Three-dimensional forward and back projection methods
US8913805B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2011 |
| Grant date | Dec 16, 2014 |
| Priority date | — |
| Expiry date | May 16, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2211/424
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Methods provided for forward and back-projection, which are referred to as separable footprint (SF) projectors: exemplified by the SF-TR and SF-TT projectors. These methods approximate the voxel footprint functions as 2D separable functions. Because of the separability of these footprint functions, calculating their integrals over a detector cell is greatly simplified and can be implemented efficiently. In some embodiments, the SF-TR projector uses trapezoid functions in the transaxial direction and rectangular functions in the axial direction. In some embodiments, the SF-TT projector uses trapezoid functions in both the axial and transaxial directions. Simulations and experiments showed that both SF projector methods are more accurate than conventional distance-driven (DD) projectors. Moreover, the SF-TT projector is more accurate than the SF-TR projector for rays associated with large cone angles. In some embodiments, the SF-TR projector has similar computation speed with the DD projector and the SF-TT projector is about two times slower.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.