CBCT Motion-Blurred Image Enhancement via Phase-Correlated Processing

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Solution Overview

Problem

Cone-beam computed tomography (CBCT) imaging is susceptible to motion-blurred artifacts due to slow gantry rotation times, leading to aliasing issues like streaks in reconstructed images, which are difficult to resolve without increasing imaging time or radiation dose.

Innovation Solution

A method and system for enhancing motion-blurred images by generating phase-correlated images through image enhancement operations, including motion extraction, filtering, and segmentation, which reduce or remove artifacts by processing projections and re-projections to create improved multi-phase images.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the gantry rotation rate is slowed down to reduce aliasing artifacts, then image quality improves, but imaging time increases substantially

Engineering Contradiction:
Improveimage qualityVSAvoidimaging time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent introduces an intermediary computational process (phase-correlated image generation and motion extraction algorithms) between the raw projections and final reconstructed image. This mediator processes the sparse projection data to synthesize higher-quality images without requiring slower physical gantry rotation, thereby resolving the contradiction between image quality and imaging time

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent performs preliminary actions by pre-processing projections into phase-correlated images and pre-extracting motion information before final reconstruction. This preliminary processing allows the system to work with enhanced data that reduces aliasing artifacts, eliminating the need for slower gantry rotation to achieve quality images

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the gantry rotation rate is slowed down to reduce aliasing artifacts, then image quality improves, but radiation dose increases

Engineering Contradiction:
Improveimage qualityVSAvoidradiation dose
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The computational intermediary processes sparse projection data obtained at faster rotation rates, extracting motion information and generating phase-correlated images that reduce aliasing artifacts. This allows achieving quality images without increasing radiation dose, as the enhancement comes from processing rather than acquiring more data

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the parameter space by transforming raw projection data into phase-correlated images with explicit motion modeling. This parameter transformation allows the system to reconstruct quality images from fewer, faster-acquired projections, avoiding both increased imaging time and increased radiation dose

Inventive Principle:
Principle #35Parameter changes

3Reliability

If CBCT data is acquired in multiple respiratory phases, then motion artifacts are captured, but aliasing streaks appear due to sparse sampling per phase

Engineering Contradiction:
Improvemotion representationVSAvoidimage quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent merges information across multiple respiratory phases by generating phase-correlated images that explicitly model the periodic motion. By combining data from multiple phases with motion extraction algorithms, the system achieves both reliable motion representation and high image quality, eliminating the aliasing streaks that appear when phases are processed independently

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2718870B1Motion-blurred imaging enhancement method and system
Publication Date: 2018.10.31 VARIAN MEDICAL SYSTEMS INC
  • EP2718870B1 patent drawingFigure 1
  • EP2718870B1 patent drawingFigure 2
  • EP2718870B1 patent drawingFigure 3

AI summary

In accordance with at least some embodiments of the present disclosure, a process for enhancing a motion-blurred image is presented. The process may include receiving a plurality of projections, wherein the plurality of projections contain computed tomography (CT) data obtained in multiple motion phases. The process may include generating an enhanced multiphase image by performing an enhancement operation based on the plurality of projections. The process may further include generating a plurality of phase-correlated images based on the plurality of projections and the enhanced multi-phase image.