Feasibility Study of Forward Electromagnetic Solutions Used in Breast Tumor Detection

Forward electromagnetic (EM) solutions must be sufficiently accurate in order to be used in the solution of the inverse problem of microwave medical imaging. Two well-known issues related to the adequacy of the forward EM solutions are: 1) the feasibility of 2-D approximations and 2) the effect of the skin interface. In this paper, we present a systematic study using the time-domain EM solver XFDTD to assess the applicability of related approximations. This preliminary investigation leads us to believe that a 2-D simulation is not an adequate representation of the forward problem and may be misleading when testing inverse solvers. Also, the skin interface must be modeled correctly regardless of how well the properties of the coupling medium match those of the breast tissue. Ultra-wide band responses are studied and numerous plots are presented to support our conclusions.