A Comparison of Image Reconstruction Methods for Ring-Array Photoacoustic Computed Tomography

Area of Science:

• Biomedical Imaging
• Medical Physics
• Optical Imaging

Background:

• Photoacoustic computed tomography (PACT) is an emerging imaging modality.
• Image reconstruction is critical for PACT system performance.
• Various reconstruction algorithms exist, each with unique trade-offs.

Purpose of the Study:

• To compare the effectiveness of four PACT image reconstruction techniques: delay-and-sum (DAS), interpolated-model-matrix-inversion (IMMI), frequency-domain model-based (FDMB), and time-reversal (TR).
• To evaluate image quality, computational efficiency, and robustness to noise and impulse response for 2D imaging.
• To provide insights for selecting the optimal reconstruction method for ring-array PACT systems.

Main Methods:

• Comparison of DAS, IMMI, FDMB, and TR reconstruction methods.
• Evaluation of image quality, computational speed, and noise robustness.
• Assessment of performance on ex vivo elongated and thin-slice targets.

Main Results:

• DAS achieved real-time performance with good image quality for elongated targets.
• IMMI and FDMB methods enhanced detail and resolution for thin-slice targets but were significantly slower.
• TR method offered reasonable resolution and detail but had the slowest reconstruction time.

Conclusions:

• Each reconstruction method has distinct strengths and limitations.
• DAS is suitable for real-time applications requiring acceptable image quality.
• Model-based methods (IMMI, FDMB) and TR are better for high-resolution imaging when speed is not critical.