Josef Pfeuffer1, Dingxin Wang2,
Christina Triantafyllou3
1MR Application Development,
Siemens Healthcare, Erlangen, D, Germany; 2US R&D, Siemens
Healthcare, Minneapolis, MN, United States; 3McGovern Institute
for Brain Research, MIT, Cambridge, MA, United States
Dynamic B0-off-resonance, caused by subject physiology (respiration), leads to dynamic image artifacts in fast imaging sequences such as pixel shifts in PE direction for blipped EPI. Image phase EPI can be used for distortion correction in a static or dynamic mode using field maps or techniques such as PLACE. Our goal was to investigate the effects of global frequency drifts on dynamic phase EPI, secondly to employ navigator methods to robustly correct for these effects and evaluate remaining image phase EPI stability. The phase temporal SD could be significantly reduced in all sessions and was demonstrated also for all different orientations.
Keywords