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US4445226A
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Multiple-energy X-ray subtraction imaging system
Assignee: Leland Stanford Junior University
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Filing: 1981-05-05
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Granted: 1984-04-24
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Expires: 2001-05-05
Abstract
Abstract Projection measurements are made at different parts of the X-ray energy spectrum. These measurements are processed to obtain image data with the soft tissue component eliminated. The processed image data is obtained before and after the administration of a contrast agent. The two sets of processed image data are combined to obtain an isolated image of the contrast agent which is immune to motion of soft tissue.
Inventors
- 👤 William R. Brody
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:45
CPC Classifications
A; A61; A61B; A61B6/00; A61B6/48; A61B6/481; A61B6/42; A61B6/4208; A61B6/4241; A61B6/482; A61B6/50; A61B6/504; H; H04; H04N; H04N5/00; H04N5/30; H04N5/32; H04N5/3205
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
161 words
In a method for providing a projection image of an administered contrast material in a region of the body the steps of: measuring the x-ray transmission through the region at a plurality of x-ray energy spectra prior to administering the contrast material; administering the contrast material; measuring the x-ray transmission through the region at the same plurality of x-ray spectra after administering the contrast material; and processing the plurality of transmission measurements made before and after the administration of contrast material to provide an image of the contrast including: combining functions of the plurality of measurements made prior to the contrast administration to provide a first data set having at least one material component of the region substantially eliminated; combining functions of the plurality of measurements made after the contrast administration to provide a second data set having the same material components substantially eliminated; and combining the first and second data sets to provide the image information of the contrast material.
Claim 2
Dependent Claim
161 words
In a method for providing a projection image of an administered contrast material in a region of the body the steps of: measuring the x-ray transmission through the region at a plurality of x-ray energy spectra prior to administering the contrast material; administering the contrast material; measuring the x-ray transmission through the region at the same plurality of x-ray spectra after administering the contrast material; and processing the plurality of transmission measurements made before and after the administration of contrast material to provide an image of the contrast including: combining functions of the plurality of measurements made prior to the contrast administration to provide a first data set having at least one material component of the region substantially eliminated; combining functions of the plurality of measurements made after the contrast administration to provide a second data set having the same material components substantially eliminated; and combining the first and second data sets to provide the image information of the contrast material.
Claim 3
Dependent Claim
43 words
The method as defined by claim 1 wherein the steps for measuring the x-ray transmission at different energy spectra includes the steps of: sequentially varying the energy spectra of the x-ray source; and detecting the transmitted x-ray beam at each x-ray source spectra.
Claim 4
Dependent Claim
61 words
The method as defined by claim 1 wherein the steps for measuring the x-ray transmission at different energy spectra includes the steps of: projecting the x-ray beam through the region whose broad energy spectrum includes each of the individual x-ray energy spectra; and detecting the transmitted x-ray beam using an energy selective detector providing individual output signals for each energy spectrum.
Claim 5
Dependent Claim
179 words
In a method for providing a projection image of an administered contrast material in a region of the body the steps of: measuring the x-ray transmission through the region at a first energy spectrum; measuring the x-ray transmission through the region at a second energy spectrum different from the first spectrum; processing the two measurements to provide a first data set having at least one material component of the region substantially eliminated; administering the contrast material in the region after the first two x-ray measurements are made; measuring the x-ray transmission through the region after the contrast material has been administered at the first energy spectrum; measuring the x-ray transmission through the region after the contrast material has been administered at the second energy spectrum; processing the two post-contrast measurements in the same way as that of the pre-contrast measurements to provide a second data set having the same material components of the region substantially eliminated; combining the first and second data sets to produce image information of the administered contrast material; and displaying the administered contrast material image.
Claim 6
Dependent Claim
179 words
In a method for providing a projection image of an administered contrast material in a region of the body the steps of: measuring the x-ray transmission through the region at a first energy spectrum; measuring the x-ray transmission through the region at a second energy spectrum different from the first spectrum; processing the two measurements to provide a first data set having at least one material component of the region substantially eliminated; administering the contrast material in the region after the first two x-ray measurements are made; measuring the x-ray transmission through the region after the contrast material has been administered at the first energy spectrum; measuring the x-ray transmission through the region after the contrast material has been administered at the second energy spectrum; processing the two post-contrast measurements in the same way as that of the pre-contrast measurements to provide a second data set having the same material components of the region substantially eliminated; combining the first and second data sets to produce image information of the administered contrast material; and displaying the administered contrast material image.
Claim 7
Dependent Claim
43 words
The method as described in claim 3 wherein the steps for measuring the x-ray transmission at different energy spectra includes the steps of: sequentially varying the energy spectra of the x-ray source; and detecting the transmitted x-ray beam at each x-ray source spectra.
Claim 8
Dependent Claim
59 words
The method as described in claim 3 wherein the steps for measuring the x-ray transmission at different energy spectra includes the steps of: projecting an x-ray beam through the region broad energy spectrum includes each of the individual x-ray energy spectra; and detecting the transmitted x-ray beam using an energy-selective detector providing individual output signals for each energy spectrum.
References Cited (Backward Citations)
US3974386A
Cited
US4029963A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-24 | 1987-10-24 | 1988-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-24 | 1991-10-24 | 1992-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-24 | 1995-10-24 | 1996-04-24 | $7700.00 | Window Closed / Lapsed |