Doppler ultrasonic screening prior to venography for deep venous thrombosis.

A total of 244 patients were examined using both ultrasonic Doppler technique and conventional venography for deep venous thrombosis. The Doppler examination was 93.8% accurate overall in detecting the condition, with a specificity of 96% and sensitivity of 85.7%. Indications for venography after Doppler evaluation include: (1) a positive or equivocal Doppler examination; and (2) critically ill patients with negative Doppler results where absolute diagnostic accuracy is essential. Had these criteria been followed in this study, 174 normal examinations would have been avoided and only six large vein thrombi (ileofemoral or popliteal) in 244 examinations would have been misdiagnosed.