Longitudinal chest-CT findings after moderate to critical COVID-19 pneumonia

Abstract

<b>Background:</b> Radiological recovery after COVID-19 pneumonia is still largely unknown. <b>Aim:</b> To describe chest–CT findings and assess radiological recovery up to one year after COVID-19 pneumonia. <b>Methods:</b> 162 patients admitted with COVID-19 pneumonia were followed for 1 year. Initial disease severity was classified as moderate (WHO ordinal scale 3), severe (WHO scale 4) or critical (WHO scale 5-7). CT-scans were obtained during admission, after 3 months and 1 year. The extent of abnormalities was scored as proposed by Pan et al (Radiology 2020;295:715-721) and dominant pattern was noted. Groups were compared by Chi square test. CT score over time was assessed by paired-samples t-test. <b>Results:</b> 89 chest-CT-scans were obtained at baseline, 94 scans after 3 months and 66 scans after 1 year. Decrease of extent score was most pronounced during the first 3 months (Figure 1). After 1 year, 33 of 66 (50%) of CT scans were normal. The main abnormalities were groundglass pattern (47%), fibrotic lesions (24%) and subpleural banding (27%). Only subpleural banding was found significantly more often after critical (8/13, 62%) than severe (5/36, 14%) or moderate (5/17, 29%) pneumonia (p&lt;0.05). <b>Conclusions:</b> Absorption of radiological abnormalities mostly occurs in the first 3 months after COVID-19 pneumonia. However, persistent abnormalities after 1 year can be found in a large proportion of patients. Figure 1 Chest CT-score at baseline, 3 months and 1 year