Estimation of pressure gradients in pulsatile flow from magnetic resonance acceleration measurements

• Published in: Magnetic resonance in medicine Vol. 44; no. 1; pp. 66 - 72
• Main Authors: Tasu, Jean-Pierre, Mousseaux, Elie, Delouche, Annie, Oddou, Christian, Jolivet, Odile, Bittoun, Jacques
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 01.07.2000; Williams & Wilkins
• Subjects: Adult; Aorta, Thoracic - physiology; Biological and medical sciences; Blood Flow Velocity - physiology; blood pressure; Blood Pressure - physiology; Cardiovascular system; Feasibility Studies; flow dynamics; Fourier Analysis; Hemorheology; Humans; Investigative techniques, diagnostic techniques (general aspects); Linear Models; Magnetic Resonance Imaging; Male; Medical sciences; Models, Cardiovascular; MRI; Phantoms, Imaging; Pulsatile Flow - physiology; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Signal Processing, Computer-Assisted; Space life sciences; Transducers, Pressure; vascular studies; Human; Fluid dynamics; Pressure gradient; Boundary condition; Nuclear magnetic resonance imaging; Acceleration measurement; Image analysis; Medical imagery; Aorta; Feasibility; Circulatory system; Newtonian fluid; Hemodynamics
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/1522-2594(200007)44:1<66::AID-MRM11>3.0.CO;2-#

A method for estimating pressure gradients from MR images is demonstrated. Making the usual assumption that the flowing medium is a Newtonian fluid, and with appropriate boundary conditions, the inertial forces (or acceleration components of the flow) are proportional to the pressure gradients. The technique shown here is based on an evaluation of the inertial forces from Fourier acceleration encoding. This method provides a direct measurement of the total acceleration defined as the sum of the velocity derivative vs. time and the convective acceleration. The technique was experimentally validated by comparing MR and manometer pressure gradient measurements obtained in a pulsatile flow phantom. The results indicate that the MR determination of pressure gradients from an acceleration measurement is feasible with a good correlation with the true measurements (r = 0.97). The feasibility of the method is demonstrated in the aorta of a normal volunteer. Magn Reson Med 44:66–72, 2000. © 2000 Wiley‐Liss, Inc.