Systems and method for scanning a continuous stream of objects

1. A method for scanning a stream of objects, said method comprising:

continuously acquiring raw data of the stream of objects using an X-ray system, the X-ray system including a detector;

rebinning the raw data of the stream of objects into at least one two- dimensional sinogram using a first resolution;

determining a leading edge and a trailing edge of a first object of the stream of objects from the at least one two-dimensional sinogram, wherein the raw data is rebinned using a second resolution different from the first resolution after the leading edge is detected; and

reconstructing a three-dimensional image of the first object using the at least one two-dimensional sinogram.

2. A method in accordance with claim 1 , further comprising placing the X-ray system in a low power state if no leading edge is determined within a period of time.

3. A method in accordance with claim 2 , further comprising restoring the X-ray system to a full power state after detecting a second object of the stream of objects.

4. A method in accordance with claim 3 , further comprising using a light sensor to detect the second object.

5. A method in accordance with claim 1 , wherein said determining a leading edge comprises:

calculating a mass represented by the at least one two-dimensional sinogram;

comparing the mass to a threshold; and

identifying the leading edge if the mass of the at least one two- dimensional sinogram is greater than the threshold.

6. A method in accordance with claim 1 , wherein said determining a trailing edge comprises:

calculating a mass represented by the at least one two-dimensional sinogram;

comparing the mass to a threshold; and

identifying the trailing edge if the mass of the at least one two- dimensional sinogram is less than the threshold.

7. A method in accordance with claim 1 , wherein the X-ray system includes a memory, said reconstructing a three-dimensional image comprises storing in the memory each two-dimensional sinogram of the at least one two-dimensional sinogram between the leading edge and the trailing edge.

8. A method in accordance with claim 7 , wherein said reconstructing a three-dimensional image further comprises:

aggregating each two-dimensional sinogram between the leading edge and the trailing edge; and

executing a reconstruction algorithm on the aggregation of two-dimensional sinograms.

9. A method in accordance with claim 8 , further comprises discarding the at least one two-dimensional sinogram if the at least one two-dimensional sinogram is not between the leading edge and the trailing edge.

10. A scanning system, comprising:

a conveyor configured to transport a stream of objects through said scanning system; and

a computed tomography (CT) system configured to generate an image of a first object of the stream of objects, said CT system comprising a detector and a control system, said control system configured to:

continuously acquire raw data of the stream of objects from said detector;

rebin the raw data of the stream of objects into at least one two- dimensional sinogram using a first resolution;

determine a leading edge and a trailing edge of the first object from the at least one two-dimensional sinogram, wherein the raw data is rebinned using a second resolution different from the first resolution after the leading edge is detected; and

reconstruct a three-dimensional image of the first object using the at least one two-dimensional sinogram.

11. A scanning system in accordance with claim 10 , wherein said control system is further configured to:

calculate a mass represented by the at least one two-dimensional sinogram;

compare the mass to a threshold; and

identify the leading edge if the mass of the at least one two-dimensional sinogram is greater than the threshold.

12. A scanning system in accordance with claim 10 , wherein said control system is further configured to:

calculate a mass represented by the at least one two-dimensional sinogram;

compare the mass to a threshold; and

identify the trailing edge if the mass of the at least one two-dimensional sinogram is less than the threshold.

13. A scanning system in accordance with claim 10 , wherein said scanning system enters a low power state if no leading edge is determined within a period of time.

14. A scanning system in accordance with claim 13 , wherein said scanning system is restored to a full power state after detecting a second object of the stream of objects.

15. A scanning system in accordance with claim 14 , wherein said scanning system uses a light sensor to detect the second object.

16. A scanning system in accordance with claim 10 , wherein said CT system comprises a memory, said CT system further configured to store in said memory each two-dimensional sinogram of the at least one two-dimensional sinogram between the leading edge and the trailing edge.

17. A scanning system in accordance with claim 16 , wherein said CT system is further configured to:

aggregate each two-dimensional sinogram between the leading edge and the trailing edge; and

execute a reconstruction algorithm on the aggregation of two-dimensional sinograms.

18. A computed tomography (CT) system, comprising:

a radiation source;

a detector configured to detect radiation emitted from said radiation source; and

a control system comprising:

an acquisition subsystem configured to continuously acquire raw data of a stream of objects from said detector;

an object detection subsystem configured to:

rebin the raw data of the stream of objects into at least one two- dimensional sinogram using a first resolution; and

determine a leading edge and a trailing edge of a first object of the stream of objects from the at least one two-dimensional sinogram, wherein the raw data is rebinned using a second resolution different from the first resolution after the leading edge is detected; and

a reconstruction subsystem configured to reconstruct an image of the first object using the at least one two-dimensional sinogram.

19. A CT system in accordance with claim 18 , wherein said control system is further configured to:

calculate a mass represented by the at least one two-dimensional sinogram;

compare the mass to a threshold; and

identify the trailing edge if the mass of the at least one two- dimensional dimensional sinogram is less than the threshold.

20. A CT system in accordance with claim 18 , further comprising a gantry rotatable about a CT plane within said CT system, said radiation source and said detector coupled to said gantry for rotation about said CT plane.