Image Processing Device Noise Reduction Material Decomposition

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Solution Overview

Problem

In interventional radiology, energy subtraction techniques used in radiation imaging systems with flat panel detectors often result in noisy material separation images due to noise from materials other than the separated bone and soft-tissue components.

Innovation Solution

An image processing method that utilizes the continuity of human body thickness to generate material decomposition images with reduced noise by obtaining and processing radiation images at different energies, employing correction and signal processing units to derive bone and soft-tissue thickness images, and then generating a thickness image by adding these components together.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If energy subtraction is used to separate bone and soft-tissue images, then material decomposition capability is improved, but noise increases due to inclusion of other materials

Engineering Contradiction:
Improvematerial decomposition accuracyVSAvoidnoise
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by utilizing the continuity constraint of thickness values across adjacent pixels. The processing unit enforces that thickness values in neighboring regions should be similar, adjusting decomposed images to satisfy this continuity condition. This reduces noise while preserving the material decomposition capability achieved through energy subtraction.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multiple radiation energy images are processed for material decomposition, then image quality improves, but processing complexity increases

Engineering Contradiction:
Improveimage qualityVSAvoidprocessing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent creates a simplified copy of the thickness information by generating a thickness map from the decomposed images and then using this map to guide noise reduction. Instead of directly processing the complex multi-energy images through multiple decomposition steps, the method copies essential thickness information and processes this simplified representation to enforce continuity, thereby reducing processing complexity while maintaining image quality.

Inventive Principle:
Principle #26Copying

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 method effectively reduces noise in material decomposition images, improving image quality by separating bone and soft-tissue components accurately, allowing for better visualization of contrast agents and medical devices in medical procedures.

Implementation Method 1

an X-ray generation unit configured to emit X-rays

Methodology Applied
Scientific EffectX-ray generation: X-Ray

Implementation Method 2

Energy subtraction is an image-capturing method in which an FPD is used. In energy subtraction, thickness images for a plurality of materials, such as a bone image and a soft-tissue image for example, can be derived from a plurality of images with different radiation energies

Methodology Applied
Scientific EffectEnergy subtraction:

Data Source

PatentEP4014874B1Image processing device, radiographic imaging system, image processing method, and program
Publication Date: 2023.12.13 CANON KK
  • EP4014874B1 patent drawingFigure 1
  • EP4014874B1 patent drawingFigure 2
  • EP4014874B1 patent drawingFigure 3

AI summary

An image processing apparatus comprises a generating unit configured to generate, based on a plurality of radiation images captured at mutually different radiation energies, a first material decomposition image that indicates a thickness of a first material and a second material decomposition image that indicates a thickness of a second material, the generating unit generates a thickness image in which the thickness of the first material and the thickness of the second material are added together.