Multi-Energy CT Noise Reduction via Spatiospectral Redundancy

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Solution Overview

Problem

Conventional CT imaging faces challenges with high image noise and partial volume effects, which compromise diagnostic quality and image resolution, especially in multi-energy CT applications where noise amplification and slice thickness trade-offs hinder the differentiation of materials and anatomical features.

Innovation Solution

A system and method that exploit redundant CT image information to reduce noise and partial volume effects by using a computer system to process CT data with an objective function incorporating total variation and spatiospectral redundancy, promoting sparsity and minimizing noise while retaining structural details.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multi-energy CT is used to differentiate materials, then material differentiation capability is improved, but image noise increases

Engineering Contradiction:
Improvematerial differentiation capabilityVSAvoidimage noise
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent combines multiple energy-specific images into a synthesized image that integrates information from different energy levels. This merging process allows material differentiation capabilities of multi-energy CT while reducing the noise penalty through complementary information fusion across energy bins.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces an intermediate synthesized image as a mediator between raw multi-energy data and final material-specific images. This intermediate representation captures complementary information from multiple energy bins and serves as a noise-reduced foundation for subsequent material differentiation tasks.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If radiation dose is divided into multiple energy bins, then multi-energy CT capability is improved, but image noise within each energy-specific image increases

Engineering Contradiction:
Improvemulti-energy CT capabilityVSAvoidimage noise within energy-specific images
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent merges multiple noisy energy-specific images into a single synthesized image that benefits from the combined signal-to-noise ratio. By integrating information across all energy bins, the synthesized image achieves lower noise levels than any individual energy-specific image while preserving multi-energy CT functionality.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If material decomposition is performed to identify and quantify materials, then material identification capability is improved, but image noise is amplified

Engineering Contradiction:
Improvematerial identification capabilityVSAvoidnoise amplification
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent performs preliminary synthesis of a low-noise intermediate image from multiple energy bins before conducting material decomposition. This preliminary action creates a cleaner input for the decomposition algorithm, reducing the amplification of noise that typically occurs during material identification and quantification processes.

Inventive Principle:
Principle #10Preliminary action

4Manufacturing precision

If thin slice thickness is used, then partial volume effect is reduced, but image noise increases

Engineering Contradiction:
Improvepartial volume effect reductionVSAvoidimage noise
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent combines information from multiple energy bins to create a synthesized image that maintains thin slice thickness for reduced partial volume effects. The merging process accumulates photon statistics across energy levels, providing sufficient signal-to-noise ratio even with thin slice geometry that would normally be too noisy.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentUS20240338866A1System and Method for High Fidelity Computed Tomography
Publication Date: 2024.10.10 MAYO FOUNDATION FOR MEDICAL EDUCATION & RESEARCH
  • US20240338866A1 patent drawing
  • US20240338866A1 patent drawing
  • US20240338866A1 patent drawing

AI summary

A system and method is provided for high fidelity multi-energy CT processing. This system and method exploits prior knowledge, where prior knowledge may include redundant information existing in the CT images, such as spatial redundancy between a thick slice and a thin slice encompassed by or close to the thick slice, or the spatiospectral redundancy between the image output of multi-energy CT processing and the source multi-energy CT images. The system and method retains structural details, spatial resolution, spectral fidelity, and noise texture while achieving noise reduction. The method reduces image noise and increases the contrast-to-noise ratio in processed images, while simultaneously maintaining image details and natural appearance of the image to enhance detectability and facilitate reader acceptance.