Fast hierarchical backprojection for 3D Radon transform
First Claim
1. A process for generating a three-dimensional electronic volume from a sinogram comprising the steps ofsubdividing the sinogram into a plurality of subsinograms;
- backprojecting each of said subsinograms to produce a plurality of corresponding sub-volumes, and aggregating said sub-volumes to create the electronic volume.
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Abstract
Data representing a three-dimensional (3D) sinogram (array of numbers) is backprojected to reconstruct a 3D volume. The transformation requires N3 log2 N operations. An input sinogram is subdivided into a plurality of subsinograms using either an exact or approximate decomposition algorithm. The subsinograms are repeatedly subdivided until they represent volumes as small as one voxel. The smallest subsinograrns are backprojected using the direct approach to form a plurality of subvolumes, and the subvolumes are aggregated to form a final volume. Two subdivision algorithms are used. The first is an exact decomposition algorithm, which is accurate, but slow. The second is an approximate decomposition algorithm which is less accurate, but fast. By using both subdivision algorithms appropriately, high quality backprojections are computed significantly faster than existing techniques.
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Citations
23 Claims
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1. A process for generating a three-dimensional electronic volume from a sinogram comprising the steps of
subdividing the sinogram into a plurality of subsinograms; -
backprojecting each of said subsinograms to produce a plurality of corresponding sub-volumes, and aggregating said sub-volumes to create the electronic volume. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 21)
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11. Apparatus for generating a three-dimensional electronic volume of an object comprising:
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means for scanning the object to generate data representing a volume of the object;
means for processing said data to generate a sinogram which includes a plurality of filtered projections;
means for subdividing said sinogram into a plurality of subsinograms;
means for backprojecting each of said subsinograms to produce a plurality of corresponding subvolumes;
means for aggregating said subvolumes to create the electronic volume; and
means for displaying the electronic volume. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 22, 23)
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Specification