Paramagnetic Rim Lesions May Support Diagnosis in People with Suspected MS

Paramagnetic rim lesions (PRLs), which are visible on susceptibility-based MRI, may serve as a useful diagnostic marker in people undergoing evaluation for multiple sclerosis (MS), according to a new study published in Neurology. The presence of PRLs was associated with increased diagnostic specificity for MS, supporting their potential role in refining early clinical assessments.

The multicenter study included 78 adults aged 18 to 64 years from the Central Vein Sign in MS (CAVS-MS) pilot study who were referred to an MS specialty clinic for diagnostic workup between 2018 and 2020. Participants underwent standardized MRI scans and clinical assessments. Investigators evaluated the presence of PRLs, their correlation with clinical presentation, and their contribution to MS diagnosis compared with conventional MRI criteria.

Key findings included the following:

• PRLs were observed in 46% (n=36) of all participants, and 89% of the PRL-positive participants fulfilled the 2017 McDonald criteria for an MS diagnosis.
• The presence of ≥1 PRL was associated with a sensitivity of 0.86 (95% CI, 0.71 to 0.95) and a specificity of 0.90 (84% CI, 0.77 to 0.97).
• The presence of ≥2 PRLs was associated with a lower sensitivity of 0.59 (95% CI, 0.42 to 0.75) but a higher specificity of 0.95 (95% CI, 0.83 to 0.99).
• Individuals with a shorter duration from initial MS symptom onset were more likely to be positive for PRLs, with 28% greater odds for PRL positivity linked to every 1 year decrease in time from symptom onset (odds ratio, 1.28 per year; 95% CI, 1.03 to 159; P=.03)

These findings suggest that incorporating PRL assessment into clinical MRI protocols may improve diagnostic accuracy in patients presenting with suspected MS, though further validation in broader clinical settings is needed.

Source: Renner B, Verter ED, Absinta M, et al. Frequency and diagnostic implications of paramagnetic rim lesions in people presenting for diagnosis to a multiple sclerosis clinic. Neurology. 2025;105(6): e213912(1)- e213912(10). doi:10.1212/WNL.0000000000213912