Renal artery stenosis: duplex Doppler evaluation.

The renal arteries of 40 patients without renal or renovascular disease were examined with duplex real-time Doppler sonography. Special views were employed to obtain adequate images and Doppler recordings from the renal arteries. Time limits were placed on the duration of the examination, the better to reflect common clinical practice. Velocity spectral analysis of the Doppler shift frequency was achieved in 82.5% of the arteries examined and a characteristic "Doppler signature" for the renal artery identified. This was compared with the Doppler signal from the renal arteries of eight patients with renal artery stenosis. Significant differences in spectral pattern were demonstrated in renal artery stenosis. These differences are illustrated and their potential for screening for renovascular disease in systemic hypertension is discussed.