The sensitivity of Chest CT for the diagnosis of COVID-19 pneu monia and imaging patterns as seen on Chest CT: a crossectional prospective study done in Addis Ababa, 2021

Background: Coronavirus disease 2019 (COVID-19) is a respiratory illness caused by a novel coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While the RT-PCR test is considered the gold standard for diagnosis, chest imaging plays an important adjunct role in diagnosing and assessing the severity of the disease, as well as identifying complications. Distinguishing COVID-19 from other infectious processes can be challenging; thus, recognizing typical imaging patterns and degrees of involvement is crucial for guiding treatment. Objective: This study aimed to assess the sensitivity of chest CT scans in comparison to the standard RT-PCR for diagnosing COVID-19. Method: A cross-sectional study was conducted using data collected from various diagnostic and treatment centers between July 1, 2021, and October 1, 2021. The chest CT scans of patients were reviewed, and a structured questionnaire was completed using a Google form. The data were exported and analyzed using SPSS version 26. Results: Chest CT analysis revealed that 95.9% of cases exhibited bilateral involvement, with 51.3% showing a peripheral distribution. Among the typical chest CT patterns, ground-glass opacities (GGO) were observed in 157 (83%) cases, consolidation in 152 (80.4%), and broncho vascular thickening in 68 (35.4%). The mean chest CT severity score was 13.6 ± 6.2, with 95 patients (49.2%) scoring above 18 (indicating severe disease). A positive correlation was found between the CT severity score and both age and diabetes, with a p-value < 0.01. There was a high probability of severe disease on chest CT among patients with diabetes mellitus (AOR = 1.6, 95% CI: 0.4-6.8). Conclusion: This study demonstrated that chest CT has a high sensitivity (82.9%) for diagnosing COVID-19 pneumonia. The predominant imaging features included ground-glass opacity, consolidation, and bronchovascular thickening, with a notable bilateral, basal, and peripheral distribution. Additionally, the study revealed a positive correlation between the chest CT severity score and both age and diabetes comorbidity. Keywords: Chest CT, COVID-19, RT-PCR