Projective MR measurements of pulse-wave velocity in the presence of reflected waves on an arterial model

A MRI projective velocity encoding sequence has been employed to determine the pulse-wave velocity in an arterial model. In order to validate the measurement method in the presence of large reflected waves, these were deliberately created in the phantom. The projective sequence was applied on two measurement sites and the wave velocity was determined from the spatial and temporal separations of the "foot" of the velocity waveform. A theoretical model that describes reflections and attenuation phenomena was compared with the authors' experimental velocity waveforms. The model showed that reflections and attenuation can explain important changes in velocity wave shapes. It also confirmed that in the presence of reflecting waves, the "foot" of the waveform can be used as a characteristic point for measurements, throughout the changes in the waveform.