US4408124A
Expired / Lapsed
US
⏱️ 0.0 years remaining
BRH Test pattern for gamma camera performance (an evaluator)
Assignee: United States Department of Health and Human Services
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Filing: 1981-04-14
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Granted: 1983-10-04
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Expires: 2001-04-14
Abstract
Abstract A test phantom for testing the performance of gamma cameras comprises a plate impervious to gamma rays having an orthogonal array of apertures defined therethrough. The apertures are uniform in size and are arranged in columns and rows. The columns are grouped such that the spacing between adjacent columns in each group differs from the spacing between adjacent columns in all of the groups, and such that the spacing between adjacent columns within each group is uniform throughout that group. The groups are arranged such that the more densely spaced groups are positioned proximate the middle of the array and the more widely spaced columns are disposed at the ends of the array. The resulting test pattern permits changes in the intrinsic resolution, uniformity and spatial distortion of a gamma camera to be observed simultaneously from a single transmission of the test pattern.
Inventors
- 👤 Peter Paras
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:00
CPC Classifications
G; G01; G01D; G01D18/00; G01T; G01T1/00; G01T1/16; G01T1/161; G01T1/164; G01T1/1641; G01T1/1648
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
97 words
A test phantom for testing performance of gamma cameras, said test phantom comprising a plate made of a material impervious to gamma rays and having an array of apertures defined therethrough, said array being arranged in parallel columns of apertures extending in a first direction and parallel rows of apertures extending in a second direction, said columns being arranged in plural groups wherein the spacing between adjacent columns in each group is different from the spacing between adjacent columns in all other groups but wherein the adjacent column spacing within each group is uniform throughout that group.
Claim 2
Dependent Claim
97 words
A test phantom for testing performance of gamma cameras, said test phantom comprising a plate made of a material impervious to gamma rays and having an array of apertures defined therethrough, said array being arranged in parallel columns of apertures extending in a first direction and parallel rows of apertures extending in a second direction, said columns being arranged in plural groups wherein the spacing between adjacent columns in each group is different from the spacing between adjacent columns in all other groups but wherein the adjacent column spacing within each group is uniform throughout that group.
Claim 3
Dependent Claim
18 words
A test phantom according to claim 1, wherein the spacing between adjacent rows is uniform throughout said array.
Claim 4
Dependent Claim
35 words
The test phantom according to claims 1 or 2, wherein said array is an orthogonal array in which all rows have the same number of apertures and all columns have the same number of apertures.
Claim 5
Dependent Claim
19 words
The test phantom according to claims 1 or 2, wherein said apertures are all the same size and shape.
Claim 6
Dependent Claim
75 words
The test phantom according to claims 1 or 2, wherein the group of columns having the smallest spacing between adjacent columns is disposed proximate the middle of said rows, the two groups having the largest and next largest spacing between adjacent columns are disposed at respective ends of said rows, and remaining groups are positioned such that adjacent column spacing becomes progressively smaller from the ends of the rows toward the center of the rows.
Claim 7
Dependent Claim
22 words
The test phantom according to claim 5, further comprising first and second sheets of lucite, said plate being sandwiched between said sheets.
Claim 8
Dependent Claim
78 words
The test phantom according to claim 6, wherein said apertures are all circular and approximately 0.25 cm in diameter, wherein said groups of columns are twelve in number, wherein each of said groups includes six columns, wherein the adjacent column spacing ranges from 0.015 cm in the group with the smallest column spacing to 0.7 cm in the group with the largest column spacing, there being increments of 0.05 cm between adjacent column spacings in the other groups.
Claim 9
Dependent Claim
14 words
The test phantom according to claim 7, wherein said plate is made of lead.
Claim 10
Dependent Claim
78 words
The test phantom according to claims 1 or 2, wherein said apertures are all circular and approximately 0.25 cm in diameter, wherein said groups are twelve in number, wherein each of said groups includes six columns, wherein the adjacent column spacing ranges from 0.015 cm in the group with the smallest column spacing to 0.7 cm in the group with the largest column spacing, there being increments of 0.05 cm between adjacent column spacings in the other groups.
Claim 11
Dependent Claim
16 words
The test phantom according to claims 1 or 2, wherein said plate is made of lead.
Claim 12
Dependent Claim
112 words
A test phantom for testing performance of gamma cameras, said test phantom comprising: a lead plate; an array of apertures defined through said lead plate, said array being arranged in parallel aperture columns extending in a first direction and parallel aperture rows extending in a second direction, said columns being arranged in plural groups wherein the spacing between adjacent columns in each group is different from the spacing between adjacent columns in other groups but wherein the adjacent column spacing within each group is uniform throughout that group, and wherein the spacing between adjacent rows is uniform throughout the array; and wherein said apertures are all the same general size and shape.
Claim 13
Dependent Claim
112 words
A test phantom for testing performance of gamma cameras, said test phantom comprising: a lead plate; an array of apertures defined through said lead plate, said array being arranged in parallel aperture columns extending in a first direction and parallel aperture rows extending in a second direction, said columns being arranged in plural groups wherein the spacing between adjacent columns in each group is different from the spacing between adjacent columns in other groups but wherein the adjacent column spacing within each group is uniform throughout that group, and wherein the spacing between adjacent rows is uniform throughout the array; and wherein said apertures are all the same general size and shape.
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) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |