Assessment of Renal Artery Stenosis: Comparison of Captopril Renography and Gadolinium-Enhanced Breath-Hold MR Angiography

• Published in: Clinical radiology 2000-05, Vol.55 (5), p.346-352
• Main Authors: BONGERS, V., BAKKER, J., BEUTLER, J.J., BEEK, F.J.A., DE KLERK, J.M.H.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Angiography, Digital Subtraction; Angiotensin-Converting Enzyme Inhibitors; Biological and medical sciences; Captopril; Contrast Media; Female; Gadolinium DTPA; Humans; Magnetic Resonance Angiography; Male; Medical sciences; Middle Aged; Nephrology. Urinary tract diseases; Nephropathies. Renovascular diseases. Renal failure; Radionuclide Imaging; Renal Artery Obstruction - diagnosis; Renal Artery Obstruction - diagnostic imaging; renal artery, stenosis, magnetic resonance imaging, radionuclide imaging, renal angiography; Renovascular diseases; Sensitivity and Specificity
• ISSN: 0009-9260; 1365-229X
• DOI: 10.1053/crad.2000.0435

AIM: To determine the accuracy of captopril renography (CR) and gadolinium-enhanced breath-hold magnetic resonance (MR) angiography in the diagnosis of 50–99% renal artery stenosis (RAS). MATERIALS AND METHODS: Forty-three patients with possible RAS, of whom 53% had renal function impairment (creatinine >130μmol/l), were included.99mTc-mercaptoacetyl triglycine (MAG3) renography was performed after an oral dose of 25mg captopril. Gadolinium-enhanced MR angiography was performed on a standard 1.5 Tesla system: TR 13.5, TE 3.5, flip angle 60°, matrix 195×512. Intra-arterial digital subtraction angiography (DSA) was the standard of reference. RESULTS: Captropril renography accurately categorized 22 of 26 patients who had either uni- or bilateral RAS of 50–99%. The sensitivity and specificity of CR for the detection of 50–99% stenosis were 85 and 71%, respectively. With MR angiography one occluded artery was incorrectly diagnosed as a stenosis. Sensitivity and specificity were 100 and 94%, respectively. The difference between the accuracies of MR angiography and CR was statistically significant (P=0.02). The accuracy of CR was lower in patients with renal impairment (70%) than in those with normal renal function (90%). CONCLUSION: MR angiography showed a high accuracy in diagnosing RAS of between 50 and 99%. CR was less accurate than MR angiography, especially in patients with renal function impairment. In patients with normal renal function, however, CR remains a useful diagnostic test.Bongers, V. (2000). Clinical Radiology55, 346–352.