JP2020005665A - Medical image diagnostic apparatus - Google Patents

Abstract

To facilitate maintenance of a top plate of a bed device, and to prevent deterioration of a picture quality or an accident caused by an abnormality of the top plate.SOLUTION: A medical image diagnostic apparatus in an embodiment includes a control part. The control part monitors vibration during movement of a top plate of a bed device, and classifies vibration detected by monitoring.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present invention relate to a medical image diagnostic apparatus.

  2. Description of the Related Art In a medical image diagnostic apparatus such as an X-ray CT apparatus or a magnetic resonance imaging apparatus, a subject such as a patient is transported to an imaging area while being placed on a top plate of a bed apparatus, and imaging is performed. In addition, the top plate of the bed apparatus is moved by a driving mechanism, and is moved by a scratch of a gear or a ball screw of the driving mechanism, a dirt on a contact surface (running surface) with a guide frame, a roller, or the like. Vibration occurs.

  If vibrations occur on the top panel during shooting, noise due to vibrations may be added to the shot image, and the image quality may be degraded. In addition, if the cause of the vibration is a crack in the top plate or the like, it may lead to an accident. For this reason, under the current situation, as a regular maintenance work, inspection and cleaning of the top plate (for example, cleaning of the back surface of the top plate) or replacement of parts are performed, and measures are taken to prevent excessive vibration of the top plate. I have.

  However, periodic maintenance work requires a lot of man-hours and depends on the capabilities of service technicians. Therefore, it is not always possible to effectively prevent image quality degradation or accidents caused by an abnormality in the top plate. .

JP 2017-202304 A JP 2010-233965 A

  The problem to be solved by the present invention is to facilitate maintenance of a top plate of a bed apparatus and to prevent deterioration of image quality or accident caused by abnormality of the top plate.

  The medical image diagnostic device according to the embodiment includes a control unit. The control unit monitors the vibration of the couch top when moving, and classifies the vibration detected by the monitoring.

FIG. 1 is a block diagram illustrating a configuration example of the X-ray CT apparatus according to the first embodiment. FIG. 2 is a perspective view showing a part of the bed apparatus. FIG. 3 is a sectional view taken along line AA in FIG. FIG. 4 is a flowchart (1) illustrating a processing example according to the first embodiment. FIG. 5 is a flowchart (2) illustrating a processing example according to the first embodiment. FIG. 6 is a diagram illustrating an example of collected data. FIG. 7A is a diagram (1) illustrating an example of a relationship between a slide position and a top plate position. FIG. 7B is a diagram (2) illustrating an example of the relationship between the slide position and the top plate position. FIG. 8A is a diagram (1) illustrating an example of vibration generated when the top board moves. FIG. 8B is a diagram (2) illustrating an example of vibration generated when the top board moves. FIG. 8C is a diagram (3) illustrating an example of vibration generated when the top board moves. FIG. 9 is a diagram illustrating an example of a screen showing a range of large or small vibration. FIG. 10 is a flowchart (3) illustrating a processing example according to the first embodiment.

  Hereinafter, embodiments of a medical image diagnostic apparatus will be described with reference to the drawings. The embodiment is not limited to the following contents. In addition, the contents described in one embodiment or modification are similarly applied to other embodiments or modifications in principle.

(1st Embodiment)
The configuration of the X-ray CT apparatus 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration example of the X-ray CT apparatus 1 according to the first embodiment. The X-ray CT apparatus 1 is an example of a medical image diagnostic apparatus. The X-ray CT apparatus 1 includes a gantry device 10, a bed device 30, and a console device 40, as shown in FIG. Although a plurality of gantry devices 10 are illustrated in FIG. 1 for convenience of explanation, the gantry device 10 is basically one as an actual configuration. In FIG. 1, the longitudinal direction of the rotation axis of the rotating frame 16 or the top plate 33 of the bed device 30 in the non-tilted state of the gantry device 10 is defined as the Z-axis direction. Also, an axis direction orthogonal to the Z axis direction and horizontal to the floor surface is defined as an X axis direction. Further, an axis direction orthogonal to the Z axis direction and perpendicular to the floor surface is defined as a Y axis direction.

  The gantry device 10 includes an X-ray tube 11, an X-ray detector 15, a rotating frame 16, an X-ray high-voltage device 17, a control device 18, a wedge 19, a collimator 20, and a DAS (Data Acquisition System). 21.

  The X-ray tube 11 is a vacuum tube that generates X-rays by irradiating thermoelectrons from a cathode (filament) to an anode (target) with a high voltage from an X-ray high voltage device 17. In the present embodiment, the present invention is applicable to a single-tube X-ray CT apparatus and a so-called multi-tube X-ray CT apparatus in which a plurality of pairs of an X-ray tube and a detector are mounted on a rotating ring. It is. Further, hardware for generating X-rays is not limited to the X-ray tube 11. For example, instead of the X-ray tube 11, a focus coil that focuses an electron beam generated from an electron gun, a deflection coil that deflects electromagnetically, and an electron beam that surrounds and deflects a half circumference of the subject P collide with the X-ray. X-rays may be generated using a fifth generation method including a target ring to be generated.

  The X-ray high voltage device 17 includes an electric circuit such as a transformer (transformer) and a rectifier, and generates a high voltage to be applied to the X-ray tube 11, and an X-ray irradiated by the X-ray tube 11. And an X-ray control circuit for controlling the output voltage according to. The high voltage generating circuit may be of a transformer type or of an inverter type. The X-ray high-voltage device 17 not only generates a high voltage, but also supplies power to the filament and supplies driving power when the anode is of a rotary type. Further, the X-ray high voltage device 17 may be provided on the rotating frame 16 or on the fixed frame (not shown) side of the gantry device 10. Note that the fixed frame is a frame that rotatably supports the rotating frame 16.

  The X-ray detector 15 detects X-rays emitted from the X-ray tube 11 and passed through the subject P, and outputs a signal corresponding to the detected X-ray dose to the DAS 21. The X-ray detector 15 includes, for example, a plurality of X-ray detection element rows in which a plurality of X-ray detection elements are arranged in a channel direction (circumferential direction) along one arc centered on the focal point of the X-ray tube 11. Have. The X-ray detector 15 has, for example, a structure in which a plurality of X-ray detection element rows in which a plurality of X-ray detection elements are arranged in a channel direction are arranged in a slice direction (row direction, row direction).

  The X-ray detector 15 is, for example, an indirect conversion type detector having a grid, a scintillator array, and a photosensor array. The scintillator array has a plurality of scintillators. The scintillator has a scintillator crystal that outputs light having a photon quantity corresponding to the incident X-ray dose. The grid is disposed on the surface of the scintillator array on the X-ray incident side, and has an X-ray shielding plate that absorbs scattered X-rays. The grid may be called a collimator (one-dimensional collimator or two-dimensional collimator). The optical sensor array has a function of converting an electric signal according to the amount of light from the scintillator, and includes, for example, an optical sensor such as a photodiode or a photomultiplier (photomultiplier: PMT). Note that the X-ray detector 15 may be a direct conversion type detector having a semiconductor element that converts an incident X-ray into an electric signal.

  The rotating frame 16 (mount base) is an annular frame that supports the X-ray tube 11 and the X-ray detector 15 to face each other, and rotates the X-ray tube 11 and the X-ray detector 15 by the control device 18. For example, the rotating frame 16 is a casting made of aluminum. The rotating frame 16 can further support the X-ray high-voltage device 17 and the DAS 21 in addition to the X-ray tube 11 and the X-ray detector 15. Further, the rotating frame 16 can further support various configurations not shown in FIG. Hereinafter, in the gantry device 10, the portion that rotates and moves together with the rotating frame 16 and the rotating frame 16 are also referred to as a rotating unit. The rotation / rotation-type (third generation CT) in which the X-ray tube 11 and the X-ray detector 15 rotate around the subject P as a unit has been described. There are various types such as Stationary / Rotate-Type (fourth generation CT) in which a large number of X-ray detection elements are fixed and only the X-ray tube 11 rotates around the subject P, and any of these types is directed to the present embodiment. Applicable.

  The detection data generated by the DAS 21 is transmitted from a transmitter having a light emitting diode (LED) provided on the rotating frame 16 to a photodiode provided on a non-rotating portion of the gantry device 10 by optical communication. And transmitted to the console device 40. Here, the non-rotating portion is, for example, a fixed frame (not shown in FIG. 1) that rotatably supports the rotating frame 16. The method of transmitting the detection data from the rotating frame 16 to the non-rotating portion of the gantry device 10 is not limited to optical communication, and any method can be used as long as data can be transmitted between the rotating portion and the non-rotating portion. It does not matter.

  The control device 18 includes a drive mechanism such as a motor and an actuator, and a circuit that controls the mechanism. The control device 18 receives an input signal from the input interface 43 or an input interface provided on the gantry device 10 and controls the operation of the gantry device 10 and the couch device 30. For example, the control device 18 controls the rotation of the rotating frame 16, the tilt of the gantry device 10, the operation of the bed device 30 and the top plate 33, and the like. For example, the control device 18 rotates the rotating frame 16 about an axis parallel to the X-axis direction based on the input tilt angle (tilt angle) information as control for tilting the gantry device 10. The control device 18 may be provided on the gantry device 10 or on the console device 40.

  The wedge 19 is a filter for adjusting the X-ray dose emitted from the X-ray tube 11. Specifically, the wedge 19 transmits and attenuates the X-rays radiated from the X-ray tube 11 so that the X-rays radiated to the subject P from the X-ray tube 11 have a predetermined distribution. Filter. For example, the wedge 19 is a wedge filter or a bow-tie filter, and is formed by processing aluminum or the like so as to have a predetermined target angle and a predetermined thickness.

  The collimator 20 is a lead plate or the like for narrowing the irradiation range of the X-ray transmitted through the wedge 19, and forms a slit by a combination of a plurality of lead plates and the like. The collimator 20 may be called an X-ray stop. The aperture and the position of the collimator 20 are adjusted by a collimator adjustment circuit (not shown). Thereby, the irradiation range of the X-ray generated by the X-ray tube 11 is adjusted.

  The DAS 21 includes an amplifier that performs an amplification process on an electric signal output from each X-ray detection element of the X-ray detector 15 and an A / D converter that converts the electric signal into a digital signal. Generate The DAS 21 is realized by, for example, a processor. The detection data generated by the DAS 21 is transferred to the console device 40.

  The couch device 30 is a device for mounting and moving the subject P to be scanned, and includes a base 31, a couch driving device 32, a top plate 33, and a support frame. The base 31 is a housing that supports the support frame 34 movably in the vertical direction. The couch driving device 32 is a driving mechanism that moves the table 33 on which the subject P is placed in the longitudinal direction of the table 33, and includes a motor, an actuator, and the like. The top plate 33 provided on the upper surface of the support frame 34 is a plate on which the subject P is placed. The bed driving device 32 may move the support frame 34 in the longitudinal direction of the top plate 33 in addition to the top plate 33. Only the top plate 33 may be moved, or a system in which the support frame of the bed apparatus 30 is moved. When applied to a standing CT, a method of moving a patient support mechanism corresponding to the top plate 33 may be used. When performing a scan (such as a helical scan or a positioning scan) involving a relative change in the positional relationship of the top plate 33 of the gantry device 10, the relative change in the positional relationship may be performed by driving the top plate 33. Alternatively, it may be performed by running the gantry device 10 or may be performed by a combination thereof.

  A vibration meter 35 is provided on the top plate 33. The vibration meter 35 is, for example, an acceleration sensor. The output signal of the vibrometer 35 is transferred to the console device 40. FIG. 2 is a perspective view showing a part of the couch device 30. For example, the vibrometer 35 is configured such that the top plate 33 of the couch device 30 has an end on the out-limit (OUT-LIMIT) side. From the base R in a state where it slides out to the limit and protrudes toward the gantry device 10 side. Since the vibrometer 35 is provided at the end of the top plate 33 on the out-limit side, the vibrometer 35 does not obstruct the X-ray path at the time of imaging. FIG. 3 is a sectional view taken along line AA in FIG. 2. In this example, a vibrometer 35 is attached to the back side of the top plate 33. Further, instead of being provided on the top plate 33, the vibrometer 35 may be attached to a support portion of the roller 36 that comes into contact with the top plate 33. The point is that the vibrometer 35 may be provided at a position where the vibration of the top plate 33 can be detected without obstructing the slide of the top plate 33. The number of the vibrometer 35 may be one or more. Further, the vibration meter 35 may be of a type that detects vibration using an image. For example, vibration may be detected from a temporal change in a part of the top plate 33 based on an image of a camera that captures the top plate 33.

  Referring back to FIG. 1, the console device 40 includes a memory 41, a display 42, an input interface 43, and a processing circuit 44. Although the console device 40 is described as being separate from the gantry device 10, the gantry device 10 may include the console device 40 or some of the components of the console device 40.

  The memory 41 is realized by, for example, a semiconductor memory device such as a RAM (Random Access Memory) or a flash memory, a hard disk, an optical disk, or the like. For example, the memory 41 stores projection data and reconstructed image data. Further, for example, the memory 41 stores a program for a circuit included in the X-ray CT apparatus 1 to realize its function. The memory 41 is also used as a non-transitory storage medium by hardware. The storage of the projection data and the reconstructed image data is not limited to the case where the memory 41 of the console device 40 is used, but a cloud server that can be connected to the X-ray CT device 1 via a communication network such as the Internet is used. The storage of the projection data and the reconstructed image data may be performed in response to a storage request from the storage device 1.

  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 is a liquid crystal display or a CRT (Cathode Ray Tube) display. The display 42 may be provided on the gantry device 10. Further, the display 42 may be a desktop type, or may be configured by a tablet terminal or the like that can wirelessly communicate with the console device 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 electric signals to the processing circuit 44. For example, the input interface 43 receives, from the operator, acquisition conditions for acquiring projection data, reconstruction conditions for reconstructing a CT image, image processing conditions for generating a post-processed image from a CT image, and the like. . For example, the input interface 43 is realized by a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touch panel, and the like. The input interface 43 may be provided on the gantry device 10. In addition, the input interface 43 may be configured by a tablet terminal or the like that can wirelessly communicate with the console device body.

  The processing circuit 44 controls the operation of the whole X-ray CT apparatus 1. For example, the processing circuit 44 has a scan control function 441, an image generation function 442, a display control function 443, and a control function 444. The processing circuit 44 is realized by, for example, a processor.

  For example, the processing circuit 44 reads a program corresponding to the scan control function 441 from the memory 41 and executes the program, thereby controlling the X-ray CT apparatus 1 to execute a scan. Here, the scan control function 441 can execute scans in various systems such as a conventional scan, a helical scan, and a step-and-shoot system.

  Specifically, the scan control function 441 moves the subject P into the imaging opening of the gantry device 10 by controlling the bed driving device 32. Further, the scan control function 441 controls the X-ray high voltage device 17 to supply a high voltage to the X-ray tube 11. Further, the scan control function 441 adjusts the aperture and the position of the collimator 20. Further, the scan control function 441 controls the control device 18 to rotate the rotating unit including the rotating frame 16. The scan control function 441 causes the DAS 21 to collect projection data. In order to reconstruct a CT image, projection data for 360 ° around the subject P is required, and projection data for 180 ° + fan angle is also required in the half-scan method. The present embodiment can be applied to any of the reconstruction methods.

  In addition, the scan control function 441 monitors the vibration of the top plate 33 during movement, classifies the vibration detected by the monitoring according to the magnitude of the vibration, and the generation pattern caused by the cause of the vibration, and according to the classification. The maintenance request to the service person and the control such as permission / prohibition of photographing are performed. Details of the processing will be described later. The scan control function 441 is an example of a control unit.

  Further, for example, the processing circuit 44 reads out a program corresponding to the image generation function 442 from the memory 41 and executes it, thereby performing logarithmic conversion processing, offset correction processing, sensitivity between channels on the detection data output from the DAS 21, and so on. Data that has been subjected to pre-processing such as correction processing and beam hardening correction is generated. The data before the pre-processing (detection data) and the data after the pre-processing may be collectively referred to as projection data. Further, for example, the image generation function 442 generates CT image data. Specifically, the image generation function 442 generates CT image data by performing a reconstruction process on the post-processed projection data using a filtered back projection method, a successive approximation reconstruction method, or the like. Further, the image generation function 442 converts CT image data into tomographic image data or three-dimensional image data of an arbitrary cross section based on an input operation received from the operator via the input interface 43.

  Further, for example, the processing circuit 44 displays a CT image on the display 42 by reading out and executing a program corresponding to the display control function 443 from the memory 41. Further, for example, the processing circuit 44 reads out a program corresponding to the control function 444 from the memory 41 and executes the program, thereby performing various functions of the processing circuit 44 based on an input operation received from the operator via the input interface 43. Control.

  Note that FIG. 1 shows a case where each processing function of the scan control function 441, the image generation function 442, the display control function 443, and the control function 444 is realized by a single processing circuit 44. It is not limited to. For example, the processing circuit 44 may be configured by combining a plurality of independent processors, and each processor may execute each program to realize each processing function. Further, each processing function of the processing circuit 44 may be realized by being appropriately distributed or integrated in a single or a plurality of processing circuits. The processing circuit 44 is not limited to the case where the processing circuit 44 is included in the console device 40, and may be included in an integrated server that performs processing on detection data acquired by a plurality of medical image diagnostic apparatuses in a lump. Although the console device 40 has been described as performing a plurality of functions on a single console, the plurality of functions may be performed by separate consoles. The post-processing may be performed at either the console device 40 or an external workstation. Further, the processing may be performed by both the console device 40 and the workstation.

  The term “processor” used in the above description is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an application specific integrated circuit (ASIC), a programmable logic device (for example, It means a circuit such as a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), or a Field Programmable Gate Array (FPGA). The processor realizes functions by reading and executing the program stored in the memory 41. Instead of storing the program in the memory 41, the program may be directly incorporated into the circuit of the processor. In this case, the processor realizes a function by reading and executing a program incorporated in the circuit. Note that each processor of the present embodiment is not limited to the case where each processor is configured as a single circuit, but may be configured as one processor by combining a plurality of independent circuits to realize its function. Good.

  FIG. 4 is a flowchart illustrating a processing example according to the first embodiment, and illustrates a processing example when the bed apparatus 30 or the table 33 is installed. In FIG. 4, the scan control function 441 moves the couchtop 33 when the couch device 30 or the couchtop 33 is installed, and measures the vibration of the couchtop 33 with the vibrometer 35 (step S11). For example, the scan control function 441 moves the top plate 33 from the initial state accommodated in the support frame 34 and sends it out to the maximum, then moves again to the initial state, and sets the vibration value ( The magnitude of vibration such as acceleration) is measured. The position of the tabletop 33 during the movement is, for example, a position represented by a distance from a point of a fixed portion of the bed apparatus 30 or the like to an end of the tabletop 33 (the initial state accommodated in the support frame 34 is 0). Here, it is referred to as a slide position. In addition, a position where the top plate 33 is moved right below the gantry device 10 and imaging is performed, and a position represented by a distance from an end of the top plate 33 is referred to as a top plate position. The slide position and the top plate position are associated one-to-one as described later.

  Next, the scan control function 441 determines a threshold value for determining a vibration level at the time of later use from the measured vibration value (step S12). Here, for example, three thresholds are determined. The first threshold value is a vibration value at which maintenance should be performed, although the imaging should not be stopped. The second threshold value is a value larger than the first threshold value, and is a vibration value that stops photographing or excludes the photographing from the photographing range. The third threshold value is a value larger than the second threshold value, and is a vibration value that causes an accident due to a crack in the top plate 33 or the like. In any case, the vibration values measured when the bed apparatus 30 is installed are not lower than the vibration values, and are determined to be appropriate values from the significance of the respective threshold values. Note that, in the case of a high-definition CT apparatus in which the resolution of imaging is increased, a high-definition mode having a high resolution and a normal mode having a resolution similar to that of a conventional apparatus are generally provided. In this case, the above-described first and second thresholds corresponding to the normal mode are equivalent, but the first and second thresholds corresponding to the high-definition mode are determined separately, and compared with the case of the normal mode. Set to a strict value (small value). Since the threshold value is determined based on the magnitude of the vibration at the time of installation, an error based on the individual difference of the bed apparatus 30 is absorbed.

  In addition, the vibration value at the time of installation is stored in association with the slide position or the top position of the top plate 33, and the vibration value at the time of the movement of the top plate 33 at the time of measurement at the same slide position or the top position is stored. The vibration value may be subtracted to obtain a variation in the vibration value, and may be compared with a uniform threshold value (first to third threshold values that do not take individual differences into account) to determine whether the vibration value is equal to or greater than the threshold value. Good.

  Steps S11 and S12 shown in FIG. 4 are steps corresponding to the scan control function 441. Steps S11 and S12 are steps in which the scanning circuit 441 is realized by the processing circuit 44 reading and executing a program corresponding to the scan control function 441 from the memory 41.

  FIG. 5 is a flowchart illustrating a processing example according to the first embodiment, and illustrates a processing example when the X-ray CT apparatus 1 is used. In FIG. 5, when the processing is started by turning on the power of the X-ray CT apparatus 1 or inputting some operation, the scan control function 441 determines whether or not the present time is the start of operation (step S201). If it is the start of operation (Yes in step S201), the scan control function 441 moves the top board 33, measures the vibration of the top board 33 with the vibrometer 35, and associates the vibration with the slide position or the top position. The vibration value is recorded (Step S202). For example, the scan control function 441 sends the top plate 33 from the initial state accommodated in the support frame 34 to the maximum, then moves to the initial state again, and measures the vibration value with respect to the sliding position of the top plate 33 during the movement. And record as collected data.

FIG. 6 is a diagram illustrating an example of collected data, in which a slide position is associated with a vibration value. The slide position can be easily converted to a top position at which imaging is performed by the gantry device 10, and as a result of the conversion, the data is data in which the top position and the vibration value are associated with each other. 7A and 7B are diagrams illustrating an example of the relationship between the slide position and the top plate position, and are diagrams in which the gantry device 10 and the top plate 33 are viewed from above. In Figure 7A, for example, a slide position L _S of the top plate 33 in the initial state is 0, and the distance from the right edge of the top plate 33 to the center of the gantry apparatus 10, L _0, as shown in FIG. 7B, the top plate 33 If There moved, relative to the slide position _{L S,} the position of the top plate 33 immediately below the gantry device 10 (top position) can be expressed by _L 0 -L _S.

  Returning to FIG. 5, when it is not the start of operation (No in step S201), the scan control function 441 uses the measurement data of the vibration at the time of the most recent movement of the top board 33 (step S203). For example, if the top board 33 has not been moved after the start of business, data recorded at the start of business is used, and if it has been moved, data recorded during the movement is used. The vibration value may be monitored during this movement, and if a vibration exceeding the third threshold value is detected, the movement may be immediately stopped.

  Next, the scan control function 441 determines whether or not a vibration equal to or greater than the first threshold value has been detected from the measured data at the start of operation or the latest (step S204). If the scan control function 441 determines that no vibration equal to or greater than the first threshold is detected (No in step S204), the scan control function 441 permits the photographing from an operator such as a laboratory technician (step S205).

  When the scan control function 441 determines that a vibration equal to or greater than the first threshold is detected (Yes in step S204), the scan control function 441 determines the type of vibration, and requests for maintenance with information on the determined vibration type ( (Urgentity: low) is notified to the serviceman (step S206). The notification is made to the portable terminal or the like possessed by the service person by a short message or an e-mail. In addition, the maintenance request is not automatically notified, but a message indicating that the maintenance request should be made is displayed on the console device 40 of the X-ray CT apparatus 1 or the like. It may be performed. Further, not only the case where the X-ray CT apparatus 1 side actively notifies, the state of vibration may be referred to by accessing the X-ray CT apparatus 1 side from an external portable terminal or the like.

  Even vibrations that do not immediately affect image quality can grow into large vibrations, so maintenance can be requested early to maintain image quality and safety. . By maintaining the image quality, noise due to vibration or the like does not ride on the captured image, so that the number of times of re-shooting is reduced, and as a result, unnecessary exposure to the patient is also prevented. Note that the actual notification to the service person is performed after determining whether or not a notification with a higher urgency described later is possible.If a notification with a higher urgency is to be performed, the notification with a lower urgency is a notification of the type of vibration. May be omitted except for.

  8A to 8C are diagrams illustrating examples of vibration generated when the top board 33 moves. FIG. 8A is an example in which vibration is periodically generated with respect to the slide position or the top plate position, and it is highly possible that a motor, a gear, or the like of a drive mechanism of the top plate 33 is damaged. FIG. 8B is an example in which vibration is suddenly generated at a specific position of the slide position or the top plate position, and there is a possibility that the running surface of the top plate 33 or the ball screw of the drive mechanism is damaged. high. FIG. 8C is an example in which a wide vibration with respect to the position occurs at a specific position of the slide position or the top plate position, and there is a possibility that dirt may be attached to the traveling surface of the top plate 33 contacting the roller. high. The scan control function 441 determines, for example, one of the types shown in FIGS. 8A to 8C from the measured vibration pattern. The service technician can perform maintenance work efficiently because the type of vibration is informed of the location where maintenance is to be intensively performed. Instead of the type of vibration, information on the cause of the vibration (scratch on motor or gear, scratch on ball screw, dirt on the running surface, etc.) and the position of the scratch or dirt (slide position, top plate position) Information may be notified.

  Returning to FIG. 5, next, the scan control function 441 determines whether a vibration equal to or greater than the second threshold is detected (step S207). When the scan control function 441 determines that vibration equal to or greater than the second threshold is not detected (No in step S207), the scan control function 441 permits the photographing from an operator such as a laboratory technician (step S205).

  If the scan control function 441 determines that vibration equal to or higher than the second threshold is detected (Yes in step S207), the scan control function 441 subsequently determines whether vibration equal to or higher than the third threshold is detected (step S208). ). If it is determined that the vibration equal to or more than the second threshold is detected (Yes in step S207), the vibration is classified according to the cause of the vibration. It may be determined whether or not a vibration equal to or greater than the threshold is detected (step S208). When the cause of the vibration is dirt, it is the same as when it is determined that the vibration equal to or higher than the third threshold is not detected. If the cause of the vibration is dirt, the danger is not high.

  When the scan control function 441 determines that the vibration equal to or more than the third threshold is detected (Yes in step S208), the scan control function 441 stops using the X-ray CT apparatus 1, notifies the serviceman, and waits for the end of the maintenance. (Step S209). The serviceman is also notified of the type or cause of the vibration.

  If the scan control function 441 determines that no vibration equal to or higher than the third threshold value is detected (No in step S208), the scan control function 441 determines the photographable range on the top 33 from the measured data at the start of operation or the latest (step S208). S210). For example, a range in which the vibration of the top plate position directly below the gantry device 10 where the imaging is performed has a vibration value less than the second threshold value can be captured, and a range in which the vibration value is equal to or more than the second threshold value cannot be captured. FIG. 9 is a diagram showing an example of a screen showing a range where the vibration is large or small. The horizontally long rectangle in the center of the figure shows the outer shape of the top plate 33, and the hatched portion shows the image with large vibration during shooting. The non-observable range is shown, and the part without hatching indicates the photographable range. When positioning image data (scanogram image data, scout image data, etc.) is acquired before the main imaging is performed, the outline of the subject P is displayed in a superimposed manner on the outer shape of the top board 33, and a part that can be imaged is displayed. It may be easy to understand.

  Returning to FIG. 5, next, the scan control function 441 permits photographing within the photographable range in response to a photographing request from an operator such as an inspection technician (step S211). For example, the scan control function 441 permits a helical scan within the photographable range. In this case, a measure is taken by setting the photographing range so as to fall within the photographable range or changing the position of the subject P. In addition, regarding the conventional scan, even if the vibration value is in the range where the vibration value is equal to or more than the second threshold value, it is considered that the vibration of the top plate 33 converges by the time of photographing. May be. Even in the case where a vibration that may cause deterioration of image quality occurs in a part of the top plate 33, an extra downtime can be prevented by defining a photographable range according to photographing conditions. As a result, it is possible to improve the imaging efficiency of the patient.

  Steps S201 to S211 shown in FIG. 5 are steps corresponding to the scan control function 441. Steps S201 to S211 are steps in which the processing circuit 44 reads out and executes a program corresponding to the scan control function 441 from the memory 41, whereby the scan control function 441 is realized.

  FIG. 10 is a flowchart illustrating a processing example according to the first embodiment, and illustrates a processing example at the time of shooting. In FIG. 10, when the process is started, the scan control function 441 measures the vibration of the top plate 33 by the vibrometer 35 when the top plate 33 moves, and records the vibration value in association with the slide position or the top position. (Step S301).

  Next, the scan control function 441 determines whether the planned shooting range has been completed (step S302). If the scan control function 441 determines that the planned shooting range has not been completed (No in step S302), the scan control function 441 subsequently determines whether a vibration equal to or greater than the second threshold is detected in the shooting range (step S302). Step S303). If the scan control function 441 determines that no vibration equal to or greater than the second threshold is detected (No in step S303), the scan control function 441 continues to move the top plate 33 and record the vibration value (step S301).

  When the scan control function 441 determines that the planned shooting range has been completed (Yes in step S302), the scan control function 441 ends the shooting (step S304).

  Next, the image generation function 442 performs reconstruction based on the projection data obtained by imaging, and generates CT image data (step S305). The CT image data is converted into tomographic image data of an arbitrary cross section or three-dimensional image data based on an input operation or the like received from the operator. The processing after the reconstruction may be performed in an external workstation or the like based on the projection data.

  Next, the display control function 443 displays, on the display 42, a CT image obtained by the reconstruction, an image based on tomographic image data of an arbitrary cross section, or three-dimensional image data (step S306).

  On the other hand, when the scan control function 441 determines that a vibration equal to or greater than the second threshold is detected (Yes in step S303), the scan control function 441 stops shooting (step S307), and subsequently detects vibration equal to or greater than the third threshold. It is determined whether or not it has been performed (step S308). When the scan control function 441 determines that vibration equal to or higher than the third threshold value is detected (Yes in step S308), the scan control function 441 stops using the X-ray CT apparatus 1, notifies a service person, and waits for maintenance (step S308). S309).

  If the scan control function 441 determines that no vibration equal to or greater than the third threshold value is detected (No in step S308), the scan control function 441 starts over from permitting photographing including determination of a photographable range (also, to a service person). If the maintenance request has not been made, the maintenance request is notified) or the use of the X-ray CT apparatus 1 is stopped, and the service person is notified to wait for the end of the maintenance (step S310).

  Steps S301 to S304 and S307 to S310 shown in FIG. 10 are steps corresponding to the scan control function 441. Steps S301 to S304 and S307 to S310 are steps in which the processing circuit 44 reads out and executes a program corresponding to the scan control function 441 from the memory 41, thereby realizing the scan control function 441.

  Step S305 illustrated in FIG. 10 is a step corresponding to the image generation function 442. Step S305 is a step in which the image generation function 442 is realized by the processing circuit 44 reading and executing a program corresponding to the image generation function 442 from the memory 41.

  Step S306 shown in FIG. 10 is a step corresponding to the display control function 443. Step S306 is a step in which the display control function 443 is realized by the processing circuit 44 reading and executing a program corresponding to the display control function 443 from the memory 41.

  Note that the order of the processes in the flowcharts described in FIG. 4, FIG. 5, or FIG. 10 may be changed within a range that does not substantially affect the result.

  According to the present embodiment, maintenance of the top plate of the bed apparatus can be facilitated, and deterioration of image quality or an accident caused by abnormality of the top plate can be prevented.

(Second embodiment)
Although the first embodiment has been described as applied to the X-ray CT apparatus 1, other medical image diagnostic apparatuses having a top plate that transports a subject to an imaging region may be similarly applied. Can be. For example, the present invention can be similarly applied to a magnetic resonance imaging apparatus and the like. In this case, if a magnetic material is used for the vibrometer, the magnetic field in the imaging region will be disturbed. A vibrometer will be provided.

  According to at least one embodiment described above, maintenance of the top plate of the bed apparatus can be facilitated, and deterioration of image quality or an accident caused by abnormality of the top plate can be prevented.

  While some embodiments of the invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. These embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 X-ray CT apparatus 18 Control apparatus 30 Bed apparatus 33 Top plate 35 Vibrometer 40 Console apparatus 44 Processing circuit 441 Scan control function

Claims (10)

A medical image diagnostic apparatus, comprising: a control unit that monitors vibrations of a couch top during movement and classifies the vibrations detected by the monitoring. The control unit classifies the vibration based on the magnitude or generation pattern of the detected vibration,
The medical image diagnostic apparatus according to claim 1. The generation pattern includes a case where vibration is generated periodically with the movement of the top plate, a case where vibration is suddenly generated at a specific position, and a case where a wide vibration is generated at a specific position. And
The medical image diagnostic apparatus according to claim 2. The control unit controls the imaging of the subject placed on the top plate based on the classification result of the vibration,
The medical image diagnostic apparatus according to claim 1. The control unit, when the magnitude of the vibration exceeds a first threshold, allows imaging if a request for imaging of a subject placed on the top plate from an operator,
The medical image diagnostic apparatus according to claim 1. The control unit, when the magnitude of the vibration exceeds the second threshold, stops imaging if the subject placed on the top plate is being imaged, and the magnitude of the vibration before imaging Allows shooting in a range excluding a range exceeding the second threshold,
The medical image diagnostic apparatus according to claim 1. The control unit, when the magnitude of the vibration exceeds a third threshold, stops the imaging of the subject placed on the top plate,
The medical image diagnostic apparatus according to claim 1. The control unit, when the magnitude of the vibration exceeds the threshold, performs a maintenance request with information on the type or cause of the vibration,
The medical image diagnostic apparatus according to claim 5. The control unit determines the threshold based on the magnitude of vibration measured at the time of installation of the top plate,
The medical image diagnostic apparatus according to claim 5. The control unit classifies the vibration using a measurement result obtained from a vibration meter that measures the vibration at the time of moving the top board,
The medical image diagnostic apparatus according to claim 1.

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