Cerebral Glucose Metabolism

Abstract

Glucose is the main substrate for energy metabolism of the brain, and the regional cerebral metabolic rate is directly related to regional brain activity. Therefore, the measurement of regional glucose metabolism is of great importance for the assessment of regional normal function and of pathological changes. Quantitation of glucose metabolism by PET is based on the 2-deoxyglucose method developed by Sokoloff and colleagues: F18-labelled deoxyglucose (FDG) is transported into the brain and phosphorylated, but cannot be further metabolised and therefore is accumulated intracellularly. The concentration of the tracer can be measured three dimensionally by PET, and together with the arterial tracer concentration, the kinetics of glucose uptake can be assessed and the regional cerebral metabolic rate of glucose (rCMRGlc) can be calculated.rCMRGlc is high in cortex and grey matter structures and low in white matter, but there are significant differences among various regions. Metabolic rate is

From Positron to Pattern: A Conceptual and Practical Overview of 18F-FDG PET Imaging and Spatial Covariance Analysis

“…Resting-state 18 F-FDG uptake is much higher in gray matter compared with white matter. In healthy controls, 18 F-FDG uptake is typically highest in the basal ganglia, primary visual cortex, cingulate cortex, and frontal cortex, with lower values in other cortical and subcortical areas, brain stem, and cerebellum (Heiss 2014).…”

“…The kinetics of accumulation of 18 F-FDG-6-PO 4 can be described with a threecompartment model (Reivich et al 1979). A description of tracer kinetic modeling is beyond the scope of this chapter and can be found elsewhere (Heiss 2014). In brief, after intravenous administration of 18 F-FDG, the regional cerebral metabolic rate of glucose (CMRglc) can be determined using the 18 F concentration in the tissue (measured with PET), the concentration of 18 F-FDG in the arterial plasma (time-activity curve of blood tracer concentration), and the concentration of glucose in the plasma.…”

“…This is a slow process (Sokoloff et al 1977). (Adapted from (Heiss 2014) with permission from Springer Verlag Heidelberg). (b) Visual representation of an 18 F-FDG PET study of a 65-year-old healthy individual.…”