Three-dimensional image reconstruction using transmission and scatter radiography methods
First Claim
1. A penetrating radiation inspection system comprising:
- at least one internal scanning subsystem having;
a radiation source configured to produce a beam of radiation, the beam having a plurality of rays, the radiation source positioned to direct the beam of radiation into an object for internal inspection during relative translational motion between the at least one internal scanning subsystem and the object; and
at least one detector positioned to at least partially measure an attenuated portion of the beam of radiation; and
a processor configured to convert an estimated density of a portion of the object to a corrected estimated density by;
determining a predicted attenuated portion using a density estimate;
comparing the predicted attenuated portion to the measured attenuated portion to determine a signal difference;
adjusting the density estimate of the portion of the object by scaling the density estimate using signal differences of rays that intersect the portion of the object; and
repeatedly adjusting the density estimate until a difference between consecutive density estimates is below a selected threshold or a predetermined number of adjustments have been completed.
3 Assignments
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Accused Products
Abstract
A method for image reconstruction includes irradiating an object with a beam of radiation from a radiation source, measuring an attenuated portion of the beam, estimating a density of the object, determining a predicted attenuated portion of the beam using the density estimate, and iteratively adjusting the density estimate of the object. The predicted attenuated portion and the measured attenuated portion are compared to determine a signal difference. The density estimate of each portion of the object is adjusted by scaling the density estimate using the average signal differences of rays that intersect the portion of the object. The density estimate may be repeatedly adjusted until a difference between consecutive density estimates is below a selected threshold or a predetermined number of adjustments have been completed. The attenuated portion of the beam may include a scattered portion and a transmitted portion.
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Citations
44 Claims
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1. A penetrating radiation inspection system comprising:
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at least one internal scanning subsystem having; a radiation source configured to produce a beam of radiation, the beam having a plurality of rays, the radiation source positioned to direct the beam of radiation into an object for internal inspection during relative translational motion between the at least one internal scanning subsystem and the object; and at least one detector positioned to at least partially measure an attenuated portion of the beam of radiation; and a processor configured to convert an estimated density of a portion of the object to a corrected estimated density by; determining a predicted attenuated portion using a density estimate; comparing the predicted attenuated portion to the measured attenuated portion to determine a signal difference; adjusting the density estimate of the portion of the object by scaling the density estimate using signal differences of rays that intersect the portion of the object; and repeatedly adjusting the density estimate until a difference between consecutive density estimates is below a selected threshold or a predetermined number of adjustments have been completed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for three-dimensional image reconstruction comprising:
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translating at least one of an object and a radiation source; irradiating the object with a beam of radiation from a radiation source, the beam having a plurality of rays; measuring an attenuated portion of the beam with a first detector in a first perspective; converting an estimated density of a plurality of portions of the object to a corrected estimated density of each portion of the object using a computer system by; determining a predicted attenuated portion of the beam in the first perspective using a density estimate; comparing the predicted attenuated portion in the first perspective to the measured attenuated portion in the first perspective to determine a signal difference of each ray in the first perspective; adjusting the density estimate of the portion of the object by scaling the density estimate using signal differences of rays that intersect the portion of the object; and repeatedly adjusting the density estimate until a difference between consecutive density estimates is below a selected threshold or a predetermined number of adjustments have been completed; and generating a three-dimensional density array representing the object using the corrected estimated densities of the portions of the object. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A method for three-dimensional image reconstruction comprising:
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obtaining a measured attenuated portion of each of at least one beam of radiation, the at least one beam having a plurality of rays, the at least one beam of radiation being from a radiation source and having been attenuated by interaction with an object; converting an estimated density of a plurality of portions of the object to a corrected estimated density of each portion of the object using a computer system by; determining a predicted attenuated portion of the at least one beam using a density estimate; comparing the predicted attenuated portion to the measured attenuated portion to determine a signal difference; adjusting the density estimate of the portion of the object by scaling the density estimate using signal differences of rays that intersect the portion of the object; and repeatedly adjusting the density estimate until a difference between consecutive density estimates is below a selected threshold or a predetermined number of adjustments have been completed; and generating a three-dimensional density array representing the object using the corrected estimated densities of the portions of the object. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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42. A method for three-dimensional image reconstruction comprising:
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obtaining a measured attenuated portion of a beam of radiation, the beam having been attenuated by interaction with an object; determining a predicted attenuated portion of the beam of radiation using a density estimate; iteratively adjusting the density estimate of the object by comparing the predicted attenuated portion and the measured attenuated portion, wherein the predicted attenuated portion is re-determined once the density estimate is adjusted; and generating a three-dimensional density array representing the object using the adjusted density estimate. - View Dependent Claims (43, 44)
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Specification