Photon Counter Detector for CT Energy Spectrum Segmentation

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Solution Overview

Problem

Conventional dual-energy X-ray imaging techniques face limitations in material discrimination due to overlapping energy spectrum, leading to system errors and reduced capability in distinguishing materials.

Innovation Solution

A CT imaging system utilizing a photon counter detector to collect photon count projection data across multiple energy windows, allowing for higher resolution and stable decomposition of energy spectrum data, which is then reconstructed to provide enhanced material discrimination and contrast ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional dual-energy X-ray imaging techniques use a scintillator-type detector to collect signals, then the total energy deposition of X rays can be measured, but the imaging result cannot reveal attenuation information of a material under certain energy due to overlapping energy spectrum

Engineering Contradiction:
Improveenergy spectrum discriminationVSAvoidmaterial discrimination capability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent divides the energy spectrum measurement into multiple discrete energy windows using a photon counter detector. Each detector element measures photon counts in specific energy ranges, segmenting the continuous energy spectrum into distinguishable bins. This segmentation eliminates the overlapping energy spectrum problem by assigning photons to specific energy windows based on their energy levels, enabling precise material discrimination through basis function decomposition of the segmented spectral data.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the conventional scintillator-type detector with a photon counter detector that directly counts photons in specific energy windows. This substitution transitions from measuring total energy deposition (analog integration) to counting individual photons in discrete energy ranges (digital measurement), thereby eliminating the fundamental limitation of energy spectrum overlap and enabling accurate spectral decomposition for material identification.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If dual-energy CT imaging is performed using multiple X-ray energy spectra, then material discrimination capability is improved to a certain extent, but system error occurs due to physical model limitations and overlapping energy spectrum

Engineering Contradiction:
Improvematerial discrimination capabilityVSAvoidimaging accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the measurement parameters by using a photon counter detector to directly measure photon counts in multiple discrete energy windows rather than measuring total energy deposition. This parameter change enables acquisition of true spectral information at multiple energy levels, allowing basis function decomposition to accurately separate material contributions. The discrete energy window measurements provide precise spectral data that eliminates the system errors inherent in conventional dual-energy methods with overlapping spectra.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If a photon counter detector is used to collect photon count projection data of multiple energy windows, then higher resolution and more stable material discrimination is achieved, but device complexity increases

Engineering Contradiction:
Improvematerial discrimination stabilityVSAvoiddetector system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a detector system that performs multiple functions: it measures photon counts across multiple energy windows simultaneously, enabling both spectral decomposition for material identification and conventional CT imaging. The photon counter detector serves as a multi-functional device that can operate in different energy window configurations, providing versatile measurement capabilities without requiring separate specialized detectors for each function, thereby managing complexity while achieving enhanced performance.

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

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 system achieves higher resolution and more stable material discrimination by using a photon counter detector for local imaging, enabling better attenuation coefficient information and atomic number mapping, applicable in medical diagnostics and industrial applications.

Implementation Method 1

a photon counter detector to collect photon count projection data of a plurality of energy windows

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP2940458B1CT imaging system and method
Publication Date: 2020.06.10 NUCTECH CO LTD
  • EP2940458B1 patent drawingFigure 1
  • EP2940458B1 patent drawingFigure 2
  • EP2940458B1 patent drawingFigure 3

AI summary

CT imaging systems and methods thereof are disclosed. A common CT scanning is performed (S41) on an object to obtain a common CT imaging. An area of interest is determined (S43) from the image. A CT scanning is performed (S44) on the area of interest under a plurality of energy windows by a photon counter detector. A high resolution image of the area of interest is reconstructed (S46). The discrimination of energy spectrum is higher and the result so obtained is more stable by using a photon counter detector to collect photon count projection data of a plurality of energy windows and thus it may be decomposed into a plurality of basis functions.