Functional imaging (e.g. PET: Positron Emission Tomography) is a non-invasive method allowing to study and understand biochemical processes in a living organism. Therefore, various radio- labeled bio-molecules, so-called tracers, are used, which are specifically produced and chosen for different bio-chemical, physiological and pharmacological processes. In order to quantify these pharmacological characteristics, a mathematical description is needed, usually in form of a kinetic model which reproduces the behavior of the tracer preferably completely but also as simple as possible. Kinetic models are built with the information obtained by a dynamic scan, i.e. from the tracer’s behavior over time in a certain three dimensional region of the living organism.
On basis of these models as well as with suitable scan protocols and reconstruction algorithms, quantitative biological images can be produced.