Method and apparatus for gamma ray detection

• US 20050173643A1
• Filed: 04/11/2005
• Published: 08/11/2005
• Est. Priority Date: 02/02/1996
• Status: Active Grant

• Current Assignee: Nova R&D Incorporated (Kromek Group PLC)
• Original Assignee: Tumay O. Tumer
• Inventors: Tumer, Tumay O.
• Granted Patent: US 7,022,995 B2
• Time in Patent Office: Days
• US Class Current: 250/370.90
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: G01T 1/006 Total absorption calorimeters; Shower detectors
• CPC Class Codes: G01T 1/1647 Processing of scintigraphic data not related to a particular imaging system G01T1/2992
• CPC Class Codes: G01T 1/2928 using solid state detectors

Abstract

A high sensitivity, three-dimensional gamma ray detection and imaging system is provided. The system uses the Compton double scatter technique with recoil electron tracking. The system preferably includes two detector subassemblies; a silicon microstrip hodoscope and a calorimeter. In this system the incoming photon Compton scatters in the hodoscope. The second scatter layer is the calorimeter where the scattered gamma ray is totally absorbed. The recoil electron in the hodoscope is tracked through several detector planes until it stops. The x and y position signals from the first two planes of the electron track determine the direction of the recoil electron while the energy loss from all planes determines the energy of the recoil electron.

Claims

1-40. -40. (canceled)

41. A method of imaging a portion of an organism, the method comprising the steps of:

providing a radioactive chemical to said portion of said organism, said radioactive chemical producing photons;

positioning a detection system proximate to said portion of said organism, wherein said detection system is comprised of at least one detector plane;

determining a direction information for a portion of said photons entering said detection system from at least one detector output signal;

processing said direction information for said portion of photons; and

displaying an image of said portion of said organism, wherein said image is based on said processed direction data.

42. The method of imaging an organism according to claim 41, wherein said organism is an animal.

43. The method of imaging an organism according to claim 41, wherein said organism is a human.

44. The method of imaging an organism according to claim 41, wherein said image can be displayed in real time.

45. The method of imaging an organism according to claim 41, wherein said image is processed and displayed after the measurement is taken.

46. The method of imaging an organism according to claim 41, wherein said detectors are made from Si, GaAs, Ge, HPGe, CdWO₄, CdTe, CdZnTe, HgI₂ and PbI₂.

47. The method of imaging an organism according to claim 41, wherein said detector system is rotated around said organism to produce a three-dimensional image of said portion of said organism.

48. The method of imaging an organism according to claim 41, wherein at least two detector systems are used around said organism to produce a three-dimensional image of said portion of said organism.

49. An imaging system for imaging a portion of an organism, said portion treated with a radioactive chemical, said radioactive chemical producing photons, further comprising:

a detection system comprised of at least one detector plane, wherein an entrance aperture of said detection system is external to said living organism and proximate to said portion of said organism, wherein a portion of said photons enter into said detection system and a portion of said photons that enter into the detection system are detected;

at least one signal is produced when a photon is detected within said detection system in said at least one detector plane;

a multi-channel readout system-coupled to said detection system;

a processor coupled to said multi-channel readout system to control said imaging system, transfer information and process information;

wherein direction information is produced for a portion of said photons entering said detection system from said at least one signal; and

an image process and display system for processing said direction information, to produce at least one image of said portion of said organism and to display said at least one image.

50. The medical imaging system according to claim 49, wherein direction and energy information is obtained from said at least one signal for a portion of said photons entering said detection system.

51. The medical imaging system according to claim 49, wherein a portion of said photons Compton scatter in said at least one detector plane.

52. The medical imaging system according to claim 49, further comprising at least one detector plane placed outside said at least one detector plane and used to stop and detect a portion of said Compton scattered portion of photons.

53. The medical imaging system according to claim 49, further comprising a shielding member proximate to said detector entrance aperture to limit background photons.

54. The medical imaging system according to claim 49, further comprising a collimator member in front of said detector entrance aperture to constrain the direction of said portion of said photons.

55. The medical imaging system according to claim 49, wherein said detector system is rotated around said organism to produce a three-dimensional image of said portion of said organism.

56. The medical imaging system according to claim 49, wherein at least two detector systems are used around said portion of said organism to produce a three-dimensional image of said portion of said organism.

57. The medical imaging system according to claim 49, wherein direction information is obtained from said at least one signal for a portion of said photons entering said detection system.

58. The medical imaging system according to claim 49, wherein energy information is obtained from said at least one signal for a portion of said photons entering said detection system.

59. The method of imaging an organism according to claim 41, wherein at least two detector systems are used around said portion of said organism to produce a stereoscopic image of said portion of said organism.

60. The medical imaging system according to claim 49, wherein at least two detector systems are used around said portion of said organism to produce a stereoscopic image of said portion of said organism.

61. The method of imaging an organism according to claim 41, wherein a DLAD or CLAD technique is used to analyze the data and produce said image.

62. The medical imaging system according to claim 49, wherein said photons have energy in the range from 1 keV to 20 MeV.

63. The method of imaging an organism according to claim 41, wherein said detector system is rotated around said portion of said organism to produce a three-dimensional image of said portion of said organism.

64. The method of imaging an organism according to claim 41, wherein said portion of said organism is the whole organism.

65. The medical imaging system according to claim 49, wherein said detector system is rotated around said portion of said organism to produce a tomographic image of said portion of said organism.

66. The medical imaging system according to claim 49, wherein said photons are x-rays or gamma rays with energy in the range from 1 keV to 20 MeV.

67. The method of imaging an organism according to claim 41, wherein said detector system is rotated around said portion of said organism to produce a tomographic-image of said portion of said organism.

68. The method of imaging an organism according to claim 41, wherein said photons are x-rays or gamma rays with energy in the range from 1 keV to 20 MeV.

69. The method of imaging an organism according to claim 41, wherein an energy information is produced for a portion of said photons entering said detection system from at least one detector output signal.