Radionuclide venography: Its place as a modality for the investigation of thromboembolic phenomena

The radionuclide venogram graphically depicts thrombotic disease and appears particularly helpful in the visualization of the external pelvic venous system, inferior vena cava, and veins of the thigh. Since the pulmonary scintigram also may be performed in conjunction with the radionuclide venogram, the patient also is screened for possible pulmonary emboli. The extent of thrombotic disease in the area imaged by radionuclide venography appears to be related to the incidence of pulmonary emboli. It is likely to image nonocclusive thrombi, those which are more likely to embolize. It provides information regarding the status of venus channels, varicose veins and venous insufficiency, in addition to the presence of thrombi. Several authors have shown a better than 90% correlation between the findings on radionuclide venography and those of the most widely accepted means of assessing thrombosis in leg veins, radiographic phlebography. The technique and clinical results of radionuclide venography as well as its advantages and disadvantages in comparison to radiographic phlebography are discussed here. A simplified, standardized method of performing radionuclide venography with a moving-table accessory is described and illustrated.