Patent Number: 
Section: claims

1. A collimator for use in single photon emission computed tomography (SPECT), which collimator comprises:a first layer comprising at least three spaced apart elongated slats forming a first array extending in a first direction; anda second layer comprising at least three spaced apart elongated slats forming a second array extending in a second direction orthogonal to said first direction,said first array having a width extending across said second direction, said second array having a width extending across said first direction, wherein each elongated slat of each array has a length extending across the entire width of the other array,each of said slats constructed of a radiation attenuation material. 2. The collimator of claim 1, wherein the space between said slats is fixed and non-variable. 3. The collimator of claim 2, wherein the space between said slats is fixed by foam. 4. The collimator of claim 2, wherein the space between said slats is fixed by guide plates having grooves into which ends of said slats are positioned. 5. The collimator of claim 2, wherein the space between said slats is fixed by grooves in the top of said first layer and grooves in the bottom of said second layer. 6. The collimator of claim 2, wherein each of said slats in a layer are tilted at an angle greater than zero and all of said slats in a layer are tilted in the same direction. 7. The collimator of claim 1, wherein the space between said slats is variable. 8. The collimator of claim 7, wherein the space between said slats at one end of said slats is less than the space between said slats at the other end of said slats. 9. The collimator of claim 8, wherein the space between the slats is varied by application of a force to both sides of the layer at one end of said slats. 10. The collimator of claim 8, wherein each of said slats in a layer are tilted at an angle greater than zero and all of said slats in a layer are tilted in the same direction. 11. The collimator of claim 7, wherein the space between said slats is varied through use of springs. 12. The collimator of claim 7, wherein the space between said slats is varied through use of plastic having air bubbles. 13. The collimator of claim 7, wherein the space between said slats is varied through use of magnetic force. 14. The collimator of claim 1, wherein each of said slats in a layer are tilted at an angle greater than zero and all of said slats in a layer are tilted in the same direction. 15. A nuclear imaging acquisition system for use in single photon emission computed tomography (SPECT), which system comprises:a collimator comprising a first layer comprising at least three spaced apart elongated slats forming a first array extending in a first direction and a second layer comprising at least three spaced apart elongated slats forming a second array extending in a second direction orthogonal to said first direction,said first array having a width extending across said second direction, said second array having a width extending across said first direction, wherein each elongated slat of each array has a length extending across the entire width of the other array, each of said slats constructed of a radiation attenuation material; anda detector having a side which detects radiation emanating from an object after passing through said collimator. 16. The nuclear imaging acquisition system of claim 15, wherein the space between said slats is fixed and non-variable. 17. The nuclear imaging acquisition system of claim 16, wherein the space between said slats is fixed by foam. 18. The nuclear imaging acquisition system of claim 16, wherein the space between said slats is fixed by guide plates having grooves into which ends of said slats are positioned. 19. The nuclear imaging acquisition system of claim 16, wherein the space between said slats is fixed by grooves in the top of said first layer and grooves in the bottom of said second layer. 20. The nuclear imaging acquisition system of claim 16, wherein each of said slats in a layer are tilted at an angle greater than zero and all of said slats in a layer are tilted in the same direction. 21. The nuclear imaging acquisition system of claim 15, wherein the space between said slats is variable. 22. The nuclear imaging acquisition system of claim 21, wherein the space between said slats at one end of said slates is less than the space between said slats at the other end of said slats. 23. The collimator of claim 22, wherein the space between the slats is varied by application of a force to both sides of the layer at one end of said slats. 24. The nuclear imaging acquisition system of claim 21, wherein the space between said slats is varied through use of springs. 25. The nuclear imaging acquisition system of claim 21, wherein the space between said slats is varied through use of plastic having air bubbles. 26. The nuclear imaging acquisition system of claim 21, wherein the space between said slats is varied through use of magnetic force. 27. The nuclear imaging acquisition system of claim 21, wherein each of said slats in a layer are tilted at an angle greater than zero and all of said slats in a layer are tilted in the same direction. 28. The nuclear imaging acquisition system of claim 15, wherein each of said slats in a layer are tilted at an angle greater than zero and all of said slats in a layer are tilted in the same direction.