Multi-Layer Collimator for SPECT Imaging Penumbra Reduction
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Solution Overview
Problem
Traditional multi-pinhole collimators for SPECT imaging face challenges in reducing overlap of radioactive ray projections, which affects spatial resolution and detection efficiency, particularly for small organs, and increasing collimator thickness to mitigate this issue is impractical due to material costs and processing difficulties.
Innovation Solution
A collimator design featuring a bottom plate with imaging through holes and a top plate with shielding through holes, arranged in an array, that secondary shields radioactive rays to reduce projection overlap, adjust light-shielding rates, and improve detection efficiency and spatial resolution, while maintaining a lower processing cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the thickness of the collimator plate is increased to reduce the penumbra region, then the projection overlap is reduced, but the material cost and processing difficulty increase excessively
Solution Approach 1:
The collimator plate is segmented into multiple layers with through-holes at different positions and orientations. Each layer segment contributes to reducing projection overlap in specific directions, achieving comprehensive penumbra reduction without requiring excessive overall thickness. The segmentation allows distributed material usage rather than concentrated thick plates.
Solution Approach 2:
The solution transitions from a single-dimensional thickness increase to a multi-dimensional arrangement of through-holes across multiple layers. By distributing shielding function across layers in the vertical dimension and varying hole orientations, the system achieves effective penumbra reduction through spatial arrangement rather than单纯的 thickness increase.
2Productivity
If the diameter of pinholes is increased to achieve higher detection efficiency, then more radioactive rays are detected, but the projection overlap is aggravated due to the penumbra region
Solution Approach 1:
The detection function is segmented across multiple layers, with each layer containing through-holes of optimized diameter. This allows individual holes to maintain smaller sizes for reduced penumbra while the cumulative effect across layers provides high detection efficiency. The segmentation distributes the detection task rather than relying on a few large holes.
Solution Approach 2:
The patent merges the shielding and detection functions into an integrated multi-layer structure. The through-holes serve dual purposes: detecting radioactive rays while their specific arrangements and orientations provide shielding against overlapping projections. This merging allows simultaneous optimization of both detection efficiency and spatial resolution.
3Device complexity
If traditional parallel-hole collimators are used, then the structure is simple, but the spatial resolution and detection efficiency cannot meet higher clinical requirements for small organs
Solution Approach 1:
The collimator structure is segmented into multiple layers with varying through-hole patterns, replacing the simple single-layer parallel-hole design. This segmentation enables tailored hole arrangements for different spatial frequencies and directions, achieving superior spatial resolution for small organs while maintaining manageable structural complexity through modular layer design.
Solution Approach 2:
The multi-layer structure with varied through-hole orientations serves multiple imaging functions simultaneously, providing both spatial resolution enhancement and detection efficiency improvement. The universal design can be adapted for different organ imaging requirements by adjusting layer parameters, making it more versatile than traditional specialized collimators.
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
The collimator effectively reduces projection overlap, enhancing detection efficiency and spatial resolution, resulting in better image quality and broader applicability with reduced material costs and processing complexity.
Implementation Method 1
radioactive rays from other parts of the human body may also generate projections on the detector through the pinholes
Implementation Method 2
the overlap of projections will be aggravated due to the influence of a penumbra region of pinhole projections
Data Source
AI summary
A collimator for a detector is disclosed. The collimator comprises: a bottom plate provided with imaging through holes distributed in an array, each of the imaging through holes comprising a first hole segment and a second hole segment, the transverse size of the first hole segment gradually decreasing in a direction from a free end to the second hole segment, and the transverse size of the second hole segment gradually decreasing in a direction from the free end to the first hole segment; a shielding case formed on the bottom plate; and a top plate disposed in the shielding case and closing at least a part of an opening of the shielding case, the top plate being provided with shielding through holes distributed in an array, and the imaging through holes being in one-to-one correspondence with the shielding through holes.