X-Ray Focal Spot Alignment Using Bending Magnet Current Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
X-ray focal spot drift relative to collimating elements causes image artifacts and affects dose prediction accuracy in medical imaging systems, particularly in CT imaging, due to factors like tube current, thermal state, and other acquisition parameters.
Innovation Solution
A built-in alignment mechanism using a functional map or look-up table to determine a bending magnet current value that maintains the X-ray focal spot position at a desired location on the detector, adjusting the electron beam's path via electromagnets, independent of acquisition parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If acquisition parameters (tube current, tube voltage, focal spot size, rotation speed, thermal state) are adjusted to improve imaging performance, then imaging quality and productivity are improved, but X-ray focal spot drift occurs causing image artifacts and reduced measurement precision
Solution Approach 1:
The system continuously monitors the actual focal spot position using detector data and compares it to the desired position. Based on this feedback, the control system dynamically adjusts the bending magnet current to compensate for drift caused by varying acquisition parameters, maintaining focal spot alignment throughout the scanning process
Solution Approach 2:
The system changes the bending magnet current parameter in response to changes in acquisition parameters. By dynamically adjusting the magnetic field strength, the electron beam path is modified to compensate for thermal drift and other effects, maintaining focal spot position stability despite variations in tube current, voltage, or rotation speed
2Reliability
If traditional alignment methods are used, then device complexity is low, but system downtime increases and calibration robustness decreases
Solution Approach 1:
The system performs self-alignment by automatically detecting focal spot position drift through detector measurements and correcting it via bending magnet adjustment. This self-service capability eliminates the need for manual realignment procedures, reducing system downtime and improving calibration robustness without requiring complex external alignment equipment
Solution Approach 2:
The bending magnet serves multiple functions: it not only focuses the electron beam but also dynamically adjusts the focal spot position to compensate for drift. This multi-functionality integrates the alignment mechanism into the existing X-ray tube structure, avoiding the need for separate complex alignment systems while improving reliability
3Ease of operation
If focal spot position is allowed to drift with acquisition parameters, then device complexity is reduced, but image quality deteriorates due to artifacts and dose prediction accuracy decreases
Solution Approach 1:
The system replaces mechanical alignment adjustments with electromagnetic control. Instead of physically repositioning components, the bending magnet uses magnetic fields to steer the electron beam and maintain focal spot position, providing continuous dynamic correction without mechanical complexity or downtime
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 mechanism improves image quality by mitigating artifacts, enhances calibration robustness, reduces system downtime, and ensures accurate dose prediction by maintaining a consistent focal spot position across varying system conditions.
Implementation Method 1
techniques include determining a bending magnet current value to utilize to maintain the X-ray focal spot position of an X-ray beam emitted from an X-ray tube
Data Source
AI summary
A system and a method for maintaining an X-ray focal spot position at a desired location on an X-ray detector of an X-ray imaging system include obtaining, via processing circuitry, a scan protocol for performing an X-ray scan with the X-ray imaging system. The system and the method also include determining, via the processing circuitry, a bending magnet current value to utilize to maintain the X-ray focal spot position of an X-ray beam emitted from an X-ray tube of the X-ray imaging system at the desired location on the X-ray detector based on a plurality of acquisition parameters of the X-ray scan. The system and the method further include utilizing, via the processing circuitry, the bending magnet current value during the X-ray scan to maintain the X-ray focal spot position at the desired location on the X-ray detector.