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

Objective: 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.

Study Design: Descriptive study.

Place And Duration Of Study: Department of Radiology and Central Research Lab, Lahore General Hospital, Lahore, from April to July, 2020.

Methodology: 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.

Results: 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.

Conclusion: 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.