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Updated: Jun 15, 2026
Comprehensive Autopsy Program for Individuals with Multiple Sclerosis
Published on: July 19, 2019
Heterogeneity of Cortical Lesion Susceptibility Mapping in Multiple Sclerosis
M Castellaro1,2, R Magliozzi2,3, A Palombit1
1From the Department of Information Engineering (M. Castellaro, A.P., E.S., A.B.), University of Padova, Padova, Italy.
Background And Purpose:
Quantitative susceptibility mapping has been used to characterize iron and myelin content in the deep gray matter of patients with multiple sclerosis. Our aim was to characterize the susceptibility mapping of cortical lesions in patients with MS and compare it with neuropathologic observations.
Materials And Methods:
The pattern of microglial activation was studied in postmortem brain tissues from 16 patients with secondary-progressive MS and 5 age-matched controls. Thirty-six patients with MS underwent 3T MR imaging, including 3D double inversion recovery and 3D-echo-planar SWI.
Results:
Neuropathologic analysis revealed the presence of an intense band of microglia activation close to the pial membrane in subpial cortical lesions or to the WM border of leukocortical cortical lesions. The quantitative susceptibility mapping analysis revealed 131 cortical lesions classified as hyperintense; 33, as isointense; and 84, as hypointense. Quantitative susceptibility mapping hyperintensity edge found in the proximity of the pial surface or at the white matter/gray matter interface in some of the quantitative susceptibility mapping-hyperintense cortical lesions accurately mirrors the microglia activation observed in the neuropathology analysis.
Conclusions:
Cortical lesion susceptibility maps are highly heterogeneous, even at individual levels. Quantitative susceptibility mapping hyperintensity edge found in proximity to the pial surface might be due to the subpial gradient of microglial activation.
Insights
Quantitative susceptibility mapping reveals heterogeneous cortical lesions in multiple sclerosis (MS). Lesion hyperintensity edges correlate with microglial activation patterns, suggesting a link to MS pathology.
Area of Science:
- Neuroimaging
- Neuropathology
- Multiple Sclerosis Research
Background:
- Quantitative susceptibility mapping (QSM) assesses iron and myelin in multiple sclerosis (MS) deep gray matter.
- Cortical lesions are a key feature of MS pathology.
Purpose of the Study:
- To characterize QSM of cortical lesions in MS patients.
- To compare QSM findings with neuropathologic observations.
Main Methods:
- Studied microglial activation in postmortem MS brain tissue (16 patients, 5 controls).
- Performed 3T MRI on 36 MS patients, including 3D double inversion recovery and 3D-echo-planar SWI.
- Analyzed QSM of 131 hyperintense, 33 isointense, and 84 hypointense cortical lesions.
Main Results:
- Neuropathology showed intense microglial activation near the pial membrane or white matter border in cortical lesions.
- QSM analysis revealed heterogeneous cortical lesion signal intensities.
- QSM hyperintensity edges near the pial surface or WM/GM interface mirrored observed microglial activation.
Conclusions:
- Cortical lesion QSM in MS is highly heterogeneous.
- QSM hyperintensity edges near the pial surface may reflect subpial microglial activation gradients.
