Characterizing the Finite Element Method Implementation of the Medium Absorbtion Correction Method for Fluence Correction of Photoacoustic Images

Building on previous work, an existing FEM model for implementing the medium absorption correction (MAC) method of fluence correction for photoacoustic imaging was refined, including improvements to boundary conditions, light source implementation, and mesh parameters. The Monte Carlo method was used to produce absorbed energy profiles for two kinds of digital phantom, representing homogeneous absorption and inhomogeneous absorption cases, and the model was used to perform MAC on them to test its performance. The effect of FEM simulation geometry and diffusion coefficient tuning was investigated by examining at three separate cases: a 1 cm square, a 2 cm square, and a 1 cm radius semicircle. The accuracy of the correction was quantified by deriving an error metric from the difference between the reconstructed fluence profile and the true fluence profile. The results of the tuning were presented, and the 2 cm square simulation geometry was found to produce the most accurate correction.