Methods and apparatus for image reconstruction

• US 20060078185A1
• Filed: 06/22/2005
• Published: 04/13/2006
• Est. Priority Date: 09/28/2004
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Hsieh, Jiang, Dong, Fang Frank, Myers, Thomas John, Sopcak, Zachary William, Conry, Anne Marie, Grekowicz, Brian, Seidenschnur, George
• Granted Patent: US 7,734,079 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• CPC Class Codes: A61B 6/027 characterised by the use of a particular data acquisition trajectory, e.g. helical or spiral
• CPC Class Codes: G06T 11/006 Inverse problem, transformation from projection-space into object-space, e.g. transform methods, back-projection, algebraic methods

Abstract

Methods and apparatus for producing an image of an object with a multi-slice imaging apparatus having a row of detectors are provided. The method includes generating a first partial image using projection data acquired at a first imaging position in a step-and-shoot imaging mode, generating a second partial image using projection data acquired at a second imaging position, and combining the partial images to form a final image.

Claims

1. A method for producing an image of an object with a multi-slice imaging apparatus, said method comprising:

generating a first partial image using projection data acquired at a first imaging position in a step-and-shoot imaging mode;

generating a second partial image using projection data acquired at a second imaging position; and

combining the partial images to form a final image.

2. The method in accordance with claim 1 wherein the first and the second imaging positions are axially adjacent.

3. The method in accordance with claim 1 wherein combining the partial images comprises combining the partial images that have been weighted to account for an axial distance between the detector and an axial location of the final image.

4. The method in accordance with claim 1 wherein the first projection data is weighted using:

5. The method in accordance with claim 1 wherein the second projection data is weighted using:

6. The method in accordance with claim 1 further comprising generating an image between detector row locations by interpolating a set of projections acquired at the corresponding locations.

7. The method in accordance with claim 6 further comprising interpolating a set of projections acquired at the corresponding locations using:

8. The method in accordance with claim 1 comprising interpolating between the images using:

9. A computed tomographic (CT) imaging system for reconstructing an image of an object, said imaging system comprising:

a detector array;

at least one radiation source; and

a computer coupled to said detector array and said radiation source, said computer configured to;

generate a first partial image using projection data acquired at a first imaging position in a step-and-shoot imaging mode;

generate a second partial image using projection data acquired at a second imaging position; and

combine the partial images to form a final image.

10. The computed tomographic (CT) imaging system in accordance with claim 9 wherein the first and the second imaging positions are axially adjacent.

11. The computed tomographic (CT) imaging system in accordance with claim 9 wherein said computer is further configured to weight the partial images to account for an axial distance between the detector and an axial location of the final image.

12. The computed tomographic (CT) imaging system in accordance with claim 9 wherein the first projection data is weighted using:

13. The computed tomographic (CT) imaging system in accordance with claim 9 wherein the second projection data is weighted using:

14. The computed tomographic (CT) imaging system in accordance with claim 9 wherein said computer is further configured to generate an image between detector row locations by interpolating a set of projections acquired at the corresponding locations.

15. The computed tomographic (CT) imaging system in accordance with claim 9 wherein said computer is further configured to interpolate a set of projections acquired at the corresponding locations using:

16. The computed tomographic (CT) imaging system in accordance with claim 9 wherein said computer is further configured to interpolate between the images using:

17. A CT imaging system in accordance with claim 9 wherein said computer is further configured to:

backproject the adjacent axial scans; and

filter the backprojected scans.

18. A computer readable medium encoded with a program code segment executable by a computer for reconstructing an image of an object, said segment programmed to instruct the computer to:

generate a first partial image using projection data acquired at a first imaging position in a step-and-shoot imaging mode;

generate a second partial image using projection data acquired at a second imaging position; and

combine the partial images to form a final image.

19. The computer readable medium in accordance with claim 18 wherein the first and the second imaging positions are axially adjacent.

20. The computer readable medium in accordance with claim 18 wherein said program code segment is further programmed to combine the partial images that have been weighted to account for an axial distance between the detector and an axial location of the final image.

21. The computer readable medium in accordance with claim 18 wherein the first projection data is weighted using:

22. The computer readable medium in accordance with claim 18 wherein the second projection data is weighted using:

23. The computer readable medium in accordance with claim 18 wherein said program code segment is further programmed to generate an image between detector row locations by interpolating a set of projections acquired at the corresponding locations.

24. The computer readable medium in accordance with claim 18 wherein said program code segment is further programmed to interpolate a set of projections acquired at the corresponding locations using:

25. The computer readable medium in accordance with claim 18 wherein said program code segment is further programmed to interpolate between the images using: