Particle and voxel approaches for simulating ultrasound backscattering from tissue

In modeling the backscattering of pulsed ultrasound from tissue, variations in compressibility are frequently approximated by assuming that an appropriate distribution of particles will produce a similar signal. For high particle densities, the computational burden can be large if simulations are conducted on a sample volume of realistic size. The approximate voxel approach offers the potential for greatly reduced computational burden, especially for three-dimensional simulations. One- and two-dimensional computer simulations were performed using both approaches with a realistic wideband Gaussian-shaped transmit signal. The mean squared errors of the simulated backscattered signals were compared to determine how the accuracy of the voxel approach depended on the scatterer concentration and voxel size selection. It is shown that the voxel approach can be used in place of the particle method with a high degree of accuracy, while considerably reducing computation time.