The MRI scan is one of the most important tools for diagnosing multiple sclerosis (MS) and for monitoring disease progression and medication effects. Increasingly strong MRI magnets (higher field strength) enable us to see abnormalities in the brain in greater detail. On the other hand, it poses challenges because these higher field strength MRIs are more sensitive to disturbances, for example due to motion, including physiological motion such as breathing and swallowing. In current practice, field strengths of up to 3 Tesla are common. The aim of this study is to compare scanning at field strengths of 3 Tesla in 10 MS patients at two different moments (baseline and 6 months) with scanning at field strengths that are higher, namely 7 and 9.4 Tesla, in order to identify the advantages and disadvantages. With the further development of this technique, the investigators may be able to make a better diagnosis in the future and detect subtle changes in the course of the disease more quickly in order to optimize treatments.

Multiple sclerosis (MS) is the most common demyelinating disease of the central nervous system. MRI has a prominent role in diagnosing and monitoring disease and treatment and is most suitable tool to study MS pathology in vivo. In recent years there has been research has been much research on the use of 7 tesla MRI in MS. There is a better signal and contrast allowing for higher resolutions. This may contribute to, among other things, higher sensitivity for detecting MS abnormalities, not only in the white matter but also in the gray matter. Furthermore, there is probably also a better specificity. This is due to the improved visualization of MS specific pathological features such as the presence of a central vein in a lesion and paramagnetic rings.

In this pilot study, the investigators study whether going beyond the field strength of 7 Tesla (7T) has additional benefits in characterizing MS lesions and to also map the limitations and challenges of scanning above 7T. More specifically, first, whether scanning above 7T might improve sensitivity to white and gray matter abnormalities in MS. Second, whether MS specific pathology, such as the central veins and the paramagnetic rings, are better visualized at the higher compared to lower field strengths. To this end, the investigators want to scan 10 relapsing-remitting MS patients for clinical field strength (3T) and also ultra-high field strengths (7T and 9.4T) at two time points (baseline and after 6 months).

If it can demonstrate through this pilot study that scanning at field strengths above 7T can benefit detection of lesions or certain pathological features, the use of this research tool can help us in future studies to better understand MS.

Inclusion Criteria:

• Relapsing remitting MS patients (according to the 2017 McDonald criteria)
• Age 18-65 years
• New brain MRI lesion in the past 15 months.

Exclusion Criteria:

• Non-compatible implanted material/devices
• Not being able to lie flat long enough (for the MRI) because of another medical condition

The investigators aim to include 10 patients from our outpatient clinic, with a known clinical diagnosis of relapsing remitting MS according to the 2017 McDonald criteria between ages of 18-65 years, who had a new lesion on their clinical brain MRI in the prior 15 months. The intention is to include patients on low-efficacy medication (interferon β, peginterferon, glatiramer acetate, teriflunomide) as well as patients on high-efficacy medication (natalizumab, ocrelizumab, alemtuzumab, fingolimod) to have a varied and representative study population. The investigators estimate it highly realistic that inclusion of these 10 patients can be achieved.