Tracer kinetic modeling: Methodology and applications

Abstract

Positron emission tomography (PET) is a medical imaging technique based on the simultaneous detection of pairs of 511-keV gamma radiations emitted by the annihilation of positrons within the subject following administration of a radiotracer. The radiotracer could be any pharmacological molecule or a natural molecule, such as water (H215O) or carbon monoxide ( 11CO, C15O), where an atom or a group of atoms are replaced with a positron emitting isotope. These two particularities (i.e., radiation emission and radiotracer labeling) provide the functionality and the versatility of PET. In addition, the use of PET to measure noninvasively biochemical and physiological reactions in a tissue as a function of time greatly contributes to a new avenue in medicine. PET has a picomolar sensitivity and can acquire images in frames of 10 s in humans and almost 3 s in small animals, providing dynamic insights in living tissues. Moreover, and since a tissue can be imaged by an appropriate radiotracer, both diseased and healthy tissues can be measured by PET. Among such applications are cancer and cognitive studies. These advantageous particularities of PET are exploited, however, at a substantially high cost, which can mainly be because of the necessity to include a cyclotron as part of the imaging center and to involve radiochemists or radiopharmacists and physicists to work within the same team in addition to clinicians. © 2011 Springer-Verlag Berlin Heidelberg.