Full field digital tomosynthesis method and apparatus
A tomosynthesis system for forming a three dimensional image of an object is provided. The system includes an X-ray source adapted to irradiate the object with a beam of X-rays from a plurality of positions in a sector, an X-ray detector positioned relative to the X-ray source to detect X-rays transmitted through the object and a processor which is adapted to generate a three dimensional image of the object based on X-rays detected by the detector. The detector is adapted to move relative to the object and/or the X-ray source is adapted to irradiate the object with the beam of X-rays such that the beam of X-rays follows in a non arc shaped path and/or a center of the beam of X-rays impinges substantially on the same location on the detector from different X-ray source positions in the sector.
1. A tomosynthesis system for forming a three dimensional image of an object, comprising:
an X-ray source configured to irradiate the object with a beam of X-rays from a plurality of positions along a path in a sector;
an X-ray detector positioned relative to the X-ray source to detect X-rays transmitted through the object; and
a processor which is configured to generate a three dimensional image of the object based on X-rays detected by the detector;
wherein:
the X-ray source irradiates the object with the beam of X-rays such that the focal spot of the beam of X-rays follows a non arc shaped path; or
a center of the beam of X-rays impinges substantially on the same location on the detector from different X-ray source positions in the sector.
2. The system of claim 1 , wherein the system comprises a mammography tomosynthesis system and the object comprises a human breast.
3. The system of claim 2 , wherein the detector is adapted to move relative to the object.
4. The system of 3 , further comprising:
a detector housing; and
a piezoelectric actuator configured to move the detector in the detector housing.
5. The system of claim 3 , wherein:
the X-ray source is configured to rotate in an arc shaped path in a first direction relative to the object; and
the detector is configured to move in a path in a plane in a second direction opposite to the first direction during rotation of the X-ray source.
6. The system of claim 3 , wherein:
the X-ray source is configured to rotate along the path in the sector in a first angular direction relative to the object, such that the focal spot of the X-ray beam moves in the first angular direction; and
the detector is configured to rotate in the direction different from the first angular direction.
7. The system of claim 3 , wherein:
the X-ray source is configured to rotate in an arc shaped path in a first angular direction relative to the object; and
the detector is configured to move in an arc shaped path in a second angular direction opposite to the first direction.
8. The system of claim 2 , wherein the X-ray source is configured to irradiate the object with the beam of X-rays such that the focal spot of the beam of X-rays follows a non arc shaped path relative to the detector.
9. The system of claim 8 , wherein the X-ray source is configured to rotate in a first angular direction along the path and to move in a second direction substantially along a second radial direction.
10. The system of claim 8 , wherein the X-ray source is configured to rotate in a first angular direction and an electron beam focal spot is adapted to change position on an X-ray target in the X-ray source to move the X-ray beam focal spot in a second direction substantially along the second radial direction.
11. The system of claim 8 , wherein the X-ray source is configured to rotate along the path in a first angular direction and move in at least one of a third and fourth directions outside a plane of rotation of the X-ray source.
12. The system of claim 8 , wherein the X-ray source is configured to rotate along the path in a first angular direction and an electron beam focal spot is configured to change position on an X-ray target in the X-ray source to move the X-ray beam focal spot in at least one of a third and fourth directions outside a plane of rotation of the X-ray source.
13. The system of claim 8 , wherein the X-ray source is configured to rotate along the path in a first angular direction and an X-ray lens is adapted move the X-ray beam focal spot in at least one of a third and fourth directions outside a plane of rotation of the X-ray source.
14. The system of claim 2 , wherein the X-ray source is configured to rotate along the path in a first angular direction and to turn in a fifth direction such that the center of the X-ray beam impinges substantially on the same location on the detector from different X-ray source positions in the sector.
15. The system of claim 2 , wherein the X-ray source is configured to rotate along the path in a first angular direction and a collimator changes a position of the X-ray beam to turn the X-ray beam in a fifth direction such that the center of the X-ray beam impinges substantially on the same location on the detector from different X-ray source positions in the sector.
16. The system of claim 2 , wherein:
the detector is configured to move relative to the object; and
the X-ray source is configured to irradiate the object with the beam of X-rays such that the focal spot of the beam of X-rays follows a non arc shaped path relative to the detector.
17. A tomosynthesis system for forming a three dimensional image of an object, comprising:
a first means for irradiating the object with a beam of X-rays from a plurality of positions along a path in a sector;
a second means for detecting X-rays transmitted through the object; and
a third means for generating a three dimensional image of the object based on X-rays detected by the second means;
wherein:
the first means is a means for irradiating the object with the beam of X-rays such that a focal spot of the beam of X-rays follows a non arc shaped path relative to the object; and
the first means is a means for irradiating the object with the beam of X-rays such that a center of the beam of X-rays impinges substantially on the same location on the second means from different first means positions in the sector.
18. The system of claim 17 , wherein the system comprises a mammography tomosynthesis system and the object comprises a human breast.
19. The system of claim 18 , wherein the second means is a means for detecting X-rays transmitted through the object and also for moving relative to the object.
20. The system of 19 , further comprising:
an actuator configured to move the second means, wherein the second means comprises a detector; and
at least one of a movable arm and combination of a rail and a motor which is configured to move the first means, wherein the first means comprises an X-ray source.
21. The system of claim 19 , wherein:
the first means is a means for irradiating the object with the beam of X-rays and also for rotating in an arc shaped path in a first direction relative to the object; and
the second means is a means for detecting X-rays transmitted through the object and also for moving in a path in a second direction opposite to the first direction during rotation of the first means.
22. The system of claim 19 , wherein:
the first means is a means for irradiating the object with the beam of X-rays and also for rotating in an arc shaped path in a first direction relative to the object; and
the second means is a means for detecting X-rays transmitted through the object and also for moving in an arc shaped path in a second direction opposite to the first direction.
23. The system of claim 19 , wherein:
the first means is a means for irradiating the object with the beam of X-rays and also for rotating in the sector in a first direction relative to the object and for moving the X-ray beam focal spot in a y-direction; and
the second means is a means for detecting X-rays transmitted through the object and also for rotating in a direction different from the first direction.
24. The system of claim 18 , wherein the first means is a means for irradiating the object with the beam of X-rays such that the focal spot of the beam of X-rays follows a non arc shaped path relative to the object.
25. The system of claim 24 , wherein the first means is a means for irradiating the object with the beam of X-rays and also for rotating in a first angular direction and for moving the focal spot of the X-ray beam in a second direction substantially along a second radial direction.
26. The system of claim 24 , wherein the first means is a means for irradiating the object with the beam of X-rays and also for rotating in a first angular direction for moving the focal spot of the X-ray beam in at least one of a third and fourth directions outside a plane of rotation of the first means.
27. The system of claim 18 , wherein the first means is a means for irradiating the object with the beam of X-rays and also for rotating in the first angular direction and for directing a center of the X-ray beam to impinge substantially on the same location on the second means from different first means positions in the sector.
28. The system of claim 18 , wherein:
the second means is a means for detecting X-rays transmitted through the object and also for moving relative to the object; and
the first means is a means for irradiating the object with the beam of X-rays such that the focal spot of the beam of X-rays follows a non arc shaped path relative to the object.
29. A tomosynthesis method of forming a three dimensional image of an object, comprising:
(a) acquiring a set of tomosynthesis projections, comprising:
moving an X-ray source along a path through a sector;
irradiating the object with a beam of X-rays from the X-ray source at a plurality of positions in the sector; and
detecting X-rays transmitted through the object with a detector; and
(b) generating a three dimensional image of the object based on the detected X-rays;
wherein:
the X-ray source irradiates the object with the beam of X-rays such that the focal spot of the beam of X-rays follows a non arc shaped and non linear path; or
a center of the beam of X-rays impinges substantially on the same location on the detector from different X-ray source positions in the sector.
30. The method of claim 29 , wherein the method comprises a mammography tomosynthesis method and the object comprises a human breast.
31. The method of claim 30 , wherein the detector moves relative to the object during the acquisition of a set of tomosynthesis projections.
32. The method of claim 31 , wherein:
the X-ray source rotates in an arc shaped path in a first direction relative to the object and periodically emits a beam of X-rays at given positions on the arc shaped path; and
the detector moves in a path in a plane in a second direction opposite to the first direction while the X-ray source rotates in the first direction.
33. The method of claim 32 , wherein the detector moves in the second direction while the X-ray source emits the beam of X-rays and the X-ray source moves in the first direction.
34. The method of claim 33 , wherein the detector moves in the second direction while the X-ray source does not emit the beam of X-rays and the X-ray source moves in the first direction.
35. The method of claim 32 , wherein the detector moves along the path in the second direction while the X-ray source does not emit the beam of X-rays and the X-ray source moves in the first direction.
36. The method of claim 31 , wherein:
the X-ray source rotates in an arc shaped path in a first direction relative to the object and periodically emits a beam of X-rays at positions on the arc shaped path; and
the detector moves in an arc shaped path in a second direction opposite to the first direction while the X-ray source rotates in the first direction.
37. The method of claim 31 , wherein:
the X-ray source rotates along the path in the sector in a first angular direction relative to the object and periodically emits a beam of X-rays;
the X-ray source moves the X-ray beam focal spot in a y-direction; and
the detector rotates in a direction different from the first direction.
38. The method of claim 30 , wherein the X-ray source irradiates the object with the beam of X-rays such that the focal spot of the beam of X-rays follows a non arc shaped path relative to the object.
39. The method of claim 38 , wherein the X-ray source rotates along the path in a first angular direction and the focal spot of the X-ray beam moves in a second direction substantially along a second radial direction.
40. The method of claim 38 , wherein the X-ray source rotates along the path in a first angular direction and the focal spot of the X-ray beam moves in at least one of third and fourth directions outside a plane of rotation of the X-ray source.
41. The method of claim 30 , wherein the X-ray source rotates along the path in a first angular direction and a center of the X-ray beam impinges substantially on the same location on the detector from different X-ray source positions along a rotational path of the X-ray source.
42. The method of claim 30 , wherein:
the detector moves relative to the object during the acquisition of a set of tomosynthesis projections; and
the X-ray source irradiates the object with the beam of X-rays such that the focal spot of the beam of X-rays follows a non arc shaped path relative to the object.
43. A tomosynthesis system for forming a three dimensional image of an object, comprising:
an X-ray source configured to periodically irradiate the object with a beam of X-rays, wherein the X-ray source is configured to emit the beam of X-rays while rotating and moving in a first direction along a path in a sector;
an X-ray detector positioned relative to the X-ray source to detect X-rays transmitted through the object, wherein the detector is configured to move in a second direction opposite to the first direction while the X-ray source moves in the first direction and the X-ray source emits the beam of X-rays; and
a processor which is configured to generate a three dimensional image of the object based on X-rays detected by the detector;
wherein:
the X-ray source is configured to rotate in an arc shaped path and to periodically emit the beam of X-rays from a plurality of positions along the arc shaped path; and
the X-ray source is configured to rotate at a first speed while the X-ray source emits the beam of X-rays and to rotate at a second speed higher than the first speed while the X-ray source does not emit the beam of X-rays.
44. The system of claim 43 , wherein:
the detector is configured to move in the second direction to minimize maximum image blurring by at least 50% compared to image blurring if the detector does not move; and
the detector is configured to move in the first direction while the X-ray source does not emit the beam of X-rays.
45. A tomosynthesis method of forming a three dimensional image of an object, comprising:
rotating an X-ray source in a first direction in a path through a sector;
emitting a beam of X-rays from the X-ray source while the X-ray source is rotating and moving along the path in the first direction;
periodically irradiating the object with the X-ray beam;
moving a detector in a second direction opposite to the first direction while the X-ray source emits the X-ray beam and the X-ray source moves in the first direction;
detecting X-rays transmitted through the object with the detector; and
generating a three dimensional image of the object based on the detected X-rays.
46. The method of claim 45 , wherein:
rotating an X-ray source in a first direction along the path through a sector comprises rotating the X-ray source in an arc shaped path at a first speed while the X-ray source emits the beam of X-rays and at a second speed higher than the first speed while the X-ray source does not emit the beam of X-rays.
47. The system of claim 46 , wherein:
the detector moves in the second direction to minimize maximum image blurring by at least 50% compared to image blurring if the detector does not move; and
the detector moves in the first direction while the X-ray source does not emit the beam of X-rays.
48. The method of claim 47 , wherein:
the X-ray source rotates through a length of about 10 to 750 microns in the first direction along the path while the X-ray source emits one X-ray beam;
the detector moves about 5 to 60 micros in the second direction while the X-ray source emits one X-ray beam; and
beam magnification is about 1.05 to 8.
49. A tomosynthesis system for forming a three dimensional image of an object, comprising:
at least two X-ray sources configured to irradiate the object with beams of X-rays from a plurality of rotationally displaced positions along a path in a sector;
an X-ray detector positioned relative to the at least two X-ray sources and movable linearly to detect X-rays transmitted through the object; and
a processor which is configured to generate a three dimensional image of the object based on X-rays detected by the detector;
wherein the at least two X-ray sources are configured to rotate in an arc shaped path in respective at least two parallel planes and a first X-ray source is offset from a second X-ray source in a direction perpendicular to the parallel planes.
50. The system of claim 49 , wherein the first X-ray source is further offset from the second X-ray source in the first direction during rotation of the first and second X-ray sources in the arc shaped path.
51. The system of claim 49 , wherein the at least two X-ray sources comprise at least four stationary X-ray sources which are configured to sequentially irradiate the object with the X-ray beams.
52. A tomosynthesis system for forming a three dimensional image of an object, comprising:
an X-ray source configured to irradiate the object with a beam of X-rays from a plurality of positions along a path in a sector;
an X-ray detector positioned relative to the X-ray source to detect X-rays transmitted through the object; and
a processor which is configured to generate a three dimensional image of the object based on X-rays detected by the detector;
wherein the X-ray source is configured to rotate along the path in the sector in a first angular direction relative to the object, such that the focal spot of the X-ray beam moves in the first angular direction; and
the detector is configured to rotate in the direction different from the first angular direction.
53. A tomosynthesis system for forming a three dimensional image of an object, comprising:
an X-ray source configured to irradiate the object with a beam of X-rays from a plurality of positions along a path in a sector;
an X-ray detector positioned relative to the X-ray source to detect X-rays transmitted through the object; and
a processor which is configured to generate a three dimensional image of the object based on X-rays detected by the detector;
wherein the X-ray source is configured to rotate in an arc shaped path in a first angular direction relative to the object; and
the detector is configured to move in an arc shaped path in a second angular direction opposite to the first direction.
54. A tomosynthesis system for forming a three dimensional image of an object, comprising:
an X-ray source configured to periodically irradiate the object with a beam of X-rays, wherein the X-ray source is configured to emit the beam of X-rays while moving in a first direction along a path in a sector;
an X-ray detector positioned relative to the X-ray source to detect X-rays transmitted through the object, wherein the detector is configured to move in a second direction opposite to the first direction while the X-ray source moves in the first direction and the X-ray source emits the beam of X-rays; and
a processor which is configured to generate a three dimensional image of the object based on X-rays detected by the detector, wherein:
the X-ray source is configured to rotate in an arc shaped path and to periodically emit the beam of X-rays from a plurality of positions along the arc shaped path; and
the X-ray source is configured to rotate at a first speed while the X-ray source emits the beam of X-rays and to rotate at a second speed higher than the first speed while the X-ray source does not emit the beam of X-rays.
55. A tomosynthesis system for forming a three dimensional image of an object, comprising:
rotating an X-ray source in a first direction in a path through a sector;
emitting a beam of X-rays from the X-ray source while the X-ray source is moving along the path in the first direction;
periodically irradiating the object with the X-ray beam;
moving a detector in a second direction opposite to the first direction while the X-ray source emits the X-ray beam and the X-ray source moves in the first direction;
detecting X-rays transmitted through the object with the detector; and
generating a three dimensional image of the object based on the detected X-rays, while rotating an X-ray source in a first direction along the path through a sector comprises rotating the X-ray source in an arc shaped path at a first speed while the X-ray source emits the beam of X-rays and at a second speed higher than the first speed while the X-ray source does not emit the beam of X-rays.