US5386446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Positional adjustment of resolution in radiation CT scanner
Assignee: Toshiba Corp
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Filing: 1993-07-06
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Granted: 1995-01-31
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Expires: 2013-07-06
Abstract
Abstract There provided is a radiation computed tomography (CT) scanner, such as an X-ray CT scaner. A CT image of an object is obtained, resolution of the CT image being affected by a resolution adjustment parameter and the object having an axis. In case of an X-ray CT scaner, the scanner comprises a couch having a longitudinal direction, the axis of the object being aligned along the longitudinal direction, an X-ray source for radiating X-rays toward the object, a detector for detecting the X-rays transmitted through the object, an element for rotating at least the X-ray source around the object, an element for at least relatively moving the X-rays in the longitudinal direction, and an element for controlling the resolution adjustment parameter. Slit members may further be provided for forming the X-rays into a given slice thickness. The parameter includes moving pitches of the couch and rotating element, a rotating speed of the rotating element, an amount of X-rays, and slit widths, according to a longitudinal position of the object.
Inventors
- 👤 Hideki Fujimoto
- 👤 Yoshinori Manabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:18
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/02; A61B6/03; A61B6/032; A61B6/04; A61B6/0487; A61B6/06; A61B6/027
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
146 words
A radiation computed tomography scanner by which a computed tomography image of an object to be examined is obtained by a helical scan, resolution of the computed tomography image being affected by a resolution adjustment parameter, the scanner comprising: a couch for supporting the object having a body axis, said object being examined along a direction of the body axis; a radiation source for emitting radiation toward the object laid on the couch so that the radiation is transmitted through the object; means for detecting the radiation transmitted through the object; means for driving the radiation source and the couch which are relatively rotatable with respect to each other and relatively linearly movable with respect to each other along the direction of the body axis in order to perform the helical scan; and means for controlling the resolution adjustment parameter simultaneously with performing the helical scan.
Claim 2
Dependent Claim
146 words
A radiation computed tomography scanner by which a computed tomography image of an object to be examined is obtained by a helical scan, resolution of the computed tomography image being affected by a resolution adjustment parameter, the scanner comprising: a couch for supporting the object having a body axis, said object being examined along a direction of the body axis; a radiation source for emitting radiation toward the object laid on the couch so that the radiation is transmitted through the object; means for detecting the radiation transmitted through the object; means for driving the radiation source and the couch which are relatively rotatable with respect to each other and relatively linearly movable with respect to each other along the direction of the body axis in order to perform the helical scan; and means for controlling the resolution adjustment parameter simultaneously with performing the helical scan.
Claim 3
Dependent Claim
41 words
The scanner according to claim 1, wherein said couch has a tabletop on which the object is laid, the tabletop representing a longitudinal direction along which the direction of the body axis is aligned and being movable along the longitudinal direction.
Claim 4
Dependent Claim
54 words
The scanner according to claim 2, wherein said driving means comprises means for rotating the radiation source and the detecting means together along a circular locus around the object and means for moving the tabletop in the longitudinal direction while the radiation source and the detecting means are rotated together by the rotating means.
Claim 5
Dependent Claim
29 words
The scanner according to claim 3, further comprising a slit means, which has an adjustable slit width, for projecting the radiation as a slice thickness in the longitudinal direction.
Claim 6
Dependent Claim
50 words
The scanner according to claim 4, wherein said resolution adjustment parameter comprises at least one of a moving pitch of the tabletop, the slit width of the slit means, an amount of radiation emitted from the radiation source, and a rotating speed of the radiation source and the detecting means.
Claim 7
Dependent Claim
45 words
The scanner according to claim 5, wherein said slit means has two slit members having adjustable slit widths, respectively, one slit member being arranged between the radiation source and the object and the other slit member being arranged between the object and the detecting means.
Claim 8
Dependent Claim
17 words
The scanner according to claim 6, wherein said radiation source is an X-ray tube for emitting X-rays.
Claim 9
Dependent Claim
47 words
The scanner according to claim 3, wherein said resolution adjustment parameter comprises at least one of a moving pitch of the tabletop in the longitudinal direction, an amount of radiation emitted from the radiation source, and a rotating speed of the radiation source and the detecting means.
Claim 10
Dependent Claim
17 words
The scanner according to claim 8, wherein said radiation source comprises an X-ray tube which emits X-rays.
Claim 11
Dependent Claim
46 words
The scanner according to claim 8, wherein said controlling means comprises means for measuring a time corresponding to a position of the tabletop in the longitudinal direction and means for changing the resolution adjustment parameter in response to the time measured by the time measuring means.
Claim 12
Dependent Claim
44 words
The scanner according to claim 8, wherein said controlling means comprises a detector for detecting a position of the tabletop in the longitudinal direction and means for changing the resolution adjustment parameter in response to the position of the tabletop detected by the detector.
Claim 13
Dependent Claim
50 words
The scanner according to claim 11, further comprising means for programming the helical scan which has a selecting means for selecting the resolution adjustment parameter manually for each of a plurality of positions of the tabletop in the longitudinal direction, the selected adjustment parameter being output to the changing means.
Claim 14
Dependent Claim
55 words
The scanner according to claim 12, further comprising means for obtaining data of a scanography image of the object, the data of the scanography image being supplied to the programming means, wherein said programming means includes a display means which displays the scanography image which is used in the selection of the resolution adjustment parameter.
Claim 15
Dependent Claim
40 words
The scanner according to claim 13, wherein said programing means has an input means for manually inputting a scan range in the longitudinal direction and the selecting means includes means for selecting the resolution adjustment parameter within the scan range.
Claim 16
Dependent Claim
72 words
The scanner according to claim 14, wherein said programming means has a further input means for manually specifying a range corresponding to a region of interest within the scan range on the scanography image displayed on the display means and said selecting means has an additional means for assigning the range of the resolution adjustment parameter of a higher resolution grade than an outer limit of the range in the longitudinal direction.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-30 | 1998-08-01 | 1999-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-30 | 2002-08-01 | 2003-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-30 | 2006-08-01 | 2007-01-31 | $7700.00 | Window Closed / Lapsed |