Simulation of in-plane flow imaging

Two methods of simulating the imaging process in magnetic resonance (MR) are explained: namely, the k-space and the isochromat summation methods. The latter method is more closely related to the actual behavior of magnetic spins, and is used in the remainder of this work. The MR image appearance of in-plane fluid flow is simulated using the isochromat summation technique. Flow-related artifacts are demonstrated, together with flow compensation, phase-contrast (PC) velocity encoding, and cine-PC measurement of pulsatile flow. The special considerations necessary for simulating pulsatile flow with a reverse flow component are discussed. Magnetic field inhomogeneities and susceptibility effects are readily incorporated. The computation time required for the simulations is discussed in some detail. Simulations of flow imaging have been found useful in the development and validation of new pulse sequences, and for teaching purposes. ©1999 John Wiley & Sons, Inc. Concepts Magn Reson 11: 379–392, 1999