PETra: software tool for a semiautomatic positron emission tomography image analysis and its application to the study of brain glucose consumption in rats

This work presents a Positron Emission Tomography (PET) image analysis tool and its application to the study of rat brain glucose consumption (PETra comes from PET+rat). The described methodology has four steps: a preprocessing of PET images, a coregistration of these images with an atlas, a semiautomatic segmentation of the regions of interest in the rat brain and a 3D reconstruction of these regions to obtain the volumes of interest. Brain glucose uptake was quantified as Standardized Uptake Value (SUV). This tool was applied to nine Wistar rats, young (4-7 months) and old (22-24 months) groups, to study the effect of aging on brain glucose consumption and the difference between sexes. Results showed a lower glucose uptake in old rats than in young rats, regardless gender; while young female rats showed higher glucose consumption than young male rats, whereas these differences disappeared with aging. The developed tool allows the quantification of glucose in rat brain. Results show the accuracy of the tool to define ranges of variation in a population of young and old rats, showing a decrease in glucose consumption in aging.