Bi-modal tissue-mimicking breast phantoms: comparison between the performance of agar- and gelatin-based phantoms

Tissue-mimicking phantoms represent a key point for the development of biomedical systems for diagnostic imaging. In this paper, new recipes for tissue-mimicking breast phantoms are proposed and tested, both dielectrically and mechanically. Phantoms mimicking human breast neoplastic tissues are considered, as they are anatomically stiffer than the surrounding healthy tissues. In our recipes, only cheap, easy-to-manage and safe components are involved, and the performance of two solidifying agents (i.e., gelatin and agar) are evaluated both from a dielectric and a mechanical point of view. Dielectric measurements are performed from 500 MHz to 40 GHz, and mechanical tests are performed with the unconfined compression approach, using a preload of 0.2 N and a test speed of 0.5 mm/min. This analysis shows that agar is more suitable for the fabrication of stiffer phantoms as compared to gelatin.