Diffraction enhanced imaging method using a line x-ray source

• US 20060072702A1
• Filed: 10/04/2004
• Published: 04/06/2006
• Est. Priority Date: 10/04/2004
• Status: Active Grant

• Current Assignee: Illinois Institute of Technology
• Original Assignee: Illinois Institute of Technology
• Inventors: Chapman, Leroy Dean
• Granted Patent: US 7,330,530 B2
• Time in Patent Office: Days
• US Class Current: 378/73
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]

Abstract

A method for detecting an enhanced image of an object by independently analyzing, detecting, digitizing, and combining images acquired on a high and a low angle side of a rocking curve of a crystal analyzer. An x-ray beam generated by a line x-ray source is collimated by a crystal monochromator including two non-matching crystals to form an x-ray area beam. The x-ray area beam is transmitted through an object to be imaged and onto an image detector and the image is digitized. The digitized images are simultaneously solved, preferably on a pixel-by-pixel basis, to derive an enhanced image which has dramatically improved contrast and spatial resolution over an image acquired through conventional radiology methods.

Claims

1. A method for detecting an image of an object with an x-ray beam, the method comprising:

diffracting the x-ray beam using non-matching monochromator crystals;

transmitting the x-ray beam through the object;

directing the transmitted x-ray beam at an angle of incidence upon a crystal analyzer;

detecting a first image of the object from a diffracted beam emitted from the crystal analyzer at a first angular position of the crystal analyzer;

detecting a second image of the object from a diffracted beam emitted from the crystal analyzer at a second angular position of the crystal analyzer; and

combining the first and second images to derive an enhanced image.

2. The method according to claim 1, wherein the non-matching monochromator crystals include a first monochromator crystal and a second monochromator crystal, the first monochromator crystal being different from the second monochromator crystal in at least one of lattice spacing or crystal type.

3. The method according to claim 2, wherein the x-ray beam is diffracted by the first monochromator crystal and the second monochromator crystal before transmitting through the object.

4. The method according to claim 2, wherein the first monochromator crystal is constructed of germanium with (3,3,3) lattice planes and the second monochromator crystal is constructed of silicon with (3,3,3) lattice planes.

5. The method according to claim 2, wherein the first monochromator crystal includes a first lattice spacing that is different from a second lattice spacing of the second monochromator crystal.

6. The method according to claim 5, wherein the first and second monochromator crystals are the same crystal type and additionally comprising heating one of the first and second monochromator crystals.

7. The method according to claim 1, wherein the x-ray beam is generated by a line x-ray source.

8. The method according to claim 1, wherein the first and second angular positions of the crystal analyzer are within a rocking curve of the crystal analyzer.

9. The method of claim 8, additionally comprising:

detecting the first image of the object at a low rocking curve angle setting of the crystal analyzer;

detecting the second image of the object at a high rocking curve angle setting of the crystal analyzer.

10. The method according to claim 1, wherein the first image and the second image are exposed on a detector capable of producing a digitized image.

11. The method according to claim 10, wherein the exposed first image and the exposed second image are digitized.

12. The method according to claim 11, wherein the digitized images are mathematically combined to form the enhanced image.

13. The method according to claim 1, wherein the enhanced image is one of a refraction image and an absolute absorption image.

14. The method according to claim 1, wherein the crystal analyzer is one of a Bragg type analyzer and a Laue type analyzer.

15. The method according to claim 1, wherein the x-ray beam has an energy level in a range of approximately 16 keV to approximately 40 keV.

16. A method for detecting an image of an object, wherein an x-ray beam is generated, the method comprising:

generating an x-ray beam from a line x-ray source;

diffracting the x-ray beam using non-matching monochromator crystals to produce an area x-ray beam;

transmitting the area x-ray beam through the object and emitting from the object a transmitted beam;

directing the transmitted beam at an angle of incidence upon a crystal analyzer;

detecting a first area image of the object from a diffracted beam emitted from the crystal analyzer at a low rocking curve angle setting of the crystal analyzer;

detecting a second area image of the object from a diffracted beam emitted from the crystal analyzer at a high rocking curve angle setting of the crystal analyzer; and

combining the first area image and the second area image to derive an enhanced area image.

17. The method according to claim 16, wherein the non-matching monochromator crystals include a first monochromator crystal and a second monochromator crystal, the first monochromator crystal being different from the second monochromator crystal in at least one of lattice spacing or kind.

18. The method according to claim 17, wherein the first monochromator crystal is constructed of germanium with (3,3,3) lattice planes and the second monochromator crystal is constructed of silicon with (3,3,3) lattice planes.

19. The method according to claim 17, wherein the first monochromator crystal includes a first lattice spacing that is different from a second lattice spacing of the second monochromator crystal.