Collimation apparatus for x-ray beam correction
US4991189A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1990 |
| Grant date | Feb 5, 1991 |
| Priority date | — |
| Expiry date | Apr 16, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG21K1/02
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A computed tomography system corrects image errors resulting from misalignment of the fan beam as a result of placement of the x-ray tube, thermal drift of the x-ray tube anode of mechanical stresses of the gantry or x-ray tube. Misalignment is determined alternately by means of a z-axis offset detector which detects movement of the exposure area of the CT fan beam or a predictive model that calculates thermal drift of mechanical deflection of the focal spot of the x-ray tube based on previous use. The system includes a collimator with a controllable z-axis position which may be controlled to reduce z-axis offset of the fan beam exposure area or to make the fan beam more parallel with the imaging plane of the CT system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.