CT Scatter Correction via Basis Material Decomposition
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Solution Overview
Problem
Computed tomography (CT) imaging systems face challenges in reducing the impact of scatter signals, which cause shading artifacts and degrade image quality and quantitative measurements.
Innovation Solution
A signal processing method and imaging system that detect the total intensity of X-rays passing through objects, estimate the scatter intensity component using basis material information, and obtain an intensity estimate of primary X-rays incident on a detector, thereby correcting for scatter and improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If scatter correction is not applied, then the imaging system is simpler and faster, but image quality and quantitative measurement accuracy are degraded due to scatter artifacts
Solution Approach 1:
The patent introduces basis material information as an intermediary to bridge the relationship between detected X-ray intensities and scatter components. By decomposing the object into basis materials and using their known scattering properties, the system can estimate scatter without requiring complex direct measurement or iterative reconstruction methods.
Solution Approach 2:
The patent transforms the scatter correction problem from a spatial domain problem to a material composition domain problem by changing parameters from raw intensities to basis material information. This parameter transformation enables more efficient scatter estimation through material-specific scattering models rather than general-purpose correction algorithms.
2Measurement precision
If scatter correction is not applied, then the processing time is reduced, but measurement precision is degraded due to scatter-induced bias
Solution Approach 1:
The patent performs preliminary decomposition of the object into basis materials before scatter estimation. By pre-characterizing the material composition and their scattering properties, the system prepares the necessary information in advance, enabling rapid scatter correction during the actual imaging process without requiring time-consuming iterative adjustments.
3Measurement precision
If basis material information is obtained for scatter estimation, then scatter correction accuracy is improved, but the processing complexity and computational load increase
Solution Approach 1:
The patent segments the object's composition into discrete basis materials, each with known scattering characteristics. This segmentation approach simplifies the overall scatter estimation problem by breaking it down into manageable components, where the scatter contribution of each basis material can be calculated independently and then combined, reducing computational complexity compared to treating the object as a homogeneous medium.
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
The method effectively reduces or eliminates scatter artifacts, enhancing image quality and quantitative measurements by accurately estimating and subtracting the scatter intensity from the total intensity of X-rays.
Implementation Method 1
detecting a total intensity of X-rays passing through an object comprising multiple materials
Implementation Method 2
basis component information of photon-electric absorption basis component and Compton scattering basis component of the object
Data Source
AI summary
A signal processing method is disclosed, which includes detecting a total intensity of X-rays passing through an object comprising multiple materials; obtaining at least one set of basis information of basis material information of the multiple materials and basis component information of photon-electric absorption basis component and Compton scattering basis component of the object; estimating a scatter intensity component of the detected X-rays based on the at least one set of basis information and the detected total intensity; and obtaining an intensity estimate of primary X-rays incident on a detector based on the detected total intensity and the estimated scatter intensity component. An imaging system adopting the above signal processing method is also disclosed.