Self-navigated simultaneous multi-slab 3D DWI

Motivation: Simultaneous multi-slab imaging (SMSlab) facilitates high-resolution diffusion-weighted imaging (DWI) with enhanced signal-to-noise ratio (SNR) efficiency, but requires navigators that compromising the scan efficiency. Goal(s): To achieve navigator-free simultaneous multi-slab DWI. Approach: For slabs that are excited simultaneously, a multiband-specific GRAPPA is employed to separate the slabs. The trajectory was optimized by an extended CAIPI sampling to ensure intersections with the kz=0 plane for each shot, and structured low-rank (SLR) reconstruction is performed to reconstruct a 2D phase map for each shot. Results: The self-navigated reconstruction demonstrated comparable image quality to that with navigator. Impact: Our method eliminated the navigator with optimized sampling and multiband specific GRAPPA reconstruction, which showed the potential to achieve optimal signal-to-noise ratio efficiency with approximately 30% shorter scanning time. This approach enables broader applications of high-resolution SMSlab DWI in neuroscience.