Cone-beam CT Image Enhancement via Generative Adversarial Networks

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current Cone-Beam Computed Tomography (CBCT) images suffer from low image quality due to artefacts and noise, which can hinder adaptive treatment planning and diagnosis, and there is a lack of efficient methods to suppress these artefacts effectively.

Innovation Solution

The use of generative adversarial networks (GANs) and cycle generative adversarial networks (CycleGANs) is employed to generate synthetic CT images from CBCT images, leveraging discriminator and generator models to learn from paired CBCT and real CT images, thereby enhancing image quality by reducing or eliminating artefacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional CBCT imaging methods are used, then the imaging process is simple and fast, but the image quality is low with significant artefacts and noise

Engineering Contradiction:
Improveimage qualityVSAvoidprocessing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

A generative adversarial network (GAN) is introduced as an intermediary processing system between the CBCT acquisition and final image output. The GAN consists of a generator network that creates enhanced images and a discriminator network that evaluates them, working together to transform low-quality CBCT images into high-quality images that resemble real CT scans while removing artefacts and noise

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces traditional image processing methods (filtering, reconstruction algorithms) with an artificial intelligence-based deep learning system. The GAN uses neural network architectures with multiple layers and parameters to perform image enhancement, substituting conventional signal processing mechanics with adaptive learning-based processing

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

2Manufacturing precision

If multiple artefact suppression methods are applied, then different types of artefacts can be addressed, but the processing becomes complex and no single method suppresses all artefacts

Engineering Contradiction:
Improveartefact suppressionVSAvoidmethod complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The GAN framework provides a universal solution that handles multiple types of CBCT artefacts (noise, streaking, beam hardening, scatter) through a single integrated processing system. The generator and discriminator networks work together to simultaneously address various artefact types without requiring separate processing steps for each artefact category

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

Solution Approach 2:

The patent transforms the image enhancement problem into a parameter optimization problem where the GAN learns optimal transformation parameters during training. The network adjusts internal parameters (weights, biases) to minimize the difference between enhanced CBCT images and reference CT images, automatically adapting to different artefact types and severity levels

Inventive Principle:
Principle #35Parameter changes

3Productivity

If traditional image processing methods are used, then processing is straightforward, but computing processing times are long and resource efficiency is low

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidprocessing time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The GAN model is trained in advance using paired CBCT and CT images, learning the complex mapping between low-quality and high-quality images beforehand. During actual CBCT processing, the pre-trained GAN can rapidly enhance images without requiring extensive real-time computation, as the heavy learning work was completed during the preliminary training phase

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11501438B2Cone-beam CT image enhancement using generative adversarial networks
Publication Date: 2022.11.15 ELEKTA AB
  • US11501438B2 patent drawing
  • US11501438B2 patent drawing
  • US11501438B2 patent drawing

AI summary

Techniques for generating an enhanced cone-beam computed tomography (CBCT) image using a trained model are provided. A CBCT image of a subject is received. a synthetic computed tomography (sCT) image corresponding to the CBCT image is generated, using a generative model. The generative model is trained in a generative adversarial network (GAN). The generative model is further trained to process the CBCT image as an input and provide the sCT image as an output. The sCT image is presented for medical analysis of the subject.