Beam Hardening Correction in Radiation Tomographic Imaging

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Solution Overview

Problem

Beam hardening artifacts in radiation tomographic images vary significantly due to individual differences in bone size, shape, and density, leading to inconsistent correction results, with some regions experiencing undercorrection or overcorrection.

Innovation Solution

An image processing method that calculates a first index based on pixel values and distances from surrounding areas to determine the amount of correction needed for each subregion, applying additional correction to reduce variability in beam hardening correction, using a second index for correlation analysis and smoothing processing to ensure accurate pixel value adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If beam hardening correction is applied to radiation tomographic images, then beam hardening artifacts are suppressed, but variability in correction results occurs due to individual differences in bone size, shape, and density

Engineering Contradiction:

Improvecorrection consistencyVSAvoidindividual variability in bone structure

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by calculating a first index for each individual subregion based on pixel values at surrounding positions and distances, enabling location-dependent correction amounts that adapt to local bone structures rather than applying uniform correction across the entire image

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the image into individual subregions and processes each subregion independently with its own correction calculation, allowing the correction to adapt to local variations in bone size, shape, and density while maintaining overall image consistency

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If conventional beam hardening correction is applied, then some beam hardening artifacts are reduced, but undercorrection or overcorrection occurs in different regions

Engineering Contradiction:

Improvecorrection accuracyVSAvoidcorrection uniformity

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes parameters by calculating correction amounts based on multiple factors including pixel values at surrounding positions and distances from each subregion, dynamically adjusting correction parameters to achieve both high accuracy and uniformity across different image regions

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses feedback by calculating the first index based on surrounding pixel values and using this information to determine the correction amount for each subregion, creating a feedback loop that ensures both accuracy and uniformity in the correction process

Inventive Principle:

Principle #23Feedback

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 variability in beam hardening correction by estimating the effect of beam hardening based on surrounding bone proximity, applying targeted corrections to improve image quality and stability.

Implementation Method 1

Radiation used in radiation tomographic imaging is continuous radiation. Therefore, as the radiation passes through a subject and attenuates, a beam hardening phenomenon occurs, wherein a high-energy portion in a radiation spectrum relatively grows and becomes hard to attenuate.

Methodology Applied

Scientific EffectBeam hardening: Absorption (EM radiation)

Data Source

PatentUS10194879B2Image processing method, image processing apparatus and radiation tomographic imaging apparatus, and program

Publication Date: 2019.02.05 GE PRECISION HEALTHCARE LLC

AI summary

To reduce variability in a result of correction by beam-hardening correction in a radiation tomographic image: There is provided an image processing apparatus comprising: a first-index obtaining component configured to obtain, for each individual subregion in a beam-hardening correction-processed image representing a body region including a bone part and a soft part, a first index indicating how much beam hardening due to the bone part affects the subregion based on pixel values at a plurality of positions surrounding the subregion and a distance from the subregion; a determining component configured to determine an amount of correction on a pixel value for the subregion using the first index for the subregion; and a pixel-value correcting component configured to correct the pixel value of the subregion according to the amount of correction on the subregion.