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Updated: Jul 13, 2026
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Quantitative magnetization transfer imaging in postmortem multiple sclerosis brain
Klaus Schmierer1, Daniel J Tozer, Francesco Scaravilli
1Department of Brain Repair and Rehabilitation, Institute of Neurology, University College London, London, United Kingdom. k.schmierer@ion.ucl.ac.uk
Purpose:
To investigate the relationship of myelin content, axonal density, and gliosis with the fraction of macromolecular protons (fB) and T2 relaxation of the macromolecular pool (T2B) acquired using quantitative magnetization transfer (qMT) MRI in postmortem brains of subjects with multiple sclerosis (MS).
Materials And Methods:
fB and T2B were acquired in unfixed postmortem brain slices of 20 subjects with MS. The myelin content, axonal count, and severity of gliosis were all quantified histologically. t-Tests and multiple regression were used for analysis.
Results:
MR indices obtained in unfixed postmortem MS 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) fB (r = -0.80, P < 0.001) and 2) axonal count (r = -0.79, P < 0.001). fB differed between 1) normal-appearing white matter (NAWM) and remyelinated WM lesions (rWMLs) (mean: fB 6.9 [SD 2] vs. 4.0 [1.8], 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 T2B and any of the histological measures.
Conclusion:
fB in MS WM is dependent on myelin content and may be a tool to monitor patients with this condition.
Insights
Quantitative magnetization transfer MRI measures, specifically the fraction of macromolecular protons (fB), correlate with myelin content and axonal density in multiple sclerosis brains, suggesting potential for patient monitoring.
Area of Science:
- Neuroimaging
- Biomarkers
- Multiple Sclerosis Research
Background:
- Multiple Sclerosis (MS) is a demyelinating disease affecting white matter (WM).
- Accurate in vivo assessment of myelin, axonal integrity, and gliosis in MS lesions is crucial for disease monitoring and therapeutic evaluation.
Purpose of the Study:
- To investigate the relationship between quantitative magnetization transfer (qMT) MRI parameters, specifically the fraction of macromolecular protons (fB) and T2 relaxation of the macromolecular pool (T2B), with myelin content, axonal density, and gliosis in postmortem multiple sclerosis (MS) brains.
Main Methods:
- qMT MRI was performed on unfixed postmortem brain slices from 20 MS subjects.
- Myelin content, axonal count, and gliosis severity were quantified histologically.
- Statistical analyses included t-tests and multiple regression to assess correlations.
Main Results:
- qMT indices (fB and T2B) from postmortem MS brains aligned with reported in vivo values.
- A strong inverse correlation was found between myelin content and fB (r = -0.80, P < 0.001), and between axonal count and fB (r = -0.79, P < 0.001).
- fB significantly differed between normal-appearing white matter, remyelinated lesions, and demyelinated lesions, while T2B showed no association with histological measures.
Conclusions:
- The fraction of macromolecular protons (fB) in MS white matter is significantly influenced by myelin content.
- fB derived from qMT MRI shows promise as a potential imaging biomarker for monitoring disease progression and treatment response in patients with multiple sclerosis.
