Radiography Detector Macro-Pixel Layout for Beam-Width Consistency
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Solution Overview
Problem
In photon counting computed tomography (PCCT) apparatuses, the effective beam width can vary depending on the arrangement of macro-pixels, potentially falling below the set beam width, leading to degraded image quality.
Innovation Solution
A radiography apparatus with a radiation detector configured to include first and second macro-pixels arranged such that the effective beam width remains within a predetermined range, using a larger first number of sub-pixels for first macro-pixels and a smaller second number for second macro-pixels, and employing an image processing unit to correct artifacts and distribute photon counts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If macro-pixels are configured by grouping sub-pixels with different numbers (first macro-pixels with six sub-pixels and second macro-pixels with five sub-pixels), then the detector can accommodate non-divisible total sub-pixel counts, but the effective beam width varies depending on the arrangement of second macro-pixels and may fall below the set beam width
Solution Approach 1:
The patent applies local quality by making different parts of the detector have different macro-pixel configurations. First macro-pixels group six sub-pixels while second macro-pixels group five sub-pixels. This local differentiation allows the system to accommodate non-divisible total sub-pixel counts while maintaining overall system functionality.
Solution Approach 2:
The patent employs asymmetry by arranging second macro-pixels at unequal pitches rather than uniform intervals. This asymmetric arrangement, combined with strategic positioning, ensures that the effective beam width remains within the predetermined range across all imaging modes, preventing beam width degradation.
2Ease of operation
If the effective beam width falls below the set beam width due to macro-pixel arrangement, then the system can operate with the given detector configuration, but the image quality of tomographic images is degraded
Solution Approach 1:
The patent implements feedback through image processing that corrects artifacts caused by the unequal pitch arrangement of second macro-pixels. The system detects the specific arrangement pattern and applies corresponding corrections to maintain image quality despite the non-uniform macro-pixel distribution.
Solution Approach 2:
The patent changes the arrangement parameters of second macro-pixels, positioning them at specific unequal pitches rather than uniform intervals. This parameter optimization ensures that the effective beam width remains within the predetermined range, preventing beam width degradation while maintaining system operability.
3Manufacturing precision
If second macro-pixels are arranged at unequal pitches to maintain effective beam width, then beam width consistency is improved, but artifacts with specific frequencies are generated in the images
Solution Approach 1:
The patent converts the potential harm of unequal pitch arrangement into a benefit by strategically positioning second macro-pixels at specific unequal pitches. This controlled asymmetry maintains effective beam width consistency while the generated artifacts have predictable frequencies that can be corrected through image processing.
Solution Approach 2:
The patent introduces image processing as an intermediary that mediates between the unequal pitch macro-pixel arrangement and the final image output. This intermediary corrects the artifacts generated by the asymmetric arrangement, eliminating the harmful effects while preserving the beam width consistency benefits.
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
Ensures consistent effective beam width across different imaging modes, maintaining image quality by preventing beam width degradation and correcting artifacts.
Implementation Method 1
incident photons are converted into charges in a semiconductor layer, and the photon counting is performed by a photon counting circuit counting the converted charges
Data Source
AI summary
The radiography apparatus performs imaging in a plurality of imaging modes having different set beam widths in a rotation axis direction. A radiation detector has a plurality of sub-pixels arranged in a first direction parallel to the rotation axis and a second direction orthogonal to the rotation axis, a plurality of first macro-pixels, each of which is obtained by grouping a first number of sub-pixels arranged in the first direction, and a plurality of second macro-pixels, each of which is obtained by grouping a second number of sub-pixels arranged in the first direction are provided and the second macro-pixels are arranged such that the effective beam width decided by the numbers of the first macro-pixels and the second macro-pixels configuring slices in a number corresponding to the set beam width is in a predetermined range in which the effective beam width does not fall below each set beam width.