Renal arterial stenosis: Prospective comparison of color Doppler US and breath-hold, three-dimensional, dynamic, gadolinium-enhanced MR angiography

PURPOSE: To compare color Doppler ultrasonography (US) with fast, breath-ho ld, three-dimensional, gadolinium-enhanced magnetic resonance (MR) angiogra phy in detecting renal arterial stenosis. MATERIALS AND METHODS: Forty-five patients with clinical suspicion of renov ascular disease were prospectively examined with intra- and extrarenal colo r Doppler US and breath-hold, gadolinium-enhanced MR angiography. Digital s ubtraction arteriography (DSA) was the standard of reference in all patient s for the number of renal arteries and degree of stenosis. RESULTS: DSA depicted 103 arteries and 52 stenoses. Color Doppler US was no ndiagnostic in two examinations. Significantly more of 13 accessory renal a rteries were detected with MR angiography (n = 12) than with color Doppler US (n = 3; P < .05). For assessing all stenoses, the sensitivity and accura cy were 94% and 91%, respectively, for MR angiography and 71% and 76%, resp ectively, for US (P < .05). The sensitivity was higher for MR angiography ( 100%) than for US (79%; P < .05) in diagnosing stenoses with at least 50% n arrowing. The specificity, accuracy, and negative predictive value in diagn osing stenoses of at least 50% narrowing were 93%, 95%, and 100% for ME ang iography and 93%, 89%, and 90% for US. CONCLUSION: Breath-hold, gadolinium-enhanced MR angiography is superior to color Doppler US in accessory renal artery detection. Although the specific ity of MR angiography is similar to that of color Doppler US, MR angiograph y has a better sensitivity and negative predictive value in depicting renal arterial stenoses.