Large field-of-view tiled grating structures for X-ray phase-contrast imaging.

X-ray grating-based interferometry promises unique new diagnostic possibilities in medical imaging and materials analysis. To transfer this method from scientific laboratories or small-animal applications to clinical radiography applications, compact setups with a large field of view (FoV) are required. Currently the FoV is limited by the grating area, which is restricted due to the complex manufacturing process. One possibility to increase the FoV is tiling individual grating tiles to create one large area grating mounted on a carrier substrate. We investigate theoretically the accuracy needed for a tiling process in all degrees of freedom by applying a simulation approach. We show how the resulting precision requirements can be met using a custom-built frame for exact positioning. Precise alignment is achieved by comparing the fringe patterns of two neighboring grating tiles in a grating interferometer. With this method, the FoV can be extended to practically any desired length in one dimension. First results of a phase-contrast scanning setup with a full FoV of 384 mm × 24 mm show the suitability of this method.

[1]  A Faisal,et al.  Increasing the field of view in grating based X-ray phase contrast imaging using stitched gratings. , 2016, Journal of X-ray science and technology.

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

[3]  Juerg Leuthold,et al.  High aspect ratio gratings for X-ray phase contrast imaging , 2012 .

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

[5]  M. Stampanoni,et al.  Compact hard X-ray grating interferometry for table top phase contrast micro CT , 2013, Medical Imaging.

[6]  K. Nugent.  Coherent methods in the X-ray sciences , 2009, 0908.3064.

[7]  S Auweter,et al.  Energy-resolved visibility analysis of grating interferometers operated at polychromatic X-ray sources. , 2014, Optics express.

[8]  Juergen Mohr,et al.  Soft X-ray lithography of high aspect ratio SU8 submicron structures , 2008 .

[9]  Franz Pfeiffer,et al.  Fabrication of diffraction gratings for hard X-ray phase contrast imaging , 2007 .

[10]  Rainer Raupach,et al.  Analytical evaluation of the signal and noise propagation in x-ray differential phase-contrast computed tomography , 2011, Physics in medicine and biology.

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

[12]  T. Hattori,et al.  Fabrication of Diffraction Grating with High Aspect Ratio Using X-ray Lithography Technique for X-ray Phase Imaging , 2007 .

[13]  Franz Pfeiffer,et al.  Inverse geometry for grating-based x-ray phase-contrast imaging , 2009 .

[14]  Urs Sennhauser,et al.  X-ray interferometer with bent gratings: Towards larger fields of view , 2011 .

[15]  High aspect ratio, Large area silicon-based gratings for X-ray phase contrast imaging , 2014, 2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS).

[16]  T E Gureyev,et al.  On the evolution and relative merits of hard X-ray phase-contrast imaging methods , 2014, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[17]  Franz Pfeiffer,et al.  Grating-based X-ray phase contrast for biomedical imaging applications. , 2013, Zeitschrift fur medizinische Physik.

[18]  Peter Modregger,et al.  Sensitivity in X-ray grating interferometry on compact systems , 2012 .

[19]  F. Pfeiffer,et al.  Phase-contrast CT: qualitative and quantitative evaluation of atherosclerotic carotid artery plaque. , 2014, Radiology.

[20]  O. Bunk,et al.  Grating interferometer based scanning setup for hard X-ray phase contrast imaging. , 2007, The Review of scientific instruments.

[21]  O. Bunk,et al.  The fractional Talbot effect in differential x‐ray phase‐contrast imaging for extended and polychromatic x‐ray sources , 2008, Journal of microscopy.

[22]  A Faisal,et al.  Note: Gratings on low absorbing substrates for x-ray phase contrast imaging. , 2015, The Review of scientific instruments.

[23]  M Stampanoni,et al.  Sensitivity of X-ray grating interferometry. , 2011, Optics express.

[24]  Franz Pfeiffer,et al.  Experimental Realisation of High-sensitivity Laboratory X-ray Grating-based Phase-contrast Computed Tomography , 2016, Scientific Reports.

[25]  Timm Weitkamp,et al.  Tomography with grating interferometers at low-brilliance sources , 2006, SPIE Optics + Photonics.

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

[27]  O. Bunk,et al.  Hard-X-ray dark-field imaging using a grating interferometer. , 2008, Nature materials.