CT systems and methods thereof

Patent metadata

Field	Value
Publication number	US-9746579-B2
Application number	US-201414576737-A
Country	US
Kind code	B2
Filing date	Dec 19, 2014
Priority date	Dec 26, 2013
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A CT system and method thereof are disclosed. The system includes: a conveyor mechanism; a first scanning stage configured to scan the object and generate a first digital signal; a second scanning stage spaced from the first scanning stage at a preset distance in a direction of the object's movement; a processing device configured to reconstruct a CT image of the object at a first image quality based on the first digital signal, and analyze the CT image; and a control device configured to adjust a scanning parameter of the second scanning stage based on an analysis result of the processing device to cause the second scanning stage to output a second digital signal. The processing device reconstructs a CT image of the object at a second image quality higher than the first image quality at least based on the second digital signal. The system takes full advantage of the distributed ray sources which replace the normal slip ring technology.

First claim

What is claimed is:

1. A Computed Tomography (CT) system, comprising:
a conveyor mechanism configured to convey and move an object under inspection linearly;
a first scanning stage comprising a first ray source, a first detector, and a first data acquisition device, and configured to scan the object and generate a first digital signal;
a second scanning stage configured to be spaced from the first scanning stage at a preset distance in a direction of the object's movement, and comprising a second ray source, a second detector, and a second data acquisition device;
a third scanning stage comprising a third ray source, a third detector, and a third data acquisition device;
a processing device configured to reconstruct a CT image of the object at a first image quality based on the first digital signal, and analyze the CT image; and
a control device configured to adjust a scanning parameter of the second scanning stage based on an analysis result of the processing device to cause the second scanning stage to output a second digital signal,
wherein the processing device is further configured to reconstruct a CT image of the object at a second image quality higher than the first image quality at least based on the first digital signal and the second digital signal;
wherein the control device is further configured to adjust a scanning parameter of the third scanning stage based on the CT image of at least the first image quality to cause the third scanning stage to output a third digital signal, and
wherein the processing device is further configured to reconstruct a CT image of the object at a third image quality higher than the first image quality at least based on the first digital signal, the second digital signal, and the third digital signal.

2. The CT system according to claim 1 , wherein when the second scanning stage scans a part of the object, the control device adjusts the scanning parameter of the second scanning stage based on an analysis result of the processing device corresponding to the part, to cause the second scanning stage to output the second digital signal.

3. The CT system according to claim 1 , wherein when the third scanning stage scans a part of the object, the control device adjusts the scanning parameter of the third scanning stage based on an analysis result of the processing device corresponding to the part, to cause the third scanning stage to output the third digital signal.

4. The CT system according to claim 1 , wherein each of the first, second and third scanning stages uses a sparse-view scanning mode.

5. The CT system according to claim 1 , wherein each of the first, second and third scanning stages uses a limited-angle scanning mode.

6. The CT system according to claim 1 , wherein each of the first, second and third ray source comprises a plurality of source points provided in a plurality of scanning planes perpendicular or nearly perpendicular to the direction of the object's movement, and in each of the scanning planes the source points are distributed along one or more continuous or discontinuous segments of line or arc.

7. The CT system according to claim 6 , wherein the source points of the second scanning stage are preset to use an increased voltage to increase ray energy when the analysis result of the processing device indicates that an increased penetrability is required to discern a metal object and its neighborhood.

8. The CT system according to claim 6 , wherein the source points of the second scanning stage are preset to use an increased number of ray sources to increase a spatial resolution when the analysis result of the processing device indicates that it is required to discern tiny objects.

9. The CT system according to claim 6 , wherein the source points of the second scanning stage are adjusted to have a preset number of activated ray sources when the analysis result of the processing device indicates that it is required to complete scanning within a prescribed time period.

10. The CT system according to claim 6 , wherein a beam spectrum for the source points of the second scanning stage is adjusted when the analysis result of the processing device indicates that a more accurate material identification is required.

11. The CT system according to claim 6 , wherein a beam intensity of the source points of each of the first, second and third scanning stages is adjusted according to a number of ray sources preset in the plane where the source points are provided.

12. The CT system according to claim 11 , wherein when the number of the source points is large, the beam intensity is increased to reduce beam-emitting time of each source point and thus ensure completion of scanning within a prescribed time period;
when the number of the source points is small, a high beam intensity is used to increase a signal-to-noise ratio of scan data.

13. A method for a Computed Tomography (CT) system comprising a first scanning stage, and a second scanning stage spaced from the first scanning stage at a preset distance in a moving direction of an object under inspection and a third scanning stage,
the method comprises:
scanning the object by the first scanning stage during the movement of the object, and generating a first digital signal;
reconstructing a CT image of the object at a first image quality based on the first digital signal, and analyzing the CT image;
adjusting a scanning parameter of the second scanning stage based on an analysis result to cause the second scanning stage to output a second digital signal;
adjusting a scanning parameter of the third scanning stage based on the CT image of at least the first image quality to cause the third scanning stage to output a third digital signal;
reconstructing a CT image of the object at a second image quality higher than the first image quality at least based on the first digital signal and the second digital signal; and
reconstructing a CT image of the object at a third image quality higher than the first image quality at least based on the first digital signal, the second digital signal, and the third digital signal.

14. The method according to claim 13 , wherein when the second scanning stage scans a part of the object, the scanning parameter of the second scanning stage is adjusted based on an analysis result corresponding to the part, to cause the second scanning stage to output the second digital signal.

Assignees

• Univ Tsinghua
• Nuctech Co Ltd

Inventors

• Zhang Li
• Chen Zhiqiang
• Huang Qingping
• Jin Xin
• Sun Yunda
• Shen Le
• Zhao Ji

Classifications

• G06T12/00

  Tomographic reconstruction from projections · CPC title

• G06T12/10

  Image preprocessing, e.g. calibration, positioning of sources or scatter correction · CPC title

• G06T2207/10072

  Tomographic images · CPC title

• G01T7/08

  Means for conveying samples received · CPC title

• G01N23/046 Primary

  using tomography, e.g. computed tomography [CT] · CPC title