Contrast-enhanced ultrasound at high mechanical index: a new method for transjugular intrahepatic portosystemic shunt follow-up.

ABSTRACT

AIM: To evaluate the diagnostic value of contrast-enhanced ultrasound (CEUS) at high mechanical index (MI) for transjugular intrahepatic portosystemic shunt (TIPS) follow-up. MATERIALS AND METHODS: Fifty patients with a suspected diagnosis of shunt dysfunction were enrolled in the present study. The patients were divided into three groups colour Doppler flow imaging (CDFI), CEUS at low MI and CEUS at high MI. The portography was used as the reference standard regarding the ability to identify shunt abnormalities. The sensitivity, specificity, area under the curve (AUC), positive predictive value, and negative predictive value were calculated. RESULTS: Out of 50 patients with a suspected diagnosis of shunt dysfunction, 18 (36%) patients had abnormal portogram findings, among which there were eight shunt occlusions and 10 stent stenosis. The sensitivity, specificity, and AUC for shunt abnormalities of CEUS at high MI are 94.4%, 93.8%, and 94%, respectively. CDFI was less sensitive and accurate than CEUS at low or high MI regarding shunt abnormality identification. Although the diagnostic results of CEUS at high MI offered relatively higher sensitivity/accuracy and correlated better with portography than that of CEUS at low MI, the difference between CEUS at low MI and high MI was not significant. The diagnostic accuracy of CDFI, CEUS at low MI, and CEUS at high MI are 50%, 70%, and 80% respectively. CONCLUSIONS: With the relatively high sensitivity and specificity compared with CDFI and CEUS at low MI, CEUS at high MI offers an alternative complementary new method to detect TIPS abnormalities in clinic.