MULTI-ENERGY X-RAY IMAGING

• US 20090283682A1
• Filed: 05/19/2008
• Published: 11/19/2009
• Est. Priority Date: 05/19/2008
• Status: Active Grant

• Current Assignee: Siemens Healthineers International AG
• Original Assignee: Varian Medical Systems International AG (Siemens AG)
• Inventors: Green, Michael, Star-Lack, Josh, Guertin, Timothy, Riem, Heinrich
• Granted Patent: US 8,633,445 B2
• Time in Patent Office: Days
• US Class Current: 250/363.100
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/06 Diaphragms
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/4014 arranged in multiple source-detector units
• CPC Class Codes: A61B 6/4035 the source being combined with a filter or grating
• CPC Class Codes: A61B 6/4233 using matrix detectors
• CPC Class Codes: A61B 6/4441 the rigid structure being a C-arm or U-arm
• CPC Class Codes: A61B 6/469 for selecting a region of interest [ROI]
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: A61B 6/5205 involving processing of raw data to produce diagnostic data
• CPC Class Codes: A61B 6/5235 combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT
• CPC Class Codes: A61B 6/5282 due to scatter
• CPC Class Codes: A61B 6/542 involving control of exposure
• CPC Class Codes: A61B 6/585 Calibration of detector units
• CPC Class Codes: A61N 2005/1054 using a portal imaging system
• CPC Class Codes: G01T 1/16 Measuring radiation intensity G01T1/29 takes precedence ; self-powered detectors G01T3/006; using an ionisation chamber filled with a liquid or solid, e.g. frozen liquid, dielectric G01T3/008

Abstract

An imaging method includes obtaining a first image data for a subset of a target region, the subset of the target region having a first metallic object, obtaining a second image data for the target region, and using the first and second image data to determine a composite image. A imaging system includes a first detector configured to provide a first projection data using a first radiation having high energy, and a second detector configured to provide a second projection data using a second radiation having low energy, wherein the first detector has a first length, the second detector has a second length, and the first length is less than 75% of the second length.

Claims

1. An imaging method, comprising:

obtaining a first image data for a subset of a target region, the subset of the target region having a first metallic object;

obtaining a second image data for the target region; and

using the first and second image data to determine a composite image.

2. The imaging method of claim 1, wherein the second image data is obtained using radiation beam having a low energy.

3. The imaging method of claim 1, wherein the first image data is obtained using radiation beam having a high energy.

4. The imaging method of claim 1, wherein the first image data is obtained using a first detector, the second image data is obtained using a second detector, wherein the first detector has an area that is smaller than an area of the second detector.

5. The imaging method of claim 1, further comprising aligning the subset of the target region with the first detector.

6. The imaging method of claim 5, wherein the act of aligning comprising positioning the first detector.

7. The imaging method of claim 6, wherein the act of positioning the first detector is performed by a positioner.

8. The imaging method of claim 5, wherein the act of aligning comprises moving a patient that contains the target region.

9. The imaging method of claim 1, further comprising substituting part of the second image data that is associated with the first metallic object, with some or all of the first image data.

10. The imaging method of claim 1, wherein the first and second projection data are obtained during a single rotation of a radiation source about the target region.

11. The imaging method of claim 1, wherein the first and second projection data are obtained during a plurality of rotations of a radiation source about the target region.

12. The imaging method of claim 1, wherein the act of obtaining the first image data comprises operating a collimator.

13. The imaging method of claim 1, wherein the collimator is operated in synchronization with a rotation of a radiation source.

14. The imaging method of claim 1, wherein the first image data and the second image data are obtained in different days.

15. The imaging method of claim 1, wherein the first image data is obtained in a first imaging session, and the second image data is obtained in a second imaging session.

16. An imaging method, comprising:

obtaining information regarding a position of a first metallic object in a region of interest; and

providing a radiation beam to irradiate a subset of the region of interest, the subset having the first metallic object.

17. The method of claim 16, further comprising obtaining information regarding a position of a second metallic object in the region of interest.

18. The method of claim 17, wherein the radiation beam is provided to irradiate the subset that contains both the first and second metallic objects.

19. The method of claim 17, wherein the radiation beam has a first beam portion and a second beam portion that is spaced apart from the first beam portion, the first and second beam portions irradiating the first and second metallic objects, respectively.

20. The method of claim 16, wherein the act of providing the radiation beam comprises using a collimator, and wherein the method further comprises rotating the collimator.

21. The method of claim 20, further comprising operating the collimator such that the first metallic object, but not the entire region of interest, is irradiated at a plurality of gantry angles.

22. An imaging system, comprising:

a first detector configured to provide a first projection data using a first radiation having high energy; and

a second detector configured to provide a second projection data using a second radiation having low energy;

wherein the first detector has a first length, the second detector has a second length, and the first length is less than 75% of the second length.

23. The imaging system of claim 22, wherein the first length is less than 35% of the second length.

24. The imaging system of claim 22, wherein the first detector comprises a plurality of high detective quantum efficiency detector elements.

25. The imaging system of claim 22, further comprising a third detector.

26. The imaging system of claim 25, wherein the first and third detectors collectively form a single imager.

27. The imaging system of claim 25, wherein the first detector has a width that is 50% to 100% wider than the third detector.

28. The imaging system of claim 25, wherein the first detector at least partially overlaps the third detector.

29. The imaging system of claim 25, wherein the first detector is disposed underneath the third detector.

30. The imaging system of claim 25, wherein the third detector comprises an EPID.

31. The imaging system of claim 25, wherein the first and third detectors are tiltable.

32. The imaging system of claim 22, wherein the second detector comprises an OBI.

33. The imaging system of claim 22, wherein the first detector is moveable along a Z-axis of the imaging system.

34. The imaging system of claim 33, wherein one or both of the first and second detectors are moveable along a X-axis of the imaging system.

35. The imaging system of claim 33, wherein the second detector is moveable along the Z-axis of the imaging system.

36. The imaging system of claim 22, wherein the first radiation is in a form of a beam, and the imaging system further comprises a collimator for changing a shape of the beam.

38. The imaging system of claim 22, wherein the first detector comprises a photo detector array coupled to an x-ray conversion layer.

39. The imaging system of claim 22, wherein the first detector comprises a photoconductor layer.

37. The imaging system of 36, wherein the collimator is configured to change the shape of the beam such that the beam irradiates a subset of a region of interest, the subset having one or more metallic objects.

40. An imaging system, comprising:

an electronic portal imaging device; and

a high detective quantum efficiency detector;

wherein the high detective quantum efficiency detector has a first length, the electronic portal imaging device has a second length, and the first length is less than 75% of the second length.

41. The imaging system of claim 40, wherein the high detective quantum efficiency detector overlaps a portion of the electronic portal imaging device.

42. The imaging system of claim 40, wherein the high detective quantum efficiency detector is underneath the electronic portal imaging device.

43. The imaging system of claim 40, wherein the high detective quantum efficiency detector and the electronic portal imaging device are integrated together to form a single imager.

44. A system for use in an imaging procedure, comprising:

a processor configured to obtain information regarding a position of a first metallic object in a region of interest; and

a collimator configured to shape a radiation beam based at least on the information regarding the position of the first metallic object.

45. The system of claim 44, wherein the collimator is configured to shape the radiation beam such that the radiation beam irradiates a subset of the region of interest that contains the first metallic object.

46. The system of claim 44, wherein the processor is also configured to obtain information regarding a position of a second metallic object in the region of interest.

47. The system of claim 46, wherein the collimator is configured to shape the radiation beam such that the radiation beam irradiates a subset of the region of interest that contains both the first and the second metallic objects.

48. The system of claim 47, wherein the collimator is configured to shape the radiation beam by moving a plurality of leaves to create two openings that correspond with the first and second metallic objects.

49. The system of claim 44, wherein the collimator is coupled to a rotatable gantry.

50. The system of claim 49, wherein an operation of the collimator is synchronized with a rotation of the gantry.

51. The system of claim 49, wherein the collimator has a plurality of leaves, the leaves having a first configuration when the collimator is at a first gantry angle, and a second configuration when the collimator is at a second gantry angle.

52. The system of claim 51, wherein the leaves in the first configuration provides an opening for allowing the first metallic object and a second metallic object to be irradiated, and the leaves in the second configuration provides two openings for allowing the respective first and second metallic objects to be irradiated.

53. The system of claim 44, further comprising a detector in operative position relative to the collimator, wherein the detector has an elongated shape.

54. The system of claim 53, wherein the detector is adjacent to an EPID, the detector having a surface area that is less than a surface area of the EPID.