Time-Resolved Contrast-Enhanced MR Angiography of Renal Artery Stenosis: Diagnostic Accuracy and Interobserver Variability

• Published in: American journal of roentgenology (1976) Vol. 174; no. 6; pp. 1583 - 1588
• Main Authors: Volk, Markus, Strotzer, Michael, Lenhart, Markus, Manke, Christoph, Nitz, Wolfgang R, Seitz, Johannes, Feuerbach, Stefan, Link, Johann
• Format: Journal Article
• Language: English
• Published: United States Am Roentgen Ray Soc 01-06-2000
• Subjects: Adult; Aged; Aged, 80 and over; Angiography, Digital Subtraction; Contrast Media; Female; Gadolinium DTPA; Humans; Magnetic Resonance Angiography; Male; Middle Aged; Observer Variation; Prospective Studies; Renal Artery - diagnostic imaging; Renal Artery - pathology; Renal Artery Obstruction - diagnosis; Renal Artery Obstruction - diagnostic imaging; Sensitivity and Specificity
• ISSN: 0361-803X; 1546-3141
• DOI: 10.2214/ajr.174.6.1741583

The purpose of this study was to evaluate diagnostic accuracy and interobserver variability of time-resolved three-dimensional gadolinium-enhanced MR angiography in the detection of renal artery stenosis in comparison with intraarterial digital subtraction angiography as the standard of reference.
Forty consecutive patients (age range, 25-81 years; mean, 62.9 +/- 11.9 years) with suspected renal artery stenosis underwent intraarterial digital subtraction angiography and gadolinium-enhanced MR angiography, performed on a 1.5-T system with fast low-angle shot three-dimensional imaging (3.8/1.49 [TR/TE], 25 degrees flip angle, 10-sec acquisition time, and 1.5-mm partition thickness). Three time-resolved phases were obtained in a single breath-hold. Digital subtraction angiography and gadolinium-enhanced MR angiography were evaluated by four observers who studied 80 main renal arteries and 19 accessory vessels to evaluate the degree of stenosis. A stenosis reducing the intraarterial diameter by more than 50% was regarded as hemodynamically significant. Interobserver variability was calculated.
Only one gadolinium-enhanced MR angiography study was not of diagnostic quality, as a result of failure of the power injector. All main branches were of diagnostic quality in 38 (97.4%) of the remaining 39 gadolinium-enhanced MR angiography studies. Seventeen (89.5%) of 19 accessory renal arteries were depicted with gadolinium-enhanced MR angiography. The overall sensitivity for significant stenoses was 92.9%. The overall specificity was 83.4%, and the overall accuracy was 85.9%. Interobserver variability of gadolinium-enhanced MR angiography exceeded that of digital subtraction angiography.
Time-resolved three-dimensional gadolinium-enhanced MR angiography is a useful noninvasive method of screening suspected renal artery stenosis because of its easy application, short examination time, and high sensitivity despite of its higher interobserver variability.