Aβ Imaging in Aging, Alzheimer's Disease, and Other Neurodegenerative Conditions

Abstract

In vivo imaging of β-amyloid (Αβ) has transformed the assessment of Αβ pathology and its changes over time, extending our insight into Aβ deposition in the brain by providing highly accurate, reliable, and reproducible quantitative statements of regional or global Aβ burden in the brain, proving essential in anti-Αβ therapeutic trials. Although cross-sectional evaluation of Αβ burden does not strongly correlate with cognitive impairment in AD, it does correlate with memory impairment and a higher risk for cognitive decline in the aging population and MCI subjects. This correlation with memory impairment, one of the earliest symptoms of AD, suggests that Αβ deposition is not part of normal aging. Longitudinal observations, coupled with different disease-specific biomarkers to assess potential downstream effects of Aβ, have confirmed that Αβ deposition in the brain starts decades before the onset of symptoms. Aβ imaging studies continue to refine our understanding of the role of Αβ deposition in Alzheimer's disease.