Patent US5457724A successfully refreshed from Google Patents.
US5457724A
Expired / Lapsed
US
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Automatic field of view and patient centering determination from prescan scout data
Assignee: General Electric Co
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Filing: 1994-06-02
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Granted: 1995-10-10
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Expires: 2014-06-02
Abstract
Abstract An x-ray CT system acquires scout data over a region of a patient prior to performing a scan. The scout data is employed to locate the patient in a succession of slices over the region. Geometric scan parameters including display field of view (DFOV), scan field of view (SFOV) and patient centering offsets (X OFF ,Y OFF ) are calculated from the scout data, displayed to the operator, and used as default values in the subsequent scan of the region.
Inventors
- 👤 Thomas L. Toth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:59
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/48; A61B6/488; A61B6/02; A61B6/03; A61B6/032; A61B6/46; A61B6/467; A61B6/469
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
165 words
A method for determining geometric scan parameters prior to scanning a patient with an x-ray CT system, the steps comprising: acquiring scout data which indicates patient attenuation of x-rays at two substantially orthogonal views; locating the edges of the patient in each view by comparing said scout data with a preset threshold; locating the center of the patient in each view by calculating the midpoint between the located edges; calculating the display field of view (DFOV) measured from the center of the patient to the most distant located edge of the patient; calculating the scan field of view (SFOV) measured from a CT system isocenter to the most distant located edge of the patient; calculating the patient offsets (Y OFF and X OFF ) measured from the CT system isocenter to the located center of the patient; and outputting as the geometric scan parameters the calculated values of DFOV, SFOV, Y OFF and X OFF scanning the patient based on the output geometric scan parameters.
Claim 2
Independent Claim
165 words
A method for determining geometric scan parameters prior to scanning a patient with an x-ray CT system, the steps comprising: acquiring scout data which indicates patient attenuation of x-rays at two substantially orthogonal views; locating the edges of the patient in each view by comparing said scout data with a preset threshold; locating the center of the patient in each view by calculating the midpoint between the located edges; calculating the display field of view (DFOV) measured from the center of the patient to the most distant located edge of the patient; calculating the scan field of view (SFOV) measured from a CT system isocenter to the most distant located edge of the patient; calculating the patient offsets (Y OFF and X OFF ) measured from the CT system isocenter to the located center of the patient; and outputting as the geometric scan parameters the calculated values of DFOV, SFOV, Y OFF and X OFF scanning the patient based on the output geometric scan parameters.
Claim 3
Dependent Claim
23 words
The method as recited in claim 1 in which the acquired scout data is corrected and low-pass filtered prior to locating said edges.
Claim 4
Dependent Claim
37 words
The method as recited in claim 1 in which scout data is acquired over a region of the patient and a plurality of pairs of substantially orthogonal views are produced at successive slice locations through the patient.
Claim 5
Independent Claim
25 words
The method as recited in clam 3 in which values for DFOV, SFOV, X OFF and Y OFF are calculated at said successive slice locations.
Claim 6
Independent Claim
25 words
The method as recited in clam 3 in which values for DFOV, SFOV, X OFF and Y OFF are calculated at said successive slice locations.
Claim 7
Dependent Claim
36 words
The method as recited in claim 4 in which the geometric scan parameters which are output are the mean value of the respective DFOV, SFOV X OFF and Y OFF values calculated at successive slice locations.
References Cited (Backward Citations)
US5034969A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-09 | 1999-04-10 | 1999-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-09 | 2003-04-10 | 2003-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-09 | 2007-04-10 | 2007-10-10 | $7700.00 | Window Closed / Lapsed |