A numerical study of magnetic resonance images of pulsatile flow in a two dimensional carotid bifurcation - A numerical study of MR images

A numerical method to simulate magnetic resonance angiographic images is pr oposed. The new method greatly simplifies the calculation of the average ph ase in a voxel, the bottleneck of previous simulations, and reduces the com putation time by more than a factor of 5. Both the Navier-Stokes and the Bl och equations are solved on the same mesh to obtain the distributions of th e modulus and phase of the magnetization. The data in the frequency domain are reordered according to the gating strategy to generate the final images . Pulsatile flow through a 2D normal carotid bifurcation is considered as a test case. Images for magnetic resonance angiography with an uncompensated gradient waveform, a velocity-compensated gradient waveform and an uncompe nsated short-TE gradient waveform are compared. Systolic Sating images are shown to have degraded image quality. Images acquired with diastolic-gating have little variation in magnetization strength throughout the pulsatile c ycle and provide a better representation of the vessel lumen. (C) 1999 IPEM . Published by Elsevier Science Ltd. All rights reserved.