JP2013064627A - Two-dimensional collimator module, radiation detector, x-ray ct apparatus, method of assembling two-dimensional collimator module, and method of manufacturing two-dimensional collimator device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-dimensional collimator module which can be assembled easily with high positional accuracy.SOLUTION: A two-dimensional collimator module comprises a plurality of first collimator plates 11 arranged in a CH (channel) direction, a plurality of second collimator plates 12 arranged in an SL (slice) direction, and first and second blocks 13, 14 sandwiching the first collimator plates 11 in the SL direction. The plurality of first collimator plates 11 include a plurality of slotted plates 11a, each having slots 111 extending in the direction of radiation formed in plurality along the SL direction, and a non-slotted plate 11b. Each of the slotted plates 11a is placed along a border, in the CH direction, of each radiation detection element of a radiation sensor module corresponding to the two-dimensional collimator module, and the non-slotted plate 11b is placed along an edge, in the CH direction, of the radiation sensor module. Each of the second collimator plates 12 is inserted through a row of slots 111 such that one end thereof touches the non-slotted plate 11b and one face thereof touches only one side wall of each slot.

Description

The present invention relates to a two-dimensional collimator module, a radiation detector, and an X-ray CT (Computed).
The present invention relates to a method for assembling a two-dimensional collimator module and a method for manufacturing a two-dimensional collimator device.

  In recent years, in X-ray CT apparatuses, the number of X-ray detectors has increased, and the influence of scattered radiation in the slice direction has become serious. Accordingly, as a collimator for removing scattered radiation arranged on the X-ray incident surface side of the X-ray detector, the collimator plate is not only in the channel direction, that is, in the X-ray fan angle direction, but also in the slice direction. That is, various two-dimensional collimators that are arranged in the cone angle direction of X-rays have been proposed.

  For example, a two-dimensional collimator has been proposed in which a collimator plate in the channel direction and a collimator plate in the slice direction are combined in a lattice pattern (see, for example, Patent Document 1 and FIGS. 1 to 7).

JP 2010-127630 A

  However, the two-dimensional collimators proposed so far are not easy to assemble. For example, in the example of Patent Document 1, since the rigidity is lowered due to the structure of the comb-shaped notch formed on the collimator plate, the collimator plate is not easily moved due to contact friction when the collimator plate is inserted into the notch. It is easy to distort and workability is not good.

  Under such circumstances, a two-dimensional collimator module that can remove scattered radiation in the channel direction and the slice direction and is easy to assemble is desired.

  The invention of the first aspect includes a plurality of first collimator plates arranged in the channel direction and a plurality of first collimator plates arranged in the slice direction so as to form a lattice in combination with the plurality of first collimator plates. A two-dimensional collimator module comprising a two-collimator plate, and a first block and a second block that sandwich and support the plurality of first collimator plates in the slice direction, wherein the plurality of first collimator plates are A plurality of slotted first collimator plates in which a plurality of slots along the radiation direction from the radiation focus are formed side by side in the slice direction, and one slotless first collimator plate in which no slots are formed The plurality of slotted first collimator plates includes a plurality of radiation detection element chips corresponding to the two-dimensional collimator module. The slotless first collimator plate is arranged corresponding to the edge position at one end along the channel direction of the plurality of radiation detection elements. The plurality of second collimator plates are inserted for each row of slots arranged in the channel direction in the plurality of first collimator plates with slots, and are in contact with the first collimator plates without slots, A plate surface on one side in the slicing direction of the two collimator plate provides a two-dimensional collimator module in contact with one of the two wall surfaces in the slicing direction of the slot.

  Here, the “slot” means an elongated opening (hole) and does not include a notch-shaped groove.

  According to a second aspect of the invention, the two-dimensional collimator module includes a fixing sheet (sheet) bonded to the plurality of first collimator plates on at least one of a radiation incident surface side and a radiation exit surface side of the two-dimensional collimator module. A two-dimensional collimator module according to a first aspect is provided.

  The invention of a third aspect provides the two-dimensional collimator module according to the first aspect or the second aspect, in which the plurality of first collimator plates are arranged in a fan shape along the channel direction.

  According to a fourth aspect of the present invention, the plurality of first collimator plates are third to third according to the first aspect, wherein each of the plurality of first collimator plates has a fan shape along a cone angle direction of a radiation beam from the radiation focus. A two-dimensional collimator module according to any one of the above aspects is provided.

  According to a fifth aspect of the invention, in any one of the first to fourth aspects, the plurality of second collimator plates are arranged in a fan shape along the cone angle direction of the radiation beam from the radiation focus. A two-dimensional collimator module according to one aspect is provided.

  The invention according to a sixth aspect provides the two-dimensional image according to any one of the first to fifth aspects, wherein each of the plurality of second collimator plates has a fan shape along the channel direction. A collimator module is provided.

  According to a seventh aspect of the invention, the second collimator plate has a thickness of 0.06 mm to 0.22 mm, and the slot has a width of 0.1 mm to 0.28 mm, which is wider than the plate thickness. A two-dimensional collimator module according to any one of the first to sixth aspects is provided.

  The invention of an eighth aspect provides the two-dimensional collimator module of the seventh aspect, wherein the slot has a width of 0.20 mm to 0.28 mm.

  A ninth aspect of the invention provides a radiation detector in which a plurality of two-dimensional collimator modules according to any one of the first to eighth aspects are arranged on the radiation incident surface side.

  An invention of a tenth aspect provides an X-ray CT apparatus provided with the radiation detector of the ninth aspect.

  An eleventh aspect of the invention is a method of assembling a two-dimensional collimator module according to any one of the first to eighth aspects, wherein the first block and the second block are between the first block and the second block. Arranging a plurality of first collimator plates including the plurality of slotted first collimator plates and the slotless first collimator plates at intervals in a channel direction; and Bringing the plurality of first collimator plates into contact with the wall surface of the first block by bringing the plurality of first collimator plates to the block side, and aligning the positions of the plurality of slots formed on the slotted first collimator plate; Inserting a plurality of second collimator plates for each row of the aligned slots and bringing the second collimator plates into contact with the slotless first collimator plates; The step of bringing the two collimator plates toward one side in the slicing direction and bringing them into contact with one wall surface in the slicing direction of the slot, and bonding the first and second blocks to the plurality of first collimator plates In addition, a method for assembling a two-dimensional collimator module including the step of bonding the plurality of first collimator plates and the plurality of second collimator plates is provided.

  A twelfth aspect of the invention is a two-dimensional collimator device comprising a step of assembling a plurality of two-dimensional collimator modules by the assembling method of the eleventh aspect and a step of arranging a plurality of the two-dimensional collimator modules in the channel direction. A manufacturing method is provided.

  According to the invention of the above aspect, the second collimator plate is inserted into the slot of the first collimator plate with the slot, contacts the first collimator plate without the slot, and also contacts the side wall of the slot. It is possible to provide a two-dimensional collimator module that is well aligned between the plate and the second collimator plate, can remove scattered radiation in the channel direction and the slice direction, is easy to assemble, and has high positional accuracy. .

It is an external view of an X-ray CT apparatus. It is a figure which shows an X-ray tube and an X-ray detection apparatus. It is a perspective view of a two-dimensional collimator module. It is a partially expanded sectional view when an X-ray detection apparatus is seen in a slice direction. It is a figure which shows a 1st collimator board and a 2nd collimator board. It is a flowchart which shows the assembly method of a two-dimensional collimator module. It is a figure for demonstrating the process of positioning a top end block and a bottom end block. It is a figure for demonstrating the process of inserting a some 1st collimator board between a top end block and a bottom end block. It is a figure for demonstrating the process of inserting a some 2nd collimator board in a slot. It is a figure for demonstrating the process of approaching and positioning a some 2nd collimator board to the top end block side. It is a figure for demonstrating the process of affixing a X-ray transmissive fixing sheet on the X-ray entrance plane side and / or the X-ray exit plane side. It is a figure for demonstrating the case which positions a 2nd collimator board using a backing plate. It is a figure which shows a mode that several 1st collimator board is positioned to a channel direction using a jig | tool.

  Embodiments of the invention will be described below.

  FIG. 1 is an external view of the X-ray CT apparatus 100. As shown in FIG. 1, the X-ray CT apparatus 100 is a scanning gantry 101 that scans a subject and collects projection data (data), and an imaging space on which the subject is placed. And a cradle 102 that enters and exits a bore of the scanning gantry 101. Furthermore, the X-ray CT apparatus 100 includes an operation console 103 that operates the X-ray CT apparatus 100 and reconstructs an image based on the collected projection data.

  The cradle 102 incorporates a motor therein and moves the cradle 102 up and down and horizontally linearly. Then, the cradle 102 places the subject and goes in and out of the bore of the scanning gantry 101.

  The operation console 103 includes an input device that receives input from an operator and a monitor that displays an image. In addition, the operation console 103 includes a central processing unit that performs control of each unit for collecting projection data of the subject, a three-dimensional image reconstruction process, and the like, and data collection for collecting data acquired by the scanning gantry 101 A buffer and a storage device for storing a program, data, and the like are provided.

  The scanning gantry 101 has an X-ray tube and an X-ray detection device for scanning a subject.

  FIG. 2 is a diagram showing an X-ray tube and an X-ray detection apparatus. Here, as shown in FIG. 2, the rotation axis direction of the scanning gantry 101 (the horizontal movement direction of the cradle 102 or the body axis direction of the subject) is the slice direction SL, and the fan angle direction of the X-ray beam 23 is the channel direction CH. To do. Further, a direction orthogonal to the channel direction CH and the slice direction SL and toward the rotation center of the scanning gantry 101 is defined as an isocenter direction I. Note that the channel direction CH, the slice direction SL, and the isocenter direction I each have an arrow direction as a + (plus) direction and an opposite direction as a − (minus) direction.

  The X-ray detection apparatus 40 includes a plurality of X-ray detector modules 50 that detect X-rays and a plurality of two-dimensional collimator modules 200 that collimate an X-ray beam (beam) 23 from the X-ray focal point 21 of the X-ray tube 20. And a base section 60 for fixing the plurality of X-ray detector modules 50 and the plurality of two-dimensional collimator modules 200 to a reference position.

  The plurality of two-dimensional collimator modules 200 are arranged along the channel direction CH to form a two-dimensional collimator device. The plurality of X-ray detector modules 50 are arranged along the channel direction CH with respect to the plurality of two-dimensional collimator modules 200. Here, one X-ray detector module 50 is attached to one two-dimensional collimator module 200. The X-ray detector module 50 is provided on the X-ray emission side of the two-dimensional collimator module 200. The X-ray detector module 50 detects an X-ray beam transmitted through the subject placed on the cradle 102 and transported to the bore. The two-dimensional collimator module 200 and the X-ray detector module 50 do not have to correspond one-to-one, and a plurality of X-ray detector modules 50 are attached to one two-dimensional collimator module 200. May be.

The X-ray detector module 50 includes a scintillator block (not shown) that receives X-rays and emits visible light, and a photodiode (photodiode that performs photoelectric conversion).
diode) has a photodiode chip (not shown) arranged two-dimensionally along the channel direction CH and the slice direction SL. In addition, the X-ray detector module 50 integrates a semiconductor chip (not shown) having a function of integrating the outputs from the photodiode chips provided on the substrate and performing output switching for changing the slice thickness. I have.

  The base portion 60 has a rectangular frame shape, and includes a pair of arc-shaped base members 61 and a pair of linear base members 62 that connect end portions of the base members 61. The base material 61 is provided with base-side positioning pins or positioning holes for positioning the plurality of two-dimensional collimator modules 200.

  In the base portion 60, the length in the slicing direction SL is, for example, 350 mm to 400 mm, the thickness is, for example, 35 mm to 40 mm, and the length of the internal space constituted by the base material 61 and the base material 62 is, for example, 300 mm. ~ 350mm. Further, the width of each two-dimensional collimator module 200 in the channel direction CH is, for example, 50 mm. Details of the two-dimensional collimator module 200 will be described later.

  As the material of the base portion 60, for example, aluminum alloy, carbon fiber reinforced plastic (CFRP), which is a composite material of carbon fiber and thermosetting resin, or the like is used. Since the aluminum alloy or CFRP is light, strong, and has high durability, when the base portion 60 rotates at high speed in the scanning gantry 101 of the X-ray CT apparatus 100, it rotates without generating extra eccentric force. be able to. Further, the base portion 60 is less likely to be distorted, and the two-dimensional collimator module 200 fixed thereto is also less likely to be distorted.

  In FIG. 2, the two-dimensional collimator module 200 is illustrated in a simplified manner, but actually, several tens of two-dimensional collimator modules 200 are fixed to one base portion 60.

  Now, the structure of the two-dimensional collimator module will be described in detail.

  FIG. 3 is a perspective view of the two-dimensional collimator module according to the present embodiment, and FIG. 4 is a partially enlarged view of the X-ray detection apparatus on which the two-dimensional collimator module according to the present embodiment is mounted in the slice direction SL. It is sectional drawing. FIG. 5 is a diagram showing a first collimator plate and a second collimator plate constituting the two-dimensional collimator module.

  As shown in FIG. 3, the two-dimensional collimator module 200 includes a plurality of first collimator plates 11, a plurality of second collimator plates 12, a top end block (first block) 13, and a bottom end block (second block). 14). The plurality of first collimator plates 11 includes a plurality of first collimator plates 11a with slots and a first collimator plate 11b without slots. In FIG. 3, the first collimator plate 11 and the second collimator plate 12 are drawn slightly in order to make the structure easy to understand, but actually, the first collimator plate 11 is about 32 to 64 pieces. The second collimator plate 12 is assumed to be about 129 to 257 sheets.

  As shown in FIG. 3, the plurality of first collimator plates 11 are arranged at intervals in the channel direction CH so that the plate surfaces are substantially parallel to each other. More specifically, as shown in FIGS. 3 and 4, the slotted first collimator plate 11a is located at the boundary in the channel direction CH of each detection element 51 of the corresponding X-ray detector module 50 when mounted. Are arranged as follows. Further, the first collimator plate 11b without a slot is disposed at a position corresponding to the outer side edge of the detection element positioned at one end in the channel direction CH of the X-ray detector module 50 corresponding to the slotless first collimator plate 11b. Has been. In this example, it is disposed at a position corresponding to the outer side edge of the detection element 51b located at the end in the + CH direction. It should be noted that the detection element located at the end opposite to the predetermined one in the channel direction CH of the X-ray detector module 50, in this example, corresponds to the outer edge of the detection element 51a located at the end in the + CH direction. The first collimator plate 11 is not disposed at the position.

  The top end block 13 and the bottom end block 14 are arranged so as to sandwich the plurality of first collimator plates 11 in the slice direction SL.

  The plurality of second collimator plates 12 are combined so as to be substantially orthogonal to the plurality of first collimator plates 11. That is, the plurality of first collimator plates 11 and the plurality of second collimator plates 12 are combined to form a lattice-like two-dimensional collimator portion.

  When the two-dimensional collimator modules 200 are arranged side by side in the channel direction CH, the first non-slot collimator plate 11b is arranged at a position corresponding to the boundary between the detector modules 50 adjacent to each other.

  The top end block 13, the bottom end block 14, the plurality of first collimator plates 11, and the plurality of second collimator plates 12 are each positioned by a predetermined method and bonded to each other with an adhesive or the like.

  Now, the components of the two-dimensional collimator module will be described in more detail.

  As shown in FIG. 5, the first collimator plate 11 has a rectangular shape or a fan shape that is gently bent. The first collimator plate 11 is made of a heavy metal that easily absorbs X-rays, such as molybdenum (molybdenum), tungsten (tungsten), lead, or the like. When the two-dimensional collimator module 200 is attached to the base portion 60, the plate surface of the first collimator plate 11 is parallel to the radiation direction of the X-ray beam 23 from the X-ray focal point 21, and the long side direction is This coincides with the slice direction SL or the cone angle direction of the X-ray beam. Here, the thickness of the first collimator plate 11 is about 0.2 mm.

  A plurality of elongate openings (holes) for inserting the second collimator plate 12, so-called slots 111, are formed on the plate surface of the slotted first collimator plate 11 a. The plurality of slots 111 are formed along the radiation direction of the X-ray beam 23 from the X-ray focal point 21 when the two-dimensional collimator module 200 is attached to the base portion 60.

  The first collimator plate 11b without a slot has the same external shape as the first collimator plate 11a with a slot, but no slot is formed on the plate surface.

  By the way, the width of the slot 111 formed in the slotted first collimator plate 11a in the slice direction SL is sufficient for the thickness of the second collimator plate 12 to facilitate the insertion of the second collimator plate 12. It is better to have a margin. On the other hand, if the width of the slot 111 is too wide, the rigidity of the first collimator plate 11 becomes low, and distortion is likely to occur during assembly or scanning. Considering these, the thickness of the second collimator plate 12 is 0.06 mm to 0.22 mm, the width of the slot 111 in the slice direction SL is 0.1 mm to 0.28 mm, and the second collimator plate 12 It is preferably wider than 12 plate thicknesses.

  In addition, when machining the slot 111 with wire discharge, there are options such as 0.1 mm diameter, 0.2 mm diameter, 0.3 mm diameter as the wire to be used, but the balance between cost and machining precision is A diameter of 0.2 mm is preferable. Considering this, the width of the slot 111 in the slice direction SL is more preferably about 0.2 mm to 0.28 mm.

  Here, the width of the slot 111 in the slice direction SL is about 0.24 mm, and the length of the slot 111 in the isocenter direction I is about 15.4 mm.

  As shown in FIG. 4, the second collimator plate 12 has a fan shape close to a rectangle. Similar to the first collimator plate 11, the second collimator plate 12 is made of a heavy metal that easily absorbs X-rays. When the two-dimensional collimator module 200 is attached to the base part 60, the plate surface of the second collimator plate 12 is parallel to the radiation direction of the X-ray beam 23 from the X-ray focal point 21 and forms its fan shape. The direction of the curved long side that coincides with the channel direction CH.

  As shown in FIG. 3, the second collimator plate 12 is inserted so as to penetrate through the slots 111 for each row of the slots 111 arranged in the channel direction CH in the plurality of first collimator plates 11a with slots. When a plurality of two-dimensional collimator modules 200 are attached to the base portion 60, as shown in FIG. 4, the first collimator plate with slots closest to the -CH direction in one of the two-dimensional collimator modules 200 adjacent to each other. The wall plate formed by 11a and the second collimator plate 12 and the wall plate of the first collimator plate 11b without a slot in the other of the two-dimensional collimator modules 200 adjacent to each other are joined together in the channel direction CH to form a lattice-like 2 Part of a dimensional collimator is formed.

  By the way, the second collimator plate 12 is displaced due to thermal deformation or the like. When such misalignment occurs, the X-ray shielding state changes, crosstalk occurs between detection cells, and the detection characteristics of the X-ray detection apparatus 20 vary. In order to suppress this, it is effective to reduce the thickness of the second collimator plate 12. On the other hand, if the plate thickness is made too thin, the rigidity becomes low, and distortion tends to occur during assembly and scanning. Considering these, the thickness of the second collimator plate 12 is preferably about 0.06 mm to 0.14 mm, and more preferably about 0.08 mm to 0.12 mm. Here, the thickness of the second collimator plate 12 is about 0.1 mm. The width of the second collimator plate 12 in the short side direction is about 15 mm.

  The top end block 13 and the bottom end block 14 are made of a lightweight metal such as aluminum or plastic.

  As shown in FIG. 3, the top end block 13 includes a column portion 13T extending in a direction orthogonal to the channel direction CH and the slice direction SL, that is, the isocenter direction I, and a flange portion 13F protruding in the −SL direction. And these are integrally formed. Accordingly, the top end block 13 has a generally inverted “L” shape when viewed in the −CH direction.

  Similarly, the bottom end block 14 has a column portion 14T extending in the isocenter direction I and a flange portion 14F protruding in the + SL direction, which are integrally formed. Therefore, the bottom end block 14 has a generally “L” shape when viewed in the −CH direction.

  Further, as shown in FIG. 3, a positioning hole is formed at the center of the flange portions 13F and 14F of the top end block 13 and the bottom end block 14, and positioning pins 135 and 145 are inserted into the holes. Have been placed. When the positioning pins 135 and 145 are fixed at the desired positions, the two-dimensional collimator module 200 is positioned at the reference position of the base portion 60.

  Four positioning holes 136 (146) are formed around the positioning pins 135 (145). These four positioning holes 136 (146) are formed so that the X-ray detection module 50 shown in FIG. 2 can be accurately attached.

  As shown in FIG. 3, the surfaces 13 a and 14 a of the top end block 13 and the bottom end block 14 facing each other are separated from the X-ray focal point 21 when the two-dimensional collimator module 200 is attached to the base portion 60. The X-ray beam 23 is formed along the radiation direction.

  The side wall 111K on the −SL direction side of the slot 111 formed in the slotted first collimator plate 11a is a reference plane, and has a predetermined accurate positional relationship with respect to the edge of the first collimator plate 11 in the slice direction SL. It is formed to have.

  An end of the first collimator plate 11 on the −SL direction side is in contact with the wall surface 13 a of the top end block 13. Further, the end on the + SL direction side of the first collimator plate 11 is substantially in contact with the wall surface 14a of the bottom end block 14, but there are some which are close to each other with a slight space due to variation in shape.

  The plate surface on the −SL direction side of the second collimator plate 12 is the above-described positioned wall surface, that is, the side wall on the −SL direction side of both wall surfaces in the slice direction SL of the slot 111 in the slotted first collimator plate 11a. It is in contact with 111K.

  Then, the + CH direction end sides of the second collimator plate 12 are in contact with the plate surface of the first collimator plate 11b without a slot.

  In such a state, the plurality of first collimator plates 11, the plurality of second collimator plates 12, the top end block 13, and the bottom end block 14 are bonded and fixed to each other with an adhesive.

  From this, the assembly method of the two-dimensional collimator module which concerns on this embodiment is demonstrated. FIG. 6 is a flowchart showing a method for assembling the two-dimensional collimator module according to the present embodiment.

  In step S111, as shown in FIG. 7, the top end block 13 and the bottom end block 14 are positioned at predetermined positions using a jig or the like.

  In step S112, as shown in FIG. 8, between the top end block 13 and the bottom end block 14, a plurality of first collimator plates 11 are arranged at intervals in the channel direction CH. At this time, the first collimator plate 11a with a slot is disposed at a position corresponding to the boundary in the channel direction CH of the plurality of X-ray detection elements corresponding to the two-dimensional collimator module. Further, only one of the plurality of X-ray detection elements arranged at the position corresponding to the end side of the X-ray detection element in the + CH direction is defined as a first collimator plate 11b without a slot.

  In step S113, the plurality of first collimator plates 11 are roughly positioned using a jig or the like. For example, as shown in FIG. 13, the upper and lower ends of the first collimator plate 11 are lightly sandwiched in the channel direction CH by comb-like members 301 and 302 having a plurality of notches. At this time, the first collimator plate 11 is movable in the slice direction SL.

  In step S114, the plurality of first collimator plates 11 are pressed toward the top end block 13 side (-SL direction). Then, the end on the −SL direction side of the first collimator plate 11 comes into contact with the wall surface 13 a of the top end block 13. As a result, each slot 111 of the slotted first collimator plate 11a substantially overlaps the channel direction CH. As a result, the second collimator plate 12 can be easily inserted into the slot 111.

  In step S115, as shown in FIG. 9, the plurality of second collimator plates 12 are inserted into the slots 111 and pushed in until they abut against the slotless first collimator plates 11b.

  In step S116, the second collimator plate 12 is pressed in the -SL direction. As a result, as shown in FIG. 10, the second collimator plate 12 abuts on the wall surface 111 </ b> K on the −SL direction side of the slot 111 and is positioned.

  In step S117, in this state, the plurality of first collimator plates 11, the plurality of second collimator plates 12, the top end block 13, and the bottom end block 14 are fixed and bonded to each other with an adhesive or the like. Thus, the two-dimensional collimator module 200 is completed.

  In order to further increase the rigidity of the two-dimensional collimator module 200, as shown in FIG. 11, the plurality of first collimator plates 11 are bonded to at least one of the X-ray incident surface side and the X-ray emission surface side. A line-permeable fixing sheet 15 may be attached. The fixing sheet 15 is made of, for example, carbon fiber reinforced plastic (CFRP) having high rigidity, light weight, and high X-ray permeability. In addition, the fixing sheet 15 has a groove formed on the long side of the first collimator plate 11, for example, and the long side of the first collimator plate 11 is inserted into the groove to be bonded. It may be.

  As described above, according to the method of assembling the two-dimensional collimator module, the first collimator plate 11 can be easily inserted into the slot 111 by aligning the position of the slot 111 by moving the first collimator plate 11 in the slice direction SL. Since the positioning can be performed by pressing the first collimator plate 11 and the second collimator plate 12 against the reference surface, the assembly is easy and the positioning accuracy is high.

  By the way, in order to facilitate the insertion of the second collimator plate 12 into the slot 111, the width of the slot 111 needs to be sufficiently larger than the thickness of the second collimator plate 12. In this case, so-called play increases, and if it is normal, the positioning accuracy of the second collimator plate 12 is deteriorated. On the contrary, if the width of the slot 111 is made as small as possible with respect to the thickness of the second collimator plate 12, the positioning accuracy of the second collimator plate 12 is improved, but the insertion of the second collimator plate 12 into the slot 111 becomes difficult. As a result, the productivity of assembly deteriorates.

  On the other hand, in the case of this example, when the second collimator plate 12 is inserted into the slot 111, the plurality of first collimator plates 11 are moved toward the top end block 13 and the position of the first collimator plate 11 in the slice direction SL is set. Since the slots 111 corresponding to each other in the channel direction CH are overlapped with each other, the insertion of the second collimator plate 12 can be facilitated as the width of the slot 111 is increased. Then, after the second collimator plate 12 is inserted, the second collimator plate 12 is brought into contact with the side wall 111K of the slot 111, which is a reference surface, so that it can be positioned with good accuracy. That is, in the two-dimensional collimator module of this example, even if the width of the slot 111 is relatively large with respect to the thickness of the second collimator plate 12, the ease of insertion of the second collimator plate 12 and the good positioning accuracy are achieved. It has an excellent feature that both can be achieved. Therefore, the degree of freedom of the width of the slot 111 and the thickness of the second collimator plate 12 is increased, and each can be set to a suitable size.

  Since the first collimator plate 11b without a slot is disposed at the end in the + CH direction, the second collimator plate can be obtained simply by bringing the second collimator plate 12 into contact with the plate surface of the first collimator plate 11b. Positioning in 12 CH directions can be performed.

  Consider a case where the first collimator plate 11a with a slot is also arranged at the end in the + CH direction. This configuration does not require the preparation of the first slotless collimator plate 11b, and can be said to be a standard configuration that will normally be considered first from the viewpoint of reducing the types of parts as much as possible.

  However, in this case, as shown in FIG. 12, the slotted first collimator plate 12 can be positioned without penetrating the slot 111 of the slotted first collimator plate 11a. The contact plate 19 must be placed on the outer surface of the 1 collimator plate 11a. If it does in this way, first, the effort which arrange | positions the contact plate 19 will increase.

  In addition, the first collimator plate 11a with a slot is thin and has a large number of slots 111. Therefore, the first collimator plate 11a has a low rigidity and is easily distorted. Therefore, a gap is generated between the contact plate 19 and the first collimator plate 1a with the slot in the + CH direction, and the tip of the second collimator plate 12 penetrates the slot 111 and slightly protrudes to the outside. is there. If they are bonded in this state, it is necessary to scrape off the projecting portion, which increases troublesome work.

  In addition, when the first collimator plate 11a with slot and the second collimator plate 12 are bonded with an adhesive, the adhesive may leak from the slot 111, and the contact plate 19 may also be bonded together. In this case, it is necessary to remove the contact plate 19 from the slot first collimator plate 11a or to scrape off the hardened adhesive.

  Thus, it can be seen that the merit of disposing the first non-slotted collimator plate 11b only at the end in the + CH direction is very large.

  According to this embodiment, a two-dimensional collimator module with a simple structure and high positional accuracy and angular accuracy can be realized. It is also very easy to assemble a two-dimensional collimator module.

  As mentioned above, although embodiment of invention was described, embodiment of invention is not limited to said embodiment, A various addition and change are possible in the range which does not deviate from the meaning of invention.

  Examples of embodiments of the invention include not only a collimator module and an assembling method thereof, but also an X-ray detector in which a plurality of such collimator modules are arranged, and an X-ray CT provided with such an X-ray detector. An apparatus is also an example of an embodiment of the invention.

  The embodiments of the invention are not limited to X-rays but can be applied to other radiation, for example, γ (gamma) rays as handled by a SPECT apparatus.

11 First collimator plate 11a First collimator plate 11b with slot First collimator plate 12 without slot Second collimator plate 13 Top end block (first block)
14 Bottom end block (second block)
13T, 14T Column portion 13F, 14F Flange portion 15 Fixed sheet 19 Baffle plate 20 X-ray tube 21 X-ray focal point 23 X-ray beam 40 X-ray detector 50 X-ray detector module 60 Base portion 61 Base material 62 Base material 100 X Line CT apparatus 101 Scanning gantry 102 Cradle 103 Operation console 111 Slot 111K Wall surface (reference surface)
135,145 Positioning pins 136,146 Positioning hole 200 Two-dimensional collimator module

Claims (12)

A plurality of first collimator plates arranged in a channel direction; a plurality of second collimator plates arranged in a slice direction so as to form a lattice in combination with the plurality of first collimator plates; A two-dimensional collimator module comprising a first block and a second block for supporting the first collimator plate in the slicing direction,
The plurality of first collimator plates includes a plurality of slotted first collimator plates in which a plurality of slots along the radiation direction from the radiation focal point are arranged in the slice direction, and one slot in which no slots are formed. Including a first collimator plate,
The plurality of slotted first collimator plates are arranged corresponding to the respective boundary positions in the channel direction of the plurality of radiation detection elements corresponding to the two-dimensional collimator module,
The slotless first collimator plate is disposed corresponding to an end position at one end along the channel direction of the plurality of radiation detection elements,
The plurality of second collimator plates are inserted for each row of slots arranged in the channel direction in the plurality of first collimator plates with slots, and are in contact with the first collimator plates without slots,
A two-dimensional collimator module in which a plate surface on one side in the slice direction of the second collimator plate is in contact with one of two wall surfaces in the slice direction of the slot.   2. The two-dimensional collimator module according to claim 1, further comprising a fixing sheet bonded to the plurality of first collimator plates on at least one of a radiation incident surface side and a radiation emission surface side of the two-dimensional collimator module.   The two-dimensional collimator module according to claim 1 or 2, wherein the plurality of first collimator plates are arranged in a fan shape along a channel direction.   The two-dimensional collimator module according to any one of claims 1 to 3, wherein each of the plurality of first collimator plates has a fan shape along a cone angle direction of a radiation beam from a radiation focus. .   The two-dimensional collimator module according to any one of claims 1 to 4, wherein the plurality of second collimator plates are arranged in a fan shape along a cone angle direction of a radiation beam from a radiation focus.   The two-dimensional collimator module according to any one of claims 1 to 5, wherein each of the plurality of second collimator plates has a fan shape along a channel direction. The thickness of the second collimator plate is 0.06 mm to 0.22 mm,
The two-dimensional collimator module according to any one of claims 1 to 6, wherein a width of the slot is 0.1 mm to 0.28 mm and is wider than the plate thickness.   The two-dimensional collimator module according to claim 7, wherein the slot has a width of 0.20 mm to 0.28 mm.   A radiation detector in which a plurality of the two-dimensional collimator modules according to any one of claims 1 to 8 are arranged on a radiation incident surface side.   An X-ray CT apparatus comprising the radiation detector according to claim 9. A method for assembling the two-dimensional collimator module according to any one of claims 1 to 8,
A plurality of first collimator plates including the plurality of first collimator plates with slots and the first collimator plates without slots are arranged at intervals in the channel direction between the first block and the second block. And a process of
By bringing the plurality of first collimator plates toward the first block, the plurality of first collimator plates are brought into contact with the wall surface of the first block, and are formed on the slotted first collimator plate. Aligning the slot positions of
Inserting each of the plurality of second collimator plates for each row of the aligned slots and contacting the slotless first collimator plate;
Bringing the plurality of second collimator plates toward one direction side in the slicing direction and bringing them into contact with one wall surface in the slicing direction of the slot;
Assembling a two-dimensional collimator module comprising bonding the first and second blocks and the plurality of first collimator plates and bonding the plurality of first collimator plates and the plurality of second collimator plates. Method.   A method for manufacturing a two-dimensional collimator device, comprising: assembling a plurality of two-dimensional collimator modules by the assembling method according to claim 11; and disposing a plurality of the two-dimensional collimator modules in a channel direction.

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