Two Approaches for tomographic density imaging using inverse scattering

Most acoustic tomography methods neglect density in order to obtain speed of sound and attenuation . However, density may provide additional sources of contrast. In this work, two approaches for density imaging inverse scattering were explored through simulations in to evaluate the feasibility of density imaging. The first consisted of inverting the wave equation by solving for single functional that depended on both speed of sound and variations. Density profiles were separated by combining at two frequencies (DF-DBIM approach). The method consisted of solving for two functionals simultaneously: that depended only on compressibility and one that only on density variations. A T-matrix approach was to relate these functionals to the scattered data. The DFDBIM allowed separation of density and speed of sound at low termination tolerance values and less than an of magnitude between the largest and smallest frequencies . However, the convergence of DF-DBIM was compromised when moderate (around 2%) terminati n tolerances were.The T-matrix approach converged when multiple frequency was used, but required a ka product smaller than one the lowest frequency. The DF-DBIM requires a very high to obtain reliable quantitative density reconstructions, while T-matrix approach requires excessively large bandwidths imaging large targets. These limitations will serve as points for further algorithmic improvements required practical implementation of density imaging on ultrasound tomographic systems.