Relating perivascular imaging measures to longitudinal lesion evolution and chronic inflammation in multiple...

Area of Science:

• Neuroimaging
• Multiple Sclerosis Pathophysiology
• Inflammatory Disease Mechanisms

Background:

• Perivascular space (PVS) alterations are implicated in the inflammatory processes of multiple sclerosis (MS).
• Understanding PVS changes may offer insights into MS lesion evolution and disease activity.

Purpose of the Study:

• To investigate the association between diffusion tensor image analysis along the PVS (DTI-ALPS) and PVS volume/number with lesion evolution in people with MS (pwMS) over a 5-year period.
• To determine if baseline DTI-ALPS or PVS metrics predict future lesion accumulation and changes in pwMS.

Main Methods:

• 182 pwMS (142 pwRRMS, 40 pwPMS) underwent clinical and MRI assessments at baseline and 5-year follow-up.
• Lesion burden (CELs, T2, T1, CLs, PRLs) and PVS metrics (DTI-ALPS, number/volume) were quantified.
• Statistical models (regression, ANCOVA) were used to assess associations, controlling for covariates and applying false discovery rate correction.

Main Results:

• Baseline DTI-ALPS in pwRRMS correlated with baseline CEL number, T1 lesion number/volume, and T2 lesion volume.
• DTI-ALPS was associated with the accumulation of new/enlarging cortical and T1 lesions, and showed a trend with newly appearing paramagnetic rim lesions (PRLs).
• The 5-year change in PVS volume was related to the presence of PRLs at baseline.

Conclusions:

• Perivascular space alterations are significantly associated with lesion evolution in people with relapsing-remitting multiple sclerosis (pwRRMS).
• DTI-ALPS emerges as a potential imaging biomarker for predicting lesion development in MS.
• PVS volume changes over time may reflect ongoing inflammatory processes, particularly those associated with PRLs.