Acquisition and reconstruction of projection data using a stationary CT geometry

• US 20080056435A1
• Filed: 03/20/2007
• Published: 03/06/2008
• Est. Priority Date: 08/30/2006
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Basu, Samit Kumar, Edic, Peter Michael, Yin, Zhye, Wu, Xiaoye, Pack, Jed Douglas, Man, Bruno De
• Granted Patent: US 7,835,486 B2
• Time in Patent Office: Days
• US Class Current: 378/9
• CPC Class Codes: A61B 6/027 characterised by the use of a particular data acquisition trajectory, e.g. helical or spiral
• CPC Class Codes: G01T 1/2985 In depth localisation, e.g. using positron emitters; Tomographic imaging (longitudinal and transverse section imaging; apparatus for radiation diagnosis sequentially in different planes, steroscopic radiation diagnosis); using external radiation sources A61B6/02

Abstract

Systems and methods are provided for acquiring and reconstructing projection data that is mathematically complete or sufficient using a computed tomography (CT) system having stationary distributed X-ray sources and detector arrays. In one embodiment, a distributed source is provided as arcuate segments offset in the X-Y plane and along the Z-axis.

Claims

1. An imaging system comprising:

two or more arcuate sources, each being configured to emit X-rays from a plurality of addressable locations; and

two or more detector arrays, wherein the X-rays emitted by a respective arcuate source are generally incident upon at least one corresponding detector array.

2. The imaging system of claim 1, wherein the combined angular length of the two or more arcuate sources is at least 180 degrees plus the fan angle of the X-ray beam.

3. The imaging system of claim 1, wherein two or more of the detector arrays have sections that overlap or are contiguous.

4. The imaging system of claim 1, wherein each detector array has an arc length of at least the arc length of the corresponding arcuate source and an additional length to accommodate the fan angle associated with the X-rays emitted by the corresponding arcuate source.

5. The imaging system of claim 1, wherein the two or more arcuate sources are displaced relative to one another along an imaging volume axis along which one or more objects to be imaged are translated.

6. The imaging system of claim 1, wherein the two or more arcuate sources are configured to be activated such that a set of helical projection data is generated.

7. The imaging system of claim 1, wherein the two or more arcuate sources are configured to be activated such that a plurality of sets of interlaced helical projection data are generated.

8. The imaging system of claim 1, wherein the two or more arcuate sources are configured to be activated such that surface-sampled projection data are generated.

9. The imaging system of claim 1, wherein the two or more arcuate sources are displaced relative to one another within a plane orthogonal to an imaging volume axis of the scanner.

10. A method for imaging a volume, comprising:

activating a plurality of addressable X-ray source locations, wherein each X-ray source location is associated with a distributed arc source of a scanner and wherein the scanner comprises two or more distributed arc sources; and

acquiring projection data generated from measurements of X-rays emitted by the X-ray source locations when activated.

11. The method of claim 10, wherein the two or more distributed arc sources are displaced relative to one another along an imaging volume axis of the scanner.

12. The method of claim 10, wherein the two or more arc sources are displaced relative to one another within a plane orthogonal to an imaging volume axis of the scanner.

13. The method of claim 10, comprising translating one or more objects through an imaging volume of the scanner during the steps of activating and acquiring.

14. The method of claim 10, wherein the plurality of addressable X-ray source locations are activated such that the acquired projection data comprises a set of helical projection data that is substantially mathematically complete.

15. The method of claim 10, wherein the plurality of addressable X-ray source locations are activated such that the acquired projection data comprises two or more sets of interlaced helical projection data that are substantially mathematically complete in the aggregate.

16. The method of claim 10, wherein the plurality of addressable X-ray source locations are activated such that the acquired projection data comprises surface-sampled projection data that are substantially mathematically complete in the aggregate.

17. The method of claim 10, wherein said activating the plurality of addressable X-ray source locations comprises sequentially activating consecutive X-ray source locations around a circumference of the scanner.

18. The method of claim 10, wherein said activating the plurality of addressable X-ray source locations comprises non-sequentially activating consecutive X-ray source locations around the circumference of the scanner.

19. The method of claim 10, wherein said activating the plurality of addressable X-ray source locations comprises simultaneously activating two or more X-ray source locations, wherein the X-rays emitted by simultaneously activating the X-ray source locations do not overlap on one or more respective detector arrays.

20. The method of claim 10, wherein said activating the plurality of addressable X-ray source locations comprises activating the X-ray source locations in a random order to sample the surface of the imaging volume.

21. One or more tangible, machine-readable media, comprising code executable to perform the acts of:

activating a plurality of addressable X-ray source locations each being associated with a distributed arc source of a scanner and wherein the scanner comprises two or more distributed arc sources; and

acquiring projection data generated from measurements of X-rays emitted by the X-ray source locations when activated.

22. The one or more tangible, machine-readable media of claim 21 wherein the code executable to perform the act of activating the plurality of addressable X-ray source locations activates the plurality of addressable X-ray source locations such that the acquired projection data comprises a set of helical projection data that is substantially mathematically complete.

23. The one or more tangible, machine-readable media of claim 21 wherein the code executable to perform the act of activating the plurality of addressable X-ray source locations activates the plurality of addressable X-ray source locations such that the acquired projection data comprises two or more sets of interlaced helical projection data that are substantially mathematically complete in the aggregate.

24. The one or more tangible, machine-readable media of claim 21 wherein the code executable to perform the act of activating the plurality of addressable X-ray source locations activates the plurality of addressable X-ray source locations such that the acquired projection data comprises surface-sampled projection data that are substantially mathematically complete in the aggregate.

25. The one or more tangible, machine-readable media of claim 21 wherein the code executable to perform the act of activating the plurality of addressable X-ray source locations sequentially activates consecutive X-ray source locations around a circumference of the scanner.

26. The one or more tangible, machine-readable media of claim 21 wherein the code executable to perform the act of activating the plurality of addressable X-ray source locations non-sequentially activates consecutive X-ray source locations around a circumference of the scanner.

27. The one or more tangible, machine-readable media of claim 21 wherein the code executable to perform the act of activating the plurality of addressable X-ray source locations simultaneously activates two or more X-ray source locations, wherein the X-rays emitted by simultaneously activating the X-ray source locations do not overlap on one or more respective detector arrays.

28. The one or more tangible, machine-readable media of claim 21 wherein the code executable to perform the act of activating the plurality of addressable X-ray source locations activates the X-ray source locations in a random order to sample the surface of the imaging volume.