Optoacoustic imaging of absorbing objects in a turbid medium: ultimate sensitivity and application to breast cancer diagnostics.

One of the major medical applications of optoacoustic (OA) tomography is in the diagnostics of early-stage breast cancer. A numerical approach was developed to characterize the following parameters of an OA imaging system: resolution, maximum depth at which the tumor can be detected, and image contrast. The parameters of the 64-element focused array transducer were obtained. The results of numerical modeling were compared with known analytical solutions and further validated by phantom experiments. The OA images of a 3 mm piece of bovine liver immersed in diluted milk at various depths were obtained. Based on the results of modeling, a signal filtering algorithm for OA image contrast enhancement has been proposed.