Dual-tracer PET/CT Imaging using 18F-AV-45 and 18F-AV-1451 for the Diagnosis of Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by an insidious onset and gradual deterioration. Clinically, it manifests as cognitive decline and behavioral changes rather than only as generalized dementia. Currently, the diagnostic accuracy of AD remains limited due to the nonspecific clinical manifestations and the low specificity of conventional examinations such as neuropsychological assessments, electroencephalography (EEG), computed tomography (CT), and magnetic resonance imaging (MRI). Positron emission tomography/computed tomography (PET/CT) provides detailed structural and functional information along with specific molecular distributions, making it increasingly valuable for the diagnosis and research of AD. We performed PET/CT scans using the radiotracers ¹⁸F-AV-45 (florbetapir) and ¹⁸F-AV-1451 (flortaucipir). The key distinction between these tracers lies in their molecular targets: ¹⁸F-AV-45 binds to β-amyloid (Aβ), whereas ¹⁸F-AV-1451 specifically targets tau protein. This study elaborates on the protocol for the combined use of both tracers in AD diagnosis, encompassing patient preparation procedures, image acquisition techniques, interpretation standards, and the clinical significance of their joint application. This dual-tracer protocol provides a sensitive, comprehensive, and non-invasive method for detecting both amyloid and tau pathology, enhancing early diagnosis, disease staging, and research on disease progression.