Abstract
BACKGROUND AND AIMS: The world has been devastated by the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from 2019 to 2023 which necessitated stratifying patients into mild, moderate, severe, and critical categories based on clinical presentation, oxygen saturation, radiological findings, and systemic inflammatory response syndrome (SIRS). This study aimed to quantify lung involvement using high-resolution computed tomography (HRCT) and correlate it with clinical severity and laboratory parameters. METHODS: This observational cross-sectional study was conducted at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, from July to September 2020. A total of 90 RT-PCR-confirmed COVID-19 patients were enrolled from outpatient and inpatient departments on the basis of clinical and laboratory parameters in accordance with Interim Guidance, 27th May, 2020 on the Management of COVID-19 from WHO. The major CT findings and CT severity score were described by using internationally standard nomenclature defined by the Fleischner Society glossary and peer-reviewed literature on viral pneumonia. CT severity scores were calculated and statistically correlated with clinical severity and laboratory markers including SpO(2), neutrophil and lymphocyte percentages, CRP, and D-dimer. A receiver operating characteristic (ROC) analysis was performed to determine a cutoff CT severity score for identifying severe cases. RESULTS: The mean CT severity score was 11.66, with severe cases showing significantly higher scores than non-severe cases (13 vs. 8.87). HRCT scores had a moderate negative correlation with SpO(2) and lymphocyte percentage, and a moderate positive correlation with neutrophil percentage, CRP, and D-dimer. A CT severity score ≥ 8.5 was identified as the threshold for severe disease on ROC analysis. CONCLUSION: Age, sex, smoking status, and comorbidities had no relation with the severity of COVID-19. HRCT severity score had moderate negative correlation with disease severity of COVID-19. HRCT severity score is also found to have moderate positive correlation with total neutrophil percentage, CRP, and D-dimer; and moderate negative correlation with total lymphocyte percentage. No correlation was also found between increasing CT severity score with the presence of comorbidities. HRCT severity scoring showed a moderate correlation with clinical severity and laboratory markers in COVID-19, supporting its utility in triage and prognostication. Integrating HRCT scoring into clinical evaluations may enhance decision-making and patient management strategies.