Analysis of kinetic rate constants in [18F] fluorodeoxyglucose model using a least square fitting package SALS (Statistical Analysis with Least Squares)

The analysis of kinetic rate constants in the compartment model for [18F] fluorodeoxyglucose (FDG) was undertaken. Four kinetic rate constants were determined with a least square fitting package SALS (Statistical Analysis with Least Squares), using the measured data of 18F activity as a function of time. SALS calculations were found to be easy and quick with high precision. The rate constants and the curves fitted by the k3* and the k4* models were compared in situations with various degree of cerebral glucose metabolism during positron emission tomography (PET) studies. The k4* model in the determination of cerebral metabolic rate for glucose (CMRqlu) was much superior than the k3* model in any given situation as it always understimates the metabolic rate. However, the k3* model produces less variation when the cerebral radioactivity curve shows steady rising pattern. (author)