US3927318A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cross-sectional fluorescent imaging system
Assignee: Individual
•
Filing: 1974-05-06
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Granted: 1975-12-16
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Expires: 1994-05-06
Abstract
Abstract A narrow x-ray beam is scanned across a cross section containing a relatively high atomic number material. When excited by the xray beam the material fluoresces and emits its characteristic radiation lines. The emission information along the entire line is collected to create a signal indicative of the line integral of the emission information. This line integral information, taken from many positions and angles in the cross section, is applied to a computer which reconstructs a cross-sectional image of the fluorescing material. The transmitted narrow beam, which represents the line integral of the density information, can simultaneously be used to create a reconstruction of the crosssectional density pattern.
Inventors
- 👤 Albert Macovski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:19
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/48; A61B6/483; A61B6/485; G; G01; G01N; G01N23/00; G01N23/22; G01N23/223; G01N2223/00; G01N2223/07; G01N2223/076
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
108 words
Apparatus for imaging fluorescent radiation from a specific material in a cross section of an object comprising: an x-ray beam directed through the cross section of the object; means for translating the x-ray beam so that all regions of the cross section are excited at a plurality of angles; means for detecting the integrated fluorescent radiation emitted along the entire x-ray beam at each position of the x-ray beam and forming a plurality of integrated emission signals; a computer for reconstructing the fluorescent radiation information of the cross section of the object from the plurality of integrated emission signals; and means for displaying the reconstructed fluorescent radiation information.
Claim 2
Dependent Claim
108 words
Apparatus for imaging fluorescent radiation from a specific material in a cross section of an object comprising: an x-ray beam directed through the cross section of the object; means for translating the x-ray beam so that all regions of the cross section are excited at a plurality of angles; means for detecting the integrated fluorescent radiation emitted along the entire x-ray beam at each position of the x-ray beam and forming a plurality of integrated emission signals; a computer for reconstructing the fluorescent radiation information of the cross section of the object from the plurality of integrated emission signals; and means for displaying the reconstructed fluorescent radiation information.
Claim 3
Dependent Claim
31 words
Apparatus as recited in claim 1 including means for correcting the plurality of integrated emission signals for the attenuation of the fluorescent radiation in the object before reaching the detector means.
Claim 4
Dependent Claim
47 words
Apparatus as recited in claim 2 wherein the means for correcting for attenuation includes an energy spectrum analyzer for separately measuring the K and K components of the fluorescent radiation and means for comparing their amplitudes to their initial emitted relative amplitudes to compute the required correction.
Claim 5
Dependent Claim
47 words
Apparatus as recited in claim 2 wherein the means for correcting for attenuation includes a pre-programmed compensator based on an object having an assumed size and absorption where the pre-programmed compensator is varied according to the distance of the x-ray beam to the edge of the object.
Claim 6
Dependent Claim
29 words
Apparatus as recited in claim 1 wherein the means for detecting the fluorescent radiation includes a plurality of gamma-ray detectors whereby a large percentage of the radiation is received.
Claim 7
Dependent Claim
32 words
Apparatus as recited in claim 1 wherein the means for detecting the fluorescent radiation includes an energy spectrum analyzer for isolating the energy level of the fluorescent radiation from the specific material.
Claim 8
Dependent Claim
14 words
Apparatus as recited in claim 6 wherein the spectrum analyzer is a pulse-height discriminator.
Claim 9
Dependent Claim
59 words
Apparatus as recited in claim 1 including: means for detecting the x-ray beam after transmission through the object at each position of the x-ray beam to form a plurality of transmission signals; means for computing the density information of the cross section of the object from the plurality of transmission signals; and means for displaying the reconstructed density information.
Claim 10
Dependent Claim
26 words
Apparatus as recited in claim 8 whereiN the means for displaying the reconstructed density information includes a composite display of the density and fluorescent radiation information.
Claim 11
Dependent Claim
24 words
Apparatus as recited in claim 9 wherein the composite display is a color display having the density and fluorescent radiation information in different colors.
Claim 12
Dependent Claim
24 words
Apparatus as recited in claim 1 including means for correcting the fluorescent radiation information for the attenuation of the x-ray beam in the object.
Claim 13
Dependent Claim
49 words
Apparatus as recited in claim 11 wherein the means for correcting for the attenuation of the x-ray beam includes a pre-programmed compensator based on an object having an assumed absorption where the attenuation at each position of the x-ray beam to each region of the cross section is calculated.
Claim 14
Dependent Claim
85 words
Apparatus as recited in claim 11 wherein the means for correcting for the attenuation of the x-ray beam comprises: means for detecting the x-ray beam after transmission through the object to form a plurality of transmission signals; means for computing the attenuation of the x-ray beam to each region of the cross section from the plurality of transmission signals; and means for correcting the fluorescent radiation information at each region of the cross section using the computed attenuation of the x-ray beam to that region.
References Cited (Backward Citations)
US3769507A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |