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Updated: Jul 16, 2025
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Paramagnetic rim lesions lead to pronounced diffuse periplaque white matter damage in multiple sclerosis
Nik Krajnc1, Victor Schmidbauer2, Joel Leinkauf2
1Department of Neurology, Medical University of Vienna, Vienna, Austria/Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria/Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
Background:
Paramagnetic rim lesions (PRLs) are an imaging biomarker in multiple sclerosis (MS), associated with a more severe disease.
Objectives:
To determine quantitative magnetic resonance imaging (MRI) metrics of PRLs, lesions with diffuse susceptibility-weighted imaging (SWI)-hypointense signal (DSHLs) and SWI-isointense lesions (SILs), their surrounding periplaque area (PPA) and the normal-appearing white matter (NAWM).
Methods:
In a cross-sectional study, quantitative MRI metrics were measured in people with multiple sclerosis (pwMS) using the multi-dynamic multi-echo (MDME) sequence post-processing software "SyMRI."
Results:
In 30 pwMS, 59 PRLs, 74 DSHLs, and 107 SILs were identified. Beside longer T1 relaxation times of PRLs compared to DSHLs and SILs (2030.5 (1519-2540) vs 1615.8 (1403.3-1953.5) vs 1199.5 (1089.6-1334.6), both p < 0.001), longer T1 relaxation times were observed in the PRL PPA compared to the SIL PPA and the NAWM but not the DSHL PPA. Patients with secondary progressive multiple sclerosis (SPMS) had longer T1 relaxation times in PRLs compared to patients with late relapsing multiple sclerosis (lRMS) (2394.5 (2030.5-3040) vs 1869.3 (1491.4-2451.3), p = 0.015) and also in the PRL PPA compared to patients with early relapsing multiple sclerosis (eRMS) (982 (927-1093.5) vs 904.3 (793.3-958.5), p = 0.013).
Conclusion:
PRLs are more destructive than SILs, leading to diffuse periplaque white matter (WM) damage. The quantitative MRI-based evaluation of the PRL PPA could be a marker for silent progression in pwMS.
Insights
Paramagnetic rim lesions (PRLs) in multiple sclerosis (MS) show longer T1 relaxation times, indicating more severe tissue damage compared to other lesion types. Evaluating the area around these lesions may predict silent disease progression in people with MS.
Area of Science:
- Neuroimaging
- Radiology
- Multiple Sclerosis Research
Background:
- Paramagnetic rim lesions (PRLs) are an established imaging biomarker in multiple sclerosis (MS).
- PRLs are associated with more severe disease progression and disability in people with MS (pwMS).
Purpose of the Study:
- To quantitatively assess magnetic resonance imaging (MRI) metrics of PRLs, diffuse susceptibility-weighted imaging (SWI)-hypointense lesions (DSHLs), and SWI-isointense lesions (SILs).
- To evaluate the periplaque area (PPA) surrounding these lesions and normal-appearing white matter (NAWM) in pwMS.
- To correlate MRI metrics with different MS subtypes.
Main Methods:
- A cross-sectional study involving 30 pwMS.
- Quantitative MRI metrics were acquired using a multi-dynamic multi-echo (MDME) sequence and processed with SyMRI software.
- Analysis included T1 relaxation times for lesions, PPA, and NAWM.
Main Results:
- PRLs exhibited significantly longer T1 relaxation times compared to DSHLs and SILs (p < 0.001).
- The PPA surrounding PRLs showed longer T1 relaxation times than the PPA of SILs and NAWM (p < 0.001).
- Patients with secondary progressive MS (SPMS) had longer T1 relaxation times in PRLs and their PPA compared to relapsing forms of MS (p=0.015 and p=0.013, respectively).
Conclusions:
- PRLs are associated with more extensive white matter damage than SILs.
- Quantitative MRI evaluation of the PRL PPA may serve as a valuable biomarker for detecting silent disease progression in pwMS.
