Characterization of a laboratory set-up for assessing the feasibility of magnetic nanoparticles enhanced microwave imaging

The use of contrast agents is gaining a huge interest in microwave imaging (MWI) of breast cancer [1]–[3] in order to discriminate the response of cancerous tissues from that of the surrounding healthy tissue, and so to reduce the occurrence of false negatives arising from the low contrast between the electric properties of cancerous and fibro-glandular tissues [4]. To this end, magnetic nanoparticles (MNPs) represent a viable and effective choice [5], [6]. Indeed, they are allowed for clinical use and can be functionalized with biological molecules able to selectively bind to cancerous cells. Moreover, the microwave magnetic response of the MNPs can be properly modulated by applying an external polarizing magnetic field (PMF), without significantly influencing the response of the surrounding healthy tissue. As a result, by exploiting a proper differential measurement strategy, one can separate the response of the background from that of the MNPs (i.e., the “useful” signal), which, if present, is unambiguously associated to the presence of a malignant lesion [5].