X-ray computer tomographic imaging device

Abstract

To achieve a compact X-ray CT device capable of performing upright radiography and supine radiography.SOLUTION: An X-ray CT device according to an embodiment includes a gantry body, a first support part, and a second support part. A gantry has: an imaging system related to imaging of an analyte; and an opening to which the analyte is inserted. The first support part has: a first rotation mechanism that rotates the gantry body around a tilt shaft; and a plurality of first movement mechanisms that move the gantry body in a vertical direction. At least two of the plurality of first movement mechanisms are arranged so as to sandwich the tilt shaft in a horizontal direction. The second support part has: a second rotation mechanism that rotates the gantry body around the tilt shaft; and a second movement mechanism that moves the gantry body in the vertical direction. The second movement mechanism is provided by the number of one or more being smaller than the number of the first movement mechanisms. The second movement mechanism is arranged between the tilt shaft and an end portion of the gantry body in the horizontal direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The embodiments disclosed in this specification and the drawings relate to an X-ray computed tomography apparatus. [Background technology]

[0002] Conventionally, there has been known an X-ray computed tomography (CT) apparatus capable of imaging a subject in a supine or upright position. The X-ray CT apparatus has a mechanism for rotating a gantry body equipped with an imaging system between imaging a subject in a supine position (hereinafter referred to as supine imaging) and imaging a subject in an upright position (hereinafter referred to as upright imaging). X-ray CT apparatuses capable of performing both supine and upright imaging include, for example, a movable bed-based type in which the top board can be used only during supine imaging, and a movable gantry-based type in which the gantry is movable for both upright and supine imaging, but the top board is fixed.

[0003] In either type, a mobile base is required to move the bed or gantry, which causes the problem of the X-ray CT system becoming larger. As the X-ray CT system becomes larger, more space is required to install the system. For this reason, one method is to install a tabletop on the gantry, which allows for the compactness of an X-ray CT system that can perform both supine and upright position imaging.

[0004] However, when a tabletop is installed on the gantry, there is a risk that the tabletop may interfere with the ceiling or floor of the CT examination room as the gantry moves during upright imaging, and so the tabletop may need to be removed from the gantry. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-77322 Summary of the Invention [Problem to be solved by the invention]

[0006] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to realize a compact X-ray CT device that can perform upright and supine position imaging. 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]

[0007] The X-ray computed tomography apparatus according to this embodiment includes a gantry main body, a first support unit, and a second support unit. The gantry has an imaging system for imaging a subject and an opening through which the subject is inserted. The first support unit includes a first rotation mechanism that rotates the gantry main body around a tilt axis and multiple first movement mechanisms that move the gantry main body in the vertical direction, with at least two of the multiple first movement mechanisms being arranged to sandwich the tilt axis in the horizontal direction. The second support unit includes a second rotation mechanism that rotates the gantry main body around the tilt axis and second movement mechanisms that move the gantry main body in the vertical direction, with the number of second movement mechanisms being one or more but fewer than the number of first movement mechanisms, and the second movement mechanisms being arranged between the tilt axis and an end of the gantry main body in the horizontal direction. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an X-ray CT apparatus according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the YZ cross section of the first support column according to the embodiment, as viewed from the X axis. [Figure 3] FIG. 3 is a cross-sectional view of the YZ cross section of the second support column according to the embodiment, as viewed from the X axis. [Figure 4] FIG. 4 is a perspective view showing a moving state of the second support column of the gantry device in the standing mode according to the embodiment. [Figure 5] FIG. 5 is a perspective view showing a moving state of the second support column of the gantry device in the standing mode according to the embodiment. [Figure 6] FIG. 6 is a perspective view showing the state of the gantry device and the state of the bed in the standing mode according to the embodiment. [Figure 7] FIG. 7 is a top view showing the state of the gantry device in the standing mode according to the embodiment. [Figure 8] FIG. 8 is a top view showing the state of the gantry device in the supine mode according to the embodiment. [Figure 9] FIG. 9 is a perspective view showing the state of the gantry device and the state of the bed in the standing mode according to a modified example. [Figure 10] FIG. 10 is a top view showing the state of the gantry device in the standing mode according to a modified example. [Figure 11] FIG. 11 is a top view showing the state of the gantry device in the supine position mode according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of an X-ray computed tomography apparatus (hereinafter referred to as an X-ray CT (computed tomography) apparatus) and a movement control method will be described with reference to the drawings. The X-ray CT apparatus according to this embodiment has a structure that can change the posture of the gantry between an upright position imaging state in which an image of a subject can be taken in an upright position and a prone position imaging state in which an image of a subject can be taken in a prone position. In the following embodiments, parts with the same reference numerals perform similar operations, and redundant explanations will be omitted as appropriate.

[0010] (Embodiment) FIG. 1 is a diagram showing an example of the configuration of an X-ray CT apparatus 1 according to an embodiment. As shown in FIG. 1, the X-ray CT apparatus 1 includes a gantry device 10 and a console device 100. For example, the gantry device 10 is installed in a CT examination room, and the console device 100 is installed in a control room adjacent to the CT examination room. The gantry device 10 and the console device 100 are connected to each other by wire or wirelessly so that they can communicate with each other. In this embodiment, an axial direction perpendicular to the floor surface, i.e., the vertical direction, is defined as the Z-axis direction, and two directions perpendicular to the Z-axis direction and perpendicular to each other are defined as the X-axis direction and the Y-axis direction, respectively.

[0011] The gantry 10 is a scanning device configured to perform X-ray CT imaging on a subject in an upright or recumbent position. The console device 100 is a computer that controls the gantry 10. The gantry 10 includes a gantry 11, a first support column 13, a second support column 14, a rotation drive unit 23, and a gantry control unit 25. The gantry 11 is also called a gantry.

[0012] The gantry 11 has an imaging system for imaging a subject and an opening 15 through which the subject can be inserted. The gantry 11 is an example of a gantry main body. The gantry 11 is a structure having a substantially rectangular parallelepiped shape. The opening 15 forms an imaging space for imaging the subject. The gantry 11 is a structure having a substantially cylindrical shape in which the opening 15 is formed. As shown in FIG. 1 , the gantry 11 houses an X-ray tube 17 and an X-ray detector 19 arranged to face each other across the opening 15. The X-ray tube 17 and the X-ray detector 19 are included in the imaging system for imaging the subject in this embodiment. Note that the imaging system may further include a data acquisition circuit (hereinafter referred to as a DAS (Data Acquisition System)) 33, a high-voltage generator 31, a collimator, a wedge, etc. In other words, the gantry 11 has an imaging system for imaging the subject.

[0013] The gantry 11 is supported as a doubly supported beam by the first support column 13 and the second support column 14 so as to be movable in the vertical direction along the first support column 13 and the second support column 14. The gantry 11 is also supported by the first support column 13 and the second support column 14 so that the orientation of the opening 15 can be changed between the vertical direction and the horizontal direction. The orientation of the opening 15 corresponds to, for example, the direction in which the top panel 30 is inserted into the opening 15, in other words, the direction along the rotation axis A1.

[0014] The base 11 has a main frame (not shown) made of metal such as aluminum, and a rotating frame 21 rotatably supported by the main frame via bearings or the like around a rotation axis A1. A ring-shaped electrode (not shown) is provided at the contact point between the main frame and the rotating frame 21. A conductive slider (not shown) is attached to the contact point of the main frame so as to make sliding contact with the ring-shaped electrode.

[0015] The first support column 13 and the second support column 14 are bases that support the gantry 11 at a distance from the floor surface. The first support column 13 is an example of a first support section. The second support column 14 is an example of a second support section. The first support column 13 and the second support column 14 have, for example, a columnar shape such as a cylindrical shape or a rectangular column shape. The first support column 13 and the second support column 14 are formed of any material such as plastic or metal. The first support column 13 and the second support column 14 are attached, for example, to the side portion of the gantry 11. The first support column 13 and the second support column 14 support the gantry 11 so that the rotation axis A1 of the opening 15 is oriented approximately perpendicular to the floor surface in a vertically slidable manner in order to perform X-ray CT imaging of a subject in a sitting or standing position.

[0016] The first support column 13 has a first rotation mechanism and a plurality of first movement mechanisms 131. The second support column 14 has a second rotation mechanism and a second movement mechanism 132. For example, the first support column 13 and the second support column 14 support the pedestal 11 so that the rotation axis A1 can rotate between the vertical direction and the horizontal direction around a horizontal axis (hereinafter referred to as the tilt axis) that is parallel to the floor surface. The pedestal 11, the first support column 13, and the second support column 14 are connected via, for example, a swivel bearing or the like so that the pedestal 11 can rotate around the tilt axis.

[0017] Here, the first support column 13 and the second support column 14 will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a cross-sectional view of the YZ cross section of the first support column according to the embodiment, as seen from the X axis. Fig. 3 is a cross-sectional view of the YZ cross section of the second support column according to the embodiment, as seen from the X axis.

[0018] 2, a first slide mechanism 51 for sliding the base 11 in the vertical direction is housed inside the housing of the first support column 13. The first slide mechanism 51 is realized by, for example, a ball screw. That is, the first slide mechanism 51 includes two screw shafts 511 and two sliders 512.

[0019] The screw shaft 511 is installed inside the housing of the first support column 13 so that its axis is parallel to the vertical direction. One end of the screw shaft 511 is rotatably supported by a support (bearing) 513. The support 513 is provided, for example, at one end of the housing of the first support column 13. The other end of the screw shaft 511 is connected to a first support column driving device (motor) 514. The first support column driving device 514 drives the motor under control of the gantry control device 25.

[0020] The first column driving device 514 is provided at the other end facing the support 513 inside the housing of the first column 13. For example, as shown in FIG. 2, the support 513 may be provided at the bottom of the housing of the first column 13, and the first column driving device 514 may be provided at the top of the housing of the first column 13. Note that the positional relationship between the support 513 and the first column driving device 514 is not limited to the above; for example, the support 513 may be provided at the top of the housing of the first column 13, and the first column driving device 514 may be provided at the bottom of the housing of the first column 13.

[0021] The slider 512 has a through hole in which a screw groove (female thread) is formed to screw into the screw groove (male thread) of the screw shaft 511. The slider 512 is screwed onto the screw shaft 511. The screw shaft 511 rotates in conjunction with the rotation of the rotation shaft of the first support column drive device 514, and the slider 512 slides in the axial direction of the screw shaft 511, i.e., in the vertical direction, as the screw shaft 511 rotates. The above-mentioned multiple screw shafts 511 and multiple sliders 512 correspond to a first movement mechanism 131 related to the movement of the gantry 11. That is, the first movement mechanism 131 is mounted on the first support column 13.

[0022] A first tilt mechanism 53 is attached to the slider 512 of the first slide mechanism 51 to support the gantry 11 rotatably around the rotation axis A1. The first tilt mechanism 53 is an example of a first rotation mechanism. The first tilt mechanism 53 rotates the gantry 12 around the tilt axis. The first tilt mechanism 53 is, for example, a structure having a substantially rectangular parallelepiped shape. The first tilt mechanism 53 is realized by, for example, an axis member 55.

[0023] The shaft member 55 is provided on the slider 512 so that its axis coincides with the tilt axis 61. The shaft member 55 may be attached directly to the slider 512 with a fastener or the like, or may be attached via an existing mechanical element. One end of the shaft member 55 is connected to a rotation drive device (motor) 23. The rotation drive device 23 is provided on the slider 512, for example. The shaft member 55 rotates in conjunction with the rotation of the rotation shaft of the rotation drive device 23. The rotation drive device 23 drives the motor under control of the gantry control device 25.

[0024] Although the rotation drive device 23 and the shaft member 55 are described as being directly connected, this is not limiting and, for example, they may be indirectly connected via a mechanical element such as a gear. Although the rotation drive device 23 is described as being provided on the slider 512, this embodiment is not limited to this and the rotation drive device 23 may be provided anywhere on the housing of the first support column 13 as long as it is directly or indirectly connected to the shaft member 55. A slit is provided in the housing of the first support column 13 along the vertical direction so that the shaft member 55 can slide in the vertical direction in conjunction with the rotation of the rotation axis A1 of the first support column drive device 514. This allows the shaft member 55 to slide in the vertical direction in conjunction with the rotation of the rotation axis A1 of the first support column drive device 514 without mechanical interference from the housing of the first support column 13, etc.

[0025] Furthermore, a plurality of linear guides 57 are provided on the first support column 13 along the vertical direction. A swivel bearing is provided on a block 59 that is movable along the linear guides 57. The block 59 moves along the linear guides 57 by driving a motor under the control of the first movement control circuit 27. The plurality of linear guides 57 and the swivel bearing correspond to a first movement mechanism 131 related to the movement of the gantry 11. That is, the first movement mechanism 131 is mounted on the first support column 13.

[0026] The first movement mechanism 131 moves the block 59 along a linear guide 57 arranged in the vertical direction under the control of the first movement control circuit 27, thereby moving the gantry 11. This allows the gantry 11 to move up and down in the vertical direction. Note that the mechanism for moving the gantry 11 in the vertical direction is not limited to a linear guide, and may be realized by a known mechanism such as a rack and pinion.

[0027] Next, the second support column 14 will be described with reference to Fig. 3. As shown in Fig. 3, a second slide mechanism 52 for sliding the base 11 in the vertical direction is housed inside the housing of the second support column 14. The second slide mechanism 52 is realized by, for example, a ball screw. That is, the second slide mechanism 52 includes a screw shaft 521 and a slider 522.

[0028] The screw shaft 521 is installed inside the housing of the second support column 14 so that its axis is parallel to the vertical direction. One end of the screw shaft 521 is rotatably supported by a support (bearing) 523. The support 523 is provided, for example, at one end of the housing of the second support column 14. The other end of the screw shaft 521 is connected to a second support column driving device (motor) 524. The second support column driving device 524 drives the motor under control of the gantry control device 25.

[0029] The second column driving device 524 is provided at the other end opposite the support member 523 inside the housing of the second column 14. For example, as shown in FIG. 3 , the support member 523 may be provided at the bottom of the housing of the second column 14, and the second column driving device 524 may be provided at the top of the housing of the second column 14. Note that the positional relationship between the support member 523 and the second column driving device 524 is not limited to the above; for example, the support member 523 may be provided at the top of the housing of the second column 14, and the second column driving device 524 may be provided at the bottom of the housing of the second column 14.

[0030] The slider 522 has a through hole in which a screw groove (female thread) is formed to be screwed onto the screw groove (male thread) of the screw shaft 521. The slider 522 is screwed onto the screw shaft 521. The screw shaft 521 rotates in conjunction with the rotation of the rotation shaft of the second support column driving device 524, and the slider 522 slides in the axial direction of the screw shaft 521, i.e., in the vertical direction, as the screw shaft 521 rotates. The screw shaft 521 and the slider 522 correspond to a second movement mechanism 132 related to the movement of the gantry 11. That is, the second movement mechanism 132 is mounted on the second support column 14.

[0031] A second tilt mechanism 54 is attached to the slider 522 of the second slide mechanism 52 to support the gantry 11 so that the gantry 11 can rotate around the rotation axis A1. The second tilt mechanism 54 is an example of a second rotation mechanism. The second tilt mechanism 54 rotates the gantry 12 around the tilt axis. The second tilt mechanism 54 is a structure having a substantially rectangular parallelepiped shape. The second tilt mechanism 54 is realized by, for example, an axis member 56.

[0032] The shaft member 56 is provided on the slider 522 so that its axis coincides with the tilt axis 61. The shaft member 56 may be attached directly to the slider 522 with a fastener or the like, or may be attached via an existing mechanical element. One end of the shaft member 56 is connected to a rotation drive device (motor) 23. The rotation drive device 23 is provided on the slider 522, for example. The shaft member 56 rotates in conjunction with the rotation of the rotation shaft of the rotation drive device 23. The rotation drive device 23 drives the motor under control of the gantry control device 25.

[0033] Although the rotation drive device 23 and the shaft member 56 are described as being directly connected, this is not limiting and they may be indirectly connected via a mechanical element such as a gear. Although the rotation drive device 23 is described as being provided on the slider 512, this embodiment is not limited to this and the rotation drive device 23 may be provided anywhere on the housing of the second support column 14 as long as it is directly or indirectly connected to the shaft member. A slit is provided in the housing of the second support column 14 along the vertical direction so that the shaft member 56 can slide in the vertical direction in conjunction with the rotation of the rotation shaft of the second support column drive device 524. This allows the shaft member 56 to slide in the vertical direction in conjunction with the rotation of the rotation shaft of the second support column drive device 524 without mechanical interference from the housing of the second support column 14, etc.

[0034] Furthermore, a linear guide 58 is provided on the second support column 14 along the vertical direction. A swivel bearing is provided on a block 60 that is movable along the linear guide 58. The block 60 moves along the linear guide 58 by driving a motor under the control of the second movement control circuit 28. The linear guide 58 and the swivel bearing correspond to a second movement mechanism 132 related to the movement of the gantry 11. In other words, the second movement mechanism 132 is mounted on the second support column 14.

[0035] The second movement mechanism 132 moves the block 60 along a linear guide 58 arranged in the vertical direction under the control of the second movement control circuit 28, thereby moving the gantry 11. This allows the gantry 11 to move up and down in the vertical direction. Note that the mechanism for moving the gantry 11 in the vertical direction is not limited to a linear guide, and may be realized by a known mechanism such as a rack and pinion.

[0036] For example, when performing supine position imaging of a subject, first tilt mechanism 53 and second tilt mechanism 54 rotate gantry 11 under the control of first movement control circuit 27 and second movement control circuit 28 so that opening 15 becomes vertical. After the subject lies down on top board 30, top board 30 is moved horizontally by bed 35, which will be described later, thereby enabling supine position imaging of the subject, as with a normal X-ray CT device.

[0037] Furthermore, when performing upright imaging of the subject, the first tilt mechanism 53 and the second tilt mechanism 54 rotate the gantry 11 so that the opening 15 is horizontal under the control of the first movement control circuit 27 and the second movement control circuit 28. The subject stands with their back against the tabletop 30, and the gantry 11 moves up and down to perform upright imaging. The first movement control circuit 27 and the second movement control circuit 28 may be provided as a single movement control circuit.

[0038] Returning to Figure 1, the X-ray tube 17 is a vacuum tube that generates X-rays by applying a high voltage from a high voltage generator 31 and supplying a filament current, causing the cathode (filament) to emit thermoelectrons toward an anode (target). X-rays are generated when the thermoelectrons collide with the target. The X-rays generated at the tube focus in the X-ray tube 17 are shaped into a cone beam, for example, via a collimator, and are then irradiated onto the subject.

[0039] For example, the X-ray tube 17 may be a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermoelectrons. Note that this embodiment is applicable to both a single-tube X-ray CT device and a so-called multi-tube X-ray CT device in which multiple pairs of X-ray tubes 17 and X-ray detectors 19 are mounted on the rotating frame 21.

[0040] The X-ray detector 19 detects X-rays that are emitted from the X-ray tube 17 and pass through the subject P, and outputs an electrical signal corresponding to the X-ray dose to the DAS 33. The X-ray detector 19 has, for example, multiple detection element rows in which multiple detection elements are arranged in the channel direction along one arc with the focus of the X-ray tube 17 as the center.

[0041] The X-ray detector 19 has a structure in which, for example, a plurality of rows of the detector elements are arranged in the slice direction (column direction, row direction). The X-ray CT apparatus 1 includes a rotate / rotate-type (third generation CT) in which the X-ray tube 17 and the X-ray detector 19 rotate together around the subject, and a stationary / rotate-type (fourth generation CT) in which a large number of X-ray detector elements arranged in a ring shape are fixed and only the X-ray tube 17 rotates around the subject, and either type can be applied to this embodiment. Hereinafter, for the sake of specificity, the X-ray CT apparatus 1 of this embodiment will be described taking a third generation CT as an example.

[0042] The X-ray detector 19 is an indirect conversion detector having, for example, a grid, a scintillator array, and a photosensor array. The scintillator array has multiple scintillators, and the scintillators have scintillator crystals that output light with a photon amount corresponding to the amount of incident X-rays. The grid is arranged on the X-ray incident side of the scintillator array and has an X-ray shielding plate that has the function of absorbing scattered X-rays.

[0043] The grid may also be called a collimator (one-dimensional collimator or two-dimensional collimator). The photosensor array has a function of converting the amount of light from the scintillator into an electrical signal according to the amount of light, and includes a photosensor such as a photomultiplier tube (PMT). The X-ray detector 19 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into an electrical signal. The X-ray detector 19 may also be a photon counting type X-ray detector. The X-ray detector 19 is an example of an X-ray detection unit.

[0044] The rotating frame 21 has an opening 15, and an X-ray tube 17 that generates X-rays is attached to the rotating frame 21. Specifically, the rotating frame 21 is an annular frame that supports the X-ray tube 17 and the X-ray detector 19 so that they face each other, and rotates the X-ray tube 17 and the X-ray detector 19 using a gantry control device 25, which will be described later. The rotating frame 21 is connected to a first tilt mechanism 53 and a second tilt mechanism 54, and is rotatably supported on the main frame via support bearings. The rotating frame 21 receives power from a rotation drive device 23 under the control of the gantry control device 25, and rotates around a rotation axis A1 at a constant angular velocity.

[0045] The rotating frame 21 supports not only the X-ray tube 17 and the X-ray detector 19, but also a high-voltage generator 31 and a DAS 33. The rotating frame 21 is housed in a substantially cylindrical housing having an opening 15 that forms an imaging space. The central axis of the opening 15 coincides with the rotation axis A1 of the rotating frame 21.

[0046] The detection data generated by the DAS 33 is transmitted, for example, by optical communication from a transmitter having a light-emitting diode (LED) to a receiver having a photodiode provided in a non-rotating part (e.g., the main frame) of the gantry 10, and then transferred to the console device 100. The method of transmitting the detection data from the rotating frame 21 to the non-rotating part of the gantry 10 is not limited to the optical communication described above, and any method of non-contact data transmission may be used.

[0047] The rotation drive device 23 generates power for rotating the rotating frame 21 under control of the gantry control device 25. The rotation drive device 23 generates power by driving at a rotation speed according to the duty ratio, etc., of a drive signal from the gantry control device 25. The rotation drive device 23 is realized by a motor such as a direct drive motor or a servo motor. The rotation drive device 23 is housed in the first support column 13 and the second support column 14, for example.

[0048] The gantry control device 25 controls the high-voltage generator 31, the rotation drive device 23, the first movement control circuit 27, the second movement control circuit 28, and the DAS 33 in accordance with commands from the console device 100. The gantry control device 25 has a function of receiving input signals from the console device 100 or an input interface attached to the gantry device 10 and controlling the operation of the gantry device 10. For example, the gantry control device 25 receives input signals and controls the rotation of the rotating frame 21 and the tilt of the gantry device 10.

[0049] The gantry control device 25 may be provided on the first support 13 or the second support 14 of the gantry device 10, or may be provided on the console device 100. The function realized by the gantry control device 25 may be implemented as a gantry control function in the processing circuit 107 of the console device 100.

[0050] The gantry control device 25 includes, as hardware resources, a processing device (processor) such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit) and a storage device (memory) such as a ROM (Read Only Memory) or RAM (Random Access Memory).The gantry control device 25 may also be realized by an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), another complex programmable logic device (CPLD), or a simple programmable logic device (SPLD).

[0051] The processing device realizes the above functions by reading and executing a program stored in the storage device. Note that instead of storing a program in the storage device, the processing device may be configured so that the program is directly embedded in the circuitry. In this case, the processing device realizes the above functions by reading and executing the program embedded in the circuitry.

[0052] The top board 30 allows a subject to be placed on it in the supine mode and can be inserted into the opening 15. The top board 30 is supported by the gantry 11 via a bed 35. Specifically, the top board 30 is held by the beds 35 provided at both ends of the opening 15 of the gantry 11. That is, as shown in FIG. 1 , the gantry 11 supports the top board 30 via the bed 35 at the inner wall portion that forms the opening 15.

[0053] The top board 30 is movable by the bed 35 along the direction in which the opening 15 penetrates. In other words, the top board 30 and the gantry 11 are fixed via the bed 35 so as to be slidable relative to the gantry 11 along the rotation axis A1 of the rotating frame 21 in the imaging system.

[0054] The bed 35 is provided in the opening 15 of the gantry 11. For example, the bed 35 is provided at both ends of the opening 15 as shown in FIG. 1. The bed 35 moves the tabletop 30 into the opening 15 under the control of a first movement control circuit 27 and a second movement control circuit 28. The bed 35 is configured, for example, by a roller guide or the like. The bed 35 can be realized by a configuration such as a friction drive or belt mechanism. Note that the bed 35 is not limited to a roller guide, friction drive, belt mechanism, or the like, and can be realized as appropriate by a known mechanism.

[0055] The bed 35 may be mounted on a vertical movement mechanism. The vertical movement mechanism, for example, mounts the bed 35 and is provided on the gantry 11. The vertical movement mechanism is capable of moving the top board 30 in a direction perpendicular to the surface of the top board 30 on which the subject P is placed. For example, the vertical movement mechanism is realized by an actuator (for example, a piston type) that can move (push up) the rotation axis of a roller guide along the Y-axis direction. Note that the means for realizing the vertical movement mechanism is not limited to an actuator.

[0056] When the orientation of the opening 15 is vertical (hereinafter referred to as upright position imaging), the first movement control circuit 27 and the second movement control circuit 28 control the bed 35 to move the top board 30 in the opposite direction to the movement direction of the gantry 11 in accordance with the movement of the gantry 11 along the vertical direction. Furthermore, during upright position imaging, the first movement control circuit 27 and the second movement control circuit 28 control the bed 35 to move the top board 30 in the opposite direction to the movement direction of the gantry 11 when the gantry 11 moves to the imaging position of the subject.

[0057] Furthermore, when a helical scan or a scanogram is performed as imaging of the subject during upright position imaging, the first movement control circuit 27 and the second movement control circuit 28 control the bed 35 to move the top 30 in the direction opposite to the movement direction of the gantry 11. When moving the top 30 in the direction opposite to the movement direction of the gantry 11, the first movement control circuit 27 and the second movement control circuit 28 control the bed 35 to move the top 30 in the opposite direction at the same movement speed as the movement speed of the gantry 11.

[0058] During upright position imaging, when a volume scan is performed as the imaging, the first movement control circuit 27 and the second movement control circuit 28 stop the movement of the gantry 11 and the movement of the top 30. Furthermore, when the orientation of the opening 15 is horizontal, the first movement control circuit 27 and the second movement control circuit 28 control the bed 35 to move the top 30 along the horizontal direction for imaging the subject. In other words, when the gantry device 10 is in the supine position mode, the first movement control circuit 27 and the second movement control circuit 28 control the bed 35 to move only the top 30 in response to a user's instruction via the operation panel 29 or the like.

[0059] The first movement control circuit 27 and the second movement control circuit 28 control the first movement mechanism 131 and the second movement mechanism 132 related to the movement of the gantry 11 and the bed 35 so that the relative positional relationship between the first support column 13, the second support column 14, the gantry 11, and the tabletop 30 becomes a predetermined positional relationship. The predetermined positional relationship corresponds to the positional relationship between the first support column 13, the second support column 14, the gantry 11, and the tabletop 30 such that the tabletop 30 does not come into contact with the floor of the examination room when the gantry 11 is rotated about the X-axis. When the relative positional relationship reaches the predetermined positional relationship, the first movement control circuit 27 and the second movement control circuit 28 control the first tilt mechanism 53 and the second tilt mechanism 54 so as to rotate the orientation of the opening 15 between the horizontal and vertical directions.

[0060] The first movement control circuit 27 and the second movement control circuit 28 are realized by the above-mentioned processor or the like. The processor that realizes the various movement control processes executed by the first movement control circuit 27 and the second movement control circuit 28 corresponds to a movement control unit. Note that in FIG. 1, the first movement control circuit 27 and the second movement control circuit 28 are mounted on the first support column 13 and the second support column 14, but they may also be mounted on the gantry 11 or the console device 100. Furthermore, the functions realized by the first movement control circuit 27 and the second movement control circuit 28 may be mounted on the processing circuit 107 or the gantry control device 25 as movement control functions.

[0061] The operation panel 29 is realized by switch buttons, a touchpad that performs input operations by touching the operation surface, a touch panel display in which a display screen and a touchpad are integrated, etc. The operation panel 29 converts input operations received from the user into electrical signals and outputs them to the gantry control device 25. The operation panel 29 accepts a selection operation, for example, to select an upright mode for imaging a subject in an upright position or a supine mode for imaging a subject in a supine position. The operation panel 29 is provided, for example, on the first support column 13.

[0062] The high voltage generator 31 has electrical circuits such as a transformer and a rectifier, and generates a high voltage to be applied to the X-ray tube 17 and a filament current to be supplied to the X-ray tube 17. The high voltage generator 31 also controls the output voltage according to the X-rays emitted by the X-ray tube 17. The high voltage generator 31 may be of a transformer type or an inverter type. The high voltage generator 31 may be provided on the rotating frame 21 or on the main frame side of the gantry 11.

[0063] The wedge (not shown) is a filter for adjusting the amount of X-rays irradiated from the X-ray tube 17. Specifically, the wedge is a filter that transmits and attenuates the X-rays irradiated from the X-ray tube 17 so that the X-rays irradiated from the X-ray tube 17 to the subject P have a predetermined distribution. The wedge is, for example, a wedge filter or a bow-tie filter, and is a filter made by processing aluminum to have a predetermined target angle and a predetermined thickness.

[0064] The collimator (not shown) is a lead plate or the like for concentrating the X-rays transmitted through the wedge into an X-ray irradiation range, and a slit is formed by combining a plurality of lead plates or the like.

[0065] The DAS 33 has an amplifier that amplifies the electrical signals output from each X-ray detection element of the X-ray detector 19 and an A / D converter that converts the electrical signals into digital signals, and generates detection data. The detection data generated by the DAS 33 is transferred to the console device 100.

[0066] The console device 100 includes a memory 101, a display 103, an input interface 105, and a processing circuit 107. Data communication between the memory 101, the display 103, the input interface 105, and the processing circuit 107 is performed, for example, via a bus (BUS).

[0067] The memory 101 is a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or an integrated circuit storage device that stores various types of information. The memory 101 stores, for example, projection data and reconstructed image data. In addition to an HDD or an SSD, the memory 101 may be a portable storage medium such as a CD (Compact Disc), a DVD (Digital Versatile Disc), or a flash memory, or a drive device that reads and writes various types of information from and to a semiconductor memory element such as a RAM (Random Access Memory). The storage area of ​​the memory 101 may be located within the console device 100 or in an external storage device connected via a network. The memory 101 also stores a control program according to this embodiment. The memory 101 stores volume data generated by a pre-scan or a main scan.

[0068] The display 103 displays various types of information. For example, the display 103 outputs medical images (CT images) generated by the processing circuitry 107, a GUI (Graphical User Interface) for receiving various operations from a user, and the like. For example, the display 103 may be a liquid crystal display (LCD), a cathode ray tube (CRT), an organic electroluminescence display (OLED), a plasma display, or any other display, as appropriate. The display 103 may also be provided on the gantry device 10. The display 103 may also be a desktop type, or may be configured as a tablet terminal or the like capable of wireless communication with the console device 100 main body. The display 103 corresponds to a display unit.

[0069] The input interface 105 accepts various input operations from a user, converts the accepted input operations into electrical signals, and outputs the electrical signals to the processing circuitry 107. For example, the input interface 105 accepts from the user acquisition conditions for acquiring projection data, reconstruction conditions for reconstructing CT images, image processing conditions for generating post-processed images from CT images, etc. As the input interface 105, for example, a mouse, keyboard, trackball, switch, button, joystick, touchpad, touch panel display, etc. can be used as appropriate.

[0070] In this embodiment, the input interface 105 is not limited to one having physical operation components such as a mouse, keyboard, trackball, switch, button, joystick, touchpad, and touch panel display. For example, an example of the input interface 105 also includes an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the device and outputs the electrical signal to the processing circuit 44. The input interface 105 is also an example of an input unit. The input interface 105 may also be provided in the gantry device 10. The input interface 43 may also be configured as a tablet terminal or the like that is capable of wireless communication with the console device 100 main body. The input interface 105 corresponds to the input unit.

[0071] The processing circuitry 107 controls the overall operation of the X-ray CT apparatus 1 in response to electrical signals of input operations output from the input interface 105. For example, the processing circuitry 107 has, as hardware resources, a processor such as a CPU, MPU, or GPU (Graphics Processing Unit), and memories such as ROM and RAM. The processing circuitry 107 executes a system control function 111, a pre-processing function 113, a reconstruction function 115, and an image processing function 117 using a processor that executes a program loaded in memory. The processing circuitry 107, which executes the system control function 111, the pre-processing function 113, the reconstruction function 115, and the image processing function 117, respectively, corresponds to a system control unit, a pre-processing unit, an image generation unit, and an image processing unit. Note that the system control function 111, the pre-processing function 113, the reconstruction function 115, and the image processing function 117 are not limited to being realized by a single processing circuit. A processing circuit may be configured by combining multiple independent processors, and each processor may execute a program to realize the system control function 111, the preprocessing function 113, the reconstruction function 115, and the image processing function 117, respectively.

[0072] The processing circuitry 107 controls each function of the processing circuitry 107 based on an input operation received from a user via the input interface 105 using the system control function 111. Specifically, the system control function 111 reads out a control program stored in the memory 101, expands it on the memory within the processing circuitry 107, and controls each unit of the X-ray CT apparatus 1 in accordance with the expanded control program. For example, the processing circuitry 107 controls each function of the processing circuitry 107 based on an input operation received from a user via the input interface 105.

[0073] The processing circuitry 107 generates data by using a preprocessing function 113, which performs preprocessing such as logarithmic conversion, offset correction, inter-channel sensitivity correction, and beam hardening correction on the detection data output from the DAS 33. Note that data before preprocessing is referred to as raw data, and data after preprocessing is referred to as projection data.

[0074] The processing circuitry 107 generates CT image data by using a reconstruction function 115 to perform reconstruction processing using a filtered back projection (FBP) method, an iterative reconstruction method, or the like on the projection data generated by the preprocessing function 113. That is, the reconstruction function 115 generates an image based on the output from the imaging system. The reconstruction function 115 stores the data of the reconstructed CT image in the memory 101.

[0075] The processing circuitry 107 uses an image processing function 117 to perform various image processing on the CT image reconstructed by the reconstruction function 115. For example, the image processing function 117 performs three-dimensional image processing such as volume rendering, surface volume rendering, image value projection processing, MPR (Multi-Planer Reconstruction) processing, and CPR (Curved MPR) processing on the CT image to generate a display image.

[0076] Conventionally, in an X-ray CT apparatus capable of imaging a subject in a supine or standing position, a moving base is required to move the bed or the gantry, which results in a problem of the X-ray CT apparatus becoming large. Therefore, the X-ray CT apparatus 1 in this embodiment realizes a compact X-ray CT apparatus by moving the second support column 14 supporting the gantry 11 in the horizontal direction. Here, the horizontal movement of the second support column 14 will be described below.

[0077] 4 and 5 are perspective views showing the movement state of the second support column 14 of the gantry device 10 in the standing mode according to this embodiment. 4 and 5 show the gantry 11, first support column 13, first tilt mechanism 53, and second tilt mechanism 54 of the gantry device 10 in the standing mode. Furthermore, the second support column 14 in this embodiment includes a support column movement mechanism 70 that moves the second support column 14 along the horizontal direction M1 when the opening 15 is oriented vertically.

[0078] As shown in Fig. 4, the second support column 14 cooperates with the support column moving mechanism 70 to move horizontally to a position where an end 141 of the second support column 14 is substantially aligned with an end 541 of the second tilting mechanism 54. Also, as shown in Fig. 5, the second support column 14 cooperates with the support column moving mechanism 70 to move horizontally to a position where an end 142 of the second support column 14 is substantially aligned with an end 542 of the second tilting mechanism 54. The second support column 14 is smaller in size than the first support column 13 at least in the horizontal direction.

[0079] Next, the positional relationship between the second support column 14 and the bed 35 will be described with reference to FIGS. 6, 7, and 8. FIG. 6 is a perspective view showing the state of the gantry device and the state of the bed in the standing mode according to an embodiment. FIG. 7 is a top view showing the state of the gantry device in the standing mode according to an embodiment. FIG. 8 is a top view showing the state of the gantry device in the lying mode according to an embodiment. FIGS. 6, 7, and 8 show the gantry 11, first support column 13, tabletop 30, bed 35, first tilt mechanism 53, second tilt mechanism 54, tilt axis 61, and support column movement mechanism 70 of the gantry device 10.

[0080] 6, 7, and 8 includes a gantry 11, a first tilt mechanism 53, and a plurality of first movement mechanisms 131, at least two of which are first support columns 13 arranged to sandwich a tilt axis 61 in the horizontal direction, a second tilt mechanism 54, and a second movement mechanism 132, the number of which is one or more but fewer than the number of the first movement mechanisms 131, and the second movement mechanism 132 includes a second support column 14 arranged between the tilt axis 61 and an end 141 of the gantry 11 in the horizontal direction. The X-ray CT apparatus 1 further includes a bed 35 having a top plate 30, and the horizontal direction is the same as the longitudinal direction of the bed 35.

[0081] 6, 7, and 8, the position of the second support column 14 is a position where the end 142 of the second support column 14 has moved to a position where it is substantially aligned with the end 542 of the second tilt mechanism 54. As shown in Fig. 6, the bed 35 moves the tabletop 30 along the longitudinal direction M2 of the bed 35. The horizontal direction M1 in which the second support column 14 moves is the same direction as the longitudinal direction M2 of the bed 35.

[0082] 6, 7, and 8, the second support column 14 is located at a position in the horizontal direction M1 that is farthest from the position of the bed 35 before the top 30 is moved. In this positional relationship, for example, as shown in Fig. 7, a predetermined distance L1 is provided in a first positional relationship between the position of the bed 35 before the top 30 is moved to the opening 15 and the position of the second support column 14 when the opening 15 is oriented in the vertical direction. In addition, for example, as shown in Fig. 8, a predetermined distance L1 is provided in a second positional relationship between the position of the bed 35 before the top 30 is moved to the opening 15 and the position of the second support column 14 when the opening 15 is oriented in the horizontal direction.

[0083] Here, the predetermined distance L1 is a distance that ensures a path for the subject to move within the examination room. The predetermined distance L1 is, for example, equal to or greater than the width of a subject carrier such as a wheelchair that allows the subject to move around in the subject carrier. This allows the X-ray CT apparatus 1 to perform imaging in both upright and supine positions, and realizes a compact X-ray CT apparatus.

[0084] The X-ray CT apparatus 1 according to the embodiment described above includes a gantry body having an imaging system for imaging a subject and an opening 15 for inserting the subject, a first rotation mechanism for rotating the gantry body around the tilt axis, and a plurality of first movement mechanisms 131 for moving the gantry body in the vertical direction, at least two of the plurality of first movement mechanisms 131 being first support parts arranged to sandwich the tilt axis 61 in the horizontal direction, a second rotation mechanism for rotating the gantry body around the tilt axis, and second movement mechanisms 132 for moving the gantry body in the vertical direction, the number of second movement mechanisms 132 being one or more and fewer than the number of the first movement mechanisms 131, and the second movement mechanisms 132 being provided with a second support part arranged between the tilt axis 61 and the end of the gantry body in the horizontal direction.

[0085] This configuration ensures a space between the bed 35 and the second support part, thereby enabling the X-ray CT apparatus 1 to perform imaging in both upright and supine positions, and realizing a compact X-ray CT apparatus.

[0086] The X-ray CT device 1 also has a table 30 on which a subject is placed and a bed 35 that moves the table 30 to the opening 15, and the horizontal direction is the same as the longitudinal direction of the table 30. The X-ray CT device 1 provides a predetermined gap L1 in a first positional relationship between the position of the table 35 before the table 30 is moved to the opening 15 and the position of the second support part when the opening 15 is oriented in the vertical direction.

[0087] Furthermore, the X-ray CT apparatus 1 provides a predetermined gap L1 in the second positional relationship between the position of the bed 35 before the top board 30 is moved to the opening 15 and the position of the second support part when the opening 15 is oriented horizontally. This allows the X-ray CT apparatus 1 to ensure a line of movement for the subject.

[0088] Furthermore, the second support part moves in the horizontal direction, and the X-ray CT apparatus 1 further includes a support part moving mechanism that moves the second support part along the horizontal direction when the orientation of the opening 15 is vertical. This allows the X-ray CT apparatus 1 to easily change the movement line of the subject depending on the imaging location and the layout of the examination room.

[0089] The above-described embodiment can be modified as needed by partially changing the configuration or functions of each device. Therefore, several modifications of the above-described embodiment will be described below as other embodiments. The following mainly focuses on differences from the above-described embodiment, and the same reference numerals will be used to designate parts that are common to the contents already described, and detailed description will be omitted. The other embodiments described below may be implemented individually or in combination as needed.

[0090] (Variation) The difference between this modified example and the embodiment is that the gantry 11 in the embodiment is a substantially rectangular parallelepiped structure, while the gantry in the modified example is a substantially cylindrical structure. Furthermore, since the gantry in the modified example is a substantially cylindrical structure, the second tilt mechanism is also a substantially arc-shaped structure. Here, the X-ray CT device according to the modified example will be described with reference to Figs. 9, 10, and 11.

[0091] Fig. 9 is a perspective view showing the state of the gantry 20 and the state of the bed 35 in the standing mode according to a modified example. Fig. 10 is a top view showing the state of the gantry 20 in the standing mode according to a modified example. Fig. 11 is a top view showing the state of the gantry 20 in the lying mode according to a modified example. Figs. 9, 10, and 11 show the gantry 12, first support column 13, tabletop 30, bed 35, first tilt mechanism 53, second tilt mechanism 543, tilt axis 61, and support column movement mechanism 70 of the gantry 20.

[0092] The gantry 12 has an imaging system for imaging the subject and an opening 15 into which the subject can be inserted. The gantry 12 is an example of a gantry main body. The opening 15 forms an imaging space for imaging the subject. The gantry 12 is a substantially cylindrical structure in which the opening 15 is formed.

[0093] The gantry 12 is supported as a doubly supported beam by the first support column 13 and the second support column 14 so as to be movable in the vertical direction along the first support column 13 and the second support column 14. The gantry 12 is also supported by the first support column 13 and the second support column 14 so as to change the orientation of the opening 15 between the vertical direction and the horizontal direction. The second tilt mechanism 543 is a structure having a substantially arc shape.

[0094] 9, 10, and 11, the position of the second support column 14 is a position where the end 142 of the second support column 14 is moved to a position where it is substantially aligned with the end 544 of the second tilt mechanism 543. As shown in Fig. 9, the bed 35 moves the tabletop 30 along the longitudinal direction M2 of the bed 35. The horizontal direction M3 in which the second support column 14 moves is the same direction as the longitudinal direction M2 of the bed 35.

[0095] 9, 10, and 11, the second support column 14 is located at a position in the horizontal direction M3 that is farthest from the position of the bed 35 before the top board 30 is moved. In this positional relationship, for example, as shown in FIG. 10, a predetermined distance L1 is provided in a third positional relationship between the position of the bed 35 before the top board 30 is moved to the opening 15 and the position of the second support column 14 when the opening 15 is oriented in the vertical direction.

[0096] 11, for example, a predetermined distance L1 is provided in a fourth positional relationship between the position of the bed 35 before the top board 30 is moved to the opening 15 and the position of the second support column 14 when the opening 15 is oriented horizontally. This allows the X-ray CT apparatus 1 according to the modified example to ensure a line of movement for the subject.

[0097] According to at least one of the embodiments and modifications described above, it is possible to realize a compact X-ray CT apparatus 1 that is capable of performing imaging in both upright and supine positions.

[0098] Although several 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 within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0099] 1... X-ray CT device, 10, 20... gantry device, 11, 12... gantry, 13... first support column, 14...second support column, 15...opening, 17...X-ray tube, 19...X-ray detector, 21...rotating frame, 23...rotation drive device, 25...mounting control device, 27...first movement control circuit, 28...second movement control circuit, 29...operation panel, 30...top board, 31...high voltage generator, 33...DAS, 35...bed, 53...first tilt mechanism, 54, 543...second tilt mechanism, 55, 56...shaft member, 57, 58... Linear guide, 59, 60... Block, 61... Tilt axis, 70...support moving mechanism, 100...console device, 101...memory, 103...display, 105...input interface, 107...processing circuit, 111...system control function, 113...preprocessing function, 115...reconstruction function, 117...image processing function, 131...first moving mechanism, 132...second moving mechanism

Claims

1. a gantry body having an imaging system for imaging a subject and an opening for inserting the subject; a first support unit including a first rotation mechanism that rotates the gantry body around a tilt axis and a plurality of first movement mechanisms that move the gantry body in a vertical direction, at least two of the plurality of first movement mechanisms being arranged to sandwich the tilt axis in a horizontal direction; a second support section including a second rotation mechanism that rotates the gantry body around the tilt axis and a second movement mechanism that moves the gantry body in the vertical direction, the number of the second movement mechanisms being one or more and less than the number of the first movement mechanisms, the second movement mechanisms being disposed between the tilt axis and an end of the gantry body in the horizontal direction; An X-ray computed tomography apparatus comprising:

2. The X-ray computed tomography apparatus according to claim 1 , wherein the second support portion has a dimension smaller than that of the first support portion at least in the horizontal direction.

3. a bed having a top plate on which the subject is placed and configured to move the top plate to the opening; The horizontal direction is the same as the longitudinal direction of the top plate.

2. The X-ray computed tomography apparatus according to claim 1.

4. a predetermined gap is provided in a first positional relationship between a position of the bed before the tabletop is moved to the opening and a position of the second support portion in the vertical direction when the opening is oriented in the first positional relationship; 4. The X-ray computed tomography apparatus according to claim 3.

5. a predetermined gap is provided in a second positional relationship between a position of the bed before the top plate is moved to the opening and a position of the second support part in the horizontal direction when the opening is oriented in the horizontal direction; 4. The X-ray computed tomography apparatus according to claim 3.

6. The second support portion moves in the horizontal direction.

6. An X-ray computed tomography apparatus according to claim 4 or 5.

7. a support portion moving mechanism that moves the second support portion along the horizontal direction when the orientation of the opening is the vertical direction; 7. An X-ray computed tomography apparatus according to claim 6.

8. The gantry body is a substantially cylindrical structure, the first rotation mechanism is a structure having a substantially rectangular parallelepiped shape, The second rotation mechanism is a substantially arc-shaped structure.

2. The X-ray computed tomography apparatus according to claim 1.

Images