Structured detectors and detector systems for radiation imaging

• US 10,520,611 B2
• Filed: 02/05/2018
• Issued: 12/31/2019
• 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): Taningco, Marcus H
• Assistant Examiner(s): Gutierrez, Gisselle M
• Application Number:
  US15/888,692
• Publication Number:
  US 20180172849A1
• Time in Patent Office: 694 Days
• Field of Search: 25036302, 378 19
• CPC Class Codes: A61B 6/025 Tomosynthesis
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/035 Mechanical aspects of CT
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/0492 using markers or indicia for aiding patient positioning
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: A61B 6/4208 characterised by using a particular type of detector
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: A61B 6/4417 related to combined acquisition of different diagnostic modalities
• CPC Class Codes: A61B 6/4435 the source unit and the detector unit being coupled by a rigid structure
• CPC Class Codes: G01N 2223/108 positrons; electron-positron annihilation
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 2223/505 scintillation
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: G01N 23/2255 using incident ion beams, e.g. proton beams
• CPC Class Codes: G01T 1/20181 Stacked detectors, e.g. for measuring energy and positional information using a combination of different types of scintillation detectors, e.g. phoswich detectors, G01T1/2008
• CPC Class Codes: G01T 1/20182 Modular detectors, e.g. tiled scintillators or tiled photodiodes stacked detectors G01T1/20181
• CPC Class Codes: G01T 1/20183 Arrangements for preventing or correcting crosstalk, e.g. optical or electrical arrangements for correcting crosstalk
• CPC Class Codes: G01T 1/20184 Detector read-out circuitry, e.g. for clearing of traps, compensating for traps or compensating for direct hits
• CPC Class Codes: G01T 1/20185 Coupling means between the photodiode and the scintillator, e.g. optical couplings using adhesives with wavelength-shifting fibres
• CPC Class Codes: G01T 1/2019 : Shielding against direct hits
• CPC Class Codes: G01T 1/22 : with Cerenkov detectors

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:

a first layer of scintillator elements, each extending in a first direction along the first layer;

a plurality of photodetectors, including strip photodetectors with a read out at both ends and continuous area photodetectors with a readout at each of the four corners, configured to convert optical signals generated by the scintillator elements into output characterizing radiation interacting therein;

a second layer of one or more semiconductor detector elements oriented edge on or face on with respect to the radiation; and

an intermediate layer between the first and second layers.

2. A detector module according to claim 1, wherein at least one of the layers comprises a plurality of scintillator fibers or optical fibers coupled to a scintillator material.

3. A detector module according to claim 2, wherein at least some of the fibers comprise at least one of encoded cores, nanocrystal materials, electroluminescent materials or wavelength shifting materials provided in an encoded pattern.

4. A detector module according to claim 1, wherein event localization information is employed to correct for optical signal propagation time within the detector module utilizing at least one of a direct event signal, a reflected signal, a cross-coupled signal, a scattered signal, a diffracted signal, a nanocrystal modified signal, an electroluminescent material modified signal, a wavelength shifted signal, or an indirect signal responsive to the event localization in the detector module.

5. An edge-on, integrated PET-CT detector system comprising a plurality of detector modules according to claim 1, wherein the radiation is incident on end faces of the scintillator elements in at least one of the layers or the photodetector elements are optically coupled to side faces thereof, and further comprising readout electronics configured for determination of an interaction position of the radiation within the scintillator elements.

6. The detector system of claim 5, wherein the radiation comprises a combination of x-ray radiation from an x-ray source and gamma radiation from a gamma source and the first and second layers have different energy response to the radiation.

7. The detector system of claim 6 further comprising at least a third layer of scintillator elements having a different energy response to the radiation than at least one of the first or second layers.

8. A detector system according to claim 5, further comprising:

an encoding pattern configured to modulate light sharing between the first and second layers, wherein the encoding pattern is adapted to modulate the optical signals as a function of position along the first and second layers;

or

a pattern of at least one nanocrystal material, electroluminescent material or wavelength shifting material applied to the scintillator elements, wherein the pattern is adapted to modulate the optical signals as a function of position along the first and second layers.

9. An imaging system comprising:

one or more detector modules configured to interrogate a material sample by detecting ionizing radiation, each detector module having;

a first layer of scintillator elements, each extending in a first direction along the first layer;

a plurality of photodetectors, including strip photodetectors with a read out at both ends and continuous area photodetectors with a readout at each of the four corners, configured to convert optical signals generated by the scintillator elements into output characterizing radiation interacting therein;

a second layer of one or more semiconductor detector elements oriented edge on or face on with respect to the radiation; and

an intermediate layer between the first and second layers;

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.

10. The imaging system of claim 9, further comprising an image processor in communication with the 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

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

11. The imaging system of claim 9, wherein the encoding technique utilizes non-optical information carriers with or without passive optical encoding or includes modifying at least one local or global electric, magnetic, electromagnetic, acoustic or thermal ionizing radiation properties of the detector modules.

12. The imaging system of claim 11, wherein:

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

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

13. A method of operating an imaging system comprising a plurality of detector modules according to claim 9, the method comprising:

interrogating a material sample with ionizing radiation;

detecting the ionizing radiation with the plurality of detector modules; and

generating images of the material sample with an image processor in communication with the detector modules, based on the ionizing radiation and the encoding technique;

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

14. The method of claim 13, 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 imaging thereof.

15. The method of claim 13, wherein the encoding technique comprises:

utilizing non-optical information carriers with or without passive optical encoding;

modifying at least one of electric, magnetic, electromagnetic, acoustic or thermal ionizing radiation properties of the at least one of the detector modules;

or

implementing ionizing radiation structured detector elements of the detector modules.