Configurable Photon-Counting X-Ray Detector for Coincidence Control
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Solution Overview
Problem
Photon-counting X-ray detectors suffer from image quality degradation due to charge sharing and coincidence events, leading to increased noise and reduced spatial resolution, which existing solutions like charge summing circuits exacerbate by increasing dead time and pulse pile-up.
Innovation Solution
A photon-counting X-ray detector with configurable counters that can switch between counting pixel-specific signals and coincidence signals, allowing flexible adaptation to different imaging conditions, using a multiplexer to select between pixel and coincidence counting modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If charge summing circuits are implemented to prevent double counting, then coincidence errors are reduced, but dead time is massively increased
Solution Approach 1:
The invention divides the pixel array into multiple groups, where each group is independently evaluated by separate evaluation electronics. This segmentation allows parallel processing of charge signals from different groups, preventing the need for sequential charge summing across the entire array, thereby reducing dead time while maintaining the ability to correct coincidence errors within each group.
Solution Approach 2:
The invention dynamically adjusts the evaluation mode for different groups of pixels based on detected charge sharing patterns. When charge sharing is detected in a particular group, coincidence correction is activated for that group; when no charge sharing is present, the system operates in standard mode. This dynamic adaptation optimizes performance by applying correction only where needed, minimizing overall dead time.
2Measurement precision
If pixel size is increased to counteract deterioration in energy resolution and DQE, then spatial resolution is improved, but high flux capability is reduced
Solution Approach 1:
By dividing the detector into multiple groups that can be independently evaluated, the system effectively increases the processing capacity for high flux conditions. Each group processes a portion of the total flux, preventing signal saturation and maintaining high flux capability while using smaller pixel sizes that preserve energy resolution.
3Measurement precision
If configurable counters are implemented to selectively count coincidence signals, then image quality is improved, but device complexity is increased
Solution Approach 1:
The invention implements configurable counters only in specific groups of pixels where charge sharing and coincidence events are most prevalent, rather than uniformly across the entire detector array. This localized approach improves image quality in critical regions while minimizing the overall increase in device complexity and resource consumption.
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 improved image quality by selectively incorporating coincidence information only when beneficial, reducing resource consumption and minimizing errors, thus optimizing detector performance across varying X-ray flux conditions.
Implementation Method 1
Incoming X-rays or photons can be converted into electrical pulses in such X-ray detectors by a suitable converter material
Data Source
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AI summary
The invention relates to a photon-counting X-ray detector (1) for recording an X-ray image data set of an object (39) through which X-ray radiation is irradiated, - comprising a converter element (3) for converting X-ray radiation into an electrical signal and a matrix with a plurality of pixel elements (5), - wherein at least a subset of the plurality of pixel elements has a signal input (7) and at least one configurable counter (9) coupled thereto, - wherein the configurable counter (9) is configured either to count a pixel count signal which is based on a signal directly received in each pixel element (5) of the subset of the plurality of pixel elements or to count a coincidence count signal which is based on the signal directly received in the respective pixel element (9) and on a coincidentally occurring signal of at least one further pixel element (5) of the plurality of pixel elements.