Impact of post-contrast MRI in the definition of active multiple sclerosis

Approach to Managing the Initial Presentation of Multiple Sclerosis: A Worldwide Practice Survey

Background and Objectives

Available disease-modifying therapies (DMTs) for multiple sclerosis (MS) are rapidly expanding; although escalation approaches aim to balance safety and efficacy, emerging evidence suggests superior outcomes for people with MS who are exposed to early high-efficacy therapies. We aimed to explore practice differences in prevailing management strategies for relapsing-remitting MS.

Methods

We used a worldwide electronic survey launched by the Practice Current section of Neurology® Clinical Practice. Questions pertained to a case of a 37-year-old woman presenting with optic neuritis. Respondents were asked to indicate their initial investigations, relapse management strategy, choice of disease-modifying therapy, and plan for follow-up imaging (contrast/noncontrast). Survey responses were stratified by key demographic variables along with 95% confidence intervals (95% CIs).

Results

We received 153 responses from 42 countries; 32.3% responders identified as MS specialists. There was a strong preference for intravenous delivery of high-dose corticosteroids (87.7%, 95% CI 80.7-92.5), and most of the responders (61.3%, 95% CI 52.6-69.4) indicated they would treat a nondisabling (mild sensory) MS relapse. When asked to select a single initial DMT, 56.6% (95% CI 47.6-65.1) selected a high-efficacy therapy (67.5% MS specialists vs 53.7% non-MS specialists). The most selected agents overall were fingolimod (14.7%), natalizumab (15.5%), and dimethyl fumarate (20.9%). Two-thirds of respondents indicated they would request contrast-enhanced surveillance MRI.

Discussion

Although there is a slight preference for initiating high-efficacy DMT at the time of initial MS diagnosis, opinions regarding the most appropriate treatment paradigm remain divided.

[Use of Gadolinium in Follow-Up MRI of Multiple Sclerosis Patients: Current Recommendations]

Multiple sclerosis is the most frequent demyelinating disease of the central nervous system and is characterized by early onset and progressive disability. Magnetic resonance imaging, due to its high sensitivity and specificity in the detection of demyelinating lesions, is the most useful diagnostic test for this disease, with the administration of gadolinium-based contrast agents being an important contribution to imaging interpretation. Although contrast is essential for diagnostic purposes, its routine use in monitoring disease activity, response to treatment, and related complications is controversial. This article aims to collate current recommendations regarding the use of gadolinium in the imaging follow-up of multiple sclerosis and establish effective and safe guidelines for clinical practice. The literature review was conducted in PubMed, using the terms 'multiple sclerosis', 'magnetic resonance imaging' and 'gadolinium', or 'contrast media'. Articles published between January 2013 and January 2023 concerning the safety of gadolinium and the use of these contrast agents in follow-up scans of adult patients diagnosed with multiple sclerosis were selected. Although no biological or clinical consequences have been unequivocally attributed to the retention of gadolinium in the brain, which were mostly reported with linear agents, health authorities have been recommending the restriction of contrast to essential clinical circumstances. In multiple sclerosis, the detection of subclinical contrast-enhancing lesions with no corresponding new/ enlarging T2-WI lesions is rare and has a questionable impact on therapeutic decisions. On the other hand, gadolinium has a higher sensitivity in the differential diagnosis of relapses, in the detection of recent disease activity, before and after treatment initiation, and in patients with a large lesion burden or diffuse/confluent T2-WI lesions. Contrary to progressive multifocal leukoencephalopathy screening, monitoring of immune restitution inflammatory syndrome also benefits from the administration of gadolinium. It is feasible and safe to exclude gadolinium-based contrast agents from routine follow-up scans of multiple sclerosis, despite their additional contribution in specific clinical circumstances that should be acknowledged by the neurologist and neuroradiologist.

Diffusion-Weighted Images and Contrast-Enhanced MRI in the Diagnosis of Different Stages of Multiple Sclerosis of the Central Nervous System

Introduction Multiple sclerosis (MS) is one of the most prevalent disorders of the central nervous system (CNS), and it can be observed in the field of radiological cross-sectional magnetic resonance imaging (MRI). The prevalence of MS in Saudi Arabia has increased as compared to the past few years. MRI is the gold standard non-invasive modality of choice in MS diagnosis according to the National Multiple Sclerosis Society (NMSS), New York City. This study aimed to highlight the significance of using diffusion-weighted images (DWIs) and the use of contrast media in the MS protocol, as well as the importance of identifying the suitable time of imaging after contrast enhancement to detect active lesions. Methods A retrospective cross-sectional study was conducted of 100 MS patients with an age range of 17 to 56 years. The data set included 41 active cases and 59 inactive cases. All patients had an MRI standard protocol of both the brain and spine in addition to DWI sequence and contrast agent (CA) injection, with images taken in early and delayed time. Results Of the patients, 71% were female and 29% were male. Active MS disease was more significant at younger ages than at older ages. Active lesions were significantly enhanced in delayed contrast images and showed high signal intensity in both the DWI and apparent diffusion coefficient (ADC) map, while inactive lesions showed no enhancement after contrast injection and showed an iso-signal intensity in both the DWI and ADC map. Conclusion The use of CA has developed over the years in the diagnosis of MS patients. In this study, the relationship between active lesions, DWI, and delayed contrast enhancement is very strong. In future research, we recommend adding a DWI sequence for the suspected active MS spine lesions in addition to delayed enhancement time in active MS after contrast injection to increase MRI sensitivity toward active MS lesions of the brain and spinal cord as well.