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Updated: Jun 11, 2025
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Paramagnetic Rim Lesions are Highly Specific for Multiple Sclerosis in Real-World Data
Christopher C Hemond1,2, Sathish K Dundamadappa3, Mugdha Deshpande1
1Departments of Neurology, University of Massachusetts Memorial Medical Center and University of Massachusetts Chan Medical School, Worcester, MA, USA.
Background:
Paramagnetic rim lesions (PRL) are an emerging biomarker for multiple sclerosis (MS). In addition to associating with greater disease severity, PRL may be diagnostically supportive.
Objective:
Our aim was to determine PRL specificity and sensitivity for discriminating MS from its diagnostic mimics using real-world clinical diagnostic and imaging data.
Methods:
This is a retrospective, cross-sectional analysis of a longitudinal cohort of patients with prospectively collected observational data. Patients were included if they underwent neuroimmunological evaluation in our academic MS center, and had an available MRI scan from the same clinical 3T magnet that included a T2*-weighted sequence with susceptibility postprocessing (SWAN protocol, GE). SWAN-derived filtered phase maps and corresponding T2-FLAIR images were manually reviewed to determine PRL. PRL were categorized as "definite," "probable," or "possible" based on modified, recent consensus criteria. We hypothesized that PRL would convey a high specificity to discriminate MS from its MRI mimics.
Results:
580 patients were evaluated in total: 473 with MS, 57 with non-inflammatory neurological disease (NIND), and 50 with other inflammatory neurological disease (OIND). Identification of "definite" or "probable" PRL provided a specificity of 98% to discriminate MS from NIND and OIND; sensitivity was 36%. Interrater agreement was almost perfect for definite/probable identification at a subject level.
Conclusions:
PRL convey high specificity for MS and can aid in the diagnostic evaluation. Modest sensitivity limits their use as single diagnostic indicators. Including lesions with lower confidence ("possible" PRL) rapidly erodes specificity and should be interpreted with caution given the potential harms associated with misdiagnosis.
Insights
Paramagnetic rim lesions (PRL) show high specificity in diagnosing multiple sclerosis (MS), distinguishing it from other neurological conditions. However, their modest sensitivity means PRL cannot be used as the sole diagnostic marker.
Area of Science:
- Neuroimaging
- Neurology
- Biomarker Discovery
Background:
- Paramagnetic rim lesions (PRL) are an emerging biomarker in multiple sclerosis (MS).
- PRL are associated with increased disease severity and may support MS diagnosis.
Purpose of the Study:
- To determine the specificity and sensitivity of PRL for differentiating MS from its mimics.
- To utilize real-world clinical and imaging data for diagnostic discrimination.
Main Methods:
- Retrospective analysis of a longitudinal cohort with prospectively collected data.
- MRI scans using a T2*-weighted sequence (SWAN protocol) were reviewed for PRL.
- PRL were categorized using modified consensus criteria (definite, probable, possible).
Main Results:
- A total of 580 patients were evaluated (473 MS, 57 NIND, 50 OIND).
- "Definite" or "probable" PRL achieved 98% specificity and 36% sensitivity in discriminating MS from NIND and OIND.
- Interrater agreement for identifying definite/probable PRL was nearly perfect.
Conclusions:
- PRL demonstrate high specificity for MS, aiding in diagnostic evaluation.
- Modest sensitivity restricts their use as standalone diagnostic indicators.
- Including "possible" PRL significantly reduces specificity, warranting cautious interpretation to avoid misdiagnosis.
