Scintillation crystal array, detector, medical imaging device, and manufacturing method
A scintillation crystal array, a detector, and a manufacturing method solve the image distortion problem in PET caused by ESR layers. The scintillation crystal array includes a plurality of scintillation crystal units, a gap is provided between each two adjacent scintillation crystal units, first reflecting layers are arranged in a part of the gaps of the scintillation crystal array, and second reflecting layers are arranged in a part of the gaps. The first reflecting layers are made of a thin film-like material, and the second reflecting layers are made of an amorphous material. By filling the gaps between the scintillation crystal units with the two types of reflecting layers, it becomes possible to leverage the high reflectivity of the thin film-like material while preventing issues in the scintillation crystal array.
1 . A scintillation crystal array, comprising: a plurality of scintillation crystal units, and a gap provided between each two adjacent scintillation crystal units, wherein
first reflecting layers are arranged in a part of the gaps of the scintillation crystal array, second reflecting layers are arranged in a part of the gaps, the first reflecting layers are made of a thin film-like material, and the second reflecting layers are made of an amorphous material;
wherein the gaps comprise first gaps arranged in a first direction and second gaps arranged in a second direction; and
a part of intersecting first gaps and second gaps in the scintillation crystal array are respectively provided with the first reflecting layers and the second reflecting layers; or
all intersecting first gaps and second gaps in the scintillation crystal array are respectively provided with the first reflecting layers and the second reflecting layers.
2 . The scintillation crystal array according to claim 1 , wherein in a case where a part of intersecting first gaps and second gaps in the scintillation crystal array are respectively provided with the first reflecting layers and the second reflecting layers, the second reflecting layers are arranged in gaps in the scintillation crystal array except the said part of intersecting first gaps and second gaps.
3 . The scintillation crystal array according to claim 1 , wherein in the first gaps and the second gaps respectively provided with the first reflecting layers and the second reflecting layers, all the first gaps are provided with the first reflecting layers and all the second gaps are provided with the second reflecting layers, or all the first gaps are provided with the second reflecting layers and all the second gaps are provided with the first reflecting layers.
4 . The scintillation crystal array according to claim 1 , wherein the first reflecting layers comprise one or more of: ESR reflecting layers, polyethylene terephthalate reflecting layers, polytetrafluoroethylene film reflecting layers, aluminum foil reflecting layers and aluminum-plated plastic reflecting layers.
5 . The scintillation crystal array according to claim 1 , wherein the second reflecting layers comprise one or more of: reflecting layers made of powder materials, reflecting layers made of liquid materials, reflecting layers made of a mixture of powder materials and liquid materials, and reflecting layers made of paste materials.
6 . The scintillation crystal array according to claim 5 , wherein the second reflecting layers comprise one or more of: barium sulfate reflecting layers, titanium dioxide reflecting layers, magnesium oxide reflecting layers and polytetrafluoroethylene powder reflecting layers.
7 . The scintillation crystal array according to claim 1 , wherein a thickness of the gap is greater than or equal to 0.01 mm and less than or equal to 0.5 mm.
8 . The scintillation crystal array according to claim 1 , wherein the first reflecting layers and the second reflecting layers are distributed in a regular or irregular manner.
9 . A detector, comprising the scintillation crystal array according to claim 1 .
10 . A method for manufacturing the scintillation crystal array according to claim 1 , comprising:
arranging the first reflecting layers in a part of the gaps of the scintillation crystal array, and arranging the second reflecting layers in a part of the gaps, wherein the first reflecting layer is made of a thin film-like material, and the second reflecting layer is made of an amorphous material.
11 . The method according to claim 10 , wherein the step of arranging the first reflecting layers in a part of the gaps of the scintillation crystal array, and arranging the second reflecting layers in a part of the gaps comprises:
splitting the scintillation crystal array into one or more array units while maintaining two or more adjacent first reflecting layers in a same row or column uninterrupted, each array unit comprising one or more rows of scintillation crystal units;
arranging each row of scintillation crystal units of each array unit in a column in a second direction, top surfaces of the scintillation crystal units facing a same side and bottom surfaces facing a same side, and adjacent scintillation crystal units being spaced apart according to a predetermined gap size, so as to obtain a plurality of first single-row crystals;
taking a plurality of first reflecting layers with a thickness equal to the predetermined gap size, a length equal to a size of the first single-row crystal in the second direction, and a width equal to a size of the first single-row crystal in a third direction, and bonding each first reflecting layer to a side surface of one first single-row crystal, an edge of the first reflecting layer being flush with an edge of the first single-row crystal, so as to obtain a plurality of second single-row crystals;
bonding the plurality of second single-row crystals, a side opposite to the side where the first reflecting layer is located in each second single-row crystal being bonded to the side where the first reflecting layer is located in another second single-row crystal, edges of two adjacent second single-row crystals being flush with each other, and each adjacent scintillation crystal units between two adjacent second single-row crystals share a same axis in the first direction, so as to obtain the array units;
after a plurality of array units being manufactured, arranging the plurality of array units into an array, adjacent array units being separated by the predetermined gap size, so as to obtain a first crystal array;
filling gaps without the first reflecting layers with the second reflecting layers in the first crystal array in a manner that the second reflecting layers slightly flow over an array surface, flattening the second reflecting layers, and scraping off redundant second reflecting layer materials on the array surface, so as to obtain a second crystal array; and
bonding the first reflecting layers to an outer side surface and an incident surface of the second crystal array, an edge of the first reflecting layer being flush with an edge of each surface, so as to obtain the scintillation crystal array after the second reflecting layers are solidified.
12 . The method according to claim 10 , wherein the step of arranging the first reflecting layers in a part of the gaps of the scintillation crystal array, and arranging the second reflecting layers in a part of the gaps comprises:
manufacturing a plurality of single-row crystals;
bonding two sides of each of a plurality of first reflecting layers with a thickness equal to a predetermined gap size, a length equal to a size of the single-row crystals in a second direction, and a width equal to a size of the single-row crystals in a third direction to side surfaces of two adjacent single-row crystals, an edge of the first reflecting layer being flush with an edge of the single-row crystal, so as to obtain a first crystal array;
cutting the first crystal array into a plurality of single-row crystals in a first direction, so that each single-row crystal comprises a plurality of scintillation crystal units and a plurality of first reflecting layers sandwiched therebetween;
setting the gap between each two adjacent single-row crystals to be the same as the predetermined gap size;
filling the gaps between each two adjacent single-row crystals with the second reflecting layers in a manner that the second reflecting layers slightly flow over an array surface, flattening the second reflecting layers, and scraping off redundant second reflecting layer materials on the array surface, so as to obtain a second crystal array; and
bonding the first reflecting layers to an outer side surface and an incident surface of the second crystal array, an edge of the first reflecting layer being flush with an edge of each surface, so as to obtain the scintillation crystal array after the second reflecting layers are solidified.
13 . The method according to claim 10 , wherein the first reflecting layers and the second reflecting layers are distributed in a regular or irregular manner.