[Measurement of brain function by positron emission tomography--clinical application of PET to neurological disorders].

: Positron emission tomography has enabled us to measure various fundamental parameters of human brain physiology and chemistry, such as cerebral blood flow, metabolism and synaptic function. Blood flow and oxygen metabolism is important for the understanding of cerebrovascular Disease. Glucose metabolism is useful for the determination of epileptic foci and for the evaluation of tumor malignancy. Measurement of pre- and post-synaptic function is applicable to the differential diagnosis of parkinsonism. Imaging analysis of functional neuroanatomy of these parameters are very promising for the early diagnosis of dementia, such as Alzheimer's disease. Developmennt of new radiotracers is expected for detection of early specific pathological changes and more previous changes underlying the deterioration of neurochemistry, such as genetic abnormalities.