Diagnosis of renal artery stenosis by spiral computed tomography angiography (CTA)

Background and objective: Computed tomographic angiography (CTA) is a new i maging technique for assessing obstructive vessel disease. Aim of the prese nt study was to evaluate the sensitvity and specifity of CTA in patients wi th suspected renal artery stenosis as compared to digital-subtraction-angio graphy (DSA), the current gold standard in the diagnosis of renal vascular hypertension. Methods: CTA and DSA were performed in 29 patients with arter ial hypertension and suspected renal artery stenosis. The predictive value of CTA was evaluated with regard to vessel anatomy, existence of stenosis a nd grade of luminal narrowing. Stenoses were quantified using a four point scoring system: Score 0: no detectable stenosis, score I: < 50% diameter st enosis, score II: greater than or equal to 50% diameter stenosis, score III : total vessel obstruction. CTA-images were compared to results obtained by DSA. Results: In 29 patients 71 renal arteries were examined in DSA-techni que. In 47 arteries score 0, in 10 arteries score I, in 13 arteries score I I and in 1 artery score III were found. The same number of vessels could be reliably assessed with CTA. In this imaging technique 40 arteries were cla ssified as score 0, 15 arteries as score I, 15 arteries as score II and I a rtery as score III. Comparing CTA with results obtained by DSA showed a 100 % sensitivity and 85% specifity of CTA imaging technique. Conclusion: CTA i s a sensible and safe diagnostic approach for exclusion of a significant re nal artery stenosis.