Spectral Filtering Multi-Energy CT Tissue Classification

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Solution Overview

Problem

Current CT imaging techniques face challenges in accurately separating tissues due to overlapping attenuation properties at single energy levels, limiting their effectiveness when different tissues have similar appearances.

Innovation Solution

The method involves obtaining images at multiple radiation energies, determining joint attenuation characteristics, and selectively filtering these values in the multi-energy space to generate enhanced images, using spectral filtering techniques to differentiate tissues based on their unique attenuation responses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If single energy CT imaging is used, then the imaging process is simple and fast, but tissue separation accuracy deteriorates due to overlapping attenuation properties

Engineering Contradiction:
Improveimaging speedVSAvoidtissue separation accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The imaging process is segmented into multiple energy acquisitions (first image at first energy, second image at second energy) to separate tissues that overlap at single energy levels. Each energy level provides complementary information that, when combined, enables accurate tissue differentiation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution transitions from single-energy to multi-energy imaging space, adding an energy dimension to the imaging process. This dimensional expansion allows discrimination of tissues with similar attenuation properties at individual energies by exploiting their different attenuation behaviors across multiple energy levels.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If multi-energy images are acquired, then tissue separation accuracy improves through distinct attenuation characteristics, but device complexity and processing requirements increase

Engineering Contradiction:
Improvetissue separation accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The multi-energy CT system uses a universal imaging platform that can operate at multiple energy levels, allowing the same hardware to perform both single-energy and multi-energy acquisitions. The system processes multiple energy datasets through a unified filtering framework that handles various tissue types and imaging scenarios.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The method creates derived images from the multi-energy acquisitions that replicate and enhance specific tissue characteristics. Spectral filtering generates enhanced images that copy and emphasize the unique attenuation signatures of different tissues, making separation more accurate without requiring entirely new hardware.

Inventive Principle:
Principle #26Copying

3Ease of manufacture

If traditional segmentation techniques are used, then the process is simple to implement, but effectiveness deteriorates when tissues share similar appearances

Engineering Contradiction:
Improveimplementation simplicityVSAvoidsegmentation effectiveness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The method changes the fundamental parameter used for segmentation from single-energy attenuation values to joint attenuation characteristics across multiple energies. By analyzing how attenuation varies with energy for different tissues, the system reliably distinguishes between tissues that appear similar at any single energy level.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Spectral filtering acts as an intermediary process that transforms multi-energy attenuation data into enhanced images with improved tissue contrast. This intermediate processing step bridges the gap between raw multi-energy data and final segmented images, making the complex multi-energy information usable for accurate segmentation.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 more accurate tissue separation and enhanced image quality by leveraging the distinct attenuation characteristics of tissues across different energy levels, improving the ability to distinguish between tissues with similar appearances.

Implementation Method 1

The image would include representations of tissues based on attenuation properties of the tissues

Methodology Applied
Scientific EffectRadiation attenuation: Absorption (EM radiation)

Data Source

PatentUS8532744B2Method and system for design of spectral filter to classify tissue and material from multi-energy images
Publication Date: 2013.09.10 GRENERAL ELECTRIC
  • US8532744B2 patent drawing
  • US8532744B2 patent drawing
  • US8532744B2 patent drawing

AI summary

A method, system and apparatus for filtering multi-energy images using spectral filtering technique is described. In one embodiment, the method includes obtaining a first image of an anatomical object corresponding to a first radiation energy. In addition, the method includes obtaining at least one additional image, herein called a second image of the anatomical object corresponding to at least one second radiation energy. The at least one second radiation energy is distinct from the first radiation energy. The method also includes determining joint attenuation characteristics of each tissue at the first radiation energy and at the second radiation energy or their derivatives. The method also includes selectively filtering attenuation value in a multi-energy space due to at least one tissue to generate a filtered image from a reference image. The reference image is one of the first image or the second image or their derivatives.