Integrating Geometric and Biomechanical Models of a Liver Tumour for Cryosurgery Simulation

In this paper, we present a 3D reconstruction approach of a liver tumour model from a sequence of 2D MR parallel cross-sections, and the integration of this reconstructed 3D model with a mechanical tissue model. The reconstruction algorithm uses shape-based interpolation and extrapolation. While interpolation generates intermediate slices between every pair of adjacent input slices, extrapolation performs a smooth closing of the external surface of the model. Interpolation uses morphological morphing, while extrapolation is based on smoothness surface constraints. Local surface irregularities are further smoothed with Taubin’s surface fairing algorithm [5]. Since tumour models are to be used in a planning and simulation system of image-guided cryosurgery, a mechanical model based on a non-linear tensor-mass algorithm was integrated with the tumour geometry. Integration allows the computation of fast deformations and force feedback in the process of cryoprobe insertion.