Tomography apparatus and method of reconstructing tomography image

1. A method of reconstructing a tomography image, the method comprising:

acquiring tomography data corresponding to a moving object by performing a tomography scan of the moving object;

reconstructing, based on the tomography data, a plurality of prior images of the moving object respectively corresponding to a plurality of time points;

generating first data by projecting a region of each of the plurality of prior images;

reconstructing a first image based on the tomography data and the first data;

generating second data by projecting a region of the first image; and

reconstructing, based on the tomography data and the second data, a plurality of second images respectively corresponding to the plurality of time points.

2. The method of claim 1 , wherein the region of each of the plurality of prior images corresponds to a region where an amount of motion of the moving object is greater than a predetermined range.

3. The method of claim 1 , wherein the first image is reconstructed using image subtraction between the tomography data and the first data.

4. The method of claim 1 , wherein the region of the first image corresponds to a region where an amount of motion of the moving object is less than a predetermined range.

5. The method of claim 1 , wherein the plurality of second images are reconstructed using image subtraction between the tomography data and the second data.

6. The method of claim 1 , wherein motion artifacts caused by motion of the moving object are reduced in the plurality of second images, as compared to those in the plurality of prior images.

7. The method of claim 1 , further comprising reconstructing at least one final image based on the first image and the plurality of second images.

8. The method of claim 1 , further comprising:

determining whether the plurality of second images satisfy a predetermined condition;

generating, when the plurality of second images satisfy the predetermined condition, third data by projecting a region of each of the plurality of second images;

reconstructing a third image based on the tomography data and the third data;

generating fourth data by projecting a region of the third image; and

reconstructing, based on the tomography data and the fourth data, a plurality of fourth images respectively corresponding to the plurality of time points.

9. The method of claim 8 , wherein motion artifacts caused by motion of the moving object are reduced in the plurality of fourth images, as compared to those in the plurality of second images.

10. The method of claim 1 , further comprising correcting at least one of the plurality of second images based on motion of the moving object.

11. The method of claim 10 , wherein the plurality of second images are reconstructed based on a plurality of data sets that are respectively acquired at the plurality of time points based on the second data, and

wherein the correcting the at least one of the plurality of second images comprises:

determining, based on a predetermined criterion, two data sets respectively corresponding to two time points from among the plurality of data sets respectively corresponding to the plurality of time points;

acquiring, based on the determined two data sets, motion information representing motion of the moving object; and

correcting at least one of the plurality of second images based on the acquired motion information.

12. The method of claim 10 , wherein the correcting the at least one of the plurality of second images comprises:

determining, based on a predetermined criterion, two second images respectively corresponding to two time points from among the plurality of second images respectively corresponding to the plurality of time points;

acquiring motion information representing motion of the moving object based on the determined two second images; and

correcting at least one of the plurality of second images based on the acquired motion information.

13. The method of claim 11 , wherein the corrected at least one of the plurality of second images corresponds to a time point between the two time points.

14. A tomography apparatus comprising:

a data acquirer configured to acquire tomography data corresponding to a moving object by performing a tomography scan of the moving object; and

an image reconstructor configured to:

reconstruct, based on the tomography data, a plurality of prior images of the moving object respectively corresponding to a plurality of time points,

generate first data by projecting a region of each of the plurality of prior images,

reconstruct a first image based on the tomography data and the first data,

generate second data by projecting a region of the first image, and

reconstruct based on the tomography data and the second data, a plurality of second images respectively corresponding to the plurality of time points.

15. The tomography apparatus of claim 14 , wherein the region of each of the plurality of prior images corresponds to a region where an amount of motion of the moving object is greater than a predetermined range.

16. The tomography apparatus of claim 14 , wherein the first image is reconstructed using image subtraction between the tomography data and the first data.

17. The tomography apparatus of claim 14 , wherein the region of the first image corresponds to a region where an amount of motion of the moving object is less than a predetermined range.

18. The tomography apparatus of claim 14 , wherein the plurality of second images are reconstructed using image subtraction between the tomography data and the second data.

19. The tomography apparatus of claim 14 , wherein motion artifacts caused by motion of the moving object are reduced in the plurality of second images, as compared to those in the plurality of prior images.

20. The tomography apparatus of claim 14 , wherein the image reconstructor is further configured to reconstruct at least one final image based on the first image and the plurality of second images.

21. The tomography apparatus of claim 14 , wherein the image reconstructor is further configured to:

determine whether the plurality of second images satisfy a predetermined condition,

generate, when the plurality of second images satisfy the predetermined condition, third data by projecting a region of each of the plurality of second images,

reconstruct a third image based on the tomography data and the third data,

generate fourth data by projecting a region of the third image, and

reconstruct, based on the tomography data and the fourth data, a plurality of fourth images respectively corresponding to the plurality of time points.

22. The tomography apparatus of claim 21 , wherein motion artifacts caused by motion of the moving object are reduced in the plurality of fourth images, as compared to those in the plurality of second images.

23. The tomography apparatus of claim 14 , wherein the image reconstructor is further configured to correct at least one of the plurality of second images based on motion of the moving object.

24. The tomography apparatus of claim 23 , wherein the plurality of second images are reconstructed based on a plurality of data sets that are respectively acquired at the plurality of time points based on the second data, and

wherein the image reconstructor is further configured to:

determine, based on a predetermined criterion, two data sets respectively corresponding to two time points from among the plurality of data sets respectively corresponding to the plurality of time points,

acquire motion information representing motion of the moving object based on the determined two data sets, and

correct at least one of the plurality of second images based on the acquired motion information.

25. The tomography apparatus of claim 23 , wherein the image reconstructor is further configured to:

determine, based on a predetermined criterion, two second images respectively corresponding to two time points from among the plurality of second images respectively corresponding to the plurality of time points,

acquire motion information representing motion of the moving object based on the determined two second images, and

correct at least one of the plurality of second images based on the acquired motion information.

26. The tomography apparatus of claim 24 , wherein the corrected at least one of the plurality of second images corresponds to a time point between the two time points.

27. A non-transitory computer-readable recording medium having a computer program recorded thereon, which, when executed by a computer, performs the method of claim 1 .