The use of positron emission tomography (PET) for diagnosing dementia especially relies upon the PET tracer uorodeoxyglucose (FDG-PET) and various tracers for detecting the presence of beta-amyloid deposits (amyloid-PET). Reduced cerebral glucose metabolism caused by nerve damages is assessed using FDG-PET. Different neurodegenerative dis- orders can be distinguished through the varying damage patterns they exhibit.
If the amyloid-PET fails to detect the presence of plaques, the Alzheimer’s diagnosis is highly unlikely. Patients displaying normal cognitive behav- iour may, however, frequently exhibit abnormal amyloid-PET results with increasing age.
FDG-PET and amyloid-PET are incorporated as relevant biomarkers into the diagnostic criteria for neurodegenerative diseases. These tools thus help to increase diagnostic reliability and to detect early stages. Research- ers deem this necessary, as neurodegenerative diseases may remain asymptomatic for decades and the initial appearance of symptoms is already preceded by considerable loss of synapses and neurons. Drug treatment is presently thought to be effective particularly during early stages. Amyloid-PET is well-suited for the early diagnosis of asympto- matic Alzheimer’s pathologies and its results serve as a selection criterion in clinical trials.