CT systems and methods thereof

Patent metadata

Field	Value
Publication number	US-9786041-B2
Application number	US-201414576705-A
Country	US
Kind code	B2
Filing date	Dec 19, 2014
Priority date	Dec 26, 2013
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A CT system and method thereof are discloses. The system includes: a fixed multi-plane multi-source X-ray generation device and a control system thereof that provide X-ray source used in luggage inspection; a single-energy, pseudo-dual-energy or spectral detector system and data transfer system that receive perspective data of X ray penetrating the luggage, and transfer the data to a computer for processing; a conveyor and a control system thereof that control a speed for moving the luggage forth and back, and perform tomogram scanning; and a host computer system that performs tomogram reconstruction and provides man-machine interaction. The system takes full advantage of characteristics, such as high speed and stability, brought by the distributed ray sources which replace the normal slip ring technology. The system also adopts the idea of inverse-geometry CT, and reduces detector area and cost by increasing the number of ray sources. With the reduction of detector area, cone-beam artifacts and cup-shape artifacts caused by scattering are also reduced, and influence of the oblique effect on registration of dual-energy data is suppressed.

First claim

What is claimed is:

1. A Computed Tomography (CT) system, comprising:
a conveyor configured to convey and move an object under inspection linearly;
a first scanning stage comprising multiple sections of ray sources, multiple sections of detectors, and a first data acquisition device, and configured to scan the object and generate a first digital signal, wherein each section of ray sources comprises a plurality of source points, and the multiple sections of ray sources and the multiple sections of detectors are arranged in an inverse-geometry CT manner;
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 multiple sections of ray sources, multiple sections of detectors, and a second data acquisition device, wherein each section of ray sources comprises a plurality of source points, and the multiple sections of ray sources and the multiple sections of detectors are arranged in an inverse-geometry CT manner;
a processor configured and operable 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 controller configured and operable to control an order in which the source points in the first and second scanning stages emit beams, and adjust a scanning parameter of the second scanning stage based on an analysis result of the processor to cause the second scanning stage to output a second digital signal;
wherein the processor reconstructs a CT image of the object at a second image quality higher than the first image quality at least based on the first and second digital signals.

2. The CT system according to claim 1 , further comprising a third scanning stage that comprises multiple sections of ray sources, multiple sections of detectors, and a third data acquisition device, wherein the multiple sections of ray sources and the multiple sections of detectors are arranged in an inverse-geometry CT manner,
the controller is further configured and operable to control an order in which the source points in the third scanning stage emit beams, so that the third scanning stage outputs a third digital signal, and
the processing device is further configured to reconstruct a CT image of the object at least based on the first, second and third digital signals.

3. The CT system according to claim 2 , wherein the multiple ray sources in the first, second and third scanning stages are provided in a plurality of scanning planes 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.

4. The CT system according to claim 1 , wherein the processor is configured and operable to analyze the object based on the first digital signal, and
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 processor indicates that an increased penetrability is required to discern a metal object and its neighborhood.

5. The CT system according to claim 1 , wherein the processor is configured and operable to analyze the object based on the first digital signal, and
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 processor indicates that it is required to discern tiny objects.

6. The CT system according to claim 1 , wherein the processor is configured and operable to analyze the object based on the first digital signal, and
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 processor indicates that it is required to complete scanning within a prescribed time period.

7. The CT system according to claim 1 , wherein the processor is configured to analyze the object based on the first digital signal, and
a beam spectrum for the source points of the second scanning stage is adjusted when the analysis result of the processor indicates that a more accurate material identification is required.

8. The CT system according to claim 2 , wherein a beam intensity of the source points of each of the first, second and third scanning stages can be adjusted according to a number of ray sources preset in the plane where the source points are provided.

9. The CT system according to claim 8 , 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; or
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.

10. 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, wherein each of the scanning stages is provided in an inverse-geometry CT manner,
the method comprises:
controlling the first scanning stage to scan the object 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;
controlling the second scanning stage to scan the object during the movement of the object, and generating a second digital signal; and
reconstructing a CT image of the object at a second image quality higher than the first image quality at least based on the first and second digital signals.

Assignees

• Univ Tsinghua
• Nuctech Co Ltd

Inventors

• Chen Zhiqiang
• Zhang Li
• Zhao Ji
• Huang Qingping
• Jin Xin

Classifications

• G06T2207/30112

  Baggage; Luggage; Suitcase · CPC title

• G01V5/005

  Physics · mapped topic

• G06T7/0002 Primary

  Inspection of images, e.g. flaw detection · CPC title

• G01V5/226 Primary

  using tomography · CPC title