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Updated: Jul 21, 2025
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Highly Sensitive 3-Tesla Real Inversion Recovery MRI Detects Leptomeningeal Contrast Enhancement in Chronic Active
Serhat Vahip Okar1, Henry Dieckhaus, Erin S Beck
1From the Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD, USA (S.V.O., E.S.B., M.I.G., M.A., D.S.R.); qMRI Core facility, National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD, USA (H.D., G.N.); Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA (E.S.B.); Office of Biostatistics, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA (G.N.); Department of Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, Bethesda, MD, USA (D.L.P.); Division of Neuroscience, Vita-Salute San Raffaele University and Hospital, Milan, Italy (M.A.); Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA (M.A.); Experimental Immunotherapeutics Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA (I.C.M.C.); Neuroimmunology Clinic, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA (A.F.); and Viral Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD20814, USA (S.J.).
Background:
Leptomeningeal contrast enhancement (LME) on T2-weighted Fluid-Attenuated Inversion Recovery (T2-FLAIR) MRI is a reported marker of leptomeningeal inflammation, which is known to be associated with progression of multiple sclerosis (MS). However, this MRI approach, as typically implemented on clinical 3-tesla (T) systems, detects only a few enhancing foci in ~25% of patients and has thus been criticized as poorly sensitive.
Purpose:
To compare an optimized 3D real-reconstruction inversion recovery (Real-IR) MRI sequence on a clinical 3 T scanner to T2-FLAIR for prevalence, characteristics, and clinical/radiological correlations of LME.
Materials And Methods:
We obtained 3D T2-FLAIR and Real-IR scans before and after administration of standard-dose gadobutrol in 177 scans of 154 participants (98 women, 64%; mean ± SD age: 49 ± 12 years), including 124 with an MS-spectrum diagnosis, 21 with other neurological and/or inflammatory disorders, and 9 without neurological history. We calculated contrast-to-noise ratios (CNR) in 20 representative LME foci and determined association of LME with cortical lesions identified at 7 T (n = 19), paramagnetic rim lesions (PRL) at 3 T (n = 105), and clinical/demographic data.
Results:
We observed focal LME in 73% of participants on Real-IR (70% in established MS, 33% in healthy volunteers, P < 0.0001), compared to 33% on T2-FLAIR (34% vs. 11%, P = 0.0002). Real-IR showed 3.7-fold more LME foci than T2-FLAIR ( P = 0.001), including all T2-FLAIR foci. LME CNR was 2.5-fold higher by Real-IR ( P < 0.0001). The major determinant of LME status was age. Although LME was not associated with cortical lesions, the number of PRL was associated with the number of LME foci on both T2-FLAIR ( P = 0.003) and Real-IR ( P = 0.0003) after adjusting for age, sex, and white matter lesion volume.
Conclusions:
Real-IR a promising tool to detect, characterize, and understand the significance of LME in MS. The association between PRL and LME highlights a possible role of the leptomeninges in sustaining chronic inflammation.
Insights
A new MRI technique, optimized 3D Real-IR, significantly improves the detection of leptomeningeal contrast enhancement (LME) in multiple sclerosis (MS) patients. This advanced method offers higher sensitivity and better characterization of LME compared to standard T2-FLAIR imaging.
Area of Science:
- Neuroimaging
- Radiology
- Inflammation Research
Background:
- Leptomeningeal contrast enhancement (LME) on T2-FLAIR MRI is linked to multiple sclerosis (MS) progression.
- Standard T2-FLAIR MRI has limited sensitivity for detecting LME, identifying it in only ~25% of MS patients.
Purpose of the Study:
- To compare an optimized 3D Real-IR MRI sequence with standard T2-FLAIR for LME detection in MS.
- To evaluate the prevalence, characteristics, and clinical/radiological correlations of LME using both MRI techniques.
Main Methods:
- Acquired 3D T2-FLAIR and Real-IR MRI scans in 154 participants (124 with MS spectrum diagnosis).
- Calculated contrast-to-noise ratios (CNR) for LME foci and assessed associations with cortical lesions, paramagnetic rim lesions (PRL), and clinical data.
Main Results:
- Optimized 3D Real-IR detected LME in 73% of participants, significantly higher than T2-FLAIR (33%).
- Real-IR identified 3.7-fold more LME foci with 2.5-fold higher CNR compared to T2-FLAIR.
- Paramagnetic rim lesions (PRL) number correlated with LME foci number, independent of age, sex, and white matter lesion volume.
Conclusions:
- Optimized 3D Real-IR MRI is a promising tool for detecting and characterizing LME in MS.
- The association between PRL and LME suggests a role for leptomeninges in chronic MS inflammation.
