18F-FDG Brain PET/MRI in Postischemic Hyperperfusion

A 58-year-old man with a past medical history of myocardial infarction and ventricular thrombus presented with successive stroke codes, initially for left arm weakness, then for dysarthria and right-sided weakness. Structural imaging showed an acute/subacute ischemic stroke in the right frontal and right parietal lobes. During the hospitalization, the patient suffered from impaired memory not attributable to the areas of ischemia, prompting a dementia workup. 18F-FDG brain PET/MRI showed no evidence of neurodegenerative disease, but instead demonstrated focal hypermetabolism in the areas of acute/subacute infarcts, which was favored to represent luxury perfusion (postischemic hyperperfusion).