Diffusion MRI of the Abdomen with Motion-robust Diffusion Encoding, Multi-shot Readout, and Optimized Slice-specific Shimming

Motivation: Single-shot and multi-shot M1-optimized diffusion imaging (MODI) are recent DWI methods used to mitigate motion and distortion artifacts, yet they often experience chemical shift-based fat suppression failures in the abdomen. Goal(s): To optimize fat suppression in multi-shot MODI-DWI of the abdomen. Approach: Slice-specific chemical shift-encoded (CSE) data-informed optimization of shims is combined with single-shot and multi-shot MODI-DWI in 7 subjects imaged at 3T. Results: Improved fat suppression and water signal excitation were observed alongside the motion and distortion artifact reduction provided by multi-shot MODI-DWI. Unwanted fat signal was reduced through this technique in areas of interest such as the liver, spleen, and ribcage. Impact: Motion-robust, low-distortion DWI of the abdomen, with reliable fat suppression is demonstrated by combining multi-shot EPI, M1-optimized DW waveforms, and an optimized slice-by-slice shimming approach. This combined method may enable improved detection and staging of cancer in the abdomen.