Tomographic Imaging with Surface Scanning Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing C-arm imaging systems face challenges in obtaining 3D images due to low mechanical precision, which affects geometric calibration, and the need for a sufficient number of projections covering a wide angular range to avoid reconstruction artifacts.
Innovation Solution
An apparatus and method that combine an X-ray imaging device with a surface-scanning device and a data control and processing system to refine geometric calibration and generate tomographic images from limited data, using a 3D mask and conventional reconstruction methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sufficient number of projections covering a wide angular range are used to reconstruct tomographic images free from artifacts, then image quality is improved, but the complexity of the system and acquisition time increase
Solution Approach 1:
The invention changes the parameter of angular range required for reconstruction. By using a limited angular range (less than 180 degrees plus cone aperture) combined with iterative reconstruction algorithms and prior information (such as sparsity constraints), the system achieves acceptable image quality without requiring the traditional wide angular range, thus simplifying the mechanical system requirements
Solution Approach 2:
The invention replaces the mechanical requirement for wide angular coverage with computational methods. Instead of mechanically rotating the C-arm through large angles to gather sufficient projections, the system uses iterative reconstruction algorithms, regularization techniques, and prior information to compensate for the limited angular data, substituting mechanical complexity with computational processing
2Measurement precision
If mechanical precision is increased to ensure repeatable source and detector positions for geometric calibration, then calibration accuracy is improved, but system cost and complexity increase
Solution Approach 1:
The invention replaces high mechanical precision requirements with computational calibration methods. By using iterative reconstruction algorithms that incorporate geometric calibration as part of the reconstruction process, and by utilizing prior information and regularization, the system achieves accurate geometric calibration without requiring mechanically precise repeatable positions of the source and detector
Solution Approach 2:
The invention introduces computational algorithms as an intermediary between the mechanical system and the final image reconstruction. These algorithms compensate for mechanical imprecision by iteratively adjusting geometric parameters during reconstruction, using prior information and optimization techniques to achieve accurate calibration despite low mechanical precision
3Productivity
If a limited angular range with increased angular step is used for projections, then acquisition time is reduced, but reconstruction artifacts increase
Solution Approach 1:
The invention changes the reconstruction approach parameter from analytical to iterative methods. By using iterative reconstruction algorithms with regularization and prior information (such as sparsity constraints in transformed domains), the system can work with limited angular ranges and increased angular steps without producing severe artifacts, maintaining image quality while improving acquisition speed
Solution Approach 2:
The invention applies preliminary processing to the projection data or the reconstruction process by incorporating prior information before final image formation. Techniques such as preprocessing with regularization, using prior anatomical information, or applying constraints based on expected image properties help mitigate artifacts that would normally result from limited angular coverage and large angular steps
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
Enables the generation of tomographic images of clinical quality with a smaller angular range and fewer projections, reducing mechanical precision requirements and radiation doses, while allowing the use of existing 2D radiology systems for extended tomographic capabilities.
Implementation Method 1
This type of system comprises at least one X-ray source and one image capture system
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
The invention relates to a device and method for generating tomograms. By means of the combination of the device and method, results equivalent to those obtained with traditional CAT systems can be obtained, using very few projections obtained in a limited angular range of movement of a source-detector assembly and/or elevated mechanical tolerance in the positioning of the source and detector. The device comprises: an X-ray imaging device with an assembly comprising an X-ray source (1) and an X-ray detector (2), with movement; a surface scanning device (4); and a data control and processing system configured to execute at least one calibration routine and one specific tomogram generation routine that uses data obtained by the X-ray imaging device and the surface scanning device to refine the geometric calibration according to the current trajectory and obtain a clinical-quality tomographic image (suitable for clinical diagnosis).