[The advantages and limitations of brain function analyses by PET].
PET has been proved to be a powerful tool for exploring the brain function. We discussed the advantages and limitations of PET for analyzing the brain function on the basis of our clinical and experimental experiences of functional imaging. A multimodality PET study measuring cerebral energy metabolism (CMRO2 and CMRglc), cerebral blood flow (CBF), oxygen extraction fraction (OEF) and neurotransmitter function (presynaptic and postsynaptic) opens up a closer insight into a precise pathophysiology of the brain dysfunction: In cerebral infarction, it reveals a state of "misery perfusion" in the acute stage, "luxury perfusion" in the intermediate stage, and proportionately decreased CBF and CMRO2 in the chronic stage. Neurotransmitter function may identify specifically a neuronal subgroup of dysfunction. Owing to the low temporal resolution of PET, a neuronal activity may propagate transsynaptically to remote areas during the period of scanning, resulting in an obscured primary site of the neuronal activity. Uncoupling between neuronal activities and cerebral energy metabolism/CBF may occur under a certain state of brain pathology, particularly after an acute destructive lesion, according to our experimental studies. Neurotransmitter function may reveal the effect of drugs on the brain function, and may be useful for developing a new method of drug therapy for brain diseases in the future.
Kato
M
M
Fukuoka Institute of Health and Environmental Sciences, Kyushu University, Fukuoka, Japan.
Taniwaki
T
T
Kuwabara
Y
Y
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000502:physiology / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D004734:Energy Metabolism; D006801:Humans; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology; D009474:Neurons / Q000502:physiology; D018377:Neurotransmitter Agents / Q000502:physiology; D014055:Tomography, Emission-Computed
D018377:Neurotransmitter Agents