Patent Number: 
Section: claims

1. An imaging system for generating three dimensional image data using X-ray backscattering from a first side of a structure, said imaging system comprising:a first X-ray source and a second X-ray source;a first rotating collimator coupled to said first X-ray source and to a second rotating collimator coupled to said second X-ray source;a first shutter coupled to said first rotating collimator and a second shutter coupled to said second rotating collimator;an X-ray detector; anda controller coupled to said first and second X-ray sources, said first and second rotating collimators, and said X-ray detector, said controller is configured to:emit a first X-ray beam through said first rotating collimator at a first point in the structure through the first side of the structure while the second shutter is closed;detect backscattered X-rays from the first X-ray beam from the first side of the structure;emit a second X-ray beam through said second rotating collimator at the first point through the first side of the structure while said first shutter is closed; anddetect backscattered X-rays from the second X-ray beam from the first side of the structure; andgenerate three dimensional image data of the structure based on the detected backscattered X-rays from the first side of the structure. 2. The imaging system of claim 1, further configured to:emit the first X-ray beam at a first point in the structure through the first side of the structure from a first angle;detect first backscattered X-rays from the first X-ray beam from the first side of the structure;generate first image data from the first backscattered X-rays;emit the second X-ray beam at the first point in the structure through the first side of the structure from a second angle;detect second backscattered X-rays from the second X-ray beam from the first side of the structure;generate second image data from the second backscattered X-rays; andcombine the first image data with the second image data. 3. The imaging system of claim 1, further comprising a platform that is coupled to the structure, wherein said imaging system is further configured to rotate relative to the first side of the structure while emitting the X-rays and detecting the backscattered X-rays. 4. The imaging system of claim 1, further configured to generate parallel slices of image data corresponding to a plurality of depths within the structure. 5. The imaging system of claim 1, further configured to combine image data from two angles along a plane that is perpendicular to the structure. 6. The imaging system of claim 1, further configured to generate first image data for a plurality of first points at a first depth, then generate second image data for a plurality of second points at a second depth in the structure. 7. The imaging system of claim 1, further configured to generate first image data at a first plurality of depths along a first plane within the structure, then generate second image data at a second plurality of depths along a second plane that is adjacent to the first plane. 8. A method for generating three dimensional image data using X-ray backscattering from a first side of a structure, said method comprising:emitting a first X-ray beam through a first rotating collimator at a first point in the structure through the first side of the structure while a first shutter of the first rotating collimator is open and a second shutter of a second rotating collimator is closed;detecting backscattered X-rays from the first X-ray beam from the first side of the structure;emitting a second X-ray beam through the second rotating collimator at the first point through the first side of the structure while the second shutter of the second rotating collimator is open and the first shutter of the first rotating collimator is closed; anddetecting backscattered X-rays from the second X-ray beam from the first side of the structure; andgenerating three dimensional image data of the structure based on the detected backscattered X-rays from the first side of the structure. 9. The method of claim 8, further comprising:emitting the first X-ray beam at a first point in the structure through the first side of the structure from a first angle;detecting first backscattered X-rays from the first X-ray beam from the first side of the structure;generating first image data from the first backscattered X-rays;emitting the second X-ray beam at the first point in the structure through the first side of the structure from a second angle;detecting second backscattered X-rays from the second X-ray beam from the first side of the structure;generating second image data from the second backscattered X-rays; andcombining the first image data with the second image data. 10. The method of claim 8, wherein the first and second rotating collimators, the first and second X-ray sources, and the X-ray detector are included in an imaging system, said method further comprising rotating the imaging system relative to the first side of the structure while emitting the X-rays and detecting the backscattered X-rays. 11. The method of claim 8, further comprising generating parallel slices of image data corresponding to a plurality of depths within the structure. 12. The method of claim 8, further comprising combining image data from two angles along a plane that is perpendicular to the structure. 13. The method of claim 8, further comprising:generating first image data for a plurality of first points at a first depth; andsubsequently generating second image data for a plurality of second points at a second depth in the structure. 14. The method of claim 8, further comprising:generating first image data at a first plurality of depths along a first plane defined within the structure; andsubsequently generating second image data at a second plurality of depths along a second plane defined within the structure that is adjacent to the first plane.