Post Mortem Quantitative MRI of the Human Brain in Situ using High-Resolution Multi-Echo FLASH

Gunther Helms¹, Walter J. Schulz-Schaeffer², Arne Wrede², Niels K. Focke³, Peter Dechent¹

For post mortem MRI of the human head at 3T, a quantitative FLASH-based protocol was established yielding parameter maps of T1, R2*=1/T2*, magnetization transfer (MT) and signal amplitude at 0.65mm isotropic resolution in about 2 hours. Major post mortem changes were rapid T2*-relaxation in vessels and progressive loss of T1-contrast at low temperature, hampering standard T1w MRI. At room temperature, MT saturation maps showed a high unchanged contrast in brain independent of altered T1 and T2*, while the MT ratio was reduced. In cooled brains, the MT contrast was slightly reduced and R2* was enhanced in the deep brain nuclei.