Diagnosis of Deep Vein Thrombosis with ⁹⁹Tc^m‐Plasmin

The diagnostic efficiency of 99Tcm-plasmin test was evaluated by X-ray contrast phlebography in 110 consecutive patients with suspected deep vein thrombosis (DVT). The test was positive in 50 of 55 patients with DVT (sensitivity 91%) and negative in 18 of 55 without DVT (specificity 33%). The positive plasmin test in patients without DVT was in most cases due to another inflammatory process or a post-thrombotic state. The 99Tcm-plasmin test is a rapid and sensitive screening method for th diagnosis of DVT, but as it is based on comparison between the legs, it may be unreliable in cases of bilateral thrombosis. The low specificity makes it less valuable in patients with concomitant inflammatory disease or previous thrombosis in either leg. When the plasmin test is positive, the diagnosis of DVT should in most cases be confirmed by X-ray contrast phlebography.