2D speed of sound mapping using a multilook reflection ultrasound tomography framework

Area of Science:

• Medical Imaging
• Biophysics
• Ultrasound Technology

Background:

• Quantitative ultrasound (QUS) aids disease diagnosis, with shear wave elastography (SWE) as a clinical standard for tissue stiffness.
• SWE limitations include low frame rates, long settling times, and sensitivity to operating conditions.
• Longitudinal speed of sound (SOS) presents a viable alternative for tissue characterization.

Purpose of the Study:

• To propose a novel framework for generating 2D sound speed maps using a commercial ultrasound probe.
• To address the limitations of current elastography techniques in clinical settings.
• To provide a more robust method for quantifying tissue properties.

Main Methods:

• A commercial ultrasound probe is localized and used for multi-view scanning of a domain.
• Round trip travel times are measured using a reflector, enabling estimation of reflector depth and inclination.
• A framework is presented to estimate the 2D sound speed map and quantify uncertainty.

Main Results:

• The proposed framework successfully generates 2D sound speed maps.
• Validation using simulated and experimental data confirms the framework's efficacy.
• The method utilizes multiple looks to enhance effective aperture and improve sound speed map fidelity.

Conclusions:

• The developed ultrasound framework offers a promising alternative to SWE for disease diagnosis and staging.
• The method provides accurate 2D sound speed mapping with quantifiable uncertainty.
• This approach has the potential to overcome limitations of current elastography techniques.