CT venography and CT angiography of the pulmonary arteries in acute pulmonary embolism

objectives: To determine the diagnostic value of CT venography after CT angiography of the pulmonary arteries using multislice helical CT in the diagnosis of acute pulmonary embolism. Methods: Between September 1999 and April 2001252 patients with clinically suspected pulmonary embolism were examined. CT angiography of the pulmonary arteries was followed by CT venography of the inferior vena cava, the iliac veins and the proximal femoral veins; after April 2000 the popliteal veins and the proximal lower leg veins were additionally investigated. The examinations were performed with a double detector and a multidetector scanner (Elscint Twin and GE Lightspeed). Results: Pulmonary embolism was found in 79/252 patients (40 central and 39 segmental/subsegmental PE). In 38/40 patients with central PE and in 22/39 patients with segmental/subsegmental PE in CT venography a deep venous thrombosis was detected, in 1/79 patient a doubled inferior vena cava could be found. In 5 patients with thrombosis of the inferior vena cava a transjugular cava filter placement was performed. In 13/173 patients without pulmonary embolism CT venography showed deep venous thrombosis. Conclusion: CT venography of the lower extremities is a practical and efficient additional examination to CT angiography in clinical suspected pulmonary embolism. It can detect the causing venous thrombosis with a high sensitivity.