Systems and methods for functional imaging using contrast-enhanced multiple-energy computed tomography

• US 7,869,862 B2
• Filed: 10/15/2003
• Issued: 01/11/2011
• Est. Priority Date: 10/15/2003
• Status: Active Grant

• Current Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Original Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Inventors: Green, Michael, Seppi, Edward J., Virshup, Gary, Partain, Larry
• Primary Examiner(s): Casler; Brian
• Assistant Examiner(s): KISH, JAMES M
• Application Number:
  US10/687,522
• Publication Number:
  US 20050084060A1
• Time in Patent Office: 2,645 Days
• Field of Search: 600/407, 600/431, 600/420, 600/436, 378/145, 382/128, 382/130
• US Class Current: 600/431
• CPC Class Codes: A61B 5/7289 Retrospective gating, i.e. associating measured signals or images with a physiological event after the actual measurement or image acquisition, e.g. by simultaneously recording an additional physiological signal during the measurement or image acquisition
• CPC Class Codes: A61B 5/7292 Prospective gating, i.e. predicting the occurrence of a physiological event for use as a synchronisation signal
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/0435 with means for imaging suspended breasts
• CPC Class Codes: A61B 6/4035 the source being combined with a filter or grating
• CPC Class Codes: A61B 6/4042 K-edge filters
• CPC Class Codes: A61B 6/405 Source units specially adapted to modify characteristics of the beam during the data acquisition process A61B6/4021, A61B6/4035 take precedence
• CPC Class Codes: A61B 6/4241 using energy resolving detectors, e.g. photon counting
• CPC Class Codes: A61B 6/4441 the rigid structure being a C-arm or U-arm
• CPC Class Codes: A61B 6/4488 Means for cooling A61B6/045 takes precedence
• CPC Class Codes: A61B 6/466 adapted to display 3D data
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: A61B 6/502 for diagnosis of breast, i.e. mammography
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 6/5288 involving retrospective matching to a physiological signal
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 2223/612 biological material
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: H01J 2235/081 : Target material

Abstract

A method of generating images of a portion of a body includes introducing a contrast agent into the body, generating a first set of image data using radiation at a first energy level after the contrast agent is introduced into the body, generating a second set of image data using radiation at a second energy level after the contrast agent is introduced into the body, and creating a volumetric composite image using the first and the second sets of image data.

Claims

1. A method of generating one or more images of a portion of a body, comprising:

introducing a contrast agent into the body;

generating a first set of image data using radiation at a first energy level after the contrast agent is introduced into the body;

generating a second set of image data using radiation at a second energy level after the contrast agent is introduced into the body;

creating a contrast-enhanced volumetric composite image using the first and the second sets of image data, wherein the contrast-enhanced volumetric composite image is created such that at least a portion of the contrast-enhanced volumetric composite image has a feature indicating cancerous tissue, and that an image contrast for bone and tissue that does not contain the contrast agent at another portion of the contrast-enhanced volumetric composite image is reduced;

at least one of storing the contrast-enhanced volumetric composite image and displaying the contrast-enhanced volumetric composite image;

determining information regarding time-resolved kinetics of the contrast agent in the body based at least in part on the volumetric composite image;

providing a first graphic that indicates the determined information; and

providing a second graphic that indicates time-resolved kinetics of a contrast agent in normal tissue, the contrast agent in the normal tissue being a same type as the contrast agent in the body;

wherein the first and second graphics are provided in a same graph for comparison.

2. The method of claim 1, wherein the contrast agent includes an element selected from the group consisting of iodine, gadolinium, holmium, erbium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, terbium, dysprosium, thulium, ytterbium, and lutetium.

3. The method of claim 1, wherein the portion of the body comprises at least a portion of a breast.

4. The method of claim 1, wherein the first energy level is below a k-edge of the contrast agent.

5. The method of claim 1, wherein the second energy level is above a k-edge of the contrast agent.

6. The method of claim 1, wherein the first and the second sets of image data are generated by performing a computed tomography procedure.

7. The method of claim 6, wherein the computed tomography procedure is performed using a cone beam.

8. The method of claim 1, wherein the first and the second sets of image data are generated by performing a MRI procedure.

9. The method of claim 1, wherein the first and the second sets of image data are generated by performing a PET procedure.

10. The method of claim 1, wherein the volumetric composite image is created by subtracting the first set of image data from the second set of image data.

11. The method of claim 1, wherein the volumetric composite image is created by

modifying the first set of image data;

modifying the second set of image data; and

subtracting the first modified set of image data from the second modified set of image data.

12. The method of claim 11, wherein the acts of modifying comprises applying a logarithmic transform to the first and the second sets of image data.

13. The method of claim 1, wherein the first and the second sets of image data are generated within 5 to 20 microseconds.

14. The method of claim 1, wherein the radiation at either or both of the first and the second energy levels are generated using a multi-energy x-ray source assembly.

15. The method of claim 1, wherein the volumetric composite image is created by removing a tissue feature, and retaining a feature attributable to the contrast agent.

16. The method of claim 1, wherein the radiation at the first and the second energy levels are generated by switching a x-ray tube voltage between a first and a second levels.

17. The method of claim 1, wherein the radiation at the first and the second energy levels are generated by impinging an electron beam onto a first target material and a second target material, respectively.

18. The method of claim 1, wherein the radiation at the first and the second energy levels are generated by filtering x-rays through a first filter and a second filter, respectively.

19. The method of claim 1, wherein the first set of image data comprises data sufficient for generating a volumetric image.

20. The method of claim 1, wherein the first set of image data comprises a plurality of image frames generated by placing a radiation source in different orientations.

21. The method of claim 20, wherein the radiation source is coupled to a gantry, and the act of placing the radiation source in different orientations comprises placing the radiation source at a first gantry angle, and placing the radiation source at a second gantry angle.

22. The method of claim 1, wherein the volumetric composite image is created by determining a first volumetric image from the first set of image, determining a second volumetric image from the second set of image, and subtracting the first volumetric image from the second volumetric image.

23. The method of claim 1, wherein the volumetric composite image is created by obtaining a set of composite images using the first and second sets of image data, the set of composite images being two-dimensional images, and constructing the volumetric composite image using the set of composite images.

24. A system of generating one or more images of a portion of a body after a contrast agent is introduced into the body, the system comprising:

means for generating a first set of image data using radiation at a first energy level after the contrast agent is introduced into the body;

means for generating a second set of image data using radiation at a second energy level after the contrast agent is introduced into the body, wherein the first energy level is below a k-edge of the contrast agent, and the second energy level is above a k-edge of the contrast agent;

means for creating a contrast-enhanced volumetric composite image using the first and the second sets of image data, wherein the means for creating is configured to create the contrast-enhanced volumetric composite image such that at least a portion of the contrast-enhanced volumetric composite image has a feature indicating cancerous tissue, and that an image contrast for bone and tissue that does not contain the contrast agent at another portion of the contrast-enhanced volumetric composite image is reduced;

means for determining information regarding time-resolved kinetics of the contrast agent in the body based at least in part on the volumetric composite image; and

means for displaying a first graphic and a second graphic in a same graph, wherein the first graphic indicates the determined information, and the second graphic indicates time- resolved kinetics of a contrast agent in normal tissue, the contrast agent in the normal tissue being a same type as the contrast agent in the body.

25. The system of claim 24, wherein the means for generating the first and the second sets of image data comprises one or more imagers.

26. The system of claim 24, further comprising a x-ray source assembly for generating the radiation at the first and the second energy levels, the x-ray source assembly having one or more target materials.

27. The system of claim 24, further comprising a x-ray source assembly for generating the radiation at the first and second energy levels, wherein the x-ray source assembly comprises a plurality of filters for filtering x-ray.

28. The system of claim 24, further comprising a x-ray source assembly for generating the radiation at the first and second energy levels, wherein the x-ray source assembly comprises a plurality of the target materials.

29. The system of claim 28, wherein the x-ray source assembly further comprises means for generating electrons, and means for impinging the electrons onto one of the plurality of the target materials.

30. The system of claim 29, wherein the means for impinging comprises an electromagnetic field generator for deflecting the electrons such that they impinge onto the one of the plurality of the target materials.

31. The system of claim 24, wherein the first set of image data comprises data sufficient for generating a volumetric image.

32. The system of claim 24, wherein the first set of image data comprises a plurality of image frames generated by placing a radiation source in different orientations.

33. The system of claim 24, wherein the means for generating the first set of image data comprises a detector and a positioner for placing the detector in different positions.

34. The system of claim 24, wherein the means for creating the volumetric composite image is configured to determine a first volumetric image from the first set of image, determine a second volumetric image from the second set of image, and subtract the first volumetric image from the second volumetric image.

35. The system of claim 24, wherein the means for creating the volumetric composite image is configured to create the volumetric composite image by obtaining a set of composite images using the first and second sets of image data, the set of composite images being two-dimensional images, and constructing the volumetric composite image using the set of composite images.

36. A non-transitory computer readable medium having a set of stored instructions, the execution of which causes a process to be performed, the process comprising:

generating a first set of image data for a bodily region that includes a contrast agent using radiation at a first energy level;

generating a second set of image data for the bodily region that includes the contrast agent using radiation at a second energy level;

creating a contrast-enhanced volumetric composite image using the first and the second sets of image data, wherein the contrast-enhanced volumetric composite image is created such that at least a portion of the contrast-enhanced volumetric composite image has a feature indicating cancerous tissue, and that an image contrast for bone and tissue that does not contain the contrast agent at another portion of the contrast-enhanced volumetric composite image is reduced;

at least one of storing the contrast-enhanced volumetric composite image and displaying the contrast-enhanced volumetric composite image;

determining information regarding time-resolved kinetics of the contrast agent in the body based at least in part on the volumetric composite image;

providing a first graphic that indicates the determined information; and

providing a second graphic that indicates time-resolved kinetics of a contrast agent in normal tissue, the contrast agent in the normal tissue being a same type as the contrast agent in the body;

wherein the first and second graphics are provided in a same graph for comparison.

37. The computer product of claim 36, wherein the first energy level is below a k-edge of a contrast agent.

38. The computer product of claim 36, wherein the second energy level is above a k-edge of a contrast agent.

39. The computer product of claim 36, wherein the first and the second sets of image data are generated by performing a computed tomography procedure.

40. The computer product of claim 36, wherein the computed tomography procedure is performed using a cone beam.

41. The computer product of claim 36, wherein the first and the second sets of image data are generated by performing a MRI procedure.

42. The computer product of claim 36, wherein the first and the second sets of image data are generated by performing a PET procedure.

43. The computer product of claim 36, wherein the volumetric composite image is created by subtracting the first set of image data from the second set of image data.

44. The computer product of claim 36, wherein the volumetric composite image is created by modifying the first set of image data;

modifying the second set of image data; and

subtracting the first modified set of image data from the second modified set of image data.

45. The computer product of claim 44, wherein the acts of modifying comprises applying a logarithmic transform to the first and the second sets of image data.

46. The computer product of claim 36, wherein the first and the second sets of image data are generated within 5 to 20 microseconds.

47. The computer product of claim 36, wherein the radiation at either or both of the first and the second energy levels are generated using a multi-energy x-ray source assembly.

48. The computer product of claim 36, wherein the volumetric composite image is created by removing a tissue feature, and retaining a feature attributable to the contrast agent.

49. The computer product of claim 36, wherein the radiation at the first and the second energy levels are generated by switching a x-ray tube voltage between a first and a second levels.

50. The computer product of claim 36, wherein the radiation at the first and the second energy levels are generated by impinging an electron beam onto a first target material and a second target material, respectively.

51. The computer product of claim 36, wherein the radiation at the first and the second energy levels are generated by filtering x-rays through a first filter and a second filter, respectively.

52. The computer product of claim 36, wherein the volumetric composite image is created by determining a first volumetric image from the first set of image, determining a second volumetric image from the second set of image, and subtracting the first volumetric image from the second volumetric image.

53. The computer product of claim 36, wherein the volumetric composite image is created by obtaining a set of composite images using the first and second sets of image data, the set of composite images being two-dimensional images, and constructing the volumetric composite image using the set of composite images.

54. A method of generating one or more images of a portion of a body, comprising:

introducing a contrast agent into the body;

generating a first set of image data using radiation at a first energy level after the contrast agent is introduced into the body;

generating a second set of image data using radiation at a second energy level after the contrast agent is introduced into the body;

creating a contrast-enhanced volumetric composite image using the first and the second sets of image data, wherein the contrast-enhanced volumetric composite image is created such that at least a portion of the contrast-enhanced volumetric composite image has a feature indicating cancerous tissue, and that an image contrast for bone and tissue that does not contain the contrast agent at another portion of the contrast-enhanced volumetric composite image is reduced; and

at least one of storing the contrast-enhanced volumetric composite image and displaying the contrast-enhanced volumetric composite image;

wherein the first and the second sets of image data are generated using one imager, the imager having a first line, a second line, a third line, and a fourth line of image elements; and

wherein the generating the first and the second sets of image data comprises;

deactivating the first and the third lines of the image elements and activating the second and the fourth lines of the image elements while applying the radiation at the first energy level; and

activating the first, the second, the third, and the fourth lines of the image elements while applying the radiation at the second energy level.

55. A non-transitory computer readable medium computer product having a set of stored instructions, the execution of which causes a process to be performed, the process comprising:

generating a first set of image data for a bodily region that includes a contrast agent using radiation at a first energy level;

generating a second set of image data for the bodily region that includes the contrast agent using radiation at a second energy level;

creating a contrast-enhanced volumetric composite image using the first and the second sets of image data, wherein the contrast-enhanced volumetric composite image is created such that at least a portion of the contrast-enhanced volumetric composite image has a feature indicating cancerous tissue, and that an image contrast for bone and tissue that does not contain the contrast agent at another portion of the contrast-enhanced volumetric composite image is reduced; and

at least one of storing the contrast-enhanced volumetric composite image and displaying the contrast-enhanced volumetric composite image;

wherein the first and the second sets of image data are generated using one imager, the imager having a first line, a second line, a third line, and a fourth line of image elements; and

wherein the generating the first and the second sets of image data comprises;

deactivating the first and the third lines of the image elements and activating the second and the fourth lines of the image elements while applying the radiation at the first energy level; and

activating the first, the second, the third, and the fourth lines of the image elements while applying the radiation at the second energy level.

56. A system of generating one or more images of a portion of a body after a contrast agent is introduced into the body, the system comprising:

means for generating a first set of image data using radiation at a first energy level after the contrast agent is introduced into the body;

means for generating a second set of image data using radiation at a second energy level after the contrast agent is introduced into the body, wherein the first energy level is below a k-edge of the contrast agent, and the second energy level is above a k-edge of the contrast agent; and

means for creating a contrast-enhanced volumetric composite image using the first and the second sets of image data, wherein the means for creating is configured to create the contrast-enhanced volumetric composite image such that at least a portion of the contrast-enhanced volumetric composite image has a feature indicating cancerous tissue, and that an image contrast for bone and tissue that does not contain the contrast agent at another portion of the contrast-enhanced volumetric composite image is reduced;

wherein the means for generating the first set of image data and the second set of image data comprises an imager having a first line of image elements, a second line of image elements, a third line of image elements, and a fourth line of image elements; and

wherein the imager is configured to deactivate the first and the third lines of the image elements and activate the second and the fourth lines of the image elements while applying the radiation at the first energy level, and activate the first, the second, the third, and the fourth lines of the image elements while applying the radiation at the second energy level.