Fig. 2

Quantitative lung CT analysis of a 55-year-old male with severe COVID-19 at admission. A Chest CT scan showing a bilateral mixed pattern (ground-glass opacities, interstitial thickening, and consolidation). B Illustration of automated lung segmentation. Yellow areas represent hyperinflated regions (%HI, − 901 to − 1000 HU); blue areas indicate normally aerated regions (%NAL, − 501 to − 900 HU); green areas represent poorly aerated regions (%PAL, − 101 to − 500 HU); red areas indicate nonaerated regions (%NNL, 100 to − 100 HU). The compromised lung volume was calculated as the sum of NNL and PAL. C 3D volumetric representation of the bilateral lungs. D Comparison among different quantitative CT parameters. The patient had 30.53% of compromised lung volume (sum of 17.72% NNL and 12.81% PAL), 67.12% NAL, and 2.35% HI