A dynamic shim approach to correct eddy-currents and concomitant-field using multi-coil AC/DC shim array

Motivation: To correct undesirable eddy-current and concomitant-fields effect in MRI acquisitions. Goal(s): To achieve successful eddy-current and concomitant-fields mitigations, paving the way for high-quality 3D-invivo diffusion MRI with high-SNR. Approach: We developed a dynamic shim approach with a multi-coil AC/DC shim-array to correct eddy-currents induced-phase in diffusion-prep encoding, and concomitant-field in long spiral in double-oblique positions. Results: Invivo experiments were performed on the AC/DC shim-array to demonstrate cardiac-gated, multi-shot 3D-diffusion-prepared DTI acquisition without need for SNR-zapping stabilizer. High-quality, high-b-value(2000 s/mm2) acquisition was achieved where a synergistic combination of shim-array and pre-pulse gradient mitigation strategies were employed to minimize eddy-current phase in this difficult case. Impact: We proposed a dynamic shim approach for robust invivo eddy-current correction in 3D-DTI with short preparation-time and high-SNR. Our results demonstrates the AC/DC coil's effectiveness in compensating challenging concomitant-fields during double-oblique slice acquisitions, especially with long-spiral sampling and high-performance gradients.