View angle tilting echo planar imaging for distortion correction

• Type of Material: Article
• Authors: Sinyeob Ahn, Emory University; Xiaoping Hu, Emory University
• Language: English
• Date: 2012-10-01
• Publisher: Wiley
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: Copyright © 2011 Wiley Periodicals, Inc.
• Final Published Version (URL): http://dx.doi.org/10.1002/mrm.23320
• Title of Journal or Parent Work: Magnetic Resonance in Medicine
• ISSN: 0740-3194
• Volume: 68
• Issue: 4
• Start Page: 1211
• End Page: 1219
• Grant/Funding Information: This work was supported in part by the National Institute of Health (grant RO1EB002009) and Georgia Research Alliance.
• Keywords: Sensitivity and Specificity; Brain; Image Enhancement; Humans; Reproducibility of Results; Artifacts; Echo-Planar Imaging; Image Interpretation, Computer-Assisted; Algorithms
• Research Categories: Engineering, Biomedical

Abstract

Geometric distortion caused by field inhomogeneity along the phase-encode direction is one of the most prominent artifacts due to a relatively low effective bandwidth along that direction in magnetic resonance echo planar imaging. This work describes a method for correcting in-plane image distortion along the phase-encode direction using a view angle tilting imaging technique in spin-echo echo planar imaging. Spin-echo echo planar imaging with view angle tilting uses the addition of gradient blips along the slice-select direction, concurrently applied with the phase-encode gradient blips, producing an additional phase. This phase effectively offsets an unwanted phase accumulation caused by field inhomogeneity, resulting in the removal of image distortion along the phase-encode direction. The proposed method is simple and straightforward both in implementation and application with no scan time penalty. Therefore, it is readily applicable on commercial scanners without having any customized postprocessing. The efficacy of the spin-echo echo planar imaging with view angle tilting technique in the correction of image distortion is demonstrated in phantom and in vivo brain imaging.