The aim of this study was to show reduction of the diaphragmatic excursion with MR fluoroscopy in patients with chronic obstructive pulmonary disease (COPD) and to compare the results with pulmonary function test (PFT). The study included 13 men and 10 women (average age 56.2) with COPD, and 9 men and 6 women (average age 55.8) as a control group. MR fluoroscopy images with Spoiled Gradient-echo pulse sequence was obtained during deep inspiration and expiration. After examination, over cine-loop display, the highest and lowest positions of the diaphragm were identified and the distance of excursion was measured. Differences in the diaphragmatic excursion between patient and healthy subjects were compared. We have also compared MR fluoroscopy results with PFT. In each person of both groups, excursion of the diaphragm was demonstrated clearly in cine-loop display. Differences of excursion between deepest and highest point of diaphragm were on average 26 and 20 mm, respectively, in the right and left side in patients and 69 and 56 mm in healthy group. Significant correlation was found between expiratory volume in 1 s and MR fluoroscopy results. MR fluoroscopy study showed that there were significant statistical differences in diaphragmatic excursion between patients with COPD and healthy subjects. Expiratory volume in 1 s is closely associated with the diaphragmatic excursion. MR fluoroscopy would seem to be a useful method for showing diaphragmatic excursion. (C) 2001 Elsevier Science Inc. All rights reserved.