Postmortem MRI of Brain Tissue

The postmortem CNS tissue donated to the lab for scientific research was first fixed in 10% formalin for two weeks and then stored in 1% formalin to avoid over-fixation. High-resolution, whole hemisphere MRI was performed on the donated tissue to identify abnormal regions, as described elsewhere. (Absinta et al., 2014 (link)) Briefly, images were placed in a postmortem imaging container filled with Fomblin (Solvay Solexis, West Deptford, NJ), which closely fit into a 32-channel head coil (NOVA medical, Wilmington MA). Images were acquired on a Magnetom 7T MRI system (Siemens, Malvern, PA) equipped with a circular-polarized transmit/32-channel receive coil. Imaging included a T₂*-weighted sequence (3D gradient-echo sequence, TR = 60 ms, multiple TEs of 6.09, 15.99, 25.89, 35.79 ms, FA = 10°, 4 averages, 88 slices, 0.42 mm isotropic resolution, acquisition time = 2.25 h per 3D slab).