Measurement of Elastic Properties of Tissue by Shear Wave Propagation Generated by Acoustic Radiation Force

“…PZFlex ® is a time-domain FE analysis package for solving acoustic wave propagation and acoustic field problems in 2D and 3D tissue models. 19) Both models were assumed to be linearly elastic, homogeneous materials. Here, C L was 1540 m=s, ρ was 1000 kg=m 3 , the temporal sampling frequency was 10 kHz, and the spatial resolution was 500 µm.…”

Section: Lldamentioning

confidence: 99%

Study on the application of shear-wave elastography to thin-layered media and tubular structure: Finite-element analysis and experiment verification

Jang

Kondo

Namita

et al. 2016

Jpn. J. Appl. Phys.

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Shear-wave elastography (SWE) enables the noninvasive and quantitative evaluation of the mechanical properties of human soft tissue. Generally, shear-wave velocity (C S) can be estimated using the time-of-flight (TOF) method. Young's modulus is then calculated directly from the estimated C S. However, because shear waves in thin-layered media propagate as guided waves, C S cannot be accurately estimated using the conventional TOF method. Leaky Lamb dispersion analysis (LLDA) has recently been proposed to overcome this problem. In this study, we performed both experimental and finite-element (FE) analyses to evaluate the advantages of LLDA over TOF. In FE analysis, we investigated why the conventional TOF is ineffective for thin-layered media. In phantom experiments, C S results estimated using the two methods were compared for 1.5 and 2% agar plates and tube phantoms. Furthermore, it was shown that Lamb waves can be applied to tubular structures by extracting lateral waves traveling in the long axis direction of the tube using a two-dimensional window. Also, the effects of the inner radius and stiffness (or shear wavelength) of the tube on the estimation performance of LLDA were experimentally discussed. In phantom experiments, the results indicated good agreement between LLDA (plate phantoms of 2 mm thickness: 5.0 m/s for 1.5% agar and 7.2 m/s for 2% agar; tube phantoms with 2 mm thickness and 2 mm inner radius: 5.1 m/s for 1.5% agar and 7.0 m/s for 2% agar; tube phantoms with 2 mm thickness and 4 mm inner radius: 5.3 m/s for 1.5% agar and 7.3 m/s for 2% agar) and SWE measurements (bulk phantoms: 5.3 m/s + 0.27 for 1.5% agar and 7.3 m/s + 0.54 for 2% agar).

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“…[1][2][3] This imaging technique has been applied to the viscosity measurement of tissues. 4,5) The accuracy of SWI was discussed by numerical simulation 6,7) and the improvement in measurement accuracy in SWI was studied. [8][9][10] Review papers have been published for SWI.…”

Section: Introductionmentioning

confidence: 99%

Novel estimation method for shear wave displacement amplitude excited by vibrator

Yamakoshi¹,

Yamazaki²,

Ishimori³

et al. 2018

Jpn. J. Appl. Phys.

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We have proposed a continuous shear wave elastography method (color Doppler shear wave imaging, CD SWI). Although this imaging method is real-time shear wave visualization in shear wave elastography, the imaging parameter is restricted to the phase of the shear wave (SW). In this paper, a novel SW amplitude estimation method, which can be used simultaneously with the CD SWI, is proposed. This method considers the dependence of the duty ratio of the fringe pattern, which appears on the color flow image, on the SW amplitude. Although calibration is required for each imaging system in advance because the duty ratio also depends on the parameters of an imaging system such as a moving target identification (MTI) filter, the proposed method provides a useful SW displacement estimation means suited for CD SWI elastography.

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Measurement of Elastic Properties of Tissue by Shear Wave Propagation Generated by Acoustic Radiation Force

Cited by 23 publications

References 31 publications

Experimental study on temperature rise of acoustic radiation force elastography

Experimental study on temperature rise of acoustic radiation force elastography

Study on the application of shear-wave elastography to thin-layered media and tubular structure: Finite-element analysis and experiment verification

Novel estimation method for shear wave displacement amplitude excited by vibrator

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