US3882310A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spatially modulated imaging system
Assignee: Raytheon Co
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Filing: 1973-09-26
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Granted: 1975-05-06
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Expires: 1993-09-26
Abstract
Abstract Noncoherent radiation, such as X-rays, is spatially coded, directed through an object and spatially detected to form a spatially coded pattern, from which an image of the object may be reconstructed. The X-ray source may be formed by X-ray fluorescence and subtraction of the holographic images formed by two sources having energy levels predominantly above and below the maximum absorption range of an agent in the object may be used to enhance contrast in the reproduced image. Constant spatial frequency coding of the source may be used to produce a spatial carrier frequency to enhance detection of low spatial frequency components of the spatially coded pattern so that images may be a more easily reconstructed such as the optical reconstruction of spatially code formed by the off-center section of a Fresnel zone pattern by converting the detected intensity pattern to a diffraction or phase pattern.
Inventors
- 👤 Harrison H Barrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:03
CPC Classifications
G; G03; G03B; G03B42/00; G03B42/02; G03B42/026
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
211 words
The method comprising the steps of: introducing into at least selected regions of an object comprising living tissue a substance having a substantially different absorption coefficient of X-rays at a predetermined energy level than said absorption coefficient of said living tissue adjacent said selected regions; spatially recording at least components of spatially distributed patterns of X-rays predominantly concentrated in regions respectively above and below said predetermined energy level which have passed through said object; said spatially distributed patterns of said X-rays having at least components of a spatially varying periodicity formed by the steps comprising directing said X-rays through a structure comprising a plurality of regions of different sizes substantially permeable to said X-rays separated by regions which are substantially less permeable to said X-rays and which have a thickness in a direction parallel to the average direction of motion of said X-rays through said structure which is less than the average dimension of said permeable regions transverse to said direction; and deriving an image of the differences in absorption of different regions of said object to said X-rays by steps comprising spatially subtracting at least portions of said spatially recorded components derived from said energy level pattern above said predetermined energy level from said pattern below said predetermined energy level.
Claim 2
Independent Claim
211 words
The method comprising the steps of: introducing into at least selected regions of an object comprising living tissue a substance having a substantially different absorption coefficient of X-rays at a predetermined energy level than said absorption coefficient of said living tissue adjacent said selected regions; spatially recording at least components of spatially distributed patterns of X-rays predominantly concentrated in regions respectively above and below said predetermined energy level which have passed through said object; said spatially distributed patterns of said X-rays having at least components of a spatially varying periodicity formed by the steps comprising directing said X-rays through a structure comprising a plurality of regions of different sizes substantially permeable to said X-rays separated by regions which are substantially less permeable to said X-rays and which have a thickness in a direction parallel to the average direction of motion of said X-rays through said structure which is less than the average dimension of said permeable regions transverse to said direction; and deriving an image of the differences in absorption of different regions of said object to said X-rays by steps comprising spatially subtracting at least portions of said spatially recorded components derived from said energy level pattern above said predetermined energy level from said pattern below said predetermined energy level.
Claim 3
Dependent Claim
29 words
The method in accordance with claim 1 wherein said step of spatially recording said spatially distributed patterns of X-rays comprises: exposing a body of X-ray fluorescent material to radiation.
Claim 4
Dependent Claim
34 words
The method in accordance with claim 2 wherein said selective absorbing substance has a sharp change in said absorption coefficient in the energy level region between the predominant intensity level regions of said patterns.
Claim 5
Independent Claim
166 words
The method of producing an X-ray image of an object comprising: producing a concentration of an agent which has a large change in X-ray absorption coefficient around a predetermined X-ray energy level in selected regions of said object; exposing said object to spatially distributed patterns of X-rays having energy level regions predominantly concentrated respectively above and below said predetermined energy level and spatially recording at least components of said patterns passing through said object; said spatially distributed patterns of X-rays having at least a component of varying spatial periodicity; and deriving an image of the locations of said regions of said object by the steps comprising subtracting at least a portion of said spatially recorded components of said patterns of X-rays having an energy level region predominantly above said predetermined energy level of said absorption coefficient change of said agent from said spatially recorded components of said patterns of X-rays having an energy level region predominantly below said predetermined energy level of said absorption coefficient change.
Claim 6
Independent Claim
166 words
The method of producing an X-ray image of an object comprising: producing a concentration of an agent which has a large change in X-ray absorption coefficient around a predetermined X-ray energy level in selected regions of said object; exposing said object to spatially distributed patterns of X-rays having energy level regions predominantly concentrated respectively above and below said predetermined energy level and spatially recording at least components of said patterns passing through said object; said spatially distributed patterns of X-rays having at least a component of varying spatial periodicity; and deriving an image of the locations of said regions of said object by the steps comprising subtracting at least a portion of said spatially recorded components of said patterns of X-rays having an energy level region predominantly above said predetermined energy level of said absorption coefficient change of said agent from said spatially recorded components of said patterns of X-rays having an energy level region predominantly below said predetermined energy level of said absorption coefficient change.
Claim 7
Dependent Claim
77 words
The method in accordance with claim 4 wherein said step of exposing said object and recording said patterns comprises spatially coding said X-rays lying predominantly above the energy level of said absorption change with a first pattern having a predetErmined spatial frequency and a first phase and spatially coding X-rays lying predominantly below the energy level of said change with a second pattern having said predetermined spatial frequency and a second phase different from said first phase.
Claim 8
Dependent Claim
20 words
The method in accordance with claim 4 wherein said second pattern is the complement or inverse of said first pattern.
Claim 9
Dependent Claim
81 words
The method in accordance with claim 4 wherein said step of spatially recording said components comprises: converting said X-rays to a lower energy level and recording a first pattern of said converted components on a first film; recording a second pattern of said converted components on a second film; and forming a composite film from said first and second films in which portions of the components of said first pattern are at least partially subtracted from components of said second pattern.
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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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |