Demonstration of venous thrombosis by computed tomography.

Thrombosis within the iliofemoral venous system was diagnosed by computed tomography (CT) in five patients. In three patients thrombosed veins were documented by venography and in all five cases, the presence of venous thrombosis was substantiated by the clinical findings. Venous thrombosis in the iliofemoral veins and inferior vena cava has a typical appearance on CT scans. A thrombosed vein appears dilated with a low density intraluminal content and a high density wall after contrast enhancement. By its anatomic location, a thrombosed vein can be differentiated from other tubular structures such as bowel loops or obstructed ureters which may have a similar appearance.