Central Vein Sign and Paramagnetic Rim Lesions in Patients with Relapsing–Remitting Multiple Sclerosis: An Assessment of Prevalence and Anatomical Location

Background/Objectives: Multiple sclerosis (MS) remains challenging to diagnose due to clinical and radiological overlap with mimicking conditions. The 2024 revisions of the McDonald criteria have incorporated the central vein sign (CVS) and paramagnetic rim lesions (PRLs) as magnetic resonance imaging (MRI) biomarkers to improve diagnostic specificity. This study assessed the prevalence and anatomical distribution of CVS and PRLs in patients with relapsing–remitting MS (RRMS). Methods: This cross-sectional study included 91 patients with RRMS diagnosed according to the 2017 McDonald criteria. MRI scans were obtained using 3T scanners, and T2-FLAIR and susceptibility-weighted angiography (SWAN) sequences were analyzed. CVS and PRLs were identified using established criteria. Patients were stratified by lesion count (<5, 5–9, ≥10), and lesions were categorized by anatomical location. Descriptive statistics, chi-square tests, and multivariable logistic regression adjusted for covariates were performed. Results: CVS was present in 69.2% of patients, while PRLs were identified in 29.7%. Both markers were more frequent in patients with higher lesion burden in univariate analysis. CVS prevalence increased significantly with lesion count (p < 0.001) and remained an independent predictor in multivariable logistic regression. PRL presence was associated with lesion count in univariate analysis but not after adjustment. Most CVS- and PRL-positive lesions were supratentorial and predominantly periventricular. No significant association was observed between CVS and PRL presence. Conclusions: CVS is a highly prevalent MRI feature in RRMS and independently associated with lesion burden, supporting its role as a diagnostically relevant imaging marker. PRLs were less prevalent and showed weaker independent associations.