Variable Speed X-ray Rotation for Artifact Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
X-ray diagnostic apparatuses face challenges in obtaining favorable tomographic images due to varying body thickness, leading to decreased S/N ratios and streak artifacts, particularly in specific view angle ranges where X-ray doses are lower.
Innovation Solution
The apparatus increases the number of views in specific view angle ranges by adjusting the frame rate or rotational speed of the X-ray source and detector, ensuring consistent data acquisition and reconstruction to improve S/N ratios and reduce artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the X-ray source and detector rotate at constant speed with predetermined frame rate, then the data acquisition is efficient and simple, but the S/N ratio decreases in specific view angle ranges where body thickness is larger
Solution Approach 1:
The patent applies dynamics by making the rotational speed of the X-ray source and detector variable rather than constant. The rotational speed is dynamically adjusted based on the view angle, rotating slower in view angle ranges where body thickness is larger (e.g., longitudinal direction, shoulder regions) to increase the number of views and improve the S/N ratio, while maintaining higher speed in other ranges to preserve acquisition efficiency.
Solution Approach 2:
The patent changes the parameter of rotational speed according to the view angle range. By modifying the rotational speed parameter dynamically during the scanning process, the system adapts to varying body thickness conditions, acquiring more projection data in challenging view angles where the S/N ratio would otherwise deteriorate.
2Measurement precision
If the number of views is increased in specific view angle ranges, then the S/N ratio improves and artifacts are reduced, but the data acquisition time and system complexity increase
Solution Approach 1:
The patent applies local quality by applying different rotational speeds to different view angle ranges rather than uniformly across all angles. Specifically, the system rotates slower only in specific ranges where body thickness causes S/N ratio deterioration (such as the longitudinal direction and shoulder regions), while maintaining normal speed in other ranges, thus locally optimizing image quality without globally increasing acquisition time.
Solution Approach 2:
The system dynamically changes the rotational speed parameter based on the current view angle range, increasing the number of views only where necessary to improve S/N ratio while maintaining overall acquisition efficiency.
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 enhances image quality by maintaining consistent data acquisition across varying view angles, reducing streak artifacts and improving the signal-to-noise ratio, especially in regions with larger body thickness.
Implementation Method 1
an X-ray source, an X-ray detector, The X-ray source irradiates an object with X-rays. The X-ray detector outputs projection data by detecting X-rays transmitted through the object.
Data Source
AI summary
According to one embodiment, an X-ray diagnostic apparatus includes an X-ray source, an X-ray detector, a rotating mechanism, a control unit, and a reconstruction unit. The source irradiates an object with X-rays. The detector outputs projection data by detecting X-rays transmitted through the object. The rotating mechanism rotates the source and the detector around the object. The control unit acquires projection data, while making the rotating mechanism rotate the source and the detector, such that the number of views in a specific view angle range becomes larger than that in other view angle ranges. The reconstruction unit configured to reconstruct an image by using acquired projection data of each view.