Fig. 4.

An example of a mesh refinement analysis being performed on temporal and spatial response of a shear wave propagation model from a Gaussian ARF excitation source. The top row images show the qualitative representation of a propagating shear front for 1.00, 0.50, and 0.125 mm node spacing, 5 ms after the simulated acoustic radiation force excitation. The left middle row plot shows the displacement profile at 5 ms at the focal depth for each of these node spacings, and the right middle row plot shows the transient displacement response at the focus of the acoustic radiation force excitation for each node spacing. The bottom plot shows how the computation time increases as a function of finer node spacing for these models. Notice that too coarse of a mesh (1.0 mm node spacing) inadequately captures the acoustic radiation force distribution and resultant shear wave morphology, while there is no benefit to over-refining the mesh from an accuracy standpoint (equivalent displacement fields for 0.5 and 0.125 mm node spacing), while there is an appreciable runtime penalty for an overly-refined mesh.