Motivation: High-resolution diffusion MRI (dMRI) at ultra-high field is challenging due to a shorter T2 and increased susceptibility-induced distortions. Goal(s): To demonstrate the feasibility of high-resolution in-vivo and ex-vivo dMRI, and tractography using the 10.5T whole-body human scanner at CMRR-Minnesota. Approach: We explored acquisition and processing approaches for pushing resolution towards the mesoscale in the non-human primate (macaque) brain, based on pulsed-gradient spin-echo (in-vivo) and diffusion-weighted steady-state free-precession (ex-vivo). Results: We showcase high-resolution dMRI datasets (0.75 mm in-vivo, 0.4 mm ex-vivo) of the macaque brain at 10.5T and we propose a pipeline from image reconstruction to biophysical modelling that enables high-resolution tractography reconstructions. Impact: We showcase for the first time the performance of the 10.5T human whole-body MRI scanner at the CMRR, University of Minnesota, for high-resolution diffusion MRI and tractography in the in-vivo and ex-vivo macaque brain.
Warrington et al. (2025) studied this question.