Protection of a gamma radiation detector with an optical modulator to modulate an amount of transmission between a gamma scintillator array and a first photodetector array

Patent metadata

Field	Value
Publication number	US-11762107-B2
Application number	US-201716470385-A
Country	US
Kind code	B2
Filing date	Dec 21, 2017
Priority date	Dec 21, 2016
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

The invention relates to a combined detector ( 660 ) comprising a gamma radiation detector ( 100 ) and an X-ray radiation detector ( 661 ). The gamma radiation detector ( 100 ) comprises a gamma scintillator array ( 101 x, y ), an optical modulator ( 102 ) and a first photodetector array ( 103 a, b ) for detecting the first scintillation light generated by the gamma scintillator array ( 101 x, y ). The optical modulator ( 102 ) is disposed between the gamma scintillator array ( 101 x, y ) and the first photodetector array ( 103 a, b ) for modulating a transmission of the first scintillation light between the gamma scintillator array ( 101 x, y ) and the first photodetector array ( 103 a, b ). The optical modulator ( 102 ) comprises at least one optical modulator pixel having a cross sectional area ( 102 ′) in a plane that is perpendicular to the gamma radiation receiving direction ( 104 ). The cross sectional area of each optical modulator pixel ( 102 ′) is greater than or equal to the cross sectional area of each photodetector pixel ( 103′ a, b ).

First claim

The invention claimed is:

1. A combined detector, comprising:
an X-ray radiation detector; and
a gamma radiation detector comprising:
a gamma scintillator array comprising a plurality of first scintillator elements for generating first scintillation light in response to received gamma quanta;
an optical modulator; and
a first photodetector array for detecting the first scintillation light generated by the gamma scintillator array;
wherein the gamma scintillator array, the optical modulator, and the first photodetector array are arranged in a stacked configuration along a gamma radiation receiving direction;
wherein the optical modulator is disposed between the gamma scintillator array and the first photodetector array for modulating a transmission of the first scintillation light between the gamma scintillator array and the first photodetector array;
wherein the optical modulator comprises at least one optical modulator pixel, the at least one optical modulator pixel having a cross sectional area in a plane that is perpendicular to the gamma radiation receiving direction;
wherein the first photodetector array comprises a plurality of photodetector pixels, each photodetector pixel of the plurality of photodetector pixels having a cross sectional area in the plane that is perpendicular to the gamma radiation receiving direction;
wherein a cross sectional area of each optical modulator pixel of the at least one optical modulator pixel is greater than or equal to a cross sectional area of each photodetector pixel of the plurality of photodetector pixels; and

wherein the X-ray radiation detector is disposed along the gamma radiation receiving direction and on an opposite side of the gamma scintillator array to the first photodetector array.

2. The combined detector according to claim 1 , wherein the gamma scintillator array comprises a gamma radiation receiving face and an opposing scintillation light output face;
wherein the opposing scintillation light output face is arranged to face the optical modulator;
wherein the gamma radiation detector further comprises a gamma radiation collimator for collimating gamma quanta; and
wherein the gamma radiation receiving face is arranged to face the gamma radiation collimator.

3. The combined detector according to claim 1 , wherein the optical modulator is configured to modulate a transmission of the first scintillation light between the gamma scintillator array and the first photodetector array by modulating at least one of i) an absorption, ii) a reflection, and iii) a scattering of the first scintillation light.

4. The combined detector according to claim 1 , wherein the optical modulator comprises i) a liquid crystal device, ii) an electrochromic device, iii) a MEMS device, iv) an electrowetting device, or v) an electrophoretic device.

5. A computed tomography (CT) imaging detector comprising:
a combined detector, which comprises:
an X-ray radiation detector, comprising: an X-ray anti-scatter grid disposed along a gamma radiation receiving direction, the X-ray radiation detector further comprising either: an X-ray scintillator array comprising a plurality of second scintillator elements for generating second scintillation light in response to received X-ray quanta: a second photodetector array for detecting the second scintillation light; wherein the second photodetector array is in optical communication with the plurality of second scintillator elements for detecting the second scintillation light; and wherein the X-ray scintillator array and the second photodetector array are arranged in a stacked configuration along the gamma radiation receiving direction; or an array of direct-conversion X-ray detector elements; wherein each direct-conversion X-ray detector element of the array of direct-conversion X-ray detector elements is configured to generate electrical signals in response to received X-ray quanta;
a gamma scintillator array comprising a plurality of first scintillator elements for generating first scintillation light in response to received gamma quanta;
an optical modulator; and
a first photodetector array for detecting the first scintillation light generated by the gamma scintillator array;
wherein the gamma scintillator array, the optical modulator, and the first photodetector array are arranged in a stacked configuration along the gamma radiation receiving direction;
wherein the optical modulator is disposed between the gamma scintillator array and the first photodetector array for modulating a transmission of the first scintillation light between the gamma scintillator array and the first photodetector array;
wherein the optical modulator comprises at least one optical modulator pixel, the at least one optical modulator pixel having a cross sectional area in a plane that is perpendicular to the gamma radiation receiving direction;
wherein the first photodetector array comprises a plurality of photodetector pixels, each photodetector pixel of the plurality of photodetector pixels having a cross sectional area in the plane that is perpendicular to the gamma radiation receiving direction;
wherein a cross sectional area of each optical modulator pixel of the at least one optical modulator pixel is greater than or equal to a cross sectional area of each photodetector pixel of the plurality of photodetector pixels; and
wherein the X-ray radiation detector is disposed along the gamma radiation receiving direction and on an opposite side of the gamma scintillator array to the first photodetector array.

6. An imaging arrangement comprising:
a combined detector, comprising: a gamma radiation detector, comprising:
a gamma scintillator array comprising a plurality of first scintillator elements for generating first scintillation light in response to received gamma quanta; an optical modulator; and a first photodetector array for detecting the first scintillation light generated by the gamma scintillator array;
wherein the gamma scintillator array, the optical modulator, and the first photodetector array are arranged in a stacked configuration along a gamma radiation receiving direction;
wherein the optical modulator is disposed between the gamma scintillator array and the first photodetector array for modulating a transmission of the first scintillation light between the gamma scintillator array and the first photodetector array;
wherein the optical modulator comprises at least one optical modulator pixel, the at least one optical modulator pixel having a cross sectional area in a plane that is perpendicular to the gamma radiation receiving direction;
wherein the first photodetector array comprises a plurality of photodetector pixels, each photodetector pixel of the plurality of photodetector pixels having a cross sectional area in the plane that is perpendicular to the gamma radiation receiving direction; and
wherein a cross sectional area of each optical modulator pixel of the at least one optical modulator pixel is greater than or equal to a cross sectional area of each photodetector pixel of the plurality of photodetector pixels; and an X-ray radiation detector disposed along the gamma radiation receiving direction and on an opposite side of the gamma scintillator array to the first photodetector array; and
an X-ray source; and
a processor in communication with the X-ray source and the optical modulator, and is configured to control a transmission of the optical modulator in a synchronization with an emission of X-ray radiation from the X-ray source.

7. The imaging arrangement according to claim 6 , wherein the processor is further configured to control the transmission of the optical modulator by switching the optical modulator between a first transmission state and a second transmission state;

Assignees

• Koninklijke Philips Nv

Inventors

• Kok Christiaan

Classifications

• G01T1/2008 Primary

  using a combination of different types of scintillation detectors, e.g. phoswich · CPC title

• G01T1/20181 Primary

  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 title

• G01T1/1617

  with scintillation detectors (G01T1/20 takes precedence) · CPC title

• G01T1/20185

  Coupling means between the photodiode and the scintillator, e.g. optical couplings using adhesives with wavelength-shifting fibres · CPC title

• G01T1/164

  Scintigraphy · CPC title