The advent of pathology-specific diagnostic methods such as amyloid positron emission tomography (PET) and tau PET has enabled early and pre-symptomatic diagnosis of Alzheimer's disease. Imaging biomarkers in nuclear medicine play a key role in elucidating the pathogenesis of Alzheimer's disease and accelerating the development of disease-modifying drugs. In this study, we describe the current status and future prospects of nuclear medicine diagnostics aimed at early detection of Alzheimer's disease to delay and prevent disease progression.