Imaging System K-Edge Component Determination
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Solution Overview
Problem
Existing imaging systems using truncated projections generate images with artifacts due to interpolation techniques and adapted backprojection filters, resulting in poor image quality.
Innovation Solution
An imaging system that determines the k-edge component of an object or substance from truncated projections and calculates non-truncated projections using a system of equations modeling the photo-electric, Compton, and k-edge effects, allowing for artifact-free image reconstruction with improved quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If interpolation techniques are used to complete truncated projections, then non-truncated projections can be obtained, but image artefacts are generated due to approximation errors
Solution Approach 1:
The patent changes the parameter approach by using energy-resolving detection to measure attenuation at multiple energy levels, transforming the problem from spatial interpolation to energy-based material decomposition. This allows direct calculation of k-edge components without interpolating missing spatial data, eliminating artefacts while completing truncated projections
Solution Approach 2:
The patent introduces k-edge component determination as an intermediary step between truncated projection acquisition and final image reconstruction. By first extracting material-specific k-edge components from truncated data, then using these components to generate complete projections, the method avoids direct interpolation of missing projection data while achieving complete image reconstruction
2Ease of operation
If adapted backprojection filters are used to backproject truncated projections, then image reconstruction is possible, but artefacts are generated in the reconstructed images
Solution Approach 1:
The patent performs preliminary action by determining k-edge components from truncated projections before the backprojection step. This preliminary material decomposition allows subsequent generation of complete projections that are free from truncation artefacts, eliminating the need for adapted backprojection filters that attempt to correct artefacts after they are introduced
3Measurement precision
If energy-resolving radiation detectors and k-edge component determination are used, then non-truncated projections can be determined from truncated data, but device complexity increases
Solution Approach 1:
The patent applies multi-functionality by using the energy-resolving detector for dual purposes: first for routine attenuation measurement across all energies, and second for specific k-edge component determination. This allows the same hardware to perform both standard CT imaging and advanced material decomposition without requiring separate specialized devices
Solution Approach 2:
The patent segments the attenuation measurement process into distinct energy-based components (photoelectric effect, Compton scattering, k-edge effects) that can be independently determined and combined. This segmentation allows complex material decomposition to be achieved through systematic analysis of energy-resolved data rather than requiring complex hardware modifications
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
The system produces images with reduced artifacts and improved quality by using energy-resolving radiation detectors and numerical methods to determine k-edge components, enabling high-quality image reconstruction without increasing the overall radiation dose.
Implementation Method 1
a combination of the photo-electric effect with a first spectrum, the compton effect with a second spectrum and the remaining attenuation of at least one of the object or of a substance within the object with a k-edge in the interesting energy range with a third spectrum (k-edge effect)
Implementation Method 2
a combination of the photo-electric effect with a first spectrum, the compton effect with a second spectrum and the remaining attenuation of at least one of the object or of a substance within the object with a k-edge in the interesting energy range with a third spectrum (k-edge effect)
Implementation Method 3
an energy-resolving radiation detector for obtaining detection signals depending on the radiation after passing through the object
Implementation Method 4
the remaining attenuation of at least one of the object or of a substance within the object with a k-edge in the interesting energy range with a third spectrum (k-edge effect)
Data Source
AI summary
The present invention relates to an imaging system for imaging an object (20) comprising a polychromatic radiation source (2) and an energy resolving radiation detector (6). The imaging system comprises further a driving device for moving the object (20) and the radiation source (2) relatively to each other, in order to acquire truncated projections from different directions. A calculation unit determines a k-edge component at least of one of the object (20) and a substance within the object (20) from the truncated projections and determines non-truncated projections from the determined k-edge component. A reconstruction unit constructs the object using the non-truncated projections.