Deep venous thrombosis with suspected pulmonary embolism: Detection with combined CT venography and pulmonary angiography

PURPOSE: To determine the frequency and location of deep venous thrombosis at computed tomographic (CT) venography after CT pulmonary angiography in a large series of patients clinically suspected of having pulmonary embolism and to compare the accuracy of CT venography with lower-extremity venous s onography. MATERIALS AND METHODS: Venous phase images were acquired from the diaphragm to the upper carves after completion of CT pulmonary angiography in 650 pa tients (373 women, 277 men; age range, 18-99 years; mean age, 63 years) to determine the presence and location of deep venous thrombosis, Results of C T venography were compared with those of bilateral lower-extremity venous s onography in 308 patients. RESULTS: A total of 116 patients had pulmonary embolism and/or deep venous thrombosis, including 27 patients with pulmonary embolism alone, 31 patient s with deep venous thrombosis alone, and 58 patients with both. Among 89 pa tients with deep venous thrombosis, thrombosis was bilateral in 26, involve d the abdominal or pelvic veins in 11, and was isolated to the abdominal or pelvic veins in four. In patients in whom sonographic correlation was avai lable, CT venography had a Sensitivity of 97% and a specificity of 100% for femoropopliteal deep venous thrombosis. CONCLUSION: Combined CT venography and pulmonary angiography can accurately depict the femoropopliteal deep veins, permitting concurrent testing for v enous thrombosis and pulmonary embolism. CT venography also defines pelvic or abdominal thrombus, which was seen in 17% of patients with deep venous t hrombosis.