Method for eliminating artifacts in scanning electron beam computed tomographic images due to cone beam geometry
US6130929A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 11, 1998 |
| Grant date | Oct 10, 2000 |
| Priority date | — |
| Expiry date | Dec 11, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S378/901
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Computed tomographic ("CT") x-ray scanning yields a discrete set of measurement values that are line integrals of attenuation coefficients .mu.(r), which attenuation coefficients may be obtained using suitable reconstruction techniques. Electronic beam computed tomograph ("EBCT") systems add error to the reconstructed attenuation coefficients owing to their unique cone geometry. A method is provided that reduces such errors. At least two scans, "tilted" by the system cone angle, collect data in the neighborhood of a reference plane normal to the system z-axis. These scans are rebinned into parallel projections, and a series expansion is considered for variation of .mu.(r) in the vicinity of the reference plane. If a first order series is considered sufficient, then two scans are required to estimate the slope A of the variation in data. The data can then be corrected for the "tilt" and line integrals on the reference plane normal to the z-axis obtained. If a second order series is necessary, two parameters A and B need to be determined from three suitably spaced scans, and the data corrected to obtain line integrals on the reference plane. The data can be corrected in the spatial d…
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