Computer-supported image reconstruction method for a three-dimensional subject

• US 20040008882A1
• Filed: 05/29/2003
• Published: 01/15/2004
• Est. Priority Date: 05/29/2002
• Status: Active Grant

• Current Assignee: Siemens Healthcare GMBH (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Schnoerr, Christoph, Reiss, Joachim, Hornegger, Joachim
• Granted Patent: US 7,280,686 B2
• Time in Patent Office: Days
• US Class Current: 382/154
• 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: G06T 2211/436 Limited angle

Abstract

A computer is supplied with at least three 2-D projections of a subject that are offset from one another by difference angles. A position in the projection surface and a respective surface data value per projection are allocated to the respective surface elements of the projection surface. On the basis of the supplied projections, the computer determines binary volume data values for a number of volume elements, a position in space being allocated to the volume elements, so that their totality represents a 3-D image of the subject.

Claims

1. A computer-supported method for reconstructing an image of a three-dimensional subject comprising the steps of:

supplying at least three two-dimensional projections of a three-dimensional subject, onto a projection surface composed of surface elements, to an evaluation computer, said projections being offset from each other by difference angles in a rotational plane;

in said evaluation computer allocating to each of said surface elements a position designation designating a position of the surface element in the projection surface, and in each projection, a surface data value; and

in said evaluation computer, allocating binary volume data values, dependent on the respective position designations and surface data values of a plurality of said surface elements, for a plurality of volume elements having respective positions in space, for generating a three-dimensional image of said subject from a totality of said volume elements.

2. A method as claimed in claim 1 wherein the step of supplying at least three two-dimensional projections to said evaluation computer comprises supplying said at least three two-dimensional projections with said difference angles being less than 90°

.

3. A method as claimed in claim 1 wherein the step of supplying at least three two-dimensional projections to said evaluation computer comprises supplying said at least three two-dimensional projections with said difference angles being equal to each other.

4. A method as claimed in claim 1 wherein the step of supplying at least three two-dimensional projections to said evaluation computer comprises supplying said at least three two-dimensional projections with said difference angles being less than 180°

.

5. A method as claimed in claim 1 wherein the step of supplying at least three two-dimensional projections to said evaluation computer comprises supplying said at least three two-dimensional projections with said difference angles being in range between 60°

and 120°

.

6. A method as claimed in claim 1 comprising supplying perspective projections to said evaluation computer as said at least three two-dimensional projections.

7. A method as claimed in claim 1 wherein the step of supplying at least three two-dimensional projections to said evaluation computer comprises supplying less than 40 two-dimensional projections to said evaluation computer.

8. A method as claimed in claim 1 wherein the step of supplying at least three two-dimensional projections to said evaluation computer comprises supplying less than 20 two-dimensional projections to said evaluation computer.

9. A method as claimed in claim 1 wherein the step of supplying at least three two-dimensional projections to said evaluation computer comprises supplying less than 10 two-dimensional projections to said evaluation computer.

10. A method as claimed in claim 1 comprising:

in said evaluation computer, determining at least one of a basic transparency of said subject and a minimum transparency of said subject; and

generating said volume data values in said evaluation computer to represent said at least one of said basic transparency and said minimum transparency.

11. A method as claimed in claim 1 comprising:

supplying to said evaluation computer at least one of a basic transparency of said subject and a minimum transparency of said subject; and

generating said volume data values in said evaluation computer to represent said at least one of said basic transparency and said minimum transparency.

12. A method as claimed in claim 1 comprising storing said volume data values in a bulk storage accessible by said evaluation computer, with volume data values for volume elements respectively having positions in space in a same plane being stored together in said bulk storage.

13. A method as claimed in claim 12 comprising storing said volume data values in DICOM format in said bulk storage.

14. A method as claimed in claim 1 comprising generating said volume data values using a discrete tomography method.

15. A method as claimed in claim 1 wherein the step of generating said three-dimensional image comprises generating a three-dimensional angiographic image of said subject.

16. A method as claimed in claim 1 wherein the step of generating said three-dimensional image comprises reconstructing a three-dimensional image of said subject composed of bone and surrounding tissue.

17. A computer program product loadable into an evaluation computer for reconstructing an image of a three-dimensional subject, said evaluation computer being supplied with at least three two-dimensional projections of a three-dimensional subject, onto a projection surface composed of surface elements, said projections being offset from each other by difference angles in a rotational plane, said computer program product causing said evaluation computer to:

allocate, to each of said surface elements, a position designation designating a position of the surface element in the projection surface, and in each projection, a surface data value; and

allocate binary volume data values, dependent on the respective position designations and surface data values of a plurality of said surface elements, for a plurality of volume elements having respective positions in space, and to generate a three-dimensional image of said subject from a totality of said volume elements.

18. A computer program product as claimed in claim 17 which allows said evaluation computer to use, as said at least three two-dimensional projections, at least three two-dimensional projections with said difference angles being less than 90°

.

19. A computer program product as claimed in claim 17 which allows said evaluation computer to use, as said at least three two-dimensional projections, at least three two-dimensional projections with said difference angles being equal to each other.

20. A computer program product as claimed in claim 17 which allows said evaluation computer to use, as said at least three two-dimensional projections, at least three two-dimensional projections with said difference angles being less than 180°

.

21. A computer program product as claimed in claim 17 which allows said evaluation computer to use, as said at least three two-dimensional projections, at least three two-dimensional projections with said difference angles being in range between 60°

and 120°

.

22. A computer program product as claimed in claim 17 which allows said evaluation computer to use perspective projections as said at least three two-dimensional projections.

23. A computer program product as claimed in claim 17 that allows said evaluation computer to use less than 40 of said two-dimensional projections.

24. A computer program product as claimed in claim 17 which allows said evaluation computer to use less than 20 two-dimensional projections to said evaluation computer.

25. A computer program product as claimed in claim 17 which allows said evaluation computer to use less than 10 two-dimensional projections to said evaluation computer.

26. A computer program product as claimed in claim 17 that causes said evaluation computer to:

determine at least one of a basic transparency of said subject and a minimum transparency of said subject; and

generate said volume data values to represent said at least one of said basic transparency and said minimum transparency.

27. A computer program product as claimed in claim 17 which causes said evaluation computer to generate said volume data values using a discrete tomography method.

28. A computer program product as claimed in claim 17 which causes said evaluation computer to generate said three-dimensional image as a three-dimensional angiographic image of said subject.

29. A computer program product as claimed in claim 17 which causes said evaluation computer to generate said three-dimensional image as a reconstructed three-dimensional image of said subject composed of bone and surrounding tissue.

30. A medical imaging system for reconstructing an image of a three-dimensional subject, comprising:

a beam source having a focus from which penetrating radiation is emitted, and a radiation detector on which said radiation is incident after penetrating a three-dimensional subject, at least said focus being rotatable around said subject in a rotational plane to produce at least three two-dimensional projections of said three-dimensional subject, onto a projection surface of said radiation detector composed of surface elements, said projections being offset from each other by difference angles in said rotational plane; and

an evaluation computer supplied with said projections which allocates, to each of said surface elements, a position designation designating a position of the surface element in the projection surface, and in each projection, a surface data value, and which allocates, dependent on the respective position designations and surface data values of a plurality of said surface elements, binary volume data values for a plurality of volume elements having respective positions in space, and generates a three-dimensional image of said subject from a totality of said volume elements.

31. A medical imaging system as claimed in claim 30 wherein said beam source and said radiation detector produce said at least three two-dimensional projections with said difference angles being less than 90°

.

32. A medical imaging system as claimed in claim 30 wherein said beam source and said radiation detector produce said at least three two-dimensional projections with said difference angles being equal to each other.

33. A medical imaging system as claimed in claim 30 wherein said beam source and said radiation detector produce said at least three two-dimensional projections with said difference angles being less than 180°

.

34. A medical imaging system as claimed in claim 30 wherein said beam source and said radiation detector produce said at least three two-dimensional projections with said difference angles being in range between 60°

and 120°

.

35. A medical imaging system as claimed in claim 30 wherein said beam source and said radiation detector produce perspective projections as said at least three two-dimensional projections.

36. A medical imaging system as claimed in claim 30 wherein said beam source and said radiation detector produce less than 40 of said two-dimensional projections.

37. A medical imaging system as claimed in claim 30 wherein said beam source and said radiation detector produce less than 20 of said two-dimensional projections.

38. A medical imaging system as claimed in claim 30 wherein said beam source and said radiation detector produce less than 10 of said two-dimensional projections.

39. A medical imaging system as claimed in claim 30 wherein in said evaluation computer determines at least one of a basic transparency of said subject and a minimum transparency of said subject, and generates said volume data values to represent said at least one of said basic transparency and said minimum transparency.

40. A medical imaging system as claimed in claim 30 wherein said evaluation computer is supplied with at least one of a basic transparency of said subject and a minimum transparency of said subject, and generates said volume data values to represent said at least one of said basic transparency and said minimum transparency.

41. A medical imaging system as claimed in claim 30 comprising a bulk storage accessible by said evaluation computer, for storing said volume data values with volume data values for volume elements respectively having positions in space in a same plane being stored together in said bulk storage.

42. A medical imaging system as claimed in claim 41 wherein said volume data values are stored in DICOM format in said bulk storage.

43. A medical imaging system as claimed in claim 30 wherein said evaluation computer generates said volume data values using a discrete tomography method.

44. A medical imaging system as claimed in claim 30 wherein said evaluation computer generates said three-dimensional image as a three-dimensional angiographic image of said subject.

45. A medical imaging system as claimed in claim 30 wherein said evaluation computer generates said three-dimensional image as a reconstructed three-dimensional image of said subject composed of bone and surrounding tissue.