Kinetic Modeling of Radiotracers

Abstract

Positron emission tomography (PET) is a powerful tool for the noninvasive measurement of biological parameters. Because of its inherently quantitative nature, PET can be used to measure radioactivity concentrations in the blood and various tissues over time. Using the proper tracer and tracer kinetic model, this information can be used to determine parameters such as blood flow, receptor availability, and substrate metabolism. In this chapter, we will first discuss the basic concept of quantitative PET measurements. Then, we will describe compartment models for blood flow, irreversible kinetics, and receptor-ligand kinetics in more detail. The use of these compartment models for the computation of voxel-wise maps of functional parameters requires the linearization of the compartment models, which is addressed in the context of both irreversible and reversible models. Finally, further simplifications that do not require dynamic scanning are briefly described. Although this chapter is by no means exhaustive, it aims to provide an introduction to the use of tracer kinetic models to derive functional parameters from PET data.