Tomographic Mapping of Kinetic Rate Constants in the Fluorodeoxyglucose Model Using Dynamic Positron Emission Tomography

A quick computing algorithm to calculate the rate constants ( k*1, k*2, k*3) in the [18F]2-fluoro-2-deoxy-d-glucose (FDG) model was developed. The algorithm solved for the rate constants pixel by pixel using a conventional least-squares method and two tables consisting of a set of various rate constants, to shorten the computing time. Five planes of rate constant images were obtained. A combined study using the dynamic FDG method and the 15O-labeled gas continuous inhalation method was performed on seven healthy male volunteers aged 26–35 years. Results indicated an apparent discrepancy between CMRglu and CMRO2 in the cerebellum, where the low glucose utilization was correlated with a low FDG phosphorylation rate ( k*3) despite a sufficient FDG transportation rate ( k*1) from plasma to tissue.