Abstract: Objective To explore the value of contrast-enhanced ultrasound (CEUS) combined with computed tomography (CT) quantitative parameters in differentiating focal nodular hyperplasia (FNH) from hepatocellular carcinoma (HCC), and to provide a reference for clinical diagnosis and treatment. Methods The clinical data of 51 HCC patients and 62 FNH patients diagnosed and treated from August 2021 to September 2024 were collected. All patients underwent non-contrast CT scans, perfusion-enhanced CT scans, and CEUS examinations. CT quantitative parameters [hepatic blood volume, hepatic blood flow, hepatic arterial perfusion (HAP), portal venous perfusion (PVP), total liver perfusion (TLP), hepatic arterial perfusion index (HPI), and mean transit time (mTT)] and CEUS characteristics [time to maximum intensity (RT), time to peak enhancement (TTP), mean transit time (MTT), and peak intensity (PI)] were compared between the two groups. Two radiologists independently analyzed the differences of the parameters. Diagnostic efficacy was evaluated using receiver operating characteristic (ROC) curves and Youden′s index. The combined detection efficacy was assessed in terms of sensitivity, specificity, and area under the curve (AUC). Results Hepatic blood volume, hepatic blood flow, and PVP were significantly higher in the HCC group than those in the FNH group (P<0.05), whereas HAP, HPI, and mTT were significantly lower (P<0.05). In CEUS, RT was shorter in the HCC group, whereas TTP, MTT, and PI were longer than those in the FNH group (P<0.05). For differentiating FNH from HCC, the sensitivity of RT, TTP, and MTT was 74.5%, 51.0%, and 47.1%, respectively; their specificity was 62.9%, 91.9%, and 74.2%; and their AUC values were 0.711, 0.743, and 0.622, respectively. The sensitivities of PI and hepatic blood volume was 56.9% and 58.8%, respectively, with specificities of 83.9% and 88.7%, and AUC values of 0.748 and 0.757. The sensitivities of hepatic blood flow,, PVP, and HPI was 76.5%, 84.3%, and 90.2%, respectively, with specificities of 87.1%, 96.8%, and 77.4%, and AUC values of 0.824, 0.949, and 0.925. The sensitivity and specificity of mTT were 86.3% and 72.6%, with an AUC of 0.814. When CEUS and CT quantitative parameters were combined, the sensitivity and specificity reached 96.1% and 96.8%, respectively, with an AUC of 0.979. Conclusion CEUS combined with CT quantitative parameters can effectively improve the diagnostic accuracy in differentiating FNH from HCC. This combined approach demonstrates high sensitivity, specificity, and accuracy, offering significant clinical value.

Key words: Contrast-enhanced ultrasound, Computed tomography quantitative parameters, Focal nodular hyperplasia, hepatocellular carcinoma, Differential diagnosis