X-ray tomographic inspection systems for the identification of specific target items

• US 10,591,424 B2
• Filed: 06/26/2012
• Issued: 03/17/2020
• Est. Priority Date: 04/25/2003
• Status: Active Grant

• Current Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Original Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Inventors: Morton, Edward James
• Primary Examiner(s): Thomas, Courtney D
• Application Number:
  US13/532,862
• Publication Number:
  US 20130251098A1
• Time in Patent Office: 2,821 Days
• Field of Search: 378 57
• CPC Class Codes: A61B 6/027 characterised by the use of a particular data acquisition trajectory, e.g. helical or spiral
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 2223/639 material in a container
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: H01J 2235/068 Multi-cathode assembly
• CPC Class Codes: H01J 35/04 Electrodes ; Mutual position thereof; Constructional adaptations therefor
• CPC Class Codes: H01J 35/045 Electrodes for controlling the current of the cathode ray, e.g. control grids

Abstract

The present specification discloses an X-ray scanning system with a non-rotating X-ray scanner that generates scanning data defining a tomographic X-ray image of the object and a processor executing programmatic instructions where the executing processor analyzes the scanning data to extract at least one parameter of the tomographic X-ray image and where the processor is configured to determine if the object comprises a liquid, sharp object, narcotic, currency, nuclear materials, cigarettes or fire-arms.

Claims

1. An X-ray scanning system comprising:

an X-ray scanner configured to generate scanning data defining a tomographic X-ray image of an object, wherein the X-ray scanner comprises an imaging volume and a plurality of X-ray sources, positioned at least partially around the imaging volume, from which X-rays are directed through the imaging volume, and wherein the X-ray scanner is configured to mimic a rotational motion of the plurality of X-ray sources without physically moving each of the plurality of X-ray sources; and

at least one processor configured to analyze the scanning data to determine at least one parameter of the tomographic X-ray image and to determine if the object comprises a detonator.

2. The X-ray scanning system of claim 1, wherein the at least one processor is configured to allocate the object to one of a plurality of categories based on the at least one parameter.

3. The X-ray scanning system of claim 1, further comprising a memory storing a plurality of programmatic instructions, wherein the programmatic instructions comprise at least one parameter extractor that, when executed by the at least one processor, is configured to identify at least one predefined feature in the tomographic X-ray image and wherein the predefined feature comprises a plurality of first level parameters of the tomographic X-ray image.

4. The X-ray scanning system of claim 3, wherein the programmatic instructions comprise at least one decision tree for constructing second level parameters based upon the X-ray image.

5. The X-ray system of claim 4, wherein the second level parameters include at least one of a contiguous volume or a predetermined shape.

6. The X-ray scanning system of claim 4, further comprising a plurality of programmatic instructions defining a search tool configured to map the constructed second level parameters of the X-ray image to predefined data.

7. The X-ray scanning system of claim 6, further comprising an alarm system configured to activate an alarm based on a result of mapping the constructed second level parameters of the X-ray image to predefined data, wherein the alarm is indicative of an object being a potential threat.

8. The X-ray scanning system of claim 3, wherein the at least one parameter extractor is configured to operate on at least one of a 2-dimensional image, a 3-dimensional image, or sinogram image data.

9. An X-ray scanning system comprising:

an X-ray scanner configured to generate scanning data defining a tomographic X-ray image of an object, wherein the X-ray scanner comprises an imaging volume and a plurality of X-ray sources, positioned at least partially around the imaging volume, from which X-rays are directed through the imaging volume and wherein the X-ray scanner is configured to mimic a rotational motion of the a plurality of X-ray sources without physically moving each of the plurality of X-ray sources; and

at least one processor configured to analyze the scanning data to determine at least one parameter of the tomographic X-ray image and to determine if the object comprises a gun.

10. The X-ray scanning system of claim 9, wherein the at least one processor is configured to allocate the object to one of a plurality of categories based on the at least one parameter.

11. The X-ray scanning system of claim 9, further comprising a memory storing a plurality of programmatic instructions, wherein the programmatic instructions comprise at least one parameter extractor that, when executed by the at least one processor, is configured to identify at least one predefined feature in the tomographic X-ray image and wherein the predefined feature comprises a plurality of first level parameters of the tomographic X-ray image.

12. The X-ray scanning system of claim 11, wherein the programmatic instructions comprise at least one decision tree for constructing second level parameters based upon the X-ray image.

13. The X-ray system of claim 12, wherein the second level parameters include at least one of a contiguous volume or a predetermined shape.

14. The X-ray scanning system of claim 12, further comprising a plurality of programmatic instructions defining a search tool for configured to map the constructed second level parameters of the X-ray image to predefined data.

15. The X-ray scanning system of claim 14, further comprising an alarm system configured to activate an alarm based on a result of mapping the constructed second level parameters of the X-ray image to predefined data, wherein the alarm is indicative of an object being a potential threat.

16. The X-ray scanning system of claim 11, wherein the at least one parameter extractor is configured to operate on at least one of a 2-dimensional image, a 3-dimensional image or sinogram image data.

17. An X-ray imaging inspection system configured to generate a three dimensional image of at least one object, comprising:

a plurality of X-ray sources distributed at least partially around an imaging volume, wherein the plurality of X-ray sources are configured to emit X-rays which are directed through the imaging volume and wherein the X-ray imaging inspection system is configured to mimic a rotational motion of the plurality of X-ray sources without physically moving each of the plurality of X-ray sources;

an X-ray detector array extending at least partially around the imaging volume and configured to detect X-rays from the plurality of X-ray sources which have passed through the imaging volume and to produce output signals dependent on the detected X-rays;

a conveyor arranged to convey the at least one object through the imaging volume; and

at least one processor configured to analyze the output signals to generate the three dimensional image and determine if the at least one object comprises a security threat.

18. The X-ray imaging inspection system of claim 17, wherein the plurality of X-ray sources is in a plane perpendicular to the direction of movement of the conveyor.

19. The X-ray imaging inspection system of claim 17, wherein each of the plurality of X-ray sources comprises a suppressor and an emitter adjacent the suppressor.

20. The X-ray imaging inspection system of claim 19, wherein each of the plurality of X-ray sources further comprises grid wires positioned above the suppressor and focusing wires parallel to the grid wires.

21. The X-ray imaging inspection system of claim 20, wherein each focusing wire is aligned with a respective grid wires.

22. The X-ray imaging inspection system of claim 20, further comprising an anode positioned above the grid wires and focusing wires.

23. The X-ray imaging inspection system of claim 20, wherein the grid wires are configured to extract a beam of electrons from an area of the emitter.

24. The X-ray imaging inspection system of claim 17, wherein each of the plurality of X-ray sources comprises an extracted beam of electrons configured to be directed at a point on an anode.

25. The X-ray imaging inspection system of claim 20, wherein each of the grid wires are configured to be selectively activated.

26. The X-ray imaging inspection system of claim 25, further comprising a control unit configured to control electrical potentials applied to each of the grid wires to selectively activate each of the grid wires.

27. The X-ray imaging inspection system of claim 17, wherein each of the plurality of X-ray sources emits X-rays for a respective period wherein the respective periods are arranged in a predetermined order.

28. The X-ray imaging inspection system of claim 17, wherein the X-ray detector array is positioned around the imaging volume such that is axially offset from the plurality of X-ray sources.

29. The X-ray imaging inspection system of claim 17, wherein the X-ray detector array comprises a plurality of individual X-ray detectors configured in a linear pattern or ring pattern.

30. The X-ray imaging inspection system of claim 17, wherein the at least one processor is further configured to multiplex the output signals to filter data, adjust gain, and format the data into a data stream.

31. The X-ray imaging inspection system of claim 17, wherein the at least one processor is further configured to generate projection data as a function of an attenuated X-ray beam intensity for X-ray beams emitted from each of the plurality of X-ray sources.

32. The X-ray imaging inspection system of claim 31, wherein the at least one processor is configured to record the projection data as a sinogram arranged in an array with a pixel number along one axis and a source angle along another axis.

33. The X-ray imaging inspection system of claim 17, wherein the at least one processor is a threat detection processor configured to execute one or more parameter extractors that identify at least one parameter in the three dimensional image.

34. The X-ray imaging inspection system of claim 33, wherein the one or more parameter extractors comprise at least one of a grey level or texture.

35. The X-ray imaging inspection system of claim 33, wherein each of the one or more parameter extractors are executed in parallel.

36. The X-ray imaging inspection system of claim 17, wherein the at least one processor is a threat detection processor configured to execute one or more parameter extractors that identify at least one parameter from the three dimensional image, wherein the at least one parameter is passed to a plurality of decision trees.

37. The X-ray imaging inspection system of claim 36, wherein the plurality of decision trees determine a set of information based on the parameters.

38. The X-ray imaging inspection system of claim 37, wherein the set of information comprises at least one of information regarding whether a volume is contiguous, a ratio of a surface area to the volume of an identified region, or a cross-correlation between a shape of the region and template shapes stored in a memory.

39. The X-ray imaging inspection system of claim 37, further comprising a plurality of programmatic instructions that, when executed by the at least one processor, maps the set of information to one of a plurality of threat probabilities.

40. The X-ray imaging inspection system of claim 17, further comprising plurality of programmatic instructions that, when executed by the at least one processor, produces a control output that automatically sorts the at least one object into one of a plurality of categories, wherein the plurality of categories comprises a clear category and a not clear category.

41. The X-ray imaging inspection system of claim 17, wherein the at least one processor is configured to identify parameters in the three dimensional image and wherein the parameters comprise at least one of a mean intensity of pixels within a region of the three dimensional image, a measure of a variance of pixel intensity within the region, or a skewedness of a distribution of pixel values.

42. The X-ray imaging inspection system of claim 41, wherein a non-skewed distribution is indicative of uniform material within the region and a skewed distribution is indicative of non-uniformities in the region.

43. The X-ray imaging inspection system of claim 17, further comprising a workstation configured to display the three dimensional image on a screen and configured to display different sorting decisions using different colors.

44. The X-ray imaging inspection system of claim 17, wherein a speed of scanning the at least one object using the X-ray source is matched to a velocity of the conveyor.

45. The X-ray imaging inspection system of claim 17, wherein the plurality of X-ray sources are configured to extend in a partial arc over the imaging volume.

46. The X-ray imaging inspection system of claim 17, wherein the X-ray source achieves 240 source rotations per second about the conveyor.

47. The X-ray imaging inspection system of claim 17, wherein the conveyor is configured to operate at a speed of 0.5 m/s.

48. The X-ray imaging inspection system of claim 17, wherein the at least one processor is further configured to maximize a distance of an anode irradiation position, relative to a previous anode irradiation position, in order to minimize an instantaneous thermal load on the anode.

49. The X-ray imaging inspection system of claim 17, wherein the X-ray detector array comprises a plurality of scatter detectors.

50. The X-ray imaging inspection system of claim 49, wherein the at least one processor is configured to acquire output signals from the plurality of scatter detectors and reconstruct the output signals from the plurality of scatter detectors into the three dimensional image.

51. The X-ray imaging inspection system of claim 17, wherein the at least one processor is further configured to execute a threat detection algorithm on the three dimensional image.

52. The X-ray imaging inspection system of claim 49, further comprising a collimator positioned in front of each of the plurality of scatter detectors.

53. The X-ray imaging inspection system of claim 17, wherein the X-ray detector array includes a plurality of detectors comprising at least one of GaAs, HgI, CdZnTe or CdTe.

54. The X-ray imaging inspection system of claim 17, wherein the at least one processor is configured to determine a position of a scattering along an X-ray beam direction by a scattered X-ray by identifying an active X-ray source of the plurality of X-ray sources and an axial position of a detector which detects the scattered X-ray.

55. The X-ray imaging inspection system of claim 17, wherein the X-ray detector array comprises a first set of detectors and a second set of detectors and wherein the first set of detectors is positioned at a different axial location along a direction of travel of the conveyor relative to the second set of detectors.

56. The X-ray imaging inspection system of claim 17, wherein the X-ray detector array comprises a first set of detectors and a second set of detectors, wherein the first set of detectors is configured to detect X-rays over a first energy range, wherein the second set of detectors is configured to detect X-rays over a second energy range, and wherein the second energy range is different than the first energy range.

57. The X-ray imaging inspection system of claim 56, wherein the at least one processor is configured to form two sets of image data using the first energy range and the second energy range.

58. The X-ray imaging inspection system of claim 57, wherein the at least one processor is configured to combine the two sets of image data.

59. The X-ray imaging inspection system of claim 56, wherein the at least one processor is configured to record, for each pixel of an image, data for the first energy range and data for the second energy range.

60. The X-ray imaging inspection system of claim 17, wherein the X-ray detector array comprises a first set of detectors and a second set of detectors, wherein the first set of detectors does not comprise a filter, and wherein the second set of detectors comprises a filter.

61. The X-ray imaging inspection system of claim 56, wherein the at least one processor is configured to acquire output signals from the first set of detectors and the second set of detectors and reconstruct the output signals from the first set of detectors and the second set of detectors into the three dimensional image.

62. The X-ray imaging inspection system of claim 17, wherein the at least one processor is further configured to execute a threat detection algorithm on the three dimensional image and wherein the X-ray detector array includes a plurality of detectors comprising at least one of CdZnTe or CdTe.

63. The X-ray imaging inspection system of claim 17, wherein the X-ray detector array comprises a first set of detectors and a second set of detectors, wherein the first set of detectors is sensitive to X-rays of a first energy range, wherein the second set of detectors is sensitive to X-rays of a second energy range, wherein the first energy range is different from the second energy range, wherein the at least one processor is configured to generate the three dimensional image from data generated by the first set of detectors and data generated by the second set of detectors, and wherein the at least one processor is configured to generate a projection image from data generated by the first set of detectors and data generated by the second set of detectors.

64. The X-ray imaging inspection system of claim 17, wherein the X-ray detector array comprises a first set of detectors and a second set of detectors, wherein the first set of detectors is configured to generate data to produce a tomographic image, wherein the second set of detectors is configured to produce a projection image.

65. The X-ray imaging inspection system of claim 64, wherein the projection image is a dual energy projection image.

66. The X-ray imaging inspection system of claim 64, wherein the second set of detectors comprise stacked detectors, wherein detectors on a top side are arranged to detect lower energy X-rays and are transparent to higher energy X-rays, and wherein detectors on a bottom side are arranged to detect the higher energy X-rays.

67. The X-ray imaging inspection system of claim 64, wherein the security threat comprises at least one of a gun or a detonator.

68. An X-ray imaging inspection system configured to generate a three dimensional image of at least one object, comprising:

a plurality of X-ray sources extending at least partially around an imaging volume, wherein the plurality of X-ray sources are configured to emit and direct X-rays through the imaging volume and wherein the X-ray imaging inspection system is configured to mimic a rotational motion of the plurality of X-ray sources without physically moving each of the plurality of X-ray sources;

an X-ray detector array extending at least partially around the imaging volume and configured to detect X-rays from the plurality of X-ray sources which have passed through the imaging volume and to produce output signals dependent on the detected X-rays, wherein the X-ray detector array includes a plurality of detectors comprising at least one of GaAs, HgI, CdZnTe or CdTe;

a conveyor arranged to convey the at least one object through the imaging volume; and

at least one processor configured to analyze the output signals to generate the three dimensional image and identify if the at least one object comprises a security threat; and

a plurality of programmatic instructions that, when executed by the at least one processor, produces a control output that automatically sorts the at least one object into one of a plurality of categories, wherein the plurality of categories comprises a clear category and a not clear category.

69. The X-ray imaging inspection system of claim 68, wherein the at least one processor is configured to form two sets of image data using data having a first energy range and data having a second energy range generated from the plurality of detectors.

70. The X-ray imaging inspection system of claim 69, wherein the at least one processor is configured to combine the two sets of image data.

71. The X-ray imaging inspection system of claim 69, wherein the at least one processor is configured to record, for each pixel of an image, data for the first energy range and data for the second energy range.

72. The X-ray imaging inspection system of claim 68, wherein the at least one processor is further configured to execute a threat detection algorithm on the three dimensional image.

73. The X-ray imaging inspection system of claim 68, wherein the plurality of detectors comprise a first set of detectors and a second set of detectors and wherein the first set of detectors is positioned at a different axial location along a direction of travel of the conveyor relative to the second set of detectors.

74. The X-ray imaging inspection system of claim 68, wherein the plurality of X-ray sources are configured to extend in a partial arc over the imaging volume.

75. The X-ray imaging inspection system of claim 68, wherein the conveyor is configured to operate at a speed of 0.5 m/s.

76. The X-ray imaging inspection system of claim 68, further comprising a workstation configured to display the three dimensional image on a screen and configured to display different sorting decisions using different colors.

77. The X-ray imaging inspection system of claim 68, wherein the at least one processor is a threat detection processor configured to execute one or more parameter extractor that identify at least one parameter in the three dimensional image.

78. The X-ray imaging inspection system of claim 68, wherein the X-ray detector array is positioned at least partially around the imaging volume such that is axially offset from the plurality of X-ray sources.

79. The X-ray imaging inspection system of claim 68, wherein each of the plurality of X-ray sources comprises an extracted beam of electrons configured to be directed at a point on an anode.

80. The X-ray imaging inspection system of claim 68, wherein the security threat comprises at least one of a gun or a detonator.