From the Guidelines
For patients with multiple sclerosis (MS), MRI follow-up intervals should be tailored to disease status, with the most recent and highest quality study recommending annual MRI scans for stable patients on disease-modifying therapy, and more frequent imaging every 3-6 months for patients with highly active disease or those at risk of serious treatment-related adverse effects, such as PML, as suggested by 1 and 1.
Key Considerations for MRI Follow-up Intervals
- Newly diagnosed patients should have a baseline MRI followed by another scan at 3-6 months, then every 6-12 months for the first 2-3 years.
- Patients at high risk of PML (JCV seropositive, treatment duration ≥18 months) should have brain MRI screening every 3–4 months using an MRI protocol that includes FLAIR, T2 weighted and diffusion weighted imaging, as recommended by 1.
- Patients at low risk of PML (JCV seronegative) should have brain MRI assessment once a year using the same MRI protocol, as suggested by 1.
- Each MRI should include T1-weighted images with and without gadolinium contrast, T2-weighted images, and FLAIR sequences to detect both new and enhancing lesions.
Adjusting MRI Intervals Based on Individual Factors
- The timing of MRI follow-up may need adjustment based on individual factors such as disease severity, treatment changes, new symptoms, or pregnancy planning.
- Regular MRI monitoring is crucial because MS can show radiological progression even when patients appear clinically stable, and early detection of treatment failure allows for timely therapeutic adjustments to prevent irreversible disability, as highlighted by 1 and 1.
Technical Details for MRI Scans
- All scans should be performed at a field strength of at least 1.5T, though higher field strengths might reveal more new lesions.
- For 2D sequences, slice thickness should be no more than 3 mm with an in-plane spatial resolution of 1 × 1 mm (voxel size 3 × 1 × 1 mm), as recommended by 1.
- Voxels in 3D sequences should be 1 mm3, as suggested by 1.
From the Research
MRI Intervals for Follow-up of MS
- The frequency of MRI intervals for follow-up of Multiple Sclerosis (MS) is crucial for monitoring disease progression and treatment efficacy 2.
- According to the European journal of neurology, brain magnetic resonance imaging (MRI) should be performed every 6 months in the first year of treatment, and at least once yearly thereafter 2.
- A spinal cord MRI should be performed once yearly in patients presenting spinal symptoms 2.
- Routine MRI surveillance provides insight into disease activity that is not evident clinically, and this information can be used to inform prognosis and guide treatment decisions 3.
- The use of MRI in monitoring MS patients can help identify patients with a poor prognosis who may require a timely switch to a second-line agent 2.
Factors Influencing MRI Intervals
- The frequency of MRI intervals may depend on the individual patient's disease activity and treatment response 4.
- Patients with relapsing-remitting MS may require more frequent MRI monitoring to assess treatment efficacy and disease progression 5.
- The assessment of 'No Evidence of Disease Activity' (NEDA) status, which includes clinical and MRI outcomes, can provide a comprehensive evaluation of disease activity 5.
Clinical Implications
- Regular monitoring of disease and therapy in patients with MS is essential for optimal management 2.
- The use of MRI in clinical practice can help guide treatment decisions and improve patient outcomes 3.
- Emerging therapies for MS, such as oral agents and monoclonal antibodies, may require more frequent MRI monitoring to assess treatment efficacy and safety 6.