Laboratory Designs and Validations of a Glandularity-adjustable Dual-purpose Breast Tissue Phantom

The objectives of this study were to develop and evaluate a breast tissue equivalent phantom that can be used for dual purposes, conventional x-ray imaging and ultrasonography. This phantom was designed based on the prototype of an intralipid-gel soft tissue mimicking phantom used for laser photothermal therapy. The glandularities and the densities of the phantom can be adjusted by modifying the ratio of intralipid and other ingredients and adding fiber powders. An adipose tissue phantom and a glandular tissue phantom were firstly developed and phantoms of different glandularities were further developed through mixing different weight proportions of adipose and glandular. To validate the properties of the phantom for the applications of x-ray imaging techniques, three methods were employed: (1) the compositions of the elements contained in the phantoms were estimated through calculations; (2) the x-ray mass attenuation coefficients of the phantom were calculated based on the elemental compositions; (3) the x-ray photon energies deposit in the phantoms with different glandularities were simulated using Geant4 Simulation Tool Kit. The results showed high agreements with the real breast tissues at corresponding breast glandularities. For the application in ultrasonography, the elasticity of the phantom was determined by measuring the value of Young's modulus and the value of 39 +/- 10 kPa indicated the satisfactory of the requirement of being used as phantom for ultrasound imaging. Therefore, the phantoms developed in this study potentially provided a solution of dualpurpose breast tissue mimicking phantom in the needs of different level of glandularity.