k-Wave toolbox for studying elastic property in Photoacoustic imaging

We report a simulation study - adopting K- wave toolbox which is presently used for optical absorption characterization - that shows the contribution of the elastic property from the photoacoustic initial pressure rise. In this simulation, we consider two different circular targets having similar radius but different contrast in physical property (optical, mechanical) and hence the initial pressure rise is used in different cases due to: 1) two different elastic coefficients 94 kPa and 202 kPa and 2) two different absorption coefficients 1 cm^-1 and 2 cm^-1. Simulation results show that the initial pressure rise due to elastic contrast is very low compared to that of optical contrast, although elastic coefficient varies strongly (~ 50 times) against optical absorption coefficient (~ 2 times) in diseased state (say, cancer). This study demonstrates not only practicality of elastic property imaging using photoacoustic initial pressure rise but also horizontal extension of practical applicability of MATLAB based k-Wave toolbox for simulation study for characterization of elastic property.