Frequency of MRI surveillance
| Clinical Indication | Frequency of Imaging | Imaging Protocol |
|---|---|---|
| RRMS, routine surveillance | Annually for at least the first 2 or 3 years after starting therapy or switching DMT | T2-weighted and contrast-enhanced T1-weighted |
| Higher risk patients (positive for JC virus serum antibodies) with >24 mo of NTZ exposure | Every 3–6 months | T2WI, T2 FLAIR, DWI, SWI (if indicated) |
| Low risk of PML (negative for JC virus serum antibodies) | Annually | T2WI, T2 FLAIR, DWI, SWI (if indicated) |
| Patients at high risk of developing opportunistic infections who are switching DMT | MRI when the current treatment is discontinued and 3–6 months after the new treatment is started | T2WI, T2 FLAIR, DWI, SWI (if indicated) |
| Patients who switch from NTZ to other therapeutics (including fingolimod, alemtuzumab, and dimethyl fumarate) | Enhanced pharmacovigilance, including brain MRI every 3–4 mo for up to 12 mo | T2WI, T2 FLAIR, DWI, SWI (if indicated) |
| Patients who require enhanced pharmacovigilance for other reasons | Every 3–6 mo | As indicated |
Note:—RRMS indicates relapsing-remitting MS.