Estimation method for sound velocity distribution for high-resolution ultrasonic tomographic imaging

Area of Science:

• Medical imaging
• Biomedical engineering
• Acoustics

Background:

• Commercial ultrasound equipment assumes a constant sound velocity (1530 or 1540 m/s) for beam formation.
• This assumption is suboptimal due to the heterogeneous nature of sound velocity within biological tissues.
• Accurate sound velocity is crucial for precise ultrasonic imaging.

Purpose of the Study:

• To propose and validate a novel method for estimating the spatial distribution of sound velocity within a region of interest.
• To overcome the limitations of fixed sound velocity assumptions in ultrasound beam formation.
• To improve the accuracy and resolution of ultrasound imaging.

Main Methods:

• Developed a method to estimate sound velocity distribution by fitting theoretical ultrasonic wave propagation times to measured values.
• Utilized the time-of-flight from scatterers to probe elements for estimation.
• Employed a phantom experiment to test the proposed method.

Main Results:

• The proposed method accurately estimated sound velocity distribution with a maximum error of 0.6% in phantom experiments.
• The estimated local sound velocity values demonstrably improved the quality of the resulting ultrasonic images.
• Successfully validated the feasibility of the novel estimation technique.

Conclusions:

• The developed method offers a significant improvement over traditional fixed sound velocity assumptions.
• This technique has the potential to enhance ultrasonic image quality in in vivo (living organism) applications.
• Accurate estimation of sound velocity distribution is key to advancing ultrasound diagnostic capabilities.