Iterative refinement of fibroglandular region with microwave breast imaging

A procedure is proposed in the context of microwave breast imaging to iteratively refine the resolution of the reconstruction model for the glandular region used by the imaging algorithm. The reconstruction model begins with a small number of large reconstruction elements and the dielectric properties are estimated over these elements. For subsequent iterations, the density of the mesh elements within the glandular region increases. The imaging algorithm uses the results from the reconstructed image of the previous step to initialize the dielectric properties of the model elements. An incident field with a higher frequency than the previous step is used. Dielectric properties over the finer model elements are estimated from the scattered data which have a higher spectral content. The procedure continues until a satisfactory resolution of the reconstructed image is achieved. The aim of the strategy is to improve the resolution of the reconstructed profile while overcoming problems associated with solving a highly non-linear and severely ill-posed inverse scattering problem. The feasibility of the algorithm is evaluated with numerical results based on a synthetically generated breast phantom.