Movable Linear Gradients Optimized on Non-Planar B0 Slice Profiles Used for Improving Spatial Encoding in a Non-Linear Low-Field MRI

Motivation: Spatial resolution in an open low-field MRI that uses surface RF coils for B1-encoding can be improved by repositioning the RF coils within FOV for each TR. However, this approach is limited by space constraints in the left-right dimension. Linear gradients, especially movable ones optimized for a slab, effectively supplement encoding in that direction. Goal(s): To improve spatial resolution in the left-right direction of an open low-field MRI. Approach: A linear gradient optimized on B0 slice volume is moved in the anterior-posterior direction dependent on readout slice location. Results: Movable gradients improve spatial encoding. Impact: There is an unmet need for open low-field MRIs that can accommodate patients of all sizes and disabilities: this approach to generating high spatial resolution images without the use of volume-encompassing gradients makes open MRI viable.