On nonlinearized inversion procedures and their application to breast imaging

Breast imaging using electromagnetic (EM) waves is challenging. One aims at the case of a pending breast immersed in a coupling medium and probed by a series of antennas (emitters and transmitters as well) set in this medium, frequencies of operation being around a couple of GHz to achieve both enough penetration and still meaningful resolution. The spatial distribution of the EM parameters is to be retrieved so as potential anomalies exhibited, priors yielded by ultrasonic (US) probing being used to that effec. Several solution methods are compared on a 4-zone 2-D model of breast (skin, fatty, fibroglandular and tumor tissues) and MRI-derived ones from the UWCEM Breast Phantom Repository. The potential of data fusion using both US and EM modalities in the course of the inversion itself instead of just introducing smart US priors is considered also.