Full-Waveform Ultrasound Modeling of Soft Tissue-Bone Interactions using Conforming Hexahedral Meshes

Full-waveform modeling serves as the basis for many emerging imaging techniques within ultrasound computed tomography. Being able to accurately depict strong material interfaces, such as in the case of soft tissue and bone, is particularly important for ensuring that these numerical methods produce physically correct results. We present a procedure for constructing digital twins of various parts of the human body through the use of conforming hexahedral meshes, which are used together with the spectral-element method to accurately model the interactions of the ultrasound wavefield at these sharp material boundaries. These computational meshes can be used for applications such as imaging tissue properties using ultrasound computed tomography, treatment planning in focused ultrasound therapy, and optimal experimental design. In silico examples of a cranial phantom and a knee phantom are presented to illustrate the effectiveness of this virtual prototyping strategy.