Radiographic tomosynthesis image acquisition utilizing asymmetric geometry

• US 6,885,724 B2
• Filed: 08/22/2003
• Issued: 04/26/2005
• Est. Priority Date: 08/22/2003
• Status: Active Grant

• Current Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Original Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Inventors: Li, Baojun, Claus, Bernhard Erich Hermann, Battle, Vianney Pierre, Eberhard, Jeffrey W., Metz, Stephen W., Al-Khalidy, Abdulrahman
• Primary Examiner(s): Church, Craig E.
• Assistant Examiner(s): Artman, Thomas R.
• Application Number:
  US10/646,023
• Publication Number:
  US 20050041768A1
• Time in Patent Office: 613 Days
• Field of Search: 378/2
• US Class Current: 378/2
• CPC Class Codes: A61B 6/025 Tomosynthesis
• CPC Class Codes: A61B 6/4464 the source unit or the detector unit being mounted to ceiling
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 2223/612 biological material
• CPC Class Codes: G01N 23/044 using laminography or tomosynthesis
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• 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 that utilize asymmetric geometry to acquire radiographic tomosynthesis images are described. Embodiments comprise tomosynthesis systems and methods for creating a reconstructed image of an object from a plurality of two-dimensional x-ray projection images. These systems comprise: an x-ray detector; and an x-ray source capable of emitting x-rays directed at the x-ray detector; wherein the tomosynthesis system utilizes asymmetric image acquisition geometry, where θ₁≠θ₀, during image acquisition, wherein θ₁ is a sweep angle on one side of a center line of the x-ray detector, and θ₀ is a sweep angle on an opposite side of the center line of the x-ray detector, and wherein the total sweep angle, θ_asym, is θ_asym=θ₁+θ₀. Reconstruction algorithms may be utilized to produce reconstructed images of the object from the plurality of two-dimensional x-ray projection images.

Claims

1. A tomosynthesis system for creating a reconstructed image of an object from a plurality of two-dimensional x-ray projection images, the system comprising:

an x-ray detector;

an x-ray source capable of emitting x-rays directed at the x-ray detector, wherein the tomosynthesis system utilizes asymmetric image acquisition geometry, where θ

₁≠

θ

₀, during image acquisition, wherein θ

₁ is a sweep angle on one side of a center line of the x-ray detector, and θ

₀ is a sweep angle on an opposite side of the center line of the x-ray detector;

wherein the total sweep angle (φ

_asym) is;

φ

_asym=θ

₁+θ

₀; and

wherein φ

_asym is about 40°

to about 60°

.

2. The tomosynthesis system of claim 1, wherein the x-ray detector is positioned at a predetermined position so that images of a region of interest, as acquired during a sweep, are centered on a center of the x-ray detector.

3. The tomosynthesis system of claim 2, wherein the predetermined position comprises at least one of:

at a center of a patient'"'"'s sternum, above the center of the patient'"'"'s sternum;

below the center of the patient'"'"'s sternum;

at a patient'"'"'s stomach;

at one or more of a patient'"'"'s extremities; and

at a patient'"'"'s limb.

4. The tomosynthesis system of claim 1, wherein at least one of the x-ray source and the x-ray detector moves during image acquisition.

5. The tomosynthesis system of claim 4, wherein at least one of the x-ray source and the x-ray detector moves in at least one of the following manners during image acquisition:

along a one-dimensional path, along a two-dimensional path, along a three-dimensional path, along an arc, along at least a portion of a circle, along at least a portion of an ellipse, along at least a portion of a hypocycloid, along at least a portion of a line, along at least a portion of a sphere, and along at least a portion of a cone.

6. The tomosynthesis system of claim 1, wherein the x-ray detector remains stationary during image acquisition.

7. The tomosynthesis system of claim 1, wherein the object being imaged moves during image acquisition, while both the x-ray source and the x-ray detector remain stationary during image acquisition.

8. The tomosynthesis system of claim 1, wherein at least one of the x-ray source and the x-ray detector moves in a translational or rotational manner during image acquisition.

9. The tomosynthesis system of claim 1, wherein x-ray scanning occurs in at least one of the following directions:

vertically, horizontally, and obliquely.

10. The tomosynthesis system of claim 1, wherein a reconstruction algorithm produces a reconstructed image of the object from the plurality of two-dimensional x-ray projection images.

11. A tomosynthesis method for creating a reconstructed image of an object from a plurality of two-dimensional x-ray projection images, the method comprising:

providing an x-ray detector;

providing an x-ray source capable of emitting x-rays directed at the x-ray detector;

utilizing asymmetric image acquisition geometry, where θ

₁≠

θ

₀, during image acquisition, wherein θ

₁ is a sweep angle on one side of a center line of the x-ray detector, and θ

₀ is a sweep angle on an opposite side of the center line of the x-ray detector;

wherein the total sweet, angle (φ

_asym) is φ

_asym=θ

₁+θ

₀; and

wherein φ

_asym is about 40°

to about 60°

.

12. The tomosynthesis method of claim 11, further comprising:

positioning the x-ray detector at a predetermined position so that images of a region of interest, as acquired during a sweep, are centered on a center of the x-ray detector.

13. The tomosynthesis method of claim 12, wherein the predetermined position comprises at least one of:

at a center of a patient'"'"'s sternum, above the center of the patient'"'"'s sternum;

below the center of the patient'"'"'s sternum;

at a patient'"'"'s stomach;

at one or more of a patient'"'"'s extremities; and

at a patient'"'"'s limb.

14. The tomosynthesis method of claim 11, further comprising:

moving at least one of the x-ray source and the x-ray detector during image acquisition.

15. The tomosynthesis method of claim 14, further comprising:

moving at least one of the x-ray source and the x-ray detector in at least one of the following manners during image acquisition;

along a one-dimensional path, along a two-dimensional path, along a three-dimensional path, along an arc, along at least a portion of a circle, along at least a portion of an ellipse, along at least a portion of a hypocycloid, along at least a portion of a line, along at least a portion of a sphere, and along at least a portion of a cone.

16. The tomosynthesis method of claim 11, further comprising:

holding the x-ray detector stationary during image acquisition.

17. The tomosynthesis method of claim 11, further comprising:

moving the object being imaged during image acquisition, while holding both the x-ray source and the x-ray detector stationary during image acquisition.

18. The tomosynthesis method of claim 11, further comprising:

moving at least one of the x-ray source and the x-ray detector in a translational or rotational manner during image acquisition.

19. The tomosynthesis method of claim 11, wherein x-ray scanning occurs in at least one of the following directions:

vertically, horizontally, and obliquely.

20. The tomosynthesis method of claim 11, further comprising:

utilizing a reconstruction algorithm to produce a reconstructed image of the object from the plurality of two-dimensional x-ray projection images.