Development of a physical anthropomorphic breast phantom for objective task-based assessment of dedicated breast CT systems

In this work we present a new methodology for creating a physical anthropomorphic breast phantom for use in dedicated breast CT (bCT) systems. We also present a method for modeling microcalcifications (MCs) in the phantom. An uncompressed digital breast was first created though analytical modeling. This virtual model is then physically realized through inkjet printing using doped ink and paper with radiographic properties similar to that of glandular and adipose tissues. In addition, MC cluster inserts were created using calcium hydroxyapatite (HA) spheres that ranged in diameter from 212-250um to 250-300um and could be inserted inside the phantom. The phantom was then assessed in terms of material realism and reproducibility using x-ray spectroscopy, a clinical full field digital mammography (FFDM) system, and a benchtop CT system. Results show that both the paper and ink used to create the physical phantom have radiographic properties which closely match reference values for glandular and adipose tissue. Further, reproducibility was confirmed through multiple prints. The phantom and MC inserts can be used to objectively assess image quality of dedicated bCT systems.