Patent Number: 
Section: claims

1. An anti-scatter grid located on a detector comprising a plurality of scintillators, the anti-scatter grid comprising:a plurality of T shaped grid walls located on the plurality of scintillators, wherein a thickness of a bottom part of a T shaped grid wall is greater than a thickness of a top part of the T shaped grid wall; anda plurality of rectangular grid walls located on the plurality of scintillators, wherein a thickness of the plurality of rectangular grid walls is uniform;wherein the plurality of rectangular grid walls and the plurality of the plurality of T shaped grid walls are located in different regions on the detector. 2. The anti-scatter grid of claim 1, wherein the detector further comprises a plurality of chips and a plurality of photosensors assembled on each of the plurality of chips, a chip of the plurality of chips being configured to process data from the plurality of photosensors, and wherein:the plurality of rectangular grid walls are located near a gap between two adjacent chips of the plurality of chips, and the plurality of shaped grid walls are located away from the gap between two adjacent chips of the plurality of chips. 3. The anti-scatter grid of claim 2, wherein a thickness of a T-shaped grid wall of the plurality of T shaped grid walls is different from a thickness of a rectangular grid wall of the plurality of rectangular grid walls so that an interspace between each two adjacent grid walls of the plurality of grid walls is uniform. 4. The anti-scatter grid of claim 2, wherein a thickness of a T-shaped grid wall of the plurality of T shaped grid walls is different from a thickness of a rectangular grid wall of the plurality of rectangular grid walls so that a ratio of a width of an interspace between each two adjacent grid walls of the plurality of grid walls to a thickness of the each two adjacent grid walls is uniform. 5. The anti-scatter grid of claim 2, wherein a height of a T-shaped grid wall of the plurality of T shaped grid walls is different from a height of a rectangular grid wall of the plurality of rectangular grid walls so that a ratio of a width of an interspace between each two adjacent grid walls of the plurality of grid walls to a height of the each two adjacent grid walls is uniform. 6. The anti-scatter grid of claim 1, wherein a height of the top part of the T shaped grid wall is greater than a height of the bottom part of the T shaped grid wall. 7. The anti-scatter grid of claim 1, wherein the anti-scatter grid is a parallel one or a focused one. 8. A detector comprising:a plurality of chips;a plurality of photosensors assembled on each of the plurality of chips, the chip being configured to process data from the photosensor;a plurality of scintillators, each scintillator of the plurality of scintillators being assembled on a photosensor of the plurality of photosensors; andan anti-scatter grid located on the plurality of scintillators, wherein the anti-scatter grid comprises:a plurality of T shaped grid walls, wherein a thickness of a bottom part of a T shaped grid wall is greater than a thickness of a top part of the T shaped grid wall; anda plurality of rectangular grid walls, wherein a thickness of the plurality of rectangular grid walls is uniform;wherein the plurality of rectangular grid walls and the plurality of the plurality of T shaped grid walls are located in different regions on the plurality of scintillators. 9. The detector of claim 8, wherein:the plurality of rectangular grid walls located near a gap between two adjacent chips of the plurality of chips, and the plurality of T shaped grid walls are located away from the gap between two adjacent chips of the plurality of chips. 10. The detector of claim 9, wherein a thickness of a T-shaped grid wall of the plurality of T shaped grid walls is different from a thickness of a rectangular grid wall of the plurality of rectangular grid walls so that an interspace between each two adjacent grid walls of the plurality of grid walls is uniform. 11. The detector of claim 9, wherein a thickness of a T-shaped grid wall of the plurality of T shaped grid walls is different from a thickness of a rectangular grid wall of the plurality of rectangular grid walls so that a ratio of a width of an interspace between each two adjacent grid walls of the plurality of grid walls to a thickness of the each two adjacent grid walls of the plurality of grid walls is uniform. 12. The detector of claim 9, wherein a height of a T-shaped grid wall of the plurality of T shaped grid walls is different from a height of a rectangular grid wall of the plurality of rectangular grid walls so that a ratio of a width of an interspace between each two adjacent grid walls of the plurality of grid walls to a height of the each two adjacent grid walls of the plurality of grid walls is uniform. 13. The detector of claim 8, wherein the chip is covered by the photosensor, the photosensor is covered by the scintillator, and the scintillator is covered by the anti-scatter grid. 14. The detector of claim 8, wherein the plurality of photosensors have a same size and are arranged in a regular way. 15. The detector of claim 8, wherein the scintillator in the chip has a same size with its corresponding photosensor and aligns with its corresponding photosensor. 16. The detector of claim 8, wherein a centerline of a T-shaped grid wall of the plurality of T-shaped grid walls is offset from a centerline of the gap between two adjacent scintillators. 17. The detector of claim 8, wherein a thickness of a T-shaped grid wall of the plurality of T-shaped grid walls is no less than a width of a gap between two adjacent scintillators. 18. The detector of claim 8, wherein the plurality of scintillators include a first scintillator and a second scintillator,the first scintillator having a same size with its corresponding photosensor and aligning with its corresponding photosensor, andthe second scintillator having a different size than its corresponding photosensor and at least one edge being misaligned from its corresponding photosensor. 19. The detector of claim 18, wherein a size of the second scintillator is greater than a size of the first scintillator. 20. A radiation imaging system, comprising:a generator configured to generate a radiation;a detector configured to detect the radiation; anda processor configured to process a radiation image,wherein the detector is as claimed in claim 8.