Extensions of nonlinear B/A parameter imaging methods for echo mode.

Area of Science:

• Ultrasound physics
• Nonlinear acoustics
• Biomedical imaging

Background:

• Accurate estimation of the nonlinear parameter B/A is crucial for advanced ultrasound applications.
• Existing B/A estimation methods often require modifications for echo mode and heterogeneous tissues.
• Finite amplitude approaches offer a robust mathematical and experimental basis for B/A assessment.

Purpose of the Study:

• To investigate nonlinear B/A parameter imaging in ultrasound echo mode.
• To extend existing B/A estimation methods for application in heterogeneous media.
• To demonstrate the feasibility of B/A imaging using experimental phantom data.

Main Methods:

• Identification and adaptation of finite amplitude approaches for echo mode B/A estimation.
• Extension of three nonlinear coefficient measurement methods to heterogeneous media.
• Simulation and experimental validation of the extended comparative method (ECM), considering probe diffraction effects.

Main Results:

• Finite amplitude methods are suitable for B/A estimation in echo mode due to simplicity and mathematical rigor.
• The extended comparative method (ECM) demonstrated superior performance in simulations for heterogeneous media, especially when accounting for probe diffraction.
• The first experimental B/A images were successfully obtained using the ECM on two distinct phantoms.

Conclusions:

• Nonlinear B/A parameter imaging is feasible in ultrasound echo mode.
• The extended comparative method (ECM) is a promising technique for B/A imaging in heterogeneous tissues.
• This work paves the way for enhanced diagnostic capabilities using nonlinear ultrasound parameters.