AORTIC PULSE WAVE VELOCITY MEASUREMENT

摘要

Embodiments of the present invention provide a measurement protocol that is able to non- invasively provide a degree of characterisation of aortic stiffness, at least qualitatively. The measurement protocol includes varying intra-thoracic pressure via a series of respiratory manoeuvres, whilst collecting aortic blood flow velocity information using a suitable scanning technique, and from which pulse wave velocity (PWV) may then be found. Plotting PWV against aortic trans-mural pressure variations caused by the changes in intra-thoracic pressure should allow a degree or aortic stiffness characterisation to be performed, in that a diseased aorta should show less variation in PWV with changes in trans-mural pressure than a healthy aorta. Also developed as another embodiment is a magnetic resonance (MR) technique for measuring aortic pulse wave velocity, which is able to achieve high temporal resolution on pulse velocity data capture, and hence lead to accurate PWV calculation. The technique uses a time sliding subtraction of velocity projections obtained from bipolar phase encoding gradients to produce velocity profiles at least every second repetition time T_R, and in some variants every T_R.