Assessment of remodeling in chronic obstructive pulmonary disease using imaging methods

INTRODUCTION While spirometry plays a key role in diagnosing chronic obstructive pulmonary disease (COPD), imaging methods including endobronchial ultrasound (EBUS) and chest computed tomography (CT) appear to be useful for investigating structural changes in the lungs.

OBJECTIVES The aim of this study was to evaluate remodeling in COPD patients using EBUS and chest CT.

PATIENTS AND METHODS The study included 33 patients with COPD, 15 patients with severe asthma, and 15 control subjects. All subjects underwent pulmonary function tests and bronchoscopy with EBUS to measure the total thickness of the bronchial wall and its layers. Additionally, in COPD patients, a chest CT was performed to measure total bronchial wall thickness.

RESULTS The total bronchial wall thickness measured by EBUS in patients with COPD (1.192 ±0.079 mm) was significantly smaller than that in asthmatic patients (1.433 ±0.230 mm, P = 0.001) and significantly greater than in control subjects (1.099 ±0.095 mm, P = 0.04), and was positively correlated with residual volume (RV) / total lung capacity (r = 0.5, P = 0.02), RV (r = 0.6, P = 0.007), and RV (%) (r = 0.5, P = 0.05). The thickness of the bronchial wall layers in patients with COPD were as follows: L1 = 0.135 ±0.018 mm, L2 = 0.151 ±0.026 mm, and L3–5 = 0.906 ±0.065 mm. There was no correlation between the thickness of the bronchial wall layers and forced expiratory volume in 1 second.

CONCLUSIONS The results of this study show that EBUS is a useful method for evaluating bronchial wall layers not only in asthma but also in COPD, and suggest that the pattern of remodeling differs in each of these diseases.