title: Comparison of shunt fraction estimation using transcolonic iodine-123-iodoamphetamine and technetium-99m-pertechnetate in a group of dogs with experimentally-induced chronic biliary cirrhosis.
abstract: Portosystemic shunt fraction estimation using transcolonic iodine-123-iodoamphetamine (IMP) has been previously validated relative to portal vein macroaggregated albumin injections using an experimental model of cirrhosis. Transcolonic technetium-99m-pertechnetate (TcO4-) has been proposed as an alternative tracer to IMP to study portal circulation in cirrhotic patients. We compared shunt fraction estimates from paired transcolonic IMP and TcO4- studies performed on a group of dogs before and after common bile duct ligation surgery. Pertechnetate over-estimated shunt fraction in 6/7 postoperative studies relative to IMP. A good correlation between the two methods was demonstrated, however, the slope of the regression line was substantially less than 1.0 with TcO4- values reaching 100% at IMP shunt values of approximately 60%. This apparent inability to accurately assess high shunt flows may limit the quantitative aspects of TcO4- studies on patients with severe portosystemic shunting.
authors.affiliation: Department of Radiological Sciences, School of Veterinary Medicine, University of California, Davis 95616.
authors.forename: P D
authors.initials: PD
authors.lastname: Koblik
authors.forename: W J
authors.initials: WJ
authors.lastname: Hornof
authors.forename: C K
authors.initials: CK
authors.lastname: Yen
authors.forename: J
authors.initials: J
authors.lastname: Komtebedde
authors.forename: E
authors.initials: E
authors.lastname: Breznock
authors.forename: P
authors.initials: P
authors.lastname: Fisher
mesh_terms: D000662:Amphetamines; D000818:Animals; D004285:Dogs; D006975:Hypertension, Portal / Q000000981:diagnostic imaging / Q000503:physiopathology; D007457:Iodine Radioisotopes; D008105:Liver Cirrhosis, Biliary / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011168:Portal System / Q000503:physiopathology*; D011877:Radionuclide Imaging; D013670:Sodium Pertechnetate Tc 99m
chemical_list: D000662:Amphetamines; D007457:Iodine Radioisotopes; C041336:4-iodoamphetamine; D013670:Sodium Pertechnetate Tc 99m