Neuroimaging for diagnosis of dementia.

Although many clinicians consider neuroimaging studies as optional for the differential diagnosis of dementia, clinical experience suggests that they can improve diagnostic accuracy. Data are limited, however, on sensitivity, specificity, and cost-effectiveness of various neuroimaging techniques. The author reviews advantages and disadvantages of neuroimaging techniques for the differential diagnosis of dementia and describes strategies used for early detection of Alzheimer's disease, including combining positron emission tomography scanning with genetic risk assessment. Such approaches could provide a means for in vivo therapeutic monitoring of brain function during experimental antidementia treatment trials.