X-ray imaging apparatus and control method for the same

Patent metadata

Field	Value
Publication number	US-9504439-B2
Application number	US-201414507951-A
Country	US
Kind code	B2
Filing date	Oct 7, 2014
Priority date	Oct 7, 2013
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

An X-ray imaging apparatus includes an X-ray source configured to radiate X-rays to a region of a subject, an X-ray detector configured to acquire a plurality of frame images related to the region of the subject by detecting the radiated X-rays, a filter configured to filter the X-rays radiated from the X-ray source, an image processor configured to set a region of interest within the region of the subject based on the plurality of frame images, and a controller configured to control the filter so that X-rays of a lower dose than a dose of X-rays made incident on the region of interest are made incident on a region of non-interest within the region of the subject, and control the X-ray detector so that a gain of the X-ray detector in the region of non-interest is greater than that in the region of interest.

First claim

What is claimed is:

1. An X-ray imaging apparatus comprising:
an X-ray source configured to radiate X-rays to a region of a subject;
an X-ray detector configured to acquire a plurality of frame images related to the region of the subject by detecting the radiated X-rays;
a filter configured to filter the X-rays radiated from the X-ray source;
an image processor configured to set a region of interest within the region of the subject based on the plurality of frame images; and
a controller configured to control the filter so that X-rays of a lower dose than a dose of X-rays made incident on the region of interest are made incident on a region of non-interest within the region of the subject, and control the X-ray detector so that a gain of the X-ray detector in the region of non-interest is greater than a gain of the X-ray detector in the region of interest.

2. The X-ray imaging apparatus according to claim 1 , wherein the controller is configured to control the X-ray detector in such a manner that a gain difference between the gain of the X-ray detector in the region of non-interest and the gain of the X-ray detector in the region of interest is proportional to a difference between the dose of the X-rays made incident on the region of non-interest and the dose of the X-ray made incident on the region of interest.

3. The X-ray imaging apparatus according to claim 1 , wherein the filter comprises:
a filter for the region of interest that is made of a filter material for attenuating the X-rays, and
a filter driver configured to move the filter for the region of interest.

4. The X-ray imaging apparatus according to claim 3 , wherein the image processor is configured to acquire information about the region of interest and information about image characteristics based on the plurality of frame images, and transmit the acquired information to the controller.

5. The X-ray imaging apparatus according to claim 4 , wherein the information about the region of interest is at least one of a position of the region of interest, a size of the region of interest, and a movement characteristic of the region of interest.

6. The X-ray imaging apparatus according to claim 4 , wherein the controller is configured to control the filter driver in such a manner that the filter driver moves the filter for the region of interest to a position corresponding to the region of non-interest based on the information about the region of interest.

7. The X-ray imaging apparatus according to claim 4 , wherein the controller is configured to determine a difference in the doses of the X-rays made incident on the region of non-interest and the region of interest based on the information about image characteristics.

8. The X-ray imaging apparatus according to claim 7 , wherein the controller is configured to control a kind or a thickness of the filter for the region of interest according to the determined difference in the doses of the X-rays.

9. The X-ray imaging apparatus according to claim 1 , wherein each pixel of the X-ray detector comprises a variable amplifier or a plurality of amplifiers.

10. The X-ray imaging apparatus according to claim 9 , wherein the controller is configured to control the X-ray detector in such a manner that the amplifier of a pixel corresponding to the region of interest has a first gain, the amplifier of a pixel corresponding to the region of non-interest has a second gain, and the first gain is smaller than the second gain.

11. The X-ray imaging apparatus according to claim 1 , wherein each pixel of the X-ray detector comprises a variable capacitance element.

12. The X-ray imaging apparatus according to claim 11 , wherein the controller is configured to control the X-ray detector in such a manner that the variable capacitance element of a pixel corresponding to the region of interest has a first capacitance, the variable capacitance element of a pixel corresponding to the region of non-interest has a second capacitance, and the first capacitance is greater than the second capacitance.

13. The X-ray imaging apparatus according to claim 1 , wherein the image processor is configured to perform setting of the region of interest in real time according to a frame rate.

14. A control method for an X-ray imaging apparatus, the control method comprising:
radiating, by an X-ray source, X-rays to a region of a subject;
acquiring, by an X-ray detector, a plurality of frame images related to the region of the subject by detecting the radiated X-rays;
setting a region of interest within the region of the subject based on the plurality of frame images;
filtering the X-rays radiated from the X-ray source so that X-rays of a lower dose than a dose of X-rays made incident on the region of interest are made incident on a region of non-interest within the subject; and
controlling the X-ray imaging apparatus in such a manner that a gain of the X-ray detector in the region of non-interest is greater than a gain in the region of interest.

15. The control method for the X-ray imaging apparatus according to claim 14 , wherein the controlling comprises controlling the X-ray imaging apparatus in such a manner that a gain difference of the X-ray detector in the region of non-interest and the region of interest is proportional to a difference in the doses of the X-rays made incident on the region of non-interest and the region of interest.

16. The control method for the X-ray imaging apparatus according to claim 14 , further comprising acquiring information about the region of interest and information about image characteristics based on the plurality of frame images.

17. The control method for the X-ray imaging apparatus according to claim 16 , wherein the filtering of the X-rays comprises moving a filter for the region of interest that attenuates the radiated X-rays to a position corresponding to the region of non-interest based on the information about the region of interest.

18. The control method for the X-ray imaging apparatus according to claim 16 , wherein the filtering of the X-rays comprises determining a difference in the doses of the X-rays made incident on the region of non-interest and the region of interest based on the information about image characteristics, and controlling a kind or a thickness of the filter for the region of interest according to the determined difference in the doses of the X-rays.

19. The control method for the X-ray imaging apparatus according to claim 14 , wherein the controlling comprises controlling the X-ray imaging apparatus in such a manner that each pixel of the X-ray detector comprises a variable amplifier or a plurality of amplifiers, the amplifier of a pixel corresponding to the region of interest has a first gain, the amplifier of a pixel corresponding to the region of non-interest has a second gain, and the first gain is smaller than the second gain.

20. The control method for the X-ray imaging apparatus according to claim 14 , wherein the controlling comprises controlling the X-ray imaging apparatus in such a manner that, when each pixel of the X-ray detector includes a variable capacitance element, the variable capacitance element of a pixel corresponding to the region of interest has a first capacitance, and the variable capacitance element of a pixel corresponding to the region of non-interest has a second capacitance, setting the first capacitance to be greater than the second capacitance.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Yi Jaemock
• Kang Dong-Goo
• Sung Young Hun

Classifications

• A61B6/405

  Source units specially adapted to modify characteristics of the beam during the data acquisition process (A61B6/4021, A61B6/4035 take precedence) · CPC title

• A61B6/4035

  the source being combined with a filter or grating · CPC title

• A61B6/4233

  using matrix detectors · CPC title

• A61B6/504

  for diagnosis of blood vessels, e.g. by angiography · CPC title

• A61B6/469

  for selecting a region of interest [ROI] · CPC title