Correlation of chest CT and RT-PCR testing for coronavirus disease 2019 (COVID-19) in China: a report of 1014 cases

Ai, T.; Yang, Z.L.; Hou, H.Y.; Zhan, C.N.; Chen, C.; Lv, W.Z.; ... ; Xia, L.M. (2020)

Article / Letter to editor

Background: Chest CT is used in the diagnosis of coronavirus disease 2019 (COVID-19) and is an important complement to reverse-transcription polymerase chain reaction (RT-PCR) tests.Purpose: To investigate the diagnostic value and consistency of chest CT as compared with RT-PCR assay in COVID-19.Materials and Methods: This study included 1014 patients in Wuhan, China, who underwent both chest CT and RT-PCR tests between January 6 and February 6, 2020. With use of RT-PCR as the reference standard, the performance of chest CT in the diagnosis of COVID-19 was assessed. In addition, for patients with multiple RT-PCR assays, the dynamic conversion of RT-PCR results (negativeto positive, positive to negative) was analyzed as compared with serial chest CT scans for those with a time interval between RT-PCR tests of 4 days or more.Results: Of the 1014 patients, 601 of 1014 (59%) had positive RT-PCR results and 888 of 1014 (88%) had positive chest CT scans. The sensitivity of chest CT in suggesting COVID-19 was 97% (95% confidence interval: 95%, 98%; 580 of 601 patients) based on positive RT-PCR results. In the 413 patients with negative RT-PCR results, 308 of 413 (75%) had positive chest CT findings. Of those 308 patients, 48% (103 of 308) were considered as highly likely cases and 33% (103 of 308) as probable cases. At analysis of serial RT-PCR assays and CT scans, the mean interval between the initial negative to positive RT-PCR results was 5.1 days +/- 1.5; the mean interval between initial positive to subsequent negative RT-PCR results was 6.9 days +/- 2.3. Of the 1014 patients, 60% (34 of 57) to 93% (14 of 15) had initial positive CT scans consistent with COVID-19 before (or parallel to) the initial positive RT-PCR results. Twenty-four of 57 patients (42%) showed improvement on follow-up chest CT scans before the RT-PCR results turned negative.Conclusion: Chest CT has a high sensitivity for diagnosis of coronavirus disease 2019 (COVID-19). Chest CT may be considered as a primary tool for the current COVID-19 detection in epidemic areas. (C) RSNA, 2020

• All authors: Ai, T.; Yang, Z.L.; Hou, H.Y.; Zhan, C.N.; Chen, C.; Lv, W.Z.; Tao, Q.; Sun, Z.Y.; Xia, L.M.
• Date: 2020-08-01
• Journal: Radiology
• Volume: 296
• Issue: 2
• Pages: E32 - E40
• DOI: doi:10.1148/radiol.2020200642
• Link: https://pubs.rsna.org/doi/10.1148/radiol.2020200642