Comparison of HRCT Chest and RT-PCR in Diagnosis of COVID-19

To compare the diagnostic accuracies of HRCT chest and RT-PCR results in diagnosis of coronavirus disease (COVID-19) in a tertiary care hospital in Lahore.

Descriptive study.

Department of Radiology and Central Research Lab, Lahore General Hospital, Lahore, from April to July, 2020.

Patients aged 18 to 83 years, who had clinically suspected symptoms of COVID-19 (fever, cough/sore throat or shortness of breath) presenting in outpatient or emergency department, were included. These patients had their HRCT chest conducted from Radiology Department and RT-PCR performed at Central Research Lab. These data were retrieved from electronic system of PACS. Results were categorised into positive and negative findings for COVID-19. Diagnostic accuracies of HRCT chest and first RT-PCR along with 95% confidence interval were calculated.

A total of 94 patients, 55 (58.5%) males and 39 (41.5%) were females. Out of them, 83% patients had positive HRCT chest findings of COVID-19, 17% had negative HRCT chest findings; while 40.4% had positive and 59.6% had negative first PCR. Among the repeat second PCR, 19.6% had negative, 1.8% had positive PCR results; while 78.6% patients didn't undergo repeat PCR. The sensitivity, specificity, NPV, PPV and accuracy of HRCT chest was 92%, 23%, 81%, 45%, and 51%; while of first RT-PCR was 45%, 81%, 23%, 92% and 51%, respectively.

The sensitivity of HRCT chest is higher (92%) as compared to first RT-PCR (45%). Key Words: COVID-19, RT-PCR, HRCT chest, Sensitivity, Specificity.