Thin-section Chest CT Imaging of Coronavirus Disease 2019 Pneumonia: Comparison Between Patients with Mild and Severe Disease

Yu, Minhua; Xu, Dan; Lan, Lan; Tu, Mengqi; Liao, Rufang; Cai, Shuhan; Cao, Yiyuan; Xu, Liying; Liao, Meiyan; Zhang, Xiaochun; Xiao, Shu-Yuan; Li, Yirong; Xu, Haibo

PURPOSE: Although CT imaging features of Coronavirus Disease 2019 (COVID-19) pneumonia have already been published in the literature, there was little attention to distinctive imaging features encountered between patients with mild and severe forms of the disease. The purpose was to compare radiological characteristics of COVID-19 pneumonia on thin-section CT upon admission between patients with mild and severe disease. MATERIALS AND METHODS: Seventy COVID-19 pneumonia patients admitted to Zhongnan Hospital of Wuhan University between January 20 and January 27, 2020 were enrolled. Based on the World Health Organization guidelines, 50 patients were categorized with mild form and 20 with severe form based on clinical conditions. Imaging features, clinical, and laboratory data were reviewed and compared. RESULTS: Patients with severe form (median age, 65.00; IQR: 54.75-75.00) were older than those with mild form of disease (median age, 42.5; IQR: 32.75-58.50) (P<0.001). Patients with severe form of disease had more lung segments involved (median number of segments: 7.5 vs. 17.5, P=<0.001) and also larger opacities (median number of segments with opacities measuring 3 cm to less than 50% of the lung segment: 5.5 vs. 2.0, P=0.006; ≥ 50% of lung segment: 7.5 vs. 0.0, P<0.001). They also had more interlobular septal thickening (75% vs. 28%, P<0.001), higher prevalence of air bronchograms (70% vs. 32%, P=0.004), and pleural effusions (40% vs 14%, P=0.017). CONCLUSION: Ground-glass opacities with or without consolidation in a peripheral and basilar predominant distribution were the most common findings in COVID-19 pneumonia. Patients with severe form of the disease had more extensive opacification of the lung parenchyma than did patients with mild disease. Interlobular septal thickening, air bronchograms, and pleural effusions were also more prevalent in severe COVID-19.