Time-resolved quantitative evaluation of diaphragmatic motion during forced breathing in a health screening cohort in a standing position: Dynamic chest phrenicography

Objective: To assess diaphragmatic motion during forced breathing in a health screening center cohort by time-resolved quantitative analysis using dynamic chest radiography and demonstrate the characteristics and associations with demographics and pulmonary function of participants. Materials and methods: This prospective study includes 174 volunteers (99 males; median 57, range 36–93 years old) that underwent dynamic chest radiography with a flat panel detector system during forced breathing in a standing position. We automatically tracked and recorded the positions of the top of the diaphragms and the excursions on images of each participant and calculated peak motion speeds based on the data. We investigated the associations with demographics and pulmonary function statistically. Results: The average excursions of the diaphragms during forced breathing were 49.1 ± 17.0 mm (right; mean ± standard deviation) and 52.1 ± 15.9 mm (left). The peak motion speeds were 26.7 ± 10.0 mm/s (right) and 32.2 ± 12.4 mm/s (left) in the inspiratory phase and 22.1 ± 12.7 mm/s (right) and 24.3 ± 10.3 mm/s (left) in the expiratory phase. Excursions and peak motion speeds of the left diaphragm were significantly greater than the right. Higher body mass index (BMI) and vital capacity (VC) were associated with greater excursions and faster peak motion speeds of the diaphragms. Conclusions: Time-resolved quantitative analysis of the diaphragms with dynamic chest radiography demonstrated the characteristics of diaphragmatic motion during forced breathing in a health screening cohort. Higher BMI and VC were associated with excursions and peak motion speeds of the diaphragms.