Diagnosis of deep venous thrombosis with 99mTc plasmin using the gamma camera

The 99mTc-plasmin-uptake test is a screening test for deep vein thrombosis with a reported sensitivity of 91%-100% and a rather low specificity of 33%-51%. In trying to improve the qualities we used gamma camera imaging and compared the results with those of the standard probe techniques and X-ray venography. In 34 patients, 23 thromboses were detected by venography. The probe technique had a sensitivity of only 75% and the gamma camera technique 100%. The specificity of both techniques was about the same (36% and 50%). A diffuse rather than focal accumulation of radioactivity was seen by the gamma camera technique, indicating that the plasmin test is not based on the detection of hot spots.