Reconstruction of speed-of-sound and electromagnetic absorption distributions in photoacoustic tomography

The conventional imaging model in photoacoustic tomography (PAT) assumes the object is acoustically homogeneous. In many practical applications of PAT this assumption may not be valid, resulting in image distortions and artifacts. Knowledge of the acoustic speed distribution of the object can be incorporated into the imaging model to mitigate such artifacts, but this information is not typically available. In this work, we propose a heuristic method for reconstructing both the acoustic speed and electromagnetic absorption distributions of a weakly scattering object. The method exploits a two-fold data redundancy that exists in a complete set of PAT measurement data. A preliminary computer-simulation study is presented to demonstrate the method.