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US4748328A
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Single photon emission computed tomograph using focused modular collimators
Assignee: University of Iowa Research Foundation
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Filing: 1986-07-10
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Granted: 1988-05-31
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Expires: 2006-07-10
Abstract
Abstract A single photon emission computed tomograph comprising a detector ring and a rotatable collimator assembly disposed within the detector ring. The rotatable collimator assembly comprises four collimator quadrants, and each of the four collimator quadrants comprises a plurality of collimator modules with their axes assembled in parallel. Each of the modules contains a plurality of inwardly directed channels focused to a single point on its own axis with a long focal length. The focal length of each of the collimator modules is individually and flexibly chosen to suit a particular imaging task. The four collimator quadrants are installed in the rotatable collimator assembly at a slightly different angular offset so as to achieve fine data sampling.
Inventors
- 👤 Wei Chang
- 👤 Peter Kirchner
- 👤 Karim Rezai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:51
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/29; G01T1/2914; G01T1/2985; A; A61; A61B; A61B6/00; A61B6/02; A61B6/03; A61B6/037; G21; G21K; G21K1/00; G21K1/02; G21K1/025
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
138 words
A single photon emission computed tomograph comprising: (a) a detector ring and (b) a rotatable collimator assembly disposed within said detector ring, said rotatable collimator assembly comprising four collimator quadrants, each of said four collimator quadrants comprising a plurality of collimator modules with their axes assembled in parallel, each of said modules containing a plurality of inwardly directed channels focused to a single point on its own axis, the focal length of each of said collimator modules being individually chosen to suit a particular imaging task, (c) wherein each of said four collimator quardants is installed in said rotatable collimator assembly at a slightly different first angular offset to achieve fine data sampling, the first angular offsets being in the range of just greater than 0° to the angle subtended by each discrete crystal in said detector ring.
Claim 2
Dependent Claim
138 words
A single photon emission computed tomograph comprising: (a) a detector ring and (b) a rotatable collimator assembly disposed within said detector ring, said rotatable collimator assembly comprising four collimator quadrants, each of said four collimator quadrants comprising a plurality of collimator modules with their axes assembled in parallel, each of said modules containing a plurality of inwardly directed channels focused to a single point on its own axis, the focal length of each of said collimator modules being individually chosen to suit a particular imaging task, (c) wherein each of said four collimator quardants is installed in said rotatable collimator assembly at a slightly different first angular offset to achieve fine data sampling, the first angular offsets being in the range of just greater than 0° to the angle subtended by each discrete crystal in said detector ring.
Claim 3
Dependent Claim
32 words
A single photon emission computed tomograph as recited in claim 1 wherein said first angular offset of each of said four quadrant ring collimators is in the range of 1.0° to 2.0°.
Claim 4
Dependent Claim
43 words
A single photon emission computed tomograph as recited in claim 1 wherein each of said four collimator quadrants is installed at a second angular offset on the order of 1/4 of said first angular offset to achieve quarter ray offset in data sampling.
Claim 5
Dependent Claim
27 words
A single photon emission computed tomograph as recited in claim 1 and further comprising a lead wedge disposed between each two adjacent ones of said collimator quadrants.
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) | 1991-05-31 | 1991-11-30 | 1992-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-31 | 1995-11-30 | 1996-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-31 | 1999-11-30 | 2000-05-31 | $7700.00 | Window Closed / Lapsed |