title: The importance of delayed imaging in the study of hepatoma with a new hepatobiliary agent.
abstract: Concentration of Tc-99m(Sn)-N-pyridoxyl-5-methyltryptophan (Tc-99m PMT), a biliary agent, in hepatic tumors was studied with delayed hepatobiliary imaging in 23 patients with histologically verified hepatocellular carcinomas. All 23 showed filling defects on liver images obtained with Tc-99m tin colloid. In the images taken 5 hr after Tc-99m PMT injection, ten cases showed increased uptake in the carcinoma, six nearly normal uptake, and seven decreased uptake. In those showing the increased uptake of Tc-99m PMT in the tumor, the ratio of the radioactivity in the lesion to that in the adjacent liver parenchyma (T/L ratio) increased progressively with time for 5 hr after injection. These results indicate that delayed Tc-99m PMT images, obtained 5 hr after injection, are useful in assessment of uptake of the radioactivity by hepatocellular carcinoma.
mesh_terms: D001659:Biliary Tract / Q000000981:diagnostic imaging*; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D004341:Drug Evaluation; D006801:Humans; D007275:Injections, Intravenous; D008099:Liver / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D015609:Organotechnetium Compounds; D011730:Pyridoxal / Q000031:analogs & derivatives*; D011877:Radionuclide Imaging; D013667:Technetium; D013997:Time Factors; D014364:Tryptophan / Q000031:analogs & derivatives*
chemical_list: D015609:Organotechnetium Compounds; C038081:technetium Tc 99m pyridoxyl-5-methyltryptophan; D011730:Pyridoxal; D013667:Technetium; D014364:Tryptophan