Comparing Differential Tissue Harmonic Imaging With Tissue Harmonic and Fundamental Gray Scale Imaging of the Liver

Abstract

Objective. The purpose of this study was to compare fundamental gray scale sonography, tissue harmonic imaging (THI), and differential tissue harmonic imaging (DTHI) for depicting normal and abnormal livers. Methods. The in vitro lateral resolution of DTHI, THI, and sonography was assessed in a phantom. Sagittal and transverse images of right and left hepatic lobes of 5 volunteers and 20 patients and images of 27 liver lesions were also acquired. Three independent blinded readers scored all randomized images for noise, detail resolution, image quality, and margin (for lesions) on a 7-point scale. Next, images from the same location obtained with all 3 modes were compared blindly side by side and rated by all readers. Contrast-to-noise ratios were calculated for the lesions, and the depth of penetration (centimeters) was determined for all images. Results. In vitro, the lateral resolution of DTHI was significantly better than fundamental sonography (P = .009) and showed a trend toward significance versus THI (P = .06). In the far field, DTHI performed better than both modes (P < .04). In vivo, 450 images were scored, and for all parameters, DTHI and THI did better than sonography (P < .002). Differential tissue harmonic imaging scored significantly higher than THI with regard to detail resolution and image quality (P < .001). The average increase in penetration with THI and DTHI was around 0.6 cm relative to sonography (P < .0001). The contrast-to-noise ratio for DTHI showed a trend toward significance versus THI (P = .06). Side-by-side comparisons rated DTHI better than THI and sonography in 54% of the cases (P < .007). Conclusions. Tissue harmonic imaging and DTHI do better than fundamental sonography for hepatic imaging, with DTHI being rated the best of the 3 techniques.

Contrast-Enhanced Tissue Harmonic Imaging versus Phase Inversion Harmonic Sonographic Imaging for the Delineation of Hepatocellular Carcinomas

“…The second factor is deeper penetration. Contrast THI could offer deeper ultrasound penetration than conventional CHI, and thus a wide viewing image could be obtained [19,[23][24][25] . The third is the higher frame rate of THI needed to create a smooth moving image compared with CHI.…”

“…Tissue harmonic imaging (THI) is a form of native harmonic imaging that provides a better signal-to-noise ratio and reduced side lobe artifacts, resulting in better performance in scanning obese patients and patients with poor acoustic windows [19][20][21][22] . The contrast-to-tissue ratio in harmonic imaging is generally limited by the tissue background signal comprising both the leakage harmonic signal and the tissue harmonic signal.…”

Current role of ultrasound in the diagnosis of hepatocellular carcinoma

“…These techniques usually sacrifice spatial and time resolution to improve sensitivity and specificity of contrast signals. Tissue harmonic imaging (THI), which is the most commonly used conventional B-mode imaging modality, is a form of native harmonic imaging that provides a better signal-to-noise ratio and reduced side lobe artifacts than the other types [49][50][51][52]. As this THI technique is based on the [53].…”

Comparison of conventional and PureWave Crystal transducer in obstetric sonography

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