Analyzing grid for phase contrast imaging and/or dark-field imaging

Patent metadata

Field	Value
Publication number	US-10679762-B2
Application number	US-201716307675-A
Country	US
Kind code	B2
Filing date	Jun 8, 2017
Priority date	Jun 8, 2016
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

The invention relates to an analyzing grid for phase contrast imaging and/or dark-field imaging, a detector arrangement for phase contrast imaging and/or dark-field imaging comprising such analyzing grid, an X-ray imaging system comprising such detector arrangement, a method for manufacturing such analyzing grid, a computer program element for controlling such analyzing grid or detector arrangement for performing such method and a computer readable medium having stored such computer program element. The analyzing grid comprises a number of X-ray converting gratings. The X-ray converting gratings are configured to convert incident X-ray radiation into light or charge. The number of X-ray converting gratings comprises at least a first X-ray converting grating and a second X-ray converting grating. Further, the X-ray converting gratings each comprise an array of grating bars, wherein the grating bars within each X-ray converting grating are arranged mutually displaced from each other in a direction perpendicular to the incident X-ray radiation by a specific displacement pitch. Further, the grating bars of the first X-ray converting grating are arranged mutually displaced from the grating bars of the second X-ray converting grating in the direction perpendicular to the incident X-ray radiation by the displacement pitch divided by the number of X-ray converting gratings.

First claim

The invention claimed is:

1. An analyzing grid for phase contrast imaging and/or dark-field imaging, comprising a number of X-ray converting gratings,
wherein the X-ray converting gratings are configured to convert incident X-ray radiation into light or charge,
wherein the X-ray converting gratings comprise at least a first X-ray converting grating and a second X-ray converting grating,
wherein each of the X-ray converting gratings comprises an array of grating bars,
wherein the grating bars within each of the X-ray converting gratings are arranged mutually displaced from each other in a direction perpendicular to an incident X-ray radiation by a specific displacement pitch, which is a distance between center lines of two adjacent grating bars,
wherein the grating bars of the first X-ray converting grating are arranged mutually displaced from the grating bars of the second X-ray converting grating in the direction perpendicular to the incident X-ray radiation, and
wherein the first X-ray converting grating and the second X-ray converting grating are arranged between two detectors configured to detect light or charge converted by the respective first and second X-ray converting gratings.

2. The analyzing grid according to claim 1 , wherein the grating bars of the first X-ray converting grating are arranged mutually displaced from the grating bars of the second X-ray converting grating in the direction perpendicular to the incident X-ray radiation by the displacement pitch divided by a number of X-ray converting gratings.

3. The analyzing grid according to claim 1 , wherein the first X-ray converting grating and the second X-ray converting grating overlap partially in the direction parallel to the incident X-ray radiation.

4. The analyzing grid according to claim 1 , wherein the X-ray converting gratings are spaced apart from each other in the direction parallel to the incident X-ray radiation by a spacer.

5. The analyzing grid according to claim 1 , wherein the first X-ray converting grating and the second X-ray converting grating are arranged substantially next to each other in the direction perpendicular to the incident X-ray radiation, wherein the X-ray converting gratings comprise reflector walls, and wherein a staggering of the X-ray converting gratings in the direction parallel to the incident X-ray radiation is implemented by the reflector walls arranged at upper face sides and omitted at lower face sides of the first X-ray converting grating and by the reflector walls arranged at lower face sides and omitted at upper face sides of the second X-ray converting grating.

6. The analyzing grid according to claim 1 , wherein the first X-ray converting grating forms a scintillator, and the second X-ray converting grating forms an anti-scatter grid.

7. The analyzing grid according to claim 1 , wherein a number of X-ray converting gratings further comprises a third X-ray converting grating, and wherein the grating bars of each of the three X-ray converting gratings are arranged mutually displaced from the grating bars of the other two X-ray converting gratings by a third of the displacement pitch.

8. The analyzing grid according to claim 1 , wherein at least some of the grating bars are provided with a discontinuous cross section when seen in the direction parallel to the incident X-ray radiation.

9. The analyzing grid according to claim 1 , wherein the X-ray converting gratings are made of at least one material comprising Csl:Tl, Ce-doped perovskites, cerium doped (yttrium-gadolinium-lutetium) based (gallium-aluminium) garnets, bismuth germanate, yttrium gadolinium oxide, solid solutions of Y, Gd and/or Lu doped with Eu3+, CsI:Na, NaI:Tl, and Srl2.

10. The analyzing grid according to claim 1 , wherein the first X-ray converting grating forms a direct conversion anode, and the second X-ray converting grating forms a direct conversion cathode, wherein the grating bars of the second X-ray converting grating are interconnected to form a common cathode for a detector.

11. The analyzing grid according to claim 10 , wherein the direct conversion anode and the direct conversion cathode are made of substantially same material separated from each other by electrically isolated walls.

12. An X-ray imaging system, comprising:
an X-ray source, and
an analyzing grid for phase contrast imaging and/or dark-field imaging, comprising a number of X-ray converting gratings,
wherein the X-ray converting gratings are configured to convert incident X-ray radiation into light or charge,
wherein the X-ray converting gratings comprise at least a first X-ray converting grating and a second X-ray converting grating,
wherein each of the X-ray converting gratings comprises an array of grating bars,
wherein the grating bars within each of the X-ray converting gratings are arranged mutually displaced from each other in a direction perpendicular to an incident X-ray radiation by a specific displacement pitch, which is a distance between center lines of two adjacent grating bars,
wherein the grating bars of the first X-ray converting grating are arranged mutually displaced from the grating bars of the second X-ray converting grating in the direction perpendicular to the incident X-ray radiation, and
wherein the first X-ray converting grating and the second X-ray converting grating are arranged between two detectors configured to detect light or charge converted by the respective first and second X-ray converting gratings,

wherein the X-ray source is configured to apply X-ray radiation to an object to be detected by the detectors.

13. A method for manufacturing an analyzing grid, comprising:
structuring a number of wafers to obtain an array of grating bars in each wafer, and
filling a space between the grating bars with X-ray converting material to obtain a number of X-ray converting gratings,
wherein the X-ray converting gratings are configured to form an analyzing grid for phase contrast imaging and/or dark-field imaging,
wherein the X-ray converting gratings are configured to convert incident X-ray radiation into light or charge,
wherein the X-ray converting gratings comprise at least a first X-ray converting grating and a second X-ray converting grating,
wherein each of the X-ray converting gratings comprises the array of grating bars,
wherein the grating bars within each of the X-ray converting gratings are arranged mutually displaced from each other in a direction perpendicular to an incident X-ray radiation by a specific displacement pitch, which is a distance between center lines of two adjacent grating bars,
wherein the grating bars of the first X-ray converting grating are arranged mutually displaced from the grating bars of the second X-ray converting grating in the direction perpendicular to the incident X-ray radiation, and
wherein the first X-ray converting grating and the second X-ray converting grating are arranged between two detectors configured to detect light or charge converted by the respective first and second X-ray converting gratings.

14. The method according to claim 13 , wherein the structuring and filling is done from only a first side of the wafer, and wherein the structuring comprises an etching.

15. A non-transitory computer-readable medium having one or more executable instructions stored thereon, which when executed by a processor, cause the processor to perform a method for manufacturing an analyzing grid, comprising:
structuring a number of wafers to obtain an array of grating bars in each wafer, and
filling a space between the grating bars with X-ray converting material to obtain a number of X-r

Assignees

• Koninklijke Philips Nv

Inventors

• Koehler Thomas
• Steadman Booker Roger
• Simon Matthias
• Ruetten Walter
• Wieczorek Herfried Karl

Classifications

• A61B6/4291

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

• A61B6/484

  involving phase contrast X-ray imaging · CPC title

• G21K2207/005

  Methods and devices obtaining contrast from non-absorbing interaction of the radiation with matter, e.g. phase contrast · CPC title

• A61B6/4035

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

• G01N23/041

  Phase-contrast imaging, e.g. using grating interferometers · CPC title