Table 3:

International panel MR imaging criteria2

Magnetic resonance imaging criteria for dissemination in space
Three of 4 of the following:
    1. One gadolinium-enhancing lesion or 9 T2-hyperintense lesions if there is no gadolinium-enhancing lesion
    2. At least one infratentorial lesion
    3. At least one juxtacortical lesion
    4. At least 3 periventricular lesions
(Note: One spinal cord lesion can be substituted for one brain lesion.)
Magnetic Resonance Imaging Criteria for Dissemination of Lesions in Time
    1 If a first scan occurs 3 mo or more after the onset of the clinical event, the presence of an enhancing lesion is sufficient to demonstrate dissemination in time, provided that it is not at the site implicated in the original clinical event. If there is no enhancing lesion at this time, a follow-up scan is required. The timing of this follow-up scan is not crucial, but 3 mo is recommended. A new T2 or enhancing lesion at this time then fulfills the criterion for dissemination in time.
    2 If the first scan is performed less than 3 mo after the onset of the clinical event, a second scan done 3 mo or more after the clinical event showing a new enhancing lesion provides sufficient evidence for dissemination in time. However, if no enhancing lesion is seen at this second scan, a further scan not less than 3 mo after the first scan that shows a new T2 lesion or an enhancing lesion will suffice.