JP7043303B2 - X-ray computer tomography equipment - Google Patents

Description

Embodiments of the present invention relate to an X-ray computer tomography apparatus.

The X-ray computer tomography apparatus is equipped with a sleeper having a top plate on which the patient is placed. Since the top plate bends due to the weight of the patient or the like, for example, when a helical scan is performed, a step is generated between the CT images of each slice or volume. In addition, since the top plate vibrates when it is moved, the image quality may deteriorate due to the vibration.

In order to suppress the bending of the top plate, a resin reinforcing plate having a low X-ray absorption rate is added to the top plate. However, even though the X-ray absorption rate is low, the reinforcing plate absorbs X-rays to some extent, so that the image quality may deteriorate.

By providing a support frame on which the top plate can be slid, it is possible to suppress the bending of the top plate. However, in order to bring the support frame closer to the gantry, the tilt angle of the gantry may be limited. In addition, since it is necessary to avoid interference with the gantry, the distance in which the support frame can be slid may be limited.

Japanese Unexamined Patent Publication No. 2016-168064 Japanese Unexamined Patent Publication No. 2013-202294 Japanese Unexamined Patent Publication No. 2017-064400

The problem to be solved by the invention is to suppress the bending of the top plate while avoiding the deterioration of the image quality and the limitation of the tilt angle.

The X-ray computer tomography apparatus according to the embodiment detects a top plate on which the subject is placed, an X-ray source that generates X-rays, and X-rays that are generated from the X-ray source and transmitted through the subject. An X-ray detector, a reinforcing plate provided inside the top plate for reducing the deflection of the top plate, and the top plate and the reinforcing plate can be moved with respect to the long axis direction of the top plate. The support mechanism for supporting and the support mechanism for moving the top plate and the reinforcing plate with respect to the long axis direction are driven, and the reinforcing plate is said to have an X-ray irradiation range from the X-ray tube. It is provided with a drive control unit that limits movement in the long axis direction.

FIG. 1 is a diagram showing a configuration of an X-ray computer tomography apparatus according to the first embodiment. FIG. 2 is a perspective view showing the appearance of the gantry according to the first embodiment. FIG. 3 is a diagram showing a cross-sectional view (YX cross-sectional view) of the support frame and the top plate according to the first embodiment. FIG. 4 is a plan view of the top plate of FIG. 3 as viewed from the back side. FIG. 5 is a diagram showing an example of a configuration of a control device and a sleeper drive device constituting the sleeper drive system according to the first embodiment. FIG. 6 is a diagram showing the movement of the top plate and the reinforcing plate when the top plate is moved from the initial position to the scanning start position according to the first embodiment. FIG. 7 is a diagram showing the movement of the top plate and the reinforcing plate when the top plate is moved from the scanning start position to the initial position according to the first embodiment. FIG. 8 is a diagram showing a cross-sectional view (YX cross-sectional view) of the support frame and the top plate according to the second embodiment. FIG. 9 is a plan view of the top plate of FIG. 8 as viewed from the back side. FIG. 10 is a diagram showing a vertical cross-sectional view (YZ cross-sectional view) of the support frame and the top plate according to the second embodiment. FIG. 11 is a diagram showing a configuration example of a control device and a sleeper drive device constituting the sleeper drive system according to the second embodiment.

Hereinafter, the X-ray computer tomography apparatus according to the present embodiment will be described with reference to the drawings.

(First Embodiment)
FIG. 1 is a diagram showing a configuration of an X-ray computer tomography apparatus 1 according to the first embodiment. Although a plurality of mounts 10 are drawn in FIG. 1 for convenience of explanation, typically, the mount 10 equipped in the X-ray computer tomography apparatus 1 is one.

As shown in FIG. 1, the X-ray computer tomography apparatus 1 has a gantry 10, a sleeper 30, and a console 40. The gantry 10 is a scanning device having a configuration for X-ray CT imaging of the subject P. The sleeper 30 is a transport device for placing the subject P, which is the target of X-ray CT imaging, and positioning the subject P. The console 40 is a computer that controls the gantry 10. For example, the gantry 10 and the sleeper 30 are installed in the CT examination room, and the console 40 is installed in the control room adjacent to the CT examination room. The gantry 10, the sleeper 30, and the console 40 are connected by wire or wirelessly so as to be able to communicate with each other. The console 40 does not necessarily have to be installed in the control room. For example, the console 40 may be installed in the same room together with the gantry 10 and the bed 30. Further, the console 40 may be incorporated in the gantry 10.

As shown in FIG. 1, the gantry 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 data acquisition circuit (DAS: Data). Acquisition System) 18.

The X-ray tube 11 generates X-rays. Specifically, the X-ray tube 11 includes a cathode that generates thermions, an anode that receives thermions flying from the cathode and generates X-rays, and a vacuum tube that holds the cathode and the anode. The X-ray tube 11 is connected to the X-ray high voltage device 14 via a high voltage cable. A filament current is supplied to the cathode by the X-ray high voltage device 14. Thermions are generated from the cathode by the supply of filament current. A tube voltage is applied between the cathode and the anode by the X-ray high voltage device 14. When the tube voltage is applied, thermions fly from the cathode toward the anode and collide with the anode to generate X-rays. The generated X-rays irradiate the subject P. Tube current flows as thermions fly from the cathode to the anode.

The X-ray detector 12 detects X-rays generated from the X-ray tube 11 and passed through the subject P, and outputs an electric signal corresponding to the detected X-ray dose to the DAS 18. The X-ray detector 12 has a structure in which a plurality of X-ray detection element sequences in which a plurality of X-ray detection elements are arranged in the channel direction are arranged in a slice direction (column direction). The X-ray detector 12 is an indirect conversion type detector having, for example, a grid, a scintillator array, and an optical sensor array. The scintillator array has a plurality of scintillators. The scintillator outputs an amount of light corresponding to the incident X dose. The grid is arranged on the X-ray incident surface side of the scintillator array and has an X-ray shielding plate that absorbs scattered X-rays. The grid may also be called a collimator (one-dimensional collimator or two-dimensional collimator). The optical sensor array converts an electric signal according to the amount of light from the scintillator. As the optical sensor, for example, a photodiode is used.

The rotating frame 13 is an annular frame that rotatably supports the X-ray tube 11 and the X-ray detector 12 around the rotation axis Z. Specifically, the rotating frame 13 supports the X-ray tube 11 and the X-ray detector 12 so as to face each other. The rotating frame 13 is rotatably supported around a rotation axis Z by a fixed frame (not shown). The rotation frame 13 is rotated around the rotation axis Z by the control device 15, so that the X-ray tube 11 and the X-ray detector 12 are rotated around the rotation axis Z. An image field of view (FOV) is set in the opening 19 of the rotating frame 13.

In the present embodiment, the rotation axis of the rotation frame 13 in the non-tilt state or the longitudinal direction of the top plate 33 of the bed 30 is orthogonal to the Z direction and the Z direction, and the direction orthogonal to the floor surface is the X direction and Z. The direction orthogonal to the direction and perpendicular to the floor surface is defined as the Y direction.

The X-ray high voltage device 14 includes a high voltage generator and an X-ray control device. The high voltage generator has an electric circuit such as a transformer and a rectifier, and generates a high voltage applied to the X-ray tube 11 and a filament current supplied to the X-ray tube 11. The X-ray control device controls the high voltage applied to the X-ray tube 11 and the filament current supplied to the X-ray tube 11. The high voltage generator may be a transformer type or an inverter type. The X-ray high voltage device 14 may be provided on the rotating frame 13 in the gantry 10 or on a fixed frame (not shown) in the gantry 10.

The wedge 16 regulates the dose of X-rays applied to the subject P. Specifically, the wedge 16 attenuates X-rays so that the dose of X-rays radiated from the X-ray tube 11 to the subject P has a predetermined distribution. For example, the wedge 16 is a metal filter formed by processing a metal such as aluminum, such as a wedge filter and a bow-tie filter. These wedges 16 are processed so as to have a predetermined target angle and a predetermined thickness.

The collimator 17 limits the irradiation range of X-rays transmitted through the wedge 16. The collimator 17 slidably supports a plurality of lead plates that shield X-rays, and adjusts the form of a slit formed by the plurality of lead plates. The collimator 17 is also called an X-ray diaphragm.

The DAS 18 reads an electric signal corresponding to the dose of X-rays detected by the X-ray detector 12 from the X-ray detector 12, amplifies the read electric signal, and integrates the electric signal over a view period. Collect detection data with digital values depending on the dose of X-rays over the view period. The detection data is also called projection data. The DAS 18 is realized by, for example, an application specific integrated circuit (ASIC) equipped with a circuit element capable of generating projection data. The projection data (detection data) generated by the DAS 18 emits light emitted from a transmitter having a light emitting diode (LED) provided in the rotating frame 13 to a non-rotating portion (for example, a fixed frame) of the gantry 10 by optical communication. It is transmitted to a receiver having a diode (LED) and transmitted from the receiver to the console 40. The method of transmitting the projection data from the rotating frame 13 to the non-rotating portion of the gantry 10 is not limited to the above-mentioned optical communication, and any method may be used as long as it is a non-contact type data transmission.

The sleeper 30 includes a base 31, a support frame 32, a top plate 33, and a sleeper drive device 34. The base 31 is installed on the floor. The base 31 is a structure that movably supports the support frame 32 in the direction perpendicular to the floor surface (Y direction). The support frame 32 is a frame provided on the upper part of the base 31. The support frame 32 slidably supports the top plate 33 along the central axis Z. The top plate 33 is a plate-shaped structure having flexibility on which the subject P is placed.

The sleeper drive device 34 is housed in the sleeper 30. The sleeper drive device 34 is a motor or an actuator that generates power for moving the top plate 33 on which the subject P is placed. The sleeper drive device 34 operates according to the control of the console 40 or the like.

The control device 15 controls the X-ray high voltage device 14, the DAS 18, and the sleeper 30 in order to perform X-ray CT imaging according to the image pickup control function 441 by the processing circuit 44 of the console 40. The control device 15 has a processing circuit having a CPU (Central Processing Unit) and the like, and a drive device such as a motor and an actuator. The processing circuit has a processor such as a CPU and a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory) as hardware resources. The control device 15 controls the pedestal 10 and the berth 30 according to, for example, an operation signal from the input interface 43 provided on the console 40, the pedestal 10, the pedestal 30, and the like. For example, the control device 15 controls the rotation of the rotating frame 13, the tilt of the gantry 10, and the operation of the top plate 33 and the sleeper 30.

The console 40 has a memory 41, a display 42, an input interface 43, and a processing circuit 44. Data communication between the memory 41, the display 42, the input interface 43, and the processing circuit 44 is performed via a bus (BUS). Although the console 40 is described as being separate from the gantry 10, the gantry 10 may include all or a part of the components of the console 40.

The memory 41 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 information. The memory 41 stores, for example, projection data and reconstructed image data. In addition to HDDs and SSDs, the memory 41 is located between a portable storage medium such as a CD (Compact Disc), a DVD (Digital Versatile Disc), and a flash memory, and a semiconductor memory element such as a RAM (Random Access Memory). It may be a drive device that reads and writes various information. Further, the storage area of the memory 41 may be in the X-ray computer tomography apparatus 1 or in an external storage apparatus connected by a network.

The display 42 displays various information. For example, the display 42 outputs a medical image (CT image) generated by the processing circuit 44, a GUI (Graphical User Interface) for receiving various operations from the operator, and the like. For example, the display 42 may be, for example, a liquid crystal display (LCD), a CRT (Cathode Ray Tube) display, an organic EL display (OELD), a plasma display, or any other display. , Can be used. Further, the display 42 may be provided on the gantry 10. Further, the display 42 may be a desktop type or a tablet type included in a tablet terminal or the like capable of wireless communication with the console 40 main body.

The input interface 43 receives various input operations from the operator, converts the received input operations into electric signals, and outputs the received input operations to the processing circuit 44. As the input interface 43, for example, a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touch pad, a touch panel display, or the like can be appropriately used. In the present embodiment, the input interface 43 is not limited to the one provided with physical operation parts such as a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touch pad, and a touch panel display. For example, an example of the input interface 43 includes an electric signal processing circuit that receives an electric signal corresponding to an input operation from an external input device provided separately from the device and outputs the electric signal to the processing circuit 44. .. Further, the input interface 43 may be provided on the gantry 10. Further, the input interface 43 may be included in a tablet terminal or the like capable of wireless communication with the console 40 main body.

The processing circuit 44 controls the operation of the entire X-ray computer tomography apparatus 1 according to the electric signal of the input operation output from the input interface 43. For example, the processing circuit 44 has a processor such as a CPU or GPU (Graphics Processing Unit) and a memory such as a ROM or RAM as hardware resources. The processing circuit 44 executes an image pickup control function 441, a reconstruction processing function 442, an image processing function 443, a scan planning function 444, and the like by executing a program expanded in the memory. It should be noted that each function 441 to 444 is not limited to the case where it is realized by a single processing circuit. A processing circuit may be formed by combining a plurality of independent processors, and each processor may execute a program to realize each function 441 to 444.

In the image pickup control function 441, the processing circuit 44 controls the X-ray high voltage device 14, the control device 15, and the DAS 18 for performing X-ray CT imaging. The processing circuit 44 controls the X-ray high voltage device 14, the control device 15, and the DAS 18 according to the imaging conditions determined by the scan planning function 444.

In the reconstruction processing function 442, the processing circuit 44 generates a CT image based on the projection data output from the DAS 18. Specifically, the processing circuit 44 performs preprocessing such as logarithmic conversion processing, offset correction processing, sensitivity correction processing between channels, and beam hardening correction on the projection data output from DAS18. Then, the processing circuit 44 performs a reconstruction process using a filter correction back projection method, a successive approximation reconstruction method, or the like on the projection data after the preprocessing to generate a CT image.

In the image processing function 443, the processing circuit 44 converts the CT image generated by the reconstruction processing function 442 into a tomographic image or a three-dimensional image of an arbitrary cross section based on the input operation received from the operator via the input interface 43. Convert.

In the scan planning function 444, the processing circuit 44 formulates a scan plan automatically or according to an instruction from the operator input via the input interface 43 or the like. The scan plan includes the X-ray irradiation range. The X-ray irradiation range according to the present embodiment means a spatial range through which X-rays pass. The X-ray irradiation range may be specified directly via the input interface or may be calculated by the processing circuit 44 based on other scan planning parameters such as FOV.

FIG. 2 is a perspective view showing the appearance of the gantry 10 according to the present embodiment. As shown in FIG. 2, the gantry 10 has a gantry body 23 in which a substantially cylindrical opening 19 is formed. The gantry main body 23 is supported so as to be tiltable around the tilt axis AT by a fixed portion 25 installed on the floor surface. The tilt axis AT is horizontally orthogonal to the central axis (rotation axis) AR of the opening 19. A sleeper 30 is installed in front of the gantry 10. As shown in FIG. 2, the sleeper 30 is arranged so that the long axis A1 of the top plate 33 is parallel to the central axis AR of the opening 19.

The support frame 32 slidably supports the top plate 33 along the long axis A1. The base 31 supports the top plate 33 so as to be able to move up and down along the vertical axis A2 vertically orthogonal to the long axis A1. The vertical axis A2 faces perpendicular to the floor surface. Hereinafter, the direction parallel to the long axis A1 of the top plate 33 will be referred to as a long axis direction or Z direction, and the direction parallel to the vertical axis A2 will be referred to as a vertical direction or a Y direction. Further, the direction in which the sleeper 30 approaches the pedestal 10 is the + Z direction, the direction in which the sleeper 30 is separated from the pedestal 10 is the −Z direction, the direction in which the sleeper 30 rises is the + Y direction, and the direction in which the sleeper 30 descends is the −Y direction. .. Further, the limit reaching position of the top plate 33 on the + Z direction side is called IN-LIMIT, and the limit reaching position of the top plate 33 on the −Z direction side is called OUT-LIMIT.

FIG. 3 is a diagram showing a cross-sectional view (YX cross-sectional view) of the support frame 32 and the top plate 33 according to the first embodiment. FIG. 4 is a plan view of the top plate 33 as viewed from the back side. As shown in FIG. 3, the top plate 33 is a plate-like structure having a hollow portion 331 formed of an arbitrary material such as carbon. A reinforcing plate 35 is provided in the hollow portion 331. The reinforcing plate 35 is provided to reduce the bending of the top plate 33 due to the subject P. The reinforcing plate 35 is formed of, for example, a hard material such as aluminum or iron. The top plate 33 and the reinforcing plate 35 are supported by a support mechanism 36 so as to be movable in the ± Z direction. The support mechanism 36 is housed in the support frame 32.

As shown in FIGS. 3 and 4, the support mechanism 36 according to the first embodiment has a top plate support mechanism 36-1 and a reinforcing plate support mechanism 36-2 that are independent of each other. The top plate support mechanism 36-1 supports the top plate 33 so as to be movable in the ± Z direction. The top plate support mechanism 36-1 is realized by, for example, a ball screw. In this case, the top plate support mechanism 36-1 has a screw 361 and a nut 362. The screws 361 are arranged parallel to the Z direction. The nut 362 has a screw hole formed with a thread groove that fits into the thread formed in the screw 361. The screw 361 is screwed into the screw hole of the nut 362. A flow path mechanism through which a plurality of balls can circulate is formed in the screw 361 and the nut 362. As the screw 361 rotates, the nut 362 slides in the Z direction after the friction is reduced by the ball.

As shown in FIG. 3, the nut 362 is connected to the top plate 33. For example, the nut 362 and the connecting body (slider) 364 are fastened with screws or the like, and the connecting body 364 and the top plate 33 are fastened with screws or the like. With the above configuration, the top plate 33 connected to the nut 362 slides in the Z direction as the screw 361 rotates. The connection method between the nut 362 and the top plate 33 is not limited to the above method, and any method may be used as long as the nut 362 and the top plate 33 can be integrally moved. Further, the top plate support mechanism 36-1 is not limited to the ball screw alone. The top plate support mechanism 36-1 may be realized by any mechanical element such as a linear motion guide as long as the top plate 33 can be moved in the ± Z direction.

As shown in FIG. 3, the reinforcing plate support mechanism 36-2 supports the reinforcing plate 35 in the hollow portion 331 so as to be movable in the ± Z direction. The reinforcing plate support mechanism 36-2 is realized by, for example, a ball screw. In this case, the reinforcing plate support mechanism 36-2 has a screw 365 and a nut 366. The screws 365 are arranged parallel to the Z direction. The nut 366 has a screw hole formed with a thread groove that fits into the thread formed in the screw 365. The screw 365 is screwed into the screw hole of the nut 366. A flow path mechanism through which a plurality of balls can circulate is formed in the screw 365 and the nut 366. As the screw 365 rotates, the nut 366 slides in the Z direction after the friction is reduced by the ball.

As shown in FIG. 3, the nut 366 is connected to the reinforcing plate 35. For example, the nut 366 and the connecting body (slider) 367 are fastened with screws or the like, and the connecting body 367 and the reinforcing plate 35 are fastened with screws or the like. With the above configuration, the reinforcing plate 35 connected to the nut 366 slides in the Z direction in the hollow portion 331 of the top plate 33 as the screw 365 rotates. A guide 368 that mechanically guides the slide of the reinforcing plate 35 is provided on the inner wall of the hollow portion 331 of the top plate 33. In addition, in order to secure a space for moving the connecting body 367 connecting the reinforcing plate 35 and the nut 366 in the ± Z direction, the movement path of the connecting body 367 in the back surface of the top plate 33 in the ± Z direction. A notch 332 is formed in the portion. The connection method between the nut 366 and the reinforcing plate 35 is not limited to the above method, and any method may be used as long as the nut 366 and the reinforcing plate 35 can be integrally moved. Further, the reinforcing plate support mechanism 36-2 is not limited to the ball screw alone. The reinforcing plate support mechanism 36-2 may be realized by any mechanical element such as a linear motion guide as long as the reinforcing plate 35 can be moved in the ± Z direction.

Next, the configuration of the sleeper drive system according to the first embodiment will be described.

FIG. 5 is a diagram showing a configuration example of the control device 15 and the sleeper drive device 34 constituting the sleeper drive system according to the first embodiment. As shown in FIG. 5, the sleeper drive device 34 includes a top plate drive control device 62, a reinforcing plate drive control device 64, and an elevating drive control device 66. The control device 15 controls the top plate drive control device 62, the reinforcing plate drive control device 64, and the elevating drive control device 66 in order to move the top plate 33 to a target position. When moving the top plate 33 in the ± Z direction, the control device 15 limits the movement of the reinforcing plate 35 in the ± Z direction according to the X-ray irradiation range, so that the top plate drive control device 62 and the reinforcing plate drive control device 64 and control. For example, when the top plate 33 is moved to the target position, the control device 15 moves the top plate 33 and the reinforcing plate 35 in the Z direction toward the target position, and does not superimpose the reinforcing plate 35 on the X-ray irradiation range. When moving to the stop position, the top plate 33 is further moved to the target position while stopping the reinforcing plate 35 at the stop position.

The top plate drive control device 62 is provided on the support frame 32, for example. The top plate drive control device 62 slides the top plate 33 in response to an operation instruction signal from the control device 15. Specifically, the top plate drive control device 62 includes a control circuit 621, a drive device 623, and a detector 625. The control circuit 621 is a servo amplifier that receives an operation instruction signal from the control device 15 and supplies electric power corresponding to the operation instruction signal to the drive device 623. The drive device 623 receives the electric power from the control circuit 621 and drives the top plate support mechanism 36-1 to be connected to slide the top plate 33. Specifically, the drive device 623 is a motor that generates power by the rotation of the drive shaft. The detector 625 is a position detector such as a rotary encoder provided on the drive shaft of the drive device 623.

The reinforcing plate drive control device 64 is provided on the support frame 32, for example. The reinforcing plate drive control device 64 slides the reinforcing plate 35 in response to an operation instruction signal from the control device 15. Specifically, the reinforcing plate drive control device 64 includes a control circuit 641, a drive device 643, and a detector 645. The control circuit 641 is a servo amplifier that receives an operation instruction signal from the control device 15 and supplies electric power corresponding to the operation instruction signal to the drive device 643. The drive device 643 receives the electric power from the control circuit 641 and drives the reinforcing plate support mechanism 36-2 to be connected to slide the reinforcing plate 35. Specifically, the drive device 643 is a motor that generates power by the rotation of the drive shaft. The detector 645 is a position detector such as a rotary encoder provided on the drive shaft of the drive device 643.

The elevating drive control device 66 is provided on the base 31, for example. The elevating drive control device 66 receives an operation instruction signal from the control device 15 and operates an elevating mechanism (not shown) to elevate (moving up and down) the top plate 33, the support frame 32, and the top plate 33. The elevating mechanism is realized by, for example, an X-link. Specifically, the elevating drive control device 66 includes a control circuit 661, a drive device 663, and a detector 665. The control circuit 661 is a servo amplifier that receives an operation instruction signal from the control device 15 and supplies electric power corresponding to the operation instruction signal to the drive device 663. The drive device 663 receives the electric power from the control circuit 661 and drives the elevating mechanism of the connection destination to elevate the support frame 32 and the top plate 33. The detector 665 is a position detector such as a rotary encoder provided on the drive shaft of the drive device 663.

Next, the movement of the top plate 33 and the reinforcing plate 35 according to the first embodiment will be described with reference to FIGS. 6 and 7.

FIG. 6 is a diagram showing the movement of the top plate 33 and the reinforcing plate 35 when the top plate 33 is moved from the initial position PI to the target position PT. The target position PT is defined as the scan start position when X-ray CT imaging is performed with the top plate 33 stopped (conventional scan). The target position PT is defined as the end point on the IN-LINIT side of the top plate 33 when performing X-ray CT imaging with the top plate 33 moved (helical scan). That is, in this case, the scan start position is the position of the top plate 33 when the imaging portion is included in the X-ray irradiation range RX. Although the position of the top plate 33 is defined in FIG. 6 by the tip of the top plate 33, it may be defined by any part of the top plate 33. The destination position PT is set by the processing circuit 44, for example, according to a user's instruction via the input interface 43. The processing circuit 44 may automatically set or switch the target position PT depending on whether the X-ray CT imaging method is conventional scan or helical scan.

Hereinafter, in the description of FIG. 6, the method of X-ray CT imaging is assumed to be helical scan. As shown in FIG. 6, the stop position PX is set at a position in front of the X-ray irradiation range RX (in the −Z direction) and close to the X-ray irradiation range RX. The stop position PX is set at a position where the reinforcing plate 35 does not overlap the X-ray irradiation range RX. The stop position PX may be set by the control device 15 according to a user's instruction via the input interface 43, for example. Further, the stop position PX may be automatically set by the control device 15 according to the X-ray irradiation range RX. For example, a position separated from the end of the X-ray irradiation range RX in the −Z direction by a predetermined distance in the −Z direction is set as the stop position PX. The predetermined distance may be 0 or several centimeters. For convenience, the control device 15 may determine the stop position PX according to the maximum irradiation range of the variable X-ray irradiation range. The control device 15 may set the stop position PX according to the set X-ray irradiation range for individual X-ray CT imaging. As a result, the optimum stop position for individual X-ray CT imaging can be set, whereby the exposure dose of the subject P can be further reduced and the bending of the top plate 33 can be further reduced.

As shown in the upper part of FIG. 6, the position of the top plate 33 in the Z direction is at a position (OUT-LIMIT) away from the gantry main body 23 to the structural limit of the sleeper 30, and the position of the top plate 33 in the Y direction. (Height) is assumed that the top plate 33 is located at the height HI where the opening can be inserted. Initially, it is assumed that the end portion of the reinforcing plate 35 in the + Z direction is located at the limit position in the + Z direction in the hollow portion of the top plate 33.

As shown in the middle of FIG. 6, the control device 15 drives the top plate support mechanism 36-1 in order to move the top plate 33 to the scan start position (not shown in FIG. 6), and also the reinforcing plate 35. The reinforcing plate support mechanism 36-2 is driven to move toward the target position PT. As a result, the reinforcing plate 35 moves in synchronization with the top plate 33. For example, the user inputs an instruction to move the top plate 33 to the start position of the helical scan via the input interface 43. The control device 15 moves the top plate 33 to the start position of the helical scan according to the user's instruction. After that, upon receiving a scan start instruction from the user or when the top plate 33 reaches the start position, the control device 15 automatically controls the X-ray high voltage device 13, the DAS 18, and the sleeper drive device 34. Perform a helical scan. In the helical scan, the top plate 33 is moved toward the target position PT.

While the top plate 33 and the reinforcing plate 35 are moving during the execution of the helical scan or the movement to the scan start position, the control device 15 uses the output signal from the detector 645 to determine the position of the reinforcing plate 35. Monitor. The control device 15 repeatedly determines whether or not the position of the reinforcing plate 35 has reached the stop position PX. Then, when the control device 15 determines that the position of the reinforcing plate 35 has reached the stop position PX, the control device 15 stops driving the reinforcing plate support mechanism 36-2 and fixes the position of the reinforcing plate 35 to the stop position PX.

As shown in the lower part of FIG. 6, after fixing the position of the reinforcing plate 35 to the stop position PX, the control device 15 fixes the position of the reinforcing plate 35 to the stop position PX and sets the top plate 33 to the target position PT. The top plate support mechanism 36-1 is driven to move to. At this time, the driving of the reinforcing plate support mechanism 36-2 is stopped. As a result, only the top plate 33 can be further moved in the + Z direction. Then, when the top plate 33 reaches the target position PT, the control device 15 controls the X-ray high voltage device 13, the DAS 18, and the sleeper drive device 34 in order to end the helical scan. At this time, the control device 15 stops the driving of the top plate support mechanism 36-1 in order to stop the top plate 33 at the target position PT.

Due to the structure of the top plate 33, the reinforcing plate 35, the top plate support mechanism 36-1 and the reinforcing plate support mechanism 36-2, the top plate is stopped even though the reinforcing plate support mechanism 36-2 is stopped. The reinforcing plate 35 may move as the 33 moves. In this case, the control device 15 drives the top plate support mechanism 36-1 and the reinforcing plate support mechanism 36-2 in order to fix the reinforcing plate 35 to the stop position PX while moving the top plate 33 in the + Z direction. Specifically, the top plate support mechanism 36-1 and the reinforcing plate support mechanism 36-2 are driven so as to move the reinforcing plate 35 in the −Z direction while moving the top plate 33 in the + Z direction.

Next, referring to FIG. 7, the top plate 33 and the reinforcing plate 35 when the top plate 33 is moved from the initial position PT set on the IN-LIMIT side to the target position PI set on the OUT-LIMIT side. Explain the movement of. FIG. 7 is a diagram showing the movement of the top plate 33 and the reinforcing plate 35 when the top plate 33 is moved from the initial position PT to the target position PI. As shown in FIG. 7, when the top plate 33 is moved from the initial position PT to the target position PI, the top plate 33 and the reinforcing plate 35 move in the opposite direction to the movement shown in FIG.

That is, as shown in the upper part of FIG. 7, the control device 15 first moves the top plate 33 to the scan start position (not shown in FIG. 7) while fixing the position of the reinforcing plate 35 to the stop position PX. Therefore, the top plate support mechanism 36-1 is driven. At this time, the driving of the reinforcing plate support mechanism 36-2 is stopped. As a result, only the top plate 33 can be moved in the −Z direction. The control device 15 moves the top plate 33 to the start position of the helical scan according to the user's instruction. After that, upon receiving a scan start instruction from the user or when the top plate 33 reaches the start position, the control device 15 automatically controls the X-ray high voltage device 13, the DAS 18, and the sleeper drive device 34. Perform a helical scan. In the helical scan, the top plate 33 is moved toward the target position PI.

While the top plate 33 and the reinforcing plate 35 are moving during the execution of the helical scan or the movement to the scan start position, the control device 15 utilizes the output signal from the detector 645 to reinforce the top plate 33. Monitor the position of 35. The control device 15 repeatedly determines whether or not the position of the reinforcing plate 35 has reached the stop position PX.

As shown in the middle stage of FIG. 7, when it is determined that the position of the reinforcing plate 35 has reached the stop position PX, the control device 15 controls the top plate support mechanism 36-1 in order to move the top plate 33 to the target position PI. At the same time, the reinforcing plate support mechanism 36-2 is also driven in order to move the reinforcing plate 35 toward the target position PI. As a result, the reinforcing plate 35 moves in synchronization with the top plate 33. Then, when the top plate 33 reaches the target position PI, the control device 15 controls the X-ray high voltage device 13, the DAS 18, and the sleeper drive device 34 in order to end the helical scan. At this time, the control device 15 stops driving the top plate support mechanism 36-1 in order to stop the top plate 33 at the target position PI, and drives the reinforcing plate support mechanism 36-2 in order to stop the reinforcing plate 35. Stop.

In FIG. 7, as an example of moving the top plate 33 and the reinforcing plate 35 to the OUT-LIMIT side, the top plate 33 is moved to the initial position PI, but the present embodiment is not limited to this. For example, the top plate 33 may move to the scan start position of the helical scan and stop. In this case, it is possible to execute a reciprocating helical scan (helical shuttle scan) by repeating the movement to the IN-LIMIT side shown in FIG. 6 and the movement to the OUT-LIMIT side shown in FIG. 7.

In this way, the reinforcing plate 35 can be stopped at the stop position PX close to the X-ray irradiation range RX, so that the reinforcing plate 35 is superimposed on the X-ray irradiation range RX while the top plate 33 is slid in the + Z direction. The bending of the top plate 33 due to the subject P can be reduced by the reinforcing plate 35 without causing it to occur. That is, according to the present embodiment, it is possible to generate a high-quality CT image with little reduction in image quality due to bending of the top plate 33. In the helical scan, the image quality between CT images due to the bending of the top plate 33 can be reduced. Further, the above method according to the present embodiment reduces or avoids interference of the support frame 32 with the gantry main body 23 as compared with the method of moving the support frame 32 together with the top plate 33 in order to reduce the bending of the top plate 33. can do. As a result, the top plate 33 can be reinforced without limiting the tilt angle of the gantry main body 23. Further, since the reinforcing plate 35 does not superimpose on the X-ray irradiation range RX, the presence of the reinforcing plate 35 does not adversely affect the image quality of the CT image.

Further, according to the first embodiment, the top plate 33 and the reinforcing plate 35 can be individually moved by the two support mechanisms 36 including the top plate support mechanism 36-1 and the reinforcing plate support mechanism 36-2. Therefore, the reinforcing plate 35 can be moved more accurately than in the second embodiment described below.

This is the end of the description of the movement of the top plate 33 and the reinforcing plate 35 according to the first embodiment.

(Second Embodiment)
The support mechanism 36 according to the first embodiment is independent of the top plate support mechanism 36-1 for the top plate 33 and the reinforcing plate support mechanism 36-2 for the reinforcing plate 35. In the support mechanism 36 according to the second embodiment, the support mechanism for the top plate 33 and the support mechanism for the reinforcing plate are integrated. Hereinafter, the X-ray computer tomography apparatus according to the second embodiment will be described. In the following description, components having substantially the same functions as those of the first embodiment are designated by the same reference numerals and will be duplicated and described only when necessary.

FIG. 8 is a diagram showing a cross-sectional view (YX cross-sectional view) of the support frame 32 and the top plate 33 according to the second embodiment. FIG. 9 is a plan view of the top plate 33 of FIG. 8 as viewed from the back side. FIG. 10 is a diagram showing a vertical cross-sectional view (YZ cross-sectional view) of the support frame 32 and the top plate 33 according to the second embodiment.

As shown in FIGS. 8, 9 and 10, the top plate 33 is a plate-like structure having a hollow portion 331. A reinforcing plate 35 is provided in the hollow portion 331. The top plate 33 and the reinforcing plate 35 are supported by a support mechanism 37 so as to be movable in the ± Z direction. The support mechanism 37 is housed in the support frame 32.

As shown in FIGS. 8, 9 and 10, the support mechanism 37 according to the second embodiment has a top plate support mechanism 37-1 and an engagement mechanism 37-2. The top plate support mechanism 37-1 is a mechanical element that movably supports the top plate 33 in the ± Z direction. The engaging mechanism 37-2 is a mechanical element that engages and disengages the top plate 33 with the reinforcing plate 35. The top plate support mechanism 37-1 is realized by, for example, a ball screw. In this case, the top plate support mechanism 37-1 has a screw 371 and a nut 372. The screws 371 are arranged parallel to the Z direction. The nut 372 has a screw hole formed with a thread groove that fits into the thread formed in the screw 371. The screw 371 is screwed into the screw hole of the nut 372. A flow path mechanism through which a plurality of balls can circulate is formed in the screw 371 and the nut 372. With the rotation of the screw 371, the nut 372 slides in the Z direction after the friction is reduced by the ball.

As shown in FIGS. 8, 9 and 10, the nut 372 is connected to the top plate 33. For example, the nut 372 and the connecting body (slider) 374 are fastened with screws or the like, and the connecting body 374 and the top plate 33 are fastened with screws or the like. With the above configuration, the top plate 33 connected to the nut 372 slides in the Z direction as the screw 371 rotates. The connection method between the nut 372 and the top plate 33 is not limited to the above method, and any method may be used as long as the nut 372 and the top plate 33 can be integrally moved. Further, the top plate support mechanism 36-1 is not limited to the ball screw alone. The top plate support mechanism 37-1 may be realized by any mechanical element such as a linear motion guide as long as the top plate 33 can be moved in the ± Z direction.

As shown in FIGS. 8, 9 and 10, an engaging mechanism 37-2 is attached to the nut 372. A fitting portion 351 is provided on the surface of the reinforcing plate 35 facing the engaging mechanism 37-2. By fitting the engaging mechanism 37-2 to the fitting portion 351 the nut 372 and the reinforcing plate 35 are coupled, whereby the top plate 33 and the reinforcing plate 35 move integrally in the ± Z direction. Can be done. In addition, in order to secure a space for engagement between the engagement mechanism 37-2 and the fitting portion 351, the movement path portion of the engagement mechanism 37-2 in the ± Z direction of the back surface portion of the top plate 33 A notch 333 is formed.

The engagement mechanism 37-2 is realized by, for example, a reciprocating engine. Specifically, it has a piston 375 and a cylinder 376. The cylinder 376 moves the piston 375 up and down in the ± Y direction. When the piston 375 protrudes from the cylinder 376, the cylinder 376 is fitted to the fitting portion 351 provided on the reinforcing plate 35. The fitting portion 351 is realized, for example, by a pair of protrusions arranged in the Z direction at intervals substantially matching the diameter of the piston 375. The top plate 33 and the reinforcing plate 35 are coupled to each other by fitting the piston 375 between the pair of protrusions 351. When the piston 375 is retracted into the cylinder 376, the connection between the nut 372 and the reinforcing plate 35 is released, and as a result, the connection between the top plate 33 and the reinforcing plate 35 is released.

Next, the configuration of the sleeper drive system according to the second embodiment will be described.

FIG. 11 is a diagram showing a configuration example of the control device 15 and the sleeper drive device 34 constituting the sleeper drive system according to the second embodiment. As shown in FIG. 11, the sleeper drive device 34 according to the second embodiment includes a top plate drive control device 62, an engagement drive control device 68, and an elevating drive control device 66. The control device 15 controls the top plate drive control device 62, the engagement drive control device 68, and the elevating drive control device 66 in order to move the top plate 33 to a target position. When moving the top plate 33 in the ± Z direction, the control device 15 engages with the top plate drive control device 62 in order to limit the movement of the reinforcing plate 35 in the ± Z direction according to the X-ray irradiation range. It controls 68 and.

The top plate drive control device 62 is provided on the support frame 32, for example. The top plate drive control device 62 slides the top plate 33 in response to an operation instruction signal from the control device 15. Specifically, the top plate drive control device 62 includes a control circuit 621, a drive device 623, and a detector 625. The control circuit 621 is a servo amplifier that receives an operation instruction signal from the control device 15 and supplies electric power corresponding to the operation instruction signal to the drive device 623. The drive device 623 is driven by receiving electric power from the control circuit 621, drives the top plate support mechanism 37-1 to be connected, and slides the top plate 33. Specifically, the drive device 623 is a motor that generates power by the rotation of the drive shaft. The detector 625 detects the positions of the top plate 33 and the reinforcing plate 35. For example, the detector 625 is a position detector such as a rotary encoder provided on the drive shaft of the drive device 623.

The engagement drive control device 68 is provided on the support frame 32, for example. The engagement drive control device 68 receives an operation instruction signal from the control device 15 and drives the engagement mechanism 37-2 to engage or disengage the top plate 33 and the reinforcing plate 35. Specifically, the engagement drive control device 68 includes a control circuit 681, a drive device 683, and a detector 685. The control circuit 681 is a servo amplifier that receives an operation instruction signal from the control device 15 and supplies electric power corresponding to the operation instruction signal to the drive device 683. The drive device 683 receives the electric power from the control circuit 681 and drives the engagement mechanism 37-2 of the connection destination to engage the top plate 33 with the reinforcing plate 35 or release the engagement. The detector 685 detects the presence or absence of engagement between the top plate 33 and the reinforcing plate 35. For example, the detector 685 is a position detector such as a rotary encoder provided on the drive shaft of the drive device 683 to detect the position of the piston 375 or the like.

Next, the movement of the top plate 33 and the reinforcing plate 35 according to the second embodiment will be described with reference to FIGS. 6 and 7.

As shown in the upper part of FIG. 6, the position of the top plate 33 in the Z direction is at a position (OUT-LIMIT) away from the gantry main body 23 to the structural limit of the sleeper 30, and the position of the top plate 33 in the Y direction. (Height) is assumed that the top plate 33 is located at the height HI where the opening can be inserted. Initially, it is assumed that the end portion of the reinforcing plate 35 in the + Z direction is located at the limit position in the + Z direction in the hollow portion of the top plate 33. Further, it is assumed that the top plate 33 is engaged with the reinforcing plate 35 by the engaging mechanism 37-2.

As shown in the middle of FIG. 6, the control device 15 drives the top plate support mechanism 37-1 to move the top plate 33 to the scan start position (not shown in FIG. 6). As a result, the reinforcing plate 35 moves integrally with the top plate 33. The control device 15 moves the top plate 33 to the start position of the helical scan according to the user's instruction. After that, upon receiving a scan start instruction from the user or when the top plate 33 reaches the start position, the control device 15 automatically controls the X-ray high voltage device 13, the DAS 18, and the sleeper drive device 34. Perform a helical scan. In the helical scan, the top plate 33 is moved toward the target position PT.

While the top plate 33 and the reinforcing plate 35 are moving during the execution of the helical scan or the movement to the scan start position, the control device 15 uses the output signal from the detector 645 to determine the position of the reinforcing plate 35. Monitor. The control device 15 repeatedly determines whether or not the position of the reinforcing plate 35 has reached the stop position PX. Then, when the control device 15 determines that the position of the reinforcing plate 35 has reached the stop position PX, the control device 15 drives the engaging mechanism 37-2 to separate the top plate 33 and the reinforcing plate 35. Specifically, the control device 15 separates the top plate 33 and the reinforcing plate 35 by retracting the piston 375 into the cylinder 376. As a result, the position of the reinforcing plate 35 is fixed to the stop position PX.

As shown in the lower part of FIG. 6, after separating the top plate 33 and the reinforcing plate 35, the control device 15 drives the top plate support mechanism 37-1 in order to move the top plate 33 to the target position PT. Since the top plate 33 and the reinforcing plate 35 are separated, the reinforcing plate 35 is stopped at the stop position PX regardless of the movement of the top plate 33. As a result, only the top plate 33 can be moved in the + Z direction. Then, when the top plate 33 reaches the target position PT, the control device 15 controls the X-ray high voltage device 13, the DAS 18, and the sleeper drive device 34 in order to end the helical scan. At this time, the control device 15 stops the driving of the top plate support mechanism 37-1 in order to stop the top plate 33 at the target position PT.

Next, with reference to FIG. 7, the movement of the top plate 33 and the reinforcing plate 35 when the top plate 33 according to the second embodiment is moved from the initial position PT to the target position PI will be described. It is assumed that the top plate 33 and the reinforcing plate 35 are separated at the start of FIG. 7. As shown in FIG. 7, when the top plate 33 is moved from the initial position PT to the target position PI, the top plate 33 and the reinforcing plate 35 move in the opposite direction to the movement shown in FIG.

That is, as shown in the upper part of FIG. 7, the control device 15 first moves the top plate 33 to the scan start position (not shown in FIG. 7) while fixing the position of the reinforcing plate 35 to the stop position PX. Therefore, the top plate support mechanism 37-1 is driven. At this time, the reinforcing plate 35 is stopped at the stop position PX. As a result, only the top plate 33 can be moved in the −Z direction. The control device 15 moves the top plate 33 to the start position of the helical scan according to the user's instruction. After that, upon receiving a scan start instruction from the user or when the top plate 33 reaches the start position, the control device 15 automatically controls the X-ray high voltage device 13, the DAS 18, and the sleeper drive device 34. Perform a helical scan. In the helical scan, the top plate 33 is moved toward the target position PI.

While the top plate 33 and the reinforcing plate 35 are moving during the execution of the helical scan or the movement to the scan start position, the control device 15 utilizes the output signal from the detector 625 to reinforce the top plate 33. Monitor the position of 35. The control device 15 repeatedly determines whether or not the position of the reinforcing plate 35 has reached the stop position PX.

As shown in the middle stage of FIG. 7, when it is determined that the position of the reinforcing plate 35 has reached the stop position PX, the control device 15 engages with the engaging mechanism 37-2 in order to engage the top plate 33 with the reinforcing plate 35. To drive. Specifically, the cylinder 376 is driven to project the piston 375 and fit it into the fitting portion 351. Then, the control device 15 drives the top plate support mechanism 37-1 in order to move the top plate 33 to the target position PI. Since the top plate 33 is engaged with the reinforcing plate 35, the reinforcing plate 35 moves integrally with the top plate 33. Then, when the top plate 33 reaches the target position PI, the control device 15 controls the X-ray high voltage device 13, the DAS 18, and the sleeper drive device 34 in order to end the helical scan. At this time, the control device 15 stops driving the top plate support mechanism 37-1 in order to stop the top plate 33 at the target position PI.

Also in the second embodiment, the reciprocating helical scan (helical shuttle scan) can be executed by repeating the movement to the IN-LIMIT side shown in FIG. 6 and the movement to the OUT-LIMIT side shown in FIG. It is possible.

In this way, the reinforcing plate 35 can be positioned at the stop position PX close to the X-ray irradiation range RX, so that the reinforcing plate 35 is superimposed on the X-ray irradiation range RX while the top plate 33 is slid in the + Z direction. The bending of the top plate 33 due to the subject P can be reduced by the reinforcing plate 35 without causing it to occur. That is, according to the present embodiment, it is possible to generate a high-quality CT image with little reduction in image quality due to bending of the top plate 33. In the helical scan, the image quality between CT images due to the bending of the top plate 33 can be reduced. Further, the above method according to the present embodiment reduces or avoids interference of the support frame 32 with the gantry main body 23 as compared with the method of moving the support frame 32 together with the top plate 33 in order to reduce the bending of the top plate 33. can do. As a result, the top plate 33 can be reinforced without limiting the tilt angle of the gantry main body 23. Further, since the reinforcing plate 35 does not superimpose on the X-ray irradiation range RX, the presence of the reinforcing plate 35 does not adversely affect the image quality of the CT image.

Further, according to the second embodiment, since the top plate 33 and the reinforcing plate 35 can be moved by a single support mechanism 37, the complexity of the device and control and the like are reduced as compared with the first embodiment. can do.

This is the end of the description of the movement of the top plate 33 and the reinforcing plate 35 according to the second embodiment.

As described above, the X-ray computer tomography apparatus 1 according to at least one embodiment includes a top plate 33, an X-ray tube 11, an X-ray detector 12, a reinforcing plate 35, support mechanisms 36, 37, and a control device 15. .. The subject P is placed on the top plate 33. The X-ray tube 11 generates X-rays. The X-ray detector 12 detects X-rays generated from the X-ray tube 11 and transmitted through the subject P. The reinforcing plate 35 is provided inside the top plate 33 to reduce the bending of the top plate 33. The support mechanisms 36 and 37 movably support the top plate 33 and the reinforcing plate 35 in the major axis direction (Z direction) of the top plate 33. The control device 15 drives the support mechanisms 36 and 37 to move the top plate 33, the reinforcing plate 35, and the Z direction, and limits the movement of the reinforcing plate 35 in the Z direction according to the X-ray irradiation range.

According to at least one embodiment described above, it is intended to suppress bending of the top plate while avoiding deterioration of image quality and limitation of tilt angle.

The term "processor" used in the above description refers to, for example, a CPU, a GPU, or an application specific integrated circuit (ASIC), a programmable logic device (for example, a simple programmable logic device (Simple Programmable Logic Device:)). It means circuits such as SPLDs, Complex Programmable Logic Devices (CPLDs), and Field Programmable Gate Arrays (FPGAs). Processors read and execute programs stored in storage circuits. In addition, instead of storing the program in the storage circuit, the program may be configured to be directly embedded in the circuit of the processor. In this case, the processor reads and executes the program embedded in the circuit. Further, the function corresponding to the program may be realized by a combination of logic circuits instead of executing the program. In addition, each processor of the present embodiment is simply for each processor. Not limited to the case where it is configured as one circuit, a plurality of independent circuits may be combined to form one processor to realize its function. Further, a plurality of components in FIG. 1 may be combined into one. It may be integrated into a processor to realize its function.

Further, in the above embodiment, the X-ray computer tomography apparatus 1 is a so-called third generation. That is, it is assumed that the X-ray computer tomography apparatus 1 is a rotation / rotation type (Rotate / Rotate-Type) in which an X-ray tube and an X-ray detector are integrally transmitted around a rotation axis. However, the X-ray computer tomography apparatus 1 according to the present embodiment is not limited to this. For example, the X-ray computer tomography apparatus 1 is a fixed / rotary type (Stationary / Rotate-Type) in which a large number of X-ray detection elements arranged in a ring shape are fixed and only an X-ray tube rotates around a rotation axis. But it may be. Further, in the X-ray computer tomography apparatus 1, a large number of X-ray detection elements arranged in a ring shape are fixed, an anode is arranged in a ring shape, and an electron beam is irradiated to the anode in a ring shape by electromagnetic deflection. It may be a generation.

Further, the processing circuit 44 is not limited to the case where it is included in the console 40, and may be included in an integrated server that collectively performs processing on detection data acquired by a plurality of medical diagnostic imaging devices.

In the above description, the X-ray computer tomography apparatus 1 according to the present embodiment is said to be a single tube type, but it can also be applied to a so-called multi-tube type.

Although some embodiments of the present invention 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 embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

1 X-ray computer tomography device 10 gantry 11 X-ray tube 12 X-ray detector 13 Rotating frame 14 X-ray high voltage device 15 Control device 16 Wedge 17 Collimeter 18 Data acquisition circuit (DAS: Data Acquisition System)
19 Opening 23 Stand body 25 Fixed part 30 Sleeper 31 Base 32 Support frame 33 Top plate 34 Sleeper drive device 35 Reinforcing plate 36 Support mechanism 36-1 Top plate support mechanism 36-2 Reinforcing plate support mechanism 37 Support mechanism 37-1 Top plate support mechanism 37-2 Engagement mechanism 40 Console 41 Memory 42 Display 43 Input interface 44 Processing circuit 62 Top plate drive control device 64 Reinforcing plate drive control device 66 Elevating drive control device 68 Engagement drive control device 331 Hollow part 351 Fitting Joint 361 Screw 362 Nut 364 Connection body 365 Screw 366 Nut 367 Connection body 368 Guide 371 Screw 372 Nut 374 Connection body 375 Piston 376 Cylinder 441 Imaging control function 442 Reconstruction processing function 443 Image processing function 444 Scan planning function 621 Control circuit 623 Drive 625 Detector 641 Control circuit 643 Drive 645 Detector 661 Control circuit 663 Drive 665 Detector 681 Control circuit 683 Drive 685 Detector

Claims (9)

The top plate on which the subject is placed and
X-ray tubes that generate X-rays and
An X-ray detector that detects X-rays generated from the X-ray tube and transmitted through the subject.
A reinforcing plate provided inside the top plate for reducing the bending of the top plate, and
A support mechanism that independently and movably supports the top plate and the reinforcing plate in the long axis direction of the top plate.
The support mechanism is driven to move the top plate and the reinforcing plate in the long axis direction, and the reinforcing plate is moved in the long axis direction according to the irradiation range of X-rays from the X-ray tube. The drive control unit that limits and
X-ray computer tomography apparatus equipped with. When the top plate is moved to a target position, the drive control unit moves the top plate and the reinforcing plate toward the target position in the major axis direction, and does not superimpose the reinforcing plate on the irradiation range. The X-ray computer tomography apparatus according to claim 1, wherein when the reinforcing plate is moved to the first position, the reinforcing plate is stopped at the first position and the top plate is further moved to the target position. The support mechanism is
A top plate support mechanism that movably supports the top plate in the long axis direction,
It has a reinforcing plate support mechanism that movably supports the reinforcing plate in the major axis direction independently of the top plate.
The X-ray computer tomography apparatus according to claim 1. The drive control unit
When the top plate is moved to a target position, the top plate support mechanism and the reinforcing plate support mechanism are driven in order to move the top plate and the reinforcing plate in the major axis direction.
When the reinforcing plate is moved to a first position that does not overlap the irradiation range, the top plate support mechanism and the top plate support mechanism are used to further move the top plate to the target position while stopping the reinforcing plate at the first position. Drives both with the reinforcing plate support mechanism or only the top plate support mechanism.
The X-ray computer tomography apparatus according to claim 3. The support mechanism is
An engagement mechanism for engaging the top plate with the reinforcing plate, and
It has a top plate support mechanism that movably supports the top plate in the long axis direction.
The X-ray computer tomography apparatus according to claim 1. The drive control unit
When the top plate is moved to a target position, the engagement mechanism is driven to engage the top plate with the reinforcing plate.
In a state where the top plate and the reinforcing plate are engaged, the top plate support mechanism is driven in order to move the top plate and the reinforcing plate in the major axis direction.
When the reinforcing plate moves to a first position that does not overlap the irradiation range, the engaging mechanism is driven to separate the top plate and the reinforcing plate.
In a state where the top plate and the reinforcing plate are separated, the top plate support mechanism is driven in order to move the top plate to the target position.
The X-ray computer tomography apparatus according to claim 5. The top plate has a hollow portion and has a hollow portion.
The support mechanism movably supports the reinforcing plate in the hollow portion in the major axis direction.
The X-ray computer tomography apparatus according to claim 1. Further provided with a setting unit for automatically or manually setting the irradiation range, the irradiation range is further provided.
The drive control unit determines the first position according to the set irradiation range.
The X-ray computer tomography apparatus according to claim 2. The X-ray computer tomography apparatus according to claim 2, wherein the first position is determined according to the maximum irradiation range of X-rays from the X-ray tube.

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