Decrease in 18F-Florbetapir Accumulation in the Cerebral Hemisphere With Hypoperfusion and Misery Perfusion Due to Chronic Atherosclerotic Occlusion of the Internal Carotid Artery.

A 67-year-old man had a slowly progressing impairment of recent memory. Cerebral angiography showed atherosclerotic occlusion of the right internal carotid artery with insufficient collateral circulation. Positron emission tomography (PET) using O-15(2) gas showed reduced cerebral blood flow, reduced cerebral metabolic rate of oxygen, and elevated oxygen extraction fraction in the precentral region of the right cerebral hemisphere. Use of F-18-florbetapir PET depicted amyloid beta deposition as decreased tracer uptake in the precentral region in the right cerebral hemisphere when compared with the contralateral hemisphere.