[Accuracy of CT angiography in the diagnosis of renal artery stenosis]

Spiral CT in the form of CT angiography (CTA) provides a new method for the investigation of the large vessels. 52 patients with suspected renovascular hypertension were examined by CTA and arterial DSA. The computer tomographic and angiographic findings in 124 renal arteries were compared. Sensitivity of CTA for demonstrating renal artery stenosis was 95\%, and for relevant stenoses it actually reached 100\%. Specificity was 92\%. Positive/negative prediction value was 85\% and 100\%. CTA proved outstandingly good for demonstrating or excluding renal artery stenosis and was superior to other imaging methods in several respects. CTA requires high contrast values, optimal timing and careful evaluation. Amongst various forms of image reconstruction, interactive viewing of the primary axial images and multiplanar reconstruction in a cine mode are essential and MIP projections are valuable.