Method and apparatus for fabrication and tuning of grating-based differential phase contrast imaging system

Patent metadata

Field	Value
Publication number	US-9700267-B2
Application number	US-201514621823-A
Country	US
Kind code	B2
Filing date	Feb 13, 2015
Priority date	Dec 21, 2012
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A method for assembling a phase contrast x-ray imaging system includes fabricating a phase grating and an absorption grating according to a preselected pitch of the gratings. The actual obtained pitches are measured and a source grating is then fabricated according to a desired design point of the imaging system.

First claim

What is claimed is:

1. A method comprising:
fabricating a phase grating and an absorption grating according to a preselected pitch;
measuring an actual pitch of the fabricated phase grating and absorption grating; and
fabricating a source grating based on the actual pitch of the fabricated phase grating and absorption grating.

2. The method of claim 1 , further comprising disposing the fabricated source grating, phase grating and absorption grating in a phase contrast imaging system, wherein the phase grating and absorption grating are each disposed in one of a pair of parallel planes.

3. The method of claim 2 , further comprising tilting one of the fabricated phase grating and absorption grating with respect to the other at a preselected tilt angle.

4. The method of claim 3 , further comprising maintaining the phase grating and absorption grating in each of the parallel planes after the step of tilting.

5. The method of claim 2 , further comprising placing an object to be imaged in the phase contrast imaging system and capturing a radiographic image of the object.

6. The method of claim 3 , further comprising placing an object to be imaged in the phase contrast imaging system and capturing a radiographic image of the object.

7. The method of claim 2 , wherein the step of fabricating the source grating includes selecting a dimension of the source grating according to p int =p 1 (p 0 +p 2 )/(2p 0 ), wherein p 0 , p 1 , and p 2 are the selected dimensions of the source, phase, and absorption grating, and wherein p int is the period of the Moire pattern.

8. A method of assembling a phase contrast imaging system, the method comprising:
fabricating a phase grating and an absorption grating according to a preselected pitch;
measuring an actual pitch of the fabricated phase grating and absorption grating; and
selecting a source grating based on the actual pitch of the fabricated phase grating and absorption grating, wherein the step of selecting comprising moving one of a plurality of source gratings secured in a gratings holder of the imaging system into a path of an x-ray beam.

9. The method of claim 8 , further comprising disposing the selected source grating, the fabricated phase grating and absorption grating in a phase contrast imaging system, wherein the phase grating and absorption grating are each disposed in one of a pair of parallel planes.

10. The method of claim 9 , further comprising tilting one of the fabricated phase grating and absorption grating with respect to the other at a preselected tilt angle.

11. The method of claim 10 , further comprising maintaining the phase grating and absorption grating in each of the parallel planes after the step of tilting.

12. The method of claim 9 , further comprising placing an object to be imaged in the phase contrast imaging system and capturing a radiographic image of the object.

13. The method of claim 10 , further comprising placing an object to be imaged in the phase contrast imaging system and capturing a radiographic image of the object.

14. The method of claim 8 , wherein the step of selecting the source grating includes selecting a source grating from the plurality of source gratings that either:
satisfies p 0 /L=p 2 /d, wherein p 0 is the selected dimension of the source grating, L is a distance between the source grating and the phase grating in the phase contrast imaging system, p 2 is the period of the absorption grating, and wherein d is a distance between the phase grating and the absorption grating in the phase contrast imaging system, or
provides a minimum difference between p 0 /L and p 2 /d from among the plurality of source gratings.

15. The method of claim 8 , wherein the step of selecting the source grating includes selecting a source grating from the plurality of source gratings that satisfies p 0 /L −p 2 /d=x wherein p 0 is the selected dimension of the source grating, L is a distance between the source grating and the phase grating in the phase contrast imaging system, p 2 is the period of the absorption grating, d is a distance between the phase grating and the absorption grating in the phase contrast imaging system, and wherein x is a preselected design value.

Assignees

• Carestream Health Inc

Inventors

• Baturin Pavlo
• Shafer Mark E

Classifications

• A61B6/587

  Alignment of source unit to detector unit · CPC title

• A61B6/484

  involving phase contrast X-ray imaging · CPC title

• A61B6/4291

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

• A61B6/4035 Primary

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