X-ray imaging systems for reducing artefacts associated with anti-scatter grids and methods of operating the same

Patent metadata

Field	Value
Publication number	US-11864932-B2
Application number	US-202117797294-A
Country	US
Kind code	B2
Filing date	Dec 8, 2021
Priority date	Dec 14, 2020
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

The disclosure relates to an X-ray imaging system for acquiring two-dimensional or three-dimensional images of a subject. A relative position of an X-ray emitting region, as seen in a coordinate system which is stationary relative to an anti-scatter arrangement and/or an X-ray sensitive surface is controlled so that a first and a second image are acquired at different relative positions of the X-ray emitting region relative to the anti-scatter arrangement and/or the X-ray sensitive surface (10). A data processing system of the imaging system generates an output image, based on each of the images. In the output image, artefacts generated by the anti-scatter arrangement, are reduced, suppressed or eliminated compared to the first and the second image.

First claim

The invention claimed is:

1. An X-ray imaging system for acquiring two-dimensional or three-dimensional images of a subject, the imaging system comprising:
an X-ray source configured to emit X-rays from one or more X-ray emitting regions;
a detector system configured to receive a portion of the X-rays, which has been passed through the subject, wherein the X-rays are received on an X-ray sensitive surface of the detector system;
an anti-scatter arrangement, which is arranged in the beam path of the X-rays between the X-ray emitting region and the detector system;
wherein the imaging system is configured to acquire a first and a second image of the subject, wherein each of the first and second images shows
(a) a same portion of a body of the subject and
(b) an image artifact generated by the anti-scatter arrangement ( 9 );

wherein the imaging system is configured to:
control a relative position of at least one of the one or more X-ray emitting regions, as seen in a coordinate system which is stationary relative to the anti-scatter arrangement and/or the X-ray sensitive surface so that the first and second images are acquired at different relative positions of the at least one X-ray emitting region relative to the anti-scatter arrangement and/or the X-ray sensitive surface; and to
generate, using a data processing system of the imaging system, an output image, based on each of the first and second images;
wherein the output image shows the portion of the body and in the output image, artefacts generated by the anti-scatter arrangement, are reduced, suppressed or eliminated compared to the first and the second image.

2. The imaging system of claim 1 , wherein the data processing system is configured to use an algorithm, which uses differences between the first and the second images, which are caused by the different relative positions of the at least one X-ray emitting region to obtain the reduction, suppression, or elimination of the artefacts associated with the anti-scatter arrangement.

3. The imaging system of claim 1 , wherein the data processing system is configured to generate the output image using a machine learning based algorithm;
wherein the machine learning based algorithm generates the output image based on data of, or derived from, the first image and the second image.

4. The imaging system of claim 3 , wherein the machine learning based algorithm comprises an artificial neural network (ANN).

5. The imaging system of claim 4 , wherein the ANN has at least two image input channels,
wherein the data processing system is configured to
(a) use a first one of the image input channels for data of, or derived from at least a portion of the first image; and
(b) use a second one of the image input channels for data of or derived from at least a portion of the second image.

6. The imaging system of claim 1 , wherein the generation of the output image comprises:
determining, using the data processing system, a plurality of image regions of the first image and a plurality of image regions of the second image, which substantially correspond to the image regions of the first image so that a plurality of pairs of substantially corresponding image regions are obtained;
sequentially processing the pairs, using the data processing system, to generate, for each of the pairs, a corresponding region of the output image.

7. The imaging system of claim 1 , wherein a distance between the different relative positions is at least 50 micrometers or at least 400 micrometers.

8. The imaging system of claim 1 ,
wherein the anti-scatter arrangement comprises a one-dimensional or two-dimensional array of cells, which are separated from each other by septa;
wherein an X-ray transmittance of each of the cells is greater than an X-ray transmittance of the septa.

9. The imaging system of claim 1 , wherein the X-ray source comprises a housing which houses and electron optical system for generating one or more election beams and a target for receiving the one or more electrons beam so that the one or more X-ray emitting regions are arranged within the housing;
wherein the imaging system is configured to control the X-ray source to controllably displace the at least one X-ray emitting region within the housing.

10. The imaging system of claim 9 , wherein at least one of (a) and (b) holds true:
(a) the electron optical system is configured to selectively deflect the electron beam so that an impingement location of the electron beam on the target is changed; wherein the control of the relative position of the at least one X-ray emitting region comprises varying the impingement location on the target using the electron optical system; and
(b) the X-ray source is configured to generate a first electron beam generating a first X-ray emitting region and a second electron beam generating a second X-ray emitting region, wherein the control of the relative position of the at least one or more X-ray emitting regions comprises actuating and deactivating the two electron beams so that the electron beams are sequentially activated.

11. The imaging system of claim 1 , further comprising an actuator, which is in operational communication with at least a portion of the anti-scatter arrangement and/or with at least a portion of the detector system;
wherein the imaging system is configured so that the variation of the position of the at least one X-ray emitting region relative to the anti-scatter arrangement and/or relative to the X-ray sensitive surface comprises controlling the actuator.

12. The imaging system of claim 1 , wherein the imaging system is configured to acquire the first and the second image within a time period of less than 20 milliseconds, or less than 200 microseconds.

13. The imaging system of claim 1 , further comprising a measurement unit which is configured to acquire position data indicate of a position of one or more of the X-ray emitting regions.

14. The imaging system of claim 13 , wherein the data processing system is configured to determine the output image further based on the position data.

15. A method for operating an X-ray imaging system for acquiring two-dimensional or three-dimensional images of a subject and for reducing artefacts which are generated by an anti-scatter arrangement of the X-ray imaging system;
wherein the X-ray imaging system comprises:
an X-ray source configured to emit X-rays from one or more X-ray emitting regions;
a detector system configured to receive a portion of the emitted X-rays, which have been passed through the subject on an X-ray sensitive surface of the detector system;

wherein the anti-scatter arrangement is arranged in the beam path of the X-rays between the subject and the detector system;
wherein the method comprises:
acquiring a first and a second image of the subject so that each of the first and second images shows at least a same portion of a body of the subject and (b) an artifact generated by the anti-scatter arrangement;
controlling a relative position of at least one of the X-ray emitting regions relative to the anti-scatter arrangement and/or the X-ray sensitive surface so that the first and second images are acquired at different relative positions of the at least one X-ray emitting region; and
generating, using a data processing system of the imaging system, an output image, based on each of the first and second images;
wherein the output image shows the portion of the body and in the output image, artefacts which are generated by the anti-scatter arrangement, are reduced, suppressed or eliminated compared to the first and the second image.

Assignees

• Koninklijke Philips Nv

Inventors

• Singh Nishant
• Engel Klaus Jürgen
• Jacobs Johannes Wilhelmus Maria
• Menser Bernd
• Miller Lester Donald
• Van Nijnatten Fred Simon Berend

Classifications

• A61B6/032 Primary

  Transmission computed tomography [CT] · CPC title

• A61B6/4007 Primary

  characterised by using a plurality of source units · CPC title

• A61B6/4291

  the detector being combined with a grid or grating · CPC title

• A61B6/5282

  due to scatter · CPC title