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Updated: Mar 24, 2026
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Lesion Heterogeneity on High-Field Susceptibility MRI Is Associated with Multiple Sclerosis Severity
D M Harrison1, X Li2, H Liu3
1From the Department of Neurology (D.M.H.), University of Maryland School of Medicine, Baltimore, Maryland Departments of Neurology (D.M.H., P.A.C.) dharrison@som.umaryland.edu.
Background And Purpose:
Susceptibility MR imaging contrast variations reflect alterations in brain iron and myelin content, making this imaging tool relevant to studies of multiple sclerosis lesion heterogeneity. In this study, we aimed to characterize the relationship of high-field, susceptibility contrasts in multiple sclerosis lesions to clinical outcomes.
Materials And Methods:
Twenty-four subjects with multiple sclerosis underwent 7T MR imaging of the brain, disability examinations, and a fatigue inventory. The inverse of T2* relaxation time (R2*), frequency, and relative susceptibility (from quantitative susceptibility mapping) were analyzed in 306 white matter lesions.
Results:
Most lesions were hypointense on R2* (88% without a rim, 5% with). Lesions that were hyperintense on quantitative susceptibility mapping were more frequent in relapsing-remitting than in progressive multiple sclerosis (54% versus 35%, P = .018). Hyperintense lesion rims on quantitative susceptibility maps were more common in progressive multiple sclerosis and patients with higher levels of disability and fatigue. Mean lesion R2* was inversely related to disability and fatigue and significantly reduced in progressive multiple sclerosis. Relative susceptibility was lower in lesions in progressive multiple sclerosis (median, -0.018 ppm; range, -0.070 to 0.022) than in relapsing-remitting MS (median, -0.010 ppm; range, -0.062 to 0.052; P = .003).
Conclusions:
A progressive clinical phenotype and greater disability and fatigue were associated with lower R2* and relative susceptibility values (suggestive of low iron due to oligodendrocyte loss) and rimmed lesions (suggestive of chronic inflammation) in this multiple sclerosis cohort. Lesion heterogeneity on susceptibility MR imaging may help explain disability in multiple sclerosis and provide a window into the processes of demyelination, oligodendrocyte loss, and chronic lesion inflammation.
Insights
Susceptibility MR imaging reveals that lesion characteristics in multiple sclerosis correlate with disease progression and symptoms. Lower iron and rimmed lesions indicate chronic inflammation and oligodendrocyte loss, impacting disability and fatigue.
Area of Science:
- Neuroimaging
- Magnetic Resonance Imaging
- Neurology
Background:
- Susceptibility MR imaging (SWI) reveals brain iron and myelin content.
- SWI is valuable for studying multiple sclerosis (MS) lesion heterogeneity.
- Understanding lesion variations is key to MS research.
Purpose of the Study:
- To investigate the relationship between high-field SWI contrasts in MS lesions and clinical outcomes.
- To characterize lesion heterogeneity using quantitative susceptibility mapping (QSM) and R2*.
Main Methods:
- 24 MS patients underwent 7T MR imaging.
- Disability and fatigue were assessed using clinical examinations and inventories.
- 306 white matter lesions were analyzed for R2*, frequency, and relative susceptibility (QSM).
Main Results:
- Most lesions were hypointense on R2*. Hyperintense lesions on QSM were more common in relapsing-remitting MS.
- Rimmed lesions on QSM correlated with progressive MS, higher disability, and fatigue.
- Lower R2* and relative susceptibility values were observed in progressive MS lesions and linked to increased disability and fatigue.
Conclusions:
- Progressive MS phenotypes, disability, and fatigue are associated with lower R2* and relative susceptibility (indicating low iron/oligodendrocyte loss) and rimmed lesions (suggesting chronic inflammation).
- Lesion heterogeneity on SWI may explain MS-related disability and reflect demyelination, oligodendrocyte loss, and chronic inflammation.
