Ultrasonic Imaging of High-contrasted Objects Based on Full-waveform Inversion: Limits under Fluid Modeling

Area of Science:

• Biomedical Engineering
• Acoustics
• Materials Science

Background:

• Quantitative ultrasound excels at imaging hard tissues due to acoustic impedance contrast.
• Full Waveform Inversion (FWI) is a powerful inverse problem-solving method for wave-medium interactions.

Purpose of the Study:

• To assess the precision of FWI for imaging test targets with high acoustic impedance contrast.
• To evaluate the impact of assuming a fluid medium on reconstruction accuracy, especially with varying shear wave attenuation.

Main Methods:

• Utilized Full Waveform Inversion (FWI) to process experimental ultrasound data.
• Employed high-resolution numerical modeling of wave propagation, simplifying the medium to a fluid.
• Analyzed sound speed reconstruction accuracy across materials with different shear wave attenuation levels.

Main Results:

• Generated sound speed images from experimental data using FWI.
• Evaluated the precision of the reconstruction under the fluid medium assumption.
• Identified limitations related to shear wave attenuation in the simplified model.

Conclusions:

• FWI demonstrates potential for imaging high acoustic impedance contrast materials.
• The fluid medium assumption in FWI requires careful consideration regarding shear wave attenuation.
• Further research should incorporate viscoelastic properties for more comprehensive modeling.