Fractal dimension and white matter changes in multiple sclerosis.

Area of Science:

• Neuroimaging
• Neurology
• Biophysics

Background:

• Multiple sclerosis (MS) causes visible and non-visible white matter (WM) changes.
• Normal-appearing white matter (NAWM) also shows abnormalities.
• Fractal dimension (FD) quantifies morphometric variability in complex structures.

Purpose of the Study:

• To evaluate FD analysis for measuring WM abnormalities in MS using conventional MRI.
• To specifically detect changes in NAWM.

Main Methods:

• Voxel-based morphometry optimized for MS to segment the brain.
• Calculation of FD for the WM-grey matter interface and skeletonized WM.
• Focused analysis of NAWM FD on lesion-free sections at the centrum semiovale level.

Main Results:

• MS patients exhibited significantly reduced whole brain WM FD compared to controls.
• Decreased FD was observed in both lesioned and NAWM areas.
• FD detected changes in NAWM, indicating early disease-phase alterations.

Conclusions:

• FD analysis is effective in identifying brain changes in MS patients, including NAWM.
• FD may serve as a valuable biomarker for diffuse central nervous system damage in early MS.
• FD offers a quantitative method to assess subtle WM abnormalities.