Right renal artery is visualized on color Doppler imaging: often part of the renal artery is visualized in one image. By angling the probe in various positions, it is possible to see part or whole of the renal artery. I find it more difficult to visualize the left renal artery than the right. But this can vary from patient to patient depending on viewing conditions, bowel gas and the acoustic window.
The right renal artery in spectral doppler tracing (above) shows normal waveform and the PSV (peak systolic velocity) is almost 60 cms./sec. at a doppler insonation angle of 42. The RI is= 0.6. The normal PSV of the renal artery is appx. 80 to 120 cms./second. It is considered abnormal if the PSV> 180 cms./second and renal artery stenosis is likely.
The segmental artery of the right kidney is studied in this spectral Doppler tracing (below). It shows an RI of 0.6 which is normal. Any RI of > 0.8 is highly suggestive of renal arterial stenosis.
The left renal artery also shows similar findings.
The spectral Doppler waveform of the left renal artery and left renal segmental arteries is also normal.