The role of positron emission tomography imaging in understanding Alzheimer's disease.

PET is a non-invasive imaging technique which allows the visualization and quantification of molecular processes, offering sensitive and early disease detection. Alzheimer's disease (AD) is a progressive neurodegenerative disorder leading to memory loss and other functional impairments. By employing different tracers targeting neurodegeneration, amyloid and tau aggregates, cholinergic neurotransmission, neuroinflammation and other processes, PET imaging enhances our understanding of the potential triggers of AD, the chronology of molecular events in AD, the detection of early AD, differentiation of AD dementia from other dementia disorders and the development of better drugs to treat AD. As such, PET imaging at different disease stages (asymptomatic, prodromal and dementia stages) is on its way to becoming a valuable routine clinical biomarker and a drug testing and research tool in AD.