Location-Dependent Spatiotemporal Antialiasing in Photoacoustic Computed Tomography

Area of Science:

• Biomedical Imaging
• Medical Physics
• Optical Imaging

Background:

• Photoacoustic computed tomography (PACT) visualizes optical absorption in biological tissues using detected ultrasonic waves.
• Accurate PACT image reconstruction relies on satisfying the spatial Nyquist criterion for ultrasonic transducer arrays.
• Failure to meet the Nyquist criterion leads to spatial aliasing artifacts, degrading image quality.

Purpose of the Study:

• To investigate the previously unstudied location dependency of the spatial Nyquist criterion in PACT.
• To develop and validate a novel location-dependent spatiotemporal anti-aliasing method for PACT.

Main Methods:

• Spatiotemporal analysis was employed to understand the location-dependent nature of the Nyquist criterion.
• A new location-dependent spatiotemporal anti-aliasing algorithm was proposed and implemented.
• The method was tested on a full-ring array geometry using numerical simulations and in vivo experiments.

Main Results:

• The spatial Nyquist criterion's requirements vary across the image domain in PACT.
• The proposed location-dependent anti-aliasing method effectively reduced aliasing artifacts.
• Image resolution was minimally affected by the implemented anti-aliasing technique.

Conclusions:

• Location-dependent analysis is crucial for addressing aliasing in PACT.
• The developed anti-aliasing method enhances PACT image fidelity.
• This approach offers improved artifact mitigation for biomedical imaging applications.