ANALYSIS OF MODELS FOR QUANTIFICATION OF ARTERIAL AND PORTAL BLOOD-FLOW IN THE HUMAN LIVER USING PET

Objective: The purpose of our study was to quantify arterial and porta l hepatic arterial blood flows. Materials and Methods: Four models wer e developed using PET. The first model consisted of the components of the liver and the portal system. The second applied ''curve analysis'' to this model. The third model introduced a portosystemic shunt facto r, whereas the last model introduced a coefficient for circulation tim e within the portal organs. In 51 patients (34 men and 17 women), PET scans of the liver were performed using the (H2O)-O-15 dynamic method. Results: Under all four models, the arterial and portal hepatic arter ial blood flows of 504 regions of interest were calculated using the n onlinear least-squares method, and results were compared by the sum of the squares of errors. Additionally, results from the (H2O)-O-15 dyna mic method were compared by results from the (CO2)-O-15 steady-state m ethod. Conclusion: Of the four models, the last model produced curves with the best fit. When hepatic blood flow was quantified using PET an d the (H2O)-O-15 dynamic method, a model applying ''curve analysis'' a nd components related to portosystemic shunting and circulation time w as found to be most accurate.