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Updated: Aug 22, 2026
Comprehensive Autopsy Program for Individuals with Multiple Sclerosis
Published on: July 19, 2019
Magnetization transfer ratio and myelin in postmortem multiple sclerosis brain
Klaus Schmierer1, Francesco Scaravilli, Daniel R Altmann
1Department of Neuroinflammation, MS NMR Research Unit, University College London, United Kingdom.
Abstract:
Several quantitative magnetic resonance (MR) measures are used to investigate multiple sclerosis (MS) in vivo. Precise quantitative investigation of the histopathological correlates of such measures has, to date, been limited. This study investigates the relationship of quantitative measures of myelin content, axonal density, and gliosis with quantitative MR measures in postmortem (PM) MS tissue. MR imaging (MRI) was performed on a 1.5T scanner and T1-relaxation time (T1-RT) and magnetization transfer ratio (MTR) maps were acquired in fresh PM brain of 20 MS subjects. Myelin content, axonal counts, and the extent of gliosis all were quantified using morphometric and digital imaging techniques. MRI and pathological data were in most cases coregistered using stereotactic navigation. Using multiple regression analysis, we detected significant correlations between myelin content (Tr(myelin)) and MTR (r = -0.84, p < 0.001) and myelin content and axonal count (-0.80, p < 0.001); MTR correlated with T1-RT (r = -0.79, p < 0.001). No association was detected between the extent of gliosis and either MR measure. MTR was significantly higher in remyelinated than demyelinated lesions (means: 30.0 [standard deviation, 2.9] vs 23.8 [standard deviation, 4.3], p = 0.008). In conclusion, MTR is affected by myelin content in MS white matter.
Insights
Magnetization transfer ratio (MTR) in multiple sclerosis (MS) brain tissue correlates with myelin content, not gliosis. This finding advances understanding of in vivo MR measures in MS pathology.
Area of Science:
- Neuroimaging
- Neuropathology
- Quantitative Magnetic Resonance Imaging
Background:
- Quantitative magnetic resonance (MR) measures are crucial for in vivo multiple sclerosis (MS) investigation.
- Histopathological validation of these quantitative MR measures has been limited.
- Understanding the relationship between MR measures and MS pathology is essential for accurate diagnosis and monitoring.
Purpose of the Study:
- To investigate the correlation between quantitative MR measures and histopathological hallmarks of MS in postmortem (PM) tissue.
- To examine the relationship of myelin content, axonal density, and gliosis with MR measures like T1-relaxation time (T1-RT) and magnetization transfer ratio (MTR).
Main Methods:
- MR imaging (MRI) including T1-relaxation time (T1-RT) and magnetization transfer ratio (MTR) maps were acquired from fresh postmortem (PM) brain tissue of 20 MS subjects at 1.5T.
- Myelin content, axonal counts, and gliosis were quantified using morphometric and digital imaging techniques.
- Stereotactic navigation was used for coregistration of MRI and pathological data, followed by multiple regression analysis.
Main Results:
- Significant correlations were found between myelin content and MTR (r = -0.84, p < 0.001) and between myelin content and axonal count (r = -0.80, p < 0.001).
- MTR also correlated significantly with T1-RT (r = -0.79, p < 0.001).
- No association was detected between gliosis and either MR measure. MTR was significantly higher in remyelinated lesions compared to demyelinated lesions (p = 0.008).
Conclusions:
- Magnetization transfer ratio (MTR) is significantly influenced by myelin content in multiple sclerosis (MS) white matter.
- These findings support MTR as a valuable quantitative MR measure for assessing myelin integrity in MS.
- Gliosis extent does not appear to be directly reflected by the investigated MR measures in this postmortem study.
