Neuroimaging in Alzheimer disease: An evidence-based review

Alzheimer disease (AD) is the most prevalent of dementia syndromes. The number of elderly individuals affected with the disease is expected to grow with increasing life expectancy. There is no definite biomarker available for the diagnosis of AD; clinical criteria are currently used. Neuroimaging can identify potentially treatable causes of dementia, and it is also sensitive to the early structural and functional changes in the brains of patients with AD. This article reviews the evidence on the usefulness of neuroimaging in clinical evaluation of AD and as a surrogate marker for early detection and disease progression.