Inspection systems and methods for synchronously positioning radioactive material

Patent metadata

Field	Value
Publication number	US-9945794-B2
Application number	US-201514932054-A
Country	US
Kind code	B2
Filing date	Nov 4, 2015
Priority date	Nov 5, 2014
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A scanning and imaging apparatus comprises a ray source configured to generate an X-ray and a detection device configured to receive an X-ray transmitted through an inspected object, wherein the ray source is configured to image the inspected object by emitting the X-ray to the inspected object. A radioactivity detector is configured to detect whether the inspected object comprises radioactive material synchronously with the process of scanning implemented by the scanning and imaging apparatus. In a case that the radioactivity detector detects radioactive material, an actual position of the radioactive material in an X-ray image of the inspected object obtained by the scanning and imaging apparatus is marked in the image. The above solutions improve the accuracy of displaying the position of the radioactive source in the X-ray image. Further, inspection of radioactive material can be implemented while scanning an image.

First claim

We claim:

1. An inspection system for synchronously positioning radioactive material, comprising:
a scanning and imaging apparatus comprising a ray source configured to generate an X-ray and a detection device configured to receive an X-ray transmitted through an inspected object, wherein the ray source is configured to image the inspected object by emitting the X-ray to the inspected object; and
a radioactivity detector configured to detect whether the inspected object comprises radioactive material synchronously with the process of scanning implemented by the scanning and imaging apparatus,
wherein in a case that the radioactivity detector detects radioactive material, an actual position of the radioactive material in an X-ray image of the inspected object obtained by the scanning and imaging apparatus is marked in the image;
wherein while the scanning and imaging apparatus starts to scan the inspected object, the radioactivity detector starts to detect and record a scanning start time; and when radioactive material is detected, the radioactivity detector transmits a time interval from a time when the radioactive material is detected to the scanning start time to the scanning and imaging apparatus as a warning start time of the radioactive material, and when it is detected that a radiation of the radioactive material ends, the radioactivity detector transmits a warning peak time and a warning end time to the scanning and imaging apparatus respectively, and then the scanning and imaging apparatus calculates the actual position of the radioactive material in the image of the inspected object based on the scanning start time, the warning start time, the warning peak time, and the warning end time; wherein the warning peak time is a time interval from a time when a peak value of the radioactive material is detected by the radioactivity detector to the scanning start time, and the warning end time is a time interval from a time when no radioactive material is detected by the radioactivity detector to the scanning start time.

2. The system according to claim 1 , wherein the radioactivity detector is arranged to be located at a predetermined distance from a main beam from the ray source in a movement direction of the inspected object.

3. The system according to claim 1 , wherein a sensor which is arranged in a corresponding position in a scanning plane of the ray source of the scanning and imaging apparatus is configured to determine that the inspected object has been scanned, or the scanning and imaging apparatus and the radioactivity detector are controlled by a synchronous signal to operate synchronously, or a high voltage is applied to the ray source to trigger the radioactivity detector to start to operate.

4. The system according to claim 1 , wherein,
the scanning start time is denoted as T 1 , a scanning end time is denoted as T 2 , and a period of time during which the whole scanning image is obtained is denoted as T;
the scanning and imaging apparatus obtains warning start information, warning peak information, and warning end information of the radioactive material from the radioactivity detector, which are denoted as Ts, Tm and Te respectively, wherein Ts, Tm and Te are time intervals from the warning start time, the warning peak time, and the warning end time to the scanning start time T 1 respectively;
ratios between the warning start, the warning peak, and the warning end in the whole scanning process are obtained by calculating Ts/T, Tm/T, and Te/T;
after the scanning implemented by the scanning and imaging apparatus ends, a total number of columns N is obtained from the detection device thereof, and is multiplied with the ratios Ts/T, Tm/T, and Te/T, to obtain numbers of columns Ns, Nm, and Ne corresponding to the respective warning start, warning peak, and warning end in the image; and the corresponding positions of the warning start, the warning peak, and the warning end in the image are obtained respectively by shifting Ns, Nm, and Ne columns from the corresponding position of the scanning start time T 1 in the image along an image formation direction.

5. The system according to claim 4 , wherein numbers of columns Ns, Nm, and Ne of the warning start, the warning peak, and the warning end are corrected or the corresponding position of the scanning start time T 1 in the image is corrected based on a distance between the radioactivity detector and the detection device of the scanning and imaging apparatus in a relative movement direction.

6. The system according to claim 1 , wherein the radioactivity detector implements radioactivity detection in a time interval between two pulses of rays emitted by the ray source, to avoid interference to the ray source.

7. The system according to claim 1 , further comprising a speed sensor configured to measure a speed of the inspected object in the detection process in a case that the scanning and imaging apparatus is static and the inspected object moves, wherein the scanning and imaging apparatus is configured to control reconstruction of the scanned image according to a movement speed related to the inspected object received from the speed sensor, and modify the data of the scanned image according to the movement speed.

8. The system according to claim 7 , wherein the inspected object moves at a predetermined speed relative to the system, and if the inspected object moves at an upper limit of a range of the predetermined speed, the scanning and imaging apparatus implements sampling at a beam emission frequency of the ray source; and
if the inspected object moves at a speed lower than the upper limit of the range of the predetermined speed, the scanning and imaging apparatus is in a sub-sampling state, and the image is reconstructed by using an interpolation method or convolution method.

9. A method for positioning radioactive material, comprising steps of:
imaging an inspected object by using a scanning and imaging apparatus comprising a ray source configured to generate an X-ray and a detection device configured to receive an X-ray transmitted through the inspected object, wherein the ray source is configured to image the inspected object by emitting the X-ray to the inspected object; and
detecting, by a radioactivity detector, whether the inspected object comprises radioactive material synchronously with the process of scanning implemented by the scanning and imaging apparatus,
wherein in a case that the radioactivity detector detects radioactive material, an actual position of the radioactive material in an X-ray image of the inspected object obtained by the scanning and imaging apparatus is marked in the image;
wherein while the scanning and imaging apparatus starts to scan the inspected object, the radioactivity detector starts to detect and record a scanning start time; and when radioactive material is detected, the radioactivity detector transmits a time interval from a time when the radioactive material is detected to the scanning start time to the scanning and imaging apparatus as a warning start time of the radioactive material, and when it is detected that a radiation of the radioactive material ends, the radioactivity detector transmits a warning peak time and a warning end time to the scanning and imaging apparatus respectively, and then the scanning and imaging apparatus calculates the actual position of the radioactive material in the image of the inspected object based on the scanning start time, the warning start time, the warning peak time, and the warning end time; wherein the warning peak time is a time interval from a time when a peak value of the radioactive material is detected by the radioactivity detector to the scanning start time, and the warning end time is a ti

Assignees

• Nuctech Co Ltd

Inventors

• Zeng Lei
• Wang Qiang
• Du long

Classifications

• G01N23/04 Primary

  and forming images of the material · CPC title

• G01V5/0066

  Physics · mapped topic

• G01V5/0075

  Physics · mapped topic

• G01V5/0016

  Physics · mapped topic

• G01V5/26

  Passive interrogation, i.e. by measuring radiation emitted by objects or goods · CPC title