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The following is a summary of “Reliability of paramagnetic rim lesion detection at 1.5T MRI in multiple sclerosis patients,” published in the January 2025 issue of Multiple Sclerosis Journal by Martire et al. 

Paramagnetic rim lesions (PRL) are valuable for multiple sclerosis (MS) diagnosis and prognosis, detectable at 7T and 3T MRI, but the visibility on 1.5T scanners needs assessment for clinical translation.  

Researchers conducted a retrospective study to evaluate the reliability of detecting PRL using commercially available susceptibility-weighted imaging (SWI) at 1.5T vs 3T MRI.  

They obtained SWI scans from 20 individuals with MS using 1.5T and 3T MRI systems. The scans had an average interval of 1.1 years and included only stable, non-enhancing lesions visible on both scans for analysis. At 3T, 2 expert raters identified PRL following the NAIMS PRL criteria, which served as the reference standard and 4 blinded raters assessed PRL at 1.5T without access to the 3T results and the discrepancies in assessments were resolved through consensus. 

The results showed that PRLs were identified in 16 out of 20 individuals. At 3T, a total of 95 PRL were detected by consensus (mean of 5 PRL per patient, range 0–30). When blinded to 3T scans, 82% of PRL (78 out of 95) were visible at 1.5T. Interrater reliability was deemed “almost perfect” for both 1.5T and 3T scans. Raters accurately classified all patients as having 1 or more PRL or not at 1.5T.  

Investigators concluded that PRLs were largely detectable at 1.5T without compromising specificity or increasing pseudo-PRL detection, potentially facilitating the clinical application in MS diagnosis and prognosis. 

Source: journals.sagepub.com/doi/10.1177/13524585251314358