Conclusion
The important result presented in this paper is the possibility of imaging the propagation of a transient low frequency shear wave in biological tissues by means of an ultra-fast ultrasonic imaging system which is described in this paper. This imaging system can produce up to 10,000 frames per second in the medium. The shear wave propagation images were obtained with 1000 and 2000 frames per second from homogeneous and heterogeneous phantoms. From these images the wavelength and the speed of the shear wave are qualitatively estimated and thus the shear modulus is obtained. Since the displacements induced by the propagating centimeter wavelength shear wave are measured locally inside the medium, we expect the resolution of this imaging technique to be the same as that of the image of the displacements. In the future, we plan to measure also the lateral displacements. With two components of the displacement vector we should be able to solve the inverse problem without the strong assumption of a perfectly incompressible medium.
Keywords
Shear Wave Axial Displacement Transient Elastography Speckle Tracking Soft LayerPreview
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