Fig. 11.
Displacement profiles in the lateral dimension for materials with Young's moduli of 1 (top row), 8.5 (middle row) and 23 kPa (bottom row) for F/1 and F/2 excitation focal configurations, 0.1 ms after the ARFI excitation. Plot (a) shows the lateral beamwidth of the ARFI excitation beams (which are not apodized). The left and center columns show comparisons of the lateral excitation beamwidths (dashed) relative to the resulting displacement profiles 0.1 ms after excitation (solid) in the lateral dimension for F/1 and F/2 excitations, respectively, while the right column shows the comparison of the F/1 (solid) and F/2 (dashed) displacement profiles. Note that the displacement profiles are more similar between F/1 and F/2 excitation configurations in the stiffer media at this time due to the faster shear wave speed (g,j).