A Hybrid Diffusion Model Enhances Multiparametric 3D Photoacoustic Computed Tomography

Area of Science:

• Biomedical Imaging
• Medical Physics
• Optical Imaging

Background:

• Photoacoustic computed tomography (PACT) offers valuable insights into biological structures and physiological functions.
• High-end PACT systems provide quality imaging but are costly and slow.
• Limited ultrasound (US) elements in PACT systems can restrict imaging capabilities.

Purpose of the Study:

• To introduce a hybrid diffusion model for PACT (HD-PACT) to enhance dynamic, multiparametric 3D imaging.
• To demonstrate HD-PACT's effectiveness with a reduced number of US elements.
• To assess HD-PACT's applicability in various biological and medical fields.

Main Methods:

• Developed and implemented a hybrid diffusion model (HD-PACT) for PACT.
• Utilized a reduced number of ultrasound (US) elements (256 out of 1024) from a hemispherical US array.
• Tested HD-PACT on different imaging planes, organisms, wavelengths, and PACT system configurations (128 and 256 US elements).

Main Results:

• HD-PACT significantly improved structural imaging quality across different conditions.
• Enabled functional imaging of hypoxia, pharmacokinetics, and angiogenesis with 256-element PACT.
• Achieved high spatiotemporal resolution for dynamic imaging of organs, brains, and cardiac functions in live animals using low-end PACT.

Conclusions:

• HD-PACT enhances dynamic multiparametric 3D PACT imaging using fewer US elements.
• The model offers improved structural and functional imaging capabilities, even with limited hardware.
• HD-PACT shows significant potential for applications in oncology, cardiology, pharmacology, and endocrinology.