The choice of test for diagnosis of venous thrombosis.

Doppler ultrasound is the preferred screening test in asymptomatic patients with high risk for venous thrombosis. Radiographic phlebography leads to definitive diagnosis in most instances. Radionuclide angiography using 99mTc MAA with delayed images to detect particle entrapment in venous blood clots can be used when radiographic phlebography is contraindicated or impractical. To detect active thrombosis in patients with past venous disease, the serial fibrinogen uptake test is the method of choice. This method is also used to monitor the efficacy of anticoagulation therapy and to detect propagating thrombosis in patients failing to respond to anticoagulation, hopefully before massive lethal pulmonary embolism occurs. Radionuclide methods are contraindicated in pregnant women and children where non invasive methods are preferred. No completely satisfactory test exists for detection of hypogastric vein thrombosis. Among the methods currently being evaluated in the laboratory the ultrasound B-scan imaging, 99mTc MAA uptake test and 99mTc mAA venous scan offer the best possibilities for successful clinical application.