Improved back-projection method for circular-scanning-based photoacoustic tomography with improved tangential...

Area of Science:

• Biomedical Imaging
• Medical Physics
• Optical Imaging

Background:

• Photoacoustic computed tomography (PACT) imaging systems often use planar transducers of finite size.
• Existing reconstruction algorithms typically assume an ideal point transducer, leading to image artifacts like spinning blur due to model mismatch.

Purpose of the Study:

• To develop and validate an improved back-projection method for PACT reconstruction that incorporates transducer geometry.
• To enhance tangential resolution and reduce image distortion in 2D circular-scanning PACT.

Main Methods:

• An improved back-projection algorithm was developed, explicitly factoring in the geometric characteristics of the transducers.
• Extensive simulations and experimental data were used to assess the method's adaptability and stability.
• The method was tested with both planar and non-planar transducers to evaluate its versatility.

Main Results:

• The proposed method effectively restored tangential distortion in PACT images for both simulated and experimental datasets.
• Tangential resolution improvement was more pronounced with larger-sized transducers.
• Reconstructed image quality was shown to be significantly influenced by transducer shape and position, even for non-planar types.

Conclusions:

• The developed PACT reconstruction method successfully mitigates blurring and improves image resolution by considering transducer geometry.
• The findings provide valuable guidance for selecting appropriate transducers and optimizing scanning strategies in PACT applications.
• This work contributes to advancing the accuracy and quality of photoacoustic imaging.