Acquisition Optimization of Ultra-High Resolution Diffusion MRI for the Next-Generation 7T scanner

Motivation: To realize the NexGen 7T's full potential for ultra-high resolution diffusion MRI. Goal(s): To explore, optimize, and share best practices for ultra-high resolution diffusion imaging on the NexGen 7T. Approach: We systematically optimized multiple acquisition approaches starting from a SAR and artifact reduction perspective (via optimization of fat saturation and coil combination approaches) and then moved on to optimization of SNR (via optimization of slice order, slew rate of diffusion gradients, and other SNR enhancing techniques). Results: The cumulative gains in SNR and reduction in SAR and artifacts allow for fast, high-quality, high-resolution diffusion imaging (≤ 0.6mm). Impact: Our study sheds light on the complex and often opaque diffusion acquisition parameter space to help the diffusion community more readily achieve mesoscale diffusion imaging, which would facilitate better characterization of complex crossing fibers as well as cortical-depth-dependant brain connectivity.