title: Noninvasive quantification of the differential portal and arterial contribution to the liver blood supply from PET measurements using the 11C-acetate kinetic model.
abstract: Our recent research has demonstrated that 11C-acetate could be a complementary tracer to 18F-fluorodeoxyglucose (FDG) in positron emission tomography (PET) imaging of hepatocellular carcinoma (HCC). In our previous modeling study, a three-compartment four-parameter model with a fixed contribution ratio of the liver's two blood supplies was proposed to characterize the kinetic behavior of 11C-acetate in liver. However, in real pathology, both tumor and nontumor liver tissue can be heterogeneous in the distribution and proportion of the two blood supplies. To further improve the accuracy of quantitative analysis, the actual proportion of the hepatic artery and portal vein (PV) in different regions of interest (ROIs) was investigated in this study. An extra parameter av was included in the model input function to describe the contribution of PV to the liver. Ten ROIs extracted from six patients were used to test the models with fixed/nonfixed weighted dual-input function. The weighted nonlinear least squares algorithm was used to estimate all of the parameters. Evaluation of the adequacy of the two models was conducted and the computer simulation was performed to test the estimation accuracy of the new model. The forward clearance K was also estimated by the linear Patlak method. The results show that the model with parameter av in the input function was more suitable for mapping the tracer time activity curves. Moreover, the estimated av value fits the practical physiological and pathological conditions well and could be a potential candidate to provide useful additional diagnostic information for the early detection of hepatic metastases.
authors.affiliation: Department of Electronic and Information Engineering, Hong Kong Polytechnic University, Hong Kong. ensrchen@eie.polyu.edu.hk
authors.forename: Sirong
authors.initials: S
authors.lastname: Chen
authors.forename: Dagan
authors.initials: D
authors.lastname: Feng
mesh_terms: D000085:Acetates / Q000493:pharmacokinetics; D001783:Blood Flow Velocity; D002244:Carbon / Q000493:pharmacokinetics; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000378:metabolism; D003198:Computer Simulation; D005240:Feasibility Studies; D006499:Hepatic Artery; D006526:Hepatitis C / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007700:Kinetics; D008099:Liver / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000378:metabolism; D008102:Liver Circulation; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D011168:Portal System; D011865:Radioisotope Dilution Technique; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed / Q000379:methods
chemical_list: D000085:Acetates; D019275:Radiopharmaceuticals; C438206:carbon-11 acetate; D002244:Carbon