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Updated: Mar 29, 2026
Positron Emission Tomography Imaging for In Vivo Measuring of Myelin Content in the Lysolecithin Rat Model of Multiple Sclerosis
Published on: February 28, 2021
Measuring longitudinal myelin water fraction in new multiple sclerosis lesions
Wendy S Vargas1, Elizabeth Monohan1, Sneha Pandya2
1Department of Neurology, Weill Cornell Medical College, New York, NY, USA.
Objectives:
Investigating the potential of myelin repair strategies in multiple sclerosis (MS) requires an understanding of myelin dynamics during lesion evolution. The objective of this study is to longitudinally measure myelin water fraction (MWF), an MRI biomarker of myelin, in new MS lesions and to identify factors that influence their subsequent myelin content.
Methods:
Twenty-three MS patients were scanned with whole-brain Fast Acquisition with Spiral Trajectory and T2prep (FAST-T2) MWF mapping at baseline and median follow-up of 6 months. Eleven healthy controls (HC) confirmed the reproducibility of FAST-T2 in white matter regions of interests (ROIs) similar to a lesion size. A random-effect-model was implemented to determine the association between baseline clinical and lesion variables and the subsequent MWF.
Results:
ROI-based measurements in HCs were highly correlated between scans [mean r = 0.893 (.764-.967)]. In MS patients, 38 gadolinium enhancing (Gd+) and 25 new non-enhancing (Gd-) T2 hyperintense lesions (5.7 months, ±3.8) were identified. Significant improvement in MWF was seen in Gd+ lesions (0.035 ± 0.029, p < 0.001) as compared to Gd- lesions (0.006 ± 0.017, p = 0.065). In the model, a higher baseline MWF (p < 0.001) and the presence of Gd (p < 0.001) were associated with higher subsequent MWF.
Conclusions:
FAST T2 provides a clinically feasible method to quantify MWF in new MS lesions. The observed influence of baseline MWF, which represents a combined effect of both resolving edema and myelin change within acute lesions, suggests that the extent of initial inflammation impacts final myelin recovery.
Insights
Myelin repair in multiple sclerosis (MS) lesions is influenced by initial inflammation. Higher baseline myelin water fraction (MWF) and gadolinium enhancement in new MS lesions predict better myelin recovery.
Area of Science:
- Neuroimaging
- Neuroinflammation
- Demyelinating Diseases
Background:
- Multiple Sclerosis (MS) is a chronic demyelinating disease of the central nervous system.
- Understanding myelin dynamics in MS lesions is crucial for developing effective myelin repair strategies.
- Myelin Water Fraction (MWF) is a sensitive MRI biomarker reflecting myelin content.
Purpose of the Study:
- To longitudinally measure MWF in new MS lesions using MRI.
- To identify factors influencing myelin content and recovery in evolving MS lesions.
- To assess the clinical feasibility of FAST-T2 for MWF quantification in MS.
Main Methods:
- Twenty-three MS patients underwent whole-brain MWF mapping with FAST-T2 at baseline and 6-month follow-up.
- Eleven healthy controls (HC) validated the reproducibility of the FAST-T2 technique.
- A random-effect model analyzed associations between baseline variables and subsequent MWF.
Main Results:
- FAST-T2 demonstrated high reproducibility in HC white matter.
- Significant MWF improvement was observed in gadolinium-enhancing (Gd+) lesions compared to non-enhancing (Gd-) lesions.
- Higher baseline MWF and the presence of Gd enhancement were associated with greater subsequent MWF.
Conclusions:
- FAST-T2 is a clinically feasible method for quantifying MWF in new MS lesions.
- Initial lesion characteristics, including baseline MWF and inflammation (Gd enhancement), significantly impact myelin recovery.
- These findings highlight the importance of early lesion activity in predicting myelin repair outcomes in MS.
