Regional cerebral glucose metabolism in healthy volunteers determined by fluordeoxyglucose positron emission tomography - Appearance and variance in the transaxial, coronal, and sagittal planes

Purpose: In this study, the contribution of the transaxial, coronal, and sa gittal planes in evaluations of regional cerebral glucose metabolism was in vestigated in healthy volunteers as determined by fluorine-18-labeled 2-deo xy-2-fluoro-D-glucose (FDG) and high-resolution positron emission tomograph y (PET). Methods: One hundred twenty-seven healthy right-handed volunteers were inje cted with 4.2 MBq/kg (0.11 mCi) body weight FDG and imaged in a PENN PET H 240 scanner, Images were corrected for scatter and random coincidences and reconstructed in all three planes into 6- to 8-mm-thick slices. The reconst ructed images were corrected for attenuation using the Chang algorithm. The transverse, coronal, and sagittal images were read independently of each o ther using a qualitative scale in which 1 = equal to, 2 = mildly, 3 = moder ately, and 4 = markedly less than the area with the highest glucose metabol ism in the respective plane. Results: The areas with the highest glucose metabolisms were the posterior cingulate gyri with mean scores of 1.1 to 1.2, thalami (1.2 to 1.3), basal ganglia (1.5 to 1.9), and visual cortex (1.6). The lowest values were found in the occipital cortex (2.7 to 2.8) and the cerebellum (2.3 to 2,4), Wher eas reliable analysis of the mesial temporal aspects was not feasible in th e sagittal plane, the anterior poles of the temporal and frontal lobes coul d not be evaluated in the coronal or the inferior temporal areas in the tra nsaxial slices. In all three planes, regional glucose metabolism was less i n the lateral temporal areas on the left than on the right (P < 0.001). The consistency of readings as measured in terms of coefficients of variation was greatest in the coronal plane for the caudates and posterior cingulate gyri, in the transaxial plane for the lateral temporal regions, and in the sagittal plane for the visual cortex. Age-dependent decreases in regional g lucose metabolism in the inferior and lateral frontal regions and the parie tal lobes were found in all three planes. Conclusions: All three projection planes must be used for a comprehensive q ualitative evaluation of the regional glucose metabolism of the brain.