Thermoacoustic tomography with correction for acoustic speed variations

Area of Science:

• Biomedical imaging
• Medical physics
• Diagnostic imaging

Background:

• Thermoacoustic tomography (TAT) reconstructs internal microwave absorption distributions by measuring boundary thermoacoustic waves.
• Current TAT algorithms assume homogeneous acoustic properties, leading to image distortions in heterogeneous biological tissues.
• Heterogeneity in acoustic properties causes blurring and distortion, particularly for small, buried objects in TAT images.

Purpose of the Study:

• To develop and validate a correction method for improving TAT image quality.
• To address image distortions caused by heterogeneous acoustic properties in biological tissues.
• To enhance the accuracy of reconstructing microwave absorption distributions using TAT.

Main Methods:

• Developed a correction method integrating ultrasonic transmission tomography (UTT) with TAT.
• Utilized UTT to characterize acoustic property variations within biological tissues.
• Applied the derived acoustic property information to correct TAT reconstruction algorithms.

Main Results:

• The proposed correction method significantly reduces image distortion and blurring in TAT.
• Numerical simulations demonstrated the effectiveness of the UTT-based correction.
• Phantom experiments confirmed the improved image quality and accuracy of the corrected TAT.

Conclusions:

• Ultrasonic transmission tomography (UTT) is effective for correcting acoustic heterogeneity in TAT.
• The developed correction method enhances the diagnostic potential of TAT for biological tissues.
• This approach improves the visualization of small structures within heterogeneous media.