Modular gamma camera plate assembly with enhanced energy detection and resolution

• US 5,614,721 A
• Filed: 12/13/1995
• Issued: 03/25/1997
• Est. Priority Date: 12/13/1995
• Status: Expired due to Term

• Current Assignee: Single Cell Technology Incorporated
• Original Assignee: Optoscint, Inc.
• Inventors: Pandelisev, Kiril A.
• Primary Examiner(s): Hannaher, Constantine
• Application Number:
  US08/572,173
• Time in Patent Office: 468 Days
• Field of Search: 250/368, 250/366
• US Class Current: 250/368
• CPC Class Codes: G01T 1/2002 Optical details, e.g. reflecting or diffusing layers
• CPC Class Codes: G01T 1/202 the detector being a crystal

Abstract

A modular gamma camera plate assembly has a mirror peripherally supported in an encircling housing. The holder is connected to the mirror and to the housing. A thin glass plate is mounted beneath the crystal and extends outward and is connected to the housing. A thin mirror extends above the crystal and is connected peripherally to the housing. The thin glass plate assembly and the mirror are sealed to the housing and pockets with desiccant are provided to prevent ingress of moisture and to getter moisture from the housing and assembly.

Claims

1. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral crystal housing with a crystal holder mounted between the crystal and the crystal housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the crystal holder against movement in the crystal housing.

2. The apparatus of claim 1, wherein the mutual engaging features further comprise at least one screw extending between the holder and the housing.

3. The apparatus of claim 1, wherein the mutual engaging features further comprise multiple screws extending between the holder and the housing.

4. The apparatus of claim 1, wherein the cladding and mirror extend around sides of the crystal and not over a top of the crystal.

5. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, wherein the mutually engaging features comprise a downward and inward sloped internal wall in the housing and a complementary upward and outward sloped outer wall on the holder.

6. The apparatus of claim 5, further comprising projections extending transverse to the surfaces for inter-engaging the surfaces and preventing relative sliding of the surfaces.

7. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, wherein the mutually engaging surface features comprise protrusions extending outward from the outer wall of the holder and complementary recesses in the inner wall of the housing.

8. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, wherein the mutually engaging surface features comprise protrusions extending inward from an inner wall of the housing and complementary recesses in an outer wall of the holder for receiving the protrusions and holding the holder against movement within the housing.

9. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, further comprising an inward facing recess in the holder and a complementary outward extension on the mirror for positioning in the inward facing recess in the holder for preventing relative movement of the holder and mirror.

10. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, further comprising an inward extending shelf at the bottom of the holder for extending inward beneath the crystal and supporting the crystal with respect to the holder.

11. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, further comprising an inward extending shelf extending inward from the housing beneath the holder and beneath the crystal for supporting the crystal on the shelf.

12. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, further comprising an inward extending shelf positioned below a peripheral portion of the crystal and extending inward from the housing and holder, and a fastener for connecting the shelf to the holder or housing.

13. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, further comprising a thin glass plate and a connector for connecting a peripheral portion of the thin glass plate to the housing and supporting the thin glass plate from the housing.

14. The apparatus of claim 13, further comprising a glass-to-metal seal or epoxy connecting a peripheral area of the thin glass plate to the housing.

15. The apparatus of claim 14, further comprising an inward cantilevered support connected to an outward portion of the housing and extending inward beneath a peripheral portion of the thin glass plate for supporting the thin glass plate.

16. The apparatus of claim 15, wherein the cantilevered support comprises an annular support extending around the entire peripheral area of the housing, and further comprising a mechanical attachment for mechanically attaching the cantilevered support to the housing.

17. The apparatus of claim 15, further comprising first and second desiccant pockets positioned adjacent the seal and spaced radially inward and radially outward with respect to each other, and desiccant disposed in the pockets for preventing ingress of moisture from without the gamma camera plate assembly and for gettering moisture in the gamma camera plate assembly during fabrication thereof.

18. The apparatus of claim 13, further comprising an L-shaped ring surrounding an edge of the thin glass plate and underlying a peripheral portion of the lower surface of the thin glass plate, and a glass-to-metal seal or epoxy between the peripheral portion and the edge of the thin glass plate and the L-shaped ring for sealing the L-shaped ring to the thin glass plate.

19. The apparatus of claim 18, further comprising an outer ring and epoxy connecting the outer ring to an outer surface of the L-shaped ring, an epoxy connecting the outer ring to an inward facing wall in the housing, a third area of epoxy connecting an upper peripheral surface of the thin glass plate to a lower surface of the housing, and desiccant pockets with desiccant disposed therein between the third area of epoxy in a recess in the housing inward of the third layer of epoxy and between the third layer of epoxy and the glass-to-metal seal or epoxy, and between the first layer of epoxy and the housing.

20. The apparatus of claim 19, further comprising a metal support ring underlying the outer ring, the second layer of epoxy and the housing, and mechanically attached to the housing for supporting the outer ring and thereby supporting the L-shaped ring and the thin glass plate on the housing.

21. The apparatus of claim 13, further comprising a thin ring on the connector spaced from the glass plate and extending from the connector, a thin ring on the housing adjacent the thin ring on the connector, the thin rings being juxtaposed and joined.

22. The apparatus of claim 13, further comprising recesses formed between the connector and the housing and deformable sealing rings in the recesses for compressing in the recesses and sealing the connector and housing.

23. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, wherein the mutual engaging features further comprise multiple screws extending between the holder and the housing, further comprising interlocks extending between the holder and the housing.

24. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, wherein the mirror is fixed to the inner surface of the holder.

25. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing for supporting the crystal in the housing, wherein the holder and the housing have mutually engaging surface features for supporting the holder against movement in the housing, wherein the mutually engaging features comprise a support extending beneath the mirror and the cladding.

26. The apparatus of claim 25, further comprising an upper support extending over the sides of the mirrors and cladding, and screws connecting the upper support to the holder.

27. The apparatus of claim 25, wherein the support extends under a peripheral surface portion of the crystal, and further comprising an upper support extending over sides of the mirror and the cladding and over a peripheral upper surface portion of the crystal, and screws connecting the upper support to the holder.

28. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder mounted between the crystal and the housing, an inward extending shelf at the bottom of the holder for extending inward beneath the crystal and supporting the crystal with respect to the holder, for supporting the crystal in the housing.

29. The apparatus of claim 28, wherein the inward extends shelf extending inward from the housing beneath the holder and beneath the crystal for supporting the crystal on the shelf.

30. The apparatus of claim 28, wherein the an inward extending shelf is positioned below a peripheral portion of the crystal and extends inward from the housing and holder, and further comprising a fastener for connecting the shelf to the holder or the housing.

31. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing with a holder for supporting the crystal in the housing, a thin glass plate and a connector for connecting a peripheral portion of the thin glass plate to the housing and supporting the thin glass plate from the housing.

32. The apparatus of claim 31, further comprising a glass-to-metal seal or epoxy connecting a peripheral area of the thin glass plate to the housing.

33. The apparatus of claim 32, further comprising an inward cantilevered support connected to an outward portion of the housing and extending inward beneath a peripheral portion of the thin glass plate for supporting the thin glass plate.

34. The apparatus of claim 33, wherein the cantilevered support comprises an annular support extending around an entire peripheral area of the housing, and further comprising a mechanical attachment for mechanically attaching the cantilevered support to the housing.

35. The apparatus of claim 31, further comprising an L-shaped ring surrounding an edge of the thin glass plate and underlying a peripheral portion of the lower surface of the thin glass plate, and a glass-to-metal seal or epoxy between the peripheral portion and the edge of the thin glass plate and the L-shaped ring for sealing the L-shaped ring to the thin glass plate.

36. The apparatus of claim 35, further comprising an outer ring and epoxy connecting the outer ring to an outer surface of the L-shaped ring, epoxy connecting the outer ring to an inward facing wall in the housing, a third area of epoxy connecting an upper peripheral surface of the thin glass plate to a lower surface of the housing, and desiccant pockets with desiccant disposed therein at opposite edges of the third area of epoxy.

37. The apparatus of claim 36, further comprising a metal support ring underlying the outer ring, the second layer of epoxy and the housing, and mechanically attached to the housing for supporting the outer ring and thereby supporting the L-shaped ring and the thin glass plate on the housing.

38. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing for supporting the crystal in the housing, and a variable thickness gamma ray window mounted over the crystal with a relatively thin portion of the window above the crystal and a relatively thick portion of the window extending over the housing for sealing to the housing.

39. A gamma camera plate assembly comprising a crystal having at least one cladding surrounding the crystal and a mirror surrounding the cladding, and a peripheral housing for supporting the crystal in the housing, and a variable thickness gamma ray window mounted over the crystal with a relatively thin portion of the window above the crystal and a relatively thick portion of the window extending over the housing for sealing to the housing, wherein the gamma ray window comprises a frame having a relatively thin dimension in a direction parallel to a plane of the window and having a relatively thick dimension transverse to the plane of the window.

40. The apparatus of claim 39, wherein the frame extends from the window in opposite directions.

41. The apparatus of claim 39, wherein the frame extends in a direction away from the crystal.

42. The apparatus of claim 39, wherein the frame extends in a direction towards the crystal.

43. The apparatus of claim 39, further comprising multiple laterally arranged crystals, and wherein the window comprises multiple thin window apertures surrounded by frame members, each window aperture overlying a crystal.

44. The apparatus of claim 43, wherein the frame members extend from the window between the multiple crystals.

45. The apparatus of claim 44, wherein the frame members extend to a thin glass plate beneath the multiple crystals.