Distinguishing intrahepatic cholangiocarcinoma from hepatocellular carcinoma in patients with and without risks: the evaluation of the LR-M criteria of contrast-enhanced ultrasound liver imaging reporting and data system version 2017

Purpose To assess the diagnostic performance of the LR-M criteria of Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System version 2017 in differentiating intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC) in patients with and without risk factors for HCC. Methods Fifty-four ICC in patients with risks and 55 ICC in patients without risks and matched control cases of HCC with and without risks (n = 59 and n = 55, respectively) were enrolled. The enhanced features of the lesions were retrospectively analyzed according to LR-M criteria. The diagnostic performances including the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity of LR-M criteria were assessed. Result Peripheral rim-like hyperenhancement, early washout (< 45 or 60s), and marked washout did not differ between ICCs with and without risks, while all of these features were more common in ICCs than in HCCs (p < 0.05) no matter if patients were with and without risk factors. Using the LR-M criteria to differentiate ICC from HCC, the AUC, sensitivity, specificity, and accuracy were 0.92, 97.25%, 87.72%, and 92.38%, respectively. If early washout onset was adjusted to < 45 s, the specificity was significantly increased to 95.61% (p = 0.004) without losing sensitivity (96.33%, p = 0.945). The rate of HCCs misdiagnosed as ICCs would decrease from 12.3 to 4.4%. Conclusion Although the LR-M criteria showed high sensitivity in distinguishing ICCs from HCCs in patients with and without risks, the specificity would be significantly increased after adjustments to current criteria.