Assessing methods for geometric distortion compensation in 7 T gradient echo functional MRI data.

ABSTRACT: Echo planar imaging (EPI) is widely used in functional and diffusion-weighted MRI, but suffers from significant geometric distortions in the phase encoding direction caused by inhomogeneities in the static magnetic field (B₀ ). This is a particular challenge for EPI at very high field (≥7 T), as distortion increases with higher field strength. A number of techniques for distortion correction exist, including those based on B₀ field mapping and acquiring EPI scans with opposite phase encoding directions. However, few quantitative comparisons of distortion compensation methods have been performed using human EPI data, especially at very high field. Here, we compared distortion compensation using B₀ field maps and opposite phase encoding scans in two different

SUBMITTER: Schallmo MP 

PROVIDER: S-EPMC8356998 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature