Spectral Image Decomposition Accuracy via Residual Region Identification

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Solution Overview

Problem

Spectral image data decomposition in spectral x-ray imaging is often inaccurate due to suboptimal processes and image acquisition inaccuracies, particularly affecting the distribution of contrast agents, which hampers clinical applications.

Innovation Solution

An apparatus and method that identify residual regions of contrast agents in virtual non-contrast images using expected structural characteristics, allowing for recalculating weights of basis functions to improve decomposition accuracy, focusing corrections on these regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If spectral image data decomposition is performed using conventional basis functions, then image data can be processed and spectral images can be generated, but the decomposition accuracy is insufficient leading to residual contrast agent artifacts

Engineering Contradiction:
Improvedecomposition accuracyVSAvoidcontrast agent residual artifacts
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by transforming the decomposition problem from conventional basis functions to a dictionary learning framework with learned basis functions and sparse coefficients. The decomposition model changes from fixed mathematical basis functions to adaptive learned dictionaries that capture the true sparsity patterns of anatomical structures, thereby improving decomposition accuracy and reducing contrast agent residuals

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses copying by creating virtual non-contrast images from the decomposed spectral data. These virtual images serve as copies that represent what the anatomy would look like without contrast agents, allowing for the identification and removal of contrast agent artifacts while preserving anatomical structures

Inventive Principle:
Principle #26Copying

2Reliability

If conventional decomposition methods are used, then processing speed is maintained, but clinical utility is reduced due to inaccurate contrast agent distribution

Engineering Contradiction:
Improveclinical utilityVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-learning dictionaries from training data before actual decomposition. The dictionary learning phase is performed in advance on representative anatomical data, so that during clinical processing, the pre-learned dictionaries can be directly applied for fast decomposition without requiring real-time iterative learning, thus maintaining processing speed while improving accuracy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the decomposition parameters from conventional fixed basis functions to adaptive sparse representations with learned dictionaries. This parameter transformation enables more accurate separation of contrast agents from anatomical structures, significantly improving clinical utility for tasks like virtual non-contrast imaging and contrast agent quantification

Inventive Principle:
Principle #35Parameter changes

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

The approach significantly enhances the accuracy of decomposed spectral image data, reducing contrast agent residuals and improving the clinical utility of spectral image data.

Implementation Method 1

functions that describe the dependence of the Compton scattering effect and/or the photoelectric effect on the energy of the radiation

Methodology Applied
Scientific EffectCompton scattering: Compton Scattering

Implementation Method 2

functions that describe the dependence of the Compton scattering effect and/or the photoelectric effect on the energy of the radiation

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP4139883B1Apparatus for determining decomposed spectral image data
Publication Date: 2024.12.04 KONINKLIJKE PHILIPS NV
  • EP4139883B1 patent drawingFigure 1
  • EP4139883B1 patent drawingFigure 2
  • EP4139883B1 patent drawingFigure 3

AI summary

The invention refers to an apparatus for determining decomposed spectral image data with an improved accuracy. The apparatus (110) comprises a spectral image data providing unit (111) for providing spectral image data, a spectral image data decomposition unit (112) for calculating a basis decomposition for the spectral image data, a virtual non- contrast image generation unit for generating a virtual non-contrast image based on the decomposed spectral image data, and a contrast agent residual identification unit (113) for identifying a residual region comprising a contrast agent residual in the virtual non-contrast image based on an expected structural characteristic of the contrast agent residual, wherein the spectral image data decomposition unit (114) is configured to calculate a new basis decomposition in the residual region. Utilizing structural characteristics of the contrast agent residual allows for a very accurate determination of contrast agent residuals and an improvement of the decomposition accuracy in this area.