Patent US4559634A successfully refreshed from Google Patents.
Patent US6000847A successfully refreshed from Google Patents.
US6000847A
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Regulation technique for densitometric correction
Assignee: Cedars-Sinai Medical Center
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Filing: 1998-04-07
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Granted: 1999-12-14
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Expires: 2018-04-07
Abstract
Abstract In a method and apparatus for scatter-glare correction in x-ray diagnostic images from a patient, a densitometric calibration phantom that reduces x-ray beam hardening effects. The calibration phantom is constructed from x-ray absorbing specks narrower than the x-ray aperture but thicker in the x-ray direction than the half-value thickness for diagnostic energy photons, the specks being aligned with the fan beams of x-rays from the x-ray source.
Inventors
- 👤 Robert Alan Close
- 👤 James Stuart Whiting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:42
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/02; G01N23/04; A; A61; A61B; A61B6/00; A61B6/52; A61B6/5258; A61B6/5282; G01N23/046; G01N2223/00; G01N2223/40; G01N2223/419; G01N2223/60; G01N2223/612
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
124 words
A calibration phantom for an x-ray imaging system for removing image degradation effects, the x-ray imaging system using x-rays within an energy range from an x-ray source having an aperture size, wherein the phantom comprises: at least two opposed surfaces; and a plurality of elongated members made of an x-ray attenuating material and lying between the surfaces, the elongated members having lengths longer than the half-value thickness of the material for x-ray photons within the energy range, and widths narrower than the aperture size of the x-ray source, the elongated members being arranged in appropriate spatial positions and orientations such that the longest dimension of each elongated member is aligned in the direction of the x-ray beam at the spatial position of that member.
Claim 2
Dependent Claim
124 words
A calibration phantom for an x-ray imaging system for removing image degradation effects, the x-ray imaging system using x-rays within an energy range from an x-ray source having an aperture size, wherein the phantom comprises: at least two opposed surfaces; and a plurality of elongated members made of an x-ray attenuating material and lying between the surfaces, the elongated members having lengths longer than the half-value thickness of the material for x-ray photons within the energy range, and widths narrower than the aperture size of the x-ray source, the elongated members being arranged in appropriate spatial positions and orientations such that the longest dimension of each elongated member is aligned in the direction of the x-ray beam at the spatial position of that member.
Claim 3
Independent Claim
198 words
A method for constructing a calibration phantom for an x-ray imaging system for removing image degradation effects, the x-ray imaging system using x-rays within an energy range from an x-ray source having an aperture size, the method comprises: providing a container having a flat bottom surface, the bottom surface defining a plurality of holes forming a first pattern; providing a flat plate below the container and parallel to the bottom surface thereof, the plate defining a plurality of holes forming a second pattern, the second pattern being similar to the first pattern but having a smaller scale, wherein each hole on the plate corresponds to a hole on the bottom of the container; passing a wire made of an x-ray absorbing material through each hole on the bottom of the container and the corresponding hole on the plate, the wire having a diameter smaller than the aperture size of the x-ray source; filling the container with an appropriate amount of liquid encasing material to a depth larger than the half-value thickness of the x-ray absorbing material for x-ray photons within the energy range; and removing the ends of the wires protruding from the encasing material after it hardens.
Claim 4
Independent Claim
198 words
A method for constructing a calibration phantom for an x-ray imaging system for removing image degradation effects, the x-ray imaging system using x-rays within an energy range from an x-ray source having an aperture size, the method comprises: providing a container having a flat bottom surface, the bottom surface defining a plurality of holes forming a first pattern; providing a flat plate below the container and parallel to the bottom surface thereof, the plate defining a plurality of holes forming a second pattern, the second pattern being similar to the first pattern but having a smaller scale, wherein each hole on the plate corresponds to a hole on the bottom of the container; passing a wire made of an x-ray absorbing material through each hole on the bottom of the container and the corresponding hole on the plate, the wire having a diameter smaller than the aperture size of the x-ray source; filling the container with an appropriate amount of liquid encasing material to a depth larger than the half-value thickness of the x-ray absorbing material for x-ray photons within the energy range; and removing the ends of the wires protruding from the encasing material after it hardens.
Claim 5
Independent Claim
125 words
A method for constructing a calibration phantom for an x-ray imaging system for removing image degradation effects, the x-ray imaging system using x-rays within an energy range from an x-ray source having an aperture size, the method comprises: providing a container having a flat bottom; placing segments of wires shorter than a predetermined length on the bottom of the container, the wires being magnetic and made of an x-ray absorbing material; apply a strong magnetic field with diverging field lines to the wire segments to align the wire segments into a diverging pattern; and filling the container with an appropriate amount of liquid encasing material to a depth larger than the half-value thickness of the x-ray absorbing material for x-ray photons within the energy range.
Claim 6
Independent Claim
125 words
A method for constructing a calibration phantom for an x-ray imaging system for removing image degradation effects, the x-ray imaging system using x-rays within an energy range from an x-ray source having an aperture size, the method comprises: providing a container having a flat bottom; placing segments of wires shorter than a predetermined length on the bottom of the container, the wires being magnetic and made of an x-ray absorbing material; apply a strong magnetic field with diverging field lines to the wire segments to align the wire segments into a diverging pattern; and filling the container with an appropriate amount of liquid encasing material to a depth larger than the half-value thickness of the x-ray absorbing material for x-ray photons within the energy range.
References Cited (Backward Citations)
US5493601A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-12-13 | 2003-06-14 | 2003-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-12-13 | 2007-06-14 | 2007-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-12-13 | 2011-06-14 | 2011-12-14 | $7700.00 | Window Closed / Lapsed |