Three-dimensional and tomographic imaging device for x-ray and gamma-ray emitting objects

• US 4,521,688 A
• Filed: 01/21/1983
• Issued: 06/04/1985
• Est. Priority Date: 01/21/1983
• Status: Expired due to Fees

• Current Assignee: Tri State Oil Tools Inc (Baker Hughes Company)
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Yin, Lo I.
• Primary Examiner(s): Anderson, Bruce C.
• Assistant Examiner(s): Hannaher, Constantine
• Application Number:
  US06/459,842
• Time in Patent Office: 865 Days
• Field of Search: 378/2, 250/363 S, 250/369
• US Class Current: 250/363.04
• CPC Class Codes: A61B 6/037 Emission tomography
• 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: H05G 1/60 Circuit arrangements for obtaining a series of X-ray photographs or for X-ray cinematography

Abstract

An instrument for obtaining quantitative, three-dimensional and tomographic information relating to x-ray and gamma-ray emitting objects and for the orthoscopic viewing of such objects includes a multiple-pinhole aperture plate (22) held spaced from an x-ray or gamma-ray to visible-light converter (24) which is coupled to a visible-light image intensifier (26). The spacing between the aperture plate and the converter is chosen such that the mini-images of an emitting object formed by the pinholes do not substantially overlap as they impinge on the converter. The output of the image intensifier is digitized by a digitizing camera (36) in terms of position and intensity and fed into a digital computer (40,42). The computer may output quantitative information relating to the emitting object directly, such as that relating to tomograms, or provide information in analogue form when coupled with a suitable viewing device (52,54), to give an orthoscopic, three-dimensional image of the object.

Claims

1. An instrument for obtaining quantitative, three-dimensional and tomographic information relating to x-ray and gamma-ray emitting objects, and for the orthoscopic viewing of such objects, comprising:

means for forming incident x-rays and gamma-rays emitted by an object into an array of substantially nonoverlapping mini-images of said object;

means spatially displaced from said forming means for converting said x-ray and gamma-ray mini-images into visible-light mini-images;

means coupled to said converting means for intensifying said visible-light mini-images;

means to digitize said intensified visible-light mini-images;

computing means for processing said digitized mini-images for tomographic and three-dimensional reconstruction of said object; and

viewing means for direct orthoscopic, three-dimensional viewing of the reconstructed x-ray and gamma-ray emitting object.

2. The instrument of claim 1 wherein said forming means is a pinhole array.

3. The instrument of claim 2 wherein said pinhole array is formed from material which is impervious to x-rays and gamma rays.

4. The instrument of claim 2 wherein the diameter of the pinholes of said pinhole array is sufficiently large for adequate collection efficiency while being sufficiently small for adequate resolution.

5. The instrument of claim 2 wherein said pinhole array is formed in a predetermined pattern.

6. The instrument of claim 5 wherein said predetermined pattern does not produce substantially overlapping mini-images of said objects on said converting means.

7. The instrument of claim 1 wherein said converting means is any scintillation or phosphor material capable of converting x-rays and gamma rays into visible light.

8. The instrument of claim 1 wherein said converting means is directly coupled to said intensifying means.

9. The instrument of claim 8 wherein said direct coupling is through a fiber optics plate.

10. The instrument of claim 9 wherein said fiber optics plate is tapered.

11. The instrument of claim 1 wherein said converting means is coupled to said intensifying means through a lens system.

12. The instrument of claim 1 wherein said converting means is located within said intensifying means.

13. The instrument of claim 1 wherein said intensifying means is a visible-light intensifier with a visible-light output.

14. The instrument of claim 1 wherein said intensifying means includes electron multiplication means.

15. The instrument of claim 1 wherein said intensifying means does not include electron multiplication means.

16. The instrument of claim 14 wherein said electron multiplication means includes at least one micro-channel plate multiplier.

17. The instrument of claim 1 wherein said intensifying means includes an output image size of substantially the same size as the array of mini-images impinging on the input of said intensifying means.

18. The instrument of claim 1 wherein said intensifying means outputs an image size different from that of the array of mini-images impinging on the input of said intensifying means.

19. The instrument of claim 18 wherein said output image size is less than said array of input mini-images.

20. The instrument of claim 18 wherein said output image size is greater than said array of input mini-images.

21. The instrument of claim 1 wherein said digitizing means is a digitizing anode of said intensifying means.

22. The instrument of claim 1 wherein said digitizing means converts the output of said intensifying means to digital words relating to the position and intensity of said mini-images.

23. The instrument of claim 1 wherein said digitizing means is a visible-light digitizing videocamera optically coupled to said intensifying means and wherein said intensifying means provides a visible-light output.

24. The instrument of claim 23 wherein said optical coupling is through a fiber optics plate.

25. The instrument of claim 24 wherein said fiber optics plate is tapered.

26. The instrument of claim 23 wherein said optical coupling is through a lens system.

27. The instrument of claim 23 wherein said digitizing camera is directly coupled to said intensifying means.

28. The instrument of claim 2 wherein said computing means processes said digitized mini-images by inverting said digitized images about their respective pinhole position.

29. The instrument of claim 2 wherein said computing means reconstructs said object through back-projection of said mini-images through their respective pinholes by computation techniques.

30. The instrument of claim 1 wherein said computing means develops tomograms of said object from said mini-images through computation techniques.

31. The instrument of claim 8 wherein said coupling is a lens system combined with a fiber optics plate.

32. The instrument of claim 1 wherein said intensifying means provides an output which inverts said array of mini-images appearing at its input.

33. The instrument of claim 1 wherein said intensifying means provides an output which is proportional to the energy of the x-rays and gamma rays emitted by said object.

34. The instrument of claim 33 wherein said digitizing means converts the output of said intensifying means to digital words relating to said energy of said x-rays and gamma-rays in addition to the position and intensity of said mini-images.

35. The instrument of claim 1 wherein said intensifying means is coupled to said digitizing means by a combination of a lens system and a fiber optics plate.

36. The instrument of claim 1 wherein said computing means includes storage means.

37. The instrument of claim 36 wherein said storage means includes a magnetic medium.

38. The instrument of claim 28 wherein said inverted mini-images are converted to analogue signals.

39. The instrument of claim 38 wherein said analogue signals are processed into a transparency with an appropriate grey-scale corresponding to said signals, said transparency being part of said viewing means.

40. The instrument of claim 38 wherein said analogue signals are processed into a false color transparency where the colors correspond to the energies of said x-rays and gamma rays of said emitting objects, said transparency being part of said viewing means.

41. The instrument of claim 38 wherein said analogue signals are employed to drive a television type display with an appropriate grey-scale corresponding to said signals, said display being part of said viewing means.

42. The instrument of claim 41 wherein said display is a color terminal with its color corresponding to the energies of the x-rays and gamma-rays emitted by said object.

43. The instrument of claim 2 wherein said viewing means includes both an analogue display and a pinhole array with substantially the same pattern as said forming means, said pinhole array being displaced from said analogue display.

44. The instrument of claim 5 wherein said viewing means includes both an analogue display and a fly'"'"'s-eye lens with substantially the same pattern as said forming means.

45. The instrument of claim 43 wherein the dimensions of said pinhole array are dependent on the dimensions of said mini-images as shown on said analogue display.

46. The instrument of claim 44 wherein the dimensions of said fly'"'"'s-eye lens are dependent on the dimensions of said mini-images as shown on said analogue display.

47. An instrument for obtaining quantitative, three-dimensional and tomographic information of x-ray and gamma-ray emitting objects, and for orthoscopic viewing of such objects, comprising:

means for forming incident x-rays and gamma rays emitted by an object into an array of substantially non-overlapping mini-images of said object;

means spatially displaced from said forming means for the detection of said x-rays and gamma-ray mini-images;

means to digitize said detected mini-images;

computing means for processing said digitized mini-images for tomographic and three-dimensional reconstruction of said object; and

viewing means for direct orthoscopic, three-dimensional viewing of the reconstructed x-ray and gamma-ray emitting object.

48. The instrument of claim 47 wherein said forming means is a pinhole array.

49. The instrument of claim 47 wherein said detection means includes an x-ray film.

50. The instrument of claim 47 wherein said detection means includes an intensifier for x-rays or gamma rays.

51. The instrument of claim 47 wherein said detection means includes a position sensitive gas proportional counter.

52. The instrument of claim 47 wherein said detection means includes a position sensitive, solid-state detector.

53. The instrument of claim 47 wherein said digitizing means includes means to indicate the position and intensity of said mini-images.

54. The instrument of claim 53 wherein said digitizing means includes means to indicate the energy of said mini-images.

55. The instrument of claim 47 wherein said computing means includes means for positional inversion of said individual mini-images.

56. The instrument of claim 47 wherein said computing means includes means for back-projection calculations of said mini-images for the reconstruction of said x-ray and gamma-ray emitting object.

57. The instrument of claim 47 wherein said computing means includes means for the development of tomograms of said x-ray and gamma-ray emitting object.

58. The instrument of claim 47 wherein said viewing means includes a transparency of said mini-images with a viewing screen with the same pattern as said array.

59. The instrument of claim 47 wherein said viewing means includes a video monitor with a viewing screen with the same pattern as said array.

60. The instrument of claim 47 wherein said detection means includes any x-ray or gamma-ray to visible-light converter in combination with photographic film.

61. The instrument of claim 47 wherein said detection means includes an x-ray and gamma-ray intensifier in combination with photographic film.

62. An instrument for obtaining quantitative, three-dimensional and tomographic information of x-ray and gamma-ray emitting objects, and for orthoscopic viewing of such objects, comprising:

means for forming incident x-rays and gamma rays emitted by an object into an array of substantially non-overlapping mini-images of said object;

means spatially displaced from said forming means for the detection of said x-ray and gamma-ray mini-images;

means to digitize said detected mini-images; and

computing means for processing said digitized mini-images for tomographic and three-dimensional reconstruction of said object.