Helical weighting algorithms for fast reconstruction
US6108575A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 20, 1998 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Feb 20, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T11/006
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
CT helical weighting algorithms wherein one source rotation, or 2.pi., worth of projection data is utilized for fast image reconstruction are described. Particularly, by using a distance function, and by selecting particular classes of such distance function, the discontinuity across the sinogram can be eliminated. Further, by imposing specific necessary conditions on such distance functions, single analytical expressions across the entire 2.pi. sinogram are obtained. Decomposition of these particular single distance functions provides exact, or approximated, fast two-filtering reconstruction algorithms, for which a given projection needs to be filtered only two times for an arbitrary number P of reconstruction planes. In addition, single weighting functions that depend only on the sum of the projection and fan angles can be utilized. Accordingly, after rebinning the fan-beam projections to parallel projections, the corresponding 2.pi. helical weighting algorithms do not include a dependency over the ray parameter (within one parallel projection). For these algorithms, weighting commutes with filtering, and reconstruction of an arbitrary number P of image planes requires only one f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.