US5528644A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-ray CT scanner and method of collecting image data in the same
Assignee: Toshiba Corp
•
Filing: 1995-01-24
•
Granted: 1996-06-18
•
Expires: 2015-01-24
Abstract
Abstract In an X-ray CT scanner, a first field of view corresponding to a reconstructed area of an image to be displayed is set. An original image data are reconstructed on the basis of a plurality of projection data in a patient in response to the first field of view. Whether or not an imaged region in the patient is larger than the first field of view is judged according to referring the original image data. A second field of view including the imaged region wholly is set in case that the imaged region is larger in area than the first field of view. Beam hardening correction data are produced on the basis of the projection data in the second field of view. The projection data are processed into the image corresponding to the first field of view with an aid of the correction data.
Inventors
- 👤 Yukihiro Ogawa
- 👤 Yusuke Toki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:27
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/02; A61B6/03; A61B6/032; A61B6/035; A61B6/58; A61B6/582; A61B6/583; Y; Y10; Y10S; Y10S378/00; Y10S378/901
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
160 words
An X-ray CT scanner, in which an image is produced on the basis of a plurality of projection data of an object being examined and the image is displayed, the scanner comprising: means for setting a first field of view corresponding to a reconstructed area of the image; means for reconstructing original image data on the basis of the projection data in response to the first field of view; means for judging whether or not an imaged region in the object is larger than the first field of view; means for setting a second field of view including the imaged region wholly in case that the imaged region is larger than the first field of view; means for producing beam hardening correction data on the basis of the projection data in the second field of view; and means for processing the projection data into the image corresponding to the first field of view with an aid of the correction data.
Claim 2
Dependent Claim
160 words
An X-ray CT scanner, in which an image is produced on the basis of a plurality of projection data of an object being examined and the image is displayed, the scanner comprising: means for setting a first field of view corresponding to a reconstructed area of the image; means for reconstructing original image data on the basis of the projection data in response to the first field of view; means for judging whether or not an imaged region in the object is larger than the first field of view; means for setting a second field of view including the imaged region wholly in case that the imaged region is larger than the first field of view; means for producing beam hardening correction data on the basis of the projection data in the second field of view; and means for processing the projection data into the image corresponding to the first field of view with an aid of the correction data.
Claim 3
Dependent Claim
14 words
The X-ray CT scanner according to claim 1, wherein said judgement is performed automatically.
Claim 4
Dependent Claim
50 words
The X-ray CT scanner according to claim 2, wherein said judgement means is comprised of an element for detecting each CT-value of a plurality of pixels located in a circumference of the original image data and an element for judging whether or not the each CT-value is CT-value of air.
Claim 5
Dependent Claim
51 words
The X-ray CT scanner according to claim 2, wherein said judgement means is comprised of an element for detecting a size of the imaged region on the basis of the projection data of the object and an element for comparing the size with a size of the first field of view.
Claim 6
Dependent Claim
28 words
The X-ray CT scanner according to claim 1, wherein said second field of view set means is comprised of setting the second field of view by manual operation.
Claim 7
Dependent Claim
23 words
The X-ray CT scanner according to claim 1, wherein said beam hardening correction data are composed of correction components of the projection data.
Claim 8
Dependent Claim
59 words
The X-ray CT scanner according to claim 6, wherein said projection data processing means comprises means for reconstructing correction image data composed of correction components of the original image data by using the correction data according to the first field of view and means for producing the image by synthesizing the correction image data and the original image data.
Claim 9
Dependent Claim
60 words
The X-ray CT scanner according to claim 6, wherein said projection data processing means comprises means for producing a plurality of projection data performed beam hardening correction by synthesizing the projection data and the correction data and means for reconstructing the image by using the projection data performed beam hardening correction on the basis of the first field of view.
Claim 10
Independent Claim
155 words
A method of collecting image data in an X-ray CT scanner, in which an image is produced on the basis of a plurality of projection data of an object being examined and the image is displayed, the method comprising: setting a first field of view corresponding to a reconstructed area of the image; reconstructing original image data on the basis of the projection data in response to the first field of view; judging whether or not an imaged region in the object is larger than the first field of view; setting a second field of view including the imaged region wholly in case that the imaged region is larger than the first field of view; producing beam hardening correction data on the basis of the projection data in the second field of view; and processing the projection data into the image corresponding to the first field of view with an aid of the correction data.
Claim 11
Independent Claim
155 words
A method of collecting image data in an X-ray CT scanner, in which an image is produced on the basis of a plurality of projection data of an object being examined and the image is displayed, the method comprising: setting a first field of view corresponding to a reconstructed area of the image; reconstructing original image data on the basis of the projection data in response to the first field of view; judging whether or not an imaged region in the object is larger than the first field of view; setting a second field of view including the imaged region wholly in case that the imaged region is larger than the first field of view; producing beam hardening correction data on the basis of the projection data in the second field of view; and processing the projection data into the image corresponding to the first field of view with an aid of the correction data.
References Cited (Backward Citations)
US5043890A
Cited
US5457724A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-06-18 | 1999-12-18 | 2000-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-18 | 2003-12-18 | 2004-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-18 | 2007-12-18 | 2008-06-18 | $7700.00 | Window Closed / Lapsed |