Evaluation of portal circulation with radioisotopes in dogs.

The objective of the present study was to contribute to the development of a noninvasive method for the evaluation of portal circulation using rectally administered radiotracers in dogs. 99mTc absorption was previously checked in rabbits and the present study reports similar results in dogs. Circulation time between the terminal large bowel and the liver (RL-t) and heart (RH-t) was determined by external counting at the hepatic and cardiac level with a large-field computerized gamma camera. In 16 animals studied, average RL-t was 5.2 s and RH-t 8.6 s. In 3 animals with partial binding of the portal vein, RL-t increased to 32, 44 and 34 s. Being noninvasive and harmless, this method could be used to study portal circulation in several physiopathological conditions of the human liver.