Titled gantry helical cone-beam Feldkamp reconstruction for multislice CT

• US 20040086075A1
• Filed: 10/30/2002
• Published: 05/06/2004
• Est. Priority Date: 10/30/2002
• Status: Active Grant

• Current Assignee: Toshiba Medical Systems Corporation (Canon Inc.)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Taguchi, Katsuyuki, Hein, Ilmar Arthur
• Granted Patent: US 6,904,117 B2
• Time in Patent Office: Days
• US Class Current: 378/4
• 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: G06T 11/006 Inverse problem, transformation from projection-space into object-space, e.g. transform methods, back-projection, algebraic methods
• CPC Class Codes: Y10S 378/901 Computer tomography program or processor

Abstract

An X-ray computed tomography apparatus includes a helical scanning device configured to collect projection data while at least one of a gantry and a couch moves along a body axial direction of an object on the couch when at least one of the gantry and the couch is tilted, the helical scanning device including an X-ray source configured to generate X-rays, and a detector disposed opposite the X-ray source and having detector elements arranged in a plurality of rows along the body axial direction, and a reconstructing device configured to reconstruct an image based on the projection data using cone-beam Feldkamp reconstruction.

Claims

1. An X-ray computed tomography apparatus, comprising:

a helical scanning device configured to collect projection data while at least one of a gantry and a couch moves along a body axial direction of an object on the couch when at least one of the gantry and the couch is tilted, thereby forming a tilted rotation axis, the helical scanning device including,

an X-ray source configured to generate X-rays and to rotate around the object, and

a detector having detector elements arranged in a plurality of rows along the body axial direction opposite the X-ray source; and

a reconstructing device configured to reconstruct an image based on the projection data using cone-beam Feldkamp reconstruction.

2. The X-ray computed tomography apparatus according to claim 1, wherein the reconstructing device comprises a mechanism configured to reconstruct the image using the cone-beam Feldkamp reconstruction according to a tilt angle when the at least one of the gantry and the couch is tilted.

3. The X-ray computed tomography apparatus according to claim 1, wherein the reconstructing device comprises a mechanism configured to reconstruct the image of a reconstructing plane according to a tilt angle when the at least one of the gantry and the couch is tilted.

4. The X-ray computed tomography apparatus according to claim 1, wherein the reconstructing device comprises a mechanism configured to shift the image based on a tilt angle when the at least one of the gantry and the couch is tilted.

5. The X-ray computed tomography apparatus according to claim 1, wherein the reconstructing device comprises a mechanism configured to shift the image in parallel with the body axial direction when data from the projection data is backprojected.

6. The X-ray computed tomography apparatus according to claim 1, wherein the reconstructing device comprises a mechanism configured to shift the image in parallel with the body axial direction based on a projection angle of the projection data.

7. The X-ray computed tomography apparatus according to claim 1, wherein the reconstructing device comprises a filtering mechanism configured to acquire at least one image of predetermined slice thickness by filtering the at least one image along the tilted rotation axis.

8. The X-ray computed tomography apparatus according to claim 1, wherein the reconstructing device comprises a filtering mechanism configured to acquire an image of predetermined slice thickness by filtering the projection data along the tilted rotation axis while the projection data is backprojected.

9. A method for X-ray computed tomography, comprising:

helically scanning an object with X-rays to collect projection data while at least one of a gantry and a couch moves along a body axial direction of an object on the couch when at least one of the gantry and the couch is tilted, thereby forming a tilted rotation axis, the helically scanning including,

generating X-rays from an X-ray source, and

detecting projection data using a detector disposed opposite the X-ray source and having detector elements arranged in a plurality of rows along the body axial direction; and

reconstructing an image based on the projection data using cone-beam Feldkamp reconstruction.

10. The method according to claim 9, wherein the reconstructing step comprises:

reconstructing the image using the cone-beam Feldkamp reconstruction according to a tilt angle when the at least one of the gantry and the couch is tilted.

11. The method according to claim 9, wherein the reconstructing step comprises:

reconstructing the image of a reconstructing plane according to a tilt angle when the at least one of the gantry and the couch is tilted.

12. The method according to claim 9, wherein the reconstructing step comprises:

shifting the image based on a tilt angle when the at least one of the gantry and the couch is tilted.

13. The method according to claim 9, wherein the reconstructing step comprises:

shifting the image in parallel with the body axial direction when the projection data is backprojected.

14. The method according to claim 9, wherein the reconstructing step comprises:

shifting the image in parallel with the body axial direction based on a projection angle of the projection data.

15. The method according to claim 9, wherein the reconstructing step comprises:

filtering the image along the tilted rotation axis to acquire an image of predetermined slice thickness.

16. The method according to claim 9, wherein the reconstructing step comprises:

filtering the image along the tilted rotation axis while the projection data is backprojected to acquire an image of predetermined slice thickness.

18. A computer program product storing instructions for execution on a computer system, which when executed by the computer system, causes the computer system to perform the method recited in any one of claims 9-16.

17. An X-ray computed tomography apparatus, comprising:

a helical scanning device configured to collect projection data while at least one of a gantry and a couch moves along a body axial direction of an object on the couch when at least one of the gantry and the couch is tilted, the helical scanning device including,

an X-ray source configured to generate X-rays, and

a detector disposed opposite the X-ray source and having detector elements arranged in a plurality of rows along the body axial direction; and

means for reconstructing an image based on the projection data using cone-beam Feldkamp reconstruction.