X-ray Grating Phase Contrast Imaging with Conventional Sources
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for generating high-contrast, localized sinusoidal or stepped-intensity modulated patterns using spatially non-coherent illumination, such as hard x-rays, are limited by the need for expensive synchrotron sources and are not suitable for imaging soft-tissue structures with low density, requiring complex setups and high-resolution detectors.
Innovation Solution
A device comprising a standard polychromatic x-ray source, a compound refractive x-ray lens or Billet split lens, and a position-sensitive detector with spatially modulated detection sensitivity, which separates and focuses x-ray beams, and uses a one- or two-dimensional grating structure as an analyzer to produce phase contrast and scattering images without relying on synchrotron sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If synchrotron sources are used to generate high-contrast modulated patterns, then image quality and phase contrast are improved, but device cost and accessibility deteriorate
Solution Approach 1:
The patent replaces expensive, complex synchrotron sources with conventional, inexpensive x-ray tubes. The x-ray tube is a simple, widely available component that can be easily replaced if needed, making the system accessible to ordinary laboratories rather than requiring specialized synchrotron facilities.
Solution Approach 2:
The patent introduces an x-ray grating as an intermediary optical element that converts the beam from a conventional x-ray tube into the required modulated pattern. This grating serves as a mediator that enables phase contrast imaging with simple sources by creating the necessary intensity modulations that would otherwise require complex synchrotron facilities.
2Device complexity
If conventional x-ray tubes are used instead of synchrotron sources, then device complexity and cost are reduced, but spatial coherence and pattern contrast deteriorate
Solution Approach 1:
The patent uses an x-ray grating with periodic structure to segment the x-ray beam into multiple beams with different paths. This segmentation creates the required intensity modulated pattern by interfering the segmented beams, thereby generating high contrast patterns even from spatially incoherent conventional x-ray tube sources.
Solution Approach 2:
The patent changes the spatial coherence parameter requirement by using a grating-based interferometer setup. Instead of requiring high spatial coherence from the source, the system uses the grating to create interference patterns that are insensitive to source coherence, effectively changing the operational parameters to match conventional x-ray tube capabilities.
3Measurement precision
If high-resolution detectors are used to resolve micrometer-scale interference patterns, then measurement precision is improved, but device cost and complexity deteriorate
Solution Approach 1:
The patent moves the interference pattern from the lateral plane to the longitudinal dimension by using the Talbot-Lau effect. The self-imaging property creates periodic intensity patterns at different distances along the beam path, allowing standard detectors to resolve the pattern by positioning at appropriate distances rather than requiring micrometer-scale lateral resolution.
Solution Approach 2:
The patent uses the Talbot self-imaging effect to create a copy of the grating pattern at a different location in space. This copied pattern appears at the Talbot distance without requiring lenses or complex optics, allowing standard detectors to capture the interference pattern with their native resolution capabilities.
4Adaptability or versatility
If the Talbot-Lau effect is used with two gratings, then phase contrast imaging is enabled with incoherent sources, but device complexity and alignment requirements increase
Solution Approach 1:
The patent makes the x-ray grating serve multiple functions: it acts as both the object grating that creates the initial modulation and the analyzer grating that detects the phase information. This multi-functionality reduces the number of components and simplifies alignment requirements while maintaining the phase contrast imaging capability with incoherent sources.
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
Enables the generation of high-contrast images using conventional x-ray sources, reducing the x-ray dose and improving image resolution, allowing for efficient use of laboratory sources and easier detection of phase and scattering features in soft-tissue structures.
Implementation Method 1
incident radiation is refracted by spatially oriented molecular and atomic planes, thereby experiencing a significant shift in phase
Implementation Method 2
a compound refractive x-ray lens or Billet split lens, and a position-sensitive detector with spatially modulated detection sensitivity, which separates and focuses x-ray beams
Implementation Method 3
an intensity grid to modulate the intensity of a beam of an X-radiation illumination beam
Implementation Method 4
The Talbot-Lau self-imaging effect, i.e., its replication in the longitudinal direction without the use of a lens, has been widely studied and used for a number of applications, including x-ray phase imaging
Implementation Method 5
The elastic scattering causes a phase shift of the wave passing through matter. Thus, the possibility to record the elastic scattering and phase shift of x-rays opens the potential for greatly enhanced contrast
Implementation Method 6
A method and device is disclosed for the generation of high-contrast, localized sinusoidal patterns or stepped-intensity modulated patterns from spatially non-coherent or coherent illumination
Data Source
AI summary
A method and device is disclosed for the generation of high-contrast, localized sinusoidal patterns or stepped-intensity modulated patterns from spatially non-coherent or coherent illumination, and using such patterns for imaging the internal features of objects.