Computed tomography facilitation method and apparatus

• US 7,486,761 B2
• Filed: 03/08/2007
• Issued: 02/03/2009
• Est. Priority Date: 03/08/2007
• Status: Active Grant

• Current Assignee: Varex Imaging Corporation
• Original Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Inventors: Moore, John F.
• Primary Examiner(s): Kiknadze; Irakli
• Application Number:
  US11/683,642
• Publication Number:
  US 20080219403A1
• Time in Patent Office: 698 Days
• Field of Search: 378/4, 378/9, 378/55, 378/57, 378/98, 378/8, 378/56, 378/62, 378/177, 378/197, 378/198, 378/208, 378/19, 378/98.8
• US Class Current: 378/9
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4014 arranged in multiple source-detector units
• CPC Class Codes: A61B 6/4266 characterised by using a plurality of detector units A61B6/4014 takes precedence
• CPC Class Codes: G01N 2223/401 image processing
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]

Abstract

A first X-ray detector (203) is positioned to detect at least the X-rays that intersect the center of rotation (201) for an object (205) with respect to an X-ray source (202). A second X-ray detector (207) is then positioned to detect X-rays that do not overlap with the X-rays as are detected by the first X-ray detector as well as X-rays (210) that intersect a periphery of a circle (209) that circumscribes an outer extreme boundary (208) of the object to be scanned.

Claims

1. A method comprising:

providing an object scanning space having a center of rotation;

providing at least a first source of X-rays;

providing a first X-ray detector in a position to detect at least the X-rays that intersect the center of rotation;

providing at least a second X-ray detector in a position to detect the X-rays that;

do not overlap with the X-rays as are detected with the first X-ray detector; and

detect at least the X-rays that intersect a periphery of a circle that circumscribes an outer extreme boundary of an object to be scanned in the object scanning space;

wherein all of the X-ray detectors as are provided are insufficient to make a complete scan of the object scanning space without providing some relative motion as between the X-ray detectors and the object scanning space;

further comprising providing a second source of X-rays wherein the first source of X-rays and the second source of X-rays are substantially opposite one another and wherein providing a first X-ray detector comprising disposing the first X-ray detector in a position that is opposite the first source of X-rays and providing a second X-ray detector comprises disposing the second X-ray detector in a position that is opposite the second source of X-rays.

2. The method of claim 1 wherein providing a first X-ray detector comprises providing a flat plate detector.

3. The method of claim 1 wherein providing a first X-ray detector comprises providing an image intensifier.

4. The method of claim 1 wherein providing a first X-ray detector comprises providing a multi-channel detector of width inadequate to cover at least half of the object scanning space.

5. The method of claim 1 wherein:

providing a first X-ray detector comprises providing a flat plate detector;

providing a second X-ray detector comprises providing a flat plate detector.

6. The method of claim 1 wherein:

providing a first X-ray detector comprises providing an image intensifier;

providing a second X-ray detector comprises providing an image intensifier.

7. The method of claim 1 wherein:

providing a first X-ray detector comprises providing a multi-channel detector of width inadequate to cover at least half of the object scanning space;

providing a second X-ray detector comprises providing a multi-channel detector of width inadequate to cover at least half of the object scanning space.

8. The method of claim 1 wherein providing a first X-ray detector in a position to detect at least the X-rays that intersect the center of rotation comprises positioning the first X-ray detector in an offset position with respect to a line that intersects both the first source of X-rays and the center of rotation.

9. The method of claim 8 wherein positioning the first X-ray detector in an offset position with respect to a line that intersects both the first source of X-rays and the center of rotation comprises positioning the first X-ray detector such that one edge of the first X-ray detector extends only a relatively small distance beyond the line that intersects both the first source of X-rays and the center of rotation and towards the second X-ray detector.

10. A method comprising:

providing an object scanning space having a center of rotation;

providing at least a first source of X-rays;

providing a first X-ray detector in a position to detect at least the X-rays that intersect the center of rotation;

providing at least a second X-ray detector in a position to detect the X-rays that;

do not overlap with the X-rays as are detected with the first X-ray detector; and

detect at least the X-rays that intersect a periphery of a circle that circumscribes an outer extreme boundary of an object to be scanned in the object scanning space;

using an offset rebinning process with the first and second X-ray detector to develop a computed tomography image of an object in the object scanning space.

11. The method of claim 10 wherein providing a first X-ray detector and providing a second X-ray detector comprises providing both the first X-ray detector and the second X-ray detector on a same side of the object scanning space and opposite the first source of X-rays.

12. The method of claim 10 wherein using the offset rebinning process with the first and second X-ray detector to develop a computed tomography image of an object in the object scanning space further comprises capturing a complete set of image data for the object by capturing image data during 360 degrees of relative rotation as between the object and the first and second X-ray detectors.

13. An apparatus comprising:

an object scanning space having a center of rotation;

a first source of X-rays;

a first X-ray detector that is disposed in a position to detect at least the X-rays that intersect the center of rotation;

at least a second X-ray detector that is disposed in a position to detect the X-rays that;

do not overlap with a majority of the X-rays as are detected with the first X-ray detector; and

detect at least the X-rays that intersect a periphery of a circle that circumscribes an outer extreme boundary of an object to be scanned in the object scanning space;

wherein all of the X-ray detectors as are disposed in a position to detect the X-rays are insufficient to make a complete scan of the object scanning space without providing some relative motion as between the X-ray detectors and the object scanning space;

further comprising;

a second source of X-rays; and

wherein the first source of X-rays and the second source of X-rays are disposed substantially opposite one another and wherein the first X-ray detector is disposed in a position that is opposite the first source of X-rays and the second X-ray detector is disposed in a position that is opposite the second source of X-rays.

14. The apparatus of claim 13 wherein the first X-ray detector comprises a flat plate detector.

15. The apparatus of claim 13 wherein the first X-ray detector comprises an image intensifier.

16. The apparatus of claim 13 wherein the first X-ray detector comprises a multi-channel detector of width inadequate to cover at least half of the object scanning space.

17. The apparatus of claim 13 wherein:

the first X-ray detector comprises a flat plate detector; and

the second X-ray detector comprises a flat plate detector.

18. The apparatus of claim 13 wherein:

the first X-ray detector comprises an image intensifier; and

the second X-ray detector comprises an image intensifier.

19. The apparatus of claim 13 wherein:

the first X-ray detector comprises a multi-channel detector of width inadequate to cover at least half of the object scanning space;

the second X-ray detector comprises a multi-channel detector of width inadequate to cover at least half of the object scanning space.

20. The apparatus of claim 13 wherein the first X-ray detector is disposed in an offset position with respect to a line that intersects both the first source of X-rays and the center of rotation.

21. The apparatus of claim 20 wherein the first X-ray detector is disposed such that one edge of the first X-ray detector extends only a relatively small distance beyond the line that intersects both the first source of X-rays and the center of rotation and towards the second X-ray detector.

22. An apparatus comprising:

an object scanning space having a center of rotation;

a first source of X-rays;

a first X-ray detector that is disposed in a position to detect at least the X-rays that intersect the center of rotation;

at least a second X-ray detector that is disposed in a position to detect the X-rays that;

do not overlap with a majority of the X-rays as are detected with the first X-ray detector; and

detect at least the X-rays that intersect a periphery of a circle that circumscribes an outer extreme boundary of an object to be scanned in the object scanning space;

a process controller that is configured and arranged to use the apparatus to conduct an offset rebinning process with the first and second X-ray detectors to develop a computed tomography image of an object in the object scanning space.

23. The apparatus of claim 22 wherein both the first X-ray detector and the second X-ray detector are disposed on a same side of the object scanning space and opposite the first source of X-rays.

24. The apparatus of claim 22 wherein the process controller is further configured and arranged to use the apparatus to conduct an offset rebinning process with the first and second X-ray detector to develop a computed tomography image of an object in the object scanning space by capturing a complete set of image data for the object by capturing image data during 360 degrees of relative rotation as between the object and the first and second X-ray detectors.