Value of contrast-enhanced ultrasound in the diagnosis of hilar cholangiocarcinoma

Abstract

Objective To investigate the clinical value of contrast-enhanced ultrasound (CEUS) in the preoperative evaluation of hilar cholangiocarcinoma. Methods The objects of this retrospective study were 72 patients who were suspected with hilar cholangiocarcinoma by conventional ultrasound, then underwent CEUS and hilar cholangiocarcinoma was finally confirmed by computed tomography (CT) or magnetic resonance imaging (MRI) in the Third Affiliated Hospital of Sun Yat-sen University from January 2005 to December 2010. There were 60 males and 12 females with age ranging from 18 to 90 years old and a median age of 65 years old. The informed consents of all patients were obtained and the ethical committee approval was received. Abdomen scanning was performed on all the patients using conventional ultrasound and CEUS. The contrast medium sulfur hexafluoride microbubbles and the low mechanical index contrast-specific imaging technique were applied. The visualization and diagnosis of classification of hilar cholangiocarcinoma by conventional ultrasound and CEUS were observed. The CT or MRI result was taken as golden standard for diagnosis. The sensitivity of visualization of tumors and diagnosis of classification by two methods were calculated. Chi-square test was used to compare the sensitivity between conventional ultrasound and CEUS. Results For the conventional ultrasound, tumors of 47 cases were visualized as hypo-echoic or hyper-echoic soft tissues mass, while 25 cases were visualized as iso-echonic and unclearly. In the arterial phase of CEUS, the hyper-enhancement was observed in 50% (36/72) patients and the iso-enhancement was observed in 22% (16/72) patients and hypo-enhancement was observed in 28% (20/72) patients. While in the venous phase, hypo-enhancement was observed in all the 72 patients and the infiltration region of tumors were clearly displayed. The visual sensitivity of hilar cholangiocarcinoma by CEUS were 1.00 (72/72), while 0.65 (47/72) by the conventional ultrasound. CEUS was superior to the conventional ultrasound (χ2=19.615, P<0.05). The sensitivity of diagnosis of classification was 0.92 (66/72) by CEUS, but was 0.83(60/72) by the conventional ultrasound. No statistically significant difference was observed(χ2=2.286, P=0.131). Conclusions Compared with the conventional ultrasound, CEUS could better display the actual infiltration region of tumors, improve the visual sensitivity for hilar cholangiocarcinoma. The sensitivity of diagnosis of classification by CEUS are comparatively higher and can play a certain role in the preoperative evaluation of hilar cholangiocarinoma. Key words: Bile duct neoplasm; Hilar; Ultrasound; Contrast medium; Preoperative evaluation