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Updated: Dec 21, 2025
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Sensitivity of the Inhomogeneous Magnetization Transfer Imaging Technique to Spinal Cord Damage in Multiple Sclerosis
H Rasoanandrianina1,2,3, S Demortière1,2,4, A Trabelsi1,2
1From the Center for Magnetic Resonance in Biology and Medicine (H.R., S.D., A.T., J.P.R., O.G., G.D., M.G., J.P., B.A., V.C.), Centre National de la Recherche Scientifique, Aix-Marseille Université, Marseille, France.
Background And Purpose:
The inhomogeneous magnetization transfer technique has demonstrated high specificity for myelin, and has shown sensitivity to multiple sclerosis-related impairment in brain tissue. Our aim was to investigate its sensitivity to spinal cord impairment in MS relative to more established MR imaging techniques (volumetry, magnetization transfer, DTI).
Materials And Methods:
Anatomic images covering the cervical spinal cord from the C1 to C6 levels and DTI, magnetization transfer/inhomogeneous magnetization transfer images at the C2/C5 levels were acquired in 19 patients with MS and 19 paired healthy controls. Anatomic images were segmented in spinal cord GM and WM, both manually and using the AMU40 atlases. MS lesions were manually delineated. MR metrics were analyzed within normal-appearing and lesion regions in anterolateral and posterolateral WM and compared using Wilcoxon rank tests and z scores. Correlations between MR metrics and clinical scores in patients with MS were evaluated using the Spearman rank correlation.
Results:
AMU40-based C1-to-C6 GM/WM automatic segmentations in patients with MS were evaluated relative to manual delineation. Mean Dice coefficients were 0.75/0.89, respectively. All MR metrics (WM/GM cross-sectional areas, normal-appearing and lesion diffusivities, and magnetization transfer/inhomogeneous magnetization transfer ratios) were observed altered in patients compared with controls (P < .05). Additionally, the absolute inhomogeneous magnetization transfer ratio z scores were significantly higher than those of the other MR metrics (P < .0001), suggesting a higher inhomogeneous magnetization transfer sensitivity toward spinal cord impairment in MS. Significant correlations with the Expanded Disability Status Scale (ρ = -0.73/P = .02, ρ = -0.81/P = .004) and the total Medical Research Council scale (ρ = 0.80/P = .009, ρ = -0.74/P = .02) were observed for inhomogeneous magnetization transfer and magnetization transfer ratio z scores, respectively, in normal-appearing WM regions, while weaker and nonsignificant correlations were obtained for DTI metrics.
Conclusions:
With inhomogeneous magnetization transfer being highly sensitive to spinal cord damage in MS compared with conventional magnetization transfer and DTI, it could generate great clinical interest for longitudinal follow-up and potential remyelinating clinical trials. In line with other advanced myelin techniques with which it could be compared, it opens perspectives for multicentric investigations.
Insights
Inhomogeneous magnetization transfer (IMT) shows higher sensitivity to spinal cord damage in multiple sclerosis (MS) than conventional MRI. This advanced technique offers potential for tracking disease progression and evaluating new MS therapies.
Area of Science:
- Neuroimaging
- Biomedical Engineering
- Neurology
Background:
- Inhomogeneous magnetization transfer (IMT) is a sensitive MRI technique for detecting myelin and has shown promise in assessing brain tissue impairment in multiple sclerosis (MS).
- The utility of IMT for evaluating spinal cord impairment in MS, relative to established MRI methods like volumetry, magnetization transfer (MT), and diffusion tensor imaging (DTI), requires further investigation.
Purpose of the Study:
- To assess the sensitivity of IMT in detecting spinal cord damage in MS.
- To compare the sensitivity of IMT with conventional MRI techniques (volumetry, MT, DTI) in the context of MS-related spinal cord impairment.
Main Methods:
- Acquired cervical spinal cord MRI data (anatomic, DTI, MT/IMT) from 19 MS patients and 19 healthy controls.
- Segmented spinal cord gray matter (GM) and white matter (WM) using manual delineation and AMU40 atlases.
- Analyzed MR metrics in normal-appearing and lesion regions, comparing patients with controls and correlating metrics with clinical scores (EDSS, MRC scale).
Main Results:
- AMU40 atlas-based segmentation demonstrated good agreement with manual delineation (Dice coefficients 0.75/0.89 for GM/WM).
- All tested MR metrics were significantly altered in MS patients compared to controls (P < .05).
- Absolute IMT ratio z-scores were significantly higher than other MR metrics (P < .0001), indicating superior sensitivity to spinal cord impairment in MS. IMT metrics showed significant correlations with clinical disability scores.
Conclusions:
- IMT exhibits significantly higher sensitivity to spinal cord damage in MS compared to conventional MT and DTI.
- IMT holds considerable clinical potential for longitudinal MS monitoring and evaluating the efficacy of potential remyelinating therapies.
- IMT opens avenues for multicenter studies and comparisons with other advanced myelin-sensitive imaging techniques.
