Role of tissue harmonic imaging in focal hepatic lesions: Comparison with conventional sonography

Abstract
The purpose of the present study was to compare iissue harmonic imaging (THI) and conventional sonography in focal hepatic lesions. Fifty patients with focal hepatic lesions were enrolled for study. Conventional grayscale and THI was performed in all the patients and two sets of images of the lesions were recorded (one each for THI and conventional) and assessed for fluid-solid differentiation, detail and overall image quality. These images were compared with conventional sonographic images and graded better, same or worse as per the case. Lesions were confirmed by fine-needle aspiration cytology (FNAC)/surgery/other modalities such as computed tomography (CT) or magnetic resonance imaging (MRI). Out of 50 patients with focal hepatic lesions, 21 patients had metastatic lesions (two single; 19 multiple) five patients had hepatocellular carcinoma (HCC), five patients had hydatid cysts, nine had simple hepatic cyst whereas five patients had liver abscess, three had focal fatty infiltration; and lymphoma and hemangioma were seen in one patient each. The first observer ranked THI better than standard sonography in 40 patients (80%) for fluid-solid differentiation, in 38 (76%) for detail and in 39 (78%) for overall image quality. The second observer ranked THI better than standard sonography in 39 patients (78%) for fluid-solid differentiation, in 40 (80%) for detail and in 42 (84%) for overall image quality. Tissue harmonic imaging provided additional information in eight patients (16%) and resulted in treatment alteration in three patients (6%). Tissue harmonic imaging was significantly better than conventional sonography for fluid-solid differentiation, detail and total image quality in focal hepatic lesions, especially in obese patients and patients with poor acoustic window.