Improved Large-FOV Dynamic MRI at 0.55T with Concomitant Field Correction

Motivation: Artifacts caused by concomitant fields are significant at lower B0 field strengths, larger distances from isocenter, and when using longer readouts. This is a significant limitation for large-FOV dynamic imaging at low- and mid- field strengths. Goal(s): To demonstrate dynamic MRI with concomitant field correction. Approach: We combine state-of-the-art dynamic MRI using undersampling and constrained reconstruction, with a concomitant field mitigation approach (MaxGIRF) that uses a higher-order encoding matrix. Results: We demonstrate significant artifact reduction in large-FOV dynamic MRI of the lung in coronal orientation at 0.55 Tesla. Impact: This work resolves one major constraint that currently limits large-FOV and off-isocenter dynamic MRI at low field strengths. This could provide better imaging of the lung, abdomen, and obese subjects, and better guidance of interventions that utilize a table shift.