Amyloid PET scan: Staging beyond reading?

Abstract

The advent of in vivo β-amyloid (Aβ) PET imaging has revolutionized the field of Alzheimer disease (AD). The opportunity to visualize, during life, one of the main neuropathologic hallmarks of the disease, i.e., Aβ deposition, has yielded considerable hope for diagnosis and treatment efficacy. From a clinical perspective, although the presence of Aβ deposition in the brain is not a sufficient criterion for AD dementia diagnosis, Aβ PET imaging is used to support or rule out the diagnosis, especially in patients with a complicated clinical course.1 Moreover, Aβ PET imaging is a powerful tool for clinical trials to enrich the sample for Aβ-positive participants, and to evaluate treatment effects on Aβ deposition. Finally, Aβ PET imaging has provided a unique opportunity to assess how Aβ deposition relates to cognitive and functional decline, brain atrophy, and hypometabolism, both cross-sectionally and longitudinally.