Collimator and detector based medical imaging systems

1. A method for examining a subject using molecular imaging, the method comprising:

filtering, by a first collimator, photons emitted from the subject;

detecting, by a first detector, photons that pass through the first collimator;

filtering, by a second collimator, photons emitted from the subject;

detecting, by a second detector, photons that pass through the second collimator; and

reconstructing, by an image processor, a medical image of the subject based on photons detected by both the first and second detectors, wherein the first and second collimators are positioned on a same side of the subject.

2. The method of claim 1 , wherein the first and second collimators are positioned such that their fields of view partially overlap in an overlapping region.

3. The method of claim 2 , wherein the reconstructing of the medical image comprises:

reconstructing a first partial image based on photons that pass through the overlapping region and are detected by the first detector; and

reconstructing a second partial image based on photons detected by the second detector, wherein the reconstructing of the second partial image uses the first partial image as an initial estimate for a volume of the overlapping region.

4. The method of claim 3 , wherein the reconstructing of the second partial image further updates the first partial image using an iterative method.

5. The method of claim 1 , wherein the medical image is an image of combined Field of Views (FOV) of the first and second collimators.

6. The method of claim 5 , wherein the photons detected by the first and second detectors are detected simultaneously.

7. The method of claim 5 , wherein the reconstructing comprises using a maximum likelihood expectation and maximization (MLEM) method during the reconstructing.

8. The method of claim 1 , further comprising displaying the reconstructed medical image on a display device.

9. A method for examining a subject using molecular imaging, the method comprising:

filtering, by a first collimator, radiation emitted from the subject;

detecting, by a first detector, radiation that pass through the first collimator;

filtering, by a second collimator, radiation emitted from the subject, wherein the first collimator partially blocks a field of view (FOV) of the second collimator;

detecting, by a second detector, radiation that pass through the second collimator; and

reconstructing, by an image processor, a medical image of the subject based on the radiation detected by both the first and second detectors, wherein the first and the second collimators are configured to be placed on a same side of the subject, and wherein the second collimator is positioned further away from the subject than the first collimator.

10. The method of claim 9 , wherein the first and second collimators comprise first and second openings, respectively, for passing through radiation emitted from the subject, wherein the first and second openings have first and second aspect ratios, respectively, of height to width, and wherein the first aspect ratio is higher than the second aspect ratio.

11. The method of claim 9 , further comprising:

filtering, by a third collimator, radiation emitted from the subject;

detecting, by a third detector, radiation that passes through the third collimator;

filtering, by a fourth collimator, radiation emitted from the subject; and

detecting, by a fourth detector, radiation that passes through the fourth collimator, wherein the third and fourth collimators are positioned on a same side of the subject that is opposite to the side of the subject where the first and second collimators are placed on.

12. The method of claim 10 , wherein the openings of the first collimator include parallel holes and the openings of the second collimator include multiple pinholes.

13. The method of claim 9 , wherein the medical image is an image of combined Field of Views (FOV) of the first and second collimators, and wherein the radiation detected by the first and second detectors are detected simultaneously.

14. The method of claim 9 , further comprising displaying the reconstructed medical image on a display device, and wherein the reconstructing comprises using a maximum likelihood expectation and maximization (MLEM) method during the reconstructing.

15. The method of claim 9 , wherein the second collimator and the second detector are configured to move about the subject while maintaining a constant distance between the second collimator and the second detector.

16. A method for examining a subject using molecular imaging, the method comprising:

filtering, by a first collimator, radiation emitted from the subject;

detecting, by a first detector, radiation that passes through the first collimator;

filtering, by a second collimator, radiation emitted from the subject wherein the first collimator partially blocks a field of view (FOV) of the second collimator;

detecting, by a second detector, radiation that pass through the second collimator; and

reconstructing, by an image processor, a medical image of the subject based on the radiation detected by both the first and second detectors, wherein the first and the second collimators are configured to be placed on a same side of the subject, the second collimator is positioned further away from the subject than the first collimator, the first collimator comprises first openings for passing through radiation, the second collimator comprises second openings for passing through radiation, the first openings have a first aspect ratio of height to width, the second openings have a second aspect ratio of height to width, and wherein the first aspect ratio is higher than the second aspect ratio.

17. The method of claim 16 , wherein the reconstructing comprises using a maximum likelihood expectation and maximization (MLEM) method during the reconstructing.

18. The method of claim 16 , wherein the first openings include parallel holes, and the second openings include multiple pinholes in a plate.

19. The method of claim 16 , wherein the first and second collimators are positioned such that their fields of view partially overlap in an overlapping region, wherein the reconstructing of the medical image comprises:

reconstructing a first partial image based on the radiation that passes through the overlapping region and is detected by the first detector; and

reconstructing a second partial image based on the radiation detected by the second detector, wherein the reconstructing of the second partial image uses the first partial image as an initial estimate for a volume of the overlapping region, and

wherein the reconstructing of the second partial image further updates the first partial image using an iterative method.

20. The method of claim 19 , wherein the medical image is an image of combined Field of Views (FOV) of the first and second collimators.