Back to results
US 8,805,037 B2Granted
Method and system for reconstruction of tomographic images
AssigneeGeneral Electric Company
InventorsJed Douglas Pack, Bruno Kristiaan Bernard DeMan, Paulo Ricardo dos Santos Mendonca, Kai Zeng
Life of this patent
Estimating the term…
Abstract
Approaches are described for generating an initial reconstruction of CT data acquired using a wide-cone system. In one implementation, frequency data may be patched in to a first scan, such as an axial scan, from a second scan, such as a helical scan. In one embodiment, an initial reconstruction may be processed (such as via a non-linear operation) to correct frequency omissions and/or errors in the reconstruction. Corrected frequency information may be utilized to improve the reconstructed image.
Claims23
A method of tomographic image reconstruction comprising:
- reconstructing a first image volume from an incomplete projection dataset that has incomplete frequency data;
- reconstructing a second image volume from a projection dataset that includes the frequency data missing from the incomplete projection dataset;
- taking the difference of the first image volume and the second image volume to produce a difference volume;
- projecting the difference volume over a set of view angles in a parallel three-dimensional geometry to produce a respective set of parallel views;
- applying shift-variant filtration to the set of parallel views to remove frequencies that are represented in at least the incomplete projection dataset to produce a set of filtered parallel views;
- backprojecting the filtered parallel views to produce a filtered difference volume;
- and
- adding the filtered difference volume to the first image volume to produce a final image volume.
5 more elements
A method for processing tomographic projection data, comprising:
- reconstructing an initial volume from a set of tomographic scan data, wherein the initial volume comprises inaccurate or incomplete frequency data;
- applying a non-linear operation to the initial volume to generate a modified volume from the initial volume, wherein the non-linear operation first assigns each voxel of the initial volume to one of a plurality of discrete composition categories based on an observed intensity for each respective voxel and, second, generates the modified volume by changing the intensity value of at least a portion of the voxels based on their respective assigned composition categories, wherein the respective intensity values are changed to values defined for the respective composition categories and wherein the modified volume comprises frequencies missing from the initial volume;
- filtering the modified volume to obtain a filtered volume representing a subset of the frequencies from the modified volume that are missing from the initial volume;
- and
- combining the filtered volume and the initial volume to generate a corrected image.
2 more elements
A method for processing tomographic projection data, comprising:
- reconstructing an initial volume from a set of tomographic scan data, wherein the initial volume comprises inaccurate or incomplete frequency data;
- applying a non-linear operation to the initial volume to generate a modified volume from the initial volume, wherein the non-linear operation first assigns each voxel of the initial volume to one of a plurality of discrete composition categories based on an observed intensity for each respective voxel and, second, generates the modified volume by changing the intensity value of at least a portion of the voxels based on their respective assigned composition categories, wherein the respective intensity values are changed to values defined for the respective composition categories and wherein the modified volume comprises frequencies missing from the initial volume;
- subtracting the initial volume from the modified volume to generate a difference volume;
- filtering the difference volume to obtain a filtered volume representing a subset of frequencies from the difference volume that are missing from the initial volume;
- and
- combining the filtered volume and the initial volume to generate a corrected image.
3 more elements
One or more non-transitory computer-readable media, encoding one or more routines which, when executed by a processor, cause the processor to perform acts comprising:
- reconstructing an initial volume from a set of tomographic scan data, wherein the initial volume comprises inaccurate or incomplete frequency data;
- applying a non-linear operation to the initial volume to generate a modified volume from the initial volume, wherein the non-linear operation first assigns each voxel of the initial volume to one of a plurality of discrete composition categories based on an observed intensity for each respective voxel and, second, generates the modified volume by changing the intensity value of at least a portion of the voxels based on their respective assigned composition categories, wherein the respective intensity values are changed to values defined for the respective composition categories and wherein the modified volume comprises frequencies missing from the initial volume;
- filtering the modified volume to obtain a filtered volume representing a subset of the frequencies from the modified volume that are missing from the initial volume;
- and
- combining the filtered volume and the initial volume to generate a corrected image.
2 more elements
An image processing system, comprising:
- a memory storing one or more routines;
- and
- a processing component configured to execute the one or more routines stored in the memory, wherein the one or more routines, when executed by the processing component:
- reconstruct an initial volume from a set of tomographic scan data, wherein the initial volume comprises inaccurate or incomplete frequency data;
- apply a non-linear operation to the initial volume to generate a modified volume from the initial volume, wherein the non-linear operation first assigns each voxel of the initial volume to one of a plurality of discrete composition categories based on an observed intensity for each respective voxel and, second, generates the modified volume by changing the intensity value of at least a portion of the voxels based on their respective assigned composition categories, wherein the respective intensity values are changed to values defined for the respective composition categories and wherein the modified volume comprises frequencies missing from the initial volume;
- filter the modified volume to obtain a filtered volume representing a subset of the frequencies from the modified volume that are missing from the initial volume;
- and
- combine the filtered volume and the initial volume to generate a corrected image.
5 more elements
Dependencies are inferred from the claim text.