Single Photon Avalanche Diode Array for Scintillator Localization
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Solution Overview
Problem
Current PET scanners face limitations in identifying small scintillator element locations due to reliance on neighboring photosensor information, which becomes inaccurate at gaps and edges, affecting spatial resolution and accuracy in nuclear imaging.
Innovation Solution
A method and system that utilize a plurality of scintillator element locations with photosensors comprising single photon avalanche diodes, acquiring breakdown data, and assigning photosensor sensitivity data to groups to determine the number of diodes in breakdown for each group, allowing identification of scintillator element locations without neighboring information, using digital silicon photomultipliers and photosensor sensitivity patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Anger logic is used to identify scintillator element locations using neighboring photosensors, then spatial resolution can be improved beyond single photosensor size, but identification accuracy deteriorates at gaps and edges where neighboring photosensor information is missing
Solution Approach 1:
The photosensor array is segmented into multiple independently readable regions, with each region capable of identifying scintillator element locations without requiring information from other regions. This segmentation eliminates the dependency on neighboring photosensors that causes inaccuracies at gaps and edges.
Solution Approach 2:
The system changes the operational parameter of the photosensors to Geiger mode, which provides digital output signals with inherent breakdown data. This parameter change enables independent identification of scintillator element locations within each photosensor region, resolving the accuracy issue at boundaries.
2Measurement precision
If smaller scintillator element locations are used to increase spatial resolution, then image resolution improves, but the difficulty of detecting and measuring increases due to limited photosensor coverage
Solution Approach 1:
The invention adds a temporal dimension to the detection process by utilizing the time-resolved breakdown data from Geiger mode photosensors. This allows small scintillator elements to be identified through their unique temporal signatures rather than relying solely on spatial distribution, making detection easier despite their small size.
Solution Approach 2:
The system introduces breakdown data as an intermediary information source that mediates between the scintillator element and the photosensor output. This intermediary provides additional information that enables detection of small scintillator elements that would otherwise be difficult to resolve.
3Measurement precision
If a light guide is used to spread scintillation light onto multiple photosensors, then identification accuracy improves through Anger logic, but device complexity increases
Solution Approach 1:
The invention extracts and eliminates the light guide component from the system. By using Geiger mode photosensors that directly detect scintillation photons and provide breakdown data, the system achieves accurate identification without requiring the light guide that spreads light across multiple photosensors, thereby reducing device complexity.
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 high-resolution identification of scintillator element locations smaller than the photosensors, improving spatial resolution and accuracy in nuclear imaging systems, even in regions with missing neighboring photosensor data, without the need for a light guide.
Implementation Method 1
a photosensor comprising an array of single photon avalanche diodes configured to break down responsive to impingement of a photon
Implementation Method 2
single photon avalanche diodes configured to break down responsive to impingement of a photon
Implementation Method 3
a plurality of scintillator element locations configured to emit a burst of photons responsive to a radiation particle being absorbed at the scintillator element location
Data Source
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AI summary
A method for scintillation event localization in a radiation particle detector comprises the steps of providing a plurality of scintillator element locations (2') configured to emit a burst of photons responsive to a radiation particle being absorbed at the scintillator element location (2') and detecting a burst of photons emitted by a scintillator element location (2') with a photosensor (5), wherein the photosensor (5) comprises an array of single photon avalanche diodes configured to break down responsive to impingement of a photon. Breakdown data (30) is acquired indicative of which of the single photon avalanche diodes are in breakdown and predetermined photosensor sensitivity data (20, 40) is provided, which assign single photon avalanche diodes to groups, wherein each group is assigned to exactly one scintillator element location (2'). Finally the number of single photon avalanche diodes in breakdown is determined for each group individually to identify the scintillator element location (2') that emitted the burst of photons.