Radiation scanning units including a movable platform

• US 8,000,436 B2
• Filed: 04/07/2008
• Issued: 08/16/2011
• Est. Priority Date: 07/24/2002
• Status: Expired due to Fees

• Current Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Original Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Inventors: Ford, John, Marc, Marcel, Seppi, Edward J.
• Primary Examiner(s): SONG, HOON K
• Application Number:
  US12/080,860
• Publication Number:
  US 20090067575A1
• Time in Patent Office: 1,226 Days
• Field of Search: 378 4- 20, 378/57
• US Class Current: 378/19
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: G01V 5/226 using tomography

Abstract

A scanning unit for inspecting objects comprises in one example a radiation source, a movable platform to support an object, and a detector positioned to receive radiation after interaction of radiation with the object. The platform is movable at least partially within a cavity defined, at least partially, below at least one of the source or the detector. In another scanning unit, a first conveyor conveys an object to a movable platform, and second and third conveyors convey the object from the platform. The second and third conveyors are at different vertical heights. In another scanning unit, images from an energy sensitive detector and a spatial detector are fused. In a method, scanning parameters during CT scanning are changed and images reconstructed before and after the change. In another method, an object is scanned with X-ray beams having first and second energy distributions, generated by the same X-ray source.

Claims

1. A scanning unit for inspecting objects, comprising:

a platform to support an object;

at least one radiation source to emit a beam of radiation;

a first, energy sensitive detector positioned to detect radiation after interaction of the beam with the object;

a second, spatial detector positioned to receive radiation after interaction of the beam with the object; and

at least one processor configured to;

fuse at least certain of the first and second images generated from radiation detected by the first, energy sensitive detector and the second, spatial detector, respectively.

2. The scanning unit of claim 1, wherein:

the platform is movable at least partially within a cavity defined, at least in part, below at least one of the source or the detector.

3. The scanning unit of claim 2, further comprising means for moving the platform along a substantially vertical axis, at least partially within the cavity.

4. The scanning unit of claim 2, wherein the cavity is defined, at least in part, by ground.

5. The scanning unit of claim 1, wherein the source is a source of X-ray radiation.

6. The scanning unit of claim 1, wherein the first and second detectors are aligned with the source to detect radiation transmitted through the object.

7. The scanning unit of claim 1, further comprising a first conveyor to convey the cargo conveyance to the platform for scanning.

8. The scanning unit of claim 7, further comprising a second conveyor to convey the object from the platform after scanning.

9. The scanning unit of claim 8, wherein the platform is rotatable, the system further comprising:

a third conveyor to convey the object from the platform after scanning;

wherein the rotatable platform is selectively configured to direct an object to the second or third platform, after scanning.

10. The scanning unit of claim 1, further comprising a second radiation source to emit a second radiation beam;

wherein the first radiation source emits a first radiation beam having a first energy distribution and the second radiation source emits a second radiation beam having a second energy distribution different than the first energy distribution.

11. The scanning unit of claim 10, wherein the first energy distribution has a peak in the MeV range and the second energy distribution has a peak in the KeV range.

12. The scanning unit of claim 1, wherein the radiation source is operational to be selectively switched between emitting a radiation beam having a first energy distribution and a radiation beam having a second energy distribution different than the first energy distribution.

13. The scanning unit of claim 1, further comprising:

a first conveyor to convey the object to the platform for scanning;

a second conveyor to convey the object from the platform after scanning, the second conveyor being at a first vertical height; and

a third conveyor to convey the object from the platform after scanning, the third conveyor being at a second vertical height different than the first vertical height;

wherein the platform is configured to selectively direct the object to one of the second conveyor or the third conveyor by moving the platform between the first height and the second height.

14. The scanning unit of claim 13, further comprising a processor configured to cause movement of the platform between the first height and second height to align the object with the second conveyor if the object passes inspection and to align the object with the third conveyor if the object has not passed inspection.

15. The scanning unit of claim 14, further comprising:

a fourth conveyor to selectively convey the object from the platform after scanning and return the object to the platform for rescanning;

wherein the platform is rotatably positionable to selectively align the object with one of the second conveyor and the fourth conveyor.

16. The scanning unit of claim 15, wherein the second conveyor and the fourth conveyor are at the first vertical height.

17. The system of claim 1, wherein the processor is configured to:

reconstruct at least one first image of at least a portion of the object, during operation, based, at least in part, on the detected radiation from the first, energy sensitive detector; and

reconstruct at least one second computed tomographic image of at least a portion of the object, during operation, based, at least in part, on the detected radiation from the first, second detector.

18. The system of claim 17, wherein at least one of the source or the first and second detectors are movable at least partially around the object, during operation.

19. The system of claim 17, wherein the platform is rotatable about an axis and at least one of the source, the platform or the first and second detectors are movable in a direction along a direction of the axis.

20. The system of claim 17, further comprising:

a rotatable gantry, wherein the source and the first and second detectors are supported by the rotatable gantry for movement at least partially around the object, during operation.

21. The system of claim 19, wherein the platform is rotatable about a vertical axis and at least one of the source, the platform or the first and second detectors are moveable along a vertical direction.

22. The system of claim 21, further comprising first and second platforms to support the source and the first and second detectors, respectively, wherein the first and second platforms are moveable along a vertical direction to move the source and the first and second detectors along the vertical direction.

23. The system of claim 1, wherein the platform is rotatable about an axis and at least one of the source, the platform or the first and second detectors are movable in a direction along a direction of the axis.

24. The system of claim 23, wherein the platform is rotatable about a vertical axis and at least one of the source, the platform or the first and second detectors are moveable along a vertical direction.

25. The system of claim 24, further comprising first and second platforms to support the source and the first and second detectors, respectively, wherein the first and second platforms are moveable in a vertical direction to move the source and the first and second detectors along the vertical direction.

26. The system of claim 1, wherein the second, spatial detector is between the first, energy sensitive detector and the radiation source.

27. The system of claim 1, further comprising:

a rotatable gantry, wherein the source and the first and second detectors are supported by the rotatable gantry for movement at least partially around the object, during operation.

28. A method of examining contents of an object, comprising:

scanning an object with a radiation beam;

detecting the radiation beam after interaction with the object with a first, spatial detector;

detecting the radiation beam after interaction with the object with a second, energy sensitive, detector;

generating first images from radiation detected by the first detector;

generating second images from radiation detected by the second detector; and

fusing at least some of the first and second images.

29. The method of claim 28, wherein the second energy sensitive detector is behind the first detector.

30. The method of claim 28, comprising reconstructing computed tomographic images from radiation detected by the first detector.

31. The method of claim 30, further comprising:

generating the radiation beam by a radiation source; and

moving at least one of the source or the first and second detectors at least partially around the object.

32. The method of claim 30, further comprising:

generating the radiation beam by a radiation source;

rotating the platform about a vertical axis; and

moving at least one of the platform, the source or the first and second detectors in along a vertical direction.

33. The method of claim 28, further comprising:

generating the radiation beam by a radiation source;

rotating the platform about an axis; and

moving at least one of the platform, the source or the first and second detectors in a direction along a direction of the axis.

34. The method of claim 28, comprising:

scanning the object with a beam of X-ray radiation.