Scout and guidance line-based retrospective motion correction for susceptibility-weighted-imaging (SWI)

Motivation: Motion artifacts are a common source of artifacts in clinical brain imaging. Goal(s): To facilitate efficient retrospective motion correction for susceptibility-weighted-imaging (SWI). Approach: A 2 sec motion-free pre-scan and the repeated acquisition of additional k-space encoding lines (guidance lines) were implemented into an GRE-based SWI. Guidance lines are played as an additional gradient-echo before the imaging echo which retains the original scan efficiency. Scout and guidance lines are then used for very rapid, fully separable motion trajectory estimation and correction. Results: In vivo, reduced motion artifacts and increased image sharpness is demonstrated across several scans with instructed subject motion. Impact: Scout and guidance-lines based retrospective motion correction is introduced for SWI. Our approach enables efficient motion artifact mitigation while being minimally disruptive to standard clinical protocols and should improve the robustness and reproducibility of clinical brain imaging.