Fig. 4.

Serial chest CT scans from a 51-year-old woman diagnosed as severe at admission. a Day 1 after disease onset: focal ground-glass opacities affected the left and right lower lobe. SaO₂ 99%. b Day 5: the main lesion located at the right lower lobe aggravated rapidly, with both extent and density increased. SaO2 99%. c Day 9: enlarged area of infection with bilateral, multifocal ground-glass opacities and consolidations. SaO₂ decreased to 80% and patient was diagnosed as severe. d Day 17: consolidations were absorbed and partially dissipated into ground-glass opacities. SaO₂ returned to normal level (98%) and patient’s symptoms significantly relieved. e Day 26: infected areas continued to be absorbed, leaving extensive ground-glass opacities. Patient discharged 2 days later. f Timeline demonstrates the dynamic change of volumetric percentage and density of this patient