An experimental study of deep-vein thrombosis using 99mTc-fibrinogen.

The in vivo and in vitro behavior of 99mTc-fibrinogen was investigated in rats, as well as the relationship between its incorporation into thrombi and gamma imaging in deep-vein thrombosis. 99mTc-Fibrinogen manifested satisfactory physicochemical and biological properties, and its in vivo stability was demonstrated by a high ability to clot in the circulating blood. High ratios of thrombus-to-blood were found between 4 and 24 h after the injection of this agent in 30-min thrombi. Among 30-min to 7-day thrombi, the highest ratio was found in 1-day thrombi and the lowest in 7-day thrombi. Hot spots on the scan were clearly visualized in fresh thrombi. It is concluded that 99mTc-fibrinogen is a very useful and promising scanning agent for the diagnosis of active thrombosis.