PET and the effects of aging and neurodegeneration on brain function: basic principles

In the first part of a three-part series on the role of positron emission tomography (PET) in the study of neurodegeneration and aging in the human brain, the authors review the historical development of the in vivo measurement of brain function resulting in recent advances in PET technology. An overview is presented of the physical principles of PET scanning and the inherent limitations of this technology to set the basis for the critical interpretation of PET data presented in the second and third parts and in the ever-increasing number of PET studies on the brain in different physiological and pathological conditions. Finally, the authors describe the ability to measure in vivo regional cerebral glucose metabolism with [(18)F]-FDG PET, regional cerebral blood flow and the distribution and binding capacity of neuroreceptors. They conclude with future perspectives of PET technology and its relevance, especially for neuropsychiatric research.