Positron Emission Tomography in Dementia of the Alzheimer Type

Abstract
Positron emission tomography (PET) has emerged as an important technique for the in vivo investigation of cerebral physiology and metabolism. Patients with dementia of the Alzheimer type (DAT) have been studied with many brain imaging procedures, including PET. Although PET studies of demented subjects may be challenging to perform and difficult to interpret, research laboratories have collected useful data on a combined patient population of several hundred subjects. The purpose of this presentation is to summarize the major findings of these groups and to discuss serial PET studies done in the Laboratory of Neurosciences (LNS) of the National Institute on Aging (NIA) Bethesda, Md, on a subject with familial DAT. Reviews of the theoretical principles and applications of PET have been published1,2; the basics can be briefly summarized. Whereas radiologic computed tomography (CT) depends on computer reconstruction of information derived from differential attenuation of an x-ray beam passing through