Simulation of phase effects in magnetic resonance flow imaging

Using a phantom containing stationary and flowing regions, the phase related effects of flow on spin echo and echo planar images have been investigated. The role of parameters such as flow direction, mean velocity, velocity modulation, gradient pulses, echo time and data sampling time in producing artifacts and the reduction of these artifacts by a flow compensating pulse have been examined. It is shown that, due to the finite data sampling window, the flow compensating pulse cannot fully correct for phase shifts even for first-order motion.