Multi-sheet Surface Rebinning for Offset Detector Tomography
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Solution Overview
Problem
Conventional cone beam X-ray tomography systems with offset detectors face limitations in image reconstruction due to restricted detector positioning, leading to incomplete data acquisition and poor image quality when using a two-dimensional inverse Radon transform.
Innovation Solution
A method involving a controller that processes X-rays or gamma rays by rebining detected data onto a non-flat surface, applying a two-dimensional weighted inverse Radon transform, and generating a three-dimensional image using a set of simultaneously solvable equations, incorporating direction point spread functions and regularization techniques to improve approximation and resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a two-dimensional inverse Radon transform is used for image reconstruction in offset detector systems, then the reconstruction process is simple and fast, but the image quality deteriorates due to incomplete data acquisition
Solution Approach 1:
The patent transitions from two-dimensional reconstruction to three-dimensional reconstruction by introducing a rebinning surface in 3D space. Projection data is rebinned onto a curved surface that accounts for the offset detector geometry, enabling accurate 3D image reconstruction from incomplete 2D data by utilizing spatial relationships in three dimensions
Solution Approach 2:
The patent introduces a rebinning surface as an intermediary structure between the offset detector data and the final image reconstruction. This intermediate surface serves as a mapping domain that transforms the problematic offset geometry into a form suitable for accurate 3D reconstruction algorithms
2Loss of information
If detectors are positioned directly opposite radiation sources, then complete attenuation data is acquired along all rays, but the system complexity increases and mechanical movement is required
Solution Approach 1:
The patent performs preliminary rebinning of projection data onto a carefully designed rebinning surface before the actual image reconstruction process. This pre-processing step organizes the offset detector data into a structured 3D format that preserves all necessary attenuation information, eliminating the need for complex mechanical positioning during acquisition
Solution Approach 2:
The patent replaces the need for mechanical positioning systems with a computational rebinning approach. Instead of physically moving detectors or sources to achieve optimal geometric coverage, the system uses mathematical rebinning algorithms to reconstruct complete attenuation data from fixed offset detector positions
3Productivity
If multiple sources are arranged around a circle in RTT systems, then the acquisition rate is improved, but attenuation data along rays at certain angles becomes immeasurable
Solution Approach 1:
The patent merges data from multiple sources arranged in a circular configuration by rebining projections onto a unified three-dimensional rebinning surface. This surface integrates information from all angular positions, combining the partial attenuation data from each source into a complete set of 3D projection data suitable for volumetric reconstruction
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 enables efficient three-dimensional image reconstruction in tomography systems with offset detectors, overcoming the limitations of incomplete data acquisition and enhancing image resolution by utilizing multi-sheet surfaces and advanced reconstruction algorithms.
Implementation Method 1
radiation is assumed to propagate along straight lines through an attenuating medium
Implementation Method 2
propagate along straight lines through an attenuating medium
Implementation Method 3
rebin each of said detected X-rays or gamma rays onto a non-flat surface
Data Source
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AI summary
The present application is directed toward the generation of three dimensional images in a tomography system having X-ray sources offset from detectors, in particular in a system where the sources are located on a plane, while detectors are located on multiple parallel planes, parallel to the plane of sources and all the planes of detectors lie on one side of the plane of sources. A controller operates to rebin detected X-rays onto a non-flat surface, perform two dimensional reconstruction on the surface, and generate the three dimensional image from reconstructed images on the plurality of surfaces.