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Updated: Jun 10, 2025
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Quantitative Analysis of Early White Matter Damage in Cuprizone Mouse Model of Demyelination Using 7.0 T MRI
Emma Friesen1, Maxina Sheft2,3, Kamya Hari2,4
1Department of Chemistry, University of Winnipeg, Winnipeg, Canada.
Abstract:
Magnetic Resonance Imaging (MRI) is commonly used to follow the progression of neurodegenerative conditions, including multiple sclerosis (MS). MRI is limited by a lack of correlation between imaging results and clinical presentations, referred to as the clinico-radiological paradox. Animal models are commonly used to mimic the progression of human neurodegeneration and as a tool to help resolve the paradox. Most studies focus on later stages of white matter (WM) damage whereas few focus on early stages when oligodendrocyte apoptosis has just begun. The current project focused on these time points, namely weeks 2 and 3 of cuprizone (CPZ) administration, a toxin which induces pathophysiology similar to MS. In vivo T2-weighted (T2W) and Magnetization Transfer Ratio (MTR) maps and ex vivo Diffusion Tensor Imaging (DTI), Magnetization Transfer Imaging (MTI), and relaxometry (T1 and T2) values were obtained at 7 T. Significant changes in T2W signal intensity and non-significant changes in MTR were observed to correspond to early WM damage, whereas significant changes in both corresponded with full demyelination. Some DTI metrics decrease with simultaneous increase in others, indicating acute demyelination. MTI metrics T2A, T2B, f and R were observed to have contradictory changes across CPZ administration. T1 relaxation times were observed to have stronger correlations to disease states during later stages of CPZ treatment, whereas T2 had weak correlations to early WM damage. These results all suggest the need for multiple metrics and further studies at early and late time points of demyelination. Further research is required to continue investigating the interplay between various MR metrics during all weeks of CPZ administration.
Insights
This study investigates early white matter damage in a mouse model of multiple sclerosis (MS). Combining multiple MRI metrics is crucial for understanding demyelination progression and resolving the clinico-radiological paradox in MS.
Area of Science:
- Neuroimaging
- Neurodegeneration
- Demyelinating Diseases
Background:
- Magnetic Resonance Imaging (MRI) is vital for tracking neurodegenerative diseases like multiple sclerosis (MS).
- A significant challenge is the clinico-radiological paradox, where MRI findings don't always correlate with clinical symptoms.
- Animal models, like the cuprizone (CPZ) model, are essential for studying early-stage white matter (WM) damage and demyelination.
Purpose of the Study:
- To investigate early white matter (WM) damage during demyelination using advanced MRI techniques.
- To evaluate the utility of various MRI metrics at different stages of the cuprizone (CPZ)-induced demyelination model.
- To explore the relationship between imaging metrics and disease progression in the context of the clinico-radiological paradox.
Main Methods:
- Utilized a cuprizone (CPZ) mouse model to induce demyelination, mimicking MS pathophysiology.
- Acquired in vivo T2-weighted (T2W) and Magnetization Transfer Ratio (MTR) maps at 7T.
- Obtained ex vivo Diffusion Tensor Imaging (DTI), Magnetization Transfer Imaging (MTI), and relaxometry (T1 and T2) values.
Main Results:
- Early WM damage showed significant T2W signal changes but non-significant MTR changes.
- Full demyelination correlated with significant changes in both T2W and MTR.
- Diffusion Tensor Imaging (DTI) metrics showed complex changes indicating acute demyelination; Magnetization Transfer Imaging (MTI) metrics exhibited contradictory alterations.
- T1 relaxation times correlated better with later disease stages, while T2 showed weak correlation with early WM damage.
Conclusions:
- Multiple MRI metrics are necessary to accurately assess demyelination across different disease stages.
- Further research is needed to fully elucidate the interplay of various MR metrics throughout the CPZ administration period.
- Understanding these early changes is critical for resolving the clinico-radiological paradox in MS and related neurodegenerative conditions.
