Weighted reconstruction methodology for optoacoustic tomographic imaging of heterogeneous acoustic samples

Some biological samples contain strongly mismatched tissues such as bones or lungs that generally produce acoustic reflections and scattering, leading to consequent image distortion if the reconstruction is performed by assuming an acoustically homogeneous medium. A weighted optoacoustic reconstruction procedure based on statistical principles is presented herein to tomographically image tissues with strong acoustic mismatch. The procedure is based on weighting the contribution of the collected optoacoustic signals to the reconstruction with the probability that they are not affected by reflections or scattering. Since such probability depends on the available information about the distribution of optical absorbers, an iterative procedure in which the reconstructted images are used to recalculate the weighting values is presented in this work. The benefit of the reconstruction procedure described herein is showcased by reconstructing a phantom containing a straw filled with air, which mimicks air-gaps in actual biological samples.