Segmented Photon-Counting CT Detector Scatter Correction

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Solution Overview

Problem

In computed tomography (CT) imaging systems, scatter photons that travel non-linear paths before reaching the detector introduce noise and artifacts in reconstructed images, as existing methods fail to effectively correct for scatter signals, particularly in systems with vertically-segmented detector elements.

Innovation Solution

A method for reducing scatter signal in CT systems involves estimating a primary signal free of scatter by analyzing readout signals from segmented detector elements, using the difference in scatter-to-primary ratios at different depths to correct for scatter, and generating scatter-corrected readout signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional scatter correction methods are used, then scatter signal reduction is achieved, but image quality deteriorates due to residual artifacts and noise

Engineering Contradiction:
Improvescatter signalVSAvoidimage quality
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The detector element is divided into multiple segments along the vertical direction, with each segment having a different depth. This segmentation allows the system to measure scatter-to-primary ratios at different depths, enabling more accurate scatter signal estimation and correction while preserving image quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a depth dimension by segmenting the detector element into multiple vertical segments at different depths. This additional dimensional information allows the system to differentiate between primary and scatter signals more effectively, resolving the contradiction between scatter reduction and image quality maintenance.

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

2Device complexity

If scatter correction is applied using single-depth detection, then processing complexity is reduced, but correction accuracy deteriorates

Engineering Contradiction:
Improvecorrection method complexityVSAvoidscatter correction accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

By segmenting the detector into multiple depth layers, the system obtains multiple measurements of scatter-to-primary ratios. This segmentation provides the additional data needed for accurate scatter correction without requiring overly complex processing algorithms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces complex mechanical scatter correction mechanisms with a computational approach that uses depth-segmented detector signals. This substitution achieves high correction accuracy through signal processing rather than mechanical means, balancing complexity and precision.

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

3Device complexity

If no scatter correction is applied, then device complexity remains low, but image accuracy deteriorates due to scatter artifacts

Engineering Contradiction:
Improvedetector configurationVSAvoidimage accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The vertical segmentation of the detector element into multiple depth segments provides the capability for scatter correction while maintaining a relatively simple detector configuration. Each segment's signal contributes to the overall correction calculation, improving image accuracy without requiring complex external correction devices.

Inventive Principle:
Principle #1Segmentation

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 improves image quality by reducing artifacts and noise in CT images by accurately estimating and correcting scatter signals, enhancing the accuracy of pixel-by-pixel scatter correction.

Implementation Method 1

the detector elements of the array generate respective electrical signals representative of internal information of the object

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

collimation effects of plates separating detector elements

Methodology Applied
Scientific EffectX-ray absorption: Absorption (EM radiation)

Data Source

PatentEP3635440B1Scatter correction technique for use with a radiation detector
Publication Date: 2024.06.26 GENERAL ELECTRIC CO
  • EP3635440B1 patent drawingFigure 1
  • EP3635440B1 patent drawingFigure 2
  • EP3635440B1 patent drawingFigure 3

AI summary

The present approach relates to scatter correction of signals acquired using radiation detectors on a pixel-by-pixel basis. In certain implementations, the systems and methods disclosed herein facilitate scatter correction for signals generated using a detector having segmented detector elements, such as may be present in an energy-resolving, photon-counting CT imaging system.