Motion and temporal B₀-shift corrections for QSM and R 2 * mapping using dual-echo spiral navigators and...

To develop an efficient navigator-based motion and temporal B₀-shift correction technique for 3D multi-echo gradient-echo (ME-GRE) MRI for quantitative susceptibility mapping (QSM) and $R_2^{*}$ mapping.

A dual-echo 3D stack-of-spiral navigator was designed to interleave with the Cartesian multi-echo gradient-echo acquisitions, allowing the acquisition of both low-echo and high-echo time signals. We additionally designed a novel conjugate phase-based reconstruction method for the joint correction of motion and temporal B₀ shifts. We performed numerical simulation, phantom scans, and in vivo human scans to assess the performance of the methods.

Numerical simulation and human brain scans demonstrated that the proposed technique successfully corrected artifacts induced by both head motions and temporal B₀ changes. Efficient B₀-change correction with conjugate-phase reconstruction can be performed on fewer than 10 clustered k-space segments. In vivo scans showed that combining temporal B₀ correction with motion correction further reduced artifacts and improved image quality in both $R_2^{*}$ and QSM images.

Our proposed approach of using 3D spiral navigators and a novel conjugate-phase reconstruction method can improve susceptibility-related measurements using MR.