Structured detectors and detector systems for radiation imaging

• US 10,274,610 B2
• Filed: 09/08/2017
• Issued: 04/30/2019
• Est. Priority Date: 09/09/2016
• Status: Active Grant

• Current Assignee: Minnesota Imaging and Engineering LLC
• Original Assignee: Minnesota Imaging and Engineering LLC
• Inventors: Nelson, Robert Sigurd, Nelson, William Bert
• Primary Examiner(s): Porta, David P
• Assistant Examiner(s): Gutierrez, Gisselle M
• Application Number:
  US15/699,458
• Publication Number:
  US 20180136340A1
• Time in Patent Office: 599 Days
• Field of Search: 25037011
• CPC Class Codes: A61B 6/4028 resulting in acquisition of views from substantially different positions, e.g. EBCT
• CPC Class Codes: A61B 6/4233 using matrix detectors
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: G01T 1/1611 using both transmission and emission sources sequentially SPECT imaging G01T1/1642; PET imaging G01T1/2985; detecting prohibited goods, e.g. weapons, explosives, hazardous substances, contraband or smuggled objects G01V5/20
• CPC Class Codes: G01T 1/1644 using an array of optically separate scintillation elements permitting direct location of scintillations G01T1/1645 takes precedence
• CPC Class Codes: G01T 1/2002 Optical details, e.g. reflecting or diffusing layers
• CPC Class Codes: G01T 1/247 Detector read-out circuitry for processing gain or off-set correction H04N

Abstract

Detector module designs for radiographic imaging include first and second layers of scintillator rods or pixel arrays oriented in first and second directions. The first and second directions are transversely oriented to define a light sharing region between the first and second layers. Encoding features may be disposed in, on or between the first and second layers, and configured to modulate propagation of optical signals therealong or therebetween.

Claims

1. A detector module comprising:

at least top and bottom layers of crossed scintillator rods comprising;

a first top layer of scintillator rods, each scintillator rod in the first layer extending in a first direction; and

a second bottom layer of scintillator rods stacked adjacent the first layer, each scintillator rod in the second layer extending in a second direction;

wherein the top and bottom layers of scintillator rods are defined in a unitary scintillator element having a light sharing region defined therein, wherein optical signals are transmitted between the respective crossed scintillator rods of the top and bottom layers;

wherein the first and second directions are transversely oriented, such that the first and second layers of scintillator rods are crossed to define the region of light sharing between the scintillator rods of the first layer and the scintillator rods of the second layer;

wherein the scintillator rods in the first layer have at least one different dimension with respect to the scintillator rods in the second layer, such that the first and second layers have one or more of different spatial, timing and energy resolution; and

wherein the scintillator rods are configured to generate the optical signals in response to one or more of x-ray radiation, gamma radiation, or particle radiation; and

a plurality of photodetector elements configured to convert the optical signals into output characterizing the radiation.

2. The detector module of claim 1, wherein the scintillator rods in the first layer have at least one different scintillator material with respect to the scintillator rods in the second layer.

3. The detector module of claim 1, wherein scintillator rods within at least one of the first and second layers have different scintillator materials from scintillator rods within another of the first and second layers.

4. The detector module of claim 1, wherein at least two or more of the scintillator rods have different cross-sectional area transverse to at least one of the first and second directions, respectively;

or wherein at least two or more of the scintillator rods have different longitudinal dimension along at least one of the first and second directions, respectively.

5. The detector module of claim 1, further comprising encoding features disposed in, on or between one or both of the scintillator rods of the first layer and the scintillator rods of the second layer, wherein the encoding features are configured to modulate propagation of the optical signals along one or both of the layers of scintillator rods or between the layers of scintillator rods.

6. The detector module of claim 1, further comprising a pattern applied to one or both of the first and second layers of scintillator rods, or between the scintillator rods, the pattern comprising at least one of a reflective, diffusive, absorptive, WLS, or photonic crystal material, nano-layered metamaterials (including nanocavities), or a refracting, diffracting or lens optical surface;

wherein the pattern is adapted to modulate propagation of the optical signals along one or both of the layers of scintillator rods, or between the layers of scintillator rods.

7. The detector module of claim 6, wherein the pattern comprises a grid of optical features having a spacing corresponding to that of the crossed scintillator rods in the first and second layers, the grid of optical features configured to modulate lateral light flow therebetween.

8. The detector module of claim 1, further comprising an offset portion of at least one of the layers of scintillator rods with respect to an adjacent one of the layers, wherein the offset portion is defined by an extension of the respective scintillator rods beyond a periphery of the adjacent layer, outside a region of light sharing between the at least one of the layers and the adjacent layer.

9. The detector module of claim 8, further comprising a photodetector element coupled to the offset portion of at least one of the layers, wherein the photodetector element is configured to sense the optical signals from the extension of the respective scintillator rods, outside the region of light sharing.

10. The detector module of claim 8, wherein the scintillator rods in at least one of the layers have a substantially same cross sectional dimension as the scintillator rods in an adjacent one of the layers.

11. An imaging system comprising one or more detector modules configured to interrogate a material sample by detecting ionizing radiation according to claim 1, and further comprising at least one of an active or passive encoding technique implemented with at least one of the detector modules or the material sample.

12. The imaging system of claim 11, further comprising an image processor in communication with the one or more detector modules, the image processor configured to generate images of the material sample based on the ionizing radiation and the encoding technique;

wherein the material sample includes biological tissue and the image processor is configured for medical imaging thereof;

wherein the material sample includes a non-tissue material and the image processor is configured for non-medical science, industry or inspection imaging thereof;

or

wherein the encoding technique utilizes non-optical information carriers with or without passive optical encoding.

13. The imaging system of claim 11, wherein the encoding technique includes modifying at least one of local or global electric, magnetic, electromagnetic, acoustic and thermal ionizing radiation properties of at least one of the detector modules.

14. The imaging system of claim 13, wherein:

the one or more detector modules include one or more of slab, block, pixelated, array, layered, 3D structured and structured ionizing radiation detector elements;

or

the encoding technique is implemented with structured ionizing radiation detector elements of the one or more detector modules.

15. The detector module of claim 1, wherein the layers of scintillator rods further comprise discrete scintillator elements having the light sharing region defined therebetween.

16. The detector module of claim 1, wherein the photodetector elements include at least one of strip photodetectors with readout at both ends and continuous area photodetectors with readout at four corners, wherein the photodetector elements are disposed at ends of the scintillator rods, the ends defining an end face having a cross sectional area transverse to a direction of parallel scintillator rods within the respective one of the layers.

17. An imaging system comprising one or more detector modules configured to interrogate a material sample by detecting ionizing radiation according to claim 5, wherein the encoding features comprise at least one of active or passive encoding on at least one of the detector modules.

18. A detector module comprising:

at least three layers of scintillators, wherein at least top and bottom layers of crossed scintillator rods comprise transversely oriented scintillator rods configured to generate optical signals in response to ionizing radiation, the transversely oriented scintillator rods extending in first and second transverse directions in the top and bottom layers, respectively;

wherein the top and bottom layers of scintillator rods are defined in a unitary scintillator element having a light sharing region defined therein, between the top and bottom layers and at least one adjacent intermediate layer between the top and bottom layers, wherein the optical signals are transmitted between the respective crossed scintillator rods of the top and bottom layers;

a plurality of photodetector elements configured to convert the optical signals into output characterizing the radiation; and

an encoding pattern configured to modulate transmission of the optical signals along one or both of the top and bottom layers of scintillator rods or between the top and bottom layers of scintillator rods;

wherein the scintillator rods in the top layer have the same dimensions or at least one different dimension with respect to the scintillator rods in the bottom layer such that the top and bottom layers have one or more of different spatial, timing and energy resolution.

19. The detector module of claim 18, wherein the layers of scintillator rods further comprise discrete scintillator elements having the light sharing region defined therebetween.

26. An imaging system comprising one or more detector modules configured to interrogate a material sample by detecting ionizing radiation according to claim 18, wherein the encoding pattern comprises at least one of active or passive encoding on at least one of the detector modules.

27. The imaging system of claim 26, further comprising an image processor in communication with the one or more detector modules, the image processor configured to generate images of the material sample based on the ionizing radiation and the encoding pattern, wherein:

the material sample includes biological tissue and the image processor is configured for medical imaging thereof;

or

the material sample includes a non-tissue material and the image processor is configured for non-medical science, industry or inspection imaging thereof.

28. The imaging system of claim 26, wherein the encoding pattern includes non-optical information carriers with or without passive optical encoding.

29. The imaging system of claim 28, wherein the one or more detector modules include one or more of slab, block, pixelated, array, layered, 3D structured and structured ionizing radiation detector elements.

30. The detector module of claim 18, further comprising an offset portion of at least one of the layers of scintillator rods with respect to an adjacent one of the layers, wherein the offset portion is defined by an extension of the respective scintillator rods beyond a periphery of the adjacent layer, outside the region of light sharing between the at least one of the layers and the adjacent layer.

31. The detector module of claim 30, further comprising a photodetector element coupled to the offset portion of at least one of the layers, wherein the photodetector element is configured to sense optical signals from the extension of the respective scintillator rods, outside the region of light sharing between the at least one of the layers and the adjacent layer.

32. The detector module of claim 30, wherein the scintillator rods in at least one of the layers have a substantially same cross sectional dimension as the scintillator rods in an adjacent one of the layers.

33. The detector module of claim 18, wherein the photodetector elements include at least one of strip photodetectors with readout at both ends and continuous area photodetectors with readout at four corners, wherein the photodetector elements are disposed at ends of the scintillator rods, the ends defining an end face having a cross sectional area transverse to a direction of parallel scintillator rods within the respective layer.

20. A detector module comprising:

at least top and bottom layers of crossed or parallel scintillator rods, wherein the top and bottom layers of scintillator rods are defined in a unitary scintillator element having a light sharing region defined therein, wherein optical signals are transmitted between the respective crossed or parallel scintillator rods of the top and bottom layers;

wherein the scintillator rods in the top layer have the same dimensions or at least one different dimension with respect to the scintillator rods in the bottom layer such that the top and bottom layers have one or more of different spatial, timing and energy resolution; and

wherein the scintillator rods are configured to generate the optical signals in response to one or more of x-ray radiation, gamma radiation, or particle radiation; and

a plurality of photodetector elements configured to convert the optical signals into output characterizing the radiation.

21. The detector module of claim 20, further comprising a plurality of dividers extending in first and second directions transverse directions in the top and bottom layers respectively, the dividers defining the scintillator rods in the respective layers.

22. The detector module of claim 21, wherein the dividers extend into the unitary scintillator element from a first major surface of the top layer and from a second major surface of the bottom layer, respectively, each of the dividers having a depth less than a thickness of the unitary scintillator element between the first and second major surfaces.

23. The detector module of claim 22, wherein the depth of the dividers varies between different scintillator rods in one or both of the first and second layers.

24. The detector module of claim 22, wherein the dividers comprise at least one of a reflective, diffusive, absorptive, refractive, diffractive, or WLS optical feature or material disposed between the respective scintillator rods.

25. The detector module of claim 20, wherein the photodetector elements include at least one of strip photodetectors with readout at both ends and continuous area photodetectors with readout at four corners, wherein the photodetector elements are disposed at ends of the scintillator rods, the ends defining an end face having a cross sectional area transverse to a direction of parallel scintillator rods within the respective layer.

34. An imaging system comprising one or more detector modules configured to interrogate a material sample by detecting ionizing radiation according to claim 20, and further comprising an encoding pattern that comprises at least one of active or passive encoding on at least one of the detector modules.

35. An imaging system comprising:

one or more detector modules configured to interrogate a material sample by detecting ionizing radiation, wherein the one or more detector modules include at least one of an edge-on detector module, a face-on detector module and a multilayer detector module comprising at least top and bottom layers of crossed or parallel scintillator rods, wherein the top and bottom layers of scintillator rods are defined in a unitary scintillator element having a light sharing region defined therein, wherein optical signals are transmitted between the respective crossed or parallel scintillator rods of the top and bottom layers;

wherein the scintillator rods in the top layer have the same dimensions or at least one different dimension with respect to the scintillator rods in the bottom layer such that the top and bottom layers have one or more of different spatial, timing and energy resolution; and

wherein the scintillator rods are configured to generate the optical signals in response to one or more of x-ray radiation, gamma radiation, or particle radiation; and

a plurality of photodetector elements configured to convert the optical signals into output characterizing the radiation; and

at least one of an active or passive encoding technique implemented with at least one of the detector modules or the material sample.

36. The imaging system of claim 35, further comprising an image processor in communication with the one or more detector modules, the image processor configured to generate images of the material sample based on the ionizing radiation and the encoding technique, wherein:

the material sample includes biological tissue and the image processor is configured for medical imaging thereof;

or

the material sample includes a non-tissue material and the image processor is configured for non-medical science, industry or inspection imaging thereof.

37. The imaging system of claim 35, wherein the encoding technique includes non-optical information carriers with or without passive optical encoding.

38. The imaging system of claim 37, wherein:

the one or more detector modules include one or more of slab, block, pixelated, array, layered, 3D structured and structured ionizing radiation detector elements;

or

the encoding technique is implemented with structured ionizing radiation detector elements of the one or more detector modules.