic pancreatitis of whom 8 had had surgery, pancreatoduodenectomy in 4 and a Puestow procedure in 4. Of the remainder, 15 had severe, 3 moderate and 2 mild chronic pancreatitis.

Results: Mean flow rates in the normal group were 8 ml/min ± 2.6 and for patients with severe chronic pancreatitis 5.8 ± 2.6. This difference was significant (student t test P < 0.05). Within the chronic pancreatitis group there were 5 patients with flow rates < 3 ml/min all with longstanding chronic calcific pancreatitis.

Significantly different sMRCP flow rates were seen in normals as compared to patients with severe chronic pancreatitis. Very low flow rates were seen in patients with long standing chronic calcific pancreatitis. Materials and methods: 46 patients with suspected pancreatic lesion were studied in preoperative evaluation, including MRI with VIBE -a fast T1w sequence tailored for dynamic 3D studies -with gadolinium DTPA dynamically, T1w FSE and T2w HASTE. The MRI findings (as described in the reports) were analysed, scored and compared to those from surgery and PAD. Results: MRI detected 45/46 lesions (one papillary tumour was missed). 17/26 neoplastic tumours were correctly characterized as malignant (sensitivity 65 %; specificity 35 %). Vascular encasement (of portal, superior mesenteric vein/artery, celiac trunk, hepatic artery and/or splenic vein/artery) was correctly described in 7/8 cases (sensitivity 87 %; specificity 94 %; PPV 100 %; NPV 97 %). Nodular metastases were correctly characterized in 1/7 (sensitivity 14 %; specificity 86 %; PPV 20 %). Lymph node enlargement (> 10 mm) was metastatic in 1/5. 0/2 liver metastases were found. The remaining 20 non-tumoral lesions were histopathologically classified as 19 inflammatory pseudotumours and 1 papillary fibrosis.

(1) Pancreatic lesions were accurately detected with MRI/VIBE.

(2) The method cannot differentiate benign from malignant lesion. Enlargement of lymph nodes was not correlated to lymph node metastases.

(3) MRI/VIBE is an efficient tool to predict resectability in patients with pancreatic tumour. Vascular encasement was well evaluated. Small liver metastases (≤ 5 mm) were not detected. Methods and materials: All available CT and MR/MRCP studies of 29 patients who underwent surgical resection were considered. The pathological exams revealed 11 IPMT with hyperplasia/low-grade dysplasia, 10 IPMT with moderate/ borderline dysplasia, 4 IPMT with high grade dysplasia/carcinoma in situ, and 4 IPMT with invasive carcinoma. 2 observers retrospectively reviewed all the images, searching for signs indicative of either benignity or malignancy. Results: Considering the criteria reported in literature, after complete evaluation of the lesions the assessment of malignancy was made in 13/29 pts after consensus, being correct in 11/13 (84.6 %) cases. The 2 false positive cases, regarding lesion histologically classified as low-grade dysplasia, the wrong diagnosis was related to their dimension (> 4 cm). In 7 false negative errors were made, concerning lesions lacking any sign indicative for malignancy (moderate/high grade dysplasia: 5; carcinoma in situ: 2). These results yielded a sensitivity, specificity, and accuracy of 61 %, 81 %, and 69 %, respectively. Conclusion: (1) The assessment of malignancy is trustworthy, and warrants surgical resection.

(2) Invasive carcinomas are always recognisable, thanks to the wall thickening, and parietal proliferations. . Additionally, T1-w contrast enhanced (ce), triphasic "volume interpolated breathheld examination" (VIBE) was performed. In a control group of 45 pts. VIBE was replaced by ce 2D-GRE. Two observers analysed data with regard to image quality, tumor conspicuity (ROC), diagnostic accuracy and interobserver variability. Results: 15/45 pts in the study-and 18/45 in the control-group had pancreatic ca. VIBE revealed the best image quality in the study-group (3.6 ± 0.5) outperforming 2D-GRE (2.5 ± 0.8) (p < 0.001). HASTE, T2-TSE and MRCP also performed less well: 2.2 -2.9 (p < 0.001). ROC-analysis (1/2. observer) showed that VIBE (0.76/ 0.76) obtained higher values than HASTE (0.74/0.67), T2-TSE (0.69/0.73) or MRCP (0.62/0.77). 2D-GRE performed signif. worse than VIBE (0.69; p < 0.05). Best diagnostic capability was obtained by combination of all sequences in the study-(0.88/0.91) and the control-group (0.72/0.78). Hence, sens. and specif. was higher in the study-(73 %/87 %) than in the control-group (58 %/75 %) (p < 0.01). Interobsever variability ranged from moderate 0.4 (HASTE), good 0.6 (VIBE; 2D GRE) to very good 0.85 (combination of all sequences). Purpose: To evaluate the use of MR perfusion imaging to monitor organ function of pancreas and kidney grafts after combined transplantation. Methods and materials: A coronal FGRE sequence was used to monitor the signal intensity of transplanted pancreas and kidney grafts, of psoas muscle and aorta before and during the first 6 min after bolus injection of 0.1 mmol Gd/kg BW. A perfusion index as the percentage of maximum signal intensity in the organ relative to the maximum signal intensity in the aorta was calculated. In a prospective study 33 patients underwent a total of 77 examinations. Mean follow-up after transplantation was 98 days (range 7 -486). Perfusion index was used to judge function as good, fair or poor. Results were correlated to clinical course and laboratory data. Results: Absolute values of perfusion index correlated with clinical course of organ function. In addition a strong correlation was found between the intraindividual course of the perfusion index and the clinical course during repeated measurements.

The perfusion index can be used to monitor organ function after combined pancreas and kidney transplantation and is especially important in follow-up examinations to assess the intraindividual course of organ function. Results: Mean number of CT examinations per patient was 3.68, maximum 27 (in those with severe pancreatitis). Mean number of series was 1.1. Mean effective dose was 4.1 mGy, maximum (performed with incremental CT and high exposition parameters) was calculated to result in 18.44 mSv. Mean dose lenght product was 292 mGycm. Risk for radiation-induced cancer could be estimated to be 0.0085 % per average examination, cumulating to 0.23 % in a patient with 27 CT examinations. As a worst case scenario, assuming that the dose per examination would have been the maximum found in this survey (18.44 mSv), the radiation risk would be 2.5 %. Conclusion: Average number of examinations, cumulative dose and estimated radiation risk resulting from CT imaging in pancreatitis patients is moderate, especially in regard to the often severe course of the disease. However especially in young patients, examination parameters should be chosen with care, and MRI should be taken into consideration.

Multidetector CT of isodense pancreatic adenocarcinoma: More there than meets the eye R.W. Prokesch 1 , L.C. Chow 2 , C.F. Beaulieu 2 , R. Bammer 2 , R.B. Jeffrey jr. 2 ; 1 Vienna/AT, 2 Stanford, CA/US Purpose: To assess the frequency of isodense pancreatic adenocarcinoma with multidetector CT (MDCT) and determine the value of secondary signs which aid in their detection. Materials and methods: 53 patients with pancreatic adenocarcinoma underwent contrast-enhanced, biphasic mutidetector CT with curved planar reformations (CPR). Tumors were initially deemed isodense or hypodense on the basis of visual inspection and then confirmed by calculation of mean attenuation differences between normal pancreatic parenchyma and tumor during the pancreatic phase. Indirect signs of pancreatic tumor were tabulated in cases where an isodense tumor was identified.

Results: Out of the 53 patients, six (11.3 %) had isodense tumors with a mean tumor-pancreas contrast of 9.25 ± 11.3 HU during the pancreatic phase and 4.15 ± 8.5 HU during the portal venous phase. Ancillary signs of a pancreatic tumor included an interrupted pancreatic duct (n = 5), dilated biliary and pancreatic ducts (n = 1), atrophic distal pancreatic parenchyma (n = 3), and mass effect/convex contour abnormality (n = 3). Mean tumor-pancreas contrast for the remaining 47 cases was 74.76 ± 35.61 HU during pancreatic phase. Conclusion: Isodense pancreatic tumors, even studied with high-resolution MDCT, represent a significant percentage of pancreatic carcinomas. With no visible tumor-pancreas contrast, indirect signs such as mass effect, atrophic distal parenchyma and an interrupted duct sign are important indicators for presence of tumor. CPR of the pancreatic duct are particularly helpful in delineating the obstructed pancreatic ductal system.

Multislice helical CT with 2D and 3D multiplanar reconstructions using minimum Intensity projection for assessment of the pancreatic ducts M. Zins, N. Bouzar, L. Fontanelle, S. Lenoir, C. Strauss, R. Palau; Paris/FR

To evaluate imaging quality of 2D and 3D multiplanar reconstructions with Minimum Intensity Projection (MinIP) in assessment of the pancreatic ducts using multislice CT. Methods and materials: 35 consecutive patients with potential disorders of the pancreas were scanned using multislice CT. The CT parameters were: 40 s scan delay for the pancreatic phase and 75 s scan delay for the portal venous phase. Pancreatic phase images were used for 2D and 3D reconstructions with the following parameters: 1.25 mm slice thickness; interval of reconstruction: 0.6 mm; the 2D and 3D data sets were evaluated in oblique axial and oblique coronal planes, using MinIP. Qualitative assessment of the multiplanar reconstructions included:

(1) visibility and size of the main pancreatic duct (MPD), (2) visibility of the major papilla, (3) visibility and size of the duct of Santorini, and (4) visibility and size of the branch ducts.

The MPD was entirely visualized in 33 patients (94 %) including 15 with non dilated MPD. The major papilla was visualized in all patients. A non-dilated duct of Santorini was visualized in 9 patients; a dilated duct of Santorini was visualized in three patients with intraductal papillary mucinous tumors of the pancreas (IPMTP). Non dilated branch ducts were visualized in two patients and dilated branch ducts were visualized in 18 patients. Purpose: To assess main pulmonary artery dimensions in normal subjects and in patients with Marfan's syndrome. Materials and methods: 50 Marfan patients (mean age 33 (10) years, 34 men, 16 women) and 15 matched control subjects (mean age 28 (4) years, 9 men, 6 women) underwent cardiac magnetic resonance imaging (MRI). Pulmonary artery dimensions were obtained on axial spin echo images at two different levels: 1) the level of the pulmonary artery root and 2) the level of the pulmonary artery bifurcation.

Results: Upper limits of normal (mean + 2 SD) at the pulmonary root and at the pulmonary artery bifurcation were 34.8 mm and 28.0 mm, respectively. Pulmonary artery dilatation was demonstrated in 37 (74 %, root) and 38 (76 %, bifurcation) of the 50 Marfan patients. There was a good correlation between pulmonary and aortic root diameter in non-operated Marfan patients (r = 0.76). Dimensions of pulmonary root were larger (38.4 mm, range 28.3 -50.7 mm) than dimensions at the pulmonary bifurcation (30.7 mm, range 21.4 -38.5 mm, p < 0.001). Marfan

A C D E F 262 patients with aortic root replacement (n = 35, root 39.7 mm, bifurcation 31.7 mm) had significantly larger pulmonary artery dimensions than non-operated Marfan patients (n = 15, root 35.5 mm, bifurcation 28.5 mm, p < 0.01). Conclusions: In the majority of Marfan patients the main pulmonary artery, particularly the pulmonary root, was dilated. A good correlation between pulmonary and aortic root diameter was demonstrated. Pulmonary artery dimensions were significantly larger in Marfan patients with aortic root replacement than in nonoperated Marfan patients. Methods and materials: Selective pulmonary DSA was performed in 91 consecutive patients with CTPH. Six bolus injections of non-ionic contrast media were used (pa-, oblique and lateral projections of both pulmonary arteries, iomeprol, 25 ml, 13 ml/s). Hemodynamics were obtained using Swan-Ganz catheters and classified in three groups depending on systolic pulmonary pressure (PAsyst): group I: < 30 mmHg, II: 30 to ≤ 60, and III: > 60 mmHg). Results: PAsyst was 21.4 ± 2.2 (group I, n = 7), 49.8 ± 8.5 (II, n = 18), and 87.0 ± 18.9 mmHg (III, n = 66). Pulmonary vascular resistance index (PVRI) was 238 ± 103 (I), 703 ± 364 (II), 1587 ± 569 dyne⋅s⋅m 2 ⋅cm −5 (III), mean cardiac index (CI) was 3.2 (I), 2.8 (II), and 2.3 l⋅min −1 ⋅m −2 (III). PCw pressure was normal in all three groups indicating normal left heart function. Contrast bolus injection caused only slightly increased PA pressure (DPAsyst: 1.1 ± 1.1 (I), 2.9 ± 2.3 (II), and 3.7 ± 3.2 mmHg (III)). After completion of angiography right atrial pressure and PAsyst were moderately increased (DRA: 1.8 (I), 2.6 (II), 3.0 mmHg (III), DPAsyst To determine the value of MRI in the diagnosis of pulmonary embolism (PE) in patients unable to sustain apnoea, e.g. in acute PE. Methods: A real time (RT) steady state free precession (SSFP, TrueFisp) sequence was adapted for the examination of the thoracic vasculature. 21 consecutive patients with suspected pulmonary embolism were prospectively examined with MRI using a RT-TrueFisp sequence and contrast enhanced MR-angiography (MRA). The clinical stages of suspected PE were as follows: chronic 4, mild 7, severe 6, massive 4. Results: 71 % of the MRA-Sequences were diagnostic, excluding all patients with massive and some with severe PE. All 21 RT-sequences were diagnostic. All 125 lobar arteries and 85 % of the segmental arteries could be evaluated, segments 4/5 being the most difficult. For the RT-Sequences, no patient preparation, ECG or breathing commands were needed. PE was diagnosed in 67 % of the patients by RT-MR. In 6 patients with PE, MRA detected 9 additional thrombotic segments. Two diseases mimicking pulmonary embolism could be diagnosed. In all remaining patients with clinically suspected severe and massive pulmonary embolism, thrombotic material could be visualized in the pulmonary arteries. Chronic and acute pulmonary embolism could be differentiated, and the effect of thrombolytic therapy on thrombus size could be visualized. Conclusion: RT-MRI allowed the examination of any patient regardless of his clinical condition in 3 min and required no preparation. Therefore, the range of indications for MRI in patients with suspected pulmonary embolism is extended. The well established MRA technique has advantages in patients able to sustain apnoea.

A differentiated approach to pulmonary embolism and deep venous thrombosis using multi-slice CT J.E. Wildberger 1 , A.H. Mahnken 1 , A.M. Sinha 1 , P. Haage 1 , S. Schaller 2 , R.W. Günther 1 ; 1 Aachen/DE, 2 Forchheim/DE Purpose: To establish a protocol for multi-slice CT (MSCT) examinations for clinically suspected pulmonary embolism (PE) using pulmonary CT-angiography and indirect CT-phlebography (CTP). Methods and materials: From February 2000 to July 2001, 161 patients (92 male, 69 female; age: m = 55.2 a ± 18.1 a) with suspected PE were examined on a MSCT (Somatom Volume Zoom; Siemens, Germany). After intravenous injection of 120 cm 3 of contrast-medium, thin collimation chest CT was performed. CTP was added if PE was present or previous examinations and clinical signs suggested deep venous thrombosis (DVT). The latter was performed using a 4 × 5 mm protocol (slice thickness 7 mm, reconstruction increment 6 mm). Venous phase scanning was completed at the level of the popliteal fossa 3 minutes after contrastmedium injection. Results: 62 patients in our series suffered from PE. 47 of these had additional deep venous thrombosis (78.3 %). The latter was ruled out in 13 patients, one patient with PE did not receive this additional examination protocol due to their poor clinical condition, one subsegmental PE was initially not detected. Of the 99 patients without PE, 47 also received indirect CTP. In 10 cases DVT was proven, which was already known from previous examinations in 8 patients. Only in 2/47 patients (4.3 %) was a previously undiagnosed DVT found, despite exclusion of PE.

The examination protocol presented is suitable for clinical use in patients with suspected PE and offers detailed examination of the venous system. If DVT is not likely, additional CTP is not recommended if PE has been ruled out by MSCT. Methods: Patients with severe chronic CTPH were evaluated using multislice CT and selective pulmonary DSA for operative treatment planning. CT findings and angiographic findings were correlated at the level of major arteries, interlobar arteries, segmental and subsegmental arteries. Diagnostic criteria included patency or occlusion, thromboembolic deposits, webs, bands, and anatomical allocation of the respective findings. Results: In 14 consecutive patients with severe CTPH, CT and DSA findings of 994 pulmonary vessel segments from major to subsegmental arteries were separately analysed. Using multislice CT 30 segments were insufficiently detected (25 subsegments, 5 segments) compared to 50 segments in DSA (37 subsegments, 11 segments, and 2 major arteries). Predominantly segment III and less often segment I arteries were insufficiently detected due to the position of the pigtail catheter. Concerning inconspicuous vessles versus occlusion or any thromboembolic alterations, the diagnostic concordance of both methods overall was 67 %, was 79.4 % for segmental arteries and 63.6 % for subsegmental arteries. Concerning patency versus complete occlusion diagnostic concordance overall was 82.4 %, was 88.6 % for segmental arteries and 77.1 % for subsegmental arteries. DSA was superior for detection of peripheral thromboembolic alterations. CT was superior for anatomical allocation. Conclusion: Multislice CT is suitable for diagnosis of CTPH on segmental and subsegmental level. However, for planning of pulmonary thrombendarterectomy both modalities, multislice CT and selective pulmonary DSA, are still necessary for exact anatomical allocation and precise visualisation of thromboembolic findings. epidemiologic, clinical and morphologic criteria as listed below. (Advanced disease was defined as hepatic insufficiency leading to OLT within the subsequent 2 years). Results: Common and characteristic findings were as follows: 81 % of patients were women with the onset of disease (diagnosis) in middle age (mean, 50.7 years, range, 26 to 71 years). The average time from diagnosis to liver transplantation was 6.1 years (range, 0.5 to 20 years). CT findings in advanced PBC often resembled those seen in other forms of cirrhosis with a small heterogeneous liver, varices and splenomegaly. The liver in less advanced disease was usually enlarged or normal in size, with a smooth contour, little atrophy and lace-like fibrosis and regenerative nodules in nearly a third. Even patients with less advanced disease frequently had varices (62 %) and ascites (24 %). Prominent lymphadenopathy was seen in 88 % of all cases. Hepatocellular carcinoma was found in only 4 patients, 2 of whom also had chronic hepatitis C. Only two patients had recurrence of PBC following OLT Conclusion: PBC is an important cause of liver failure with distinctive clinical and CT findings that may allow confident diagnosis and management. 

We reviewed retrospectively the imaging studies of five patients (4 women; aged 16 -25 years) with liver nodules associated with a spontaneous intrahepatic portosystemic venous shunt. Color-doppler ultrasoud (US), helical-CT and arteriography were performed in all patients and MRI in 4 patients. Nodules location, number, size, density or signal, homogeneity and pattern of vascularition were evaluated. Hepatic vascularization, the morphologic type of the shunt and portal hypertension features were also analyzed. These findings were correlated to pathological results (transcutaneous biopsy of the nodules (n = 3); transplantation (n = 2)). Results: Sonography and angiography demonstrated a portohepatic venous shunt (persistent Arantius ductus (n = 1), congenital absence of portal vein (n = 2), left portohepatic venous shunt (n = 1), left portoatrial shunt (n = 1)). Hepatic arterialisation were observed in segment where no portal flow was seen and where hepatic nodules were present. The number of nodules in each patients was at least 3 with a size ranging from 1 to 12 cm. Most lesions were heterogeneous, hypoechoic on US, hypodense on CT, hyperintense on T1, slightly hyperintense on T2 and enhanced slightly and heterogeneously on arterial phase after contrast injection. Histological results showed nodular hyperplasia in the liver suggestive of focal nodular hyperplasia in all cases and adenoma in one case. Conclusion: These findings emphasised the hypothesis that nodular transformation of the liver is probably due to the lack of portal blood flow and hepatic arterialisation and is usually of benign type.

High resolution multislice spiral CT in liver metastasis: Comparison of a high resolution vs a low resolution protocol F. Fraioli, C. Catalano, A. Laghi, F. Pediconi, A. Napoli, R. Brillo, M. Danti, R. Passariello; Rome/IT Purpose: To evaluate the sensitivity and specificity of multislice spiral CT (MSCT) in the assessment of patients with suspected liver metastasis and to compare two different acquisition protocols. Material and methods: 50 patients referred for different neoplasms underwent MSCT. All patients underwent intraoperative ultrasound or, in case of diagnosis of unresectability in the first examination, a follow up CT at three months. Pre (4 × 2.5 mm collimation) and post-contrast (4 × 1 mm collimation, 1 mm and 5 mm reconstruction interval) acquisitions, during arterial and portal venous phases were performed after i.v. administration of 140 ml of c.a. at 4 ml/s. Two observers blindly evaluated either 5 mm axial images or 1 mm axial and relative MPRs, in terms of presence and number of lesions. Results: CT correctly showed 123 (92 %) of the 133 liver lesions shown at intraoperative ultrasound in 42 patients. CT correctly evaluated all lesions greater than 2 cm in size. Regarding lesions smaller than 2 cm in size CT evaluated as cyst 4 lesions shown at intraoperative ultrasound as metastasys. Real time interaction 3D data set with 1 mm axial images, allowed to identify 24 subcapsular lesions.

Sensitivity, specificity and accuracy in detection of smaller lesions smaller than 1 cm was 98 %, 94 % and 97 % using 1 mm axial images and 89 %, 93 % and 90 % using 5 mm protocol. Conclusion: High resolution MSCT with 3D data is a very accurate technique in the assessment of patients with liver metastases.

The difference of images secretory and non-secretory carcinoid tumours using standard CT and functional techniques J.B. Cwikla, J.R. Buscombe, A.J. Watkinson, M.E. Caplin, A.J.W. Hilson; London/GB Functional and anatomical imaging modalities can underestimate presence or extent of disseminated carcinoid and should be used together. Aim of study was to assess if there is any difference in imaging pictures between secretory and nonsecretory carcinoid and toconsider both techniques. Overall 50 patients, all with confirmed carcinoid. There were 31 patients with primary disease. Half of the patients had secreting tumours with carcinoid syndrome. CT and 111 In Octreotide study was performed in each case, using standard imaging protocol. In non-function tumours CT was able detect disease within liver in rate of 0.53. 111 In Octreotide was positive in all patients. Different sites within abdomen and chest in patients with non-secretory tumours CT and functional imaging detected with rate as follows: pancreas 0.57/0.71, paraaortic nodes 0.7/0.8, gut and/or mesentery 0.67/ 0.83. Other site of tumour spread: chest, pelvis, spleen or bone using CT was 0.25 and 111 In Octreotide 0.92. Those patients with secretory tumours had results as follows: liver deposits using CT in 0.96, 111 In Octreotide 0.91. In this group of patients other sites of tumour deposits within abdomen and chest CT and functional imaging detected with rate as follows: pancreas 0.25/1, paraaortic nodes 0.79/ 0.93, gut and/or mesentery involvement both 0.61. Other site of tumour spread like chest, pelvis, spleen or bone involvement using CT was 0.41 and 111 In Octreotide 0.82. These results suggest that any imaging modality is perfect to detect carcinoid deposits, additionally there is a difference with deposits distribution of carcinoid in patients with secretory and non-secretory tumours.

Lymphoma therapy monitoring by multislice perfusion-CT W. Römer, L. Muresan, R. Repp, A. Taubald, H. Greess, W.A. Kalender, W.A. Bautz; Erlangen/DE Purpose: The high frequent acquisition of multislice CT data after contrast medium bolus injection allows quantification of tumor perfusion. It was our goal to assess therapy induced changes of tumor perfusion early after initiation of lymphoma treatment using dedicated software to calculate parametric images. Method: Dynamic MSCT was performed in 19 patients with lymphoma before and 7 days after initiation of chemotherapy. After automatic bolus injection of 80 ml contrast medium (flow 8 ml/s), two 10 mm-sections through the largest tumor region were scanned for 40 s (Siemens Somatom Volume Zoom). The arterial input function was derived from the largest arterial vessel in the field of view. Perfusion indices were calculated using graphical analysis and displayed as parametric color coded images. Results: At baseline, all lymphoma lesions were visible in perfusion images by an enhanced perfusion index (0.474 ml/min/ml). Seven days after initiation of chemotherapy, tumor perfusion decreased by 46 % in high grade NHL and Hodgkin's lymphoma, whereas in two patients with low grade NHL the perfusion index increased by 55 %. In contrast, 2D-tumor size only decreased by 19 % and 11 %, resp. Conclusion: These results indicate that chemotherapy-induced changes of tumor perfusion may be assessed by perfusion MSCT and documented in parametric images. In highly responsive tumors like high grade NHL and Hodgkin's lymphoma, therapy induced perfusion changes occur within the first 7 days after therapy and precede morphologic changes. We hypothesize that outcome of therapy may be predicted as early as 7 days after treatment.

The effect of intravenous secretin administration on hepatic enhancement during CT examinations of the abdomen S.M. Lyon, T. Fotheringham, P. O'Sullivan, M.F. Given, M.J. Lee; Dublin/IE Purpose: Intravenous secretin increases blood flow to the pancreas in animals. In an associated study we found that IV secretin caused significantly increased enhancement of the portal venous (PV) system. This study investigated the effect of secretin on hepatic enhancement.

Methods: 32 patients (mean age 70; range 47 -88) were enrolled. Triple phase helical CT of the abdomen was performed on successive days so that each patient acted as their own control. All patients had intra-abdominal malignancy and the study was approved by the hospital ethics committee. Unenhanced and enhanced CT in the arterial phase and PV phase was performed without (day 1)and with (day 2) secretin (100 IU) given at t = 0 s (n = 10), t = 60 s (n = 5), t = 120 s (n = 5), t = 180 s (n = 4), t = 240 s (n = 4), t = 300 s (n = 3). Percent enhancement of the liver was calculated using ROI's obtained from studies with and without secretin. Results: Overall mean hepatic enhancement in the portal venous phase was 109 % without secretin and 117 % with secretin. The relative increase in hepatic enhancement after secretin when compared to hepatic enhancement without secretin was 13 % at t = 0, 16.6 % at t = 60 s, 24.6 % at t = 120 s, 18.9 % at t = 180, 3.1 % at t = 240 and 19.5 % at t = 300 s. PV/SMV enhancement was significantly increased in all secretin studies (p < 0.05) when compared with non-secretin studies. Conclusion: Secretin administration causes an increase in hepatic enhancement which may lead to better lesion conspicuity. The optimal timing for secretin administration and its effect on lesion-liver contrast differences will be determined as more patients are recruited. Study completion is expected in November 2001.

Imaging findings in extraosseous multiple myeloma M. Patlas, I. Hadas-Halpern, C. Reinus, E. Libson; Jerusalem/IL Purpose: Extraosseous manifestations are rare and are found in less than 5 % of patients with multiple myeloma. The purpose of this study is to illustrate the imaging features of extraosseous myeloma and to heighten the awareness of this phenomenon.

We retrospectively reviewed the radiological files of 200 myeloma patients. Patients in whom the extraosseous masses were in contiguity with bony involvement were excluded from the study. Results: Seven of the 200 (3.5 %)myeloma patients had extraosseous masses. There were 2 men and 5 women and the age range was 48 -82 years old (mean age 60 years). CT was available in five patients, mammography in three cases, and ultrasound in one case. Biopsy revealed the diagnosis of plasmacytoma in all cases. The gamut of findings included breast masses (three patients), supraclavicular lymph nodes (1 patient), pancreas and stomach (1 patient), adrenal and pleura (1 patient), thyroid cartilage (1 patient). More than one site was present in 2 of the 7 patients (adrenal and pleura; pancreas and stomach). Soft tissue plasmacytomas presented as relatively well-defined masses of various sizes, and could not be differentiated from other malignant or benign lesions on the basis of the imaging findings alone. Conclusions: Exraosseous myeloma is very uncommon in multiple myeloma.

Radiologists should be aware of this occurence so that extensive unnecessary interventions can be avoided when extraosseous sites of disease are encountered.

Quality indicators in radiology management: A methodology development study P.E. Varga 1 , E. Belicza 1 , E. Sík 2 , G. Nagy 3 ; 1 Budapest/HU, 2 Szekszárd/HU, 3 Zalaegerszeg/HU Purpose: Quality indicators are widely used in healthcare. Though imaging is involved in almost all diagnostic procedure, few quality indicators are accepted in radiology. Method: Repeated X-ray examination data were collected in 3 hospitals. The 3-month multicenter study aimed to develop an indicator as well as to test the indicator development method itself, using common data sheets. In the 886 repeated examinations, the influence of different reasons of repetition was analysed. Results: 21 causes were identified. Inappropriate exposition or positioning were leading causes, in 71.6 % of the cases in Hospital 1, 72.6 % in Hospital 2 and 22.0 in Hospital 3. Failure of the equipment was the second cause: 25.0 %, 7.9 % and 0.1 %, respectively. Low rates in Hospital 3 can be attributed to the newly equipped digital X-ray department. In other words: Hospital 1 and 2 pay the price of the lack of investment with repeated examinations. Day-section has a higher influence than workload: though the majority of the examinations were carried out during normal hours, 23.7 % of the repetitions occur on night duty. Nearly half of the technicians involved found the data sheet too detailed and they proposed to modify HIS for automatic registration. As repeated examination means increased risk for the patient and the institution, economical consequences will be demonstrated. Conclusion: Repeated X-ray examination proved to be an appropriate quality indicator, as it is profession-specific, relevant and convenient for benchmarking. Data collection is easy and economic data can be linked. Quality management can be based on reason analysis. Materials and methods: Of 59 patients who were referred for percutaneous drainage of hepatic abscess between 1995 and 2001, cases with incorrect diagnosis or without pre-procedural contrast-enhanced CT were excluded, and 78 abscesses in 47 patients (29 -79 years, M:F = 35:12) were included. 24 patients had the predisposing factor such as hepatocholedocholithiasis (n = 7), the history of biliary (n = 6) or gastrointestinal (n = 5) malignancy, or others. Findings in dual-phase helical CT (n = 34) or single-phase CT (n = 13) were analyzed concerning the enhancement pattern of the abscess wall and adjacent parenchyma, and the presence of the thrombosis of intrahepatic vasculature.

The abscess wall appeared as single layer of hyperdense ring in 38 lesions (48 %) or as double target (inner hyperdense ring and outer hypodense ring) in 32 lesions (41 %). There was thrombosis in the hepatic vein (n = 20) and/or portal vein (n = 18) noted in 30 cases (64 %). In cases with dual-phase CT, regional difference in parenchymal attenuation was noted in 28 cases (82 %), showing wedge-shaped hyperdense area surrounding the absecss in arterial phase (n = 24) or hypodense area peripheral to the abscess in portal phase (n = 11). Of those cases with regional difference in parenchymal attenuation, 21 cases (75 %) had venous thrombosis (p = 0.07, Fisher's exact test).

The abscess wall has characteristic enhancement pattern on dynamic CT. The enhancement pattern of adjacent parenchyma is more complex, and it may be associated with the venous thrombosis. The liver is the most commonly damaged organ in children following blunt abdominal trauma. A conservative non-operative approach is now the recognised standard of care. Computerised Tomography (CT) is the primary imaging modality of choice. This conservative approach can result in bile duct damage remaining undetected for several days. We have evaluated the pre-emptive use of TBIDA hepatoscintigraphy, to detect biliary leakage prior to the patient becoming symptomatic. At Birmingham Children's Hospital, all patients who have a history of trauma and clinical suspicion of abdominal injury undergo an abdominal CT. In those cases where there was liver fracture greater than 4.0 cm or involving the portahepatitis, a TBIDA study was performed. 21 patients underwent an abdominal CT abdomen. 7 patients had a significant liver injury, all with fluid in the peritoneum and additionally had a TBIDA study. In 2 patients the TBIDA demonstrated activity within the peritoneal cavity. Intraoperative cholangiograms confirmed the biliary leaks that were surgically stented. Both patients were asymptomatic with no evidence of a biliary peritonitis. The TBIDA in a third patient demonstrated a biloma that on follow-up ultrasound has shown to be shown to be the site of a portovenous fistula. All patients showed good recovery and returned to a normal lifestyle. TBIDA hepatoscintigraphy, when used pre-emptively, can detect biliary damage prior to the development of clinical symptoms. This early detection improves surgical outcome and reduces hospital stay. The investigation also allows the detection of other potential intrahepatic complications.

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Acute pancreatitis in childhood L. Laufer, O. Kleiner, G. Greenberg, Z. Cohen, Y. Hertzanu; Beer Sheva/IL Purpose: Acute pancreatitis in children is rare. The aim of this study was to demonstrate the spectrum of imaging findings in relation to the aetiology. Materials and methods: 46 children aged 1 -18 a between 1984 and the year 2000 were diagnosed at our hospital with acute pancreatitis. The diagnosis was established using clinical data, US and CT examinations. A history of trauma was present in 22 children, 20 cases were considered to be idiopathic. The other cases were secondary to biliary stones, thalassemia, steroid treatment and chemotherapy. Results: There is a considerable difference between traumatic and nontraumatic pancreatitis. The imaging in most cases of idiopathic pancreatitis was normal or minimal changes were showed. The children with pancreatic injury demonstrated a large range of imaging findings. Laceration or fracture (13 cases), local or diffuse pancreatic enlargement (16), nonhomogenous structure (20), and pseudocyst formation (6). The tail was involved twice as frequently as the head.

The study showed a large difference between the 2 groups. The contribution of imaging in diagnosis of idiopathic cases was minimal and follow-up was unnecessary. The imaging of posttraumatic pancreatitis demonstrates a large spectrum of pathology in the early examination and follow-up studies.

When can balloon dilatation of esophageal strictures in children be considered successful? J. Lisý jr., J. Snajdauf, M. Vyhnánek, S. Tuma, J. Neuwirth; Prague/CZ Purpose: Healing of a stricture by scar formation after balloon dilatation results in narrowing of the eosophageal lumen and reccurrence of dysphagia. Consequently repeated dilatations are usually necessary. The authors tried to establish the delay after dilatation when the procedure could be considered successful and further dilatation or surgery was not indicated. Methods and materials: Eosophageal strictures in 49 children were treated by 189 balloon dilatations in total. 20 children had an anastomotic stricture after surgery for eosophageal atresia, 12 had a reflux stricture, 6 a tight cuff after Nissen fundoplication causing achalasia, 6 a corrosive stricture, 4 congenital stenosis and 1 a stricture after radiation. Dilatations were considered successful, when absence of dysphagia lasted for at least 1 year after dilatation and the patient hadn't undergone surgery. Results: One procedure completely treated the stricture in 11 children (22 %). None of them had surgery. Repeated procedures were neccessary in 38 patients (78 %). The delay between dilatations in the case of repeated procedures ranged from 1 week to 3 years. Dilatation avoided surgery in 27 cases (56 %). Only 6 of these patients had more than a 6 month delay between procedures. The remaining 11 children (22 %) required surgery after repeated unsuccessful dilatations. However in none was there a need for repeat dilatation later than 6 months following a previous procedure. Conclusion: The authors conclude that a delay of 6 months after dilatation is the key time for evaluation of success rate of eosophageal balloon dilatation.

Crohn's disease in paediatric patients: MR imaging of the small bowel using PEG solution as an oral contrast medium A. Laghi, I. Carbone, I. Baeli, R. Iannaccone, P. Paolantonio, F. Iafrate, C. Catalano, R. Passariello; Rome/IT Purpose: The aim of this study was to evaluate MR findings of the small bowel using PEG solution as an oral contrast medium in paediatric patients with suspected Crohn's disease. Subjects and methods: Twelve patients with clinical and laboratory findings indicating possible Crohn's disease underwent MR study of the small bowel. After an overnight fast, immediately before MR examination, a fixed amount of 10 ml/kg of weight of PEG solution was orally administered. No antispasmodic drug or other drugs were given. MR study was performed using HASTE (TR/TE/acq.t.: inf/90 ms/ 18 s) and truFISP (TR/TE/acq.t.: 4.8 ms/2.3 ms/14 s) sequences obtained sequentially for up to 20 minutes, in axial and coronal planes. T1 weighted FLASH sequences (TR/TE/acq.t.: 140 ms/5.3 ms/16 s) were acquired before and after dynamic contrast medium administration (0.1 mmol/kg of Gd-DTPA). Image were analysed by consensus by two experienced gastrointestinal radiologists. Results: Seven patients presented positive findings for Crohn's disease. MR findings were represented by: wall thickening of the terminal ileal loop, with stricture in three cases. Following contrast medium administration wall enhancement was observed in all the cases.

Conclusion: MR imaging of the small bowel after oral administration of PEG solution is a reliable, reproducible, and safe imaging modality for the evaluation of Crohn's disease.

Colonic duplication: Clinical presentation and imaging features M.-J.G.J.G. Grandsaerd, M.P. Hartkamp, C. Boetes, P. Rieu, C. Buonomo, C.E. van Die, J.G. Blickman; Nijmegen/NL Purpose: To make the imager and clinician aware that colonic duplication may present at birth, associated with other congenital anomalies or late, as an isolated finding. In the latter instance, the duplication almost always features connecting lumens. Material and methods: We reviewed the clinical and radiological features of 9 cases of colonic duplication over the last 10 years. There were 7 girls and 2 boys. Their age at presentation was either newborn (6, all girls) or between 4 and 11 years old (2 boys, 1 girl). All had contrast enemas, and 3 underwent abdominal CT. Results: Those that presented at birth had multiple associated congenital anomalies, including partial and complete VATER associations (5, all girls), duplication of the bladder in 2, uterus and vagina in 2, as well as situs inversus totalis in 1 girl. The older presenting children all had long-standing symptoms of constipation and distended abdomens. All duplications had connecting lumens. Conclusion: Duplication of the colon is a rare congenital anomaly. This report illustrates that there are 2 peaks of presentation: perinatally and later in childhood. Furthermore, in the former group multiple associated congenital anomalies are present in all (or almost all) cases. As opposed to other GI duplications, these colonic duplications displayed connecting lumens.

Renal parenchymal volume assessment with 3D ultrasound in paediatric uroradiology G.A. Fritz, M. Riccabona, E. Ring; Graz/AT Purpose: To prospectively investigate the accuracy of renal volume assessment using three-dimensional ultrasound (3DUS) compared to the results of 2DUS, CT/ MRI, or scintigraphy in neonates, infants and children. Methods and materials: 60 patients (mean age 9.81 ± 8.1 years) underwentadditional to conventional US and other conventional imaging as appropriate -3DUS of the kidney for anatomical and volumetrical assessment. 3DUS was performed with a Voluson (Kretztechnik/GE, Austria/USA) or an external 3D-system (Echotech/GE, Germany/USA). Volume calculations were performed in 2DUS applying the ellipsoid equation V = (p/6) × L × W × AP, for 3DUS using the system specific volumetric software; in CT/MRI volume was calculated by planimetric analysis, and for scintigraphy the renal volume was quantified as relative renal volume. Volume measurement focused on renal parenchyma, a dilated renal collecting system was subtracted. Results: In 55/60 patients at least one 3DUS acquisition/kidney was of diagnostic quality. 3DUS volume measurements were accurate compared to CT/MRI (± 5 %). 2DUS volume estimates showed a larger variation and difference (± 10 %), particularly in kidneys with dilated collecting systems or scars, volumes differed significantly. There was a good correlation of relative renal volume in 3DUS compared to scintigraphy in patients without acute pyelonephritis or other perfusion alterations. Conclusion: 3DUS is applicable to the paediatric genito-urinary tract. 3DUS is a more accurate method than 2DUS for assessment of (relative) renal parenchymal volume, particularly valuable in patients with hydronephrosis. 3DUS improves sonographic potential and can be considered a useful adjunct to conventional imaging.

Pediatric excretory MR urography A. Borthne, C. Pierre-Jerome, K. Gjesdal, T. Storaas; Oslo/NO Purpose: Normal-sized ureters are difficult to visualise in neonates and small children with the HASTE-technique (hydrography). An additional contrast-enhanced T1-weighted Fast Gradient Echo (FGE)sequence was used for improvement of the image quality. Methods and materials: An experimental study with 3 pigs was first performed to validate the excretion-technique. We then studied 34 patients (17 neonates and 17 children) with the same technique. After injection of Gadolinium and 5 mg of frusemide, contiguous coronal FGE images were acquired with: matrix 163 × 512, TR 2.6 ms, flip angle 60, FOV 260 mm, slice thickness 3.3 mm, gap 1.6 mm, NSA 6. 2-and 3-dimensional reconstructions of the entire genitourinary system were performed, followed by quantitative and qualitative image analysis.

In all neonates the excretion technique proved better than hydrography; 79 % of the ureters were completely visualised. In children 4 patients with obstruction/reduced kidney function were better seen with hydrography. All the others were better or equally visualised with the excretion technique: complete assessment of the ureters were achieved in 74 % of the children. The mean diameters of the ureters in neonates were: 3 mm (proximal), 4 mm (middle) and 3 mm (distal segment); in children: 4 mm, 6 mm and 4 mm respectively. Conclusion: Excretory MR Urography is better than the non-enhanced HASTEtechnique (hydrography) for the assessment of the entire excretory system in neonates and children, except for those patients with marked obstruction or reduced kidney function.

Grade one vesicoureteral reflux -an undergrading? K. Darge 1 , G. Roessling 2 , J. , with the intravesical application of microbubbles containing the US contrast medium Levovist, were performed successively during one examination session. Any grade I reflux detected on VCUG was compared to the reflux grade of the respective VUS. Furthermore, in an in-vitro set-up simulating the urinary tract the possibility of passive ascension of microbubbles in the ureter was examined using a UV-spectrometer. Results: Grade I reflux was identified on VCUG in 22 patients comprising of 23 kidney-ureter-units [KUUs] . In 7 KUUs the reflux was also grade I on VUS. In the remaining 16 KUUs microbubbles were detected in the renal pelvises, the grades of VUR being 2 and 3 in 12 and 4 KUUs, respectively. Prior to the administration of the US contrast medium dilated ureters were seen in 13 KUUs. The renal pelvis was dilated only in 2 cases. In the in-vitro set-up using the same US contrast medium, despite the absence of counter-flow no microbubbles were detected at the site corresponding to the renal pelvis. Conclusion: Microbubbles detected in the renal pelvis can only have been actively propagated by the reflux pressure and do not ascend passively up the ureter. 70 % of the grade I refluxes diagnosed in the VCUG are actually grade II or higher.

Review of imaging before and after surgery for posterior urethral valves N.P. Power, K. McHugh, I. Gordon, D. Wilcox, P. Duffy, P. Ransley; London/GB Purpose: To compare the imaging appearances on both micturating cystourethrography (MCUG)and ultrasound (U/S)before and after surgery for posterior urethral valves (PUV). To determine the clinical effectiveness of routine postsurgical MCUG. Materials and methods: The imaging findings of 43 boys, of whom 7 had two operations for PUV were reviewed. MCUG was performed before and after each operation making 100 MCUG in total. Features evaluated included the appearances of the bladder, posterior and anterior urethra, the presence of vesico-ureteric reflux (VUR) and the contemporaneous U/S results. Age at surgery and creatinine results were also noted. Results: Age at surgery ranged from 6 days to 5 years 9 months. 50 % were less than a month at surgery. VUR was detected in 40 % of patients; most of these were unchanged post-operatively. The commonest bladder abnormality was trabeculation (82 %); 75 % were unchanged on follow-up. 50 % of patients had a small volume bladder. When the posterior urethra was visualised it was invariably dilated. 52 % of patients had an apparently narrow anterior urethra initially; most improved on follow-up. The commonest U/S findings were bilateral hydroureteronephrosis (62 %)and bladder wall thickening (42 %), although 4 % of pre-operative U/S were normal. Most patients had little change in U/S features. 78 % had a fall in creatinine post-operatively. Conclusion: A small number of boys with PUV may have normal U/S appearances. Imaging appearances on both MCUG and U/S are frequently unchanged after PUV resection. As patient management depends on several factors including renal function and cystoscopy findings, we question the clinical effectiveness of routine post-operative MCUG.

The transbrachial approach for sclerotherapy in paediatric varicoceles P. Agresti, S. Pieri, L. de Medici, G. Fiocca, A. Calisti; Rome/IT Introduction: Percutaneous sclerotherapy has gained wide acceptance in the treatment of male and female varicocele. We introduced the percutaneous approach into the paediatric population, because it is minimally invasive, uses local anesthesia, is minimally traumatic and less expensive than a surgical option. We report our 10 year experience with the transbrachial approach. Materials and method: From 1991 to 2000 we have done 425 procedures. Inclusion criteria were positives at physical, Doppler and ultrasound examination for varicocele type I, grade III, and II only if symptomatic. Phlebography was done under local anesthesia, with a transbrachial approach. We first try to enter the right spermatic vein and then work on the left side. Sclerotheraphy was done with tetra-decilsolfato (Trombovar). Follow up with clinical examination was done at 1 -6 -12 months and 6 -12 months with colour-Doppler Ultrasound. Results: Median age was 14.7 years. Symptoms were present in only 3 % of boys. There were 78/425 bilateral varicoceles, 15 on the right and the remainder on the left. There were good clinical results with sclerosis in 95 % of the treated boys. Discussion: Percutaneous sclerotherapy of varicoceles is a safe, effective and less expensive option than surgical therapy, especially in the bilateral form, with a low complication rate. Methods: 20 Patients with fractures of the mandible underwent MRI (Gradient Echo sequences before and after contrast administration). Continuity of the nerve was evaluated by visual inspection, signal intensity was measured by region of interest in 4 different locations.

The nerve could be evaluated in all 20 cases. The continuity or the disruption of the nerve detected on MRI was confirmed by the surgical findings in all patients. There was no difference in the increase in signal intensity after contrast enhancement between patients with and without disruption of the nerve. Some patients with neurological deficit without disruption of the nerve, showed a decrease of signal intensity distal the fracture. All the other patients without neurological deficit had an increase of signal intensity from proximal to distal. Conclusion: It is possible to detect the disruption of the nerve by MRI. The reason why the signal intensity in some patients decreases seems to be unclear. As we used Gradient Echo sequences, which in particular show blood flow effects, it might be possible to measure a reduced blood circulation in the perineurium distal the fracture by regions of interest. Beside prevention of neurological deficits, this might be another argument for urgent surgical treatment.

BMD measurements in the jaw from dental CT images. Verification of the method and first applications in dental implantology A. Beer, P. Homolka, A. Gahleitner, M. Tschabitscher, R. Nowotny, H. Bergmann; Vienna/AT Purpose: In implant dentistry, both bone quantity and quality, are of vital importance for preoperative planning. While bone quantity is well defined, different approaches on measuring bone quality exist. Usually quite crude grading schemes are applied, that may not provide a quantitative measure for local bone quality exactly at the intended implantation site.

A C D E F 268 Methods and materials: A calibration standard with known concentrations of Hydroxyapatite is scanned simultaneously with the patient using an adapted Dental-CT technique. Conversion of Hounsfield numbers to BMD values is accomplished using a linear relationship. BMD is evaluated locally using full CT image resolution on reformatted views to evaluate possible implant sites. Results: In a cadaver mandible pilot study a strong correlation (R 2 > 0.85) between BMD and the insertion torque of dental implants is demonstrated. Therefore, BMD may serve as an estimate of achievable primary implant stability and thus, as a measure of bone quality. First clinical applications are going to be presented. Conclusion: Since a correlation with mechanical bone properties and accepted measures of primary implant anchorage has clearly been established, preoperatively determined BMD values of the jaw bone could help to assess possible implant sites to optimize primary stability and long term prognosis of the implants by guiding the surgeon through the choice of best suited implant site or implant type and preparation technique.

Periapical dental findings evaluated with coronal sinus CT C.R. Krestan, P.L. Peloschek, C. Czerny, S. Grampp, A. Gahleitner; Vienna/AT Purpose: To evaluate the frequency of chronic peripical periodontitis (CAP) in teeth in the upper jaw using coronal sinus CT. Methods: We reviewed 95 coronal sinus CT examinations (CT-Secura, Philips Medical Systems, Best, the Netherlands) from non-selected clinical patients. Sinus CT was performed with the patient in the prone position with a collimation of 3 mm from the ventral border of the frontal sinus to the posterior edge of the sphenoid sinus. Reconstruction was done using a high-resolution bone algorhythm. The frequency and size of hypodense periapical lesions was determined by two radiologists in a consensus reading. Frequency and severity of artifacts from restoration dentistry and disease of the maxillary sinus was recorded. Results: In 4 out of 95 patients (4.2 %) periapical disease (CAP) could be dignosed. In 40 of these 95 patients metal artifacts reduced the image quality of the periapical region. The regions 16 and 26 were most affected by artifacts. There was no statistically significant difference between the site of periapical disease and concomitant sinus disease. Conclusion: In up to 4 percent of non-selected patients, referred for sinus imaging, we found periapical dental disease on coronal standard CT. Although coronal sinus CT is not the method of choice for evaluating dental disease, it is worth to pay attention to periapical disease.

Atypical non-odontical chronic jaw pain: Findings on panoramic radiographs and dental-CT-scans correlated with histology and microbiology P.L. Peloschek, D. Turhani, F. Watzinger, M. Püregger, I. Sulzbacher, J. Sailer, C. Czerny; Vienna/AT Purpose: The aim of this study was to compare radiographic, histological and microbiological findings of patients with atypical non-odontical pain of the jaw. Patients and methods: From 1998 to 2001 20 out-patients with jaw pain of uncertain origin were prospectively analysed by panoramic radiographs and CT following open biopsy. The axial CT scans (Philips CT Secura; 120 kV, 70 mA, scan time 2 seconds, slice thickness 1 mm, table index 1 mm, high resolution filter) were reformatted using Dental-CT software (Philips EasyVision, Dental Reformatting Package). Usually no contrast enhancing media were given. Inclusion criteria were long-term patient history with pain and/or swelling located in a tooth-free region and unclear conventional and panoramic radiographs. Exclusion criteria were previous fractures, osteoradionecrosis and dental residuals. In this cohort, laboratory parameters were inconclusive. The bicortical bone-biopsies were classified following histological and microbiological findings. Radiographic findings were correlated with the results of the histological and microbiological examinations. Results: 20 patients could be included. No significant correlation between radiological and microbiological or histological findings was found. Histological diagnosis included unspecific post-inflammatory changes, active osteomyelitis and healthy specimen. Conclusion: The use of conventional radiographs, panoramic radiographs and Dental-CT in the diagnosis of chronical atypical non-odontical pain of the jaw should be re-thought. If panoramic radiographs give no appropriate information in finding a focus in chronic pain of a tooth-free region, Dental-CT will not give further information. Maybe dynamic MRI will resolve this diagnostic dilemma. Appropriate studies are in progress.

Does a dose reduction by a factor of 27 affect the diagnostic value of multirow detector helical CT of the sinuses? D. Tack, J. Widelec, J.-M. Bailly, C. Delcour; Charleroi/BE Purpose: To compare multiplanar reformations (MPR) and volume rendering technique (VRT) as well as virtual endoscopic views (VE) obtained from helical multirowdetector computed tomographic (MRDCT) respectively with low-dose and standard-dose acquisitions in patients with sinusitis. Method/materials: 50 consecutive patients with headache referred for a standard dose brain CT and in whom a sinusitis was found or had to be excluded had a second acquisition with a low dose technique (Volume Zoom, Siemens). Following parameters were used for the standard dose acquisition: collimation 4 × 1 mm, rotation time: 0.75 s, 140 kV, 150 mAs, pitch: 0.875, CTDIW: 57.2 mGy, reconstruction width and increment 1.25 and 0.8 mm; low-dose acquisition: collimation 4 × 1 mm, rotation time: 0.5 s, 120 kV, 10 mAs, pitch: 2, CTDIW: 2.04 mGy. Coronal, axial and sagital 2 mm thick MPR and selected VRT and VE views were obtained from both native image sets and analysed on workstations by 3 radiologists who had to state the normal or abnormal appearence of 16 different anatomic regions. The effective dose was computer simulated. Results: In 785 of of 800 regions of interest, no difference was found by all 3 readers. In the remaining 15 regions, 2 of 3 readers stated that low-dose and standard dose images were equivalent. Computer simulated effective dose were respectively for standard-dose and low-dose MRDCT of 1.72 and 0.063 mSv. Purpose: Due to the complex anatomy of the facial bones CT examinations of fractures in at least two planes are required for reliable diagnosis and operative planning. However, in some cases examination can be performed in the axial plane only. Therefore high quality MPRs from axial CT-datasets have to be obtained. Aim of this study was to analyse the influence of collimation, reconstructed slice thickness/increment, reconstruction-kernel, tube current and ultra high resolution (UHR) and non-UHR acquisition on detectability of facial fractures. Methods and materials: A cadaver head with artificial blunt facial trauma was examined using a Siemens Somatom Volume Zoom unit (Siemens, Erlangen, Germany). Acquisition parameters were: collimation 2 × 0.5 vs 4 × 1 vs 4 × 2.5 mm, tube current 120 vs 90 vs 60 mAs, UHR and non-UHR, reconstructed slice thickness/increment 0.5/0.3 vs 1.0/0.6 vs 3/1.5 mm. Out of these volume datasets coronar and sagittal MPRs were obtained with the following reformation parameters: slice thickness 0.5 -3 mm, overlapping 0.5 -3 mm. 6 fracture locations were scored blinded by 5 experienced radiologists. Inter-observer variability was determined with the Κ-test. Differences in fracture detection of the respective algorithms were assessed with Wilcoxon-and Friedman-tests to p < 0.05. Results: Detectability of fractures was higher in 2 × 0.5 mm collimation (p = 0.001 to p < 0.0005). UHR is superior to non-UHR (p = 0.001). 120 mAs exceeded 90 and 60 mAs (p < 0.0005) in UHR and non-UHR, respectively. Thin MPRs (0.5/ 0.5 mm, 1/0.5 mm) are superior to thick MPRs (p = 0.023 to p < 0.0005), whereas there is no significant difference between 0.5/0.5 mm and 1/0.5 mm (p = 0.317). Conclusion: Our data reliably prove that for subtle fractures thin MPRs (0.5/0.5 mm, 1/0.5 mm) should be obtained out of thin slices (0.5 mm) with 120 mAs in UHR.

Multi slice CT with 3D reconstruction in the maxillofacial diseases F.M. Drudi, S. Padula, A. Righi, F. Trippa, P. Ricci, F. Cascone, R. Passariello; Rome/IT Purpose: Aim of our study was to demonstrate the utility of 3D-reconstruction and virtual endoscopy in the planning of surgical intervention and evaluation of treatment in maxillofacial diseases. Materials and methods: Thirteen patients (mean age 42; range 22 -67 years) underwent multi-slice CT examination (slice thickness 1 mm; scan time 2.8 seconds; rotation time 0.4 seconds; feed rotation 4 mm) using intravenous contrast agent, if necessary. Volumetric data sets were post-processed with Vitrea 2 (Vital Images, Milwakee) volume rendering software.

Results: In 7 patients who presented keratocyst, 3D-reconstruction permitted an exact definition of volume and site of the cyst. Also the trigeminal mandibular nerve branch pathway was clearly depicted. After surgery 3D-reconstruction showed a complete "restitutio ad integrum" of the bone. In 3 patients, who presented floor-ofmouth carcinoma, 3D-reconstruction was performed before treatment to evaluate the dimensions of the mass and to exclude bone involvement. After treatment the examination was repeated to evaluate response to therapy. One patient who had undergone numerous operations for bilateral cleft leap, was studied to plan further surgery and to control the outcome. In 2 patients who presented maxillary sinus osteoma, 3D-reconstruction evidenced tumor origin. Virtual endoscopy showed the exact position of the neoplasia in relation to the maxillary sinus floor and permitted postsurgical evaluation of the maxillary sinus floor. Conclusions: Multi-slice CT with 3D-reconstruction and virtual endoscopy are useful tools in the evaluation of maxillofacial diseases before and after therapy.

Facial hemangiomas as anexternal manifestation of the segmental angiodysplasia: MRI and MRA diagnosis V. Panov, A. Ivanov, M. Inaneishvily, A. Nadtotchi; Moscow/RU Purpose: Diagnosis of facial soft tissues angiodysplasia (FAD) is not hard because of its well-known clinical symptoms. Ultrasonography with color Doppler mapping, invasive selective and super selective X-ray angiography are usually used for the evaluation of tumor volume, its syntopy, morphological structure variants and identification of main supplying vessels. The main task of this presentation is to the show possibilities of noninvasive MR-imaging (MRI) and MR-angiography (MRA) in FAD diagnosis. Methods & materials: 38 patients with different forms of FAD were examined. All MRI and MRA examinations were obtained on a 1 T MRI system Harmony (Siemens, Germany) and were compared with noninvasive ultrasound and invasive X-ray angiographic data. Results: In 7 patients MRI has found the following arterial abnormalities: different forms of unclosed Willis ring (4 cases); significant middle cerebral arteries asymmetry (4 cases); lateral choroid artery displacement (1 case). In 5 patients vascular malformations were found: intracranial arterial malformations in 4 patients, meningeal venous malformations in 1 case. The disadvantages of MRI were: the long time of examination, the necessity of sedation in young patients (younger than 5 -8 years) and in patients with claustrophobia. Conclusion: Use of noninvasive MRA made it possible to establish that in some cases FAD was an external manifestation of a segmental angiodysplasia which could be diagnosed only by the combination of noninvasive ultrasound and invasive X-ray angiography. MRI and MRA allow to obtain the same information about FAD as traditional methods but has additional advantages in diagnosis of such lesions due to opportunities for intracranial arterial and venous visualization.

From CT through *.STL to RISM: A few real steps in the future of craniofacial surgery A. Nadtotchi, V. Roginskij, O. Topol'nitskij, A. Evseev; Moscow/RU Purpose: The evaluation of CT-datasets allows the possibility of creation of realsize facial skeleton individual stereolitographic plastic models (RISM).

Methods & materials: 20 children with severe diseases and abnormalities of facial skeleton were examined by CT (conventional or spiral): 6 patients had mandibular tumors, 4 patients had mandibular congenital deformations and 5 patients had postoperative defects, and 5 children had complex craniofacial syndroms. After CT examination, the CT-dataset was transformed into the specially produced computerized stereolitographic files (*.STL). STL-files were send to the computer operated stereolitographic device that finaly created the facial skeleton RISM.

The RISM was used not only for diagnosis but as an aid for operation planning in each individual case. Using the RISM it was easier for surgeons to define the access and operation techniques and to choose the optimal localisation of osteotomy lines. The RISM was used as the base for preoperative manufacturing of exactly anatomical endoprotheses. This application of RISM-technology is very progressive because: (1) it allows an increase in both the quality of preparation of endoprothesis and in their organospecificity; (2) it allows a decrease in the duration of operation of 1.5 -2.0 hours. Where it was necessary to enlarge the mandible with compression-distraction apparatus, RISM allowed definition of construction and optimal position of compression-distraction devices. Conclusion: RISM will be used not only as diagnostic model, but as important and powerful aid in the different branches of cranio-facial surgery. That is why we are sure that the system "CT -*.STL -RISM" is a real step in the future of surgery. Purpose: Investigate the utility of CT Cystography in the study of bladder tumors. Method and materials: 10 patients with bladder tumours, ranging from solitary polypoid lesion to multiple endoluminal lesions with diffuse alterations of mucosal surface, were studied with CT cystography and the results compared with conventional cystoscopy. Radiologists were blinded to the results of cystoscopy. CT cystography was performed with one helical acquisition of 3 mm slices at pitch 1.5, with images reconstructed each 1 mm. In all patients, the bladder was inflated with room air via a Foley catheter. The data were then downloaded to a workstation and reviewed, both on axial 2D and with 3D-intraluminal navigation. Results: Tumour lesions (12) of the 8 patients having localized lesions were recognized on the CT data. This included one small lesion less than 5 mm. In the two patients having diffuse bladder involvement, CT cystography was able to detect the major polypoid lesions, but also identify a diffuse irregularity of the bladder inner surface corresponding to the spread of the lesions over the entire mucosal surface. CT axial data also predicted the extra-serosal spread of the disease by contiguity to the inner part of the anterior abdominal wall, which was confirmed by open surgery the day after CT cystography. Urologists found the 3D images very similar to their own cystoscopy images. Conclusions: Recognition of bladder wall tumours is feasible by means of CT cystography. Lesions equal or bigger than 5 mm were shown.

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Three-dimensional volume and surface rendered ultrasound of the urinary bladder: Early experience G. Helweg, A. Klauser, L. Pallwein, A.H. Schuster, G. Feuchtner, A. Stenzl, D. zur Nedden, F. Frauscher; Innsbruck/AT Purpose: We evaluated the feasibility of three-dimensional (3D) surface and volume rendered ultrasonography (US) for detection and differentiation of urinary bladder lesions. Methods and materials: Fourteen patients suspicious for bladder tumours on two-dimensional (2D) US underwent 3D imaging of the bladder prior to cystoscopy and transurethral bladder biopsy. The suspicious areas on 2D US were evaluated using the PerspectiveTM 3D US (Acuson, MoutainView, CA). Tumour volume was calculated using the built-in software. Documentation was done on video and printouts. The US findings of 2D and 3D US were compared with endoscopic findings and the biopsy results. Results: Eight of 14 patients (57 %) had biopsy proven bladder cancers. In addition to conventional 2D US, the mean time for the assessment of 3D data sets was 2.5 minutes (range: 2.0 -4.0 min). 3D US allowed a better visualization of the inner contour, corresponding to the mucosal layer of the bladder. 3D surface and volume rendered US data sets, enabled the correct diagnose of a benign lesion in 5 of 6 patients, and of cancer in 7 of 8 patients. This revealed an overall accuracy of 85 % for differentiating benign from malignant lesions. The tumour volume was overestimated ≥ 20 % in 4 of 8 patients with cancer compared to cystoscopy measurements. Conclusions: 3D volume and surface rendered US improves the differentiation between benign and malignant lesions of the urinary bladder, compared with conventional 2D US. This technique requires only a short additional examination time and does not put any burden on the patient.

Use of FLAIR sequences for detection and local staging of bladder tumours with MRI M. Di Girolamo 1 , A. Roncacci 1 , G. Brughitta 2 , D. Fini 2 , S. Cavalaglio 2 , V. David 1 ; 1 Rome/IT, 2 Grottaferrata/IT Purpose: To increase the accuracy of MRI in the detection and local staging of bladder tumours by using FLAIR sequences. Method and materials: 32 patients with bladder tumours detected by US underwent MRI using 0.5 and 1.5 T superconductive magnet. We performed SE T1weighted (TR: 500 ms, TE: 30 ms), TSE T2-weighted (TR: 2500 ms, TE: 120 ms) and FLAIR sequences (TR: 6000 ms, TE: 150 ms, TI: 2000 ms, N.Ex.: 4; Acq.time: 7 min 30 s) on axial scans. The contrast to lesion ratio was evaluated in all sequences. All the patients underwent cystoscopy with transurethral biopsy and 14 had subsequent cystectomy. Results: In comparison with other sequences, FLAIR sequence was more sensitive in the detection of bladder neoplasms. This sequence demonstrates the hyperintense signal of bladder neoplasms from the filled bladder lumen with no signal. The sensitivity in the identification of bladder neoplasms was 100 % with FLAIR sequences, 89.6 % with TSE T2-weighted sequences and 86.2 % with SE T1-weighted sequences. That was due to the higher signal to lesion ratio of the FLAIR sequences in comparison with the others. In fact on FLAIR sequences the mean value of contrast to lesion ratio of bladder neoplasm was 33.1 while on SE T1-weighted sequences and TSE T2-weighted sequences was respectively 15.2 and 29.2. FLAIR sequences allowed the detection of small papillomas (less than 2 mm). TSE T2-weighted sequences were more sensitive in the study of bladder wall infiltration. Conclusions: FLAIR sequences were more sensitive in the detection of bladder neoplasms, due to their higher contrast to lesion ratio and can be very helpful in the visualization of small papillomas, especially when multifocal. Purpose: Evaluation of the diagnostic performance of virtual MR-cystoscopy for the assessment of bladder tumours. Materials and methods: 35 patients with bladder tumours were examined with a 1.5 T scanner, using a T2-weighted 3D-TSE-sequence (TR = 2911 ms, TE = 500 ms) with a voxel size of 1.1 × 1.0 × 1.5 mm 3 . In 10 patients the new "sensitivity-encoding"-technique (SENSE) was used, which allows a higher spatial resolution without increasing scanning time. The bladder-wall was divided into 6 re-gions, which were analysed separately for the presence of tumours by 3 radiologists without knowledge of the tumour location. Findings of conventional cystoscopy and operation served as standard of reference. Results: 39 of 43 tumours were detected by virtual cystoscopy with 6 false positive results, resulting in an overall sensitivity of 90 % and a specificity of 95 %. All tumours larger than 1 cm (21/21, sensitivity 100 %) and 17 of 22 tumours smaller than 1 cm (sensitivity 79 %) were detected. The tumours missed had a size of 5 mm or smaller. On the average, the time needed for virtual-endoscopic reconstruction was 15 minutes. With the new SENSE-technique, spatial resolution could be improved without increasing scan-time. Limitations of virtual cystoscopy are the detection of flat lesions and the differentiation between neoplastic and inflammatory lesions. Conclusion: Virtual cystoscopy is a promising, completely non-invasive tool for the diagnosis and follow-up of bladder tumours. By using the new SENSE-technique, the spatial resolution can be further improved.

MR virtual cystoscopy detection and staging of bladder lesions before performing conventional cystoscopy V. Panebianco, R. Iannaccone, I. Sansoni, A. Laghi, C. Catalano, M. Ciccariello, P. Paolantonio, R. Passariello; Rome/IT Purpose: To identify and to stage bladder lesions with MR-cystoscopy combining axial and virtual images. Methods and materials: 31 patients with suspected or known diagnosis of bladder tumour underwent MR cystoscopy. We used natural contrast (urine) for bladder distention, monitoring bladder filling with 3DFLASH sequence with i.v. c.m. (optimal results after 20 min). MRI examinations were performed on a 1.5 T Siemens Vision plus MR imager. We obtained a 2D FSE sequence on axial planes. For evaluation of bladder wall, we performed a T1 weighted GRE sequence, with and without fat suppression, pre and post Gd-DTPA (0.0025 mmol/kg) i.v. injection. A 3DSPGRE sequence was obtained for monitoring bladder filling and for virtual endoscopy analysis, prior to furosemide (1 cm 3 ) administration. Real time endoscopic views were reconstructed using volume-rendering reconstrution algorithm (Vitrea 2.2, Vital Images). Results: Image quality was considered optimal in all cases. A total of 24 lesions were detected and confirmed at biopsy. In 4 cases no lesions were evident at MRI and at conventional cystoscopy. All lesions were evident on morphological T1 and T2 weighted images, with size ranging of 4 -20 mm. MR virtual cystocopy allowed detection of the same lesions than conventional cystoscopy, providing comparable images. However, endoscopic images did not show intramural and extravescical extension of the tumour, whereas these findings were easily appreciated on morphological T1 and T2 weighted images. Conclusions: MR Virtual cystoscopy optimises detection and staging of the bladder pathology by combining axial T1 and T2 weighted and VE images.

Three-dimensional visualization of pelvic lymph nodes in staging and treatment of urinary bladder cancer using high-resolution MRI A. Welmers 1 , B. Schrier 1 , H. Huisman 1 , J.R. Fielding 2 , L. O'Donnell 2 , W.M.L.L. Deserno 1 , R. Kikinis 2 , J.G. Blickman 1 , J.O. Barentsz 1 ; 1 Nijmegen/NL, 2 Boston, MA/US Purpose: In this study we evaluated the possibilities of 3D modeling in lymph node visualization for surgical guidance during lymph node dissection (LND) in bladder cancer using high resolution MR data. Methods and materials: MRI was performed on a 1.5 T MRI using the 3D T1-w MP-RAGE sequence (TR 11.4, TE 4.4, 1.4 mm isometric voxel-size) with a pelvic phased-array coil. An IV USPIO contrast agent was used to enhance the visibility of the lymph nodes. Bladder, iliac vessels, ureters, obturatory nerves and lymph nodes were manually segmented from the MR data, using the software "3D-Slicer". From these segmentations 3D models were created. In total 25 patients with histology proven urinary bladder cancer were evaluated. In all cases LND was performed. Five patients had enlarged metastatic lymph nodes, which were all segmented. During LND the 3D models were used as a guiding tool for removing lymph nodes. Results: In all patients a 3D model was created successfully, showing iliac vessels, ureters, obturatory nerves and lymph nodes. The 3D models allowed accurate localization of normal and metastatic nodes in relation to the surrounding structures, which enabled the surgeons to find and remove more lymph nodes than without this technique. Conclusions: This technique simplifies visualization of lymph nodes. This increases urologist awareness of the exact location of lymph nodes, which results in a higher yield of nodes at node dissection.

Long FOV whole body 3D MRI using continuous table motion S.J. Riederer, D.G. Kruger, P.J. Rossman, R.C. Grimm; Rochester, MN/US Purpose: Current methods for imaging an extended longitudinal field of view (FOV) in MRI either use multiple fixed stations or rapid 2D axial imaging similar to single slice, helical CT. The purpose of this work was to develop a method for 3D MR imaging of an arbitrarily long FOV using continuous table motion. Methods and materials: A method was developed in which data are collected as the table is moved continuously through the MR scanner gantry. After Fourier transformation along the readout direction, every echo is assigned to hybrid (x, ky, kz) space, with longitudinal (x) location determined by table position at the time of the echo. As the table moves, all desired phase encodings are measured periodically. The method was tested in phantom, animal, and human studies. Table velocity ranged from 0.8 to 3.0 cm/s. The longitudinal FOV for readout ranged from 15 to 30 cm, and the total FOV was as large as 170 cm. Results: Complete 3D image sets were formed of objects up to ten times longer than the FOV of the acquisition. Correction for position at sub-pixel precision is critical to suppress ghosting artifacts. Contrast-enhanced studies in pigs demonstrate the ability to follow the contrast bolus in peripheral runoff studies. Results in humans suggest the feasibility of whole body imaging. Conclusions: 3D MR acquisition during continuous table motion has been demonstrated. It offers potentially reduced acquisition time vs. fixed station 3D methods and improved SNR vs. rapid serial 2D axial acquisition.

Spatial resolution in T1-weighted conventional SE and TSE sequences: Phantom measurements and in vivo results C. Fellner, F.A. Fellner, J.-C. Georgi, W.A. Kalender; Erlangen/DE Purpose: Assessment of spatial resolution in T1-weighted TSE sequences with different echo train lengths (ETLs) compared with an SE sequence using phantom measurements and examination of healthy volunteers. Materials and methods: T1-weighted TSE sequences with different ETLs (3, 5, 9) and an SE sequence with identical pixel size (0.8 mm) were evaluated with a custom-built resolution phantom offering resolution patterns from 0.1 mm to 1.5 mm in steps of 0.1 mm and in 25 healthy volunteers focusing on the cranial nerves. The resolution in the phantom images was assessed visually, and the standard deviation in an ROI containing the 0.8 mm stack was evaluated. Image quality and delineation of cranial nerves (II, III, V) of the in vivo measurements were assessed by an experienced radiologist blinded to the sequence technique. Statistical evaluation of the visual evaluation was done using Wilcoxon's test (p < 0.05). Results: The visual evaluation of phantom images yielded identical results for the SE and the TSE sequences with short ETLs (3, 5); for an ETL of 9 the spatial resolution was deteriorated. The quantitative evaluation, however, showed a continuous decrease of the standard deviation with increasing ETL. Image quality of in vivo images and delineation of cranial nerves was significantly superior in SE images compared with TSE images -even if a very short ETL was applied. Conclusion: Qualitative as well as quantitative evaluation of spatial resolution and anatomical details correspondingly revealed disadvantageous results for T1weighted TSE sequences with increasing ETL. This result was even more pronounced in the in vivo examinations.

Deep brain stimulation during interventional MRI: Safety issues R. Girnus, V. Hesselmann, K. Luyken, B. Krug, G. Nimtz, K. Lackner; Cologne/DE Purpose: To investigate safety aspects of linear conductive devices in interventional MRI. Materials and methods: The temperatures occuring in long wires placed in a 1.5 T MRI (Philips, Gyroscan Intera) were measured. The temperature increases (δT) at the tip of the electrode were determined using a MR-compatible opticalfiber-temperature system. The end of the wire was surrounded by 3 cm 2 of a 0.9% NaCl solution. The length and the position of the wire were tested as parameters influencing the HF-induced increases in temperature. Furthermore the influence of the sequence was taken into account. Result: The temperature increase of the wire aligned parallel to the z-direction and symmetric to the isocentrum showed a significant dependence on the length. A resonance length of about 2 m could be observed, with a äT of 30°C at the tip located in the saline solution during a TSE-sequence (SAR = 3.9 W/kg). By moving the wire out of the isocentrum in x or y direction, the heating effect exceeded 100°C at the electrode tip. The äT fell below 2°C, if the wire length was different

C D E F 272 from 2 m, the part of the wire inside the scanner bore was minimized and the wire was located in the center of the bore parallel to the z-direction. In general the äT can be reduced by applying gradient echo sequences with low flipangels. Conclusion: Under controlled conditions mentioned above it seems feasible to put a wire or stimulation electrode into an MR without risk of burning.

Liver iron overload: comparison of two methods in measuring liver R2* values. Correlation with serum ferritin concetration (SFC) and liver iron concentration (LIC) T.G. Maris 1 , O. Papakonstantinou 1 , E. Chryssou 1 , V. Ladis 2 , S. Kostaridou 2 , N. Papanikolaou 1 , P.K. Prassopoulos 1 , N. Gourtsoyiannis 1 ; 1 Iraklion/GR, 2 Athens/GR Purpose: To compare liver R2* (R2* = 1/T2*) values obtained by means of quantitative MRI (R2*-QMRI) using two regression analysis models and correlate them with LIC and SFC. Materials and methods: Liver R2* values were calculated in 10 thalassaemic patients, and 10 normal subjects on an 1.5 T MRI system using a breathhold multislice-double-echo spoiled GRE sequence with initial parameters: TR/TE1/TE2 160/ 2.7/5.3 ms. The sequence was repeated four times, each time altering inter-echo time spacing. T2* calculated image maps were post-proccessingly reconstructed using four different fitting methods (a, b, c, d) . Methods (a) and (b) were based on a simple linear regression model applied to image pixel data. Methods (c) and (d) were based on a weighted linear regression model on which pixel data were weighted according to background image random noise figures. Results: Differences of mean R2* values between patients and normal subjects were considered extremely significant (t = 19.25, p < 0.0001). R2* values correlated much closer with LIC levels (r = 0.89, p < 0.005) when using weighted linear regression models (c) and (d) than when using normal regression ones (a) and (b) (r = 0.85, p < 0.005). R2* were moderately correlated to SFC values regardless the use of the regression model (r = 0.6, p < 0.05). R2* values were linearly correlated with LIC [R2 × (s −1 ) = 4.94 + 93.94 LIC (mg/g) −1 , r = 0.89, p < 0.005] Conclusion: R2* when calculated using weighted regression methods on 1.5 T systems seem to be a valuable means for the evaluation of liver iron overload when LIC does not exceed 8 mg/g (liver dry weight).

Improved MRI-monitoring during RF-hyperthermia H. Reinl 1 , M. Peller 1 , M. Hagmann 2 , R. Issels 1 , M.F. Reiser 1 ; 1 Munich/DE, 2 Salt Lake City, UT/US Purpose: In a MRI-hyperthermia hybrid-system T1 relaxation-time changes are investigated for monitoring hyperthermia of deeply seated tumors. A water-bolus is needed for power transmission into the patient body. The signal of this bolus limits image quality by signal compression and artifacts. This can be avoided by using D2O which would result in additional technical effort and high costs. The purpose of our study is to improve image quality, spatial and temporal resolution by using a paramagnetic suspension of magnetite instead. Material and methods: All experiments were done on the hybrid-system which consists of a 0.2 T open MR-system and a hyperthermia system with a MR-compatible phased array applicator and an integrated MR receive-coil. The tested paramagnetic suspension was a commercially available ferrofluid (MSG W11, Ferrofluidics Corp.), normally used for material separation. A polyamidacryl gelphantom mimicking the human body was used for heating experiments. Results: We found ferrofluid in a low concentration as a useful substitute. In the 0.2 T system a concentration of 0.25 % showed optimum results. Below 0.2 % the bolus is still slightly visible and above 0.3 % the MR system is no longer tuneable. No artifacts are induced in this concentration-range. Conclusion: By using the new bolus-filling an extinction of the bolus artifacts and a significant improvement in SNR, spatial and temporal resolution are possible. This method of signal extinction in MRI may be adapted to other experimental demands where MR-invisible fluids are necessary.

Stereological estimations of liver volume from MR images M. Mazonakis, J. Damilakis, T.G. Maris, P.K. Prassopoulos, N. Gourtsoyiannis; Iraklion/GR Purpose: To investigate the possibility of generating stereological estimations of liver volume from magnetic resonance (MR) images. Methods and materials: 38 consecutive patients underwent 1.5 T abdominal MR imaging. Two radiologists evaluated the MR images and found that the liver size appeared normal in 27 and increased in 11 cases. Liver volume was estimated using the Cavalieri method of modern design stereology in combination with point counting. The effect of the separation distance between test points of the grid in the efficiency of stereological estimations was examined. A systematic sampling of MR sections was performed to find the minimum number of sections needed to provide acceptable volume estimations. Results: For both subgroups of patients with normal and increased liver size, it was found that 100 -150 test points counted on 7 -8 systematically sampled MR sections may provide reliable liver volume estimations with a coefficient of error (CE) of less than 5 %. The mean time required for the stereological measurements was approximately 10 min. The mean liver volume for the patients with normal and increased liver size was found to be 1477.7 ± 230.7 and 1944.7 ± 196.1 cm 3 , respectively.

The proposed volumetric technique may provide efficient liver volume estimations from MR images in patients presenting both normal and increased liver size.

Improvement of diagnostic accuracy of PET imaging using a high performance in-line PET-CT system: Preliminary results T.F. Hany, H.C. Steinert, G.W. Goerres, A. Buck, G.K. von Schulthess; Zürich/CH Purpose: We describe the first application and optimisation of a novel in-line system combining a high performance clinical positron emission tomograph (PET) scanner and a fast multi-slice helical computer tomograph (CT) scanner in a single machine (PET-CT) for tumour staging. Methods: We examined 53 patients with diagnosed or highly suspected malignancy. Non-contrast-enhanced CT data with 4 different tube currents (10, 40, 80 and 120 mA) were acquired, followed by PET acquisition.

Step-wise image analysis was performed using PET images alone compared to co-registered PET-CT with increasing CT energies (PET-CT10, … PET-CT120). Clinical or pathological staging was used as standard of reference for lesion-by-lesion as well as on patient based analysis. Results: The following accuracy ratios for classifying tumour lesions were calculated: PET alone 91 %, PET-CT10 97 %, PET-CT40 97 %, PET-CT80 98 %, PET-CT120 98 % and a significant difference was found between PET alone and co-registered images (chi square p < 0.01). Conclusion: PET-CT fusion in a combined scanner using non-enhanced lowdose CT with 80 mA is significantly increasing diagnostic accuracy regarding lesion classification, and by using the CT scan for transmission correction will reduce the acquisition time by 30 % when compared to PET imaging alone.

Transmission scanning for attenuation correction in cardiac SPECT studies: Patient effective dose and radiogenic risk K. Perisinakis, J. Damilakis, N. Gourtsoyiannis; Iraklion/GR Purpose: To determine patient effective dose and associated radiogenic risk from the transmission scanning performed during cardiac SPECT myocardial perfusion studies to correct scintigraphic images for attenuation and scatter effects. Materials and methods: Transmission scans were obtained using an OPTIMA NX GE system, which involved an L-shaped dual headed gamma camera equipped with transmission scan hardware. Two flat scan boxes each containing a collimated rod source of gadolinium 153 were mounted on the gantry opposite each detector. A Rando anthropomorphic phantom was used to determine radiation dose from transmission scanning in 14 organs and tissues using 352 thermoluminescent dosemeters. For each projection the resulting effective dose was calculated using the ICRP 60 tissue weighting factors. Radiation risk was determined using age and sex related radiation induced fatal cancer risk factors. Results: The effective dose corresponding to a typical 5 s acquisition per transmission scan was 620 pSv. The organs receiving the highest amount of radiation dose is the lung and the oesophagus. The average lifetime risk for fatal malignancy is 4.9 × 10 −8 for US and 3.9 × 10 −8 for UK population. Conclusion: Present data allow the accurate estimation of patient effective dose and associated radiation detriment risk from myocardial perfusion SPECT studies.

Purpose: Assessment of three different rectal agents (water, ultrasound gel and methylcellulose) for their suitability for colorectal imaging in multislice CT Material and methods: 115 patients with colorectal diseases underwent MSCT with varying rectal contrast agents in a prospective study. Images were assessed by two independent CT-experienced radiologists. CT scans were analyzed for the following criteria: contrast of wall versus lumen (W/L), contrast of pathological wall versus lumen (P/L), distension of anal verge, distension of colon and artefacts (Ar). A rating scale of 1 (no) to 5 (severe) was used. Interobserver variability was assessed by kappa statistics. Results: Mean rating values of methylcellulose were higher in contrast of wall/ lumen (4.66 ± 0.6), pathological wall/lumen (4.73 ± 0.5) and least rate of artefacts (4.13 ± 0.7) than of water (W/L 4.36 ± 0.8; P/L 4.36 ± 0.7; Ar 3.76 ± 0.9) and ultrasound gel (W/L 2.4 ± 0.96; P/L 2.55 ± 1.01; Ar 1.76 ± 0.9). The distension of the anal verge was better in using ultrasound gel (4.5 ± 0.6) and methylcellulose (4.35 ± 0.7) than in water (2.82 ± 1.1). With water the best distension of colon (4.1 ± 1.1) could be obtained, it was nearly equal to methylcellulose (3.82 ± 0.8), but remarkable superior to ultrasound gel (1.5 ± 0.6). Air artefacts only appeared in ultrasoundgel. An excellent interobserver correlation was found for the contrast of pathological wall versus lumen of methylcellulose (k = 0.81). A high rate of agreement between the criteria of both radilogists in final diagnosis could be achieved. Conclusion: Rectal filling with methylcellulose significantly improves diagnostic confidence in colorectal examinations. Ease of application and lack of use suggest to use as a clinical routine.

CT differentiation of colorectal mucinous and nonmucinous carcinoma E. Ko, H. Ha; Seoul/KR Purpose: To evaluate the CT findings which can help differentiate mucinous from nonmucinous colorectal carcinoma.

CT scans of 86 patients with pathologically proven mucinous colorectal carcinoma during a 10-year period, were analyzed. As a control group, 105 consecutive patients with pathologically proven nonmucinous colorectal carcinoma in a 3-month period were included. Retrospective review of CT was performed by two radiologists in consensus who were blind to the pathologic results. CT scans were analysed with regard to the site and length of involved segment and types of morphological features, bowel wall thickening and contrast enhancement patterns, degree of contrast enhancement in solid portion of the tumor. Also evaluated were the presence of calcification, obstruction, lymphadenophathy, pericolic infiltration, local tumor extension, and distant metastasis. In heterogeneous masses, the extent of hypoattenuated areas within tumor was graded into three. Statistical analyses were performed by using Student t-test and Pearson's ÷ 2 -test. Results: As compared with nonmucinous carcinoma, mucinous carcinoma showed more severe (p = 0.026) and more eccentric (p = 0.025) bowel wall thickening. Heterogeneous contrast enhancement was more common in mucinous carcinoma (p < 0.001). Significant difference was noted in the extent of hypoattenuated areas within tumor (p < 0.001). The solid portion of mucinous carcinoma showed hypoattenuation while nonmucinous carcinoma showed hyperattenuation (p = 0.001). Although statistical values were not obtained, the presence of intratumoral calcification was more frequent in mucinous carcinoma (21 % vs 5). Conclusion: CT is very useful in the differentiation of mucinous from nonmucinous colonic adenocarcinoma.

Usefulness of the hydrogen peroxide enhancement in the diagnosis of the anal and ano-vaginal fistulas I. Sudol-Szopinska, W. Jakubowski, M. Szczepkowski, D. Sarti; Warsaw/PL Purpose of the study was to assess the usefulness of contrast-enhanced anal endosonography (AES) with hydrogen peroxide in the diagnosis of the anal fistulas. Method and material: A Bruel & Kjaer Scanner with a 7.0 MHz transducer was used. After visualization of the fistula tract in non-contrast AES, hydrogen peroxide was introduced into the fistula tract through the external opening in 22 patients with different types of anal fistulas. Results: Both contrast-and non-contrast AES revealed 13 transsphincteric, 3 intersphincteric, 2 suprasphincteric and 4 ano-vaginal fistulas. Simple tracts were found in 16 cases and complex in 6 cases in non-contrast AES. Contrast-enhanced AES revealed 19 simple and 3 complex fistulas. 15 internal openings visible in non-contrast AES were confirmed in contrast-enhanced AES in 6 cases, which additionally found 11 more internal openings. In all cases, surgery confirmed the diagnoses of the contrast-enhanced AES. Conclusion: Contrast-enhanced AES appears to be superior to non-contrast AES in preoperative assessment of the anal and ano-vaginal fistulas and in locating of the internal openings.

Contrast-enhanced multislice CT colonography in the diagnosis and staging of colorectal cancer I. Carbone, A. Laghi, R. Iannaccone, I. Baeli, R. Ferrari, F. Mangiapane, F. Iafrate, C. Catalano, R. Passariello; Rome/IT Purpose: To evaluate the role of CT colonography (CTC) in patients with suspected colorectal cancer. Methods and materials: Forty-eight patients (21 females and 27 males; age range 41 -78) underwent conventional colonoscopy (CC) and CTC for suspected colorectal mass. Multislice spiral CT (Somatom Plus 4 Volume Zoom, Siemens, Germany) examination of the abdomen and pelvis was performed after routine bowel preparation and colonic distention with room air. Patients were scanned in prone and supine positions using the following parameters: slice collimation, 2.5 mm; slice thickness, 3.0 mm; reconstruction interval, 1 mm; mAs, 80 (prone) and 120 (supine). 130 ml of contrast medium were administered i.v. during the supine acquisition with a 60 s delay time. Images were subsequently downloaded and analysed on a dedicated workstation. Surgical specimens were used as the standard of reference against which the findings of CC and CTC were compared. Results: CC failed to visualize the entire colon in 27 patients due to occlusive neoplasms. CTC allowed whole-colon evaluation in all the cases and correctly detected and staged 43 out of 48 colorectal cancers. Ten synchronous colonic lesions (8 adenomatous polyps, 2 carcinomas) were identified in 10 different patients at CTC. Liver metastases were detected in 10 patients.

Conclusion: Contrast-enhanced multislice CTC is a valuable tool for the preoperative staging of CRC. This imaging modality is very useful for presurgical planning due to whole-colon evaluation even in the presence of stenosing lesions, as well as optimal assessment of bowel wall invasion, lymphoadenopathies, and hepatic parenchyma.

Detection of colorectal lesions with CT colonography: Comparison with conventional colonoscopy in 165 patients I. Carbone, A. Laghi, R. Iannaccone, I. Baeli, R. Ferrari, S. Trenna, C. Catalano, R. Passariello; Rome/IT Purpose: To compare the performance of CT colonography with that of conventional colonoscopy (CC) in a blinded, prospective study in 165 patients with suspected colorectal lesions. Methods: 165 patients, all referred for CC, underwent preliminary CT colonography. After standard oral colonoscopy preparation and colonic distension with room air, CT colonography was performed either with a single-slice (Somatom Plus 4; Siemens, Erlangen, Germany) or multislice (Somatom Plus 4 Volume Zoom, Siemens, Germany) scanner. Imaging parameters for the single-slice scanner were: 3.0 mm slice collimation; 6.0 mm/s table speed; 0.75 s tube rotation; 2.0 mm reconstruction interval; 512 × 512 matrix; 120 mAs; 130 kVp; and scan time 35 -47 s. Imaging parameters for the multislice scanner were: 1.0 mm slice collimation; 8.0 mm/s table speed; 0.5 s tube rotation; 1.0 mm reconstruction interval; 80 mAs; 120 kVp; and scan time 25 -32 s. CT images of all suspected lesions were analyzed on a workstation and subsequently compared to CC findings. Results: There were 30 colorectal cancers and 37 polyps identified at CC. CT colonography correctly detected all cancers, as well as 11 of 12 polyps of 10 mm in diameter or larger (sensitivity, 92 %); 14 of 17 polyps between 6 and 9 mm (sensitivity, 82 %); and 4 of 8 polyps of 5 mm or smaller (sensitivity, 50 %). The per-patient sensitivity and specificity were 92 % and 97 %, respectively. Conclusion: CT colonography has a diagnostic sensitivity similar to that of CC for the detection of colorectal lesions larger than 6 mm in diameter.

Colorectal polyps: Improvement of detection with multi-slice CT colonoscopy J. Wessling, R. Fischbach, D. Domagk, E. Neumann, S. Schierhorn, W.L. Heindel; Münster/DE Purpose: To compare the performance of virtual and conventional colonoscopy for the detection of colorectal polyps using a multi-slice spiral CT scanner (MSCT). Material and methods: 48 patients (20 women, 28 men, mean age 61.5 years) with clinical indication for conventional colonoscopy were prospectively studied using a MSCT (Somatom Volume Zoom, Siemens, Forchheim). Examination was performed after standard oral colonoscopy preparation and colonic distension with room air and i.v. Buscopan. Images were obtained in prone and supine position using a detector configuration of 4 × 1 mm, a feed of 5 mm/rotation at 140 mAs and 120 kV. Slice thickness and reconstruction increment were 3 and 1.5 mm, respectively. CT data were assessed by 2 blinded radiologists on a Vitrea workstation (Vital Images, USA) using a software with multiplanar and volume-rendering capabilities. Results: 33 patients had normal findings on conventional colonoscopy. A total of 30 polyps and 2 carcinoma were identified in 15 patients. MSCT-colonoscopy detected all carcinomas and 23 polyps (77 %). 3 of 3 polyps were 10 mm or more (100 %), 6 of 7 polyps were 6 to 9 mm (86 %) and 14 of 20 were smaller 6 mm (70 %). There were 13 false positive findings for polyps (10 were smaller 6 mm) and no false positive finding of cancer. Conclusions: Compared to single-slice-CT, multi-slice CT colonoscopy increases the rate of detection of small colorectal polyps in particular. However, false positve results still remain a problem.

Does contrast enhancement contribute to CT colography? A.R. Gillams, V. Munikrishnan, W.R. Lees; London/GB Purpose: Controversy persists over the usefulness of IV contrast in CT colography. Enhancement in small lesions should facilitate detection particularly when there is adjacent fluid. We measured the attenuation values of polyps and cancers both before and after IV contrast. Materials and methods: Forty-nine patients, 32 male, mean age 57 (42 -80) were studied. All patients had routine bowel preparation, IV smooth muscle relaxant and rectal air insufflation. Supine and prone imaging was performed using a multi-slice CT, collimation 1 mm, effective slice width 1.25 mm and pitch 1.2. The second acquisition was performed 30 s after pump injection of 100 -150 ml of IV contrast injected at 5 ml/s. All lesions were confirmed on colonoscopy. The attenuation values of polyps and cancers were measured both before and after IV contrast. Results: Eighteen cancers were detected and 28 polyps. Mean polyp size was 12 mm (3 -25 mm). Both cancers and polyps demonstrated enhancement following IV contrast enhancement but was more marked in polyps. The mean attenuation value in the cancers prior to contrast was 53 ± 16 and following contrast 105 ± 26. The mean attenuation value in the polyps prior to contrast was 62 ± 11 and following contrast was 113 ± 26. The mean increase for cancers was 39 and for polyps 51. Conclusion: Contrast enhancement is seen in both polyps and cancers but is more marked in polyps. Enhancement could be used where there is diagnostic doubt on the pre-contrast imaging.

Colour Doppler visualization of hemorrhoidary arteries during transrectal US A. Sias, V. Alvino, F. Lecca, G. Mallarini; Cagliari/IT Purpose: The scope of this work is to evaluate the usefulness of color Doppler transrectal US in the visualization of hemorrhoidal artery in patients undergoing non invasive surgery for hemorrhoids. Material and methods: We have examined 25 patients undergoing Doppler-guided hemorrhoidal artery ligation for the treatment of hemorrhoids with modified Morinaga technique. Discussion: New surgical less-invasive techniques of treatment of hemorrhoids are being developed. One of this techniques involves the use of a modified proctoscope for artery ligation. Colour Doppler during transrectal US was used to evaluate the position of terminal arteries originating from the superior rectal artery. We were able to confirm the arrangement of these terminal arteries at 1, 3, 5, 7, 9, 11 as seen in the lithotomy position. This was noted first by Meintjes in 2000. Conclusion: Colour Doppler transrectal US allowed a clear visualization of hemorrhoidal arteries in the fixed position described by Meintjes. Our study was the first to show the reliability of this classification. Although useful, well tolerated, quick and easy to perform, we do not recommend routine use of Colour Doppler transrectal US in all patients undergoing treatment for hemorrhoids with modified Morinaha technique. This examination can be useful in those with recurrent secondary hemorrhage, as it can help avoiding further bleeding problems.

Results: Volunteers: Using the corrections the mean difference between the volume of the 3 He-MRI and the PFT measured -74 ml (r = 0.9). Patients: After the corrections the mean difference measured 616 ml (r = 0.96). Functioning lung grafts contributed 66 ± 6 %, their corresponding native IPF lungs 34 ± 6 % to total ventilated volume. Conclusion: 3 He-MRI of the lung offers a new approach to regional determination of ventilated lung volume. The volunteers show good correlation and high consistence of the absolute values between 3 He-MRI and PFT. The patients with SLTX show good correlation and the possibility to measure the individual contribution of the graft in comparison to the native lung. He-MRI (300 ml hyperpolarized 3 He gas; FLASH 2D, TR/TE 11/4.2 ms, FA < 10°, slice thickness 10 mm, pixel size 4.2 × 2.7 mm, coronal) were performed. HRCT was evaluated for 3 main lesions: airway disease (bronchial wall thickening, air trapping), emphysema, and fibrosis. 3 He MRI was assessed for three main ventilation defects. Functional compromise was scored on a 4-point scale independently for HRCT and 3 He-MRI by two readers and compared to forced expiratory volume in 1 s (FEV1) and residual volume (RV). Results: 63 ventilation defects were depicted in total: 70 % in both, 18 % only on 3 He-MRI and 12 % only on HRCT. Mean HRCT score was 2.7, mean 3 He-MRI score 2.5, mean FEV1 was 60 %. There was no relevant correlation between HRCT and FEV1 (r = 0.3), but between 3 He-MRI and FEV1 (r = 0.7), exhibiting significant differences between scores 2 and 3 (p < 0.05) as well as 3 and 4 (p < 0.05). There was no relevant correlation between HRCT and RV (r = 0.1), but for 3 He-MRI (r = 0.6). Conclusion: In comparison to paired in-and expiratory HRCT, 3 He-MRI has a higher sensitivity in the detection of ventilation defects and correlates better with LFT. Thus, functional information is predicted better using 3 He-MRI. No single lung function test index correlates well with the severity of emphysema. The aim was to develop a composite pulmonary function score that best reflects the CT quantification of emphysema. Material and methods: The HRCT scans of 97 cases of emphysema were scored objectively using a density mask. The following standard pulmonary function tests (PFT): DLco, Kco, FEV1, total lung capacity (TLC), residual volume (RV) were recorded. Stepwise regression was used to identify the combination of PFTs that best fitted the HRCT score Results: Significant negative correlations were found between the HRCT emphysema scores and DLco, Kco and FEV1 (R 2 = 0.39, R 2 = 0.36 and R 2 = 0.42 respectively) and positive correlations with TLC and RV (R 2 = 0.29 and R 2 = 0.37 respectively). A composite score representing the best fit combination of PFTs against the CT emphysema score was: 24. Purpose: This study evaluated the relationships between high resolution computed tomography (HRCT) morphologic quantification of bronchiectasis and clinical and lung function parameters. Materials and methods: 60 Chinese with steady state bronchiectasis underwent thoracic HRCT scan and full lung function tests. Exacerbation frequency/year and 24 h sputum volume were determined. Extent of bronchiectasis, bronchial wall thickening, and presence of small airway abnormalities and mosaic attenuation were evaluated in each lobe, including lingula. Relationships between lung function, sputum volume, clinical exacerbation and HRCT parameters were analysed. Results: Exacerbation frequency was associated with bronchial wall thickening (r = 0.32, p = 0.03); 24 h sputum volume with bronchial wall thickening, small airway abnormalities (r = 0.30, 0.39, p < 0.05), and FEV11, FEV1/FVC and FEF25 -75(r = -0.33, -0.29, -0.32; p < 0.05). Extent of bronchiectasis, bronchial wall thickening and mosaic attenuation were respectively related to FEV11 (r = -0.43 to -0.60 p < 0.001), FEF25 -75(r = -0.38 to -0.57; p < 0.001), FVC (r = -0.36 to -0.46, p < 0.01), and FEV11/FVC (r = -0.31 to -0.49, p < 0.01). After multiple regression bronchial wall thickening remained a significant determinant of airflow obstruction, while small airway abnormalities remained associated with 24 h sputum volume. Women in general had milder disease than men, but showed more HRCT-functional correlations. Conclusion: This study has established a link between morphologic HCRT parameters and clinical activity, and emphasised the role of BWT in bronchiectasis. There are gender differences in bronchiectasis with respect to disease severity and sensitivity to HRCT evaluation.

Morphology and lung function in healthy smoking and non-smoking men: A 5-year follow-up study J.D. Vikgren, M. Boijsen, B. Bake, U. Tylén; Gothenburg/SE Purpose: There is demand for a reliable method for early detection of smoking induced disease. Healthy smokers can present with or without normal lung function. Having abnormal lung function, the smokers present with airway obstruction and/or emphysema. A possible way to elucidate early smoking induced changes, bronchiolitis, could be analysis of E/I quotient. Material and methods: Our study was a follow-up study. Subjects were recruited from the randomised epidemiological study "Men born 1933 in Göteborg". HRCT and lung function tests were performed with a five-year interval. Smokers were subdivided according to presence of emphysema or not at the beginning of the study. Computer calculation of E/I quotient was performed, i.e. quotient between cross-sectional area and mean attenuation values in inspiration and expiration. Visual quantitation of emphysema and air trapping was evaluated by consensus. Results: At follow-up there was a significant increase of the E/I quotient for mean attenuation for smokers with and without emphysema, but also for non-smokers. E/I quotient for cross-sectional area showed a significant decrease at follow-up

C D E F 276 only for smokers without emphysema. There was a significant progression in emphysema for smokers. Analysis of the relation to lung function parameters as FEV 1.0, FVC, CO-uptake and N2-test are in progress. Conclusion: There is a progress of emphysema with continued smoking. An increased E/I quotient has been interpreted as obstruction, but the fact that the E/I quotient increases in smokers as well as non-smokers requires further analysis.

Mediastinal lymphadenopathy in left heart failure: Correlation of CT abnormalities with clinical and echocardiographic findings V. Chabbert 1 , G. Canevet 1 , G. Philippe 1 , P. Otal 1 , V. Delannoy 2 , F.G. Joffre 1 , M. Rémy-Jardin 1 ; 1 Toulouse/FR, 2 Lille/FR Purpose: To evaluate the frequency of mediastinal lymphadenopathy due to left heart failure on computed tomography (CT) scans in correlation with clinical and echocardiographic findings. Materials and methods: 31 consecutive patients (mean age, 69 years) with left heart failure in a subacute phase were included in a prospective study between september 2000 and august 2001. CT examinations (HRCT and spiral CT scans) and transthoracic echocardiography were performed within 24 hours after presentation. CT follow-up were obtained within 8 days after initiation of medical treatment. Results: At presentation, dyspnea was graded as type IV (39 %), III (39 %), II (19 %) and I (3 %). Mean ejection fraction was 39 %. Enlarged mediastinal lymph nodes were seen in 42 % of cases, heterogeneous in 23 %, with a hazy perilymphadenopathy fat in 38.5 % of cases. All patients had pleuroparenchymal abnormalities due to left heart failure. Peribronchovascular thickening, septal thickening, fissures thickening, ground-glass attenuation, condensations, micronodules and pleural effusions were present respectively in 20 %, 71 %, 71 %, 74 %, 16 %, 16 % and 74 % of cases. After treatment, dyspnea was graded as type III (16 %), II (61 %) and I (23 %). Lymphadenopathy decreased in size in 38.5 %, was stable in 38.5 %, disappeared in 23 %, and weas heterogeneous in 20 %, fat abnormalities disappeared in all cases. Pleuroparenchymal abnormalities decreased in 74 %, disappeared in 19.5 % and were stable in 6.5 %. 

We examined 23 consecutive patients (138 lung lobes) referred for the assessment of possible airways disease using multislice CT. The thorax was scanned contiguously at 1 mm slice thickness and this was reconstructed at 1 mm slice thickness (lung windows utilising high spatial frequency algorithm) in the axial (10 mm apart), sagittal (4 per lung) and coronal (6) plane. Pedal wheel reconstructions were also performed. Axial images were assessed by 2 chest radiologists with and without the help of MPR at two separate occasions. The presence of bronchiectasis, emphysema and bronchiolitis in each lobe was documented on a confidence scale of 0 -3 (0 no disease, 3 definite disease). Result: There was no significant difference (p = 0.280) in the mean confidence in the diagnosis of airways disease with the help of MPR [Observer A (1.98 axial, 2.01 MPR); Observer B (2.88 axial, 2.71 MPR)]. In addition, weighted kappa showed no improvement in inter-observer agreement (kappa = 0.566 for axial; kappa = 0.530 for MPR). Isolated cases wherein MPR was beneficial were noted, particularly in patients with bronchiectasis (3 patients). Due to the small number, this did not reach statistical significance. Conclusion: Our results did not demonstrate a significant increase in confidence in the diagnosis of airways disease. MPR was beneficial in a few selected cases of bronchiectasis. Methods and materials: 40 consecutive patients were randomized into 2 groups of 20 patients each. Group 1 underwent SSCT with a standard protocol for the study of the airways and group 2 underwent MSCT with the following protocol: 4 × 1 mm slice collimation, pitch 7 (1.75 M), 1 mm slice width, 0.8 mm reconstruction increment. Two radiologists evaluated by consensus the axial images and VB reconstructions in order to assess the degree of visualization of the bronchial tree according to a three point scale (grade 0, 1 and 2). Results: On axial images, MSCT yielded better results in the evaluation of the segmental bronchi of the middle lobe (32 bronchi rated as grade 2 by MSCT vs 16 by SSCT; p < 0.05), of the anterior segmental bronchus of the left upper lobe (19 rated as grade 2 by MSCT vs 10 by SSCT; p < 0.05) and of inferior segmental bronchus of the lingula (18 rated as grade 2 by MSCT vs 8 by SSCT; p < 0.05). Evaluation of lobar and segmental bronchi was always possible when VB was obtained from MSCT data sets whereas 53/280 bronchi were scored 0 when VB was obtained from SSCT. Subsegmental bronchi could be better evaluated with MSCT than SSCT either on axial images or VB (p < 0.05). Conclusion: MSCT with 1 mm collimation significantly improves the visualization of segmental and subsegmental bronchi and is particularly useful for oblique oriented bronchi. Methods: Over a one year period 96 patients had by pCT. 10 patients were directly examined by pCT on admission day on ICU. For this purpose a special interventional suite was prepared directly on ICU. In this suite radiological modalities like radiography, sonography and portable angiography can be performed under intensive care monitoring and therapy. CT examinations are even possible by using pCT in this special suite. On day of admission patients underwent extensive evaluation using modalities of this special interventional suite. Results: In two cases a bedside CT procedure was performed the others were performed in the intervention suite on ICU. In 80 % of the cases a final diagnosis could be determined by CT examination. In 40 % CT findings led to follow up evaluations by pCT. Even 40 % of CT examinations led to direct therapeutic consequences such as surgical intervention. 60 % of the CT indications were assessed as necessary or essential by an experienced ICU physician. Half of the follow up examinations had also direct therapeutic consequences. 

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Results: Using the SENSE technique the temporal resolution and spatial coverage could be increased from 12 slices per 1.7 s up to 20 slices per 1.4 s. As a consequence of the increase in k-space velocity using SENSE the typical susceptibility artifacts of EPI sequences at the skull base were almost negligible. The S/N is strongly influenced by the specific coil arrangement and the actual number of profiles in k-space. For the applied double loop coil and a SENSE factor of two the S/N equals that of the standard scan (head coil) in superficial temporal regions and is reduced by a factor of 0.65 to 0.8 in central and occipital regions. However, the increased temporal resolution compensated for the decrease in S/N and the calculated parameter maps were always of good diagnostic quality. With a dedicated coil the SENSE technique allows substantial improvement in perfusion imaging.

Diffusion weighted MR imaging in the early diagnosis of periventricular leukomalacia A. Bozzao, F. Garaci, S. Marziali, R. Floris, G. Simonetti; Rome/IT -presented by F. Fasoli; Rome/IT Purpose: The use of MR diffusion weighted imaging in detecting hypoxic-ischemic encephalopathy (HIE) in neonates is still controversial. Moreover few reports concern pre-term infants with possible periventricular leukomalacia (PVL). We examined the ability of this technique to detect cerebral changes of acute PVL. Methods: Fifteen MR examinations were performed in eleven preterm infants. Imaging comprised conventional and diffusion-weighted (DW) sequences. Conventional, DW sequences and apparent diffusion coefficient (ADC) maps as well as US obtained in the acute phase were compared. All the neonates underwent US follow-up 6 and 12 months after delivery, those with suspect PVL also underwent MRI follow-up at two months and one year. Qualitative and quantitative evaluations were performed to assess the presence of DWI changes compatible with PVL.

Results: DWI showed signal hyperintensity associated with decreased ADC values in 3 subjects (27 %); in these patients conventional MRI sequences were interpreted as normal and US (performed at the same time) as doubtful in 2 and compatible with PVL in one. MRI and US follow-up confirmed severe damage in all these patients. In one neonate hemorrhages involving the germinative matrix were identified at MRI and US without signs of PVL. Follow-up MRI and US confirmed the absence of PVL 3 months later. In eight neonates MRI was considered normal. In these subjects US follow-up confirmed no signs of PVL. Apart from the well known image artefacts time consuming reconstruction periods often inhibit continuing data acquisition, particularly if sequences are used with more than one acquisition or with built-in postprocessing capabilities to automatically generate ADC-maps. By using these sequences as the last sequence in the whole examination prior to the start of the subsequent examination of the next patient this time delay can be reduced. The aim of this prospective study was to find out if there is any diagnostically significant difference between acquisition of EPI-DWI images before and after intravenous application of Gd-DTPA.

In 203 patients a EPI-DWI sequence was used (TR/TE: 4000/100, 19 slices, 6 mm slice thickness, 230 FOV) both as the first (before i.v. CM) and the last sequence after CM. The MR indications were ischemic stroke, encephalitis, multiple sclerosis and brain tumor with and without disturbed blood brain barrier. The MRI images were rated by two blinded, neuroradiologically experienced radiologists. Results: Intravenous CM had no influence on the diagnostic information of the images. There were no significant signal differences even in lesions with pronounced disturbances of the blood brain barrier. Conclusion: It is possible to use EPI-DWI after CM application without loss of clinical information. The proposed approach allows to reduce examination times. Brain perfusion studies with trans cranial colour Doppler using ultrasound contrast media G. Salvaggio, G. Caruso, T.V. Bartolotta, A. Scisca, G. Caputo, R. Lagalla, A.E. Cardinale; Palermo/IT Purpose: To evaluate the intracranial micro circulation using trans-cranial color Doppler (TCCD) with a contrast medium (Levovist). Material and methods: 25 patients, (age range: 41 -73 years; mean age 64 years) affected by mellitus diabetes were selected. 20 healty volunteers (mean age: 63 years) acted as control. The examinations were performed using an ATL HDI 5000 ultrasound unit provided with a Phased Array 3.25 MHz probe. Mechanical index was calibrated to high value in order to obtain microbubbles rupture under ultrasound beam exposition. After positioning of an operator defined region of interest, intensity/time curves related to the parenchymal micro circulation were plotted, and the areas under the curves were calculated. Results: In all controls, the areas under the curve showed a mean value greater than 0.05 that we considered as cut-off value of normal perfusion. On the other hand, the diabetic patients showed a lower mean value, to indicate a micro circulation disease. Conclusion: Thanks to software improvements and ever more effective algorithms, contrast-enhanced TCCD is able to provide information on brain perfusion non invasively and at low cost. Purpose: To present our initial clinical experience with a one-piece design 8-channel neuro-array coil for MRI of the brain. Methods and materials: MRI examinations of the brain were performed in 5 normal volunteers using an 8-channel parallel acquisition technique (PAT) optimized neuro-array head coil (MRI Devices Corporation, Wisconsin, USA), and a standard circularly-polarized (CP) volume head coil. Examinations were performed on a 1.5 T superconducting magnet (Sonata, Siemens AG, Germany). Signal-to-noise ratios were calculated and compared for the two coils in various anatomical locations including peripheral (cortex, subcortical white matter, etc.) and central (e.g. corpus callosum, sella, brainstem, etc.) parts of the brain. Results: The 8-channel neuro-array coil provided excellent high-resolution imaging with anatomical coverage of the entire head. In the peripheral portions of the brain, SNR was 50 -100 % superior to that obtained with a standard CP volume head coil. In the deeper parts of the brain SNR was at least equally good. The neuro-array coil is PAT optimized and allows the use of SENSE/SMASH type sequences with flexible phase encoding. Conclusion: The 8-channel neuro-array head coil provided excellent high-resolution MRI of the entire brain. SNR was markedly improved, especially in the peripheral parts of the brain. The PAT optimized imaging capablities can be used to decrease imaging time, improve spatial resolution, or a combination of both.

Genetic approach to CT appearance of brain ischemic stroke L. Cyrylowski, A. Ciechanowicz, A. Fabian, I. Goracy; Szczecin/PL Purpose: There is evidence that an allelic variation in the angiotensin converting enzyme (ACE) gene may confer an increased risk of cardiovascular disease. The aim of our study was to evaluate the relationship between the ACE insertion/deletion (I/D) polymorphism and the prevalence of brain ischemic stroke as well as between the polymorphism and CT type of ischemic stroke. Materials and methods: The ACE I/D genotype was identified by polymerase chain reaction in 46 patients (26 males and 20 females) with brain ischemic stroke, and in 100 controls (50 males and 50 females). To assess the polymorphism frequencies, statistical analysis was performed. Results: The D/D polymorphism frequency was significantly higher in the stroke group than in the controls (32.6 % vs. 13 %; p < 0.01). The I/I and I/D polymorphism frequencies were similar in both groups (26.1 % vs. 30 %, and 41.3 % vs. 57 %, respectively; p > 0.05). Conclusion: A positive association between the ACE D/D allele and ischemic stroke was found in our study. The ACE D/D allele may be an independent risk factor for the development of cerebrovascular disease. . The motorized C-arm provides fluoroscopic images during a 190° orbital rotation computing a 119 mm data cube. From these 3D data sets MPR reconstructions were obtained. All images were evaluated by four independent readers for the detection and extend of fracture lines. All fractures were classified according to the Müller AO-classification. To confirm the results, the specimens were finally surgically dissected. Results: 93 % of the fractures were detected with CR, 97 % with ISO-C-3D and 100 % with CT. Differences between CR and CT were significant (p = 0.046), not significant between ISO-C-3D and CT (p = 0.157). With CR 27 % of the fractures were correctly classified, 96 % with ISO-C-3D and 100 % with CT. There was again no significant difference between CT and ISO-C-3D (p = 0.066), but between CT and CR (p < 0.001).

The preliminary results suggest a remarkable efficient detection of tibial joint fractures with the ISO-C-3D. The evaluation of fractures with the ISO-C-3D is better than with CR alone and comparable to that of CT-scans. Even if image quality is definitely inferior to CT, ISO-C-3D may be useful in planning operative reconstructions and evaluating surgical results in orthopaedic surgery of the limbs. 

Dynamic ultrasonography in evaluation of muscular trauma A.K. Nath, R. Bouras; Muscat/OM Purpose: Role of dynamic ultrasonography in muscular trauma. Methods and materials: 50 male football players (aged 20 to 30 years) presenting with clinical muscular trauma in the thigh and calf region were evaluated in this study. Dynamic ultrasonography of both the affected and contralateral normal region, with Toshiba Power Vision 6000 ultrasound equipment using 7.5 MHz phased array linear transducer, in sagittal, coronal and angulated axis was performed, both without contraction and with contraction of the muscles. Needle aspiration of suspected hematomas was performed for diagnosis and treatment. All muscles tears and hematomas were studied and followed up after 72 hours, until complete healing. Results: 46 of the total 50 patients had muscle tears and/or hematomos in thigh and calf region. 4 pateints had no abnormality. 32 patients had clear-cut muscle tears appearing as echogenic retracted portions surrounded by hematomas ranging from highly reflective mass to complete echo poor areas were observed on follow up. The remaining 14 patients had partial tears. Healed tears appeared as highly reflective scar tissue.

(1) Ultrasonography is very useful in diagnosis, management, and followup of muscle tears and hematomas.

(2) Dynamic ultrasonography is essential for diagnosis of partial tears.

Ultrasound and color Doppler imaging of thrombosis of gemellary veins in patients with "tennis leg" lesion M. Dahmane 1 , C. Martinoli 1 , S. Bianchi 2 , F. Zandrino 3 , F. Monetti 1 , A. Beghello 1 , S. Paltenghi 1 , L.E. Derchi 1 ; 1 Genova/IT, 2 Geneve/CH, 3 Alessandria/IT Purpose: To assess with ultrasonography (US) and color Doppler imaging (CD) the association between rupture of distal myotendineous junction of the medial gastrocnemius ("tennis leg" lesion) and thrombosis of gemellary veins. Materials and methods: 32 consecutive patients with suspected "tennis leg" lesion were prospectively examined with 12 -5 MHz US and CD to confirm the diagnosis and evaluate the possible association with thrombosis of gemellary veins. The US study had to be extended to the most proximal portion of the leg, to image the veins up to the popliteal; both compression evaluation and a CD exam were obtained to confirm patency. Results: 30/32 patients had typical "tennis leg" lesions; 1 had a ruptured Baker cyst; 1 had proximal rupture of gastrocnemius muscle. An associated thrombosis of the gemellary veins was detected in 6 cases (18 %); none had extension to the popliteal vein.

Conclusions: Presence of associated thrombosis of the gemellary veins has to be considered in patients with "tennis leg" lesion, and the US examination technique has to be changed accordingly. In this study, we report our experience regarding the usefulness of MRI in the evaluation of traumatic and microtraumatic bone pathology.

We performed MRI examinations in 4324 patients with knee pain and a negative plain film examination where a post traumatic or non traumatic pathology at the level of the joints (knee, ankle, wrist, elbow and hip) was suspected. MRI examinations were performed with a low field dedicated unit for the study of limbs (E-Scan and Artoscan Esaote) and in some cases with an high field MRI unit (Vision Plus Siemens). We used SE T1 and Turbo-T2 sequences, GE and STIR. In some patients we administered i.v. contrast media.

In 964 cases we demonstrated the presence of post traumatic bone alterations or bone alterations not related to trauma that were not visible on conventional radiological examinations. In 112 the bone alteration was the most important finding. In 42 patients, a follow-up MRI after 1 month allowed correlation between the evolution of the clinical symptoms and the changes in the appearance of the bone injury. In 75 patients, it was very useful to correlate the changes in the bone appearance with the clinical outcome. Conclusions: In our experience MRI has been very important in the evaluation of traumatic, post traumatic or non traumatic bone pathology and for a correct therapeutic assessment of the patient. Purpose: To compare bone bruise patterns identified at MRI incurred by impaction, distraction and shear injuries correlated with microtome sections and histopathology. Methods: Freshly harvested sheep cadaveric limbs were imaged on a 1.5 T Philips MRI Intera Scanner following exposure to impaction, distraction and shear forces. Each limb was imaged using SE T1 and STIR sequences. Following imaging, the cadaveric limb was sectioned using a microtome and pattern of trabecular damage correlated with identified bone bruise at MRI. Results: Impaction forces produce poorly marginated globular bone bruises with extensive concertina type trabecular damage. Distraction forces produce localised bone bruises in a linear pattern perpendicular to the axis of distraction with localised trabecular disruption, attenuation and stretching. Shear injuries produce linear bone bruises obliquely oriented with localised linear disruption of trabeculae on microtome sections. Conclusion: Bone bruise patterns are dictated by mechanism. MRI appearances reflect the underlying extent of trabecular damage at histopathology. To determine the diagnostic accuracy of contrast-enhanced, three-dimensional panoramic-table-MR angiography in the assessment of pelvic and peripheral arteries compared with conventional digital subtraction angiography as the standard of reference.

In 169 patients with suspected peripheral arterial vascular disease, both conventional digital subtraction angiography and three-dimensional MR angiography using an automatic tracking technique were performed. In a prospective blinded analysis, each vascular segment (29 segments per patient) was evaluated for the presence of obstructive stenosis, graded as normal (0 -10 %), mild (10 -50 %), severe (50 -99 %), or occlusion (100 %). Results: Obstructive lesions were identified and graded correctly with MR angiography. Overall sensitivity and specificity for the detection of hemodynamically significant disease (severe stenosis) on panoramic MR angiographic images were 93 % and 97.7 %, and for the detection of occlusive disease were 95 % and 99.8 %, respectively.

The diagnostic accuracy of contrast-enhanced, three-dimensional panoramic- Purpose: With 3D-MR-Angiography gaining more acceptance for assessing the arterial system, the amount of data produced requires new tools for visualization of the datasets. Recently, a new volume rendering method, "Stereo Viewing", has become available. The purpose of this study was to assess the potential diagnostic gain by "Stereo Viewing" in comparison to combined MIP and MPR for various vascular territories.

Over an 8-month period 3D-MRA was performed in 40 patients. MRAs were obtained of the carotid, pulmonary, renal and pelvic arterial systems. Imaging was performed on a 1.5 T MR scanner (Sonata®, Siemens). Image sets were analyzed on a workstation (Virtuoso®, Siemens, Germany), firstly based on a combination of MIP and MPRs, and a second time based on MIP, MPRs and "Stereo Viewing". The data sets were analyzed using a 5-point confidence scale ranging from 'stenosis/occlusion definitely present' to 'stenosis/occlusion definitely not present'. In addition to the level of confidence, the time required to reach the diagnosis was documented.

Results: The addition of "Stereo Viewing" led to a significant increase in diagnostic confidence regarding the presence/absence of stenosis/occlusion in all anatomic regions, evidenced by a greater area under the ROC curve (p < 0.05). "Stereo Viewing" prolonged the analysis process by an average of 10 %. Conclusion: "Stereo Viewing" is an effective and accurate tool for assessing complex 3D-MRA datasets as it provides more diagnostic confidence compared to the combination of common post-processing techniques (MIP + MPR). The added time needed for "Stereo Viewing" results in enhanced diagnostic confidence. Purpose: Image quality of DSA of the hands is still superior to CE-MRA due to the lower spatial resolution of CE-MRA which is limited by the passage time of the contrast bolus through the arteries. The aim of this study was to demonstrate that temporary blood flow interruption with an inflated blood pressure cuff during the arterial first-pass can significantly increase imaging time and spatial resolution. Materials and methods: 8 volunteers and 3 Raynaud patients were examined with TAC-CEMRA on a 1.5 T MR machine (Philips Intera). A blood pressure cuff was placed around the upper arm. After timing (BolusTrac), 5 ml iv. Gadolinium-DOTA was administered and TAC-CEMRA was performed. After cuff inflation at 200 mmHg during the arterial phase, a 3D-gradient echo imaging sequence (TR 4.7 ms, TE1.6, flip 35°, matrix 512 × 1024, FOV 300, 0.7 mm-partitions) was acquired. Slopes of histograms were measured perpendicular to the radial and one arch artery and CNR calculated. Results were compared to a classic CE-MRA study in all volunteers. Results: Compared to the classic first-pass MRA with pixel dimensions of 1.17 × 0.59 mm, the use of TAC-CEMRA allowed a significant increase in spatial resolution with voxels down to 0.59 × 0.29 mm. This gain did not impede the CNR which was not statistically significantly different ( 

A C D E F 282 Materials and methods: 4 patients underwent PTA of a single distal SFA stenosis. Lesion length was < 1 cm. HR-MRI (Magnetom Vision, Siemens) was performed within 16 hours after the intervention using axial T1-w, fat-saturated contrast enhanced T1-w, T2-w and 3D-TOF sequences. Maximum matrix size was 320 × 512, minimum voxel size 0.49 × 0.49 × 2.0 mm. Contrast enhanced MR angiography was employed for assignment of exact matching sites. IVUS (3.5 F, 40 MHz) images were recorded with a standardized motorized pullback system (pullback speed 1.0 mm/s). Quantitative analysis for each segment included minimum and maximum luminal diameter and cross sectional lumen area. Morphologic analysis included the absence or presence and extent of dissection. Results: Precise pre-and post-PTA assignment of 16 segments was successfully carried out according to our protocol. The lumen increase measured 100 % to 400 % with a remarkable agreement between IVUS and HR-MRI. Post PTA correlation for cross sectional lumen area (r = 0.90) was better compared to pre PTA analysis (r = 0.80). HR-MRI detected 7/7 IVUS proven dissections while digital subtraction angiography failed to demonstrate 4/7 dissections. Conclusion: Our preliminary findings suggest that HR-MRI has a high potential for non-invasive in-vivo assessment of quantitative and morphologic changes in atherosclerotic SFA lesions following angioplasty. The method for quantitatively determining contrast medium (CM) concentration by measuring the T2*-effect (Brady, 1990 ) was adapted to T2w liver-MRI. The CM used was an indium-doted SPIO. Three groups of study animals (liver cirrhosis, hepatitis, fatty liver) and a control group were investigated (15 rats/group). SE and GRE imaging was performed (n = 6/group, 7.5 µmol/kg bw); 3 rats received no CM and 3 animals each 15 and 25 µmol/kg. T2-relaxation time of all livers were measured ex vivo by relaxometry, and CM concentrations were determined. Q-values representing the phagocytosed CM were computed from the pre-and postcontrast SI on both the SE and GRE images. Spearman's correlation coefficient between CM concentrations and T2-relaxation rates was significant in the control group at 0.506 (p < 0.05). In the 3 study groups, Pearson's correlation coefficient (PCC) between CM and T2-relaxation rates was significant, ranging from 0.627 -0.717 (p < 0.05) -a positive correlation between CM and T2-relaxation rates in all groups. PCC between Q-values and CM concentrations was significant at 0.767 (SE) and 0.587 (GRE) (p < 0.05) -positive correlation between the CM and Q-values. The Mann-Whitney test yielded a significant difference in the QSE values between the liver cirrhosis and fatty liver groups compared with controls (p < 0.05).

Regarding QGRE values, a significant difference was identified only for the fatty liver group versus controls (p < 0.05).

The animal experiments suggest that quantitative determination of phagocytic capacity as a functional parameter using contrast-enhanced MRI has a potential for differentiating diffuse liver disease from healthy livers. Results: In the detection of focal liver lesions, unenhanced plus dynamic plus late phase enhanced MRI was more accurate than unenhanced plus dynamic and than unenhanced plus late phase enhanced examinations, which were more accurate than unenhanced imaging. The accuracy and observer confidence in the characterization of focal liver lesions were higher when dynamic examination was considered. Methods and materials: 45 patients were prospectively investigated using a 1.5 T Magnetom (Siemens Symphony; Philips ACS NT). The sequence protocol included T2w TSE and T1w SE/GRE scans using unenhanced and SPIO-enhanced studies (Endorem: 15 µmol/kg bw). Diagnostic criteria unenhanced were: homogeneous isointensity/mild hyperintensity (T2w); homogeneous iso-/mild hypointensity (T1w); scar detection. The uptake of the SPIO-particels was calculated comparing contrast-enhanced with unenhanced scans. Results: The standard of reference was histopathology providing surgery (liver resection) or needle biopsy. As a second option Gadolinium-enhanced MRI was accepted within a timeframe of 6 month. In the resection group sensitivity was 95.2 % with a specificity of 95.8 %. Signal intensity was homogeneous in T1-and T2w unenhanced sequences and similar to surrounding parenchyma in 37 out of 44 cases (group 1). In eight cases the lesion was heterogeneous hyperintense in T2w and hypointense in T1w scans unenhanced (group 2). Group 1 documented a significant signal intensity loss using SPIO-enhanced T2w sequences compared with unenhanced prtocols. For group 2 a statistical significant decreased uptake of SPIO-particles was documented. Histopathology revealed high degree of fibrotic changes (group2). Using SPIO-enhanced MRI detection and delineation of central scar tissue was increased compared to unenhanced MRI. Conclusion: SPIO-enhanced MRI is an effective imaging tool for the diagnosis of FNH nodules providing morphological and functional details sufficient for characterization. Purpose: Capillary and cavernous hemangiomas represent the most frequent benign lesions of the liver; atypical features due to complications may simulate different lesions; the rare occurrence of other vascular histotypes makes the differential diagnosis even harder. The aim of our study was to describe their imaging features and discuss their differential diagnosis.

We reviewed CT, MR images in 152 patients. CT protocol included: 5 mm collimation, pitch 1.5 injection of iodinated contrast medium in the arterial, porto-venous and delayed phases. MR protocol included 5 -8 mm slice thickness, T1, T2 weighted sequences and post-Gd evaluation. We evaluated the morpho-structural appearance and the contrast enhancement of the lesions. The comparison between different imaging modalities, the dynamic of contrast enhancement, the follow-up, the bioptic and surgical specimens allowed for the correct diagnosis in all the cases. Results: We identified the typical patterns of capillary hemangioma (50), cavernous hemangioma (65), giant hemangioma (10). In 5 case we demonstrated intratumoral hemorrhage, in 7 cases prevalent jaline and/or stromal components, in 6 cases calcifications. We also found 2 hemangioendotheliomas (1 single, 1 multiple), 4 hemangiosarcomas (2 showing extravisceral growth, 3 multinodular, 1 single), 3 Kaposi's sarcomas (2 showing peri-portal infiltration, 1 multinodular). Conclusions: CT and MR demonstrate an elective role in the identification and often in the characterization of vascular tumors of the liver in adults. The presence of complications is also well depicted. MR gives important information regarding the structure of the lesions and in particular of the hemorrhagic components.

Methods: 12 children (5 m/7 f, mean age 14.3 ± 2.1 a) suffering from Marfan's syndrome were consecutively chosen from the Department of Pediatric Genetics. Bone ultrasound attenuation (BUA) and Speed of sound (SOS) were calculated by SAHARA (Hologic, USA). The Standard-Deviation-Scores (SDS) for both parameters were calculated using regional normative data (3299 children). and porosity index (PI) were estimated automatically from radiogrammetric measurements and bone texture analysis of the three middle metacarpal bones. For statistical analysis each case was pair-matched to a sex-and age-related healthy control.

The mean BMD was 0.53 ± 0.04 g/cm 2 in the Marfan group versus 0.53 ± 0.08 g/cm 2 in the control group. Only PI showed a significant difference: 1.99 ± 1.14 versus 5.14 ± 2.22 (p < 0.05). Conclusion: BMD was very similar in our patients with Marfan syndrome compared to the reference population. Statistically significant differences were only observed for the porosity index. Data in the literature concerning osteoporosis in Marfan patients is ambiguous. Our findings may indicate a specific textural disturbance in the bones of Marfan patients which does not result in overall altered bone density. There are potential limitations due to specific anatomic properties of the metacarpal bones in Marfan syndrome. Radiogrammetric based bone densitometry seems to be of promising clinical value in pediatric patients receiving X-rays of the wrist and hand routinely for determination of skeletal maturity. This new technology might be able to give additional information and reduce radiation exposure. Gender-specific standard-deviation-scores (SDS) were calculated using age, height and weight matched regional normative data (3299 healthy children). Follow-up was performed in 9 children during bisphosphonate-treatment over a period of 2 years. Results: 20 patients had OI type I, 6 had OI type IV. Age-matched BUA values were < −2 SD in 9/20 patients, < −1 SD in 6/20 patients and normal in the remaining children with type 1. 13/20 patients had SOS values below −2 SD, 4/20 below −1 SD and 3 were within the normal range. No BUA and SOS-values below −2 SD were observed in type 4; and 2/6 patients had values below −1 SD. 1/6 patients had SOS values < −1 SD, the others were within the normal range. Mean bone values differences were significant: −1.82 SD/−0.10 SD (BUA) and −2.34 SD/0.02 SD (SOS). There was a strong correlation of BUA and SOS (r = 0.90, p < 0.01). 4/9 children showed a significant increase of BUA and SOS (more than 1 SD), 1/9 a slight increase in values during follow-up treatment, 4 had no change. In all treated cases fracture rates were significantly reduced. Conclusion: Ultrasound based bone densitometry may be of clinical value in children suffering from OI. OI type I causes severe disturbances of bone mineralization in contrast to type 4.

Ultrasound based bone densitometry of the os calcis measured on asthmatic children using regional normative data A. (SOS)). BUA/SOS correlation was significant (r = 0.62; p < 0.01). Conclusion: Bone densitometry of the os calcis using ultrasound appears promising in detecting disturbances of bone mineralisation in children treated with low dose topical steroids. SOS was more sensitive in detection of bone mineralisation in comparison to BUA. Girls seemed to be osteopenic more often. In contrast to steroid intake, asthma severity does not correlate significantly with bone mineralisation disturbances.

The use of MRI in the evaluation of paediatric wrist trauma K. Johnson, A. Page, F. Haigh; Birmingham/GB Traumatic wrist injury in children is common but detection of fractures and other injuries can be difficult. We have evaluated the role of MR imaging in the assessment of paediatric wrist trauma. 99 children with a history of wrist trauma in whom the there was either a discrepancy in the clinical assessment and the plain radiographic findings or normal radiographs and persisting symptoms underwent an MRI examination of the wrist. All MRI examinations were performed within 2 weeks of the initial trauma, 76 % within 6 days. 101 MRI examinations were performed (2 children has repeat examinations). 34 (34 %) patients with normal plain radiographs had fractures detected on MR imaging (59 % in the carpus and 41 % in the radius and ulna). In 20 patients there was a discrepancy between the plain radiographic findings and the clinical assessment and in 12 cases (60 %) MRI detected further occult fractures and soft tissue injuries. No patient with a negative MRI examination has represented with a complication of the initial injury, indicating that MRI has a 100 % negative predictive value for wrist injuries. MR examination of the wrist in children significantly alters management. MR imaging detects radiographically and clinically occult fractures and soft tissue injuries. The technique is well tolerated by children. Methods and materials: 21 patients (age 3 -16 years; m = 11, f = 10) suffering from juvenile aseptic osteonecrosis (Legg-Calvé-Perthes disease), underwent MRI in a 0.5 T MR-scanner (Gyroscan T5 NT, Philips, Eindhoven, The Netherlands) using a fat-suppressed STIR sequence, T2-weighted turbo spin-echo and T1-weighted spin-echo sequences. Postcontrast T1-weighted sequences were performed in each patient after administration of 0.1 mmol gadolinium/kg bodyweight (Magnevist, Schering, Berlin, Germany). All examinations were retrospectively assessed by two paediatric radiologists, evaluating the signal patterns of the femoral head and the metaphysis in each sequence in consensus. The MR features and the diagnostic accuracy were analyzed for the different sequences and compared to conventional X-ray.

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Results: Based on the fat-suppressed and the contrast enhanced T1-weighted images, six different signal patterns were differentiated within the femoral head as well as three different signal patterns being identified within the metaphysis. Combinations of separate signal patterns within one thigh were a common finding, representing different stages of necrosis and reparation. For the differentiation of viable and necrotic osseous fragments, the administration of contrast material was mandatory.

The combination of fat-suppressed and contrast enhanced T1weighted images allows distinct staging of juvenile aseptic necrosis. A combination of these imaging modalities permits an efficient surveillance of the Legg-Calvé-Perthes disease.

The Purpose: Saethre-Chotzen syndrome is an autosomal dominant syndrome with craniostenosis and syndactylies. The purpose was to evaluate the variability of anomalies on hand and feet radiographs of patients with genetically proven Saethre-Chotzen syndrome or Muenke-type coronal synostosis.

We evaluated radiographs of the hands in 31 patients, 25 with Saethre-Chotzen syndrome related to TWIST gene mutations and 6 with Muenke-type mutation. X-rays of the feet were available in 27 cases. The age range was between 1 month and 36 years. Radiographs were evaluated by 2 radiologists in respect of morphological anomalies. Results: We found a bone age delay in 10/27 patients, whose epiphyses were not fused. A brachyphalangy was noted in 22/31 patients, clinodactyly in 18/31. Partial syndactyly occured in 16 cases, involving the soft tissues of the 2 nd web space and additionally the 3 rd in 3 cases. 7/31 patients presented with partial carpal fusion, affecting the trapezoid and the trapezium in 5. Coned epiphyses were present in 16/16 patients. Other anomalies included a duplicated distal phalanx of the hallux (n = 9), a triangular deformity of the epiphyses of the distal phalanx of the hallux (n = 10), partial syndactyly (n = 11) and brachyphalangy (n = 10). Conclusion: Saethre-Chotzen syndrome and Muenke-type mutation have a variety of morphological anomalies of the hand and foot in which skeletal anomalies such as brachyphalangy and syndactyly are non-specific signs. Different patterns of anomalies between both are a duplicated distal end and triangular shaped epiphysis of the hallux, which were only detected in patients with Saethre-Chotzen syndrome. Purpose: Saethre-Chotzen syndrome (SCS) and Muenke-type mutation FGFR3 Pro250Arg (MTM) are both complex syndromes with skeletal anomalies such as craniosynostosis, syndactylism and cervical spine abnormalities. In this study we analysed the variable cervical spine abnormalities identified on radiographs for specific features in patients with genetically proven SCS and MTM. Methods and materials: Cervical spine radiographs of 20 patients (11 female, 9 male; mean age 6 a) were reviewed by to 2 radiologists with experience of skeletal dysplasias. The patient population included 17 patients with SCS and 3 patients with MTM. The appearance of the vertebral bodies, the posterior elements including the neural arch and the atlanto-axial joint were assessed. X-rays of the hands and feet were available in 10 patients. Results: Fusion of vertebral bodies and posterior elements were noted in 3 patients (level C2/3, C3/4 and C5/6). An isolated fusion of posterior elements occurred in 8 patients (level C 1/2 (n = 1), C2/3 (n = 7), C 4/5 (n = 1), C5/6 (n = 2)). 5/10 patients with cervical spine fusion additionally showed carpal and/or tarsal fusion. In 7/20 patients an enlarged vertebral space between C 1/2 was found. A hypoplastic neural arch was detected in 5 patients and a long spinous process at C7 in a single case. The atlanto-axial joint space had a mean distance of 3.4 mm (range 2 -9 mm). Conclusion: SCS and MTM display a great variety of cervical anomalies, however the radiological signs are morphologically non-specific. However, cervical vertebral fusion in these patients is often associated with carpal and/or tarsal fusions.

Ultrasound and MRI in children with pyomyositis A. Trusen, M. Beissert, G. Schutz, B. Chittka, D. Hahn; Würzburg/DE Purpose: Pyomyositis is an acute bacterial infection of the skeletal muscles, most often caused by staph. aureus. The purpose of our study was to evaluate the role of ultrasound and MRI in the diagnosis of pyomyositis. Material and methods: 11 children with myositis were evaluated. The areas involved included the pelvic region (n = 4), the shoulder (n = 4), the thigh (n = 1), the lower leg (n = 1) and the elbow region (n = 1). All patients were examined by ultrasound, 9 of them had MRI. Symptoms and signs included swelling, pain and inflammation. Results: In 7/11 the correct diagnosis was made by ultrasound. In 4 cases, 3 involving the pelvic region the ultrasound diagnosis was initially incorrect. In one child where the diagnosis of a tumour was made both on ultrasound and MRI, the diagnosis of a proliferative myositis was subsequently made by histology after ultrasound guided biopsy. The extent of myositis was determined better with MRI than ultrasound. In the extremities an abscess was detected by ultrasound, the accompaniing osteomyelitis could only be detected with MRI. Conclusion: In cases of suspected myositis ultrasound is the primary imaging modality, however, it has a lower sensitivity in the pelvic region. MRI is necessary to exclude osteomyelitis and often to determine the exent of inflammation.

A C D E F 286 Materials and methods: 4 healthy volunteers and 7 patients with tongue tumors underwent videofluoroscopy and real-time MRI before and after tumor-resection, using a T1-FFE sequence (TR = 3.2, TE = 0.9, fa = 10, slice thickness 1.5 cm) with 6 images per second. Images were acquired in the midsagittal plane. Swallowing of diluted Magnevist-enteral solution, phonation of test words and defined testmovements of the tongue were evaluated. Results were analysed by 2 radiologists in comparison to videofluoroscopy as the standard of reference concerning overall quality of the depiction of tongue-movement and deglutition (MRI better, equally good or worse), and depiction of the stages of swallowing (from 0 = not recognisable to 3 = very good depiction). Results: In all cases, the important stages of swallowing could be successfully depicted with real-time MRI. However, quality of videofluoroscopy was considered to be better in all subjects. Discrete pathologies like laryngeal penetration could only be seen on videofluoroscopy. Depiction of tongue-movement was better with real-time MRI in 13/18 cases and equally good in 5/18 cases. This was due to the better soft tissue contrast of MRI and the lacking of artefacts from teeth and metall implants. Conclusion: Real-time MRI can successfully depict the normal physiology of swallowing. For the analysis of dysphagia, quality is inferior to videofluoroscopy, while for the analysis of tongue movement-disorders, real-time MRI is superior to videofluoroscopy. 

Examinations were performed on a 1.5 T scanner (Philips NT Intera), equipped with sensitivity-encoding MRI (SENSE) imaging software. SENSE shortens acquisition time by reducing the number of phase encoding steps, using the coil sensitivity as an encoding effect. 5 volunteers and 5 patients suffering from post-operative dysphagia were examined using a sagittal dynamic T1w 2D FFE sequence with 8 frames/s (TR/TE 2.2/1.1 ms, 30°, slice 15 mm, matrix 144 × 256, FOV 230 mm, 124 ms/image, SENSE reduction factor 2). Water and yogurt (spiked with gadolinium 1:50) with a bolus size of 3 -15 ml were used as oral contrast agents. Oral and pharyngeal swallowing phases were assessed. Results: Oral and pharyngeal transit, laryngeal closure, epiglottic tilting and PE sphincter opening upon swallowing could be visualized in all volunteers. Boluses of yogurt ≥ 5 ml were found most useful. In 4 patients, residue and intra-or postdeglutitive aspiration and in 1 patient nasal regurgitation could be seen realtime. Conclusion: MR fluoroscopic visualization of swallowing is possible using realtime 2D FFE imaging with SENSE. Our initial experience indicates that functional swallowing abnormalities such as aspiration can be assessed with real-time MRI. The leading symptoms were globus pharyngis or dysphagia, which could not be verified by means of endoscopy or ENT-examination. In 40 % of the patiens reflux disease was indentified as underlying disease be means of pH-monitoring. 80 % showed reflux-associated motility disorders in videofluoroscopy. 82 % of them showed a dysfunction of the upper esophageal sphincter, which could not be found by other diagnostic tool. Due to the resultant pressure elevation they showed constant/inconstant Zenker's diverticula of pharyngeal pouches of different degree. In 85 % of those patients motility disorders of the oesophageal body were detected 6 -7 % of them sufferd from a delayed cleaning function of the oesophageal tube. In the remaining collective hypermotile disturbances like segmental not propulsive contractions or reflux-associated non specific motility disorders could be verified. The results of the study will be demonstrated by digital and videofluoroscopic recordings.

Evaluation of patients with dysphagia by modified barium swallow examination U. Coskun, M. Cigiltepe; Ankara/TR Purpose: To determine the perceived radiologic abnormalities of dysphagia with modified barium swallow examination. Materials and methods: 250 patients with dysphagia were undergone modified barium swallow examination. Utilization of a thickener abled us to determine the deglutition skill in different consistencies in anteroposterior, and lateral planes. Results: The perceived radiologic pathologies are as follows. Oral Phase: 35 % of the patiens with bolus formation whereas 42 % with bolus transfer problems. Pharyngeal Phase: 85 % of patients revealed pulling in pyriform sinuses, 55 % had ventriculer residue 73.5 % problems with basal tongue retraction, 13.5 % had abnormal epiglottic tilt, 27 % delayed elevation of the pharynx and hyoid elevation problems. Premature spill is seen in 25 % of them with stasis at the valleculae or pyriform sinuses, 15 % had aspiration and 7 % of them had backflow reflux. Functional swallow refleks was delayed in 65 %. Oesphageal Phase: 15 % had upper oesophageal pathologies. 7 % had lower esophageal pathologies and 5 % had diffuse peristaltism disorder. Conclusion: In our centre each study is tailored to the clinical history, the patients ability to undergo the examination, and the initial flouroscopic findings. According to the findings intervention techniques were establihed. Those included positioning, alteration of the food texture, oral motor range of motion exercise. According to the results aspiration and aspiration related pneumonia free status was achieved.

Mealtime and videofluoroscopic fluids features affecting deglutitive events S. De Giorgi, A. Carniato; Treviso/IT A four years experience in dysphagic patients suggested that assessment of deglutition tested with videofluoroscopic fluids, doesn't closely enough reproduce deglutition with mealtime fluids. With this technique in fact only poor and approximate indications can be given to swallowing therapist concerning food to be used for rehabilitation. The aim is to give clinicians more precise and objective information about deglutition assessment. Density and viscosity of videofluoroscopic fluids were measured and compared by means of a precision balance and a viscosimeter. Videofluoroscopic fluids were more dense and viscous than mealtime food. Different abilities to manage boluses in relation to their density and viscosity during each stage of swallowing were examined as well. The analysis of a recurrent aspiration pneumonia is difficult in newborns or children. Besides the special requests of radioprotection the diminuished capacity of collaboration of small children is a considerable problem. Therefore we use a dynamic recording unit with cine-fluoroscopy and with a videorecording system. The test-bolus consists of Jotrolan (Isovist R), which is a iso-osmolar, non ionic hydrosoluble preparation with a reduced pneumotoxicity. The taste is sugarlike. The analysis of the study should be done with the pediatrician or the paediatric ENT-specialist in order to integrate the clinical findings with the radiologic pattern. The differentiation between an oral and a pharyngeal morphologic or functional swallowing disorder is of special therapeutic interest. In the analysis of the swallowing disorder the individual situation of the study has to be considered, since a rejection might be misinterpreted as a swallowing disorder of the first, the volontary phase. Functional disorders as a complete or an incomplete paralysis of the velum or the pharynx, dysfunctions of the upper esophageal sphincter and alterations of the sensomotoric system can be differentiated with a high precision. The sensitive diagnostic tool allows to find an individual treatment plan in accordance to the therapy of Castillo-Morales, Voita, Pörnbacher or Bobart for the single infant. Patient examples will be shown and discussed. We studied up to now more than 10000 patients of which nearly 3500 had a neurologic disorder.

Only an adequate pretherapeutic work-up of the pathomechanism of an aspiration allows a correct therapeutic approach. The aim of the study is to assess the efficiency of the close cooperation of swallowing therapists and diagnostic radiologists, specially trained in the analysis of the pathomechanism of swallowing. The differentiation of the "pre-", "intra-" and "postdeglutitive" aspiration, which means aspiration before, during and after the triggering of swallowing reflex, turned out to have a great impact in the differential therapy of aspiration. Moreover on the basis of dynamic imaging other important pathomechanisms of aspiration could be detected, which were the bases of the application of new therapeutic manoevers. By means of videofluoroscopy we examined patients before and after therapy. In 80 % of them a sufficient swallowing rehabilitation without aspiration could be achieved. Videoflouroscopy shortened the time of training-hospitalisation, because the therapist could immediately center on the relevant exercises for swallowing rehabilitation.

Conclusion: Dynamic evaluation of the neurologic impaired patient makes rehabilitation more efficient and shortens hospitalisation-time and costs. 

Flat panel X-ray detector radiography: Comparison with storage phosphor radiographs and conventional radiographs P. Boehm, P. Homolka, S. Grampp, C. Czerny, A. Ba-Ssalamah, H. Imhof; Vienna/AT Purpose: To compare images obtained with a flat-panel X-ray detector based on amorphous silicon technology with conventional screen film radiographs and storage phosphor radiographs using different exposure parameters to evaluate dose reduction and image quality in skeletal radiology.

A digital X-ray detector (Trixell, Siemens, Erlangen, Germany) based on cesium iodide and amorphous silicon technology was used. State of the art screen film radiographs and storage phosphor radiographs (ADC system, AGFA) were compared with digital detector images obtained at doses equivalent to those obtained with system speed of 200 (hand: speed 50, femur and tibia: speed 100). In vitro human cadaver specimen (femur, tibia, head, lumbar/thoracic spine, hand) were embedded in a PMMA tube filled with water. A conventional and storage phosphor radiograph and digital detector radiograph were made of each specimen by varying the exposure parameters (kV, mAs). The resulting 228 images were evaluated independently by 3 radiologists using a subjective ranking (grade 1 -3) rating exposure, contrast resolution, spatial resolution and soft tissue presentation. From each group the best image was chosen and separately evaluated for comparison. Results: Radiation doses for digital detector images were equivalent or below the other methods giving the same or better diagnostic performance.

The diagnostic performance of digital detector radiographs compared with conventional radiographs and storage phosphor radiographs suggests that this technology will be a useful tool in diagnostic imaging.

Comparison of a flat panel digital detector to screen-film by X-ray images of the hand T. Pollack, H. Pauls, K. Köhler, R. Friedberg, U. Günl, F. Stösslein; Dresden/DE Purpose: To evaluate the image quality of hand images obtained with a new flat panel digital detector to those obtained with an extremity screen-film system. Methods and materials: Hand images were obtained on 50 patients presenting for a rheumatologic baseline or follow-up exam. The patients were imaged such that one hand, selected randomly, was imaged with a digital flat panel table system (General Electric, XR/d, Milwaukee, WI) and the other with an extremity 100-speed screen-film (SF) system (Agfa, Curix HT 1.000G Plus). The DR images were printed using a laser printer. All images were obtained using the same X-ray tube and generator, without a grid, 100 cm source-to-detector distance, 50 kV, and 2.5 -3.2 mAs (dependent on the patient acquired with matched techniques). Five radiologists scored pairs of images DR vs. SF using a 5-point scale (−2 clearly worse to +2 clearly better). Observers were asked to score the image quality of eight anatomical criteria. Results: All anatomical structures were scored equal or higher with the flat panel system compared to screen-film. Comparing the digital flat panel to screen-film, DR was graded statistically superior: by 3 of 5 readers for cortical structures, by 3 readers for trabecular structures and by 4 readers for border structures, soft tissues and overall image quality. None of the observers rated the SF statistically superior to DR for any category.

The results demonstrate that the digital flat panel system with a 200 µm pixel size produced equal or superior hand images with respect to all anatomical criteria.

Cost-effective data recording device for mobile C-arm which has only analogue output: Optimizing ordinary software of video-capturing and real time MPEG compression with limited funds A. Sada, W. Ikeda, E. Nakagaki, K. Hisazumi, I. Imai, K. Nakanishi; Osaka/JP Purpose: In our department, a mobile C-arm is used for routine digital subtraction angiography (DSA) because of limited funds. The purpose of our study is to find an adequate data saving device for this mobile C-arm which was equipped with only analogue output. Materials and methods: A Philips BV 312 mobile C-arm was used as DSA. All DSA images were obtained at five images per second and imaging matrix was 752 × 582. This machine has no facility for a data transport system. Imaging data were generated by a video cassette recorder as an analogue output. A personal computer (Macintosh powerbook G4) and mobile C-arm were connected through the analogue-digital converting and real time MPEG-1 compressing system (The pixela). From July 2001 to September 18 2001, 20 cases of DSA were performed (abdominal aortogram: 8, celiac arteriogram: 15, SMA: 15, renal arteriogram: 6, common iliac arteriogram: 9, the others: 75). The compressed image qualities were evaluated. The amount of data and cost were estimated.

Results: Compression was about 3.7 %. Average compressed data per one-series of DSA was 3.2 MB. Average data per patient was 20.6 MB. Therefore, about 32 patients' data can be saved on 640 MB MO disks and two MO disks will be required per year in our department. Conclusion: With limited funds, our device (using ordinary computer and the real time MPEG compression software) was useful for saving the imaging data of DSA using a mobile C-arm system which has only analogue output.

Hodgkin's disease -radiological procedures for determination of clinical stage L. Todoric; Belgrade/YU Purpose: To assess the value of US, CT and lymphography in determination of the clinical stage of the Hodgkin's disease and to evaluate the reliability of the techniques in identifying the spread of disease into infradiaphragmatic lymph nodes. Methods: 100 patients with histologically confirmed diagnosis were examined using all three methods before the onset of treatment. The clinical stage of the disease was based on US and CT findings. Lymphography was performed as the last diagnostic procedure. After this final staging took place. We compared and statistically analyzed US, CT, and lymphographic findings as well as the change of clinical stage after lymphography. Results: Lymphography did not show high aortic lymph nodes. US and CT did not show the changes in small or normal size nodes especially in pelvic region. Statistically significant differences in alteration of the clinical stage, before and after lymphography, has been demonstrated in all stages. Conclusion: Lymphography enables a more accurate evaluation of lymph nodes in the pelvic and aortic region in comparison with US and CT and the assessment of the clinical stage resulting in an optimal therapeutic approach to Hodgkin's disease. 

A C D E F 288 Methods and materials: Five patients with chronic low back pain and two volunteers underwent routine Magnetic Resonance Imaging (MRI) protocol for the lumbar spine. A 3-plane localizer sequence was taken with and without a standard supportive cushion. The angle of lumbar lordosis was calculated by two 'blinded', experienced radiologists from consensus measurements of the angles at the L5/ S1 and L1/L2 levels using a ruler line tool on a workstation. Results: Observations in the seven subjects who underwent lumbar spine imaging (MRI) with and without the supportive cushion showed no change in the degree of lordosis; the mean angle with the supportive cushion was 46.7° (SD. 17.5) and 48.2° (SD. 17.6) without. The mean of the difference between the measurements for each subject was −0.14 (SD. 4.05). Conclusion: As the use of supportive cushions produces no practical change in the lumbar lordosis, the decision to employ them should be made entirely with respect to patient comfort.

The military radiographer: A profession in constant evolution E. Martinello, A. Giardino, M. Pari, C. Turchetti, C. Ottonello, S. Panica; Rome/IT Diagnostic imaging in military medicine can be divided into two branches: clinical (in homeland and in field hospitals) and forensic. The clinical branch is performed in all clinical hospitals, while the forensic branch is performed both in clinical hospitals and in dedicated medical forensic military centers. In the clinical branch, field hospital radiological activity (FHRA)is very specific and interesting; it is performed in the homeland (great disasters or accidents) and abroad (military operations, as peace-keeping/enforcing). FHRA is influenced by three important factors: mass (high spatial-temporal concentration of injured personnel), environment (e.g.: tropical countries: infectious or climatic changes or unusual diseases, and injurious agents, ballistical or thermal. A special modular Rx unit (8 parashutable packages) that can be easily and rapidly assembled and disassembled, and a US unit with 3.5 and 7.5 MHz probe are available in our field hospitals. The modular Rx unit is composed of a "C" arm, TV unit with fluoroscopy, radiographic facilities and the ability to print on US type film. In the near future dedicated CT units, digital radiology devices and dry film processing units shall also be available. Methods and material: Over a two year period, 95 patients ranging from 5 to 80 years with or without an intraspinal component of the lesion were subjected to FNAC. All were performed with 20/22 to gauge needle. Two or three passes were made. US guided biopsy was performed with 5 -7 MHz linear probe with a free hand technique. CT was performed using a lead wire grid for accurate location. Results: Of these 45 (67.16 %) were benign and 22 (32.87 %) were malignant. 6 patients underwent CT guided FNAC as US guided was negative. The success rate of US guided FNAC was 33/45 (73.3 %) and that of CT guided 34/46 (73.9 %). A conclusive diagnosis could not be reached in 18 patients due to insufficient material caused by necrosis, clot or blood. Conclusion: Image guided FNAC is an effective and safe procedure for evaluation of spinal and para spinal lesions for effective patient management. To evaluate the value of MRI as an adjunct to clinical and sonographic findings for the prenatal diagnosis of fetal malformation as well as for the assessment of maternal disorders during pregnancy. Methods: 77 women with complicated pregnancies (fetal pathologies n = 71, maternal pathologies n = 6, mean age of gestation 26.82 ± 6.88 weeks) were referred for MRI. Imaging was performed in a 1.5 T System (GEMS) using T2w SSFSE sequences. Images were analysed with regard to fetal and maternal abnormalities. Findings were correlated with sonography, postnatal clinical and imaging findings and/or autopsy. Results: Most of the fetuses (n = 37) had isolated pathologies of the CNS. In 7 cases complex malformation syndromes were present. The remaining pathologies included pulmonary (n = 6), gastrointestinal (n = 2) and other (n = 20) pathologies. MRI was equal or even superior to sonography for diagnosing cerebral malformation. Due to the small size, the lack of real time examination and the missing flow information, the diagnostic confidence of MRI was lower for pathologies of the heart, abdominal organs and extremities. Maternal disorders included anomalies of the uterus (n = 2), myoma (n = 2), 1 cervical carcinoma and 1 borderline ovarian tumour. Purpose: Aim of this work was to compare the new 3D MR-histerosalpingography with the X-ray conventional one in the evaluation of female infertility. Method and materials: 15 infertile female patients (aging 29 -43 years, mean 35) were studied with a 1.5 T magnet unit (GE Horizon 8.5) using a T2 weighted FSE sequences on axial and coronal plane and a 3D Fast SPGR sequence (3D MRA sequence) on coronal plane after injection of a diluted gadolinium solution into the uterine cavity via a balloon catheter. All the data were compared with conventional X-ray hysterosalpingography.

The tomographic images provided a complete evaluation of the uterus and ovaries. The 3D MR technique provided the evidence of the uterine cavity and the patency of the Fallopian tube with a complete concordance with X ray histerosalpingography. However the accuracy in detecting the Fallopian tube calibre was considered inferior with MRI than X-ray by two expert radiologists. Two Fallopian tube stenosis were missed at 3D MR-histerosalpingography. Conclusion: 3D MR histerosalpingography may represent a real promising technique in the non-invasive evaluation of the infertile female. The main advantage is related to the lack of ionising radiation in these young females. Up to date, in our experience, the MR technique does not have the same accuracy as X-ray in detecting the Fallopian tube. Improvement in spatial resolution probably have to be considered. The purpose of this study was to establish MR pelvimetric reference values in a large study taking into account the mode of delivery. Intra-and interobserver errors and intra-individual variability of MR measurements were assessed in a complementary volunteer study. Methods and materials: MR pelvimetric measurements of 781 women (28.9 ± 5.2 a) were reviewed and correlated to obstetric history in order to establish normative values. 2 subgroups were identified: (1) spontaneous deliveries, and (2) cases undergoing caesarean section or vacuum extraction due to fetalpelvic disproportion. In addition, MR pelvimetry was performed 5 times in 10 female volunteers (34.7 ± 6.0 a) on a 1.5 T system using T1w FSPGR sequences. All measurements were then performed twice by 5 different observers to assess intra-and interobserver errors and intra-individual variability. Results: Mean obstetric conjugate measured 116.6 ± 10.8 mm, interspinous distance 106.6 ± 9.5 mm, intertuberous distance 114.8 ± 12.3 mm, transverse diameter 125 ± 9.8 mm and sagittal outlet 112.8 ± 11.0 mm. There were significantly different measurements in the 2 subgroups (p < 0.001), with wider measurements in the spontaneous delivery group. In the volunteer study intra-, interobserver and intra-individual reliabilities were accurate for obstetric conjugate (0.94 -0.96), interspinous distance (0.92 -0.95) and transverse diameter (0.95 -0.98), however they were poorer for intertuberous distance (0.64 -0.87) and sagittal outlet (0.66 -0.85).

The normative values established in this study stratified for mode of delivery are likely to influence obstetrical decision making in the future. Intertuberous distance and sagittal outlet presented the largest variabilities. Obstetric decisionmakers would be justified in approaching this parameter with caution. 

A single-shot echo-planar diffusion MR sequence with 2 b-values (0 -500 s/mm 2 ) in the 3 planes of space (x, y, z) was implemented on a 1.5 T magnet and systematically added to a routine liver protocol including T1-, T2-and gadolinium-enhanced T1-weighted sequences in 66 patients. 52 FLL were evaluated in 43 patients separated in 5 groups: metastases (n = 9); hepatocellular carcinomas (HCC, n = 9); benign hepatocellular lesions (BHL) including focal nodular hyperplasias and adenomas (n = 15); hemangiomas (n = 7); and biliary cysts (n = 3). The ADCs were measured on the normal and the cirrhotic liver and on the FLL. The results were then compared between the groups of patients.

The liver parenchyma and the FLL were found to be isotropic. The ADC (× 10 −3 mm 2 /s) of the cirrhotic liver (1.37 ± 0.52) was lower than that of the normal liver (1.83 ± 0.36, p < 0.05). Signal intensities of the focal lesions were rated by two radiologists as follows: hypointense, isointense, hyperintense, and markedly hyperintense. Lesion-to-liver contrast-to-noise ratio (C/N) was measured for a quantitative assessment. Results: On ferumoxides-enhanced FSE images, 92 % of cysts were 'markedly hyperintense' and most of the other lesions were 'hyperintense', and the mean C/N of cysts was significantly higher than that of other focal lesions. T2*-weighted GRE images showed most lesions with similar hyperintensities and the mean C/N was not significantly different each other. T1-weighted in-phase images showed all FNHs and hemangiomas, 29 (69 %) HCCs and 8 (20 %) metastases as 'hyperintense'. On T1-weighted out-of-phase GRE images, all HCCs and metastasis except one were iso-or hypointense, while all of the FNHs and hemangiomas were hyperintense. Ring enhancement was more commonly seen on the out-ofphase images than on the in-phase images.

Conclusions: Addition of T1-weighted in-phase and out-of-phase GRE images is helpful for characterizing focal lesions in ferumoxides-enhanced MR imaging. was acquired before and immediately following i.v. injection of 0.1 mmol/kg of gadodiamide, during arterial and portal-venous phases. In-phase and opposedphase images were calculated at the end of the sequence; subtraction was performed for each series of images on the main console. Results: Images of diagnostic quality were obtained in all the cases. Nine metastases, 3 hemangiomas and 9 cysts were detected, all showing low signal intensity on unsubtracted and subtracted images. Increase in lesion/liver contrast was observed on subtracted images (p < 0.05). Three hepato-cellular carcinomas previously treated with chemioembolization showed high signal on in-phase images and low signal in opposed-phase images; after subtraction bright signal was observed with increase in liver/lesion contrast (p < 0.05). Focal fatty areas showed bright signal on subtracted images. In two patients with diffuse liver steatosis, three metastases were missed in both opposed-phase and subtracted images, but they were visible as low signal intensity nodules in in-phase images.

In-phase and opposed-phase images with electronic subtraction may help in identifying focal liver steatosis and increase lesion/liver contrast in case of fat-containing lesions.

Which is the optimal phase for the detection of hypervascular liver lesions with multislice helical CT? Comparison beetween early and late arterial phase R. Basilico, M. Ricciardi, A. Di Credico, E. Cucci, L. Bonomo; Chieti/IT Purpose: To compare early and late arterial phase imaging with multislice CT in the detection and conspicuity evaluation of hypervascular liver lesions. Materials and methods: 50 patients with known hypervascular liver lesions (20 HCCs, 15 metastases, 10 haemangiomas, 5 FNHs) were evaluated with double arterial phase CT. CT examinations were performed with multislice CT scanner using 4 × 2.5 mm collimation and 3 mm slice thickness during administration of 130 cm 3 of contrast agent (400 mg I/ml) at 4 cm 3 /s. After a test bolus, early and late arterial phase images were obtained serially during a single breath hold in a cranio-caudal direction, with interscan delay of 4.0 seconds and mean scanning time of 10.5 seconds for each phase. Each set of images were evaluated in consensus by two blinded, experienced radiologists. They determined lesion detection rates, recorded lesion size and scored the conspicuity of lesions on a scale 1 -4.

The mean scanning delay for the early arterial phase was 21.5 seconds (range 13 -28 seconds), whereas the mean delay for the late arterial phase was 36 seconds (range 27.5 -42.5 seconds). The number of lesions detected was 118 with early phase and 242 with late phase (p < 0.01). Late arterial phase resulted in 51 % increase in detection rate versus early arterial phase. Lesion conspicuity and diameter significantly increased on late arterial phase. The detection of hypervascular liver lesions did not significantly improved with early and late arterial phase evaluated in combination. Conclusions: Late arterial phase imaging (15 seconds after the peak enhancement in the aorta) significantly improves the detection of hypervascular liver lesions. 

A C D E F 292 Material and methods: 24 consecutive patients underwent MRI of the liver using a 1.5 T system with 30 mT/m gradients with phased array bodycoil. Imaging protocol includes T2w TSE with and without fatsaturation and breathhold T1w Flash. Seven T1w 3D Flash datasets with parallel imaging (VIBE with SENSE; TR/TE/ matrix/slice thick./acq.t.: 6.21 ms/3.16 ms/256 × 192/4 mm/14 s) was performed as dynamic contrast study during infusion of Gd-DTPA i.v. Additional postcontrast breathhold T1w Flash was acquired. Results: Images of diagnostic quality were obtained in all cases. Normal findings were observed in 6, ecchinococcus cyst in one, liver metastases in 3, hemangiomas in 4 and hepatocellular carcinoma in 12 cases. Dynamic contrast studies gives important additional informations about the perfusion of focal hepatic lesions. With a slice thickness of 4 mm in VIBE sequence even in small hemangiomas typical contrast behaviours are seen. Hepatocellular carcinomas are detected best in VIBE sequence in early arterial phase compared with other sequences. Conclusion: The VIBE sequence with SENSE technique covers the whole liver within one breathhold. Thus dynamic contrast studies in a slice thickness of 4 mm are possible and important perfusion informations of liver lesions are available in a high spatial resolution. We think that this MR technique is a very promisable tool for liver diagnostic.

The value of MRI in the diagnosis of hepatic tuberculoma F.H. Yan, M.S. Zeng, K.R. Zhou; Shanghai/CN Purpose: To analyse the MRI findings of hepatic tuberculoma, to discuss the value of MRI in the diagnosis and differencial diagnosis. Methods and materials: Ten cases with hepatic tuberculoma underwent MR SE sequence and FMPSPGR sequence dynamic contrast scanning. Results: MRI findings of total 12 lesions in 10 cases appeared as: (1)SE sequence: all lesions were hypointense on T1WI, 10 lesions were inhomogeneous hypointense on T2WI (central hypointense and peripheral hyperintense in 8 lesions and punctual hyperintense in the center in 2 lesions). The other 2 lesions showed as hyperintense.

(2) FMPSPGR dynamic contrast scanning: 10 lesions had no enhancement and 2 lesions had slight peripheral enhancement on the arterial phase, all lesions had various patterns of enhancement on the portal venous and delayed phase scanning, mainly peripheral enhancement and internal septal enhancement. Conclusion: MRI could reflect the pathological changing of hepatic tuberculoma and be of great value in the diagnosis and differencial diagnosis.

Comparative study of CTAP and MnDPDP enhanced MRI of the liver in the pre-operative evaluation of colorectal metastases E.J. van der Jagt, T. Kok, M.J.H. Slooff; Groningen/NL Purpose: To compare the sensitivity of CTAP (Computer Tomography during Arterial Portography) with MnDPDP enhanced MRI in assessing the exact number of liver metastases before liver surgery. Material and methods: In 30 patients evaluated for surgical treatment of metastases of colorectal carcinoma, we performed CTAP and MRI with MnDPDP contrast medium (Teslascan). Peroperative ultrasonography performed jointly by surgeon and radiologist served as the gold standard. CTAP and MRI were evaluated by two experienced radiologists blinded to the results of the operative findings and the result of the other technique. Results: In 18 patients at operation 37 metastases were found, and 1 focal nodular hyperplasia. CTAP correctly showed 31 (81.6 %) and MnDPDP enhanced MRI 24 (65 %)of these lesions. Of the missed meastases in MRI 7 were smaller than 7 mm and 10 smaller than 1 cm. Two were missed because of technical failure, two of three by interpretative failure were found in retrospect. CTAP showed 13 lesions thought to be metastases not proven by surgery, whereas MRI only scored 3 false positive findings. In the non operated group 6 patients underwent PETscanning showing a total of 15 metastases in the liver. 13 of these were shown by CTAP and 14 by MRI. When this group of patients is added to the operated group, sensitivity for CTAP rises to 83 % and for MRI to 70 %. Conclusion: MnDPDP-enhanced MRI is less sensitive than CTAP (70 % versus 83 % of proven lesions) but showes less false positive lesions. = 1) , SLE (n = 1), idiopathic (n = 1)), cystic acinar transformation (n = 3), oncocytic endocrine tumor (n = 1) and isolated polycystic disease (n = 1). We reviewed retrospectively the preoperative investigations (computed tomography, cholangio-MRI, US-endoscopy, pancreatography) and correlated them to the histological results. Results: CT and MRI showed isolated abnormalities of the pancreatic ducts in 7 patients involving the main pancreatic duct (MPD) (n = 3) and the branch duct dilatation (n = 5). The MPD was normal (n = 4), dilated (n = 3) or stenosed (n = 1). The cystic lesions involved the head and/or uncinate process (n = 4), the body and/or tail (n = 3). The location was diffuse (n = 3) or multifocal (n = 1). The number of cystic lesions varied from 3 to 20 or more and the size was less than 10 mm. A solid tumor was demonstrated in one patient. Correlation with US-endoscopy was good. None of the 8 patients were found to have mucous extrusion through the papilla. Pancreatography was normal in 1 case, showed a communication between the cystic lesions and MPD in 2 cases or a stenosis in one case. Ductal biopsies performed in 5 cases (EUS-guided n = 3; transpapillary n = 2) revealed epithelial proliferation in 2 patients and were non-informative in 3. The pancreatic resection consisted with a pancreatico-duodenectomy in 6 patients and total pancreatectomy in 2. To compare MR cholangiography to multislice CT cholangiography without biliary contrast agent in the assessment of patients with biliary obstruction. Methods and materials: 25 patients with clinical or biochemical signs of biliary obstruction were studied. MR cholangiography was performed with a 1.5 T unit, using respiratory-triggered three-dimensional fast-spin-echo and HASTE sequences; source images, maximum intensity projection, and multiplanar reformatted images were evaluated. CT cholangiography was performed using a multislice scanner, without biliary contrast agent, with intravenous injection of iodinated contrast material; axial, minimum intensity projection, and multiplanar reformatted images were evaluated. CT and MR findings were compared to ERCP in 17 patients, PTC in 6, intraoperative cholangiography in 2. Six patients underwent surgery or fine needle aspiration. Results: ERCP, PTC, surgery, and pathology demonstrated: 10 pancreatic, 2 gallbladder, 2 Klatskin's, and 1 ampullary carcinomas; 1 bile duct obstruction due to enlarged hilar lymph nodes; 7 patients with choledocholithiasis; 1 chronic pancreatitis; 1 patient with negative findings. Regarding site of obstruction, agreement was observed among CT, MR cholangiography and conventional cholangiography in all cases. Concerning the cause of obstruction, the correct diagnosis was made in 23 patients by both MR and CT cholangiography. In two patients with choledocolithiasis, CT cholangiography was judged to be negative, but stones were correctly identified by MR cholangiography. Conclusion: In the assessment of patients with biliary obstruction, multislice CT cholangiography can be considered a useful diagnostic tool alternative to MR cholangiography, which is still the non-invasive standard of reference in the evaluation of the biliary tract. 

MDCT-CA was performed as part of a comprehensive preoperative assessment in 30 potential living liver donors (16 women, 14 men; mean age 31 years). For display of the biliary system, MDCT of the liver (slice thickness/ collimation 1 mm, pitch 6 mm, table speed 12 mm/s) was performed 25 ± 5 minutes following intravenous administration of meglumine iodipamide (Biliscopin). Subsequent MDCT angiography was added to depict the topographic relationship between biliary and vascular structures. MDCT findings were correlated with intraoperative findings (n = 14). Results: MDCT-CA was diagnostic in all 30 patients. 21 of 30 patients presented with variations in biliary anatomy. These include drainage of liver segment four into right hepatic duct (n = 9), additional right/left segmental ducts draining into the common hepatic duct (n = 8) or the left hepatic duct (n = 4) and trifurcation at the upper confluence (n = 3). Biliary-vascular topography was well depicted in all cases. Intraoperative assessment confirmed the preoperative MDCT-CA findings in all 14 cases. Conclusion: Variations in biliary anatomy appear to be the rule rather than the exception. MDCT-CA represents a non-invasive means for accurately assessing biliary morphology. A continuous helical data set of the heart was acquired in 50 patients (group 1) using the standard protocol with constant tube current, and in 50 patients (group 2) using an alternative protocol with reduced radiation exposure during the systolic phase. The standard deviations (SD) of predefined regions of interest (ROIs) were determined as a measure of image noise and were tested for significant differences.

Results: There was no significant difference between group 1 and group 2 in respect of image noise. Radiation exposure with and without tube current modulation was 1.0 mSV and 1.9 mSv, respectively (p < 0.0001) for males and 1.4 mSv and 2.5 mSv, respectively (p < 0.0001) for females. Thus there was a mean dose reduction of 48 % for males and 45 % for females, respectively. Conclusion: ECG-controlled tube current modulation allows significant dose reduction when performing retrospectively ECG gated MSCT of the heart. Purpose: To analyse myocardial contrast dynamics and to calculate myocardial perfusion parameters using ECG-triggered multirow-detector computed tomography (MDCT). Methods and materials: 9 patients with a suspicion of or known CAD underwent retrospectively ECG-gated MDCT angiography of the coronary arteries. Prior to CTA data acquisition a prospectively ECG-triggered transaxial dynamic scan (4 × 5 mm) over 35 heart beats was applied to analyze myocardial enhancement patterns with subsequent assessment of perfusion parameters. Contrast enhancement was provided by administration of 40 ml of Iopromid 300 at a speed of 8 ml/s followed by a 50 ml saline flush. Sequential image data was analyzed to calculate maximum left ventricular (LV) and myocardial signal intensity (SI) increase and for maximum SI upslope. All data were normalized to the LV input function. In addition quantitative measurements were performed using a Fermi-function. Coronary angiography was available in all patients.

The LV SI increase showed an amplitude of 244 ± 62 HU (136 -324 HU) and an up-slope of 39.7 ± 4.6 (34.0 -45.6). The range of SI increase in myocardium was 31 ± 10 HU. Within myocardial regions the normalized SI increase and upslope were 0.13 ± 0.07 and 0.065 ± 0.022, respectively. In regions of impaired blood supply SI amplitudes and SI upslopes tended to be lower. Quantitative flow calculations revealed values close to those within normal myocardium (0.73 ± 0.20 ml/g/min).

The use of MDCT scanners the assessment of myocardial contrast dynamics is possible. However, ventricular coverage so far is insufficient. With optimized contrast enhancement protocols the reliability may be even better. So far, the relatively low myocardial enhancement leads to a low SNR.

A C D E F 296 Method/materials: In 30 children (22 male, 8 female, mean age 9.1 years) with suspected aortic isthmus stenosis or re-stenosis MR imaging was obtained using a 1.5 T body scanner (Magnetom Vision, Siemens). An optimized 3D GE sequence with double-slab excitation (TR 12.3 ms, TE 5.5 ms, slab thickness 12.5 mm) was used in a sagittal plane. In 14 children an additional CE MRA was performed using a standard 3D GE sequence with short TR/TE (~6 ms/~1 ms) after intravenous administration of gadolinium (0.1 mmol/kg). Source images and maximum intensity projections (MIP) were analyzed, evaluating blood-tissue contrast as well as size and focal stenoses of the aortic arch. Results: In 21 of 30 an aortic coarctation could be found. Using the double-slab technique, in 87 % the image quality was high and there was a low sensitivity to flow and breathing motion. There was a good blood-tissue contrast without the use of contrast agent. Using a combined analysis of source images and MIP diagnostic accuracy could be improved. Conclusion: MR imaging represents an excellent tool for non-invasive examination of the cardiovascular system of children. The double slab method allows recording of a large 3D data set in an adequate measurement time especially in small infants, which were not able to hold their breath, and it is well suited for 3D reconstruction.

Evaluation of the TAIS stent in short de novo coronary lesions I.V. Pershukov 1 , T.A. Batyraliev 1 , A.N. Samko 2 , Z.A. Niyazova-Karben 1 , Y. Pya 1 , Y.N. Belenkov 2 ; 1 Gaziantep/TR, 2 Moscow/RU Purpose: The TAIS is a new balloon-expandable, stainless steel, tubular stent. This study was designed to assess the safety and efficacy of this novel coronary stent and by indirect comparison to indicate equivalence with other formal stent studies. Methods and materials: Patients with angina and a single short (< 15 mm) de novo lesion in a native coronary artery of ≥ 2.75 mm diameter were included. A total of 588 patients were allocated in 2 centers. Most patients (59 %) had stable angina, and 34 % of lesions were type B2 -C. Clinical data was collected at sixand nine-month follow-up. In the first 308 patients angiography was routinely performed at six months. The remaining 280 patients were merely followed up clinically. Results: No stent deployment failure occurred, as well as acute or subacute stent thrombosis. The primary end-point of the study, the six-month MACE-rate was 12.3 %, which is similar to the calculated 15 % MACE-rate in comparable reference studies. Secondary end-points included among others restenosis at six months in the first population. The target vessel diameter was 3.13 ± 0.51 mm. Minimal lumen diameter pre/post procedure and at follow-up was 0.81 ± 0.33, 2.97 ± 0.44, 2.21 ± 0.77 mm, respectively. The binary restenosis rate was 15.5 %. Conclusion: The coronary TAIS stent is safe and effective as a primary device for the treatment of native coronary artery lesions in patients with stable or unstable angina pectoris. Clinical and angiographic results are in the statistical range of equivalence with comparable studies with other current stents. The aim of this study is to asses if the BMI affects the amount of pulmonary atelectasis developing after general anaesthesia, and its effect on atelectasis evolution. Material and methods: Two groups of volunteers aged from 27 to 66 years old were prospectively randomised. They all underwent surgical celioscopy. 20 patients with a BMI over 35 kg/m 2 underwent a gastroplasty and 10 patients representing the control group (BMI under 30 kg/m 2 ) underwent a cystectomy. Before induction of general anaesthesia, three CT sections of 7 mm, were acquired in expiration at the level of interventricular septum. Immediately after surgery and 24 hours later, three CT sections were acquired at the same level. With a threshold of −1000 to +100 Hounsfield units, the surface of pulmonary parenchyma was manually extracted from the CT sections. The amount of pulmonary atelectasis was determined with a −100 to +100 HU threshold. Results: A statistically significant difference was observed in comparing the group with a BMI over 35 kg/m 2 and the control group in the development of pulmonary atelectasis (p = 0.0021) and in its evolution (24 h p = 0.0008).

The BMI affects the amount of pulmonary atelectasis developing after general anaesthesia and its evolution at 24 hours.

Lymphomatoid granulomatosis: Pulmonary abnormalities and correlation with pathology A. Patsalides, G. Atac, U. Hegde, W. Wilson, N. Patronas; Bethesda, MD/US Lymphomatoid granulomatosis (LYG) represents an angiodestructive lymphoproliferative disorder. Immunosuppression is a major risk factor for the development of LYG and the lungs represent the most commonly affected organ. The purpose of our presentation is to report the pattern of respiratory tract involvement in LYG and assess evolution of these lesions after treatment. 22 patients, six females and 16 males, ranging in age from 26 to 73 years (mean, 48 years) were enrolled on a study on the diagnosis and treatment of LYG. The diagnosis was confirmed by lung biopsy in all patients. CT imaging was performed in all patients upon entering the protocol and follow up scans were performed after the initial evaluation in order to assess the effect of treatment. Pulmonary involvement was evident in all patients. Masses were identified in 19, alveolar and/or interstitial infiltrates in 20, and lymphadenopathy in five patients. Pleural effusion was present in six and pleural thickening in one patient. Eight patients were found to have pulmonary cavities. Pathology studies showed infiltration of the pulmonary parenchyma by lymphoid cells with prominent perivascular distribution. Granulomas with various degrees of ischemia and necrosis were also present. On follow up studies, partial or complete resolution of the pulmonary lesions was noted after treatment. The pattern of pulmonary involvement in patients with LYG is consistent with the pathological findings. The imaging findings are not specific. Pulmonary biopsy is therefore essential for the establishment of an accurate diagnosis. Imaging studies however are useful for evaluating the response to treatment. Method: 13 patients with histologically diagnosed neoplasms underwent initial assessment with clinical examination, pulmonary function tests and high resolution CT. Pulmonary clearance studies were carried out using using a proprietary nebulizer (Amertec, UK) and baselines were obtained contemporaneously with pre-treatment HRCT. Investigations were repeated immediately after treatment and at one and four months. Results were documented independently and compared to determine the presence, severity and timing of changes. Results: Eight patients were able to complete the study; one died and four were withdrawn on medical grounds. Clearance was unaffected by treatment in only one patient, the rest showing a marked increase. In five patients clearance increased immediately post-treatment and occurred in both irradiated and contralateral lung. Only 3 of 8 patients showed demonstrated late changes on HRCT; there was no corresponding change in the contralateral lung on HRCT. There was no correlation between radiation dose and alteration in lung clearance.

The pilot study confirms that 99 Tc DTPA pulmonary clearance studies are a highly sensitive method of detecting radiation pneumonitis and presumed contralateral sympathetic pneumonitis, and confirms that pulmonary radiation has a systemic in addition to local effect.

Optimization of the acquisition protocol M. Rémy-Jardin, A. Amara, P. Campistron, I. Mastora, V. Delannoy, J. Rémy; Lille/FR Purpose: To evaluate the accuracy of 3 mm thick reconstructed sections in the diagnosis of bronchiectasis with MSCT. Materials and methods: 40 consecutive patients suspected of bronchiectasis underwent MSCT of the entire thorax with a 4 × 1 mm collimation. From each data set, two series of images were systematically reconstructed with a high-spatial frequency algorithm: 1 mm (Group 1) and 3 mm (Group 2) thick scans, at 10 mm intervals. Three observers independently analyzed the presence of bronchiectasis and associated abnormalities on Group 1 and Group 2 lung images. Results: No significant difference between Group 1 and Group 2 was found in: (a) the detection of bronchiectasis [Group 1: n = 24 (60 %); Group 2: n = 23 (57.5 %); (p = 0.08)]; (b) the evaluation of the extent of bronchiectasis [focal: Group 1; n = 10 (25 %) and Group 2; n = 7 (17.5 %); (p = 0.39) and diffuse: n = 16 (40 %) in both groups]; (c) the characterisation of bronchiectasis [cylindrical: Group 1: n = 24 (60 %); Group 2: n = 21 (53 %); p = 0.08; varicose: Group 1: n = 5 (12.5 %); Group 2: n = 6 (15 %); p = 0.56; cystic (Group 1: n = 2 (5 %); Group 2: n = 2 (5 %)]. Apart from the identification of abnormal bronchial wall thickening (Group 2: n = 35; 87.5 % vs Group 1: n = 31; 77.5 %; p < 0.05), recognition of associated abnormalities did not differ between the two groups. Conclusion: A comparable accuracy of 3 mm and 1 mm thick reconstructed scans in the detection and characterization of bronchiectasis allows the recommendation of a 4 × 2.5 mm collimation with reconstruction of 3 mm thick scans in the screening of bronchiectasis, reducing the radiation dose of MSCT examinations by 20 %. Purpose: For the development, optimization and validation of inhalation therapies it is important to develop a model that covers individual anatomical data, application process, deposition and uptake of applied medication. Using CFD, velocities and deposition within the individually segmented tracheo-bronchial tree were simulated. Material and methods: Multislice CT datasets (n = 20) of the lung were segmented using a hybrid segmentation algorithm to detect the tracheo-bronchial-tree. This algorithm consists of: (a) 3D seeding process, (b) 2D bronchus finder (fuzzy-logicsystem), (c) 2D module to identify peripheral bronchi (template-matching). The influence of three reconstruction kernels on the segmentation process was inves-tigated. The hybrid system was compared to a merely threshold-based segmentation tool by visual assessment performed by two radiologists. The segmented images were used to reconstruct the 3D geometry of the tracheo-bronchial airways. This is meshed using an unstructured tetrahedral mesh. Flow analysis and particle tracking model is carried out using CFD to simulate in-and expiratory breath velocities.

Results: Due to the combination of the 3-step algorithm it is possible to segment down to the 8 th generation of bronchi semiautomatically. Depending on the kernel used the following sensitivity ranges were obtained: 5 th generation 80 -90 %, 6 th 70 -80 % and 7 th 50 -60 %. Calculation of the velocity during in-and expiration revealed a ratio of up to 2.4 (peripheral bronchi/trachea). Conclusion: Combining individual anatomical data derived from radiological images and a comprehensive model of the respiratory tract enables the simulation of distribution and deposition of inhaled drugs. Support: EC (IST-1999-14004: "COPHIT"), British Council B-0863 09:40

CT bronchography: Assessment and validation of two approaches for 3D reconstruction C.I. Fetita 1 , F. Preteux 1 , C. Beigelman-Aubry 2 , P.A. Grenier 2 ; 1 Evry/FR, 2 Paris/FR Purpose: To validate and compare two reconstruction techniques leading to the 3D CT bronchography, by means of a scoring system established with respect to a reference anatomical bronchial tree.

The study was conducted on volumetric helical data sets obtained from 20 patients with various chronic airway diseases. Acquisitions were performed during breath holding following a full inspiration without any contrast agent. Axial images were reconstructed with 1.25 mm thickness and 0.6 mm intervals. For each patient, the bronchial tree was reconstructed using 2 different techniques. The first one consists in a slice-by-slice segmentation of airway lumens followed by a 3D reconstruction using a topological propagation and filtering. The second one is fully-3D and relies on a diffusive-aggregative Markovian modeling, which takes advantage of the structural and topological features of the airways. In both cases, the bronchial tree was visualized in a CT bronchogram mode, using a semi-transparent volume rendering technique. The images were assessed independently by 2 radiologists using a scoring system established on the basis of a reference bronchial tree defined up to the subsegmental level. Results: The bronchial tree was reconstructed up to the 6 th order by both techniques without any significant difference (96 % accuracy and 97 % robustness). The fully 3D technique running twice faster, proved in addition the capability to reconstruct smaller bronchi distal to the 6 th order. Conclusion: 3D bronchography obtained from multislice CT is an accurate technique to reconstruct the airways up to the 6 th -7 th order of division. . The results were compared to 50 patients, which were examined with a standard protocol (120 mAs: G120). All other parameters were kept constant. Subjective image quality was rated using a three point scale. Objective criteria, based on signal-tonoise measurements, were assessed. Results: Image quality was sufficient in all cases. Subjective gradings of image quality, based on soft tissue window settings, were 1.1 for the 120 mAs protocol, 1.1 (G+10), 1.1 (G±0), 1.3 (G−10), and 1.2 (G−20), for the body weight adapted protocols. Objective criteria showed mean standard deviation values of 5.7 HU for the 120 mAs protocol. For the dose reduced protocols, values were calculated as 7.6 HU (G+10), 7.9 HU (G±0), 8.7 HU (G−10) and finally 9.1 HU (G−20). Best correlation for the whole subgroup was achieved for the −10 protocol, with nearly constant noise related to the body weight in all patients. Conclusions: By deriving mAs values from body weight estimation, an individually adapted protocol for chest CT can be recommended. With an adaptation of the tube current time product (x mAs = m − 10, m … body weight in kg), a well balanced examination, even in soft-tissue window settings, can be performed. Therefore, for other types of CT scanners, analogous protocols may be adapted. Highland Heights, OH/US Purpose: Current CT liver perfusion methods typically involve limited (2 cm or less) z-axis coverage with the results displayed in the form of axial cross-sectional perfusion maps. We implemented a full-organ liver perfusion technique and explored the usefulness of providing full-organ volume-rendered perfusion maps. Methods: Ten CT liver perfusion studies were acquired (technique) for patients with hepatic masses using a series of 5 consecutive acquisitions of the liver during one breathold after the injection of a bolus of contrast (4 -5 ml/s). Images of each slice location were acquired every 8.5 seconds. Liver perfusion maps were produced using previously published techniques and displayed in both axial and volume rendered modes. Results: Multislice-Spiral acquisitions with a pitch of 1.5 and a 0.5 s rotation enabled full coverage of the liver, portal vein and spleen, which were used as inputs for the perfusion calculation. Both the axial and volume-rendered perfusion maps depicted characteristic perfusion patterns of various types of hepatic tumors. Small tumors were depicted as area of hyperperfusion, while advanced tumors exhibited a ring of hypervascular tissue surrounding a necrotic core. Perfusion values of normal liver tissue corresponded to expected physiological ranges. Further investigation is warranted to understand the sampling rate required for clinically relevant quantitative measurements. Conclusion: Multislice CT scanners may enable full organ assessments of liver perfusion. Volume rendering of perfusion images allows potentially superior assessment of perfusion abnormalities and might be used to predict the effectiveness of chemo-and thermoablation therapy. (ratios) were determined using AMARES. Additionally, absolute values of phosphorous metabolites were determined using SLOOP and an concentration of 2.5 mmol for ATP as internal standard, including corrections for inhomogenous B1-fields, T1 relaxation. 10 healthy volunteers and 10 patients with liver chirrosis were included. Results: AMARES allowed relative quantification (metabolite ratios) in all volunteers, however, only in 7/10 patients, due to low signal to noise ratios. Using, SLOOP as postprocessing method, all acquired 31 P-spectra had sufficient signal to noise ratios for all analyzed metabolites. In healthy liver parenchyma, absolute concentrations for PME, Pi and PME were 2.3 ± 0.8, 1.5 ± 0.6 and 15 ± 6.2 mmol respectively. For patients PME and Pi increased to 6.2 ± 3.8 and 1.8 ± 0.7, PDE showed no significant changes (15.2 ± 7.2). Conclusion: Using SLOOP, significant changes of energy metabolism, which is a parameter for hepatic vitality, can be observed in patients with chronic liver disease. Compared to conventional postprocessing packages, SLOOP allows for a robust and quantitative assessment. Methods and materials: CT scans of 408 patients with 311 malignant (79 primary and 232 metastatic) and 97 benign changes were retrospectively rewieved over a 5-year period. There were 181 women and 227 men. The study protocol consisted of 5 and 8 mm slices of the liver area. Images were obtained before and after intravenous injection of non-ionic contrast agent (Iopromidum 623.40 mg/ml) in a standard dosage 2 cm 3 /kg, as a bolus. Original films were rewieved and sought in favour of capsular retraction by two independent radiologists. The number, location, size, density of the tumor and presence of capsular retraction were evaluated. The final diagnosis of focal changes was based on histopathological findings. Results: Twelve of 408 patients (prevalence 2.9 %) revealed retraction of liver capsule, which was associated with adjacent hepatic tumor. All 12 tumors were proven pathologically to be malignant (4 hepatocellular carcinoma, 3 colorectal metastases, 1 stomach cancer metastasis, 1 epithelioid hemangioendothelioma, 1 prostate cancer metastasis, 1 breast cancer metastasis and 1 carcinoid).

The occurrence of capsular retraction adjacent to the liver tumor in our study was a rarely observed but a specific sign (specificity 100 %) of a malignant process. Purpose: VirtualProbe® (IôDP, Paris, France) is ultrasound acquisition and post processing software that uses an electromagnetic field to acquire positional data, allowing retrospective multiplanar 3D rescanning through a volume of tissue. The aim of this study is to assess the accuracy of measurements made from the reformatted images of normal structures. Methods and materials: 30 patients referred for exams of the kidney (9) and abdomen (21) were enrolled. Each patient had a conventional ultrasound exam, followed by the VirtualProbe®. The average of 3 measurements of sagittal right (30) and left kidney (28), sagittal bladder (9), sagittal spleen (20), CBD (21), and GB wall (18) were recorded. The correlation of the measurements between both methods was caclulated. Analysis of variance for measurements of structures < 1 cm (CBD, GB wall) was performed to assess for the intra-observer variability.

The correlation coefficients between methods were 0.84, 0.90, 0.96, and 0.83 for the right and left kidney, bladder, and spleen. The correlation coefficients were 0.62 and 0.23 for the CBD and the GB wall. The correlation coefficient for CBD and GB was 0.56. The variance of measurements for the CBD and GB was 0.22 cm for conventional and 0.24 cm for VirtualProbe®. Although it exists a statistical difference between both methods for these two structures (p = 0.023), the absolute value of the measurement difference (0.02 cm) was less than the intraobserver variability of the conventional data alone (S.D. = 0.09 cm). To evaluate the possible role of multislice CT (MSCT) in the preoperative evaluation of patients candidate to laparoscopic splenectomy. Material and methods: 32 patients underwent MSCT with 0.5 seconds gantry rotation time. Pre (4 × 2.5 mm collimation) and post-contrast (4 × 1 mm collimation) acquisitions, during arterial and portal venous phases were performed after i.v. administration of 140 ml of non ionic contrast agent at 4 ml/s, with a delay time of respectively 22 and 60 seconds. Real time interaction with the post-contrast 3D data set was performed on a dedicated workstation to determine total spleen volume, and to assess arterial and venous vascular anatomy. For volumetric determination an hand-trace editing was used to calculate spleen mass to select candidates for laparoscopic procedure. Results: At surgery mean volume was 998 cm 3 . Calculation based on CT provided a mean error of 8 %. In none of the patients undergoing laparoscopic splenectomy, a conversion in laparotomy was needed. Five patients underwent laparotomic splenectomy because of spleen volume greater than 1200 cm 3 . In all cases optimal vascular detail was achieved. Conclusion: High resolution MSCT afforded complete parenchymal, vascular, and volumetric preoperative evaluation of potential laparoscopic splenectomy. Volumetric determination provided accurate and reproducible information.

Changing the imaging paradigm in ultrasound: Can 3D technology improve productivity, decrease sonographer work-load and maintain study quality? M.J. O'Neill, S.I. Lee, J.F. Simeone, G.J. Harris, P.J. Whelan, P.R. Mueller; Boston, MA/US Purpose: VirtualProbe® (IôDP, Paris, France) is ultrasound acquisition and post processing software that uses an electromagnetic field to acquire positional data, allowing retrospective multiplanar 3D rescanning through a volume of tissue. The aim of this study was to assess the workflow impact for both sonographers and radiologists as well as overall image quality when conventional ultrasound examination was converted to an off-line interpretation model. Methods and materials: 38 patients referred for exams of the kidney (9), thyroid (8) and abdomen (21) were enrolled. Each patient had a conventional ultrasound exam, followed by the VirtualProbe®. The 3D data were blindly reviewed. The time for conventional vs. 3D performance/review was compared for sonographer and radiologist. The diagnostic findings between both methods were compared. Radiologist desire to rescan a patient was recorded on an ascending 5 point scale.

The average scanning and image review/rescanning time for the sonographer was 14.2, 17.5, and 15.6 min during the conventional and 3.9, 7.0, and 3.8 min during the 3D for renal, abdomen and thyroid. The average review/ interpretation time for the radiologist was 1.3, 1.5, 1.6 min for the conventional and 1.3, 2.7, 3.0 min for 3D for renal, abdomen and thyroid. The desire to rescan averaged 3.4/5 and 1.2/5 for conventional and VirtualProbe. All findings on conventional scans were observed on 3D. 2 findings were observed during the 3D only. Conclusion: VirtualProbe® allows for a 3 fold increase in sonographer efficiency while minimally increasing radiologist time. Overall study quality was not different between both methods.

Predictive ultrasound factors of an adequate biliary drainage through an endoprosthesis in proximal biliary obstructions Z. Spirchez, M. Tantau, B. Diaconu, O. Anton; Cluj-Napoca/RO Purpose: To study the ultrasound performance in the evaluation of an internal biliary drainage through an endoscopically inserted endoprosthesis in proximal biliary obstructions. Materials and methods: 32 patients (14 males, 18 females, mean age 56, range 41 -82) with proximal biliary obstruction due to hilar tumors, treated by biliary stenting using plastic, 7 -12 F, stents were studied. The efficacy of the drainage was assessed clinically and by biochemical parameters. Ultrasonographically the size of the right and left hepatic ducts (RHD/LHD) and the intrahepatic bile ducts were noted before and after stenting. The presence and degree of aerobilia and the position of the stent (the proximal end above or below the stenosis) were noted after stenting. of pancreatic structures and abnormalities were evaluated using a three point grading scheme. Furthermore the differentiation of cystic versus solid tumors was compared. Results: In the detection of pancreatic lesions there was no statistically significant difference between both modalities (overall sensitivity 67 % with THI and 64 % with BM, specificity 100 % with THI and 97 % with BM). The differentiation between simple cystic, complicated cystic or solid tumors, is improved with THI. The visibility of the pancreas was not sufficient in 23 % because of technical problems (eg. meteorism). In patients with adequate visualisation of the pancreas the pancreatic duct could not be sufficiently delineated in 38 % with THI and 59 % with BM. Conclusions: Image contrast and delineation of the pancreas as well as diagnostic accuracy are improved with THI in comparison to conventional sonography.

Characterization of focal liver lesions by pulse inversion harmonic imaging (PIHI) with Levovist in patients with cirrhosis B. Forgács 1 , E. Quaia 2 , M. Bertolotto 2 , L. Crocè 2 , L. Dalla Palma 2 ; 1 Budapest/HU, 2 Trieste/IT Purpose: The aim of this study was to determine capabilities of Pulse Inversion Harmonic Imaging (PIHI) with Levovist in characterization of focal liver lesions in cirrhotic liver. Methods and materials: 39 liver focal lesions in 25 consecutive cirrhotic patients identified by baseline ultrasound (US), were evaluated by color Doppler (CD) and PIHI. PIHI was performed 30 seconds (vascular phase) and 3 -5 minutes (late phase) after Levovist injection. Helical CT (HCT) (n = 15) or surgical/bioptic histologic findings (n = 10) were considered as reference procedures. Results: 30 lesions classified as hepatocellular carcinoma (HCC) by reference procedures appeared hypoechoic (n = 19), isoechoic (n = 5) or hyperechoic (n = 6) on baseline US, with basket pattern (n = 10), vessels within tumor (n = 6), peripheral (n = 4) or no vascular pattern (n = 10) on CD. On PIHI they appeared hyperechoic (n = 26) or isoechoic (n = 4) on vascular phase and prevalently hypoechoic (n = 22) or isoechoic (n = 6) and rarely hyperechoic (n = 2) on late phase. Four (4) lesions classified as regenerative nodules by reference procedures appeared hypoechoic on baseline US, with peripheral (n = 1) or no vascular pattern (n = 3) on CD. On PIHI they appeared hypoechoic (n = 3) or isoechoic (n = 1) on vascular phase, remaining prevalently hypoechoic (n = 3) or isoechoic (n = 1) on late phase. Five (5) lesions classified as hemangioma by reference procedures appeared hyperechoic (n = 4) or hypoechoic (n = 1) on baseline US with few flow signal on CD. On PIHI they revealed progressive fill-in or dot-like enhancement during vascular and late phase. Conclusions: PIHI with Levovist had identified some typical enhancement pattern in focal liver lesions in cirrhotic patients. Conclusions: MRI has low sensitivity to identify small lymph nodes. When visible, MRI with SINEREM has high sensitivity to identify metastatic lymph nodes; the overall low specificity was due to a learning curve in the first cases. When objective data are combined with subjective impression of the Radiologist results are quite satisfactory. To assess the performance of MS-325, a Gd-based and albumin-bound contrast agent, for the differentiation of normal and tumor-bearing (VX2) lymph nodes of rabbits with interstitial MR lymphography. Materials and methods: Experiments were conducted on 4 mature male White New Zealand rabbits. Fully anesthetized, the animals underwent MR examination twice: prior to and three weeks following implantation of VX2-tumor cells to the left flank. For each session 1.0 ml of undiluted MS-325 was injected subcutaneously into both dorsal foot pads. 3D MR imaging was performed on a 1.5 T whole body scanner prior to as well as 5, 10, and 15 minutes post injection of the compound. Contrast medium uptake in the individual lymph nodes and the lymph node size were determined. Finally all animals were euthanized and lymph nodes were analyzed by histopathology. Results: Interstitial MR lymphography with MS-325 visualized lymphatic structures as well as popliteal and inguinal lymph nodes in all animals. VX2 tumours were well differentiated from surrounding tissues in all rabbits. Maximum enhancement values were present 10 minutes following contrast medium injection in both normal and tumour-invaded lymph nodes. ROI measurements in normal lymph nodes revealed statistically significant higher CNR values compared to tumourbearing lymph nodes. Vastly reduced contrast medium uptake in tumour invaded lymph nodes permitted easy detection thereof. The size of normal and tumor-invaded nodes was not significantly different.

In addition to providing a means for display of the normal lymphatic system, MS-325-enhanced MR lymphography allows for depiction of direct tumour invasion in lymph nodes.

Interstitial MR lymphography in rabbits: Assessment of inflammatory and normal lymph nodes by different gadolinium-based contrast agents (DOTA, P760, P792) C.U. Herborn, T.C. Lauenstein, F.M. Vogt, M. Goyen, J.F. Debatin, S.G. Rühm; Essen/DE Purpose: To assess three different gadolinium-based contrast medium compounds in order to distinguish normal from reactive inflammatory lymph nodes by interstitial MR lymphography in rabbits. Materials and methods: Experiments were conducted on 9, fully anesthetized mature White New Zealand rabbits. In each set of three rabbits 1.0 ml of undiluted Gd-DOTA, P760, or P792 (Guerbet, France) was injected subcutaneously into the dorsal foot pads. Whereas Gd-DOTA is an extracellular, commercially available contrast medium agent, the latter are new macromolecular compounds, undergoing pre-clinical testing. MR examinations were performed three times in each rabbit prior to as well as 2 and 14 days following induction of inflammatory lymph node reaction by the application of Freund's complete adjuvant. Imaging was performed on a 1.5 T MR system using conventional 3D sequences. Contrast uptake in the individual lymph nodes as well as the lymph node sizes were determined. Results: Interstitial MR lymphography visualized popliteal and inguinal lymph nodes with all evaluated contrast agents. Maximal enhancement occurred 10 minutes after contrast medium injection for all three tested compounds. Inflammatory lymph nodes revealed statistically significant higher CNR values compared to normal nodes (p < 0.05). Average CNR values for the macromolecular contrast medium agents (P760, P792) and the extracellular compound (Gd-DOTA) were not statistically different. Furthermore, the size of inflammatory and normal nodes was not significantly different.

Tuesday B A C D E F 307 Conclusion: All three contrast medium agents appear well suited for interstitial MR lymphography to visualize popliteal and inguinal lymph nodes in rabbits. Determination of contrast medium uptake can aid in differentiating reactive inflammatory from normal lymph nodes.

Initial experience with MR-lymphography and employment of iron oxide contrast material for the detection of metastatic lymph node involvement in rectal cancer W. Purpose: To evaluate MR-Lymphography by employment of iron oxide contrast material (SINEREM) in the preoperative evaluation of lymph node (LN) metastases of rectal cancer. Method/materials: MR-Lymphography of the pelvis was performed using plain and enhanced MR images after 24 to 36 hours after intravenous administration of superparamagnetic iron oxides at a dosage of 2.6 mg Fe/kg b.w. Conventional T1and T2-weighted spin-echo sequences as well as T2-weighted gradient echo sequences were performed. A total of 8 patients were examined. MRI findings were correlated to histopathology in every case. Results: A total of 108 LN in 8 patients were histopathologically evaluated and the findings correlated with MRI. 7 LN metastases were detected histopathologically. MRI was able to detect 6 of the 7 metastatic LN. The size of the analysed LN was approx. 5 mm in most of the cases. All malignant LN presented with a size between 10 and 25 mm. MRI missed one LN metastasis with a size of 6 mm. 3 LN metastasis had a size between 6 -10 mm, 2 LN metastasis were 16 -20 mm in size, and 1 LN metastasis had a max. diameter of 25 mm. Conclusions: MR-Lymphography with employment of the new iron oxide contrast material is a promissing imaging modality for the detection of LN metastasis. Studies with a large study population need to further evaluate the potential of this imaging modality.

Optical imaging of lymph nodes -a new technique for lymphography P. Wunderbaldinger 1 , C. Bremer 2 , U. Mahmood 3 , L. Josephson 3 ; 1 Vienna/AT, 2 Münster/DE, 3 Charlestown, MA/US Purpose: To validate the use of near infrared fluorescence imaging (NIRF) using enzyme sensitive optical probes for lymph node detection. Material and methods: An optical contrast probe that is activated by cystein proteases was used to visualize lymph nodes by NIRF reflectance imaging. In order to quantitate the uptake of the optical probe in lymphatic tissue the biodistribution was assessed using the 111 In labeled optical probe. Sixteen Balb-c mice were injected either intravenously (I.V., n = 10) or subcutaneously (S.C., n = 6) with the NIRF-probe (2 µmol Gy/animal) and imaged 24 hours after injection. Signal intensities and target-to-background ratios of various lymph nodes were measured by manual regions of interest (ROIs). Additional signal intensity measurements were performed of excised lymph nodes (n = 21) from I.V. injected mice (24 hours after injection) and compared to excised lymph nodes (n = 8) of non-injected mice.

The probe employed in this study was lymphotropic with about 3 -4 % accumulation in lymph nodes (3.4 ± 0.8 %ID/g). Lymph nodes showed a high fluorescence signal throughout the body after I.V. injection (96 ± 7.8 AU) and/or regionally after S.C. injection (141 ± 11.5 AU). The signal intensities of lymph nodes was significantly higher after S.C. probe administration compared to IV administration (p < 0.01), as was the target-to-background ratio after S.C. administration (6.6 ± 0.81 vs 4.8 ± 0.67; p < 0.05). Measurements of the excised lymph nodes (after I.V. injection) confirmed a significant increase in lymph node fluorescence signal (26 ± 7.6 AU vs. 146 ± 10.9 AU; p < 0.0001). Conclusion: Detection and visualization of lymph nodes is feasible by NIRF imaging using enzymatic activatable optical probes.

Ultrasmall superparamagnetic iron oxide particles (USPIO) in magnetic resonance imaging (MRI) of primary malignant lymphoma: Are there changes in signal intensity of enlarged lymph nodes after contrast application? G. Michna 1 , J. Kromeier 1 , J. Laubenberger 1 , G. Paul 2 , M. Langer 1 ; 1 Freiburg/DE, 2 Bonn/DE Purpose: The aim of this study was to assess the potential value of MRI with USPIO-particles (G534-70, SINEREM®) for the nodal staging in primary malignant lymphoma. According to several studies normal tissue in liver, spleen, and lymph nodes shows an uptake of USPIO particles due to phagocytic activity of RES-cells. Material and methods: Ten patients with histologically proven untreated primary malignant lymphoma were studied. Pre-and post contrast injections of SINEREM® MR-scans were obtained from 9 patients. The relative signal intensities of 23 lymph nodes with a size of more than 10 millimeters were measured. We compared (incl. SD) the delta of mean values of pre and post contrast signal intensities in T1-w and T2-w images.

Results: The diameter of lymph nodes ranges from 13 mm to 105 mm. In T1-w images the delta of mean values of pre-and post contrast signal intensities varied between 0.70 and 1.62. Post contrast images showed no significant change in signal intensity. In T2-w images the delta of mean values of pre-and post contrast signal intensities varied between 0.60 and 1.20. There was no significant change in signal intensity in post contrast images. Conclusion: There were no significant changes in signal intensity in post contrast T1-w and T2-w images in primary malignant lymphoma. This finding suggests that in these enlarged lymph nodes no active RES-cells are present to phagocytise the USPIO agent due to the malignant involvement.

Ionic and non-ionic iodinated contrast media induce neutrophil apoptosis through a caspase-dependent pathway N.F. Fanning, B.J. Manning, H.P. Redmond, J.G. Buckley; Cork/IE Purpose: Iodinated contrast media (ICM) can induce apoptosis (programmed cell death) in renal and myocardial cells. Following intravascular injection, circulating immune cells are exposed to high concentrations of ICM. As neutrophils constitutively undergo apoptosis, we hypothesised that ICM may adversely affect neutrophil survival. Our aim was, therefore, to investigate the effect of ICM on neutrophil apoptosis. Materials and methods: Neutrophils were isolated from healthy subjects and cultured in vitro with ionic (diatrizoate and ioxaglate) and non-ionic (iohexol and iotrolan) ICM. Neutrophil apoptosis was quantified by annexin V flow cytometry, and caspase dependence determined using the caspase inhibitor zVAD-fmk (100 µmol). Results: Data presented as percentage apoptosis ± S.E.M. Iso-iodine concentrations (20 mg/ml) of ionic (diatrizoate 69.6 ± 2.9; ioxaglate 58.9 ± 2.0) and non-ionic (iohexol 57.3 ± 2.9; iotrolan 57.1 ± 2.6) ICM significantly induced neutrophil apoptosis over control levels (47.7 ± 1.4, n = 10). Ionic ICM had a more significant (p < 0.01) apoptotic effect than non-ionic ICM (p < 0.05). Furthermore, ICM reversed the anti-apoptotic effect of lipopolysaccharide (1000 ng/ml) treated neutrophils (23.0 ± 3.5 to 61.2 ± 5.3; n = 4; p < 0.05). Iohexol induction of apoptosis is caspase dependent as zVAD-fmk reversed its pro-apoptotic effects to control levels (75.7 ± 2.7 to 53.7 ± 1.1; p < 0.05).

These results clearly demonstrate that ICM promote apoptosis in unactivated and activated neutrophils by a caspase-mediated mechanism. A recent report suggests that ICM can increase the incidence of local and systemic septic complications in patients with mild acute pancreatitis (Carmona-Sanchez R.; Arch Surg, 2000; 135:1280-4) . ICM, through induction of neutrophil apoptosis, could have significant deleterious effects on host immune defence and resolution of an inflammatory response.

Effect of intravenous injection of iopromide on regional renal blood flow and medullary oxygen tension in diabetic rats F. Palm, P.-O. Carlsson, P. Hansell, A. Fasching, O. Hellberg, A. Nygren, P. Liss; Uppsala/SE Purpose: Hemodynamic disturbances with subsequent renal medullary ischemia have been suggested as key mechanism in the pathogenesis of contrast media (CM)-induced nephropathy. Increased risk of CM-induced renal failure is seen during diabetes mellitus with nephropathy. The present study investigated the effect of an

A C D E F 308 injection of the CM iopromide (600 mg I/kg) on regional renal blood flow (cortical and outer medulla) and oxygen tension (outer medulla) in streptozotozin induced four-or nine-week-diabetic Wistar Furth rats. Material and methods: Oxygen tension was measured with modified Clark-type microelectrodes and blood flow with laser-Doppler flow probes. Results: Administration of CM decreased the outer medullary oxygen tension in non-diabetic animals by ∼ 35 %. This response was absent in diabetic animals. Renal outer medullary blood flow of non-diabetic animals increased after CMadministration and remained elevated (∼ 25 %). In contrast, no change in outer medullary blood flow occurred in the diabetic animals. Glucose infused non-diabetic animals responded similarly in medullary oxygen tension to normoglycemic animals, but similarly to diabetic animals in medullary blood flow, following CMinjection. Conclusion: We conclude that diabetic animals have an altered response in renal outer medullary blood flow and oxygen tension to CM compared to normoglycemic animals. However, in contrast to corresponding control rats, outer medullary oxygen tension did not decrease in diabetic animals, which suggests other mechanisms than hemodynamic changes to explain the increased renal failure frequency in this risk group for CM-induced nephropathy.

Doppler intensitometry: Quantitative comparison of two ultrasound contrast agents in humans J.-M. Correas 1 , V. Dhalluin-Venier 1 , L. Bridal 1 , P. Burns 2 , O. Hélénon 1 ; 1 Paris/FR, 2 Toronto, ON/CA Purpose: To quantify the Doppler signal enhancement following the injection of two different ultrasound contrast agents (USCAs) in humans, Levovist® (Schering SA, Germany) and Optison® (FSO69, Mallinckrodt, USA). Materials: 24 patients received 2 bolus injection of Optison® (1, 2, 3, and 4 ml, randomized dose) and 1 injection of Levovist® (2.5 g, 5 ml, 400 mg/ml). The continuous Doppler signals from the radial artery were digitized to calculate mean duration of the enhancement, peak enhancement and area under the time-intensity curve (AUC). In 3 patients, the Doppler signals could not be analyzed due to wrist movement artifacts. Results: The duration of the enhancement was respectively (mean ± standard deviation) 255 ± 50 s for the Levovist® and 307 ± 93, 304 ± 78, 301 ± 85 and 386 ± 97 s for each dose of Optison® (1, 2, 3, and 4 ml). Peak enhancement was respectively 17.8 ± 5.1 dB for the Levovist® and 20.4 ± 3.4, 21.6 ± 3.4, 21.9 ± 2.8 and 22.3 ± 2.2 dB for each dose of Optison®. AUC was respectively (linear units) 5009 for the Levovist® and 6311, 10765, 13522 and 15854 for each dose of Optison®. A linear relationship was found between the dose of Optison® and the enhancement (r > 0.97). Levovist® enhancement exhibited a larger variability between patients. Purpose: This study was designed to validate the reliability of the AO comprehensive classification using routine radiographs to predict the intra-operative findings.

A second goal of this study was to assess interobserver variability of this classification.

The radiographs or computed radiographs (CR) of the thoracic and lumbar spines of 32 patients (18 male, 14 female) from Jan 2000 to March 2001, were reviewed retrospectively by four separate observers, two experienced staff and two residents without knowledge of the operative findings. Each fracture was categorized according to the AO comprehensive spinal fracture classification into type A, type B or type C injuries based on agreed well defined radio-logic criteria. This was compared to the intra-operative findings which assessed the integrity of the posterior ligament complex and mobility of the injured segments.

The concordance of the radiologic classification and the intra-operative findings was 75 % (24/32) for orthopedic spine surgeon, 62 % (19/32) for orthopedic resident, 54 % (17/32) for skeletal radiology staff, and 66 % (22/32) for radiology resident. The mean correct designation of the fracture classification was 64.5 %. There were 28 % (9/32) of fractures categorized as type A injuries by 50 % or more of the observers which proved to be type B injuries at surgery. Conclusion: The use of plain films or CR to categorize fractures of the thoracolumbar spine according to the AO classification was associated with a designation of 28 % of unstable B injuries as stable type A injuries. There is moderate interobserver variability. with suspected spine injury were evaluated using Rx and spiral CT performed in admitting area. All patients received standard thoracic CT (5 mm/pitch 1.5) and abdominal CT (8 mm/pitch 1.5) according to an established trauma protocol including sagittal MPR reconstructions of suspicious vertebral bodies. Rx and CT were independently evaluated by two blinded radiologists for detectability of fracture signs and classified in three groups (G1 -G3): definitely fractured (G1); non conclusive result (G2); definitely no fracture (G3). All suspected fractures were confirmed by an additional high resolution CT (2 mm -3 mm/pitch 1.5) and clinical follow up. Results: In 21 patients (37 %) of the 56 patients a spine fracture could be depicted. 2 fractures were missed in Rx, none in CT. 98 % of the CT reports and 89 % of the Rx reports were classified correctly true positive (G1) or true negative (G3). 8.4 % of Rx-reports were non conclusive (G2), but only 1 % in CT. In comparison CT versus Rx sensitivity was 1/0.88, specificity 0.98/0.92, positive predictive value 0.93/0.92 and negative predictive value 1/0.97 Conclusion: Using an established standard CT protocol for chest and abdomen examination with slice thickness of 5 mm and 8 mm respectively all relevant spine fractures can be detected. These results suggest that Rx of thoracic and lumbar spine is not mandatory in the admitting area, when thoracic and abdominal CT is performed.

Correlation between CT and clinical findings in patients with spine injuries -analysis of 193 cases T. Turek, M. Sasiadek; Wroclaw/PL Purpose: To analyze the correlation between CT appearances of spine injuries and clinical findings and thus to establish the clinical significance of the finding at CT. Methods and materials: CT studies have been performed in 193 patients after spine injury. In most of them plain films of the spine were performed prior to CT. 27 patients had also MR. Head CT was performed in 25 cases and chest CT in 18 patients. CT findings (the presence of fractures and facet joints injuries, number of involved vertebrae and spinal columns, narrowing of spinal canal, instability features, intervertebral disc lesions, normal study, etc.) have been compared statistically with clinical symptoms (pain, spinal medulla injury, radicular symptoms, disturbance of consciousness, etc.). Results: There was statistically significant correlation found between clinical signs of spinal medulla injury and several CT symptoms (instability, spinal canal narrowing, number of affected vertebrae and columns, facet joint lesions). In patients with pain and no severe neurological signs there was positive correlation with a normal CT study. Radicular symptoms have been associated with intervertebral disc lesions and in chronic cases with degenerative changes of the spine. Consciousness disturbances have been negatively correlated with spine fractures, while positively with normal CT appearance of the spine and traumatic changes on head CT. Conclusion: CT symptoms of spine injury are highly correlated with severity of the clinical and neurological findings, except for consciousness disturbances which are associated with simultaneous head injury. Thus, CT is very helpful in establishing prognosis and treatment planning. The purpose of this study is to evaluate the efficiency and safety of self-expandable stent insertion in patients with acute colonic malignant obstruction before elective surgical resection. Between March 1999 and March 2001, 24 patients (15 males and 9 females, mean age 74, range 41 -93) were included. All the patients were scored ASA III. Colonic cancers were located between the rectosigmoid and the middle part of the descending colon. All patients had plain abdominal radiography and CT scan to demonstrate the complete obstruction of the colon and to localise the stenosis. Immediate technical success was obtained in 23 of 24 patients (96 %). The mean time between stent insertion and surgery was 6 days (3 to 9). In 2 cases (8 %), stents were misplaced and did not covered the lesion which required the insertion of an other stent. In 2 (8 %)other cases, the stent was initially well positioned but migrated secondarily which required the insertion of a second stent in one and a surgery in a other one. Colonic perforation occurred in 3 (12 %) patients. These 3 patients underwent surgery, one of them developed an abscess which required percutaneous drainage under radiological guidance, other (8 %) patients underwent ileostomia because of a missprepared colon by stent dysfunction (obstruction). There was no more morbidity (21 %) and no death (0 %) at the moment. Self-expandable stent insertion is an efficient minimally invasive procedure that allows for single-stage surgery. However, this technique is quite difficult to perform and may be associated with some complications. Sites of obstruction were antro-duodenum (n = 18), postoperative anastomotic site (n = 19; 12 gastroenterostomy, six esophagojejunostomy, and one duodenojejunostomy). All stents were covered with polyurethane. The size of the stent ranged from 15 -20 mm in diameter and 7 -20 cm in length. With fluoroscopic guidance, covered self-expandable metallic stents were placed. Results: Stent placement was technically successful in all patients without or with the gastrostomy (n = 3) and balloon dilatation (n = 3). After stent placement, symptoms improved in all but one patient, who had another stenosis at the proximal jejunum. During the follow-up of 2 -73 (mean 13) weeks, stent migration occurred in four patients (10.8 %) 1 -41 days after the procedure. Those patients were treated successfully by means of placing a second covered metallic stent (n = 3) or endoscopic reposition (n = 1). Recurred obstructive symptoms due to tumor overgrowth (n = 2) and mechanical failure of stent (n = 2) were noted. One of tumor overgrowth and both of the mechanical failure of stent were treated by means of coaxial placement of a second covered stent with good clinical result. Conclusion: Fluoroscopy-guided placement of covered self-expandable metallic stents can be considered as the primary choice for the palliation of malignant obstructions in those patients. The laparoscopically placed adjustable gastric band (Lap-Band™) has been popularised as a minimally invasive, adjustable and completely reversible surgical technique for the management of morbid obesity. We report our experience with particular emphasis on the radiological aspects of follow-up and patient results in terms of short-term weight loss and complications. Methods: Between May 1998 and December 2000 50 patients were treated (8 male/42 female) with a mean age of 37 years (range 30 -48 years). The technique of fluoroscopy guided band inflation is illustrated with particular emphasis on radiological lessons learned. A new method of measurement of pouch volume and the passage within the band is described.

Results: Mean number of radiology-guided inflations per patient was 2.6 (range 1 -7). The volume used for inflation was noted to be critical, with 0.5 ml making the difference between complete obstruction and optimal band inflation. The mean hospital stay was 2.8 days (range 2 -10 days). 4 % had gastric pouch formation and 4 % had nonfatal pulmonary embolism. There was no mortality. The follow-up was up to 30 months. The mean BMI decreased from the pre-operative level of 43 kg/m 2 (range 38 -55 kg/m 2 ) to 34.5 kg/m 2 .

The lap band is an effective procedure in the treatment of morbid obesity. Initial weight loss is comparable with other open bariatric procedures but with the added benefit of a shorter hospital stay, less pain and a low frequency of complications. Fluoroscopy guidance is useful in puncturing the subcutaneous valve and mandatory in assessing optimal band inflation.

Radiological percutaneous gastrostomy with ballon retained catheters in malignant upper digestive tract obstruction H.-P. Dinkel, J. Triller; Berne/CH Purpose: To assess success and feasibility of radiological percutaneous gastrostomy in malignant pharyngeal or esophageal obstruction where endoscopic passage was impossible. Methods: We report a prospective series of 30 consecutive patients with esophageal and/or head and neck tumors who required artificial enteral feeding by means of gastrostomy. In all patients endoscopic passage was not possible or extremely difficult. In order to avoid surgical gastrostomy we performed a radiological gastrostomy using the following technique. First, the stomach was punctured under fluoroscopic guidance and gastropexy using 3 -4 Cope-type t-fasteners was performed. Then a balloon-type gastrostomy catheter was inserted using a peel-away sheath.

Results: PG was technically successful in all cases. The gastrostomy remained for 5 to 26 weeks. Complications occurred in 10 % (2 minor, 1 major). One patient developed a peristomal leakage due to bowel atony and incomplete voiding of the stomach managed by insertion of a jejunal nutrition catheter through the gastrostomy tract whereafter the leakage subsided an the gastrostomy tract healed. One patient had minor suture infection and delayed gastric voiding. In one patient the early catheter dislocation and peritonitis occurred due to erroneous food injection into the balloon port. Conclusion: Radiological gastrostomy by means of ballon-retained catheters is a feasible and relative safe procedure. Most complications can be managed conservatively or interventionally. Care should be taken to avoid erroneous injection into the balloon port, especially within the first week of PG in order to avoid tube dislocation. To compare the diagnostic accuracies of sonography, scintigraphy in diagnosing ileocecal Crohn's disease (CD) and assessing its activity compared to enteroclysis and final diagnosis. Method: A retrospective analysis of the studies of 54 patients (30 females, 24 males, ages of 18 -71) with verified CD (operation: 8, biopsy: 50 cases). located to the ileocecal region was made. All patients had enteroclysis, sonography (4 -8 MHz receiving frequency with Native Tissue Harmonic Imaging, and measurement of the flow in the superior mesenteric artery (SMA)) and 45 of them had 99 Tc AgAb immunoscintigraphy with SPECT. The results were compared. Results: Overall sensitivity of enteroclysis, sonography and immunoscintigraphy was 100 %, 89 % and 71 %. In early Crohn disease (12 cases) the sensitivities were 100 %, 75 % and 40 % respectively. In detecting active disease (determined by the presence of ulcerations or fistulas in enteroclysis) immunoscintigraphy had 70 % sensitivity, 33 % specificity. Increased SMA flow had 76 % sensitivity; 100 % specificity, while wall thickening (> 3 mm) had 92 % sensitivity; 33 % specificity. Using a combined sonographic criteria (presence of destroyed wall stratification or detection of fistulas or abscesses or increased SMA flow) 96 % sensitivity and 100 % specificity is obtained. Surgical indications (fistulas or abscesses) were detected in 6/8 cases by both enteroclysis and sonography. Conclusion: Although the sensitivity of sonography in early CD is not sufficient for detecting suspected CD, for follow up in advanced cases sonography could replace enteroclysis. New combined sonographic criteria gives excellent correlation with enteroclysis detected activity. Sensitivity for detecting abscesses might compensate for missed fistulas.

Crohn disease: Evaluation of small and large bowel with combined CT enteroclysis and CT colonography A. Cieszanowski, K. Wojciechowski, R. Pacho, B. Pruszynski; Warsaw/PL Purpose: To evaluate the new method -combined CT enteroclysis and CT colonography -for the assessment of whole bowel in patients with Crohn's disease. Method and materials: 20 patients suspected of having Crohn's disease underwent CT colonography after i.v contrast material injection. In 10 of them 1500 ml of fluid was administered by nasoenteric tube positioned in the duodenojejunal region (CT enteroclysis) and in another 10 patients water was given orally (1500 -2000 ml), beginning 30 -40 minutes before the examination. Intestinal and extraintestinal abnormalities were evaluated. Small bowel distention was assessed in 4 grade scale (good = 4, poor = 1). Results were compared to enteroclysis, colonoscopy and intraoperative findings. Results: In 15 patients with confirmed Crohn's disease CT correctly identified all involved small bowel (n = 17) and colonic (n = 8) segments, although underestimated their length in 5 cases (20 %). Mesenteric involvement was seen in 10 of 15 patients with Crohn's disease (67 %), lymphadenopathy in 14 (93 %), perianal disease in 6 (40 %), abscess and fistula in 1 patient (7 %). The distention of small bowel was significantly better on CT enteroclysis (mean score 3.3) than on CT performed after oral fluid administration (mean score 2.7). Conclusion: Both techniques enabled simultaneous evaluation of small and large bowel during single examination and allowed identification of all involved bowel segments, although, visualization of small bowel was significantly better with the use of CT enteroclysis than after oral administration of fluid. Material and methods: 50 patients affected by CD were examinated at 1.5 T, using fat and non fat-suppressed T2 w HASTE sequences after administration of a negative superparamagnetic oral contrast agent and T1w FLASH sequences, pre and post Gd-DTPA injection. All patients underwent endoscopy, US, barium studies (gold standard), 7 had surgery. All MRI data were blindly evaluated by two radiologists. The degree of strictures, the presence of small bowel dilation, adhesions, sinus tracts, fistulas, abscesses, biliary, pancreatic and renal abnormalities were evaluated. Results: MRI correctly detected 95 % of strictures (100/105), 100 % of adhesions (47), 85 % of fistulas (18/21), 100 % of abscesses (5), hydronephrosis (2), biliary, renal and pancreatic stones (5). In 6/50 patients (12 %) MRI showed complications undetected by the gold-standard modalities. Conclusions: MRI is a promising method to assess main complications of CD.

Differentiation of inflammatory bowel diseases by hydro-MRI K. Schunk, S. Reiter, A. Kern, S. Schadmand-Fischer, T. Orth; Mainz/DE Purpose: To assess hydro-MRI regarding the differentiation of inflammatory bowel diseases.

After an oral bowel opacification using 1000 ml of a 2.5 % mannitol solution and a rectal bowel opacification using 250 -500 ml of an 0.9 % saline solution, axial and coronal breath hold sequences ± Gd-DTPA (HASTE ("half-Fourier acquisition single-shot turbospinecho") and dynamic FLASH ("fast low angle shot")) were acquired in 27 patients with inflammatory bowel disease. By MRI findings, Crohn's disease (CD; n = 15) and ulcerative colitis (UC; n = 12) should be differentiated. Results: CD and UC showed significant differences regarding the number of affected bowel segments (2.3 ± 1.5 vs. 1.2 ± 0.5; p = 0.01), the incidence of nodular bowel wall thickening (1/15 vs. 8/12; p = 0.002), and the incidence of a blurred demarcation of the inflamed bowel wall against the surrounding mesenterial fat tissue (9/15 vs. 1/12); p = 0.007). There were no significant differences regarding the contrast enhancement of the inflamed bowel wall (+37.7 ± 28.3 % vs. Results: Before treatment unenhanced PD showed circumscribed hypervascularity of affected bowel loops, consistent with acute disease relapse, in 13/18 patients (72.2 %); in 5 patients the typical acute stage hypervascularity was demonstrated only with CE-PD (p < 0.05). In seven patients with complete clinical recovery no residual enhancement of the affected loop was found at post-treatment follow-up by either unenhanced or CE-PD. Of the patients with clinical persistence of acute disease, 6 (54.5 %) showed typical hypervascularity on conventional unenhanced PD, 4 (36.3 %) had hypervascularity documented only on CE-PD (p < 0.05) and 1 (9.2 %)had no enhancement detected even after contrast administration. CE-PD had higher sensitivity (90.8 %) compared to conventional PD and 100 % specificity.

Purpose: To assess feasibility, safety, and effectiveness of percutaneous imageguided radio-frequency (RF) thermal ablation of the lung.

The research project includes an experimental animal study and two clinical phases. In the animal study, 12 rabbits will undergo in vivo RF ablation of lung tissue. Rabbits will be sacrificed and histologic analysis of the specimens will be performed to assess cell viability. The clinical part of the project includes two phases: (1) 10 patients with resectable cancerous nodules will undergo CT-guided RF ablation and subsequent pulmonary resection and pathology examination of surgical specimens; (2) 30 patients with unresectable lung tumors will undergo CT-guided RF treatment; in these cases the outcome of RF ablation will be assessed by follow-up CT studies performed 1 month after the procedure

A C D E F 314 and at 3-month intervals thereafter. RF ablations are performed by using a 150 W generator (RITA Medical Systems) and a 15 gauge, 9 hook expandable electrodeneedle. Results: To date, 8 New Zealand White rabbits underwent in vivo fluoroscopyguided RF of lung tissue. Two rabbits were sacrificed immediately, one after 24 hours, two after 3 days, two after 2 weeks, and one after 1 month. On gross examination, round, sharply demarcated thermal lesions measuring 21.4 ± 2.1 mm in diameter were observed in all cases. Histopatology analyses confirmed coagulation necrosis with no intervening viable cell. Conclusion: Findings of the animal study showed that RF ablation of pulmonary rabbit parenchima can be safely and effectively performed via a percutaneous, transthoracic approach, thus prompting the start of clinical studies. B-0922 10:40 2-component fibrin clue injection for needle tract obliteration during CTguided percutaneous cutting biopsy of lung lesions M.C. Freund 1 , C. Riedl-Huter 1 , K.M. Unsinn 1 , M. Hackl 2 , T. Schmid 1 , W.R. Jaschke 1 ; 1 Innsbruck/AT, 2 Natters/AT Purpose: Pneumothorax is the most common complication of percutaneous lung biopsy. In order to reduce the incidence for pneumothorax a commercially available 2-component fibrin glue (Tissucol® Duo Quick) was injected in the puncture tract during the withdrawal of the coaxial sheath at the end of the examination. Methods and materials: In total 120 consecutive adult patients underwent CTguided percutaneous biopsy for histological evaluation of an intrapulmonary lesion utilizing a 17 -18 G coaxial cutting biopsy system. All lesions were surrounded by aerated lung parenchyma and were located within 0.5 -12.0 cm distance (mean, 3.3 cm) from the pleural surface. Lesion size measured 0.8 -10.0 cm (mean, 3.6 cm), in total 1 -8 biopsy passes per lesion (mean, 3.6) were performed, and in 57/120 patients a perilesional hemorrhage 0.7 -4.5 cm diameter (mean, 1.9 cm) was observed. Patients were assigned to undergo biopsy either without (group I) or with (group II) the use of a 2-component fibrin glue. All patients were observed after biopsy; after 2 -4 hours a spiral-CT of the thorax and after approximately 24 hours a chest radiography was performed for pneumothorax detection.

The rate of CT-proven pneumothorax resp. for chest tube insertion in group I was 40 % resp. 4 % and in group II 10 % resp. 2 %. Conclusion: The injection of a 2-component fibrin glue in the puncture tract during withdrawal of the coaxial sheath significantly reduces the incidence for pneumothorax as well as the rate for chest tube insertion.

Parietal extrapleural saline for the reduction of pneumothorax in percutaneous lung biopsies (PLB) T. Petsas, I. Tsota, C.P. Kalogeropoulou, M. Karamesini, N. Samaras, D. Dougenis, I. Dimopoulos; Patras/GR Purpose: In this study we evaluate the efficacy of extrapleural injection of normal saline at the initial procedural phase of percutaneous lung biopsy in order to prevent pneumothorax. Methods: 66 patients underwent PLB under CT guidance, for diagnosis of lung lesions. The patients were randomized in either group A or B. In 33 patients (group A) normal saline was injected beneath the parietal pleura just before the procedure. In the remaining 33 patients (group B) no saline was used. All biopsies were conducted under CT using a 19 G -22 G coaxial needle system. In group A, after local anesthetic infusion, the needle was advanced in the subpleural fat and 20 -30 ml of saline were injected extrapleurally, in order to create a bulge of pleura into the lung parenchyma, adjacent to the lesion. All patients had CT scan 15 min after, and plain chest radiogram after 4 hours after the procedure in order to evaluate the presence of pneumothorax. Results: The procedure was well tolerated in group A. Pneumothorax developed in 3 patients (9.1 %) in group A. In group B, pneumothorax occured in 7 patients (21.2 %) and in one instance drainage was required (3.03 %). The technique prolonged the duration of the procedure 9 -17 min in group A. Conclusion: Our results suggest that extrapleural injection of saline reduces PLB induced pneumothorax. It is a supplementary technique, which can be used in patients who are prone to develop pneumothorax.

Application of a new specially designed guide stylet set in chest biopsies T. Petsas, C.P. Kalogeropoulou, I. Tsota, D. Karnabatidis, P. Angele, D. Siablis, I. Demitrios; Patras/GR Purpose: We evaluate the efficacy of a specially designed guide-stylet for percutaneous chest procedures.

In 50 patients, who underwent percutaneous procedures (lung biopsies n = 30, mediastinal n = 10, spinal and rib lesions n = 10), a new specially designed guide stylet set was used. The set is composed of a guide stylet and a 22 Chiba needle. The guide stylet is made of stainless steel with a diameter of 0.41 mm (William Cook Europe A/S, Bjaeverskov, Denmark) The 22 G Chiba needle is initially introduced in the thoracic wall and the guide stylet is advanced through the needle towards the lesion. When the stylet has been correctly directed, the needle is also advanced towards the same direction. The stylet serves either as a guide for the biopsy needle, or as an exchange wire in cases where a larger (Core or Tru-Cut) needle is required for adequate sampling. The stylet can be curved before its insertion inside the 22 G needle in order to reach lesions which require redirection of the needle. For this purpose a torque device is used to point to the direction of the curved stylet Results: The technique was easy to perform in all cases. Five patients with lung biopsies developed pneumothorax (16.66 %). The stylet was advanced beyond the lesion in 4 cases, without clinical consequences and without this affecting the biopsy outcome. Conclusions: Our results suggest that the guide-stylet is a useful tool for percutaneous procedures, especially biopsies, in cases were the lesions to be reached, are difficult in approach.

New technique for CT guided lung biopsy K. Ishii 1 , Y. Wada 2 , J. Kanekawa 2 , T. Takahashi 2 ; 1 Moriya/JP, 2 Ibaraki/JP Purpose: We establish both new device and a biopsy method to localize lesions in term of three-dimensions by CT in order to perform the biopsy of small nodular lesions in the lung field confidently, safely, and rapidly. Material and method: We carried out CT guided lung biopsy in 20 cases of nodular lesions more than 5 mm in diameter. None of them contained calcifications. We simulated a targeting line by using a new device for CT guidance, "TARG" developed by us. We then confirmed the right track of the guiding needle. The biopsy needle that we used was "Pro-MAG". The average time needed to complete the procedure was fifteen minutes. Results: Ten lesions were primary lung cancer. One of them was ground glass opacity lesion measuring 7 mm in diameter. This is what we call carcinoma of type A classified by Noguchi. One case was lung metastasis from colon cancer (8 mm in diameter). Conclusion: This technique enables us to obtain enough material by pinpointing and shooting peripheral lung lesions approximately 10 mm in diameter. We strongly believe that this technique contributes significantly to the progress of lung cancer treatment.

CT guided percutaneous fine needle biopsy of small (≤ 15 mm) lung lesions in outpatients: Safety and efficacy of the procedure compared to inpatients M. Romano, M. Gentile, M. Midulla, M. Salvatore; Naples/IT Objective: Compare safety and efficacy of CT guided fine needle biopsy (FNAB) of small (≤ 15 mm) lung lesions in inpatients and outpatients. Materials and methods: 100 consecutive inpatients (65 M, 35 F, mean age 56) and 100 consecutive outpatients (72 M, 28 F, mean age 50) who underwent CT guided FNAB of small lung lesions at our Institution from May 1999 to July 2001 were included. Lesion size, thickness of aerated lung traversed, number of needle passes, presence of emphysema were recorded for the two patient groups. 22 G Chiba needles and the roll-over technique (1 hour) were used for all patients; in the absence of significant pneumothorax at a subsequent expiratory chest roentgenogram, outpatients were allowed to go home and instructed to return in case of dyspnea or unusual symptoms. Incidence of pneumothorax and other complications, need for tube insertion and percentage of diagnostic samples were noted for both groups. Results: No statistical differences were observed in lesion size, thickness of aerated lung traversed, needle passes, presence of emphysema between the groups. We had 15 pneumothoraces in inpatients, two requiring a small caliber chest tube, and 12 in outpatients, all within 1 hour from the procedure, none requiring a tube. Citology diagnosed a malignant lung neoplasm in 58 outpatients and 64 inpatients, absence of malignant cells in 33 and 25; the sample was inadequate in 9 and 11 respectively. All differences are nonsignificant. Conclusion: CT guided FNAB of small lung lesions in outpatients is a safe and reliable procedure, allowing significant decrease in hospitalization costs.

Tuesday B A C D E F 317 nant, 3 % ADH. The highest rate of malignancy was seen in indication C (47 %) > A (32 %) > B (28 %) > E (20 %) > D (18 %). In the 71 % benign cases MRVB was able to avoid diagnostic surgery. Conclusion: MRVB is a reliable tool, which allows to solve problems of MR-detected lesions. Good training is a prerequisite.

Radiological or surgical port device implantation: A 4-year institutional analysis of procedure performance, quality of life and cost for breast cancer iv chemotherapy P.Y.R. Marcy sr. 1 , C. Bailet 1 , N. Magne 1 , J.C. Machiavello 1 , J.C. Gallard 2 ; 1 Nice/FR, 2 Caen/FR Purpose: To evaluate the safety, efficacy, quality of life and cost of percutaneous radiologic arm port (PAP) and surgical subclavian port (SSP) devices.

This study involved a retrospective review of 200 port device implantation procedures (100 PAP, 100 SSP) performed over a 4-year period, in breast cancer patients. Parameters analyzed included technical success, procedure duration, complications, analysis of the quality of life and cost evaluation for both techniques.

The success rate for port implantation was higher for PAP than for SSP (96 % versus 91 %). PAP was subsequently performed in 2 of ten patients in whom SSP procedure had failed; and SSP in 1 of the three PAP failure cases. SSP and PAP were performed without conscious sedation (i.e., local anesthesia only). Mean implant duration time was 168/222 days, the overall complication rate (R/S) was 9 % versus 13 % (0.24 -0.4/1000 patient-days). Mean implant duration time (R vs S), without any complication or death, was 193 d vs 233 d. Median number of chemotherapy courses was 6 (R = S). 6 %, and 7 % respectively of the devices had to be removed prematurely. Complication rate was 7 % and 9 %. Febrile neutropenia cases occurred in 2 % of each file, without occurrence of any port infection. Direct costs (R/S) were respectively 230.8 vs 219.1 • . Conclusion: Advantages of R over S include higher success rates, shorter procedure duration, higher cosmetic result despite a 5 % relative overcost for R placement. To study functional recovery after surgical damage to the supplementary motor area (SMA). Patients and methods: 6 patients were studied before and after resection of a medial frontal tumor, and compared to 7 healthy subjects. All of the patient group presented with an SMA syndrome. fMRI examinations (1.5 T) included functional axial EG-EPI and anatomical images. Tasks consisted of flexion/extension of the fingers and a complex digital sequence of both hands. Data analysis was performed using SPM99 software. Results: In control subjects and in patients during movements of the hand ipsilateral to the tumor, activation was present in the contralateral hemisphere in the primary sensorimotor cortex, postSMA, and both secondary sensory cortex. During complex movements, additional activation was present in the contralateral preSMA, anterior cingulum, ipsilateral primary sensory cortex, lateral premotor area, and both parietal lobules. Before surgery, activation patterns were similar. However, during simple movements contralateral to the tumor, additional activation was present in the ipsilateral postSMA and lateral premotor area. During complex movements, activation was also present in the ipsilateral preSMA and anterior cingulum. After resection of the SMA, the preSMA and the anterior cingulum of the healthy hemisphere were also activated during simple movements. During complex movements, activation in the ipsilateral preSMA and lateral premotor area was stronger.

These results suggest that there is a dysfunction of the SMA ipsilateral to the tumor before surgery, and that the SMA, anterior cingulum, and lateral premotor area in the healthy hemisphere are involved in the functional recovery following surgery. Purpose: First experiences in comparing different methods for localization of brain function in the setting of neuronavigated guided surgery. Maximum accuracy by using the same MRI-3D-dataset for fMRI and neuronavigation. Material and methods: 12 patients suffering from intracerebral tumours in the central region performed a finger-tapping task of the contralateral hand in fMRI. Activated areas were superimposed on a 3D-GE-MRI dataset including the surface fiducials for neuronavigated surgery. The coordinates of the voxel with highest statistical threshold was determined and compared with the coordinates of maximal response using intraoperative monopolar cortical stimulation. Results: In all patients central sulcus and postcentral gyrus were identified by fMRI. In 2 patients intraoperative stimulation was not possible. In 10 patients coordinates of maximum activation differed by 12 mm mean euclidean distance (stdev. 7 mm, range 2 to 28 mm). The distance was mainly dependent on the different approach of cortical stimulation to the surface of the brain and fMRI activation in the depths of central sulcus (hand motor area). Larger distances were due to a distorted morphology of central area from invading tumour. There was no influence of tumour histology, had motion during the fMRI experiment or hemiparesis. Conclusion: In the setting of neuronavigated guided surgery and intraoperative monitoring, fMRI may help to guide the placement of a cortical electrode on the surface of the brain. Maximum stimulation or activation points differ due to the approach, especially if morphology of the central area is distorded by tumour. This has to be considered in preoperative planning.

3D MR reconstruccion for neurosurgical planning F. Matute, A. Saiz Ayala, J. Arrazola García, J. Jimenez del Rio, C. Saldaña; Madrid/ES Purpose: We used three-dimensional reconstructed magnetic resonance images for planning the operations of 40 patients with intraxial brain tumors and vascular malformations. We studied the cases of these patients to determine the advantages and current limitations of our computer assisted surgical planning technique as it applies to the treatment of neurosurgical cases.

We assessed the cortical surface-anatomy combining with vascular images using a single volumetric acquisition scanning technique from 3D SPGR. In collaboration with neurosurgeons, we obtained tangential and oblique views, that simulates as properly as possible, the real surgical field. This technique, allow us not only to localize the lesion and define the tumor margins but to identify the superficial cortical veins related to the tumor. This multiplanar superficial venography will be used as a road map by the neurosurgeons at the moment of the craniotomy. In addition, a introperative electrical stimulation mapping was performed to assesses eloquent cortices. Results: In each case neurosurgeons could easily reach the lesion with minimum risk because the combination of our multiplanar reconstruction model and intraoperative electrical mapping. Conclusion: Our technique is a easy and useful way of proper determining brain surface and venous anatomy over the tumor. This technique can be used to choose the best method of intervention, to minimize the surgical risk and to select the best surgical approach.

Intraoperative MRI in a stereotactical operation unit: Report on the first two cases V. Hesselmann, R. Girnus, U. von Smekal, M. Hoevels, B. Krug, V. Sturm, K. Lackner; Cologne/DE Purpose: To introduce practical issues for interventional procedures controlled by MRI (Gyroscan Intera, Philips, Best, The Netherlands) in a stereotactical operation unit.

We report on a MRI-controlled stereotactically guided catheter implantation for interstitial irradiation with iodine 125 seeds (case 1) in a patient with glioblastoma and the implantation of electrodes for deep brain stimulation (Medtronics, Minneapolis, USA) in a patient with Parkinson's disease (case

A C D E F 318 2). Patients were placed on a MRI-compatible operation table and fixed in a MRIcompatible stereotactic head frame (MRC-Systems, Heidelberg, Germany). Trajectory and target planning had been done prior to the intervention with a computerized stereotactic treatment planning system (Fischer Leibinger Freiburg, FRG). Anatomical (T2-TSE, T1-SE), real-time MRI and functional imaging (fmri) using a fingertapping paradigm was performed in both cases. In case 1 fMRI was performed after placement of the head frame for localizing the motor hand area. In case 2 fMRI was performed during deep brain stimulation of the subthalamic nucleus. Results: In case 1 the trajectory for the catheter with 125 I seed was remodeled after fMRI. Performance on fMRI for monitoring the effect of deep brain stimulation was poor in case 2, as the localizer of the stereotactical system caused severe distortions of EPI-images. Monitoring the placement of deep brain electrodes could easily be controlled MRI with T2-weighted spin echo sequences. Conclusion: Intraoperative MRI revealed decisive information during operation procedures such as brain shift, fMRI and placement of catheters and electrodes. For fMRI metallic materials are to be removed out of the scanner.

Neurovascular compression of the rostral medulla as a cause of essential hypertension? Prospective MR study in hypertensive and normotensive subjects J. Zizka 1 , J. Ceral 1 , P. Elias 1 , L. Klzo 1 , M. Solar 1 , J. Tintera 2 ; 1 Hradec Kralove/CZ, 2 Prague/CZ Purpose: Several experimental studies assigned vascular compression of the left rostral ventrolateral medulla (LRVM) as a possible cause of essential hypertension. Published data concerning the MR imaging of the neurovascular compression of the medulla oblongata widely differ, particularly due to methodological incongruities. The aim of the study is to conduct a blinded prospective MR study of normotensive and hypertensive individuals. Methods and materials: We examined 32 patients with severe essential hypertension (mean age 52 ± 9 years) and 40 normotensive subjects (mean age 53 ± 10 years). MR imaging protocol consisted of transverse and coronal T2 TSE (slice thickness 3 mm), transverse 3D TOF MRA (0.8 mm) and 3D CISS (1 mm) sequences. The presence and degree of vascular compression at the lower brain stem and particularly at the LRVM were evaluated together with the conspicuity of the anatomical structures on different MR imaging sequences. Results: Among 32 hypertensive patients, 24 (75 %) showed neurovascular contact of the medulla at any location and 6 (19 %) at the LRVM. In the control group of 40 normotensive subjects, 32 (80 %) showed neurovascular contact of the medulla and 13 (32 %) of the LRVM. Compared to T2 TSE and 3D TOF imaging sequences, 3D CISS offered better contrast resolution of neural and vascular structures and superior delineation of the outer vascular contours. Conclusion: Neurovascular compression of medulla oblongata is a frequent finding in both hypertensive and normotensive subjects. Our results do not support the hypothesis of neurovascular compression at the LRVM as an etiological factor of essential hypertension.

Volume estimation of the fornix in patients with organic amnesias using co-axial MR images Q.Y. Gong 1 , D. Montaldi 1 , A.R. Mayes 1 , J. Aggleton 2 , J.R. Hanley 3 , D. Scutt 1 , N. Roberts 1 ; 1 Liverpool/GB, 2 Cardiff/GB, 3 Essex/GB Purpose: The fornix is the principal tract that links the hippocampus with the midline diencephalon. The relative contribution of the fornix in human memory is debated and a reliable method is required for estimating the extent of fornix damage in patients with anterograde amnesias. This study aims to develop an efficient and unbiased approach for estimating the fornix volume on 3D MR images. Subjects and methods: 12 healthy subjects and four patients with organic amnesia (one or other of the fornices were severed) were recruited. MR examinations were performed using a 1.5 T SIGNA (General Electric, Milwaukee), and T1weighted images were obtained using a 3D SPGR pulse sequence (TR/TE 34/ 9 ms, flip angle 30°, slice thickness 1.6 mm). Image analysis was performed using ANALYZE TM (Mayo Foundation, Rochester) and mri3dX (http://www.liv.ac.uk/mariarc/mri3dX). Analysis algorithm using reformatted co-axial MR images was developed based on the Pappus method of modern design stereology. Results: The measurement reliability for fornix volume were obtained (CV = 3.61 %; r = 0.98). Fornix volume in controls obtained was 0.46 ± 0.07 ml on the right and 0.46 ± 0.10 ml on the left. In three of four patients with radiological evidence of severance of either the left and/or right fornix, significant atrophy of the ipsilateral fornix was demonstrated, and ranged between 46.1 % and 22.3 %.

The developed technique provides an efficient and mathematically unbiased approach for estimating the fornix volume on co-axial sections, and can be applied to assess the extent of fornix atrophy in patients with organic amnesia.

Voxel based morphometry in narcolepsy S.C.A. Steens 1 , S. Overeem 1 , C.D. Good 2 , G.J. Lammers 1 , M.A. van Buchem 1 ; 1 Leiden/NL, 2 London/GB Purpose: Recently, a close association between narcolepsy and HLA-DqB1*0602 was found and linked to loss of hypocretin production by hypothalamic neurons, as suggested by lack of CSF-hypocretin-1 levels. The aim of this study was to assess potential (autoimmune-based) hypothalamic degeneration using voxel-based morphometry. Methods/materials: 15 narcoleptics and 15 age-and sex-matched controls were included. All patients were HLA-DqB1*0602-positive, had typical findings during polysomnographic and Multiple Sleep Latency testing, and had no CSF-hypocretin-1. To optimize gray-white matter contrast, we used a 3D-T1 gradient-echo sequence with TR/TE 26/12 ms, flip-angle 45°, 256 × 256 matrix, 100 slices of 1.5 mm and FOV 250 mm. VBM was used for brain extraction, spatial linear and non-linear normalization, segmentation and smoothing. Univariate analyses for gray and white matter were performed with statistical parametric mapping, employing the General Linear Model. Regionally specific increases or decreases in gray or white matter between groups were assessed, with age, sex and global mean voxel values as confounders (p < 0.05, corrected for whole brain volume). Because of our strong prior hypothesis for structural change in the hypothalamic region, we also assessed uncorrected data with a small volume correction for the hypothalamus (p < 0.001). Results: No significant regional differences in gray and white matter could be detected between narcoleptics and controls, even with reduced thresholds and small volume corrections for the hypothalamus. Conclusion: No evidence is found for structural changes in the hypothalamic region. Either the hypothalamic changes are too subtle to be detected using VBM, or the hypocretin neurons remain intact but are not able to synthesize hypocretin.

Evaluation of requests for MRI performed during 2 weeks in Stockholm, Sweden B. Isberg, O. Flodmark, L. Zachrisson, H. Jorulf, Y. Palmquist; Stockholm/SE Over the last years the use of MRI as a diagnostic tool has increased as the method has been recognised as the most efficient way to investigate a variety of clinical conditions. In Stockholm the use of MRI has rapidly increased to a level of today 40 MR examinations per 1000 inhabitants and year. A study was undertaken as an attempt to answer the question whether or not the indications for the MR study, were considered appropriate or not. Method: All requests for 3205 MRI studies performed during two weeks in the County of Stockholm were collected and reviewed. Material: The information on each request form was evaluated by one of four experts. Two experts were clinicians two were radiologists. These experts were asked to evaluate whether the indications for study were considered appropriate or not. Results: In the total material 43 % of the studies were thought to be indicated, 21 % probably indicated, 16 % were thought probably not to be indicated, while 17 % were clearly not indicated. In another 3 %, the material was inadequate and the indication was not possible to evaluate. There were clear differences between different groups of referring physicians in their pattern of using MRI as a diagnostic tool. As an example, specialists in hospital practice had the highest proportion of indicated requests.

The results of this study strongly supports the need for ongoing education and precise guidelines in the proper utilisation of MRI as a diagnostic tool.

Standardized virtual endoscopic approach to the intracisternal course of the cranial nerves V -VIII R. Klingebiel, C. Heine, R. Lehmann; Berlin/DE Purpose: Standardization of a virtual endoscopic (VE) approach to the intracisternal course of cranial nerves (CNs) V -VIII. Methods and material: Magnetic resonance imaging (MRI) of the basal cisterns was performed in 6 healthy volunteers on a 1.5 T unit, using a CISS sequence with an isotropic voxel size of 0.5 3 mm. Data post processing (PP) was effected by means of direct volume rendering (VR), comprising the CN's complete intracisternal course as well as their root-entry-zone. Subsequently, 12 patients with clinical signs of intracisternal pathology were investigated by standardized VE approach.

The PP time was recorded and image quality and diagnostic value were rated by consensus reading of two neuroradiologists, using a five-point score (1 = insufficient, 5 = excellent). Results: 2 -4 virtual endoscopic views were needed per CN for comprehensive intracisternal visualization (N. V = 4, N. VI = 2, N. VII/VIII = 4). The PP time per CN varied between 7 -15 minutes. The average scores for image quality and diagnostic value amounted to 4.5 and 4.4, respectively. In 11/12 patients comprehensive VE CN imaging was achieved. In 4/11 patients variations of the VE views were required. Different intracisternal pathologies were assessed by the VE approach such as neurovascular conflicts between the AICA and the CNs V, VI and VIII at the REZ level. Conclusion: Comprehensive intracisternal 3D visualization of the CNs V -VIII is possible within a routine imaging setting, provided direct volume rendering and standardized PP protocols are used.

The value of the sagittal median nerve diameter in the diagnosis of median nerve entrapment O.J. Sommer 1 , H. Czembirek 2 , H. Gruber 1 , P. Kovacs 1 , M. Stiskal 2 , F. Kömürcü 2 ;

Tuesday B A C D E F 321 Material and methods: 23 patients with suspected carotid artery stenosis were examined with MSCTA after bolus administration of 80 ml of nonionic contrast agent at 4 ml/s. Before the acquisition, a test bolus of 16 ml of c.a. at 4 ml/s was performed. Real time interactive 3D evaluation was performed on a dedicated workstation. The degree of stenosis and the morphology of the plaque (qualitative and quantitative) were evaluated. In all patients DSA was also performed and considered the standard of reference. Results: Excellent image quality was obtained in all cases, without venous filling. Good correlation with DSA was achieved using the interactive 3D assessment. A perfect correlation between MSCTA and DSA regarding the degree of stenosis was seen in 42 carotids. In 3 carotids, with moderate stenosis at DSA, MSCTA showed a severe stenosis, due to the presence of calcification. The values of sensitivity, specificity and accuracy were respectively 96 %, 82 % and 91 %. Regarding the morphology of the plaque, MSCTA correctly demonstrated all ulcerated plaques, also showing the presence, by means of quantitative assessment, of calcium, fibrous stroma and lipid. Conclusion: MSCTA surpasses all the limitations of single slice spiral CTA regarding venous overprojection and volume coverage. Real time 3D interaction is necessary to correctly demonstrate the degree of stenosis. MSCTA appears to be particularly valid in the assessment of plaque morphology and therefore in treatment planning.

Carotid artery stenosis: Accuracy of noninvasive imaging G. Mansueto, M. D'Onofrio, A. Guarise, P. Tamellini, C. Procacci; Verona/IT Purpose: This study prospectively compared contrast-enhanced magnetic resonance angiography (CEMRA) and Doppler ultrasound (DopplerUS) with digital substraction angiography (DSA) and endarterectomy findings to determinate the accuracy in assessing carotid artery stenosis.

In this prospective study from January to May 2001, 32 patients underwent carotid endarterectomy, 21 studied by CEMRA, DopplerUS and DSA and 11 with CEMRA and DopplerUS. The degree of stenosis of 41 carotid arteries (21 patients) was analyzed with CEMRA and DopplerUS and compared with DSA (reference standard) by using the Spearman rank correlation coefficient (Rs). In 9/32 patient eversion endarterectomy was performed; thus it was possible to compare CEMRA, DopplerUS and DSA with the specimen measurement (reference standard). In 23/32 standard endarterectomies the presence of ulcers was documented to determinate the accuracy of noninvasive imaging. Results: There was a significant correlation between CEMRA and DSA (Rs = 0.81; P < 0.001) and between DopplerUS and DSA (Rs = 0.086; P < 0.001) for degree of stenosis. Overestimation was the most frequent error, even in the specimen comparison. There was one false positive for CEMRA and DopplerUS and one false negative for DSA, so the accuracy was the same at 89 %. Ulcers were most frequently seen at CEMRA. Conclusion: There was a significant correlation between CEMRA, DopplerUS and DSA for estimating the degree of stenosis with the same accuracy by comparing with specimen measurements. CE MRA was shown to be the best imaging modality to detect plaque ulceration.

Multislice spiral CT angiography vs. time resolved contrast enhanced MR angiography in the assessment of carotid artery stenosis F. Pediconi, C. Catalano, A. Laghi, F. Fraioli, A. Napoli, M. Danti, R. Ferrari, R. Passariello; Rome/IT Purpose: To compare multislice CT angiography (MSCTA) with contrast enhanced MR Angiography (MRA) in patients with suspected carotid artery stenosis. Material and methods: 23 patients with suspected carotid artery stenosis were examined with MSCTA and MRA using a 1.5 T magnet. MSCTA was performed after bolus administration of 80 ml of c.a. at 4 ml/s. Before the acquisition, a test bolus with 16 ml of c.a. at 4 ml/s was performed. CE-MRA was performed using a multiphase sequence after bolus administration of 15 ml of Gd-DTPA at 2 ml/s. A real time interactive 3D assessment of MSCTA images was performed in all cases, while MRA images were assessed using a standard MIP algorithm on the magnet console. The two techniques were compared for degree of stenosis and plaque morphology, using DSA as standard of reference. Results: With both techniques images were diagnostic and free from artifact. No significant difference between the two techniques, regarding the degree of stenosis, was seen; the values of sensitivity, specificity and accuracy were respectively of 96, 100 and 97 % for both techniques. Qualitative assessment allowed us to correctly demonstrate the morphology of the plaque in all cases with CTA, while MRA correctly demonstrated 10 of 12 ulcerated plaques.

Although multislice spiral CT encompasses most of the problems of spiral CTA, contrast enhanced MRA provides a simpler way to achieve comparable results, using well tolerated contrast agents and without ionizing radiation, regarding the degree of stenosis. Nevertheless, MSCTA also appears accurate in the assessment of plaque morphology.

Power Doppler screening for carotid artery stenosis in cardiac surgery patients V. Beslagic, F. Dalagija, Z. Merhemic; Sarajevo/BA Purpose: To assess the use of power Doppler imaging as a screening tool for detecting carotid stenosis in the preoperative evaluation of cardiac surgery patients admitted at University Clinical Center Sarajevo in an eighteen month period. Material and methods: We surveyed 174 patients admitted for cardiac surgery. Imaging methods were power doppler, duplex Doppler, MRA, DSA. A two phase study was performed. In the first, a prospective preoperative evaluation of 60 patients was performed using duplex Doppler. During the second phase, prospective preoperative evaluation of 114 patients was performed using power Doppler imaging. In patients with 50 % stenosis or more, duplex Doppler was performed. Imaging methods for further evaluation of 70 % and above stenosis, in both groups, were MRA and intravenous DSA. Results: Stenosis of 60 % or more was found in 11 (19 %) patients in the first phase group and in 27 (24 %) of patients in the second phase group. Stenosis of 70 % and above was found in 4 (7 %) patients in the first phase group, and in 12 (11 %) patients in the second phase group. Adequate images were achieved in 89 % of the power Doppler studies compared with 82 % in the duplex Doppler studies.

Conclusion: Power Doppler, as a screening tool for carotid stenosis, is a low risk, fast, cost effective method with accurate results. Using power Doppler to screen patients and duplex Doppler to evaluate significant carotid stenosis with possible further diagnostic evaluation with MRA and DSA, an optimal imaging approach is achieved.

Cerebral hemodynamics in patients with vertebral artery hypoplasia comparing those with and without atherosclerotic lesions of carotid arteries S.G. Mazur, I.I. Glazovska, V.V. Kuznetsov; Kiev/UA Purpose: Comparison of brain hemodynamics in patients with vertebral artery hypoplasia (VAH) comparing those with and without atherosclerotic lesions of the carotid arteries. Methods and materials: We examined 102 patients, 51 males and 51 females, mean age 51 ± 15 years: (1) 58 patients without a history or signs of cerebrovascular diseases and without carotid stenosis: 31 with VAH (1A) and 27 without VAH (1B); (2) 44 patients with ischemic stroke caused by atherosclerotic lesions of the carotid arteries: 19 with VAH (2A) and 25 without VAH (2B). We used a sonography system "Elegra" (Siemens) to measure the vessel diameters, volume blood flow velocities (VF), total cerebral volume blood flow (TVF) -VF through both internal carotid arteries (VFICA) + VF through both VA (VFVA). Results: Group 1A had lower VFVA than 1B (p < 0.05), but there was no significant difference between TVF in these two groups. TVF in Group 2A (0.36 ± 0.038 l/min) was lower compared with Group 2B (0.51 ± 0.071 l/min, p < 0.001) resulting in a lower VFVA in Group 2A (0.028 ± 0.087 l/min and 0.12 ± 0.051 l/min respectively, p < 0.001). Gropp 2B versus 2A patients had a higher severity of arterial narrowing. Conclusions: Patients with VAH without stenotic lesions of the carotid arteries have brain hemodynamic compensation through the carotid arteries and contralateral vertebral artery. VAH in patients with cerebral atherosclerosis evokes decompensation of cerebral hemodynamics and causes ischemic stroke with a lower grade of carotid stenosis than in patients without VAH. Purpose: The aim of this work was to retrospectively evaluate with MRI, 45 patients affected by anterior knee pain without clinical symptoms of meniscal or ligamentous injuries. Materials and methods: 45 patients with anterior knee pain entered this study. MR examination was performed using 0.2 T dedicated and 1.5 T whole body MR units. In 5 cases dedicated MR unit was performed to have kinematic evaluation of the knee at three different degrees of flexion. In 25 cases i.v. injection of contrast media was performed. All the patients underwent arthroscopy. Results: In all the cases MRI revealed a region of altered signal intensity in the superior aspect of the Hoffa's body. Arthroscopy revealed the presence of synovial thickening in 25 cases and enlargement of the patello-femoral synovial recess in 20 cases. In 14 cases of synovial thickening infusion MRI showed in 8 cases contrast enhancement suggesting an acute stage of inflammation and in 5 cases no enhancement was found due to the presence of synovial fibrous tissue. In 9 cases of histologically proved villonodular synovitis SE T2W sequences showed a region of non homogeneous high signal intensity because of the presence of spots of low signal intensity. In all the 5 patients showing synovial thickening of the Hoffa's body apex, kinematic MR revealed impingement with the femoro-patellar joint. Conclusion: Our experience demonstrates that MRI, eventually completed by kinematic study and/or infusion of contrast media, may be considered the method of choice in the evaluation of the synovial impingement of the knee.

Cystic degeneration of the lateral meniscus of the knee: MRI evaluation before and after arthroscopic treatment using radiofrequency energy A. Barile, A.V. Giordano, M. Caulo, M. Sabatini, F. Iannessi, G. Bonanni, V. Calvisi, C. Masciocchi; L'Aquila/IT Purpose: 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: Forty-one patients entered this study. 18 patients underwent arthroscopic selective meniscectomy and 23 patients underwent arthroscopic selective meniscectomy and radiofrequency treatment (Arthocare, Sunnyvale, CA) of the meniscal remnant. All of them were submitted to MRI and clinical evaluation three months later. In 9 cases MRI examination was performed before and after the surgical treatment. MRI examination was performed using a dedicated 0.2 T (Artoscan Esaote Italy) and a 1.5 T superconductive unit (GE Signa Horizon USA) employing SE T1-w, SE T2-w and GE T2-w sequences in axial and longitudinal scan planes. In 3 cases Arthro-RM was also performed. Clinical evaluation included physical examination and a questionnaire. Results: Clinical evaluation did not show statistically significant discordance between the two groups. MRI follow-up after 3 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.

Bone-patellar tendon-bone (BTPT) ACL reconstruction of the knee: Diagnostic imaging evaluation of failures compared to second-look arthroscopy A. Barile, G. Cerone, A.V. Giordano, L. Zugaro, A. Catalucci, G. Bonanni, V. Calvisi, C. Masciocchi; L'Aquila/IT Purpose: To evaluate the capability of diagnostic imaging in cases of failed anterior cruciate ligament (ACL) reconstruction. Materials and methods: 16 patients submitted to ACL surgical reconstruction with patellar tendon entered this study. All the patients were clinically suspected of ACL reconstruction failures and had diffuse pain and/or joint swelling or instability. All of them underwent MRI from 3 to 12 months after surgery. All patients underwent plain film and 11/16 CT. In all cases MR study was performed using dedicated 0.2 T or whole-body superconductive 1.5 T units; in 12 cases arthro-MRI was also employed. Results: In 5 patients enlargement of the graft related to the presence of significant synovial reaction were found. In 4 cases synovial reaction was exuberant (Cyclops syndrome). In 3 patients the bone tunnels were not perfectly aligned and standard examination revealed the presence of osteophytosis of the intercondylar fossa. In 2 cases the bad positioning of the interference screws was found. In the last 2 cases MRI documented a tear of the graft. In all the cases arthroscopic second look confirmed the MRI diagnosis. Conclusion: MR manifested very accurate evaluation of the ACL autograft because of its high contrast resolution and multiplanarity. In our experience MRI eventually completed with arthro-MRI may be considered the method of choice in the evaluation of ACL reconstruction failures.

Dynamic MRI in the evaluation of femoro-patellar disorders M. Mastantuono, E. Bassetti, M. Francone, M. Valeo, R. Passariello; Rome/IT Purpose: Alterations of femoro-patellar biomechanics in the young and sports practicing subjects may determine the development of early involutive process and painful conditions. In our experience we verified the potential offered by kinematic studies of the extensor complex on sagittal and axial planes and we developed an innovative method of study that permits a correct clinical assessment of in this particular problem.

We used a 0.2 T dedicated magnet, dedicated to the study of limbs with an adapting device holding the knee at different angles of flexion. We obtained images in different positions of flexion-extention acquired with a SE T1 and T2 and G.E. sequences slice thickness 2 -3 mm without gap. We studied 27 healthy volunteers and 39 patients with anterior pain or instability of knee joint of which was suspected of being femoro-patellar in origin.

In 29 patients the correlations between cartilage and subchondral bone sufference and the cinemotion findings were significant. Conclusion: Our method differs from the other dynamic studies described in the literature in that it allows volume study and permits a clear evaluation of the dynamic relationship between rotule and troclear articular surfaces.

Postoperative meniscus: Assessment with dual-detector spiral CT arthrography of the knee C. Mutschler, B. vande Berg, F.E. Lecouvet, P. Poilvache, J.E. Dubuc, B. Maldague, J. Malghem; Brussels/BE Purpose: To evaluate dual-detector spiral computed tomography (CT) arthrography of the knee in the assessment of the postoperative meniscus. Materials and methods: Two observers retrospectively determined in consensus the meniscal changes observed in 20 consecutive patients who have had partial meniscectomy (n = 23) and who underwent dual-detector spiral CT arthrography of that knee for recurrent symptoms before second-look arthroscopy. At CT arthrography, postoperative menisci were considered to be either stable (no tear or small partial tear) or unstable (meniscal separation, complete tear, large partial tear, displaced meniscal fragment). The sensitivity, specificity, and positive and negative predictive values for the detection of unstable meniscal tears among all postoperative menisci at spiral CT arthrography was determined with second-look knee arthroscopy as the standard.

The sensitivity and specificity for the detection of unstable postoperative meniscal tears among all postoperative menisci were 85 % and 90 %, respectively, with positive and negative predictive values of 92 % and 82 %, respectively. Conclusion: Dual-detector spiral CT arthrography of the knee is an accurate method for detecting unstable meniscal tears among postoperative menisci. Purpose: To analyze MR-pathology of the knee joint at different stages of osteoarthritis and to find out whether pain, stiffness and limited function assessed clinically correlate with the degree of pathology assessed on MR images and radiographs. Material and methods: The study population consisted of 50 patients with varying degrees of osteoarthritis. Osteoarthritis was graded clinically using the WOMAC (Western Ontario and McMaster University) score and on the basis of conventional radiographs using the standard KL (Kellgren-Lawrence) score. In addition MR imaging was performed at 1.5 T using a high-resolution fat-suppressed, spoiled gradient echo sequence, T2-weighted fat suppressed fast spin echo sequences and T1-weighted spin echo sequences. All images were analyzed by two readers concerning cartilage lesions, bone marrow edema and pathology of the ligaments and menisci. These findings were correlated with the clinical and the radiological score. Results: 13/16 joints with a KL-score of 4 showed full thickness cartilage lesions and bone marrow edema. Meniscal tears were found in all joints with KL-score 4. Cruciate ligament pathology was found in 5/13 KL-score 3 and 9/16 KL-score 4 joints. The KL-score correlated well with the extent of MR-pathology. Correlations between the extent of cartilage damage, bone marrow edema and the KL-score versus the WOMAC-score were non-significant (p > 0.05). Conclusion: A high percentage of meniscal and ligamentous pathology, bone marrow edema and severe cartilage lesions could be shown in advanced osteoarthritis. However, a significant correlation between clinical findings and the extent of MR-and X-ray pathology could not be demonstrated. Purpose: Evaluation of real-time MRI in the assessment of velopharyngeal closure in comparison to videofluoroscopy. Materials and methods: 1 healthy volunteer and 7 patients with suspected velopharyngeal insufficiency (age from 5 -19 years, mean 9 years) underwent videofluoroscopy and real-time MRI, using a TSE "zoom" sequence (TR = 170 ms, TE = 21 ms, slice thickness 6 mm) with 6 images per second. Images were acquired in the midsagittal, the coronal and axial plane at the level of maximal velopharyngeal closure during phonation of test words. Results were analysed by 2 radiologists in comparison to videofluoroscopy as the standard of reference concerning overall quality of the depiction of the velopharyngeal isthmus and the pattern of velopharyngeal closure in all three image planes. Results: In all cases, real-time MRI could correctly depict the pattern of velopharyngeal closure in correspondence to videofluoroscopy: velopharyngeal insufficiency with wide open velopharyngeal portal (n = 2), with moderate open velopharyngeal portal (n = 1), close approximation of the velum (n = 1) and velum touching the dorsal phayryngeal wall (n = 3). In 3 cases, the coronal plane was not of diagnostic quality in MRI due to motion-artefacts. In one case, MRI showed an asymmetric movement of the pharyngeal walls which could not be seen in videofluoroscopy.

Conclusion: Real-time MRI can successfully analyse the pattern of velopharyngeal closure even in small children. Being a non-invasive method, it avoids the radiation exposure of videofluoroscopy and the discomfort of nasoendoscopy.

Evaluation of the movements of the oro-pharyngeal cavity during phonation with different voice intensity using MRI M. Di Girolamo, G. Ruoppolo, E. Iannicelli, M. Mattei, A. Carriero, V. David; Rome/IT Purpose: The aim of this study was to evaluate with MRI the movements of the different anatomical structures of the oro-pharyngeal cavity during the utterance of the fundamental vowels with different voice intensity.

We have evaluated 30 volunteers using a 0.5 T MR superconductive unit (Philips Medical System). We performed Turbo-Field-Echo sequence (TR: 12 ms; TE: 6 ms; TI: 900 ms; N.Ex.: 4; Acq. Time: 6 s) with midsagittal scan (slice thickness: 8 mm). The volunteers were asked to perform a prolonged emission of the fundamental vowels [a], [i], and [u] with normal voice intensity (50 dB) and with loud voice (70 dB). The voice intensity was measured with a phonometer before the MR acquisitions. On each midsagittal scan we measured the area of the mouth and pharyngeal lumen. Results: In all the patients we accurately evaluated the movement and the activity of the lips, tongue, soft palate and the pharynx. Comparing the utterance of loud voice to normal voice, we found an increase of the area of the mouth lumen for the vowels [a] and [u] and an increase of the area of pharyngeal lumen for the vowel [i].

The intensity of voice emission depends not only on subglottic air pressure and glottic rim dimension but also upon the oro-pharyngeal cavity volume.

The three-dimensional CT study of the upper airway of obstructive sleep apnea syndrome: An oral appliance can change the volume of oro-and nasopharynx W. Zhang; Beijing/CN Purpose: To evaluate the utility of the spiral CT and post processing with 3D remodelling to review the anatomical abnormalities and the changes of the upper airway of OSAS with or without an oral appliances in the mouth. Method/materials: 15 OSAS patients who had ideal oral appliance therapy have undergone spiral CT with or without the oral appliances in the mouth. Scan was obtained with 3 mm collimation at 1.0:1 pitch from nasopharynx to the level of the hyoid bone at end expiration. 3D remodeling, RaySum and MPR were performed at the workstation. Luminal area at naso-, oro-and hypopharyngeal levels, the distance of the posterior airway space and distance between the hyoid bone and mandibular plan were measured. Results: Oro-and nasopharyngeal areas were significant larger in patients with oral appliances than in patients without oral appliances, P < 0.05 (478.07 mm 2 ± 104.29 vs 374.86 mm 2 ± 135.72 and 175.50 mm 2 ± 80.30 vs 112.50 mm 2 ± 65.05). No differences of hypopharyngeal areas were found between patients with or without oral appliances, P > 0.2 (202.36 mm 2 ± 119.78 vs 250.43 mm 2 ± 103.78).

The three dimensional spiral CT scanning had many advantages in the evaluation and measurment the upper airway in patients with OSAS, these results show the main therapeutic mechanism of oral appliance use is the volume change of the oro-and nasopharynx.

Static and dynamic evaluation with MRI of larynx and oro-pharingeal cavity in professional opera singers M. Di Girolamo, G. Ruoppolo, F. Assael, M. Minnetti, E. Iannicelli, V. David; Rome/IT Purpose: To assess the anatomical configuration of phonetic organs by MRI in singers with different vocal range. Methods and materials: 26 professional opera singers (7 tenors, 5 basses, 8 sopranos, 6 mezzosopranos) underwent MRI, performing both static and dynamic studies. We performed TSE T2-weighted axial scans at the level of larynx in order to evaluate the area of superior surface of vocal cord. In the dynamic study, the singers were asked to perform a prolonged vocalization at a confortable tonality of the foundamental vowels a. We performed a midsagittal Turbo-Field-Echo scan (acq.time: 6 s) at the level of the oro-pharyngeal cavity measuring the area of the mouth and pharyngeal lumen. These data underwent statistical evaluation using the Mann-Whitney U-test. Results: We determine the average size of the vocal cord (sopranos: 0.71 cm 2 ; mezzosopranos: 1.20 cm 2 ; tenors: 1.58 cm 2 ; basses: 2.88 cm 2 ) and of mouth and pharyngeal lumen (sopranos: 15.8 cm 2 ; mezzosopranos: 14.6 cm 2 ; tenors: 23.6 cm 2 ; basses: 32.2 cm 2 ). The differences in vocal cord size between sopranos and mezzosopranos (P: 0.0641) and between tenors and basses (P: 0.0833) are tendentially statistically significant. The variation in vocal tract size during the ut-

Tuesday B A C D E F 327 terance of the vowel a between tenors and basses is considered tendentially statistically significant (P: 0.0833) while the difference between sopranos and mezzosopranos is not statistically significant (P: 0.6434).

We demonstrate a correlation between the vocal cord's surface and the vocal tract configuration and the vocal tessitura of a singer. Long vocal cord and wide vocal tract are characteristic of singers with low-pitched voice types (bass, baritone, contralto, mezzosoprano) while short vocal cord and narrow vocal tract are characteristic of singers with high-pitched voice types (tenor, soprano).

Correlation between Arnold Chiari malformation and sleep apnea syndrome (SAS) I. Thomassin 1 , K. Marsot-Dupuch 1 , V. Stahl 2 , F. Bourquin 2 , F. Parker 1 , P. Lasjaunias 1 ; 1 Le Kremlin Bicêtre/FR, 2 Bobigny/FR Purpose: To identify morphologic abnormalities on cervical MRI exams among patients suffering from sleep apnea syndrome and Arnold Chiari malformation. Materials and methods: 13 patients suffering from severe apnea syndrome (30/ mn) were referred for surgery of Arnold Chiari malformation. Pre-and post-contrast sagittal and axial T1 W and T2W images of the brainstem and cervical cord were performed. Were studied the cerebello-medullary cistern, the angle between posterior border of brainstem and cerebellum, location of cerebellar tonsilla, cervicooccipital junction and ventricular system. Results: Three brainstem abnormalities were detected (two isolated and one in a complex malformative syndrome). 9 patients have filling of cerebello-medullary cistern and a diminution of the angle between the posterior border of the brainstem and the cerebellum. Anterior translation of cerebellar tonsils was noticed. Discussion: Many authors have studied obstructive SAS which was partially explicated by laryngo-pharyngeal abnormalities. Associated transient ischemic attacks are well known. Our study suggested that abnormalities of brainstem may alter the function of respiratory nuclei and tracks and that brainstem abnormalities may be linked with sleep apnea syndrome. Conclusion: Sleep apnea syndrome may be associated with lesions of brainstem. Further larger study should be done to prove a statistical correlation. However radiologists should look for posterior fossa abnormalities when exploring patients referred for sleep apnea syndrome.

Comparison of differently viscous iodinated and barium-containing contrast agents in the detection of pharyngeal perforation M. Keberle, G. Wittenberg, A. Trusen, W. Baumgartner, D. Hahn; Würzburg/DE Purpose: Unlike in the investigation of esophageal perforation, the more radiopaque barium-suspensions are not as important as iodinated aqueous contrast agents for the detection of pharyngeal perforations. This study was performed to find out whether the highly different viscosities (of iodinated and barium-containing contrast agents with comparable radiopacities) are a reason for this. Methods: Viscosity, subjective difference in contrast, and CT-density of an iodinated aqueous (Telebrix) and a 50 wt/vol% barium-containing contrast agent (Micropaque) were determined. Moreover, to exclude postoperative perforation, 104 patients were prospectively examined by pharyngography using both contrast media. Pharyngographies of patients with perforation were later compared by two independent readers. All patients with perforation were followed up clinically to exclude complications due to barium-application. Results: In-vitro comparison showed comparable radiopacity but the 50 wt/vol% barium-suspension was much more viscous than the iodinated contrast agent. In total, during pharyngography, 14 perforations were clearly delineated with the iodinated aqueous contrast agent. However, two of them were not detected with the barium-suspension. All the other perforations presented equally. Conclusions: Given a sufficient radiopacity, a low viscosity appears to be essential for a contrast agent to detect pharyngeal perforation. Thus, we recommend the sole use of an iodinated contrast agent (if suspicion of aspiration as isoosmolar variant) for this purpose.

Percutaneous tracheostomy (PT) in the intensive care unit (ICU) using ultrasound guidance T. Geroukis, D. Voultsinou, A. Papachillea, V. Kalpakidis, P. Palladas; Thessaloniki/GR Purpose: To present the ultrasonographic investigation of anterior neck structures conducted prior to the performance of PT in the ICU patients. To determine whether the ultrasonographic contribution could reduce the complication rate and improve the outcome of these patients.

We studied 26 ICU patients, with an average age of 58. The ultrasound investigation was performed with bedside portable equipment in the ICU immediately prior to the tracheostomy, indicating the point of puncture and analyzing the relationships of the anatomic structures lying in the vicinity of the tracheostomy site. Results: In 13 patients the thyroid isthmus was extending over the TR1-TR2 space and in 8 patients a considerable isthmus thickness was calculated. Goiter was found in 7 patients whereas clinical examination indicated this in only in 3 patients.

The clinical examination was unable to evaluate by palpation the guiding points in 6 patients. In all these cases the anatomical relations required were satisfactorily visualized ultrasonographically. Complications included hemorrhage, pneumothorax and subcutaneous emphysema.

The ultrasonographic results influenced the decision for surgical or transcutaneous tracheostomy or surgical management during the procedure in three cases but small complications were unavoidable. With increased practice and better evaluation of the ultrasound results, the radiologist can play a vital role in the management of the ICU patient.

Possibilities of spiral CT in differential diagnosis of carotid chemodectomas G. Results: Chemodectomas were revealed in 23 pts, neurinomas in 8 pts and carotid arteries aneurysms in 11 pts. Among 23 chemodectomas there were 19 carotid and 4 vagal tumours. The analysis of data revealed that chemodectomas were characterised with early (arterial phase) pronounced (up to 200 HU) contrast enhancement. Sometimes a low density area can be seen in center of the lesion. Neurinomas are characterized with less pronounced enhancement (up to 100 HU). "Spots" and "stripes" of the contrasted vessels stand out against parenchyma in neurinomas. There was no significant difference (p < 0.01) of average density rates in arterial phase in chemodectomas (171.2 ± 45.8 HU) and in neurinomas (64 ± 26 HU). There was a simultaneous contrast enhancement both in aneurysm and in surrounding vessels. Additional information valuable for differential diagnosis was not obtained in venous and delayed phases. Simultaneous enhancement of tumor and carotid arteries gives the possibility of evaluat Ing their relationship and the involvement of carotid arteries in pathological processes. Conclusion: Spiral CT with bolus contrast enhancement allows differentiation of tumors and other pathological masses of the carotid space and allows a 3D-image of the area of interest to be obtained for surgery planning.

Acute calcific retropharyngeal tendinitis M. Tassart, C. Le Breton, F. Bahlouli, N. Szelei, J. Bigot; Paris/FR Purpose: To improve early diagnosis of an under recognized cause of cervical pain and stiffness whose initial misdiagnosis can lead to parenteral administration of antibiotics or even open biopsy Materials and methods: Two patients (1 male, 33 a; 1 female: 47 a) were admitted to the hospital with dysphagia, severe neck discomfort and fever. Lateral radiographs of the cervical spine were performed in 2 patients, computed tomography in 2 and MRI in 1. Using non-steroidal anti inflammatory medications (interruption of antibiotics), the two patients had complete resolution of the symptoms within one week Results: The calcification of the prevertebral muscle was demonstrated by CT for 2 patients and identified on lateral radiography in one case only. The soft tissue swelling was seen both on CT and MRI. Conclusion: Acute calcific tendinitis is an under recognized disease which can be initially misdiagnosed as retropharyngeal or nasopharyngeal abscess, leading to unecessary parenteral injection of antibiotics or even biopsy. The radiologist has an important role to ensure the definitive diagnosis: in our 2 cases, specific imaging led to the correct diagnosis. To test the hypothesis that the single testicular artery is low resistance, and two further arteries (cremasteric/differential) are high resistance, we examined the spermatic cord vessels in a cohort of healthy men. Materials and methods: Patients presenting for a scrotal US with normal testes and epididymis were recruited. The right and left spermatic cords were examined from the superior aspect of the testis to the external inguinal ring to locate the testicular, cremasteric and differential arteries. A 15L8w multifrequency (8 -13 MHz) linear array probe (Acuson CA) identifed each artery as separate, allowing a spectral Doppler waveform to be recorded. The resistive index (RI) from each artery was measured three times (right and left) and the mean calculated. The three arteries were labelled A (lowest RI) B and C (two higher RI). Results: 51 patients (median age 39 a, range 18 -79 a) were examined. The RI's on the right were: A: 0.71 ± 0.05, B: 0.82 ± 0.05, C: 0.84 ± 0.04 and the left A: 0.70 ± 0.06, B: 0.84 ± 0.04, C: 0.83 ± 0.05. A paired t-test demonstrated a significant difference of the combined right and left measurements for AvsB (p < 0.001) and AvsC (p < 0.001) but not BvsC (p = 0.3). Conclusion: Although it is not possible to identify a named artery in the spermatic cord, consistently one artery has a significantly lower RI than the other two arteries. This finding may be useful as an adjuvant parameter in the assessment of scrotal pathology in particular with patients with spermatic cord torsion.

Age related changes in testicular perfusion and serum androgen levels O.J. Sommer 1 , K. Kharom 2 , T. Zils 2 , H. Czembirek 2 , H. Pflüger 2 , E. Plas 2 ; 1 Innsbruck/AT, 2 Vienna/AT Purpose: To assess the peripheral vascular resistance of small testicular arteries in different age groups and to match these results with age and androgen levels. Materials and methods: 94 testicular units of 47 healthy subjects were investigated. According to age, patients were divided into 5 groups (30 -39, 40 -49, 50 -59, 60 -69, > 70 a). Using high resolution sonography (7 -13 MHz, Elegra, Siemens, Erlangen) including power mode we measured resistive indices (RI) and pulsatility indices (PI) of centripetal testicular arteries of the lobuli testes excluding mediastinal arteries. Androgen (testosterone, free testosterone, FSH, LH, sexual hormone binding globulin) levels were evaluated between 8 and 10 a.m. and correlated with age, RI and PI values. Results: There was a significant difference of 0.58 to 0.67 in RI (p = 0.025) and 0.94 to 1.29 in PI (p = 0.0005) values between young and old men. With the exception of sexual hormone binding globulin (SBHG) (4.8 versus 2.5; p < 0.05) no significant correlation of androgens with age, RI or PI was shown.

Our study suggests a positive correlation of age with the peripheral resistance of small testicular arteries, i.e. an increase of peripheral resistance with increasing age. SBHG showed a positive correlation with age, RI and PI values. The other androgens do not seem to relate with RI and PI values of the aging male. 

Consecutive patients referred for scrotal US were examined with a 15 L8w multifrequency (8 -13 MHz) linear array probe (Acuson, CA). If a focal testicular lesion was identified, the abnormality was re-examined with colour Doppler mode (7 -12 MHz). Vascularity was classified into, (A) no intra lesional vessels, (B) surrounding but no intra lesional vessels, (C) Intra lesional vessels present and subdivided into (1) vessels crossing (2) disordered vessels (3) complete infilling. US findings were correlated with histology or findings confirmed on follow up. Results: Over a 24 month period a total of 2032 patients were examined. 53 focal abnormalities in 44 patients were found. The distribution of vascular patterns was as follows: A: 9, B: 5, C1: 26, C2: 9, C3: 2. 27 primary testicular tumours (seminomas, teratomas) were detected, 26 showing a C1 (criss cross pattern), a single well differentiated teratoma showing no intra lesional vessels (A). Nine patients demonstrated a C2 vascular pattern; 4 secondary tumours, 3 acute myeloid leukaemia, 1 chronic fibrosis and a single patient without histological diagnosis. The C1 pattern was present in 95 % of primary testicular tumours.

The presence of the 'criss cross' vascular pattern allows confident diagnosis of primary testicular tumours, although not differentiating seminomas from teratomas. With the improvement in probe technology, vascularity of testicular tumours proves to be an important differentiating feature.

Varicocele and venous insufficiency in left low extremity S. Deftereos, G. Alexiadis, G. Kafetzis, S. Touloupidis, J. Manavis; Alexandroupolis/GR

The aim of our study is to compare the rate of incidence of varicocele and venous insufficiency in left low extremity. The flow pattern of left common iliac, external iliac, common femoral and great saphenous veins were evaluated with colour Doppler sonography (CDS) in 32 patients (19 -22 years old) with clinically suspected left varicocele. The same veins were also evaluated with CDS in 15 clinically healthy voluntaries (same age range).

In 24 patients of the first group (32 patients with clinically suspected varicocele) when Valsalva manouvre was performed with the patient in upright position, flow reversed for a period of one or more seconds in left common femoral vein. Thus the diagnosis of venous insufficiency was made. In the second group (15 clinically normal males) normal findings were found in thirteen persons. In the remaining two young men the diagnosis of venous insufficiency were made. The CDS of scrotum revealed varicocele in both of them. On the basis of these findings and also because of the anastomotic branches between the veins of scrotum and low extremity we believe that a CDS evaluation of the flow pattern in left common iliac, left common femoral and great saphenous veins must be performed before surgical treatment of varicocele in order to avoid the possibility of varicocele recurrence.

Quantitative evaluation of scrotal veins by colour Doppler US in healthy population A. Cina, T. Pirronti, R. Foschi, G. Restaino, G. Oliva, A. Pignatelli, D. Ribatti; Rome/IT Scrotal varicocele (SV) is a very common disease of the male population. Presently, colour Doppler ultrasonography (CDUS) represents the most frequently adopted technique for confirming the clinical diagnosis of SV and for a treatment indication. Despite for several years CDUS has been clinically used in cases of SV, discriminating quantitative values are not reported in medical literature. This is at least partly due to the lack of studies of CDUS patterns obtained from large populations of healthy subjects. The aim of this paper is to investigate the role of ECD in instrumental diagnosis of male varicocele, the implications in selecting the patients who require treatment, and to investigate the risk of SV overdiagnosis by adopting the qualitative criteria currently used. We prospectively examined by CDUS a population of 150 healthy and symptomless subjects, with a negative clinical examination for varicocele, and a normal spermiogram. We found that the normal value range of the maximum diameter of scrotal veins (2.62 ± 0.53 mm) widely overlaps with the values currently accepted for a varicocele diagnosis (1.5 -3.0 mm). Furthermore, a venous reflux, a criteria adopted also for the diagnosis of subclinical varicocele, was present in 53 % of the normal population. These data show that there is a risk of SV overdiagnosis by using CDUS. The quantitative criteria for SV diagnosis should be re-examined. The patients group included 10 UVJs with grade I -II and 5 UVJs with grade III -IV of reflux. Urethra-to-orifice distance (UOD) and length of intravesical and submucosal parts of the ureter were measured. Results: In normal cases ureteral orifices were situated on equal distances from urethra, the UOD was 11.2 ± 2.8 mm (mean ± SD). The length of intravesical part of the ureter was 24.9 ± 6.6 mm and correlated with height (correlation coefficient 0.78), body surface area (0.73) and weight (0.66). The length of submucosal part of the ureter was 12.6 ± 3.1 mm and correlated with body surface area (0.85), weight (0.83) and height (0.82). The ratio between intravesical and submucosal parts of the ureter was 1.95 ± 0.3. There was no significant difference between the normal values and values of all 10 low-grade reflux UVJs. In 4 from 10 spontaneous resolution of the reflux during 1-year period was found. The grade III -IV reflux orifices (5 UVJs) were situated farther from urethra than opposite normal orifices, the UOD was 14.2 ± 2.5 mm. The intravesical part of the ureter was short (9 ± 2.1 mm) and submucosal part was absent in all cases. None high-grade reflux was resolved spontaneously. Conclusion: Ultrasonography is a valuable noninvasive method of examination of UVJs and may be useful in vesicoureteric reflux assessment.

Comparison of contrast-enhanced colour Doppler targeted biopsy to conventional systematic biopsy: Impact on prostate cancer detection F. Frauscher, A. Klauser, L. Pallwein, A.H. Schuster, H. Volgger, G. Helweg, D. zur Nedden; Innsbruck/AT Purpose: We investigated whether a limited biopsy approach with contrast-enhanced colour Doppler ultrasound (CDUS) targeted biopsy of the prostate could detect cancers as well as grey-scale US guided systematic biopsy with a larger number of biopsy cores.

We examined 230 men (PSA ≥ 1.25 ng/ml). Two independent examiners evaluated each subject. One investigator performed contrastenhanced targeted biopsies (≤ 5) into hypervascular regions in the peripheral zone during intravenous infusion of Levovist™. Subsequently, a second examiner performed 10 systematic biopsies of the prostate. Cancer detection rates for the two techniques were compared. Results: Cancer was detected in 69/230 subjects (30 %). Cancer was detected in 56/230 subjects (24.4 %) by contrast-enhanced targeted biopsy, and in 51/230 patients (22.2 %) with systematic biopsy. Cancer was detected with targeted biopsy alone in 17 subjects, and with systematic biopsy alone in 13 subjects. Overall cancer detection rate was not significantly different for targeted and systematic biopsy (p = 0.53). The detection rate of targeted biopsy cores (118/1139) was significantly better than that of systematic biopsy cores (123/2300) (p < 0.001). Targeted biopsy in a patient with cancer is 2.6 times more likely to detect prostate cancer than a systematic biopsy. Conclusions: Contrast-enhanced CDUS targeted biopsy detected as many cancers as systematic biopsy with fewer than half the number of biopsy cores. Although an increase in cancer detection rate is obtained by combining targeted and systematic techniques in this screening population, contrast-enhanced targeted biopsy alone is a reasonable approach to reduce the number of biopsy cores.

Intermittent contrast-enhanced ultrasonography for prostate cancer detection A. Klauser, L. Pallwein, W. Horninger, F. Frauscher, G. Helweg, D. zur Nedden; Innsbruck/AT Purpose: We investigated the usefulness of intermittent contrast-enhanced ultrasonography (US) in the detection of prostate cancer. Methods and materials: Nineteen patients with an elevated prostate-specific antigen level (³ 2.5 ng/ml) or an abnormal digital rectal examination were enrolled in the study. We used an i.v. US contrast agent (Levovist™). Continuous greyscale, intermittent grey-scale, phase inversion grey-scale, and colour and power Doppler US of the prostate were performed. Sonographic findings were correlated with biopsy results.

After US contrast agent administration we found significant enhancement on both grey-scale and Doppler images (p < 0.01). In 3 isoechoic tumours we only detected focal enhancement using intermittent imaging. Focal areas of enhancement were identified in only 1 patient (5 %) without cancer. Conclusions: Intermittent contrast-enhanced US of the prostate seems to be useful for selective enhancement of malignant prostatic tissue. Therefore, this technique may be useful for targeted biopsies. Power Doppler sonography was more sensitive in detection of tumoral vessels than PD sonography and increased PPV from 81 % to 87 %, NPV from 75 % to 82 %, sensitivity from 80 % to 90 %, specificity from 77 % to 86 %. Conclusion: 3D PD TRUS examination is more informative than PD TRUS examination in detection prostate cancer. 3D PD TRUS examination can be used as a diagnostic tool in addition to complex examination of patients with suspected prostate cancer.

TRUS CD and MRI with contrast agent in the evaluation of local recurrence after radical prostatectomy F.M. Drudi, S. Petta, A. Carbone, A. Righi, F. Trippa, P. Ricci, R. Passariello; Rome/IT Purpose: Aim of our study was to evaluate sensitivity of US CD and MRI, both with contrast medium enhanced, in the detection of local recurrence of prostate cancer after radical prostatectomy and to evaluate the specificity of these techniques in distinguishing recurrent cancer from fibrosis. Materials and methods: Twelve patients (mean age 64.4; range 56 -73) presented with increasing PSA values (> 0.4 ng/ml) in a variable period (mean time elapsed 3 years; range 3 months to 4 years). All patients underwent bone scintigraphy before and after treatment, MRI (Gadolinium DTPA i.v. 2 ml/s, 20 ml total. Flash T1 Fat Sat 20 slice thickness 5 mm), grey scale TRUS, TRUS CD (Levovist SHU508) and TRUS guided multiple biopsy. Presence of colour signal and MR signal after c.a. was considered sign of recurrence, absence of recurrence or fibrosis.

The results were compared to biopsy showing a sensitivity of 100 % and a specificity of 100 % for CD, while MR showed a sensitivity of 100 % and a specificity of 80 %. CD showed colour signal after c.a. in all positive patients. MR showed local recurrence in 5 patients: 4 cases had been evidenced already at CD examination and confirmed by biopsy, while one was a false positive. Scintigraphy detected distant bone metastases in 2 patients, one of which also presented local recurrence.

Conclusions: From this early experience we can say that TRUS CD with c.a. is a valid tool as compared to MR in the evaluation of local tumour recurrence in patients with rising serum levels of PSA after radical prostatectomy. 

Contrast media in MR, CT and DSA angiography

MDCT in emergency radiology: Is a standardized chest and/or abdomen protocol sufficient for evaluation of thoracic and lumbar spine trauma?

Percutaneous image-guided radio-frequency thermal ablation of the lung

Bilateral inferior petrosal sinus sampling in Cushing's syndrome; final solution?

 16:20 Multi detector CT in morphological assessment of pulmonary veins in patients with focal atrial fibrillation J. Baqué, V. Huart, A. Azzarine, A. Hakime, B. Cauchemez, E. Mousseaux; Paris/FR Purpose: To analyse the appearances of the pulmonary veins (PV) in patients with focal atrial fibrillation (FAF) initiated by ectopic beats in the PV, compared to a control group. Material and methods: The appearances of the PV were assessed in 10 patients with FAF originating from the pulmonary veins (confirmed by electrophysiological study) and in 10 asymptomatic patients screened for coronary artery disease. The patients were paired by age and gender (age 50 ± 14 years). Each patient underwent ECG-gated contrast-enhanced multi-detector CT (MDCT) of the heart. The diameter of each of the four PV was calculated on 1 mm thick slices on axial and coronal oblique images and was measured at the ostium and at 5, 10 and 15 mm. Both the mean and the maximal diameters were calculated for each vein. Any anomalies or abnormalities of the heart and vessels were also described. Results: The maximal diameters of proximal portions of the right superior (18.6 ± 3 vs 16.2 ± 2 mm; p < 0.05) and the left inferior (18.1 ± 2 vs 15.4 ± 2 mm; p < 0.05) PV were significantly dilated in FAF patients compared to controls. The right inferior (19.9 ± 4 vs 17.4 ± 2 mm) and left superior veins (19.1 ± 3 vs 16.8 ± 2 mm) were not significantly different between the two groups. Conclusion: On MDCT images, the proximal portion of right superior and left inferior PV was significantly dilated in patients with FAF initiated by ectopic pulmonary beats. Accurate evaluation of the appearances of the PV gives valuable and complementary information before selective cannulation of each vein and percutaneous radiofrequency ablation procedure.

Evaluation of left atrium and pulmonary veins with MRI and MRA before and after circumferential radiofrequency ablation of pulmonary vein ostia for atrial fibrillation F. De Cobelli, F. Gugliotta, R. Mellone, M. Venturini, C. Pappone, A. Del Maschio; Milan/IT Purpose: The pulmonary veins (PVs) and surrounding ostial areas frequently house focal triggers or reentrant circuits critical to genesis of atrial fibrillation (AF). A new anatomic treatment aimed at isolating each PVs from the left atrium (LA) by circumferential radiofrequency (RF) lesions around their ostia has been developed. We evaluated the role of MRI and MRA in assessment of PVs and LA before and after RF ablation. Method and materials: 12 patients with resistant AF underwent MRI and MRA before and the day after RF ablation. 8 patients underwent MR after 3 months. MR images were obtained with black-blood ECG-triggered breath-hold multishotFSE sequences with double and triple inversion pulses (IR-MSFSE) (TR/TE 2 × RR/ 40, ETL = 32). MRAs were acquired with efgre 3D sequences (TR/TE/TI/FA 5.4/ 1.6/30/30°) with gadolinium injection and reconstructed with MIP and volume rendering. Results: At the pretreatment MRA, all four PVs were visualized in all patients. In four patients, the following anatomic variants were found: a common ostium of the left superior (LS) and inferior (LI) PVs; a single ostium of the LS and LIPVs; a posterior ostium of LIPV; 3 separate right PVs ostia. At the post-treatment MRI, high signal intensity was detected in the atrial wall around veins ostia due to oedema; in three patients a thin pericardial effusion was evident. At three months follow-up, the LA volume was significantly decreased in patients who had sinus rhythm restoration; with MRA, a left inferior PV stenosis was found. Conclusion: MR is useful in evaluation of patients with AF before and after RF ablation of PVs ostia.

Preoperative planning and intraoperative navigation with 3D-reconstructions and image guidance for robotically-assisted coronary artery bypass grafting T.C. Mamisch 1 , G. Zuend 2 , J. Gruenenfelder 2 , S.P. Hoerstrup 2 , F.A. Jolesz 3 , R.M.M. Seibel 1 , M. Turina 2 , R. Kikinis 3 ; 1 Mülheim a. d. Ruhr/DE, 2 Zürich/CH, 3 Boston, MA/US Objective: Closed chest coronary artery bypass grafting with the use of a telemanipulator is still performed in very few numbers worldwide. Preoperative planning and intraoperative navigation might be a helpful tool for increasing success rates of this procedure. The most promising accomplishments of image guidance in surgery are three-dimensional image-processing algorithms.Methods: Creation of 3D-visualization involves segmentation from acquired crosssectional images. In 15 patients cross-sectional images were obtained by CT and MR. Images were digitally transferred via an internal high-speed to the surgical planning laboratory. We primarily used high-end computer workstations Sparcand Ultrasparc (Sun Microsystems, Mountain View, CA), equipped with specially developed software, the 3D-Slicer for registration, filtering of regions of interest, semi-automated segmentation and 3D-visualization. Results: Preoperative planning with identification of target vessels and assessment of wall quality, as well as the possibility of image-guided surgery can be obtained by the 3D-visualization of the acquired data-sets. Together with the development of semi-automated segmentation, 3D rendering, integration of different image-modalities, intraoperative navigation and tracking can be provided for closed chest coronary artery bypass grafting. Conclusion: 3D-image guidance in surgical procedures for preoperative planning in a non-invasive fashion, as well as intraoperative navigation and tracking of robotically-assisted instruments are very helpful in detecting complex coronary lesions and calcified vessels which facilitate closed chest coronary artery bypass procedures. Patients with intramural vessels or severe calcification can be identified and the operative technique can be chosen adequately.

Subsecond spiral CT angiography for detection of small pulmonary thrombi: An experimental study K. Li, Y. Li, X. Du; Beijing/CN Purpose: To evaluate the diagnostic value of subsecond spiral CT pulmonary angiography (CTPA) to detect the small pulmonary thrombi (diameter 2.5 -3.5 mm) in canine models. Methods: CTPA was performed as a control study in 23 dogs. Pulmonary embolism was induced in the dogs by administation of autologous blood clots, after that CTPA and X-ray pulmonary angiography (XPA) were performed. The images were evaluated on a workstation by two radiologists and the image findings were compared with that of pathological dissections. Results: 22 pulmonary embolism models were successfully made in this study and 110 thrombi were found during pulmonary artery dissection. The thrombi were same number as that injected and the all thrombi located in segment and subsegment of pulmonary arteries, of which 107 thrombi were in field of the view (FOV). 90 thrombi were found with CTPA, whereas 82 thrombi with XPA. The sensitivity of the CTPA and XPA was 84.1 %, 76.6 %, respectively, and the positive predictive values were 93.8 % and 94.3 % respectively for the diagnosis of small pulmonary thrombi. Conclusion: Subsecond spiral CT angiography has a high diagnostic value for detection of small experimental pulmonary thrombi in dogs, and the result is superior to routine X-ray pulmonary angiography.

Diagnosis of acute pulmonary embolism with contrast-enhanced MR angiography: An experimental study K. Li, Y. Li, X. Du; Beijing/CN Purpose: To assess the diagnostic value of three-dimentional Gadolinium-DTPA contrast-enhanced Magnetic Resonance Angiography (3D ceMRA) in acute pulmonary embolism (PE). Methods: Seventeen dogs with acute pulmonary embolism induced by autologous blood clots were examined with 3D ceMRA using a fast spoiled gradient echo technique and with X-ray pulmonary angiography (XPA). The findings were compared with pathological dissection. Results: The 3D ceMRA signs of acute PE were: total vessel occlusion (30/41), pulmonary perfusion defect (23/41), partial filling defect (3/41) and central filling defect (1/41) in the pulmonary artery. The sensitivity of 3D ceMRA was 82.9 %, specificity 98.2 %, whereas the sensitivity and specificity of XPA was 75.6 %, 97.9 %, respectively. Conclusion: 3D ceMRA for the detection of acute PE demonstrated high sensitivity and specificity, but the technique needs to be confirmed by further clinical trials.

Cardiac imaging in infants with aortic isthmus stenosis: A comparison of contrast enhanced MRA and a high-resolution 3D double slab technique U. Kramer, F. Dammann, J. Breuer, L. Sieverding, C.D. Claussen; Tübingen/DE Purpose: Comparison of a three-dimensional gradient-echo (GE) sequence with interleaved double-slab excitation versus a contrast enhanced (CE) MRA for the assessment of the great thoracic vessels in children with congenital heart disease.Purpose: To assess applicability and diagnostic performance of a standardized multidetector row spiral CT (MDCT)-trauma imaging protocol for evaluation of the thoracic and lumbar spine in patients with blunt or spinal trauma. Material and methods: MDCT (Siemens Somatom VolumeZoom, Germany) was performed in 86 patients with a history of thoracoabdominal blunt or spinal trauma. All imaging was acquired using a collimation of 4 × 2.5 mm and a pitch of 6. Based on this raw data set, the spine was targeted reconstructed using the following parameters: slice width 3 mm; reconstruction interval 1.5 mm. Two readers separately assessed imaging quality of spinal structures for diagnostic purposes. In addition, both readers evaluated all patients for spinal fractures using five-point confidence scale (1 = fracture definitely absent, 2 = fracture probably absent, 3 = equivocal, 4 = fracture probably present, 5 = fracture definitely present). The number and level of fractures were categorized and correlated to thin section MDCT and/or surgical findings. Results: Visibility of spinal anatomic details for diagnostic purposes was rated as excellent by reader 1/2 in 927/862 levels and good in 119/184 levels of 1046 spinal levels using a standardized trauma protocol. Scoring on the confidence scale was 4.6 (± 0.8) in case of fractures and 1.1 (± 0.1) in case of no fractures, respectively. 20 of 21 spinal fractures (98 %) were correctly depicted by each reader. An anterior wedge fracture was missed by both readers. Conclusion: Evaluation of the thoracic and lumbar spine is possible with targeted image reconstruction based on standardized chest and/or abdomen MDCT data sets.

Whole body spiral CT in trauma patients -part II: Spinal injuries J. von Schlippenbach, T. Albrecht, K.-J. Wolf; Berlin/DE Purpose: To assess the accuracy of a standardized "whole body" spiral-CT protocol in the initial work-up of spinal injuries in trauma patients and to compare spiral-CT with conventional radiography. Methods: 46 trauma patients with potentially life threatening injuries underwent a spiral-CT of the skull base and neck (collimation/table speed/reconstruction interval: 3/5/3 mm), chest, abdomen and pelvis (5/7.5/5) immediately after resuscitation. Additional dedicated axial and sagittal high-resolution reconstructions of the entire spine were performed from the data sets. 40 patients also had conventional radiographs of the spine. CT findings were compared with conventional radiographs and final diagnoses at discharge or death. Results: Image quality was adequate in 39/46 CTs and 28/40 conventional spine series. In the remaining cases at least one area of the spine was not adequately imaged, in CT this was most often the thoracic spine. The final diagnoses included 8 cervical, 19 thoracic and 23 lumbar spine fractures; 7 fractures were instable. On CT, all but 1 thoracic and 3 lumbar spine fractures were diagnosed. None of the undetected fractures were instable. On conventional radiography, 1 cervical, 2 thoracic and 5 lumbar spine fractures were missed; again none of these were instable. Conclusion: CT was superior to conventional radiography and allowed fast and accurate diagnoses of the vast majority of spinal fractures, and missed no instable fractures. In our experience, time consuming conventional spine radiography is dispensable with this approach in most cases. Part I: B-0206 (SS 401)

Magnetic resonance imaging in traumatized intervertebral discs N.A. Ghanem, P. Uhrmeister, C.A. Müller, C. Altehoefer, M. Markmiller, M. Langer; Freiburg/DE Purpose: Evaluation of MRI in trauma patients with traumatized adjacent discs of fractured vertebrae before dorsoventral stabilization Material and methods: A prospective diagnostic study with 15 trauma patients (12 male, 3 female, mean age: 40 years, range: 17 -72) was performed on a 1.5 T Magnetom. The preoperative MRI using sagittal T1-W-SE and T2-W-TSE was compared to the gold standard being intraoperative discography which was carried out on both intervertebral dics adjacent to the fractured vertebrae within a time frame of 1.8 days (0 -3). Beside signal alterations of adjoining intervertebral disc, morphological changes such as disc herniation and annular tears were evaluated in 30 adjacent discs.

In 12/15 (80 %) patients and in 24/30 of the intervertebral adjacent discs, the results of both imaging findings were concordant. In 3 patients the adjoining discs were normal. Concerning the positive concordant imaging findings, MRI and discography both revealed traumatized adjacent dics in 6 cases. In 3 cases the upper adjacent disc was injured. Among these 15 traumatized discs, 9 intraosseous herniations into the fractured vertebrae and 6 anuluar tears were depicted. In 3 patients the findings were discordant. In one case MRI was false positive whereas discography as the gold standard demonstrated no lesion. In 2 cases MRI failed to detect a disc injury. Conclusion: MRI as a noninvasive method may detect traumatized adjacent intervertebral dics, but MRI is inferior compared with intraoperative discography although it does reveal additional preoperative information prior to dorsoventral stabilization.

MRI in traumatic lesions of cervical intervertebral disc B.W. Raab, U. Fischer, G. Kernbach-Wighton, K.S. Saternus, E. Grabbe; Göttingen/DE Purpose: To demonstrate typical findings on MRI in traumatic lesions of the intervertebral discs of the cervical spinal column. Materials and methods: MRI was evaluated in 2 groups of patients with traumatic changes of the cervical spine column including an injury of intervertebral discs. The study included 6 in-vivo examinations of patients and 8 postmortem examinations (neck specimen, C1 -T1 including the skull base) of human corpses after an acceleration trauma. Disc lesions were verified intraoperatively in all patients or macroscopically by sections of the specimen. Results: The variability of traumatic lesions of the intervertebral disks ranged from small detachments of the disc from the vertebral body to large ruptures of the entire disc. Extensive lesions of the disks were correlated with other injuries such as fractures or ligamental trauma. MRI depicted all lesions with extension to the entire disk due to morphologic changes in HR-sequences and/or signal alteration in Inversion Recovery and T2-WI sequences. Most of the circumscribed disc detachments seen macroscopically were not detectable with MR imaging. Conclusions: MRI allows a reliable diagnosis of significant lesions of the cervical intervertebral discs after trauma. Small detachments of the disc, however, will be missed.

Cervical spine injuries in elderly patients: Does trauma mechanism and age influence the distribution, type and stability? F. Lomoschitz 1, 2 , C.C. Blackmore 2 , K.F. Linnau 2 , S.K. Mirza 2 , F.A. Mann 2 ; 1 Vienna/AT, 2 Seattle, WA/US Purpose: The purpose of our study was to describe types and distribution of cervical spine injuries in consecutive elderly patients in regard to causative trauma mechanism and to patient age. Materials and methods: The distribution and type of 225 cervical spine injuries in 149 consecutive subjects older than 65 years over a 5-year interval were retrospectively assessed. For each subject, initial imaging studies were reviewed and injuries were classified. The trauma mechanism (falls from standing or seated height vs. mechanisms consistent with higher energy) and initial clinical and neurological status were recorded. Data were correlated according to patients' age (65 -75 a and > 75 a) and causative trauma mechanism. Results: The majority of patients (64 %) had injuries to the upper cervical spine. Multilevel injuries were frequent (40 %). The main causes for cervical spine injuries were motor vehicle crashes in "young elderly" (65 -75 a) (61 %) and falls from standing or seated height in "old elderly" (> 75 a) (40 %). Fracture patterns at risk for neurologic deterioration were common (> 50 %), even in absence of acute myelopathy or radiculopathy. Subjects older than 75 years, independent of causative mechanism, and patients who fell from standing height, independent of age, were more likely to have injuries of the upper cervical spine (p = 0.026 and p = 0.006, respectively). Conclusion: Injuries of the cervical spine in elderly patients tend to involve more than one level with consistent clinical instability. "Old elderly" patients (> 75 years) and subjects who fall from standing height are more prone to injuries of the upper cervical spine.

The fluid sign in acute vertebral compression fractures on MRI A. Baur, A. Stäbler, R.H. Dürr, M.F. Reiser; Munich/DE Purpose: To evaluate the occurrence of the linear fluid sign in acute osteoporotic and neoplastic vertebral compression fractures in magnetic resonance imaging (MRI). Methods and materials: The study group comprised 87 consecutive patients with a total of 107 acute vertebral compression fractures due to osteoporosis or neoplastic infiltration. The MRI protocol included unenhanced T1-weighted spin echo (SE) and short-tau inversion recovery sequences (STIR) on a 1.5 T system. Confirmation of diagnosis was made by surgery, follow-up MRI examinations, clinical follow-up or unequivocal imaging findings. Results: All fractures showed hypointensity on T1-weighted SE images and hyperintensity on STIR images, both in cases of osteoporosis (n = 65) and tumor (n = 41). In the fractured vertebral bodies the fluid sign appeared as a circumscribed lesion adjacent to the fractured end-plates, which exhibits signal intensities isointense to cerebrospinal fluid. The shape of the fluid sign was linear (n = 18), triangular (n = 5) or focal (n = 2). It was associated statistically significant with the osteoporotic cause of a fracture (n = 23, 35 %; chi square p < 0.001). The fluid sign occurred also in 2 cases of neoplastic compression fractures (5 %). At the site of the fluid sign histologic correlation demonstrated osteonecrosis, edema and fibrosis.

The linear fluid sign represents areas of osteonecrosis with accumulation of fluid in acute vertebral compression fractures. It is highly indicative of osteoporosis, but may occur rarely in metastatic fractures. To compare the efficacy and stability of two different, "second generation", self-expandable, metallic, covered stents in patients with lower third malignant oesophageal strictures. Material and methods: 53 patients with inoperable disease were randomised to receive either an Ultraflex (n = 31) or Flamingo (n = 22) covered oesophageal stent. All procedures were performed in the Interventional Radiology suite using fluoroscopic guidance. Dysphagia before and after stent placement was scored on a 5-point scale and the incidence of early and late complications was compared between the two groups.

The initial technical success rate was 100 % in both groups. Improvement in the dysphagia score was demonstrated in both groups at both short and long-term follow-up (mean reduction of 2 points). No significant difference was seen in the improvement of dysphagia between the two groups. The early (migration, severe reflux and perforation) and late (haematemesis, tumour ingrowth) complication rates were similar in both groups. Purpose: MND is characterized by bulbar symptoms resulting in reduced respiratory function, diaphragmatic paralysis and weakening of respiratory muscles. Nutrition is a prognostic factor for survival but surgical or percutaneous endoscopic gastrostomy is not well tolerated. RIG can be safely deployed with severe respiratory compromise. We describe our experience using a modified technique, which allows safe percutaneous puncture of a high subcostal stomach.

MND patients requiring nutritional support were selected for a RIG as a consequence of a sub-normal vital capacity. The standard procedure for RIG insertion was adhered to, with use of four T-fastners to secure a gastropexy. To take account of the high subcostal site of the stomach, the procedure was modified, performed with lateral screening, allowing for constant visualization of the puncture needles, to confidently puncture the anterior stomach wall.Results: This modified technique has been employed in 35 patients (20 male and 15 female, median age 62 years, range 31 -81 years) over a 36 month period. 28 standard radiological gastrostomy tubes were inserted, six were self retaining devices. The procedure was successful in 34 patients (97 %), 7 tubes were reinserted (20 %, all standard radiological tubes) over a variable period of time. The one failure was due to a high subcostal stomach in an obese patient. Conclusion: Diaphragmatic palsy presents a technical challenge for insertion of a RIG in the conventional manner. Using lateral screening a high success rate is achieved, and should be the method of choice for MND patients with respiratory compromise. 

Nineteen uncovered SEMS (diameters: 18 -22 mm, length: 60 -90 mm) were placed using fluoroscopic guidance in fifteen patients via a per-oral route using standard catheter and guidewire techniques. Nine patients had pyloric obstruction. Four had undergone gastric pull-up operations or partial oesophagogastrectomy for oesophageal or gastric carcinoma with pyloric dysfunction not responsive to balloon dilatation. Five patients had inoperable oesophageal or gastric carcinoma involving the pylorus. Six other patients had duodenal obstruction secondary to pancreatic carcinoma. In only three patients were two stents required to cover the obstruction. Four patients with malignant obstructive jaundice required concurrent stenting of the common bile duct. Results: All patients were able to consume an adequate diet after stent insertion. One stent migrated proximally into the fundus at day two in a patient with gastric carcinoma involving the pylorus. He presented five days later with perforation of the antrum at the tumour site which required emergency surgery. Of the remaining patients (seven have died) none have experienced recurrent symptoms of gastric outflow obstruction over a mean follow-up period of fourteen weeks. Conclusion: Non-endoscopic placement of SEMS under fluoroscopic guidance is a safe and effective treatment for outflow obstruction secondary to pyloric and duodenal stenosis. It is particularly effective in the palliation of malignant disease, but also has a role on the treatment of pyloric dysfunction after gastric pull-up surgery. Purpose: Reference methods in diagnosis of Crohn's disease are endoscopy and small bowel follow-through. Involvement and activity of proximal segments of the small bowel is difficult to evaluate. Our purpose was to develop a sensitive, easy to perform and minimal-invasive method for imaging small bowel without radiationexposure for mostly young patients. Methods: 30 patients (18 female/12 male) with suspected or established Crohn's disease were included. The patients were administered orally 1.5 l of a mannitolsolution (2.5 %) within 1 hour before imaging. A rectal mannitol-solution filling was also employed. Butylscopolamin was administrated i.v. HASTE and fs-HASTEsequences and T1-BH-sequences were acquired before and after (fs-T1-BH) i.v. Gd-DTPA administratio in transversal and coronal orientation. The images were analysed by three radiologist using a standardised protocol. In all cases a correlation with ultrasound-imaging was performed. Results: Alterations indicative of Crohn's disease were noted in 21 patients. In these cases we detected wall thickening with an average of 7.1 mm and with a mean length of 11.5 cm. The signal-intensity-increase after contrastmedium-application of thickened bowel wall was 58 %. Normal bowel-wall had an increase of signal-intensity after Gd-DTPA of 38 %. 11 relevant stenoses (37 %), 2 abscesses (6 %) and 9 fistulas were visualized (31 %). In ultrasound imaging we detected 9 cases with a stenosis (31 %), 5 fistulous tracts (17 %) and 1 case (3 %) with an abscess. Conclusion: Mannitol-MRI of small bowel in patients with suspected or established regional enteritis is a promising method for the diagnosic work-up and renders results superior to ultrasound imaging.

Inflammatory bowel disease in children: Helical CT with water enema administration G. Tognini 1 , F. Ferrozzi 1, 2 , G. Zuccoli 3 , A. Patti 1 , P. Bini 1 , P. Pavone 1 ; 1 Parma/IT, 2 Cremona/IT, 3 Reggio Emilia/IT Purpose: The diagnosis of inflammatory bowel disease (IBD) in children, due to the non specificity of the clinical picture, is often difficult and delayed. The aim of our study was to assess the role of helical CT after water enema administration in the diagnosis and staging of IBD.Materials and methods: 33 consecutive patients with IBD (19 FF, 14 MM) age range: 4 -15 years underwent spiral CT examination of the abdomen. The imaging protocol consisted of 5 mm collimation, pitch: 1.5, injection of iodinated contrast medium with high flow rates: 3 -3.5 ml/s. The lumen of the colon was filled with water (300 -1000 ml); oral administration of water was also performed in order to obtain gastric and duodenal distension. We evaluated: wall thickening, structure and enhancement of the involved segments, polypoid components, mesenteric fat involvement, adenopathies, extraparietal flogistic complications. 33/33 underwent endoscopic and bioptic confirmations: 23/33 were Crohn's disease, 8 Ulcerative Colitis, 2 showed non specific features. Results: Wall thickening (26/33), increased contrast enhancement (23/33), endoluminal pseudopolyps (7/33), fibrofatty proliferation (9/33), edematous infiltration (6/33), mesenteric adenopathies (19/33), abscesses and flogistic complications (10/33). In 21/33 patients CT allowed for the correct differentiation between Crohn's disease and Ulcerative Colitis.

The morpho-structural evaluation which can be obtained by means of helical CT and water enema administration allow for an accurate study of the intra and extraluminal manifestations of the IBD. CT was found useful in the diagnosis but mainly in the follow-up of patients with IBD giving important differentiating criteria.

CT signs of active Crohn's disease and comparison with immunscintigraphy G. Tóth, G. Szentmártoni, T. Györke, E.K. Makó; Budapest/HU Purpose: This retrospective study compares the diagnostic yields of CT and immunscintigraphy in the assesment of activity in Crohn's disease. We evaluated which CT signs are the best predictive signs of the activity in Crohn's disease.

We examined 126 patients with clinically suspected Crohn's disease. We studied patients first with bifasic dinamic helical CT and 4 -7 days later with immunscintigraphy. CT studies were performed in a standard fashion: collimation 8 mm, feed 12 mm, reconstruction 5 mm. I.v. contrast administration flow 3.5 ml/s, volume 1.5 ml/kg, delay 40 s in a caudo-cranial direction. We were searching for bowel wall thickening, increased contrast enhancement of the bowel wall, mesenterial signs, fistulas and abscesses, and enlarged lymph nodes. CT results were correlated with immunscintigraphy. Results: In cases where the affected loops showed thickened wall (4 -10 mm) increased contrast enhancement and sourranded by a fibrofatty proliferation, with increased vascularisation the immunscintigraphy was positive in 91 % of patients. When we saw fistulas, abscesses and a thickened bowel wall (10 mm or more), with increased vascularisation in mesentery with prominent enlarged lymph nodes the immunscintigraphy was always positive. Conclusion: Contrast enhanced spiral CT study is a goog tool in the assesment of the activity in Crohn's disease. Results: In 10 cases the embolization failed: no bronchial artery catheterized in the bleeding side (n = 6), pulmonary artery bleeding due to central excavated lung tumors (n = 2), right intercosto-bronchial trunk with a doubt about a spinal radicular artery (n = 1), unstable catheter position (n = 1) and technical problem (n = 1). Among the 61 patients with at least one bronchial artery selectively catheterized (included 4 non-embolized), bronchial hypervascularisation was visualized in 58 associated with nonbronchial systemic hypervascularisation in 4 cases. The immediate control of bleeding was obtained in 72 %. Long-term result was 61.4 %.Complications were: acute but transient renal failure (n = 1), cerebral ischemia (n = 2) with one definitive deficit. Conclusion: Tumours are responsible of 12.3 % of massive hemoptysis and embolization is efficient. The bleeding is rarely due to nonbronchial arteries. Stroke incidence is increased in comparison with other hemoptysis probably because of elderly patients.

Intraoperative transthoracic ultrasonography for the localization of hidden pulmonary nodules during thoracoscopy F. Coppola, M. Piolanti, F. Gruppioni, S. Papa, M.P. Di Simone, S. Mattioli, G. Gavelli; Bologna/IT Purpose: The purpose of this study was the evaluation of intraoperative sonography in the detection of hidden pulmonary nodules during thoracoscopic resection.

To perform intrathoracic ultrasonography an endosonographic linear probe with high-frequency transducer (7.5 -10 MHz) was employed. 40 patients, entered the study; 52 pulmonary nodules were preoperatively detected, 50 by spiral CT and 2 by PET. 10 sonographic examinations were performed during thoracotomic surgery and 30 examinations during thoracoscopy. The times needed to reach lung collapse and to localize the targets were recorded.

Complete lung collapse is essential to perform intraoperative sonography and can be accomplished by single controlateral lung intubation and ventilation for 45 minutes at least. The sonographic examination is quick, unless the patient is affected by obstructive disease (such as centrilobular emphysema): retained air in the parenchyma reduces the explorability. All but one preoperatively detected lesions and two further unknown lesions were localized by intraoperative sonography. There were no complications related to the procedure. Conclusions: Intraoperative sonography proved itself to be a reliable and satisfactory localization technique of lung nodules during thoracoscopy. In comparison with the other localization techniques it shows several advantages, such as the capability of revealing preoperative occult lesions and determining the surgical borders. The aim of this study was to assess the accuracy of wire-versus carbon-localization in SLOBB.

A total of 1115 SLOBBs were performed from 01/94 until to 12/97 in 1068 female patients (age range, 22 -90 years) on a prone stereotactic unit (Mammotest, Fisher Imaging, Denver, CO). In 1007 cases successful SLOBB was verified either by a malignant histopathological diagnosis or by immediate mammographic evaluation after surgery. In 582 (58 %) of these cases the lesion was localised with a wire, in 410 cases (41 %) carbon was used. Both methods were used to localise the remaining 15 cases (1.4 %). A lesion was considered as missed when it could be still seen on mammography performed after surgery. Results: Ten out of 1007 cases (1 %) were missed at SLOBB. Of these, 5 lesions had been localised by wire (5/582; miss-rate 0.9 %) and 5 lesions with carbon (5/410; miss-rate 1.2 %). There were no significant differences in miss-rates between wire-and carbon-localisation (p > 0.05). Conclusion: Both wire-and carbon-localisation are reliable and accurate in the localisation of non-palpable breast lesions undergoing SLOBB. Considering the fact that wire-localisation is far more expensive than carbon-localisation the routine use of carbon should be considered. Histological results of SCNB and surgical biopsy were compared and scored for each needle size on a three point scale (1 = no agreement, 2 = partial agreement, 3 = complete agreement) to determine the optimal needle size for such lesions.

Results: There were 69 masses, 13 asymmetric densities, and 53 calcifications. A diagnosis of malignancy was found at surgery in 1/135 (0.7 %) [1 ductal carcinoma in situ]. The remaining 134 lesions revealed a benign histology. The 11 G needle (score = 3) scored better than both 14 G needles (score = 2.9). Conclusion: Based on the relative low rate of carcinomas SCNB should not be performed routinely in probably benign lesions (BI-RADS 3). Mammographical short time follow-up seems to be more useful to confirm the benign nature of such lesions. If SCNB will be performed 11 G needles seem to be advantageous.

Does the preoperative core-cut biopsy influence the appearance of local recurrence of breast cancer? U.G. Aichinger, J. Ammon, R.W.S. Schulz-Wendtland, I. Kuchar, W.A. Bautz; Erlangen/DE Objective: Retrospective study to evaluate if preoperative core-cut biopsy influences the incidence of local recurrence of breast cancer and metastasis -a phenomenon described after puncture biopsies of the pancreas and the prostate. Material and methods: Core-cut biopsy was performed on 150 patients with suspected breast cancer before undergoing surgery in the period 1992 -1993. The clinical outcome of 123 patients was analysed retrospectively over a period of seven years. 66 had undergone breast conservation therapy, 57 had had a mastectomy. Adjuvant therapy was also included in the evaluation. Results: Local recurrence after breast conserving therapy (BCT) was seen in 11 of 66 patients (17 %), and in 7 of 57 (12 %) after mastectomy (MRM). The rate of local relapse after radiotherapy (RT) was 8 of 43 (19 %) (BCT) and 4 of 25 (16 %) (MRM) respectively. In the group without RT 3 of 23 (13 %) (BCT) and 3 of 22 (9 %) (MRM) relapsed respectively. In two cases the biopsy site was not removed. One of those, not having had a RT, had a local recurrence. Conclusion: According to the literature, breast cancer local recurrence rate is 1 -2 % per year. In our group recurrence rate reached 1.9 % totally per year and 2.1 % after BCT being in agreement with international studies. No higher rate of local recurrence or metastasis was seen after core-cut biopsy. Nevertheless the biopsy site should be removed in any case.

Multicenter evaluation of stereotactic vacuum biopsies of mammographically indeterminate or suspicious lesions 

The consensus was achieved based on the existing literature and on the experience of the participants using a consensus process as suggested by Sackett. Results: Complete standard imaging work-up is the prerequisite before a decision for percutaneous breast biopsy is made. The following lesions are considered well-suited for vacuum biopsy: microcalcifications, small non-palpable masses with or without microcalcifications. The following indications may not be (as well) suited: architectural distortion (suspected radial scar) or lesions close to the skin. Needle access (angulation of compression, stroke margin) must be exactly documented. Acquisition of > 20 cores (11 G) shall be routinely attempted (goals: radiologic removal of lesions < 10 mm to increase diagnostic reliability, decrease of underestimates). Documentation of scout, pre-, post-fire and post-biopsy images and another orthogonal view after biopsy are required. Final diagnosis must consider imaging-histopathologic correlation, and for certain histopathologic entities the result on an interdisciplinary conference. Standard documentation of the examination and of 6 months-follow-up is required. The closed architecture of 1.5 T whole body magnets makes it difficult to perform MR-guided biopsies at high-field strength. The aim of this study was to investigate the feasibility of MR-guided breast biopsy using a remote-controlled robotic system which assists the localisation of the target and runs inside the magnet. Materials and methods: 13 patients with suspicious lesions (diameter 19 ± 11 mm) in MR-mammography were biopsied using the robotic system. After localisation of the lesion the robotic system positioned the troacar at the correct position. The troacar was inserted into the breast in front of the lesion. The specimen was taken in coaxial technique using a 13 G core needle biopsy gun. In case of malignant histology the patient underwent open surgery afterwards.

The biopsy procedure inside the magnet was completely performed without interruption in all cases. Operation proved the histological finding of breast cancer in 5 cases. One patient was diagnosed as atypical ductal hyperplasia by biopsy and turned out to have an invasive ductal carcinoma. 8 patients showed benign lesions and will be followed up.

The current study demonstrated the feasibility of breast biopsies inside the magnet of a whole body scanner using a robotic system. One false negative case was due to tissue shift during the insertion of the troacar into the breast. First experiences with two patients show the procedure to be feasible. In future imaging, biopsy and therapy of breast lesions should be possible in one single patient session using this robotic system. To assess the feasibility of assessment of stent-graft patency by contrast-enhanced magnetic resonance angiography (CE-MRA). Materials and methods: 9 bifurcated abdominal aortic aneurysm (AAA) stentgrafts made of nitinol, elgiloy or stainless steel were investigated regarding their appearance on MR imaging. The stent-grafts were positioned in a phantom filled with aqueous gadolinium solution. Coronal and axial three-dimensional gradient echo sequences were performed (TR 8.1 ms/TE 1.3 ms, FA 40°). Relative signal intensity reduction within the stent-grafts and the difference of the real stent-graft lumen as compared to the lumen measured on the MR images were calculated. Results: The graft lumen was depicted in 6 prosthesis. The lumen of stainless steel stent-grafts showed a complete signal void. Relative narrowing of the inner diameter on the MR images was less in the proximal part of the stent-grafts than in their legs. With a gadolinium dilution of 1:20 the artifical narrowing of the proximal lumen ranged from 7.1 % to 59.5 %, whereas in the stent-graft legs the visible lumen was diminished between 2.4 % to 71.8 %. Only three stent-grafts presented with a lumen reduction on the MR images of less than 33 % along the whole prothesis length. Conclusion: To differentiate between artifacts and stenoses, a knowledge of the degree of signal intensity reduction and artificial lumen narrowing within AAA stentgrafts is essential. Stent-graft composition and the design of the stent-graft influence the artifact behaviour and lumen visibility as displayed on CE-MRA. Only a minority of the investigated stent-grafts is suitable for imaging by CE-MRA. 

28 patients with AAA undergoing endovascular stent grafting were included in the study. Helical CT scanning was performed within one week following stent graft implantation with a scanning protocol of collimation 5 mm, pitch 1.0, and a 2 mm reconstruction interval. Contrast enhancement was given to all patients with a total volume of 100 ml, flow rate of 2 ml/s and scan delay of 30 seconds. All patients received a Zenith TM /AAA endovascular graft with uncovered supra renal struts of 2.5 cm length placed above the level of the renal arteries. VIE images were created for each patient with Analyze AVW 1.0. The follow-up period ranged from 1 to 12 months (mean 6.9 ± 4.7 months). Results: 4 of 28 coeliac arteries, 23 of 28 superior mesenteric arteries, 28 of 28 right renal arteries and 28 of 29 left renal arteries were covered by the stent struts to different extents. VIE demonstrated the number of metal wires crossing the arterial ostia and the configurations of these stent struts relative to the arterial ostia such as partial or complete encroachment. Follow up CT scanning showed that all of these aortic arterial branches were patent. Conclusion: VIE is a novel imaging technique to visualise the 3D intraluminal relationship of the aortic stent struts to the arterial ostia in patients with AAA following suprarenal stent grafting.

The current system consists of a see-through, headmounted display, a tracking system, computer system and tracked surgical instruments. Interaction with the system is provided through voice and speech. The system produces a computer-generated image overlaid onto the real world, using virtual "hanging windows" for information display eg. CT/MR scans, real-time fluoroscopy, vital signs, live video (endoscopy), step-by-step instructions, dictation/ communication screens, 3D models of anatomy and other information to assist the radiologist during a procedure. In addition, different pre-and post-stent 3D models of the aortic aneurysm from recent procedures can be brought up within the environment for comparison or as a reference. The user can also bring up patient-specific 3D reconstructions. Results: This system provides assistance during AAA stent placement. All previous imaging series (CT-, MR-, and conventional angiography), stent planning data, 3D models of the aneurysm and monitoring of vital signs are shown on one screen (head mounted display) in "hanging windows" on request. The software provides a real-time surgical simulation system with integrated monitoring and information retrieval and a voice input/output subsystem.

The system provides all the important information on one screen (head mounted display) and can be used to assist various tasks such as stent implantation procedures in the interventional radiological theater.

A.M. Grozaj, T. Pfammatter, M. Lachat, U. Wolfensberger, P.R. Hilfiker; Zürich/CH Purpose: To report midterm results of endovascular stent-grafting in patients with ruptured abdominal aortic aneurysm (rAAA). Materials & methods: 17 patients (3 women, 14 men; mean age 73 years) with rAAA were treated with bifurcated endoprostheses. Preinterventional assessement was performed with CT (n = 17), ultrasound (n = 5) and angiography (n = 1). All patients were a high operative risk. The procedure was performed under local (n = 12) or general anesthesia (n = 5). Follow-up CTA was performed after 1 day, 6 weeks, 3, 6, 12 months and annually. Results: Immediate technical success was achieved in 16 patients (94 %). One needed conversion to open surgery due to progressive hemodynamic instability. Mean intervention time was 149 min (± 114), mean ICU stay 2.6 days (± 0.85) and mean hospitalization 10 days (± 5). The 30 day mortality was 0 %. Within 30 days one patient was treated with hemofiltration and three had reinterventions: replacement with homograft of an infected iliac-femoral extension SG; SG extension for retroperitoneal bleeding; embolization of the inferior mesenteric artery. In the mean follow-up period of 8 months two endovascular reinterventions were performed: SG implantation for graft disconnection; thrombolysis of a stent leg. One patient needed elective late conversion to open surgery after 14 months due to SG migration. Aneurysmal diameter decreased in 58.8 %, increased in 5.8 % and remained unchanged in 35.3 % of patients. Conclusion: Endovascular treatment of rAAA with SG implantation is feasible and safe. This technique seems to be a valuable alternative to emergency open surgery with its high mortality.

Emergency treatment of thoracic aorta diseases by endovascular stentgraft L. Lovato, R. Fattori, G. Napoli, C. Grazia, F. Settepani, G. Gavelli; Bologna/IT Purpose: Surgery of the thoracic aorta is characterized by high mortality and morbidity, especially if performed in an emergency. We report our experience in emergency endovascular treatment of the thoracic aorta. Material and methods: From 1997, 58 patients underwent endovascular treatment of the thoracic aorta. Seven (2 type B acute aortic dissections, 2 traumatic aortic ruptures, 1 penetrating aortic ulcer and 2 surgical prosthesis dehiscences) presented with clinical and/or imaging findings of impending aortic rupture and were treated as an emergency. Before the procedure, spiral CT was used to define the lesion's anatomy. All procedures were performed in the operating theatre and monitored by a radiographic C-arm system and by echocardiography. Results: Stent-graft implant was successful in all patients. No death nor complication occured during the procedure. In 4 cases, immediately after stent-graft implant, surgical drainage of a hemothorax was performed. The average time of Intensive Care Unit stay was 12 ± 8 hours, while hospital stay was 7 ± 5 days. In 6 patients a spiral CT follow-up showed complete aneurysmal exclusion; 1 case showed persisting leakage over 3 months and was converted to surgery. Conclusion: Endovascular stent treatment of thoracic aorta diseases could be a very effective option and an alternative to surgery, especially in an emergency.

Endovascular treatment of thoracic aortic aneurysms and dissections with the use of customized stent-grafts Q. Sénéchal, F. Koskas, P. Cluzel, J.-D. Singland, E. Kieffer, P.A. Grenier; Paris/FR Purpose: To describe our experience with the use of a custom stent-grafts for the treatment of thoracic aortic aneurysms and dissection. Patients and methods: From January 1996 to September 2001, 28 aneurysms and 11 dissections were selected to be treated using custom stent-grafts of different designs. Custom stent-grafts were constructed with Gianturco Z stents sutured together and covered with polyester (Twillweave, Vascutek, Innachinnan, Scotland). Endovascular treatment of aortic arch aneurysms combined with extraanatomic bypasses were used in 7 cases. Elephant trunk in one step was used in three cases. Endovascular bypasses were used as the second step of the elephant trunk technique in two cases. Results: Four patients (10 %) were converted to standard open repair. No leakage of the thoracic aneurysms was observed at follow-up. Sealing of the primary tear in thoracic aortic dissections was successful in all cases. Three patients died of myocardial infarction in the perioperative period. Conclusion: Custom stent-grafts in the endovascular treatment of thoracic aortic pathology achieve good results. Endovascular treatment of aortic arch aneurysms combined with extra-anatomic bypasses provides a less invasive method of treatment of these complex lesions. Longer follow-up is needed for the device.

Percutaneous treatment of thoracic aortic dissections and thoracic aortic aneurysms using commercially available stent-grafts F. Fanelli, F. Salvatori, M. Rossi, G. Marcelli, F. Venditti, P. Rossi; Rome/IT Purpose: To report our preliminary experience in the treatment of thoracic aortic dissections and thoracic aortic aneurysms (TAA) using endovascular stent-grafts. Methods and materials: From November 2000, 16 patients were treated using a commercially available stent-graft: Thoracic Excluder (W.L. Gore). Twelve cases were performed in the angio-suite and 4 in the OR under general or epidural anesthesia. TAA: 6 patients. In two patients (12.5 %), with a short proximal neck, the origin of the left subclavian artery was covered by the stent-graft. Dissection: 10 patients with type B dissection, 7 acute and 3 chronic. Two cases were complicated by renal ischemia treated by renal stenting. The primary entry tear was located in 7 patients less than 2 cm from the origin of the left subclavian artery which was covered by the stent-graft. Results: After a follow-up ranging from 2 to 10 months, all patients are in a good condition with no signs of paraplegia. TAA: Technical success with complete exclusion of the aneurysm was evident in all cases. Dissection: 1 technical complication (6.25 %) was observed during stent-graft deployment of antegrade extension of the dissection into the ascending aorta which was surgically managed. In all cases progressive thrombosis of the false lumen developed. In 3 cases (18.7 %) an endoleak was detected: one, originating from the subclavian artery was treated by coil embolization; one sealed spontaneously after 6 months; the last one is under control. Conclusion: Endovascular techniques represent a new frontier in the treatment of thoracic dissection and TAA, but further evaluations are mandatory to clearly understand its efficacy. 

The probability of location of breast mass margin in digitised mammograms F. Sendra-Portero, E. Ristori-Bogajo, E. Nava-Baro, M. Martínez-Morillo; Málaga/ES Purpose: Most of the computational problems in segmentation are originated by tortuous contours which are difficult to be perceives by either a computer segmentation program or a human observer. A method based on successive interactive segmentations of breast masses in digitised mammograms to plot the probability of location of the mass contour is introduced. Materials and methods: 81 digitised mammograms including 94 masses with different type of margins were studied. The border of each mass was outlined with a digitising tablet, encompassing all densities considered as part of the mass, including spicules and tracts. Two observers repeated the same procedure three times. The segmentations of the same image were split off between them 48 hours at least. A labelled image was obtained from the six binary images of each case, giving seven possible values per pixel, from 0 to 6. Thus, the lines that delimit each value are considered "isoprobability lines", encompassing a probability equal to 1.00; 0.83; 0.67; 0.50; 0.33 and 0.17 to find the mass margin. Results: When the margin is well defined the isoprobability lines are closed one each other, with a sharp transition from 1 to 0. In exchange, when the margin is illdefined obscured or speculated, the isoprobability lines spread out. In those combined type margins the uncertainly zones are clearly distinguished from well defined zones. Conclusion: Images obtained by this method can be used as a reference pattern to evaluate automatic or semi-automatic computer-aided segmentation systems of breast masses. Results: MFE-VQ employing 16, 25, and 36 CVs identified clusters that could be attributed to known suspicious regions in each case. The lesions could clearly be differentiated from surrounding tissue. In 7 patients, single clusters could be related to motion artifacts based on signal dynamics and cluster localization. In addition, a self-organized subclassification within the lesions could be achieved in up to 4 clusters w.r.t. fine-grained local differences in MRI signal amplitude and dynamics.

Conclusions: MFE-VQ by deterministic annealing is a useful strategy for the analysis of contrast-enhanced MRI mammography time-series without time-consuming interactive contour tracing of regions of interest by human observers, thus enabling segmentation of suspicious lesions. In addition, a subclassification w.r.t. local differences of perfusion patterns inside suspicious regions can be achieved. In three dimensional medical imaging like CT or MRI, knowledge based approaches foster the robustness and reliability of segmentation processes. A robust fully automatic segmentation is a desirable task to acquire objective and accurate results. A 3D surface model for the segmentation of parenchymal organs in CT-and MRI-datasets has been developed.

The necessary training set for the surface model is computed from semiautomatically generated triangulated surface meshes of the objects. The generated surface model is capable of learning the characteristic shape and gravalue information stored in the training set. The optimization is performed by iteratively moving the surface points of the model towards fitting image structures under the constraints of its grayvalue and shape information. Two different 3D surface models have been developed: A milt model consisting of 10 training objects, and a kidney model generated from 7 left kidneys. The two models have been tested on 6 unknown milt-and also 6 unknown kidney-datasets.

The total cover between the model and the organs varied between 70 % and 80 %, which is a respectable result in the face of the small training set. Further the computing time of the model optimization lies in contrast to other approaches within a few minutes on a standard PC.

To overcome the problems segmenting organic structures in 3Ddatasets using arbitrary methods, a knowledge-based 3D surface model has been successfully introduced. The segmentation accuracy of the model can be actually improved by using a larger training set in future.

Use of the DICOM file format for quantitative analysis of brain images M. Larobina 1 , A. Prinster 1 , M. Quarantelli 1 , A. Ciarmiello 1 , J.P. Hornak 2 , B. Alfano 1 ; 1 Naples/IT, 2 Rochester, NY/US Purpose: To review our experience using DICOM format files to perform quantitative analysis of MR brain images.

We use an algorithm that performs segmentation and volumetric measurement of normal and abnormal brain tissue. The method is based on calculations of relaxation rates of brain tissues from spin-echo images. The algorithm reads DICOM format images, and requires repetition time, magnetic field strength, slice location, FOV, and matrix size information from the DICOM file header. We have applied the algorithm to studies performed on GE Signa 1.0 T, GE Signa 1.5 T, Philips Gyroscan NT 1.5 T, Picker Eclipse 1.5 T, and Siemens Magnetom 1.5 T. Results: Images generated by these scanners reveal that the manufacturers interpret DICOM standard differently. In some cases, the file header reports fields with structure or content not always in accordance with the DICOM standards. Deviations in the DICOM header usually do not render the file unreadable, but do hinder the use of the header information and the DICOM format.

The DICOM format has the potential to become the format of choice for all the post-processing of MR images. Unfortunately, the standard is too complex to easily discover if violations of the standard are present. We emphasize the need to have a way to know if a set of DICOM files is totally compliant with the DICOM standard. The use of images that are labeled DICOM-compliant except for information reported in one field represents a non-negligible problem.

Multi-slice CT for visualization of pulmonary embolism using perfusion weighted color maps J. Purpose: To evaluate the feasibility of a new technique for perfusion weighted colour display of lung parenchyma density derived from multi-slice CT (MSCT) data sets for visualization of pulmonary embolism (PE). Methods and materials: Imaging of patients with suspected PE was performed on a MSCT (Somatom Volume Zoom; Siemens, Forchheim, Germany) after intravenous application of 120 cm 3 of contrast-medium. Based on thin collimation axial slices (slice thickness 1.25 mm, reconstruction increment 0.8 mm), a new image processing technique was deployed. Automated 3D-segmentation of the lungs was performed followed by threshold based extraction of major airways and vascular structures. The filtered volume data were color encoded and finally overlayed onto the original CT-images. This color encoded display was presented in axial, coronal and sagittal plane orientation. In ten patients with excluded PE as well as in ten patients with proven PE the new technique was performed. Results: In ten patients, considered negative regarding PE on MSCT, lung densitometry showed a homogeneous distribution of color encoded densities without circumscribed decreased or increased areas. In the patient group with proven PE, low density values on perfusion weighted colour maps were found distally to the occluded pulmonary arteries. Conclusion: Our initial experience indicates that lung densitometry with an optimized colour encoded display of the density distribution within the lung parenchyma may provide additional information in patients with suspected or proven PE. The evaluation of first-pass myocardial perfusion imaging in patients with coronary artery disease (CAD) represents a complex issue in the field of cardiac MRI. Commercially available software allows placement of regions of interests (ROIs) into the myocardium and calculation of mean signal-intensity over time. However, small perfusion defects may be missed using this method due to the large area of ROIs. Purpose of our study was to develop a pixel-based evaluation software for MR myocardial perfusion images.

We chose a Matlab based approach (Matlab Version 6.1). Our software enables the user to register the images using a least-square-algorithm. Images can be filtered with a median filter. Maximum upslope and area-under-the-curve for the signal intensity are calculated for each pixel and shown graphically. Myocardial perfusion measurements were performed in 10 patients with angiographically proven CAD using a SR-TrueFISP-2D-sequence (TR 2.4 ms/TE 1.2 ms). MR perfusion data were analysed with our software and compared to SPECT and angiography. Results: Data of 8 patients could be adequately analysed with the software developed. Parameters upslope and area-under-the-curve in regions found to be malperfused by MRI correlated well with angiographically detected coronary artery stenosis and hypoperfused areas detected by SPECT. Main limitation of the method was incorrect registration of images, caused by cardiac arrhythmia and patient motion. Conclusions: Semi-automated pixel-based analysis of perfusion measurement is possible and the promising results of this analysis correlate with angiographic and SPECT findings. Artefact free data acquisition and image registration are important and the limiting factor for pixel-based analysis. Purpose: To evaluate clinical feasibility of spatial domain filtering as an alternative to additional image reconstruction using different kernels in chest CT. Methods and materials: 40 adult patients with clinical suspicion of pulmonary embolism were examined utilizing multi-slice CT (Somatom Volume Zoom, Siemens, Germany). Two sets of images were reconstructed using lung (B50) and soft tissue (B30) kernels, respectively. Additionaly, B50 images were filtered in the spatial domain, producing images largely equivalent to B30 images. Diagnostic images were compared to the initially reconstructed B30 images. Subjective image quality was rated using a three point scale (1 = excellent, 2 = fair, 3 = nondiagnostic). Results: Filtered images provided 10 central emboli, 19 segemental thrombi and 20 emboli on the subsegmental level in the 20 patients with proven pulmonary embolism. Latter was excluded in the other 20 subjects. Subjective gradings of image quality, based on soft tissue settings were comparable for all data sets. Therefore, these filtered images provided exactly the same diagnostic accuracy for central, segmental and subsegmental pulmonary embolism compared to conventional soft tissue reconstructions.

The new method presented has proven to be clinically feasible and should therefore be implemented in the clinical enviroment. Online modifications of image sharpness and pixel noise in real time will potentially replace the need for multiple reconstructions using different kernels.

Volume rendering of portal liver vessels: Correlation between 3D recostruction parameters and image quality G. Luccichenti, F. Cademartiri, P. Pavone; Parma/IT Purpose: Aim of this work is to determine the influence of the scan, density values and opacity curves in three-dimensional reconstruction with volume rendering technique of portal liver vessels. Methods and material: 22 patients with previous abdominal CT or US underwent spiral CT during the arterial and the portal phase with the following parameters: collimation 3 mm, feed 4.5 mm, pitch 1.5, increment 1 mm. Images were sent to a workstation running on a NT platform equipped with Vitrea 2.0 (Vital Images, USA) allowing 3D reconstructions in order to generate volume rendering of the liver vascular supply. Density values of portal vessel (P) and liver (L) parenchyma were measured and correlated with 3D image quality and the parameters of three different opacity curves (OC) utilized to obtained them. Results: Better visualisation of arterial supply was obtained with non linear opacity curves. It was possible to clearly demostrate them up to the fifth generation. Significative correlations were observed between curve parameters (C), liver and portal vessels densities ratios (C vs P and C vs L r = 0.67 and r = 0.82 respectively for linear OC and r = 0.82 and r = 0.84 for non linear OC). Correlation between C and 3D image quality was r = 0.22 and r = 0.52 for linear and non linear OC respectively. P/L density ratio poorly correlate with 3D image quality r = 0.34. Wilcoxon test was significant between the three opacity curves. Conclusion: 3D image quality mainly depends on scan quality. Density ratios are important to set the opacity curve parameters.

Direct volume rendering based interactive virtual colonoscopy D. Jocha, J. Koloszár; Budapest/HU Purpose: Virtual colonoscopy is a non-invasive computerized medical examination method for examining the interior of the human colon, aiding the detection of polyps. Nowadays systems for this purpose are slow and/or require special hardware and have many other problems making their usage difficult and limited. Our purpose was to develop a system without these disadvantages. Materials and methods: In our study we have examined the most popular approaches to the problems of high-speed rendering and navigation within the colon, and devised our own algorithms. Our intent was to make them fast and reliable enough to be implementable on a consumer-end PC system, instead of state of the art high-end workstations, and to minimize off-line calculations. Results: We present our idea of a real-time direct volume rendering based visualization technique combined with an on-line computer aided interactive navigation method for the examination of volume data constructed from CT scans. These algorithms have been implemented in our colon visualization program called ColVis. The results are promising, the current implementation is close to the real-time requirements (∼ 2 seconds/frame). Conclusion: According to our results virtual colonoscopy can be an everyday diagnostic method in the near future. Results: ACL and PCL avulsion fractures occurred with equal frequency. ACL avulsion fractures occurred more commonly in adults than previously believed. About one half of ACL avulsion fractures are partial, involving the anteromedial bundle only, one quarter are comminuted and one-half are extended. PCL avulsion fractures occur in an older age group than ACL avulsion fractures. The majority are complete, half are comminuted (between the individual PCL bundles) and half are extended. When compared to anteroposterior and lateral radiographs, CT is helpful at delineating the fracture margins (for Type I and II fractures) and at delineating comminution and extent in PCL injuries. Three-dimensional CT allows good perception of the fracture type and tibial bony defect as a prelude to operative reduction.

This study leads to a better understanding regarding the relative freqeuncy and variablity of cruciate avulsion fractures and indicates those areas where CT is particularly helpful.

Dual-detector spiral CT arthrography of the knee: Assessment of anterior cruciate ligament and associated meniscal tears B. vande Berg, F.E. Lecouvet, P. Poilvache, J.E. Dubuc, B. Maldague, J. Malghem; Brussels/BE Purpose: To assess dual-detector spiral computed tomography (CT) arthrography of the knee in the evaluation of anterior cruciate ligament (ACL) and associated meniscal tears.

The ACL and meniscal abnormalities in 125 consecutive patients who underwent dual-detector spiral CT arthrography of the knee were evaluated based on both initial interpretations and retrospective review of CT images and were compared with arthroscopic findings. The sensitivity and specificity of CT arthrography for the detection of ACL tears and of meniscal lesions in ACLabnormal knees were determined. Results: The sensitivities and specificities for the detection of ACL tears were 90 % and 96 %, respectively, at initial interpretation and 95 % and 99 %, respectively, at retrospective interpretation. The sensitivities and specificities for the detection of meniscal tears in ACL-abnormal knees were 92 % and 88 %, respectively, at prospective initial interpretation and 96 % and 94 %, respectively, at retrospective interpretation. Conclusion: Dual-detector spiral CT arthrography of the knee is an accurate method for detecting ACL and associated meniscal tears. 2D-TOF unenhanced and 3D-spoiled-GRE contrast-enhanced images were acquired. Unmatched, randomized evaluation of images was performed on-site and by two off-site blinded reviewers. The change from unenhanced MRA in total diagnostic quality (TDQ) was evaluated for each patient using a five-point scale. Evaluation was made also of the number of vascular lesions detected, confidence in lesion characterization and the ability to grade stenoses. A full safety assessment was performed. Results: Both off-site reviewers noted a significant improvement in TDQ from preto post-contrast at all but the lowest dose. The increase appeared to plateau at 0.1 mmol/kg. The dose effect was significant for the on-site reviewers (p = 0.005) and off-site reviewer 2 (p < 0.001) but not for off-site reviewer 1 (p = 0.06). For all but the lowest dose group, Gd-BOPTA increased (a) the number of patients with lesions detected and, for most patients, the number of lesions detected per patient; (b) confidence in lesion characterization; (c) the percentage of stenoses visualized clearly enough for grading (reviewers 1 and 2 graded 80 -95 % and 57 -80 % of stenoses, respectively). All doses were well tolerated. The overall incidence of adverse events was 9.6 %. Conclusion: CE-MRA of the pelvic arteries using Gd-BOPTA is safe and significantly more effective than TOF-MRA. A dose of 0.1 mmol/kg appears the most suitable. Purpose: The purpose of this study was to evaluate the feasibility of blood pool contrast-enhanced MRA to visualize the arterial and venous vessel tree and to detect deep venous thrombosis (DVT) of the lower extremities. Material and methods: Nine consecutive patients with pulmonary embolism (mean age: 46 ± 9) were randomized to various doses of NC100150 (between 0.75 and 6 mg Fe/kg b.w.). A T1W 3D-GRE sequence (TE: 2.0 ms, TR: 5.0 ms) was used. Two observers blinded to the dose of contrast agent assessed image quality, contrast attenuation and appearance of thrombi.Results: Qualitative assessment of overall MRA image quality and semiquantitative vessel scoring revealed good to excellent delineation of venous and arterial vessel segments independent of the dose of NC100150. However, quantitative ROI analysis revealed a significantly higher S/N ratio in the high dose group compared to the mid and low dose groups of NC100150 (p < 0.01). Between dose groups, S/N ratio was independent of vessel type (artery or vein) and vessel segment localization (proximal or distal). All seven venous thrombi (mean length 7.2 ± 0.95 cm) were characterized by a very low SI, which was only 16.6 ± 7 % of the SI in adjacent venous segments (p < 0.0001).Conclusions: High quality MR angiograms of the lower extremities can be obtained using low concentrations of NC100150 in combination with a strong T1W 3D-GRE sequence. The obvious delineation of venous thrombi suggest that this technique may be potentially used as a non-invasive "one-stop shopping" tool in the evaluation of thromboembolic disease.

Injection-associated pain in femoral arteriography: A European multicentre study comparing safety and efficacy of Iodixanol and Iomeprol C. Manke 1 , F. Cognet 2 , A. Page 3 , J. Pueyo 4 , N. Batakis 5 ; 1 Regensburg/DE, 2 Dijon/FR, 3 Winchester/GB, 4 Mallorca/ES, 5 Athens/GR Purpose: To evaluate injection-associated pain, safety, and efficacy with the isoosmolar contrast medium iodixanol (Visipaque 270 mg I/ml) compared with iomeprol (Iomeron 300 mg I/ml) in femoral arteriography. Materials and methods: A prospective, multicentre, double-blind, randomised, parallel-group clinical trial was performed in nine hospitals in Europe. Of the 352 patients evaluated, 176 received iodixanol and 176 received iomeprol during peripheral arteriography (automated stepping intra arterial DSA). The first injection was standardised (volume 80 ml, flow rate 10 ml/s), additional injections were performed according to needs. The injection-associated pain, safety and efficacy were evaluated. Adverse events were recorded during the procedure and up to 72 hours after the examination.

The iodixanol group reported statistically significant less injection-associated pain than the iomeprol group after first injection (7.4 % vs. 18.5 %; p = 0.002), and after all injections (10.9 % vs. 20.2 %; p = 0.02). No significant differences were found between the iodixanol group and the iomeprol group for frequency of contrast-related adverse events (1.7 % vs. 1.7 %). Overall diagnostic utility was excellent/good for 86.8 % of the patients in the iodixanol group and 86.7 % in the iomeprol group (p = NS).

In this trial iodixanol 270 mg I/ml caused significantly less injectionassociated pain during femoral arteriography than iomeprol 300 mg I/ml and was shown to be equally safe. Despite lower iodine concentration, iodixanol provided similar diagnostic efficacy to iomeprol.

Optimizing vessel enhancement for CTA of the pulmonary vasculature by contrast media dilution C.W. Bader 1 , J.M. Froehlich 1 , H.A. Lohr 1 , J. Sousa 2 , C.L. Zollikofer 1 , K. Wentz 1 ; 1 Winterthur/CH, 2 Wädenswil/CH Purpose: To verify the hypothesis, that with a defined amount of 27 g iodine a higher injection rate of diluted contrast media (Iobitridol) results in higher vessel enhancement in pulmonary CTA Methods and materials: After bolus timing, CTAs were performed in 93 patients divided into 2 groups: group A with 48 patients (age 66 ± 17 a, 90 ml CM, 300 mg/ml concentration, flow 3 ml/s) and group B with 45 patients (age 66 ± 15 a, 108 ml CM, 250 mg/ml concentration, flow 4 ml/s). Each CM application was followed by a saline flush of 30 ml. Contrast enhancement of the pulmonary trunc, right and left main arteries and lower lobe arteries was measured. Results: Contrast enhancement of the pulmonary trunc was 342 ± 87 HU in group A and 382 ± 80 HU in group B, the right pulmonary artery 321 ± 86 and 352 ± 79 HU, the left pulmonary artery 311 ± 83 and 353 ± 78 HU. In the right lower lobe artery contrast enhancement was 309 ± 88 HU in group A and 335 ± 83 HU in group B, the left lower lobe artery 310 ± 88 and 342 ± 84 HU and the mean enlancement values of all measured pulmonary arteries was 319 ± 86 and 353 ± 82 HU. The effect on vascular enhancement was most significant (z-test, two sided p-values) in the pulmonary trunc (p = 0.002) followed by all measured pulmonary arteries (p = 0.05) and least remarkable in the lower lobe arteries.

With an identical amount of 27 g iodine, the higher injection rate of diluted CM leads to a significant increase of vessel enhancement in CTA of the pulmonary vasculature. With exact bolus timing this can be used to reduce the applied dose of iodine per patient. Purpose: To evaluate prospectively diagnostic accuracy of 1 mol gadobutrol as a contrast agent for intraarterial X-ray digital subtraction angiography (DSA) in comparison to iodinated, non-ionic contrast media and 0.5 mol gadolinium-DTPA. Methods: Flush arteriograms (ascending, descending, abdominal aorta, iliac and femoral arteries) and selective angiograms (carotid, renal and visceral arteries) were obtained from bilateral femoral arterial access (5 F sheaths) in ten domestic pigs (70 kg body weight). Digital subtracted angiograms were obtained during injecton of non-diluted 1 mol gadobutrol, 300 mg I/ml iopromide, or 0.5 mol gadopentetate. Injection parameters (volume and velocity) were similar for all three contrast agents. In paired arteries, two different contrast media were used during the same angiographic run. Diagnostic quality and accuracy of the angiograms were evaluated on a three-step scale by three independent blinded investigators. Results: Sufficient angiographic images were obtained in 90 % of cases using iodinated contrast material. Gadobutrol achieved sufficient non-selective angiograms in 64 %. Selective angiograms were sufficient in 98 % using iodinated contrast material, 90 % using 1 mol Gadobutrol and 48 % using 0.5 mol Gd-DTPA. Adverse reactions to any of the used contrast agents were not noted. Conclusion: 1 mol Gadobutrol solution allows X-ray digital subtraction angiography with an diagnostic accuracy equivalent to 300 mg/ml iodinated contrast media, if selective injections are performed. Flush aortograms are of inferior image quality to iodinated contrast material. 1M Gadobutrol achieves significantly better image quality compared with 0.5 mol gadolimium solutions.

High iodine concentration non ionic contrast agent. Comparison with lower iodine concentration in peripheral multislice CT angiography C. Catalano, A. Laghi, R. Brillo, F. Fraioli, F. Pediconi, A. Napoli, I. Reitano, R. Passariello; Rome/IT Purpose: Multislice CT (MSCT) has already proved a very accurate technique in the assessment of different vascular pathologies. Purpose of this study was to determine whether high iodine concentration non ionic contrast agent could improve vascular enhancement and vessel conspicuity. Material and methods: 60 patients referred for MSCT angiography (MSCTA) of the aorta and peripheral arteries were included in the study. All examinations were performed with a MSCT using a fixed delay time of 28 seconds. In all patients a standard amount of 40 g of iodine was administered at 4 ml/s. All patients were randomly assigned to one of three following groups: group 1 consisting of 100 ml of 400 mg I/ml; group 2 consisting of 113 ml of 350 mg I/ml; group 3 consisting of 133 ml of 300 mg I/ml. ROIs were obtained at different. A qualitative assessment was also made by two observers, regarding image quality and vessel conspicuity. Results: No significant difference was detected between the 350 and the 400 mg I/ml contrast agents at the level of the aorta, pelvic and thigh arteries; a 13 % difference was found between the 300 and 400 mg I/ml in the same districts. With the 400 mg I/ml a significant increase in vascular enhancement of respectively 16 and 21 % was seen in the popliteal and infrapopliteal arteries. Conclusion: A significant improvement in contrast enhancement and vessel conspicuity can be achieved in MSCTA by means of high iodine concentration contrast agents.