Segmented PET Detector Module for Light Collection and Timing Resolution

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Solution Overview

Problem

Current PET scanner designs face challenges in achieving optimal light collection and processing efficiency due to trade-offs between detector module size, optical isolation, and counting capacity, leading to limitations in spatial and timing resolution, as well as manufacturing and maintenance complexities.

Innovation Solution

A segmented detector module design with optically isolated sub-arrays and shared photosensors, where each sub-array is covered by a group of photosensors and connected through trigger zones to minimize light contamination and allow independent calibration and replacement, enhancing light collection and processing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a large array of photosensors is used to cover the entire crystal array, then light collection efficiency is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvelight collection efficiencyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The crystal array is divided into multiple sub-arrays, with each sub-array covered by a dedicated group of photosensors. This segmentation allows the system to achieve high light collection efficiency for each sub-array while managing overall device complexity through modular design and independent processing channels.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the detector module is designed as a single integrated unit, then manufacturing is simplified, but the ability to perform independent calibration and replacement of faulty components is reduced

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidindependent calibration and replacement capability
Core Design Contradiction:
Ease of manufactureVSEase of repair

Solution Approach 1:

The detector module is segmented into multiple independent sub-arrays, where each sub-array can be independently calibrated, tested, and replaced. This segmentation enables faulty components to be identified and replaced individually without requiring replacement of the entire detector module, while still allowing the module to function as an integrated unit during operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each sub-array within the detector module is designed with uniform structural characteristics and can be independently calibrated. This local uniformity allows for simplified manufacturing of individual sub-arrays while enabling independent quality control and calibration of each segment, balancing manufacturing simplicity with repairability.

Inventive Principle:
Principle #3Local quality

3Device complexity

If photosensors are shared between adjacent sub-arrays to reduce the total number of photosensors, then device complexity is reduced, but light contamination between sub-arrays increases

Engineering Contradiction:
Improvenumber of photosensorsVSAvoidlight contamination
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The system segments the crystal array into multiple sub-arrays, with each sub-array having its own dedicated photosensors. This segmentation prevents light contamination between sub-arrays by ensuring optical isolation, while the modular design allows for efficient use of photosensors within each sub-array group without requiring excessive redundancy.

Inventive Principle:
Principle #1Segmentation

4Device complexity

If the detector module processes signals from all sub-arrays simultaneously through a single channel, then device complexity is reduced, but processing speed and timing resolution deteriorate

Engineering Contradiction:
Improvesignal processing structureVSAvoidprocessing speed
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The signal processing system is segmented into multiple independent processing channels, with each channel dedicated to processing signals from a specific sub-array. This segmentation enables parallel processing of signals from different sub-arrays, significantly improving processing speed and timing resolution compared to sequential processing through a single channel.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple processing channels operate simultaneously and continuously to process signals from different sub-arrays without interruption. This continuous parallel processing maintains high processing speed and timing resolution by eliminating the sequential bottlenecks that would occur with single-channel processing.

Inventive Principle:
Principle #20Continuity of useful action

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

This design improves timing resolution, increases manufacturing efficiency, and reduces costs by allowing independent module testing and replacement, while maintaining high count rates and light collection efficiency.

Implementation Method 1

an array of scintillation crystal elements and a plurality of photosensors. The array of the scintillation crystal elements includes a plurality of substantially optically isolated sub-arrays

Methodology Applied
Scientific EffectScintillation: Scintillation

Implementation Method 2

The plurality of photosensors are arranged to cover the array of crystal elements and configured to receive light emitted from the array of crystal elements

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP2461183B1Positron emission tomography detector module, radiation detector, positron emission tomography scanner system, method of processing signals, and method of manufacturing radiation detector module
Publication Date: 2018.10.03 TOSHIBA MEDICAL SYST CORP
  • EP2461183B1 patent drawingFigure 1A~1B
  • EP2461183B1 patent drawingFigure 1C~1D
  • EP2461183B1 patent drawingFigure 2

AI summary

A PET detector module (220) according to one embodiment includes an array (203) of scintillation crystal elements and a plurality of photosensors (201). The array (203) includes a plurality of substantially optically isolated sub-arrays (301, 302, 303). The photosensors (201) are arranged to cover the array (203) and configured to receive light emitted from the array (203). The sub-arrays (301, 302, 303) are optically isolated so that light emitted from an individual scintillation crystal located in a corresponding sub-array is concentrated so as to be primarily received only by those photosensors that cover the corresponding sub-array. At least one photosensor, which receives light emitted from crystals in a first sub-array, also receives light emitted from crystals in one and only one sub-array that is adjacent to the first sub-array.