Temporal lung changes on thin-section CT in patients with COVID-19 pneumonia

We examined characteristics of chest CT during different time periods for patients with coronavirus disease 2019 (COVID-19) pneumonia in Huizhou, China. This study included 56 COVID-19 patients having abnormal CT acquired between January 22 and March 3, 2020. Scans of 56 patients were classified into 4 groups (Group 1-Group 4) based on the date on which scan was obtained at the 1st, 2nd, 3rd week and longer than 3 weeks after illness onset. Forty-five patients with follow-up scans were categorized into 4 groups according to extents that lesions reduced. GGO was prevalent in Groups 1-4 (58.1-82.6%). Consolidation was the more common in Group 2 (26.2%) and then declined in Group 3 and 4 (20.0%; 9.7%). The highest frequency of fibrous stripes occurred in Group 3 (46.7%) and then decreased to 35.5% in Group 4. CT scores were higher for Group 2 than others. Among 45 follow-up patients, 11 (24.4%) of them recovered with lesions reducing ≥75% and had shorter hospital durations compared with others. There were temporal patterns of lung abnormalities in COVID-19 patients, with the highest extent of lesion involvement occurring in the 2nd week. Isolation and review are required for COVID-19 patients who have been discharged from hospital.