| Background:Intrahepatic cholangiocarcinoma(ICC) is a malignancy arising from the epithelium of the gradeⅡintrahepatic bile duct to hering’s canal of biliary tree, ICC is the second most common primary liver malignancy following hepatocellular carcinoma(HCC), accounting for approximately 15-20% of all primary liver cancers. The incidence and mortality were increasing worldwide. ICC is commonly occurred in normal liver, but more and more ICCs were detected in cirrhotic liver. Contrast-enhanced ultrasound(CEUS) has been widely used to diagnose focal liver lesions in recent years, but the appearance of ICC on CEUS was similar to that of HCC in patients with cirrhosis, Differentiation between them is essential for surgical planning and prognosis assessment because ICC and HCC have different biological behaviour and prognosis, the performance of CEUS diagnosing focal liver lesions was questioned. ICCs were difficult to diagnose, the outcome of ICC was poor, there were lack of special characteristics of ICC on CEUS.Objective:We retrospectively evaluated the CEUS imaging of ICC in this study, analyzing the enhancement characteristics of CEUS on arterial phase, portal venous phase and late phase by visualization and pathological features of the tumor. Then, we compared the clinical outcome of ICC patients in different groups. The main aims of this study were as follows:1、Compare CEUS imaging features of ICC and HCC in cirrhotic patients, to verify if detailed analysis of temporal enhancement patterns on CEUS may help differentiate ICC from HCC in this compelling clinical situation.2、(1) Study the characteristics of ICC on CEUS in more patients and investigate the main factors that influence the enhancement patterns of ICC on CEUS, with special emphasis on underlying liver diseases, tumor size, and tumor cell differentiation, and(2) to analyze the correlations between the enhancement patterns on CEUS and pathological findings of ICC.3、Analyze the correlation between the enhancement pattern of ICC on CEUS on arterial phase and prognostic factors, comparing the clinical outcome of ICC patients with different enhancement patterns.Materials and methods1、Thirty three ICC and fifty HCC in cirrhosis were enrolled in the first part of this study. The contrast kinetics of ICC and HCC was analyzed and compared. Intensity of the tumor and surrounding liver tissue in different periods were measured using a Sonomath software. Tumor/tissue ratio of enhancement intensity was calculated by dividing enhancement intensity of tumor with enhancement intensity of surrounding liver tissue in the same still image.2、Ninety-six patients with 96 pathologically confirmed ICCs underwent CEUS were enrolled in the second part of this study. CEUS images were retrospectively evaluated for tumor enhancement patterns in the arterial, portal and late phases. The arterial enhancement patterns were correlated with clinicopathological factors. The possible influencing factors were correlated with pathologic findings.3、One hundred and ninety seven ICC patients were enrolled in the third part of this study. CEUS images were retrospectively analyzed, different enhancement patterns were correlated with prognostic factors. The disease free survivals were analyzed for patients in different groups.Results:1、Statistical analysis did not reveal significant difference between ICC and HCC in the time of contrast first appearance and arterial peak maximum time. ICC displayed much earlier washout than that of HCC(47.93±26.45 seconds vs 90.86±31.26 seconds) in the portal phase, and most ICC(87.9 %) showed washout before 60 seconds than HCC(16.0%). Much more ICC(78.8 %) revealed marked washout than HCC(12.0%) while most HCC(88.0%) showed mild washout or no washout in late part of the portal phase(90-120 seconds). Twenty six out of thirty three ICC(78.8%) demonstrated both early washout(<60seconds) and marked washout in late part of the portal phase, whereas, only six of fifty HCC(12.0%)showed these temporal enhancement features(p =0.000).When both early washout and marked washout in the portal phase are taken as diagnostic criterion for ICC, the diagnostic performance results were as follows:the sensitivity was 78.8%, the specificity 88.0%, the positive predictive value was 81.3%, the negative predictive value was 86.3% and the accuracy was 84.3% by CEUS.2、Thirty-six(37.5%) patients with ICC demonstrated rim-like enhancement, and 60(62.5%) exhibited non-rim-like enhancement in the arterial phase on CEUS. The incidence of non-rim-like-enhancing ICCs was higher in patients with cirrhosis(79.3%) and chronic viral hepatitis(75.0%) than patients with no chronic liver disease(41.0%, P=0.001). The sizes of the ICCs with homogeneous hyper-enhancement were significantly smaller than those with inhomogeneous hyper-enhancement(P=0.007). Arterial non-rim-like-enhancing ICCs showed higher microvessel density(MVD) and arterial density(AD) and less fibrous stroma and necrosis than rim-like-enhancing ICCs. Arterial inhomogeneous-enhancing ICCs had lower MVD and AD and much more fibrous stroma and necrosis than homogeneous-enhancing ICCs.3、Seventy-eight(39.6%) patients with ICC demonstrated rim-like enhancement, and 119(60.4%) exhibited non-rim-like enhancement in the arterial phase on CEUS. Chronic liver disease(cirrhosis or chronic virus hepatitis)(P =0.000), vascular invasion(P =0.025), regional lymph node metastasis(P =0.044), and number of tumors were significantly correlated with the arterial enhancement patterns of ICC. The disease free survival time in patients with arterial rim-like enhancement patterns ICC was significantly shorter than that of non-rim-like group, patients with chronic liver disease, single tumor, without vascular invasion or without regional lymph node metastasis had longer disease free survival time.Conclusions:1. Analysis of detailed temporal enhancement features on CEUS is helpful differentiate ICC from HCC in cirrhosis.If a nodule in cirrhotic liver displays hyper-enhancement in the arterial phase followed by early and marked washout in the portal phase, the nodule is highly suspicious of ICC rather than HCC.2. The enhancement pattern of ICCs in the arterial phase on CEUS was affected by a liver cirrhosis and chronic viral hepatitis and tumor size. The amount of MVD, AD, fibrous stroma and necrosis in ICC tumors may be responsible for the difference in the enhancement patterns.3. Chronic liver disease, vascular invasion, regional lymph node metastasis, and number of tumors were significantly correlated with the arterial enhancement patterns of ICC. The disease free survival time in patients with arterial rim-like enhancement patterns ICC was significantly shorter than that of non-rim-like group, patients with chronic liver disease, single tumor, without vascular invasion or without regional lymph node metastasis had longer disease free survival time. The arterial enhancement pattern of ICC on CEUS may be a newly imaging indicator for predicting the prognosis of ICC patients preoperatively. |
PDF Full Text Request