Contrast-Enhanced Ultrasound With Ultrasound Localization Microscopy for Differentiating Benign From Malignant Focal Liver Lesions.

OBJECTIVE

To investigate the value of quantitative parameters derived from ultrasound localization microscopy (ULM) in differentiating benign from malignant focal liver lesions (FLLs), and to evaluate its added diagnostic value compared with conventional contrast-enhanced ultrasound (CEUS) visual assessment.

METHODS

In this prospective study, patients with focal liver lesions underwent CEUS and ULM imaging. Blinded visual assessment of CEUS images and quantitative ULM parameter extraction were performed. Multivariate analysis identified predictors for a ULM model. Diagnostic performance of CEUS, ULM, and combined approaches was compared by ROC analysis.

RESULTS

The study included 68 patients with 73 lesions (26 benign and 47 malignant). Compared with benign lesions, malignant FLLs showed significantly different values for multiple ULM quantitative parameters, including microvessel density, flow velocity, perfusion index, vascular tortuosity, and microvessel diameter (all p < 0.05). Multivariate stepwise logistic regression identified three independent predictors: percentage of microvessel density ratio, perfusion index, and mean microvessel diameter. The ULM quantitative model based on these parameters achieved an AUC of 0.855 (95% CI: 0.768-0.942) for differentiating benign from malignant FLLs, outperforming CEUS visual assessment (AUC: 0.808; 95% CI: 0.698-0.918). Combining both approaches further improved the AUC to 0.928 (95% CI: 0.868-0.988), significantly better than CEUS alone (p < 0.001).

CONCLUSION

ULM quantitative parameters effectively differentiated benign from malignant FLLs, providing incremental diagnostic value beyond CEUS visual assessment. The combined approach offers comprehensive morphological and functional information, significantly improving diagnostic performance and serving as a promising complementary tool for clinical decision-making.