Evidence-based guidelines: MAGNIMS consensus guidelines on the use of MRI in multiple sclerosis-clinical implementation in the diagnostic process

GAMER-MRI in Multiple Sclerosis Identifies the Diffusion-Based Microstructural Measures That Are Most Sensitive to Focal Damage: A Deep-Learning-Based Analysis and Clinico-Biological Validation

Conventional magnetic resonance imaging (cMRI) in multiple sclerosis (MS) patients provides measures of focal brain damage and activity, which are fundamental for disease diagnosis, prognosis, and the evaluation of response to therapy. However, cMRI is insensitive to the damage to the microenvironment of the brain tissue and the heterogeneity of MS lesions. In contrast, the damaged tissue can be characterized by mathematical models on multishell diffusion imaging data, which measure different compartmental water diffusion. In this work, we obtained 12 diffusion measures from eight diffusion models, and we applied a deep-learning attention-based convolutional neural network (CNN) (GAMER-MRI) to select the most discriminating measures in the classification of MS lesions and the perilesional tissue by attention weights. Furthermore, we provided clinical and biological validation of the chosen metrics-and of their most discriminative combinations-by correlating their respective mean values in MS patients with the corresponding Expanded Disability Status Scale (EDSS) and the serum level of neurofilament light chain (sNfL), which are measures of disability and neuroaxonal damage. Our results show that the neurite density index from neurite orientation and dispersion density imaging (NODDI), the measures of the intra-axonal and isotropic compartments from microstructural Bayesian approach, and the measure of the intra-axonal compartment from the spherical mean technique NODDI were the most discriminating (respective attention weights were 0.12, 0.12, 0.15, and 0.13). In addition, the combination of the neurite density index from NODDI and the measures for the intra-axonal and isotropic compartments from the microstructural Bayesian approach exhibited a stronger correlation with EDSS and sNfL than the individual measures. This work demonstrates that the proposed method might be useful to select the microstructural measures that are most discriminative of focal tissue damage and that may also be combined to a unique contrast to achieve stronger correlations to clinical disability and neuroaxonal damage.

DeepGRAI (Deep Gray Rating via Artificial Intelligence): Fast, feasible, and clinically relevant thalamic atrophy measurement on clinical quality T2-FLAIR MRI in multiple sclerosis

BACKGROUND

Thalamic volume loss is a key marker of neurodegeneration in multiple sclerosis (MS). T2-FLAIR MRI is a common denominator in clinical routine MS imaging, but current methods for thalamic volumetry are not applicable to it.

OBJECTIVE

To develop and validate a robust algorithm to measure thalamic volume using clinical routine T2-FLAIR MRI.

METHODS

A dual-stage deep learning approach based on 3D U-net (DeepGRAI - Deep Gray Rating via Artificial Intelligence) was created and trained/validated/tested on 4,590 MRI exams (4288 2D-FLAIR, 302 3D-FLAIR) from 59 centers (80/10/10 train/validation/test split). As training/test targets, FIRST was used to generate thalamic masks from 3D T1 images. Masks were reviewed, corrected, and aligned into T2-FLAIR space. Additional validation was performed to assess inter-scanner reliability (177 subjects at 1.5 T and 3 T within one week) and scan-rescan-reliability (5 subjects scanned, repositioned, and then re-scanned). A longitudinal dataset including assessment of disability and cognition was used to evaluate the predictive value of the approach.

RESULTS

DeepGRAI automatically quantified thalamic volume in approximately 7 s per case, and has been made publicly available. Accuracy on T2-FLAIR relative to 3D T1 FIRST was 99.4% (r = 0.94, p < 0.001,TPR = 93.0%, FPR = 0.3%). Inter-scanner error was 3.21%. Scan-rescan error with repositioning was 0.43%. DeepGRAI-derived thalamic volume was associated with disability (r = -0.427,p < 0.001) and cognition (r = -0.537,p < 0.001), and was a significant predictor of longitudinal cognitive decline (R2 = 0.081, p = 0.024; comparatively, FIRST-derived volume was R2 = 0.080, p = 0.025).

CONCLUSIONS

DeepGRAI provides fast, reliable, and clinically relevant thalamic volume measurement on multicenter clinical-quality T2-FLAIR images. This indicates potential for real-world thalamic volumetry, as well as quantification on legacy datasets without 3D T1 imaging.

Quantitative MRI texture analysis in chronic active multiple sclerosis lesions

OBJECTIVE

Recently, there has been an increasing interest in "chronic enlarging" or "chronic active" multiple sclerosis (MS) lesions that are associated with clinical disability. However, investigation of dynamic lesion volume changes requires longitudinal MRI data from two or more time points. The aim of this study was to investigate the application of texture analysis (TA) on baseline T1-weighted 3D magnetization-prepared rapid acquisition gradient-echo (MPRAGE) images to differentiate chronic active from chronic stable MS lesions.

MATERIAL AND METHODS

To identify chronic active lesions as compared to non-enhancing stable lesions, two MPRAGE datasets acquired on a 3 T MRI at baseline and after 12 months follow-up were applied to the Voxel-Guided Morphometry (VGM) algorithm. TA was performed on the baseline MPRAGE images, 36 texture features were extracted for each lesion.

RESULTS

Overall, 374 chronic MS lesions (155 chronic active and 219 chronic stable lesions) from 60 MS patients were included in the final analysis. Multiple texture features including "DISCRETIZED_HISTO_Energy", "GLCM_Energy", "GLCM_Contrast" and "GLCM_Dissimilarity" were significantly higher in chronic active as compared to chronic stable lesions. Partial least squares regression yielded an area under the curve of 0.7 to differentiate both lesion types.

CONCLUSION

Our results suggest that multiple texture features extracted from MPRAGE images indicate higher intralesional heterogeneity, however they demonstrate only a fair accuracy to differentiate chronic active from chronic stable MS lesions.

Recommendations for the coordination of Neurology and Neuroradiology Departments in the management of patients with multiple sclerosis

INTRODUCTION

Magnetic resonance imaging (MRI) is widely used for the diagnosis and follow-up of patients with multiple sclerosis (MS). Coordination between Neurology and Neuroradiology departments is crucial for performing and interpreting radiological studies as efficiently and as accurately as possible. However, improvements can be made in the communication between these departments in many Spanish hospitals.

METHODS

A panel of 17 neurologists and neuroradiologists from 8 Spanish hospitals held in-person and online meetings to draft a series of good practice guidelines for the coordinated management of MS. The drafting process included 4 phases: 1) establishing the scope of the guidelines and the methodology of the study; 2) literature review on good practices or recommendations on the use of MRI in MS; 3) discussion and consensus between experts; and 4) validation of the contents.

RESULTS

The expert panel agreed a total of 9 recommendations for improving coordination between neurology and neuroradiology departments. The recommendations revolve around 4 main pillars: 1) standardising the process for requesting and scheduling MRI studies and reports; 2) designing common protocols for MRI studies; 3) establishing multidisciplinary committees and coordination meetings; and 4) creating formal communication channels between both departments.

CONCLUSIONS

These consensus recommendations are intended to optimise coordination between neurologists and neuroradiologists, with the ultimate goal of improving the diagnosis and follow-up of patients with MS.

Neuroimaging Correlates of Cognitive Dysfunction in Adults with Multiple Sclerosis

Cognitive impairment is a frequent and meaningful symptom in multiple sclerosis (MS), caused by the accrual of brain structural damage only partially counteracted by effective functional reorganization. As both these aspects can be successfully investigated through the application of advanced neuroimaging, here, we offer an up-to-date overview of the latest findings on structural, functional and metabolic correlates of cognitive impairment in adults with MS, focusing on the mechanisms sustaining damage accrual and on the identification of useful imaging markers of cognitive decline.

Neuronal and glial CSF biomarkers in multiple sclerosis: a systematic review and meta-analysis

Multiple sclerosis (MS) is a neurodegenerative disease associated with inflammatory demyelination and astroglial activation, with neuronal and axonal damage as the leading factors of disability. We aimed to perform a meta-analysis to determine changes in CSF levels of neuronal and glial biomarkers, including neurofilament light chain (NFL), total tau (t-tau), chitinase-3-like protein 1 (CHI3L1), glial fibrillary acidic protein (GFAP), and S100B in various groups of MS (MS versus controls, clinically isolated syndrome (CIS) versus controls, CIS versus MS, relapsing-remitting MS (RRMS) versus progressive MS (PMS), and MS in relapse versus remission. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, we included 64 articles in the meta-analysis, including 4071 subjects. For investigation of sources of heterogeneity, subgroup analysis, meta-regression, and sensitivity analysis were conducted. Meta-analyses were performed for comparisons including at least three individual datasets. NFL, GFAP, t-tau, CHI3L1, and S100B were higher in MS and NFL, t-tau, and CHI3L1 were also elevated in CIS patients than controls. CHI3L1 was the only marker with higher levels in MS than CIS. GFAP levels were higher in PMS versus RRMS, and NFL, t-tau, and CHI3L1 did not differ between different subtypes. Only levels of NFL were higher in patients in relapse than remission. Meta-regression showed influence of sex and disease severity on NFL and t-tau levels, respectively and disease duration on both. Added to the role of these biomarkers in determining prognosis and treatment response, to conclude, they may serve in diagnosis of MS and distinguishing different subtypes.

Recent advances in development of nanomedicines for multiple sclerosis diagnosis

Multiple sclerosis (MS) is a neurodegenerative disease with a high morbidity and disease burden. It is characterized by the loss of the myelin sheath, resulting in the disruption of neuron electrical signal transmissions and sensory and motor ability deficits. The diagnosis of MS is crucial to its management, but the diagnostic sensitivity and specificity are always a challenge. To overcome this challenge, nanomedicines have recently been employed to aid the diagnosis of MS with an improved diagnostic efficacy. Advances in nanomedicine-based contrast agents in magnetic resonance imaging scanning of MS lesions, and nanomedicine-derived sensors for detecting biomarkers in the cerebrospinal fluid biopsy, or analyzing the composition of exhaled breath gas, have demonstrated the potential of using nanomedicines in the accurate diagnosis of MS. This review aims to provide an overview of recent advances in the application of nanomedicines for the diagnosis of MS and concludes with perspectives of using nanomedicines for the development of safe and effective MS diagnostic nanotools.

Pharmacovigilance during treatment of multiple sclerosis: early recognition of CNS complications

An increasing number of highly effective disease-modifying therapies for people with multiple sclerosis (MS) have recently gained marketing approval. While the beneficial effects of these drugs in terms of clinical and imaging outcome measures is welcomed, these therapeutics are associated with substance-specific or group-specific adverse events that include severe and fatal complications. These adverse events comprise both infectious and non-infectious complications that can occur within, or outside of the central nervous system (CNS). Awareness and risk assessment strategies thus require interdisciplinary management, and robust clinical and paraclinical surveillance strategies. In this review, we discuss the current role of MRI in safety monitoring during pharmacovigilance of patients treated with (selective) immune suppressive therapies for MS. MRI, particularly brain MRI, has a pivotal role in the early diagnosis of CNS complications that potentially are severely debilitating and may even be lethal. Early recognition of such CNS complications may improve functional outcome and survival, and thus knowledge on MRI features of treatment-associated complications is of paramount importance to MS clinicians, but also of relevance to general neurologists and radiologists.

Standardization and digitization of clinical data in multiple sclerosis

Standardization is necessary to ensure the reliability of clinical data and to enable longitudinal and cross-sectional comparisons of data obtained in different centres and countries. In patients with multiple sclerosis (MS), standardized clinical data are needed for monitoring of disability and for collecting real-world evidence for use in research. This Perspective describes attempts to improve the standardization and digitization of clinical data in MS, including digital electronic health recording systems and applications that attempt to offer a comprehensive assessment of patients' neurological deficits and their effects on daily life. Despite the challenges raised by regulatory, ethical and data-privacy considerations, the standardization and digitization of clinical data in MS is expected to generate new insights into the pathophysiology of the disease and to contribute to personalized patient care.

3D Quantitative Synthetic MRI in the Evaluation of Multiple Sclerosis Lesions

BACKGROUND AND PURPOSE

Synthetic MR imaging creates multiple contrast-weighted images based on a single time-efficient quantitative scan, which has been mostly performed for 2D acquisition. We assessed the utility of 3D synthetic MR imaging in patients with MS by comparing its diagnostic image quality and lesion volumetry with conventional MR imaging.

MATERIALS AND METHODS

Twenty-four patients with MS prospectively underwent 3D quantitative synthetic MR imaging and conventional T1-weighted, T2-weighted, FLAIR, and double inversion recovery imaging, with acquisition times of 9 minutes 3 seconds and 18 minutes 27 seconds for the synthetic MR imaging and conventional MR imaging sequences, respectively. Synthetic phase-sensitive inversion recovery images and those corresponding to conventional MR imaging contrasts were created for synthetic MR imaging. Two neuroradiologists independently assessed the image quality on a 5-point Likert scale. The numbers of cortical lesions and lesion volumes were quantified using both synthetic and conventional image sets.

RESULTS

The overall diagnostic image quality of synthetic T1WI and double inversion recovery images was noninferior to that of conventional images (P = .23 and .20, respectively), whereas that of synthetic T2WI and FLAIR was inferior to that of conventional images (both Ps < .001). There were no significant differences in the number of cortical lesions (P = .17 and .53 for each rater) or segmented lesion volumes (P = .61) between the synthetic and conventional image sets.

CONCLUSIONS

Three-dimensional synthetic MR imaging could serve as an alternative to conventional MR imaging in evaluating MS with a reduced scan time.

Administration of CD4+CD25highCD127-FoxP3+ Regulatory T Cells for Relapsing-Remitting Multiple Sclerosis: A Phase 1 Study

BACKGROUND

Multiple sclerosis (MS) is an immune-mediated disease in which autoimmune T conventional (T_conv) cells break the blood-brain barrier and destroy neurons of the central nervous system. It is hypothesized that CD4⁺CD25^highCD127^-FoxP3⁺ T regulatory (T_reg) cells may inhibit this destruction through suppressive activity exerted on T_conv cells.

METHODS

We present the results of a phase 1b/2a, open-label, two-arm clinical trial in 14 patients treated with autologous T_reg cells for relapsing-remitting MS. The patients received either expanded ex vivo T_reg cells intravenously (intravenous [IV] group, n = 11; dose 40 × 10⁶ T_reg cells/kg of body weight) or freshly isolated T_reg cells intrathecally (intrathecal [IT] group, n = 3; dose 1.0 × 10⁶ T_reg cells). Importantly, patients were not treated with any other disease-modifying drugs for at least 6 months before the recruitment and during the follow-up.

RESULTS

No severe adverse events were observed. Self-assessed quality of life (EuroQol-5 Dimensions [EQ-5D] form) did not change and did not differ significantly between the groups. A total of 12 relapses were noted in five intravenously treated patients, who had from one to three attacks per year. Three out of ten participants who completed the trial in the IV group deteriorated more than 1 point on the Expanded Disability Status Scale (EDSS) during the follow-up. At the same time, no patients in the IT group experienced a relapse or such a deterioration in the EDSS. No significant differences were found in the Multiple Sclerosis Functional Composite (MSFC) scale in both the IV and IT groups. Magnetic resonance imaging (MRI) scans revealed a significantly lower change in the T2 lesion volume in the IT group compared to the IV group. The increase in the number of new T2 lesions during the follow-up was significant for the IV group only. There were no significant changes in the level of T_reg cells or T_conv cells in the peripheral blood throughout the follow-up or between the groups. Interestingly, T_reg cells in all patients consisted of two different phenotypes: peripheral T_reg cells Helios(-) (≈ 20%) and thymic T_reg cells Helios(+) (≈ 80%). The analysis of the cytokine pattern revealed higher levels of transforming growth factor-α and proinflammatory factors MCP3, CXCL8, and IL-1RA in the IT group compared with the IV group.

CONCLUSIONS

No serious adverse events were reported in the 14 patients with MS treated with T_reg cells in this study. The results suggest that IT administration is more promising than IV administration. Because of the low number of patients recruited, the statistical results may be underpowered and further studies are necessary to reach conclusions on efficacy and safety.

TRIAL REGISTRATION

EudraCT: 2014-004320-22; registered 18 November 2014.

Clinical feasibility of longitudinal lateral ventricular volume measurements on T2-FLAIR across MRI scanner changes

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Central and whole brain atrophy are faster in MS patients with disability progression.

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These measures can be reliably assessed on clinically-available FLAIR images.

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They are meaningful even with longitudinal scanner and field strength changes.

Background

Greater brain atrophy is associated with disability progression (DP) in patients with multiple sclerosis (PwMS). However, methodological challenges limit its routine clinical use.

Objective

To determine the feasibility of atrophy measures as markers of DP in PwMS scanned across different MRI field strengths.

Methods

A total of 980 PwMS were scanned on either 1.5 T or 3.0 T MRI scanners. Demographic and clinical data were retrospectively collected, and the presence of DP was determined according to standard clinical trial criteria. Lateral ventricular volume (LVV) change was measured with the NeuroSTREAM technique on clinical routine T2-FLAIR images. Percent brain volume change (PBVC) was measured using SIENA and ventricular cerebrospinal fluid (vCSF) % change was measured using VIENA and SIENAX algorithms on 3D T1-weighted images (WI). Stable vs. DP PwMS were compared using analysis of covariance (ANCOVA). Mixed modeling determined the effect of MRI scanner change on MRI-derived atrophy measures.

Results

Longitudinal LVV analysis was successful in all PwMS. SIENA-based PBVC and VIENA-based changes failed in 37.6% of cases, while SIENAX-based vCSF failed in 12.9% of cases. PwMS with DP (n = 241) had significantly greater absolute (20.9% vs. 8.7%, d = 0.66, p < 0.001) and annualized LVV % change (4.1% vs. 2.3%, d = 0.27, p < 0.001) when compared to stable PwMS (n = 739). In subjects with both analyses available, both 3D-T1 and T2-FLAIR-based analyses differentiated PwMS with DP (n = 149). However, only NeuroSTREAM and VIENA-based LVV/vCSF were able to show greater atrophy in PwMS that were scanned on different scanners. PBVC and SIENAX-based vCSF % changes were significantly affected by scanner change (Beta = −0.16, t-statistics = −2.133, p = 0.033 and Beta = −2.08, t-statistics = −4.084, p < 0.001), whereas no MRI scanner change effects on NeuroSTREAM-based PLVVC and VIENA-based vCSF % change were noted.

Conclusions

LVV-based atrophy on T2-FLAIR is a clinically relevant measure in spite of MRI scanner changes and mild disability levels.

Three-Year Effectiveness of Dimethyl Fumarate in Multiple Sclerosis: A Prospective Multicenter Real-World Study

BACKGROUND

Dimethyl fumarate (DMF) has demonstrated efficacy in phase III studies. However, real-world data are still limited.

OBJECTIVE

The objective of this study was to describe the profile of patients who receive DMF and to assess the effectiveness of DMF regarding relapses, disability progression, magnetic resonance imaging activity, and NEDA (No Evidence Disease Activity)-3 status in a Spanish population in a real-world setting.

METHODS

We conducted a multicenter prospective study of patients who started DMF between 2014 and 2019 in Spain. Three subgroups were considered: naïve, switch to DMF because of inefficacy, and switch to DMF because of adverse effects. The effects of DMF on clinical and radiological measures were evaluated.

RESULTS

Among 886 patients, 25.3% were naïve, 28.8% switched because of adverse effects, and 45.9% because of inefficacy. Median follow-up was 38.9 (interquartile range 22.6-41.8) months. Annualized relapse rates were 0.15, 0.10, and 0.10 at 12, 24, and 36 months respectively, and 77.7% of patients were relapse free at month 42. At 12, 24, and 42 months, 96.1%, 87.4%, and 79.7% of patients were progression free, respectively. The number of T1 gadolinium-enhancement (T1Gd+) lesions was 0.19, 0.14, and 0.18 at 12, 24, and 36 months. NEDA-3 status at month 42 was maintained by 49.8% of patients. Relapsing was associated with higher annualized relapse rates the year before (hazard ratio 1.34, p < 0.001) and to the inefficacy switch vs naïve group (hazard ratio 1.76, p = 0.003). A higher baseline Expanded Disability Status Scale score was associated with disability progression (hazard ratio 1.15, p = 0.003) and more T1Gd+ lesions (hazard ratio 1.07, p < 0.001) with radiological progression. A higher baseline Expanded Disability Status Scale score, a larger number of T1Gd+ lesions, and a switch because of inefficacy (vs adverse events) were all risk factors for losing NEDA-3 status. DMF was discontinued in 29.9% of patients, in 13.5% because of inefficacy.

CONCLUSIONS

Our findings confirm the sustained effectiveness of DMF on the clinical and radiological activity of multiple sclerosis in a real-world setting, both in naïve patients and in those switching from other multiple sclerosis therapies.

Adding brain volume measures into response criteria in multiple sclerosis: the Río-4 score

PURPOSE

Brain volume changes (BVC) on therapy in MS are being considered as predictor for treatment response at an individual level. We ought to assess whether adding BVC as a factor to monitor interferon-beta response improves the predictive ability of the (no) evidence of disease activity (EDA-3) and Río score (RS-3) criteria for confirmed disability progression in a historical cohort.

METHODS

One hundred one patients from an observational cohort treated with interferon-beta were assessed for different cutoff points of BVC (ranged 0.2-1.2%), presence of active lesions (≥ 1 for EDA/≥ 3 for RS), relapses, and 6-month confirmed disability progression (CDP), measured by the Expanded Disability Status Scale, after 1 year. Sensitivity, specificity, and positive and negative predictive values for predicting confirmed disability progression at 4 years in original EDA (EDA-3) and RS (RS-3) as well as EDA and RS including BVC (EDA-4 and RS-4) were compared.

RESULTS

Adding BVC to EDA slightly increased sensitivity, but not specificity or predictive values, nor the OR for predicting CDP; only EDA-3 showed a trend for predicting CDP (OR 3.701, p = 0.050). Adding BVC to RS-3 (defined as ≥ 2 criteria) helped to improve sensitivity and negative predictive value, and increased OR for predicting CDP using a cutoff of ≤ - 0.86% (RS-3 OR 23.528, p < 0.001; RS-4 for all cutoffs ranged from 15.06 to 32, p < 0.001). RS-4 showed areas under the curve larger than RS-3 for prediction of disability at 4 years.

CONCLUSION

Addition of BVC to RS improves its prediction of response to interferon-beta.

E.U. paediatric MOG consortium consensus: Part 2 - Neuroimaging features of paediatric myelin oligodendrocyte glycoprotein antibody-associated disorders

Imaging plays a crucial role in differentiating the spectrum of paediatric acquired demyelinating syndromes (ADS), which apart from myelin oligodendrocyte glycoprotein antibody associated disorders (MOGAD) includes paediatric multiple sclerosis (MS), aquaporin-4 antibody neuromyelitis optica spectrum disorders (NMOSD) and unclassified patients with both monophasic and relapsing ADS. In contrast to the imaging characteristics of children with MS, children with MOGAD present with diverse imaging patterns which correlate with the main demyelinating phenotypes as well as age at presentation. In this review we describe the common neuroradiological features of children with MOGAD such as acute disseminated encephalomyelitis, optic neuritis, transverse myelitis, AQP4 negative NMOSD. In addition, we report newly recognized presentations also associated with MOG-ab such as the 'leukodystophy-like' phenotype and autoimmune encephalitis with predominant involvement of cortical and deep grey matter structures. We further delineate the features, which may help to distinguish MOGAD from other ADS and discuss the future role of MR-imaging in regards to treatment decisions and prognosis in children with MOGAD. Finally, we propose an MRI protocol for routine examination and discuss new imaging techniques, which may help to better understand the neurobiology of MOGAD.

An International Standardized Magnetic Resonance Imaging Protocol for Diagnosis and Follow-up of Patients with Multiple Sclerosis: Advocacy, Dissemination, and Implementation Strategies

Standardized magnetic resonance imaging (MRI) protocols are important for the diagnosis and monitoring of patients with multiple sclerosis (MS). The Consortium of Multiple Sclerosis Centers (CMSC) convened an international panel of MRI experts to review and update the current guidelines. The objective was to update the standardized MRI protocol and clinical guidelines for diagnosis and follow-up of MS and develop strategies for advocacy, dissemination, and implementation. Conference attendees included neurologists, radiologists, technologists, and imaging scientists with expertise in MS. Representatives from the CMSC, Magnetic Resonance Imaging in MS (MAGNIMS), North American Imaging in Multiple Sclerosis Cooperative, US Department of Veteran Affairs, National Multiple Sclerosis Society, Multiple Sclerosis Association of America, MRI manufacturers, and commercial image analysis companies were present. Before the meeting, CMSC members were surveyed about standardized MRI protocols, gadolinium use, need for diffusion-weighted imaging, and the central vein sign. The panel worked to make the CMSC and MAGNIMS MRI protocols similar so that the updated guidelines could ultimately be accepted by international consensus. Advocacy efforts will promote the importance of standardized MS MRI protocols. Dissemination will include publications, meeting abstracts, educational programming, webinars, "meet the expert" teleconferences, and examination cards. Implementation will require comprehensive and coordinated efforts to make the protocol easy to access and use. The ultimate vision, and goal, is for the guidelines to be universally useful, usable, and used as the standard of care for patients with MS.

Ultra-high-field 7-T MRI in multiple sclerosis and other demyelinating diseases: from pathology to clinical practice

Magnetic resonance imaging (MRI) is essential for the early diagnosis of multiple sclerosis (MS), for investigating the disease pathophysiology, and for discriminating MS from other neurological diseases. Ultra-high-field strength (7-T) MRI provides a new tool for studying MS and other demyelinating diseases both in research and in clinical settings. We present an overview of 7-T MRI application in MS focusing on increased sensitivity and specificity for lesion detection and characterisation in the brain and spinal cord, central vein sign identification, and leptomeningeal enhancement detection. We also discuss the role of 7-T MRI in improving our understanding of MS pathophysiology with the aid of metabolic imaging. In addition, we present 7-T MRI applications in other demyelinating diseases. 7-T MRI allows better detection of the anatomical, pathological, and functional features of MS, thus improving our understanding of MS pathology in vivo. 7-T MRI also represents a potential tool for earlier and more accurate diagnosis.

Single-subject structural cortical networks in clinically isolated syndrome

BACKGROUND

Structural cortical networks (SCNs) represent patterns of coordinated morphological modifications in cortical areas, and they present the advantage of being extracted from previously acquired clinical magnetic resonance imaging (MRI) scans. SCNs have shown pathophysiological changes in many brain disorders, including multiple sclerosis.

OBJECTIVE

To investigate alterations of SCNs at the individual level in patients with clinically isolated syndrome (CIS), thereby assessing their clinical relevance.

METHODS

We analyzed baseline data collected in a prospective multicenter (MAGNIMS) study. CIS patients (n = 60) and healthy controls (n = 38) underwent high-resolution 3T MRI. Measures of disability and cognitive processing were obtained for patients. Single-subject SCNs were extracted from brain 3D-T1 weighted sequences; global and local network parameters were computed.

RESULTS

Compared to healthy controls, CIS patients showed altered small-world topology, an efficient network organization combining dense local clustering with relatively few long-distance connections. These disruptions were worse for patients with higher lesion load and worse cognitive processing speed. Alterations of centrality measures and clustering of connections were observed in specific cortical areas in CIS patients when compared with healthy controls.

CONCLUSION

Our study indicates that SCNs can be used to demonstrate clinically relevant alterations of connectivity in CIS.

Fully automated longitudinal segmentation of new or enlarged multiple sclerosis lesions using 3D convolutional neural networks

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A fully automated segmentation of new or enlarged multiple sclerosis (MS) lesions.

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3D convolutional neural network (CNN) with U-net-like encoder-decoder architecture.

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Simultaneous processing of baseline and follow-up scan of the same patient.

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Trained on 3253 patient data from over 103 different MR scanners.

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Fast (<1min), robust algorithm with segmentation results in inter-rater variability.

The quantification of new or enlarged lesions from follow-up MRI scans is an important surrogate of clinical disease activity in patients with multiple sclerosis (MS). Not only is manual segmentation time consuming, but inter-rater variability is high. Currently, only a few fully automated methods are available. We address this gap in the field by employing a 3D convolutional neural network (CNN) with encoder-decoder architecture for fully automatic longitudinal lesion segmentation.

Input data consist of two fluid attenuated inversion recovery (FLAIR) images (baseline and follow-up) per patient. Each image is entered into the encoder and the feature maps are concatenated and then fed into the decoder. The output is a 3D mask indicating new or enlarged lesions (compared to the baseline scan). The proposed method was trained on 1809 single point and 1444 longitudinal patient data sets and then validated on 185 independent longitudinal data sets from two different scanners. From the two validation data sets, manual segmentations were available from three experienced raters, respectively. The performance of the proposed method was compared to the open source Lesion Segmentation Toolbox (LST), which is a current state-of-art longitudinal lesion segmentation method.

The mean lesion-wise inter-rater sensitivity was 62%, while the mean inter-rater number of false positive (FP) findings was 0.41 lesions per case. The two validated algorithms showed a mean sensitivity of 60% (CNN), 46% (LST) and a mean FP of 0.48 (CNN), 1.86 (LST) per case. Sensitivity and number of FP were not significantly different (p < 0.05) between the CNN and manual raters.

New or enlarged lesions counted by the CNN algorithm appeared to be comparable with manual expert ratings. The proposed algorithm seems to outperform currently available approaches, particularly LST. The high inter-rater variability in case of manual segmentation indicates the complexity of identifying new or enlarged lesions. An automated CNN-based approach can quickly provide an independent and deterministic assessment of new or enlarged lesions from baseline to follow-up scans with acceptable reliability.

Advanced MRI features in relapsing multiple sclerosis patients with and without CSF oligoclonal IgG bands

Oligoclonal IgG bands (OCB) in cerebrospinal fluid (CSF) are important in diagnosis of multiple sclerosis (MS). We evaluated the MRI features of clinically definite MS subjects with and without CSF-OCB. Relapsing MS subjects were recruited from a prospective registry in a university center. CSF-OCB were detected using isoelectric focusing and lgG-specific immunofixation. MRI metrics including brain volumes, lesion volumes and microstructural measures, were analyzed by FMRIB Software Library (FSL) and Statistical Parametric Mapping (SPM). Seventy-five subjects with relapsing MS were analyzed. Forty-four (59%) subjects had an interval MRI at around 1 year. CSF-OCB were detected in 46 (61%) subjects. The OCB-positive group had a higher proportion of cerebellar lesions than the OCB-negative group (23.9% vs. 3.4%, p = 0.057). Except for amygdala volumes which were lower in the OCB-positive group (p = 0.034), other regional brain volumes including the subcortical deep gray matter and corpus callosum were similar. The two groups also showed comparable brain atrophy rate. For DTI, the OCB-positive group showed significantly higher mean diffusivity (MD) value in perilesional normal-appearing white matter (p = 0.043). Relapsing MS patients with and without CSF-OCB shared similar MRI features regarding volumetric analyses and DTI microstructural integrity.

Imaging in Pediatric Multiple Sclerosis : An Iconographic Review

Pediatric-onset multiple sclerosis (POMS) is defined by a first multiple sclerosis (MS) attack occurring before 18 years old and is diagnosed by demonstration of dissemination in time (DIT) and space (DIS). Although guidelines evolved over the years, they always recognized the importance of magnetic resonance imaging (MRI) for diagnosis. The 2017 McDonald criteria are increasingly used and have been validated in several cohorts. The use of MRI is the most important tool for the early diagnosis, monitoring, and assessment of treatment response of MS and standard protocols include precontrast and postcontrast T1, T2, fluid attenuation inversion recovery (FLAIR) and diffusion sequences. A distinctive MS lesion compromises white matter and it is well-demarcated and confluent, showing demyelination, inflammation, gliosis, and relative axonal preservation. Considering the growing recognition of pediatric MS as a differential diagnosis for children presenting with a clinical central nervous system event, we present a POMS lesions guide (periventricular, juxtacortical, infratentorial, spinal cord, cortical, tumefactive, black hole, contrast-enhanced). Owing to its rareness, POMS is a diagnosis by exclusion and MRI plays a fundamental role in distinguishing POMS from other demyelinating and non-demyelinating conditions. Three main groups of disorders can mimic POMS: inflammatory, metabolic and tumoral; however, imaging patterns earlier described lower the possibilities of alternative diagnoses and strongly suggest POMS when likely.

Early Diagnosis of Multiple Sclerosis Based on Optical and Electrochemical Biosensors: Comprehensive Perspective

Background:

Multiple Sclerosis (MS) involves an immune-mediated response in which body’s immune system destructs the protective sheath (myelin). Part of the known MS biomarkers are discovered in cerebrospinal fluid like oligoclonal lgG (OCGB), and also in blood like myelin Oligodendrocyte Glycoprotein (MOG). The conventional MS diagnostic methods often fail to detect the disease in early stages such as Clinically Isolated Syndrome (CIS), which considered as a concerning issue since CIS highlighted as a prognostic factor of MS development in most cases.

Methods:

MS diagnostic techniques include Magnetic Resonance Imaging (MRI) of the brain and spinal cord, lumbar puncture (or spinal tap) that evaluate cerebrospinal fluid, evoked potential testing revealing abnormalities in the brain and spinal cord. These conventional diagnostic methods have some negative points such as extensive processing time as well as restriction in the quantity of samples that can be analyzed concurrently. Scientists have focused on developing the detection methods especially early detection which belongs to ultra-sensitive, non-invasive and needed for the Point of Care (POC) diagnosis because the situation was complicated by false positive or negative results.

Results:

As a result, biosensors are utilized and investigated since they could be ultra-sensitive to specific compounds, cost effective devices, body-friendly and easy to implement. In addition, it has been proved that the biosensors on physiological fluids (blood, serum, urine, saliva, milk etc.) have quick response in a non-invasive rout. In general form, a biosensor system for diagnosis and early detection process usually involves; biomarker (target molecule), bio receptor (recognition element) and compatible bio transducer.

Conclusion:

Studies underlined that early treatment of patients with high possibility of MS can be advantageous by postponing further abnormalities on MRI and subsequent attacks.

:

This Review highlights variable disease diagnosis approaches such as Surface Plasmon Resonance (SPR), electrochemical biosensors, Microarrays and microbeads based Microarrays, which are considered as promising methods for detection and early detection of MS.

Serum neurofilament light chain predicts long term clinical outcomes in multiple sclerosis

Serum neurofilament light chain (NfL) is emerging as an important biomarker in multiple sclerosis (MS). Our objective was to evaluate the prognostic value of serum NfL levels obtained close to the time of MS onset with long-term clinical outcomes. In this prospective cohort study, we identified patients with serum collected within 5 years of first MS symptom onset (baseline) with more than 15 years of routine clinical follow-up. Levels of serum NfL were quantified in patients and matched controls using digital immunoassay (SiMoA HD-1 Analyzer, Quanterix). Sixty-seven patients had a median follow-up of 18.9 years (range 15.0–27.0). The median serum NfL level in patient baseline samples was 10.1 pg/mL, 38.5% higher than median levels in 37 controls (7.26 pg/mL, p = 0.004). Baseline NfL level was most helpful as a sensitive predictive marker to rule out progression; patients with levels less 7.62 pg/mL were 4.3 times less likely to develop an EDSS score of ≥ 4 (p = 0.001) and 7.1 times less likely to develop progressive MS (p = 0.054). Patients with the highest NfL levels (3rd-tertile, > 13.2 pg/mL) progressed most rapidly with an EDSS annual rate of 0.16 (p = 0.004), remaining significant after adjustment for sex, age, and disease-modifying treatment (p = 0.022). This study demonstrates that baseline sNfL is associated with long term clinical disease progression. sNfL may be a sensitive marker of subsequent poor clinical outcomes.

Visualizing the Central Nervous System: Imaging Tools for Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders

Multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) are autoimmune central nervous system conditions with increasing incidence and prevalence. While MS is the most frequent inflammatory CNS disorder in young adults, NMOSD is a rare disease, that is pathogenetically distinct from MS, and accounts for approximately 1% of demyelinating disorders, with the relative proportion within the demyelinating CNS diseases varying widely among different races and regions. Most immunomodulatory drugs used in MS are inefficacious or even harmful in NMOSD, emphasizing the need for a timely and accurate diagnosis and distinction from MS. Despite distinct immunopathology and differences in disease course and severity there might be considerable overlap in clinical and imaging findings, posing a diagnostic challenge for managing neurologists. Differential diagnosis is facilitated by positive serology for AQP4-antibodies (AQP4-ab) in NMOSD, but might be difficult in seronegative cases. Imaging of the brain, optic nerve, retina and spinal cord is of paramount importance when managing patients with autoimmune CNS conditions. Once a diagnosis has been established, imaging techniques are often deployed at regular intervals over the disease course as surrogate measures for disease activity and progression and to surveil treatment effects. While the application of some imaging modalities for monitoring of disease course was established decades ago in MS, the situation is unclear in NMOSD where work on longitudinal imaging findings and their association with clinical disability is scant. Moreover, as long-term disability is mostly attack-related in NMOSD and does not stem from insidious progression as in MS, regular follow-up imaging might not be useful in the absence of clinical events. However, with accumulating evidence for covert tissue alteration in NMOSD and with the advent of approved immunotherapies the role of imaging in the management of NMOSD may be reconsidered. By contrast, MS management still faces the challenge of implementing imaging techniques that are capable of monitoring progressive tissue loss in clinical trials and cohort studies into treatment algorithms for individual patients. This article reviews the current status of imaging research in MS and NMOSD with an emphasis on emerging modalities that have the potential to be implemented in clinical practice.

[Ocrelizumab for treatment of multiple sclerosis]

Ocrelizumab ist ein monoklonaler Antikörper, der sich gegen das Differenzierungsantigen CD20 richtet und zu einer effektiven längerfristigen Depletion von Lymphozyten, insbesondere von B‑Zellen, führt. Unlängst publizierte Phase-3-Studien belegen, dass Ocrelizumab sowohl bei der Behandlung der schubförmigen als auch der primär progressiven Multiplen Sklerose (MS) wirksam ist. Darauf basierend wurde Ocrelizumab als erstes Medikament zur Behandlung der primär chronisch-progredienten MS zugelassen. Um diesen Durchbruch besser in den Kontext des heutigen MS-Therapiekanons einordnen zu können, lohnt sowohl ein Blick zurück auf die Entwicklung der antikörpervermittelten CD20-Depletion als auch auf die der Zulassung zugrunde liegenden Studien sowie deren Extensionsphasen. Diese Übersichtsarbeit diskutiert die verfügbaren Daten zur Wirksamkeit und Sicherheit der langfristigen B‑Zell-Depletion bei MS-Patienten und erörtert den aktuellen Kenntnisstand zur Rolle von B‑Lymphozyten in der Immunpathogenese der MS.

Recommendations of the Polish Medical Society of Radiology and the Polish Society of Neurology for the routinely used magnetic resonance imaging protocol in patients with multiple sclerosis

Magnetic resonance imaging (MRI) is a widely used method for the diagnosis of multiple sclerosis (MS) that is essential for the detection and follow-up of the disease. The Polish Medical Society of Radiology (PLTR) and the Polish Society of Neurology (PTN) present the second version of the recommendations for examinations routinely conducted in magnetic resonance imaging departments in patients with MS, which include new data and practical comments for electroradiology technicians and radiologists. The recommended protocol aims to improve the MRI procedure and, most importantly, to standardise the method of conducting scans in all MRI departments. This is crucial for the initial diagnostics that are necessary to establish a diagnosis as well as monitor patients with MS, which directly translates into significant clinical decisions. MS is a chronic idiopathic inflammatory demyelinating disease of the central nervous system (CNS), the aetiology of which is still unknown. The nature of the disease lies in the CNS destruction process disseminated in time and space. MRI detects focal lesions in the white and grey matter with high sensitivity (with significantly less specificity in the latter). It is also the best tool to assess brain atrophy in patients with MS in terms of grey matter volume and white matter volume as well as local atrophy (by measuring the volume of thalamus, corpus callosum, subcortical nuclei, hippocampus) as parameters that correlate with disability progression and cognitive dysfunctions. Progress in magnetic resonance techniques, as well as the abilities of postprocessing the obtained data, has become the basis for the dynamic development of computer programs that allow for a more repeatable assessment of brain atrophy in both cross-sectional and longitudinal studies. MRI is unquestionably the best diagnostic tool used to follow up the course of the disease and to treat patients with MS. However, to diagnose and follow up the patients with MS on the basis of MRI in accordance with the latest standards, an MRI study must meet certain quality criteria, which are the subject of this paper.

Early imaging predictors of long-term outcomes in relapse-onset multiple sclerosis

The clinical course of relapse-onset multiple sclerosis is highly variable. Demographic factors, clinical features and global brain T2 lesion load have limited value in counselling individual patients. We investigated early MRI predictors of key long-term outcomes including secondary progressive multiple sclerosis, physical disability and cognitive performance, 15 years after a clinically isolated syndrome. A cohort of patients with clinically isolated syndrome (n = 178) was prospectively recruited within 3 months of clinical disease onset and studied with MRI scans of the brain and spinal cord at study entry (baseline) and after 1 and 3 years. MRI measures at each time point included: supratentorial, infratentorial, spinal cord and gadolinium-enhancing lesion number, brain and spinal cord volumetric measures. The patients were followed-up clinically after ∼15 years to determine disease course, and disability was assessed using the Expanded Disability Status Scale, Paced Auditory Serial Addition Test and Symbol Digit Modalities Test. Multivariable logistic regression and multivariable linear regression models identified independent MRI predictors of secondary progressive multiple sclerosis and Expanded Disability Status Scale, Paced Auditory Serial Addition Test and Symbol Digit Modalities Test, respectively. After 15 years, 166 (93%) patients were assessed clinically: 119 (72%) had multiple sclerosis [94 (57%) relapsing-remitting, 25 (15%) secondary progressive], 45 (27%) remained clinically isolated syndrome and two (1%) developed other disorders. Physical disability was overall low in the multiple sclerosis patients (median Expanded Disability Status Scale 2, range 0-10); 71% were untreated. Baseline gadolinium-enhancing (odds ratio 3.16, P < 0.01) and spinal cord lesions (odds ratio 4.71, P < 0.01) were independently associated with secondary progressive multiple sclerosis at 15 years. When considering 1- and 3-year MRI variables, baseline gadolinium-enhancing lesions remained significant and new spinal cord lesions over time were associated with secondary progressive multiple sclerosis. Baseline gadolinium-enhancing (β = 1.32, P < 0.01) and spinal cord lesions (β = 1.53, P < 0.01) showed a consistent association with Expanded Disability Status Scale at 15 years. Baseline gadolinium-enhancing lesions was also associated with performance on the Paced Auditory Serial Addition Test (β = - 0.79, P < 0.01) and Symbol Digit Modalities Test (β = -0.70, P = 0.02) at 15 years. Our findings suggest that early focal inflammatory disease activity and spinal cord lesions are predictors of very long-term disease outcomes in relapse-onset multiple sclerosis. Established MRI measures, available in routine clinical practice, may be useful in counselling patients with early multiple sclerosis about long-term prognosis, and personalizing treatment plans.

Spinal Cord Involvement in MS and Other Demyelinating Diseases

Diagnostic accuracy is poor in demyelinating myelopathies, and therefore a challenge for neurologists in daily practice, mainly because of the multiple underlying pathophysiologic mechanisms involved in each subtype. A systematic diagnostic approach combining data from the clinical setting and presentation with magnetic resonance imaging (MRI) lesion patterns, cerebrospinal fluid (CSF) findings, and autoantibody markers can help to better distinguish between subtypes. In this review, we describe spinal cord involvement, and summarize clinical findings, MRI and diagnostic characteristics, as well as treatment options and prognostic implications in different demyelinating disorders including: multiple sclerosis (MS), neuromyelitis optica spectrum disorder, acute disseminated encephalomyelitis, anti-myelin oligodendrocyte glycoprotein antibody-associated disease, and glial fibrillary acidic protein IgG-associated disease. Thorough understanding of individual case etiology is crucial, not only to provide valuable prognostic information on whether the disorder is likely to relapse, but also to make therapeutic decision-making easier and reduce treatment failures which may lead to new relapses and long-term disability. Identifying patients with monophasic disease who may only require acute management, symptomatic treatment, and subsequent rehabilitation, rather than immunosuppression, is also important.

Assessment of lesions on magnetic resonance imaging in multiple sclerosis: practical guidelines

MRI has improved the diagnostic work-up of multiple sclerosis, but inappropriate image interpretation and application of MRI diagnostic criteria contribute to misdiagnosis. Some diseases, now recognized as conditions distinct from multiple sclerosis, may satisfy the MRI criteria for multiple sclerosis (e.g. neuromyelitis optica spectrum disorders, Susac syndrome), thus making the diagnosis of multiple sclerosis more challenging, especially if biomarker testing (such as serum anti-AQP4 antibodies) is not informative. Improvements in MRI technology contribute and promise to better define the typical features of multiple sclerosis lesions (e.g. juxtacortical and periventricular location, cortical involvement). Greater understanding of some key aspects of multiple sclerosis pathobiology has allowed the identification of characteristics more specific to multiple sclerosis (e.g. central vein sign, subpial demyelination and lesional rims), which are not included in the current multiple sclerosis diagnostic criteria. In this review, we provide the clinicians and researchers with a practical guide to enhance the proper recognition of multiple sclerosis lesions, including a thorough definition and illustration of typical MRI features, as well as a discussion of red flags suggestive of alternative diagnoses. We also discuss the possible place of emerging qualitative features of lesions which may become important in the near future.

Pediatric multiple sclerosis: from clinical basis to imaging spectrum and differential diagnosis

Pediatric multiple sclerosis (MS) deserves special attention because of its impact on cognitive function and development. Although knowledge regarding pediatric MS has rapidly increased, understanding the peculiarities of this population remains crucial for disease management. There is limited expertise about the efficacy and safety of current disease-modifying agents. Although pathophysiology is not entirely understood, some risk factors and immunological features have been described and are discussed herein. While the revised International Pediatric MS Study Group diagnostic criteria have improved the accuracy of diagnosis, the recently revised McDonald criteria also offer some new insights into the pediatric population. It is fundamental that radiologists have strong knowledge about the vast spectrum of demyelinating disorders that can occur in childhood to ensure appropriate diagnosis and provide early treatment.

The proportion of myeloid-derived suppressor cells in the spleen is related to the severity of the clinical course and tissue damage extent in a murine model of multiple sclerosis

Multiple Sclerosis (MS) is the second cause of paraplegia among young adults, after all types of CNS traumatic lesions. In its most frequent relapsing-remitting form, the severity of the disease course is very heterogeneous, and its reliable evaluation remains a key issue for clinicians. Myeloid-Derived sSuppressor Cells (MDSCs) are immature myeloid cells that suppress the inflammatory response, a phenomenon related to the resolution or recovery of the clinical symptoms associated with experimental autoimmune encephalomyelitis (EAE), the most common model for MS. Here, we establish the severity index as a new parameter for the clinical assessment in EAE. It is derived from the relationship between the maximal clinical score and the time elapsed since disease onset. Moreover, we relate this new index with several histopathological hallmarks in EAE and with the peripheral content of MDSCs. Based on this new parameter, we show that the splenic MDSC content is related to the evolution of the clinical course of EAE, ranging from mild to severe. Indeed, when the severity index indicates a severe disease course, EAE mice display more intense lymphocyte infiltration, demyelination and axonal damage. A direct correlation was drawn between the MDSC population in the peripheral immune system, and the preservation of myelin and axons, which was also correlated with T cell apoptosis within the CNS (being these cells the main target for MDSC suppression). The data presented clearly indicated that the severity index is a suitable tool to analyze disease severity in EAE. Moreover, our data suggest a clear relationship between circulating MDSC enrichment and disease outcome, opening new perspectives for the future targeting of this population as an indicator of MS severity.

Monitoring of radiologic disease activity by serum neurofilaments in MS

Objective

To determine whether serum neurofilament light chain (sNfL) levels are associated with recent MRI activity in patients with relapsing-remitting MS (RRMS).

Methods

This observational study included 163 patients (405 samples) with early RRMS from the Study of Early interferon-beta1a (IFN-β1a) Treatment (SET) cohort and 179 patients (664 samples) with more advanced RRMS from the Genome-Wide Association Study of Multiple Sclerosis (GeneMSA) cohort. Based on annual brain MRI, we assessed the ability of sNfL cutoffs to reflect the presence of combined unique active lesions, defined as new/enlarging lesion compared with MRI in the preceding year or contrast-enhancing lesion. The probability of active MRI lesions among patients with different sNfL levels was estimated with generalized estimating equations models.

Results

From the sNfL samples ≥90th percentile, 81.6% of the SET (OR = 3.4, 95% CI = 1.8-6.4) and 48.9% of the GeneMSA cohort samples (OR = 2.6, 95% CI = 1.7-3.9) was associated with radiological disease activity on MRI. The sNfL level between the 10th and 30th percentile was reflective of negligible MRI activity: 1.4% (SET) and 6.5% (GeneMSA) of patients developed ≥3 active lesions, 5.8% (SET) and 6.5% (GeneMSA) developed ≥2 active lesions, and 34.8% (SET) and 11.8% (GeneMSA) showed ≥1 active lesion on brain MRI. The sNfL level <10th percentile was associated with even lower MRI activity. Similar results were found in a subgroup of clinically stable patients.

Conclusions

Low sNfL levels (≤30th percentile) help identify patients with MS with very low probability of recent radiologic disease activity during the preceding year. This result suggests that in future, sNfL assessment may substitute the need for annual brain MRI monitoring in considerable number (23.1%–36.4%) of visits in clinically stable patients.

What role should spinal cord MRI take in the future of multiple sclerosis surveillance?

INTRODUCTION

In multiple sclerosis (MS), inflammatory, demyelinating, and neurodegenerative phenomena affect the spinal cord, with detrimental effects on patients' clinical disability. Although spinal cord imaging may be challenging, improvements in MRI technologies have contributed to better evaluate spinal cord involvement in MS.

AREAS COVERED

This review summarizes the current state-of-art of the application of conventional and advanced MRI techniques to evaluate spinal cord damage in MS. Typical features of spinal cord lesions, their role in the diagnostic work-up of suspected MS, their predictive role for subsequent disease course and clinical worsening, and their utility to define treatment response are discussed. The role of spinal cord atrophy and of other advanced MRI techniques to better evaluate the associations between spinal cord abnormalities and the accumulation of clinical disability are also evaluated. Finally, how spinal cord assessment could evolve in the future to improve monitoring of disease progression and treatment effects is examined.

EXPERT OPINION

Spinal cord MRI provides relevant additional information to brain MRI in understanding MS pathophysiology, in allowing an earlier and more accurate diagnosis of MS, and in identifying MS patients at higher risk to develop more severe disability. A future role in monitoring the effects of treatments is also foreseen.

MAGNIMS consensus recommendations on the use of brain and spinal cord atrophy measures in clinical practice

Early evaluation of treatment response and prediction of disease evolution are key issues in the management of people with multiple sclerosis (MS). In the past 20 years, MRI has become the most useful paraclinical tool in both situations and is used clinically to assess the inflammatory component of the disease, particularly the presence and evolution of focal lesions - the pathological hallmark of MS. However, diffuse neurodegenerative processes that are at least partly independent of inflammatory mechanisms can develop early in people with MS and are closely related to disability. The effects of these neurodegenerative processes at a macroscopic level can be quantified by estimation of brain and spinal cord atrophy with MRI. MRI measurements of atrophy in MS have also been proposed as a complementary approach to lesion assessment to facilitate the prediction of clinical outcomes and to assess treatment responses. In this Consensus statement, the Magnetic Resonance Imaging in MS (MAGNIMS) study group critically review the application of brain and spinal cord atrophy in clinical practice in the management of MS, considering the role of atrophy measures in prognosis and treatment monitoring and the barriers to clinical use of these measures. On the basis of this review, the group makes consensus statements and recommendations for future research.

2D linear measures of ventricular enlargement may be relevant markers of brain atrophy and long-term disability progression in multiple sclerosis

OBJECTIVES

Aim of this study was to investigate the reliability and validity of 2D linear measures of ventricular enlargement as indirect markers of brain atrophy and possible predictors of clinical disability.

METHODS

In this retrospective longitudinal analysis of relapsing-remitting MS patients, brain volumes were computed at baseline and after 2 years. Frontal horn width (FHW), intercaudate distance (ICD), third ventricle width (TVW), and 4th ventricle width were obtained. Two-dimensional measures associated with brain volume at correlation analyses were entered in linear and logistic regression models testing the relationship with baseline clinical disability and 10-year confirmed disability progression (CDP), respectively. Possible cutoff values for clinically relevant atrophy were estimated via receiver operating characteristic (ROC) analyses and probed as 10-year CDP predictors using hierarchical logistic regression.

RESULTS

Eighty-seven patients were available (61/26 = F/M; 34.1 ± 8.5 years). Moderate negative correlations emerged between ICD and TVW and normalized brain volume (NBV; p < 0.001) and percentage brain volume change per year (PBVC/y) and FHW, ICD, and TVW annual changes (p ≤ 0.005). Baseline disability was moderately associated with NBV, ICD, and TVW (p < 0.001), while PBVC/y predicted 10-year CDP (p = 0.01). A cutoff percentage ICD change per year (PICDC/y) value of 4.38%, corresponding to - 0.91% PBVC/y, correlated with 10-year CDP (p = 0.04). These estimated cutoff values provided extra value for predicting 10-year CDP (PBVC/y: p = 0.001; PICDC/y: p = 0.03).

CONCLUSIONS

Two-dimensional measures of ventricular enlargement are reproducible and clinically relevant markers of brain atrophy, with ICD and its increase over time showing the best association with clinical disability. Specifically, a cutoff PICDC/y value of 4.38% could serve as a potential surrogate marker of long-term disability progression.

KEY POINTS

• Assessment of ventricular enlargement as a rapidly accessible indirect marker of brain atrophy may prove useful in cases in which brain volume quantification is not practicable. • Two-dimensional linear measures of ventricular enlargement represent reliable, valid, and clinically relevant markers of brain atrophy. • A cutoff annualized percentage brain volume change of - 0.91% and the corresponding annualized percentage increase of 4.38% for intercaudate distance are able to discriminate patients who will develop long-term disability progression.

SWAN-Venule: An Optimized MRI Technique to Detect the Central Vein Sign in MS Plaques

BACKGROUND AND PURPOSE

Multiple sclerosis lesions develop around small veins that are radiologically described as the so-called central vein sign. With 7T MR imaging and magnetic susceptibility-based sequences, the central vein sign has been observed in 80%-100% of MS lesions in patients' brains. However, a lower proportion ∼50% has been reported at 3T using susceptibility-weighted angiography (SWAN). Our aim was to assess a modified version of SWAN optimized at 3T for sensitive detection of the central vein sign.

MATERIALS AND METHODS

Thirty subjects with MS were scanned on a 3T clinical MR imaging system. 3D T2-weighted FLAIR and optimized 3D SWAN called SWAN-venule, were acquired after injection of a gadolinium-based contrast agent. Patients showing >3 focal white matter lesions were included. The central vein sign was recorded by 2 trained raters on SWAN-venule images in the supratentorial brain.

RESULTS

Twenty patients showing >3 white matter lesions were included. A total of 380 white matter lesions (135 periventricular, 144 deep white matter, and 101 juxtacortical) seen on both FLAIR and SWAN-venule images were analyzed. Overall, the central vein sign was detected in 86% of the white matter lesions (periventricular, 89%; deep white matter, 95%; and juxtacortical, 78%).

CONCLUSIONS

The SWAN-venule technique is an optimized MR imaging sequence for highly sensitive detection of the central vein sign in MS brain lesions. This work will facilitate the validation and integration of the central vein sign to increase the diagnostic certainty of MS and further prevent misdiagnosis in clinical practice.

New MRI lesions and topography at 6 months of treatment initiation and disease activity during follow up in relapsing remitting multiple sclerosis patients

Objective: The objective of this study was to assess if the presence of new lesions and their topography on the reference MRI have a prognostic value regarding disease activity during the follow up in relapsing remitting multiple sclerosis (RRMS) patients.Methods: Retrospective cohort study that included patients with RRMS who had a reference MRI (performed at 6 months from the onset of a DMT) and radiological and clinical follow up for at least two years. We identified the number of new MRI lesions and their topography at reference MRI and during the follow up. Cox proportional hazards model analysis was used to evaluate the association between new lesions on reference MRI and the appearance of new lesions and/or clinical relapses at 24-month follow-up.Results: 56 patients were included, 13 (23.2%) showed new lesions in the reference MRI. The presence of new lesions at reference MRI predicted the occurrence of new lesions at month 24 (HR 3.1, CI 95% 2.5-5.8). The number of lesions and the infratentorial topography at reference MRI were associated with an increased risk of new radiological activity during follow up (HR 3.5, IC95% 3.1-6.1 and HR 2.4, IC95% 1.9-2.7 respectively).Conclusion: New lesions at the reference MRI in terms of number and topography increase the risk of radiological disease activity during the follow up.

A fully convolutional neural network for new T2-w lesion detection in multiple sclerosis

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A deep learning model for new T2-w lesions detection in multiple sclerosis is presented.

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Combining a learning-based registration network with a segmentation one increases the performance.

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The proposed model decreases false-positives while increasing true-positives.

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Better performance compared to other supervised and unsupervised state-of-the-art approaches.

Introduction: Longitudinal magnetic resonance imaging (MRI) has an important role in multiple sclerosis (MS) diagnosis and follow-up. Specifically, the presence of new T2-w lesions on brain MR scans is considered a predictive biomarker for the disease. In this study, we propose a fully convolutional neural network (FCNN) to detect new T2-w lesions in longitudinal brain MR images.

Methods: One year apart, multichannel brain MR scans (T1-w, T2-w, PD-w, and FLAIR) were obtained for 60 patients, 36 of them with new T2-w lesions. Modalities from both temporal points were preprocessed and linearly coregistered. Afterwards, an FCNN, whose inputs were from the baseline and follow-up images, was trained to detect new MS lesions. The first part of the network consisted of U-Net blocks that learned the deformation fields (DFs) and nonlinearly registered the baseline image to the follow-up image for each input modality. The learned DFs together with the baseline and follow-up images were then fed to the second part, another U-Net that performed the final detection and segmentation of new T2-w lesions. The model was trained end-to-end, simultaneously learning both the DFs and the new T2-w lesions, using a combined loss function. We evaluated the performance of the model following a leave-one-out cross-validation scheme.

Results: In terms of the detection of new lesions, we obtained a mean Dice similarity coefficient of 0.83 with a true positive rate of 83.09% and a false positive detection rate of 9.36%. In terms of segmentation, we obtained a mean Dice similarity coefficient of 0.55. The performance of our model was significantly better compared to the state-of-the-art methods (p < 0.05).

Conclusions: Our proposal shows the benefits of combining a learning-based registration network with a segmentation network. Compared to other methods, the proposed model decreases the number of false positives. During testing, the proposed model operates faster than the other two state-of-the-art methods based on the DF obtained by Demons.

Detecting neurodegenerative pathology in multiple sclerosis before irreversible brain tissue loss sets in

Background

Multiple sclerosis (MS) is a complex chronic inflammatory and degenerative disorder of the central nervous system. Accelerated brain volume loss, or also termed atrophy, is currently emerging as a popular imaging marker of neurodegeneration in affected patients, but, unfortunately, can only be reliably interpreted at the time when irreversible tissue damage likely has already occurred. Timing of treatment decisions based on brain atrophy may therefore be viewed as suboptimal.

Main body

This Narrative Review focuses on alternative techniques with the potential of detecting neurodegenerative events in the brain of subjects with MS prior to the atrophic stage. First, metabolic and molecular imaging provide the opportunity to identify early subcellular changes associated with energy dysfunction, which is an assumed core mechanism of axonal degeneration in MS. Second, cerebral hypoperfusion has been observed throughout the entire clinical spectrum of the disorder but it remains an open question whether this serves as an alternative marker of reduced metabolic activity, or exists as an independent contributing process, mediated by endothelin-1 hyperexpression. Third, both metabolic and perfusion alterations may lead to repercussions at the level of network performance and structural connectivity, respectively assessable by functional and diffusion tensor imaging. Fourth and finally, elevated body fluid levels of neurofilaments are gaining interest as a biochemical mirror of axonal damage in a wide range of neurological conditions, with early rises in patients with MS appearing to be predictive of future brain atrophy.

Conclusions

Recent findings from the fields of advanced neuroradiology and neurochemistry provide the promising prospect of demonstrating degenerative brain pathology in patients with MS before atrophy has installed. Although the overall level of evidence on the presented topic is still preliminary, this Review may pave the way for further longitudinal and multimodal studies exploring the relationships between the abovementioned measures, possibly leading to novel insights in early disease mechanisms and therapeutic intervention strategies.

Consensus recommendations for the diagnosis and treatment of multiple sclerosis: 2019 revisions to the MENACTRIMS guidelines

With evolving diagnostic criteria and the advent of new oral and parenteral therapies for MS, most current diagnostic and treatment algorithms need revision and updating. The diagnosis of MS relies on incorporating clinical and paraclinical findings to prove dissemination in space and in time, and exclude alternative diseases that can explain the findings at hand. The differential diagnostic workup should be guided by clinical and laboratory red flags to avoid unnecessary tests. Appropriate selection of multiple sclerosis (MS) therapies is critical to maximize patient benefit. The current guidelines review the scientific evidence supporting treatment of acute relapses, radiologically isolated syndrome, clinically isolated syndrome, relapsing remitting MS, and progressive MS. The purpose of these guidelines is to provide practical recommendations and algorithms for the diagnosis and treatment of MS based on current scientific evidence and clinical experience.