NONLINEAR ESTIMATION OF THE LATERAL DISPLACEMENT USING TISSUE INCOMPRESSIBILITY

Using the incompressibility property of soft tissue, high quality late ral displacement distributions can be reconstructed from accurate axia l displacement measurements and noisy lateral displacement estimates. Previous methods appropriate for small deformations have been extended for high magnitude deformations requiring a nonlinear model. Problems arising in incompressibility processing for large deformations are co nsidered. Applications of nonlinear incompressibility methods to ultra sonic measurements on gel-based, tissue equivalent phantoms are given. Lateral displacement images reconstructed with nonlinear methods are compared to those reconstructed with linear methods for both small and large deformations.