Method and system for creating three-dimensional images using tomosynthetic computed tomography

• US 6,289,235 B1
• Filed: 03/05/1998
• Issued: 09/11/2001
• Est. Priority Date: 03/05/1998
• Status: Expired due to Fees

• Current Assignee: Wake Forest University Health Sciences
• Original Assignee: Wake Forest University
• Inventors: Webber, Richard L., Horton, Roger A.
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): SHAW, SHAWNA JEANNINE
• Application Number:
  US09/034,922
• Time in Patent Office: 1,286 Days
• Field of Search: 600/426, 378/38, 378/166, 378/205-207, 378/23, 382/128, 382/131, 382/285, 382/287, 382/289, 382/295, 382/298, 356/393, 356/398, 356/401, 356/247, 356/248
• US Class Current: 600/426
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 6/512 Intraoral means
• CPC Class Codes: G06T 11/005 Specific pre-processing for tomographic reconstruction, e.g. calibration, source positioning, rebinning, scatter correction, retrospective gating
• CPC Class Codes: G06T 11/008 Specific post-processing after tomographic reconstruction, e.g. voxelisation, metal artifact correction
• CPC Class Codes: G06T 2211/436 Limited angle

Abstract

A system for constructing image slices through a selected object, the system comprising an identifiable fiducial reference in a fixed position relative to the selected object, wherein the fiducial reference comprises at least two identifiable reference markers. A source of radiation is provided for irradiating the selected object and the fiducial reference to form a projected image of the selected object and the fiducial reference which is recorded by a recording medium.

Claims

1. A system for constructing image slices through a selected object comprising:

a. an identifiable fiducial reference located at a fixed position relative the selected object, to fiducial reference having a total number of degrees of freedom associated therewith greater or equal to the total number of degrees of freedom of the system;

b. a source of radiation for irradiating the selected object and the fiducial reference;

c. a recording medium for recording a projected image of the selected object and the fiducial reference; and

d. an image synthesizer for analyzing parameters related to positions and sizes of the images detected upon said recording medium to produce image translation data, and for reconstructing a tomographic slice from said object images and said translation data;

whereby the fiducial reference, the source of radiation, and the recording medium are moved arbitrarily relative to one another.

2. The system in accordance with claim 1 wherein the recording medium includes a CCD device.

3. The system in accordance with claim 1 wherein the fiducial reference comprises at least five identifiable reference markers in a fixed geometry relative to each other.

4. The system in accordance with claim 3 wherein at least four of the reference markers are co-planar.

5. The system in accordance with claim 4 wherein a maximum of any two of the four co-planar reference markers are co-linear.

6. The system in accordance with claim 5 wherein a fifth reference marker is not co-planar with the four co-planar reference markers.

7. The system in accordance with claim 1 wherein the source of radiation comprises an electron source for irradiating the selected object and the fiducial reference with electrons.

8. The system in accordance with claim 1 wherein the source of radiation comprises a visible light source for irradiating the selected object and the fiducial reference, and the recording medium comprises a photographic recording medium for recording photographic images of the selected object and fiducial reference.

9. The system in accordance with claim 8 wherein the source of radiation and the recording medium comprise a video camera.

10. A system for tomosynthesis of multiple projected object images of a selected object comprising:

a. a recording medium for electron microscopy images for recording multiple projected object images at different arbitrary positions relative to the selected object;

b. a fiducial reference located at a fixed reference position relative to the selected object for producing multiple projected reference images upon said image detector, the fiducial reference having a total number of degrees of freedom associated therewith greater or equal to the total number of degrees of freedom of the system; and

c. an image synthesizer for analyzing parameters related to positions and sizes of the reference images detected upon said image detector to produce image translation data, and for reconstructing a tomographic slice from said object images and said translation data.

23. A system in accordance with claim 10 wherein the recording medium for electron microscopy images is an electron microscope image detector.

11. An apparatus for tomosynthesis of multiple object images of a selected object irradiated by a source of radiation comprising:

a. an image detector for detecting said multiple object images;

b. a fiducial reference positioned at a fixed position relative to the selected object for producing multiple reference images on said image detector to yield composite images of said reference and object images detected upon said image detector, the fiducial reference having a total number of degrees of freedom associated therewith greater or equal to the total number of degrees of freedom of the system; and

c. an image synthesizer for analyzing parameters related to positions and sizes of reference images of said composite images detected upon said image detector to produce image translation data, and for reconstructing a tomographic slice from said composite images and said image translation data.

whereby the fiducial reference, the source of radiation, and the image detector are moved arbitrarily relative to one another.

12. The apparatus in accordance with claim 11 wherein said fiducial reference includes a metallic bead.

13. The apparatus in accordance with claim 11 wherein said image detector includes a first image detecting medium for recording said multiple object images and a second image detecting medium supported in a fixed position at a selected angle of orientation relative to said first image detecting medium for recording said composite images.

14. The apparatus in accordance with claim 11 wherein said image detector comprises an image detector for detecting electron microscope images.

15. A method for synthesizing an image slice through a selected object at a selected slice position through the object from a plurality of projected images of the object comprising the steps of:

a. recording projected images of the selected object and a fiducial reference on a recording means at different arbitrary relative positions between (1) a source of radiation, (2) the selected object and fiducial reference, and (3) a recording medium, the fiducial reference having a total number of degrees of freedom associated therewith greater or equal to the total number of degrees of freedom of the system; and

b. synthesizing an image slice of the selected object at a selected slice position through the object from the projected images.

16. The method in accordance with claim 15 wherein the step of recording projected images includes the step of moving the object and the fiducial reference relative to the source of radiation and the recording medium.

17. The method in accordance with claim 16 wherein the step of moving the object and the fiducial reference relative to the source of radiation and the recording means includes the steps of:

a. maintaining the source of radiation and the recording means in a fixed position; and

b. placing the object and the fiducial reference on a conveyer for moving the object and the fiducial reference relative to the source of radiation and the recording medium.

18. The method in accordance with claim 15 wherein the step of recording projected radiographic images includes the step of moving the source of radiation relative to the object and fiducial reference and the recording medium.

19. The method in accordance with claim 15 wherein the step of synthesizing an image of the selected object at a selected slice position through the object includes the steps of:

a. projectively warping each projected image onto a virtual projection plane;

b. generating an image slice through the object at a selected slice position.

20. The method in accordance with claim 19 further comprising the step of scaling each projected image by a magnification factor.

21. The method in accordance with claim 15 wherein the step of recording projected images of the selected object and the fiducial reference comprises the step of recording electron microscope images of the selected object and the fiducial reference.

22. The method in accordance with claim 15 wherein the step of recording projected images of the selected object and the fiducial reference comprises the step of recording visible light images of the selected object and the fiducial reference.