X-ray grating interferometer phase contrast imaging
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Solution Overview
Problem
Conventional medical x-ray imaging struggles with low contrast in soft tissues due to the lack of phase shift information, which is not recorded in conventional absorption-based imaging, limiting diagnostic capabilities for tissues like soft tissues, vessels, cartilages, and lungs.
Innovation Solution
A digital radiographic phase-contrast imaging system using an x-ray grating interferometer with a source grating, phase grating, and analyzer grating to produce images at different relative beam energies, enabling the collection of phase shift information with a single x-ray exposure, suitable for large field of view radiographic medical imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional absorption-based x-ray imaging is used, then the imaging system is simple and fast, but the contrast in soft tissues is poor
Solution Approach 1:
The patent introduces an x-ray grating interferometer as an intermediary device between the x-ray source and detector. This interferometer includes a phase grating that modulates the x-ray beam to encode phase shift information, and an analyzer grating that decodes this information at the detector plane. The intermediary interferometer system enables recovery of phase shift information that would otherwise be lost in conventional absorption-based imaging, thereby improving soft tissue contrast and diagnostic capability without requiring fundamental changes to the overall imaging architecture.
2Reliability
If spectral imaging techniques are implemented in conventional absorption imaging, then material differentiation is improved, but the system complexity increases
Solution Approach 1:
The patent merges spectral imaging capability with phase contrast imaging by integrating the grating interferometer with an energy-resolving detector. This combination allows simultaneous acquisition of both phase shift information and energy-dependent absorption information in a single imaging setup. The merged system provides material differentiation through spectral analysis while maintaining the relative simplicity of the grating interferometer approach, avoiding the need for separate spectral imaging systems.
3Loss of information
If multiple x-ray exposures at different energies are performed, then spectral information is obtained, but the imaging time and motion artifacts increase
Solution Approach 1:
The patent implements continuous spectral phase contrast imaging by combining the grating interferometer with an energy-resolving detector that can distinguish different x-ray energies. This continuous action approach captures both phase and spectral information in a single uninterrupted exposure, eliminating the need for multiple sequential exposures. The system continuously records energy-dependent phase shifts across the entire x-ray spectrum simultaneously, thereby obtaining complete spectral information without increasing imaging time or introducing motion artifacts.
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
Enhances contrast in low-absorbing tissues, improving diagnostic capabilities by capturing both absorption and phase shift information, enabling clearer imaging of soft tissues and other low-contrast areas with reduced radiation dose and motion artifacts.
Implementation Method 1
the principle of PCI is based on the wave nature of x-rays, where refraction and diffraction properties need to be considered
Implementation Method 2
the principle of PCI is based on the wave nature of x-rays, where refraction and diffraction properties need to be considered
Implementation Method 3
an analyzer grating to interact with the periodic pattern at a Talbot distance behind the phase grating
Implementation Method 4
an analyzer grating to interact with the periodic pattern at a Talbot distance behind the phase grating
Implementation Method 5
a polychromatic x-ray source to provide a beam having a spectrum of energies
Implementation Method 6
an energy-resolving detector to distinguish between different energies of the beam
Data Source
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AI summary
Embodiments of methods and apparatus are disclosed for obtaining a phase-contrast digital radiographic imaging system and methods for same that can include an x-ray source for radiographic imaging; a beam shaping assembly including a collimator and a source grating, an x-ray grating interferometer including a phase grating, and an analyzer grating; and an x-ray detector, where a single arrangement of the beam shaping assembly, the x-ray grating interferometer and a position of the detector is configured to provide spectral information (e.g. at least two images obtained at different relative beam energies).