Deep vein thrombosis of lower extremities. Diagnosis by real time ultrasonography.

In 150 patients with possible deep venous thrombosis in the lower extremities, the diagnostic accuracy of real time ultrasonography (US) with 3.5, 5.0 or 7.5 MHz transducers was assessed using venography as standard. In the area of the common femoral/popliteal vein, US was correct in 147 patients, giving an accuracy of 98 percent. There were no false negative studies, giving a sensitivity of 100 percent (60/60) and three false positive studies, giving a specificity of 97 percent (87/90). The results were almost the same using all the three frequencies. The simplicity and accuracy of US make it a useful diagnostic tool.