Multi-Spectral X-Ray Image Reconstruction Using Prior Material PDFs

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Solution Overview

Problem

Current image reconstruction techniques in multi-spectral imaging struggle to effectively decompose X-ray attenuation into Compton scattering and photoelectric absorption contributions, leading to suboptimal image quality due to the lack of well-defined spectral dependence models.

Innovation Solution

The method involves acquiring measurement data at multiple X-ray energy levels and defining prior information using a joint probability density function (PDF) between basis components to reconstruct multi-spectral images, incorporating Compton scattering and photoelectric absorption contributions, thereby improving image quality and reducing noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional image reconstruction techniques are used without prior information, then the reconstruction process is simpler, but the image quality and material discrimination capability deteriorate

Engineering Contradiction:
Improveimage qualityVSAvoidreconstruction complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by defining prior information about material properties (such as atomic number, density ranges, and composition constraints) before the image reconstruction process. This prior information is incorporated into the reconstruction algorithm to guide the decomposition of attenuation coefficients into Compton scattering and photoelectric absorption components, thereby improving image quality and material discrimination without requiring overly complex reconstruction procedures.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If spectral dependence modeling is performed without prior knowledge, then the process is more straightforward, but the accuracy of Compton scattering and photoelectric absorption decomposition deteriorates

Engineering Contradiction:
Improvedecomposition accuracyVSAvoidmodeling complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by incorporating prior knowledge about material parameters (atomic number Z, density ρ, and composition ratios) into the spectral dependence model. The model uses these parameter constraints to accurately determine the Compton scattering coefficient μ_Compton and photoelectric absorption coefficient μ_photoelectric at different energy levels, improving decomposition accuracy while managing modeling complexity through physically-based parameter relationships.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multi-spectral imaging is performed at multiple energy levels, then material discrimination capability is improved, but the complexity of data acquisition and processing increases

Engineering Contradiction:
Improvematerial discriminationVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the total X-ray attenuation coefficient μ(E) into distinct energy-dependent components: Compton scattering μ_Compton(E) and photoelectric absorption μ_photoelectric(E). By acquiring data at multiple energy levels and separately reconstructing these components using prior material information, the system achieves improved material discrimination while managing processing complexity through component-wise reconstruction rather than treating all attenuation data uniformly.

Inventive Principle:
Principle #1Segmentation

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 the generation of multi-spectral images with improved material discrimination and reduced noise by selectively smoothing images and incorporating known material properties into attenuation coefficients, resulting in better material decompositions.

Implementation Method 1

The first event is known as Compton scatter and denotes the tendency of an X-ray photon passing through the material to be scattered or diverted from the original beam path

Methodology Applied
Scientific EffectCompton scattering: Compton Scattering

Implementation Method 2

The second event is known as photoelectric absorption and denotes the tendency of an X-ray photon passing through the material to be absorbed by the material

Methodology Applied
Scientific EffectPhotoelectric absorption: Photoelectric Effect

Data Source

PatentUS7760848B2Method and system for generating a multi-spectral image of an object
Publication Date: 2010.07.20 GE PRECISION HEALTHCARE LLC
  • US7760848B2 patent drawing
  • US7760848B2 patent drawing
  • US7760848B2 patent drawing

AI summary

A method for generating a multi-spectral image of an object is provided. The method comprises acquiring measurement data at a plurality of X-ray energy levels and defining a plurality of image voxels in one or more regions comprising the object. The method then comprises obtaining prior information associated with a plurality of image voxels comprising the object. The prior information is defined by a joint probability density function (PDF) between a plurality of basis components. The method further comprises reconstructing the measurement data to generate a multi-spectral reconstructed image of the object based on the prior information.