Method and system for creating task-dependent three-dimensional images

• US 20040008809A1
• Filed: 04/14/2003
• Published: 01/15/2004
• Est. Priority Date: 07/24/1998
• Status: Active Grant

• Current Assignee: Richard L. Webber
• Original Assignee: Richard L. Webber
• Inventors: Webber, Richard L.
• Granted Patent: US 6,801,597 B2
• Time in Patent Office: Days
• US Class Current: 378/8
• CPC Class Codes: A61B 6/5258 involving detection or reduction of artifacts or noise
• CPC Class Codes: A61B 6/548 Remote control of the apparatus or devices
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: Y10S 378/901 Computer tomography program or processor

Abstract

A system and method for producing three-dimensional representations of an object. A first series of projected images of the selected object is recorded in a first projection plane and a second series of projected images of the selected object is recorded in a second projection plane. The first and the second series of projected images are rendered at a common magnification. The first set of projected images is then integrated into a first three-dimensional volume and the second set of projected images is integrated into a second three-dimensional volume. The three-dimensional representation of the object is then produced by combining one projected image from the first set of projected images with one projected image from the second set of projected images. Alternatively, the three-dimensional representation is produced by merging the first three-dimensional volume with the second three-dimensional volume.

Claims

1. A method for determining temporal changes of a selected object comprising the steps of:

a. generating a first set of slices of the selected object;

b. generating a second set of slices of the selected object;

c. correlating each slice of the first set of slices with a corresponding slice of the second set of slices;

d. aligning each slice of the first set of slices with the corresponding slice of the second set of slices to maximize the overlap of each slice of the first set of slices with the corresponding slice of the second set of slices;

e. determining a difference between each slice of the first set of slices and the corresponding slice of the second set of slices; and

f. displaying the difference illustrating the temporal changes associated with the selected object.

2. A method for determining temporal changes of a selected object comprising the steps of:

a. generating a first set of slices of the selected object;

b. generating a second set of slices of the selected object;

c. correlating each slice of the first set of slices with a corresponding slice of the second set of slices;

d. aligning each slice of the first set of slices with the corresponding slice of the second set of slices to maximize the overlap of each slice of the first set of slices with the corresponding slice of the second set of slices;

e. determining a difference between each slice of the first set of slices and the corresponding slice of the second set of slices; and

f. combining the differences between each slice to form a composite difference representing a three-dimensional image of the temporal changes associated with the selected object.

3. A method for determining temporal changes of a selected object comprising the steps of:

a. providing at least one fiducial reference in fixed position relative to the selected object;

b. generating a first set of slices of the selected object and fiducial reference;

c. generating a second set of slices of the selected object and fiducial reference;

d. correlating each slice of the first set of slices with a corresponding slice of the second set of slices;

e. aligning each slice of the first set of slices with the corresponding slice of the second set of slices by aligning the fiducial reference in each slice of the first set of slices with the fiducial reference in the corresponding slice of the second set of slices;

f. determining a difference between each slice of the first set of slices and the corresponding slice of the second set of slices.

4. A method for synthesizing a three-dimensional representation of a selected object from a plurality of projected radiographic images of the selected object comprising the steps of:

a. providing at least one radiographic recorder for recording radiographic images of the selected object;

b. providing at least one fiducial reference in fixed position relative the selected object;

c. providing at least one source of radiation for irradiating the selected object and the fiducial reference to enable projected radiographic images of the selected object and the fiducial reference to be recorded on the radiographic recorder;

d. recording a first projected radiographic image of the selected object and fiducial reference in a first projection plane;

e. recording a second projected radiographic image of the selected object and fiducial reference in a second projection plane, the second projection plane intersecting the first projection plane at a known angle;

f. transforming each of the first and the second projected radiographic images to render each of the projected radiographic images at a common magnification;

g. registering the first and second projected radiographic images using the known angle and projected images of the fiducial reference;

h. extruding the transformed first and second projected radiographic images such that the transformed first and the second projected radiographic images occupy the same volume; and

i. combining the first and second projected radiographic images into a three-dimensional representation of the selected object.

5. The method according to claim 4 wherein the known angle is 90 degrees.

6. The method of claim 4 comprising the step of limiting the three-dimensional representation to the logical intersection of the first and second projected radiographic images.

7. The method according to claim 4 wherein the combining step uses a nonlinear technique to combine the images.

8. A method according to claim 7 wherein the nonlinear technique assigns a value to each pixel of the combined image equal to a maximum value of the attenuation values of a corresponding pixel in the projected images.

9. A method according to claim 7 wherein the nonlinear technique assigns a value to each pixel of the combined image equal to a minimum value of the attenuation values of a corresponding pixel in the projected images.

10. The method of claim 4 comprising the steps of:

a. recording a third projected radiographic image in a third projection plane, the third projection plane intersecting the first projection plane at a second known angle;

b. transforming the third projected radiographic image to render the 3^rd radio-graphic image at the same magnification as 1^st image;

c. extruding the transformed third projected such that the transformed first, second, and third projected radiographic images occupy the same volume; and

d. combining the third projected radiographic image with the three-dimensional representation of the selected object.

11. The method of claim 10 comprising the step of limiting the three-dimensional representation to the logical intersection of the first, second, and third projected radiographic images.

12. The method according to claim 10 wherein the combining step uses a nonlinear technique to combine the images.

13. A method according to claim 12 wherein the nonlinear technique assigns a value to each pixel of the combined image equal to a maximum value of the attenuation values of a corresponding pixel in the projected images.

14. A method according to claim 12 wherein the nonlinear technique assigns a value to each pixel of the combined image equal to a minimum value of the attenuation values of a corresponding pixel in the projected images.

15. A method for synthesizing a three-dimensional representation of a selected object from a plurality of projected images of the selected object comprising the steps of:

a. providing at least one radiographic recorder for recording optical images of the selected object;

b. providing at least one fiducial reference in fixed position relative the selected object, the fiducial reference occupying a volume and defining at least six points, the six points defining faces of the volume.

c. providing at least one source of radiation for irradiating the selected object and the fiducial reference to enable projected radiographic images of the selected object and the fiducial reference to be recorded on the radiographic recorder;

d. recording a first projected radiographic image of the selected object in a first projection plane;

e. recording a second projected radiographic image of the object in a second projection plane, the second projection plane intersecting the first projection plane at a known angle;

f. transforming each of the first and the second projected radiographic images to map images of the at least one fiducial reference into an orthogonal, affine representation of one of the faces;

g. extruding the transformed first and second projected radiographic images such that the transformed first and the second projected radiographic images occupy the same volume; and

h. combining the first and second projected radiographic images into a three-dimensional representation of the selected object.

16. The method of claim 15 comprising the step of limiting the three-dimensional representation to the logical intersection of the first and second projected radiographic images.

17. The method of claim 15 comprising the steps of:

a. recording a third projected radiographic image in a third projection plane, the third projection plane intersecting the first projection plane at a second known angle;

b. transforming the third projected radiographic image to map the image of at least one fiducial reference into an orthogonal, affine representation of one of the faces;

c. extruding the transformed third projected radiographic image such that the transformed first, second, and third projected radiographic images occupy the same volume; and

d. combining the third projected radiographic image with the three-dimensional representation of the selected object.

18. A method for synthesizing a three-dimensional representation of a selected object from a plurality of projected radiographic images of the selected object comprising the steps of:

a. providing at least one radiographic recorder for recording radiographic images of the selected object;

b. providing at least one fiducial reference in fixed position relative the selected object;

c. providing at least one source of radiation for irradiating the selected object and the fiducial reference to enable projected radiographic images of the selected object and the fiducial reference to be recorded on the radiographic recorder;

d. recording a first set of projected radiographic images of the selected object;

e. recording a second set of projected radiographic images of the object;

f. transforming each of the first and the second sets of images to render each image at a common magnification;

g. integrating the first set of transformed radiographic images into a first three-dimensional volume and integrating the second set of transformed radiographic images into a second three-dimensional volume;

h. rotating the second three-dimensional volume by an angle corresponding to the angular disparity between the first and the second three-dimensional volumes; and

i. merging the first and the second three-dimensional volumes to form a three-dimensional representation of the selected object.

19. The method according to claim 18 wherein the angular disparity between the first and second three-dimensional volumes is 90 degrees.

20. The method according to claim 18 wherein the merging step uses a nonlinear technique to combine the three-dimensional volumes.

21. A method according to claim 19 wherein the nonlinear technique assigns a value to each pixel of the combined three-dimensional volumes equal to a maximum value of the attenuation values of a corresponding pixel in the first and second three-dimensional volumes.

22. A method according to claim 19 wherein the nonlinear technique assigns a value to each pixel of the combined three-dimensional volumes equal to a minimum value of the attenuation values of a corresponding pixel in the first and second three-dimensional volumes.

23. The method according to claim 18 wherein the merging step is an average.