Intra‐renal Doppler wave‐form analysis as a screening test for renal artery stenosis

A double-blinded trial was performed comparing Doppler interrogation of intra-renal arteries with findings at renal angiography in the assessment of renal artery stenosis. Fifty-three consecutive patients were studied. Previously reported parameters and cut-off values were used for predicting the presence of renal artery stenosis with Doppler. Doppler wave-form analysis proved relatively specific (91%) but insensitive (68%) to the presence of renal artery stenosis (of greater than 60%) if acceleration parameters were used alone. The technique of using a difference in mean resistive indices was found to be both insensitive (61%) and non-specific (54%). Patients with fibromuscular dysplasia, branch vessel stenoses, multiple renal arteries and chronic renal impairment proved to cause the most false negatives. Young patients with normal arteries were the source of the few false positive results. The interrogation of intra-renal arteries does not have appropriate sensitivity to be useful as a screening test for renal artery stenosis.