X-ray backscatter system for imaging at shallow depths
First Claim
1. An apparatus for x-ray imaging of a target region of an object at shallow depths comprising:
- (a) an x-ray source generating a cone beam at least one peak voltage in the range of from approximately 10 keV to approximately 500 keV;
(b) a planar template receiving said cone beam, said template in the range of from approximately 2.5 cm to approximately 30 cm from said source, said template having a pinhole with a width and an area in the range of from approximately 0.01 mm2 to approximately 4 mm2, said template passing only said x-rays impinging on said pinhole as a pencil beam;
(c) means for moving said template in the plane of said template in increments of approximately one half of said pinhole width so as to scan said target region with a spatial resolution of one half of said pinhole width; and
(d) a detector having a scintillator with a thickness in the range of from approximately 0.5 mm to approximately 3 cm, said scintillator having an opening through which said pencil beam passes to said target region, said scintillator being adapted to be located adjacent to said target region;
(e) whereby, as said pencil beam scans said target region, backscatter x-rays from said target region are received by said scintillator, which are used to form images of said target region.
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Accused Products
Abstract
The apparatus has an x-ray source that emits an x-ray cone beam through a tubular, x-ray-blocking guide to a planar template with a small pinhole to produce a pencil beam. The template is movable so the pencil beam can scan the target region to be imaged. Between the template and target region is an x-ray detector assembly with a plastic scintillator. The scintillator has an opening about the same size and shape as the target region that allows the pencil beam to pass to the target region. Photo-multiplier detectors receive the light generated by the backscattered x-rays in the scintillator. The method of the present invention employs the apparatus. Multiple x-rays source locations permit the generation of 3D images.
18 Citations
19 Claims
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1. An apparatus for x-ray imaging of a target region of an object at shallow depths comprising:
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(a) an x-ray source generating a cone beam at least one peak voltage in the range of from approximately 10 keV to approximately 500 keV; (b) a planar template receiving said cone beam, said template in the range of from approximately 2.5 cm to approximately 30 cm from said source, said template having a pinhole with a width and an area in the range of from approximately 0.01 mm2 to approximately 4 mm2, said template passing only said x-rays impinging on said pinhole as a pencil beam; (c) means for moving said template in the plane of said template in increments of approximately one half of said pinhole width so as to scan said target region with a spatial resolution of one half of said pinhole width; and (d) a detector having a scintillator with a thickness in the range of from approximately 0.5 mm to approximately 3 cm, said scintillator having an opening through which said pencil beam passes to said target region, said scintillator being adapted to be located adjacent to said target region; (e) whereby, as said pencil beam scans said target region, backscatter x-rays from said target region are received by said scintillator, which are used to form images of said target region. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for x-ray imaging a target region of an object at shallow depths comprising the steps of:
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(a) providing, in the following order, an x-ray source, a planar template having a pinhole having an area in the range of from approximately 0.01 mm2 to approximately 4 mm2, and a detector assembly with a scintillator parallel to said template and having a thickness in the range of from approximately 0.5 mm to approximately 3 cm, said scintillator being adapted to be located adjacent to said target region; (b) said x-ray source emitting an x-ray cone beam to said template at least one peak voltage in the range of from approximately 10 keV to approximately 500 keV, (c) said template blocking said x-ray cone beam except at said pinhole, said pinhole passing said x-ray cone beam as a pencil beam; (d) said pencil beam passing through an opening in said scintillator and impinging on said target region; (e) moving said template in the plane of said template such that said pencil beam scans said target region; (f) said scintillator receiving backscatter x-rays from said target region; and (g) forming images of said target region from said backscatter x-rays. - View Dependent Claims (8, 9, 10, 11)
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12. A method for x-ray imaging a target region of an object at shallow depths comprising the steps of:
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(a) providing, in the following order, at least three x-ray sources at different locations, a planar template having a pinhole having an area in the range of from approximately 0.01 mm2 to approximately 4 mm2, and a detector assembly with a scintillator parallel to said template and having a thickness in the range of from approximately 0.5 mm to approximately 3 cm, said scintillator being adapted to be located adjacent to said target region; (b) each of said x-ray sources emitting x-ray cone beams successively to said template at least one peak voltage in the range of from approximately 10 keV to approximately 500 keV; (c) said template blocking each of said x-ray cone beams except at said pinhole, said pinhole passing each of said x-ray cone beams as a pencil beam; (d) each of said pencil beams passing through an opening in said scintillator sheet and impinging on said target region; (e) moving said template in the plane of said template such that each of said pencil beams scans said target region; (f) said scintillator receiving backscatter x-rays from said target region; and (g) forming images of said target region from said backscatter x-rays from said x-ray sources. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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Specification