Pencil excitation with interleaved fourier velocity encoding: NMR measurement of aortic distensibility.
A technique is presented for rapidly and noninvasively determining aortic distensibility, by NMR measurement of pulse-wave velocity in the aorta. A cylinder of magnetization is excited along the aorta, with Fourier-velocity encoding and readout gradients applied along the cylinder axis. Cardiac gating and data interleaving improve the effective time resolution to as high as 3 ms. Wave velocities are determined from the position of the foot of the flow wave in the velocity profiles. Evidence of helical flow distal to the aortic arch can be seen in normal subjects, while disturbed flow patterns are visible in patients with aneurysms and dissections.
Hardy
C J
CJ
GE Corporate Research and Development Center, Schenectady, New York 12301, USA.
Bolster
B D
BD
McVeigh
E R
ER
Iben
I E
IE
Zerhouni
E A
EA
D000328:Adult; D001013:Aorta, Thoracic / Q000473:pathology / Q000502:physiology* / Q000503:physiopathology; D001014:Aortic Aneurysm / Q000473:pathology / Q000503:physiopathology; D001783:Blood Flow Velocity; D004548:Elasticity; D005583:Fourier Analysis; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*