Performance of CO-RADS in the diagnosis of COVID-19 in hemodialysis patients.

Introduction: Different data systems have been used to reach a common decision in the interpretation of chest computed tomography (CT) scans for the detection of COVID-19 infection. The aim of our study was to determine the usefulness of the COVID-19 Reporting and Data System (CO-RADS) for COVID-19 in patients undergoing hemodialysis.

Methods: We included 90 hemodialysis patients who underwent chest CT and had samples available for real-time reverse transcription-polymerase chain reaction (RT-PCR). The files of the patients were retrospectively reviewed and the data were recorded. Image interpretation and CO-RADS staging were performed retrospectively by two radiologists experienced in COVID-19 patients, blinded to the RT-PCR results. The RT-PCR results were then compared with the CO-RADS stages obtained. The success of CO-RADS in diagnosing COVID-19 was evaluated according to its prediction of a positive RT-PCR result. At the same time, the relationship between CO-RADS stages and prognosis was also evaluated.

Results: Patients were divided into two groups according to the RT-PCR results, of which 38 (42.2%) had positive results. Validity tests of CO-RADS were performed according to the RT-PCR test. While 71.1% of patients with CO-RADS ≥4 were RT-PCR (+), 13.2% of patients with CO-RADS ≤2 were RT-PCR (+) (p < 0.001). CO-RADS ≥4 detected COVID-19 with 71.1% sensitivity and 51.9% specificity. ROC analysis confirmed the diagnostic performance of CO-RADS for predicting RT-PCR positivity with AUC = 0.73 (95% CI: 0.63-0.84). The relationship between CO-RADS stages and mortality was not significant (p = 0.21).

Conclusion: CO-RADS is moderately sensitive and poorly specific for the diagnosis of COVID-19 in hemodialysis patients. In these patients, CO-RADS would be more useful to exclude other infections than to diagnose COVID-19.