3D printed anthropomorphic physical phantom for mammography and DBT with high contrast custom materials, lesions, and uniform chest wall region
Anthropomorphic breast phantoms mimic anatomy to evaluate the performance of clinical mammography and digital breast tomosynthesis (DBT) systems. Our goal is to make a phantom that mimics clinically relevant appearance of a patient to allow for improved imaging systems and lesion detection. We previously presented a voxelized 3D printed physical phantom with breast tissue anatomy and a uniform chest wall for evaluating standard QC metrics. In the current study, metal ink resolution patterns were designed for the uniform chest wall spanning 1.5 to 10 lp/mm to cover the resolution range of mammography and DBT systems, and including test objects and fiducial markers for future automated processing. The previous phantom had a limited range of 36%-64% breast density using the commercial photopolymer inks TangoPlus and VeroWhite. Several doped materials were tested with the aim of increasing the contrast of the fibroglandular breast tissue in the previous phantom. We created custom-made photopolymers doped with several materials, including tungsten, to increase breast density, as well as iodine to simulate contrast-enhanced lesions. We also measured a new, commercial photopolymer ink, VeroPureWhite, which corresponds to 92% breast density. The tungsten-doped material allows for 33-100% breast density range in the phantom, more than double the density range in our previous phantom. To our phantom with normal anatomy, we also added lesion inserts in the form of 3D-printed mass lesions with varying sizes and contrasts and uniform, commercially produced iodine inserts to investigate interactions of lesions without and with contrast in breast tissue.