Radiation scanning of objects for contraband

• US 20070003003A1
• Filed: 09/01/2006
• Published: 01/04/2007
• Est. Priority Date: 07/24/2002
• Status: Active Grant

• Current Assignee: Varex Imaging Corporation
• Original Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Inventors: Ford, John, Marc, Marcel, Seppi, Edward
• Granted Patent: US 7,369,640 B2
• Time in Patent Office: Days
• US Class Current: 378/9
• CPC Class Codes: G01N 2223/423 multispectral imaging-multiple energy imaging
• CPC Class Codes: G01N 23/04 and forming images of the material
• CPC Class Codes: G01T 1/2985 In depth localisation, e.g. using positron emitters; Tomographic imaging (longitudinal and transverse section imaging; apparatus for radiation diagnosis sequentially in different planes, steroscopic radiation diagnosis); using external radiation sources A61B6/02
• CPC Class Codes: G01V 5/226 using tomography

Abstract

In one example, a scanning unit for examining contents of a cargo container is disclosed comprising a first path through the scanning unit for transport of a cargo container and one or more sources of respective beams of radiation. At least one of the one or more sources are movable across a second path transverse to the first path. The second path extends partially around the first path. The scanning unit further comprises a detector extending partially around the first path. The detector is positioned to detect radiation interacting with the cargo container during scanning, such as radiation transmitted through the container. The at least one source and the detector are positioned so that the cargo container is transportable along the first path, between the source and the detector. A transport system may be provided to convey the object through the scanning unit, along the first path.

Claims

1. A scanning unit for examining contents of a cargo container, the scanning unit comprising:

a first path through the scanning unit for transport of a cargo container;

one or more sources of respective beams of radiation, at least one of the one or more sources being movable across a second path transverse to the first path, the second path extending partially around the first path; and

a detector extending partially around the first path, the detector being positioned to detect radiation interacting with the cargo container during scanning;

wherein the at least one source and the detector are positioned so that the cargo container is transportable along the first path, between the source and the detector.

2. The scanning unit of claim 1, wherein the cargo container is supported by a vehicle;

and

the detector and the at least one source of radiation are positioned to allow the cargo container and the vehicle to be transported therebetween.

3. The scanning unit of claim 1, wherein, during operation:

the detector is positionable, at least in part, beneath the first path, below ground; and

the at least one source is positionable above the first path.

4. The scanning unit of claim 1, wherein the second path is arcuate.

5. The scanning unit of claim 4, further comprising:

an arcuate rail along the arcuate second path;

wherein the at least one source is coupled to the arcuate rail.

6. The scanning unit of claim 5, wherein the at least one source is movable with respect to the rail.

7. The scanning unit of claim 5, wherein the rail is movable to move the at least one source along the second path.

8. The scanning unit of claim 5, wherein the arcuate rail forms at least part of a circle.

9. The scanning unit of claim 4, wherein the second path is at least partially circular.

10. The scanning unit of claim 1, comprising at least one energy sensitive detector.

11. The scanning unit of claim 1, further comprising a processor electrically coupled to the detector, the processor being programmed to reconstruct computed tomography images based, at least in part, on data received from the detector.

12. The scanning unit of claim 11, wherein:

the second path and the detector extend sufficiently around the object to collect sufficient data for computed tomographic imaging.

13. The scanning unit of claim 1, further comprising a transport system to convey the object through the scanning unit, along the first path.

14. The scanning unit of claim 1, wherein each of the at least one sources is a linear accelerator.

15. The scanning unit of claim 1, wherein the at least one source is mechanically movable across the second path.

16. The scanning unit of claim 15, comprising:

a plurality of sources, each mechanically movable across a single, common path.

17. The scanning unit of claim 1, wherein the detector is stationary.

18. The scanning unit of claim 1, wherein the at least one source is adapted to generate radiation of at least 1 MeV.

19. The scanning unit of claim 1, wherein the at least one source and the detector are positioned to scan a cargo container having a height and/or width of at least about 1.5 meters.

20. The scanning unit of claim 1, wherein the at least one of the one or more sources are adapted to scan the cargo container with two different energy distributions.

21. The scanning unit of claim 20, wherein at least one of the one or more sources are operational to selectively switch between emitting radiation having a first energy distribution and radiation having a second energy distribution different than the first energy distribution.

22. The scanning unit of claim 20, wherein at least one of the one or more sources emits radiation having a first energy distribution and at least one of the one or more sources emits radiation having a second energy distribution different than the first energy distribution.

23. The scanning unit of claim 20, further comprising a second, energy sensitive, detector;

wherein the first detector is between the second detector and the at least one source.

24. The scanning unit of claim 23, further comprising a processor electrically coupled to the first detector and the second detector, the processor being programmed to:

reconstruct computed tomography images based on data received from the first detector;

reconstruct energy based images based on data received from the second detector; and

fuse the images based on data from the first detector with the images based on the data received from the second detector.

25. The scanning unit of claim 1, wherein the detector is positioned to detect radiation transmitted through the cargo container.

26. A method of examining contents of a cargo container, comprising:

moving at least one radiation source with respect to a cargo container;

scanning at least a portion of the cargo container with at least one radiation beam from the at least one radiation source at a plurality of angles;

detecting radiation interacting with the cargo container; and

reconstructing images based, at least in part, on the detected radiation.

27. The method of claim 26, further comprising:

processing data based on the detected radiation to form computed tomographic images of at least the portion of the cargo container.

28. The method of claim 26, comprising:

moving the at least one source in a first direction; and

moving the cargo container along a path in a second direction transverse to the first direction.

29. The method of claim 26, further comprising:

detecting radiation transmitted through the cargo container by a stationary detector.

30. The method of claim 26, comprising:

scanning the cargo container with a radiation beam having a first energy distribution; and

scanning the cargo container with a radiation beam having a second energy distribution different from the first energy distribution.

31. The method of claim 30, comprising:

detecting radiation with a first, spatial detector;

detecting radiation with a second, energy sensitive, detector; and

processing data based on the detected radiation from the first and second detectors to form respective computed tomographic images of the cargo container.

32. The method of claim 31, comprising:

fusing corresponding computed tomographic images from the radiation detected from the first and second detectors.

33. The method of claim 26, comprising scanning a cargo container having a height and/or width of at least about 1.5 meters.

34. The method of claim 26, wherein the cargo container is supported by a vehicle during scanning.

35. The method of claim 26, comprising:

moving the at least one source along a single arc extending only partially around the cargo container.

36. The method of claim 26, comprising:

moving the one or more sources along a rail.

37. The method of claim 26, wherein:

the rail extends only partially around the object.

38. A scanning unit for examining contents of a cargo container, the scanning unit comprising:

a first path through the scanning unit for transport of a cargo container;

one or more sources of respective beams of radiation, at least one of the one or more sources being movable across a second path transverse to the first path, the second path extending at least partially around the first path; and

a detector extending at least partially around the first path, the detector being positioned to detect radiation interacting with the cargo container during scanning;

wherein the at least one source and the detector are positioned so that the cargo container is transportable along the first path, between the source and the detector.