Spiral CT angiography of renal arteries: comparison with angiography

A prospective study was carried out to determine the accuracy of spiral CT angiography (CTA) in the detection of renal artery stenosis (RAS). Eighty-t wo patients with arterial hypertension underwent CTA and digital subtractio n angiography (DSA) to exclude RAS. For CTA a contrast medium bolus of 100- 150 ml (flow rate 3 ml/s) was injected. A 24 or 40 s CTA was started at the origin of the superior mesenteric artery after a delay time determined by test bolus injection (collimation = 2 mm, - pitch = 1/1.5). For stenosis de tection transverse images supported by maximum intensity projections (MIP) or multiplanar reconstruction projections were used. Of 197 renal arteries examined (including 33 accessory arteries), 34 RAS were visualized using DS A. With CTA, one hemodynamic RAS was missed and one additional hemodynamic RAS was found. Sensitivity/specificity was calculated to be 94%/ 98%. For h emodynamically relevant RAS (> 50%) the sensitivity/specificity was 96%/99% . CTA additionally depicted five adrenal masses. The high accuracy rate of RES detection thus allows the use of CTA as a screening method in patients with arterial hypertension to exclude a renovascular cause.