high performance computing on graphics processing units: hgpu.org

The simulation of ultrasound images is usually based on two main strategies: either a linear convolution or the use of an acoustic model. However, only the linear propagation of the pressure wave is considered on the simulation tools generally used. CREANUIS is a recent simulation tool (freely available on the Internet) which implements the nonlinear propagation of the wave to create realistic ultrasound images and opens new simulations perspectives based on nonlinear propagation: amplitude modulation, pulse inversion, second harmonic inversion… The nonlinear propagation in CREANUIS is simulated using a generalization of the angular spectrum method (GASM). This approach is implemented on a graphic processing unit (GPU) for a fast computation. Moreover, in GASM simulation, the possible inhomogeneity of the nonlinear parameter can be considered. It directly impacts the increase of the harmonics during propagation and consequently the resulting RF image. These resulting images perfectly translate the nonlinear parameter change in the medium. The link between echogenic or not areas and nonlinearity is conducted. Finally, the total computation time for CREANUIS (fundamental and second-harmonic image) compared to FieldII (fundamental image only) is reduced by a factor comprised between 2 and 4 according to the geometric considerations.