US5138167A
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Split energy radiation detection
Assignee: ALABAMA FOR UNIVERSITY OF ALABAMA IN BIRMINGHAM UNIVERSITY STATION BIRMINGHAM AL 35294, University of, Trustees of
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Filing: 1991-01-23
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Granted: 1992-08-11
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Expires: 2011-01-23
Abstract
Abstract An energy discriminating apparatus and method is disclosed for use in connection with digital radiography and fluoroscopy. In use of the detection system and method an x-ray source is actuated to direct x-rays through a patient's body, the x-rays including both higher and lower energy radiation. A first detector element, including a plurality of segments, is positioned opposite the source to receive and respond predominantly to x-rays in a lower energy range, the remaining x-rays, being generally of higher energy, passing through the first detector element. A second detector element, also including a plurality of segments, each segment including a phosphor coating layer and a sensor, is positioned to receive and respond to the higher energy radiation passing through the first element. The sensors are coupled respectively to each detector element segment for substantially simultaneously sensing the response and spatial location, relative to the detector elements, of radiation to which each detector element respectively responds. A filter element is interposed between the first and second detectors to enhance discrimination in the energy response of the respective detector elements. Particular preferred detector phosphor materials are identified. The sensors produce separately and simultaneously information representing patterns of relatively lower and higher energy emergent from the patient's body. Digital data processing and conversion equipment responds to the sensors to produce digital information representing each of said images, which can be digitally processed to enhance image characteristics. Rare earth tantalates and semiconductor materials can also be used as radiation detection layers.
Inventors
- 👤 Gary T. Barnes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:32
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G01T1/2018; G01T1/20181; G01T1/20182; G01T1/20185; G01T1/202
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
182 words
An energy discriminating radiation detector comprising: a) a first element comprising a first material of a kind which is preferentially responsive to penetrative radiation of a first energy range, said response being defined by a first characteristic, said first characteristic defining a first peak radiation absorptive energy value; b) a second element comprising a second material different from said first material and of a kind which is preferentially responsive to penetrative radiation of a second energy range said response being defined by a second characteristic, said second energy range extending higher than said first energy range, said second characteristic defining a second peak radiation absorptive energy value higher than said first peak energy value, said second element being positioned to receive radiation which has penetrated through a portion of said first element, and c) a filter of penetrative radiation interposed between said first and second elements, said filter comprising material and having thickness such that said filter exhibits a main radiation attenuation roll off with respect to energy, said roll off occurring at an energy value lower than said second peak value.
Claim 2
Dependent Claim
182 words
An energy discriminating radiation detector comprising: a) a first element comprising a first material of a kind which is preferentially responsive to penetrative radiation of a first energy range, said response being defined by a first characteristic, said first characteristic defining a first peak radiation absorptive energy value; b) a second element comprising a second material different from said first material and of a kind which is preferentially responsive to penetrative radiation of a second energy range said response being defined by a second characteristic, said second energy range extending higher than said first energy range, said second characteristic defining a second peak radiation absorptive energy value higher than said first peak energy value, said second element being positioned to receive radiation which has penetrated through a portion of said first element, and c) a filter of penetrative radiation interposed between said first and second elements, said filter comprising material and having thickness such that said filter exhibits a main radiation attenuation roll off with respect to energy, said roll off occurring at an energy value lower than said second peak value.
Claim 3
Dependent Claim
18 words
The detector of claim 1 wherein: said roll off occurs substantially between said first and second peak values.
Claim 4
Dependent Claim
97 words
A dual layer radiation detector comprising: a) a first portion aligned to receive penetrative radiation from a source; b) a second portion aligned with said first portion to receive radiation from said source subsequent to its passage through said first portion, said second portion comprising a material different from that of said first portion, and c) a radiation filtration layer interposed between said first and second portions, said radiation filtration layer comprising a portion of one or more materials having an atomic number of between 24 and 58, and being approximately 0.2 to 1.0 millimeters in thickness.
Claim 5
Dependent Claim
97 words
A dual layer radiation detector comprising: a) a first portion aligned to receive penetrative radiation from a source; b) a second portion aligned with said first portion to receive radiation from said source subsequent to its passage through said first portion, said second portion comprising a material different from that of said first portion, and c) a radiation filtration layer interposed between said first and second portions, said radiation filtration layer comprising a portion of one or more materials having an atomic number of between 24 and 58, and being approximately 0.2 to 1.0 millimeters in thickness.
Claim 6
Dependent Claim
103 words
An energy discriminating radiation detector comprising: a) a first component comprising a first quantity of semiconductor material which is preferentially responsive to body-penetrative radiation of a first energy range; b) a second component comprising a quantity of semiconductor material which is preferentially responsive to penetrative radiation of a second energy range extending higher than said first energy range, said second component being positioned to receive radiation which has penetrated through a portion of said first component, and c) means coupled to said first and second components to produce electrical signals representing an image of radiation when incident on said first and second components.
Claim 7
Dependent Claim
103 words
An energy discriminating radiation detector comprising: a) a first component comprising a first quantity of semiconductor material which is preferentially responsive to body-penetrative radiation of a first energy range; b) a second component comprising a quantity of semiconductor material which is preferentially responsive to penetrative radiation of a second energy range extending higher than said first energy range, said second component being positioned to receive radiation which has penetrated through a portion of said first component, and c) means coupled to said first and second components to produce electrical signals representing an image of radiation when incident on said first and second components.
Claim 8
Dependent Claim
96 words
A radiation detector system comprising: a) a source for propagating radiation along a path; b) a detector assembly spaced from said source and interposed in said second path, said detector assembly comprising: i) a first portion of said semiconductor material interposed in said path; ii) a second portion of semiconductor material interposed in said path and aligned with said first portion behind said first portion with respect to said source, and c) means coupled to said first and second portions of semiconductor material for producing an electrical representation of radiation when incident on said detector assembly.
Claim 9
Dependent Claim
96 words
A radiation detector system comprising: a) a source for propagating radiation along a path; b) a detector assembly spaced from said source and interposed in said second path, said detector assembly comprising: i) a first portion of said semiconductor material interposed in said path; ii) a second portion of semiconductor material interposed in said path and aligned with said first portion behind said first portion with respect to said source, and c) means coupled to said first and second portions of semiconductor material for producing an electrical representation of radiation when incident on said detector assembly.
Claim 10
Dependent Claim
29 words
The system of claim 5, wherein said first and second portions comprise material selected from the group including lead oxide, mercuric iodide, gallium arsenide, cadmium telluride, germanium and silicon.
Claim 11
Dependent Claim
20 words
The system of claim 5, wherein: a) said first portion comprises germanium, and b) said second portion comprises lead oxide.
Claim 12
Dependent Claim
20 words
The system of claim 5, wherein: a) said first portion comprises germanium, and b) said second portion comprises mercuric iodide.
Claim 13
Dependent Claim
21 words
The system of claim 5, wherein: a) said first portion comprises gallium arsenide, and b) said second portion comprises lead oxide.
Claim 14
Dependent Claim
21 words
The system of claim 5, wherein: a) said first portion comprises gallium arsenide, and b) said second portion comprises mercuric iodide.
Claim 15
Dependent Claim
21 words
The system of claim 5, wherein: a) said first portion comprises cadmium telluride, and b) said second portion comprises lead oxide.
Claim 16
Dependent Claim
82 words
An energy discriminating radiation detector comprising: a) a first component comprising a first material of a first kind which is preferentially responsive to penetrative radiation of a first energy range; b) a second component comprising a rare earth tantalate material and aligned to receive penetrative radiation subsequent to its passage through said first component, and c) means coupled to said first and second components to produce electrical signals representing an image of radiation when incident respectively on said first and second components.
Claim 17
Dependent Claim
82 words
An energy discriminating radiation detector comprising: a) a first component comprising a first material of a first kind which is preferentially responsive to penetrative radiation of a first energy range; b) a second component comprising a rare earth tantalate material and aligned to receive penetrative radiation subsequent to its passage through said first component, and c) means coupled to said first and second components to produce electrical signals representing an image of radiation when incident respectively on said first and second components.
Claim 18
Dependent Claim
23 words
The detector of claim 12, wherein said rare earth tantalate is selected from the group of yttrium tantalate, gadolinium tantalate and lutetium tantalate.
Claim 19
Dependent Claim
12 words
The detector of claim 13, wherein said first component comprises yttrium oxysulfide.
Claim 20
Dependent Claim
183 words
An energy discriminating radiation imaging system comprising: a) a source for causing propagation of penetrative radiation through a portion of a subject to emerge therefrom in a pattern; b) an energy discriminating radiation detector located to receive said- pattern of penetrative radiation, said detector comprising: i) first material of a first kind which is preferentially responsive to penetrative radiation of a first energy range, said first material having a primary radiation absorber comprising an element having an atomic number in the range of 37 to 57; ii) a second material different in kind from said first material and of a kind which is preferentially responsive to penetrative radiation of a second energy range extending higher than said first energy range, said second material being positioned to receive radiation which has penetrated through a portion of said first material, said second material having a primary radiation absorber comprising an element having an atomic number in the range of 56 to 83, and iii) means coupled to said first and second materials to produce electric signals representing radiation response by said first and second materials.
Claim 21
Dependent Claim
183 words
An energy discriminating radiation imaging system comprising: a) a source for causing propagation of penetrative radiation through a portion of a subject to emerge therefrom in a pattern; b) an energy discriminating radiation detector located to receive said- pattern of penetrative radiation, said detector comprising: i) first material of a first kind which is preferentially responsive to penetrative radiation of a first energy range, said first material having a primary radiation absorber comprising an element having an atomic number in the range of 37 to 57; ii) a second material different in kind from said first material and of a kind which is preferentially responsive to penetrative radiation of a second energy range extending higher than said first energy range, said second material being positioned to receive radiation which has penetrated through a portion of said first material, said second material having a primary radiation absorber comprising an element having an atomic number in the range of 56 to 83, and iii) means coupled to said first and second materials to produce electric signals representing radiation response by said first and second materials.
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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) | 1995-08-11 | 1996-02-10 | 1996-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-11 | 2000-02-10 | 2000-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-11 | 2004-02-10 | 2004-08-11 | $7700.00 | Window Closed / Lapsed |