Methods and apparatus for modifying slice thickness during a helical scan
US6023494A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1996 |
| Grant date | Feb 8, 2000 |
| Priority date | — |
| Expiry date | Dec 19, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2223/612
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention, in one form, is a method for modifying slice thickness during a helical scan without interrupting the scan. The method includes identifying adjacent and different regions within an object to be scanned. A transition region also is identified to include a portion of each of two adjacent regions and the interface therebetween. Slice thickness is modified during the scan so that redundant data is obtained in the transition region. Particularly, in one embodiment, a variable collimator is used to scan a first region with a first slice thickness. The variable collimator is rotated at the interface between the two adjacent regions, without interrupting table translation, to scan the second region with a second slice thickness. When changing the slice thickness, the collimator also is swept so that the x-ray beam with the second slice thickness re-scans a portion of the first region within the transition region. More particularly, the collimator is swept so that the transition region is scanned with both slice thicknesses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.