Shear wave attenuation measurement of tissue-mimicking materials using a two-point frequency shift method

Abstract

Shear wave elastography (SWE) is a method used in several clinical applications for assessment of soft tissue viscoelastic properties. SWE uses an acoustic radiation force (ARF) to produce laterally propagating shear waves to obtain the wave velocity. Here, we present a two-point shear wave attenuation coefficient measurement method without using a rheological model. The technique uses information related to the magnitude spectrum frequency shift of shear waves measured at only two lateral locations. We examined how the distance from the start of the ARF push and the distance between the two locations affected the attenuation coefficient estimates. We tested this method on digital phantom data created using local interaction simulation approach in viscoelastic media and on data acquired from phantom and ex vivo liver experiments. We compared the results from the two-point method with other two techniques used for assessing shear wave attenuation: the frequency-shift-based (FS) method and attenuation measuring ultrasound shearwave elastography. In comparison with the FS method, our technique does not assume that the shape parameter of the Gamma function is constant over a lateral distance. Tests conducted showed that the proposed method is feasible to provide robust attenuation estimates based on two measurement points in tissue-mimicking materials and ex vivo liver tissue.Shear wave elastography (SWE) is a method used in several clinical applications for assessment of soft tissue viscoelastic properties. SWE uses an acoustic radiation force (ARF) to produce laterally propagating shear waves to obtain the wave velocity. Here, we present a two-point shear wave attenuation coefficient measurement method without using a rheological model. The technique uses information related to the magnitude spectrum frequency shift of shear waves measured at only two lateral locations. We examined how the distance from the start of the ARF push and the distance between the two locations affected the attenuation coefficient estimates. We tested this method on digital phantom data created using local interaction simulation approach in viscoelastic media and on data acquired from phantom and ex vivo liver experiments. We compared the results from the two-point method with other two techniques used for assessing shear wave attenuation: the frequency-shift-based (FS) method and attenuation measu...