six-week follow-up chest ct changes after severe covid-19 pneumonia in arak city, iran

Background: coronavirus disease 2019 (covid-19) can lead to lung damage.methods: this study examines the clinical characteristics of 190 patients with severe covid-19 admitted to a designated hospital in arak, iran, from initial diagnosis with chest ct to the recovery stage in the sixth week.results: serial evaluation of ct imaging features over time of covid-19 showed that peripheral ggo with or without consolidation, especially in the posterior or lower lung zones, were the most common features (p < 0.001 - 0.002). during the first week of follow-up, patients demonstrated a higher prevalence of halo signs, peribronchvascular opacities, bronchial wall thickening, tree-in-bud appearance, and lobar in consolidations compared with pulmonary ct scans performed at the sixth week of onset. covid-19 pneumonia showed the most severe pulmonary involvement approximately 10 days after symptom onset. after active treatment, in the second follow-up, these consolidations were complete resolution and regressed relatively faster than recovery from other types of lesions, as shown by chest ct imaging. in severe covid-19, ground-glass opacities, consolidation, particularly in lower regions of the lungs, crazy-paving patterns, air bronchograms, and reverse halo signs are often found on the initial ct examinations (days 7 to 10). most of these severe features gradually regressed in the absorption phase (on days 40 to 42 in early diagnosis and treatment).conclusion: ct imaging plays a crucial role in detecting pneumonia and has a high sensitivity in detecting covid-19 pneumonia but cannot be used as gold-standard for covid-19 diagnosis.