Among all the clinical indications for which radiologists, nuclear medicine physicians, neurologists, neurosurgeons, psychiatrists (and others examining disorders of the brain) order and read brain PET scans, demand is greatest for those pertaining to dementia and related disorders. This demand is driven by the sheer prevalence of those conditions, coupled with the fact that the differential diagnosis for causes of cognitive impairment is wide and often difficult to distinguish clinically. The conceptual framework by which evaluation and management of dementia is guided has evolved considerably during the last decade
