Comparison between 99Tcm-porcine plasmin and 99Tcm-labelled erythrocytes in diagnosis of deep vein thrombosis.

In 20 patients with suspect deep venous thrombosis (DVT), scintillation detector measurements were performed over each leg during the first 60 min after intravenous injection of 99Tcm-porcine plasmin. Thereafter, 99Tcm-labelled autologous erythrocytes were injected i.v. and repeat measurements were performed. Finally, scintillation camera images of both legs were obtained. Phlebography was used as a reference method. A close relationship (P less than 0.01) was found between the scintillation detector measurements, both in patients with DVT (n = 11) and in patients without DVT (n = 9). Thus, 99Tcm-plasmin is not specifically bound to the thrombus. Rather the clinical utility of the test depends mainly on circulatory changes secondary to the thrombus. Scintillation camera images of 99Tcm-erythrocytes in the legs were not useful for diagnosis of DVT in the calves but showed a high specificity for DVT in the popliteal and femoral veins.