[Diagnosis of deep venous thrombosis of the lower limbs by computed tomography]

In the CT scan of a patient with knee tumor and deep vein thrombosis confirmed by phlebography, the casual observation of a thrombus image in the vein was made, characterized by wall contrastation in opposition to a lack of luminar contrastation. Then, CT scans of the lower limbs and the pelvic region were performed in 14 patients with suspected DVT, who were followed consecutively. Diagnosis of ruptured Baker cyst was made in one patient and DVT in 13 patients. DVT was demonstrated in both lower limbs of three patients. Diagnosis of DVT was confirmed in six of seven exams involving the legs. CT scan could detect thrombi in muscular veins and in deep femoral and internal iliac veins. In six patients with suspected pulmonary embolism, CT scan was also made of the thoracic region and showed pleuropulmonary involvement concomitant with lower limb DVT. The characteristic image of DVT in CT is that of a contrasted ring. Its brightness may be due to contrastation of the venous wall through its vasa vasorum, whereas the thrombus obstructs the luminar flow of the contrast medium. Reproducibility of the characteristic image of thrombus presence in the vein at different levels of the lower limbs and pelvic region gives CT the status of alternative diagnosis means for DVT. False negatives and false positives should be evaluated.