Preliminary experience of contrast-enhanced ultrasound with high mechanical index in the diagnosis of renal artery stenosis

Abstract

Objective To evaluate the value of contrast-enhanced ultrasound (CEUS) with high mechanical index(MI) in the diagnosis of renal artery stenosis(RAS). Methods Twenty-one patients with RAS including 3 patients after renal transplantation were studied. Ultrasound contrast agent SonoVue was used and MI was set at about 1 when the CEUS was performed. All patients were examined with conventional color Doppler sonography and CEUS. The diagnostic results of ultrasound were compared with those of intravenous digital subtraction angiography ( DSA), CT angiography(CTA) and MR angiography (MRA). Results The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of conventional color Doppler sonography were 85. 7%, 57. 1 % , 80. 0% , 66. 7% and 76. 2%, respectively, those of CEUS were 100%, 66.7%, 88.2%, 100% and 90.5%, respectively. Conclusions CEUS with high MI which improves the imaging of renal artery depicts the margin of the vascular lumen directly and clearly. It may be more helpful in the diagnosis of RAS. Key words: Ultrasonography; Microbubbles; Renal artery stenosis