Comparison of Lung CT Scan Findings upon Admission and Three Months after the Discharge of Patients with COVID-19

Background and Objective: There is not enough information about the long-term pulmonary complications of patients with COVID-19. This prospective study aimed to compare the findings of lung CT scan upon admission and three months after the discharge of patients with COVID-19. Materials and Methods: This prospective study was conducted on 60 patients with COVID-19 hospitalized in Shahid Beheshti and Sina hospitals in Hamadan, Iran, in 2020-2021. The lung CT scan results of the patients upon admission and three months later were assessed and compared by an experienced radiologist quantitatively and qualitatively after obtaining and recording the demographic characteristics, risk factors, and clinical findings. Results: The mean score of lung involvement upon hospitalization of the patients was 3.7±1.4, and three months after discharge, it was determined at 1.1±1.2. The most frequent findings in the initial CT scan of the patients were ground-glass opacification, mixed GGO, and bands with frequencies of 60%, 36.7%, and 18.3%, respectively. After three months, CT scan results of 32 (53.3%) patients showed lung involvement and an abnormal finding in the lung, the most common of which were ground-glass opacification, mixed GGO, and bands with frequencies of 30%, 13.3%, and 10.0%, respectively. Patients who had pulmonary involvement three months after discharge had a higher average lung involvement score during hospitalization (4.4±1.5 vs. 2.9±0.7, P=0.001). Conclusion: Abnormal CT scan results of the lung three months after discharge is common in COVID-19 patients, among whom patients with more pulmonary involvement during hospitalization have more abnormal findings