Quantitative X-ray phase-contrast computed tomography at 82 keV.

Potential applications of grating-based X-ray phase-contrast imaging are investigated in various fields due to its compatibility with laboratory X-ray sources. So far the method was mainly restricted to X-ray energies below 40 keV, which is too low to examine dense or thick objects, but a routine operation at higher energies is on the brink of realisation. In this study, imaging results obtained at 82 keV are presented. These comprise a test object consisting of well-defined materials for a quantitative analysis and a tooth to translate the findings to a biomedical sample. Measured linear attenuation coefficients ? and electron densities ?e are in good agreement with theoretical values. Improved contrast-to-noise ratios were found in phase contrast compared to attenuation contrast. The combination of both contrast modalities further enables to simultaneously assess information on density and composition of materials with effective atomic numbers Z? > 8. In our biomedical example, we demonstrate the possibility to detect differences in mass density and calcium concentration within teeth.

[1]  Franz Pfeiffer,et al.  Experimental results from a preclinical X-ray phase-contrast CT scanner , 2012, Proceedings of the National Academy of Sciences.

[2]  Franz Pfeiffer,et al.  Quantitative phase-contrast tomography of a liquid phantom using a conventional x-ray tube source. , 2009, Optics express.

[3]  Dan Stutman,et al.  Talbot phase-contrast x-ray imaging for the small joints of the hand , 2011, Physics in medicine and biology.

[4]  A Bravin,et al.  High-resolution brain tumor visualization using three-dimensional x-ray phase contrast tomography , 2007, Physics in medicine and biology.

[5]  Franz Pfeiffer,et al.  X-ray grating interferometer for materials-science imaging at a low-coherent wiggler source. , 2011, The Review of scientific instruments.

[6]  F. Brudevold,et al.  The distribution and composition of density fractions from human crown dentine. , 1969, Archives of oral biology.

[7]  Peter Modregger,et al.  High resolution, large field of view x-ray differential phase contrast imaging on a compact setup , 2011 .

[8]  Maria del Pilar Gutiérrez-Salazar,et al.  Microhardness and chemical composition of human tooth , 2003 .

[9]  Arne Tapfer,et al.  Recent developments in x-ray Talbot interferometry at ESRF-ID19 , 2010, Optical Engineering + Applications.

[10]  S. Weidmann,et al.  Variations of enamel density in sections of human teeth. , 1967, Archives of oral biology.

[11]  Claus Urban,et al.  Dual energy phase contrast x-ray imaging with Talbot-Lau interferometer , 2010 .

[12]  Franz Pfeiffer,et al.  Phase-contrast imaging and tomography at 60 keV using a conventional x-ray tube source. , 2009, The Review of scientific instruments.

[13]  Karen J. Olsen,et al.  X-Ray Form Factor, Attenuation and Scattering Tables (version 2.0) , 2003 .

[14]  Timm Weitkamp,et al.  Quantitative phase and absorption tomography with an X-ray grating interferometer and synchrotron radiation , 2011 .

[15]  O. Bunk,et al.  Phase retrieval and differential phase-contrast imaging with low-brilliance X-ray sources , 2006 .

[16]  Franz Pfeiffer,et al.  X-ray phase-contrast tomography of porcine fat and rind. , 2011, Meat science.

[17]  Aimin Yan,et al.  X-ray phase-attenuation duality and phase retrieval. , 2005, Optics letters.

[18]  Franz Pfeiffer,et al.  High-resolution tomographic imaging of a human cerebellum: comparison of absorption and grating-based phase contrast , 2010, Journal of The Royal Society Interface.

[19]  O. Bunk,et al.  Hard x-ray phase tomography with low-brilliance sources. , 2007, Physical review letters.

[20]  E. McCullough,et al.  Photon attenuation in computed tomography. , 1975, Medical physics.

[21]  Franz Pfeiffer,et al.  Assessment of grating-based X-ray phase-contrast CT for differentiation of invasive ductal carcinoma and ductal carcinoma in situ in an experimental ex vivo set-up , 2013, European Radiology.

[22]  Franz Pfeiffer,et al.  Soft-tissue phase-contrast tomography with an x-ray tube source , 2009, Physics in medicine and biology.

[23]  Johannes Kenntner,et al.  Fabrication and characterization of analyzer gratings with high aspect ratios for phase contrast imaging using a Talbot interferometer , 2012 .

[24]  Guang-Hong Chen,et al.  Quantitative imaging of electron density and effective atomic number using phase contrast CT. , 2010, Physics in medicine and biology.

[25]  A. Momose.  Recent Advances in X-ray Phase Imaging , 2005 .

[26]  C. David,et al.  The First Analysis and Clinical Evaluation of Native Breast Tissue Using Differential Phase-Contrast Mammography , 2011, Investigative radiology.

[27]  Franz Pfeiffer,et al.  Toward Clinical X-ray Phase-Contrast CT: Demonstration of Enhanced Soft-Tissue Contrast in Human Specimen , 2010, Investigative radiology.

[28]  Axel Lange,et al.  Numerical correction of X-ray detector backlighting , 2012 .

[29]  J. H. Hubbell,et al.  XCOM: Photon Cross Section Database (version 1.2) , 1999 .

[30]  Atsushi Momose,et al.  High-speed X-ray phase imaging and X-ray phase tomography with Talbot interferometer and white synchrotron radiation. , 2009, Optics express.

[31]  Franz Pfeiffer,et al.  X-ray phase imaging with a grating interferometer. , 2005, Optics express.

[32]  A. Ritter,et al.  Grating-based high energy X-ray interferometry with the Medipix-detector in simulation and measurement , 2010 .