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

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.

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.

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).

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.