PET-Imaging bei Demenzerkrankungen
摘要
Positron emission tomography (PET) imaging has become a central tool in the diagnosis of neurodegenerative disorders. 18F‑Fluorodeoxyglucose (FDG)-PET reflects cerebral glucose metabolism and reveals regional changes in neuronal activity, supporting the differential diagnosis of dementias and their subtypes. However, it does not provide information about the underlying proteinopathy. In contrast, amyloid-PET enables the visualization of insoluble amyloid plaques, thereby allowing a biological diagnosis of Alzheimer’s disease (AD). This is particularly relevant given the recent approval of disease-modifying therapies for AD. Quantification methods, such as the Centiloid scale, standardize PET results and are crucial for the assessment of amyloid reduction as a measure of treatment response in clinical trials. The early phase of amyloid-PET can serve as a proxy for cerebral perfusion, thus, facilitating the detection of concomitant neurodegenerative changes with a single tracer administration. Tau-PET visualizes aggregated tau deposits and correlates more closely with clinical symptoms than other biomarkers. Limitations of first-generation tracers, such as off-target binding, are expected to be reduced by second-generation tau tracers. Consequently, these tracers could potentially be employed as markers for non-AD tauopathies in the future. The development of novel tracers for other proteinopathies, in addition to amyloid and tau, as well as associated processes like neuroinflammation, may further enhance the precision and individualization of dementia diagnosis and support targeted therapeutic strategies.