A pilot, longitudinal, 24-week study to evaluate the effect of interferon beta-1a subcutaneous on changes in susceptibility-weighted imaging-filtered phase assessment of lesions and subcortical deep-gray matter in relapsing-remitting multiple sclerosis

Magnetic resonance imaging detection of deep gray matter iron deposition in multiple sclerosis: A systematic review

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease involving immune-mediated damage. Iron deposition in deep gray matter (DGM) structures like the thalamus and basal ganglia have been suggested to play a role in MS pathogenesis. Magnetic Resonance Imaging (MRI) imaging methods like T2 and T2* imaging, susceptibility-weighted imaging, and quantitative susceptibility mapping can track iron deposition storage in the brain primarily from ferritin and hemosiderin (paramagnetic iron storage proteins) with varying levels of tissue contrast and sensitivity. In this systematic review, we evaluated the role of DGM iron deposition as detected by MRI techniques in relation to MS-related neuroinflammation and its potential as a novel therapeutic target. We searched through PubMed, Embase, and Web of Science databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, against predetermined inclusion and exclusion criteria. We included 89 articles (n = 6630 patients), and then grouped them into different categories: i) methodological techniques to measure DGM iron, ii) cross-sectional and group comparison of DGM iron content, iii) longitudinal comparisons of DGM iron, iv) associations between DGM iron and other imaging and neurobiological markers, v) associations with disability, and vi) associations with cognitive impairment. The review revealed that iron deposition in DGM is independent yet concurrent with demyelination, and that these iron deposits contribute to MS-related cognitive impairment and disability. Variability in iron distributions appears to rely on a positive feedback loop between inflammation, and release of iron by oligodendrocytes. DGM iron seems to be a promising prognostic biomarker for MS pathophysiology.

Evaluation of the 'ring sign' and the 'core sign' as a magnetic resonance imaging marker of disease activity and progression in clinically isolated syndrome and early multiple sclerosis

Background

Brain lesions with a hypointense ring or core were described in multiple sclerosis on susceptibility weighted imaging.

Objective

The purpose of this study was to study the evolution and prognostic relevance of susceptibility weighted imaging hypointense lesions in clinically isolated syndrome and early multiple sclerosis.

Methods

Sixty-six early multiple sclerosis and clinically isolated syndrome patients were followed over a median period of 2.9 years (range 1.6–4.6 years) and underwent 3T magnetic resonance imaging including 3D susceptibility weighted imaging and T2-weighted fluid-attenuated inversion recovery. We assessed the presence of susceptibility weighted imaging hypointense core or ring lesions, and Expanded Disability Status Scale at baseline and follow-up.

Results

Of 611 lesions at baseline, 64 (10.5%) had a susceptibility weighted imaging hypointense core, and 28 (4.6%) had a susceptibility weighted imaging hypointense ring. Hypointense ring lesions were larger (p < 0.001) and more T1w hypointense (p = 0.002) than others. During follow-up, hypointense core lesions became susceptibility weighted imaging isointense (52 lesions, 81%); few developed into hypointense ring lesions (two lesions, 3%). Hypointense ring lesions did not shrink on T2-weighted fluid-attenuated inversion recovery images (p = 0.077, trend towards more enlargement compared to others), while hypointense core lesions more often shrunk in comparison to lesions without a hypointense core (p = 0.002). The number of susceptibility weighted imaging hypointense ring lesions at baseline correlated with Expanded Disability Status Scale progression at follow-up (p = 0.021, R = 0.289).

Conclusion

In our cohort of patients with clinically isolated syndrome or early multiple sclerosis, susceptibility weighted imaging hypointense ring lesions were only rarely detectable, but did not shrink and were associated with future disability progression.

Discriminative analysis of regional evolution of iron and myelin/calcium in deep gray matter of multiple sclerosis and healthy subjects

BACKGROUND

Combined R2* and quantitative susceptibility (QS) has been previously used in cross-sectional multiple sclerosis (MS) studies to distinguish deep gray matter (DGM) iron accumulation and demyelination.

PURPOSE

We propose and apply discriminative analysis of regional evolution (DARE) to define specific changes in MS and healthy DGM.

STUDY TYPE

Longitudinal (baseline and 2-year follow-up) retrospective study.

SUBJECTS

Twenty-seven relapsing-remitting MS (RRMS), 17 progressive MS (PMS), and corresponding age-matched healthy subjects.

FIELD STRENGTH/SEQUENCE

4.7T 10-echo gradient-echo acquisition.

ASSESSMENT

Automatically segmented caudate nucleus (CN), thalamus (TH), putamen (PU), globus pallidus, red nucleus (RN), substantia nigra, and dentate nucleus were retrospectively analyzed to quantify regional volumes, bulk mean R2*, and bulk mean QS. DARE utilized combined R2* and QS localized changes to compute spatial extent, mean intensity, and total changes of DGM iron and myelin/calcium over 2 years.

STATISTICAL TESTS

We used mixed factorial analysis for bulk analysis, nonparametric tests for DARE (α = 0.05), and multiple regression analysis using backward elimination of DGM structures (α = 0.05, P = 0.1) to regress bulk and DARE measures with the follow-up Multiple Sclerosis Severity Score (MSSS). False detection rate correction was applied to all tests.

RESULTS

Bulk analysis only detected significant (Q ≤ 0.05) interaction effects in RRMS CN QS (η = 0.45; Q = 0.004) and PU volume (η = 0.38; Q = 0.034). DARE demonstrated significant group differences in all RRMS structures, and in all PMS structures except the RN. The largest RRMS effect size was CN total R2* iron decrease (r = 0.74; Q = 0.00002), and TH mean QS myelin/calcium decrease for PMS (r = 0.70; Q = 0.002). DARE iron increase using total QS demonstrated the highest correlation with MSSS (r = 0.68; Q = 0.0005).

DATA CONCLUSION

DARE enabled discriminative assessment of specific DGM changes over 2 years, where iron and myelin/calcium changes were the primary drivers in RRMS and PMS compared to age-matched controls, respectively. Specific DARE measures of MS DGM correlated with follow-up MSSS, and may reflect complex disease pathology.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018.

Iron in Multiple Sclerosis and Its Noninvasive Imaging with Quantitative Susceptibility Mapping

Iron is considered to play a key role in the development and progression of Multiple Sclerosis (MS). In particular, iron that accumulates in myeloid cells after the blood-brain barrier (BBB) seals may contribute to chronic inflammation, oxidative stress and eventually neurodegeneration. Magnetic resonance imaging (MRI) is a well-established tool for the non-invasive study of MS. In recent years, an advanced MRI method, quantitative susceptibility mapping (QSM), has made it possible to study brain iron through in vivo imaging. Moreover, immunohistochemical investigations have helped defining the lesional and cellular distribution of iron in MS brain tissue. Imaging studies in MS patients and of brain tissue combined with histological studies have provided important insights into the role of iron in inflammation and neurodegeneration in MS.

Iron in Multiple Sclerosis and Its Noninvasive Imaging with Quantitative Susceptibility Mapping

Iron is considered to play a key role in the development and progression of Multiple Sclerosis (MS). In particular, iron that accumulates in myeloid cells after the blood-brain barrier (BBB) seals may contribute to chronic inflammation, oxidative stress and eventually neurodegeneration. Magnetic resonance imaging (MRI) is a well-established tool for the non-invasive study of MS. In recent years, an advanced MRI method, quantitative susceptibility mapping (QSM), has made it possible to study brain iron through in vivo imaging. Moreover, immunohistochemical investigations have helped defining the lesional and cellular distribution of iron in MS brain tissue. Imaging studies in MS patients and of brain tissue combined with histological studies have provided important insights into the role of iron in inflammation and neurodegeneration in MS.