A computationally efficient FEM platform for comprehensive simulations of photoacoustic imaging

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Computational Science

Background:

• Existing photoacoustic imaging (PAI) simulators face limitations due to simplified numerical methods and basic geometries.
• There is a need for a physics-based simulation method that accurately models the entire PAI process.

Purpose of the Study:

• To develop a comprehensive finite element method (FEM) platform for PAI simulations.
• To model all physics processes from laser irradiation to image reconstruction for realistic results.

Main Methods:

• The platform integrates ray optics, bioheat transfer, solid mechanics, elastic waves, and pressure acoustics.
• Time-explicit numerical methods ensure computational efficiency for preclinical studies.
• Validated against k-wave simulations and experimental tests using a realistic breast phantom.

Main Results:

• FEM simulations showed a 0.6 °C temperature increase in the tumor area due to laser irradiation.
• Thermoelastic expansion generated maximum pressure stress of 853,000 N m^-2.
• Acoustic waves with 446 kPa maximum pressure were produced and propagated for image reconstruction.

Conclusions:

• The versatile FEM platform accurately simulates PAI, including intermediate steps.
• Applicable to diverse scenarios like PAI of different body parts and evaluating beamforming methods.
• Potential applications include hyperthermia monitoring and training AI models.