Segmented X-ray Diffraction Grating for Phase-Contrast Imaging
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Solution Overview
Problem
In differential phase-contrast imaging, the analyzer grating partially absorbs X-ray radiation, limiting its utilization for recording image data, which reduces the efficiency of X-ray radiation usage.
Innovation Solution
A diffraction grating with alternating sub-areas, where one sub-area changes the phase of X-ray radiation and the other sub-area is X-ray transparent, allowing for increased radiation usage by alternating the grating structure to record both phase-contrast and density information during image acquisition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional analyzer grating with continuous grating structure is used, then phase-contrast imaging is achieved, but X-ray radiation is partially absorbed limiting image data recording efficiency
Solution Approach 1:
The analyzer grating is segmented into alternating first sub-areas with grating structure and second sub-areas that are X-ray transparent, arranged in a chessboard pattern. This segmentation allows different regions to serve different functions: grating sub-areas for phase-contrast information and transparent sub-areas for density information, thereby reducing overall radiation absorption while maintaining imaging capability.
Solution Approach 2:
Different sub-areas of the analyzer grating are assigned different local properties: first sub-areas have grating structure for phase modulation, while second sub-areas are made X-ray transparent. This local differentiation optimizes the grating's performance by allowing simultaneous capture of phase-contrast and density information with reduced radiation loss.
2Measurement precision
If the analyzer grating absorbs more X-ray radiation to improve image quality, then contrast is enhanced, but the efficiency of X-ray radiation usage decreases
Solution Approach 1:
The analyzer grating is designed to perform multiple functions simultaneously: the first sub-areas provide phase-contrast information while the second transparent sub-areas provide density information. This multi-functionality allows both types of imaging data to be captured in a single exposure, improving radiation usage efficiency without sacrificing image contrast quality.
3Ease of manufacture
If a uniform grating structure is used across the entire analyzer grating area, then manufacturing is simplified, but radiation absorption is increased reducing usable X-ray dose
Solution Approach 1:
The grating structure is divided into repeating units of first and second sub-areas arranged in a chessboard pattern. This segmented approach maintains manufacturing simplicity through periodic repetition while significantly reducing radiation absorption by incorporating transparent regions, thereby increasing the usable X-ray dose.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the utilization of X-ray radiation, allowing for the recording of both phase-contrast and density information, thereby improving the efficiency of X-ray imaging systems by reducing radiation absorption and increasing the amount of usable X-ray dose.
Implementation Method 1
the bars are arranged such that they change the phase of an X-ray radiation
Implementation Method 2
the bars of the analyzer grating are X-ray absorbing such that they are changing the amplitude of X-ray radiation passing the grating
Implementation Method 3
a phase grating for X-ray differential phase-contrast imaging comprising a plurality of portions of a first sub-area and a plurality of portions of a second sub-area
Data Source
Figure 1
Figure 2
Figure 3a~5
AI summary
The present invention relates to differential phase-contrast imaging, in particular to a structure of a diffraction grating, e.g. an analyzer grating and a phase grating, for X-ray differential phase-contrast imaging. In order to make better use of the X-ray radiation passing the object, a diffraction grating (14) for X-ray differential phase-contrast imaging is provided with at least one portion (24) of a first sub-area (26) and at least one portion (28) of a second sub-area (30). The first sub-area comprises a grating structure (54) with a plurality of bars (34) and gaps (36) being arranged periodically with a first grating pitch P G (38), wherein the bars are arranged such that thy change the phase and/or amplitude of an X-ray radiation and wherein the gaps are X-ray transparent. The second sub-area is X-ray transparent and wherein the at least one portion of the second sub-area provides an X-ray 1 transparent aperture (40) in the grating. Portions of the first and second sub-areas are arranged in an alternating manner in at least one direction (42).