Detector module unit, radiation detector and x-ray computer tomography apparatus

Abstract

To efficiently cool a signal processing circuit.SOLUTION: A detector module unit according to an embodiment includes a detecting element array, a signal processing circuit, a holding plate, and a housing. The detecting element array has a plurality of detecting element for converting a radiation ray into an electric signal arranged therein. The signal processing circuit processes the electric signal. The holding plate holds the detecting element array and the signal processing circuit. The housing has a first surface and a second surface opposed to each other through the holding plate and is thermally connected with the signal processing circuit. The first surface and the second surface of the housing has fins, respectively.SELECTED DRAWING: Figure 5B

Description

[Technical field]

[0001] The embodiments disclosed in the specification and drawings relate to a detector module unit, a radiation detector, and an X-ray computed tomography apparatus. [Background technology]

[0002] Conventionally, detectors configured by arranging a plurality of detector module units have been known as radiation detectors used in radiation diagnostic devices such as X-ray computed tomography (CT) devices and PET (Positron Emission Tomography) devices. In such radiation detectors, a signal processing circuit included in the detector module unit generates heat when irradiated with radiation, and therefore a cooling structure for cooling the signal processing circuit is generally provided in order to prevent failure of the detection element due to heat generation from the signal processing circuit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-104667 A [Patent Document 2] Patent Publication No. 2021-43201 [Patent Document 3] JP 2006-284394 A [Patent Document 4] JP 2002-344180 A Summary of the Invention [Problem to be solved by the invention]

[0004] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to cool a signal processing circuit more efficiently. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described below can also be positioned as other problems. [Means for solving the problem]

[0005] A detector module unit according to an embodiment includes a detection element array, a signal processing circuit, a holding plate, and a housing. The detection element array has an array of detection elements that convert radiation into an electric signal. The signal processing circuit processes the electric signal. The holding plate holds the detection element array and the signal processing circuit. The housing has a first surface and a second surface that face each other via the holding plate, and is thermally connected to the signal processing circuit. The first surface and the second surface of the housing each have fins. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an X-ray CT apparatus according to the first embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of the configuration of the X-ray detector according to the first embodiment. [Diagram 3] FIG. 3 is a diagram illustrating an example of the configuration of the detector module according to the first embodiment. [Figure 4A] FIG. 4A is a diagram illustrating an example of the configuration of a detector module unit according to a comparative example of the first embodiment. [Figure 4B] FIG. 4B is a diagram illustrating an example of the configuration of a detector module unit according to a comparative example of the first embodiment. [Figure 5A] FIG. 5A is a diagram showing an example of the configuration of a detector module unit according to the first embodiment. [Figure 5B] FIG. 5B is a diagram showing an example of the configuration of the detector module unit according to the first embodiment. [Figure 6A]FIG. 6A is a diagram showing an example of the configuration of a detector module unit according to the second embodiment. [Figure 6B] FIG. 6B is a diagram showing an example of the configuration of the detector module unit according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] (First embodiment) Hereinafter, embodiments of a detector module unit, a radiation detector, and an X-ray CT apparatus disclosed in the present application will be described with reference to the drawings. The configurations shown in the drawings are schematic, and the dimensions of each component and the dimensional ratios between the components shown may differ from the actual ones. Furthermore, the dimensions of the same component and the dimensional ratios between the components may be shown differently between the drawings.

[0008] In the following embodiments, an example will be described in which the detector module unit and radiation detector disclosed in the present application are applied to an X-ray detector of an X-ray CT scanner. Also, in the following embodiments, an example will be described in which the technology disclosed in the present application is applied to an X-ray CT scanner including a detector module unit and a photon-counting detector.

[0009] FIG. 1 is a diagram showing an example of the configuration of an X-ray CT apparatus according to the first embodiment.

[0010] For example, as shown in Fig. 1, an X-ray CT apparatus 1 according to this embodiment includes a gantry device 10, a bed device 30, and a console device 40. For convenience of explanation, a plurality of gantry devices 10 are shown in Fig. 1.

[0011] In this embodiment, the rotation axis of the rotating frame 13 in the non-tilted state or the longitudinal direction of the table top 33 of the bed device 30 is defined as the Z-axis direction, the axial direction perpendicular to the Z-axis direction and horizontal to the floor surface is defined as the X-axis direction, and the axial direction perpendicular to the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction.

[0012] The gantry device 10 is a device that irradiates an object P (such as a patient) with X-rays, detects the X-rays that have passed through the object P, and outputs them to a console device 40. The gantry device 10 has an X-ray tube 11, an X-ray detector 12, a rotating frame 13, a control device 15, a wedge 16, an X-ray aperture 17, and an X-ray high voltage device 14.

[0013] The X-ray tube 11 is a vacuum tube that generates X-rays by irradiating thermoelectrons from a cathode (filament) to an anode (target) by application of high voltage from the X-ray high voltage device 14. For example, the X-ray tube 11 is a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermoelectrons.

[0014] The wedge 16 is a filter for adjusting the amount of X-rays irradiated from the X-ray tube 11. Specifically, the wedge 16 is a filter that transmits and attenuates the X-rays irradiated from the X-ray tube 11 so that the X-rays irradiated from the X-ray tube 11 to the subject P have a predetermined distribution. For example, the wedge 16 is a filter made of processed aluminum so as to have a predetermined target angle and a predetermined thickness. The wedge 16 is also called a wedge filter or a bow-tie filter.

[0015] The X-ray aperture 17 includes a lead plate or the like for narrowing down the irradiation range of the X-rays transmitted through the wedge 16, and a slit is formed by combining a plurality of lead plates or the like.

[0016] The X-ray detector 12 detects X-rays irradiated from the X-ray tube 11 and passing through the subject P. Specifically, the X-ray detector 12 has a plurality of detection elements arranged in the channel direction along one arc with the focus of the X-ray tube 11 as the center. For example, the X-ray detector 12 has a structure in which a plurality of detection element rows, each having a plurality of detection elements arranged in the channel direction, are arranged in the row direction (also called the slice direction or row direction). Here, a collimator is installed on the X-ray incidence surface side of the X-ray detector 12 in order to reduce scattered X-rays. The collimator may also be called an anti-scatter grid or a post-collimator.

[0017] Each of the multiple detection elements outputs a signal capable of measuring the energy value of an X-ray photon every time an X-ray photon is incident on the detection element. Specifically, the detection element is composed of multiple electrodes, and outputs an electrical signal corresponding to the incident X-ray photon every time an X-ray photon is incident on the detection element. For example, the detection element may be made of CZT (cadmium zinc telluride: CdZnTe), CdTe (cadmium telluride), Ge (germanium), Si (silicon), or the like. Note that the detection element may be made of other types of semiconductor crystals such as a scintillator crystal.

[0018] That is, the X-ray detector 12 is a direct conversion type detector having a semiconductor element as a detection element that converts incident X-rays into an electric signal. Note that the X-ray detector 12 may be an indirect conversion type detector that combines a phosphor that is excited by X-rays and emits light, and an optical sensor that converts the light generated by the phosphor into an electric signal.

[0019] The X-ray detector 12 also includes a signal processing circuit connected to the above-mentioned multiple detection elements and processing the electrical signal output from each detection element. The signal processing circuit counts the number of X-ray photons incident on the detection element by performing pulse height discrimination on pulses having heights proportional to the individual charge amounts of the electrical signals output from the detection elements. The signal processing circuit also measures the energy of the counted X-ray photons by performing arithmetic processing based on the magnitude of each charge. The signal processing circuit also performs A / D (Analog to Digital) conversion on the signals from the detection elements, outputting the count result of the number of X-ray photons as a digital data signal. For example, the signal processing circuit is realized by an application specific integrated circuit (ASIC).

[0020] Moreover, the X-ray detector 12 has a DAS (Data Acquisition System) that outputs detection data based on a signal output from the signal processing circuit. The DAS generates detection data based on a signal of the counting result of X-rays output from the X-ray detector 12. Here, the detection data is, for example, a sinogram. The sinogram is data that arranges the results of counting processing of X-rays incident on each detection element at each position of the X-ray tube 11. Specifically, the sinogram is data that arranges the results of counting the number of X-ray photons in a two-dimensional orthogonal coordinate system with the view direction and channel direction as axes. For example, the DAS generates a sinogram for each row in the slice direction of the X-ray detector 12. Then, the DAS transfers the generated detection data to the console device 40.

[0021] The X-ray high voltage device 14 has electric circuits such as a transformer and a rectifier, and includes a high voltage generator having a function of generating a high voltage to be applied to the X-ray tube 11, and an X-ray control device that controls the output voltage according to the X-ray output irradiated by the X-ray tube 11. The high voltage generator may be of a transformer type or an inverter type. The X-ray high voltage device 14 may be provided on the rotating frame 13 described later, or may be provided on the fixed frame (not shown) side of the gantry device 10. Here, the fixed frame is a support frame that rotatably supports the rotating frame 13.

[0022] The rotating frame 13 is an annular frame that supports the X-ray tube 11 and the X-ray detector 12 so as to face each other and rotates the X-ray tube 11 and the X-ray detector 12 using a control device 15, which will be described later. In addition to the X-ray tube 11 and the X-ray detector 12, the rotating frame 13 also supports an X-ray high voltage device 14.

[0023] Here, the rotating frame 13 is rotatably supported by a non-rotating portion (e.g., a fixed frame, not shown) of the gantry device 10. The rotation mechanism includes, for example, a motor that generates a rotational driving force, and a bearing that transmits the rotational driving force to the rotating frame 13 to rotate it. The motor is provided, for example, in the non-rotating portion, and the bearing is physically connected to the rotating frame 13 and the motor, and the rotating frame 13 rotates in response to the rotational force of the motor.

[0024] In addition, the rotating frame 13 and the non-rotating part are provided with a non-contact or contact communication circuit, which allows communication between the unit supported by the rotating frame 13 and the non-rotating part or an external device of the gantry 10. For example, when optical communication is adopted as the non-contact communication method, the detection data generated by the DAS is transmitted by optical communication from a transmitter having a light emitting diode (LED) provided on the rotating frame 13 to a receiver having a photodiode provided on the non-rotating part of the gantry 10, and is further transferred from the non-rotating part to the console device 40 by the transmitter. Note that, as the communication method, in addition to the above, a non-contact data transmission method such as a capacitive coupling method or an electromagnetic wave method, or a contact data transmission method using a slip ring and an electrode brush may be adopted.

[0025] The control device 15 has a processing circuit having a CPU (Central Processing Unit) and the like, and a driving mechanism such as a motor and an actuator. The control device 15 has a function of receiving an input signal from the console device 40 or an input interface 43 attached to the gantry device 10 and controlling the operation of the gantry device 10 and the bed device 30. For example, the control device 15 receives an input signal and controls the rotation of the rotating frame 13, the tilt of the gantry device 10, and the operation of the bed device 30 and the tabletop 33. The control of tilting the gantry device 10 is realized by the control device 15 rotating the rotating frame 13 around an axis parallel to the X-axis direction based on inclination angle (tilt angle) information input by the input interface 43 attached to the gantry device 10. The control device 15 may be provided in the gantry device 10 or in the console device 40.

[0026] The bed device 30 is a device on which the subject P to be scanned is placed and moved, and includes a base 31, a bed driving device 32, a top plate 33, and a support frame 34. The base 31 is a housing that supports the support frame 34 so that it can move in the vertical direction. The bed driving device 32 is a motor or actuator that moves the top plate 33, on which the subject P is placed, in the longitudinal direction of the top plate 33. The top plate 33, which is provided on the upper surface of the support frame 34, is a plate on which the subject P is placed. Note that the bed driving device 32 may move the support frame 34 in the longitudinal direction of the top plate 33 in addition to the top plate 33.

[0027] The console device 40 is a device that accepts operations of the X-ray CT apparatus 1 by an operator and reconstructs CT image data using detection data collected by the gantry device 10. The console device 40 has a memory 41, a display 42, an input interface 43, and a processing circuit 44. Note that, although an example in which the console device 40 and the gantry device 10 are separate entities will be described here, the gantry device 10 may include the console device 40 or some of the components of the console device 40.

[0028] The memory 41 is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory), a flash memory, a hard disk, an optical disk, etc. The memory 41 stores, for example, projection data and CT image data.

[0029] The display 42 displays various types of information. For example, the display 42 outputs medical images (CT images) generated by the processing circuitry 44, a GUI (Graphical User Interface) for receiving various operations from an operator, and the like. For example, the display 42 is a liquid crystal display or a CRT (Cathode Ray Tube) display. Note that, for example, the display 42 may be provided on the gantry device 10. Also, for example, the display 42 may be a desktop type, or may be configured as a tablet terminal or the like capable of wireless communication with the console device 40 main body.

[0030] The input interface 43 receives various input operations from an operator, converts the received input operations into electrical signals, and outputs the electrical signals to the processing circuit 44. For example, the input interface 43 receives from the operator scan conditions for collecting projection data, reconstruction conditions for reconstructing CT image data, image processing conditions for generating post-processed images from CT images, and the like. For example, the input interface 43 is realized by a mouse, a keyboard, a trackball, a switch, a button, a joystick, and the like. Note that the input interface 43 may be provided in the gantry device 10, for example. Also, for example, the input interface 43 may be configured by a tablet terminal or the like capable of wireless communication with the console device 40 main body.

[0031] The processing circuitry 44 controls the overall operation of the X-ray CT apparatus 1. For example, the processing circuitry 44 executes a system control function 441, a pre-processing function 442, a reconstruction processing function 443, and an image processing function 444.

[0032] The system control function 441 controls various functions of the processing circuit 44 based on an input operation received from an operator via the input interface 43. For example, the system control function 441 controls a CT scan executed in the X-ray CT device 1. The system control function 441 also controls the generation and display of CT image data in the console device 40 by controlling a pre-processing function 442, a reconstruction processing function 443, and an image processing function 444.

[0033] The pre-processing function 442 generates projection data by performing pre-processing such as logarithmic conversion processing, offset correction processing, inter-channel sensitivity correction processing, beam hardening correction, etc. on the detection data output from the DAS of the X-ray detector 12. Note that the data before pre-processing (detection data) and the data after pre-processing may be collectively referred to as projection data.

[0034] The reconstruction processing function 443 performs reconstruction processing using a filtered back projection method, an iterative reconstruction method, or the like on the projection data generated by the preprocessing function 442 to generate CT image data (reconstructed image data).

[0035] The image processing function 444 converts the CT image data generated by the reconstruction processing function 443 into tomographic image data of an arbitrary cross section or three-dimensional image data by a known method based on an input operation received from an operator via the input interface 43. Note that the generation of the three-dimensional image data may be performed directly by the reconstruction processing function 443.

[0036] Here, for example, the processing circuitry 44 is realized by a processor. In this case, each processing function possessed by the processing circuitry 44 is stored in the memory 41 in the form of a program executable by a computer. Then, the processing circuitry 44 realizes a function corresponding to each program by reading out each program from the memory 41 and executing it. In other words, the processing circuitry 44 in a state in which each program has been read out has each processing function shown in the processing circuitry 44 in FIG. 1.

[0037] Here, the above-mentioned processing functions are realized by a single processing circuit 44. However, for example, the processing circuit 44 may be configured by combining multiple independent processors, and each processor may execute a program to realize each processing function. Each processing function of the processing circuit 44 may be appropriately distributed or integrated into a single or multiple processing circuits. Each processing function of the processing circuit 44 may be realized by a mixture of hardware and software such as a circuit. Here, an example in which a single memory 41 stores a program corresponding to each processing function has been described, but the embodiment is not limited to this. For example, a configuration in which multiple storage circuits are distributed and the processing circuit 44 reads and executes a corresponding program from each storage circuit may be used.

[0038] The above describes the overall configuration of the X-ray CT device 1 according to this embodiment. In this configuration, the X-ray detector 12 in this embodiment is configured by arranging a plurality of detector module units, each of which is configured to be independent and individually replaceable.

[0039] FIG. 2 is a diagram showing an example of the configuration of the X-ray detector 12 according to the first embodiment.

[0040] For example, as shown in Fig. 2, the X-ray detector 12 is formed as a whole in the shape of a circular arc along the channel direction, and is aligned so that the center of the circular arc coincides with the position of the X-ray tube 11, and is fixed to the rotating frame 13 shown in Fig. 1. Here, the axial direction of the circular arc of the X-ray detector 12 coincides with the row direction, and the radial direction coincides with the X-ray irradiation direction.

[0041] The X-ray detector 12 includes a plurality of detector module units 121 arranged in the channel direction.

[0042] The multiple detector module units 121 are attached to a support member included in the X-ray detector 12 while being arranged in the channel direction. Here, the detector module units 121 are each configured to be independently attachable and detachable to the support member, and each unit includes a detector module 1211, a holding plate 1212, and a housing 1213.

[0043] The detector module 1211 has a detector element array in which a plurality of the above-mentioned detector elements are arranged, and the above-mentioned signal processing circuit, and is held by a holding plate 1212. The holding plate 1212 is disposed between the detector module 1211 and a housing 1213, and is fixed to the housing 1213 in a state in which it holds the detector module 1211. The housing 1213 supports the holding plate 1212, and houses therein a circuit board on which the above-mentioned DAS and the like are mounted.

[0044] FIG. 3 is a diagram showing an example of the arrangement of the detector module 1211 according to the first embodiment.

[0045] For example, as shown in FIG. 3, the detector module 1211 includes a plurality of detector elements 12111 constituting a detector element array, a signal processing circuit 12112, and a fixed block 12113.

[0046] The multiple detection elements 12111 are disposed on the surface of the signal processing circuit 12112 and are electrically connected to the signal processing circuit 12112. The signal processing circuit 12112 is communicatively connected to a circuit board in the housing 1213 via an FPC (Flexible Printed Circuit) not shown. The fixing block 12113 supports the signal processing circuit 12112 and is fixed to the holding plate 1212 with fixing devices such as screws.

[0047] In this embodiment, the fixing block 12113 and the holding plate 1212 are each formed of a material having thermal conductivity. The signal processing circuit 12112 and the holding plate 1212 are thermally connected via the fixing block 12113.

[0048] In general, in such a detector module unit 121, it is considered that the signal processing circuit 12112 included in the detector module 1211 will generate heat depending on the amount of X-rays irradiated from the X-ray tube 11. On the other hand, the detection element 12111 connected to the signal processing circuit 12112 usually has a set upper limit on temperature, and the risk of failure increases when it becomes too hot. Therefore, in order to prevent the detection element 12111 from failing, it is necessary to cool the signal processing circuit 12112.

[0049] For this reason, the detector module unit 121 according to this embodiment has a cooling structure for cooling the signal processing circuit 12112.

[0050] For example, one example of such a cooling structure may be a structure in which fins are provided on the holding plate 1212 that holds the detector module 1211 in the detector module unit 121, and the signal processing circuit 12112 is cooled by ventilating the fins.

[0051] 4A and 4B are diagrams showing a configuration example of a detector module unit 121 according to a comparative example of the first embodiment. Here, Fig. 4A is a perspective view showing the appearance of the detector module unit 121 according to the comparative example of the first embodiment. Also, Fig. 4B is a side view showing a cooling structure in the detector module unit 121 according to the comparative example of the first embodiment.

[0052] 4A and 4B, in the detector module unit 121, a structure may be considered in which fins 9214 having multiple protrusions are provided on the side of the holding plate 1212 that holds the detector module 1211, close to the housing 1213, and cooling air is ventilated between the protrusions of the fins 9214. Here, in FIG. 4B, the range indicated by the dashed line indicates the cooling area formed by the fins 9214.

[0053] However, in such a cooling structure, since it is necessary to ventilate air in a small cooling area, the heat dissipation area is small, and it is difficult to sufficiently cool the signal processing circuit 12112. Furthermore, if the height of the fins 9214 is increased to increase the heat dissipation area, the length of the FPC for connecting the detector module 1211 to the circuit board in the housing 1213 must be extended, which may deteriorate the signal quality and cause unnecessary image quality. Therefore, it is necessary to transfer the heat generated by the signal processing circuit 12112 to a wider area to cool it in a place that does not affect the length of the FPC of the detector module 1211.

[0054] For this reason, the detector module unit 121 of this embodiment is configured to be able to cool the signal processing circuit 12112 more efficiently by transferring the heat generated by the signal processing circuit 12112 over a wider area.

[0055] Specifically, in this embodiment, the housing 1213 of the detector module unit 121 has a first surface and a second surface opposed to each other via the holding plate 1212, and is thermally connected to the signal processing circuit 12112. The first surface and the second surface of the housing 1213 each have fins.

[0056] An example of the configuration of the detector module unit 121 according to this embodiment will be described in detail below.

[0057] 5A and 5B are diagrams showing a configuration example of the detector module unit 121 according to the first embodiment. Here, Fig. 5A is a perspective view showing the appearance of the detector module unit 121 according to the first embodiment. Also, Fig. 5B is a side view of the detector module unit 121 according to the first embodiment as seen in the column direction.

[0058] For example, as shown in FIGS. 5A and 5B, a detector module unit 121 according to this embodiment includes a detector module 1211, a holding plate 1212, and a housing 1213.

[0059] Here, the housing 1213 is entirely made of a material having thermal conductivity, and is thermally connected to the holding plate 1212. As a result, the housing 1213 is thermally connected to the signal processing circuit 12112 of the detector module 1211 via the holding plate 1212 and the fixing block 12113 shown in FIG.

[0060] The housing 1213 also has a first surface 12131 and a second surface 12132 that are arranged to face each other with the holding plate 1212 interposed therebetween. Here, the first surface 12131 is an example of a first surface. The second surface 12132 is an example of a second surface.

[0061] Specifically, the first surface portion 1231 and the second surface portion 12132 are arranged in a state in which they sandwich the channel direction side of the holding plate 1212 from both sides at the end portion closer to each detector module 1211, and are thermally connected to the holding plate 1212.

[0062] In this embodiment, fins 1214 having multiple protrusions 12141 are provided on the outer side surfaces of each of the first surface portion 12131 and the second surface portion 12132. Specifically, the fins 1214 are provided over substantially the entire outer side surfaces of each of the first surface portion 12131 and the second surface portion 12132. Furthermore, the multiple protrusions 12141 included in the fins 1214 are each formed in a rod shape extending in the slice direction, and are arranged in parallel at regular intervals in the X-ray irradiation direction.

[0063] In this configuration, in this embodiment, for example, a blower or the like provided in the X-ray detector 12 ventilates cooling air between the protrusions 12141 of the fins 1214 provided on each of the first surface 12131 and the second surface 12132 of the housing 1213. Here, in FIG. 5B, the range indicated by the dashed line indicates the cooling area formed by the fins 1214.

[0064] According to this configuration, by providing fins 1214 on each of the two surfaces of the housing 1213 thermally connected to the signal processing circuit 12112 of the detector module 1211, a larger heat dissipation area can be secured compared to the case where fins are provided on the holding plate 1212 as in the comparative example described above. Also, since there is no need to increase the height of the holding plate 1212 compared to the case where fins are provided on the holding plate 1212, a large heat dissipation area can be secured without affecting the length of the FPC for connecting the detector module 1211 and the circuit board.

[0065] Therefore, according to the first embodiment, the heat generated by the signal processing circuit 12112 can be transferred to a wider range for cooling, and the signal processing circuit 12112 can be more efficiently cooled. In addition, it is possible to reduce the risk of the detection element 12111 failing due to the heat generated by the signal processing circuit 12112, and to prevent deterioration of signal quality and poor image quality that may occur when the FPC is extended.

[0066] The main configuration of the detector module unit 121 according to the first embodiment has been described above, but the detector module unit 121 according to this embodiment further includes the following configuration.

[0067] Specifically, in this embodiment, the housing 1213 further includes a heat transfer member with high thermal conductivity provided on the first surface and the second surface.

[0068] 5B, for example, a graphite sheet 1215 having high thermal conductivity is attached over substantially the entire inner side surface of each of the first surface 12131 and the second surface 12132 of the housing 1213. The end portions of the first surface 12131 and the second surface 12132 close to the detector module 1211 are thermally connected to the holding plate 1212 with the graphite sheet 1215 sandwiched therebetween. Here, the graphite sheet 1215 is an example of a heat transfer member.

[0069] With this configuration, the signal processing circuit 12112 can be cooled even more efficiently.

[0070] In this embodiment, the housing 1213 further has rail shapes provided on the outer side surfaces of the first surface and the second surface.

[0071] For example, as shown in FIG. 5B, groove-shaped rails 1216 extending along the row direction are formed on the ends of the outer side surfaces of the first surface portion 12131 and the second surface portion 12132 of the housing 1213 close to the detector module 1211. Here, on each of the first surface portion 12131 and the second surface portion 12132 of the housing 1213, the rails 1216 are provided in parallel with the protrusions 12141 included in the fins 1214, thereby constituting a part of the fins 1214. When the detector module unit 121 is replaced, the rails 1216 slide while engaging with a replacement jig or the like attached to a support member included in the X-ray detector 12, thereby guiding the movement of the detector module unit 121 in the attachment / detachment direction. Here, the rails 1216 are an example of a rail shape.

[0072] According to such a configuration, a part of the fins 1214 provided on the housing 1213 can be used as an exchange mechanism for exchanging the detector module unit 121.

[0073] In this embodiment, the housing 1213 has a box shape configured by connecting a first surface and a second surface with a connecting member.

[0074] For example, as shown in FIG. 5B, the housing 1213 includes a first joining block 12171 arranged at an end closer to the holding plate 1212 and a second joining block 12172 arranged at an end farther from the holding plate 1212, and is configured by joining the first face portion 12131 and the second face portion 12132 with the first joining block 12171 and the second joining block 12172, respectively. As a result, the housing 1213 is formed in a box shape with the first face portion 12131 and the second face portion 12132 as side surfaces and the first joining block 12171 and the second joining block 12172 as upper and lower surfaces. Here, the first joining block 12171 and the second joining block 12172 are an example of a joining member. The joining member may be a stud or the like.

[0075] According to such a configuration, the detector module unit 121 can be made into a box-like shape with a high section modulus, and it is possible to increase the strength against the centrifugal force generated when the X-ray tube 11 and the X-ray detector 12 are rotated by the rotating frame 13. Alternatively, it is possible to reduce the weight of the detector module unit 121 while maintaining the strength against the centrifugal force during rotation.

[0076] In addition, in this embodiment, the detector module unit 121 further includes a circuit board arranged in the housing 1213 and a shielding member that blocks X-rays incident on the circuit board, and the shielding member is arranged between the holding plate 1212 and the circuit board and held by a connecting member.

[0077] For example, as shown in FIG. 5B, the detector module unit 121 includes a circuit board 1218 arranged in a housing 1213, and an X-ray shielding plate 1219 for shielding X-rays incident on the circuit board 1218. The circuit board 1218 includes the above-mentioned DAS, a power supply circuit for supplying power to the signal processing circuit 12112 of the detector module 1211, and the like. The X-ray shielding plate 1219 is fixed and held on a surface of a first joining block 12171 arranged between the holding plate 1212 and the circuit board 1218, the surface facing the holding plate 1212. Here, the circuit board 1218 is an example of a circuit board. The X-ray shielding plate 1219 is an example of a shielding member.

[0078] With this configuration, since the housing 1213 is formed in a box shape, by installing an X-ray shielding plate 1219 on the first joining block 12171 which forms the upper surface of the housing 1213, it is possible to easily protect the circuit board 1218 from X-rays.

[0079] (Modification of the first embodiment) In the above-described embodiment, fins are provided on the first surface and the second surface of the housing 1213, but the embodiment is not limited to this.

[0080] For example, fins may be further provided on a side surface of holding plate 1212 facing the inside of housing 1213. Also, fins may be further provided on a side surface of either one or both of first joining block 12171 and second joining block 12172 included in housing 1213 facing the inside of housing 1213.

[0081] According to such a configuration, the heat dissipation area can be further expanded by the additional fins, and the cooling efficiency of the signal processing circuit 12112 can be further improved.

[0082] In the above-described embodiment, the X-ray detector 12 includes a plurality of detector module units 121 arranged in the channel direction. In such a configuration, the fins 1214 of adjacent detector module units 121 may be provided such that the protrusion 12141 included in the fin 1214 of one detector module unit 121 faces the protrusion 12141 included in the fin 1214 of the other detector module unit 121, or such that the protrusion 12141 included in the fin 1214 of one detector module unit 121 faces the gap between the protrusion 12141 included in the fin 1214 of the other detector module unit 121.

[0083] For example, if the fins 1214 of adjacent detector module units 121 are arranged so that the protrusion 12141 included in the fin 1214 of one detector module unit 121 faces the gap between the protrusion 12141 included in the fin 1214 of the other detector module unit 121, cooling air will more easily flow to the tips of each protrusion 12141 included in the fin 1214. With this configuration, the cooling effect of the fins 1214 can be improved, and the cooling efficiency of the signal processing circuit 12112 can be further improved.

[0084] Furthermore, in the above-described embodiment, the fins 1214 are provided over substantially the entire outer side surface of each of the first surface portion 12131 and the second surface portion 12132, but the embodiment is not limited to this.

[0085] For example, in the housing 1213, it is assumed that the amount of heat transferred from the signal processing circuit 12112 increases the closer to the position of the detector module 1211. Therefore, for example, the fins 1214 may be provided only on the side of each of the first surface 12131 and the second surface 12132 of the housing 1213 that is closer to the detector module 1211 where the amount of heat transferred from the signal processing circuit 12112 is assumed to be greater. Also, for example, the fins 1214 may be provided on the inner side surfaces of each of the first surface 12131 and the second surface 12132, or may be provided on both the outer side surface and the inner side surface.

[0086] In addition, in the above-described embodiment, the multiple protrusions 12141 included in the fin 1214 are each formed in a rod shape extending in the slice direction and are arranged in parallel at regular intervals in the X-ray irradiation direction, but the embodiment is not limited to this.

[0087] For example, the number of protrusions 12141 may be increased by decreasing the intervals between the protrusions 12141 included in the fins 1214 in the first surface 12131 and the second surface 12132 of the housing 1213, the closer to the detector module 1211 where the amount of heat transferred from the signal processing circuit 12112 is assumed to be large. Also, for example, the protrusions 12141 may be formed in a rod shape extending in the X-ray irradiation direction, and may be arranged in parallel at intervals in the slice direction.

[0088] Second Embodiment In the above-mentioned first embodiment, an example was described in which the first and second surfaces of the housing 1213 of the detector module unit 121 each have fins as a cooling structure for cooling the signal processing circuit 12112, but the cooling structure is not limited to this.

[0089] For example, the first surface and the second surface of the housing 1213 of the detector module unit 121 may each have a flow path for circulating a coolant such as cooling water. Such an example will be described below as a second embodiment. Note that the second embodiment will be described mainly with respect to the differences from the first embodiment, and detailed description of the contents common to the first embodiment will be omitted.

[0090] 6A and 6B are diagrams showing a configuration example of a detector module unit 121 according to the second embodiment. Here, Fig. 6A is a perspective view showing the appearance of the detector module unit 121 according to the second embodiment. Also, Fig. 6B is a side view of the detector module unit 121 according to the second embodiment as viewed in the column direction.

[0091] For example, as shown in FIGS. 6A and 6B, a detector module unit 121 according to this embodiment includes a detector module 1211, a holding plate 1212, and a housing 1213.

[0092] Here, the housing 1213 is entirely made of a material having thermal conductivity, and is thermally connected to the holding plate 1212. As a result, the housing 1213 is thermally connected to the signal processing circuit 12112 of the detector module 1211 via the holding plate 1212 and the fixing block 12113 shown in FIG.

[0093] The housing 1213 also has a first surface 12131 and a second surface 12132 that are arranged to face each other with the holding plate 1212 interposed therebetween. Here, the first surface 1231 is an example of a first surface. The second surface 1232 is an example of a second surface.

[0094] Specifically, the first surface portion 1231 and the second surface portion 12132 are arranged in a state in which they sandwich the channel direction side of the holding plate 1212 from both sides at the end portion closer to each detector module 1211, and are thermally connected to the holding plate 1212.

[0095] In this embodiment, a cooling pipe 121X for circulating a refrigerant such as cooling water within each of the first surface portion 12131 and the second surface portion 12132 is embedded in each of the first surface portion 12131 and the second surface portion 12132. Here, the cooling pipe 121X is an example of a flow path.

[0096] The cooling pipe 121X provided on the first surface portion 12131 is composed of an inlet 121Xi through which the refrigerant flows in, an outlet 121Xo through which the refrigerant that has flowed inside the first surface portion 12131 flows out, and an internal cooling pipe connecting the inlet 121Xi and the outlet 121Xo.

[0097] Here, the inlet 121Xi is disposed on the side closer to the detector module 1211, and the outlet 121Xo is disposed on the side farther from the detector module 1211 than the inlet 121Xi. Also, the internal cooling pipe is disposed so as to circulate inside the first surface portion 12131 from the side closer to the detector module 1211 to the side farther from the detector module 1211. As a result, the coolant flows through the first surface portion 12131 on the side closer to the detector module 1211, and then flows on the side farther from the detector module 1211.

[0098] The cooling pipes 121X provided on the second surface 12132 are also provided in the same manner as the cooling pipes 121X provided on the first surface 12131. That is, even in the second surface 12132, the coolant flows through the side closer to the detector module 1211, and then flows through the side farther from the detector module 1211.

[0099] As described above, it is assumed that the amount of heat transferred from the signal processing circuit 12112 in the housing 1213 increases the closer to the detector module 1211. Therefore, by providing the cooling pipe 121X so that the refrigerant flows on the side closer to the detector module 1211 and then on the side farther from the detector module 1211, as described above, a cooler refrigerant flows in areas with a larger amount of heat, and a wide range of the first surface portion 12131 and the second surface portion 12132 can be efficiently cooled.

[0100] According to this configuration, by providing the cooling pipes 121X on each of the two faces of the housing 1213 thermally connected to the signal processing circuit 12112 of the detector module 1211, a larger heat dissipation area can be secured compared to the case where fins are provided on the holding plate 1212 as in the comparative example described above. Also, since there is no need to increase the height of the holding plate 1212 compared to the case where fins are provided on the holding plate 1212, a large heat dissipation area can be secured without affecting the length of the FPC for connecting the detector module 1211 and the circuit board.

[0101] Therefore, according to the second embodiment, similarly to the first embodiment, the heat generated by the signal processing circuit 12112 can be transferred to a wider range for cooling, and the signal processing circuit 12112 can be cooled more efficiently. In addition, it is possible to reduce the risk of the detection element 12111 breaking down due to the influence of the heat generated by the signal processing circuit 12112, and to prevent deterioration of signal quality and poor image quality that may occur when the FPC is extended.

[0102] (Modifications of the first and second embodiments) In the above-mentioned first and second embodiments, the detector module unit and the radiation detector disclosed in the present application are applied to an X-ray CT apparatus equipped with a photon-counting detector, but the embodiments are not limited thereto. For example, the detector module unit and the radiation detector disclosed in the present application can be similarly applied to an X-ray CT apparatus equipped with an integral type (current mode measurement method) detector.

[0103] In addition, there are various types of X-ray CT devices, such as the Rotate / Rotate-Type (third generation CT) in which the X-ray tube and detector rotate as a single unit around the subject, and the Stationary / Rotate-Type (fourth generation CT) in which a large number of X-ray detection elements are fixed in a ring-shaped array and only the X-ray tube rotates around the subject, and the detector module unit and radiation detector disclosed in this application can be similarly applied to any type of X-ray CT device.

[0104] In the above-described first and second embodiments, examples have been described in which the technology disclosed in the present application is applied to the X-ray detector of an X-ray CT apparatus as a detector module unit and a radiation detector, but the embodiments are not limited thereto. For example, the detector module unit and the radiation detector disclosed in the present application can be similarly applied to other radiation detectors and radiation diagnostic apparatuses, such as a gamma ray detector and a PET apparatus.

[0105] In addition, the term "processor" used in the above description means a circuit such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an Application Specific Integrated Circuit (ASIC), a programmable logic device (e.g., a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)). When the processor is a CPU, for example, the processor realizes a function by reading and executing a program stored in a memory circuit. On the other hand, when the processor is an ASIC, for example, instead of storing a program in a memory circuit, the function is directly incorporated as a logic circuit in the circuit of the processor. Note that each processor in this embodiment is not limited to being configured as a single circuit for each processor, but may be configured as a single processor by combining multiple independent circuits to realize the function. Furthermore, the multiple components in FIG. 1 may be integrated into a single processor to realize the function.

[0106] In addition, in the above-mentioned embodiment and modified examples, each component of each device shown in the figure is a functional concept, and does not necessarily have to be physically configured as shown in the figure. In other words, the specific form of distribution or integration of each device is not limited to that shown in the figure, and all or a part of it can be functionally or physically distributed or integrated in any unit according to various loads, usage conditions, etc. Furthermore, all or any part of each processing function performed by each device can be realized by a CPU and a program analyzed and executed by the CPU, or can be realized as hardware using wired logic.

[0107] Furthermore, among the processes described in the above-mentioned embodiments and modifications, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically by a known method. In addition, the information including the processing procedures, control procedures, specific names, various data and parameters shown in the above documents and drawings can be changed arbitrarily unless otherwise specified.

[0108] According to at least one of the embodiments described above, the signal processing circuit can be cooled more efficiently.

[0109] Although some embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations of embodiments can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0110] 1 X-ray CT device 12 X-ray detector 121 Detector module unit 1211 Detector Module 12111 Detector element 12112 Signal processing circuit 1212 Retaining plate 1213 Case 12131 First surface 12132 Second Face 1214 Finn 1215 Graphite Sheet 1216 Rail 12171 First Combined Block 12172 Second Combined Block 1218 Circuit Board 1219 X-ray shielding plate 121X cooling tube

Claims

1. A detection unit that converts radiation into electrical signals, A signal processing circuit that processes the aforementioned electrical signal, A holding structure that holds the detection unit and the signal processing circuit and is thermally connected to the signal processing circuit, Equipped with, The retaining structure has a main surface having an area greater than or equal to the area of ​​the other outer surfaces of the retaining structure. Heat dissipation fins are provided on the main surface. Detector module unit.

2. The detection unit includes a detection element array in which a plurality of detection elements that convert the radiation into electrical signals are arranged, The detector module unit according to claim 1.

3. The retaining structure is A retaining plate that holds the detection unit and the signal processing circuit, A housing that supports the aforementioned retaining plate, Includes, The aforementioned main surface is provided on the housing, The detector module unit according to claim 1 or 2.

4. The signal processing circuit and the housing are thermally connected via the retaining plate, The detector module unit according to claim 3.

5. Further comprising a fixing block that supports the signal processing circuit and is fixed to the retaining plate, The signal processing circuit and the retaining plate are thermally connected via the fixing block. The detector module unit according to claim 3.

6. The fixing block, the retaining plate, and the housing are each formed of a heat-conducting material, The detector module unit according to claim 5.

7. The holding structure further comprises a heat transfer member with high thermal conductivity provided on the surface portion having the main surface, The detector module unit according to claim 1 or 2.

8. The heat transfer member includes a graphite sheet provided on the inside of the surface portion having the main surface, The detector module unit according to claim 7.

9. The main surface is a surface that faces an adjacent detector module unit when the plurality of detector module units are arranged in a predetermined arrangement direction. The detector module unit according to claim 1 or 2.

10. The heat dissipation fin includes a plurality of protrusions arranged at intervals from each other, A groove is formed between adjacent protrusions. The detector module unit according to claim 1 or 2.

11. The groove extends from one end to the other of the main surface in a direction perpendicular to both the incident direction of the radiation and the arrangement direction in which the plurality of detector module units are arranged, and is open at both ends in that direction. The detector module unit according to claim 10.

12. The retaining structure has two main surfaces facing opposite directions from each other, The heat dissipation fins are provided on each of the two main surfaces. The detector module unit according to claim 1 or 2.

13. The holding structure is provided on the main surface and further has a rail shape that guides the movement of the detector module unit in the attachment / detachment direction, The rail shape constitutes a part of the heat dissipation fin. The detector module unit according to claim 1 or 2.

14. The holding structure has a box shape including a first surface portion and a second surface portion that face each other, and a connecting member that connects the first surface portion and the second surface portion, The outer surface of at least one of the first surface portion and the second surface portion is the main surface. The detector module unit according to claim 1 or 2.

15. A circuit board disposed inside the holding structure, A shielding member that shields radiation incident on the circuit board, Furthermore, The shielding member is held by the connecting member. The detector module unit according to claim 14.

16. A detection element array in which multiple detection elements that convert radiation into electrical signals are arranged, A signal processing circuit that processes the aforementioned electrical signal, A retaining plate that holds the detection element array and the signal processing circuit, A housing having a first surface and a second surface facing each other via the retaining plate, and thermally connected to the signal processing circuit, Equipped with, The first and second surfaces of the housing each have a flow path for circulating refrigerant. Detector module unit.

17. The flow channels provided on the first surface and the second surface are An inlet located on the side closer to the aforementioned detection element array, An outlet located further from the detection element array than the inlet, Having, The detector module unit according to claim 16.

18. comprising a plurality of detector module units arranged in a predetermined arrangement direction, Each of the plurality of detector module units comprises the detector module unit described in claim 1 or 2. Radiation detector.

19. Each of the plurality of detector module units is a detector module unit according to claim 10, The heat dissipation fins of adjacent detector module units are arranged such that the gap between the protrusions included in the heat dissipation fins of one detector module unit and the protrusions included in the heat dissipation fins of the other detector module unit faces each other. The radiation detector according to claim 18.

20. An X-ray tube that irradiates the subject with X-rays, An X-ray detector that detects X-rays irradiated from the X-ray tube and transmitted through the subject, Equipped with, The X-ray detector comprises the radiation detector described in claim 18. X-ray computed tomography (X-ray) scanner.

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