Fieldmap-Free Retrospective Registration and Distortion Correction for EPI-Based Diffusion-Weighted Imaging

Clare Poynton¹, Mark Jenkinson², Carlo Pierpaoli³, William Wells III⁴

We evaluate a recent method for EPI B0 distortion correction in a test framework that was previously developed for evaluating B0 distortion correction methods for DWI. The correction method uses structural MRI, segmentation, registration, and physics-based estimation of a fieldmap, and accounts for unknown shim parameters. The predicted fieldmap is subsequently used to unwarp the EPI. The test framework uses a specially collected set of DWI data and associated methodology that analyzes the variability in FA and trace following correction. The distortion correction method produces results that agree well with current fieldmap-based methodology.