Patent Number: 
Section: claims

1. An apparatus, comprising:an x-ray source operable to generate x-ray beams;a collimator comprising one or more leaves configured to modify the x-ray beams, wherein each of at least one of the one or more leaves comprises at least a portion that is partially x-ray attenuating configured to modulate a beam quality of the x-ray beams passing therethrough to provide for imaging or treatment of a body portion, and each of the portion covers an entire field of view of the x-ray beams on the body portion being imaged or treated, and the portion has a substantially uniform thickness;a motorized system operable to move the one or more leaves independently in or out of the x-ray beams; anda controller configured to synchronize an activation of the x-ray source with an activation of the motorized system, wherein the one or more leaves move in synchronization with the activation of the x-ray beams. 2. The apparatus of claim 1 wherein the x-ray source is operable to generate the x-ray beams in pulses and the motorized system is operable to move the one or more leaves in synchrony with operation of the x-ray source thereby allowing modification of the x-ray beams on a pulse to pulse basis. 3. The apparatus of claim 1 wherein each of the one or more leaves is movable to cover an entire field of view of the x-ray beams. 4. The apparatus of claim 3 wherein each of the one or more leaves is configured to modulate the beam quality of the x-ray beam. 5. The apparatus of claim 4 wherein each of the one or more leaves comprises a same material that partially attenuates x-rays. 6. The apparatus of claim 4 wherein each of the one or more leaves comprises a different material that partially attenuates x-rays. 7. The apparatus of claim 1, wherein the at least one of the one or more leaves is configured to modify energy of the x-ray beams passing therethrough to provide for imaging or treatment of a body portion. 8. A collimator assembly, comprising:two or more leaves configured to modify an x-ray beam, wherein a substantially entire portion of each of the two or more leaves is partially x-ray attenuating configured to modulate a beam quality of the x-ray beam passing therethrough to provide for imaging or treatment of a body portion, the substantially entire portion of each of the two or more leaves has a substantially uniform thickness; anda motorized system operable to move the two or more leaves independently in or out of the x-ray beam;wherein the two or more leaves are movable to define an aperture to allow a first beam portion passing through the aperture and a second beam portion passing through a thickness of each of the two or more leaves, wherein the two or more leaves are configured to move synchronously with an activation of the x-ray beam, thereby providing a modified beam for imaging or treatment of a body portion, the modified beam comprising the first beam portion having a first beam quality and the second beam portion having a second beam quality. 9. The collimator assembly of claim 8 wherein each of the two or more leaves is movable to cover an entire field of view of the x-ray beam. 10. The collimator assembly of claim 8 comprising four leaves, whereinadjacent two leaves are movably in directions perpendicularly to each other, andeach of the four leaves is movable to cover an entire field of view of the x-ray beam. 11. The collimator assembly of claim 10 wherein each of the four leaves is configured to modulate the beam quality of the x-ray beam. 12. The collimator assembly of claim 11 wherein each of the four leaves comprises a same material that partially attenuates x-rays. 13. The collimator assembly of claim 12 wherein the four leaves are moveable to define the aperture to allow the first portion of the x-ray beam passing through the aperture and the second portion of the x-ray beam passing through thicknesses of the four leaves, thereby providing the modified beam comprising the first beam portion having the first beam quality and the second beam portion having the second beam quality. 14. The collimator assembly of claim 11 wherein each of the four leaves comprises a different material that partially attenuates x-rays. 15. The apparatus of claim 8, wherein the at least one of the one or more leaves is configured to modify energy of the x-ray beams passing therethrough to provide for imaging or treatment of a body portion. 16. An imaging method, comprising:positioning a body portion containing a region of interest;directing an x-ray beam to the body portion, wherein the x-ray beam has a first beam portion directed to the region of interest and a second beam portion directed to the rest of the body portion, wherein the first beam portion has a first beam quality and the second beam portion has a second beam quality different from the first beam quality; andacquiring an image including the region of interest and the rest of the body portion;wherein the first and second beam portions are provided by a collimator assembly comprising two or more leaves, wherein a substantially entire portion of each of the two or more leaves partially attenuates x-rays and has a substantially uniform thickness, the two or more leaves are confiqured to move synchronously with an activation of the x-ray beam defining an aperture, thereby allowing the first beam portion passing through the aperture to the region of interest and the second beam portion passing through thicknesses of the two or more leaves to the rest of the body portion to provide for imaging or treatment. 17. The method of claim 16 wherein the x-ray beam is generated by an x-ray source, and wherein each of the two or more leaves of the collimator assembly is independently moveable in synchrony with operation of the x-ray source such that the aperture is defined substantially in real time with generation of the x-rays. 18. The imaging method of claim 16, wherein each of the two or more leaves is configured to modify energy of the x-ray beams passing through the thicknesses of the two or more leaves. 19. An imaging method, comprising:positioning a body portion to be imaged;acquiring a first image of the body portion using a first pulse of x-rays having a first energy;acquiring a second image of the body portion using a second pulse of x-rays having a second energy;computing a third image using the first and second images;wherein the first and second pulses of x-rays are generated by an x-ray source and modulated by a collimator assembly, wherein the collimator assembly comprises two or more leaves each being independently moveable in synchrony with operation of the x-ray source such that a beam quality of at least one of the first and second pulses of x-rays is modulated by one of the two or more leaves moving in synchronization with an activation of the at least one of the first and second pulses by passing through a thickness of the one of the two or more leaves, wherein the one of the two or more leaves comprises at least a portion that covers an entire field of view of the at least one of the first and second pulses on the body portion being imaged and the portion has a substantially uniform thickness. 20. The method of claim 19 wherein a beam quality of each of the first and second pulses of x-rays is modulated by one of the two or more leaves substantially in real time with the activation of the each of the first and second pulses by passing through a thickness of the one of the two or more leaves, and each of the two or more leaves comprises at least a portion that covers an entire field of view of each of the first and second pulses on the body portion being imaged and the portion has a substantially uniform thickness. 21. The imaging method of claim 19, wherein each of the two or more leaves is configured to modify energy of at least one of the first and second pulses of x-rays. 22. An apparatus, comprising:an x-ray source operable to generate x-ray beams;a collimator comprising one or more leaves configured to modify the x-ray beams, wherein each of at least one of the one or more leaves comprises at least a portion that covers an entire field of view of the x-ray beams on a body portion being imaged or treated, wherein the portion is partially x-ray attenuating configured to substantially uniformly change energy of the x-ray beams penetrating through a thickness of the portion;a motorized system operable to move the one or more leaves independently in or out of the x-ray beams; anda controller configured to synchronize an activation of the x-ray source with an activation of the motorized system wherein the one or more leaves move in synchronization with the activation of the x-ray beams. 23. The apparatus of claim 22, wherein the portion of the at least one of the one or more leaves substantially uniformly stops x-ray photons having a given energy level or range. 24. The apparatus of claim 22, wherein the portion of the at least one of the one or more leaves substantially uniformly stops x-ray photons having energies at or below a given level.