title: Development of realistic physical breast phantoms matched to virtual breast phantoms based on human subject data.
abstract: OBJECTIVE
  Physical phantoms are essential for the development, optimization, and evaluation of x-ray breast imaging systems. Recognizing the major effect of anatomy on image quality and clinical performance, such phantoms should ideally reflect the three-dimensional structure of the human breast. Currently, there is no commercially available three-dimensional physical breast phantom that is anthropomorphic. The authors present the development of a new suite of physical breast phantoms based on human data.
  
  
  METHODS
  The phantoms were designed to match the extended cardiac-torso virtual breast phantoms that were based on dedicated breast computed tomography images of human subjects. The phantoms were fabricated by high-resolution multimaterial additive manufacturing (3D printing) technology. The glandular equivalency of the photopolymer materials was measured relative to breast tissue-equivalent plastic materials. Based on the current state-of-the-art in the technology and available materials, two variations were fabricated. The first was a dual-material phantom, the Doublet. Fibroglandular tissue and skin were represented by the most radiographically dense material available; adipose tissue was represented by the least radiographically dense material. The second variation, the Singlet, was fabricated with a single material to represent fibroglandular tissue and skin. It was subsequently filled with adipose-equivalent materials including oil, beeswax, and permanent urethane-based polymer. Simulated microcalcification clusters were further included in the phantoms via crushed eggshells. The phantoms were imaged and characterized visually and quantitatively.
  
  
  RESULTS
  The mammographic projections and tomosynthesis reconstructed images of the fabricated phantoms yielded realistic breast background. The mammograms of the phantoms demonstrated close correlation with simulated mammographic projection images of the corresponding virtual phantoms. Furthermore, power-law descriptions of the phantom images were in general agreement with real human images. The Singlet approach offered more realistic contrast as compared to the Doublet approach, but at the expense of air bubbles and air pockets that formed during the filling process.
  
  
  CONCLUSIONS
  The presented physical breast phantoms and their matching virtual breast phantoms offer realistic breast anatomy, patient variability, and ease of use, making them a potential candidate for performing both system quality control testing and virtual clinical trials.
authors.affiliation: Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 and Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708.
authors.forename: Nooshin
authors.initials: N
authors.lastname: Kiarashi
authors.affiliation: Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708.
authors.forename: Adam C
authors.initials: AC
authors.lastname: Nolte
authors.affiliation: Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Sturgeon
authors.affiliation: Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27708.
authors.forename: William P
authors.initials: WP
authors.lastname: Segars
authors.affiliation: Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710.
authors.forename: Sujata V
authors.initials: SV
authors.lastname: Ghate
authors.affiliation: Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708.
authors.forename: Loren W
authors.initials: LW
authors.lastname: Nolte
authors.affiliation: Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710; Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708; Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708; Medical Physics Graduate Program, Duke University, Durham, North Carolina 27708; and Department of Physics, Duke University, Durham, North Carolina 27708.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Samei
authors.affiliation: Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710; Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708; Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708; and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27708.
authors.forename: Joseph Y
authors.initials: JY
authors.lastname: Lo
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging; D000818:Animals; D001940:Breast; D002114:Calcinosis / Q000000981:diagnostic imaging; D003198:Computer Simulation; D004528:Egg Shell; D004867:Equipment Design; D006801:Humans; D008327:Mammography; D008954:Models, Biological; D019047:Phantoms, Imaging; D066330:Printing, Three-Dimensional; D012867:Skin / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed