Tomosynthesis in a limited angular range

• US 6,813,334 B2
• Filed: 10/19/2001
• Issued: 11/02/2004
• Est. Priority Date: 10/20/2000
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Koppe, Reiner, Op De Beek, Johannes Catharina Antonius, Klotz, Erhard Paul Arthur
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US10/082,865
• Publication Number:
  US 20020141532A1
• Time in Patent Office: 1,110 Days
• Field of Search: 378/21, 378/23, 378/24, 378/27, 378/62, 378/4, 378/5, 378/6
• US Class Current: 378/21
• CPC Class Codes: A61B 6/025 Tomosynthesis
• CPC Class Codes: A61B 6/4441 the rigid structure being a C-arm or U-arm
• CPC Class Codes: A61B 6/4464 the source unit or the detector unit being mounted to ceiling

Abstract

A method and system of forming an X-ray layer image of an object being examined by an X-ray device having an X-ray source and an X-ray detector is described. At least one of the X-ray source and the X-ray detector can be displaced in an angular range around the object in order that X-ray projection images are acquired from different directions. When forming only a single X-ray layer image, or a plurality of X-ray layer images of parallel layers of the object, the time required for the acquisition of the X-ray projection images is notably reduced by forming the X-ray layer image directly from the X-ray projection images, where the resulting X-ray layer image is situated in a plane which extends essentially perpendicularly to the bisector of the angular range of displacement. The angular range of displacement can be less then 180°. The system and method is notably applicable to a C-arm X-ray device, in which the angular range can be chosen at will.

Claims

1. A method of forming an X-ray layer image of an object with an X-ray device having an X-ray source and an X-ray detector, comprising the steps of:

displacing the X-ray source and the X-ray detector in an angular range around the object in order to acquire X-ray projection images; and

forming an X-ray layer image directly from the X-ray projection images without creating an intermediary three-dimensional data set, the formed X-ray layer image being situated in a plane which extends essentially perpendicularly to a bisector of the angular range;

wherein the angular range of displacement is less than 180°

.

2. The method as claimed in claim 1, wherein the position of the angular range relative to the object can be changed.

3. The method as claimed in claim 1, wherein the angular range lies between 90°

and 180°

.

4. The method as claimed in claim 1, wherein the angular range is less than 90°

.

5. The method as claimed in claim 1, wherein 100 or less X-ray projection images are acquired in order to form the X-ray layer image.

6. The method as claimed in claim 1, wherein no more than about 80 X-ray projection images are acquired in order to form the X-ray layer image.

7. The method as claimed in claim 1, wherein a plurality of X-ray layer images of the object which extend essentially parallel to one another are formed from the acquired X-ray projection images.

8. The method as claimed in claim 1, wherein the X-ray projection images are acquired by means of a C-arm X-ray device.

9. The method as claimed in claim 1, wherein a plurality of X-ray layer images of neighboring thin layers are combined in order to form an X-ray layer image of a thicker slice.

10. The method as claimed in claim 1, wherein the X-ray source and the X-ray detector are displaced along a circular trajectory around the object in order to acquire X-ray projection images.

11. The method as claimed in claim 1, wherein the X-ray source and the X-ray detector are displaced in opposite directions in parallel planes in order to acquire X-ray projection images.

12. The method as claimed in claim 11, wherein only one of the X-ray source or the X-ray detector is displaced in order to acquire X-ray projection images.

15. The method as claimed in claim 1, wherein between about 60 and about 80 X-ray projection images are acquired in order to form the X-ray layer image.

13. An X-ray device comprising:

an X-ray source and an X-ray detector, each situated on an opposite side of an object being examined for the acquisition of X-ray projection images of the object, wherein at least one of the X-ray source and the X-ray detector are movable so that X-ray projection images are acquired in an angular range around the object;

an image processing unit for forming an X-ray layer image from the X-ray projection images; and

a control unit for controlling the X-ray device;

wherein only X-ray projection images in an angular range of less than 180°

are acquired in order to form the X-ray layer image; and

wherein the image processing unit forms the X-ray layer image directly from the X-ray projection images without creating an intermediary three-dimensional data set, where the formed X-ray layer image is situated in a plane which extends essentially perpendicularly to a bisector of the angular range.

14. The X-ray device as claimed in claim 13, wherein the X-ray device includes a C-arm system.

16. A method of forming an X-ray layer image of an object with an X-ray device having an X-ray source and an X-ray detector, comprising the steps of:

displacing the X-ray source and the X-ray detector over a less than 180°

angular range around an object being examined in order to acquire less than 100 X-ray projection images; and

forming at least one X-ray layer image directly from the less than 100 X-ray projection images without creating an intermediary three-dimensional data set, the formed X-ray layer image being situated in a plane which extends essentially perpendicularly to a bisector of the angular range.