Study of99Tcm-Annexin V Distribution in Inferior Vena Cava Thrombus Models of Rabbits

To study⁹⁹Tc^m-Annexin V distribution in inferior vena cava thrombus models of rabbits and uptake of⁹⁹Tc^m-Annexin V in fresh and old venous thrombus. Rabbits(n=15) were randomly grouped into 3 groups(the fresh thrombus group，old thrombus group，and control group). The rabbits of two thrombus groups developed inferior vena cava thrombus models by operations. The control group received sham operation. The fresh thrombus group and control group rabbits were injected⁹⁹Tc^m-Annexin V after operating 1d; the old thrombus group 14 d. After 1 h all rabbits were killed by injecting overdose pentobarbital sodium. The thrombus (or the inferior vena cava about 3cm below inferior pole of right kidney level in the control group rabbits)，blood，thrombus area inferior vena cava，head lateral inferior vena cava (except the control group)，thigh muscle，stomach，myocardium，pulmonary，liver，kidney，spleen，bone and small intestine were obtained from all group rabbits. The ex tissue and blood were weighed and measured by a Well-type detector. The percentage of the injected dose per gram of ex tissue (or blood) was calculated by the above data. The thrombus to blood，thrombus area inferior vena cava，head lateral inferior vena cava and thigh muscle ratios were calculated by percentage of the injected dose per gram of ex tissue (or blood) . The test was used to compare the fresh thrombus group and old thrombus group by SPSS 17.0. The percentage of the injected dose per gram of thrombi（0.018 94±0.002 16%ID/g）in the fresh thrombus group was higher than the old thrombus group (0.004 73±0.001 28%ID/g), P<0.05. The thrombus to blood，thrombus area inferior vena cava，head lateral inferior vena cava and muscle ratios (3.42±1.06，26.32±13.60，31.23±16.00，111.62±52.23) in the fresh thrombus group were higher than the old thrombus group(0.98±0.09，5.12±2.01，6.25±2.38，21.82±5.93) ,P<0.05 for all. All the thrombi of the fresh thrombus group were confirmed fresh mixed thrombi by Hematoxylin-eosin stains. All the thrombi of the old thrombus group were confirmed old mixed organized thrombi by Hematoxylin-eosin stains. ⁹⁹Tc^m-Annexin V may be used to venous thrombus imaging and discriminate fresh venous thrombus from old one by imaging.