Detailed analysis of temporal features on contrast enhanced ultrasound may help differentiate intrahepatic cholangiocarcinoma from hepatocellular carcinoma in cirrhosis

Abstract

Aim: To verify if detailed analysis of temporal enhancement patterns on contrast enhanced ultrasound (CEUS) may help differentiate intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC) in cirrhosis.

Methods: Thirty three ICC and fifty HCC in cirrhosis were enrolled in this study. The contrast kinetics of ICC and HCC was analyzed and compared.

Results: 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(<60 seconds) 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 sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 78.8%,88.0%,81.3%,86.3%,and 84.3% respectively by CEUS.

Conclusions: 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.

Figure 1. Intrahepatic cholangiocellular carcinoma (ICC) in a 48-year old man with cirrhosis.

A1 Conventional ultrasound shows a hypoechoic nodule of 22-enhanced ultrasound, the lesion appears as homogeneous hyperenhancement 19 seconds after the administration of contrast agent. A3 The lesion shows first wash-out 38 seconds after the injection of contrast agent. A4 The lesion appears as marked wash-out at 50 seconds after the administration of contrast agent.

Figure 2. Hepatocellular carcinoma (HCC) with moderate differentiation in a 31-year old man with cirrhosis.

B1 Conventional ultrasound displays a hypoechoic nodule of 20-out appearance at 95 seconds after injection of contrast agent. B4 The lesion appears as mild wash-out 179 seconds after the administration of contrast agent.

Figure 3. Intrahepatic cholangiocellular carcinoma (ICC) in a 42-year old man with cirrhosis. C1

Conventional ultrasound shows a hypoechoic nodule of 46-out appearance 48 seconds after injection of contrast agent. C4 The lesion appears as marked wash-out 91 seconds after the administration of contrast agent.

Figure 4. Hepatocellular carcinoma (HCC) with moderate differentiation in a 72-year old man with cirrhosis.

D1 Conventional ultrasound shows a hypoechoic nodule of 41(L L) of liver. D2 The lesion shows heterogeneous hyperenhancement 25 seconds after the administration of contrast agent at CEUS, the non-hyperenhancement area at the central part of the lesion indicating necrosis. D3 The lesion shows no wash-out appearance 60 second after injection of contrast agent. D4 The lesion displays mild wash-out 185 seconds after the administration of contrast agent.

Figure 5. Frequency distribution of washout onset in portal phase (seconds).

Washout onset is earlier in patients with intrahepatic cholangiocellular carcinoma (ICC) than in those with hepatocellular carcinoma (HCC).

Figure 6. Frequency distribution of peak extent of washout in portal phase (Tumor/tissue ratio of intensity) in portal phase.

The peak extent of washout is greater in patients with intrahepatic cholangiocellular carcinoma (ICC) than in those with hepatocellular carcinoma (HCC).