Correct Ghosting and Distortion Artifacts in EPI by Phase Labeling for Additional Coordinate Encoding (PLACE)
Xiang Q, Ye F
University of British Columbia
A simple method is introduced for both N/2 ghost and distortion correction in EPI. Two images are acquired by otherwise identical sequences differing only by an additional gradient lobe along phase encoding direction, creating a relative phase ramp across the field-of-view. The undistorted original y-coordinate of each voxel is encoded as additional phase information that is used to achieve both N/2 ghost and distortion correction. The technique has been demonstrated successfully in phantom and animal studies. The images can also be used as reference scans to allow both deghosting and undistortion of every image in a time series.