Ultrasonographic evaluation of focal hepatic lesions: comparison of pulse inversion harmonic, tissue harmonic, and conventional imaging techniques.

A prospective study was performed to evaluate whether pulse inversion harmonic imaging and tissue harmonic imaging improve the lesion conspicuity and change ultrasonographic characteristics of focal hepatic lesions. Three radiologists evaluated 97 focal hepatic lesions by consensus: cirrhosis-related nodules (n = 23), metastases (n = 23), hemangiomas (n = 27), and cysts (n = 24). In our study, pulse inversion harmonic imaging was judged superior to both tissue harmonic imaging and conventional imaging in conspicuity and overall quality for cirrhosis-related nodules, metastases, and cysts (P < 0.05). Compared with conventional imaging, both pulse inversion harmonic imaging and tissue harmonic imaging provided better conspicuity, clearer internal echogenicity, and stronger through-transmission of cysts (P < 0.05). Pulse inversion harmonic imaging was judged to be better in depicting internal morphology for cirrhosis-related nodules and metastases than conventional imaging (P < 0.05). For hemangiomas, no statistically significant difference was found in all parameters except better posterior enhancement by tissue harmonic imaging than other techniques. In conclusion, pulse inversion harmonic imaging showed the best conspicuity and also enhanced characteristics of both cystic and solid hepatic lesions. Tissue harmonic imaging was judged superior to conventional imaging in evaluating cysts but was not beneficial for solid lesions. The results of this trial may be specific to the machine used for this study.