Fig. 1

Illustration of Volume Density (V) and Euler-Poincaré Characteristic (χ) for PRM^fSAD. Presented are representative coronal slices for the (A) expiratory CT scan with associated (B) PRM^fSAD overlay (yellow). Included are the (C) volume density and (D) Euler-Poincaré Characteristic of PRM^fSAD. Blue and Magenta boxes indicate two lung regions with elevated V^fSAD that have negative and positive χ^fSAD, respectively. The subject is a GOLD 3 female aged 53 with FEV₁% predicted of 32% and percent volume of PRM^fSAD of 40%