Background: Paramagnetic rims have been observed as a feature of some multiple sclerosis (MS) lesions on susceptibility-sensitive magnetic resonance imaging (MRI) and indicate compartmentalized inflammation.

Objective: To investigate clinical, MRI, and intrathecal (cerebrospinal fluid, CSF) associations of paramagnetic rim lesions (PRLs) using 3T MRI in MS.

Methods: This is a retrospective, cross-sectional analysis. All patients underwent 3T MRI using a T2*-weighted sequence with susceptibility postprocessing (susceptibility-weighted angiography (SWAN) protocol, GE). SWAN-derived filtered-phase maps and corresponding T2-FLAIR images were manually reviewed to determine PRL. Descriptive statistics, t-tests, and regression determined demographic, clinical, MRI, and CSF associations with PRL.

Results: A total of 147 MS patients were included; 79 of whom had available CSF. Forty-three percent had at least one PRL. PRL status (presence/absence) did not vary by sex or Expanded Disability Status Scale (EDSS) but was associated with younger age, shorter disease duration, worse disease severity, high-efficacy therapy use, and poorer dexterity, as well as lower age-adjusted brain volumes and cognitive processing speeds. PRL status was moreover associated with blood-brain barrier disruption as determined by pathologically elevated albumin quotient. Sensitivity analyses remained supportive of these findings.

Conclusion: PRLs, an emerging noninvasive biomarker of chronic neuroinflammation, are confirmed to be associated with greater disease severity and newly shown to be preliminarily associated with blood-brain barrier disruption.