As with any postmortem study, the effects of tissue fixation must be considered19. The MRI properties of postmortem tissue can change as a result of decomposition and chemical fixation. T2 values have been observed to be lower in fixed postmortem brain than in vivo for both white and grey matter18. The postmortem brain tissue samples in this study were fixed for at least two months, as required for T2 values to stabilize1819. The overall distribution of signal abnormalities are similar to those obtained in previous postmortem MRIs, which showed more laminar structure in the SN compared to in vivo scans611. T1-weighted sequencing with the magnetization transfer contrast pulse used here did not create an NM-specific contrast in the SNc1011. The reduction of T1 contrast at the high field strength and the proton microenvironment may have limited tissue T1 contrast due to changes in the penetration of the tissue by the fixative2032.