Atlas-based Improved Prediction of Magnetic Field Inhomogeneity for Distortion Correction of EPI Data

Citation:

Poynton C, Jenkinson M, Wells III WM. Atlas-based Improved Prediction of Magnetic Field Inhomogeneity for Distortion Correction of EPI Data. Med Image Comput Comput Assist Interv. 2009;12 (Pt 2) :951-9.

Date Published:

2009

Abstract:

We describe a method for atlas-based segmentation of structural MRI for calculation of magnetic fieldmaps. CT data sets are used to construct a probabilistic atlas of the head and corresponding MR is used to train a classifier that segments soft tissue, air, and bone. Subject-specific fieldmaps are computed from the segmentations using a perturbation field model. Previous work has shown that distortion in echo-planar images can be corrected using predicted fieldmaps. We obtain results that agree well with acquired fieldmaps: 90% of voxel shifts from predicted fieldmaps show subvoxel disagreement with those computed from acquired fieldmaps. In addition, our fieldmap predictions show statistically significant improvement following inclusion of the atlas.

Last updated on 05/04/2017