Clinical Role of Brain PET in Alzheimer Disease in the Era of Disease-Modifying Therapies.

Alzheimer disease (AD) is the leading cause of dementia, with an estimated 6.9 million Americans aged 65 and older living with Alzheimer dementia today, with this number projected to grow to 13.8 million by 2060. Amyloid and τ accumulation underpin our understanding of the pathophysiology of AD, with the abnormal accumulation of these proteins leading to neurodegeneration. With the recent approval of antiamyloid monoclonal antibody therapies for patients with early-stage Alzheimer disease by the Food and Drug Administration, there is renewed energy and focus on brain imaging for diagnosis, triage, and monitoring of patients with neurodegenerative disease. Furthermore, PET imaging of amyloid and τ has revolutionized our understanding of dementia progression and staging, and influences patient management in the clinical setting. We aim to update radiologists on the evolving role of amyloid and τ PET in clinical practice, emphasizing the need for standardized workflows and the integration of molecular imaging data with other disease biomarkers. We also discuss the clinical implications of amyloid and τ PET, including their impact on diagnosis and treatment decisions, as well as the challenges of reimbursement and workforce capacity. With recent shifts in the AD management landscape, it is crucial for radiologists to keep abreast of recent advances in clinical practice, thereby ensuring effective patient care.