The Impact of Amyloid and Tau PET on Alzheimer Disease Diagnostics: AJR Expert Panel Narrative Review

Amyloid and tau PET have contributed significantly to the understanding of the biology of Alzheimer disease (AD), aided development of biomarker-driven AD diagnostic criteria, and facilitated approval of the first disease-modifying drugs for AD. As opportunities to use amyloid and tau PET in the clinic have expanded, several factors will affect their application and real-world impact in patients with AD. First, quantification of amyloid and tau PET interpretations, supported by appropriate visual confirmation, will be needed for monitoring therapy response. Also, amyloid and tau PET will need to be balanced with emerging biofluid assays from CSF and blood. Blood-based biomarkers, although still requiring validation, have particular potential to complement PET use; nonetheless, the topographic information uniquely provided by tau PET will remain important in clinical practice. Additionally, the proper use of amyloid and tau PET for clinical management will require an understanding and consideration of mixed pathology, as is usually present in AD, along with continued advances in imaging technology to better address copathology. Further research and investment in this evolving field will improve diagnostic accuracy and therapeutic approaches, ultimately benefiting outcomes in patients with AD.