Introduction     Diagnosis of Mild Cognitive Impairment and Alzheimer's Disease Karen L. Bell, M.D.     Treatment Strategies for Dementia and Mild Cognitive Impairment Mary Sano, Ph.D.     Treatment of Depression, Agitation, and Psychosis in Dementia Davangere P. Devanand, M.D.     Recognition of Vascular Dementia, Dementia with Lewy Bodies, and Frontotemporal Dementia Lawrence S. Honig, M.D., Ph.D.     Neuropsychology of Mild Cognitive Impairment, Alzheimer's Disease, Dementia with Lewy Bodies, and Frontotemporal Dementia Penne Sims, Ph.D.     Neuroimaging in Dementia Scott A. Small, M.D.     Neurobiological Correlates       Metabolism in Imaging       Imaging Modalities       Diagnostic Specificity       Early Detection         Genetics of Neurodegenerative Disease: Alzheimer's Disease, Frontotemporal Dementia Jennifer Williamson-Catania, M.S.     Legal and Ethical Issues for Patients with Dementia Daniel G. Fish, Esq.     Posttest         Accreditation     Reference List     Acknowledgements		Neuroimaging in Dementia Scott A. Small, M.D. Neurobiological Correlates   The introduction of the CAT scan in the 1970s transformed the way we practice neurology, perhaps more than any other technical development. Imaging studies are a generic recommendation when evaluating a patient who presents with dementia, but, unlike in other areas of neurology, they are primarily used to rule out or confirm a diagnosis. For stroke, multiple sclerosis, or neoplasm, we use imaging to precisely diagnose and follow the course of a disease. The utility of imaging for Alzheimer's disease has not been fully realized.   Recent advances in both technical developments in imaging and in understanding the basic pathophysiology of Alzheimer's disease have brought us to the cusp of using imaging very effectively for patients with dementia.   Among brain scientists and brain practitioners, the neurobiological correlates of imaging are key and are sometimes neglected. To order appropriate tests, we must focus on what exactly we are trying to measure, rather than focusing on the physics or epidemiological outcomes of imaging. This is particularly important because imaging is rapidly advancing; what I tell you now could change in a year or two. Because of that, I will focus on basic neurobiological principles that will help you sort through the wide and growing array of imaging modalities.   There are two basic questions you should always ask when you are thinking of ordering an imaging test: what is the physiological source of the signal that generates the image? and what is the anatomical resolution? I will be returning to these questions frequently.         Anatomical Resolution   All imaging techniques can be dichotomized into those with a macroscopic resolution and those with a microscopic resolution. Courtesy of Dr. Scott Small           Source and Resolution                 Physiological Source "Structure" MRI, CT "Function" fMRI, PET, SPECT   The typical distinction in terms of physiological source between structural and functional imaging causes confusion. Courtesy of Dr. Scott Small       PREVIOUS | NEXT