Anti-scatter Grid Dynamic Alignment in X-ray Systems
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Solution Overview
Problem
In X-ray image acquisition systems, especially C-arm systems, the anti-scatter grid's position often deviates due to structural deformations and movement, leading to reduced image quality due to misalignment between the X-ray beam focus and the grid focus, which existing technologies fail to adequately compensate for.
Innovation Solution
An X-ray image acquisition system with a device comprising a measurement unit, control unit, and shifting unit that determines the displacement between the X-ray beam focus and the anti-scatter grid's focus, generating a shifting signal to align the grid with the beam focus, using a motor-driven shifting unit to adjust the anti-scatter grid's position in one or two dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a thick anti-scatter grid with high grid ratio is used, then scatter reduction and image contrast are improved, but the grid is more sensitive to misalignment between beam focus and grid focus due to structural deformations in C-arm systems
Solution Approach 1:
The patent implements a dynamic alignment system where the anti-scatter grid's position is continuously adjustable through a motor-driven shifting mechanism. The control unit receives alignment information from the measurement unit and dynamically shifts the grid in the shifting direction to maintain proper alignment between the X-ray beam focus and grid focus, even during system rotations and deformations. This transforms the static grid into a dynamic component that adapts to changing conditions.
Solution Approach 2:
The patent establishes a closed-loop feedback system consisting of three units: measurement unit (detects alignment status), control unit (processes alignment information and generates control signals), and shifting unit (adjusts grid position). The measurement unit continuously monitors the alignment between beam focus and grid focus, feeds this information to the control unit, which then commands the shifting unit to correct any misalignment. This feedback mechanism ensures reliable alignment despite structural deformations in the C-arm system.
2Device complexity
If the anti-scatter grid position is fixed, then the device complexity is reduced, but misalignment occurs during system rotation and deformation leading to reduced image quality
Solution Approach 1:
The patent transforms the fixed grid into a dynamically adjustable component. The shifting unit, driven by a motor, enables the grid to move in a specific shifting direction to maintain alignment with the beam focus during system rotation and deformation. This dynamic capability compensates for the complexity introduced by additional components, ensuring high alignment precision throughout the system's range of motion.
Solution Approach 2:
The patent changes the positional parameter of the anti-scatter grid dynamically. The control unit calculates the required shifting amount based on alignment information from the measurement unit and commands the shifting unit to adjust the grid's position accordingly. This parameter adjustment ensures that the grid remains properly aligned with the beam focus despite changes in system configuration during rotation and deformation.
3Ease of operation
If manual adjustment mechanisms with screws are used, then the grid can be repositioned, but the adjustment precision and speed are insufficient for real-time alignment compensation during imaging
Solution Approach 1:
The patent replaces the manual mechanical adjustment mechanism (screws) with an automated motor-driven shifting system. The motor-driven shifting unit responds to electrical control signals from the control unit, enabling precise and rapid adjustment of the grid position. This substitution eliminates the imprecision and slowness of manual screw adjustment, allowing real-time alignment compensation during imaging procedures.
Solution Approach 2:
The patent implements a self-aligning system where the measurement unit automatically detects misalignment between the beam focus and grid focus, the control unit calculates the required correction, and the shifting unit executes the adjustment without manual intervention. This self-service mechanism continuously maintains optimal alignment during imaging, eliminating the need for operator intervention and ensuring consistent alignment precision.
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 solution allows the use of thicker anti-scatter grids with higher grid ratios, significantly improving image quality by reducing scatter and maintaining high contrast, even during system rotations and deformations.
Implementation Method 1
an X-ray radiation source emits X-ray radiation from a focal spot that is defined by the position where an electron beam hits an anode of the X-ray radiation source
Implementation Method 2
an anti-scatter grid, which is a plate in front of the X-ray detector that has lead or a similarly high absorbing material such as tungsten strips that are positioned such that only X-ray radiation originating from the focal spot can pass through wherein other (scattered) X-ray radiation will be absorbed
Implementation Method 3
The shifting unit is configured to, based on the shifting signal, shift the anti-scatter grid in at least one direction to align the anti-scatter grid with the X-ray beam focus position
Data Source
Figure 1a~1b
Figure 2a~3
Figure 4a~5
AI summary
The present invention relates to a device for controlling a position of an anti-scatter grid in an X-ray image acquisition system, the device (10) comprising: a measurement unit (12); a control unit (14); and a shifting unit (16); wherein the measurement unit (12) is configured to determine an X-ray beam focus position (37) of an X-ray radiation source of the X-ray image acquisition system with respect to an X-ray detector of the X-ray image acquisition system; wherein the control unit (14) is configured to generate a shifting signal based on a displacement (18) between the X-ray beam focus position (37) and a grid focus position (35) of the anti-scatter grid; and wherein, based on the shifting signal, the shifting unit (16) is configured to shift an anti-scatter grid of the X-ray image acquisition system in at least one direction to align the anti-scatter grid with the X-ray beam focus position (37), provides an improved anti-scatter grid for X-ray acquisition systems. The invention provides the use of an improved anti-scatter grid (26) for X-ray acquisition systems (20).