Utility of intrarenal Doppler ultrasound in the diagnosis of renal artery stenosis

Purpose: To determine the utility of intrarenal Doppler parameters and wave form analysis in a hypertensive population screened for renal artery stenos is (RAS). Materials and methods: Sixty five patients were studied (122 kidn eys) with intrarenal. Doppler sonography. Doppler waveforms of three differ ent areas from each kidney were obtained (superior, middle and inferior lev el). Waveform morphology, acceleration time (AT), acceleration (Ac) and res istive index (RI) were evaluated in each kidney, comparing retrospectively the Doppler findings with the angiographic results. Results: Arteriography demonstrated 33 (27.2%) renal arteries with stenosis (18 with RAS > 75%). S tatistically significant differences for AT and Ac were found among the pat ients with RAS > 75% and the other groups (P < 0.01). An AT > 80 ms and an Ac less than or equal to 1 m/s(2) showed a sensitivity of 89% and a specifi city of 99%, for the diagnosis of RAS > 75%. Better results were obtained i n patients less than 50 years old (100% of sensitivity and specificity). Th e morphologic analysis of the Doppler waveform had poor results but the det ection of a waveform grade 0 had a high specificity (98%). An additional co mparison of both kidneys didn't improve the results. Conclusion: Intrarenal Doppler waveform analysis using quantitative measurements (AT and Ac) is a n adequate technique for the diagnosis of severe RAS in previously selected patients, especially in younger patients ( < 50 years). (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.