Figure 2.

CT scan 3-D airway tree and PRM map for a participant who had never used tobacco (A) and a participant with COPD (B). 3-D airway tree (in blue) with the lung segmentation overlaid, as well as the PRM map (green = normal, yellow = small airways disease, red = emphysema) is provided for two representative participants. The participant who had never used tobacco (A) is a 71-year-old woman with FEV₁ of 115.3% predicted and FEV₁ to FVC ratio of 74.8%. The participant with COPD (B) is a 64-year-old woman with FEV₁ of 46.9% predicted and FEV₁ to FVC ratio of 52.9%. Compared with the participant who had never used tobacco, the participant with COPD showed a visually and quantitatively reduced number of CT scan airways as measured by total airway count (TAC; patient who had never used tobacco, TAC = 300; patient with COPD, TAC = 128) and increased extent of small airways disease as measured by PRM functional small airway disease (patient who had never used tobacco, CT PRM functional small airway disease = 28.8%; patient with COPD, CT PRM functional small airway disease = 49.6%). PRM = parametric response mapping.