Optimization of Effective Parameters on Acoustic Radiation Force Shear Waves Interference Patterns Elastography by Using a Finite Element Model

Abstract

Purpose: Variations in the mechanical properties of soft tissues may be a sign of a disease. Since some disease like fibrosis or cancer change the stiffness of related tissues, we can assess the disease of a soft tissue with its elasticity. The elastic stiffness properties of soft tissues can be estimated using locally induced displacements and shear waves. Materials and Methods: A two-dimensional plane finite element model has been created as soft tissue. The soft tissue has been exposed to two Amplitude Modulated High Intensity Focused Ultrasound transducer (AMHIFU), hence shear wave interference patterns which can be captured by lower frame rate imaging are generated. The acoustic radiation force created by a self-focusing ultrasound transducer has been determined from an ultrasound pressure field simulation. A Gaussian function was fitted to the resulting Acoustic Radiation Force (ARF) field and implemented in the form of a body force in the finite element model. Results: The effect of different excitation parameters for their optimization in the elasticity estimation has been investigated. Conclusion: In the result section, the effect of ARF excitation parameters on shear wave elasticity measurements has been represented. Shear wave interference pattern elastography which does not need high frame rate imaging with optimized parameters can be used as a non-invasive method for measuring the elastic stiffness of soft tissues.

Keywords

• Elastography
• Shear Wave
• Elasticity
• Acoustic Radiation Force
• Ultrasound
• Finite Element Model