Resting Pet Brain Image Analysis

Cognitive declining with normal aging and sex difference in behavior are thought to be resulted from change or difference in neuron activity. The objective of the present work was to determine, by analyzing the positron emission tomography (PET) images acquired under the resting state, the neural mechanism underlying the changes in cognitive as a function of age and sex. This study examined the correlation between cerebral glucose metabolism and age, and evaluated the sex differences on cerebral glucose metabolism.All subjects were divided into two subgroups according to the sex: females and males. After spatial and count normalization, the patterns of glucose metabolism as a function of age and sex were investigated using a statistical parametric mapping (SPM) analysis. One-sample t-test was used to study the effects of age on cerebral glucose metabolism. Significant age-related glucose metabolism decreases in females were observed in frontal lobe, temporal lobe and occipital lobe, and glucose metabolism was significantly increased with normal aging in parietal lobe. In males, significant age-related decreases in glucose metabolism were noted in frontal lobe, temporal lobe and corpus callosum in interhemispheric. However, significant positive correlations between glucose metabolism and age were observed in frontal lobe, temporal lobe, parietal lobe, cerebellum and brainstem. Two-sample t-test was used to compare the glucose metabolism between females and males. Males had lower glucose metabolism than females in prefrontal cortex, right parahippocampal gyrus and right superior temporal gyrus. Significant clusters where males had higher glucose metabolism than females were founded in temporal lobe, parietal lobe, frontal lobe and cingulate gyrus in limbic lobe. The differences of brain function in the resting state suggest that the differences in cognitive and behavioral processing have biological substrates.