Aberration correction for time-domain ultrasound diffraction tomography.

Area of Science:

• Acoustic imaging
• Wave propagation
• Medical physics

Background:

• Time-domain diffraction tomography reconstructs sound speed variations from acoustic scattering data.
• Current methods have limitations in finite signal bandwidth and aberration effects.
• Applications include ultrasonic mammography and inverse scattering problems.

Purpose of the Study:

• To extend and analyze time-domain diffraction tomography methods.
• To develop and evaluate aberration correction techniques for improved imaging.
• To address the lack of a general solution for the linearized time-domain inverse scattering problem.

Main Methods:

• Developed an approximate solution to the linearized inverse scattering problem using a delay-and-sum method.
• Proposed two aberration correction methods: one using straight-ray approximation for delay computation, and another applying delays directly to linearized reconstruction.
• Utilized far-field time-domain acoustic scattering measurements.

Main Results:

• Demonstrated that the linearized time-domain inverse scattering problem has no general solution for finite signal bandwidth.
• Showcased that aberration correction methods significantly improve image quality for large scatterers.
• Extended the parametric range of time-domain diffraction tomography by approximately a factor of 2.

Conclusions:

• Aberration correction is crucial for enhancing the performance of time-domain diffraction tomography.
• The developed methods offer a general approach to aberration correction in acoustic imaging.
• The findings advance the capabilities of quantitative imaging in applications like ultrasonic mammography.