Global experience in brain amyloid imaging.

Abstract

Brain amyloid imaging has become a crucial tool in diagnosing and understanding Alzheimer's disease (AD) and related neurodegenerative disorders. The introduction of amyloid positron emission tomography (PET) with [¹¹C]Pittsburgh Compound-B ([¹¹C]PiB) in the early 2000s marked a breakthrough in visualizing amyloid-β (Aβ) deposition in vivo. Subsequent development of ¹⁸F-labeled tracers, such as [¹⁸F]florbetapir, [¹⁸F]flutemetamol, and [¹⁸F]florbetaben, improved accessibility and extended imaging capabilities. However, global adoption remains uneven due to disparities in healthcare infrastructure, costs, and regulatory frameworks. In high-income countries, amyloid PET is increasingly used in clinical workflows, particularly for differentiating atypical dementia cases and selecting patients for anti-amyloid therapies like aducanumab and lecanemab. Despite its high sensitivity and specificity, challenges persist regarding its clinical utility, particularly in cognitively normal individuals with amyloid accumulation. Research is focusing on integrating amyloid PET with other biomarkers-tau PET, cerebrospinal fluid analysis, and plasma assays-to improve diagnostic accuracy. Geographical variations in amyloid PET research and implementation reveal North America and Europe as leaders, while access remains limited in low- and middle-income countries. Efforts such as the Worldwide Alzheimer's Disease Neuroimaging Initiative aim to enhance global standardization and accessibility. Emerging trends in artificial intelligence (AI)-assisted imaging analysis and next-generation tracers promise further improvements. Addressing ethical concerns related to preclinical screening and ensuring equitable access to amyloid PET are critical for optimizing its role in neurology and nuclear medicine worldwide.