Design, Manufacturing and Quality Assessment of 3D-Printed Anthropomorphic Breast Phantom for Mammography

Radiological anthropomorphic phantoms are objects that mimic patient’s anatomy when imaged by x-rays. These objects play a major role in optimizing radiation dose and image quality, allowing repeated exposure without exposing patients to harmful ionizing radiation. The goal of this study was to create a three-dimensionally-printed (3D-printed) phantom that would allow production of images that closely match those of human breast produced in digital mammography. We determined the attenuation properties of the Gray V4 resin using an imaged step-wedge. Gray values in image were associated with corresponding material thickness and a real mammogram was converted to two-dimensional (2D) matrix with elements whose values correspond to material thickness. Geometrical corrections for perspective and projection were taken into account. A standard triangle language (STL) file was used as input for the 3D printer. The quality of the printed phantom was evaluated by comparing its images to those of the real patient mammogram using different quantifying measures in spatial and frequency domain. The calculated similarity index (SSIM) was approximately 0.99, which indicates that SLA 3D printing technology can be successfully utilized to produce mammography phantoms.