Rate constants from three-compartment modeling of dynamic PET for F-18-FDG metabolism. Comparison of therapy-naive patients (white regions) and patients on HAART (gray regions). k1 (ml/min/ml) and k2 (min–1) represent the inward and outward transport, respectively, from the extracellular into the intracellular compartment. k3 (min–1) is the rate constant for the phosphorylation of F-18-FDG. Data are median and interquartile range; the bars represent the complete range. P values represent results of Mann-Whitney statistics between groups.