Delineation of cortical pathology in multiple sclerosis using multi-surface magnetization transfer ratio imaging

Area of Science:

• Neuroimaging
• Biomarkers
• Multiple Sclerosis Research

Background:

• Multiple sclerosis (MS) involves cortical gray matter pathology.
• Sub-pial demyelination is a key feature of MS.
• Developing accessible biomarkers for cortical changes is crucial.

Purpose of the Study:

• To assess cortical surface magnetization transfer ratio (csMTR) on inner, mid, and outer cortical boundaries.
• To evaluate csMTR as a biomarker for cortical gray matter pathology in MS.
• To investigate the relationship between csMTR and clinical disability in MS patients.

Main Methods:

• Acquired 3 Tesla MRI anatomical and MTR images from 25 MS patients and 12 controls.
• Smoothed MTR maps along meshes representing inner, mid, and outer neocortical boundaries.
• Utilized mixed model analysis and age regression to evaluate csMTR reductions.

Main Results:

• Focal csMTR reductions were most prominent on the outer cortical surface in specific brain regions.
• MS patients showed age-dependent csMTR reductions, with some reaching a plateau.
• The difference in csMTR between inner and outer cortex correlated with clinical disability in MS patients.

Conclusions:

• Multi-surface analysis of csMTR is a sensitive marker for cortical sub-pial abnormalities in MS.
• csMTR measurements can serve as clinically accessible biomarkers for MS brain pathology.
• These findings advance understanding of MS-related cortical changes and their clinical relevance.