Diagnostic value of chest CT in Iranian patients with suspected COVID-19

Background: In the current COVID-19 pandemic, there is a rising need for a rapid and reliable diagnostic tool. We hypothesized that chest computed tomography (CT) can be a potential alternative for reverse transcription-polymerase chain reaction (RT-PCR). The aim of this study was to compare the diagnostic value of chest CT and RT-PCR in Iranian patients with suspected COVID-19.

Methods: In a retrospective, single-center case series, 568 consecutive hospitalized or outpatient patients with suspected COVID-19 underwent chest CT and/or RT-PCR testing at Imam Reza Hospital, the tertiary teaching hospital of Tabriz University of Medical Sciences in Iran, from February 21 and March 28, 2020.

Results: The sensitivity of chest CT for signifying COVID-19 was 64% (95% CI: 56%-71%) on the basis of positive RT-PCR results as a standard method. CT imaging also had a specificity of 77% (95% CI: 73%-81%), positive predictive value of 35% (95% CI: 0.31-0.39), negative predictive value of 66% (95% CI: 0.61-0.69), positive likelihood ratio of 2.79 (95% CI: 2.26-3.46), and negative likelihood ratio of 0.47 (95% CI: 0.38-0.57).

Conclusion: Chest CT had higher specificity in the diagnosis of COVID-19 than that of the previous studies. Therefore, it can play a crucial role in the early diagnosis. Similar to the previous studies, the typical CT features were patchy ground-glass opacities as well as peripheral aspects of the lungs consolidations.