Figure 3.
Typical cases of the total LS, total lung CTVI metrics (LC), the percentage of low attenuation areas (% LAA-950insp; the percentage of lung voxels below −950 HU in end-inspiration, % LAA-856exp; the percentage of lung voxels below −856 HU in end-expiration) for GOLD report-based classification. As the COPD grade increased, the LS decreased. A similar trend was exhibited by LC, % LAA-950insp, and % LAA-856exp. COPD, chronic obstructive pulmonary disease; CTVI, CT ventilation image; HU, Hounsfield unit; LAA, low attenuation area; LS, lung stress.
