Dynamic enhancement pattern of intrahepatic cholangiocarcinoma on contrast-enhanced ultrasound: the correlation with cirrhosis and tumor size

To retrospectively evaluate the dynamic enhancement pattern of contrast-enhanced ultrasound (CEUS) in intrahepatic cholangiocarcinoma (ICC) of varying sizes and hepatic backgrounds.CEUS was performed in 98 pathologically confirmed ICCs (n = 3930 mm, n = 5930 mm; n = 45 with cirrhosis and n = 53 with normal liver). The dynamic enhancement pattern of CEUS was retrospectively analyzed.In the arterial phase, heterogeneous hyper-enhancement was more frequent in ICCs with cirrhosis (21/45, 46.7% vs. 11/53, 20.8% in ICCs with normal liver, p = 0.009), while peripheral hyper-enhancement and hypo-enhancement were more common in ICCs with normal liver (14/53, 26.4%; 11/53, 20.8% vs. 2/45, 4.4%; 2/45, 4.4% in ICCs with cirrhosis, p = 0.005 and 0.033, respectively). There were no significant differences between portal and delayed phases. In ICCs30 mm, homogeneous hyper-enhancement was more frequently identified (27/39, 69.2% vs. 10/59, 16.9% in ICCs30 mm, p0.001), whereas in ICCs30 mm, heterogeneous, and peripheral hyper-enhancement were more commonly observed (26/59, 44.1% vs. 6/39, 15.4% in ICCs30 mm, p = 0.004, and 14/59, 23.7% vs. 2/39, 5.1% in ICCs30 mm, p = 0.023, respectively). The washout pattern in portal and delayed phases were not significantly different in ICCs with different sizes. 60.7% (17/28) ICCs30 mm and 85.2% (23/27) ICCs30 mm with cirrhosis, together with 66.7% (14/21) ICCs30 mm with normal liver displayed intense contrast agent uptake (homogeneous or heterogeneous hyper-enhancement) in arterial phase followed by washout in portal and delayed phase, which was much higher than that in ICCs30 mm with normal liver (34.4%, 11/32, p0.001,0.001 and =0.027, respectively).The CEUS dynamic enhancement pattern of ICC varies with size and hepatic background. The enhancement pattern is indistinguishable from hepatocellular carcinoma on CEUS in most ICCs with cirrhosis and in most ICCs30 mm with normal liver.