X-ray imaging with pixelated detector

Patent metadata

Field	Value
Publication number	US-9599577-B2
Application number	US-201113818696-A
Country	US
Kind code	B2
Filing date	Aug 30, 2011
Priority date	Sep 6, 2010
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

The invention relates to a method and an imaging system ( 100 ) for generating X-ray images. The system ( 100 ) comprises at least one X-ray source, preferably an array of X-ray sources ( 101 a - 101 d ), and an X-ray detector ( 103 ) with an array of sensitive pixels ( 103 a - 103 e ). A collimator ( 102 ) is arranged between the X-ray source and the detector such that two openings (P) of the collimator ( 102 ) allow the passage of X-rays towards two neighboring pixels ( 103 a - 103 e ) while the region between said pixels is substantially shielded. This shielding of the usually insensitive regions between pixels reduces unnecessary X-ray exposure. A sufficiently large X-ray intensity can be achieved by using a plurality of small X-ray sources ( 101 a - 101 d ).

First claim

The invention claimed is:

1. An X-ray imaging system for generating X-ray projections of an object, comprising:
a plurality of X-ray sources for generating an X-ray beam;
a stationary single integrated X-ray detector that comprises an array of at least two sensitive pixels having X-ray insensitive regions in between, wherein a detection signal of these pixels corresponds to image information at a particular point of the generated projection;
a stationary collimator that comprises at least two openings which allow the passage of X-rays from the plurality of X-ray sources such that each of at least two neighboring pixels of the single integrated X-ray detector is illuminated by X-rays passing through both of the at least two openings while the X-ray insensitive region between said pixels is at least partially shielded by the collimator;
an object space between the collimator and the X-ray detector where an object to be imaged can be accommodated, wherein the stationary collimator is disposed between the plurality of X-ray sources and the object space.

2. The X-ray imaging system according to claim 1 ,
wherein a size and an arrangement of one opening of the at least two openings and one X-ray source of the plurality of X-ray sources are such that only one pixel of the array of the at least two sensitive pixels is illuminated through said one opening by said one X-ray source.

3. The X-ray imaging system according to claim 2 , wherein X-rays from at least two of the plurality of X-ray sources traverse through a same opening of the at least two openings and illuminates two different pixels.

4. The X-ray imaging system according to claim 1 ,
wherein the collimator comprises an array of openings which are in one dimension or in two dimensions aligned with the pixels of the detector such that by illumination with the plurality of X-ray sources, areas of the radiation sensitive pixels are illuminated with a higher intensity than the radiation insensitive regions between them in at least one direction of the pixel array.

5. The X-ray imaging system according to claim 1 ,
wherein a size of the pixels ranges between about 0.1 mm and about 2 mm and/or a pitch of the pixels ranges between about 0.5 mm and 2 mm.

6. The X-ray imaging system according to claim 1 ,
wherein a width of the openings of the collimator ranges between about 100 μm and 500 μm, and/or a pitch of the openings of the collimator ranges between about 100 μm and 500 μm.

7. The X-ray imaging system according to claim 1 , wherein a size and an arrangement of each opening of the at least two openings and each X-ray source of the plurality of X-ray sources is such that one pixel of the array of the at least two sensitive pixels is illuminated by X-rays passing through all of the at least two openings from all of the X-ray sources.

8. The X-ray imaging system according to claim 1 , further comprising:
an X-ray generator with the plurality of X-ray sources, wherein any two of the plurality of X-ray sources is arranged to illuminate a same set of pixels through the openings of the collimator such that an area of the radiation sensitive pixels is illuminated with a higher intensity than the radiation insensitive regions between them in at least one direction of the pixel array.

9. The X-ray imaging system according to claim 8 ,
wherein the plurality of X-ray sources and the collimator openings are arranged in a quasi-periodical pattern.

10. The X-ray imaging system according to claim 1 , further comprising:
an X-ray generator with the plurality of X-ray sources, wherein the plurality of X-ray sources covers an area of less than about 10 mm 2 .

11. The X-ray imaging system according to claim 1 , further comprising:
an X-ray generator with the plurality of X-ray sources, wherein the X-ray generator comprises an emission area with modulated emission intensity.

12. The X-ray imaging system according to claim 11 ,
wherein the X-ray generator comprises electron optics and/or a structured electron emitter for bombarding the emission area with electrons in a pattern that generates an array of emission peaks.

13. The X-ray imaging system according to claim 12 ,
wherein the electron emitter is structured in a pattern corresponding to the pattern of the X-ray source array.

14. The X-ray imaging system according to claim 12 ,
wherein the electron emitter comprises carbon nanotubes.

15. The X-ray imaging system according to claim 11 ,
wherein the X-ray generator comprises a spatially extended X-ray emitter disposed behind a mask with holes.

16. The X-ray imaging system of claim 1 , wherein a diameter of an individual X-ray source is less than one hundred microns.

17. The X-ray imaging system of claim 1 , wherein a diameter of an individual X-ray source is less than fifty microns.

18. The X-ray imaging system of claim 1 , wherein the plurality of all X-ray sources covers an area of less than ten square millimeters.

19. The X-ray imaging system of claim 1 , and further comprising:
an X-ray absorbing grating with a plurality of pinholes,
wherein the X-ray absorbing grating is disposed between at least one of the plurality of X-ray sources and the collimator,
wherein X-ray radiation emitted by the single X-ray source is absorbed by the X-ray absorbing grating and traverses the plurality of pinholes, providing a plurality of X-ray sub-sources, and
wherein the collimator allows the passage of the X-rays emitted by the X-ray sub-sources such that the at least two neighboring pixels of the detector are illuminated and at least partially shields the X-ray insensitive region from the X-rays emitted by the X-ray sub-sources.

20. A method for generating an X-ray projection with an X-ray imaging system, said method comprising the following steps:
generating an X-ray beam with a plurality of X-ray sources;
detecting X-rays of said beam at positions of pixels of an array of pixels of a stationary single integrated X-ray detector having X-ray insensitive regions in between, wherein a detection signal of these pixels corresponds to image information at a particular point of the generated projection;
allowing passage of X-rays of said X-ray beam through two openings of a stationary pre-object collimator such that at least two neighboring pixels of the single integrated X-ray detector are each illuminated by X-rays passing through both of the two openings while the X-ray insensitive region between said pixels is at least partially shielded by the collimator;
d) accommodating an object to be imaged between the collimator and the detector.

Assignees

• Engel Klaus Juergen
• Vogtmeier Gereon
• Koninklijke Philips Nv

Inventors

• Engel Klaus Juergen
• Vogtmeier Gereon

Classifications

• H01J2235/068

  Multi-cathode assembly · CPC title

• G21K1/025

  using multiple collimators, e.g. Bucky screens; other devices for eliminating undesired or dispersed radiation · CPC title

• G01N23/04 Primary

  and forming images of the material · CPC title

• G21K2207/00

  Particular details of imaging devices or methods using ionizing electromagnetic radiation such as X-rays or gamma rays · CPC title