In vivo measurement of pulsewave velocity in small vessels using intravascular MR

A one-dimensional intravascular MR (IVMR) technique for the measurement of pulsewave velocity in a single cardiac cycle is presented. The technique wa s used to measure pulsewave velocity in vivo in the intact rabbit model, wh ere its sensitivity to different hemodynamic states was demonstrated using a pharmacological intervention with phenylephrine and nitroprusside. IVMR m easurements of pulsewave velocity were found to increase with mean arterial pressure, as expected. Further, IVMR-based pulsewave velocity estimates we re in agreement with those measured by pressure catheters and direct disten sibility measurement. Because of their rapidity and highly localized nature , these measurements of vessel elasticity may complement the high-resolutio n vascular imaging information gained in an IVMR examination. This could al low assessment of atherosclerotic plaques and facilitate immediate treatmen t decisions. Magn Reson Med 45:53-60, 2001. (C) 2001 Wiley-Liss, Inc.