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Updated: May 17, 2026
Comprehensive Autopsy Program for Individuals with Multiple Sclerosis
Published on: July 19, 2019
Segmentation of magnetization transfer ratio lesions for longitudinal analysis of demyelination and remyelination in
Robert A Brown1, Sridar Narayanan1, Douglas L Arnold1
1McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, 3801 Rue University, Montreal, Canada H3A 2B4.
Abstract:
We demonstrate a new technique to quantify longitudinal changes in magnetization transfer ratio (MTR) magnetic resonance imaging (MRI). These changes are indicative of demyelination and remyelination. This technique comprises a definition of ΔMTR lesions, which are identified directly from the MTR images, and an automatic procedure for segmenting these lesions. We used this technique to analyze MTR changes in lesions of subjects with rapidly progressing multiple sclerosis before and after treatment with immunoablation and autologous stem cell transplant. Subjects who experienced clinical improvement after treatment showed significantly improved MTR recovery in lesions that were recovering during treatment (p<0.0001) while those who were clinically stable after treatment showed significantly poorer MTR recovery (p=0.002). The statistical power of this technique to detect treatment effects on MTR recovery was shown to be considerably better than previous methods. These results suggest that longitudinal measurements of MTR in ΔMTR lesions may be an important technique for the assessment of treatment effects on remyelination in clinical trials.
Insights
A new magnetic resonance imaging (MRI) technique quantifies changes in magnetization transfer ratio (MTR) to track demyelination and remyelination in multiple sclerosis. Improved MTR recovery in lesions correlated with clinical improvement after stem cell therapy.
Area of Science:
- Neuroimaging
- Radiology
- Biomedical Engineering
Background:
- Longitudinal changes in magnetization transfer ratio (MTR) on magnetic resonance imaging (MRI) reflect demyelination and remyelination processes.
- Accurate quantification of these changes is crucial for assessing therapeutic efficacy in neurodegenerative diseases like multiple sclerosis (MS).
Purpose of the Study:
- To introduce and validate a novel technique for quantifying longitudinal MTR changes in MS lesions.
- To assess the technique's ability to detect treatment effects on remyelination.
Main Methods:
- Development of a technique defining ΔMTR lesions directly from MTR images.
- Implementation of an automated procedure for segmenting these ΔMTR lesions.
- Application of the technique to analyze MTR changes in MS patients before and after immunoablation and stem cell transplant.
Main Results:
- Clinically improved patients showed significantly better MTR recovery in lesions compared to clinically stable patients (p<0.0001 vs. p=0.002).
- The new technique demonstrated superior statistical power in detecting treatment effects on MTR recovery compared to previous methods.
- Significant correlation observed between MTR recovery and clinical outcomes.
Conclusions:
- Longitudinal MTR measurements in ΔMTR lesions offer a sensitive method for evaluating remyelination.
- This technique holds promise for assessing treatment efficacy in multiple sclerosis clinical trials.
- The findings support the use of MTR changes as a biomarker for therapeutic response in MS.
