Year: 2026
Type: preprint
Abstract: MRI of fixed tissue is an excellent way to study pathological changes caused by different diseases with great anatomical detail. It is, however, known that properties of tissue change with fixation. The aim of this study was to determine the variability of several quantitative MRI (qMRI) parameters in fixed brain tissue obtained from donors unaffected by neurological conditions and investigate the existence of quantitative parameters which vary little between specimens. We introduce a 3D method for high-resolution mapping of water content, T 1 and T 2 * relaxation times and parameters characterising magnetisation transfer and apply it at 3T to 7 whole, fixed human brains (3 male, 4 female, aged between 47 and 79 years, mean age 67 years). The qMRI parameters determined include relaxation rates T 1 and T 2 *, MT ratio and T 1 and T 2 * after MT. From these we can further derive semiquantitative MT parameters such as the exchange rate (k trans ) and bound pool fraction (f bound ). Correlations between these parameters are investigated. In addition, truly quantitative water content determined non-invasively with MRI is reported on whole human post mortem brains – to our knowledge, for the first time. Water content was found to have mean values of 73% for WM and 85% for GM with standard deviation below 2.5% over 7 brains, and thus a few percent units higher than in vivo (69% and 81%) and of comparable constancy.
Authors: A.-M. Oros-Peusquens, N.J. Shah
Institutions: Forschungszentrum Jülich, RWTH Aachen University
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7125410998