An integrated approach to correction for off-resonance effects and subject movement in diffusion MR imaging

This paper presents a method for retrospective estimation and correction of eddy current (EC)-induced distortions and subject movement in diffusion MR imaging. In addition, a susceptibility-induced field can be supplied and is incorporated in a way that accurately reflects that the susceptibility- and EC-induced fields behave differently in the presence of subject movement. The core of the method is to register the individual volumes to a model-free prediction of what each volume should look like, which enables its use on high b-value data where image contrast varies dramatically across volumes.

The authors demonstrate that the linear EC model commonly used is insufficient for their high spatial and angular resolution data, acquired with Stejskal-Tanner gradients on 3T and 7T Siemens scanners, and that a higher-order model performs significantly better. The method was already in extensive practical use, adopted by four major projects, the WU-UMinn HCP, the MGH HCP, the UK Biobank, and the Whitehall studies, to correct for distortions and subject movement, underscoring its practical impact on large-scale diffusion imaging.