Tomographic Image Reconstruction Using Weight Map Artifact Correction
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Solution Overview
Problem
Current X-ray tomography technologies face challenges in generating clear 3D images due to degraded resolution in the depth direction and severe artifacts caused by artificial materials like metals, which affect image quality and depth perception.
Innovation Solution
The method involves acquiring and processing projection data from multiple views within a limited angular range, using a weight map to correct pixel values and reduce artifacts, specifically ripple and undershoot artifacts, by employing frequency modulation transformations and filtered back-projection techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If tomosynthesis image reconstruction is performed using limited angular range projection data, then 3D medical images can be generated, but resolution in the depth direction is degraded
Solution Approach 1:
The patent applies iterative reconstruction techniques that modify reconstruction parameters and weighting factors across multiple iterations to improve depth resolution. The system adjusts convergence criteria, regularization parameters, and projection weighting to optimize image quality within the limited angular range, transforming the reconstruction process from a single-pass analytic method to a multi-stage iterative optimization process.
2Measurement precision
If iterative reconstruction technique is used to increase image quality, then image quality improves, but reconstruction time becomes long and image is highly dependent on reconstruction parameters
Solution Approach 1:
The patent implements preliminary preprocessing steps including projection data correction, noise filtering, and initial image estimation before the main iterative reconstruction process. By preparing the data and establishing initial conditions in advance, the system reduces the number of iterations needed for convergence and minimizes parameter tuning requirements during the actual reconstruction phase.
Solution Approach 2:
The system employs a hybrid approach where only critical portions of the reconstruction process use computationally intensive iterative methods, while other portions use faster analytic techniques. This selective application of reconstruction methods achieves acceptable image quality with reduced overall reconstruction time compared to full iterative processing of all projection data.
3Quantity of substance
If artificial material such as metallic material is inserted into the object, then X-ray attenuation increases, but severe artifacts occur in the reconstructed image
Solution Approach 1:
The patent identifies regions containing high-attenuation materials like metal through thresholding and classification algorithms, then applies specialized correction techniques specifically targeted at these problematic regions. By detecting the presence of artifacts and applying corrective weighting or interpolation methods only in affected areas, the system converts the harmful artifact-generating property of metal into a manageable condition that can be corrected through localized processing.
Solution Approach 2:
The reconstruction algorithm applies different processing strategies to different regions of the image based on local characteristics. Areas with metal implants receive specialized artifact reduction processing including modified weighting schemes and interpolation methods, while regions without metal use standard reconstruction algorithms. This localized approach maintains image quality in metal-free regions while actively reducing artifacts in metal-affected regions.
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 enhancing depth perception, allowing for clearer reconstruction of tomography images even when metallic materials are present, thereby improving diagnostic accuracy.
Implementation Method 1
the principle that a degree of attenuation varies according to an attenuation coefficient of a material constituting the object as the X-rays pass through the object
Data Source
AI summary
An embodiment of the present disclosure provides a method of generating a tomography image and an X-ray imaging apparatus operating according to the method, whereby when a material with a high X-ray attenuation rate is inserted into an object, an image quality may be improved by reducing ripple artifacts and/or undershoot artifacts that may occur in a tomography image that is a captured X-ray image of the object.