- Imaging Study (CT or MRI) compatible with AD or age-related changes (absence of significant abnormalities that may explain cognitive decline, such as multiple lacunar infarcts or a single prior infarct >1 cubic cm, microhemorrhages or evidence of a prior hemorrhage > 1 cubic cm, evidence of cerebral contusion encephalomalacia, aneurysm, vascular malformation, or space occupying lesion such as an arachnoid cyst or brain tumor).