Longitudinal Multiparametric Quantitative MRI Evaluation of Acute and Chronic Multiple Sclerosis Paramagnetic Rim...

Area of Science:

• Neuroimaging
• Radiology
• Biomarkers

Background:

• Paramagnetic rim lesions (PRLs) in multiple sclerosis (MS) indicate active disease with complex iron and myelin alterations.
• Conventional MRI methods face challenges in accurately quantifying these changes.
• Understanding these alterations is crucial for monitoring MS progression.

Purpose of the Study:

• To perform a comprehensive multiparametric MRI analysis of paramagnetic rim lesions (PRLs) in progressive MS patients.
• To investigate the iron and myelin dynamics within PRLs using advanced imaging techniques.
• To correlate imaging findings with disease activity and tissue damage.

Main Methods:

• A retrospective, longitudinal study involving 95 progressive MS subjects with persistent PRLs.
• Utilized 3-Tesla MRI with susceptibility-weighted, T1-weighted, T2-weighted, and fluid-attenuated inversion recovery sequences.
• Quantitative magnetic susceptibility (QS), R2*, and standardized T1w/T2w ratio (sT1w/T2w) were measured for whole lesion, core, and rim.

Main Results:

• Chronic PRLs showed decreased sT1w/T2w and R2*, with increased QS compared to non-PRLs.
• Tissue damage accumulation was more pronounced in acute/chronic PRLs versus non-PRLs at 96 weeks.
• Acute PRLs demonstrated partial recovery, while chronic PRLs indicated irreversible damage.

Conclusions:

• Multiparametric MRI assessment of PRLs provides valuable insights into iron and myelin changes.
• This approach holds potential for evaluating chronic active PRLs in progressive MS.
• The findings support the use of advanced MRI techniques for MS lesion characterization.