Intrarenal Doppler findings of upstream renal artery stenosis: a preliminary report.

To diagnose 60% or greater diameter-reducing stenosis of the renal artery (RAS), color Doppler imaging (CDI) and angiography were performed on 44 hypertensive and 16 normotensive cases. In this prospective, double-blind study we evaluated the related intrarenal waveform changes. In both the right and left kidneys of normotensive cases, at the level of interlobar arteries, the results indicated a symmetric finding in peak systolic/end diastolic velocities (S/D), pulsatility index (PI) and resistive index (RI) ratios. The results in the stenotic kidneys among the hypertensive group indicated that index values were significantly lower in the stenotic kidneys than those of the contralateral kidneys, the kidneys of control and nonstenotic hypertensive cases. To quantify this observation we suggest "perfusion indexes," which require more studies on a greater number of hypertensive cases. It was concluded that measuring the index values of intrarenal arterial waveforms is easier and more accessible in diagnosing RAS than obtaining those of the main renal artery.