Analysis of Diaphragmatic Motion with Prone Positioning Using Dynamic MRI

The objective of this study was to quantitatively analyze differences in diaphragmatic motion between supine and prone positioning during resting breathing using dynamic Magnetic Resonance Imaging.Total diaphragmatic motion (TDM), defined as total excursion of the anterior (ANT), central (CNT), and posterior (PST) diaphragm, was 61 mm in the supine position and 63 mm in the prone position. No significant difference in TDM was apparent in response to change in positioning. Diaphragmatic motion was greatest in the PST > CNT > ANT with supine positioning, and PST > ANT = CNT with prone positioning. In both positions, motion tended to be greatest in the posterior diaphragm. However, relative changes in CNT and PST were less with prone than with supine positioning. These findings suggest that ventilation in the posterior lung fields is decreased to a greater extent with prone than with supine positioning.