title: Low-dose, phase-contrast mammography with high signal-to-noise ratio.
abstract: Differential phase-contrast X-ray imaging using a Talbot-Lau interferometer has recently shown promising results for applications in medical imaging. However, reducing the applied radiation dose remains a major challenge. In this study, we consider the realization of a Talbot-Lau interferometer in a high Talbot order to increase the signal-to-noise ratio for low-dose applications. The quantitative performance of π and π/2 systems at high Talbot orders is analyzed through simulations, and the design energy and X-ray spectrum are optimized for mammography. It is found that operation even at very high Talbot orders is feasible and beneficial for image quality. As long as the X-ray spectrum is matched to the visibility spectrum, the SNR continuously increases with the Talbot order for π-systems. We find that the optimal X-ray spectra and design energies are almost independent of the Talbot order and that the overall imaging performance is robust against small variations in these parameters. Discontinuous spectra, such as that from molybdenum, are less robust because the characteristic lines may coincide with minima in the visibility spectra; however, they may offer slightly better performance. We verify this hypothesis by realizing a prototype system with a mean fringe visibility of above 40% at the seventh Talbot order. With this prototype, a proof-of-principle measurement of a freshly dissected breast at reasonable compression to 4 cm is conducted with a mean glandular dose of only 3 mGy but with a high SNR.
authors.affiliation: Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany; GE Global Research, 85748 Garching, Germany.
authors.forename: Lukas B
authors.initials: LB
authors.lastname: Gromann
authors.affiliation: GE Global Research, 85748 Garching, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Bequé
authors.affiliation: Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Scherer
authors.affiliation: Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Willer
authors.affiliation: Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Birnbacher
authors.affiliation: Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany.
authors.forename: Marian
authors.initials: M
authors.lastname: Willner
authors.affiliation: Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Herzen
authors.affiliation: Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Grandl
authors.affiliation: Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Hellerhoff
authors.affiliation: GE Global Research, 85748 Garching, Germany.
authors.forename: Jonathan I
authors.initials: JI
authors.lastname: Sperl
authors.affiliation: Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Pfeiffer
authors.affiliation: GE Global Research, 85748 Garching, Germany.
authors.forename: Cristina
authors.initials: C
authors.lastname: Cozzini
keywords: (050.2770) Gratings; (050.5080) Phase shift; (170.0110) Imaging systems; (340.7450) X-ray interferometry