Radiation detector and scanner

• US 10,459,091 B2
• Filed: 09/30/2016
• Issued: 10/29/2019
• Est. Priority Date: 09/30/2016
• Status: Active Grant

• Current Assignee: Varex Imaging Corporation
• Original Assignee: Varex Imaging Corporation
• Inventors: Shedlock, Daniel, Nisius, David T, Star-Lack, Josh M, Donnald, Samuel, Virshup, Gary F, Clayton, James E
• Primary Examiner(s): Fox, Dani
• Application Number:
  US15/283,082
• Publication Number:
  US 20180095188A1
• Time in Patent Office: 1,124 Days
• 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 1/20187 Position of the scintillator with respect to the photodiode, e.g. photodiode surrounding the crystal, the crystal surrounding the photodiode, shape or size of the scintillator

Abstract

A system operable for detecting radiation to scan an object includes scintillators that have respective lengths that are greater than their respective widths and an imager that has a planar array of pixels. The scintillators are coupled to the imager with their respective longitudinal axes parallel to each other. An incoming radiation beam that has passed through the object enters the scintillators through respective surfaces of the scintillators that are transverse to the longitudinal axes, and is converted by the scintillators into light that is received by respective subsets of the planar array of pixels.

Claims

1. A system operable for detecting radiation, the system comprising:

an imager comprising a first planar array of pixels; and

a plurality of scintillators;

wherein each scintillator has a length, height and a width;

wherein each scintillator has a first end opposite from a second end on a longitudinal axis of the scintillator and that are separated by a distance that is the length of the scintillator;

wherein the length of each scintillator is greater than its respective width such that each scintillator is a rectangular cuboid;

wherein each scintillator has a first surface at its first end that is transverse to its respective longitudinal axis and that is configured to receive an incoming radiation beam;

wherein the scintillators are coupled to the imager such that the respective longitudinal axes of the scintillators are parallel to each other;

wherein an incoming radiation beam, that enters the scintillators through their respective first surfaces is converted by the scintillators into light that is received by respective subsets of the first planar array of pixels;

wherein the imager generates signals in response to the light that is received by the subsets of the first planar array of pixels; and

wherein the system is configured such that only a subset of the signals is sampled per sample interval and the subset of signals corresponds to less than all of the pixels that receive the light.

2. The system of claim 1, wherein the scintillators are coupled to the imager such that the longitudinal axes are parallel to the first planar array of pixels.

3. The system of claim 2,

wherein the imager further comprises a second planar array of pixels separated from the first planar array by light-reflective material,

wherein the scintillators traverse the first planar array, the light-reflective material, and the second planar array, and

wherein light generated in the scintillators downstream of the first planar array is reflected by the light-reflective material to the second planar array.

4. The system of claim 1, wherein the scintillators are coupled to the imager such that the longitudinal axes are perpendicular to the first planar array of pixels.

5. The system of claim 1, wherein each scintillator comprises light-reflective material on each of its respective surfaces except on its first surface and except on a second surface facing the imager.

6. The system of claim 1, wherein each scintillators comprises light-reflective material on its respective surfaces except on its first surface and except on at least a portion of a second surface facing the imager.

7. The system of claim 1, wherein the length of each scintillator is at least two times greater than its respective width.

8. A system for scanning an object, the system comprising:

a plurality of detectors, each of the detectors operable for receiving a radiation beam that is generated by a source and that travels a path that passes through the object,

wherein each of the detectors comprises;

an imager comprising rows and columns of pixels arrayed on a planar surface;

a plurality of scintillators coupled to the imager;

wherein each scintillator has a length, height and a width;

wherein each scintillator has a first end opposite from a second end on a longitudinal axis of the scintillator and that are separated by a distance that is the length of the scintillator;

wherein the length of each scintillator is greater than its respective width such that each scintillator is a rectangular cuboid;

wherein each scintillator has a first surface at its first end that is transverse to its respective longitudinal axis and that is configured to receive an incoming radiation beam;

wherein the scintillators are coupled to the imager with their respective longitudinal axes parallel to each other and parallel to the path of the radiation beam;

wherein the radiation beam enters the scintillators through their respective first surfaces and is converted by the scintillators into light that is received by respective subsets of the first planar array of pixels at the imager; and

wherein the pixels that receive the light generate signals in response thereto; and

circuitry coupled to the imager that converts the signals generated by the pixels into electrical signals;

wherein the system is configured such that only a subset of the signals is sampled per sample interval and the subset of signals corresponds to less than all of the pixels that receive the light.

9. The system of claim 8, wherein the scintillators are coupled to the imager such that the longitudinal axes are parallel to the planar surface.

10. The system of claim 9,

wherein the rows and columns of pixels comprise a first array of rows and columns of the pixels and a second array of rows and columns of the pixels,

wherein the second array is separated from the first array by light-reflective material,

wherein the scintillators traverse the first array, the light-reflective material, and the second array, and

wherein light generated in the scintillators downstream of the first array is reflected by the light-reflective material to the second array.

11. The system of claim 8, wherein the scintillators are coupled to the imager such that the longitudinal axes are perpendicular to the planar surface.

12. The apparatus of claim 8, wherein each scintillator comprises light-reflective material on each of its respective surfaces except on its first surface and except on its second surface facing the imager.

13. The system of claim 8, wherein each scintillator comprises light-reflective material on each of its respective surfaces except on its first surface and except on at least a portion of a second surface of the scintillator facing the imager.

14. The system of claim 8, wherein the system is configured such that the subset of the signals includes only the signals from less than all of the rows of pixels.

15. A method for scanning an object, the method comprising:

receiving, at a plurality of scintillators, an incoming radiation beam that has passed through the object;

wherein each scintillator has a first end opposite from a second end on a longitudinal axis of the scintillator and that are separated by a distance that is the length of the scintillator;

wherein each scintillator has a length, height and a width;

wherein the length of each scintillator is greater than its respective width such that each scintillator is a rectangular cuboid;

wherein each scintillator has a first surface at its first end that is transverse to its respective longitudinal axis and that is configured to receive an incoming radiation beam;

wherein the plurality of scintillators are coupled to an imager with their respective longitudinal axes parallel to each other;

wherein the incoming radiation beam enters the scintillators through their respective first surfaces;

wherein the imager comprises pixels;

and

wherein the radiation beam is converted by the scintillators into light;

receiving the light from the scintillators at subsets of the pixels at the imager; and

converting the light into electrical signals; and

sampling, per sample interval, only a subset of the electrical signals, which corresponds to less than all of the pixels that receive the light, to generate information about the object.

16. The method of claim 15, wherein the imager comprises rows and columns of pixels arrayed on a planar surface, wherein the scintillators are coupled to the imager such that the longitudinal axes are parallel to the planar surface.

18. The method of claim 16, wherein only the scintillators are coupled to the imager such that the longitudinal axes are perpendicular to the planar surface.

19. The method of claim 16, wherein only the signals from less than all of the rows of pixels are sampled per sample interval.

20. The method of claim 15, wherein the scintillators comprise light-reflective material that causes the light generated by the scintillators to reflect within the scintillators.

17. The method of 16,

wherein the rows and columns of pixels comprise a first array of rows and columns of the pixels and a second array of rows and columns of the pixels,

wherein the second array is separated from the first array by light-reflective material,

wherein the scintillators traverse the first array, the light-reflective material, and the second array, and

wherein light generated in the scintillators downstream of the first array is reflected by the light-reflective material to the second array.