Color-coded duplex sonography for noninvasive diagnosis and grading of renal artery stenosis.

The accuracy of color-coded duplex sonography (CCDS) in screening hypertensive patients for renal artery stenosis (RAS) was assessed using a semi-quantitative waveform analysis. Our special aims were to separate between moderate and high grade stenoses and to evaluate the accuracy of the method in imaging both the whole course of the renal arteries and accessory renal arteries. Included in the prospective, angiographically controlled study were 135 consecutive patients with 268 renal arteries, of which 195 arteries (73%) could be visualized both proximally and distally by CCDS. Only three of 15 accessory renal arteries could be identified by CCDS. In 42 RAS > or = 50% sensitivity of CCDS was 93%, specificity 92%, and overall accuracy 92%. The sensitivity in identifying RAS > or = 75% was 92%, and none of the high grade stenoses were missed. Because of difficulties in visualizing the middle portion of the renal artery, we carefully examined this part of the artery in 116 additional patients. Whereas the proximal and the distal parts could be visualized in 77% of the renal arteries, signals from the middle third could be derived only in 60% on the right, and in 39% on the left side. Provided that the renal arteries were visualized both proximally and distally, a hemodynamically effective RAS could be excluded with high probability. Moreover, exact grading of high-grade stenoses was possible in all cases but one. An advantage of CCDS over conventional duplex sonography appears to be the time-saving examination. Since a low prevalence of RAS impairs the positive predictive value of CCDS, the examination should be reserved for patients with a strong clinical suspicion of renovascular hypertension.

[Color-coded duplex sonography of liver tumors. Does the blood supply permit a conclusion on staging?]. / Farbkodierte Duplexsonographie von Lebertumoren. Erlaubt die Blutversorgung eine Aussage zur Dignität?

Real-time ultrasonography is a sensitive screening method in patients with suspected liver tumors. However, sonomorphology does not differentiate between benign and malignant tumors. In a prospective study we examined patients with liver tumors with color-coded duplex ultrasonography to find out whether the perfusion status of the liver tumor permits a differential diagnosis. A total of 108 patients with liver tumors were included, and the results of color-coded duplex sonography were compared with histology, MRI and CT. No correlation was seen between the final diagnosis and the perfusion pattern. The vascular status visualized by color-coded duplex ultrasonography does not permit differentiation between benign and malignant liver tumors.

[Diagnosis of deep venous thrombosis of the leg using color-coded duplex sonography]. / Diagnostik der tiefen Beinvenenthrombose mit der farbkodierten Duplexsonographie.

One hundred and twenty-nine lower limbs in 103 patients with suspected deep leg vein or pelvic vein thrombosis were examined by colour-coded duplex sonography and the results compared with phlebography. The deep veins could be demonstrated from the popliteal to the distal external iliac vein and internal structure and blood-flow could be evaluated. The procedure can diagnose not only occluding thrombus, but also thrombus with surrounding blood flow and post-thrombotic changes. Fresh venous thromboses can be recognised with a sensitivity of 96% and a specificity of 97%. Colour-coded duplex sonography is a simple, rapid and reliable method in all patients with suspected deep vein thrombosis. Our experience suggests that it can replace phlebography for the above-mentioned venous territories and problems.