key: cord-0950266-74z73zxc authors: Joob, Beuy; Wiwanitkit, Viroj title: Computed Tomographic Findings in COVID-19 date: 2020-03-13 journal: Korean J Radiol DOI: 10.3348/kjr.2020.0164 sha: 22d4e261fc42fe05842c33994089c433bf389631 doc_id: 950266 cord_uid: 74z73zxc nan To the Editor, Thank you for your comments regarding our online article on computed tomography (CT) findings in two cases of coronavirus disease 2019 (COVID-19), which caused an outbreak in China (1) . Recent studies documented that human-to-human transmission of the novel coronavirus 2019 (2019-nCoV) is the epidemiologic characteristic of COVID-19 (2, 3). As of February 25, 2020, the World Health Organization (WHO) reported 80239 confirmed cases globally, and 2700 deaths in 34 countries, including China, Korea, Japan, the United States of America, Canada, Italy, and Iran (4). In short, 2019-nCoV has spread worldwide. Fever and cough are the most frequent initial symptoms of COVID-19 and may facilitate the diagnosis of infection with 2019-nCoV (5) . Regarding the CT characteristics, we agree that the features of 2019-nCoV infection detected by imaging modality are diverse. Ground-glass opacity (GGO), pulmonary consolidation, pulmonary nodules, and diffuse GGO with thickened interlobular septa were observed in patients with COVID-19 pneumonia. However, pleural effusion and thoracic lymphadenopathy were uncommon. The characteristics of the opacities were also variable and included linear and rounded morphology, "crazy-paving" pattern, and the "reverse halo" sign (6). Among these CT findings, GGO and consolidations were always observed at different stages of COVID-19 development (5) . Previous studies have shown that the lobe involvement was most frequently distributed along the bronchovascular bundles or subpleural regions in the bilateral lungs (6-8), which is consistent with the CT findings in the two cases that we reported. However, not all of the patients with COVID-19 had abnormal CT features. A recent study has shown that 98% (50/51) of patients had abnormal chest CT characteristics, and one patient (1/51, 2%) had normal results on chest CT (9) . Even though COVID-19 can be confirmed by the detection of the nucleic acid of the virus, CT examinationas the imaging modality-has an important role in detecting abnormalities in the pulmonary parenchyma in patients with suspected COVID-19 pneumonia. Therefore, the combination of repeated swab tests and CT examinations can be helpful for diagnosing individuals with high clinical suspicion of 2019-nCoV infection but negative in the realtime reverse transcriptase-polymerase chain reaction (rRT-PCR) screening (9) . CT images and the detection of nucleic acid can mutually complement each other in the diagnosis of COVID-19. In conclusion, COVID-19 pneumonia is a human-to-human transmitted disease, and fever and cough may be its initial symptoms. The 2019-nCoV has certain specific signs on CT imaging. However, not all cases display abnormal chest CT results, and the detection of the nucleic acid of the virus is the best way to diagnose patients with suspected COVID-19. Therefore, clinical history, manifestations, and the rRT-PCR amplification of the viral DNA from a sputum sample can be considered to represent the comprehensive analysis necessary to diagnose COVID-19 infection. ORCID iDs Bing Fan https://orcid.org/0000-0003-4439-6150 Xiaoqi Lin https://orcid.org/0000-0002-0760-3950 Pinggui Lei https://orcid.org/0000-0001-7610-0292 Novel coronavirus pneumonia outbreak in 2019: computed tomographic findings in two cases Sensitivity of chest CT for COVID-19: comparison to RT-PCR Time course of lung changes on chest CT during recovery from 2019 novel coronavirus (COVID-19) pneumonia Novel coronavirus pneumonia outbreak in 2019: computed tomographic findings in two cases Early transmission dynamics in Wuhan, China, of novel coronavirusinfected pneumonia Importation and human-to-human transmission of a novel coronavirus in Vietnam Coronavirus disease 2019 (COVID-19) situation report-36 Time course of lung changes on chest CT during recovery From 2019 novel *These authors contributed equally to this work. Corresponding author: Bing Fan, MD, Department of Radiology, Jiangxi Provincial People's Hospital, Aiguo Road No. 92 COVID-19) pneumonia Chest CT findings in coronavirus disease-19 (COVID-19): relationship to duration of infection 2019 novel coronavirus (2019-nCoV) pneumonia CT imaging features of 2019 novel coronavirus (2019-nCoV) Sensitivity of chest CT for COVID-19: comparison to RT-PCR