Fig. 2

Thin-section CT images for severe and non-severe patients. a-c Images of a 25-year-old woman with non-severe COVID-19 pneumonia (CT score = 2) who had the symptoms of dry cough and fever. The axial, coronal and sagittal CT images all presented subpleural GGO (with craving stone sign) in the lower lobes of both lungs (white arrows). d-f Images of a 55-year-old woman with non-severe COVID-19 pneumonia (CT score = 1) who had the symptom of fever. The axial, coronal and sagittal CT images all presented GGO in the anterior segment of the upper lobe of the right lung, containing air bronchogram (white arrowheads) and vascular thickening (white arrow). g-i Images of a 52-year-old man with severe COVID-19 pneumonia (CT score = 4) who had the features of fever and comorbidity (diabetes, hypertension). The axial, coronal and sagittal CT images showed diffuse large regions of GGO with partial consolidation and interlobular septal thickening (white arrow). j-l Images of a 64-year-old man with severe COVID-19 pneumonia (CT score = 4) who had the symptoms of fever and cough. The axial, coronal and sagittal CT images showed diffuse large regions of GGO, accompanying consolidation (black arrows), and beaded air bronchogram (black arrowheads)