Purpose: X-ray Induced Acoustic Tomography and proton acoustic ultrasound imaging has seen a whole host of novel applications in the past decade, with additional imaging modalities and set-ups continuously being explored and reported in the literature. Modelling such new techniques in simulation is an important research impetus in order to better enable the theoretical simulation and analysis of such new imaging techniques. We present our work using k-wave MATLAB simulations to model these novel imaging modalities.
Methods: We have employed the k-wave toolbox to model various detection set-ups, samples, and source geometries and strength in thermoacoustic imaging and sample analysis. We have designed a simulation workflow for this that is extendable to modelling of all thermoacoustic phenomenon. Firstly, the source geometry is imported into MATLAB. Secondly, the geometry and intensity information of the source is converted to an initial pressure rise using thermoacoustic pressure calculating equations. Thirdly, this initial pressure is allowed to propagate in the simulation geometry, and is detected at all detector elements. Lastly, time-reversal reconstruction is employed at the detectors, allowing for reconstruction of the initial pressure without requiring detector-specific reconstruction algorithms. We employ this workflow for proton-acoustic and x-ray acoustic imaging, further stipulating that k-wave simulations have useful applications in the modelling of all thermoacoustic phenomena.
Results: In a wide array of imaging modalities, our simulation workflow was able to generate simulations useful for optimization of imaging methods. This versatile workflow successfully reconstructed the energy deposition of various thermoacoustic modalities in agreement with known parameters regarding excitation source geometry
Conclusion: k-wave coupled with Monte Carlo Simulations are useful tool for preliminary modelling of all thermoacoustic phenomenon for any transducer array element geometry and excitation source. This simulation workflow can be useful for all researchers seeking to model thermoacoustic imaging