Microwave calcaneus phantom for bone imaging applications

Microwave imaging can be used as an alternate modality for monitoring bone health. Dielectrically accurate, anthropomorphic phantoms play vital role in testing of imaging prototype prior to clinical applications. However, no study to date has proposed cortical and trabecular hone phantoms. This paper presents a multilayered 3D-printed human calcaneus structure. Further, we have proposed liquid based tissue phantoms that mimic the dielectric properties of skin, muscle, cortical bone and trabecular bone. Tissue phantoms are composed of Trition X-100, water and salt. The dielectric properties were measured across 0.5-8.5 GHz. Each layer of the 3D-printed structure was filled with corresponding tissue phantom. The combined average percentage difference between dielectric properties of reference data and proposed tissue phantoms was found to be 2.9% for trabecular bone, 7.3% for cortical hone, 7.1% for muscle, and 8.7% for skin over the full measured frequency band. These tissue phantoms and 3D printed human calcaneus structure can be used as a valuable test platform for microwave diagnostic studies.