Robust motion- and $$$\delta B_0$$$ -correction for high-resolution QSM at 7T

Motivation: Quantitative susceptibility mapping (QSM) provides valuable clinical information and is widely used, especially at ultra-high field (7T). Due to long echo times, QSM acquisitions are extra sensitive to the changes in B0 ($$$\delta\textbf{B}_0$$$), such as those secondary to motion. Goal(s): To provide purely data-driven motion and $$$\delta\textbf{B}_0$$$ correction for QSM. Approach: We use the self-navigated DISORDER k-space re-ordering, originally proposed for motion correction, to additionally estimate $$$\delta\textbf{B}_0$$$. Within-scan motion and $$$\delta\textbf{B}_0$$$ are then retrospectively corrected during image reconstruction. Results: We show improved reconstruction in all 5 scanned volunteers when additionally correcting $$$\delta\textbf{B}_0$$$. This directly improves QSM. Impact: The proposed method can result in improved image quality when scanning in presence of motion and , e.g. due to heavy breathing. Combining this approach with an optimized QSM protocol will provide motion- and -robust QSM.