Elasticity imaging of inhomogeneous media using inverse filtering with multiple shear wave generation

Abstract

Most diseases like cancer cause to change of tissue mechanical properties described by elasticity. Elastography visualizes these changes and aids in early and differential diagnosis of diseases. Shear wave imaging is one of principles of elastography, and using the speed of shear wave generated by mechanical vibration or the acoustic radiation force impulse. Conventional shear wave imaging uses time-of-flight method; however, it causes artifact by reflection and refraction of shear wave. We proposed a method for shear wave elasticity imaging that combines inverse filtering with multiple shear wave sources induced by acoustic radiation force. Shear waves are induced by pushing pulse and recorded by ultrafast imaging, and repeated at multiple pushing points that are sparsely located. An inverse filter can be applied to virtually focus shear waves on an arbitrary point. Shear wave speed is obtained by a measured shear wavelength and its image is constructed by scanning the focal point. An inverse filter can ...