Table 1:

Frequency of MRI surveillance

Clinical IndicationFrequency of ImagingImaging Protocol
RRMS, routine surveillanceAnnually for at least the first 2 or 3 years after starting therapy or switching DMTT2-weighted and contrast-enhanced T1-weighted
Higher risk patients (positive for JC virus serum antibodies) with >24 mo of NTZ exposureEvery 3–6 monthsT2WI, T2 FLAIR, DWI, SWI (if indicated)
Low risk of PML (negative for JC virus serum antibodies)AnnuallyT2WI, T2 FLAIR, DWI, SWI (if indicated)
Patients at high risk of developing opportunistic infections who are switching DMTMRI when the current treatment is discontinued and 3–6 months after the new treatment is startedT2WI, 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 moT2WI, T2 FLAIR, DWI, SWI (if indicated)
Patients who require enhanced pharmacovigilance for other reasonsEvery 3–6 moAs indicated
  • Note:—RRMS indicates relapsing-remitting MS.