Tomographic reconstruction of three-dimensional volumes using the distorted born iterative method.

Area of Science:

• Ultrasonic imaging
• Inverse scattering methods
• Three-dimensional (3-D) reconstruction

Background:

• Real-world imaging involves 3-D objects, yet inverse scattering research often uses 2-D models.
• 3-D inverse scattering methods are crucial for advancing ultrasonic tomography applications.

Purpose of the Study:

• To investigate 3-D ultrasonic tomography reconstructions using 2-D slices and full 3-D methods.
• To analyze the impact of focal number, speed of sound contrast, and scatterer size on image quality.
• To assess the effectiveness of different transducer array configurations for 3-D reconstructions.

Main Methods:

• Utilized the 2-D distorted Born iterative method (DBIM) to generate 2-D image slices from 3-D data.
• Reconstructed spherical targets using arrays with elevation-focused rectangular elements.
• Performed full 3-D DBIM reconstructions with point-like transducers for comparison.
• Designed and evaluated practical transducer arrays for 3-D DBIM.

Main Results:

• 2-D slicing showed vertical blurring correlated with transducer point-spread functions at low speed of sound contrast (c).
• Increasing c in 2-D slicing led to vertical overshoot artifacts, reduced by smaller focal numbers and larger targets.
• Full 3-D DBIM eliminated overshoot artifacts and improved spatial resolution.
• Transducer array configuration significantly impacts 3-D reconstruction quality.

Conclusions:

• 3-D DBIM offers superior image reconstruction in ultrasonic tomography compared to 2-D slicing methods.
• Optimizing transducer array design is critical for achieving high-quality 3-D ultrasonic images.
• This research provides insights for practical array design in 3-D ultrasonic tomography.