Back-projection algorithm in generalized form for circular-scanning-based photoacoustic tomography with improved...

Area of Science:

• Biomedical Optics
• Medical Imaging
• Photoacoustic Tomography

Background:

• Back-projection algorithm is standard for circular-scanning photoacoustic tomography (CSPAT) due to efficiency and robustness.
• Conventional models for point or infinite-sized detectors cause blurring in off-center targets with finite-sized transducers.
• Existing methods struggle with tangential resolution issues in CSPAT reconstructions using common planar transducers.

Purpose of the Study:

• To develop a generalized back-projection algorithm model for CSPAT reconstruction.
• To address and improve the tangential resolution of off-center targets with finite-sized planar transducers.
• To provide a versatile reconstruction method applicable to various detector types in CSPAT.

Main Methods:

• Introduced a novel back-projection model approximating the transducer's response with a virtual detector.
• Determined the virtual detector's optimal distance using a phase square difference minimization scheme.
• Validated the generalized model's applicability to point and infinite planar detectors.

Main Results:

• The proposed method significantly enhances tangential resolution for off-center targets in CSPAT.
• Reconstructed image quality is substantially improved compared to conventional and modified back-projection methods.
• Findings confirmed through both computational simulations and experimental validations.

Conclusions:

• A generalized back-projection algorithm model effectively restores tangential resolution in CSPAT with finite planar transducers.
• The method is adaptable for point and large-size planar transducers, offering a unified approach.
• Potential applications include guiding CSPAT system design for cancer detection, such as in human breast imaging.