ZTE in highly inhomogeneous B0 regime.

Motivation: : ZTE has proven to be a powerful MRI sequence for ultrashort T2 tissues, but it fails to produce useful images in the presence of strong field inhomogeneities. Goal(s): To develop a method to correct artifacts induced by strong B0 inhomogeneities in ZTE sequences, based on on-the-fly B0 maps. Approach: A B0 map, obtained by phase difference between two fast SPRITE sequences, is fed into an encoding matrix for posterior image reconstruction by Kaczmarz’s Algebraic Reconstruction Techniques. Results: Geometric distortions and hyperintense regions resulting from B0 strong quadratic components are largely reverted with this approach. Impact: This method can be exploited for e.g. dental imaging with ZTE in affordable low-field MRI systems, and can be generalized to other non-Cartesian sequences. Furthermore, it may prove useful for imaging with extreme magnet geometries as in e.g. single-sided MRI.