Renal artery stenosis: detection and quantification with spiral CT angiography versus optimized digital subtraction angiography.

Abstract

To compare spiral computed tomographic (CT) angiography with optimized digital subtraction angiography (DSA) for accurate detection and quantification of renal artery stenosis. In 71 consecutive patients with possible renovascular hypertension, spiral CT angiography was performed of the renal arteries before DSA. Optimized DSA (performed with projection angles calculated from axial spiral CT source images) was used as the standard. Two independent observers evaluated spinal CT angiograms for the presence and grade of renal artery stenosis. Sensitivity, specificity, and interobserver variability were calculated. With spiral CT angiography, all 166 renal arteries and accessory arteries were identified correctly by both reviewers. Overall sensitivity and specificity for assessment of stenoses of grade 0 (none), grade 1 (1%-49%), grade 2 (51%-99%), and grade 3 (occlusion) were 97% and 100%, 92% and 98%, 96% and 96%, and 100% and 100%, respectively. Agreement was strong between spiral CT angiographic and DSA findings in assessment of all grades of stenosis (kappa coefficient, 0.9 and 0.9, respectively) for the two observers. Spiral CT angiography enabled accurate assessment of renal artery stenosis in patients with possible renovascular hypertension and may assist in selecting patients for interventional treatment.