Enhancing Microwave Breast Tomography with Microwave-Induced Thermoacoustic Imaging

Finite-element based microwave to- mographic system can successfully recover dielectric properties of the human breast, aiming to image malignant breast tissues. When compared with mi- crowave radar imaging, microwave tomography re- quires simpler electronics and antenna design due to its narrowband operation. However, the narrowband feature limits the resolution of the nite-element mesh often used to recover the dielectric properties of the breast, as there is no a priori information for mesh renement in the critical location within the breast. In this paper, we present a two-dimensional model of a microwave imaging system with monopole antennas and pressure sensors placed in an interleav- ing arrangement around the breast in its pendant position. The proposed system would synergistically function together with the microwave tomographic modality in a fashion that is envisioned as follows: (1) The system uses a monopole antenna to trig- ger microwave absorption and, consequently, heating and expansion of the tumor. (2) The array of pres- sure transducers placed around the breast detect the thermally-induced pressure signals. (3) These signals are used to construct a preliminary breast image. (4) The image is used to generate a non-uniform nite- element mesh, with increased renement around the suspected tumor locations. (5) The rened mesh is fed to an algorithm utilized by the microwave tomo- graphic system to solve the inverse problem, which will now have a priori information and will hence have improved resolution in its resulting image.