Macroscopic B0 Inhomogeneity Corrected QSM Based on a Field Mapping Algorithm Using a Single-Scan 3D Z-Shim Multi-Echo GRE.

Dongyeob Han¹, Yoonho Nam¹, Sung-Min Gho¹, Dong-Hyun Kim¹

Quantitative Susceptibility Mapping (QSM) based on phase data of gradient echo (GRE) is a novel technique for measuring susceptibility differences of the tissue. However, the macroscopic B0 inhomogeneity due to air/tissue boundary causes artifacts which is a common drawback of the GRE1. Furthermore, the effect of the macroscopic B0 inhomogeneity become worse as the echo time increases, and this is critical to QSM studies which have long echo times. To overcome this problem, we propose a 3D z-shim multi-echo GRE pulse sequence which can generate B0 inhomogeneity compensated QSM and a simple robust algorithm for B0 inhomogeneity compensated field map.