Multi-Energy CT Material Property Extraction via Statistical Analysis

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Solution Overview

Problem

Single-Energy Computed Tomography (SECT) cannot reliably differentiate between materials with significantly different physical properties, as they may appear similar in a CT scan, making it difficult to accurately determine material properties for radiation treatment planning.

Innovation Solution

Multi-Energy Computed Tomography (MECT) is used, which involves obtaining images at different energy levels to differentiate materials by analyzing how they appear at various energies, employing statistical analysis and calibration curves to enhance material identification and treatment planning accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If single-energy CT scanning is used, then the imaging process is simple and fast, but the ability to differentiate between materials with different physical properties is poor

Engineering Contradiction:
Improvematerial differentiation accuracyVSAvoidimaging system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by utilizing multiple energy levels (kVp values) for CT scanning. Instead of using a single energy level, the system acquires images at different energies (e.g., 80kVp, 140kVp) and processes these multi-energy datasets to differentiate materials. This allows the system to distinguish between materials like iodine and calcium that appear similar in single-energy images, thereby improving material differentiation accuracy without requiring fundamentally new imaging hardware

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an additional dimension by adding energy level variation to the traditional CT imaging process. By acquiring images across multiple energy levels and using statistical analysis (e.g., histograms, machine learning algorithms) on this extended data space, the system creates a more robust basis for material identification. This dimensional expansion allows differentiation based on energy-dependent attenuation characteristics that are not visible in conventional single-energy images

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

2Measurement precision

If single-energy CT scanning is used, then the scanning process is quick, but the precision of material property determination is insufficient

Engineering Contradiction:
Improvematerial property measurement accuracyVSAvoidscanning and processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements preliminary action by performing statistical analysis and material classification algorithms during the image reconstruction phase, rather than requiring separate measurement steps. The system pre-processes the multi-energy CT data using histograms and machine learning models to generate material property maps simultaneously with image formation, thereby improving measurement precision without adding significant time to the overall workflow

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses calibration curves and reference material databases that store pre-measured attenuation characteristics for various materials at different energy levels. During analysis, the system compares patient data against these pre-established references to rapidly determine material properties, improving measurement accuracy while minimizing additional scanning or processing time required

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

MECT improves the accuracy of material identification and treatment planning by allowing differentiation of materials based on their distinct responses to different energy levels, providing more precise determination of material properties.

Implementation Method 1

Single-Energy Computed Tomography (SECT) is currently the cornerstone of radiation treatment planning... the first image is created using a first energy having a first energy level, and wherein the second image is created using a second energy having a second energy level

Methodology Applied
Scientific EffectX-Ray: X-Ray

Implementation Method 2

How materials appear in a CT scan depends on the scanning energy and the material in question... two materials with significantly different physical properties may appear similar in the single energy CT image

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentUS11253214B2Statistical method for material property extraction from multi-energy images
Publication Date: 2022.02.22 SIEMENS HEALTHINEERS INTERNATIONAL AG
  • US11253214B2 patent drawing
  • US11253214B2 patent drawing
  • US11253214B2 patent drawing

AI summary

An apparatus for determining material property, includes: an interface configured to obtain a first HU value associated with a first image of an object, and to obtain a second HU value associated with a second image of the object, wherein the first image is created using a first energy having a first energy level, and wherein the second image is created using a second energy having a second energy level that is different from the first energy level; and a processing unit configured to determine a weighted property value for the object based at least in part on the first HU value and the second HU value.