Inverse X-ray Scatter Correction via Density Volume
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Solution Overview
Problem
Computed tomography (CT) imaging systems face challenges in reducing scatter artifacts, which result in image imperfections despite the use of anti-scatter grids, due to the complexity and cost associated with two-dimensional grids, and the inefficiency of existing computational scatter correction algorithms.
Innovation Solution
A method involving the generation of a density integrated volume and inverse tracking of scattered X-rays from the detector to the source to create a scatter profile, allowing for scatter correction in reconstructed images, which reduces computational time and improves image quality by eliminating redundant integration processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If two-dimensional (2D) anti-scatter grids are used to reduce scatter, then scatter rejection is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex mechanical 2D anti-scatter grids with a computational scatter correction system that uses processor-based algorithms to estimate and remove scatter from projection data. This substitution eliminates the need for physically complex 2D grids while achieving scatter rejection through software processing of X-ray transmission data.
Solution Approach 2:
The patent creates a computational model (scatter estimation volume) that replicates the scatter distribution without requiring physical 2D grids. By generating and processing a digital representation of scatter patterns through ray tracing algorithms, the system achieves scatter correction without the mechanical complexity of 2D grid structures.
2Object-affected harmful factors
If conventional computational scatter correction algorithms are used, then scatter artifacts are reduced, but computational time increases
Solution Approach 1:
The patent performs preliminary scatter estimation by generating a scatter estimation volume and pre-calculating scatter contributions before final image reconstruction. By estimating scatter in advance using ray tracing through the attenuation map and storing results in a scatter estimation volume, the system reduces the computational burden during the actual reconstruction process, thereby reducing total computational time.
Solution Approach 2:
The patent divides the scatter correction process into distinct computational stages: generating the attenuation map, performing ray tracing to estimate scatter, storing results in a scatter estimation volume, and applying correction to projection data. This segmentation allows each stage to be optimized independently and enables parallel processing, reducing overall computational time compared to conventional monolithic algorithms.
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 suppresses scatter artifacts, enhancing image quality by accurately capturing scatter profiles and reducing computational time, thereby improving the overall performance of CT imaging systems.
Implementation Method 1
One or more scattered X-rays are tracked beginning at the detector and proceeding toward the source to generate a scatter profile for a plurality of discrete locations on the detector
Data Source
AI summary
Approaches for deriving scatter information using inverse tracking of scattered X-rays is disclosed. In certain embodiments scattered rays are tracked from respective locations on a detector to a source of the X-ray radiation, as opposed to tracking schemes that proceed from the source to the detector. In one such approach, the inverse tracking is implemented using a density integrated volume that reduces the integration steps performed.