X-Ray Tube Current Modulation for CT Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current computed tomography imaging systems face challenges in achieving images valuable for diagnosis with the smallest radiation dose due to limitations in reaching the determined expected current values during X-ray tube modulation.
Innovation Solution
A method and apparatus for modulating current in computed tomography imaging systems by selecting discrete data points as approach points, establishing an actual current modulation curve that approximates the expected current values with a variation rate within system limits, and adjusting approach factors to optimize current values at peak and valley points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the X-ray tube is driven by a relatively large current, then a clear image may be obtained, but the human body is exposed under a large radiation dose
Solution Approach 1:
The patent applies dynamics by implementing time-varying current modulation during the scanning process. The tube current is dynamically adjusted according to the scanning angle and patient anatomy, transitioning from static to dynamic control. This allows the system to use higher current only when and where needed (at peak points requiring better penetration) while reducing current in other regions, thereby maintaining image quality while minimizing overall radiation dose.
Solution Approach 2:
The patent implements local quality by applying different current levels to different angular positions during scanning. Instead of using uniform current throughout, the system identifies peak points requiring higher current for adequate penetration and applies elevated current selectively at those locations, while using lower current at other positions. This localized approach ensures diagnostic image quality at critical areas while reducing radiation exposure in less demanding regions.
2Object-affected harmful factors
If the X-ray tube is driven by a relatively small current, then the human body is exposed under a small radiation dose, but a serious image distortion may occur
Solution Approach 1:
The system dynamically modulates current based on real-time scanning parameters and anatomical variations. By continuously adjusting current levels during scanning rather than maintaining a constant low level, the system prevents image distortion at critical peak points while keeping overall radiation dose low. The dynamic response ensures adequate current is delivered when anatomical density requires it.
Solution Approach 2:
The patent applies preliminary action by pre-calculating and identifying peak points in the scanning trajectory before actual scanning occurs. The system determines in advance where higher current will be needed based on expected anatomical structures, and prepares the current modulation profile accordingly. This proactive approach ensures that sufficient current is available at critical positions without unnecessarily increasing dose throughout the entire scan.
3Adaptability or versatility
If an ideal current modulation curve is determined based on current modulation technology, then different expected current values can be determined according to different scanning angle, but an actual current value can not reach the determined expected current value due to an inherent limitation of the computed tomography imaging system
Solution Approach 1:
The patent applies partial action by selectively targeting only the most critical parameters for accurate current control. Instead of attempting to match the ideal modulation curve at every single point (which would be impossible due to system limitations), the system focuses on accurately controlling current at identified peak points where diagnostic quality is most sensitive. This selective approach achieves reliable current control where it matters most while accepting approximate control elsewhere.
Solution Approach 2:
The system handles parameter changes by transforming the continuous ideal current modulation curve into a discrete set of target points (peak points) with specific current requirements. By changing from a continuous parameter control problem to a discrete point-based control problem, the system makes the control task achievable within hardware limitations. The modulation approach adapts parameters (current values, timing, duration) to match system capabilities while maintaining diagnostic effectiveness.
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 approach ensures that actual current values in the X-ray tube approximate expected values, maintaining a suitable variation rate, thereby generating diagnostic-quality images with the lowest radiation dose, and allows for varying degrees of approximation suitable for different scenarios.
Implementation Method 1
The X-ray source typically includes an X-ray tube which can emit X-ray under the drive of a tube current
Implementation Method 2
the attenuated X-ray beam is received by the detector. Then, an analog value is converted into a digital value
Data Source
AI summary
A method and apparatus of current modulation in a computed tomography imaging system are provided. The method may include: selecting a plurality of sample points from an expected current modulation curve as approach points; establishing an actual current modulation curve, wherein an actual current value of the actual current modulation curve at an approach point approximates an expected current value of an expected current modulation curve, and a variation rate of the actual current is within an allowed range of the computed tomography imaging system; and modulating a current in an X-ray tube of the computed tomography imaging system according to the actual current modulation curve. According to the disclosure, an image valuable to the diagnosis can be obtained with the smallest radiation dose.