Single shot analyzer grating for differential phase contrast X-ray imaging and computed tomography

Patent metadata

Field	Value
Publication number	US-12379331-B2
Application number	US-202017639558-A
Country	US
Kind code	B2
Filing date	Sep 4, 2020
Priority date	Sep 6, 2019
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

In accordance with the invention, an X-ray amplitude analyzer grating adapted for use in an interferometric imaging system, the interferometric imaging system comprising an X-ray source and an X-ray detector with an X-ray fringe plane between the X-ray source and the X-ray detector, wherein an X-ray fringe pattern is formed at the X-ray fringe plane, wherein the X-ray amplitude analyzer grating is provided. The X-ray amplitude analyzer grating comprises a plurality of grating pixels across two dimensions of the X-ray amplitude analyzer grating, wherein each grating pixels of the plurality of grating pixels has a different pattern with respect to all adjacent grating pixels to the grating pixel so that all adjacent grating pixels do not have a same pattern as the grating pixel.

First claim

What is claimed is:

1. An X-ray analyzer grating configured for use in a one shot interferometric imaging system with image resolution recovery, the interferometric imaging system comprising an X-ray source and an X-ray detector with an X-ray fringe plane between the X-ray source and the X-ray detector, wherein an X-ray fringe pattern is formed at the X-ray fringe plane, wherein the X-ray analyzer grating located at the X-ray fringe plane, comprises:
a plurality of grating pixels across two dimensions of the X-ray analyzer grating, wherein each grating pixel of the plurality of grating pixels has a shifted phase with respect to adjacent grating pixels in at least two dimensions to the grating pixel so that adjacent grating pixels in at least two dimensions have a shifted phase with respect to the grating pixel.

2. The X-ray analyzer grating, as recited in claim 1 , wherein the interferometric imaging system is a one shot X-ray differential phase contrast imaging system.

3. The X-ray analyzer grating, as recited in claim 1 , wherein each grating pixel of the plurality of grating pixels has a shifted phase with respect to all nearest neighbor grating pixels.

4. The X-ray analyzer grating, as recited in claim 1 , wherein the X-ray analyzer grating has at least one of a one-dimensional grating pattern and a two-dimensional grating pattern.

5. The X-ray analyzer grating, as recited in claim 1 , wherein the X-ray analyzer grating is one of planar, cylindrically curved, and spherically curved.

6. The X-ray analyzer grating, as recited in claim 1 , wherein each of the grating pixels of the plurality of grating pixels is part of a unit cell of at least 2×2 grating pixels.

7. The X-ray analyzer grating, as recited in claim 6 , wherein each of the grating pixels of the plurality of grating pixels is part of a unit cell of 2×3 grating pixels, 3×2 grating pixels, 3×3 grating pixels, 4×4 grating pixels.

8. An X-ray system for imaging an object in one shot, wherein the X-ray system comprises:
an X-ray source;
an X-ray detector with a plurality of detector pixels is spaced apart from the X-ray source;
an X-ray grating between the X-ray source and the X-ray detector; and
an analyzer grating between the X-ray grating and the X-ray detector, wherein the analyzer grating has a plurality of grating pixels across two dimensions, wherein a grating pixel has a phase shifted with respect to grating pixels adjacent in at least two dimensions to the grating pixel.

9. The X-ray system, as recited in claim 8 , wherein the object is placed between the X-ray source and the analyzer grating.

10. The X-ray system, as recited in claim 8 , wherein the X-ray source provides X-rays with energies ranging from 1 keV to 1 MeV.

11. The X-ray system, as recited in claim 8 , wherein a plurality of grating pixels forms an at least 2×2 unit cell, wherein each grating pixel of the at least 2×2 unit cell has a pattern that is different from patterns of all other grating pixels of the at least 2×2 unit cell.

12. The X-ray system, as recited in claim 8 , further comprising a computer system connected to the X-ray detector, comprising:
a processor; and
computer readable media, comprising:
computer readable code for receiving X-ray detection data for a single shot filtered by the analyzer grating from the X-ray detector; and
computer readable code for using the X-ray detection data for the single shot filtered by the analyzer grating to create an image of the object by reconstructing each detector pixel from the single shot.

13. The X-ray system, as recited in claim 8 , wherein the X-ray system is part of a computed tomography system.

14. The X-ray system, as recited in claim 8 , wherein the X-ray system has an X-ray fringe plane between the X-ray source and the X-ray detector, wherein an X-ray fringe pattern is formed at the X-ray fringe plane and wherein the analyzer grating is located sufficiently close to the X-ray fringe plane to allow for a measurement of the X-ray fringe pattern using the analyzer grating.

15. The X-ray system, as recited in claim 14 , wherein the X-ray fringe pattern has a pitch and wherein the analyzer grating has a pitch, wherein the pitch of the analyzer grating is within 5% of the pitch of the X-ray fringe pattern.

16. The X-ray system, as recited in claim 12 , wherein the computer readable code for using the X-ray detection data for the single shot to create an image by reconstructing each detector pixel from the single shot uses resolution recovery comprising at least one of simple curve fitting, spatially varying curve fitting, and artificial neural network reconstruction to create the image.

17. The X-ray system, as recited in claim 8 , wherein the X-ray detector has a detector pixel size in a range from 500 nanometers to 50 millimeters.

18. The X-ray system, as recited in claim 8 , wherein the X-ray detector, wherein each grating pixel of the plurality of grating pixels has 1 adjacent detector pixel, 1×2 adjacent detector pixels, 2×1 adjacent detector pixels, 2×2 adjacent detector pixels, 3×3 adjacent detector pixels, or a plurality of adjacent detector pixels.

19. A method for X-ray imaging an object in an X-ray system comprising an X-ray source, an X-ray detector, an X-ray grating between the X-ray source and object, and an analyzer grating between the X-ray grating and the X-ray detector, wherein the analyzer grating has a plurality of grating pixels across two dimensions, wherein each grating pixel has a shifted phase with respect to grating pixels adjacent to the grating pixel in at least two dimensions, the method comprising:
passing X-rays from the X-ray source through the object, the X-ray grating and the analyzer grating to the X-ray detector in a single shot, wherein the analyzer grating is not moved;
receiving X-ray detection data from the X-ray detector; and

using the X-ray detection data to create at least one of an intensity image, an amplitude image, and a phase image with image resolution recovery of the object by reconstructing each detector pixel from the single shot.

20. The method, as recited in claim 19 , wherein using the X-ray detection data to create an image of the object, comprises:
determining variations in recorded X-ray detection data corresponding to adjacent grating pixels for a single shot; and
using the determined variations in recorded X-ray detection data corresponding to adjacent grating pixels for the single shot and data from a reference shot to create at least one of an absorption contrast image, differential phase contrast image, and dark-field contrast image with image resolution recovery of the object.

21. The method, as recited in claim 19 , wherein a plurality of grating pixels forms a plurality of unit cells of an at least 2×2 grating pixel, wherein each unit cell of the plurality of unit cells has a grating pixel that is shifted from patterns of all other grating pixels of the unit cell.

22. The method, as recited in claim 19 , wherein the X-ray system is part of a computed tomography system.

23. The method, as recited in claim 19 , wherein the X-ray system has an X-ray fringe plane between the X-ray source and the X-ray detector, wherein an X-ray fringe pattern is formed at the X-ray fringe plane and wherein the analyzer grating is located sufficiently close to the X-ray fringe plane to allow for a measurement of the X-ray fringe pattern using the analyzer grating.

24. The method, as recited in

Assignees

• Univ Leland Stanford Junior

Inventors

• Yuen Max
• Cheng Yao-Te
• Hansen Paul Christopher
• Hesselink Lambertus

Classifications

• G06T12/30

  Image post-processing, e.g. metal artefact correction · CPC title

• G01N2223/419

  computed tomograph · CPC title

• G01N2223/401

  image processing · CPC title

• G01N2223/30

  Accessories, mechanical or electrical features · CPC title

• G01N2223/04

  and measuring absorption · CPC title