Figure 4.

i Illustration of the axisymmetric finite-element model used for the simulations, showing the mesh, the dimensions, the location of the focus and the resulting displacements. ii Incremental displacement at four different equally spaced frames obtained in one gel, showing especially the propagation of the shear wave from the focus. iii Shear storage modulus (G′) and shear loss modulus (G″) versus frequency in the (a) polyacrylamide gel, (b) 4.7% gelatin and (c) 6.5% gelatin gel phantom for both rheometry and HMI as indicated