[Non-invasive methods for vascular studies in the diagnosis of deep venous thrombosis]. / Les méthodes non vulnérantes d'exploration vasculaire pour le diagnostic de la thrombose veineuse profonde.

The sonographic diagnosis of deep venous thrombosis must be made up of a functional continuous wave Doppler study of the whole deep venous system of the limbs, including leg veins, as well as saphenous veins. Then, high resolution B-mode real time sonography is used for the detection of direct (echogenic thrombus) or indirect (incompressible vein) signs of thrombosis. This noninvasive approach offers a good sensitivity (about 96%) and a high level of specificity (about 98%). Moreover, B-mode sonography can ensure the differential diagnosis (hematoma, extrinsic compression...) in most cases. So, X-Ray venography is required only when an interventional therapy is planned (thrombectomy, fibrinolysis, inferior vena cava interruption...), or when the noninvasive techniques are not able to show the upper limit of the thrombosis (especially for iliac veins or inferior vena cava), or when there is still a doubt about deep venous thrombosis. Therefore, the number of X Ray venographies can be consistently reduced, thus decreasing both cost and risks.

Real-time B-mode ultrasonography for better specificity in the noninvasive diagnosis of deep venous thrombosis.

In order to evaluate the usefulness of B-mode ultrasonography in the diagnosis of deep vein thrombosis, a prospective study was performed on 145 patients. Each patient was examined with occlusive venous plethysmography, continuous wave Doppler, real-time B-mode ultrasonography, and radiographic contrast phlebography. The diagnostic sensitivity and specificity versus phlebography were 91 and 82.1 per cent, respectively, for plethysmography, 92 and 86.6 per cent for Doppler, and 94 and 100 per cent for B-mode sonographic scanning. The combined noninvasive approach reached a 96 per cent sensitivity. B-mode ultrasonography demonstrated a mass in eight cases, and showed a superficial venous thrombosis in four cases, among the 45 patients without deep vein thrombosis. B-mode ultrasonography, therefore, appears to be very useful in obtaining a better specificity and differential diagnosis.