Water/fat Separated Distortion-Free Diffusion-Weighted Imaging in the Head and Neck

Motivation: Diffusion-weighted imaging (DWI) in the head and neck region is often hindered by significant B0 field inhomogeneity, leading to severe image distortion and residual fat artifacts. Goal(s): We aim to achieve distortion-free diffusion-weighted imaging with robust water/fat separation and sufficient signal-to-noise ratio (SNR) in the head and neck. Approach: We employ an M1-nulled diffusion-prepared multi-echo fast spin echo (FSE) sequence for distortion-free fat/water separation and B0 robustness, replacing motion-stabilizing gradients with shot-weighted reconstruction to enhance SNR efficiency. Results: Images show significant reduction in residual fat artifacts and image distortion compared to a vendor provided multi-shot diffusion-weighted method. Impact: Diffusion-prepared FSE using shot-weighted reconstruction and multi-echo water/fat separation is robust to significant B0 variations, with relatively high SNR efficiency. This enables reliable use of DWI for assessing cancer and other abnormalities in the head and neck, complementing contrast-enhanced imaging.