Radiation detector module, radiation detector, and x-ray ct apparatus

Abstract

A radiation detector module of an embodiment has a radiation detecting element, a first electrode, a second electrode, and a mark. The radiation detecting element detects radiation that is incident from an incident surface. The first electrode is provided on the incident surface side of the radiation detecting element. The second electrode is provided so as to face the first electrode with the radiation detecting element interposed therebetween. The mark is provided in at least either one of the incident surface of the radiation detecting element or the first electrode.

Description

TECHNICAL FIELD

[0001] The embodiments disclosed in the present specification and drawings relate to a radiation detector module, a radiation detector, and an X-ray CT apparatus. BACKGROUND

[0002] A plurality of radiation detector modules are arranged side by side in a radiation detector. In a case where radiation is detected by the plurality of radiation detector modules arranged side by side, the positioning accuracy of the radiation detector modules greatly affects the detection accuracy of the radiation detector. Conventionally, when the radiation detector modules are positioned, for example, a pin provided at a mounting portion of the radiation detector module is used as a reference.

[0003] However, in the positioning using the pin as a reference, it is difficult to improve the accuracy. In particular, the detection accuracy of the radiation detector is greatly affected by the relative positional relationship between the plurality of radiation detector modules arranged side by side. However, the positioning using the pin as a reference does not directly adjust the positional relationship between the plurality of radiation detector modules, and thus it is difficult to improve the accuracy of the positioning of the radiation detector modules.

[0004] [Patent Literature]

[0005] [Patent Literature]

[0006] [Patent Literature 1] Japanese Patent Application Laid-Open No. 2009-18154

[0007] [Patent Literature 2] Japanese Patent Application Laid-Open No. 2011-85479

[0008] [Patent Literature 3] Japanese Patent Application Laid-Open No. 2009-76690 SUMMARY

[0009] The technical problem to be solved by the embodiments disclosed in the present specification and drawings is to improve the positioning accuracy of the radiation detector modules. However, the technical problem to be solved by the embodiments disclosed in the present specification and drawings is not limited to the above-described technical problem. The technical problem corresponding to each effect of each structure shown in the embodiments described later can be positioned as another technical problem.

[0010] The radiation detector module of the embodiments has a radiation detecting element, a first electrode, a second electrode, and a mark. The radiation detecting element detects radiation incident from an incident surface. The first electrode is provided on the incident surface side of the radiation detecting element. The second electrode is provided to face the first electrode with the radiation detecting element interposed therebetween. The mark is provided on at least either one of the incident surface of the radiation detecting element or the first electrode. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1is a configuration diagram of the X-ray CT apparatus 1 of the first embodiment.

[0012] Figure 2 is a diagram that enlarges and represents a portion of the X-ray detector unit 15A of the first embodiment.

[0013] Figure 3 is a diagram that represents a surface of the detection element 62 when the through-hole 61A of the first embodiment is observed from the upper side.

[0014] Figure 4 is a diagram that represents a state in which the detector module 100 of the first embodiment is observed from the upper side.

[0015] Figure 5 is a diagram that observes the X-ray detector unit 15A of the first embodiment from the upper side.

[0016] Figure 6 is a flowchart that represents a procedure of manufacturing the X-ray detector unit 15A of the first embodiment.

[0017] Figure 7 is a diagram that observes the detector module 100 of the second embodiment from the upper side.

[0018] Figure 8 is a diagram that observes the X-ray detector unit 15A of the second embodiment from the upper side.

[0019] Figure 9A is a diagram that represents other examples of the marker.

[0020] Figure 9B is a diagram that represents other examples of the marker.

[0021] Figure 9C is a diagram that represents other examples of the marker.

[0022] Figure 10 is a diagram that enlarges and represents a portion of the X-ray detector unit 15B of the third embodiment.

[0023] Figure 11 is a diagram that observes the X-ray detector unit 15B of the third embodiment from the upper side.

[0024] Figure 12 is a diagram that represents a case in which the estimation processing of the position of each pixel is performed using the pencil beam PB of the fourth embodiment. DETAILED DESCRIPTION

[0025] Hereinafter, a radiation detector module, a radiation detector, and an X-ray CT apparatus according to an embodiment will be described with reference to the drawings.

[0026] (First Embodiment)

[0027] Figure 1 1 is a block diagram of an X-ray CT apparatus 1 according to an embodiment. The X-ray CT apparatus 1 includes, for example, a gantry device 10, a bed device 30, and a console device 40. Figure 1 For ease of explanation, the gantry apparatus 10 is shown in both the Z-axis direction and the X-axis direction. However, in reality, the gantry apparatus 10 is a single entity. In the embodiment, the rotation axis of the rotating frame 17 in the non-tilted state or the longitudinal direction of the top plate 33 of the bed apparatus 30 is defined as the Z-axis direction, the axis perpendicular to the Z-axis direction and horizontal to the ground is defined as the X-axis direction, and the direction perpendicular to the Z-axis direction and vertical to the ground is defined as the Y-axis direction. The X-ray CT apparatus 1 captures contrast CT images for diagnostic imaging.

[0028] The gantry device 10 includes, for example, an X-ray tube 11 , a wedge 12 , a collimator 13 , an X-ray high voltage device 14 , an X-ray detector 15 , a data acquisition system (DAS) 16 , a rotating frame 17 , and a control device 18 .

[0029] The X-ray tube 11 generates X-rays by irradiating thermal electrons from the cathode (filament) toward the anode (target) using a high voltage supplied by an X-ray high-voltage device 14. The X-ray tube 11 comprises a vacuum tube. For example, the X-ray tube 11 is a rotating anode X-ray tube that generates X-rays by irradiating a rotating anode with thermal electrons.

[0030] The wedge 12 is a filter used to adjust the X-ray dose emitted from the X-ray tube 11 to the subject P, the target of diagnostic imaging. The wedge 12 attenuates the X-rays that pass through it, ensuring that the X-ray dose distribution emitted from the X-ray tube 11 to the subject P is a predetermined distribution. The wedge 12 is also called a wedge filter or a bow-tie filter. For example, the wedge 12 is made of aluminum machined to a predetermined target angle or thickness.

[0031] The collimator 13 is a mechanism for narrowing the range of X-rays transmitted through the wedge 12. For example, the collimator 13 forms a slit by combining multiple lead plates, thereby narrowing the range of X-rays. The collimator 13 is sometimes also called an X-ray aperture. The narrowing of the range by the collimator 13 can also be mechanically driven.

[0032] The X-ray high voltage device 14 has, for example, a high voltage generating device and an X-ray control device. The high voltage generating device has a circuit including a transformer and a rectifier, and generates a high voltage applied to the X-ray tube 11. The X-ray control device controls the output voltage of the high voltage generating device according to the amount of X-rays that should be generated in the X-ray tube 11. The high voltage generating device can be boosted by the above-described transformer or by an inverter. The X-ray high voltage device 14 can be provided on the rotating frame 17 or on a fixed frame (not shown) of the stand device 10.

[0033] The X-ray detector 15 detects the intensity of the X-rays generated by the X-ray tube 11 and incident after passing through the subject P. The X-ray detector 15 outputs an electric signal (or an optical signal, etc.) corresponding to the detected intensity of the X-rays to the DAS 16. The X-ray detector 15 is, for example, a so-called photon counting detector that counts photons to measure X-rays. The X-ray detector 15 can also be a scintillator. The X-ray detector 15 is an example of a radiation detector. The detailed structure of the X-ray detector 15 is described later.

[0034] The DAS 16 has, for example, an amplifier, an integrator, and an A / D converter. The amplifier performs amplification processing on the electric signal output from each X-ray detecting element of the X-ray detector 15. The integrator integrates the electric signal that has been subjected to the amplification processing during the entire observation period. The A / D converter converts the electric signal representing the integration result into a digital signal. The DAS 16 outputs detection data based on the digital signal to the console device 40.

[0035] The rotating frame 17 is a circular ring-shaped rotating member that rotates the X-ray tube 11, the wedge 12, and the collimator 13 in a state of being held opposite to the X-ray detector 15. The rotating frame 17 is supported by a fixed frame so as to be rotatable about the subject P introduced into the inside. The rotating frame 17 also supports the DAS 16. The detection data output from the DAS 16 is transmitted from a transmitter provided to the rotating frame 17 and having a light emitting diode (LED) to a receiver provided to a non-rotating portion (for example, a fixed frame) of the stand device 10 and having a photodiode by optical communication, and is transmitted to the console device 40 through the receiver. In addition, as a transmission method of the detection data from the rotating frame 17 to the non-rotating portion, the above-described method using optical communication is not limiting, and any non-contact type transmission method can be adopted. The rotating frame 17 is not limited to a circular ring-shaped member as long as it can support and rotate the X-ray tube 11 and the like, and can be an arm-like member.

[0036] The X-ray CT apparatus 1 is, for example, a Rotate / Rotate-type X-ray CT apparatus (third generation CT) in which both the X-ray tube 11 and the X-ray detector 15 are supported by the rotating frame 17 and rotated around the subject P, but is not limited thereto, and can be a Stationary / Rotate-type X-ray CT apparatus (fourth generation CT) in which a plurality of X-ray detecting elements arranged in a circular ring are fixed to a stationary frame and the X-ray tube 11 is rotated around the subject P.

[0037] The control device 18 has, for example, a processing circuit having a processor such as a CPU (Central Processing Unit), and a drive mechanism including a motor, an actuator, and the like. The processing circuit realizes these functions, for example, by executing a program stored in a storage device (storage circuit) by a hardware processor.

[0038] The hardware processor is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an Application Specific Integrated Circuit (ASIC), a programmable logic device (for example, a Simple Programmable Logic Device (SPLD), or a Complex Programmable Logic Device (CPLD), a Field Programmable Gate Array (FPGA)), or the like. Instead of storing a program in the storage device, the hardware processor can be configured to directly load the program into the circuit of the hardware processor. In this case, the hardware processor realizes the functions by reading out and executing the program loaded into the circuit. The hardware processor is not limited to being configured as a single circuit, and a plurality of independent circuits can be combined to configure one hardware processor, which realizes each function. The storage device can be a non-temporary (hardware) storage medium. In addition, a plurality of components can be integrated into one hardware processor to realize each function.

[0039] The control device 18, for example, rotates the rotating frame 17, or inclines the table of the table device 10, or moves the top plate 33 of the couch device 30 by a raising and lowering operation, or radiates (irradiates) X-rays from the X-ray tube 11. The control device 18 can be provided on the table device 10 or on the console device 40.

[0040] The diagnosis bed device 30 is a device that places the subject P, which is a scan target, and introduces it into the inside of the rotating frame 17 of the stand device 10. The diagnosis bed device 30 has, for example, a base 31, a diagnosis bed drive device 32, a top plate 33, and a support frame 34. The base 31 includes a frame that supports the support frame 34 so as to be movable in the vertical direction (Y-axis direction). The diagnosis bed drive device 32 includes a motor, an actuator. The diagnosis bed drive device 32 moves the top plate 33, on which the subject P is placed, in the length direction (Z-axis direction) of the top plate 33 along the support frame 34. The top plate 33 is a plate-shaped member that places the subject P.

[0041] The console device 40 has, for example, a memory 41, a display 42, an input interface 43, and a processing circuit 50. In the embodiment, the console device 40 is described as being separate from the stand device 10, but part or all of the components of the console device 40 can be included in the stand device 10.

[0042] The memory 41 is realized by, for example, a semiconductor storage element such as a RAM (Random Access Memory), a flash memory, a hard disk, an optical disk, or the like. The memory 41 stores, for example, detection data, projection data, reconstructed image data, CT image data, and the like. These data can also be stored in an external memory (or in addition to the memory 41) that the X-ray CT device 1 can communicate with, instead of being stored in the memory 41. The external memory is, for example, a memory that is controlled by a cloud server that accepts read / write requests from the cloud server that manages the external memory.

[0043] The display 42 displays various information. For example, the display 42 displays a medical image (CT image) generated by the processing circuit, a GUI (Graphical User Interface) image that accepts various operations by an operator such as a doctor or a technician, and the like. The display 42 is, for example, a liquid crystal display or a CRT (Cathode Ray Tube), an organic EL (Electroluminescence) display, or the like. The display 42 can also be provided on the stand device 10. The display 42 can be a desktop type, or a display device (for example, a tablet terminal) that can perform wireless communication with the main body of the console device 40.

[0044] The input interface 43 accepts various input operations by an operator, and outputs an electric signal that represents the content of the accepted input operation to the processing circuit 50. For example, the input interface 43 accepts input operations of a collection condition when collecting detection data or projection data, a reconstruction condition when reconstructing a CT image, an image processing condition when generating a post-processed image from a CT image, and the like.

[0045] The input interface 43 is implemented by, for example, a mouse, a keyboard, a touch panel, a trackball, a switch, a button, a joystick, a camera, an infrared sensor, a microphone, or the like. The input interface 43 can also be implemented by a display device (for example, a tablet terminal) capable of performing wireless communication with the main body of the console device 40.

[0046] In addition, in the present specification, the input interface is not limited to having a physical operation member such as a mouse or a keyboard. For example, an electric signal processing circuit that receives an electric signal corresponding to an input operation from an external input device provided separately from the device and outputs the electric signal to a control circuit is also included in the example of the input interface.

[0047] The processing circuit 50 controls the overall operation of the X-ray CT device 1. The processing circuit 50 has, for example, a control function 51, a pre-processing function 52, a reconstruction processing function 53, and an image processing function 54. The processing circuit 50 implements these functions, for example, by a hardware processor executing a program stored in a storage device (storage circuit).

[0048] The hardware processor refers to, for example, a CPU, a GPU, an application specific integrated circuit, a programmable logic device or a composite programmable logic device, a field programmable gate array, or the like. Instead of storing a program in a storage device, the program can be directly loaded into the circuit of the hardware processor. The hardware processor is not limited to being configured as a single circuit, and a plurality of independent circuits can be combined to configure one hardware processor and implement each function. The storage device can also be a non-transitory (hardware) storage medium. In addition, a plurality of constituent elements can be integrated into one hardware processor to implement each function.

[0049] Each constituent element possessed by the console device 40 or the processing circuit 50 can also be decentralized and implemented by a plurality of hardware. The processing circuit 50 can not be a structure possessed by the console device 40, but can be implemented by a processing device capable of communicating with the console device 40. The processing device is, for example, a workstation connected to one X-ray CT device, or a device (for example, a cloud server) connected to a plurality of X-ray CT devices and collectively performing processing equivalent to the processing circuit 50 described below. Each function included in the processing circuit 50 can be decentralized in a plurality of circuits, or can be made available by starting application software stored in the storage 41.

[0050] The control function 51 controls various functions of the processing circuit 50 based on an input operation accepted by the input interface 43. The pre-processing function 52 performs pre-processing such as logarithmic transformation processing or offset correction processing of detection data output by the DAS 16, inter-channel sensitivity correction processing, beam hardening correction, and generates projection data, and stores the generated projection data in the storage 41.

[0051] The reconstruction processing function 53 performs a reconstruction process based on a filtered backprojection method, an iterative approximate reconstruction method, or the like on the projection data generated by the preprocessing function 52, generates CT image data, and stores the generated CT image data in the storage 41.

[0052] The image processing function 54 converts the CT image data into three-dimensional image data or cross-sectional image data of an arbitrary cross section based on an input operation accepted by the input interface 43, by a known method. The conversion into three-dimensional image data can also be performed by the preprocessing function 52.

[0053] Next, the structure of the X-ray detector 15 will be described. The X-ray detector 15 is provided with a plurality of X-ray detector units 15A in parallel. Figure 2 is an enlarged view of a portion of the X-ray detector unit 15A. The X-ray detector unit 15A is provided with, for example, a plurality of radiation detector modules (hereinafter, detector modules) 100 and a positioning plate 200. The plurality of detector modules 100 are provided in parallel with each other and are fixed to the positioning plate 200. The plurality of detector modules 100 are positioned with the relative positions thereof adjusted. The detector module 100 is a column of X-ray detection elements.

[0054] The detector module 100 is provided with, for example, a first electrode 61, a detection element 62, a second electrode 63, a substrate layer 64, and a mounting member 65. In the following description, the side of the detector module 100 on which the first electrode 61 is provided is sometimes referred to as the upper side, and the side on which the second electrode 63 is provided is sometimes referred to as the lower side.

[0055] The first electrode 61 is provided on the surface side (upper side) of the detection element 62. The first electrode 61 is an HV (High Voltage) electrode having a higher potential than the second electrode 63. The first electrode 61 is formed, for example, by vapor deposition of a metal as a raw material on the surface of the detection element 62. The first electrode 61 can also be formed by a method other than vapor deposition.

[0056] The detection element 62 is composed of, for example, CdTe or CZT. The detection element 62 detects radiation that has entered from the incident surface on the surface side of the detector module 100. The plurality of detector modules 100 are arranged in a linear shape on the positioning plate 200 having a substantially cuboid shape. The detection element 62 is an example of a radiation detection element.

[0057] The second electrode 63 is provided on the back surface of the detection element 62. The second electrode 63 is provided in opposition to the first electrode 61 with the detection element 62 interposed therebetween. The second electrode 63 is an LV (Low Voltage) electrode. By applying electric current to the first electrode 61 and the second electrode 63, radiation is detected in the detection element 62.

[0058] A substrate layer 64 is provided on the back surface side of the second electrode 63. The substrate layer 64 supports the first electrode 61, the detection element 62, and the second electrode 63. The substrate layer 64 has, for example, a support substrate. An IC chip or the like is mounted on the support substrate. The electrical elements are connected to each other by a wiring cable or the like, for example.

[0059] The mounting member 65 is housed in a plurality of positioning holes 71 formed in the positioning plate 200 and is fixed to the positioning plate by screws 72. The substrate layer 64 is fixed to the mounting member 65 by screws or the like not shown. The substrate layer 64 is fixed to the mounting member 65, and thus the detector module 100 is fixed with respect to the positioning plate 200.

[0060] Further, a through-hole 61A is formed in the first electrode 61. At the portion where the through-hole 61A is formed, a part of the surface of the detection element 62 is exposed. When the through-hole 61A is viewed from the upper side of the first electrode 61, the exposed part of the surface of the detection element 62 can be visually recognized. Figure 3 is a view showing the surface of the detection element 62 when the through-hole 61A is viewed from the upper side.

[0061] A mark 66 is provided on the exposed part of the surface of the detection element 62. The mark 66 includes, for example, a portion formed by covering the entire surface of the detection element 62 viewed from the through-hole 61A with the same material as the first electrode 61 and digging the center position thereof. The mark 66 is formed by making the portion of the surface of the detection element 62 viewed from the through-hole 61A to be formed with the mark 66 into a masked state when the first electrode 61 is formed by evaporation of metal. The mark 66 is formed with a border portion 62A which frames the mark 66 on the surface of the detection element 62 viewed from the through-hole 61A.

[0062] Figure 4 is a view showing the state of the detector module 100 when viewed from the upper side. A plurality of second electrodes 63 are provided on the detector module 100, for example. The second electrodes 63 are all substantially rectangular in plan view. The plurality of second electrodes 63 are arranged in a matrix. One pixel is constituted for one second electrode 63.

[0063] Two through-holes 61A are formed in the first electrode 61 to view the opposite corners of each four second electrodes 63 located at the diagonal positions of the first electrode 61 among the plurality of second electrodes 63 arranged in a matrix. Marks 66 are provided on the surfaces of the detection elements 62 viewed from the two through-holes 61A. The marks 66 are provided at a plurality of positions (two positions in the first embodiment) on the surfaces of the detection elements 62. The through-holes 61A are provided only at positions from which the marks 66 can be visually recognized from the incident surface side. The through-holes 61A can also be provided at positions other than the positions from which the marks 66 can be visually recognized from the incident surface side.

[0064] Figure 5 is a view of the X-ray detector unit 15A as viewed from the upper side. A plurality of detector modules 100 are arranged side by side on the X-ray detector unit 15A. Two through-holes 61A are formed on each of the plurality of detector modules 100, and a mark 66 is provided at a position observed from the through-hole 61A (refer to Figure 3 ). By making the positions of the marks 66 of the adjacent detector modules 100 observed from the through-holes 61A coincide with each other, the adjacent detector modules 100 are positioned to each other.

[0065] The mark 66 is provided based on the position of the second electrode 63. The mark 66 is provided, for example, in order to position the plurality of detector modules 100 in such a manner that the pixels of the adjacent detector modules 100 are aligned. The pixels in the detector module 100 are based on the position and range of the second electrode 63, and thus the mark 66 is used for the alignment of the second electrode 63 with the second electrode 63 in the other detector module 100 adjacent thereto.

[0066] Next, the manufacturing sequence of the detector module 100 is described, and then the manufacturing sequence of the X-ray detector unit 15A is described. In manufacturing the detector module 100, first, the substrate layer 64 is manufactured, and the second electrode 63 is manufactured on the surface of the substrate layer 64, for example, by evaporation. Then, the detection element 62 is formed on the surface of the second electrode 63.

[0067] When the detection element 62 is formed, the first electrode 61 is formed by evaporating a metal that becomes the first electrode 61 on the surface of the detection element 62. When the metal that becomes the first electrode 61 is evaporated, the portion that becomes the through-hole 61A and the portion that becomes the mark 66 are masked. In this way, the mark 66 is edged by the edging portion 62A of the same material as the first electrode 61. The layer of the first electrode 61 can also be formed after the layer of the edging portion 62A and the mark 66 are formed. The through-hole 61A can also be formed by etching treatment or the like after the metal that becomes the first electrode 61 is evaporated on the entire surface of the detection element 62.

[0068] Next, the sequence of manufacturing the X-ray detector unit 15A is described. Figure 6 is a flowchart showing an example of the manufacturing sequence of the X-ray detector unit 15A. In manufacturing the X-ray detector unit 15A, first, the assembled detector module 100 is held, for example, by a robot hand, and is arranged on the positioning plate 200 (step S101). This state is a state in which the detector module 100 has not yet been fixed with respect to the positioning plate 200.

[0069] Next, the camera photographs the detector module 100 from above (step S103), and the camera transmits the photographed image to a control device not shown. The control device performs image analysis on the transmitted image, and sets the position of each detector module 100 based on the positions of the marks 66 provided on each of the plurality of detector modules 100 in the image. The control device controls the robot based on the set positions of the detector modules 100, and minutely adjusts the positions of the adjacent detector modules 100 (step S105).

[0070] Next, after minutely adjusting the positions of the detector modules 100, the camera photographs the detector modules 100 from above, and adjusts the positions of the detector modules 100 based on the marks 66 provided on each of the plurality of detector modules 100 in the image. In the adjustment of the positions of the detector modules 100, the marks 66 of the adjacent detector modules 100 are aligned with each other, and further the second electrodes 63 are aligned with each other. Next, the control device determines whether the adjustment of the positions of the detector modules 100 is completed (step S107). In the case where it is determined that the adjustment of the positions of the detector modules 100 is not completed, the process returns to step S105, and the positions of the detector modules 100 are minutely adjusted.

[0071] In the case where it is determined that the adjustment of the positions of the detector modules 100 is completed, the detector modules 100 are fixed to the mounting members 65, and the mounting members 65 are fixed to the positioning plate 200 by the screws 72, whereby the detector modules 100 are fixed to the positioning plate 200 (step S109). In this way, the manufacture of the X-ray detector unit 15A is completed.

[0072] In the detector module 100 of the first embodiment, the marks 66 for alignment of the pixels are provided to the detection element 62 between the detector module 100 and the adjacent detector module 100. The through-holes 61A are provided to the first electrode 61 so that the marks 66 provided to the detection element 62 are visually recognized. Therefore, since the positioning is performed while the marks 66 are observed, the positioning accuracy of the detector module 100 can be improved.

[0073] (Second Embodiment)

[0074] Next, the second embodiment will be described. In the first embodiment, the through-holes 61A are provided to only two positions where the marks 66 are provided in the first electrode 61, but in the second embodiment, the through-holes 61A are provided to more positions. For example, the through-holes 61A are provided to a plurality of positions including a position from which the marks 66 can be visually recognized from the incident surface side and a position other than the position. Figure 7 is a view of the detector module 100 of the second embodiment viewed from the upper side.

[0075] The detector module 100 of the second embodiment, like the first embodiment, has a plurality of second electrodes 63 arranged in a matrix. Through-holes 61A are provided at positions of the first electrodes 61 corresponding to the corners opposite the respective 4 second electrodes 63 located at diagonal positions of the first electrodes 61. Therefore, the through-holes 61A are provided more than in the first embodiment.

[0076] A mark 66 is provided on the surface of the detection element 62 observed from the 2 through-holes 61A provided in the plurality of through-holes 61A at the corners opposite the respective 4 second electrodes 63 located at diagonal positions of the first electrodes 61. Therefore, the through-holes 61A are provided more than the number of marks 66 on the first electrodes 61.

[0077] The plurality of through-holes 61A provided in the first electrodes 61 are provided corresponding to the positions of the second electrodes 63. Therefore, the plurality of through-holes 61A are arranged in a symmetrical shape on the surface of the first electrodes 61, and are arranged in a so-called balanced form. Also, since the through-holes 61A are provided at the corners opposite the respective 4 second electrodes 63, the area of the portion of the first electrodes 61 opposite the second electrodes 63 is not too small.

[0078] Figure 8 is a view of the X-ray detector unit 15A of the second embodiment as viewed from above. In the X-ray detector unit 15A of the second embodiment, a mark 66 is provided in the plurality of detector modules 100 at a position observed from the 2 through-holes 61A located at diagonal positions of the first electrodes 61 (see Figure 2 ). By making the positions of the marks 66 observed from the through-holes 61A of adjacent detector modules 100 coincide with each other, the adjacent detector modules 100 are positioned with respect to each other.

[0079] In the detector module 100 of the second embodiment, the same effects as the detector module 100 of the first embodiment are obtained. Furthermore, in the detector module 100 of the second embodiment, a plurality of through-holes 61A are provided in the first electrodes 61 corresponding to the positions of the second electrodes 63. Therefore, in the first electrodes 61, voltage is applied uniformly to the second electrodes 63, in other words, to the pixels, and thus the detection accuracy of the detection element 62 can be improved.

[0080] (Examples of other marks)

[0081] In each of the above embodiments, the mark 66 is in a substantially cross shape, but can be in another shape. Figure 9A through Figure 9C are views showing other examples of marks. For example, as shown in Figure 9AAs shown, the mark 81 is formed on the surface of the detection element viewed from the through-hole 61A, from the same material as the first electrode 61 or a different material. In this case, the mark 81 can be formed on the surface of the detection element 62 before the first electrode 61 is formed. Alternatively, the mark 81 can be formed by performing a mask process in addition to a portion that becomes the mark 81, or the mark 81 can be formed by performing an etching process.

[0082] Alternatively, as shown in FIG. 6, a mark 81 can be formed on the surface of the detection element viewed from the through-hole 61A. Figure 9B As shown, a circular mark 82 is formed on the surface of the detection element viewed from the through-hole 61A. Alternatively, as shown in FIG. 7, a substantially T-shaped mark 83 can be formed on the surface of the detection element viewed from the through-hole 61A. Figure 9C As shown, a circular mark 82 is formed on the surface of the detection element viewed from the through-hole 61A. Alternatively, as shown in FIG. 7, a substantially T-shaped mark 83 can be formed on the surface of the detection element viewed from the through-hole 61A.

[0083] In each of the above embodiments, the mark 66 is provided on the surface of the detection element 62. In contrast, the mark 66 can be provided on the surface of the first electrode 61. In this case, the mark 66 can be provided at the same time as the first electrode 61 is formed by masking the position where the mark 66 is provided and evaporating metal on the surface of the detection element 62. The mark 66 can be formed after the first electrode 61 is formed by performing an etching process. The mark 66 can be provided on both the surface of the first electrode 61 and the surface of the detection element 62.

[0084] Further, in each of the above embodiments, two marks 66 are provided, but one mark 66 can be provided, or more than three marks 66 can be provided. The marks 66 can be provided at the same position between adjacent detector modules 100, but can be provided at different positions between adjacent detector modules 100. The mark 66 can be formed from a material different from the material of the first electrode 61. For example, the mark 66 can be provided by applying paint or the like to the surface of the detection element 62 or the first electrode 61.

[0085] (Third Embodiment)

[0086] Next, the third embodiment will be described. In the first embodiment, the through-hole 61A that makes it possible to visually recognize the mark 66 from the incident surface side is provided on the first electrode 61, but in the third embodiment, a through-hole that makes it possible to visually recognize the mark 66 from the incident surface side is also provided on the electrode film provided on the upper side of this first electrode 61.

[0087] Figure 10 is a view that enlargedly shows a portion of the X-ray detector unit 15B of the third embodiment. Figure 10The X-ray detector unit 15B shown is provided with an electrode film 67 with respect to Figure 2 The electrode film 67 is provided on the upper side of each of the first electrodes 61 of the detector module 100 included in the X-ray detector unit 15A. The electrode film 67 is electrically conductive and has a film shape. The electrode film 67 uniformly supplies a voltage supplied from a voltage source (not shown) to each of the first electrodes 61 of the detector module 100.

[0088] A through-hole 67A is formed in the electrode film 67. At the portion where the through-hole 67A is formed, a portion of the surface of the detection element 62 is exposed via the through-hole 61A of the first electrode 61. When the through-hole 67A is observed from the upper side of the electrode film 67, the exposed portion of the surface of the detection element 62 can be visually recognized. A mark 66 is provided on the exposed portion of the surface of the detection element 62, for example. Figure 3

[0089] Figure 11 is a view of the X-ray detector unit 15B of the third embodiment as viewed from the upper side. In the X-ray detector unit 15B, a plurality of detector modules 100 are provided side by side. In each of the plurality of detector modules 100, two through-holes 61A are formed in the first electrode 61, and a mark 66 is provided at a position observed from the through-hole 61A (refer to Figure 3 ). In addition, a through-hole 67A is provided at a position corresponding to the mark 66 of the electrode film 67. When the through-hole 67A is observed from the upper side of the electrode film 67, the mark 66 on the surface of the detection element 62 can be visually recognized via the through-hole 61A of the first electrode 61. By making the positions of the marks 66 observed from the through-holes 67A of the adjacent detector modules 100 to each other coincide with each other, the adjacent detector modules 100 can be positioned to each other.

[0090] In the X-ray detector unit 15B of the third embodiment, between the adjacent detector modules 100, the mark 66 for performing the alignment of the pixels is provided on the detection element 62. The through-hole 61A that makes it possible to visually recognize the mark 66 provided on the detection element 62 is provided in the first electrode 61, and the through-hole 67A that makes it possible to visually recognize the mark 66 provided on the detection element 62 via the through-hole 61A is provided in the electrode film 67. Therefore, since the positioning is performed while the mark 66 is observed, the positioning accuracy of the detector module 100 can be improved.

[0091] (Fourth Embodiment)

[0092] Next, the fourth embodiment will be described. In the fourth embodiment, when the positioning of the detector module 100 is performed, the estimation processing of the position of each pixel is performed using a pencil beam. Figure 12 ​is a view showing a case where the estimation processing of the position of each pixel using the pencil beam PB is performed in the fourth embodiment.

[0093] As shown in Figure 12 the detector module 100 from the upper side of the first electrode 61. At this time, the irradiation of the X-ray source 300 is performed while moving the irradiation position of the pencil beam PB in the detector module 100 in a prescribed direction (for example, the D direction). Further, the irradiation of the X-ray source 300 can also be performed while moving the irradiation position of the pencil beam PB in the detector module 100 in a direction orthogonal to the D direction of the upper side surface of the first electrode 61. The pencil beam PB has, for example, a beam size that is the same as or smaller than the size of each pixel. The pencil beam PB can also have a beam size that is larger than the size of each pixel.

[0094] The position of the pixel (the position of the second electrode 63) is estimated by observing the change in the electric signal output from the detector module 100 accompanying the change in the irradiation position of the pencil beam PB. In the example shown in Figure 12 the irradiation position of the pencil beam PB is the position PT1, PT2, PT3, the output value (the electric signal) of the detector module 100 indicates a peak value PK. In this case, it can be estimated that the positions PT1, PT2, PT3 at which the output value shows the peak value PK are the center positions of each pixel (the center positions of the second electrode 63). Such estimation processing can be performed in the processing circuit 50 of the console device 40, for example, and the estimation result is output to the display 42.

[0095] In the X-ray detector unit of the fourth embodiment, the estimation processing of the position of each pixel is performed using the pencil beam in order to perform the alignment of the pixels between it and the adjacent detector module 100. Therefore, it is possible to improve the positioning accuracy of the detector module 100.

[0096] According to at least one embodiment described above, there is provided a radiation detecting element that detects radiation incident from an incident surface, a first electrode provided on the incident surface side of the radiation detecting element, a second electrode provided opposite the first electrode with the radiation detecting element interposed therebetween, and a mark provided on at least one of the incident surface of the radiation detecting element or the first electrode, whereby the positioning accuracy of the radiation detector module can be improved.

[0097] Several embodiments were explained, but these embodiments are suggested as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in other various ways, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments or variations thereof are included in the scope or spirit of the invention, and are also included in the scope of the invention and equivalents thereof recited in the claims.

[0098] With regard to the above embodiments, the following notes are disclosed as one aspect of the invention and optional features.

[0099] (Note 1)

[0100] A radiation detector module comprising:

[0101] A radiation detection element that detects radiation incident from an incident surface;

[0102] A first electrode provided on the incident surface side of the radiation detection element;

[0103] A second electrode provided opposite the first electrode with the radiation detection element interposed therebetween; and

[0104] A mark provided on at least either the incident surface of the radiation detection element or the first electrode.

[0105] (Note 2)

[0106] The mark can also be provided based on the position of the second electrode.

[0107] (Note 3)

[0108] The mark can also be provided on the incident surface of the radiation detection element such that a through-hole that allows the mark to be visually recognized from the incident surface side is provided on the first electrode.

[0109] (Note 4)

[0110] The through-hole can also be provided only at a position at which the mark can be visually recognized from the incident surface side.

[0111] (Note 5)

[0112] The through-hole can also be provided at a plurality of positions including a position at which the mark can be visually recognized from the incident surface side.

[0113] (Note 6)

[0114] A plurality of the marks can also be provided.

[0115] (Note 7)

[0116] Also, the mark can be configured to include the same material as the first electrode.

[0117] (Paragraph 8)

[0118] Also, the first electrode can be provided by evaporating a material for the radiation detection element, and the mark can be provided by being masked when the first electrode is formed.

[0119] (Paragraph 9)

[0120] Also, the mark can be used for alignment of the second electrode with the second electrode in an adjacent other radiation detector module in a radiation detector provided with a plurality of radiation detector modules.

[0121] (Paragraph 10)

[0122] Also, an electrode film that supplies a voltage to the first electrode can be further provided on the incident surface side of the first electrode, and a through-hole that allows the mark to be visually recognized from the incident surface side can be provided in the electrode film.

[0123] (Paragraph 11)

[0124] A radiation detector provided with the above-described radiation detector module.

[0125] (Paragraph 12)

[0126] An X-ray CT device provided with the above-described radiation detector, the radiation being X-rays.

[0127] (Paragraph 13)

[0128] Also, the through-hole provided in the electrode film can allow the mark to be visually recognized from the incident surface side via the through-hole provided in the first electrode.

[0129] (Paragraph 14)

[0130] Also, the mark and the through-hole of the first electrode can be provided at positions corresponding to corners opposite four of the plurality of second electrodes arranged in a matrix.

[0131] (Paragraph 15)

[0132] Also, the first electrode can be provided by evaporating a material for the radiation detection element, and the mark can be provided by being masked when the first electrode is formed and forming a border portion that borders the mark.

[0133] (Paragraph 16)

[0134] Also, the marker can have any one shape of a cross shape, a circle, and a T shape.

Claims

1. A radiation detector module, comprising: a radiation detecting element that detects radiation that has been incident from an incident surface; a first electrode that is provided on the incident surface side of the radiation detecting element; a second electrode that is provided so as to face the first electrode with the radiation detecting element interposed therebetween; and a mark that is provided on the incident surface of the radiation detecting element and is used for alignment of pixels between adjacent detector modules, wherein a through-hole that makes it possible to visually recognize the mark from the incident surface side is provided in the first electrode.

2. The radiation detector module of claim 1, wherein, The mark is provided based on the position of the second electrode.

3. The radiation detector module of claim 1, wherein, The through-hole is provided only at a position at which the mark can be visually recognized from the incident surface side.

4. The radiation detector module of claim 1, wherein, The through-hole is provided at a plurality of positions including a position at which the mark can be visually recognized from the incident surface side.

5. The radiation detector module of claim 1, wherein, A plurality of the marks are provided.

6. The radiation detector module according to any one of claims 1 to 5, wherein, The mark is configured to include the same raw material as the first electrode.

7. The radiation detector module according to any one of claims 1 to 5, wherein, The first electrode is provided by vapor deposition of a raw material with respect to the radiation detecting element, and the mark is provided by being masked when the first electrode is formed.

8. The radiation detector module according to any one of claims 1 to 5, wherein, The radiation detector module is provided in a radiation detector that includes a plurality of radiation detector modules, and the mark is used for alignment of the second electrode with the second electrode in an adjacent other radiation detector module.

9. The radiation detector module according to any one of claims 1 to 5, wherein, An electrode film that is provided on the incident surface side of the first electrode and supplies a voltage to the first electrode is further provided, and a through-hole that makes it possible to visually recognize the mark from the incident surface side is provided in the electrode film.

10. A radiation detector that includes the radiation detector module according to any one of claims 1 to 9.

11. An X-ray CT apparatus that includes the radiation detector according to claim 10, wherein the radiation is X-rays.

Images