Quantitative Lung Morphometry Analysis

H&E stained sections were photographed using an Olympus microscope with an in built digital camera system at 100× magnification (Olympus, Tokyo, Japan). Alveolar size was estimated from the mean chord length of the airspace, as previously described [19 (link)]. Alveolar septal wall thickness was estimated using Image J software, adapting the method described previously for bone trabecular thickness, for the lung [19 (link)]. 10× magnification images were obtained with Olympus 1X70 Microscope using Cellsens Dimension software. Radial alveolar count (RAC) and secondary septal crests were done as previously described [24 (link),25 (link)].