Imaging apparatus and method with event sensitive photon detection
View Patent ↗An imaging apparatus ( 10 ) includes a photon detector ( 20 ) and an accessing circuit ( 44 ) coupled thereto. The photon detector ( 20 ) detects photons and generates signals in response thereto. The accessing circuit ( 44 ) reads out the signals from the photon detector ( 20 ) at a sufficiently high rate so that it operates in an event sensitive mode. The apparatus ( 10 ) also includes a signal processing module ( 15 ) for processing the signals and generating data regarding the images of the object. In accordance with various embodiments of the present invention, the signal processing module ( 15 ) may include a spatial resolution circuit ( 56 ), a photon energy resolution circuit ( 57 ), a temporal resolution circuit ( 58 ), or any combination thereof.
1. A method for examining an object, comprising:
directing an externally generated radiation beam towards an object to generate a positron-electron annihilation process to produce photons in the object;
detecting the photons;
generating a signal in response to the detected photons; and
determining a characteristic of the object based at least on the signal.
2. The method of claim 1 , wherein the object comprises at least a portion of an animal body.
3. The method of claim 1 , wherein the object comprises a non-animal object.
4. The method of claim 1 , wherein the object comprises a passenger, a luggage or a cargo, and the determining a characteristic of the object comprises determining whether the object contains contraband or explosive.
5. The method of claim 1 , wherein the object comprises a mineral rock, and the determining a characteristic of the object comprises determining whether the object contains a diamond.
6. The method of claim 1 , wherein the determining comprises generating data regarding the object.
7. The method of claim 6 , wherein the data comprises image data.
8. The method of claim 6 , wherein the data comprises PET or SPECT data.
9. The method of claim 1 , wherein the characteristic of the object comprises a composition, an electron density, an atomic number density, a mass density, a morphology, an appearance, or a functionality.
10. The method of claim 1 , wherein the directing the externally generated beam comprises directing a pencil-beam, a fan beam, or a cone beam towards the object.
11. The method of claim 1 , further comprising accessing the signal as the signal is generated and before the signal integrates with another signal.
12. The method of claim 1 , wherein the determining comprises identifying one or a combination of a spatial coordinate, a time of generation, and an energy of the detected photons.
13. The method of claim 1 , wherein the detecting the photons comprises using a first detector to sense a first photon generated in a positron-electron annihilation process, and using a second detector to sense a second photon generated in the positron-electron annihilation process.
14. The method of claim 13 , wherein the determining a characteristic of the object comprises determining whether the first photon and the second photon both originated from the same positron-electron annihilation process based at least on a time when the first photon is detected in the first detector and a time when the second photon is detected in the second detector.
15. The method of claim 13 , wherein the determining a characteristic of the object comprises determining an energy level associated with the first photon and an energy level associated with the second photon.
16. The method of claim 15 , wherein the determining an energy level further comprises considering only signals associated with an energy level that is approximately 0.5 MeV or higher.
17. The method of claim 13 , wherein the determining a characteristic of the object further comprises determining an origin of the first and second photons where the positron-electron electron annihilation process occurred.
18. The method of claim 1 , wherein:
the step of directing an externally generated radiation beam comprises using a radiation source;
the step of detecting the photons comprises using a first detector and a second detector; and
the radiation source is not located between the first and the second detectors.
19. A system for examining an object, comprising:
means for externally generating a radiation beam and directing the radiation beam towards an object to generate a positron-electron annihilation process to produce photons in the object;
means for detecting the photons;
means for generating a signal in response to the detected photons; and
means for determining a characteristic of the object based at least on the signal.
20. The system of claim 19 , wherein the means for externally generating the radiation beam comprises means for generating a pencil-beam, a fan beam, or a cone beam.
21. The system of claim 19 , further comprising means for accessing the signal as the signal is generated and before the signal integrates with another signal.
22. The system of claim 19 , wherein the means for determining a characteristic of the object comprises means for generating data regarding the object.
23. The system of claim 19 , wherein the means for detecting the photons comprises a first detector and a second detector, and the means for externally generating the radiation beam is not located between the first and the second detectors.
24. A method for examining an object, comprising:
generating a particle in an object;
detecting the particle;
generating a signal using a detector in response to the detected particle;
accessing the generated signal using an accessing circuit that has an accessing rate equal to or greater than a signal generating rate associated with the detector; and
analyzing the signal to generate data regarding the object.
25. The method of claim 24 , wherein the generating a particle comprises directing a beam towards the object.
26. The method of claim 25 , wherein the directing a beam comprises directing a pencil-beam, a fan beam, or a cone beam towards the object.
27. The method of claim 24 , wherein the generating a particle comprises introducing a radioactive isotope into the object.
28. The method of claim 24 , wherein the particle comprises a photon generated in a positron-electron annihilation process.
29. The method of claim 24 , wherein the particle comprises a proton, a positron, a neutron, or an electron.
30. The method of claim 24 , wherein the analyzing comprises identifying one or a combination of a spatial coordinate, a time of generation, and an energy of the detected particle.
31. The method of claim 24 , wherein the object comprises at least a portion of a body of a patient undergoing a positron emission tomography (PET) scanning or a single-photon emission computed tomography (SPECT) scanning.
32. The method of claim 24 , wherein the object comprises a passenger, a luggage or a cargo, and the process further comprising determining whether the object contains contraband or explosive based at least on the generated data.
33. The method of claim 24 , wherein the object comprises a mineral rock, and the process further comprising determining whether the object contains a diamond.
34. The method of claim 24 , wherein the signal generating rate is associated with a rate at which particles are detected.
35. A system for examining an object, comprising:
means for generating a particle in an object;
means for detecting the particle;
means for generating a signal in response to the detected particle;
an accessing circuit for accessing the generated signal the accessing circuit having an accessing rate ectual to or greater than a signal generating rate associated with the means for generating; and
means for analyzing the signal to generate data regarding the object.
36. The system of claim 35 , wherein the means for generating a particle comprises means for directing a beam towards the object.
37. The system of claim 35 , wherein the means for generating a particle comprises means for introducing a radioactive isotope into the object.
38. The system of claim 35 , wherein the particle comprises a photon generated in a positron-electron annihilation process.
39. The system of claim 35 , wherein the particle comprises a proton, a positron, a neutron, or an electron.
40. The system of claim 35 , wherein the means for analyzing comprises means for identifying one or a combination of a spatial coordinate, a time of generation, and an energy of the detected particle.
41. The system of claim 35 , wherein the signal generating rate is associated with a rate at which particles are detected by the means for detecting.
42. An imaging apparatus, comprising:
a conversion panel configured to generate a light photon in response to a radiation;
a photo detector array aligned with the conversion panel and configured to generate a signal in response to the light photon received from the conversion panel;
an access circuit coupled to the photo detector array, the accessing circuit having accessing rate equal to or greater than a signal generating rate associated with the photo detector; and
a signal processing circuit coupled to the access circuit and configured to generate image data in response to the signal received by the access circuit.
43. The apparatus of claim 42 , wherein the photo detector array having a plurality of amorphous silicon photo detectors arranged in a two dimensional array.
44. The apparatus of claim 42 , wherein the access circuit being configured to read signals generated in the photo detector array at a rate between approximately 10 4 and 10 8 times per second.
45. The apparatus of claim 42 , wherein the access circuit being further configured to reset the photo detector array after reading one or more signals therefrom.
46. The apparatus of claim 42 , further comprising
an additional conversion panel positioned adjacent to the conversion panel, the additional conversion panel configured to generate a light photon in response to a radiation; and
an additional photo detector array aligned with the additional conversion panel, the additional photo detector array coupled to the access circuit and is configured to generate a signal in response to the light photon received from the additional conversion panel.
47. The apparatus of claim 46 , wherein the signal processing circuit being further configured to determine whether a radiation detected at the conversion panel is associated with a radiation detected at the additional conversion panel based at least on a position of a radiation source relative to the conversional panel and the additional conversional panel.
48. The apparatus of claim 46 , wherein the signal processing circuit being configured to determine whether a radiation detected at the conversion panel is associated with a radiation detected at the additional conversion panel based at least on an energy level of a radiation detected at the conversion panel and an energy level of a radiation detected at the additional conversion panel.
49. The apparatus of claim 46 , wherein the signal processing circuit being configured to determine whether a radiation detected at the conversion panel is associated with a radiation detected at the additional conversion panel based at least on a position of a first particle detected at the conversion panel and a position of a second particle detected at the additional conversion panel.
50. The apparatus of claim 42 , further comprising an accelerator configured to direct a radiation beam onto an object to generate the radiation.
51. The apparatus of claim 42 , further comprising a platform for supporting an object.
52. The apparatus of claim 42 , wherein the signal generating rate is associated with a rate at which photons are received by the conversion panel. for supporting an object.