Radiation image acquisition system and radiation image acquisition method

Patent metadata

Field	Value
Publication number	US-11237278-B2
Application number	US-202016890325-A
Country	US
Kind code	B2
Filing date	Jun 2, 2020
Priority date	Sep 30, 2015
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

A radiation image acquisition system includes a radiation source that outputs radiation toward an object, a scintillator that has an input surface to which the radiation output from the radiation source and transmitted through the object is input, converts the radiation input to the input surface into scintillation light, and is opaque to the scintillation light, an image capturing means that includes a lens portion focused on the input surface and configured to image the scintillation light output from the input surface and an image capturing unit configured to capture an image of the scintillation light imaged by the lens portion and outputs radiation image data of the object A, and an image generating unit that generates a radiation image of the object based on the radiation image data output from the image capturing means.

First claim

The invention claimed is:

1. A system for acquiring a radiation image of a moving object, comprising:
a radiation source configured to output X-rays toward the object;
a scintillator having an input surface and configured to convert the X-rays transmitted through the object into scintillation light, the scintillator being opaque to the scintillation light;
a scintillator holder configured to hold the scintillator in a state where at least a portion of the scintillator is located within an X-rays flux of the radiation source;
a lens focused on the entire input surface of the scintillator and configured to image the scintillation light output from the input surface;
a line scan camera configured to capture an image of the scintillation light imaged by the lens in accordance with movement of the object and output radiation image data of the object; and
an image generator configured to generate a radiation image of the object based on the radiation image data,
wherein the scintillator holder is configured to hold the scintillator such that the input surface is inclined with respect to an optical axis of the lens and an optical axis of the radiation source.

2. The system according to claim 1 , wherein the lens is disposed so as to be opposed to the input surface.

3. The system according to claim 1 , further comprising a conveyer disposed between the radiation source and the scintillator and configured to convey the object in a conveying direction.

4. The system according to claim 1 , wherein the line scan camera includes an area image sensor configured to perform time delay integration driving and capture the image of the scintillation light imaged by the lens by performing charge transfer on a light receiving surface in synchronization with movement of the object.

5. The system according to claim 1 , wherein a tube voltage of the radiation source is configured to be adjusted within a range of 10 kV to 300 kV, and a thickness of the scintillator is within a range of 10 μm to 1,000 μm.

6. The system according to claim 1 , wherein a tube voltage of the radiation source is configured to be adjusted within a range of 150 kV to 1,000 kV, and a thickness of the scintillator is within a range of 100 μm to 50,000 μm.

7. The system according to claim 1 , wherein the image generator is configured to generate the radiation image of the object based on a lookup table for contrast conversion corresponding to at least a thickness of the scintillator.

8. The system according to claim 1 , wherein the radiation source is configured to output X-rays including characteristic X-rays of not more than 20 keV, and X-rays transmitted through the object and converted by the scintillator includes characteristic X-rays of not more than 20 keV.

9. A method for acquiring a radiation image of a moving object, comprising:
outputting X-rays from a radiation source toward the object;
converting the X-rays transmitted through the object into scintillation light by using a scintillator that is opaque to the scintillation light;
imaging the scintillation light output from an input surface of the scintillator onto an line scan camera by using a lens focused on the entire input surface of the scintillator, wherein the scintillator is disposed such that the input surface is inclined with respect to an optical axis of the lens and an optical axis of the radiation source;
capturing an image of the imaged scintillation light by using the line scan camera in accordance with movement of the object and outputting radiation image data of the object; and
generating a radiation image of the object based on the radiation image data.

10. The method according to claim 9 , further comprising conveying the object in a conveying direction by using a conveyer disposed between the radiation source and the scintillator.

11. The method according to claim 9 , wherein the line scan camera includes an area image sensor configured to perform time delay integration driving, and
the capturing performs charge transfer on a light receiving surface of the area image sensor in synchronization with the movement of the object.

12. The method according to claim 9 , wherein a thickness of the scintillator is within a range of 10 μm to 1,000 μm, and
in the outputting X-rays, a tube voltage of the radiation source is within a range of 10 kV to 300 kV.

13. The method according to claim 9 , wherein a thickness of the scintillator is within a range of 100 μm to 50,000 μm, and
in the outputting X-rays, a tube voltage of the radiation source is within a range of 150 kV to 1,000 kV.

14. The method according to claim 9 , wherein the generating generates the radiation image of the object based on a lookup table for contrast conversion corresponding to at least a thickness of the scintillator.

15. The method according to claim 9 , wherein outputting X-rays outputs X-rays including characteristic X-rays of not more than 20 keV, and the converting converts X-rays transmitted through the object and including characteristic X-rays of not more than 20 keV into the scintillation light.

Assignees

• Hamamatsu Photonics Kk

Inventors

• SUGIYAMA Mototsugu
• Onishi Tatsuya
• Suyama Toshiyasu

Classifications

• G01T1/20 Primary

  with scintillation detectors · CPC title

• G01T7/08

  Means for conveying samples received · CPC title

• G01N23/04 Primary

  and forming images of the material · CPC title

• G06T2207/10116

  X-ray image · CPC title

• G06T5/009

  Physics · mapped topic