Ability of a phase shift US contrast agent to improve imaging of the main renal arteries.
OBJECTIVE
To evaluate the ability of a phase shift contrast agent to improve Doppler sonographic imaging of the main renal arteries in cases of suspected renal artery stenosis.


METHODS
In 25 patients in whom renal artery stenosis was suspected, baseline Doppler sonography was performed followed by two studies performed after blinded administration of contrast material or placebo (saline). Each kidney (n = 45) was evaluated for (a) visualization of the main renal artery on a scale of 0-4, (b) presence of accessory renal arteries, and (c) direct Doppler sonographic findings suggestive of renal artery stenosis. Correlative magnetic resonance angiography was performed in 24 patients, and angiograms were obtained in eight kidneys with stenosis at one or both imaging studies.


RESULTS
Contrast enhancement was observed in 23 patients. Enhancement was 8-20 minutes. Renal artery visualization scores improved from a mean of 2.56 and 2.71 on baseline and noncontrast scans, respectively, to 3.69 after administration of contrast material. Contrast-enhanced images depicted seven kidneys with accessory renal arteries not seen at other studies. Two of eight cases of stenosis were seen only with contrast-enhanced sonography.


CONCLUSIONS
Use of the phase shift contrast agent appears to enable a reduction in the number of equivocal findings of renal artery stenosis.
Melany
M L
ML
Department of Radiological Sciences, University of California Los Angeles, USA.
Grant
E G
EG
Duerinckx
A J
AJ
Watts
T M
TM
Levine
B S
BS
D000328:Adult; D000368:Aged; D003287:Contrast Media; D005466:Fluorocarbons; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D012077:Renal Artery / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000473:pathology; D012078:Renal Artery Obstruction / Q000175:diagnosis / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler; D010420:Pentanes
D003287:Contrast Media; D005466:Fluorocarbons; C008806:perfluoropentane; D010420:Pentanes