Difference in diaphragmatic motion during tidal breathing in a standing position between COPD patients and normal subjects: time-resolved quantitative evaluation using dynamic chest radiography with flat panel detector system (“dynamic X-ray phrenicography”)

Highlights • Dynamic X-ray phrenicography is a useful method for the evaluation of the diaphragms. • Its radiation dose is comparable to conventional two projection chest radiography. • Diaphragm motion during tidal breathing is larger in COPD than in normal subjects. • Higher BMI is also associated with increased excursions of the bilateral diaphragm.