Full-Waveform Inversion for Breast Ultrasound Tomography Using Line-Shape Modeled Elements.

Area of Science:

• Geophysics
• Seismic Imaging
• Acoustics

Background:

• Full-waveform inversion (FWI) is a powerful seismic imaging technique.
• Traditional FWI often models transducer elements as point sources, leading to artifacts like staircasing.
• Accurate modeling of transducer element geometry is crucial for high-resolution seismic data.

Purpose of the Study:

• To integrate the spatial shapes of transducer elements into the full-waveform inversion framework.
• To overcome limitations of point-source approximations in FWI.
• To enhance the accuracy and stability of seismic imaging reconstructions.

Main Methods:

• Transducer elements are modeled as line segments (cross-sections in the 2D imaging plane).
• The Fourier collocation method is used to represent element shapes via discrete convolution.
• Excitation and recorded signals are weighted based on spatial distribution, avoiding staircasing artifacts.

Main Results:

• Reduced root mean square errors in reconstructed images.
• Increased structural similarity of the inverted images.
• Improved stability and accelerated convergence speed of the inversion process.

Conclusions:

• Modeling transducer element shapes is beneficial when element size approaches acoustic wavelengths.
• The proposed method enhances the fidelity and efficiency of full-waveform inversion.
• This approach offers a more robust solution for seismic imaging challenges.