Radiation detector and radiation detector module

A radiation detector according to an embodiment includes a plurality of radiation detector modules and a fixing frame. When a radiation detector module is attached to the fixing frame, a guiding part with a groove shape formed at an end of a support member of the radiation detector module on a side of the fixing frame is fitted to a guiding pin provided to an end of the fixing frame, so that the radiation detector module is positioned in a radiation irradiation direction while a movement thereof in a channel direction and a row direction is restricted.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2018-146698, filed on Aug. 3, 2018; the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a radiation detector and a radiation detector module.

BACKGROUND

Conventionally, a medical image diagnosis apparatus that utilizes radiation, such as an X-ray computed tomography (CT) apparatus or a positron emission tomography (PET) apparatus, includes a radiation detector for detecting radiation from which projection data is generated. Some radiation detectors include a plurality of radiation detector modules, each radiation detector module being individually replaceable.

DETAILED DESCRIPTION

A radiation detector according to an embodiment includes a plurality of radiation detector modules and a fixing frame. The radiation detector modules each include a detection surface where a plurality of detecting elements configured to detect radiation are arranged in a channel direction and a row direction, and a support member configured to support the detecting elements. The fixing frame is configured to fix a position of each of the radiation detector modules so that the radiation detector modules are arranged in the channel direction and attached and the detection surfaces of the radiation detector modules are arranged in the channel direction. A guiding pin is provided at an end of the fixing frame in the row direction, the guiding pin extending in a radiation irradiation direction. A guiding part with a groove shape is formed at an end of the support member on a side of the fixing frame in the row direction, the guiding part extending in the radiation irradiation direction. When the radiation detector module is attached to the fixing frame, the guiding part is fitted to the guiding pin so that the radiation detector module is positioned in the radiation irradiation direction while a movement thereof in the channel direction and the row direction is restricted.

One embodiment of a radiation detector and a radiation detector module is described with reference to the drawings. The structure illustrated in each drawing is schematic and the size of each element or the size ratio between the elements in the drawing may be different from the actual ones. Between the drawings, the size of the same element or the size ratio between the elements may be different.

The embodiment below describes an example in which the radiation detector and the radiation detector module according to the present disclosure are used in an X-ray CT apparatus.

FIG. 1is a diagram illustrating a structure example of the X-ray CT apparatus according to the embodiment.

For example, as illustrated inFIG. 1, an X-ray CT apparatus1according to the present embodiment includes a gantry10, a couch30, and a console40. For the convenience of the description,FIG. 1illustrates a plurality of gantries10.

In the present embodiment, a longitudinal direction of a rotation axis of a rotary frame13in a non-tilt state or a couch top33of the couch30is defined as “Z-axis direction”. In addition, an axial direction that is orthogonal to the Z-axis direction and is parallel to a floor surface is defined as “X-axis direction”. Furthermore, an axial direction that is orthogonal to the Z-axis direction and is perpendicular to the floor surface is defined as “Y-axis direction”.

The gantry10irradiates a subject P (patient, for example) with an X-ray, detects the X-ray having transmitted through the subject P, and outputs the detected X-ray to the console40. The gantry10includes an X-ray tube11, an X-ray detector12, the rotary frame13, a controller15, a wedge16, an X-ray diaphragm17, and an X-ray high-voltage device14.

The X-ray tube11is a vacuum tube that generates an X-ray by delivering thermions from a cathode (filament) to an anode (target) with the application of high voltage from the X-ray high-voltage device14. For example, the X-ray tube11is an X-ray tube of a rotation anode type, which generates the X-ray by delivering thermions to the rotating anode.

The wedge16is a filter that regulates the amount of X-ray emitted from the X-ray tube11. Specifically, the wedge16is a filter that transmits and attenuates the X-ray from the X-ray tube11so that the X-ray to be emitted from the X-ray tube11to the subject P has a predetermined distribution. One example of the wedge16is a filter formed by processing aluminum so as to have a predetermined target angle or a predetermined thickness. Note that the wedge16is called a wedge filter or a bow-tie filter.

The X-ray diaphragm17includes a lead plate or the like to narrow down the irradiation range of the X-ray that has transmitted through the wedge16, and by combining a plurality of lead plates or the like, a slit is formed.

The X-ray detector12detects the X-ray that has been emitted from the X-ray tube11and transmitted through the subject P. Specifically, the X-ray detector12includes a plurality of detecting element rows where the detecting elements are arranged in the channel direction along one arc around a focal point of the X-ray tube11. For example, the X-ray detector12has a structure in which a plurality of detecting element rows, each row having the detecting elements arranged in the channel direction, are arranged in a row direction (also referred to as a slice direction).

For example, the X-ray detector12is an indirect conversion type detector including a collimator, a scintillator array, and an optical sensor array. The scintillator array includes a plurality of scintillators, each scintillator including a scintillator crystal that outputs light with the photon quantity corresponding to the incident X-ray quantity. The collimator (also referred to as grid) is disposed on a surface of the scintillator array on the X-ray incidence side, and includes an X-ray blocking plate that absorbs the scattering X-ray. For example, the collimator is a one-dimensional collimator or a two-dimensional collimator. The optical sensor array includes a plurality of optical sensors, each optical sensor outputting an electric signal based on the amount of light output from the corresponding scintillator. For example, the optical sensor array includes another optical sensor such as a photomultiplier tube (PMT). Note that the X-ray detector12may be a direct conversion type detector including a semiconductor element that converts the incident X-ray into an electric signal.

The X-ray detector12includes a data acquisition system (DAS) that processes the electric signal output from each detecting element. The DAS includes an amplifier that amplifies the electric signal output from each detecting element of the X-ray detector12, and an A/D converter that converts the electric signal into a digital signal, and generates detection data. The detection data generated by the DAS is transferred to the console40.

The X-ray high-voltage device14includes electric circuits such as a transformer (trans) and a rectifier, and also includes a high-voltage generator with a function of generating the high-voltage to be applied to the X-ray tube11and an X-ray controller that controls the output voltage based on the output of the X-ray emitted from the X-ray tube11. The high-voltage generator may be a transformer type or an inverter type. Note that the X-ray high-voltage device14may be provided to the rotary frame13to be described below, or to a support frame (not shown) that rotatably supports the rotary frame13in the gantry10.

The rotary frame13is an annular frame that supports the X-ray tube11and the X-ray detector12, which are provided to face each other, and rotates the X-ray tube11and the X-ray detector12by the use of the controller15to be described below. The rotary frame13includes and supports the X-ray high-voltage device14in addition to the X-ray tube11and the X-ray detector12. The detection data generated by the DAS in the X-ray detector12is transmitted from a transmitter including a light-emitting diode (LED) provided to the rotary frame13, to a receiver including a photodiode provided to a non-rotary part of the gantry10(for example, support frame) through optical communication, and transferred to the console40. A method of transmitting the detection data from the rotary frame13to the non-rotary part of the gantry10is not limited to the aforementioned optical communication and may be any method that enables the non-contact data transmission.

The controller15includes a processing circuitry including a central processing unit (CPU) or the like, and a driving mechanism such as a motor and an actuator. The controller15includes a function of controlling the operation of the gantry10and the couch30upon receiving an input signal from an input interface43attached to the console40or the gantry10. For example, upon receiving the input signal, the controller15controls to rotate the rotary frame13, tilt the gantry10, or operate the couch30and the couch top33. Note that the control of tilting the gantry10is performed by causing the controller15to rotate the rotary frame13around an axis parallel to the X-axis direction on the basis of the inclination angle (tilt angle) information input from the input interface43provided to the gantry10. Note that the controller15may be provided to the gantry10or the console40.

The couch30is a device on which the subject P to be scanned is mounted and moved, and includes a base31, a couch driving device32, the couch top33, and a support frame34. The base31is a housing that supports the support frame34in a manner that the support frame34can be moved in the vertical direction. The couch driving device32is a motor or an actuator that moves the couch top33with the subject P mounted thereon in a major-axis direction of the couch top33. The couch top33provided to an upper surface of the support frame34is a plate on which the subject P is mounted. The couch driving device32may move, in addition to the couch top33, the support frame34in the major-axis direction of the couch top33.

The console40is a device that receives the operator's operation of the X-ray CT apparatus1and reconstructs the CT image data using the detection data collected by the gantry10. The console40includes a memory41, a display42, the input interface43, and a processing circuitry44. In the example described here, the console40and the gantry10are separate bodies; however, the gantry10may include the console40or a part of the console40.

The memory41is formed by, for example, a semiconductor memory element such as a random access memory (RAM) or a flash memory, a hard disk, an optical disk, or the like. The memory41stores the projection data or the CT image data, for example.

The display42displays various kinds of information. For example, the display42outputs medical images (CT images) generated by the processing circuitry44, a graphical user interface (GUI) for receiving various operations from the operator, and the like. The display42is, for example, a liquid crystal display or a cathode ray tube (CRT) display. The display42may be provided to the gantry10, for example. In another example, the display42may be a desktop type or formed as a tablet terminal that can communicate wirelessly with the main body of the console40.

The input interface43receives various input operations from the operator, converts the received input operation into electric signals, and outputs the signals to the processing circuitry44. For example, the input interface43receives, from the operator, a collecting condition when collecting the projection data, a reconstructing condition when reconstructing the CT image data, an image processing condition when generating a processed image from the CT image, and the like. For example, the input interface43is formed by a mouse, a keyboard, a track ball, a switch, a button, a joystick, or the like. For example, the input interface43may be provided to the gantry10or formed as a tablet terminal or the like that can communicate wirelessly with the main body of the console40.

The processing circuitry44controls the entire operation of the X-ray CT apparatus1. For example, the processing circuitry44performs a system controlling function441, a preprocessing function442, a reconstructing function443, and an image processing function444.

The system controlling function441controls various functions of the processing circuitry44on the basis of the input operation received from the operator through the input interface43. For example, the system controlling function441controls the CT scan performed in the X-ray CT apparatus1. The system controlling function441controls the preprocessing function442, the reconstructing function443, and the image processing function444, so as to control the generation or display of the CT image data in the console40.

The preprocessing function442performs the preprocessing such as a logarithmic transformation process, an offset correction process, an inter-channel sensitivity correction process, or a beam hardening correction, on the detection data output from the DAS of the X-ray detector12, and generates the preprocessed projection data. The data (detection data) before the preprocessing and the data after the preprocessing may be collectively referred to as the projection data.

The reconstructing function443performs a reconstructing process using a filtered back projection, a successive approximation reconstruction, or the like, on the projection data generated in the preprocessing function442, and generates the CT image data (reconstructed image data).

The image processing function444converts the CT image data, which have been generated by the reconstructing function443, into tomographic data along an arbitrary cross section or three-dimensional image data by a known method on the basis of the input operation received from the operator through the input interface43. Note that the three-dimensional image data may be directly generated by the reconstructing function443.

Here, for example, the processing circuitry44is achieved by the processor. In this case, the processing functions in the processing circuitry44are stored in the memory41in the form of computer programs that can be performed by a computer. By reading and executing each computer program in the memory41, the processing circuitry44achieves the function corresponding to that computer program. In other words, the processing circuitry44that has read out the computer program has the processing function of the processing circuitry44illustrated inFIG. 1.

Here, each processing function is achieved by one processing circuitry44; however, the processing circuitry44may be formed by combining a plurality of independent processors and each processing function may be achieved by causing each processor to execute the computer program. Each processing function of the processing circuitry44may be achieved dispersedly or integrally in one or a plurality of process circuitries. In addition, each processing function of the processing circuitry44may be achieved by mixing hardware such as circuitry and software. In this example, one memory41stores the computer program corresponding to each processing function; however, the embodiment is not limited to this example. For example, a plurality of storage circuitries may be dispersedly disposed and the processing circuitry44may read out the corresponding computer program from the individual storage circuitry and executes the computer program.

The overall structure of the X-ray CT apparatus1according to the present embodiment has been described. In this structure, the X-ray detector12in the X-ray CT apparatus1according to the present embodiment includes the X-ray detector modules and each X-ray detector module is independently replaceable. In such a structure, for example, in the occurrence of the abnormality in the X-ray detector12, the X-ray detector module with the abnormality can be replaced independently; therefore, the downtime of the system can be shortened.

FIG. 2is a diagram illustrating a structure example of the X-ray detector12according to the present embodiment.

For example, as illustrated inFIG. 2, the X-ray detector12according to the present embodiment has an approximately arc-like shape as a whole, with a center of the arc being fixed to the rotary frame13so as to coincide with the position of the X-ray tube11. Here, the circumferential direction of the arc in the X-ray detector12coincides with the channel direction. In addition, the axial direction of the arc in the X-ray detector12coincides with the row direction. Furthermore, the radial direction of the arc in the X-ray detector12coincides with an X-ray irradiation direction. In each drawing referred to in the description below, the channel direction is indicated by an arrow C, the row direction is indicated by an arrow R, and the X-ray irradiation direction is indicated by an arrow I.

Specifically, the X-ray detector12includes a plurality of X-ray detector modules121, a collimator122, a first fixing frame123, a second fixing frame124, a first support frame125, a second support frame126, and a light-blocking plate127. The X-ray detector12is one example of radiation detectors.

The X-ray detector module121includes a detection surface1211, a support member1212, and a DAS1213. Note that the X-ray detector module121is one example of radiation detector modules.

The detection surface1211is formed by having the detecting elements for detecting the X-ray arranged in the channel direction and the row direction. Specifically, the detection surface1211is formed by having the detecting element rows, each having the detecting elements arranged in the channel direction, arranged in the row direction.

The support member1212supports the X-ray elements that form the detection surface1211. Specifically, the support member1212is formed to have an approximately rectangular parallelepiped shape, and on a surface of the support member1212that faces the X-ray tube11, the detection surface1211is fixed.

The DAS1213includes an amplifier that amplifies the electric signal output from each detecting element in the X-ray detector12, and an A/D converter that converts the electric signal into a digital signal, and generates the detection data. Specifically, the DAS1213is structured as a board having the amplifier and the A/D mounted thereon, and is attached to the surface of the support member1212that is opposite to the detection surface1211so as to extend along the X-ray irradiation direction.

The collimator122is formed by having a plurality of collimator plates disposed in a lattice form, and removes the scattering ray from the X-ray that enters each X-ray detector module121. Specifically, the collimator122is formed to have an approximately arc-like shape along the channel direction, and is disposed to cover the detection surface1211of the X-ray detector module121.

The first fixing frame123and the second fixing frame124fix the positions of the X-ray detector modules121so that the X-ray detector modules121are arranged in the channel direction and attached and the detection surfaces1211of the X-ray detector modules121are arranged in the channel direction.

Specifically, the first fixing frame123is fixed at one end in the row direction of the collimator122, and the second fixing frame124is fixed at the other end in the row direction of the collimator122. To the first fixing frame123and the second fixing frame124, the X-ray detector modules121that are arranged in the channel direction are attached along the surface of the collimator122that is opposite to the surface thereof facing the X-ray tube11. In the description below, the first fixing frame123and the second fixing frame124are collectively referred to as the fixing frame unless they need to be distinguished.

The first support frame125and the second support frame126support the collimator122and the fixing frames. Specifically, the first support frame125and the second support frame126support the collimator122and the fixing frames so as to hold them from both sides in the row direction, and in this state, the first support frame125and the second support frame126are fixed to the support frame (not shown) of the gantry10.

The light-blocking plate127reduces the amount of light entering the detection surface1211of each X-ray detector module121. For example, the light-blocking plate127is a member formed of a material that can suppress the light and has a shape like a thin plate. The light-blocking plate127is attached to the first support frame125and the second support frame126so as to cover the entire collimator122.

The X-ray detector12according to the present embodiment is configured so that each X-ray detector module121is independently detachable from the fixing frame with the other adjacent X-ray detector modules121left attached.

When the X-ray detector module121is detached with the other adjacent X-ray detector modules121left attached, the X-ray detector module121to be detached may interfere with the attached X-ray detector module121. Therefore, a worker needs to perform the exchanging operation carefully.

In view of the above, the X-ray detector12according to the present embodiment is configured to enable the worker to exchange the X-ray detector module121more easily.

Specifically, in the present embodiment, when the X-ray detector module121is attached to the fixing frame, the X-ray detector module121is positioned in the X-ray irradiation direction while the movement thereof in the channel direction and the row direction is restricted.

FIG. 3is a diagram illustrating a structure example of the X-ray detector module121according to the present embodiment.FIG. 4is a diagram illustrating a structure example of the first fixing frame123according to the present embodiment.

For example, as illustrated inFIG. 3, the support member1212of the X-ray detector module121includes a guiding part12121, a fixing hole12122, a first positioning pin12123, a second positioning pin12124, a guidance groove12125, and a jig fixing hole12126.

The guiding part12121is formed at one end of the support member1212in the row direction and has a groove shape that extends in the X-ray irradiation direction. Specifically, at one end of the support member1212in the row direction, the guiding part12121is provided at an approximately central position in the channel direction and is formed to have a cross section, which is orthogonal to the X-ray irradiation direction, that is like a letter U. Here, the guiding part12121is provided to the support member1212at the end that, when the X-ray detector module121is attached to the first fixing frame123and the second fixing frame124, comes to the first fixing frame side.

The fixing hole12122is provided at the other end of the support member1212in the row direction, and is formed so as to penetrate the support member1212in the X-ray irradiation direction. Specifically, the fixing hole12122is provided at an approximately central position in the channel direction at the end of the support member1212that is opposite to the end where the guiding part12121is provided in the row direction.

The first positioning pin12123is provided to the surface of the support member1212on the side that faces the first fixing frame123, and is formed to project in the X-ray irradiation direction. Specifically, the first positioning pin12123is formed to have a long and thin stick shape, and is provided to project from between the detection surface1211and the guiding part12121on the surface of the support member1212on the side that faces the first fixing frame123.

The second positioning pin12124is provided to the surface of the support member1212on the side that faces the second fixing frame124, and is formed to project in the X-ray irradiation direction. Specifically, the second positioning pin12124is formed to have a long and thin stick shape similar to the first positioning pin12123, and is provided to project from between the detection surface1211and the fixing hole12122on the surface of the support member1212on the side that faces the first fixing frame123.

The guidance groove12125is provided to each side surface of the support member1212in the channel direction and is formed to extend in the row direction. Specifically, the guidance groove12125is formed to have a planar bottom surface and have uniform width in the X-ray irradiation direction along the entire length in the row direction in each surface of the support member1212in the channel direction.

The jig fixing hole12126is provided to an end surface of the support member1212that is opposite to the guiding part12121in the row direction, and includes a screw formed on the inside. Specifically, the jig fixing hole12126is provided at an approximately central position in the X-ray irradiation direction and in the channel direction on the end surface of the support member1212that is opposite to the guiding part12121in the row direction.

On the other hand, for example, as illustrated inFIG. 4, the first fixing frame123includes a guiding pin1231and a positioning hole1232in the present embodiment.

The guiding pin1231is provided at the end of the first fixing frame123in the row direction so as to extend in the X-ray irradiation direction. Specifically, the guiding pin1231is a stick-shaped member whose cross-sectional shape that is orthogonal to the longitudinal direction is circular. The guiding pin1231has one end fixed while being inserted in the hole of the first fixing frame123, and the other end extending in the X-ray irradiation direction from the surface of the first fixing frame123on the side that faces the X-ray detector module121.

The positioning hole1232is provided to the surface of the first fixing frame123on the side that faces the support member1212of the X-ray detector module121, and is formed to extend in the X-ray irradiation direction. Specifically, the positioning hole1232is a hole to position the X-ray detector module121at an attachment position that is determined in advance with respect to the first fixing frame123in the channel direction and the row direction. The positioning hole1232is formed at the position where the first positioning pin12123of the X-ray detector module121is to be disposed when the X-ray detector module121is disposed at that attachment position.

Although not shown inFIG. 4, the second fixing frame124also includes a positioning hole that extends in the X-ray irradiation direction on the surface on the side that faces the support member1212of the X-ray detector module121. Specifically, the positioning hole, which extends in the X-ray irradiation direction, is formed at the position where the second positioning pin12124of the X-ray detector module121is to be disposed when the X-ray detector module121is disposed at that attachment position.

In the present embodiment, when the X-ray detector module121is attached to the fixing frame, the aforementioned structure causes the guiding part12121of the support member1212to be fitted to the guiding pin1231of the first fixing frame123; therefore, the X-ray detector module121can be positioned in the radiation irradiation direction while the movement thereof in the channel direction and the row direction is restricted.

Then, in the present embodiment, when the X-ray detector module121is attached to the fixing frame, the aforementioned structure causes the first positioning pin12123to be fitted to the positioning hole1232of the first fixing frame123and the second positioning pin12124to be fitted to the positioning hole of the second fixing frame124with the guiding part12121of the support member1212fitted to the guiding pin1231; thus, the position in the channel direction and the row direction is fixed.

Here, for example, the groove width of the guiding part12121of the support member1212in the channel direction is larger than the width of the guiding pin1231of the first fixing frame123in the channel direction, and the difference from the width of the guiding pin1231in the channel direction is smaller than the gap from the adjacent X-ray detector module121that is attached to the first fixing frame123.

That is to say, in the present embodiment, the groove width of the guiding part12121provided to the support member1212may be different from the width of the guiding pin1231of the first fixing frame123in the channel direction, and may be larger than the width of the guiding pin1231within the range not interfering with the adjacent X-ray detector module121. In this case, the X-ray detector module121with the guiding part12121fitted to the guiding pin1231can move in the channel direction within the range not interfering with the adjacent X-ray detector module121.

Thus, for example, when attaching the X-ray detector module121to the fixing frame, the worker first fits the guiding part12121to the guiding pin1231of the first fixing frame123to roughly check the attachment position of the X-ray detector module121, and then, fits the positioning pin to the positioning hole of the fixing frame while minutely adjusting the position of the X-ray detector module121; thus, the X-ray detector module121can be attached in the end.

Furthermore, in the present embodiment, when the X-ray detector module121is attached to the fixing frame, the guidance groove12125of the support member1212is slidably supported by the jig provided to the guidance groove12125of the support member1212of another attached X-ray detector module121; thus, the X-ray detector module121is guided to move to the X-ray irradiation direction to approach obliquely the fixing frame.

FIG. 5is a diagram illustrating a structure example of the jig according to the present embodiment.

For example, as illustrated inFIG. 5, a jig50has a stick-like shape, and includes a guidance part51, an attachment part52, and an attachment screw53.

The guidance part51is formed to project in the channel direction from the support member1212when the jig50is attached to the guidance groove12125of the support member1212of the X-ray detector module121along the approximately entire length of the jig50. The guidance part51includes an inclined surface that is formed to approach the first fixing frame123in the X-ray irradiation direction from the end disposed opposite to the guiding part12121in the row direction to the end disposed on the guiding part12121side when the jig50is attached to the guidance groove12125of the support member1212of the X-ray detector module121.

The attachment part52is provided at the end disposed opposite to the guiding part12121in the row direction when the jig50is attached to the guidance groove12125of the support member1212of the X-ray detector module121, and formed to extend from the end to the position of the jig fixing hole12126of the support member1212.

The attachment screw53is rotatably attached to an end of the attachment part52, and by the engagement of the jig50with the jig fixing hole12126with the jig50fitted to the guidance groove12125of the support member1212of the X-ray detector module121, the jig50is fixed to the support member1212.

In the present embodiment, when the X-ray detector module121is attached to the fixing frame, the aforementioned structure causes the guidance groove12125of the support member1212to be moved in the row direction in sliding contact with the inclined surface of the guidance part51of the jig50attached to the guidance groove12125of the support member1212of the other attached radiation detector module; thus, the X-ray detector module121is guided to move to the X-ray irradiation direction so as to approach the fixing frame obliquely.

FIGS. 6 and 7are diagrams illustrating how the X-ray detector module121according to the present embodiment is attached.

Here,FIGS. 6 and 7illustrate the three X-ray detector modules121that are provided adjacent to each other in the X-ray detector12.FIG. 6is a front view in which each X-ray detector module121is viewed in the row direction.FIG. 7is a side view in which each X-ray detector module121is viewed in the channel direction and each include the cross section along line S-S inFIG. 6. Note thatFIGS. 6 and 7do not illustrate the DAS1213of each X-ray detector module121.

In the example inFIGS. 6 and 7, a first X-ray detector module121-1at the center is to be attached, and a second X-ray detector module121-2and a third X-ray detector module121-3on both sides are already attached to the fixing frame.

In this case, for each of the second X-ray detector module121-2and the third X-ray detector module121-3that are already attached to the fixing frame, the jig50is attached to the guidance groove12125on the side where the first X-ray detector module121-1to be attached is disposed. Then, the jig50that is attached to each of the second X-ray detector module121-2and the third X-ray detector module121-3is fixed to each X-ray detector module with the attachment screw53.

After that, as illustrated inFIG. 6(a)andFIG. 7(a), the first X-ray detector module121-1is inserted between the second X-ray detector module121-2and the third X-ray detector module121-3in the row direction from an end where the guiding part12121is provided.

Here, the first X-ray detector module121-1is inserted in a state where the end of the guidance groove12125of the support member1212is hung on the inclined surface of the guidance part51of the jig50attached to each of the second X-ray detector module121-2and the third X-ray detector module121-3. Thus, the guidance groove12125of the support member1212of the first X-ray detector module121-1is slidably supported by the jig50that is attached to each of the second X-ray detector module121-2and the third X-ray detector module121-3. That is to say, the sliding surface within the guidance groove12125of the support member1212of the first X-ray detector module121-1is slidably supported by the inclined surface that is provided, obliquely to the sliding surface, to the jig50attached to the guidance groove12125of the support member1212of each of the second X-ray detector module121-2and the third X-ray detector module121-3; thus, the first X-ray detector module121-1is guided to move to the X-ray irradiation direction so as to approach the fixing frame obliquely.

After that, as illustrated inFIG. 6(b)andFIG. 7(b), the first X-ray detector module121-1is further inserted between the second X-ray detector module121-2and the third X-ray detector module121-3in the row direction.

Here, the X-ray detector module121is moved in the row direction with the guidance groove12125of the support member1212in sliding contact with the inclined surface of the guidance part51of the jig50attached to each of the second X-ray detector module121-2and the third X-ray detector module121-3; thus, the X-ray detector module121is guided to move to the X-ray irradiation direction so as to approach the fixing frame obliquely.

After that, as illustrated inFIG. 6(c)andFIG. 7(c), the first X-ray detector module121-1is further inserted between the second X-ray detector module121-2and the third X-ray detector module121-3in the row direction until the guiding part12121is fitted to the guiding pin1231of the first fixing frame123.

Here, by the fitting of the guiding part12121of the support member1212to the guiding pin1231of the first fixing frame123, the X-ray detector module121is guided to move to the X-ray irradiation direction as to approach the fixing frame obliquely while the movement of the X-ray detector module121in the channel direction and the row direction is restricted.

After that, as illustrated inFIG. 6(d)andFIG. 7(d), the first X-ray detector module121-1is attached to the first fixing frame123after being moved toward the first fixing frame123in the X-ray irradiation direction.

Here, the first X-ray detector module121-1is pressed by a fixing member toward the first fixing frame123from the side opposite to the first fixing frame123; thus, the first X-ray detector module121-1is moved in the X-ray irradiation direction and attached to the first fixing frame123.

FIG. 8is a diagram illustrating the state in which the X-ray detector module121according to the present embodiment is attached to the fixing frame.

For example, as illustrated inFIG. 8, in the present embodiment, a screw is formed at the end of the guiding pin1231provided to the first fixing frame123. With the guiding part12121fitted to the guiding pin1231, the X-ray detector module121is pressed to the first fixing frame123by the fixing member1214provided with a screw to be engaged with the screw of the guiding pin1231from the side opposite to the first fixing frame123; thus, the X-ray detector module121is fastened to the first fixing frame123.

Here, for example, the fixing member1214is formed to be longer than the DAS1213when the X-ray detector module121is positioned relative to the first fixing frame123in the X-ray irradiation direction. Thus, the worker can reach for the fixing member1214over the DAS1213and can operate the fixing member1214; thus, without the interruption by the DAS1213, the worker can easily attach the X-ray detector module121to the first fixing frame123.

In addition, in the present embodiment, the surface of the second fixing frame124that faces the support member1212of the X-ray detector module121includes a screw hole. On the other hand, an end of the support member1212of the X-ray detector module121that faces the second fixing frame124includes a penetration hole that penetrates in the X-ray irradiation direction. The X-ray detector module121is fastened to the second fixing frame124by having a screw1215, which is screwed into the screw hole of the second fixing frame124, inserted into the penetration hole from the side opposite to the second fixing frame124and causing the screw1215to press the X-ray detector module121to the second fixing frame124.

Thus, in the present embodiment, the X-ray detector module121, when attached to the fixing frame, has the guiding part12121of the support member1212fitted to the guiding pin1231of the first fixing frame123; thus, the X-ray detector module121is positioned in the radiation irradiation direction while the movement thereof in the channel direction and the row direction is restricted.

In the present embodiment, the X-ray detector module121, when attached to the fixing frame, has the guidance groove12125of the support member1212slidably supported by the jig attached to the guidance groove12125of the support member1212of the other attached X-ray detector module121; thus, the X-ray detector module121is guided to move to the X-ray irradiation direction so as to approach the fixing frame obliquely.

For example, in the case where the X-ray detector module121is attached to the fixing frame, the X-ray detector module121may be inserted linearly in the row direction and moved to the X-ray irradiation direction just before the X-ray detector module121is attached to the fixing frame. In contrast to this structure, in the present embodiment, the X-ray detector module121is guided to move to the X-ray irradiation direction so as to approach the fixing frame obliquely; therefore, moving the X-ray detector module121to the X-ray irradiation direction just before the X-ray detector module121is attached to the fixing frame requires a shorter distance. Thus, the risk of the interference between the X-ray detector module to be attached and the attached X-ray detector module121can be reduced more.

In addition, in the present embodiment, the X-ray detector module121is attached and fixed to the fixing frame that is fixed to the collimator122; therefore, the X-ray detector module121can be positioned more accurately to the collimator122.

Thus, according to the present embodiment, the worker can perform the operation more easily in attaching the X-ray detector module121.

In the above description, mainly, an example of attaching the X-ray detector module121is explained. However, in the present embodiment, the worker can perform the operation more easily also when detaching the X-ray detector module121.

That is to say, in the present embodiment, when the X-ray detector module121is detached, the guiding part12121of the support member1212is fitted to the guiding pin1231of the first fixing frame123similarly; thus, the X-ray detector module121is positioned in the radiation irradiation direction while the movement thereof in the channel direction and the row direction is restricted.

In the present embodiment, when the X-ray detector module121is detached from the fixing frame, the guidance groove12125of the support member1212is slidably supported by the jig attached to the guidance groove12125of the support member1212of the other attached X-ray detector module121; thus, the X-ray detector module121is guided to move to the X-ray irradiation direction so as to be separated obliquely from the fixing frame.

As described above, in the present embodiment, the worker can exchange the radiation detector module more easily.

In the aforementioned embodiment, the guiding part12121is formed so that the cross section thereof orthogonal to the X-ray irradiation direction is a U-like shape; however, the embodiment is not limited to this shape. For example, the guiding part12121may have a trapezoidal or rectangular cross section that is orthogonal to the X-ray irradiation direction.

In the embodiment described above, the radiation detector and the radiation detector module according to the present disclosure are used for the X-ray CT apparatus; however, the embodiment is not limited thereto. For example, the radiation detector and the radiation detector module according to the present disclosure are similarly used for other medical image diagnosis apparatuses that utilize the radiation, such as a PET apparatus.

The term “processor” used in the above description refers to, for example, a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), a field programmable gate array (FPGA), or the like. The processor achieves the function by reading out and executing a computer program in the memory41. The computer program may be, instead of being saved in the memory41, directly incorporated in the circuit of the processor. In this case, the processor achieves the function by reading and executing the computer program incorporated in the circuit. As for the processor in the present embodiment, a single circuit may be formed for each processor or one processor may be formed by combining a plurality of independent circuits to achieve the function. In addition, a plurality of elements in each drawing may be integrated into one processor to achieve the function.

In the embodiment and modifications described above, the function of each element of each device in the drawing is conceptual and the element is not necessarily structured physically as illustrated in the drawing. That is to say, the specific mode of the dispersion and integration of the devices is not limited to the illustrated ones and each device can be entirely or partially structured dispersed or integrated functionally or physically in an arbitrary unit in accordance with various kinds of loads or use situations, for example. Each processing function to be performed in each device may be entirely or arbitrarily partially achieved by the CPU or the computer program that is analyzed and executed in the CPU, or achieved as hardware by wired logic.

Among the processes described in the above embodiment and modifications, all or a part of the processes described to be performed automatically can be performed manually, or on the contrary, all or a part of the processes described to be performed manually can be performed automatically by a known method. In addition, the information including the process procedure, the control procedure, the specific names, various data and parameters, and the like, given in the document or illustrated in the drawings can be changed as appropriate unless specifically stated.

According to at least one embodiment described above, the worker can exchange the radiation detector module more easily.