Model-based tomographic optoacoustic reconstructions in acoustically attenuating media

Acoustic attenuation influences the transmission of the ultrasonic waves excited optoacoustically in biological samples, in a way that the amplitude of the waves is reduced as they propagate through acoustically attenuating tissues. Furthermore, being dependent on frequency, acoustic attenuation also causes broadening of the time-resolved optoacoustic signals, which in turn leads to blurring of features and overall deterioration of image quality. The effects of acoustic attenuation are more prominent for the high frequency components of the optoacoustic waves and they must be taken into account for high resolution imaging. In this work, we modify a model-based reconstruction algorithm to incorporate the effects of acoustic attenuation in tomographic optoacoustic imaging set-ups. As the waves propagate from the excitation until the measurement points, they undergo space and frequency dependent attenuation, which can be effectively accounted for using the suggested model-based approach. The simulation results obtained showcase a good performance of the introduced method in terms of resolution improvement.