Cone beam CT scanning

• US 8,964,934 B2
• Filed: 04/25/2013
• Issued: 02/24/2015
• Est. Priority Date: 04/25/2013
• Status: Expired due to Fees

• Current Assignee: Moshe Ein-Gal
• Original Assignee: Moshe Ein-Gal
• Inventors: Ein-Gal, Moshe
• Primary Examiner(s): SONG, HOON K
• Application Number:
  US13/870,196
• Publication Number:
  US 20140321605A1
• Time in Patent Office: 670 Days
• Field of Search: 378/4, 378/10
• US Class Current: 378/10
• CPC Class Codes: A61B 6/027 characterised by the use of a particular data acquisition trajectory, e.g. helical or spiral
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: G01N 2223/3301 beam is modified for scan, e.g. moving collimator
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]

Abstract

A CBCT system is described that includes a radiation source for emitting a cone beam of radiation in a beam direction towards an object, a detector for detecting the cone beam of radiation, and a positioner for moving the radiation source and the object according to a scanning trajectory. The system is operated according to a sampling pattern that includes intersections of the scanning trajectory and a reconstruction trajectory, wherein motion of the radiation source is substantially confined to a spherical shell. The positioner moves the radiation source at a speed higher than a highest speed of the object by a factor of at least 10. The largest angular discrepancy between any vector in a range of the scanning trajectory and the nearest sample of the scanning trajectory does not exceed 10°, preferably 6° and more preferably 3°.

Claims

1. A cone beam computerized tomography (CBCT) system comprising:

a radiation source for emitting a cone beam of radiation in a beam direction towards an object;

a detector for detecting said cone beam of radiation;

a positioner for moving said radiation source and said object according to a scanning trajectory; and

a controller in communication with said positioner, said controller operable to operate said radiation source according to a sampling pattern that includes intersections of the scanning trajectory and a reconstruction trajectory,

wherein motion of said radiation source is substantially confined to a spherical shell, and wherein said positioner is operable to move said radiation source at speed higher than a highest speed of the object by a factor of at least 10, and wherein a largest angular discrepancy between any vector in a range of the scanning trajectory and a nearest sample of the scanning trajectory does not exceed 10°

.

2. The system according to claim 1, wherein the largest angular discrepancy between any vector in the range of the scanning trajectory and the nearest sample of the scanning trajectory does not exceed 6°

.

3. The system according to claim 1, wherein the largest angular discrepancy between any vector in the range of the scanning trajectory and the nearest sample of the scanning trajectory does not exceed 3°

.

4. The system according to claim 1, wherein said positioner is operable to rotate the object about a vertical rotational axis.

5. The system according to claim 1, wherein said detector center is stationary.

6. The system according to claim 1, wherein said positioner is operable to rotate said radiation source and said detector about a vertical rotational axis.

7. The system according to claim 1, wherein said positioner is operable to cause reciprocating motion of said radiation source along an arc.

8. The system according to claim 7, wherein said arc is tilted away from a horizontal or vertical plane.

9. The system according to claim 7, wherein said arc is circular with a circle center, and the circle center coincides with a center of the detector.

10. The system according to claim 1, further comprising a detector positioner operable to position said detector so as to face said radiation source.

11. The system according to claim 1, wherein said positioner comprises at least one of a device for moving a radiation source housing, electron optics operable to focus and deflect an electron beam in vacuum toward a radiation-producing target or toward a set of discrete radiation-producing targets, and a sequencer operable to sequentially trigger multiple radiation sources.

12. The system according to claim 1, further comprising a processor in communication with said detector, the processor operable to receive detector data related to the sampling pattern and reconstruct the object or a portion thereof according to reconstruction algorithms related to the reconstruction trajectory.

20. The method according to claim 1, further comprising receiving detector data related to the sampling pattern and reconstructing the object or a portion thereof according to reconstruction algorithms related to the reconstruction trajectory.

13. A method for CBCT comprising:

emitting a cone beam of radiation from a radiation source in a beam direction towards an object;

detecting said cone beam of radiation with a detector;

moving said radiation source and said object according to a scanning trajectory; and

operating said radiation source according to a sampling pattern that includes intersections of the scanning trajectory and a reconstruction trajectory,

wherein motion of said radiation source is substantially confined to a spherical shell, and wherein said radiation source is moved at speed higher than a highest speed of the object by a factor of at least 10, and wherein a largest angular discrepancy between any vector in a range of the scanning trajectory and a nearest sample of the scanning trajectory does not exceed 10°

.

14. The method according to claim 13, wherein the largest angular discrepancy between any vector in the range of the scanning trajectory and the nearest sample of the scanning trajectory does not exceed 6°

.

15. The method according to claim 13, wherein the largest angular discrepancy between any vector in the range of the scanning trajectory and the nearest sample of the scanning trajectory does not exceed 3°

.

16. The method according to claim 13, wherein said object is rotated about a vertical rotational axis.

17. The method according to claim 13, wherein said detector center is stationary.

18. The method according to claim 13, wherein said radiation source is moved in a reciprocating motion along an arc.

19. The method according to claim 18, wherein said arc is tilted away from a horizontal or vertical plane.