Slit-slat collimation
View Patent ↗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.
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.