Regional IVIM-DWI Abnormalities in Normal-Appearing White Matter and Lesion Tissue in Relapsing-Remitting Multiple...

Area of Science:

• Neuroimaging
• Diffusion-weighted MRI
• Multiple Sclerosis Research

Background:

• Normal-appearing white matter (NAWM) in relapsing-remitting multiple sclerosis (RR-MS) may harbor undetected abnormalities.
• Conventional MRI may not visualize subtle white matter changes in RR-MS.
• Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) offers advanced insights into tissue microstructure.

Purpose of the Study:

• To assess if IVIM-DWI can detect regional NAWM abnormalities in RR-MS patients.
• To evaluate IVIM-DWI's capability in differentiating non-lesional white matter from lesion tissue in RR-MS.
• To explore the utility of IVIM-DWI parameters (ADC, D, D*, f) in characterizing white matter in RR-MS.

Main Methods:

• Retrospective cross-sectional study involving 189 RR-MS patients and 26 healthy controls.
• IVIM-DWI parameters (ADC, D, D*, f) were measured in specific white matter regions (genu, splenium, frontal, posterior).
• Comparison of regional NAWM in RR-MS with control white matter and analysis of lesion tissue.

Main Results:

• Posterior white matter in RR-MS showed significant abnormalities with lower ADC, D, D*, and f compared to controls.
• Splenium exhibited higher ADC and D, but lower D* in RR-MS patients.
• Lesion tissue demonstrated significantly higher ADC, D, and D* compared to both NAWM and control white matter.

Conclusions:

• Regional IVIM-DWI successfully identified region-specific NAWM abnormalities in RR-MS, most notably in the posterior white matter.
• The findings suggest IVIM-DWI's potential within an exploratory imaging framework for RR-MS.
• Further research with larger, matched longitudinal cohorts is necessary to establish clinical and prognostic utility.