Aortic Pulse Wave Velocities Using Real-Time Phase-Contrast MRI

Purpose: To evaluate aortic pulse wave velocities obtained by real-time phase-contrast (PC) MRI in comparison to cine PC MRI. Methods: Real-time PC MRI of eight healthy volunteers employed highly undersampled radial FLASH sequences and phase-sensitive image reconstructions by regularized nonlinear inversion (NLINV) at 40 ms temporal resolution and 1.3 mm in-plane resolution. Pulse wave velocities were analyzed for combinations of 2, 3 and 4 locations of aortic flow using time-to-upslope and cross-correlation methods. Results: For the time-to-upslope analysis mean pulse wave velocities ranged from 3.5 to 3.9 m s-1 for real-time PC MRI and from 3.5 to 3.8 m s-1 for cine PC MRI. A cross-correlation analysis of the same data resulted in 2.9 to 3.3 m s-1 and 3.3 to 3.7 m s-1, respectively. Conclusion: Real-time PC MRI determined aortic pulse wave velocities from single cardiac cycles in close correspondence to values obtained by cine PC MRI.