Scatter Kernel Estimation for CT Image Artifacts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Computerized tomography (CT) imaging systems face issues with image degradation due to scattered radiation, which causes artifacts and loss of resolution and contrast in CT image slices, leading to spatial and temporal errors in the imaging process.
Innovation Solution
The use of symmetric and asymmetric kernels to estimate scattered radiation in radiographic projections, allowing for the correction of scattered radiation effects in CT imaging systems by generating estimates of scattered radiation amounts based on distance and object thickness, thereby improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional CT imaging is performed without scattered radiation correction, then the imaging process is simple and fast, but image quality degrades due to scattered radiation causing artifacts and loss of resolution and contrast
Solution Approach 1:
The patent applies preliminary action by estimating scattered radiation before it degrades the image quality. The system calculates scattered radiation contributions from all pixels and subtracts this estimate from the measured projection data, preventing artifacts and resolution loss before they occur in the final image reconstruction
Solution Approach 2:
The patent introduces an intermediary computational step that models scattered radiation as a separate entity. By using convolution with a scatter kernel to estimate scattered radiation, the system mediates between the raw projection data and the final image, removing scattered radiation effects without requiring hardware modifications
2Measurement precision
If scattered radiation estimation and correction is applied, then image accuracy and clarity improve, but the computational complexity and processing time increase
Solution Approach 1:
The patent applies partial action by implementing scattered radiation correction only where needed - using convolution with a scatter kernel to estimate scattered radiation contributions from all pixels. This selective correction approach improves image accuracy in regions affected by scattered radiation without requiring complete reprocessing of all image data, thus reducing overall processing time
3Ease of operation
If scattered radiation is not corrected, then the imaging process remains simple, but spatial errors and temporal errors occur in the pixel data
Solution Approach 1:
The patent extracts scattered radiation as a separate component from the total measured radiation. By convolving the projection data with a scatter kernel to estimate scattered radiation, then subtracting this extracted scattered component from the original measurement, the system removes spatial and temporal errors while maintaining operational simplicity
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 the impact of scattered radiation errors, enhancing the accuracy and clarity of CT images by accounting for scattered radiation in the imaging process, leading to improved spatial resolution and contrast.
Implementation Method 1
when a quantum of radiation is absorbed by a portion of the object, one or more scattered rays are often generated that deviate from the transmission path of the incident radiation
Implementation Method 2
collecting the non-absorbed radiation onto a two-dimensional imaging device, or imager, which comprises an array of pixel detectors
Data Source
AI summary
Several related inventions for estimating scattered radiation in radiographic projections are disclosed. Several of the inventions use scatter kernels of various forms, including symmetric and asymmetric forms. The inventions may be used alone or in various combinations with one another. The resulting estimates of scattered radiation may be used to correct the projections, which can improve the results of tomographic reconstructions. Still other inventions of the present application generate estimates of scattered radiation from shaded or partially shaded regions of a radiographic projection, which may be used to correct the projections or used to adjust the estimates of scattered radiation generated according to inventions of the present application that employ kernels.