A New Method for the Determination of Aortic Pulse Wave Velocity

J. Harle, M. J. Graves, I. B. Wilkinson, S. Howarth, J. H. Gillard Medical Physics, University of Cambridge Hospitals NHS Foundation Trust, Cambridge, United Kingdom, Radiology, University of Cambridge Hospitals NHS Foundation Trust, Cambridge, United Kingdom, Clinical Pharmacology, University of Cambridge Hospitals NHS Foundation Trust, Cambridge, United Kingdom Introduction Aortic pulse wave velocity (PWV) has been reported to progressively increase with age as elastic properties of the arterial system decline. Phase contrast MRA offers a powerful technique that, with optimization, can provide an accurate and non-invasive means of assessing PWV at multiple aortic locations, providing new clinical markers of cardiovascular risk attributable to regional aortic stiffness. Herein, provisional results are given of an ongoing clinical trial assessing age-related aortic PWV within two volunteer groups, consisting of healthy individuals aged below 30 and a second group aged over 60. As a further aspect of the study, different methods of data-set analysis were compared for each group, in order to address variations in the literature regarding the characteristic of the propagating pulse wave that is used to correlate time delay between slices. A methodology typical of several literature reports using percentage of peak velocity is compared to a new proposed technique that uses a percentage of sum flow for cross-correlation and ‘triggering’ of time delay between slices.