X-ray CT scanner and method for installing units within the gantry of the X-ray CT scanner

Abstract

To reduce weight and increase rigidity of the whole rotation part including a rotary frame.SOLUTION: An X-ray CT apparatus includes a gantry. The gantry includes: a rotary base supported so as to be rotatable; a plurality of units fixed to the rotary base; and a fixing member installed while being separated from the rotary base to fix at least two of the units to each other.SELECTED DRAWING: Figure 2A

Description

Technical Field

[0001] The embodiments disclosed in this specification and the drawings relate to an X-ray CT apparatus, and a method for attaching and detaching units within the gantry of the X-ray CT apparatus.

Background Art

[0002] The rotation speed of the gantry of an X-ray CT (Computed Tomography) apparatus has been increasing year by year. For example, the gantry has a drum-shaped (cylindrical) rotating base (rotating body). Inside the drum-shaped rotating base, a plurality of units are provided. The plurality of units here are, for example, an X-ray tube, a heat exchanger (cooler) for the X-ray tube, a starter unit for rotating the anode (target) of the X-ray tube, an X-ray detector, a high voltage generator, and the like. When the rotation speed of the gantry increases, the magnitude of the centrifugal force applied to the plurality of units increases. Therefore, when the drum-shaped rotating base is configured to have high rigidity, the mass of this rotating base tends to increase.

[0003] When the mass of the drum-shaped rotating base increases, the amount of electric power required to rotate this rotating base also increases.

[0004] Also, there is a technique of attaching a frame for supporting units to the side surface of the rotating base. However, in this technique, a large centrifugal force generated by high-speed rotation is applied to each unit. Therefore, in order to increase the rigidity of the frame and the rotating base to which the frame is attached, the size and mass of the frame and the rotating base increase. Also, in order to compensate for the shortage of the mAs value due to high-speed rotation, generally the size and mass of each unit tend to increase. Therefore, in this technique, it is difficult to increase the rigidity and reduce the weight of the rotating part so as to cope with high-speed rotation.

[0005] From these things, it is desired to reduce the weight and increase the rigidity of the entire rotating part including the rotating base.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2007-37873 [Patent Document 2] Japanese Patent Publication No. 2007-130119 [Overview of the project] [Problems that the invention aims to solve]

[0007] One of the problems that the embodiments disclosed in this specification and drawings aim to solve is to reduce the weight and increase the rigidity of the entire rotating part, including the rotating base. However, the problems that the embodiments disclosed in this specification and drawings aim to solve are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be positioned as other problems. [Means for solving the problem]

[0008] The X-ray CT apparatus of the embodiment includes a gantry. The gantry includes a rotatably supported rotating base, a plurality of units fixed to the rotating base, and a separate fixing member provided spaced apart from the rotating base for fixing at least two of the plurality of units to each other. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows an example of the configuration of an X-ray CT apparatus according to the first embodiment. [Figure 2A] Figure 2A shows an example of the configuration of the mounting device according to the first embodiment. [Figure 2B] Figure 2B shows an example of a detailed configuration of a part of the mounting device according to the first embodiment. [Figure 3] Figure 3 is a diagram illustrating an example of a method for fixing a unit to a rotating frame according to the first embodiment. [Figure 4]Figure 4 shows an example of the configuration of a unit according to the first embodiment. [Figure 5A] Figure 5A is a flowchart illustrating an example of the procedure for installing the unit according to the first embodiment. [Figure 5B] Figure 5B is a flowchart illustrating an example of the procedure for removing the unit according to the first embodiment. [Figure 6] Figure 6 shows an example of the configuration of a mounting device according to the second embodiment. [Figure 7A] Figure 7A shows an example of the configuration of the mounting device 10b in a state where the second cover 55b is open according to the third embodiment. [Figure 7B] Figure 7B shows an example of the configuration of the mounting device 10b in the state in which the second cover 55b is closed according to the third embodiment. [Figure 8] Figure 8 is a diagram illustrating another example of a color map. [Modes for carrying out the invention]

[0010] The following describes in detail embodiments of the X-ray CT apparatus and the method for installing and removing units within the gantry of the X-ray CT apparatus, with reference to the attached drawings. Furthermore, the X-ray CT apparatus and the method for installing and removing units within the gantry of the X-ray CT apparatus according to this application are not limited to the embodiments described below. The embodiments can also be combined with other embodiments or prior art to the extent that there is no inconsistency in the content. In the following description, similar components are given common reference numerals, and redundant explanations may be omitted.

[0011] (First embodiment) Figure 1 shows an example of the configuration of an X-ray CT apparatus 1 according to the first embodiment. As shown in Figure 1, the X-ray CT apparatus 1 according to the first embodiment includes a gantry device 10, a patient table device 30, and a console device 40.

[0012] Here, in FIG. 1, the rotation axis of the rotating frame 13 or the longitudinal direction of the top plate 33 of the bed device 30 in the non-tilted state is defined as the Z-axis direction. The Z-axis direction is an example of the scan axis direction. Also, the axial direction that is orthogonal to the Z-axis direction and horizontal with respect to the floor surface is defined as the X-axis direction. Further, the axial direction that is orthogonal to the Z-axis direction and the X-axis direction and perpendicular to the floor surface is defined as the Y-axis direction. Note that FIG. 1 is drawn of the gantry device 10 from multiple directions for the purpose of explanation, and shows the case where the X-ray CT apparatus 1 has one gantry device 10.

[0013] The gantry device 10 includes an X-ray tube 11, an X-ray detector 12, a rotating frame 13, an X-ray high voltage device 14, a control device 15, a wedge 16, a collimator 17, and a DAS (Data Acquisition System) 18. Note that the gantry device 10 is also referred to as a gantry.

[0014] The X-ray tube 11 is a vacuum tube having a cathode (filament) that generates thermoelectrons and an anode (target) that generates X-rays upon receiving the collision of thermoelectrons. The X-ray tube 11 generates X-rays to irradiate the subject P by irradiating thermoelectrons from the cathode toward the anode by applying a high voltage from the X-ray high voltage device 14. For example, the X-ray tube 11 includes a rotating anode type X-ray tube that generates X-rays by irradiating thermoelectrons to a rotating anode.

[0015] The X-ray detector 12 detects the X-rays irradiated from the X-ray tube 11 and passed through the subject P, and outputs a signal corresponding to the detected X-ray dose to the DAS 18. The X-ray detector 12 has, for example, a plurality of detector element arrays in which a plurality of detector elements are arranged in the channel direction (channel direction) along an arc centered on the focal point of the X-ray tube 11. The X-ray detector 12 has, for example, a structure in which a plurality of detector element arrays in which a plurality of detector elements are arranged in the channel direction are arranged in the column direction (slice direction, row direction).

[0016] For example, the X-ray detector 12 is an indirect conversion type detector having a grid, a scintillator array, and an optical sensor array. The scintillator array has a plurality of scintillators. Each scintillator has a scintillator crystal that outputs light in an amount of photons corresponding to the incident X-ray dose. The grid is disposed on the X-ray incident side surface of the scintillator array and has an X-ray shielding plate that absorbs scattered X-rays. Note that the grid may also be referred to as a collimator (1D collimator or 2D collimator). The optical sensor array has a function of converting the amount of light from the scintillator into an electrical signal, and has, for example, optical sensors such as photodiodes. Note that the X-ray detector 12 may be a direct conversion type detector having a semiconductor element that converts the incident X-ray into an electrical signal.

[0017] The rotating frame 13 is an annular frame that oppositely supports the X-ray tube 11 and the X-ray detector 12 and rotates the X-ray tube 11 and the X-ray detector 12 by the control device 15. For example, the rotating frame 13 is a casting made of aluminum. Note that, in addition to the X-ray tube 11 and the X-ray detector 12, the rotating frame 13 can further support an X-ray high voltage device 14, a wedge 16, a collimator 17, a DAS 18, etc. Further, the rotating frame 13 can further support various configurations not shown in FIG. 1. The various configurations supported by the rotating frame 13 will be described later. Note that the rotating frame 13 is also referred to as a rotating base, a rotating body, etc. Also, in the gantry device 10, the rotating frame 13 and the parts that rotate and move together with the rotating frame 13 are also referred to as a rotating part.

[0018] The X-ray high voltage device 14 has an electric circuit such as a transformer (transformer) and a rectifier, and has a high voltage generating device that generates a high voltage to be applied to the X-ray tube 11, and an X-ray control device that controls the output voltage corresponding to the X-ray generated by the X-ray tube 11. The high voltage generating device may be a transformer type or an inverter type. Note that the X-ray high voltage device 14 may be provided on the rotating frame 13 or may be provided on a fixed frame not shown.

[0019] The control device 15 includes a processing circuit with a CPU (Central Processing Unit), etc., and a drive mechanism such as a motor and actuator. The control device 15 receives input signals from the input interface 43 and controls the operation of the frame device 10 and the bed device 30. For example, the control device 15 controls the rotation of the rotating frame 13, the tilt of the frame device 10, and the operation of the bed device 30 and the top plate 33. For example, the control device 15 includes a rotary drive device 52 (see Figure 2A) that includes bearings and a motor for rotating the rotating frame 13. The rotary drive device 52 of the control device 15 rotates the rotating frame 13 around an axis of rotation parallel to the Z-axis direction. The control device 15 may be installed on the frame device 10 or on the console device 40.

[0020] The wedge 16 is a filter used to adjust 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 distribution of X-rays irradiated from the X-ray tube 11 to the subject P becomes a predetermined distribution. For example, the wedge 16 is a wedge filter or a bow-tie filter, which is a filter made of aluminum or the like processed to have a predetermined target angle and thickness.

[0021] The collimator 17 is a lead plate or the like used to narrow the irradiation range of X-rays that have passed through the wedge 16, and a slit is formed by combining multiple lead plates or the like. The collimator 17 is sometimes called an X-ray diaphragm. In Figure 1, the wedge 16 is shown to be placed between the X-ray tube 11 and the collimator 17, but the collimator 17 may also be placed between the X-ray tube 11 and the wedge 16. In this case, the wedge 16 transmits and attenuates the X-rays that are irradiated from the X-ray tube 11 and whose irradiation range has been limited by the collimator 17.

[0022] The DAS18 collects X-ray signals detected by each detection element of the X-ray detector 12. For example, the DAS18 has an amplifier that amplifies the electrical signals output from each detection element and an A / D converter that converts the electrical signals into digital signals, thereby generating detection data.

[0023] The data generated by DAS18 is transmitted via optical communication from a transmitter having a light-emitting diode (LED) on the rotating frame 13 to a receiver having a photodiode located on the non-rotating part of the mounting device 10 (e.g., a fixed frame, which is not shown in Figure 1), and then transferred to the console device 40. Here, the non-rotating part is, for example, a fixed frame that rotatably supports the rotating frame 13. The method of transmitting data from the rotating frame 13 to the non-rotating part of the mounting device 10 is not limited to optical communication; any non-contact data transmission method or a contact-type data transmission method may be used.

[0024] The patient bed apparatus 30 is a device for placing and moving the subject P to be photographed, and comprises a base 31, a patient bed drive 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 patient bed drive device 32 is a drive mechanism that moves the top plate 33 on which the subject P is placed in the direction of the long axis of the top plate 33, and includes a motor and actuator, etc. 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. In addition to moving the top plate 33, the patient bed drive device 32 may also move the support frame 34 in the direction of the long axis of the top plate 33.

[0025] The console device 40 includes a memory 41, a display 42, an input interface 43, and a processing circuit 44. Although the console device 40 is described separately from the mounting device 10, the mounting device 10 may include the console device 40 or some of its components.

[0026] Memory 41 can be implemented using, for example, semiconductor memory elements such as RAM (Random Access Memory) or flash memory, a hard disk, or an optical disc. Memory 41 stores, for example, projection data or CT image data. It can also store, for example, programs for circuits included in the X-ray CT scanner 1 to perform various functions. Memory 41 may also be implemented using a group of servers (cloud) connected to the X-ray CT scanner 1 via a network.

[0027] The display 42 displays various types of information. For example, the display 42 may display various images generated by the processing circuit 44, or it may display a GUI (Graphical User Interface) to receive various operations from the operator. For example, the display 42 may be a liquid crystal display or a CRT (Cathode Ray Tube) display. The display 42 may be a desktop type, or it may be composed of a tablet terminal or the like that which can communicate wirelessly with the console device 40. Also, the display 42 is just one example of a display unit.

[0028] The input interface 43 receives various input operations from the operator, converts the received input operations into electrical signals, and outputs them to the processing circuit 44. In addition, the input interface 43 receives input operations from the operator such as scan conditions, reconstruction conditions when reconstructing CT image data, and image processing conditions when generating post-processed images from CT image data.

[0029] For example, the input interface 43 can be implemented by a mouse, keyboard, trackball, switch, button, joystick, touchpad for input operations by touching the operating surface, touchscreen with an integrated display screen and touchpad, non-contact input circuit using an optical sensor, audio input circuit, etc. The input interface 43 may also be provided on the mounting device 10. Furthermore, the input interface 43 may consist of the console device 40 main unit and a tablet terminal or the like that can communicate wirelessly. Moreover, the input interface 43 is not limited to those equipped with physical operating components such as a mouse or keyboard. For example, an electrical signal processing circuit that receives electrical signals corresponding to input operations from an external input device provided separately from the console device 40 and outputs these electrical signals to a processing circuit 44 is also included as an example of the input interface 43.

[0030] The processing circuit 44 controls the operation of the entire X-ray CT apparatus 1. For example, the processing circuit 44 executes control function 441, preprocessing function 442, reconstruction processing function 443, and image processing function 444. Here, for example, each processing function executed by the control function 441, preprocessing function 442, reconstruction processing function 443, and image processing function 444, which are components of the processing circuit 44 shown in Figure 1, is recorded in memory 41 in the form of a program that can be executed by a computer. The processing circuit 44 is, for example, a processor, and by reading each program from memory 41 and executing it, it realizes the function corresponding to each program that has been read. In other words, the processing circuit 44 in the state in which each program has been read has the functions shown in the processing circuit 44 of Figure 1.

[0031] In Figure 1, the control function 441, preprocessing function 442, reconstruction processing function 443, and image processing function 444 are shown as being implemented by a single processing circuit 44, but the embodiments are not limited to this. For example, the processing circuit 44 may be composed of a combination of multiple independent processors, with each processor implementing each program to realize each processing function. Furthermore, each processing function of the processing circuit 44 may be implemented by appropriately distributing or integrating them across one or more processing circuits.

[0032] The control function 441 controls various processes based on input operations received from the operator via the input interface 43. Specifically, the control function 441 controls the CT scan performed by the gantry device 10. For example, the control function 441 controls the collection of counting results in the gantry device 10 by controlling the operation of the X-ray high-voltage device 14, the X-ray detector 12, the control device 15, the DAS 18, and the patient table drive device 32. To give one example, the control function 441 controls the collection of projection data in the positioning scan, which collects positioning images (scan images), and the main scan, which collects images used for diagnosis.

[0033] Furthermore, the control function 441 displays images and other images based on various image data stored in the memory 41 on the display 42.

[0034] The preprocessing function 442 generates projection data by applying preprocessing such as logarithmic transformation, offset correction, inter-channel sensitivity correction, beam hardening correction, scattered radiation correction, and dark count correction to the detection data output from DAS18. The data after preprocessing is also referred to as raw data. The detection data before preprocessing and the raw data after preprocessing are also referred to as projection data.

[0035] The reconstruction processing function 443 generates CT image data by performing reconstruction processing on the projection data generated by the preprocessing function 442, using methods such as filtered back projection and iterative reconstruction. The reconstruction processing function 443 stores the reconstructed CT image data in the memory 41.

[0036] The image processing function 444, based on input operations received from the operator via the input interface 43, converts the CT image data generated by the reconstruction processing function 443 into image data such as tomographic images of arbitrary cross-sections or 3D images obtained through rendering processing, using known methods. The image processing function 444 stores the converted image data in the memory 41.

[0037] The configuration of the X-ray CT apparatus 1 according to the first embodiment has been described above. Based on the above configuration, the X-ray CT apparatus 1 performs the following processes to reduce the weight and increase the rigidity of the entire rotating part, including the rotating frame 13.

[0038] Figure 2A is a diagram showing an example of the configuration of the mounting device 10 according to the first embodiment. Figure 2B is a diagram showing an example of a detailed configuration of a part of the mounting device 10 according to the first embodiment. The left side of Figure 2A shows an example of the internal structure of the mounting device 10 in an XY plan view. The right side of Figure 2A shows an example of the internal structure of the mounting device 10 in a ZY plan view.

[0039] As shown in Figure 2A, the mounting device 10 includes a cover, a rotating frame 13, a rotary drive device 52, a number of units (six units in the example in Figure 2A) 53, and a cross member 54.

[0040] The cover of the mounting device 10 houses the rotating frame 13, the rotary drive device 52, a plurality of units 53, and the cross member 54. The cover of the mounting device 10 is made of reinforced resin such as FRP. The cover of the mounting device 10 includes a first cover 55a and a second cover 55b. The first cover 55a is provided to cover the area of ​​the rotating part on the rotary drive device 52 side of the entire area of ​​the rotating part. The second cover 55b is provided to be openable and closable relative to the first cover 55a. For example, when the second cover 55b is closed relative to the first cover 55a, the second cover 55b is provided to cover the area of ​​the rotating part on the unit 53 side of the entire area of ​​the rotating part. The second cover 55b is opened when attaching a unit 53 to the rotating frame 13, when attaching a cross member 54 to a unit 53, when removing a cross member 54 from a unit 53, and when removing a unit 53 from the rotating frame 13.

[0041] As described above, the rotating frame 13 is rotatably supported by a fixed frame or the like. For example, the rotating frame 13 rotates on a plane parallel to the XY plane, with an axis parallel to the Z-axis direction as its axis of rotation. The rotating frame 13 is composed of an annular member having a side surface and two main surfaces, with a hole formed in the center of these main surfaces. That is, the rotating frame 13 according to this embodiment is annular, not cylindrical. The rotating frame 13 is, for example, a casting made of aluminum. As shown in Figure 2A, a plurality of units 53 are fixed to one of the two main surfaces of the rotating frame 13. A rotation drive device 52 is provided on the other main surface of the rotating frame 13.

[0042] The multiple units 53 are the X-ray tube 11, the X-ray high-voltage device 14, and the X-ray detector 12, etc. Alternatively, the multiple units 53 may be a starter unit for rotating the anode of the X-ray tube 11, or a heat exchanger (cooler) for the X-ray tube 11. When describing each of the multiple units 53 separately, the reference numerals 53a to 53f are used instead of reference numeral 53. For example, unit 53a is the X-ray tube 11, unit 53b is a heat exchanger for the X-ray tube 11, and unit 53c is a starter unit. Also, unit 53d is the X-ray detector 12, unit 53e is an inverter unit for the X-ray high-voltage device 14, and unit 53f is a boost unit for the X-ray high-voltage device 14.

[0043] Multiple units 53 are fixed to the rotating frame 13. Specifically, as described above, multiple units 53 are fixed to one of the two main surfaces of the rotating frame 13. Figure 3 is a diagram illustrating an example of how to fix the units 53 to the rotating frame 13 according to the first embodiment.

[0044] Of the multiple units 53, unit 53d of the X-ray detector 12 is fixedly mounted to a beam protruding from one of the two main surfaces of the rotating frame 13. Meanwhile, the other units 53 are fixedly mounted to the aforementioned main surface of the rotating frame 13 via brackets 60, as shown in Figure 3. In the following description, the main surface of the rotating frame 13 to which the units 53 are fixed will be referred to as the "mounting surface".

[0045] The bracket 60 is an L-shaped member, formed by bending a long, narrow plate-shaped member at approximately 90 degrees. Specifically, the bracket 60 is composed of a long, narrow first plate-shaped member and a long, narrow second plate-shaped member that extends in a direction that intersects the direction in which the first plate-shaped member extends at approximately 90 degrees.

[0046] The first plate-shaped member of the bracket 60 is attached to the unit 53. Therefore, the bracket 60 is attached to the unit 53 such that the second plate-shaped member of the bracket 60 protrudes from the unit 53. The bracket 60 is then fixed to the mounting surface such that the main surface of the second plate-shaped member of the bracket 60 that is on the side facing the mounting surface of the rotating frame 13 is aligned with the mounting surface. Specifically, the main surface of the second plate-shaped member of the bracket 60 on the mounting surface side and the mounting surface of the rotating frame 13 are fixed together by fastening members such as bolts and nuts. In this way, the unit 53 is attached and fixed to the rotating frame 13 via the bracket 60. Note that the bolt is an example of a first fastening member inserted in the Z-axis direction.

[0047] When the user attaches the unit 53 to the rotating frame 13, they open the second cover 55b and attach and secure the unit 53 to the rotating frame 13 using fastening members such as bolts and nuts in the manner described above.

[0048] Furthermore, when the user removes unit 53 from the rotating frame 13, they open the second cover 55b and remove the fixing member to detach unit 53 from the rotating frame 13.

[0049] The fastening members, such as bolts and nuts, are visible to the user when viewed from the Z-axis direction with the second cover 55b open. Therefore, the user can easily open the second cover 55b and insert or remove the fastening members, such as bolts and nuts, in the Z-axis direction. Accordingly, in this embodiment, the user can easily attach the unit 53 to the rotating frame 13 or remove the unit 53 from the rotating frame 13.

[0050] The cross member 54 is an annular member. For example, the cross member 54 may be a casting made of a metal such as aluminum. However, the cross member 54 is not limited to such a casting as long as it has high strength. The cross member 54 connects multiple units 53 and firmly fastens the multiple units 53 together. In other words, the cross member 54 fixes the multiple units 53 to each other.

[0051] Figure 4 shows an example of the configuration of a unit 53 according to the first embodiment. As shown in Figure 4, each of the multiple units 53 has a groove 70 formed therein. Specifically, on the side of the unit 53 opposite to the side facing the rotating frame 13, a groove 70 is formed that conforms to the shape of the cross member 54 so that the cross member 54 can be fitted into it.

[0052] The cross member 54 is fitted into grooves 70 formed in the multiple units 53, thereby fixing the multiple units 53 together. Since the cross member 54 has a predetermined rigidity, the positional relationship of the multiple units 53 to which the cross member 54 is attached is fixed by both the rotating frame 13 and the cross member 54. In particular, in one embodiment, the groove 70 is formed on the surface opposite to the surface that the rotating frame 13 contacts for each of the multiple units 53. As a result, the positional relationship of the multiple units 53 is fixed on both the contact surface and the opposite surface, resulting in support and fixing on two surfaces. This makes it possible to achieve the desired rigidity.

[0053] Furthermore, as indicated by the double arrows in Figure 2A, the cross member 54 is a separate component from the rotating frame 13 and is spaced apart from the rotating frame 13 in the Z-axis direction. Specifically, the cross member 54 is spaced apart from the rotating frame 13 in the Z-axis direction so that a gap is provided between it and the rotating frame 13. Now, referring to Figure 2B, it will be explained how the positional relationship of the multiple units 53 is fixed by the cross member 54, which is spaced apart from the rotating frame 13 in the Z-axis direction. For example, the bracket 60 (see Figure 3) fixes the portion 57 of the multiple units 53 on the rotating frame 13 side in the Z-axis direction to the rotating frame 13. This fixes the positional relationship of the multiple portions 57 of the multiple units 53 on the rotating frame 13 side in the Z-axis direction. Also, as described above, since the cross member 54 has a predetermined rigidity, the positional relationship of the multiple portions 58 of the multiple units 53 on the opposite side of the rotating frame 13 in the Z-axis direction is fixed by the cross member 54. In this way, the cross member 54 fixes the multiple units 53 by fixing the portion 58 opposite to the portion 57 on the rotating frame 13 side in the Z-axis direction of the multiple units 53.

[0054] Note that the cross member 54 may not be an annular member, but rather a plate-shaped or rod-shaped member, or an arc-shaped member with a curved surface (for example, a member corresponding to one of four equal parts obtained by dividing a cylinder with a predetermined thickness in the circumferential direction). In this case, the cross member 54 fixes at least two of the multiple units (six units) 53 to each other. For example, the cross member 54 may fix three or more of the multiple units (six units) 53 to each other. The cross member 54 is an example of a fixing member and a second fixing member.

[0055] When the user attaches the cross member 54 to the unit 53, they open the second cover 55b and push the cross member 54 into the groove 70 in the Z-axis direction to secure it in place. In this way, the user secures the unit 53 via the cross member 54 while the cross member 54 is in contact with the unit 53 by pressing it against the unit 53 in the Z-axis direction.

[0056] Furthermore, when the user removes the cross member 54 from the unit 53, they open the second cover 55b and pull the cross member 54 out of the groove 70 to remove it from the unit 53. In this case, the user pulls the cross member 54 out in the opposite direction to when it is fitted into the groove 70.

[0057] The cross member 54 is visible as exposed when viewed from the Z-axis direction with the second cover 55b open. Therefore, the user can easily open the second cover 55b and insert or remove the cross member 54 in the Z-axis direction. Thus, in this embodiment, the user can easily attach the cross member 54 to the unit 53 or remove the cross member 54 from the unit 53.

[0058] Next, an example of the procedure for installing unit 53 within the stand unit 10 of the X-ray CT apparatus 1 will be described. Figure 5A is a flowchart illustrating an example of the procedure for installing unit 53 according to the first embodiment. The procedure shown in Figure 5A is performed after the user opens the second cover 55b.

[0059] As shown in Figure 5A, in step S101, with the second cover 55b open, the user attaches and secures the unit 53 to the rotating frame 13 using fastening members such as bolts and nuts.

[0060] Then, in step S102, with the second cover 55b open, the user attaches and fixes the cross member 54 to the unit 53 by pushing and fitting the cross member 54 into the groove 70 in the Z-axis direction. In this way, the cross member 54 fixes multiple units 53 to each other. In this manner, the user fixes the unit 53 via the cross member 54 by pressing the cross member 54 against the unit 53 in the Z-axis direction.

[0061] Next, an example of the procedure for removing unit 53 within the stand unit 10 of the X-ray CT apparatus 1 will be described. Figure 5B is a flowchart illustrating an example of the procedure for removing unit 53 according to the first embodiment. The procedure shown in Figure 5B is performed after the user opens the second cover 55b.

[0062] As shown in Figure 5B, in step S201, with the second cover 55b open, the user removes the cross member 54 from the unit 53 by pulling the cross member 54 out of the groove 70 in the opposite direction to when the cross member 54 is fitted into the groove 70.

[0063] Then, in step S202, with the second cover 55b open, the user removes the unit 53 from the rotating frame 13 by removing the fastening members such as bolts and nuts.

[0064] The X-ray CT apparatus 1 according to the first embodiment has been described above. In the first embodiment, the rotating frame 13, a plurality of units 53, and a cross member 54 are integrated into a rotating structure. Therefore, the rotating part including this rotating structure has high rigidity by utilizing the mechanical strength of each unit 53. In addition, the rotating part is lightweight. Accordingly, according to the first embodiment, the entire rotating part including the rotating frame 13 can be made lighter and more rigid.

[0065] Furthermore, since the overall weight of the rotating part can be reduced, the amount of power required to rotate the rotating frame 13 can be reduced.

[0066] Furthermore, as described above, the cross member 54 is spaced apart from the rotating frame 13 in the Z-axis direction so that a gap is provided between it and the rotating frame 13. Therefore, compared to a conventional drum-shaped rotating base that does not have such a gap, in the first embodiment, air flows more easily from the rotation center of the rotating part toward the outer circumference. As a result, according to the first embodiment, heat can be easily dissipated and the rotating part can be cooled more efficiently. In addition, as a result the airflow within the mounting device 10 is improved, noise caused by stagnant air can be reduced. Furthermore, as heat dissipation is improved, the amount of heat dissipated by the fan can be reduced, and as a result the noise from the fan can also be reduced.

[0067] (Second embodiment) In the first embodiment, a case in which an annular or arc-shaped cross member 54 is used was described. However, the cross member may also be polygonal. Therefore, such an embodiment will be described as the second embodiment. In the description of the second embodiment, the differences from the first embodiment will be mainly described, and descriptions of configurations similar to the first embodiment may be omitted.

[0068] Figure 6 shows an example of the configuration of the gantry device 10a according to the second embodiment. The X-ray CT apparatus according to the second embodiment differs from the X-ray CT apparatus 1 according to the first embodiment in that it includes a gantry device 10a instead of a gantry device 10.

[0069] The frame device 10a differs from the frame device 10 according to the first embodiment in that it has a cross member 54a instead of the cross member 54. As shown in Figure 6, the cross member 54a has an octagonal shape. This is because there are eight units 53 fixed by the cross member 54a. In other words, in the second embodiment, for example, if the number of units 53 fixed by the cross member 54a is W (W is an integer of 3 or more), the cross member 54a has a W-shaped polygon. If the number of units 53 fixed by the cross member 54a is two, the cross member 54a will have a shape like a rod-shaped member bent at one point. The cross member 54a is an example of a fixing member and a second fixing member.

[0070] The X-ray CT apparatus according to the second embodiment has been described above. According to the second embodiment, the same effects as those of the first embodiment can be obtained.

[0071] (Third embodiment) The cross member 54 according to the first embodiment or the cross member 54a according to the second embodiment may be provided on the inner surface of the second cover 55b, and when the second cover 55b is closed, the cross member 54 or the cross member 54a may be configured to fix a plurality of units 53. Therefore, such an embodiment will be described as the third embodiment. In the description of the third embodiment, the differences from the first and second embodiments will be mainly described, and descriptions of configurations similar to those of the first and second embodiments may be omitted.

[0072] Figures 7A and 7B show an example of the configuration of the gantry device 10b according to the third embodiment. The X-ray CT apparatus according to the third embodiment differs from the X-ray CT apparatus 1 according to the first embodiment and the X-ray CT apparatus according to the second embodiment in that it includes a gantry device 10b instead of gantry devices 10 and 10a.

[0073] Figure 7A shows the second cover 55b in the open position, and Figure 7B shows the second cover 55b in the closed position. In the mounting device 10b, the cross member 54 or cross member 54a is rotatably supported on the inner surface of the second cover 55b. For example, the cross member 54 or cross member 54a is attached to the second cover 55b via bearings. For example, as shown in Figure 7B, when the second cover 55b is closed, the second cover 55b supports the cross member 54 or cross member 54a so that it can rotate along the XY plane.

[0074] Furthermore, as shown in Figure 7B, when the second cover 55b is closed, the cross member 54 or cross member 54a is attached to and fixed to the multiple units 53. Therefore, according to the third embodiment, the user can attach the cross members 54, 54a to the units 53 with only the simple task of closing the second cover 55b. For this reason, the user can easily attach the cross members 54, 54a to the units 53.

[0075] Furthermore, the user can remove the cross members 54 and 54a from the unit 53 with the simple task of opening the second cover 55b. Therefore, the user can easily remove the cross members 54 and 54a from the unit 53.

[0076] The X-ray CT apparatus according to the third embodiment has been described above. According to the third embodiment, as described above, the user can easily attach the cross members 54, 54a to the unit 53. Furthermore, according to the third embodiment, the same effects as those of the first and second embodiments can be obtained.

[0077] (Fourth embodiment) The first to third embodiments described the case in which one annular or arc-shaped cross member 54, 54a is used. However, multiple cross members may be used. Therefore, such an embodiment will be described as the fourth embodiment. In the description of the fourth embodiment, the differences from the first to third embodiments will be mainly described, and descriptions of configurations similar to those in the first to third embodiments may be omitted.

[0078] Figure 8 shows an example of the configuration of the gantry device 10c according to the fourth embodiment. The X-ray CT apparatus according to the fourth embodiment differs from the X-ray CT apparatus 1 according to the first embodiment in that it includes a gantry device 10c instead of a gantry device 10.

[0079] The support structure 10c differs from the support structure 10 of the first embodiment in that it has multiple cross members 54b instead of a single cross member 54. As shown in Figure 8, the support structure 10c has six cross members 54b. This is because there are six units 53 that are fixed by the cross members 54b. That is, in the fourth embodiment, for example, if the number of units 53 fixed by all the cross members 54b is W (W is an integer of 3 or more), then the number of cross members 54b used will be W. If the number of units 53 fixed by all the cross members 54b is two, then one or two cross members 54b will be used. A cross member 54b is an example of a fixing member.

[0080] For example, of the six cross members 54b, one cross member 54b fixes one pair of units 53a and 53b to each other. Another cross member 54b fixes another pair of units 53c and 53d to each other. The same applies to the other cross members 54b. The "certain cross member 54b" described above is an example of a first fixing member. The "other cross members 54b" described above is an example of a second fixing member.

[0081] In the fourth embodiment, a groove similar to the groove 70 described above may be formed in the unit 53, and the cross member 54b may be attached to the unit 53 by fitting it into this groove. Alternatively, the user may attach the cross member 54b to the unit 53 using sheet metal, screws, or the like.

[0082] The X-ray CT apparatus according to the fourth embodiment has been described above. According to the fourth embodiment, although the number of cross members is increased compared to the first to third embodiments, the overall mass of the cross members can be reduced. This makes it possible to further reduce the weight of the entire rotating part, including the rotating frame 13. Furthermore, according to the fourth embodiment, the same effects as the first embodiment can be obtained.

[0083] According to at least one embodiment described above, it is possible to reduce the weight and increase the rigidity of the entire rotating part, including the rotating frame 13.

[0084] While several embodiments have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of symbols]

[0085] 1 X-ray CT device 10, 10a, 10b, 10c Mounting device 13 rotation frames 53 units 54, 54a, 54b Cross members

Claims

1. The gantry includes a rotatably supported rotating base, a plurality of units fixed to the rotating base, and a separate fixing member provided spaced apart from the rotating base for fixing at least two of the plurality of units to each other. The gantry further comprises a cover that houses the rotating base, the plurality of units, and the fixing member, The cover includes a first cover and a second cover that can be opened and closed relative to the first cover. The fixing member is mounted on the second cover such that it is rotatably supported, and the fixing member secures the at least two units to each other when the second cover is closed relative to the first cover. X-ray CT device.

2. The rotating base is composed of an annular member having a hole in the center and having side surfaces and two main surfaces. The X-ray CT apparatus according to claim 1, wherein at least two of the units are fixed to one of the two main surfaces.

3. The X-ray CT apparatus according to claim 2, wherein the fixing member fixes the portion of the at least two units opposite to the portion on the rotating base side.

4. The X-ray CT apparatus according to any one of claims 1 to 3, wherein the fixing member fixes three or more of the plurality of units to each other.

5. The X-ray CT apparatus according to any one of claims 1 to 3, wherein the fixing member includes a first fixing member that fixes one pair of units from the plurality of units to each other, and a second fixing member that fixes the other two units to each other.

6. The X-ray CT apparatus according to any one of claims 1 to 5, wherein the fixing member is provided spaced apart from the rotating base such that a gap is provided between it and the rotating base.

7. The X-ray CT apparatus according to any one of claims 1 to 6, wherein the fixing member is fitted into grooves formed in the at least two units to fix the at least two units.

8. A step of fixing multiple units to the surface of a rotating base, comprising fixing a bracket that is fixed so as to protrude from each unit and has a surface along the surface, and the surface of the rotating base with a first fixing member inserted in the direction of the scan axis, The steps include fixing at least two of the plurality of units fixed to the rotating base to each other by pressing a second fixing member against the at least two units in the scan axis direction, thereby fixing the at least two units via the second fixing member, Includes, The step of fixing the at least two units is to close the second cover relative to the first cover of a cover which houses the rotating base, the plurality of units, the bracket, the first fixing member, and the second fixing member, the second cover being openable and closable relative to the first cover, rotatably supporting the second fixing member, and to which the second fixing member is attached such that when closed relative to the first cover, the at least two units are fixed together by the second fixing member, thereby fixing the at least two units. Method for installing units within the gantry of an X-ray CT scanner.

9. The cover is the cover of the X-ray CT apparatus, The step of opening the cover is performed before the step of fixing the bracket and the surface of the rotating base with the first fixing member. The method according to claim 8, wherein the first fixing member and the second fixing member appear to be exposed when viewed from the scan axis direction with the cover open.

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