Enhancement Patterns of Intrahepatic Cholangiocarcinoma on Contrast-Enhanced Ultrasound: Correlation with Clinicopathologic Findings and Prognosis

To evaluate the correlations between the enhancement pattern of intrahepatic cholangiocarcinoma (ICC) on contrast-enhanced ultrasound (CEUS) and clinicopathologic findings and prognosis, a retrospective study was performed on 197 patients with mass-forming ICC who underwent pre-operative CEUS and surgical resection. The contrast medium we employed in CEUS was SonoVue, which contains microbubbles consisting of sulfur hexafluoride bubbles within a phospholipid shell. This study was approved by the institutional review board with informed consent waived. Patients were classified into an arterial rim-like enhancement group or an arterial non-rim-like enhancement group, and arterial enhancement patterns were correlated with clinicopathologic factors. Overall survival (OS) times were calculated using the Kaplan–Meier method, and differences between groups were compared with the log-rank test. Univariate and multivariate Cox regression models for OS were used to evaluate the independent prognostic factors. The mean and range of ICC tumor size of the arterial rim-like group (59.41 ± 22.09 mm, 20–100 mm) were similar to those of the arterial non-rim-like group (59.82 ± 30.35 mm, 14–162 mm, p = 0.914). Arterial enhancement patterns were correlated with chronic viral hepatitis or cirrhosis, vascular invasion, lymph node metastasis and single/multiple tumors. A total of 78 patients (39.6%) exhibited arterial rim-like enhancement, and the other 119 patients (60.4%) exhibited arterial non-rim-like enhancement. Arterial enhancement pattern (p = 0.045), vascular invasion (p = 0.005), lymph node metastasis (p = 0.000) and number of tumors (p = 0.001) were independent prognostic factors for OS. The arterial non-rim-like enhancement pattern of ICC on CEUS is an independent prognostic factor for better OS and may offer new information for predicting the prognosis of ICC patients before surgical resection.