Diagnostic Value of Acoustic Radiation Force Impulse (ARFI) Elastography for Differentation of Hemangiomas from Malignant Liver Lesions during Conventional Abdominal Ultrasound

Abstract

Background and aimSolid focal liver lesions (FLLs) are very common findings during conventional abdominal ultrasound (US). Among benign FLLs, hemangiomas are very frequent. Acoustic Radiation Force Impulse (ARFI) is an ultrasound-based elastography method, able to non-invasively evaluate the stiffness of FLLs. Aim of this study was to assess the diagnostic value of US ARFI, for characterizing hemangiomas Vs malignant FLLs. Inclusion criteria were presence of hemangiomas or malignant FLLs; definite diagnosis by histological evaluation or ≥ 1 radiological exam with contrast medium (CT, MRI, CEUS). ARFI quantification was performed with an Acuson S3000 ultrasound system (Siemens®, Munich, Germany). Two experienced operators performed five measures per lesion and five measures in the surrounding liver. One-hundred-and-nine FLLs (44 Hemangiomas [HEs], 38 Hepatocellular Carcinomas [HCCs] and 27 metastases [METs]) were examined. HEs showed a significantly lower stiffness compared to malignant FLLs (HEs median value 1.32, IQR 0.97-1.84 m/sec; malignant lesions median value 2.72, IQR 2.00-3.54 m/sec; p<0.001) [Figure 1A]. Conversely, no differences were found for nodule-to-parenchyma ARFI ratios and between HCCs and METs. ARFI values were able to correctly differentiate malignant lesions with a c-statistics of 0.85 (95%CI 0.77-0.93) and sensitivity of 75.4%/specificity of 84.1% at a cut-off of 2.00 m/sec. This study highlights the possibilities arising from the new technologies available in conventional abdominal US. In particular, our results suggest that ARFI can distinguish between HEs and malignant lesions (HCCs and METs) at a cut-off of 2.00 m/sec.