Dielectric, Mechanical and Acoustic Characterization of Multi-Modal Tissue-Mimicking Breast Phantoms

The characterization of tissue-mimicking materials (TMMs) represents a critical step in the development and the testing of new imaging systems, involving different modalities based on millimeter (mm) and ultrasound (US) waves. In this work, two breast phantoms (i.e., a breast fat TMM and a tumor TMM) for multimodal imaging were produced and characterized from a dielectric, mechanical and acoustic point of view. The dielectric characterization was carried out in order to estimate the dielectric permittivity in the frequency range of 0.5-40 GHz. The mechanical measurements of these phantoms, instead, were performed to determine their Young's modulus at 5% strain with a pre-load of 0.2 N and a test speed of 0.5 mm/min. Then, the acoustic characterization was carried out too, in order to determine the US wave speed and attenuation in these TMMs. In this preliminary work, both the TMMs were found able to reproduce the abovementioned physical properties of the corresponding breast tissues.