Analysis of three- and four-compartment models for in vivo radioligand-neuroreceptor interaction

✍ Scribed by Barry R. Zeeberg; Henry N. Wagner Jr

• Publisher: Springer
• Year: 1987
• Tongue: English
• Weight: 964 KB
• Volume: 49
• Category: Article
• ISSN: 1522-9602
• DOI: 10.1016/s0092-8240(87)80008-3

✦ Synopsis

Currently applied three-compartment models for analyzing kinetic data derived from in vivo positron emission tomographic (PET) studies of radioligand-neuroreceptor interactions require assumptions which may not be strictly valid. Such assumptions include very rapid kinetics for nonspecific binding and the absence of multiple specific receptors or subtypes. Computer simulations, based on an exact analytical solution of the relevant differential equations, indicate the numerical errors that can arise when the assumptions are invalid. We propose a fourcompartment model which requires fewer assumptions. A simple relationship is derived for expressing the microscopic rate constants of either the three-or four-compartment model as explicit functions of the experimentally-observed macroscopic rate constants. This could eliminate the need for time-consuming, iterative, non-linear, curve-fitting approaches and numerical integration. The usefulness of the four-compartment model is limited, however, by the sensitivity and temporal resolution of current PET imaging devices.