Diagnostic Accuracy of High-Resolution Computed Tomography Chest in COVID-19; Our First Pandemic Experience

Abstract

Background: COVID 19 pneumonia is global pandemic and affects the human life in every aspect. Although RT-PCR test is considered as gold standard for its diagnosis but imaging also plays a pivotal role. Objective: The aim of our study was to review the diagnostic accuracy of HRCT scan chest in detecting COVID 19 pneumonia compare with the RT-PCR test and investigate its different features on HRCT scan. Study Design: Cross sectional study. Settings: Department of Radiology, Ghulam Muhammad Mahar Medical College Sukkur / SMMBBMU, Larkana Pakistan. Duration: Ten months from March 2020 till December 2020. Methods: All consecutive patients with suspected clinical findings of COVID19 pneumonia or respiratory symptoms who underwent PCR test and chest CT scan were included in the study. Diagnostic efficacy of HRCT scan was calculated and correlated with both CT and RT-PCR results. Results: Our study included 112 patients (63 male and 49 female, mean age 42 years ± 5 years). Among them 55.0% of cases showed CT positive findings and 45.0% of cases showed RT-PCR positive results. Calculated sensitivity, specificity and accuracy of CT scan was 96%, 56% and 74% respectively. Chest CT findings in almost all patients (100%) were patchy areas of ground glass opacities (GGO), associated with involvement of bilateral in 90% and multi-segmental and peripheral distribution in 95% of cases. Conclusion: Study concludes that HRCT scan chest appears to have a very high sensitivity and accuracy in detection of various features of lung involvement in symptomatic as well as high risk COVID 19 patients especially with negative PCR test. But it cannot exclude as specificity is low. The most common CT scan feature was patchy areas of ground glass opacity (GGO) in bilateral lung with peripheral and posterior distribution.