Meeting Banner
Abstract #2421

Distortion Correction Using the Susceptibility Based Field Map Estimation in Echo Planar Imaging Reconstruction

Hiroyuki Takeda1, Boklye Kim1

1Radiology, University of Michigan, Ann Arbor, MI, United States

Reconstructed EPI images suffer from geometric distortion often due to the magnetic field inhomogeneity and significantly undermine the performance of activity analyses. In this work, we focus on a fundamental approach of the susceptibility-induced magnetic field inhomogeneity map to retrospectively recover the spin density map for EPI image reconstruction. By modeling the acquisition process, we identify the effect of the field inhomogeneity to the EPI reconstruction, and then obtain distortion-free density images using a regularized least-square method. Result shows that our approach works effectively for recovering the original undistorted image with an accurate estimate of the field map.

Abstract PDF

Keywords

absolute accurate accurately acknowledgments acquisition activities added affect affects analyses anatomical applying approaches assumed assuming asymmetrical atlas available axis beyond brain chosen coil column common compute computed condition constant construct constructed convenience convolution convolving correction currently dataset density described directly distorted distortion distortions domain dwell effectively enables encoding error errors estimation estimator examine expressed field final find form forward free functionality future generate generated geometric geometrically grant head human identify important in vivo include induced inhomogeneity kernel known least makes mapped matrix measured model modeling motion necessary noise onto original performance pilot planar plays position prevalent process radiology reconstruct reconstructed reconstruction recover registering registration regularization regularized related represents resolution respectively restoration retrospectively rewrite role sample samples save scanning segmented sensitivity session significantly simulated simulation simulations since slice space spatial spin square stacked step strongly structures subject suffer susceptibility system take taking transfer transform transformed unchanged underscore uniformly unknown upper variation vector worth zero