Rapid Volume Shimming with Gradient Reversed EPI

Kevin Koch¹, Eric Printz¹, Dan Xu¹

It has previously been demonstrated that EPI acquisitions with reversed phase-encode blip polarities can be used to correct image distortions. A by-product of these methods is a shift map that maps the two source images together. Here, we demonstrate that one of the algorithms previously utilized for distortion correction purposes can be modified to produce high-SNR volumetric field maps for shimming purposes. These results suggest that such methods could be used to collect spatially accurate volumetric field maps for shimming purposes in a matter of seconds.