Contribution of Contrast–Enhanced Sonography in the Detection of Intrahepatic Cholangiocarcinoma

Objectives The purpose of this study was to evaluate the contribution of contrast‐enhanced sonography in the diagnosis of intrahepatic cholangiocarcinoma up to 3 cm and analyze its dynamic enhancement patterns. Methods Forty‐five patients (29 male and 16 female; mean age ± SD, 61.3 ± 10.7 years; range, 38–79 years) with a preliminary diagnosis of intrahepatic cholangiocarcinoma by contrast‐enhanced sonography were retrospectively analyzed. For each nodule, the enhancement pattern, level, and dynamic change during the arterial, portal, and late phases after the injection of a sulfur hexafluoride microbubble contrast agent were evaluated. Results Among the 35 patients with a histopathologic diagnosis of intrahepatic cholangiocarcinoma, 18 nodules showed hyperenhancement during the arterial phase, and 17 showed hypoenhancement. Heterogeneous, peripheral, and partial enhancement were found in 24, 8, and 2 nodules, respectively. However, only 1 nodule showed homogeneous enhancement. During the portal phase, 34 nodules showed hypoenhancement, and 1 showed isoenhancement. Hypoenhancement during the late phase was observed in all cases. Ten patients had a misdiagnosis of intrahepatic cholangiocarcinoma. Conclusions Intrahepatic cholangiocarcinoma up to 3 cm may display a variety of arterial enhancement patterns on contrast‐enhanced sonography. However, some other nodules may manifest findings similar to those of intrahepatic cholangiocarcinoma.