The study of brain aging has been revolutionized through advances in molecular neuroscience, cognitive neuroscience, and brain imaging. The application of new concepts and techniques has permitted investigators to explore the changes in structure, function, and biochemistry in living humans in order to unravel mechanisms that underlie both age-related cognitive decline and preservation of cognition into old age. This book reviews both the basic science and clinical applications of brain imaging in the study of brain aging. Topics reviewed include technical issues associated with imaging studies in older brains, pathology of brain aging, structural changes in the aging brain, changes in dopamine function, and mechanisms of brain reserve and plasticity. The use of genetics in combination with brain imaging and the use of animal models are also explored. Clinical applications include the diagnosis and prediction of cognitive decline using a variety of different imaging approaches as well as a detailed description of amyloid imaging using PET scanning. Other topics include functional MRI studies in aging, the use of imaging in therapeutic monitoring and drug development, and the role of large-scale databases. The volume contains information both for those involved in brain imaging research and for those new to the field who are in need of a systematic overview.