Meeting Banner
Abstract #2420

Comparison of EPI Geometric Distortion Correction Using Field Mapping and Forward/reverse Phase Encoding Directional EPI Scans

Wanyong Shin1, Erik Beall1, Ken Sakaie1, Mark Lowe1

1Radiology, Cleveland Clinic, Cleveland, OH, United States

Since EPI images with forward (for.)/reverse (rev.) phase encoding (PE) directions provide voxel shifts in opposite directions, several approaches have been proposed to calculate voxel displacement (VD) map in PE direction using the two, in short, 2PE method here. Since both field map (FM) and 2PE methods generate VD maps, the direct voxel-wise comparison of VD maps between FM and 2PE method would provide the comprehensive insight of pros/cons of 2PE. In this study, we compare VD maps from FM and 2 PE methods, and demonstrate their performance and limitation.

Abstract PDF

Keywords

acknowledges acquisition analyzed anatomical applied approaches aspect author authors axes background bandwidth bland brain built calculation called clinic code codes commonly comprehensive cons consistency consistently correct correction correlation cost dale defined deformation demonstration described determined diameter direct directional directly displacement distortion distortions dual edge employed employs encoding excessive fast field filtering forward front full function generate geometric gradient gradients gratefully home implementation includes inhomogeneities insight institute inversed invoke invoked isotropic iteratively leading leads limitation lobe lose mapping maps mark measures medical merit might minimizing modulation native necessarily noise opposite optimized original package paradigm parts performance planar plot popularly priori processing promising proposed pros providing puts radiology rapid rapidly readout real recently reduce reflects refocusing regularization represent require resolution restricts reverse robust running scalp scripts several sharper shin short since slices smooth smoothing smoothness solutions source spatial spin squares still sufficient support supported surprising systemically technical toolbox typical varies whole width wise