Ultrasound shear wave viscoelastic imaging combined with shear wave elastography for characterization of focal liver lesions.

The aim of this prospective study is to explore the clinical value of shear wave viscoelastic (SWV) imaging and its combination with shear wave elastography (SWE) in discriminating focal liver lesions. We enrolled consecutive participants with unclear focal liver lesions from January 2024 to December 2024. These patients were prospectively assigned to shear wave measurements. The Crius A20 (Mindray, Shenzhen, China) ultrasound system equipped with a SC7-1U convex probe (frequency range, 1.2-6.0 MHz; mid frequency, 3.5 MHz) was used to perform viscoelasticity and stiffness measurements within the lesion and in the liver parenchyma of the right liver lobe. Shear wave frequency dispersion (FD), Voigt model-based viscosity (Vi) and liver stiffness (LS) of FLLs and background liver parenchyma, corresponding lesion-to-background ratios (Fr, Vr, Lr) were obtained for analysis. Histology and at least two contrast-enhanced imaging modalities served as the reference for the characterization of FLLs. Final diagnosis included 119 cases of malignant and 92 cases of benign FLLs. Malignant lesions contained 44 cases of hepatocellular carcinoma. The AUC of the combination of LS-FD-Vi for differentiating malignant from benign FLLs was 0.734 (95 %CI, 0.669-0.793), which was significantly higher than any single parameter. Also, LS-Vi-Vr combination presented the best diagnostic performance for discriminating HCCs from benign FLLs, the AUC of which is 0.822 (95 %CI, 0.747-0.882). The AUC of LS-Lr-Vr combination is 0.826 (95 %CI, 0.768-0.875) for discriminating HCCs from other FLLs. SWV imaging can provide additional viscoelastic information about FLLs before operation. SWV combined with SWE demonstrated optimal diagnostic performance for recognizing HCCs and malignant FLLs.