In vitro validation of MR measurements of arterial pulse-wave velocity in the presence of reflected waves

A magnetic resonance imaging projective velocity encoding sequence was used to determine the pulse-wave velocity in an artery model. To this end, a we ll-defined flow phantom simulating flow propagation in large arteries was u sed. In order to validate the measurement method in the presence of large r eflected waves, these were deliberately created in the phantom. The project ive sequence was applied to two measurement sites and the wave velocity was determined from the spatial and temporal separations of the foot of the ve locity waveform. A theoretical model describing reflection and attenuation phenomena was compared with experimental velocity waveforms. The model show ed that reflections and attenuation can explain the important changes in ve locity waveforms. The model also confirmed that in the presence of reflecti ng waves, the foot of the waveform can be used as a characteristic point fo r measurements through changes in the waveform. (C) 2001 Wiley-Liss, Inc.