Segmented Collimator Modules for CT Imaging Artifact Reduction
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Solution Overview
Problem
Collimator modules in CT systems experience thermal mechanical movement and g-loading motion artifacts, leading to image artifacts such as rings and bands, and require tight tolerance control due to shared scatter plates, which affects image resolution and precision.
Innovation Solution
The collimator assembly features collimator modules with primary collimation grids and separate scatter plates, where each module performs unique primary collimation and absorbs scattered radiation, avoiding shared plate boundaries to reduce thermal mechanical sensitivity and tolerance requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If collimator modules share a scatter plate across module boundaries, then device complexity is reduced, but manufacturing precision deteriorates due to gain shift from positional changes in the shared plate
Solution Approach 1:
The collimator assembly is divided into independent collimator modules, each with its own dedicated scatter plate. This segmentation eliminates the shared scatter plate configuration, allowing each module to be manufactured and positioned independently without requiring tight tolerance control at module boundaries, thereby resolving the contradiction between device complexity and manufacturing precision.
2Measurement precision
If collimator modules use tight sensor to sensor gaps, then measurement precision is improved, but device complexity increases due to required tolerance control
Solution Approach 1:
By segmenting the collimator into independent modules with dedicated scatter plates, the system allows for larger sensor to sensor gaps without compromising image resolution. Each module operates independently, eliminating the need for tight tolerance control at boundaries while maintaining measurement precision through the individual module design.
3Device complexity
If collimator modules use larger sensor to sensor gaps, then device complexity is reduced, but measurement precision deteriorates due to reduction in image resolution
Solution Approach 1:
The independent module design with dedicated scatter plates allows each module to maintain its collimation function independently. This segmentation enables larger sensor to sensor gaps without reducing image resolution, as each module's performance is not dependent on precise alignment with adjacent modules.
4Reliability
If collimator modules are subject to thermal mechanical movement, then reliability deteriorates due to module to module variation, but device complexity increases if temperature control is implemented
Solution Approach 1:
By dividing the collimator into independent modules with dedicated scatter plates, the system isolates thermal mechanical movements to individual modules. This segmentation prevents module to module variation and image artifacts without requiring active temperature control, as each module's thermal expansion does not affect adjacent modules.
Solution Approach 2:
The primary collimation grid and scatter plate are combined into a single integrated component for each module. This merging eliminates the relative movement between separate plates and grids, reducing image artifacts from g-loading and thermal expansion without adding complex temperature control systems.
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 reduces image artifacts, allows for wider detector coverage, and enables higher rotation speeds without the need for precise temperature control, improving image quality and system performance.
Implementation Method 1
a scintillator assembly configured to receive incident radiation and configured to convert incident radiation into lower energy optical photons for transmission to the detector array
Implementation Method 2
Each collimator module includes multiple plates configured to absorb scattered radiation
Data Source
AI summary
A collimator for an imaging detector assembly of a computed tomography imaging system is provided. The collimator includes a collimator module that includes a primary collimation grid having a first edge and a second edge. The primary collimation grid includes multiple radiation absorbing elements spaced apart from each other and configured to provide primary beam collimation. A first radiation absorbing element is disposed on the first edge and a second radiation absorbing element is disposed on the second edge. The collimator module includes multiple plates located on a side of the primary collimation grid and configured to absorb scattered radiation. A respective plate of the multiple plates is disposed over a respective radiation absorbing element of the multiple radiation absorbing elements of the primary collimation grid except the second radiation absorbing element disposed on the second edge of the primary collimation grid.