Figure 3

Depiction of a small airway captured for analysis. The airway is associated with vessels, which are excluded from morphometric analysis of airway walls. The sub-epithelial basement membrane of the airway wall free from vessel association is traced. A region of interest of defined band depth (5, 10, 15, 20, 25, 30, and 35 μm) is projected into the parenchyma from the sub-epithelial basement membrane trace (black lines). The stain of interest (α-SMA) is quantified by the software as a percentage of the total band area for each band depth.