Renal artery stenosis evaluation: Diagnostic performance of gadobenate dimeglumine-enhanced MR angiography - Comparison with DSA

Purpose: To prospectively determine diagnostic performance and safety of contrast material-enhanced (CE) magnetic resonance (MR) angiography with 0.1 mmol per kilogram of body weight gadobenate dimeglumine for depiction of significant steno-occlusive disease ( >= 51% stenosis) of renal arteries, with digital subtraction angiography ( DSA) as reference standard. Materials and Methods: This multicenter study was approved by local institutional review boards; all patients provided written informed consent. Patient enrollment and examination at centers in the United States complied with HIPAA. Two hundred ninety-three patients ( 154 men, 139 women; mean age, 61.0 years) with severe hypertension ( 82.2%), progressive renal failure ( 11.3%), and suspected renal artery stenosis ( 6.5%) underwent CE MR angiography with three-dimensional spoiled gradient-echo sequences after administration of 0.1 mmol/kg gadobenate dimeglumine at 2 mL/sec. Anteroposterior and oblique DSA was performed in 268 ( 91.5%) patients. Three independent blinded reviewers evaluated CE MR angiographic images. Sensitivity, specificity, and accuracy of CE MR angiography for detection of significant steno-occlusive disease ( >= 51% vessel lumen narrowing) were determined at segment ( main renal artery) and patient levels. Positive and negative predictive values and positive and negative likelihood ratios were determined. Interobserver agreement was analyzed with generalized kappa statistics. A safety evaluation ( clinical examination, electrocardiogram, blood and urine analysis, monitoring for adverse events) was performed. Results: Of 268 patients, 178 who were evaluated with MR angiography and DSA had significant steno-occlusive disease of renal arteries at DSA. Sensitivity, specificity, and accuracy of CE MR angiography for detection of 51% or greater stenosis or occlusion were 60.1%-84.1%, 89.4%-94.7%, and 80.4%-86.9%, respectively, at segment level. Similar values were obtained for predictive values and for patient-level analyses. Few CE MR angiographic examinations (1.9%-2.8%) were technically inadequate. Interobserver agreement for detection of significant steno-occlusive disease was good ( 79.9% agreement; kappa = 0.69). No safety concerns were noted. Conclusion: CE MR angiography performed with 0.1 mmol/kg gadobenate dimeglumine, compared with DSA, is safe and provides good sensitivity, specificity, and accuracy for detection of significant renal artery steno-occlusive disease. (C) RSNA, 2008.