Combination of VAT and Z-Shimming in Echo Planar Imaging for Distortion Correction and Signal Recovery

Sinyeob Ahn¹, Xiaoping Hu¹

Image distortion and signal loss are detrimental artifacts caused by field inhomogeneity in gradient-echo EPI (GE-EPI). This work describes the combination of view angle tilting (VAT) with z-shimming to address both artifacts in GE-EPI. VAT was implemented with parallel imaging to make it practical for EPI. VAT corrects in-plane distortion in the phase-encoding direction while z-shimming reduces signal loss. The combined sequence was used to generate images with improved quality, particularly in the frontal and inferior orbito-frontal regions of human brain.