Dynamic Prepatient Collimator Control for CT Dose Reduction
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Solution Overview
Problem
Current CT scanning technologies face challenges in reducing radiation dose while maintaining image quality, as increased dose leads to radiation damage and existing methods either compromise image quality or increase computer processing demands.
Innovation Solution
A method and apparatus that dynamically control the opening and closing of fanbeam channels based on a prepatient collimator model, adjusting the opening angle according to the rotation angle of the X-ray tube, particularly at initial and end stages of scanning, to reduce radiation dose without compromising image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the X-ray dose is increased to improve image quality, then the image quality is improved, but the radiation damage increases
Solution Approach 1:
The patent segments the fanbeam into multiple channels and selectively controls each channel's opening and closing based on the rotation angle. By dividing the beam into segments and controlling them independently, the system maintains image quality in critical regions while reducing radiation in less critical regions, thus resolving the contradiction between image quality and radiation damage.
Solution Approach 2:
The patent implements dynamic control of the prepatient collimator channels based on the real-time rotation angle of the X-ray tube. The opening angle and active channels are adjusted dynamically throughout the scanning process, allowing the system to optimize the balance between image quality and radiation dose at each stage of the scan.
2Object-affected harmful factors
If the opening angle of the prepatient collimator is reduced to lower radiation dose, then the radiation dose is reduced, but the image quality may deteriorate
Solution Approach 1:
The patent applies local quality control by adjusting the opening angle and activating specific channels based on the local requirements at different rotation angles. Rather than uniformly reducing the opening angle throughout the scan, the system selectively controls which channels are active, maintaining image quality where needed while reducing radiation dose in other regions.
3Object-affected harmful factors
If fanbeam channels are optimized to reduce dose, then the radiation dose is reduced, but the reconstruction algorithm complexity increases
Solution Approach 1:
The patent performs preliminary action by pre-calculating and storing the dynamic changing model of the prepatient collimator based on the rotation angle before the actual scanning process. This pre-computation allows the reconstruction algorithm to work with pre-organized data, reducing the computational complexity during the actual reconstruction phase while still achieving dose reduction through selective channel control.
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 effectively reduces radiation dose and associated damage while ensuring the quality of reconstructed images without increasing computer processing requirements, by optimizing channel usage during the scanning process.
Implementation Method 1
The checked human body is measured by a high-sensitivity device based on different X-ray absorptance and transmittance of different tissues of the human body
Data Source
AI summary
A method and an apparatus for scanning with a lowered dose are provided. The method includes: determining a dynamic changing model of a prepatient collimator according to a rotation angle of a tube in a scanning mode; in a case that the scanning mode is a normal scan, controlling an opening angle of the prepatient collimator according to the dynamic changing model of the prepatient collimator at an initial stage and an end stage of the normal scan; and in a case that the scanning mode is a scan with phase control, controlling an opening angle of the prepatient collimator according to the dynamic changing model of the prepatient collimator at an initial stage and an end stage of a phase of the scan with phase control.