Micro–Computed Tomography Measurements of Peripheral Lung Pathology in Chronic Obstructive Pulmonary Disease

Background: The smaller airways, < 2 mm in diameter, offer little resistance in normal lungs, but become the major site of obstruction in chronic obstructive pulmonary disease (COPD).Objective: To examine bronchiolar remodeling and alveolar destruction in COPD using micro–computed tomography (micro-CT).Methods: Micro-CT was used to measure the number and cross-sectional lumen area of terminal bronchioles (TB) and alveolar mean linear intercept (Lm) in 4 lungs removed from patients with very severe (GOLD-4) COPD and 4 unused donor lungs that served as controls. These lungs were inflated with air to a transpulmonary pressure (PL) of 30 cm H2O and held at PL 10 cm H2O while they were frozen solid in liquid nitrogen vapor. A high resolution CT scan was performed on the frozen specimen prior to cutting it into 2-cm thick transverse slices. Representative core samples of lung tissue 2 cm long and 1 cm in diameter cut from each slice were fixed at −80°C in a 1% solution of gluteraldehyde in pure acetone, post-fi...