Image distortion correction for MRI in low field permanent magnet systems with strong B₀ inhomogeneity and gradient field nonlinearities.

ABSTRACT:

Objective

To correct for image distortions produced by standard Fourier reconstruction techniques on low field permanent magnet MRI systems with strong [Formula: see text] inhomogeneity and gradient field nonlinearities.

Materials and methods

Conventional image distortion correction algorithms require accurate [Formula: see text] maps which are not possible to acquire directly when the [Formula: see text] inhomogeneities also produce significant image distortions. Here we use a readout gradient time-shift in a TSE sequence to encode the [Formula: see text] field inhomogeneities in the k-space signals. Using a non-shifted and a shifted acquisition as input, [Formula: see text] maps and images were reconstructed in an iterative manner. In each iteration, [Formula: see text] ma

SUBMITTER: Koolstra K 

PROVIDER: S-EPMC8338849 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature