Ultrasonographic Evaluation of Focal Hepatic Lesions : Comparison of Fundamental, Tissue Harmonic, Fundamental Compound and Harmonic Compound Imaging Techniques

ABSTRACT

PURPOSE: To compare the ultrasonographic image quality of fundamental imaging (FI), tissue harmonic imaging (THI), fundamental compound imaging (FCI), and harmonic compound imaging (HCI) in the evaluation of focal hepatic lesions. MATERIALS AND METHODS: Ninety-four focal hepatic lesions (27 hemangiomas, 15 hepatocellular carcinomas, 14 metastases, and 38 cysts) in 74 patients [30 males and 44 females aged 33-82 (mean, 55) years] were included in our study. All patients underwent FI, THI, FCI, and HCI using an HDI 5000 Sono CT scanner (Advanced Technology Laboratories, Bothell, CA., U.S.A.) with a 2-5MHz convex transducer. Images were analysed by two abdominal radiologists who used a 4-point scale and reached a consensus. In the case of solid lesions, four parameters, as follows, were evaluated lesion conspicuity, internal morphology, overall image quality, and peripheral halo. For cysts, three parameters (internal artifact, sharpness of margin, and posterior enhancement) were assessed. For statistical analysis, the Scheffe method (ANOVA test) was used. RESULTS: For solid lesions (hemangioma, hepatocellular carcinoma, and metastasis), THI, FCI and HCI were superior to FI in terms of lesion conspicuity, internal morphology and overall image quality (p<0.05), though for peripheral halo, the four imaging techniques were not statistically different. For cysts, THI, FCI and HCI revealed clearer internal artifact and better margin sharpness than FI (p<0.05), while in terms of posterior enhancement, THI was superior to both FI and FCI, and HCI was superior to FCI (p<0.05). CONCLUSION: For the evaluation of focal hepatic lesions, harmonic imaging techniques (i.e. THI and HCI) appear to provide better image quality than fundamental imaging techniques (i.e. FI and FCI). There is, however no significant difference in image quality between the two harmonic techniques.