Evaluation of renal artery stenosis with dynamic gadolinium-enhanced MR angiography.

OBJECTIVE: The purpose of this study was to compare dynamic gadolinium-enhanced three-dimensional spoiled gradient-recalled MR angiography with conventional arteriography in the evaluation of proximal renal artery stenosis (RAS). MATERIALS AND METHODS: MR angiography and conventional arteriographic examinations of 30 patients evaluated for RAS were analyzed retrospectively. Three-dimensional MR angiography was performed with an RF spoiled gradient-recalled imaging sequence acquired during the dynamic i.v. injection of gadolinium (0.2-0.3 mmol/kg), MR data and conventional arteriograms were independently evaluated for the number and location of renal arteries and the degree and location of stenoses. The patients had a mean age of 70 years old and a mean serum creatinine level of 2.9 mg/dl, reflecting a population in whom atherosclerotic RAS was the primary concern. RESULTS: Gadolinium-enhanced MR angiography revealed 100% of main renal arteries. For RAS of 50% or greater occlusion, the technique was 100% sensitive and 71% specific; the negative predictive value was 100%. The technique was 100% sensitive and 71% specific for RAS of 75% or greater occlusion. CONCLUSION: Dynamic gadolinium-enhanced three-dimensional spoiled gradient-recalled MR angiography has a high sensitivity for revealing proximal RAS and is a quick and reliable technique for obtaining helpful anatomic information.