Scintillator Module Alignment Features for CT Detector Assembly
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Solution Overview
Problem
Current CT detector systems face challenges in manufacturing large modules for full z-axis coverage due to alignment and adhesion issues between scintillators and collimators, leading to increased costs and reduced reliability.
Innovation Solution
A scintillator module design featuring a grid of pixelated scintillators with a reflector having notches for precise alignment and adhesion of an anti-scatter grid, using an adhesive in the gaps between notches to secure the plates, allowing for accurate and robust assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If smaller modules are abutted to extend detector coverage along the Z-axis, then detector coverage area is improved, but alignment precision between collimators and scintillators deteriorates
Solution Approach 1:
The detector is divided into multiple smaller modules that can be abutted together to extend the Z-axis coverage. Each module contains its own collimator and scintillator array, allowing independent fabrication and assembly while maintaining overall system functionality and achieving greater coverage area.
Solution Approach 2:
Alignment features (protrusions and recesses) are pre-formed on the collimator and scintillator components during manufacturing. These features are prepared in advance to guide and constrain the relative positioning of collimators and scintillators during assembly, ensuring precise alignment without requiring complex real-time adjustment procedures.
2Manufacturing precision
If optical alignment features are used to position collimator with respect to scintillator pixels, then alignment precision is improved, but ease of manufacture deteriorates due to difficulty in optical alignment
Solution Approach 1:
The patent replaces complex optical alignment procedures with simple mechanical alignment features. Protrusions on the collimator fit into corresponding recesses on the scintillator block, providing self-aligning mechanical constraints that are much easier to implement during assembly than optical alignment methods while achieving comparable or superior precision.
3Object-affected harmful factors
If reflector material is applied on scintillator to prevent stray light, then image quality is improved, but adhesion strength between collimator and scintillator deteriorates
Solution Approach 1:
The reflector material is applied to the scintillator block surface, but the collimator makes contact with the scintillator at specific localized areas (through the protrusion-recess interface) where the reflector does not interfere with adhesion. This local differentiation allows the reflector to perform its stray light prevention function over most of the surface while maintaining adhesion strength at the critical contact points.
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 enables precise alignment and improved adhesion of anti-scatter grids to scintillators, enhancing image quality, reducing manufacturing costs, and improving detector reliability by allowing for scalable detector coverage without redesign.
Implementation Method 1
The material used in these detectors generally use scintillation crystal/photodiode arrays, where the scintillation crystal absorbs X rays and converts the absorbed energy into visible light
Implementation Method 2
A photodiode is used to convert the light to an electric current
Data Source
AI summary
A scintillator module for a CT detector includes an array of pixelated scintillators extending in a first direction at a first spacing, and extending in a second direction at a second spacing, a reflector on the array and between the pixelated scintillators, the reflector having a first thickness and forming notches having a second thickness that is greater than the first thickness. The module includes an anti-scatter grid having plates, each plate extending along a length such that, when the CT detector is positioned in a CT system, the length of the plates extend approximately toward a focal spot. The plates are separated from one another at one of the first spacing and the second spacing, and two of the notches have a gap therebetween that engages one of the plates. An adhesive positioned in the gap to adhere the one plate to the reflector.