Application specific emission and transmission tomography

• US 20020143249A1
• Filed: 03/27/2002
• Published: 10/03/2002
• Est. Priority Date: 03/30/2001
• Status: Active Grant

• Current Assignee: Duke University
• Original Assignee: Duke University
• Inventors: Peter, Joerg, Tornai, Martin P., Bowsher, James E.
• Granted Patent: US 7,609,808 B2
• Time in Patent Office: Days
• US Class Current: 600/425
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/502 for diagnosis of breast, i.e. mammography
• CPC Class Codes: A61B 6/583 using calibration phantoms

Abstract

A compact and mobile gantry for 3-dimensional Application Specific Emission and/or Transmission Tomography (ASETT) imaging of the breast in single photon or coincidence emission modes, and single photon, or coincidence, or x-ray transmission modes. While the ASETT gantry was designed, built and evaluated for imaging metabolically active lesions in the pendant breast, it can also be used to image other organs and objects. This system overcomes physical constraints associated with imaging a pendulous breast in prone patients, while simultaneously satisfying sampling criteria for sufficient data collection in the pendulous breast reference frame. When combined with an offset cone-beam tomographic x-ray transmission imaging system, this dual modality ASETT system could provide simultaneous and coregistered structural and functional information about large or dense breasts, breasts with indeterminate x-ray mammography, and could also be used to accurately 3-dimensionally guide biopsy or surgical resection. Moreover, with the offset beam orientation, the transmission system is designed to have a variable FOV and minimize overall absorbed breast dose.

Claims

1. An imaging system for generating images of a body part suspended within an imaging area of the system, comprising:

a support having a rotation axis extending through the imaging area and at least one imaging device having an imaging device axis which passes through a first imaging device field of view, the imaging device being mounted to the support so as to be selectively movable in three dimensions, including radial movement relative to the rotation axis, rotational movement about the rotation axis, vertical movement parallel to the rotation axis, and pivoting movement about a pivot axis perpendicular to said rotation axis, whereby said imaging device can be selectively moved along a path that defines a curved 3-dimensional surface.

2. An imaging system as in claim 1, further including a support for supporting a patient so that a body part to be imaged is suspended within the imaging area.

3. An imaging system as in claim 1, wherein said imaging device comprises a gamma camera.

4. An imaging system as in claim 1, wherein said imaging device comprises a SPECT camera.

5. An imaging system as in claim 1, wherein said at least one imaging device comprises a pair of gamma cameras for coincidence imaging.

6. An imaging system as in claim 1, wherein said at least one imaging device comprises a pair of detectors for Positron Emission Tomography (PET).

7. An imaging system as in claim 1, wherein said imaging device comprises an X-ray imaging system.

8. An imaging system as in claim 7, wherein said imaging device axis is laterally offset from said rotation axis and said support is mounted for rotational movement through at least about 180 degrees, whereby when the body part is greater than the imaging device field of view, an entire volume of said body part can be sufficiently sampled to accurately reconstruct the object distribution.

9. An imaging system as in claim 8, wherein said imaging device axis is inclined with respect to said rotation axis to maximize a path of x-rays through an object disposed in said field of view.

10. An imaging system as in claim 1, further comprising an X-ray source and an X-ray detector disposed diametrically opposite said X-ray source, said X-ray source and X-ray detector being disposed such that a line extending from said X-ray source to said X-ray detector is disposed at an angle to said imaging device axis.

11. An imaging system as in claim 10, wherein said angle is between about 45 and 135 degrees.

12. An imaging system as in claim 1, wherein said imaging device axis is laterally offset from said rotation axis and said support is mounted for rotational movement through at least about 180 degrees, whereby when the body part is greater than the imaging device field of view, an entire volume of said body part can be sufficiently sampled to accurately reconstruct the emission activity and/or object distributions.

13. An imaging system as in claim 12, wherein said support is mounted for rotation through and including 360 degrees.

14. An imaging system as in claim 13, wherein said imaging device comprises an X-ray source and X-ray detector mounted diametrically opposite one another.

15. An imaging system as claim 1, wherein said imaging device can be selectively moved along a three-dimensional path that defines substantially a banded orbit.

16. An imaging system as claim 1, wherein said imaging device can be selectively moved along a path that defines substantially a hemisphere.

18. A gantry as in claim 17, wherein said translation assembly displaces said imaging device support radially of said rotary axis.

19. A gantry as in claim 17, wherein said imaging device support comprises an elevation assembly for selectively displacing an imaging device mounted thereto radially with respect to said pivot axis for selectively changing a radius of rotation of the imaging device or for following a contour of the surface of the body part.

20. A gantry as in claim 17, wherein the imaging device support is mounted so that an emission receiving face of an imaging device disposed thereon can be selectively disposed generally parallel to and adjacent a surface of the body part.

21. A gantry as in claim 20, wherein said translation assembly comprises a cradle system for providing at least ±

45°

angular motion and wherein said imaging device support is mounted to said cradle system, whereby an imaging device mounted to said imaging device support may be selectively displaced through an angle of at least about 90°

.

22. A gantry as in claim 21, wherein said imaging device support comprises a platform and an elevation assembly for selectively displacing said platform from said cradle, for selectively changing a radius of rotation of the imaging device or for following a contour of the surface of the body part.

23. A gantry as in claim 21, further comprising an imaging device mounted to said imaging device support, said imaging device comprising a SPECT camera.

24. A gantry as in claim 17, further comprising an imaging device mounted to said imaging device support, and wherein an axis of said imaging device axis is laterally offset from said rotation axis and said rotary support assembly is mounted for rotational movement through at least about 180 degrees

25. A gantry as in claim 17, comprising first and second imaging devices mounted to said imaging device support assembly for being disposed on generally diametrically opposite sides of said body part.

26. A gantry as in claim 17, wherein said translation assembly comprises a cradle system and further comprising a pair of detectors for Positron Emission Tomography (PET), one respectively mounted adjacent each end of said cradle.

27. A gantry as in claim 17, wherein said translation assembly comprises a cradle system and further comprising an x-ray source mounted adjacent one end of said cradle and a detector mounted adjacent a second end of said cradle for x-ray computed tomography.

28. A gantry as in claim 17, further comprising an imaging device mounted to said imaging device support, and further comprising an X-ray source and an X-ray detector disposed diametrically opposite said X-ray source, said X-ray source and X-ray detector being disposed such that a line extending from said X-ray source to said X-ray detector is disposed at an angle to an axis of said imaging device.

29. A gantry as in claim 28, wherein said angle is between about 45 and 135 degrees.

30. A gantry as claim 17, wherein said imaging device can be selectively moved along a three-dimensional path that defines substantially a banded orbit.

31. A gantry as claim 17, wherein said imaging device can be selectively moved along a path that defines substantially a hemisphere.

17. A gantry for dedicated 3-dimensional tomographic imaging of a body part, comprising:

an imaging device support assembly including an imaging device support and a translation assembly for displacing said imaging device support relative to a said body part; and

a rotary support assembly for rotating said imaging device support assembly about a rotary axis thereof, for displacing said imaging device support about a periphery of said body part, at a radius of rotation determined at least in part by said imaging device support assembly,

wherein at least one of said imaging device support assembly and said rotary support assembly is height adjustable to determine a spacing of an imaging device mounted to said imaging device support from said body part,

wherein said imaging device support assembly is configured to provide selective displacement of an imaging device mounted thereto through an angle φ

about a pivot axis perpendicular to said rotation axis, and

wherein at least one of said imaging device support and said translation assembly is configured to selectively radially displace an imaging device mounted thereto relative to the rotation axis.

32. A method for three-dimensional tomographic imaging of a pendent breast comprising:

placing and supporting a patient in a prone position with a target breast depending downwardly from the supported patient;

positioning at least one imaging device adjacent a surface of the pendent target breast; and

selectively displacing said imaging device in a direction radial to a central axis of said pendent breast, in a rotary direction about a rotational axis along at least a part of a circumferential surface of the breast, through a pivot angle about a pivot axis transverse to said rotational axis, and vertically with respect to the prone patient so that said imaging device follows an approximate three-dimensional surface of at least a portion of said breast.

33. A method as in claim 32, wherein said step of selectively displacing includes incrementally rotating the imaging device about the pendent breast such that measurements of the pendent breast are taken at a number of angular orientations.

34. A method as in claim 32, including mounting said imaging device so that an axis of a field of view thereof is laterally offset from said rotation axis and selectively rotating said imaging device through at least about 180 degrees.

35. A method as in claim 34, wherein said imaging device comprises an X-ray imaging system and further including mounting said imaging device so that said field of view axis thereof is inclined with respect to said rotation axis to maximize a path of x-rays through the pendant breast disposed in said field of view.

36. A method as in claim 32, wherein said imaging device comprises a SPECT camera.

37. A method as in claim 32, wherein said at least one imaging device comprises a pair of detectors for Positron Emission Tomography (PET).

38. A method as in claim 32, further comprising guiding a biopsy or tissue extraction device to a target region within the pendant breast and obtaining a tissue sample.