Diagnostic Performance of HRCT Scan of Chest in the Evaluation of COVID-19 Pneumonia: Comparison to RT-PCR

Background & purpose: This study was designed to evaluate the diagnostic performance of HRCT scan of chest in comparison to RT-PCR in the diagnosis of coronavirus disease 2019 (COVID-19). Materials & Methods: This study was conducted in the Department of Radiology & Imaging, Rajshahi Medical College Hospital, Rajshahi that included 150 patients over a period of eight months from April, 2020 to December, 2020. Using RT-PCR as the reference standard, the performance of HRCT scan of chest in the diagnosis of COVID-19 was assessed. In addition, the common HRCT findings, CT severity, demographic distribution of the disease were also analyzed. Results: The mean age of patients was 51.8±14.5 years, age range was from 24 to 82 years. There was a male predominance with 1.58:1. Cough (86.7%) &dyspnoea (74.7%) were the predominant clinical symptoms. Commonest CT features were GGO (97.1%) & GGO with consolidation (49.0%) followed by fibrosis (48%). Majority of the patients had all five lobes involved (51%) & CT severity showed majority with 25-50% involvement (28%) followed by 50-75% involvement in 22.3% patients. Specificity, sensitivity, positive predictive value, negative predictive value, accuracy & reliability were 97%, 43.7%, 93.5%, 63.6%, 91.3% & 0.88 respectively. Conclusion: HRCT chest has a very high sensitivity for diagnosis of COVID-19. HRCT chest should be considered as complementary to RT-PCR & a primary tool for detection of COVID-19 in this pandemic situation.