Table I.
FEA Simulation Parameters for the Two Simulations*
| Em | Inclusion | 13 500 | 13 500 |
| (Pa) | Background | 4500 | 4500 |
| νm | Inclusion | 0.45 | 0.47 |
| Background | 0.47 | 0.47 | |
| k | Inclusion | 50 × 10 −11 | 25 × 10 −11 |
| (m·s −1) | Background | 5 × 10 −11 | 25 × 10 −11 |
| g1, τ1(s) | Inclusion | 0.02, 1 | 0.02, 5 |
| g2, τ2(s) | 0.04, 5 | 0.04, 25 | |
| Background | 0.08, 20 | 0.06, 5 | |
| 0.16, 100 | 0.12, 25 | ||
| Acquisition time (s) | 2000 | 2000 | |
For both phantoms the initial elastic response indicates that the inclusion is stiffer than the background. In the second simulation, the viscoelastic properties of the inclusion and background, modeled by k and νm, and the time constants τ1 and τ2, are similar. In the second simulation, the viscoelastic properties of the inclusion and background, modeled by the permeability k, relaxation amplitudes g1 and g2, and time constants τ1 and τ2, are similar.