Method and system for CT imaging using a distributed X-ray source and interpolation based reconstruction

• US 20060233295A1
• Filed: 04/18/2005
• Published: 10/19/2006
• Est. Priority Date: 04/18/2005
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Basu, Samit Kumar, Edic, Peter Michael, De Man, Bruno Kristiaan Bernard
• Granted Patent: US 7,227,923 B2
• Time in Patent Office: Days
• US Class Current: 378/4
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4028 resulting in acquisition of views from substantially different positions, e.g. EBCT
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: H05G 1/52 Target size or shape; Direction of electron beam, e.g. in tubes with one anode and more than one cathode

Abstract

A method for Computed Tomography (CT) imaging is provided. The method comprises rotating a gantry at a substantially slow rotation speed about a volume of interest. The gantry comprises a combination of X-ray source points. The X-ray source points comprise one or more discrete emission points and an arc of discrete or continuous X-ray source points. The method then comprises obtaining projection data from the combination of X-ray source points and performing a suitable reconstruction based on the projection data obtained from the combination of X-ray source points, to generate one or more reconstructed images.

Claims

1. A method for Computed Tomography (CT) imaging, the method comprising;

rotating a gantry at a substantially slow rotation speed about a volume of interest, wherein the gantry comprises a combination of X-ray source points, and wherein the X-ray source points comprise one or more discrete emission points and an arc of discrete or continuous X-ray source points;

obtaining projection data from the combination of X-ray source points comprising;

obtaining a first projection data set by individually activating the one or more discrete emission points at multiple angular positions about the volume of interest; and

obtaining a second projection data set at a plurality of view angle positions by activating the arc of discrete or continuous X-ray source points to emanate X-ray beams illuminating a central region of interest; and

performing a suitable reconstruction based on the projection data obtained from the combination of X-ray source points, to generate one or more reconstructed images,

2. The method of claim 1, wherein the rotation time of the gantry is between about fifteen seconds and about twenty seconds

3. The method of claim 1, wherein the one or more discrete emission points comprise X-ray tubes.

4. The method of claim 1, wherein the one or more discrete emission points and the arc of discrete or continuous X-ray source points arc rotated by mechanically rotating the emission points about the field of view.

5. The method of claim 1, wherein the one or more discrete emission points and the arc of discrete or continuous X-ray source points are individually activated in a sequential manner about a field of view.

8. The method of claim 1, further comprising interpolating a plurality of projections comprising the second projection data set to generate a set of time-resolved, interpolated projections, wherein each interpolated projection characterizes the projection data from the central region of interest at a particular instant in time

9. The method of claim 8, wherein interpolating the plurality of projections comprising the second projection data set comprises using phase data related to the plurality of projections.

10. The method of claim 8, wherein interpolating the plurality of projections comprising the second projection data set comprises using a set of phase data and frequency content information related to the plurality of projections.

11. The method of claim 9, wherein the phase data is generated from the acquired projection data related to the plurality of projections.

6. (canceled)

7. (canceled)

12. A method for Computed Tomography (CT) imaging, the method comprising:

rotating a gantry at a substantially slow rotation speed about a volume of interest, wherein the gantry comprises one or more discrete emission points and an arc of discrete or continuous X-ray source points;

obtaining a first projection data set comprising a plurality of projections, by individually activating the one or more discrete emission points at multiple angular positions about the volume of interest;

obtaining a second projection data set comprising a plurality of projections at a plurality of view angle positions, by activating the arc of discrete or continuous X-ray source points to emanate X-ray beams illuminating a central region of interest;

interpolating the plurality of projections comprising the second projection data set to generate a set of time-resolved, interpolated projections, wherein each interpolated projection characterizes the projection data from the central region of interest at a particular instant in time; and

combining the first projection data set and the set of interpolated projections to generate one or more time-resolved reconstructed images.

13. The method of claim 12, wherein the rotation time of the gantry is between about fifteen seconds and about twenty seconds.

14. The method of claim. 12, wherein the one or more discrete emission points comprise X-ray tubes.

15. The method of claim 12, wherein the one or more discrete emission points and the arc of discrete or continuous X-ray source points are rotated by mechanically rotating the emission points about the field of view.

16. The method of claim 12, wherein the one or more discrete emission points and the arc of discrete or continuous X-ray structure points are individually activated in a sequential manner about a field of view.

17. The method of claim 12, wherein interpolating the plurality of projections comprising the second projection data set comprises using a set of phase data and frequency content information related to the plurality of projections.

18. A Computed Tomography (CT) imaging system, the system comprising:

a gantry configured to rotate at a substantially slow rotation speed about a volume of interest, wherein the gantry comprises one or more discrete emission points and an arc of discrete or continuous X-ray source points, and wherein the one or more discrete emission points arc configured to individually emit streams of radiation at multiple angular positions about the volume of interest and wherein the arc of discrete or continuous X-ray source points is configured to emanate streams of radiation illuminating a central region of interest;

a detector configured to detect the streams of radiation from the one or more discrete emission points and the arc of discrete or continuous X-ray source points, and generate one or more signals responsive to the streams of radiation, and

a computer configured to receive and process the one or more signals from the detector to generate projection data and perform a suitable reconstruction on the projection data, to generate one or more reconstructed images wherein the computer is further configured to obtain;

a first projection, data set, wherein the first projection data set is generated by individually activating the one or more discrete emission points at multiple angular positions about the volume of interest and

a second projection data set, wherein the second projection data set is generated at a plurality of view angle positions, by activating the arc of discrete or continuous X-ray source points to emanate X-ray beams illuminating a central region of interest.

19. The system of claim 18, wherein the rotation time of the gantry is between about fifteen seconds and about twenty seconds.

20. The system of claim 18, wherein the one or more discrete emission points comprise X-ray tubes.

21. The system of claim 18, wherein the one or more discrete emission points and the arc of discrete or continuous X-ray source points are rotated by mechanically rotating the emission points about the field of view.

22. The system of claim 18, wherein the one or more discrete emission points and the arc of discrete or continuous X-ray source points are individually activated in a sequential manner about a field of view.

25. The system of claim 18, wherein the computer is further configured to interpolate a plurality of projections comprising the second projection data set using a set of phase data and frequency content information related to the plurality of projections.

23. (canceled)

24. (canceled)