Method and apparatus using a virtual detector for three-dimensional reconstruction from x-ray images

• US 6,236,704 B1
• Filed: 06/30/1999
• Issued: 05/22/2001
• Est. Priority Date: 06/30/1999
• Status: Expired due to Term

• Current Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Original Assignee: Siemens Corporate Research Incorporated (Siemens AG)
• Inventors: Navab, Nassir, Mitschke, Matthias
• Primary Examiner(s): BRUCE, DAVID VERNON
• Application Number:
  US09/345,076
• Time in Patent Office: 692 Days
• Field of Search: 378/4, 378/15, 378/19, 378/901
• US Class Current: 378/4
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4405 the apparatus being movable or portable, e.g. handheld or mounted on a trolley
• CPC Class Codes: A61B 6/4441 the rigid structure being a C-arm or U-arm
• CPC Class Codes: A61B 6/587 Alignment of source unit to detector unit
• CPC Class Codes: G01N 23/044 using laminography or tomosynthesis
• CPC Class Codes: G06T 5/80 Geometric correction
• CPC Class Codes: H04N 23/30 for generating image signals from X-rays
• CPC Class Codes: H04N 5/32 Transforming X-rays cameras or camera modules for generating image signals from X-rays H04N23/30; circuitry of SSIS for transforming X-rays into image signals H04N25/30
• CPC Class Codes: Y10S 378/901 Computer tomography program or processor

Abstract

Compensation can be provided for rotational and translational motion of a detector relative to the X-ray source in a C-arm X-ray device by warping the image on the detector plane to a virtual detector plane and then mapping the image into three-dimensional space. By using a virtual detector, the computations required to reconstruct the three-dimensional model are greatly simplified.

Claims

1. A method, comprising the steps of:

directing a source of X-ray energy from a plurality of angles through an object of interest onto a detector plane, creating images on the detector plane;

warping the images on the detector plane onto a virtual detector plane fixed in space with respect to the source; and

back-projecting the images on the virtual detector into three-dimensional space.

2. A method as set forth in claim 1, where the step of warping the images on the detector plane onto a virtual detector plane comprises the step of applying a planar transformation to the images.

3. A method as set forth in claim 1, where the step of warping the images on the detector plane onto a virtual detector plane comprises the step of selecting the detector plane for one of the images as the virtual detector plane.

4. A method as set forth in claim 1, where

the step of directing a source of X-ray energy through an object of interest comprises the step of directing the source from a marker plate; and

the step of warping the image on the detector plane onto a virtual detector plane comprises the step of warping the image with respect to the aspect of the image of the marker plate on the detector plane.

5. An apparatus, comprising:

means for directing a source of X-ray energy from a plurality of angles through an object of interest onto a detector plane, creating images on the detector plane;

means for warping the images on the detector plane onto a virtual detector plane fixed in space with respect to the source; and

means for back-projecting the images on the virtual detector into three-dimensional space.

6. An apparatus as set forth in claim 5, where the means for warping the images on the detector plane onto a virtual detector plane comprises means for applying a planar transformation to the images.

7. An apparatus as set forth in claim 5, where the means for warping the images on the detector plane onto a virtual detector plane comprises means for selecting the detector plane for one of the images as the virtual detector plane.

8. An apparatus as set forth in claim 5, where

the means for directing a source of X-ray energy through an object of interest comprises means for directing the source from a marker plate; and

the means for warping the image on the detector plane onto a virtual detector plane comprises means for warping the image with respect to the aspect of the image of the marker plate on the detector plane.

9. An apparatus, comprising:

C-arm X-ray apparatus for directing a source of X-ray energy from a plurality of angles through an object of interest onto a detector plane, creating images on the detector plane;

computer apparatus, including data storage apparatus, for warping the images on the detector plane onto a virtual detector plane fixed in space with respect to the source; and

image-processing apparatus for back-projecting the images on the virtual detector into three-dimensional space.

10. An apparatus as set forth in claim 9, where the computer apparatus for warping the images on the detector plane onto a virtual detector plane comprises programmable computer apparatus for applying a planar transformation to the images.

11. An apparatus as set forth in claim 9, where the computer apparatus for warping the images on the detector plane onto a virtual detector plane comprises computer apparatus for selecting the detector plane for one of the images as the virtual detector plane.

12. An apparatus as set forth in claim 9, where

the C-arm X-ray apparatus for directing a source of X-ray energy through an object of interest comprises apparatus for directing the source from a marker plate; and

the computer apparatus for warping the image on the detector plane onto a virtual detector plane comprises computer means for warping the image with respect to the aspect of the image of the marker plate on the detector plane.