ABSTRACT
Usefulness of per-rectal portal scintigraphy by 123I-IMP has already been admitted. We assessed whether 99mTc-HM-PAO, another agent used for cerebral blood flow scintigraphy, could be utilized for scintigraphic evaluation of the portal system. Animal experiments were carried out to evaluate the usefulness of the examination. Shunt indices obtained from per-rectal portal scintigraphy by 123I-IMP and 99mTc-HM-PAO in shunt models and shunt rate obtained by direct injection of 99mTc-MAA into the inferior mesenteric vein under laparotomy were compared. Correlation coefficient of each agent with 99mTc-MAA was 0.90 for 99mTc-HM-PAO and 0.80 for 123I-IMP. It was also noted that as larger quantity of the tracer could be administrated in 99mTc-HM-PAO than in 123I-IMP, absorption from rectum was optimum and liver extraction fraction was 94.4%. Therefore, we concluded that 99mTc-HM-PAO was useful for per-rectal portal scintigraphy.
Subject(s)
Organotechnetium Compounds , Oximes , Portal System/diagnostic imaging , Amphetamines , Animals , Iodine Radioisotopes , Iofetamine , Liver/metabolism , Male , Organotechnetium Compounds/pharmacokinetics , Oximes/pharmacokinetics , Portal System/metabolism , Rabbits , Radionuclide Imaging , Rectum/metabolism , Technetium Tc 99m Aggregated Albumin , Technetium Tc 99m ExametazimeABSTRACT
We discovered that 99mTc-EHIDA commonly used for hepatobiliary scintigraphy could also be administered per-rectally, with adequate absorption and optimal visualization of the portal system. To evaluation its usefulness, we experimented on rabbits using the method. Portal scintigraphy with rectal administration of 99mTc-EHIDA, 123I-IMP and 99mTc-RBC were performed in normal rabbits and in extrahepatic portal shunt model rabbits. Images of the liver and thorax were obtained and shunt indices were calculated from the count values of liver and lung or heart. Then the shunt indices were compared with shunt rate derived from direct injection of 99mTc-MAA into inferior mesenteric vein. Correlation between shunt rate of 99mTc-MAA and shunt indices of 99mTc-RBC, 123I-IMP and 99mTc-EHIDA were 0.64, 0.75 and 0.78, respectively, with 99mTc-EHIDA having the most favourable results. We concluded that 99mTc-EHIDA per-rectal portal scintigraphy is a noninvasive, quantitative, inexpensive and simple method for evaluation of portal circulation system. Also, we think that this method would be applicable to human usage from our experience with normal volunteers.
Subject(s)
Imino Acids , Organotechnetium Compounds , Portal Vein/diagnostic imaging , Administration, Rectal , Amphetamines , Animals , Drug Evaluation , Erythrocytes , Imino Acids/administration & dosage , Iofetamine , Male , Organotechnetium Compounds/administration & dosage , Rabbits , Radionuclide Imaging , Technetium , Technetium Tc 99m Aggregated Albumin , Technetium Tc 99m Diethyl-iminodiacetic AcidABSTRACT
The effect of iron on the liver function was studied in rats. A total of 40 rats were divided into four groups. Group 1 was given iron; Group 2, carbon tetrachloride; Group 3, a combination of iron and carbon tetrachloride; and Group 4 was the control. The changes in liver function were evaluated by using hepatobiliary and liver scintigraphy as the index of hepatocyte function and reticuloendothelial system function, respectively. Determination of liver CT number and a histological study were made at the same time. The administration of iron activated the reticuloendothelial system function per unit of liver weight. However, because of the decrease in liver weight, the total reticuloendothelial system function did not change at all. In the group given iron and carbon tetrachloride, liver cirrhosis and siderosis in the reticuloendothelial system occurred. Dysfunction in the reticuloendothelial system was more severe in this group than in the group given carbon tetrachloride only, by hepatocyte dysfunction was more mild. It is doubtful that the administration of iron after liver dysfunction had developed, which caused acceleration of fibrosis and reduction of liver blood flow, led to the enhancement of the reticuloendothelial system dysfunction.
