Clinical Features and Temporal Lung Radiographic Changes in 25 Patients Recovering from COVID-19 Pneumonia: A Retrospective Case-Control Study.

BACKGROUND Little is known of the changes in lung radiographic characteristics over time in patients recovering from COVID-19. This study analyzed the clinical features and temporal lung radiographic changes in patients with moderate and severe COVID-19 pneumonia who did not require invasive mechanical ventilation during the acute and convalescent periods. MATERIAL AND METHODS The data of 25 patients with COVID-19 pneumonia from January 29, 2020, to November 24, 2020, who did not require invasive mechanical ventilation and who were followed up were retrospectively collected. The 25 patients were divided into severe and moderate groups. Clinical characteristics and computed tomography (CT) manifestations were compared. A total of 121 consecutive thin-slice CT scans were collected at 4 weeks, 2 months, and 5 months after admission to evaluate lung abnormalities in the patients. The CT score was used to assess disease severity. RESULTS The severe group had a lower rate of nucleic acid conversion within 10 days of admission and higher D-dimer, creatine kinase, and lactate dehydrogenase values. In the severe group, hospital stay was longer and hospitalization costs were higher. The average CT score of the severe group peaked in the second week, while the moderate group peaked in the first week and then decreased over time. There were no statistically significant differences in the average CT score between the 2 groups at the 5-month follow-up. CONCLUSIONS The pulmonary lesions of patients recovering from COVID-19 and who do not require invasive mechanical ventilation were gradually absorbed and resolved over time.