Excitation of shear waves inside of rubberlike material by focused ultrasound

Андреев, В. Г.; Pishalnikov, Yury; Руденко, О. В.; Sapozhnikov, Oleg A.; Dmitriev, V. N.; Sarvazyan, Armen

doi:10.1121/1.417814

Cited by 4 publications

(3 citation statements)

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“…The radiation force induced in tissue by the HIFU beam causes tissue displacement along the beam axis which then results in shear wave propagation in transverse direction (Andreev et al 1997, Pishchalnikov et al 2002. The maximum value of this displacement over time within the HIFU pulse depends on the amplitude of the radiation force per unit volume F 0 , characteristic transverse beam radius a and the tissue shear wave velocity c t .…”

Section: Evaluation Of Time-to-boil and Tissue Displacement Due To Ra...mentioning

confidence: 99%

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Mechanical damage thresholds for hematomas near gas-containing bodies in pulsed HIFU fields

et al. 2022

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Objective: Boiling histotripsy (BH) is a novel high intensity focused ultrasound (HIFU) application currently being developed for non-invasive mechanical fractionation of soft tissues and large hematomas. In the context of development of BH treatment planning approaches for ablating targets adjacent to gas-containing organs, this study aimed at investigation of the ultrasound pressure thresholds of atomization-induced damage to the tissue-air interface and correlation of the danger zone dimensions with spatial structure of nonlinear HIFU field parameters. Approach: A flat interface with air of freshly clotted bovine blood was used as an ex vivo model due to its homogenous structure and higher susceptibility to ultrasound-induced mechanical damage compared to soft tissues. Three 1.5 MHz transducers of different F-numbers (0.77, 1 and 1.5) were focused at various distances before or beyond a flat clot surface, and a BH exposure was delivered either at constant, high-amplitude output level, or at gradually increasing level until a visible damage to the clot surface occurred. The HIFU pressure field parameters at the clot surface were determined through a combination of hydrophone measurements in water, forward wave propagation simulation using “HIFU beam” software and an image source method to account for the wave reflection from the clot surface and formation of a standing wave. The iso-levels of peak negative pressure in the resulting HIFU field were correlated to the outlines of surface erosion to identify the danger zone around the BH focus. Main results: The outline of the danger zone was shown to differ from that of a typical BH lesion produced in a volume of clot material. In the prefocal area, the zone was confined within the 4 MPa contour of the incident peak-to-peak pressure; within the main focal lobe it was determined by the maximum BH lesion width, and in the postfocal area – by the transverse size of the focal lobe and position of the first postfocal pressure axial null. Significance: The incident HIFU pressure-based danger zone boundaries were outlined around the BH focus and can be superimposed onto in-treatment ultrasound image to avoid damage to adjacent gas-containing bodies.

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Section: Evaluation Of Time-to-boil and Tissue Displacement Due To Ra...mentioning

confidence: 99%

“…the tissue displacement can be evaluated as follows: et al 1997, Pishchalnikov et al 2002, Poliachik et al 2014. The radiation force amplitude F 0 is defined by the peak heating rate in the HIFU beam H max and the tissue properties: Prieur, Sapozhnikov 2017).…”

Section: Evaluation Of Time-to-boil and Tissue Displacement Due To Ra...mentioning

confidence: 99%

Mechanical damage thresholds for hematomas near gas-containing bodies in pulsed HIFU fields

et al. 2022

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“…The computational simulations were performed taking into consideration the propagation of a plane shear wave, which in the experiment had an approximately cylindrical wave front, but the phase of the cylindrical shear wave changed linearly with distance traveled in the r direction, which is greater than one-tenth of the shear wavelength (Andreev et al 1997). SDUV is an acoustic radiation force based method that measures tissue shear modulus and viscosity by characterizing cylindrical shear wave speed dispersion (Chen et al 2004), so these researchers verified that phase of the cylindrical shear wave changed linearly with distance traveled in the radial direction when this distance was greater than one-tenth of the shear wavelength.…”

Section: Computational Simulationmentioning

confidence: 99%

Errors in phase velocity estimation owing to the method used for shear wave waveform phase extraction

Parcero¹,

Costa‐Júnior²,

Machado³

2019

Biomed. Phys. Eng. Express

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In ultrasound elastography, the shear wave phase velocity, c s , is often used to calculate the stiffness, which can indicate whether a biological tissue has an abnormality. The shear wave phase velocity can also be used to compute shear wave dispersion, which can be related to viscosity or guided wave effects. The most common methods used for extracting the phase from waveform vibration to estimate c s are the Kalman filter (KF), the fast Fourier Transform (FFT), and the Levenberg-Marquardt Algorithm (LMA). Currently, there are no studies in the literature comparing the performance of these methods; hence, this study aims to show the error in estimating the phase velocity obtained with the mentioned methods and to compare them through computational simulations and experiments. In the computational simulations, the absolute value of mean and the standard deviation of relative error of c s were evaluated as a function of signal-to-noise ratio, number of cycles of the shear wave, pulse repetition frequency, and initial phase. The experimental setup used an ultrasonic benchtop system, with a 2.104-MHz frequency transducer, T V , to generate acoustic radiation force at a plastic sphere and consequently induce shear wave propagation in a 7% gelatin phantom. Another ultrasonic benchtop system, with a 4.89-MHz frequency transducer, was used on pulse-echo mode to monitor the shear wave propagation at different positions within the phantom. The computational simulation results demonstrated that LMA and KF demonstrated the best performance in extracting the phase employed to estimate the shear wave phase velocity. In some situations, the c s values obtained by means of KF, FFT, and LMA methods in the experimental results presented a statistical difference, but the highest differences between the mean of c s was smaller than 0.03 m s −1 .

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Ultrasound shear wave imaging for bone

Peach

2000

Ultrasound in Medicine & Biology

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Excitation of shear waves inside of rubberlike material by focused ultrasound

Cited by 4 publications

References 0 publications

Mechanical damage thresholds for hematomas near gas-containing bodies in pulsed HIFU fields

Mechanical damage thresholds for hematomas near gas-containing bodies in pulsed HIFU fields

Errors in phase velocity estimation owing to the method used for shear wave waveform phase extraction

Ultrasound shear wave imaging for bone

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