System and method for an adaptive morphology x-ray beam in an x-ray system

• US 7,272,208 B2
• Filed: 09/21/2004
• Issued: 09/18/2007
• Est. Priority Date: 09/21/2004
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Inventors: Anderton, Richard Larry, Yatsenko, Dimitri Victorovich
• Primary Examiner(s): Glick; Edward J.
• Assistant Examiner(s): Kiknadze; Irakli
• Application Number:
  US10/945,649
• Publication Number:
  US 20060062353A1
• Time in Patent Office: 1,092 Days
• Field of Search: 378/16, 378/19, 378/98.7, 378/98.8, 378/145, 378147-153, 378156-159
• US Class Current: 378/145
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4035 the source being combined with a filter or grating
• CPC Class Codes: A61B 6/542 involving control of exposure
• CPC Class Codes: G21K 1/10 Scattering devices; Absorbing devices; Ionising radiation filters

Abstract

The present invention provides for an x-ray system and method using dynamic automated spatial modulation of an x-ray beam. The system includes an x-ray source transmitting a spatially modulated beam towards an object to be imaged, an x-ray detector receiving the beam and measuring a plurality of intensities across the beam, a beam processor controlling the beam intensity profile, and an image processor producing an output image signal. The detector produces a residual image based on at least the intensities measured at the detector. The beam intensity profile may be based on at least some of the following: (a) the residual image from the x-ray detector, (b) current beam intensities, (c) regions on interest in the image, and (d) predicted or measured object motion in the image. The system'"'"'s output image is based on one or more of said residual image and said beam intensity signal.

Claims

1. An x-ray imaging system using spatial modulation of an x-ray beam, said system including:

an x-ray source transmitting said beam towards an object to be imaged, said x-ray source generating said beam so that said beam includes a plurality of x-ray intensities varying spatially and temporally and based on at least a beam intensity signal;

an x-ray detector receiving said beam after an interaction between said beam and said object, said detector measuring a plurality of residual intensities of said beam and producing a residual image signal based on at least said residual intensities;

a beam processor creating said beam intensity signal based on at least one of a previous beam intensity signal, said residual intensities, a region of interest in said object, and anticipated object motion; and

an image processor producing an output image signal, said output image signal based on one or more of said residual image signal and said beam intensity signal.

2. The system of claim 1, wherein said plurality of x-ray intensities is dynamically altered by said x-ray source.

3. The system of claim 1, wherein said plurality of x-ray intensities is altered by said x-ray source to match one or more of a distribution of anticipated radiographic thicknesses in said imaged object, a distribution of said regions of interest in said imaged object, and a distribution of regions of motion in said imaged object.

4. The system of claim 1, wherein said beam intensity signal is based on at least said residual image signal.

5. The system of claim 1, further including a filter , said filter filtering said beam transmitted by said x-ray source by altering amounts of attenuation of said beam.

6. The system of claim 5, wherein said filter creates said spatially modulated beam using x-ray dodging.

7. The system of claim 5, wherein said filter creates said spatially modulated beam by moving an arrangement of radiographically opaque elements during an image integration period so that such motion causes various regions in said beam to be blocked for various portions of said image integration period in said x-ray detector.

8. The system of claim 7, wherein at least one of said radiographically opaque elements changes a spatial orientation or occludes another element to alter said beam transmitted by said x-ray source.

9. The system of claim 7, wherein said arrangement of radiographically opaque elements are produced by configurable juxtapositions of a plurality of basis filters, each of said basis filters including a combination of said radiographically opaque elements.

10. The system of claim 5, wherein said beam processor converts said beam intensity signal into a modulator configuration signal and communicates said modulator configuration signal to said filter, and said filter alters said amounts of attenuation based on at least said modulator configuration signal.

11. The system of claim 10, wherein said modulator configuration signal causes a position of one or more of said basis filters to change.

12. The system of claim 1, wherein said x-ray source transmit so that said beam varies temporally during an image integration period.

13. A method for x-ray imaging with spatial modulation of an x-ray beam, said method including:

transmitting said beam towards an object to be imaged, an x-ray intensity field of said beam varying across said beam, said intensity field based on at least a beam intensity signal;

receiving said beam at an x-ray detector;

measuring a plurality of intensities of said beam at said detector;

creating a residual image signal based on at least said intensities measured at said detector; and

producing an output image signal, said output image signal based on one or more of said residual image signal and said beam intensity signal,

wherein said beam intensity signal is based on one or more of a predicted information density and said intensities measured at said detector.

14. The method of claim 13, further including dynamically altering said beam intensity field.

15. The method of claim 13, wherein said beam intensity field includes one or more of a distribution of radiographic thicknesses in imaged object, a distribution of regions of interest, and a distribution of regions of anticipated object motion.

16. The method of claim 13, wherein said beam intensity signal is based on at least said residual image.

17. The method of claim 13, wherein said transmitting step includes transmitting an essentially uniform x-ray beam and further including creating a spatially modulated x-ray beam by filtering said essentially uniform beam, said creating step including altering an amount of attenuation of said essentially uniform beam to various degrees across said essentially uniform beam.

18. The method of claim 17, further including employing x-ray dodging to create said beam intensity field.

19. The method of claim 18, wherein said employing x-ray dodging step includes moving one or more configurable arrangements of radiographically opaque elements during an image integration period of said detector so that various portions of said essentially uniform beam remain blocked for various portions of said image integration period.

20. The method of claim 17, further including:

converting a beam intensity signal into a modulator configuration signal, wherein said field is based on at least said beam intensity signal; and

communicating said modulator configuration signal to a filter, wherein said creating step includes employing said filter in order to alter said amount of attenuation based on at least said modulator configuration signal.

21. The method of claim 13, further including varying said x-ray intensity field temporally during an image integration period.

22. A system for creating an x-ray image using spatial modulation of an x-ray beam, said system including:

an x-ray source producing said beam toward an object to be image, wherein said object includes at least one predicted information density, said predicted information density including at least one of a radiographic thickness, a region of interest, and a region of object motion, said beam including a field of continually varying x-ray intensities;

an object to be imaged including at least one predicted information densities, said predicted information density including at least one of a radiographic thickness, a region of interest, and a region of object motion;

a detector creating a residual image based on at least x-ray intensities of said beam received at said detector and attenuated by one or more of said object and said predicted information density; and

a beam processing unit examining said residual image in order to determine at least one modification to said field of continually varying x-ray intensities transmitted in at least one subsequent beam transmitted by said source.

23. The system of claim 22, wherein said beam processing unit communicates said modification to said field of continually varying x-ray intensities to one or more of said source and a filter disposed between said source and said object.

24. The system of claim 22, wherein said beam processing unit continually modifies said field of continually varying x-ray intensities in subsequent beams transmitted by said source.

25. The system of claim 22, wherein said beam processing unit modifies said field of continually varying x-ray intensities in at least one subsequent beam transmitted by said source based on at least a change in said predicted information density.

26. The system of claim 22, further including an image processing unit combining a representation of said x-ray intensity field and said residual image to create an output image.

27. The system of claim 26, wherein said beam processing unit and said image processing unit are included in an external beam modification device to augment a conventional system with dynamic beam modulating capabilities.

28. An imaging system, comprising:

a source transmitting a beam of energy toward an object to be imaged;

a detector receiving a residual beam of the beam of energy after it passes through the object wherein said detector measures beam intensities in the residual beam; and

a beam processor receiving data related to the beam intensities and communicating a beam intensity signal to said source, wherein said source alters and spatially modulates the beam of energy according to the beam intensity signal.

29. The imaging system of claim 28, further comprising:

an image processor that receives residual image data based on the residual beam and produces a displayed image signal; and

a display that receives the displayed image signal.

30. The imaging system of claim 28, wherein the beam of energy is an x-ray beam.

31. The imaging system of claim 28, wherein the spatially modulated beam is constructed to match a distribution of radiographic thicknesses of the object.

32. The imaging system of claim 28, wherein the spatially modulated beam is constructed to match a distribution of a region of interest of the object.

33. The imaging system of claim 28, wherein the spatially modulated beam is constructed to match a distribution of regions of sustained motion in the object.

34. The imaging system of claim 28, wherein said beam processor completes a feedback loop that one of periodically and continuously updates a beam intensity field.

35. The imaging system of claim 28, further comprising a beam-modulating filter positioned between said source and the object.

36. The imaging system comprising:

a source transmitting a beam of energy toward an object to be imaged;

a detector receiving a residual beam of the beam of energy after it passes through the object wherein said detector measures beam intensities in the residual beam; and

a beam processor receiving data related to the beam intensities and communicating a beam intensity signal to said source,

wherein said source alters and spatially modulates the beam of energy according to the beam intensity signal, and

wherein said source alters the beam of energy by moving a narrow beam back and forth in a raster pattern over particular areas of the object while varying the beam'"'"'s intensity temporally.

37. An imaging method, comprising:

transmitting a beam of energy toward an object to be imaged with a source;

measuring beam intensities in a residual beam;

receiving data related to the beam intensities;

communicating a beam intensity signal to the source, and

spatially modulating the beam of energy based on said communicating.

38. The method of claim 37, wherein the beam of energy is an x-ray beam.

39. The method of claim 37, wherein said spatially modulating comprises matching the beam of energy to a distribution of radiographic thicknesses of the object.

40. The method of claim 37, wherein said spatially modulating comprises matching the beam of energy to a region of interest of the object.

41. The method of claim 37, wherein said spatially modulating comprises matching a distribution of regions of sustained motion in the object.

42. The method of claim 37, further comprising one of periodically and continuously updating a beam intensity field.

43. A system for creating an x-ray image using spatial modulation of an x-ray beam, said system including:

a beam processing unit examining a residual image in order to determine at least one modification to a field of varying x-ray intensities transmitted in at least one subsequent x-ray beam transmitted by an x-ray source, the x-ray source generating said beam so that said beam includes a plurality of x-ray intensities varying spatially and temporally,

wherein said x-ray source produces said subsequent x-ray beam towards an object to be imaged, said object including at least one predicted information density that includes at least one of a radiographic thickness, a region of interest, and a region of object motion,

wherein said residual image is created by an x-ray detector and is based on at least x-ray intensities of an x-ray beam received at said detector previous to said subsequent x-ray beam and attenuated by one or more of said object and said predicted information density.

44. The system of claim 43, wherein said beam processing unit modifies said field of x-ray intensities in at least one subsequent beam transmitted by said source.

45. The system of claim 43, wherein said beam processing unit communicates said modification to one or more of said source and a filter disposed between said source and said object.

46. The system of claim 43, wherein said beam processing unit modifies said field of x-ray intensities in at least one subsequent beam transmitted by said source based on at least a change in said predicted information density.

47. The system of claim 46, wherein said beam processing unit and said image processing unit are included in an external beam modification device of an x-ray imaging system.

48. The system of claim 43, further including an image processing unit combining a representation of said x-ray intensity field and said residual image to create an output image.