ABSTRACT
Venography became a significant part of the diagnostic armamentarium in the 1970s, and enabled clinicians to diagnose deep vein thrombosis (DVT) reliably, without the need to base the diagnosis entirely on clinical findings, since they are poor and imperfect ways of identifying often deadly conditions. Direct venography requires the infusion of contrast into a peripheral vein, and relies on preferential flow of the contrast medium towards the heart. Ascending venography, as the name implies, is based on contrast flow in the bloodstream that is upward or central in the direction of the heart along pressure gradients. Diagnosis of DVT was the main indication for ascending venography until ultrasound took its place. In many cases, acute DVT causes occlusion of the vein, which will then be seen on the venography as an abrupt termination of the contrast-filled vein. However, direct contrast venography still has a place in the evaluation of the patient with complex venous abnormalities.
