title: X-ray phase-contrast tomosynthesis for improved breast tissue discrimination.
abstract: OBJECTIVE
  Attenuation-based tomosynthesis has proven to successfully resolve the glandular tissue overlap present in mammography. However, the ability of tomosynthesis to differentiate tumorous and glandular tissue remains limited, due to the small differences in X-ray attenuation in breast tissue. One possibility to overcome this limitation and to further increase the diagnostic value of tomosynthesis exams, is the application of recently developed grating-based phase-contrast methods, which provide complementary information on the phase shift and the local scattering power of the sample. In this study, we report on first phase-contrast breast tomosynthesis results of a mastectomy sample slice with an invasive ductal carcinoma.
  
  
  METHODS
  A slice of a mastectomy sample with histologically proven invasive ductal cancer was imaged at the synchrotron radiation source ESRF (Grenoble, France). We used a two-grating interferometer setup at the ninth fractional Talbot distance and with an X-ray energy of 23 keV. In grating interferometry absorption, differential phase, and scattering images are recorded simultaneously. The tomosynthesis scan comprises 61 projections. Multimodal tomosynthesis results were reconstructed using a standard filtered back-projection approach. Our findings are supported by a comparison of tomographic views to histopathology.
  
  
  RESULTS
  Phase-contrast tomosynthesis combines the advantage of improved soft-tissue discrimination in phase-contrast imaging with the ability of tomosynthesis to provide a third dimension so that improved feature visibility is not hampered by superposition artifacts. Our results indicate superior diagnostic value due to the depth resolution supplied in tomosynthesis imaging; a region of necrotic tissue that is obscured in a projection image can clearly be depicted in one single tomosynthesis slice. Compared to absorption tomosynthesis alone, soft tissue contrast is significantly enhanced in phase-contrast tomosynthesis views, where fibrous structures are clearly visible.
  
  
  CONCLUSIONS
  In this article we present the first proof-of-principle grating-based phase-contrast tomosynthesis of a mastectomy sample section. A comparison of conventional attenuation with phase-contrast and dark-field tomosynthesis indicates that complementary information from three signals yields an increase in diagnostic value, which is verified in a comparison of our results to histological sections of the sample. As grating-based phase-contrast mammography efficiently works with conventional lab sources, our benchmark results indicate the potential benefit of translating phase-contrast tomosynthesis into a clinical setting.
authors.affiliation: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany. Electronic address: Schleede@tum.de.
authors.forename: Simone
authors.initials: S
authors.lastname: Schleede
authors.affiliation: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany; Medical Radiation Physics, Lund University, 22185 Lund, Sweden. Electronic address: martin.bech@tum.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Bech
authors.affiliation: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 München, Germany. Electronic address: Susanne.Grandl@med.uni-muenchen.de.
authors.forename: Susanne
authors.initials: S
authors.lastname: Grandl
authors.affiliation: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 München, Germany. Electronic address: Aniko.Sztrokay@med.uni-muenchen.de.
authors.forename: Aniko
authors.initials: A
authors.lastname: Sztrókay
authors.affiliation: Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Strasse 1, 21502 Geesthacht, Germany. Electronic address: julia.herzen@hzg.de.
authors.forename: Julia
authors.initials: J
authors.lastname: Herzen
authors.affiliation: Institute of Pathology, Ludwig-Maximilians-Universität München, Thalkirchner Str. 36, 80337 Munich, Germany. Electronic address: doris.mayr@med.uni-muenchen.de.
authors.forename: Doris
authors.initials: D
authors.lastname: Mayr
authors.affiliation: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany. Electronic address: marco.stockmar@ph.tum.de.
authors.forename: Marco
authors.initials: M
authors.lastname: Stockmar
authors.affiliation: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany. Electronic address: potdevinguillaume@gmail.com.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Potdevin
authors.affiliation: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany; European Synchrotron Radiation Facility (ESRF), 6, Rue Jules Horowitz, 38000 Grenoble, France. Electronic address: irene.zanette@tum.de.
authors.forename: Irene
authors.initials: I
authors.lastname: Zanette
authors.affiliation: European Synchrotron Radiation Facility (ESRF), 6, Rue Jules Horowitz, 38000 Grenoble, France. Electronic address: alexander.rack@esrf.fr.
authors.forename: Alexander
authors.initials: A
authors.lastname: Rack
authors.affiliation: Synchrotron Soleil, L'Orme der Merisiers, Saint Aubin, 91192 Gir-sur-Yvette, France. Electronic address: weitkamp@synchrotron-soleil.fr.
authors.forename: Timm
authors.initials: T
authors.lastname: Weitkamp
authors.affiliation: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany. Electronic address: franz.pfeiffer@ph.tum.de.
authors.forename: Franz
authors.initials: F
authors.lastname: Pfeiffer
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging* / Q000601:surgery; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008408:Mastectomy; D010865:Pilot Projects; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Breast imaging; Grating interferometer; Mammography; Tomosynthesis; X-ray phase contrast