Hida T, et al. - In this prospective study, researchers evaluated the diaphragmatic motion in patients with chronic obstructive pulmonary disease (COPD) during forced breathing by time-resolved quantitative analysis using dynamic chest radiography and demonstrated the characteristics and differences from normal subjects. For this investigation, they involved 31 COPD patients and a matched control of 31 normal subjects on age, sex, height, and weight, who had chest radiographs during forced breathing using dynamic chest radiography. Based on the criteria of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) (GOLD 1, n = 3; GOLD 2, n = 12; GOLD 3, n = 13; GOLD 4, n = 3), COPD patients were classified. According to findings, time-resolved quantitative analysis of diaphragms with dynamic chest radiography showed differences in diaphragmatic motion between normal subjects and COPD groups during forced breathing. During forced breathing, diaphragm excursions in the GOLD 3/4 group were significantly lower than in the GOLD 1/2 group and normal subjects.