PENCIL EXCITATION WITH INTERLEAVED FOURIER VELOCITY ENCODING - NMR MEASUREMENT OF AORTIC DISTENSIBILITY

A technique is presented for rapidly and noninvasively determining aor tic distensibility, by NMR measurement of pulse-wave velocity in the a orta. A cylinder of magnetization is excited along the aorta, with Fou rier-velocity encoding and readout gradients applied along the cylinde r axis, Cardiac gating and data interleaving improve the effective tim e resolution to as high as 3 ms. Wave velocities are determined from t he position of the foot of the flow wave in the velocity profiles, Evi dence of helical flow distal to the aortic arch can be seen in normal subjects, while disturbed flow patterns are visible in patients with a neurysms and dissections.