Flow-induced artifact elimination in magnetic resonance images

摘要

Magnetic resonance imaging of a blood vessel exhibits flow artifacts, or signal loss, around a constriction (26) due to turbulent fluid flow. Signal loss in a region (27) prior to the constricted region (26) is primarily caused by convective acceleration, and this signal loss is substantially eliminated by performing an acceleration compensation process. Signal loss in a region (32) situated after the constriction (26) is primarily caused by velocity fluctuations, and this signal loss is cured by an imaging process which does not rely on the phase of the electromagnetic excitation signal(s) for spatial localization. Examples of imaging processes for minimizing signal loss due to turbulence include a projection reconstruction process (34) and a two dimensional slice selection process (56). Further, the two dimensional slice selection process (56) may be used for generating instantaneous velocities of fluid flowing through a fluid channel. Also, if a number of instantaneous velocities are produced over a time period, then fluctuation velocities can be determined via time-resolved averaging.