Value of contrast-enhanced sonography in differential diagnosis of focal liver lesions

Objective To study the clinical value of contrast-enhanced sonography(CEUS) in differential diagnosis of focal liver lesions(FLL).Methods CEUS using a novel contrast medium SonoVue showed 258 FLL in 164 patients.A typical lesion was observed in patients with multiple lesions.CEUS data were retrospectively analyzed.Biopsy was performed under the guidance of CEUS.A final diagnosis was made according to pathological examination,typical findings at contrast-enhanced CT or MRI and follow-up.Results Of the 164 patients,83 were diagnosed with malignant lesion and 81 with benign lesion.The initial enhancement time of malignant and benign lesions was(19.6±8.1)s and(22.1±9.2)s,respectively(P=0.066).However,the sustained time of malignant lesions from the initial enhancement to the clearance of contrast medium was significantly shorter than that of benign lesions(64.3±31.3)s vs(205.6±48.0)s,(P=0.000).The specificity,sensitivity,and accuracy of CEUS in differential diagnosis between benign and malignant lesions were 93.9%,92.5% and 93.2%,respectively.The accuracy of CEUS was over 90% in diagnosis of hepatocellular carcinoma(HCC),metastatic hepatic carcinoma(MHC),hepatic haemangioma,regenerative nodules(RN),focal nodular hyperplasias(FNH) and focal fatty sparing of liver.Conclusion CEUS can rapidly enhance FLL in arterial phase but cannot diagnose it as a malignant tumor.Delayed enhancement of liver nodules is the typical feature of most benign lesions.