Scanning system for differential phase contrast imaging

• US 9,750,465 B2
• Filed: 12/08/2010
• Issued: 09/05/2017
• Est. Priority Date: 12/10/2009
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Engel, Klaus Juergen, Geller, Dieter, Vogtmeier, Gereon, Koehler, Thomas
• Primary Examiner(s): Kao, Glen
• Application Number:
  US13/514,312
• Publication Number:
  US 20120236992A1
• Time in Patent Office: 2,463 Days
• Field of Search: 378 4, 378 8, 378 20, 378 62, 378 95, 378125, 378136, 378205, 378208, 378209
• CPC Class Codes: A61B 6/00 Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment instruments measuring radiation intensity for application in the field of nuclear medicine, e.g. in vivo counting, G01T1/161; apparatus for taking X-ray photographs G03B42/02
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4291 the detector being combined with a grid or grating
• CPC Class Codes: A61B 6/484 involving phase contrast X-ray imaging
• CPC Class Codes: A61B 6/488 involving pre-scan acquisition
• CPC Class Codes: A61B 6/5241 combining overlapping images of the same imaging modality, e.g. by stitching

Abstract

The invention relates to the field of X-ray differential phase contrast imaging. For scanning large objects and for an improved contrast to noise ratio, an X-ray device (10) for imaging an object (18) is provided. The X-ray device (10) comprises an X-ray emitter arrangement (12) and an X-ray detector arrangement (14), wherein the X-ray emitter arrangement (14) is adapted to emit an X-ray beam (16) through the object (18) onto the X-ray detector arrangement (14). The X-ray beam (16) is at least partial spatial coherent and fan-shaped. The X-ray detector arrangement (14) comprises a phase grating (50) and an absorber grating (52). The X-ray detector arrangement (14) comprises an area detector (54) for detecting X-rays, wherein the X-ray device is adapted to generate image data from the detected X-rays and to extract phase information from the X-ray image data, the phase information relating to a phase shift of X-rays caused by the object (18). The object (18) has a region of interest (32) which is larger than a detection area of the X-ray detector (18) and the X-ray device (10) is adapted to generate image data of the region of interest (32) by moving the object (18) and the X-ray detector arrangement (14) relative to each other.

Claims

1. An X-ray device for imaging an object, comprising:

an X-ray emitter arrangement, and

an X-ray detector arrangement,

wherein the X-ray emitter arrangement is adapted to emit an X-ray beam through the object onto the X-ray detector arrangement,

wherein the X-ray beam is spatially at least partially coherent,

wherein the X-ray beam is fan-shaped,

wherein the X-ray detector arrangement comprises a phase grating and an absorber grating,

wherein the X-ray detector arrangement comprises a detector for detecting X-rays,

wherein the X-ray detector is an area detector,

wherein the X-ray device is adapted to generate image data from the detected X-rays and to extract phase information from the X-ray image data, the phase information relating to a phase shift of X-rays caused by the object,

wherein the object has a region of interest which is larger than a detection area of the X-ray detector and the X-ray device is adapted to generate image data of the region of interest by moving the object and the X-ray detector arrangement relative to each other, wherein the X-ray emitter arrangement comprises an X-ray source with switchable emitter lines, wherein the X-ray emitter arrangement, in a direction of relative movement, of the X-ray detector arrangement with respect to the X-ray emitter arrangement, that is orthogonal to the beam, is larger than the X-ray detector arrangement, wherein the X-ray device is adapted to switch the emitter lines such that solely the emitter lines opposite to the X-ray detector arrangement are switched on.

2. The X-ray device of claim 1, wherein the X-ray emitter lines are adapted to generate said X-ray beam, wherein the X-ray emitter lines comprises a cathode with carbon nanotubes.

3. The X-ray device of claim 1, further comprising:

an actuator for moving the object with respect to the x-ray emitter arrangement and the x-ray detector arrangement;

an actuator for moving the X-ray detector arrangement with respect to the object;

an actuator for moving at least one of the X-ray emitter arrangement and the X-ray detector arrangement around the object;

or

any combination of the actuators.

4. The X-ray device of claim 1, wherein the X-ray device is adapted to move at least one of the phase grating, the absorber grating and a source grating such that the at least one grating remains fixed with respect to the object, when relative movement among any of the object, the X-ray emitter arrangement and the X-ray detector arrangement occurs.

5. The X-ray device of claim 1, wherein the X-ray device is adapted to analyze an X-ray intensity of the X-rays at the X-ray detector arrangement during a first scan step.

6. The X-ray device of claim 5, wherein the X-ray device is adapted to set an intensity of the X-rays emitted by the X-ray emitter arrangement for a second scan step based on the analyzed X-ray intensity of the first scan step.

7. The X-ray device of claim 5, wherein the X-ray device is adapted to set a scan speed of a second scan step based on the analyzed X-ray intensity of the first scan step.

8. An X-ray device for imaging an object, comprising:

an X-ray emitter arrangement, and

an X-ray detector arrangement,

wherein the X-ray emitter arrangement is adapted to emit an X-ray beam through the object onto the X-ray detector arrangement,

wherein the X-ray beam is spatially at least partially coherent,

wherein the X-ray beam is fan-shaped,

wherein the X-ray detector arrangement comprises a phase grating and an absorber grating,

wherein the X-ray detector arrangement comprises a detector for detecting X-rays,

wherein the X-ray detector is an area detector,

wherein the X-ray device is adapted to generate image data from the detected X-rays and to extract phase information from the X-ray image data, the phase information relating to a phase shift of X-rays caused by the object,

wherein the object has a region of interest which is larger than a detection area of the X-ray detector and the X-ray device is adapted to generate image data of the region of interest by moving the object and the X-ray detector arrangement relative to each other, wherein said device has a focal spot, and wherein the movement-based generating entails rotating said X-ray detector arrangement around an axis that goes through said focal spot while said focal spot remains stationary.

9. The X-ray device of claim 8, said rotating being performed to cover a larger field of view than obtained without said rotating.

10. The X-ray device of claim 8, wherein said object includes a person having a torso that has a longitudinal direction, said beam passing through said torso at an angle transverse to said longitudinal direction.

11. The X-ray device of claim 8, wherein the beam is cone-shaped with two dimensions of the cone orthogonal to an axis of the cone being equal or differing.

12. A non-transitory computer-readable medium embodying a computer program for controlling an X-ray device, said program having instructions executable by a processor for performing a plurality of acts, from among said plurality there being the acts of:

generating a fan-shaped X-ray beam that is spatially at least partially coherent,

transmitting the X-ray beam through an object, a phase grating and an absorber grating onto an X-ray area detector,

generating image data from X-rays detected by the X-ray area detector,

extracting phase information from the image data, the phase information relating to a phase shift of X-rays caused by the object;

moving, relative to each other, the object and an X-ray detector arrangement comprising said X-ray area detector; and

generating image data of a region of interest of the object, wherein the region of interest is larger than a detection area of the X-ray area detector, wherein said X-ray beam has a focal spot and among said plurality there further being the act of rotating said X-ray detector arrangement around an axis that goes through said focal spot while said focal spot remains stationary.

13. The computer readable medium of claim 12, wherein said object includes a person having a torso that has a longitudinal direction, said beam passing through said torso at an angle transverse to said longitudinal direction.

14. The computer readable medium of claim 12, wherein said generating is such that said beam is cone-shaped with two dimensions of the cone orthogonal to an axis of the cone being equal or differing.

15. A non-transitory computer readable medium embodying a computer program for controlling an X-ray device, said program having instructions executable by a processor for performing a plurality of acts, from among said plurality there being the acts of:

emitting, via an X-ray emitter arrangement, an X-ray beam through the object onto an X-ray detector arrangement, wherein the X-ray beam is spatially at least partially coherent, wherein the X-ray beam is fan-shaped, wherein the X-ray detector arrangement comprises a phase grating and an absorber grating, wherein the X-ray detector arrangement comprises a detector for detecting X-rays, wherein the X-ray detector is an area detector;

generating, via said X-ray device, image data from the detected X-rays;

extracting phase information from the X-ray image data, the phase information relating to a phase shift of X-rays caused by the object, wherein the object has a region of interest which is larger than a detection area of the X-ray detector;

generating image data of the region of interest by moving the object and the X-ray detector arrangement relative to each other, wherein the X-ray emitter arrangement comprises an X-ray source with switchable emitter lines, wherein the X-ray emitter arrangement, in a direction of relative movement, of the X-ray detector arrangement with respect to the X-ray emitter arrangement, that is orthogonal to the beam, is larger than the X-ray detector arrangement; and

switching the emitter lines such that solely the emitter lines opposite to the X-ray detector arrangement are switched on.

16. The computer readable medium of claim 15, wherein the X-ray device is adapted to move at least one of the phase grating, the absorber grating and a source grating such that the at least one grating remains fixed with respect to the object, when relative movement among any of the object, the X-ray emitter arrangement and the X-ray detector arrangement occurs.

17. The computer readable medium of claim 15, wherein the X-ray device is adapted to analyze an X-ray intensity of the X-rays at the X-ray detector arrangement during a first scan step.

18. The computer readable medium of claim 17, wherein the X-ray device is adapted to set an intensity of the X-rays emitted by the X-ray emitter arrangement for a second scan step based on the analyzed X-ray intensity of the first scan step.

19. The computer readable medium of claim 17, wherein the X-ray device is adapted to set a scan speed of a second scan step based on the analyzed X-ray intensity of the first scan step.