CT Sinogram Extension Using Anatomical Template Registration
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Solution Overview
Problem
CT scans that focus on a region of interest result in truncated sinograms due to missing measurements from surrounding tissues, leading to image artefacts and inaccurate attenuation of surrounding tissue, which existing methods struggle to effectively address.
Innovation Solution
A method and apparatus that utilize a template sinogram retrieved from a database, matched to the anatomic contours of the subject, to extend the real sinogram by simulating attenuation in surrounding tissues, followed by image registration and reconstruction to generate an enlarged sinogram free of artefacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If CT scan is directed to a region of interest to minimize radiation exposure, then radiation exposure is reduced, but the sinogram becomes truncated due to missing measurements from surrounding tissues
Solution Approach 1:
The patent applies preliminary action by using shape data acquired before the CT scan to predict and complete the sinogram data. The method retrieves a template sinogram from a database based on the subject's shape, performs image registration to align the template with the actual scan, and uses the registered template to fill in missing measurements. This preliminary preparation and matching process allows the system to recover information that would otherwise be lost due to the region-of-interest scanning approach.
2Use of energy by moving object
If region of interest CT-scan is performed to minimize radiation exposure, then radiation exposure is reduced, but image artefacts are introduced into the reconstructed image
Solution Approach 1:
The patent uses a template sinogram as an intermediary element to bridge the gap between the limited region-of-interest measurements and the complete image reconstruction. The template sinogram, retrieved from a database and matched to the subject's shape, serves as a mediator that provides the missing attenuation information from surrounding tissues. By registering this intermediary template data with the actual scan data, the system eliminates image artefacts while maintaining the benefits of reduced radiation exposure.
3Measurement precision
If template sinogram is used to extend real sinogram by simulating attenuation in surrounding tissues, then image accuracy is improved, but computational complexity increases
Solution Approach 1:
The patent applies the copying principle by retrieving a pre-computed template sinogram from a database that represents typical attenuation patterns for subjects with similar shapes. Instead of performing complex simulations from scratch, the system copies the relevant attenuation information from the template and adapts it to the specific subject through image registration. This approach significantly reduces computational complexity while maintaining high image accuracy, as the heavy computational work has already been performed during template creation and storage.
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
The method produces reconstructed images with improved accuracy and reduced artefacts, particularly at the border of the region of interest and surrounding tissues, enhancing image quality and reducing radiation exposure.
Implementation Method 1
A computed tomography (CT) scan uses computer-processed combinations of many X-ray (or Röntgen) measurements taken from different angles
Data Source
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AI summary
Apparatus, method and computer program code for processing computed tomography (CT) scan data is disclosed. The method includes: receiving (202) a real sinogram from a CT scanning of a region of interest of a subject; receiving (204) shape data representing anatomic contours of a body part containing the region of interest of the subject; retrieving (206) a template sinogram from among a plurality of stored template sinograms based on the anatomic contours of the body part; performing (210) an image registration between the real sinogram and the template sinogram to obtain a registered template sinogram; and generating (212) an enlarged sinogram from the real sinogram by adding the non-overlapping parts from the registered template sinogram.