ABBREVIATED MOMENT-COMPENSATED PHASE-ENCODING

To achieve correct spatial location of blood vessels, first order grad ient moment nulling applied to the phase encoding axes can be used. Ho wever, gradient moment nulling prolongs echo time (TE), which may degr ade the flow image in regions of complex flow. The fact that abbreviat ed moment compensated phase-encoding (AMCPE) can be used to apply part ial flow compensation to the phase-encoding axes to prevent spatial mi sregistration of vessels without requiring the use of long echo times or using arbitrary chosen TE is demonstrated. AMCPE defines two cutoff lines in k-space. The flow-induced phase is completely compensated fo r values between the cutoff lines and partially compensated beyond the cutoff lines. The AMCPE technique has been tested on both a flow phan tom and a human volunteer. The AMCPE images from both the in vivo and the in vitro study demonstrate correctly imaged flow. Computer simulat ions have been performed to analyze the penalty caused by the incomple te flow compensation. The result shows that the ripple artifacts due t o the incomplete flow compensation are unobservable when 60%-70% of k- space is completely flow compensated.