Rationale and Objectives. The authors compared Doppler ultrasound (US)
with computed tomographic (CT) angiography in the evaluation of steno
sis of the main renal artery. Materials and Methods. Fifty-six patient
s who had undergone conventional angiography of the renal arteries par
ticipated in a prospective comparison of Doppler us (45 patients) and
CT angiography (52 patients). US evaluation included both the main ren
al artery and segmental renal arteries. Results. There were 27 main re
nal arteries with a least 50% stenosis in 20 patients. In 36 patients,
there was no significant stenosis. All cases of main renal artery ste
nosis detected with Doppler US of the segmental arteries were also ide
ntified with Doppler US of the main renal artery. The by-artery sensit
ivity (63%) of US of the main renal artery was greater than that (33%)
of US of the segmental arteries. CT angiography was more sensitive (9
6%) than Doppler US (63%) in the detection of stenosis, but the specif
icity of CT (88%) was similar to that of US (89%). The difference in t
he area under the receiver operating characteristic curve (AUC) betwee
n CT (AUC 0.94) and US (AUC = 0.82) was statistically significant (P =
.038). Conclusion. Doppler US of the main renal artery is more sensit
ive than Doppler US of segmental arteries in the detection of stenosis
. CT angiography is more accurate than Doppler US in the evaluation of
renal artery stenosis.