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Updated: Dec 6, 2025
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Paramagnetic Rims in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder: A Quantitative Susceptibility
Jinhee Jang1, Yoonho Nam1,2, Yangsean Choi1
1Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Background And Purpose:
Iron retained by activated microglia and macrophages in multiple sclerosis (MS) lesions may serve as a marker of innate immune system activation. Among several magnetic resonance imaging (MRI) methods, there has been recent interest in using quantitative susceptibility mapping (QSM) as a potential tool for assessing iron levels in the human brain. This study examined QSM findings in MS and neuromyelitis optica spectrum disorder (NMOSD) lesions obtained with 3-T MRI to assess imaging characteristics related to paramagnetic rims around brain lesions in MS and NMOSD.
Methods:
This study included 32 MS and 21 seropositive NMOSD patients. MRI images were obtained using two 3-T MRI devices (Ingenia, Philips Healthcare; and Magnetom Verio, Siemens Healthineers) during routine diagnosis and treatment procedures. Multi and single echo gradient echo magnitude and phase images were obtained for QSM reconstruction. QSM images were used to characterize the detected lesions, and the findings were compared between MS and NMOSD.
Results:
Totals of 71 and 35 MRI scans were performed during the study period in MS and NMOSD patients, respectively. In QSM images, paramagnetic rims were found in 26 (81.2%) MS patients and 1 (4.8%) NMOSD patient. Eight of the 22 MS patients and only 1 of the 10 NMOSD patients who underwent follow-up MRI showed new paramagnetic rims. The paramagnetic rim lesions appeared after enhancement or in new T2-weighted lesions without enhancement.
Conclusions:
Paramagnetic rims might be a characteristic MRI finding for MS, and therefore they have potential as an imaging marker for differentially diagnosing MS from NMOSD using 3-T MRI.
Insights
Paramagnetic rims detected by quantitative susceptibility mapping (QSM) on 3-T MRI are a potential imaging biomarker for multiple sclerosis (MS), helping differentiate it from neuromyelitis optica spectrum disorder (NMOSD). This iron-related finding is more prevalent in MS lesions.
Area of Science:
- Neuroimaging
- Neuroimmunology
- Radiology
Background:
- Iron accumulation in activated microglia and macrophages within multiple sclerosis (MS) lesions indicates innate immune system activation.
- Quantitative susceptibility mapping (QSM) is an emerging magnetic resonance imaging (MRI) technique for assessing brain iron levels.
Purpose of the Study:
- To investigate QSM findings in MS and neuromyelitis optica spectrum disorder (NMOSD) lesions using 3-T MRI.
- To evaluate the characteristics of paramagnetic rims around brain lesions in MS and NMOSD.
Main Methods:
- Included 32 MS and 21 NMOSD patients undergoing routine 3-T MRI scans on Philips and Siemens devices.
- Acquired multi- and single-echo gradient echo images for QSM reconstruction.
- Characterized lesions on QSM images and compared findings between MS and NMOSD groups.
Main Results:
- Paramagnetic rims were identified in 81.2% of MS patients versus 4.8% of NMOSD patients.
- New paramagnetic rims developed in 8/22 MS patients and 1/10 NMOSD patients on follow-up MRI.
- These rims were associated with contrast enhancement or new T2-weighted lesions.
Conclusions:
- Paramagnetic rims observed on QSM represent a potential characteristic MRI finding for MS.
- This imaging marker may aid in the differential diagnosis of MS from NMOSD using 3-T MRI.
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