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US5583903A
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Computed tomography apparatus
Assignee: Toshiba Corp
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Filing: 1995-12-01
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Granted: 1996-12-10
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Expires: 2015-12-01
Abstract
Abstract In a computed tomography apparatus which irradiates an X-ray ray fan beam to a slice of a subject body from various directions around the slice, detects the image data of the X-ray ray that has passed the subject body to obtain projection data, and performs reconstruction computation on the projection data to acquire the tomographic image of the slice of the subject body, a main detector which has a plurality of rows of detection elements are aligned in association with a plurality of slices of the subject body and detects projection data of a plurality of slices at a time, a profile detector which has the same number of rows of detection elements as the main detector and measures a profile in the slice direction of the amount of X-ray ray incident to the main detector, and a data processing device for compensating the projection data output from the main detector in accordance with the output of the profile detector.
Inventors
- 👤 Yasuo Saito
- 👤 Kazuyuki Ihira
- 👤 Hiroaki Miyazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:53
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/02; A61B6/03; A61B6/032; A61B6/40; A61B6/4021; A61B6/4064; A61B6/4085; G; G01; G01N; G01N23/00; G01N23/02; G01N23/04; G01N23/046; G01N2223/00; G01N2223/40; G01N2223/419; G01N2223/60; G01N2223/612
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
92 words
A computed tomography apparatus comprising: means for irradiating radiation ray on slices of a subject body; detector means, including multiple lines of detection elements arranged in association with said slices, for receiving radiation ray irradiated from said irradiating means to detect radiation ray transmission data of said slices; means for measuring an intensity distribution of radiation ray, irradiated from said irradiating means, in a direction perpendicular to the slices; and means for compensating said radiation ray transmission data slice by slice in accordance with said intensity distribution measured by said measuring means.
Claim 2
Dependent Claim
92 words
A computed tomography apparatus comprising: means for irradiating radiation ray on slices of a subject body; detector means, including multiple lines of detection elements arranged in association with said slices, for receiving radiation ray irradiated from said irradiating means to detect radiation ray transmission data of said slices; means for measuring an intensity distribution of radiation ray, irradiated from said irradiating means, in a direction perpendicular to the slices; and means for compensating said radiation ray transmission data slice by slice in accordance with said intensity distribution measured by said measuring means.
Claim 3
Dependent Claim
49 words
The computed tomography apparatus according to claim 1, wherein said intensity distribution measuring means is located at a distance from said irradiating means equal to a distance of said detector means therefrom, and comprises rows of detection elements equal in number to said detection elements of said detector means.
Claim 4
Dependent Claim
68 words
The computed tomography apparatus according to claim 1, wherein said intensity distribution measuring means is located at a distance from said irradiating means equal to a distance of said detector means therefrom, and comprises rows of detection elements fewer in number than said detection elements of said detector means, and means for acquiring an intensity distribution of radiation ray at each row of said detector means by interpolation.
Claim 5
Dependent Claim
102 words
The computed tomography apparatus according to claim 1, wherein said intensity distribution measuring means is located at a distance from said irradiating means different from a distance of said detector means therefrom, and comprises rows of detection elements equal in number to said detection elements of said detector means, and a row pitch of said intensity distribution measuring means is set in accordance with a ratio of said distance between said irradiating means and said detector means to said distance between said irradiating means and said intensity distribution measuring means and a row pitch of said detection elements of said detector means.
Claim 6
Dependent Claim
66 words
The computed tomography apparatus according to claim 4, wherein said intensity distribution measuring means is located closer to said irradiating means than said detector means, and comprises rows of detection elements equal in number to said detection elements of said detector means, and said row pitch of said intensity distribution measuring means is smaller than said row pitch of said detection elements of said detector means.
Claim 7
Dependent Claim
53 words
The computed tomography apparatus according to claim 1, wherein said detector means and said intensity distribution measuring means are constituted by arranging detection element blocks in a matrix form, said detector means outputs radiation ray transmission data for each detection element, and said intensity distribution measuring means outputs intensity data for each row.
Claim 8
Dependent Claim
28 words
The computed tomography apparatus according to claim 1, wherein said detector means and said intensity distribution measuring means are formed adjacent to each other on a same substrate.
Claim 9
Dependent Claim
28 words
The computed tomography apparatus according to claim 1, wherein said detector means and said intensity distribution measuring means are formed apart from each other on a same substrate.
Claim 10
Dependent Claim
27 words
The computed tomography apparatus according to claim 1, wherein said detector means and said intensity distribution measuring means are on separate substrates located adjacent to each other.
Claim 11
Dependent Claim
27 words
The computed tomography apparatus according to claim 1, wherein said detector means and said intensity distribution measuring means are on separate substrates set apart from each other.
Claim 12
Dependent Claim
33 words
The computed tomography apparatus according to claim 1, wherein said intensity distribution measuring means is provided on one end of a row extending from each row of detection elements of said detector means.
Claim 13
Dependent Claim
33 words
The computed tomography apparatus according to claim 1, wherein said intensity distribution measuring means is provided on both ends of a row extending from each row of detection elements of said detector means.
Claim 14
Dependent Claim
30 words
The computed tomography apparatus according to claim 1, wherein said intensity distribution measuring means has a collimator facing said irradiating means for eliminating radiation ray having passed a subject body.
Claim 15
Dependent Claim
59 words
The computed tomography apparatus according to claim 1, wherein said compensation means obtains a ratio of a reference value PROF(ini) of an output of said intensity distribution measuring means to a current value PROF(scan) and compensates a current value MAIN of said detector means as follows in accordance with said ratio: MAIN'=MAIN×PROF(ini)/PROF(scan) where MAIN' is a value after compensation.
References Cited (Backward Citations)
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