LIB Biomedical Imaging Laboratory INSERM, CNRS, ICT Cardiothoracic Imaging Unit & Radiology Department, ICAN Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital (AP-HP), Sorbonne Université, Paris, France.
Department of Radiology, APHP, Sorbonne Universités, Paris, France.
PLoS One. 2020 Nov 23;15(11):e0242840. doi: 10.1371/journal.pone.0242840. eCollection 2020.
To evaluate the diagnostic performance of the initial chest CT to diagnose COVID-19 related pneumonia in a French population of patients with respiratory symptoms according to the time from the onset of country-wide confinement to better understand what could be the role of the chest CT in the different phases of the epidemic.
Initial chest CT of 1064 patients with respiratory symptoms suspect of COVID-19 referred between March 18th, and May 12th 2020, were read according to a standardized procedure. The results of chest CTs were compared to the results of the RT-PCR.
546 (51%) patients were found to be positive for SARS-CoV2 at RT-PCR. The highest rate of positive RT-PCR was during the second week of confinement reaching 71.9%. After six weeks of confinement, the positive RT-PCR rate dropped significantly to 10.5% (p<0.001) and even 2.2% during the two last weeks. Overall, CT revealed patterns suggestive of COVID-19 in 603 patients (57%), whereas an alternative diagnosis was found in 246 patients (23%). CT was considered normal in 215 patients (20%) and inconclusive in 1 patient. The overall sensitivity of CT was 88%, specificity 76%, PPV 79%, and NPV 85%. At week-2, the same figures were 89%, 69%, 88% and 71% respectively and 60%, 84%, 30% and 95% respectively at week-6. At the end of confinement when the rate of positive PCR became extremely low the sensitivity, specificity, PPV and NPV of CT were 50%, 82%, 6% and 99% respectively.
At the peak of the epidemic, chest CT had sufficiently high sensitivity and PPV to serve as a first-line positive diagnostic tool but at the end of the epidemic wave CT is more useful to exclude COVID-19 pneumonia.
根据法国全国封城时间，评估初始胸部 CT 对有呼吸道症状的 COVID-19 相关肺炎患者的诊断性能，以更好地了解胸部 CT 在疫情不同阶段的作用。
2020 年 3 月 18 日至 5 月 12 日期间，对 1064 例有呼吸道症状的疑似 COVID-19 患者进行了初始胸部 CT 检查，根据标准化程序进行了阅读。胸部 CT 结果与 RT-PCR 结果进行了比较。
546 例（51%）患者的 RT-PCR 结果为 SARS-CoV2 阳性。封城第二周的阳性 RT-PCR 率最高，达到 71.9%。封城六周后，阳性 RT-PCR 率显著下降至 10.5%（p<0.001），甚至在最后两周下降至 2.2%。总体而言，CT 显示 603 例（57%）患者存在 COVID-19 模式，246 例（23%）患者存在其他诊断。215 例（20%）患者 CT 结果正常，1 例患者 CT 结果不确定。CT 的总体敏感性为 88%，特异性为 76%，PPV 为 79%，NPV 为 85%。在第 2 周，相同的数字分别为 89%、69%、88%和 71%，而在第 6 周分别为 60%、84%、30%和 95%。在封城结束时，当 PCR 阳性率变得极低时，CT 的敏感性、特异性、PPV 和 NPV 分别为 50%、82%、6%和 99%。
在疫情高峰期，胸部 CT 具有足够高的敏感性和 PPV，可以作为一线阳性诊断工具，但在疫情高峰期过后，CT 更有助于排除 COVID-19 肺炎。
