Motion and temporal B-shift corrections for QSM and mapping using dual-echo spiral navigators and conjugate-phase reconstruction.

PURPOSE

To develop an efficient navigator-based motion and temporal B-shift correction technique for 3D multi-echo gradient-echo (ME-GRE) MRI for quantitative susceptibility mapping (QSM) and mapping.

THEORY AND METHODS

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 B shifts. We performed numerical simulation, phantom scans, and in vivo human scans to assess the performance of the methods.

RESULTS

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

CONCLUSION

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