Renal artery stenosis and accessory renal arteries: accuracy of detection and visualization with gadolinium-enhanced breath-hold MR angiography.

Abstract

To determine the accuracy of gadolinium-enhanced breath-hold magnetic resonance (MR) angiography in the diagnosis of renal artery stenosis and visualization of accessory renal arteries. Forty-four patients suspected of having renal artery stenosis and 10 potential kidney donors, all of whom were scheduled to undergo elective intraarterial digital subtraction angiography (DSA), were studied. Three-dimensional gradient-echo gadolinium-enhanced MR angiography was performed at 1.5 T with the following parameters: repetition time, 13.5 msec; echo time, 3.5 msec; flip angle, 60 degrees; 195 x 512 matrix; 400-mm field of view; and 6-cm imaging volume consisting of 15 4-mm-thick partitions reconstructed every 2 mm. Gadopentetate dimeglumine (30 mL) was injected with a power injector. MR angiograms were assessed before the standard of reference, intraarterial DSA, was performed. Four MR angiograms were not evaluable because of poor image quality. MR angiography enabled visualization of all but one of the 121 arteries. In four small accessory arteries, a stenosis could not be excluded owing to inadequate spatial resolution. MR angiography enabled the correct diagnosis in 30 of the 31 arteries with a grade 2 (50%-99%) stenosis and in seven of the 10 occluded arteries. Sensitivity and specificity for correct identification of a grade 2 stenosis were 97% and 92%, respectively. Gadolinium-enhanced MR angiography is an accurate, minimally invasive method for detecting renal artery stenosis and is reliable for visualizing accessory renal arteries.