Arterial Distensibility and Pulse Wave Velocity Evaluated by MRI

Aortic PWV can also be measured by Magnetic Resonance Imaging (MRI). This procedure allows the user to select two regions of interest along the aorta, recording a flow-time curve (Fig. 2.15). As a matter of fact, PWV can be given by the ratio of the distance between two artery points and the time delay between the two aortic flow curves (Fig. 2.16) [10]. MRI can also measure PWV at a single aortic location (ascending aorta, aorta arch, or descending aorta), providing useful hemodynamic information in different vascular diseases. However, the evaluation of the aortic blood flows by MRI appears to be very general and, consequently, the acquisition of PWV inaccurate (Figs. 2.17 and 2.18). This is the reason why MRI cannot be considered as a standard reference method, but it is a reliable procedure for the segmental evaluation of arterial compliance as it permits an accurate measurement of the variation of the vascular diameter during the cardiac cycle.

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