X-ray CT apparatus, control method, and control program

Abstract

To efficiently switch a photographing mode.SOLUTION: The X-ray CT apparatus includes a scanner part, a support part, and a control part. The scanner unit includes an imaging system. The support part includes a lifting mechanism for lifting the scanner part and a tilt mechanism for tilting the scanner part, and supports the scanner part. The control unit controls the elevation mechanism and the tilt mechanism so as to move the scanner unit to different pre-imaging positions between a first imaging mode for imaging a subject in a first state and a second imaging mode for imaging the subject in a second state.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The embodiments disclosed in this specification and the drawings relate to an X-ray CT apparatus, a control method, and a control program. [Background technology]

[0002] X-ray CT scanners (X-ray computed tomography scanners) are generally designed so that the subject is in a supine position on a bed, but upright X-ray CT scanners that can take images of subjects in an upright position are also in practical use. In addition, there are also upright / supine X-ray CT scanners that can switch between a mode for taking images of subjects in an upright position (upright imaging mode) and a mode for taking images of subjects in a supine position (upright imaging mode). With upright / supine X-ray CT scanners, it is possible to switch between taking images in a supine position and an upright position by changing the angle of the scanner. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-106083 Summary of the Invention [Problem to be solved by the invention]

[0004] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to enable efficient switching of shooting modes. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problem. Problems corresponding to the effects of the configurations shown in the embodiments described below can also be positioned as other problems. [Means for solving the problem]

[0005] The X-ray CT apparatus according to this embodiment includes a scanner unit, a support unit, and a controller. The scanner unit has an imaging system. The support unit has a lifting mechanism that raises and lowers the scanner unit and a tilting mechanism that tilts the scanner unit, and supports the scanner unit. The controller controls the lifting mechanism and the tilting mechanism to move the scanner unit to different pre-imaging positions in a first imaging mode for imaging a subject in a first state and a second imaging mode for imaging the subject in a second state. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an X-ray CT apparatus according to this embodiment. [Figure 2] FIG. 2 is a conceptual diagram showing the state of the scanner unit in the standing position photographing mode according to this embodiment. [Figure 3] FIG. 3 is a conceptual diagram showing the state of the scanner unit in the sitting position imaging mode according to this embodiment. [Figure 4] FIG. 4 is a conceptual diagram showing the state of the scanner unit in the supine position imaging mode according to this embodiment. [Figure 5] FIG. 5 is a flowchart showing an example of the operation of the X-ray CT apparatus according to this embodiment. [Figure 6] FIG. 6 is a diagram showing an example of the pre-imaging position of the scanner unit in the standing position imaging mode. [Figure 7] FIG. 7 is a diagram showing an example of the pre-imaging position of the scanner unit in the standing position imaging mode. [Figure 8] FIG. 8 is a diagram showing an example of the pre-imaging position of the scanner unit in the supine position imaging mode. [Figure 9] FIG. 9 is a diagram showing an example of the pre-imaging position of the scanner unit in the supine position imaging mode. [Figure 10] FIG. 10 is a flowchart showing an example of automatic drive control of the X-ray CT apparatus according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment of an X-ray CT apparatus (X-ray computed tomography apparatus), a control method, and a control program will be described in detail with reference to the drawings. In the following embodiments, parts with the same reference numerals perform similar operations, and redundant explanations will be omitted as appropriate. Hereinafter, one embodiment will be described with reference to the drawings.

[0008] FIG. 1 is a diagram showing an example of the configuration of an X-ray CT apparatus 1 according to this embodiment. As shown in FIG. 1, the X-ray CT apparatus 1 includes a scanner unit 10, a bed 30, and a console 40. Although FIG. 1 illustrates multiple scanner units 10 for ease of explanation, the apparatus may actually include one or multiple scanner units. The scanner unit 10 is a scanning device configured to perform X-ray CT imaging of a subject P. The bed 30 is a transport device on which the subject P to be subjected to X-ray CT imaging is placed and which positions the subject P. The console 40 is a computer that controls the scanner unit 10. For example, the scanner unit 10 and the bed 30 are installed in a CT examination room, and the console 40 is installed in a control room adjacent to the CT examination room. The scanner unit 10, the bed 30, and the console 40 are connected to each other by wire or wirelessly so that they can 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 as the scanner unit 10 and the bed 30. The console 40 may also be incorporated into the scanner unit 10 .

[0009] As shown in FIG. 1, the scanner unit 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 system (DAS) 18.

[0010] The X-ray tube 11 irradiates the subject P with X-rays. Specifically, the X-ray tube 11 includes a cathode that generates thermoelectrons, an anode that generates X-rays upon receiving thermoelectrons flying from the cathode, and a vacuum tube that holds the cathode and anode. The X-ray tube 11 is connected to the X-ray high voltage device 14 via a high-voltage cable. A tube voltage is applied between the cathode and the anode by the X-ray high voltage device 14. The application of the tube voltage causes thermoelectrons to fly from the cathode toward the anode. A tube current flows as the thermoelectrons fly from the cathode toward the anode. X-rays are generated when the thermoelectrons collide with the anode.

[0011] The X-ray detector 12 detects X-rays emitted from the X-ray tube 11 and passing through the subject P, and outputs an electrical signal corresponding to the detected X-ray dose to the DAS 18. The X-ray detector 12 has a structure in which multiple X-ray detection element rows, each having multiple X-ray detection elements arranged in the channel direction, are arranged in the slice direction (row direction). The X-ray detector 12 is, for example, an indirect conversion type detector having a grid, a scintillator array, and a photosensor array. The scintillator array has multiple scintillators. The scintillator outputs light with an amount of light corresponding to the amount of incident X-rays. The grid is arranged on the X-ray incidence surface side of the scintillator array and has an X-ray shielding plate that absorbs scattered X-rays. The grid is sometimes called a collimator (one-dimensional collimator or two-dimensional collimator). The photosensor array converts the light into an electrical signal corresponding to the amount of light from the scintillator. For example, a photodiode is used as the photosensor.

[0012] The X-ray detector 12 may be a photon-counting detector. In the case of a photon-counting detector, the scintillator converts incident X-rays into photons, the number of which corresponds to the intensity of the incident X-rays. The photosensor array amplifies the light received from the scintillator, converts it into an electrical signal, and generates an output signal (energy signal) having a peak value corresponding to the energy of the incident X-rays.

[0013] Furthermore, the X-ray detector 12 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into an electrical signal.

[0014] The rotating frame 13 is an annular frame that supports the X-ray tube 11 and the X-ray detector 12 rotatably around a rotation axis (Z-axis). Specifically, the rotating frame 13 supports the X-ray tube 11 and the X-ray detector 12 so that they face each other. In addition to the X-ray tube 11 and the X-ray detector 12, the rotating frame 13 also supports the X-ray high-voltage generator 14 and the DAS 18. The rotating frame 13 is supported on a fixed frame (not shown) so that it can rotate around the rotation axis. The rotation mechanism includes, for example, a motor that generates a rotational driving force and a bearing that transmits the rotational driving force to the rotating frame 13 to rotate it. The motor is provided on the fixed frame, and the bearing is physically connected to the rotating frame 13 and the motor, so that the rotating frame 13 rotates in response to the rotational force of the motor. The rotation of the rotating frame 13 around the rotation axis causes the X-ray tube 11 and the X-ray detector 12 to rotate around the rotation axis. The rotating frame 13 is an example of a rotating unit.

[0015] The X-ray high voltage device 14 has a high voltage generator and an X-ray control device. The high voltage generator has electrical circuits such as a transformer and a rectifier, and generates a high voltage to be applied to the X-ray tube 11 and a filament current to be supplied to the X-ray tube 11. The X-ray control device controls the output voltage according to the X-rays emitted by the X-ray tube 11. The high voltage generator may be of a transformer type or an inverter type. The X-ray high voltage device 14 may be provided on the rotating frame 13 within the scanner unit 10, or on a fixed frame (not shown) within the scanner unit 10.

[0016] The wedge 16 adjusts the dose of X-rays irradiated onto the subject P. Specifically, the wedge 16 attenuates the X-rays so that the dose of X-rays irradiated from the X-ray tube 11 onto the subject P has a predetermined distribution. For example, the wedge 16 is made of a metal plate such as aluminum, such as a wedge filter or a bow-tie filter.

[0017] The collimator 17 limits the irradiation range of the X-rays that have passed through the wedge 16. The collimator 17 slidably supports multiple lead plates that shield the X-rays, and adjusts the shape of the slits formed by the multiple lead plates. The collimator 17 is sometimes called an X-ray aperture.

[0018] The DAS 18 reads out an electrical signal from the X-ray detector 12 corresponding to the X-ray dose detected by the X-ray detector 12. The DAS 18 amplifies the read-out electrical signal and integrates the electrical signal over a view period to collect detection data having a digital value corresponding to the X-ray dose over the view period. The detection data is also called projection data. The DAS 18 is realized, for example, by an application specific integrated circuit (ASIC) equipped with circuit elements capable of generating projection data. The projection data is transmitted to the console 40 via a non-contact data transmission device or the like.

[0019] In this embodiment, an integral type X-ray detector 12 and an X-ray CT device 1 equipped with an integral type X-ray detector 12 are described as examples, but the technology according to this embodiment can also be applied to a photon counting type X-ray detector.

[0020] The rotating frame 13 and the fixed frame are each provided with a non-contact or contact communication circuit, and these communication circuits enable communication between the unit supported on the rotating frame 13 and an external device of the fixed frame or the scanner unit 10. For example, if optical communication is used as the non-contact communication method, the detection data generated by the DAS 18 is transmitted by optical communication from a transmitter having a light-emitting diode (LED) provided on the rotating frame 13 to a receiver having a photodiode provided on the fixed frame of the scanner unit 10, and the data is then transferred from the fixed frame to the console 40 by the transmitter. Note that, other communication methods may also be used, such as non-contact data transmission methods such as capacitive coupling and radio wave methods, as well as contact data transmission methods using a slip ring and electrode brushes.

[0021] The control device 15 controls the X-ray high-voltage generator 14 and the DAS 18 to perform X-ray CT imaging in accordance with the imaging control function 442 of the processing circuit 44 of the console 40. The control device 15 includes a processing circuit having a central processing unit (CPU) or a micro processing unit (MPU), and a drive mechanism such as a motor and an actuator. The processing circuit includes, as hardware resources, a processor such as a CPU and memory such as a read-only memory (ROM) or a random access memory (RAM). The control device 15 executes various functions using a processor that executes programs loaded in the memory. Note that various functions are not limited to being implemented by a single processing circuit. A processing circuit may be configured by combining multiple independent processors, and each processor may execute a program to implement each function. The control device 15 may also be implemented using an ASIC or a field programmable gate array (FPGA). Additionally, the control device 15 may be realized by other Complex Programmable Logic Devices (CPLDs) or Simple Programmable Logic Devices (SPLDs).

[0022] The control device 15 has a function of controlling the operation of the scanner unit 10 and the bed 30 in response to input signals from an input interface 43 (described later) attached to the console 40 or the scanner unit 10, or in response to control signals from the processing circuit 44. For example, the control device 15 receives input signals to control the rotation of the rotating frame 13, control the tilt of the scanner unit 10, and control the operation of the bed 30 and the tabletop 33. Note that the control of tilting the scanner unit 10 is realized by the control device 15 rotating the rotating frame 13 around an axis parallel to the X-axis direction based on inclination angle (tilt angle) information input via an input interface attached to the scanner unit 10. Note that the control device 15 may be provided in the scanner unit 10 or in the console 40.

[0023] The bed 30 includes a base 31, a support frame 32, a top plate 33, and a bed driving device 34. The base 31 is placed on the floor. The base 31 is a housing that supports the support frame 32 so that it can move vertically (in the Y-axis direction) relative to the floor. The support frame 32 is a frame provided on top of the base 31. The support frame 32 supports the top plate 33 so that it can slide along the rotation axis (Z-axis). The top plate 33 is a flexible plate on which the subject P is placed.

[0024] The bed driving device 34 is housed in the housing of the bed 30. The bed driving device 34 is a motor or actuator that generates power to move the support frame 32 on which the subject P is placed and the tabletop 33. The bed driving device 34 operates under the control of the processing circuitry 44, the console 40, etc.

[0025] 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). Note that although the console 40 will be described as being separate from the scanner unit 10, the scanner unit 10 may include the console 40 or some of the components of the console 40.

[0026] The memory 41 is a storage device such as a hard disk drive (HDD), a solid state drive (SSD), or an integrated circuit storage device that stores various information. In addition to an HDD or SSD, the memory 41 may be a portable storage medium such as a compact disc (CD), a digital versatile disc (DVD), a Blu-ray (registered trademark) disc (BD), or a flash memory. The memory 41 may also be a drive device that reads and writes various information from and to semiconductor memory elements such as flash memory and RAM. The storage area of ​​the memory 41 may be located within the X-ray CT apparatus 1 or may be located in an external storage device connected via a network.

[0027] The display 42 displays various types of information. Any of a variety of displays can be used as the display 42, as appropriate. For example, a liquid crystal display (LCD), a cathode ray tube (CRT) display, an organic electroluminescence display (OLED), or a plasma display can be used as the display 42. The display 42 may be provided anywhere in the control room. The display 42 may also be provided in the scanner unit 10. The display 42 may be a desktop type, or may be configured as a tablet terminal or the like capable of wireless communication with the main body of the console 40. The display 42 may also be one or more projectors.

[0028] The input interface 43 accepts various input operations from the operator, converts the accepted input operations into electrical signals, and outputs the electrical signals to the processing circuit 44. Examples of the input interface 43 that can be used include a mouse, keyboard, trackball, switch, button, joystick, touchpad, and touch panel display, as appropriate. In this embodiment, the input interface 43 is not limited to a device equipped with physical operating components such as a mouse, keyboard, trackball, switch, button, joystick, touchpad, and touch panel display. For example, an electrical signal processing circuit that receives electrical signals corresponding to input operations from an external input device provided separately from the device and outputs the electrical signals to the processing circuit 44 is also included as an example of the input interface 43. The input interface 43 may also be provided in the scanner unit 10. The input interface 43 may also be configured as a tablet terminal or the like that is capable of wireless communication with the console 40 main body.

[0029] The processing circuitry 44 controls the overall operation of the X-ray CT apparatus 1 in response to electrical signals of input operations output from the input interface 43. The processing circuitry 44 generates image data based on electrical signals output from the X-ray detector 12. For example, the processing circuitry 44 has, as hardware resources, a processor such as a CPU, MPU, or GPU, and memories such as ROM and RAM. The processing circuitry 44 executes a system control function 441, an imaging control function 442, a scanner unit control function 443, an image generation function 444, a determination function 445, and a display control function 446 by using a processor that executes programs loaded in the memory.

[0030] Note that each function is not limited to being realized by a single processing circuit, but may be realized by combining multiple independent processors to form a processing circuit, and each processor may execute a program to realize each function.

[0031] In the system control function 441, the processing circuitry 44 controls each part of the X-ray CT apparatus 1 according to the deployed control program. Also, in the system control function 441, the processing circuitry 44 controls the driving of the bed 30 via the control device 15.

[0032] In the imaging control function 442, the processing circuitry 44 controls the X-ray high voltage generator 14, the control device 15, and the DAS 18 in accordance with imaging conditions to perform X-ray CT imaging.

[0033] In the scanner unit control function 443, the processing circuitry 44 controls the lifting mechanism and the tilt mechanism to move the scanner unit to different pre-imaging positions in a first imaging mode for imaging the subject P in a first state and a second imaging mode for imaging the subject P in a second state. The first state and the second state are any two of the supine position, standing position, and sitting position. In this embodiment, the pre-imaging positions include a retracted position where the scanner unit is retracted so as not to interfere with the movement of the subject P in preparation for imaging, and an imaging start position where imaging of the subject P can be started.

[0034] In the image generation function 444, the processing circuitry 44 performs reconstruction processing on projection data related to the subject P to generate a CT image. The reconstruction processing may be performed using a filtered back projection method or an iterative reconstruction method. Alternatively, the reconstruction processing may be performed by incorporating denoising processing using machine learning into these methods. The processing circuitry 44 converts the CT image into a cross-sectional image of an arbitrary cross section or a rendering image of an arbitrary viewpoint. The conversion is performed based on an input operation received from an operator via the input interface 43. For example, the processing circuitry 44 performs three-dimensional image processing such as volume rendering, surface volume rendering, pixel value projection processing, MPR (Multi-Planer Reconstruction) processing, and CPR (Curved MPR) processing on the reconstructed image data to generate a rendering image of an arbitrary viewpoint.

[0035] In the determination function 445, the processing circuitry 44 determines whether or not the subject P is present in the opening of the scanner unit 10 based on information from the sensor or camera. The sensor and camera are assumed to be, for example, a pressure sensor placed on the bottom plate and a camera attached to the ceiling or wall, respectively, as will be described later with reference to Figures 6 and 7. In addition, in the determination function 445, the processing circuitry 44 refers to the examination order and the imaging protocol to determine whether the subject's state in the next imaging is the first state or the second state.

[0036] In display control function 446, processing circuitry 44 displays the generated CT images and rendering images, for example, on display 42.

[0037] Although the console 40 has been described as a single console that executes multiple functions, multiple functions may be executed by separate consoles. The processing circuitry 44 is not limited to being included in the console 40, but may also be included in an integrated server that collectively processes projection data acquired by multiple medical image diagnostic devices. Post-processing may be performed by either the console 40 or an external workstation. Furthermore, processing may be performed simultaneously by both the console 40 and the workstation.

[0038] There are various types of X-ray CT apparatus 1, such as third-generation CT and fourth-generation CT, and any of these types can be applied to this embodiment. Here, the third-generation CT is a rotate / rotate-type in which the X-ray tube and detector rotate together around the subject. The fourth-generation CT is a stationary / rotate-type in which a large number of X-ray detection elements arranged in a ring shape are fixed, and only the X-ray tube rotates around the subject.

[0039] Although not shown, the X-ray CT apparatus 1 may include a communication interface. The communication interface is an interface that connects the X-ray CT apparatus 1 to a workstation, a PACS (Picture Archiving and Communication System), an HIS (Hospital Information System), a RIS (Radiology Information System), etc. via a LAN (Local Area Network) or the like. The communication interface transmits and receives various types of information to and from the connected workstation, PACS, HIS, and RIS.

[0040] Next, the state of the scanner unit for each imaging mode according to this embodiment will be described with reference to the conceptual diagrams of FIGS.

[0041] FIG. 2 is a conceptual diagram showing the state of the scanner unit 10 in an imaging mode (hereinafter also referred to as an upright imaging mode) for imaging a subject P in a standing position. In this embodiment, an X-ray CT apparatus for both lying and standing positions is assumed. That is, in the upright imaging mode, the scanner unit 10 is fixed in a position where the opening OP faces vertically and is connected to a support unit 20 that stands upright in the vertical direction. The scanner unit 10 and the support unit 20 are connected via a tilt mechanism and an elevation mechanism. The tilt mechanism rotates the scanner unit 10. For example, a general rotation mechanism using gears, a conveyor, or the like may be used. The elevation mechanism moves the scanner unit 10 up and down in the vertical direction. For example, a general linear motion mechanism such as a rack and pinion mechanism may be used. The subject P is positioned in an upright position within the opening OP, and the subject P is imaged by moving the scanner unit 10 up and down using the elevation mechanism.

[0042] 3 is a conceptual diagram showing the state of the scanner unit 10 in an imaging mode for imaging a subject P in a seated position (hereinafter also referred to as a seated position imaging mode). In this embodiment, the seated position imaging mode includes both a case where the subject is seated in a chair and a case where the subject is seated in a wheelchair. As in the standing position imaging mode, the opening OP of the scanner unit 10 faces vertically. The subject P is positioned in the opening OP while seated in a wheelchair or chair, and the scanner unit 10 is moved up and down by the lifting mechanism to image the subject P.

[0043] Next, FIG. 4 is a conceptual diagram showing the state of the scanner unit 10 in an imaging mode for imaging the subject P in a supine position (hereinafter also referred to as a supine position imaging mode).

[0044] 4, the scanner unit 10 is rotated 90 degrees from the orientation in the upright position imaging mode, and the opening OP faces horizontally. The subject P is in a supine position on the tabletop 33, and the tabletop 33 is moved so as to enter the opening OP, thereby imaging the subject P. That is, in the upright position imaging mode and the supine position imaging mode, the body axis direction of the subject is approximately perpendicular to each other. The scanner unit 10 may be movable in the horizontal direction. For example, the support unit 20 itself has a drive mechanism that drives the scanner unit 10 along the longitudinal direction of the bed 30, and the scanner unit 10 moves horizontally together with the support unit 20. Furthermore, although an example in which there is one support unit 20 is shown, another support unit 20 may be arranged at a position opposite to the scanner unit 10, so that two support units 20 are arranged.

[0045] Next, a first operation example of the X-ray CT apparatus according to this embodiment will be described with reference to the flowchart in Fig. 5. Here, it is assumed that the first state is a standing position and the second state is a lying position. Note that the first state and the second state may be any two of the standing position, sitting position, and lying position.

[0046] In step SA1, the processing circuitry 44 uses the determination function 445 to determine, for example, by referring to the examination order, whether the imaging mode is the first imaging mode in which the subject P is in the first state or the second imaging mode in which the subject P is in the second state. If the imaging mode is the first imaging mode, the process proceeds to step SA2, and if the imaging mode is the second imaging mode, the process proceeds to step SA5. In step SA2, the scanner unit control function 443 causes the processing circuitry 44 to move the scanner unit 10 to the retracted position in the first state, where the scanner unit 10 is retracted so as not to interfere with the movement of the subject P in preparation for imaging.

[0047] In step SA3, the subject P is set. In the first state, the subject P is guided by, for example, a technician to stand in the opening OP of the scanner unit 10. In step SA4, the scanner unit control function 443 causes the processing circuitry 44 to move the scanner unit 10 to the imaging start position in the first state where imaging of the subject P can be started.

[0048] In step SA5, the scanner unit control function 443 causes the processing circuitry 44 to move the scanner unit 10 to the retracted position in the second state, where the scanner unit 10 is retracted so as not to interfere with the movement of the subject P in preparation for imaging. In step SA6, the subject is set. In the second state, the subject P is guided to lie on the top board 33 of the bed 30 by, for example, the technician.

[0049] In step SA7, the system control function 441 and the scanner unit control function 443 cause the processing circuitry 44 to move the top board 33 or the scanner unit 10 to the imaging start position in the second state where imaging of the subject P can be started. In step SA8, the imaging control function 442 causes the processing circuitry 44 to perform imaging, and projection data of the subject P is acquired.

[0050] In this way, the scanner unit control function 444 and / or the system control function 441 control the processing circuitry 44 to move to the pre-imaging position in the first imaging mode (steps SA2 and SA4) or to the pre-imaging position in the second imaging mode (steps SA5 and SA7) depending on the state of the subject. After the imaging is performed in step SA8, the processing circuitry 44 may automatically move the scanner unit 10 or the bed 30 to the retracted position using the scanner unit control function 443 and the system control function 441. This eliminates the need for a technician to manually operate the scanner unit 10 or the bed 30 to the retracted position from the console 40 or the like in order to move the subject, thereby improving the workflow.

[0051] When the scanner unit 10 or the tabletop 33 is automatically moved to the retracted position, a sound, voice guide, or the like may be output to alert the subject P. When an imaging plan is created by inputting data into the console 40, a plan for automatically moving the scanner unit 10 or the bed 30 to the retracted position may be automatically generated at the end of the imaging plan. This plan may also be editable so that it can be deleted if unnecessary.

[0052] 5, it is assumed that the determination is made from the imaging modes relating to two states, but the determination may be made for each of the three imaging modes, standing position imaging mode, sitting position imaging mode, and lying position imaging mode. That is, the processing circuit 44 determines which state it is, standing position imaging mode, sitting position imaging mode, or lying position imaging mode, using the determination function 445, and performs the same processing.

[0053] Next, FIG. 6 shows an example of the pre-photographing position of the scanner unit 10 in the standing position photography mode when the scanner unit 10 is in the retracted position.

[0054] In FIG. 6 , the opening OP of the scanner unit 10 is indicated by a dashed line. Using the scanner unit control function 443, the processing circuit 44 drives the tilt mechanism 81 to tilt the scanner unit 10 so that the opening OP faces vertically, and drives the lifting mechanism 82 to fix the scanner unit 10 at the highest position within the range in which the scanner unit 10 can be moved vertically, setting the highest position as the retracted position. This allows the subject P to easily enter and exit the imaging range on the bottom plate 21. The processing circuit 44 may also use the determination function 445 to determine whether the subject P is present in the scanner unit 10 based on information from a camera 85 attached to the ceiling or wall or a pressure sensor 86 mounted on or embedded in the bottom plate 21. Specifically, if the presence of the subject P is determined in an image captured by the camera 85, for example, using image processing or a machine learning model, the processing circuit 44 may determine that the subject P is present in the scanner unit 10. In the case of the pressure sensor 86, if the output value of the sensor is equal to or greater than a threshold value, it may be determined that the subject P is present in the scanner unit 10. Note that the presence of the subject P may be determined not only by the camera 85 but also by a distance measuring sensor arranged on the ceiling. The pressure sensor 86 is an example of a sensor. The camera 85 is an example of a camera.

[0055] 7 shows an example of the pre-shooting position of scanner unit 10 in the standing position shooting mode when it is in the shooting start position. The area indicated by the two-dot chain line shows the case where scanner unit 10 is in the retracted position. The scanner unit control function 443 causes the processing circuitry 44 to drive the elevator mechanism 82 to move the scanner unit 10 vertically downward from the retracted position shown in FIG. 6, and fix the scanner unit 10 at a position where imaging can be started, as the imaging start position. For example, the scanner unit 10 is positioned near the subject's head. The imaging start position may be set according to the physique of the subject P based on patient information. Alternatively, a table may be prepared in which the size of the subject P (for example, height) is associated with a fixed position at which the scanner unit 10 is fixed as the imaging start position, and the imaging start position according to the physique of the subject P may be determined by referring to the table.

[0056] In the sitting position imaging mode, since the subject P is seated, at least one of the pre-imaging positions (retracted position and imaging start position) may be set lower than in the standing position imaging mode. Although not shown in FIGS. 6 and 7, the position of the bed 30 in the standing position imaging mode and the sitting position imaging mode may be such that the top board 33 is moved to the lowest position and the farthest position from the scanner unit 10.

[0057] Next, FIG. 8 shows an example of the pre-imaging position of the scanner unit 10 in the supine position imaging mode when the scanner unit 10 is in the retracted position. In the case of the supine position imaging mode, when switching from the upright position imaging mode to the supine position imaging mode, the scanner unit 10 rotates, and therefore the processing circuit 44 also controls the bed 30, for example, by the system control function 441, to move the support frame 32 and the tabletop 33 away from the scanner unit 10. Then, by the scanner unit control function 443, the processing circuit 44 drives the tilt mechanism 81 to tilt the scanner unit 10 so that the opening OP faces the horizontal direction, and drives the lifting mechanism 82 to fix the tabletop 33 of the bed 30 at a height that allows it to be inserted into the opening OP of the scanner unit 10. The scanner unit 10 and the bed 30 are controlled in a coordinated manner, thereby setting the retracted position.

[0058] Note that, for example, if rails are formed between the support unit 20 and the floor surface in an examination room, and the support unit 20 is moved horizontally on the rails by a drive mechanism, thereby allowing the scanner unit 10 itself to move in the longitudinal direction of the bed 30, i.e., in the horizontal direction, the scanner unit 10 may be moved horizontally without moving the bed 30, with the position where the scanner unit 10 is farthest from the bed 30 being set as the retracted position. Of course, the processing circuitry 44 may be controlled by the system control function 441 and the scanner unit control function 443 to move both the bed 30 and the scanner unit 10 so as to move them away from each other.

[0059] Next, FIG. 9 shows an example of the pre-imaging position of the scanner unit 10 in the supine position imaging mode when the scanner unit 10 is in an imaging-enabled position. 8 toward the opening OP of the scanner unit 10, and sets the imaging start position at a position where imaging of the subject P in a supine position can be started, and fixes the top 33. If the scanner unit 10 itself is movable in the horizontal direction, the imaging start position may be set by moving the scanner unit 10 in a direction approaching the bed 30.

[0060] In addition, when imaging in different modes is performed successively, it is generally assumed that after the examination of the subject P, the technician will confirm that the subject P has left the imaging range and manually move the scanner unit 10 or the bed to the evacuation position for the next imaging mode. Therefore, a camera and a sensor may be used to perform control to automatically move to the pre-imaging position for the next imaging mode.

[0061] An example of automatic drive control of the X-ray CT apparatus 1 according to this embodiment will be described with reference to the flowchart of FIG.

[0062] In step SB1, the processing circuitry 44 determines the imaging mode for the next imaging based on the examination order or the imaging protocol for the next imaging by the determination function 445.

[0063] In step SB2, the processing circuit 44 controls the scanner unit control function 443 to move the scanner unit 10 or the bed 30 to a pre-imaging position corresponding to the next imaging depending on the determined imaging mode. That is, depending on whether the imaging mode is standing position, sitting position, or lying position, the scanner unit 10 or the bed 30 is moved to the corresponding pre-imaging position.

[0064] In step SB3, the imaging control function 442 causes the processing circuit 44 to perform imaging. In step SB4, the processing circuitry 44, for example, by the system control function 441 or the determination function 445, refers to the examination order and determines whether or not there is a next imaging. If there is a next imaging, the process returns to step SB1 and repeats the same process. On the other hand, if there is no next imaging, the process ends.

[0065] After processing step SB4, the processing circuit 44 may use the judgment function 445 to determine, based on the image information from the camera 85 or the sensor value from the pressure sensor 86, that the subject has left the opening OP of the scanner unit 10 and the movement range (driving range) of the scanner unit 10, and may be controlled to automatically transition to the next shooting mode.

[0066] According to the present embodiment described above, a pre-shooting position is set for each shooting mode, such as standing shooting mode, sitting shooting mode, and lying shooting mode, and when a specific shooting mode is detected or specified, the lifting mechanism and tilt mechanism are controlled to move the scanner unit to the corresponding pre-shooting position.

[0067] In the past, for example, a technician would manually press a button to raise or lower the scanner unit to move it to a retracted position or an imaging start position for each imaging session, or would hold down a button to tilt the scanner unit to set it when changing from upright imaging mode to prone imaging mode. According to this embodiment, however, the scanner unit can be moved automatically or with a single button operation to the pre-imaging positions set for each imaging mode, i.e., the retracted position and imaging start position, without the need for the conventional procedures. As a result, the scanner unit can be easily moved to the pre-imaging position for each imaging mode, enabling efficient imaging mode switching and improving workflow.

[0068] The term "processor" used in the above description refers to a circuit such as a CPU, a GPU, an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). A processor realizes its functions by reading and executing a program stored in a memory circuit. Note that instead of storing a program in a memory circuit, the processor may be configured so that the program is directly embedded in the circuit. In this case, the processor realizes its functions by reading and executing the program embedded in the circuit. Furthermore, instead of executing a program, the function corresponding to the program may be realized by combining logic circuits. Note that each processor in this embodiment is not limited to being configured as a single circuit, but may be configured as a single processor by combining multiple independent circuits to realize its function. Furthermore, multiple components may be integrated into a single processor to realize its function.

[0069] Although several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations of embodiments can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0070] 1 X-ray CT device 10 Scanner unit 11 X-ray tube 12 X-ray detector 13 Rotating Frame 14 X-ray high voltage device 15 Control device 16 Wedge 17 Collimator 18 Data Acquisition System (DAS) 20 Support part 21 Bottom plate 30 berths 31 Foundation 32 Support frame 33 Top plate 34 Bed drive unit 40 Console 41 memory 42 Display 43 Input Interface 44 Processing circuit 81 Tilt mechanism 82 Lifting mechanism 85 Camera 86 Pressure Sensor 441 System Control Functions 442 Shooting control function 443 Scanner control function 444 Image generation function 445 Judgment Function 446 Display Control Function OP opening

Claims

1. a scanner unit having an imaging system; a support section that supports the scanner section and has a lifting mechanism that lifts and lowers the scanner section and a tilting mechanism that tilts the scanner section; a control unit that controls the lifting mechanism and the tilting mechanism to move the scanner unit to different pre-imaging positions in a first imaging mode for imaging a subject in a first state and a second imaging mode for imaging the subject in a second state; An X-ray CT device comprising:

2. 2. The X-ray CT apparatus according to claim 1, wherein the body axis directions of the subject in the first imaging mode and the second imaging mode are substantially perpendicular to each other.

3. 2. The X-ray CT apparatus according to claim 1, wherein the first state and the second state are any two of a standing position, a sitting position, and a lying position.

4. 2. The X-ray CT apparatus according to claim 1, wherein the pre-imaging position is a retracted position where the object is retracted so as not to interfere with movement of the object in preparation for imaging, or an imaging start position where imaging of the object can be started.

5. a determination unit that determines whether the next imaging is to be performed in the first imaging mode or the second imaging mode by referring to an examination order and an imaging protocol; The X-ray CT apparatus according to claim 4 , wherein the control unit controls the scanner unit to move to the retracted position in accordance with the imaging mode determined by the determination unit.

6. the support unit has a drive mechanism that drives the scanner unit along a longitudinal direction of a bed on which the subject is placed, The X-ray CT apparatus according to claim 1 , wherein the control unit controls the drive mechanism to move the scanner unit to the pre-imaging position.

7. 2. The X-ray CT apparatus according to claim 1, further comprising a determination unit that determines whether the subject is present within the scanner unit based on information from a sensor or a camera.

8. 1. A control method for an X-ray CT apparatus including a scanner unit having an imaging system, an elevation mechanism for elevating the scanner unit, a tilt mechanism for tilting the scanner unit, and a support unit for supporting the scanner unit, the method comprising: controlling the lifting mechanism and the tilting mechanism to move and rotate the scanner unit to different pre-imaging positions in a first imaging mode for imaging the subject in a first state and a second imaging mode for imaging the subject in a second state; Control method.

9. 1. A control program for an X-ray CT apparatus including a scanner unit having an imaging system, an elevation mechanism for elevating the scanner unit, a tilt mechanism for tilting the scanner unit, and a support unit for supporting the scanner unit, the program comprising: On the computer, realizing a control function of controlling the lifting mechanism and the tilting mechanism so as to move and rotate the scanner unit to different pre-imaging positions in a first imaging mode for imaging a subject in a first state and a second imaging mode for imaging the subject in a second state; Control program.

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