Tomography apparatus and method for reconstructing tomography image thereof

1. A tomography apparatus comprising:

one or more processors which:

acquire partial images of an object that are used for acquiring first information indicating a motion amount of the object and include a first image acquired at a first time by using data acquired in a first angular section, which has an angle of less than 180° and into which the first time is included, and a second image acquired at a second time by using data acquired in a second angular section facing the first angular section, which has an angle of less than 180° and into which the second time is included, wherein the second angular section does not overlap with the first angular section,

acquire the first information indicating the motion amount of the object by using the first image and the second image, and

reconstruct a target image of the object at a target time, which is one of time points between the first time and the second time, based on the first information,

wherein the target time is included in an angular section different from the first angular section and the second angular section.

2. The tomography apparatus of claim 1 , wherein the first information is acquired by comparing only the first image and the second image.

3. The tomography apparatus of claim 1 , wherein the object imaged in the first image and the object imaged in the second image are different from each other in at least one among a size, a position, and a shape.

4. The tomography apparatus of claim 1 , wherein the time points are selected between the first time and the second time to be different from one another, and

a degree of motion correction of the object in the target image varies in response to the target time being selected to correspond to the time points.

5. The tomography apparatus of claim 1 , wherein the target time is selected to correspond to a middle angle between the first angular section and the second angular section, and

in the target image, a motion correction of the object is improved in response to the target time being selected to correspond to the middle angle, as compared to the motion correction of the object when the target time does not correspond to the middle angle.

6. The tomography apparatus of claim 1 , wherein the first information indicates the motion amount of a surface forming the object corresponding to the time points between the first time and the second time, as information corresponding to a motion vector field between the first image and the second image.

7. The tomography apparatus of claim 6 , wherein the motion vector field is measured by using non-rigid registration.

8. The tomography apparatus of claim 6 , wherein, in the first information, values of the time points and values of the motion amount of the surface indicated as the motion vector field have a linear relationship.

9. The tomography apparatus of claim 1 , wherein the one or more processors acquire the first image and the second image by using raw data acquired by performing a tomography scan in a one-cycle section that is less than one 360° turn, and

the first angular section and the second angular section are a start section and an end section of the one-cycle section, respectively.

10. The tomography apparatus of claim 1 , wherein the one or more processors reconstruct the target image by using pieces of projection data corresponding to views that are raw data acquired by performing a tomography scan while rotating a rotating frame of a gantry for less than one 360° turn.

11. The tomography apparatus of claim 1 , wherein the first information comprises information about motions of a surface of the object in all directions.

12. The tomography apparatus of claim 1 , wherein the one or more processors estimate the motion amount of the object at the target time based on the first information and reconstruct the target image based on the estimated motion amount.

13. The tomography apparatus of claim 1 , wherein the one or more processors reconstruct the target image by warping the partial images representing parts of the object, based on the first information.

14. The tomography apparatus of claim 1 , wherein the one or more processors reconstruct the target image by warping a center of a voxel indicating the object, based on the first information, and performing back-projection with respect to a position of the warped voxel.

15. The tomography apparatus of claim 1 , further comprising:

a display which displays a user interface (UI) which receives information indicating a relationship between time and the motion amount of the object as the first information,

wherein the one or more processors acquire the first information based on the information indicating the relationship between the time and the motion amount of the object.

16. The tomography apparatus of claim 1 , wherein the one or more processors perform a tomography scan in a section having an angle equal to a sum of 180° and an additional angle, in a half reconstruction method using a rebinned parallel beam.

17. The tomography apparatus of claim 1 , wherein the one or more processors acquire projection data corresponding to a section having an angle equal to a sum of 180° and an additional angle, and

the additional angle is from about 30° to about 70°.

18. The tomography apparatus of claim 1 , further comprising:

a display which displays a user interface screen comprising a menu for setting the target time.

19. The tomography apparatus of claim 1 , further comprising:

a display which displays a screen comprising at least one among the first information, a user interface screen for setting the first information, the target time, and the target image.

20. The tomography apparatus of claim 1 , wherein the one or more processors divide projection data acquired by performing a tomography scan while a rotating frame of a gantry is rotated around the object, into conjugate view sectors, acquire pairs of the partial images in the conjugate view sectors, and acquire the first information by using the pairs of the partial images corresponding to the conjugate view sectors, and

wherein the second angular section and the first angular section are included into a pair of the conjugate view sectors.

21. The tomography apparatus of claim 1 , further comprising:

a display which displays a medical image; and

a user interface for setting a region of interest of the medical image,

wherein the one or more processors extract a surface included in the region of interest, set at least one among the first angular section, the second angular section, a start position of a one-cycle section, an end position of the one-cycle section, and the target time based on a direction of the extracted surface, acquire the first image and the second image in the first angular section and the second angular section, respectively, corresponding to a setting, and acquire the first information indicating the motion amount of the object by using the first image and the second image.

22. The tomography apparatus of claim 1 , wherein the one or more processors set at least one among the first angular section, the second angular section, the first time, the second time, a start position of a one-cycle section, an end position of the one-cycle section, and the target time, based on a moving direction of the object.

23. The tomography apparatus of claim 1 , wherein the object is at least one among a heart, abdomen, womb, brain, breast, and liver.

24. The tomography apparatus of claim 1 , wherein the object is a heart that is expressed by a surface, and

the heart comprises at least one of tissues having different brightness values in a predetermined area.

25. The tomography apparatus of claim 1 , wherein the one or more perform a tomography scan according to at least one among an axial scanning method and a helical scanning method.

26. The tomography apparatus of claim 1 , wherein the one or more processors acquire additional information that is information about extraneous motion generated due to at least one among an object movement and external factors outside of the object during a tomography scan, and acquire the first information indicating the motion amount of the object based on the first image, the second image, and the additional information.

27. The tomography apparatus of claim 1 , wherein the one or more processors acquire pairs of the partial images that image a same portion of the object, by using a helical scanning method, and acquire the first information by using the pairs of the partial images.

28. A method for reconstructing a tomography image, the method comprising:

acquiring partial images of an object that are used for acquiring first information indicating a motion amount of the object and include a first image acquired at a first time by using data acquired in a first angular section, which has an angle of less than 180° and into which the first time is included, and a second image acquired at a second time by using data acquired a second angular section facing the first angular section, which has an angle of less than 180° and into which the second time is included, wherein the second angular section does not overlap with the first angular section;

acquiring the first information indicating the motion amount of the object at time points between the first time and the second time, by using the first image and the second image; and

reconstructing a target image of the object at a target time, which is one of the time points, based on the first information,

wherein the target time is included in an angular section different from the first angular section and the second angular section.

29. The method of claim 28 , wherein the acquiring the first information comprises:

acquiring the first information by comparing only the first image and the second image.

30. The method of claim 28 , wherein the object imaged in the first image and the object imaged in the second image are different from each other in at least one among a size, a position, and a shape.

31. The method of claim 28 , wherein the time points are selected between the first time and the second time to be different from one another, and

a degree of a motion correction of the object in the target image varies in response to the target time being selected to correspond to the time points.

32. The method of claim 28 , wherein the target time is selected to correspond to a middle angle between the first angular section and the second angular section, and

in the target image, a motion correction of the object is improved in response to the target time being selected to correspond to the middle angle, as compared to the motion correction of the object when the target time does not correspond to the middle angle.

33. The method of claim 28 , wherein the first information indicates the motion amount of a surface forming the object corresponding to the time points between the first time and the second time, as information corresponding to a motion vector field between the first image and the second image.

34. The method of claim 33 , wherein the motion vector field is measured by using non-rigid registration.

35. The method of claim 33 , wherein, in the first information, values of the time points and corresponding values of the motion amount of the surface indicated as the motion vector field have a linear relationship.

36. The method of claim 28 , wherein the acquiring the first image and the second image comprises acquiring the first image and the second image by using raw data obtained by performing a tomography scan in a one-cycle angular section that is less than one 360° turn, and

the first angular section and the second angular section are a start section and an end section of the one-cycle angular section, respectively.

37. The method of claim 28 , wherein the reconstructing the target image comprises:

reconstructing the target image by using pieces of projection data corresponding to views that are raw data acquired by performing a tomography scan while rotating a rotating frame of a gantry for less than one 360° turn.

38. The method of claim 28 , wherein the first information comprises information about a motion of a surface of the object in all directions.

39. The method of claim 28 , wherein the reconstructing the target image comprises:

estimating the motion amount of the object at the target time based on the first information; and

reconstructing the target image based on the estimated motion amount.

40. The method of claim 28 , wherein the reconstructing the target image comprises:

reconstructing the target image by warping the partial images of portions of the object, based on the first information.

41. The method of claim 28 , wherein the reconstructing the target image comprises:

warping a center of a voxel indicating the object, based on the first information; and

reconstructing the target image by performing a back-projection with respect to a position of the warped voxel.

42. The method of claim 28 , further comprising:

receiving information indicating a relationship between the time points and values of the motion amount of the object indicated by the first information through a user interface screen,

wherein the acquiring the first information comprises acquiring the first information based on the information indicating the relationship between the time points and the values of the motion amount of the object.

43. The method of claim 28 , wherein the acquiring the first image and the second image comprises performing a tomography scan in a section having an angle equal to a sum of 180° and an additional angle, in a half reconstruction method using a rebinned parallel beam.

44. The method of claim 28 , further comprising acquiring projection data corresponding to an angle equal to a sum of 180° and an additional angle,

wherein the additional angle has a value from about 30° to about 70°.

45. The method of claim 28 , further comprising:

displaying a user interface screen comprising a menu for setting the target time.

46. The method of claim 28 , further comprising:

displaying a screen comprising at least one among the first information, a user interface screen for setting the first information, the target time, and the target image.

47. The method of claim 28 , wherein the acquiring the first image and the second image comprises:

dividing projection data acquired by performing a tomography scan while a rotating frame of a gantry is rotated around the object, into conjugate view sectors; and

acquiring pairs of the partial images in the conjugate view sectors,

wherein the acquiring the first information comprises acquiring the first information by using the pairs of the partial images corresponding to the conjugate view sectors, and

wherein the second angular section and the first angular section are included into a pair of the conjugate view sectors.

48. The method of claim 28 , further comprising:

displaying a medical image; and

setting a region of interest of the medical image,

wherein the acquiring the first image and the second image comprises:

extracting a surface included in the region of interest,

setting at least one among the first angular section, the second angular section, a start position of a one-cycle angular section, an end position of the one-cycle angular section, and the target time based on a direction of the extracted surface,

acquiring the first image and the second image in the first angular section and the second angular section, respectively, and

acquiring the first information indicating the motion amount of the object by using the first image and the second image.

49. The method of claim 28 , further comprising:

setting at least one among the first angular section, the second angular section, the first time, the second time, a start position of a one-cycle angular section, an end position of the one-cycle angular section, and the target time, based on a moving direction of the object.

50. The method of claim 28 , wherein the object comprises at least one among a heart, abdomen, womb, brain, breast, and liver.

51. The method of claim 28 , wherein the object comprises a heart that is expressed by a surface, and

the heart comprises at least one of tissues having different brightness values in a predetermined area.

52. The method of claim 28 , further comprising:

performing a tomography scan according to at least one among an axial scanning method and a helical scanning method.

53. The method of claim 28 , further comprising acquiring additional information that is information about an extraneous motion generated due to at least one among an object movement and external factors outside of the object during a tomography scan,

wherein the acquiring the first information comprises acquiring the first information indicating the motion amount of the object based on the first image, the second image, and the additional information.

54. The method of claim 28 , wherein the acquiring the first image and the second image comprises acquiring pairs of the partial images that image a same portion of the object, by using a helical scanning method, and

the acquiring the first information comprises acquiring the first information by using the pairs of the partial images.

55. The tomography apparatus of claim 1 , wherein the first image and the second image are reconstructed by a partial angle reconstruction method, and

the target image is reconstructed by a half reconstruction method or full reconstruction method.

56. The tomography apparatus of claim 1 , wherein the motion amount indicates motion information in a time period between the first time and the second time.