Anti-charge-sharing grid for photon-counting CT detection pixels
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Solution Overview
Problem
Photon counting computed tomography systems face reduced spectral performance due to charge-sharing effects, where charge from a single photon is shared between neighboring detection pixels, leading to a loss of energy information and reduced image quality, and existing solutions like anti-scatter grids compromise detective quantum efficiency.
Innovation Solution
A detection values determination system with an anti-charge-sharing grid that clusters detection pixels, allowing charge-sharing correction only within clusters, thereby minimizing the area covered by the grid and maintaining high detective quantum efficiency while correcting for intracluster charge sharing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an anti-scatter grid is provided to cover regions between anode pads to reduce charge sharing, then charge sharing is suppressed, but detective quantum efficiency is significantly reduced
Solution Approach 1:
The detection surface is divided into clusters of detection pixels, with anti-charge-sharing grid structures positioned between clusters rather than between all individual pixels. This segmentation approach suppresses charge sharing at the cluster level while leaving inter-pixel regions within clusters uncovered, thereby maintaining detective quantum efficiency while reducing charge sharing effects.
Solution Approach 2:
The anti-charge-sharing grid is selectively applied only in specific regions between clusters of detection pixels, rather than uniformly across the entire detection surface. This localized application suppresses charge sharing where it most impacts spectral performance while preserving detective quantum efficiency in regions where the grid is not present.
2Measurement precision
If an anti-charge-sharing grid covers all regions between detection pixels to suppress charge sharing, then charge sharing is reduced, but the area covered by the grid increases leading to lower detective quantum efficiency
Solution Approach 1:
The detection surface is segmented into discrete clusters of detection pixels, with anti-charge-sharing grid structures positioned only between these clusters. This segmentation reduces the total area covered by the grid compared to a uniform grid covering all inter-pixel regions, thereby suppressing charge sharing between clusters while maintaining higher detective quantum efficiency.
3Measurement precision
If charge sharing correction considers all neighboring detection pixels, then correction accuracy is improved, but computational complexity and technical effort increase
Solution Approach 1:
The charge sharing correction process is segmented to consider only detection pixels within the same cluster as the reference pixel, rather than all neighboring pixels across the entire detection surface. This clustered approach maintains correction accuracy for the most significant charge sharing effects while reducing computational complexity and technical effort by limiting the correction scope to local clusters.
Solution Approach 2:
The charge sharing correction is applied locally within each cluster of detection pixels, focusing computational resources on correcting charge sharing in regions where it most impacts measurement precision. This local correction approach achieves sufficient accuracy while minimizing the overall computational burden and technical effort required.
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 provides charge-sharing-corrected detection values with improved quality and high detective quantum efficiency by suppressing charge sharing between clusters and correcting remaining intracluster sharing with low technical effort, enhancing the accuracy of photon count values and image generation.
Implementation Method 1
the detection pixels are clustered by using an anti-charge-sharing grid which is mounted on the array of detection pixels for suppressing charge sharing between different clusters of detection pixels
Implementation Method 2
the detection pulse providing unit may comprise a conversion material for converting the photons into electrical pulses
Data Source
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AI summary
The invention relates to a detection values determination system, especially for photon-counting CT scanners, comprising a detection pulse providing unit for providing detection pulses for an array of detection pixels 17, which is provided with an anti-charge- sharing grid 15 for suppressing charge sharing between different clusters 14 of the detection pixels, wherein the detection pulses are indicative of the energy of photons incident on the detection pixels. Charge-sharing-corrected detection values are determined based on the provided detection pulses, wherein for determining a charge-sharing-corrected detection value for a detection pixel of a cluster only detection pixels of the same cluster are considered. This allows for a relatively high detective quantum efficiency, wherein the technical efforts for providing the charge sharing correction can be relatively low.