Motivation: High-resolution diffusion MRI reveals human brain's fine-scale structure/connectivity. Goal(s): We aim to push the limit of spatial resolution for in-vivo human dMRI. Approach: An integrated approach leveraging state-of-the-art acquisition/reconstruction, hardware and correction techniques is employed to enable ultra-high-resolution dMRI. First, a recently developed Romer-EPTI acquisition is employed to obtain SNR gain while achieving distortion-free motion-robust dMRI. Second, Connectome-2.0 scanner with ultra-high-gradient performance further boosts SNR through shortened TE and echo-spacings. Third, correction techniques are proposed and integrated into EPTI reconstruction to address strong concomitant and eddy-current fields caused by strong gradients. Results: We achieved distortion-free in-vivo mesoscale dMRI at an unprecedented 387um-iso resolution. Impact: We achieved in-vivo dMRI at 387-um-isotropic resolution with whole-brain coverage by leveraging SNR-efficient distortion-free Romer-EPTI acquisition, ultra-high-gradient-performance Connectome 2.0 scanner, and correction techniques that address strong concomitant and eddy-current fields caused by the strong gradients.
Wang et al. (Tue,) studied this question.