Renal artery stenosis: should we study the main renal artery or segmental vessels?

PURPOSE: To compare the sonographic diagnosis of renal artery stenosis (RAS) with Doppler interrogation of the main renal artery versus Doppler ultrasonography of segmental vessels. MATERIALS AND METHODS: The main renal artery-to-aortic peak systolic velocity ratio (RAR) and early systolic acceleration in segmental arteries were obtained in 186 patients. Conventional arteriographic correlation was available for 42 kidneys in 21 patients. Paired receiver operating characteristic (ROC) analyses were performed to evaluate RAR and minimum, average, and maximum early systolic acceleration in these 42 kidneys. RESULTS: Minimum early systolic acceleration was a better test than RAR (P = .05). Minimum early systolic acceleration plus RAR resulted in improved sensitivity for detection of RAS, but this improvement was not significant (P = .16). CONCLUSION: Minimum early systolic acceleration is the ultrasonographic method of choice to screen for RAS. RAR may provide marginal improvement in sensitivity but is probably not warranted in most clinical situations.