Application of Contrast‐Enhanced Sonography for Diagnosis of Space‐Occupying Lesions in the Extrahepatic Bile Duct

OBJECTIVES: To investigate the application of contrast-enhanced sonography compared with conventional sonography and contrast-enhanced computed tomography (CT) for diagnosis of space-occupying lesions in the extrahepatic bile duct. METHODS: Seventy-two patients with pathologic diagnoses of space-occupying lesions in the extrahepatic bile duct were retrospectively recruited. All patients underwent conventional sonography, contrast-enhanced sonography, and contrast-enhanced CT. The sensitivity, specificity, and diagnostic accuracy were compared. RESULTS: Among the 72 patients, 11 cases were benign, and 61 were malignant. The diagnostic accuracy rates for conventional sonography, contrast-enhanced sonography, and contrast-enhanced CT were 66.67% (48 of 72), 90.28% (65 of 72), and 88.89% (64 of 72), respectively. The Youden index showed that contrast-enhanced sonography (0.811) was comparable with contrast-enhanced CT (0.720) and better than conventional sonography (0.159). There were significant differences in accuracy between conventional and contrast-enhanced sonography (P= .001) and conventional sonography and contrast-enhanced CT (P = .001); however, there was no significant difference between contrast-enhanced sonography and contrast-enhanced CT (P = .785). There were significant differences in sensitivity between conventional and contrast-enhanced sonography (P= .006) and conventional sonography and contrast-enhanced CT (P = .006) but no significant difference between contrast-enhanced sonography and contrast-enhanced CT (P > .99). There were no significant differences in specificity among the techniques (P > .05). There was a significant difference in the number of lesions with clear boundaries displayed: 16 on conventional sonography and 56 on contrast-enhanced sonography (P = .006). CONCLUSIONS: Contrast-enhanced sonography can show the dynamic blood supply in space-occupying pathologic regions of the extrahepatic bile duct. The diagnostic accuracy of contrast-enhanced sonography in the extrahepatic bile duct was higher than that of conventional sonography and comparable with that of contrast-enhanced CT. Therefore, contrast-enhanced sonography may be a promising imaging technique for diagnosis of space-occupying lesions in the extrahepatic bile duct.