The purpose of this study was to evaluate radiological findings obtained from lung ultrasound (LUS) and computed tomography (CT) in COVID-19 survivors with persistent clinical symptoms and its correlation.

This single-centre prospective study evaluated COVID-19 survivors who were admitted to our department and had a previous diagnosis of COVID-19 with lung involvement on CT scan. After admission, chest CT and LUS were performed and scored. 115 pairs of LUS examinations and chest CT scans underwent analysis. All chest CT scans were evaluated for presence of radiological alterations and the scans were scored by AI in percentages of lung involvement in ground glass opacities (GGO). Lung ultrasound examinations were scored based on the presence of pleural line irregularities.

The study enrolled 72 patients, 35 of them underwent a second follow-up examination. The most frequent findings on CT were GGO (75%), subpleural lines (65%), traction bronchiectasis (33,8%) and consolidations (28,8%). Mean percentages of GGO were statistically significantly lower in the second examination, p<0,001.

The most frequent LUS abnormalities were irregular pleural line (56,9%), subpleural consolidation (26,5%) and B-line (26,5%) in the first examination and, respectively 38,3%, 14% and 13,8% in the second.

The lung ultrasound score was strongly correlated with percentages of lung involvement in ground glass opacities (r=0,71) and was significantly higher in the group with fibrotic like changes with mean value of 19,4 SD 5,7, p<0,0001. 

Conclusion: Lung ultrasound should be considered as a diagnostic method in the follow-up examination in patients with persistent clinical symptoms after recovering from COVID-19.