Detecting mechanical abnormalities in prostate tissue using FE-based image registration.

An image registration-based elastography algorithm is presented for assessing the stiffness of tissue regions inside the prostate for the purpose of detecting tumors. A 3D finite-element model of the prostate is built from ultrasound images and used to simulate the deformation of the prostate induced by a TRUS probe. To reconstruct the stiffness of tissues, their Young's moduli are varied using Powell's method so that the mutual information between a simulated and deformed image volume is maximized. The algorithm was validated using a gelatin prostate phantom embedded with a cylindrical inclusion that simulated a tumor. Results from the phantom study showed that the technique could detect the increased stiffness of the simulated tumor with a reasonable accuracy.