Variable Pinhole Collimator for SPECT Imaging Adaptability
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Solution Overview
Problem
Conventional pinhole collimators in radiographic imaging devices, such as gamma cameras and SPECT devices, have fixed acceptance angles and hole diameters, leading to degraded resolution and sensitivity, especially when imaging regions of interest (ROI) at varying positions and sizes, and existing variable collimators are bulky and complex due to multiple laminated plates and driving mechanisms.
Innovation Solution
A variable pinhole collimator with pinhole plates of different sizes at the same radius, featuring rotation operation holes and a driving module that sequentially positions pinhole formation holes for overlapping, allowing adjustable acceptance angles and hole diameters, simplifying the structure and reducing size and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional pinhole collimator with fixed acceptance angle and hole diameter is used, then the structure is simple, but the resolution and sensitivity are degraded when imaging regions of interest at varying positions and sizes
Solution Approach 1:
The pinhole collimator transitions from a fixed structure to a dynamic one by enabling rotation of the pinhole plate around the focal axis. This rotation allows the acceptance angle and hole diameter to be adjusted according to different ROI positions and sizes, resolving the contradiction between adaptability and structural simplicity.
Solution Approach 2:
The collimator is segmented into multiple pinholes arranged at different radii from the focal axis. Each pinhole can be independently positioned by rotation, allowing selective adjustment of acceptance angles and hole diameters to match varying ROI requirements without complicating the overall structure.
2Adaptability or versatility
If multiple laminated plates and driving mechanisms are added to create a variable collimator, then the acceptance angle and hole diameter become adjustable, but the collimator becomes bulky and complex
Solution Approach 1:
Instead of using multiple laminated plates, the invention segments the collimator into a single pinhole plate with multiple pinholes at different radii. This segmentation allows variable acceptance angles and hole diameters to be achieved through rotation of one plate rather than stacking multiple plates, significantly reducing weight.
Solution Approach 2:
A single pinhole plate serves multiple functions by containing pinholes at various radii from the focal axis. Rotation of this universal plate allows the same physical structure to provide different acceptance angles and hole diameters, eliminating the need for multiple specialized plates and reducing overall weight.
3Adaptability or versatility
If multiple laminated plates and driving mechanisms are added to create a variable collimator, then the acceptance angle and hole diameter become adjustable, but the collimator size increases
Solution Approach 1:
The collimator design segments the pinhole array into a single plate with radially distributed pinholes rather than stacking multiple plates in the thickness direction. This segmentation maintains adjustability of acceptance angle and hole diameter through rotation while minimizing collimator thickness.
Solution Approach 2:
The invention transitions from adjusting collimator parameters in the thickness direction (multiple laminated plates) to adjusting them in the rotational dimension. By arranging pinholes at different radii and rotating the plate, the system achieves variable acceptance angles and hole diameters without increasing collimator thickness.
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 flexible pinhole shape formation, improving resolution and sensitivity by focusing on specific ROIs with reduced collimator thickness and complexity, enhancing imaging quality and reducing the need for excessive radioactive material.
Implementation Method 1
The collimator 10 geometrically limits the gamma rays emitted from the living body region so that only the gamma rays emitted from the necessary sites are incident on the radiation detector 20
Implementation Method 2
The gamma rays having passed through the collimator 10 and reacted with the scintillator 21 are converted into low energy electromagnetic waves of a type that can be easily detected by the scintillator 21
Implementation Method 3
the light guide portion 22, and the detected position or energy thereof is stored in a computer (not shown), thereby acquiring an image
Data Source
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AI summary
The present invention relates to a variable pinhole collimator and a radiographic imaging device using same, in which the variable pinhole collimator includes: a plurality of pinhole plates formed in each plate surface thereof with a plurality of pinhole formation holes having different sizes along a circumferential direction, formed in each plate surface thereof with a plurality of rotation operation holes around the rotation axis along the circumferential direction, and configured to be laminated in an incidence direction of radiation; and a driving module inserted into the rotation operation holes of the plurality of pinhole plates in the incidence direction to rotate the plurality of pinhole plates about the rotation axis, and configured to rotate the plurality of pinhole plates to form a pinhole in the overlapping area. Accordingly, various pinhole shapes can be achieved since it is possible to change parameters constituting a pinhole of the pinhole collimator.