Slit-slat collimation

• US 7,831,024 B2
• Filed: 03/19/2007
• Issued: 11/09/2010
• Est. Priority Date: 03/17/2006
• Status: Active Grant

• Current Assignee: Trustees Of The University Of Pennsylvania (University of Pennsylvania)
• Original Assignee: Trustees Of The University Of Pennsylvania (University of Pennsylvania)
• Inventors: Lewitt, Robert M., Accorsi, Roberto, Metzler, Scott
• Primary Examiner(s): Glick; Edward J
• Assistant Examiner(s): Artman; Thomas R
• Application Number:
  US12/293,422
• Publication Number:
  US 20090304150A1
• Time in Patent Office: 1,331 Days
• Field of Search: 378/149, 378/150, 250/363.1
• US Class Current: 378/150
• CPC Class Codes: G01T 1/1648 Ancillary equipment for scintillation cameras, e.g. reference markers, devices for removing motion artifacts, calibration devices adapted for flow studies G01T1/1647
• CPC Class Codes: G02B 27/30 Collimators

Abstract

This invention is directed to a collimator and collimation techniques. Specifically, the invention is directed to a collimator and method for collimation wherein the collimator combines the resolution and sensitivity properties of pinhole Single Photon Emission Computed Tomography (SPECT) imaging with the 2D complete-sampling properties of fan-beam collimators.

Claims

1. A slit-slat collimator, comprising:

a collimator frame having a frusto-pyramidal housing disposed thereon, said frusto-pyramidal housing having a rectangular base, a rectangular top and open sides defined by a trapezoidal shape, wherein said housing provides lead shielding;

a plurality of axial septa;

a plurality of spacers;

a means for alignably stacking said axial septa and said spacers; and

an adjustable aperture plate mounted on said rectangular top comprising at least one adjustable aperture members.

2. The collimator of claim 1, wherein said collimator frame is detachably attached to a detector head on a scanner.

3. The collimator of claim 1, wherein said adjustable aperture plate defines pinholes therein.

4. The collimator of claim 3, wherein said pinholes are aligned axially.

5. The collimator of claim 1, wherein said adjustable aperture plate defines an axial slit therein.

6. The collimator of claim 1, wherein said aperture plate defines apertures comprising a variety of geometric diameters, pitches, acceptance angles, hole shapes, or a combination thereof.

7. The collimator of claim 1, wherein said axial septa have a trapezoidal shape.

8. The collimator of claim 7, wherein said axial septa have holes disposed thereon along the sides of said trapezoid.

9. The collimator of claim 1, wherein said axial septa are less than 1 mm thick.

10. The collimator of claim 1, further comprising a plurality of Rohacall strips between said axial septa.

11. The collimator of claim 1, wherein said adjustable aperture members form at least one slit.

12. The collimator of claim 1, wherein said adjustable aperture members form an elevated central slit.

13. The collimator of claim 1, wherein said adjustable aperture members form an elevated side slit.

14. The collimator of claim 1, wherein said adjustable aperture members form a focused aperture slit.

15. The collimator of claim 1, wherein said axial septa form a focused slat assembly.

16. The collimator of claim 1, further comprising a plurality of slits disposed transaxially from said aperture plate and aligned along the sides of said collimator frame.

17. A slit-slat collimator, comprising:

a collimator frame having a frusto-pyramidal housing disposed thereon, said frusto-pyramidal housing having a rectangular base, a rectangular top and open sides defined by a trapezoidal shape, wherein said housing provides lead shielding;

an aperture forming unit selected from the group consisting of a pair of symmetric aperture forming members, an axial septum or both;

a means for alignably stacking said aperture forming unit; and

an adjustable aperture plate mounted on said rectangular top comprising at least one aperture forming unit.

18. The collimator of claim 17, wherein said collimator frame is detachably attached to a detector head on a scanner.

19. The collimator of claim 17, wherein said adjustable aperture plate defines pinholes therein.

20. The collimator of claim 19, wherein said pinholes are aligned axially.

21. The collimator of claim 17, wherein said adjustable aperture plate defines an axial slit therein.

22. The collimator of claim 17, wherein said aperture plate defines apertures comprising a variety of geometric diameters, pitches, acceptance angles, hole shapes, or a combination thereof.

23. The collimator of claim 17 wherein said axial septum has a trapezoidal shape.

24. The collimator of claim 23, wherein said axial septum has holes disposed thereon along the sides of said trapezoid.

25. The collimator of claim 17, wherein said axial septum is less than 1 mm thick.

26. The collimator of claim 17, wherein said aperture forming members have a pentagonal shape.

27. The collimator of claim 26, wherein said aperture forming members vary in thickness and pentagon angles, thereby varying the geometric diameter, pitch, acceptance angle, hole shape, or a combination thereof of the apertures of said aperture plate.

28. The collimator of claim 17, further comprising a plurality of slits disposed transaxially from said aperture plate and aligned along the sides of said collimator frame.

29. A method of collimating electromagnetic radiation, comprising the steps of:

selecting a particular electromagnetic radiation for collimation, said radiation output from a specimen of interest;

positioning a detector of said particular radiation in a location useful for gathering information about said specimen and associated with said particular radiation;

using a slit-slat collimator, comprising;

a collimator frame having a frusto-pyramidal housing disposed thereon, said frusto-pyramidal housing having a rectangular base, a rectangular top and open sides defined by a trapezoidal shape, wherein said housing provides lead shielding;

a plurality of axial septa;

a plurality of spacers;

a means for alignably stacking said axial septa and said spacers; and

an adjustable aperture plate mounted on said rectangular top comprising at least one adjustable aperture members; and

adjusting said aperture plate to adjust collimation aperture.

30. The method of claim 29, wherein said collimator frame is detachably attached to a detector head on a scanner.

31. The method of claim 29, wherein said adjustable aperture plate defines pinholes therein.

32. The method of claim 31, wherein said pinholes are aligned axially.

33. The method of claim 29, wherein said adjustable aperture plate defines an axial slit therein.

34. The method of claim 29, wherein said aperture plate defines apertures comprising a variety of geometric diameters, pitches, acceptance angles, hole shapes, or a combination thereof.

35. The method of claim 29, wherein said axial septa have a trapezoidal shape.

36. The method of claim 35, wherein said axial septa have holes disposed thereon along the sides of said trapezoid.

37. The method of claim 29, wherein said axial septa are less than 1 mm thick.

38. The method of claim 29, further comprising a plurality of Rohacall strips between said axial septa.

39. The method of claim 29, wherein said adjustable aperture members form at least one slit.

40. The method of claim 29, wherein said adjustable aperture members form an elevated central slit.

41. The method of claim 29, wherein said adjustable aperture members form an elevated side slit.

42. The method of claim 29, wherein said adjustable aperture members form a focused aperture slit.

43. The method of claim 29, wherein said axial septa form a focused slat assembly.

44. The method of claim 29, further comprising a plurality of slits disposed transaxially from said aperture plate and aligned along the sides of said collimator frame.

45. An imaging system, comprising:

an electromagnetic radiation point source;

a detector panel having an array of detector elements disposed thereon; and

a slit-slat collimator, comprising;

a collimator frame having a frusto-pyramidal housing disposed thereon, said frusto-pyramidal housing having a rectangular base, a rectangular top and open sides defined by a trapezoidal shape, wherein said housing provides lead shielding;

a plurality of axial septa;

a plurality of spacers;

a means for alignably stacking said axial septa and said spacers; and

an adjustable aperture plate mounted on said rectangular top comprising at least one adjustable aperture members.

46. The method of claim 45, wherein said collimator frame is detachably attached to a detector head on a scanner.

47. The method of claim 45, wherein said adjustable aperture plate defines pinholes therein.

48. The method of claim 47, wherein said pinholes are aligned axially.

49. The method of claim 45, wherein said adjustable aperture plate defines an axial slit therein.

50. The method of claim 45, wherein said aperture plate defines apertures comprising a variety of geometric diameters, pitches, acceptance angles, hole shapes, or a combination thereof.

51. The method of claim 45, wherein said axial septa have a trapezoidal shape.

52. The method of claim 51, wherein said axial septa have holes disposed thereon along the sides of said trapezoid.

53. The method of claim 45, wherein said axial septa are less than 1 mm thick.

54. The method of claim 45, further comprising a plurality of Rohacall strips between said axial septa.

55. The method of claim 45, wherein said adjustable aperture members form at least one slit.

56. The method of claim 45, wherein said adjustable aperture members form an elevated central slit.

57. The method of claim 45, wherein said adjustable aperture members form an elevated side slit.

58. The method of claim 45, wherein said adjustable aperture members form a focused aperture slit.

59. The method of claim 45, wherein said axial septa form a focused slat assembly.

60. The method of claim 45, further comprising a plurality of slits disposed transaxially from said aperture plate and aligned along the sides of said collimator frame.