Quantitative magnetization transfer imaging in postmortem multiple sclerosis brain

Purpose: To investigate the relationship of myelin content, axonal density, and,gliosts with the fraction of macromolecular protons (f(B)) and T-2 relaxation of the macromolecular pool (T-2B) acquired using quantitative magnetization transfer (qMT) MRI in postmortem brains of subjects with multiple. sclerosis (MS). Materials and Methods: f(B) and T-2B were acquired unfixed fixed postmortem brain, slices, of 20 subjects with MS. The myelin content, axonal count, and of gliosis Were, all quantified histologically. t-Tests and multiple regression were used for analysis. Results: MR indices obialned in unfixed postmortem brains were consistent with in vivo values reported in the literature. A significant, correlation was detected between Tr-(myelin) (inversely proportional to myelin content) and 1) f(B) (r = -0.80, P<10.001) and 2,) axonal count,(r = -0.79.P < 0.001). fB differed between 1 nomal-appearing white matter (NAWM),and remyelinated,WM lesions (rWMLs) (mean: f(B) 6.9 [SD 2] vs. 4.0 [1.81, P = 0.01), and 2) rWMLs and demyelinated WMLs (mean: 4.2 [2.2] vs. 2.5[1.3], P 0.016). No association was detected between T-2B and any of the histological measures Conclusion: fB in MS,WM is dependent on, myelin, condition may be a tool to monitor patients with this condition.