Multi-parameter X-ray computed tomography

• US 8,121,249 B2
• Filed: 06/04/2010
• Issued: 02/21/2012
• Est. Priority Date: 06/04/2009
• Status: Active Grant

• Current Assignee: Virginia Tech Intellectual Properties, Inc.
• Original Assignee: Virginia Tech Intellectual Properties, Inc.
• Inventors: Wang, Ge, Cong, Wenxiang
• Primary Examiner(s): Taningco, Alexander H
• Application Number:
  US12/794,160
• Publication Number:
  US 20100310037A1
• Time in Patent Office: 627 Days
• Field of Search: 378/6, 378/7, 378/86, 378/87
• US Class Current: 378/6
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/06 Diaphragms
• CPC Class Codes: A61B 6/4291 the detector being combined with a grid or grating
• CPC Class Codes: A61B 6/583 using calibration phantoms

Abstract

The present invention relates to the field of x-ray imaging. More particularly, embodiments of the invention relate to methods, systems, and apparatus for imaging, which can be used in a wide range of applications, including medical imaging, security screening, and industrial non-destructive testing to name a few. Specifically provided as embodiments of the invention are systems for x-ray imaging comprising: a) a first collimator-and-detector assembly having a first operable configuration to provide at least one first dataset comprising primary x-ray signals as a majority component of its data capable of being presented as a first image of an object subjected to x-ray imaging; b) a second collimator-and-detector assembly having a second operable configuration or wherein the first collimator-and-detector assembly is adjustable to a second configuration to provide at least one second dataset comprising primary and dark-field x-ray signals as a majority component of its data capable of being presented as a second image of the object; and c) a computer operably coupled with the collimator-and-detector assemblies comprising a computer readable medium embedded with processing means for combining the first dataset and the second dataset to extract the dark-field x-ray signals and produce a target image having higher contrast quality than the images based on the first or second dataset alone. Such systems can be configured to comprise at least two collimator-and-detector assemblies or configurations differing with respect to collimator height, collimator aperture, imaging geometry, or distance between an object subjected to the imaging and the collimator-and-detector assembly.

Claims

1. A method for producing an x-ray image comprising:

providing at least one first dataset of primary x-ray signals as a majority of its data capable of being presented as a first image of an object subjected to x-ray imaging;

providing at least one second dataset comprising dark-field x-ray signals and primary x-ray signals as a majority of its data capable of being presented as a second image of the object;

combining the first dataset and the second dataset using a computer comprising a computer readable medium embedded with processing means for obtaining a target dataset having more dark-field (small-angle scattering) x-ray signals than the first or second dataset alone for producing a target image of the object which has higher contrast quality than the images based on the first or second dataset alone.

2. The method of claim 1 comprising providing the first and second datasets using collimator-and-detector assemblies or configurations that differ with respect to collimator height, collimator aperture, imaging geometry, or distance between an object subjected to the imaging and the collimator-and-detector assembly.

3. The method of claim 1, wherein the computer readable medium embedded with processing means is based on:

a) Radon transform data with respect to a small-angle scattering coefficient distribution derived from the principle of photon energy conservation;

4. The method of claim 3 further comprising a computer readable medium embedded with processing means for performing x-ray dark-field tomography (XDT) from the extracted dark-field x-ray data.

5. The method of claim 3, wherein the target image based on the extracted dark-field x-ray data is produced in a radiographic/2D mode.

6. The method of claim 3, wherein the target image based on the extracted dark-field x-ray data is produced in a tomographic or stereographical or tomosynthesis mode.

7. The method of claim 3 further comprising performing x-ray dark-field tomography (XDT) from the extracted dark-field data to characterize small-angle scattering properties in terms of one or more parameters, or to characterize small-angle scattering properties in terms of Rayleigh scattering coefficient, or to characterize Rayleigh scattering phase function.

8. A system for x-ray imaging comprising:

a first collimator-and-detector assembly having a first operable configuration to provide at least one first dataset comprising primary x-ray signals as a majority of its data capable of being presented as a first image of an object subjected to x-ray imaging;

a second collimator-and-detector assembly having a second operable configuration or wherein the first collimator-and-detector assembly is adjustable to a second configuration to provide at least one second dataset comprising primary and dark-field x-ray signals as a majority of its data capable of being presented as a second image of the object;

a computer operably coupled with the collimator-and-detector assemblies comprising a computer readable medium embedded with processing means for combining the first dataset and the second dataset to extract the dark-field x-ray signals and produce a target image having higher contrast quality than the images based on the first or second dataset alone.

9. The system of claim 8, wherein at least two of the collimator-and-detector assemblies or configurations differ with respect to collimator height, collimator aperture, imaging geometry, or distance between an object subjected to the imaging and the collimator-and-detector assembly.

10. The system of claim 8, wherein the computer readable medium embedded with processing means is based on:

a) Radon transform data with respect to a small-angle scattering coefficient distribution derived from the principle of photon energy conservation;

11. The system of claim 10 further comprising a computer readable medium embedded with processing means for performing x-ray dark-field tomography (XDT) from the extracted dark-field x-ray data.

12. A method of x-ray imaging comprising:

collecting x-ray data with a collimator-and-detector assembly configured to provide at least one first dataset comprising primary x-ray signals as a majority of its data;

adjusting the collimator-and-detector assembly to a second configuration for collecting at least one second dataset comprising primary and dark-field x-ray signals as a majority of its data or collecting the second dataset with a second collimator-and-detector assembly configuration;

computing the first and second datasets with a computer operably coupled with the collimator-and-detector assembly and comprising a computer readable medium embedded with processing means for extracting the dark-field x-ray signals for producing a target image having a higher contrast quality than an image based on the first or second dataset alone.

13. The method of claim 12 further comprising collecting x-ray data with additional collimator-and-detector assemblies or additional collimator-and-detector adjustments and computing two or more of the datasets to extract the dark-field signals for producing an image.

14. The method of claim 12, wherein at least two of the collimator-and-detector assemblies or adjustments differ with respect to collimator height, collimator aperture, imaging geometry, or distance between an object subjected to the imaging and the collimator-and-detector assembly.

15. The method of claim 12, wherein the collecting data comprises detecting x-ray photons in a spectrally resolving fashion, or at least one collimator-and-detector assembly or adjustment is configured to detect Compton scattering photons in a spectrally resolving fashion.

16. The method according to claim 15 further comprising performing x-ray dark-field tomography (XDT) and Compton scattering imaging from the extracted spectral x-ray data.

17. The method of claim 12, wherein at least one collimator-and-detector assembly or adjustment is configured to allow fan-beam or cone-beam scanning along a general trajectory.

18. The method of claim 17, wherein the trajectory is circular or spiral loci.

19. The method of claim 12, wherein the computer readable medium embedded with processing means is based on:

a) Radon transform data with respect to a small-angle scattering coefficient distribution derived from the principle of photon energy conservation;

20. The method of claim 12, wherein the target image based on the extracted dark-field x-ray data is produced in a radiographic/2D mode.

21. The method of claim 12, wherein the target image based on the extracted dark-field x-ray data is produced in a tomographic or stereographical or tomosynthesis mode.

22. The method of claim 12 further comprising performing x-ray dark-field tomography (XDT) from the extracted dark-field data to characterize small-angle scattering properties in terms of one or more parameters, or to characterize small-angle scattering properties in terms of Rayleigh scattering coefficient, or to characterize Rayleigh scattering phase function.