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US5485501A
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Method for the operation of an automatic x-ray exposure unit
Assignee: Siemens AG
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Filing: 1994-08-10
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Granted: 1996-01-16
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Expires: 2014-08-10
Abstract
Abstract An x-ray examination installation includes an x-ray source for irradiating an examination subject with x-rays, and an automatic exposure unit having a radiation detector composed of a matrix of detector elements. Only the output signals of specified detector elements, which define the measuring field within which an optimum exposure should ensue, are utilized for generating a signal which is then supplied to the x-ray source for controlling the exposure dose. The automatic exposure unit is operated according to a method wherein a distribution of the grayscale values in a test image is first calculated, and subsequently the main image is produced with the previously-calculated distribution of grayscale values superimposed in the main image.
Inventors
- 👤 Horst Aichinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:34
CPC Classifications
H; H05; H05G; H05G1/00; H05G1/08; H05G1/60; H05G1/26; H05G1/30; H05G1/36; H05G1/38; H05G1/42; H05G1/44
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
198 words
A method for operating an automatic x-ray exposure unit having a radiation detector composed of a matrix of detector elements, comprising the steps of: selecting a predetermined dose which produces a complete exposure at said radiation detector of an examination subject; during a first time span, activating an x-ray source to emit a first dose pulse by selective adjustment of an x-ray source voltage for dimensioning said first dose pulse so as to be insufficient for generating a complete exposure even with a smallest density of said subject; during a second time span following said first time span, serially reading out image data from said radiation detector generated as a result of said first dose pulse and storing said image data in a first image memory; calculating a grayscale value frequency of occurrence distribution of the image data in said first image memory; and during a third time span following said second time span, generating a primary image of an examination subject dependent on said distribution and storing said primary image in a second image memory, and adding said image in said first image memory to said image in said second image memory to produce a final image.
Claim 2
Independent Claim
198 words
A method for operating an automatic x-ray exposure unit having a radiation detector composed of a matrix of detector elements, comprising the steps of: selecting a predetermined dose which produces a complete exposure at said radiation detector of an examination subject; during a first time span, activating an x-ray source to emit a first dose pulse by selective adjustment of an x-ray source voltage for dimensioning said first dose pulse so as to be insufficient for generating a complete exposure even with a smallest density of said subject; during a second time span following said first time span, serially reading out image data from said radiation detector generated as a result of said first dose pulse and storing said image data in a first image memory; calculating a grayscale value frequency of occurrence distribution of the image data in said first image memory; and during a third time span following said second time span, generating a primary image of an examination subject dependent on said distribution and storing said primary image in a second image memory, and adding said image in said first image memory to said image in said second image memory to produce a final image.
Claim 3
Dependent Claim
26 words
A method as claimed in claim 1 comprising the additional step of generating a displayable image corresponding to said final image exclusively using said radiation detector.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-15 | 1999-07-17 | 2000-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-15 | 2003-07-17 | 2004-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-15 | 2007-07-17 | 2008-01-16 | $7700.00 | Window Closed / Lapsed |