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Updated: Oct 21, 2025
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Smoldering lesions in MS: if you like it then you should put a rim on it
Catarina Pinto1,2, Melissa Cambron3, Adrienn Dobai4,5
1Neuroradiology Department, Centro Hospitalar Universitário Do Porto, Porto, Portugal.
Purpose:
In multiple sclerosis (MS), chronic active/smoldering white matter lesions presenting with hypointense rims on susceptibility-weighted imaging (SWI) of the brain have been recognized as an important radiological feature. The aim of this work was to study the prevalence of paramagnetic rim lesions (RLs) in MS patients in a clinical setting and to assess differences in demographic and clinical variables regarding the presence of RLs.
Methods:
All 3 T brain magnetic resonance (MR) studies performed in MS patients between July 2020 and January 2021 were reviewed. In all patients, RLs were assessed on three-dimensional (3D) SWI images and the T2 FLAIR lesion load volume was assessed. Demographic, laboratory (oligoclonal bands in CSF), and clinical data, including functional status with Expanded Disability Status Scale (EDSS), were retrieved from the clinical files.
Results:
Of the 192 patients, 113 (59%) presented with at least 1 RL. In the RL-positive group, the mean RL count was 4.81 ranging from 1 to 37. There was no significant difference in the number of RLs between the different types of MS (p = 0.858). Regarding the presence of RLs, there were no significant differences based on gender (p = 0.083), disease duration (p = 0.520), treatment regime (p = 0.326), EDSS score (p = 0.103), and the associated T2 FLAIR lesion load volume.
Conclusion:
SWI RLs were frequently detected in our cohort regardless of the MS type, T2 FLAIR lesion load volume, demographic features, disease duration, or clinical score. Our results suggest that RLs are not associated with more severe forms of the disease. Today, RLs can be seen on 3 T 3D SWI, although this is not a clinical standard sequence yet. Therefore, it should be considered an additional helpful MR sequence in the diagnostic workup of MS, although more studies are warranted to establish the role of RLs as prognostic markers.
Insights
Paramagnetic rim lesions (RLs) are common in multiple sclerosis (MS) brain scans. These lesions, detected via susceptibility-weighted imaging (SWI), do not appear linked to disease severity or specific patient demographics.
Area of Science:
- Radiology
- Neuroscience
- Medical Imaging
Background:
- Chronic active/smoldering white matter lesions in multiple sclerosis (MS) are characterized by hypointense rims on susceptibility-weighted imaging (SWI).
- These paramagnetic rim lesions (RLs) are recognized as a significant radiological feature in MS.
Purpose of the Study:
- To determine the prevalence of RLs in MS patients within a clinical setting.
- To investigate potential differences in demographic and clinical variables associated with the presence of RLs.
Main Methods:
- Review of 3 Tesla (3T) brain MRI studies in MS patients from July 2020 to January 2021.
- Assessment of RLs on three-dimensional (3D) SWI images and T2 FLAIR lesion load.
- Collection of demographic, CSF oligoclonal band status, and clinical data, including Expanded Disability Status Scale (EDSS).
Main Results:
- 113 out of 192 (59%) MS patients exhibited at least one RL.
- The mean RL count in positive cases was 4.81 (range 1-37).
- No significant differences in RL presence were found concerning MS type, gender, disease duration, treatment, EDSS score, or T2 FLAIR lesion load.
Conclusions:
- RLs are frequently detected on 3T 3D SWI in MS patients, irrespective of disease type, lesion load, or clinical status.
- The findings suggest RLs are not indicative of more severe MS forms.
- SWI RLs represent a valuable addition to MS diagnostic workup, though further research is needed to confirm their prognostic value.
