| 摘要 |
Data representing a three-dimensional-3D sinogram, samples of the 3D Radon Transform (10, 12) is backprojected to reconstruct a 3D volume. The backprojection requires O(N3log2 N) plane-integral projections. An input sinogram (10, 12) is subdivided into a plurality of subsinograms using eithe r an exact (12a, 12h) or approximate (24a, 24h) decomposition algorithm. The subsinograms are repeatedly subdivided until they represent volumes as small as one voxel. The smallest subsinograms are backprojected using the direct approach to form a plurality of subvolumes, and the subvolumes are recursive ly aggregated (18a, 18h, 20, 28a, 28h, 30) 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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