US4532425A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gamma camera with light guide having greater index of refraction
Assignee: GE Medical Systems Israel Ltd
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Filing: 1982-08-04
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Granted: 1985-07-30
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Expires: 2002-08-04
Abstract
Abstract A gamma camera comprises a scintillation crystal having an index of refraction of 1.80-190, a collimator for imaging the object on one face of the scintillation crystal, an array of photodetectors arranged around the opposite face of the scintillation crystal, and a light guide interposed between the opposite face of the scintillation crystal and the plurality of photodetectors. The light guide is selected to have an index of refraction of at least 1.60, higher than in the conventional gamma camera, whereupon it has been found that the detection efficiency and the positional accuracy of each scintillation event can be increased, to thereby increase the sensitivity and the spatial resolution of the gamma camera.
Inventors
- 👤 Adi Abileah
- 👤 Giora Gafni
- 👤 Miguel O. Simerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:02
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G01T1/202; G01T1/2002
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
91 words
A gamma camera including a scintillation crystal, a collimator for transferring a gamma-ray image to one face of the crystal, a plurality of photomultiplier tubes arrayed at the opposite face of said crystal for receiving the light photons emitted by the crystal as a result of the absorption thereby of gamma rays, and a transparent light guide interposed between said opposite face of the crystal and said photomultiplier tubes, said crystal having an index of refraction of 1.80-1.90, and said light guide having an index of refraction of at least 1.60.
Claim 2
Dependent Claim
91 words
A gamma camera including a scintillation crystal, a collimator for transferring a gamma-ray image to one face of the crystal, a plurality of photomultiplier tubes arrayed at the opposite face of said crystal for receiving the light photons emitted by the crystal as a result of the absorption thereby of gamma rays, and a transparent light guide interposed between said opposite face of the crystal and said photomultiplier tubes, said crystal having an index of refraction of 1.80-1.90, and said light guide having an index of refraction of at least 1.60.
Claim 3
Dependent Claim
31 words
The gamma camera of claim 1. wherein the index of refraction of the scintillation crystal is 1.84, and the index of refraction of the light guide is from 1.6 to 1.7.
Claim 4
Dependent Claim
24 words
The gamma camera according to claim 1, wherein the index of refraction of the light guide is greater than that of the scintillation crystal.
Claim 5
Dependent Claim
29 words
The gamma camera according to claim 3, wherein the index of refraction of the scintillation crystal is 1.84, and the index of refraction of the light guide is 1.95.
Claim 6
Dependent Claim
32 words
The gamma camera according to claim 1, wherein said light guide is bonded to said scintillation crystal by glue having an index of refraction approximately equal to that of said light guide.
Claim 7
Dependent Claim
20 words
The gamma camera according to claim 1, wherein the surface of said light guide adjacent to said photoconductor is roughened.
Claim 8
Dependent Claim
25 words
A gamma camera according to claim 1 wherein the index of refraction of said light guide is uniform in the direction defined by said collimator.
Claim 9
Dependent Claim
19 words
A gamma camera according to claim 7 wherein the index of refraction of said light guide is uniform throughout.
Claim 10
Dependent Claim
26 words
A gamma camera according to each of claim 2 wherein the index of refraction of said light guide is uniform in the direction by said collimator.
Claim 11
Dependent Claim
18 words
A gamma camera according to claim 3 wherein the index of refraction of said light guide is uniform.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-29 | 1989-01-28 | 1989-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-29 | 1993-01-28 | 1993-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-29 | 1997-01-28 | 1997-07-30 | $7700.00 | Window Closed / Lapsed |