Abstract: Objective To evaluate the value of contrast-enhanced ultrasound (CEUS) characteristics and quantitative parameters in differentiating dysplastic nodules (DN) of cirrhosis from small hepatocellular carcinoma (SHCC). Methods A retrospective study included 45 SHCC patients and 45 DN patients admitted to Hanzhong Central Hospital between January 2020 and December 2025. All underwent CEUS. Qualitative features (enhancement level and type in arterial, portal, and delayed phases) and quantitative parameters [regional blood volume (RBV), regional blood flow (RBF) in three phases] were compared. Multivariate logistic regression analysis was used to identify independent differentiating factors between DN and SHCC, and receiver operating curve (ROC) analysis was used to validate the diagnostic performance. Results The SHCC group had significantly higher arterial enhancement level, arterial RBV and arterial RBF, and significantly lower portal enhancement level, delayed enhancement level, portal RBV and delayed RBV than the DN group (P<0.05). Multivariate analysis confirmed portal enhancement level, arterial RBV, portal RBV, delayed RBV and arterial RBF as independent factors (P<0.05); arterial RBV and RBF were risk factors, whereas others were protective factors. Combined detection achieved an AUC of 0.970, sensitivity 97.8% and specificity 91.1%, superior to single indicators (P<0.05). Conclusion CEUS qualitative features and quantitative parameters (RBV, RBF) effectively distinguish DN from SHCC. Portal enhancement level, arterial RBV, portal RBV, delayed RBV and arterial RBF are key indicators, and their combined application improves diagnostic accuracy with important clinical value.

Key words: Contrast-enhanced ultrasound, Dysplastic nodule of cirrhosis, Small hepatocellular carcinoma, Differential diagnosis, Quantitative parameter, ROC curve