Demonstration of gravity-dependent lung perfusion with contrast-enhanced magnetic resonance imaging

Imaging of lung perfusion using contrast-enhanced dynamic magnetic resonanc e (MR) was performed in both the supine and prone positions in six voluntee rs. Regions of interest (ROIs) were chosen in the dependent and nondependen t portions of the right lung, The percentage increase in signal intensity ( SI) and the mean slope were calculated, In the supine position, the dorsal ROI had a greater increase in SI (236.0% vs. 156.9%, P < 0.05) and a faster rise in the slope of enhancement (55.1%/sec vs. 30.1%/sec, P < 0.05) than the ventral ROI. After changing to the prone position, higher peak enhancem ent (234.3% vs. 177.4%, P < 0.05) and faster slopes (59.6%/sec vs. 35.3%/se c, P < 0.05) shifted to the anterior ROI, We conclude that dynamic contrast -enhanced MR imaging is sensitive to demonstrate gravitationally dependent differences in lung perfusion. J, Magn, Reson, Imaging 1999;9: 557-561, (C) 1999 Wiley-Liss, Inc.