High-resolution 3D-MRI of postmortem brain specimens fixed by formalin and gadoteridol

The choice of embedding media affects image quality, tissue R2*, and susceptibility behaviors in post‐mortem brain MR microscopy at 7.0T

“…Between scanning sessions, slices were thoroughly washed with PBS for at least 1 h and were then kept in the corresponding medium for at least 1 h. For D 2 O embedding, the fresh medium was exchanged once to facilitate tissue penetration and minimize PBS contributions. Of note, brain slices and embedding media were kept at room temperature for 2–5 h in total to ensure stable thermal conditions during scanning . During scanning, embedding media temperatures were continuously monitored using a fiber optic temperature sensor (Neoptix Inc., Québec, Canada).…”

“…SNR and CNR for cortex/WM and LN/WM were calculated from high‐resolution MPRAGE, early‐echo GRE (GRE‐TE1), and late‐echo GRE (GRE‐TE2) images. Early‐echo GRE and MPRAGE images were chosen because proton density/T 1 ‐weighted MPRAGE images had previously been shown to have strong GM/WM contrast for formalin‐fixed tissue samples . Late‐echo GRE was also assessed to evaluate the CNR properties from a primarily T 2 * ‐weighted constrast.…”

“…Of note, brain slices and embedding media were kept at room temperature for 2-5 h in total to ensure stable thermal conditions during scanning. 39 During scanning, embedding media temperatures were continuously monitored using a fiber optic temperature sensor (Neoptix Inc., Québec, Canada).…”

“…Early-echo GRE and MPRAGE images were chosen because proton density/T 1 -weighted MPRAGE images had previously been shown to have strong GM/WM contrast for formalin-fixed tissue samples. 11,39 Late-echo GRE was also assessed to evaluate the CNR properties from a primarily T 2 * -weighted constrast. SNR was calculated according to the difference method 40 using:…”

Optimization of Inversion Time for Postmortem Fluid-attenuated Inversion Recovery (FLAIR) MR Imaging at 1.5T: Temperature-based Suppression of Cerebrospinal Fluid

“…[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Interpreting the relationship of imaging findings to cause of death requires knowledge of normal postmortem imaging findings. However, consensus regarding what constitutes a normal appearance on PMMR images is difficult because T 1 and T 2 values change according to body temperature.…”