Gamma Imaging Detector with Segmented Compton Planes for Multi-Source Imaging

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Solution Overview

Problem

Existing Compton camera designs are limited by parallax error when imaging a patient in nuclear medicine, have low detection efficiency, and are restricted to single-source nuclide measurements, lacking applicability in environments with multiple radiation sources and requiring improved detection efficiency for high-energy nuclides.

Innovation Solution

An imaging detector system with synchronized detectors of varying atomic numbers, segmented into voxels, records coincidence events and uses statistical image reconstruction methods to create activity and directional distributions, applicable in near and far fields, overcoming the limitations of traditional Compton cameras.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a classic two-plane Compton camera design is used, then the detection principle is established, but parallax error occurs when imaging a patient at finite distance

Engineering Contradiction:
Improveimaging precisionVSAvoidparallax error
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The detector system is segmented into multiple detector planes with varying atomic numbers, where each plane is divided into detector elements. This segmentation allows for more precise tracking of gamma radiation paths and reduces parallax error by providing multiple measurement points along the radiation trajectory through the patient.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different detector planes use materials with different atomic numbers optimized for specific energy ranges and interaction types. The first plane uses low-Z material for Compton scattering, while subsequent planes use higher-Z materials for absorption, creating local quality variations that improve overall measurement precision and reduce imaging errors.

Inventive Principle:
Principle #3Local quality

2Productivity

If traditional Compton camera designs are used, then the basic detection function is achieved, but detection efficiency is low

Engineering Contradiction:
Improvedetection efficiencyVSAvoidenergy loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent merges multiple detection functions into a single integrated detector system. By combining Compton scattering detection in the first plane with photoelectric absorption detection in subsequent planes, and by utilizing all detector element combinations rather than requiring specific pairs, the system achieves much higher detection efficiency while maintaining energy resolution.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The detector system is designed to perform multiple functions: Compton scattering detection, photoelectric absorption detection, and coincidence event detection across all detector planes. This multi-functionality allows the system to detect a broader range of gamma radiation interactions, significantly improving overall detection efficiency.

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

3Adaptability or versatility

If classic Compton camera designs are used, then single-source nuclide measurement is achieved, but applicability in environments with multiple radiation sources is limited

Engineering Contradiction:
Improvemulti-source detection capabilityVSAvoidsource discrimination information
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The system uses feedback from coincidence events across multiple detector planes to distinguish between different radiation sources. By analyzing the spatial and temporal patterns of coincidence events and applying energy windowing techniques, the system can identify and separate signals from multiple sources, maintaining source discrimination capability in complex radiation environments.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent adds dimensional complexity by utilizing multiple detector planes in the third dimension, rather than relying solely on two-dimensional detector arrangements. This three-dimensional detection geometry provides additional information for source localization and discrimination, enabling the system to distinguish between multiple radiation sources in complex spatial configurations.

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

4Use of energy by stationary object

If conventional SPECT is used, then imaging is achieved, but energy range is limited and detection efficiency is very low due to collimators

Engineering Contradiction:
Improveenergy rangeVSAvoiddetection efficiency
Core Design Contradiction:
Use of energy by stationary objectVSProductivity

Solution Approach 1:

The patent extracts and eliminates the collimator component from the imaging system. By using Compton scattering physics and coincidence detection instead of mechanical collimation, the system achieves high detection efficiency without the energy-dependent efficiency losses inherent in collimator-based SPECT systems, enabling effective imaging across a broad energy range from 140 keV to 640 keV and beyond.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enhances detection efficiency, expands the energy range to include high-energy nuclides, and enables imaging in environments with multiple radiation sources, providing real-time directional distribution measurements.

Implementation Method 1

A frequently used direction-dependent detection principle is Compton scattering of gamma radiation by an electron in the detector material

Methodology Applied
Scientific EffectCompton scattering: Compton Scattering

Implementation Method 2

The scattered gamma radiation then falls onto the second plane, whose high-Z detectors have a high probability of absorbing radiation in this energy range

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3825736B1Imaging detector system for gamma radiation using unidirectional and bidirectional compton scattering processes
Publication Date: 2025.08.06 HELLMA MATERIALS GMBH & CO KG
  • EP3825736B1 patent drawingFigure 1~2c
  • EP3825736B1 patent drawingFigure 3(a)~4b
  • EP3825736B1 patent drawingFigure 5a~6b

AI summary

A device for generating one or more images of the source distribution of a gamma radiation field in the near and far field is described. The device comprises: • a detector system containing a group of several synchronized detectors for detecting radiation, • system electronics that register coincidence events, • a data acquisition system that stores the measurement data of the coincidence events, and • an analysis unit that performs image reconstruction, reconstructing one or more images of the source distribution of the radiation field.