A gamma camera method for the evaluation of deep-vein thrombosis in the leg. Application of 99mTc-labelled heparin.

99mTc-labelled heparin was used to examine acute deep-vein thrombosis in the leg. 99mTc-heparin (4 mCi) was injected into a dorsal foot vein. Rapid-sequence scintiphotos were taken of the lower legs and thighs. One hour after the injection, images were taken to reveal possible late accumulation of 99mTc-heparin in the thrombi. The venous outflow was assessed by a strain gauge technique. X-ray phlebography was performed on the same or the subsequent day. All patients having an abnormal X-ray phlebography also had an abnormal isotope phlebography. Acute deep-vein thrombosis in the leg can be diagnosed reliably with the combined method of 99mTc-heparin scintigraphy and measurement of venous outflow. Late accumulation of 99mTc-heparin in thrombi of the deep veins was seen in 6 of 12 patients with acute thrombosis. Patients with chronic changes were difficult to evaluate, since the resolution of the scintillation camera does not allow detection of minor changes.