Pharmacokinetic modeling in dynamic scintigraphy of the hepatobiliary system

Relevance. Pharmacokinetic modeling is one of the main methods for evaluating the results of radionuclide studies. It can be used to track changes in scintigraphic images over time to evaluate the functions of the hepatobiliary system, as well as to calculate the corresponding quantitative indicators that characterize the various functions of the organs and tissues under study. The complexity of such modeling consists in two aspects. On the one hand, the excessive simplification of anatomical and physiological features of the body when dividing it into kinetic compartments, which can lead to the loss or distortion of important diagnostic information, on the other -in excessive consideration of all possible relationships of the functioning of organs and systems, which, on the contrary, will lead to the appearance of an excessive amount of absolutely useless for clinical interpretation of mathematical data, or the model becomes completely unsolvable. Purpose of work. To develop the compartmental model of kinetics of radiopharmaceutical in the human body in the study of the hepatobiliary system using the dynamic scintigraphy method. Material and methods. The work is based on the principles and methods of pharmacokinetics of drugs (compartmental modeling). To identify the parameters of the pharmacokinetic model, we used the results of dynamic scintigraphy of the hepatobiliary system of a patient with choledocholithiasis before and after endoscopic papillosphincterotomy. Results. Various methods of identification of model parameters based on quantitative data of hepatobiliscintigraphy are proposed. The results of pharmacokinetic modeling for dynamic scintigraphy of the hepatobiliary system in cases of non-visualizing gallbladder (four-compartment model) and visualizing gallbladder with stimulation of its emptying (five-compartment model) are presented and analyzed. Conclusions. From the comparative analysis of model curves "Activity-time" for different zones of interest the time of stimulation of gallbladder emptying is justified, which normally should be 35-40 minutes from the beginning of the study.

hepatobiliary system, modeling, radiopharmaceutical, pharmacokinetics, scintigraphy