Rigid and multirigid motion-mitigated MRI with self-gated Cartesian acquisition

Motivation: Rigid or multirigid motion remains a challenge for brain or musculoskeletal imaging. The unintentional motions can degrade the MR image quality and affect diagnosis. Goal(s): To apply a self-gated Cartesian acquisition for rigid or multirigid motion-mitigated MRI of the brain and knee. Approach: A previously developed spoiled gradient echo sequence with self-gated rotating Cartesian k-space acquisition (ROCK) was applied. Motion information can be extracted from the self-gating projections, which can be used for motion-mitigated reconstruction. Results: The self-gating projections can detect the motion in all three directions with high sensitivity. Quality of the reconstructed image using self-gating is significantly improved. Impact: The self-gating technique can detect rigid or multirigid motions with high sensitivity. It is also robust for different readout directions. With a minimal acquisition time overhead, this technique enables motion-mitigated reconstruction and the image quality is significantly improved.