Susceptibility tensor imaging of ex vivo human hemibrain using 7T human MR scanner

Motivation: High-resolution ex vivo susceptibility tensor imaging (STI) shows promise in visualizing detailed microstructural neuroanatomy related to tissue magnetic susceptibility contrast but is usually challenging with large human brain samples. Goal(s): This work aimed to demonstrate a feasible protocol for STI on postmortem human hemibrain using a 7T human MR scanner. Approach: De-identified human brain samples of the left hemisphere were collected, prepared, and scanned with a 3D multi-echo gradient echo sequence with 0.5 mm isotropic resolution. Results: Multi-orientation quantitative susceptibility mapping and STI with a maximum of 12 orientations were obtained. Myelinated fibers and iron deposition in cortical substructures were visualized. Impact: The proposed ex vivo MRI protocol is expected to be helpful to researchers interested in STI. The ex vivo STI acquired through this protocol may provide anatomical references for in vivo STI studies.