Tetrahedron beam computed tomography

• US 7,760,849 B2
• Filed: 04/12/2007
• Issued: 07/20/2010
• Est. Priority Date: 04/14/2006
• Status: Active Grant

• Current Assignee: William Beaumont Hospital (Beaumont Health)
• Original Assignee: William Beaumont Hospital (Beaumont Health)
• Inventors: Zhang, Tiezhi
• Primary Examiner(s): KAO, CHIH CHENG G
• Application Number:
  US11/786,781
• Publication Number:
  US 20070280408A1
• Time in Patent Office: 1,195 Days
• Field of Search: 378/4, 378/9, 378/11, 378/12, 378/14, 378/16, 378/21, 378/22
• US Class Current: 378/4
• CPC Class Codes: A61B 6/025 Tomosynthesis
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/06 Diaphragms
• CPC Class Codes: A61B 6/4028 resulting in acquisition of views from substantially different positions, e.g. EBCT
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: A61B 6/4405 the apparatus being movable or portable, e.g. handheld or mounted on a trolley
• CPC Class Codes: A61B 6/4441 the rigid structure being a C-arm or U-arm
• CPC Class Codes: A61B 6/4488 Means for cooling A61B6/045 takes precedence
• CPC Class Codes: A61B 6/466 adapted to display 3D data
• CPC Class Codes: A61B 6/583 using calibration phantoms
• CPC Class Codes: G21K 1/025 using multiple collimators, e.g. Bucky screens; other devices for eliminating undesired or dispersed radiation
• CPC Class Codes: H01J 2235/062 Cold cathodes
• CPC Class Codes: H01J 2235/068 Multi-cathode assembly
• CPC Class Codes: H05G 1/70 Circuit arrangements for X-ray tubes with more than one anode; Circuit arrangements for apparatus comprising more than one X ray tube or more than one cathode H05G1/58 takes precedence

Abstract

A method of imaging an object that includes directing a plurality of x-ray beams in a fan-shaped form towards an object, detecting x-rays that pass through the object due to the directing a plurality of x-ray beams and generating a plurality of imaging data regarding the object from the detected x-rays. The method further includes forming either a three-dimensional cone-beam computed tomography, digital tomosynthesis or Megavoltage image from the plurality of imaging data and displaying the image.

Claims

1. A cone-beam computed tomography system comprising:

an x-ray source that emits an x-ray beam;

a slot that intercepts said x-ray beam so that a plurality of fan-shaped x-ray beams emanate from said slot towards an object, wherein said slot moves relative to said x-ray source;

a detector receiving fan-shaped x-rays after said fan-shaped x-rays pass through said object, said detector generating an imaging signal for each of said received fan-shaped x-rays; and

a computer connected to said detector so as to receive said imaging signals for each of said received fan-shaped x-rays, wherein said x-ray source, said slot and said detector rotate about said object so that multiple imaging signals are reconstructed by said computer to generate a three-dimensional cone-beam computed tomography image therefrom; and

a display connected to said computer and displaying said three-dimensional cone-beam computed tomography image.

2. The cone-beam computed tomography system of claim 1, wherein said x-ray source comprises a kV x-ray source.

3. The cone-beam computed tomography system of claim 1, wherein said slot rotates about said x-ray source.

4. The cone-beam computed tomography system of claim 1, wherein said slot is stationary with respect a housing that contains said x-ray source.

5. The cone-beam computed tomography system of claim 4, wherein said x-ray source comprises an anode and a cathode, wherein said cathode emits electrons which strike multiple, discrete areas of space occupied by said anode.

6. The cone-beam computed tomography system of claim 1, wherein said detector is a flat panel imager.

7. The cone-beam computed tomography system of claim 6, wherein said flat panel imager comprises an array of amorphous silicon detector elements.

8. The cone-beam computed tomography system of claim 7, wherein said array is a two-dimensional array.

9. The cone-beam computed tomography system of claim 1, wherein said x-ray source comprises an anode and a cathode, wherein said cathode emits electrons which strike a single area of space occupied by said anode.

10. The cone-beam computed tomography system of claim 1, wherein said x-ray source comprises an anode and a cathode, wherein said cathode emits electrons which strike multiple, discrete areas of space occupied by said anode.

11. The cone-beam computed tomography system of claim 1, wherein said computer causes said detector to read only certain areas of said detector for each fan-shaped x-ray beam received.

12. The cone-beam computed tomography system of claim 1, wherein said x-ray source comprises a source of particles that strike a target, wherein an intensity of each of said plurality of fan-shaped x-ray beams is modulated by modulating a current of said particles striking said target.

13. A method of imaging an object, comprising:

i) emitting from an x-ray source a plurality of x-ray beams in fan-shaped form towards the object and imaging data is generated that is a two-dimensional image of said object generated from detecting said plurality of x-ray beams and wherein said emitting comprises collimating a single x-ray beam with a moving collimator that moves relative to said single x-ray beam so as to generate said plurality of x-ray beams;

ii) detecting x-rays that pass through said object due to said emitting an x-ray beam with a detector;

iii) generating image data regarding said object from said detected x-rays; and

iv) rotating said x-ray source and said detector relative to said object and continuously repeating steps i)-iv) until a sufficient number of imaging data regarding said object is generated so as to form a three-dimensional cone-beam computed tomography image therefrom;

forming a three-dimensional cone-beam computed tomography image from said sufficient number of imaging data; and

displaying said three-dimensional cone-beam computed tomography image.

14. The method of claim 13, wherein said three-dimensional cone-beam computed tomography image is formed from at most one full rotation of said x-ray source and detector about said object.

15. The method of claim 13, wherein said moving collimator rotates.

16. The method of claim 13, wherein said emitting comprises sequentially forming x-ray beams off of different areas of an anode of said x-ray source.

17. The method of claim 16, wherein said emitting comprises sequentially forming x-ray beams off of said different areas of said anode by sequentially directing electrons from a single cathode of said x-ray source towards said different areas.

18. The method of claim 13, wherein said x-ray beam has an energy in a kilovolt range.

19. The method of claim 13, further comprising modulating intensities of each of said plurality of fan-shaped x-ray beams by modulating a current of particles striking a target that generate said plurality of fan-shaped x-ray beams.

20. A method of imaging an object, comprising:

directing a plurality of x-ray beams in a fan-shaped form towards an object, wherein said directing comprises collimating a single x-ray beam with a moving collimator that moves relative to said single x-ray beam so as to generate said plurality of x- ray beams;

detecting x-rays that pass through said object due to said directing said plurality of x-ray beams;

generating a plurality of imaging data regarding said object from said detected x-rays;

forming a three-dimensional cone-beam computed tomography image from said plurality of imaging data; and

displaying said three-dimensional cone-beam computed tomography image.

21. The method of claim 20, wherein said moving collimator rotates.

22. The method of claim 20, wherein said directing comprises sequentially forming x-ray beams off of different areas of an anode of an x-ray source.

23. The method of claim 22, wherein said directing comprises sequentially forming x-ray beams off of said different areas of said anode by sequentially directing electrons from a single cathode of said x-ray source towards said different areas.

24. The method of claim 20, wherein said x-ray beam has an energy in a kilovolt range.

25. A digital tomosynthesis system comprising:

an x-ray source that emits an x-ray beam;

a slot that intercepts said x-ray beam so that a plurality of fan-shaped x-ray beams emanate from said slot towards an object, wherein said slot moves relative to said x-ray source;

a detector receiving fan-shaped x-rays after they pass through said object, said detector generating an imaging signal for each of said received fan-shaped x-rays; and

a computer connected to said detector so as to receive said imaging signals for each of said received fan-shaped x-rays, wherein said x-ray source, said slot and said detector rotate about said object so that multiple imaging signals are reconstructed by said computer to generate a digital tomosynthesis image therefrom; and

a display connected to said computer and displaying said digital tomosynthesis image.

26. The digital tomosynthesis system of claim 25, wherein said x-ray source comprises a kV x-ray source.

27. The digital tomosynthesis system of claim 25, wherein said detector is a flat panel imager.

28. The digital tomosynthesis system of claim 25, wherein said x-ray source comprises an anode and a cathode, wherein said cathode emits electrons which strike a single area of space occupied by said anode.

29. The digital tomosynthesis system of claim 25, wherein said x-ray source comprises an anode and a cathode, wherein said cathode emits electrons which strike multiple, discrete areas of space occupied by said anode.

30. The digital tomosynthesis system of claim 25, wherein said x-ray source comprises a source of particles that strike a target, wherein an intensity of each of said plurality of fan-shaped x-ray beams is modulated by modulating a current of said particles striking said target.

31. A method of imaging an object, comprising:

i) emitting from an x-ray source an x-ray beam in a fan-shaped form towards an object, wherein said emitting comprises moving a slot relative to said x-ray source;

ii) detecting x-rays that pass through said object due to said emitting an x-ray beam with a detector;

iii) generating image data regarding said object from said detected x-rays; and

iv) rotating said x-ray source and said detector relative to said object and continuously repeating steps i)-iv) until a sufficient number of imaging data regarding said object is generated so as to form a digital tomosynthesis image therefrom;

forming a digital tomosynthesis image from said sufficient number of imaging data; and

displaying said digital tomosynthesis image.

32. The method of claim 31, wherein said x-ray beam has an energy in a kilovolt range.

33. The method of claim 31, wherein said emitting comprises emitting a plurality of x-ray beams in fan-shaped form towards the object, said method further comprising modulating intensities of each of said plurality of fan-shaped x-ray beams by modulating a current of particles striking a target that generate said plurality of fan-shaped x-ray beams.

34. A tetrahedron beam computed tomography system comprising:

an x-ray source that sequentially emits a plurality of x-ray beams at different positions along a scanning direction;

a collimator that intercepts said plurality of x-ray beams so that a plurality of fan-shaped x-ray beams emanate from said collimator towards an object, wherein said plurality of fan-shaped x-ray beams form a tetrahedron volume;

a detector receiving fan-shaped x-rays after said fan-shaped x-rays pass through said object, said detector generating an imaging signal for each of said received fan-shaped x-rays; and

a computer connected to said detector so as to receive said imaging signals for each of said received fan-shaped x-rays, wherein said x-ray source, said collimator and said detector rotate about said object so that multiple imaging signals are reconstructed by said computer to generate a three-dimensional tetrahedron beam computed tomography image therefrom; and

a display connected to said computer and displaying said three-dimensional quasi-cone-beam computed tomography image.

35. The tetrahedron beam computed tomography system of claim 34, wherein said x-ray source comprises a kV x-ray source.

36. The tetrahedron beam computed tomography system of claim 34, wherein said collimator comprising a plurality of slots, wherein each of said plurality of said slots corresponds to one of said different positions.

37. The tetrahedron beam computed tomography system of claim 36, wherein said collimator is stationary with respect to said x-ray source.

38. The tetrahedron beam computed tomography system of claim 34, wherein said detector is a one-dimensional array of individual detector elements.

39. The tetrahedron beam computed tomography system of claim 38, wherein said collimator focuses said fan-shaped x-ray beams onto said detector.

40. The tetrahedron beam computed tomography system of claim 34, wherein said x-ray source comprises an anode and a plurality of distinct cathodes aligned along said scanning direction, wherein each of said plurality of cathodes emits electrons which strike areas of space occupied by said anode that correspond to said different positions.

41. The tetrahedron beam computed tomography system of claim 34, wherein said x-ray source comprises an anode and a single cathode-aligned along said scanning direction, wherein electrons are emitted from different areas of said single cathode so as to strike areas of space occupied by said anode that correspond to said different positions.

42. The tetrahedron beam computed tomography system of claim 34, further comprising a controller to control said x-ray source to sequentially emit said plurality of x-ray beams at said different positions along said scanning direction.

43. A quasi-cone-beam computed tomography system comprising:

an x-ray source that sequentially emits a plurality of x-ray beams at different positions along a scanning direction;

a collimator that intercepts said plurality of x-ray beams so that a plurality of fan-shaped x-ray beams emanate from said collimator towards an object;

a detector receiving fan-shaped x-rays after said fan-shaped x-rays pass through said object, said detector generating an imaging signal for each of said received fan- shaped x-rays wherein said detector is a one-dimensional array of individual detector elements; and

a computer connected to said detector so as to receive said imaging signals for each of said received fan-shaped x-rays, wherein said x-ray source, said collimator and said detector rotate about said object so that multiple imaging signals are reconstructed by said computer to generate a three-dimensional quasi-cone-beam computed tomography image therefrom; and

a display connected to said computer and displaying said three-dimensional quasi-cone-beam computed tomography image; and

wherein said collimator focuses said fan-shaped x-ray beams onto said detector.

44. A quasi-cone-beam computed tomography system comprising:

an x-ray source that sequentially emits a plurality of x-ray beams at different positions along a scanning direction;

a collimator that intercepts said plurality of x-ray beams so that a plurality of fan-shaped x-ray beams emanate from said collimator towards an object;

a detector receiving fan-shaped x-rays after said fan-shaped x-rays pass through said object, said detector generating an imaging signal for each of said received fan- shaped x-rays and said detector is linear that extends along a direction perpendicular to said scanning direction; and

a computer connected to said detector so as to receive said imaging signals for each of said received fan-shaped x-rays, wherein said x-ray source, said collimator and said detector rotate about said object so that multiple imaging signals are reconstructed by said computer to generate a three-dimensional quasi-cone-beam computed tomography image therefrom; and

a display connected to said computer and displaying said three-dimensional quasi-cone-beam computed tomography image.

45. The quasi-cone-beam computed tomography system of claim 44, wherein said x-ray source comprises a kV x-ray source.

46. The quasi-cone-beam computed tomography system of claim 44, wherein said collimator comprising a plurality of slots, wherein each of said plurality of said slots corresponds to one of said different positions.

47. The quasi-cone-beam computed tomography system of claim 46, wherein said collimator is stationary with respect to said x-ray source.

48. The quasi-cone-beam computed tomography system of claim 44, wherein said detector is a one-dimensional array of individual detector elements.

49. The quasi-cone-beam computed tomography system of claim 44, wherein said plurality of fan-shaped x-ray beams form a tetrahedron volume.