The optimal solution of inverse problems as raised in medical imaging requires consideration of the global diffraction process, encoding the mechanical and spatial characteristics of the medium crossed. From the thermodynamic basis, it is possible to set the non linear propagation equation of the wave in the medium according, for instance, to the impedance and the celerity distributions and to raise the forward problem. However, ambiguities and lack of complete data, coarse approximations (straight path, lst/2nd order Born's or Rytov's development, far field measurement...) prevent traditional images from being an exact representation. In fact, a much more accurate evaluation can be reached if one approaches the object by computer simulation, thus solving the forward problem. The aim of the current project is to propose a new philosophy of medical imaging which makes best use of all the a priori information available -primordial if one wants to obtain a high spatial resolution, compensate for the lack of observability and reach quantitative measurement - in order to reproduce the non linear propagation of the wave by simulating the medium crossed. The phantom created will constitute the solution sought without requiring the explicit resolution of the ill-conditioned inverse problem. On this basis, we will carry out Acoustical Elasticity Imaging since thereis less change in the physical parameters of the tissues during the variou pathological and physiological processes than in their elasticity; up to 2-3 orders of magnitude; thus providing an excellent contrast between normal and diseased tissue. The application to 3D prostate imaging with an operational sensor will be performed.
The project is composed of three principal parts:
- mathematical modeling of the region of interest for computer simulation of the prostate under externel action. Optimization of the mathematical model;
- creation of proper numerical methods for two types of quantitative estimation of the prostate (for brief estimation in real time and for more detailed esti
- creation of a knowledge base of pathological prostate tissue and entry of dat