X-ray CT Windmill Artifact Reduction via Frequency Segmentation
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Solution Overview
Problem
Current methods for reducing windmill artifacts in X-ray CT images, particularly those with high-frequency components, are insufficient, leading to unclear organ boundaries and decreased contrast in medical imaging.
Innovation Solution
A medical image processing device and method that extracts organ components from high-frequency images in the rotation axis direction, removes artifacts by subtracting these components, and generates corrected images to reduce windmill artifacts, thereby maintaining organ boundary clarity and contrast.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional artifact reduction methods are applied to remove windmill artifacts, then artifact reduction is achieved, but organ boundary clarity deteriorates and contrast decreases
Solution Approach 1:
The patent segments the image processing into distinct frequency components. It separates high-frequency components (containing organ boundary information) from low-frequency components (containing windmill artifact information) by applying a high-pass filter in the frequency domain. This segmentation allows selective processing of different frequency bands to address the contradiction between artifact removal and boundary preservation.
Solution Approach 2:
The patent applies different processing strategies to different frequency regions. High-frequency components are preserved with minimal modification to maintain organ boundary clarity, while low-frequency components undergo artifact reduction processing. This local quality approach ensures that each frequency band is treated according to its characteristic information content, resolving the contradiction between artifact removal and boundary preservation.
2Object-affected harmful factors
If noise removal processing is applied to reduce windmill artifacts, then artifact reduction is achieved, but image contrast deteriorates
Solution Approach 1:
The patent employs dynamic processing where the degree of artifact reduction is adjusted based on the frequency characteristics of different image regions. By applying frequency-selective processing that adapts to local frequency content, the system dynamically balances artifact removal with contrast preservation, avoiding the uniform processing that causes contrast deterioration.
Solution Approach 2:
The patent changes processing parameters selectively across different frequency bands. It applies different filtering strengths and processing intensities to high-frequency and low-frequency components, with stronger artifact reduction applied to low-frequency regions where windmill artifacts dominate, and milder processing applied to high-frequency regions where organ boundaries are located. This parameter differentiation resolves the contradiction between artifact removal and contrast maintenance.
Data Source
AI summary
Even a windmill artifact including a high-frequency component in a plane perpendicular to a rotation axis can be reduced and a boundary of an organ can be made to be clear to maintain the contrast.The invention relates to a medical image processing device and includes an image acquiring unit that acquires a 3D volumetric image, a Z high-frequency image generating unit that generates a Z high-frequency image which is a high-frequency component in a rotation axis direction from the 3D volumetric image, an organ component extracting unit that extracts an organ component from the Z high-frequency image, an artifact component extracting unit that extracts an artifact component on the basis of the Z high-frequency image and the organ component, and a corrected image generating unit that generates a corrected image by subtracting the artifact component from the 3D volumetric image.