Anchored Kernel Scatter Estimation for Resolution-Preserving CT Correction
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Solution Overview
Problem
Scatter in radiological imaging modalities such as CT and cone-beam CT degrades image quality by reducing contrast and introducing noise and artifacts, and existing scatter correction methods amplify noise and can lead to resolution degradation.
Innovation Solution
The method involves separating radiation data into primary and scatter components, using generating functions and scatter models to estimate and subtract the scatter component, applying different filters to each component to reduce noise and artifacts independently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If scatter correction methods are applied to improve image quality, then noise and artifacts are reduced, but resolution degradation occurs
Solution Approach 1:
The patent segments the scatter correction process into distinct components: estimating scatter using a scatter-only image from shadow regions, processing the scatter component separately with denoising filters, and processing the primary component separately. This segmentation allows different processing strategies to be applied to different components, reducing overall noise without degrading the resolution of the primary image content.
Solution Approach 2:
The patent extracts the scatter component from the total detected signal by using shadow regions where only scatter is present. By isolating and removing the scatter component through subtraction, the method reduces noise and artifacts in the final image while preserving the primary signal resolution, as the scatter removal is based on extracted shadow region data rather than aggressive filtering of the entire image.
2Measurement precision
If scatter estimation is performed using shadow regions to improve accuracy, then scatter correction quality improves, but image processing complexity increases
Solution Approach 1:
The patent performs preliminary action by acquiring shadow region data during the same scan as the primary image data, before reconstruction. The scatter estimation using shadow regions is performed as a pre-processing step to generate a scatter-only image, which is then used to correct the primary image. This preliminary scatter estimation improves accuracy by using actual measured shadow data rather than theoretical models, while the complexity is managed by performing the calculation during the existing scan acquisition.
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 improves image quality by reducing noise and artifacts while preserving resolution, achieving a balanced compromise between noise reduction and resolution preservation in scatter-corrected images.
Implementation Method 1
CT is a technique based on x-ray transmission through a patient to create images of sections of the body
Implementation Method 2
The scatter signal detected by the same element also represents the x-rays that are scattered from other x-ray paths into the elements
Data Source
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AI summary
A radiological imaging apparatus is provided that includes a radiation source for emitting radiation, a radiation detector positioned to receive radiation emitted by the radiation source and generate radiation data, wherein the radiation data comprises a primary component and a secondary component, and a data processing system. The data processing system is configured to apply image transforms to the primary component using generating functions, build a scatter model basis using the transforms, adjust parameters in the scatter model to fit scatter using the scatter model basis, generate an estimated scatter image by using the fitted scatter model, and modify the radiation data using the scatter image to decrease the scatter in the radiation data thereby generating a scatter corrected image.