[Color-coded duplex ultrasonography in the diagnosis of renal artery stenosis].

To diagnose possible renal artery stenosis in 120 patients (36 women, 84 men; mean age 57.3 [21-84] years) colour duplex sonography (CDS) of the renal arterial tree was performed before 53 intraarterial angiographies and 67 central venous digital subtraction angiographies. The criterion of stenosis was a maximal flow velocity of > 180 cm/s in the colour duplex sonogram and a diameter reduction of > 50% in the angiogram. CDS demonstrated the renal artery bed in 209 of 247 renal arteries (85%). 84 of the 209 had regional maximal velocities of > 180 cm/s. The sensitivity and specificity of CDS when comparing it with both angiographic methods (in 185 cases that could be evaluated, in 74 of them with abnormal results) were 91 and 88.2%, respectively. Comparing CDS results with those by intraarterial angiography alone (88 cases, with 51 abnormal findings), sensitivity and specificity were 92.1 and 91.8%, respectively. These results demonstrate that CDS can reliably demonstrate flow obstructions in the renal arterial tree and can thus be recommended for the diagnosis of renovascular hypertension.