X-ray CT apparatus and operation control method for x-ray CT apparatus

Abstract

According to an embodiment, this X-ray CT apparatus includes a frame, a stand, and a control unit. The frame has an opening into which a subject is inserted. The stand has a tilt mechanism for tilting the frame. The control unit controls the tilt mechanism so that one end of a scanner unit on the movement path of the subject is in a movement assistance state higher than the other end.

Description

X-ray CT device and operation control method for X-ray CT device

[0001] The embodiments disclosed in this specification and the drawings relate to an X-ray CT apparatus and an operation control method for an X-ray CT apparatus.

[0002] In the field of X-ray computed tomography (CT), there is known an X-ray CT device capable of performing standing and sitting position radiography to capture tomographic images, three-dimensional images, dynamic images, etc. of a patient (subject) in a standing or sitting position. This type of X-ray CT device has, for example, a scanner and a support (stand) that can drive the scanner up and down. The scanner has an X-ray tube and an X-ray detector arranged opposite each other and has an opening (scanner opening).

[0003] The scanner's range of motion is limited by physical constraints such as the ceiling height of the room where the X-ray CT device is installed (hereinafter referred to as the examination room) and the scanner's thickness. Therefore, even when the scanner is moved to its highest position, patients may have to bend down when passing under the scanner to move under the opening.

[0004] Japanese Patent Application Laid-Open No. 2022-065380

[0005] One of the problems that the embodiments disclosed in this specification and drawings aim to solve is to improve the workflow, including patient movement before and after an examination. However, the problems that the embodiments disclosed in this specification and drawings aim to solve are not limited to the above problem. Problems corresponding to the effects of the configurations shown in the embodiments described below can also be considered as other problems.

[0006] An X-ray CT apparatus according to an embodiment includes a gantry, a stand, and a controller. The gantry has an opening into which a subject is inserted. The stand has a tilt mechanism that tilts the gantry. The controller controls the tilt mechanism so that one end of the scanner unit on a movement path of the subject is in a movement assist state in which the one end is higher than the other end.

[0007] FIG. 1 is a diagram showing an example of the configuration of an X-ray CT system according to the first embodiment. FIG. 2 is a perspective view showing the positional relationship between a gantry device and a subject during CT imaging according to the first embodiment. FIG. 3 is a diagram showing an example of a cross section of a scanner according to the first embodiment. FIG. 4 is a flowchart showing a processing procedure by the X-ray CT system according to the first embodiment. FIG. 5 is a diagram showing a scanner in a standby state according to the first embodiment. FIG. 6 is a diagram showing a scanner in an entry assistance state according to the first embodiment. FIG. 7 is a diagram showing a state in which a subject enters according to the first embodiment. FIG. 8 is a diagram showing a scanner in a standby state according to a modified example of the first embodiment. FIG. 9 is a diagram showing a scanner in an exit assistance state according to a modified example of the first embodiment. FIG. 10 is a diagram showing a state in which a subject exits according to a modified example of the first embodiment. FIG. 11 is a diagram showing an example of the configuration of an X-ray CT system according to a second embodiment. FIG. 12 is a flowchart showing a processing procedure by the X-ray CT system according to the second embodiment. FIG. 13 is a diagram showing a scanner in an entry prevention state according to another modified example. FIG. 14 is a diagram showing a scanner in an exit prevention state according to another modified example.

[0008] Hereinafter, an embodiment of an X-ray computed tomography apparatus (hereinafter referred to as an X-ray CT apparatus) will be described in detail with reference to the drawings. In the following description, components having substantially the same functions and configurations are designated by the same reference numerals, and redundant description will be given only when necessary.

[0009] (First Embodiment) FIG. 1 is a block diagram showing an example of the configuration of an X-ray CT apparatus 1 according to the first embodiment. The X-ray CT apparatus 1 has a gantry device 10 and a console device 60. For example, the gantry device 10 is installed in an imaging room, and the console device 60 is installed in an operation room adjacent to the imaging room. The gantry device 10 and the console device 60 are connected to each other by wire or wirelessly so that they can communicate with each other. The gantry device 10 is a scanning apparatus configured to perform CT imaging of a patient in a sitting or standing position. The console device 60 is a computer that controls the gantry device 10.

[0010] First, the configuration of the gantry 10 will be described. The gantry 10 includes a scanner 11, a support 13 that supports the scanner 11, and an operation panel 29. The support 13 supports the scanner 11 so that it can be raised and lowered and tilted relative to the floor surface. The gantry 10 may also be referred to as a gantry device.

[0011] The scanner 11 is a substantially annular structure and has an opening 15 that penetrates in the Z-axis direction in FIG. 1 . A patient is inserted into the opening 15 during CT imaging. The patient is an example of a subject. The opening 15 is a through-hole that penetrates the scanner 11 in the thickness direction of the scanner 11. The central axis A1 of the opening 15 is substantially perpendicular to the longitudinal direction of the scanner 11 and substantially horizontal to the thickness direction of the scanner 11. The scanner 11 houses an X-ray tube 17 and an X-ray detector 19. The X-ray tube 17 and the X-ray detector 19 are arranged to face each other with the opening 15 in between. The scanner 11 is an example of a scanner unit.

[0012] The scanner 11 has a fixed frame, which is a non-rotating part, a rotating frame, which is a rotating part, and a rotation mechanism that rotates the rotating frame relative to the fixed frame. The rotating frame is supported by the fixed frame so as to be rotatable around the central axis A1 of the opening 15. The rotation mechanism includes a motor that generates a rotational driving force and a bearing that transmits the rotational driving force to the rotating frame. The motor is provided, for example, on the fixed frame. The bearing is physically connected to the rotating frame and the motor. The rotational driving force of the motor is transmitted to the rotating frame via the bearing, causing the rotating frame to rotate.

[0013] The rotating frame is an annular frame that supports the X-ray tube 17 and the X-ray detector 19 so that they face each other and rotates the X-ray tube 17 and the X-ray detector 19 using a control device 25, which will be described later. In addition to the X-ray tube 17 and the X-ray detector 19, the rotating frame also supports a high-voltage generator 31 and a DAS 33, which will be described later.

[0014] The support 13 is a base that supports the scanner 11 at a distance from the floor. The support 13 is an example of a stand. The support 13 has a columnar shape, such as a cylindrical or rectangular columnar shape. The support 13 is formed of any material, such as plastic or metal. The support 13 is attached, for example, to the side of the scanner 11. The support 13 supports the scanner 11 so that it can move vertically relative to the floor surface to perform CT scans of a patient in a seated or standing position. The support 13 also supports the scanner 11 so that it can tilt around a tilt axis. The support 13 is an example of a stand that has an elevation mechanism that raises and lowers the scanner 11 and a tilt mechanism that tilts the scanner 11. FIG. 1 illustrates an example in which two support columns 13 are provided at positions facing each other across the scanner 11. However, the number of support columns 13 may be one, three, or more. Furthermore, although the support 13 has been described as having a columnar shape fixed to the floor, it may have a configuration having multiple links. The support 13 may be, for example, a robot arm with multiple degrees of freedom provided on the floor surface. For example, one support 13 may be provided at only one end (one side) of the scanner 11, and the scanner 11 may be supported by the single support 13. The support 13 may have any shape, such as a U-shape, as long as it can support at least one side of the scanner 11.

[0015] Hereinafter, a state in which the central axis A1 of the opening 15 is substantially parallel to the vertical direction will be referred to as the non-tilted state, and a state in which the central axis A1 of the opening 15 is tilted with respect to the vertical direction will be referred to as the tilted state. The tilt angle of the central axis A1 of the opening 15 with respect to the vertical direction will be referred to as the tilt angle. The tilt angle is, for example, within a range of ±90 degrees, with the non-tilted state being 0 degrees. The direction of the rotation axis of the rotating frame (the central axis A1 of the opening 15) in the non-tilted state will be defined as the Z-axis direction, the direction perpendicular to the Z-axis direction and from the center of rotation toward the support 13 supporting the rotating frame as the X-axis direction, and the direction perpendicular to the Z-axis and X-axis as the Y-axis direction. The Z-axis direction will also be referred to as the up-down direction, vertical direction, or perpendicular direction. The tilted state may be any state in which the central axis A1 of the opening 15 is tilted with respect to the vertical direction. For example, the tilted state may be achieved by tilting the scanner 11 about an axis other than the central axis A1 as the rotation axis, or by moving a portion of the scanner 11 in the up-down direction.

[0016] An elevator drive device for sliding the scanner 11 in the vertical direction is housed inside the support 13. The elevator drive device is an example of an elevator mechanism for raising and lowering the scanner 11. The elevator drive device generates power for sliding the scanner 11 in the vertical direction under control of the control device 25. Specifically, the elevator drive device generates power by driving at a rotational speed according to the duty ratio, etc., of a drive signal from the control device 25. The support 13 receives power from the elevator drive device and slides the scanner 11 in the vertical direction relative to the support 13. The elevator drive device is realized by a motor such as a servo motor, for example.

[0017] The support 13 and the scanner 11 are connected via bearings or the like, and the scanner 11 is connected so as to be tiltable around a tilt axis A2. The tilt axis A2 is, for example, a central axis of tilt that is substantially parallel to the X-axis direction. When the scanner 11 tilts relative to the support 13 around the tilt axis A2, the central axis A1 of the opening 15 is inclined relative to the vertical direction. With the scanner 11 tilted to any angle around the tilt axis A2, standing position CT imaging for a standing patient and sitting position CT imaging for a sitting patient are possible.

[0018] A tilt drive device is housed inside the support 13 for tilting the scanner 11 around the tilt axis relative to the support 13. The tilt drive device is an example of a tilt mechanism for tilting the scanner 11. The tilt drive device generates power for tilting the scanner 11 around the tilt axis in accordance with control from the control device 25. The support 13 receives power from the tilt drive device and tilts the scanner 11 relative to the support 13. The tilt drive device is realized by a motor such as a servo motor, for example.

[0019] FIG. 2 is a perspective view showing the positional relationship between the gantry 10 and the patient during CT imaging. As shown in FIG. 2, an entry path E is set on the gantry 10, along which the patient enters the imaging position. The imaging position is set directly below the opening 15 of the scanner 11. The entry path E is the patient's movement path relative to the opening 15 and is the path the patient takes when entering the opening 15 of the scanner 11. The entry path E is, for example, a path extending along the Y-axis direction between the support columns 13 from outside the scanner 11 to the imaging position directly below the opening 15. In FIG. 2, the entry path E is set from one side (the front side of the page in FIG. 2) to the other side (the back side of the page in FIG. 2) in the Y-axis direction. Before CT imaging, the patient enters the imaging position via the entry path E. At this time, the patient enters under the scanner 11 from outside the scanner 11 and enters the imaging position directly below the opening 15. The movement route may be any route that the patient takes when entering the imaging position, and may be the route that the patient actually takes, or a route that follows marks or lines installed on the floor of the examination room to guide the patient.

[0020] 3 is a cross-sectional view of the scanner in the YZ plane passing through the central axis of the opening, and is used to explain the structure of the opening 15. The opening 15 has a central portion 151, an upper expanded diameter portion 152, and a lower expanded diameter portion 153. The central portion 151 is disposed in the center of the opening 15 in the direction along the central axis A1. The diameter of the opening 15 increases from the central portion 151 toward the ends of the opening 15 in the direction along the central axis A1. In other words, the opening 15 has a flared structure.

[0021] Furthermore, the portion of the scanner 11 that is located on the entrance path E is referred to as the entrance path forming section 111. The entrance path forming section 111 is one end of the scanner 11 that is located on the front side as seen from the patient P about to enter the opening 15. The entrance path forming section 111 is, for example, a portion of the scanner 11 that is located at approximately the same position as the central axis A1 of the opening 15 in the X-axis direction and on the negative side of the central axis A1 in the Y-axis direction (the left side of the paper in FIG. 3 ). The entrance path forming section 111 forms, for example, one end (one side) of the scanner 11 that is on the entrance path E side.

[0022] The central portion 151 is located between the X-ray tube 17 and the X-ray detector 19. X-rays are irradiated in the central portion 151. The upper expanded diameter portion 152 is provided above the central portion 151 and expands in diameter upward. The inner circumferential surface of the upper expanded diameter portion 152 has a surface that curves outward upward. The lower expanded diameter portion 153 is provided below the central portion 151 and expands in diameter toward the bottom end. The inner circumferential surface of the lower expanded diameter portion 153 has a curved surface that curves outward downward. The diameter of the opening 15 is smallest at the central portion 151. Furthermore, the diameter D2 of the upper expanded diameter portion 152 and the diameter D3 of the lower expanded diameter portion 153 are larger than the diameter D1 of the central portion 151. Furthermore, the diameter at the upper end of the upper expanded diameter portion 152 and the diameter at the lower end of the lower expanded diameter portion 153 are larger than the diameter D1 of the central portion 151.

[0023] The operation panel 29 is an input interface attached to the side of the support 13. The operation panel 29 may be implemented by switch buttons, a touchpad for performing input operations by touching the operation surface, a touch panel display in which a display screen and a touchpad are integrated, a speaker for outputting audio guides or alerts, or the like. The operation panel 29 may be a tablet terminal equipped with a touch panel display. The operation panel 29 accepts various input operations from a user, converts the accepted input operations into electrical signals, and outputs the electrical signals to the control device 25. The user may be, for example, a radiologist or a doctor. The operation panel 29 accepts a selection operation for selecting, for example, a sitting position imaging mode for imaging a patient in a seated position or a standing position imaging mode for imaging a patient in a standing position. The operation panel 29 also accepts an operation for raising and lowering the scanner 11 and an operation for tilting the scanner 11. The operation panel 29 also accepts an operation from the user to select whether to place the scanner 11 in the entrance assistance state described below. Furthermore, if a projector (a laser that projects an imaging range or a reference line of the imaging range onto the patient's surface) is provided on the gantry device 10, the operation panel 29 receives an operation to switch the projector on and off. The operation panel 29 is an example of an input unit.

[0024] The X-ray tube 17 is a vacuum tube that generates X-rays by irradiating thermoelectrons from a cathode (filament) toward an anode (target) when a high voltage is applied from the high-voltage generator 31. For example, the X-ray tube 17 is a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermoelectrons.

[0025] The X-ray detector 19 detects X-rays emitted from the X-ray tube 17 and transmitted through the patient, and outputs an electrical signal corresponding to the X-ray dose to the DAS 33. The X-ray detector 19 has, for example, multiple X-ray detection element rows, each of which has a plurality of X-ray detection elements arranged in the channel direction along an arc centered on the focal point of the X-ray tube 17. The X-ray detector 19 has, for example, a structure in which multiple X-ray detection element rows, each of which has a plurality of X-ray detection elements arranged in the channel direction, are arranged in the slice direction (row direction). The X-ray detector 19 is an indirect conversion type detector having, for example, a grid, a scintillator array, and a photosensor array. The scintillator array has multiple scintillators, each of which has a scintillator crystal that outputs light with a photon amount corresponding to the dose of incident X-rays. The grid is arranged on the X-ray incident side of the scintillator array and has an X-ray shielding plate that absorbs scattered X-rays. The grid is also sometimes called a collimator (one-dimensional collimator or two-dimensional collimator). The photosensor array has a function of converting the amount of light from the scintillator into an electric signal according to the amount of light, and has a photosensor such as a photomultiplier tube (PMT). The X-ray detector 19 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into an electric signal. The X-ray detector 19 is an example of an X-ray detection unit.

[0026] The DAS 33 (Data Acquisition System) has an amplifier that amplifies the electrical signals output from each X-ray detection element of the X-ray detector 19 and an A / D converter that converts the electrical signals into digital signals, and generates detection data (digital data). The detection data generated by the DAS 33 is called raw data. The raw data is a set of digital values ​​of X-ray intensity identified by the channel number and column number of the X-ray detection element that generated the raw data, and the view number indicating the acquired view. The raw data is supplied to the console device 60, for example, via a non-contact data transmission device (not shown) housed in the scanner 11.

[0027] The control device 25 has a processing circuit including a CPU and the like, and a driving mechanism including a motor and an actuator. The control device 25 has a function of receiving signals from the console device 60 and controlling the operation of the gantry device 10. The control device 25 may be provided in the gantry device 10 or in the console device 60.

[0028] Next, the configuration of the console device 60 will be described. The console device 60 has a memory 61, a display 62, an input interface 63, and a processing circuit 64. Data communication between the memory 61, the display 62, the input interface 63, and the processing circuit 64 is performed via a bus. Note that, although the console device 60 will be described as being separate from the gantry device 10, the gantry device 10 may include the console device 60 or some of the components of the console device 60.

[0029] Although the console device 60 will be described below as a single console that executes multiple functions, multiple functions may be executed by separate consoles. For example, the functions of the processing circuit 64, such as the control function 644 described below, may be distributed and installed in different console devices.

[0030] The memory 61 is a storage device such as a hard disk drive (HDD), a solid state drive (SSD), or an integrated circuit that stores various information. The memory 61 may be a portable storage medium such as a compact disc (CD), a digital versatile disc (DVD), or a flash memory, in addition to an HDD or SSD. The memory 61 may also be a drive device that reads and writes various information from and to semiconductor memory elements such as flash memory and random access memory (RAM). The storage area of ​​the memory 61 may be located within the console device 60 or in an external storage device connected via a network.

[0031] The memory 61 stores programs executed by the processing circuitry 64, various data used in processing by the processing circuitry 64, and the like. The memory 61 stores, for example, projection data, reconstructed image data, control programs, and the like. As the programs, for example, programs that are installed in advance on a computer from a network or a non-transitory computer-readable storage medium and cause the computer to realize each function of the processing circuitry 64 are used. Note that the various data handled in this specification are typically digital data. The memory 61 is an example of a storage unit.

[0032] The display 62 displays various types of information. For example, the display 62 outputs medical images (CT images) generated by the processing circuitry 64, a GUI (Graphical User Interface) for receiving various operations from the user, and the like. For example, the display 62 is a liquid crystal display or a CRT (Cathode Ray Tube) display. The display 62 may be provided on the gantry device 10. The display 62 may also be a desktop type, or may be configured as a tablet terminal or the like capable of wireless communication with the console device 60 main body. The display 62 is an example of a display unit.

[0033] The input interface 63 accepts various input operations from the user, converts the accepted input operations into electrical signals, and outputs the electrical signals to the processing circuitry 64. For example, the input interface 63 accepts input operations from the user, such as acquisition conditions for acquiring projection data, reconstruction conditions for reconstructing CT images, and image processing conditions for generating post-processed images from CT images. For example, the input interface 63 may be implemented by a mouse, keyboard, trackball, switch buttons, joystick, a touchscreen integrating a display screen and a touchpad, a non-contact input circuit using an optical sensor, and a voice input circuit, all of which are used to perform various processes in the processing circuitry 64. The input interface 63 is connected to the processing circuitry 64 and converts input operations received from the user into electrical signals and outputs the electrical signals to the control circuitry. Note that, in this specification, the input interface is not limited to those having physical operating components such as a mouse and keyboard. For example, an electrical signal processing circuit that receives electrical signals corresponding to input operations from an external input device provided separately from the device and outputs the electrical signals to the processing circuitry 64 is also included as an example of an input interface. The input interface 63 may be provided in the gantry device 10, or may be configured as a tablet terminal or the like capable of wireless communication with the console device 60. The input interface 63 is an example of an input unit. The input interface 63 also receives input from the user as to whether or not to place the scanner 11 in the entry assistance state described below.

[0034] The processing circuitry 64 controls the overall operation of the X-ray CT apparatus 1. The processing circuitry 64 is a processor that executes a system control function 641, an acquisition function 642, a determination function 643, and a control function 644 by calling and executing programs in the memory 61.

[0035] 1, the system control function 641, the acquisition function 642, the determination function 643, and the control function 644 are described as being implemented by a single processing circuit 64, but this is not limited to this. For example, a processing circuit may be configured by combining multiple independent processors, and each processor may execute a program to implement each function. Furthermore, the system control function 641, the acquisition function 642, the determination function 643, and the control function 644 may be referred to as a system control circuit, an acquisition circuit, a determination circuit, and a control circuit, respectively, or may be implemented as individual hardware circuits. The above description of the functions executed by the processing circuit 64 also applies to the following embodiments and modifications.

[0036] Although the console device 60 is described as a single console that executes multiple functions, the multiple functions may be executed by separate devices. For example, the functions of the processing circuitry 64 may be distributed and installed in different devices.

[0037] The term "processor" used in the above description refers to circuits such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), 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). If the processor is, for example, a CPU, the processor realizes its function by reading and executing a program stored in a memory circuit. On the other hand, if the processor is, for example, an ASIC, the program is not stored in a memory circuit, but the function is directly incorporated into the processor circuit as a logic circuit. 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 in FIG. 1 may be integrated into a single processor to realize its function. The above description of "processor" also applies to the following embodiments and modifications.

[0038] The processing circuitry 64 performs overall control of the X-ray CT apparatus 1 according to this embodiment using a system control function 641. Specifically, the processing circuitry 64 reads out a control program stored in the memory 61, expands the program on the memory, and controls each component of the X-ray CT apparatus 1 according to the expanded control program. For example, in the system control function 641, the processing circuitry 64 controls CT imaging using the gantry device 10, generation of CT image data using projection data transmitted from the gantry device 10, conversion of the CT image data into tomographic image data or three-dimensional image data of any cross section, and display of the generated image on the display 62. The processing circuitry 64 that realizes the system control function 641 is an example of a system control unit.

[0039] The processing circuitry 64 acquires an operation signal from the input interface 63 or the operation panel 29 through the acquisition function 642. In the acquisition function 642, the processing circuitry 64 acquires an operation signal indicating that an operation to transition the scanner 11 to an entrance assist state has been input through the input interface 63 or the operation panel 29. The operation signal is used as information including information indicating that a patient has entered or is about to enter the opening 15. In the following description, the patient's entry into the opening 15 may also be referred to as "entry." In other words, the operation signal is an example of subject information including information indicating that a patient has entered or is about to enter the opening 15. The processing circuitry 64 realizing the acquisition function 642 is an example of an acquisition unit.

[0040] The entry assistance state is, for example, a non-tilted state in which the scanner 11 is tilted to facilitate patient entry. The entry assistance state is an example of a movement assistance state. The entry assistance state is a state in which the scanner 11 is tilted so that the portion of the scanner 11 located on the entry path E is elevated. That is, the entry assistance state is a state in which the entry path forming unit 111 located on the entry path E is higher than the other end (opposite side) of the scanner 11. The entry assistance state is set, for example, so that a gap (clearance) is secured between the ceiling of the examination room and the scanner 11, and so that the height of the scanner 11 from the floor surface at the portion through which the patient passes when entering the opening 15 is maximized. That is, the entry assistance state is set so that the scanner 11 does not come into contact with the ceiling, and so that the height of the lower end of the opening 15 at the entry path forming unit 111 located on the entry path E is maximized. The height of the lower end of the opening 15 at the entry path forming unit 111 is maximized compared to other portions of the scanner 11. Therefore, the entrance assistance state is a state in which the scanner 11 does not interfere with the ceiling of the examination room and the height of the opening 15 from the floor (the height of the lower end of the opening 15 in the entrance path forming portion 111) is at its maximum. The height and tilt angle of the scanner 11 in the entrance assistance state are preset according to the height of the ceiling of the examination room, the height of the support column 13, the vertical movement range of the scanner 11, the shape of the opening 15, the thickness of the scanner 11, etc. If there is a limited gap between the support column 13 and the ceiling of the examination room, the entrance assistance state is, for example, a state in which the scanner 11 is raised to the maximum height of its movement range and is tilted as far as possible without contacting the ceiling. Note that the height of the lower end of the scanner 11 in the entrance assistance state only needs to be higher than the height of the lower end of the scanner 11 in the standby state. For example, the scanner 11 may be located at a position lower than the maximum height of its movement range. Alternatively, the tilt angle of the scanner 11 may be approximately at its maximum, rather than at its maximum angle without contacting the ceiling.

[0041] The processing circuitry 64 determines, using the determination function 643, whether or not the patient is about to enter the opening 15 based on the operation signal acquired by the acquisition function 642, and determines whether or not to put the scanner 11 into the entrance assistance state based on the determination result of whether or not the patient is about to enter the opening 15. For example, when an operation to transition to the entrance assistance state is input via the input interface 63 or the operation panel 29, the processing circuitry 64 determines that the patient will enter the opening 15. Alternatively, for example, when the user presses a specific physical button on the input interface 63 or the operation panel 29, the processing circuitry 64 determines that the patient will enter the opening 15. Alternatively, for example, when the user touches or clicks a specific icon or button displayed on the screen of the input interface 63 or the operation panel 29, the processing circuitry 64 determines that the patient will enter the opening 15. Alternatively, for example, when the user analyzes a camera image acquired from a camera installed in the examination room to detect a specific user gesture, the processing circuitry 64 determines that the patient will enter the opening 15. The processing circuit 64 that realizes the determination function 643 is an example of a determination unit. It may be determined whether to place the scanner 11 in the entrance assistance state based on the operation signal and the patient's height. In this case, the processing circuit 64 acquires the patient's height in addition to the operation signal using the acquisition function 642, and determines whether to place the scanner 11 in the entrance assistance state based on the operation signal and the patient's height using the determination function 643.

[0042] Based on the determination by the determination function 643 that the scanner 11 should be placed in the entrance assistance state, the processing circuit 64 controls at least one of the lifting drive device and the tilting drive device using the control function 644 so that the scanner 11 is placed in the entrance assistance state. In the control function 644, the processing circuit 64 controls the lifting drive device and the tilting drive device to control the lifting and tilting movements of the scanner 11 based on, for example, preset parameters related to the entrance assistance state. The control to place the scanner 11 in the entrance assistance state may involve simultaneous control of the lifting drive device and the tilting drive device, or may involve separate control. The parameters related to the entrance assistance state include, for example, the height of the scanner 11 in the entrance assistance state, the speed during the lifting and tilting movement, the tilt angle of the scanner 11, and the tilt speed during the tilting movement. The processing circuit 64 that realizes the control function 644 is an example of a control unit.

[0043] Next, the operation of the X-ray CT scanner 1 according to this embodiment will be described. FIG. 4 is a flowchart showing an example of the procedure of the entrance assistance process executed by the processing circuitry 64. The entrance assistance process is executed when the X-ray CT scanner 1 is in standby mode. FIG. 5 is a diagram showing the state of the gantry 10 in standby mode. In the standby mode, the scanner 11 is in a non-tilted state and positioned at the highest position within its vertical range of motion. Note that in the standby mode, the scanner 11 may be positioned below the highest position within its vertical range of motion, or may be tilted. The patient P waits outside the gantry 10 on the entrance path E. The gantry 10 is installed in an examination room having a ceiling B with a height H1. The gap H3 between the gantry 10 and the ceiling B is calculated by subtracting the height H2 of the support columns 13 from the height H1 of the ceiling. Therefore, the height H4 of the entrance path forming section 111 from the floor is smaller than the height H2 of the support columns 13.

[0044] Although the gap H3 between the gantry 10 and the ceiling B has been described as being calculated using the height H2 of the support pillar 13, this is not limitative. For example, instead of the height H2 of the support pillar 13, the gap H3 between the gantry 10 and the ceiling B may be defined using the height of the top surface of the scanner 11 when the scanner 11 is at its highest position. In this case, the gap H3 between the gantry 10 and the ceiling B is determined by subtracting the height of the top surface of the scanner 11 when the scanner 11 is at its highest position from the height H1 of the ceiling.

[0045] The processing procedures described below are merely examples, and each process may be modified as much as possible. Furthermore, steps may be omitted, replaced, or added as appropriate depending on the embodiment.

[0046] (Entry Assistance Processing) (Step S101 ) The processing circuit 64 acquires an operation signal from the input interface 63 or the operation panel 29 by the acquisition function 642 .

[0047] (Step S102) The processing circuit 64 uses the determination function 643 to determine whether or not to transition the scanner 11 to the entrance assistance state based on an operation signal from the input interface 63 or the operation panel 29. If the processing circuit 64 does not acquire an operation signal indicating that an operation to transition the scanner 11 to the entrance assistance state has been performed, the determination function 643 determines that the scanner 11 should not be transitioned to the entrance assistance state (step S102—No). In this case, the control function 644 does not execute control to transition the scanner 11 to the entrance assistance state, and the scanner 11 remains in a standby state. If the processing circuit 64 acquires an operation signal indicating that an operation to transition the scanner 11 to the entrance assistance state has been performed, the determination function 643 determines that the scanner 11 should be transitioned to the entrance assistance state (step S102—Yes).

[0048] (Step S103) When a determination is made to transition to the entrance assistance state, the processing circuit 64, using the control function 644, reads the entrance assistance state parameters from the memory 61 and controls the lifting drive device and tilting drive device to transition the scanner 11 from the standby state to the entrance assistance state. Figure 6 is a diagram showing the state of the platform device 10 in the entrance assistance state. For example, if the scanner 11 is located at a position lower than the height specified for the entrance assistance state, the processing circuit 64 raises the scanner 11 to a predetermined height at a predetermined lifting speed and tilts the scanner 11 at a predetermined tilt speed until the scanner 11 reaches a predetermined tilt angle. Furthermore, when transitioning from the standby state to the entrance assistance state, the scanner 11 tilts around the tilt axis A2, the entrance path forming portion 111 of the scanner 11 rises, and the opposite side of the entrance path forming portion 111 descends.

[0049] In the entrance assistance state, the position of the entrance path forming unit 111 is higher than in the standby state. Therefore, in the entrance assistance state, the height H5 of the entrance path forming unit 111 from the floor surface is greater. Hereinafter, the height of the entrance path forming unit 111 from the floor surface is also referred to as the entrance height. As shown in Figures 5 and 6, the entrance height H5 in the entrance assistance state is greater than the entrance height H4 in the standby state.

[0050] The entrance height H5 in the entrance assistance state is the height of the inner peripheral surface of the lower end of the opening 15 in the entrance path formation portion 111. In this embodiment, the opening 15 is formed in a flared structure that widens outward. Therefore, compared to when the opening 15 is formed in a substantially cylindrical shape whose diameter does not change along the central axis A1, the inner peripheral surface of the lower end of the opening 15 is located outward, and therefore the entrance height H5 in the entrance assistance state is greater.

[0051] When the transition to the entrance assistance state (step S103) is completed, the processing circuitry 64 ends the entrance assistance process. As shown in Figure 7, the patient P passes under the entrance path forming unit 111 in the entrance assistance state and moves to the imaging position below the opening 15. Thereafter, CT imaging is performed at the imaging position in a standing or sitting position.

[0052] The X-ray CT apparatus 1 of this embodiment includes a scanner 11 having an opening 15 through which a patient is inserted, and a support column 13 that supports the scanner 11. The support column 13 includes a tilt drive device that tilts the scanner 11. The X-ray CT apparatus 1 controls the tilt mechanism so that one end of the scanner 11 on the path of movement of the subject relative to the opening 15 is in an entrance assistance state in which it is higher than the other end.

[0053] The entrance assist state is a tilt state in which the central axis A1 of the opening 15 of the scanner 11 is inclined relative to the support column 13. The entrance assist state is a state in which the ceiling B and the scanner 11 do not interfere with each other and the height of the opening 15 from the floor is maximized. That is, the entrance assist state is a state in which there is a clearance between the ceiling B and the scanner 11 and the height of the scanner 11 located on the entrance path E is maximized. Specifically, the entrance assist state is a state in which the scanner 11 is tilted so that the height H4 of the inner circumferential surface of the lower expanded diameter portion 153 of the opening 15 in the entrance path forming portion 111 is maximized. The entrance path E is set in advance according to the layout of the examination room, the arrangement of the support column 13, and the like. The height and tilt angle of the scanner 11 in the entrance assist state are set in advance based on the height H1 of the ceiling B, the height H2 of the support column 13, the thickness of the scanner 11, the position of the tilt axis A2, and the like.

[0054] With the above-described configuration, according to the X-ray CT apparatus 1 of this embodiment, before guiding the patient to the imaging position below the opening 15 prior to CT imaging, a user such as a radiographer or doctor can operate the operation panel 29 to place the scanner 11 in the entrance assistance state. When the scanner 11 is in the entrance assistance state, the portion of the scanner 11 closest to the patient is elevated, making it less likely that the patient's head will interfere with the scanner 11. This allows the patient to move below the opening 15 in a comfortable position without having to lower their head or bending over, or with less bending over required. This reduces the burden on the patient when entering the imaging position and improves the workflow, including the movement of the patient before and after the examination.

[0055] Furthermore, even if the height of the support pillar 13 is low and the maximum position in the movable range of the scanner 11 is low, the height H4 of the scanner 11 on the entrance route E can be ensured by tilting the scanner 11. In other words, if there is a gap between the ceiling of the examination room and the scanner 11, the height H4 of the scanner 11 on the entrance route E can be ensured without providing a support pillar 13 with a height that matches the height H1 of the ceiling.

[0056] Furthermore, in the X-ray CT apparatus 1 of this embodiment, the opening 15 has a flared structure, and the diameter increases from the central portion 151 toward the lower end of the lower expanded diameter portion 153. Therefore, the diameter D3 of the opening 15 at the lower end of the lower expanded diameter portion 153 is larger than the diameter D1 at the central portion 151. This makes it possible to increase the height H4 of the opening 15 in the entrance assistance state while maintaining the diameter D1 at the central portion 151, thereby further reducing the burden on the patient when entering the imaging position.

[0057] The X-ray CT apparatus 1 of this embodiment further includes an operation panel 29 that accepts a user's input regarding whether or not to place the scanner 11 in the entrance assistance state. The operation panel 29 includes a button that accepts a user's instruction to start control of placing the scanner 11 in the entrance assistance state. The determination information is an input signal indicating that the user has input an operation to place the scanner 11 in the entrance assistance state via the operation panel 29. The user can place the scanner 11 in the entrance assistance state, which allows for easier patient entry, simply by performing a single action of pressing a button on the operation panel 29. Furthermore, in the control of placing the scanner 11 in the entrance assistance state, the control of the lifting mechanism and the control of the tilt mechanism may be performed simultaneously or separately. Furthermore, in the control of placing the scanner 11 in the entrance / exit assistance state, the tilt angle may be controlled in multiple stages. For example, the scanner 11 may be tilted 10 degrees each time the user presses the button. Furthermore, for example, the tilt angle of the scanner 11 may be determined in proportion to the number of times the user presses the button within a predetermined period of time. In this case, for example, the tilt angle may be determined as 10 degrees if the button is pressed once within the predetermined time, 20 degrees if pressed twice, and 30 degrees if pressed three times. Also, the tilt angle of scanner 11 may be determined according to the number of times the button is pressed by the user within the predetermined time. In this case, the tilt angle may be determined as 5 degrees if the button is pressed once within the predetermined time, 10 degrees if pressed twice, and 20 degrees if pressed three times, and the number of times the button is pressed does not have to be proportional to the tilt angle.

[0058] (Variation 1 of the First Embodiment) In the first embodiment, the opening 15 has the flared shape, but it may have a substantially cylindrical shape whose diameter does not change along the central axis A1. Even in this case, the height H4 from the floor of the entrance path forming section 111 in the entrance assistance state is greater than that in the standby state, thereby reducing the burden on the patient when entering.

[0059] (Variation 2 of the First Embodiment) In the first embodiment, a tilt drive device having a tilt axis A2 parallel to the X-axis direction extending from the opening 15 toward the support column 13 is used. However, this is not limited to this. For example, if the scanner 11 is supported by a single support column 13 and a patient enters from the side opposite the support column 13, a tilt axis parallel to the Y-axis direction may be set so that the side of the scanner 11 farthest from the support column 13 rises when the patient enters. Alternatively, multiple tilt axes whose tilt direction can be selected depending on the situation may be set. In this case, the processing circuitry 64 may determine the direction in which the patient will enter using the determination function 643 and select a tilt axis to be driven from among the multiple tilt axes so that the portion of the scanner 11 located on the entrance path rises. The direction in which the patient will enter is determined, for example, by analyzing a camera image acquired from a camera installed in the examination room. The camera may be attached, for example, to the ceiling or wall of the examination room, the X-ray CT scanner 1, or the like. Alternatively, an infrared sensor that detects objects within a certain distance may be provided in the scanner 11, and the detection result of the infrared sensor may be used to determine the direction in which the patient is entering or about to enter.

[0060] When the scanner 11 is in the entry assistance state, it is not only easy for the patient to enter the imaging position from the outside, but also for the patient to exit from the imaging position via the entry route. Therefore, if the patient's entry route and exit route are the same, the scanner 11 may be in the entry assistance state not only when the patient enters before CT imaging, but also when the patient exits after CT imaging. The exit route is the patient's movement path relative to the opening 15, and is the path the patient takes when exiting the opening 15 of the scanner 11. Note that the movement path may be any path the patient takes when exiting from the imaging position, and may be the path the patient actually moves along, or a path following marks or lines installed on the floor of the examination room to guide the patient. In this case, the entry assistance state may be referred to as an exit assistance state or an entry / exit assistance state.

[0061] Furthermore, as shown in FIG. 8 , when the entrance path E and the exit path F are different, the entrance assist state and the exit assist state may be set separately. The exit assist state is an example of a movement assist state. For example, when the exit path F is set on the opposite side of the entrance path E in the Y-axis direction, the exit assist state is set so that a clearance is secured between the ceiling of the examination room and the scanner 11 and the height from the floor of the exit path forming unit 112, through which the user exits through the opening 15, is maximized. The exit path forming unit 112 is a portion of the scanner 11 located on the exit path F and forms one end (one side) of the scanner 11 on the exit path F side. The exit assist state is a state in which the scanner 11 is tilted so that the exit path forming unit 112 located on the exit path F is elevated. In other words, the exit assist state is a state in which the exit path forming unit 112 located on the exit path F is higher than the other end (opposite side) of the scanner 11. Hereinafter, the height of the exit path forming section 112 from the floor surface is also referred to as the exit height. As shown in Figures 8 and 9, the exit height H7 in the exit assistance state is greater than the exit height H6 in the standby state. The exit height H7 in the exit assistance state is the height of the inner circumferential surface of the lower end of the opening 15 in the exit path forming section 112. Furthermore, because the opening 15 is formed with a flared structure that widens outward, the inner circumferential surface of the lower end of the opening 15 is positioned outward, and the exit height H7 in the exit assistance state is greater than when the opening 15 is formed in a substantially cylindrical shape whose diameter does not change along the central axis A1.

[0062] When CT imaging of the patient is completed, the user operates the input interface 63 or the operation panel 29 to place the scanner 11 in the exit assist state before the patient exits. The processing circuitry 64 acquires, via the acquisition function 642, an operation signal indicating that an operation to transition the scanner 11 to the exit assist state has been input via the input interface 63 or the operation panel 29. The operation signal in this case is used as information including the patient's exit through the opening 15. In other words, the operation signal is an example of subject information including the patient's exit through the opening 15. Next, the processing circuitry 64 determines, via the determination function 643, whether the patient will exit through the opening 15 based on the operation signal acquired via the acquisition function 642, and determines whether to place the scanner 11 in the exit assist state based on the determination result of whether the patient will exit through the opening 15. Then, based on the control function 644's determination that the patient will exit the opening 15 and that the scanner 11 should be placed in the exit assist state, the processing circuit 64 controls at least one of the lift drive device and the tilt drive device so that the scanner 11 is placed in the exit assist state. In the exit assist state, as shown in FIG. 10 , the patient can easily exit the imaging position, thereby reducing the burden on the patient when exiting the imaging position. Furthermore, the patient can intuitively understand that it is OK to exit when the scanner 11 is placed in the exit assist state.

[0063] (Second Embodiment) A second embodiment will be described. This embodiment is a modification of the configuration of the first embodiment as follows. Descriptions of configurations and operations similar to those of the first embodiment will be omitted. In the first embodiment, the entry assistance state was entered in response to a user operation, but in this embodiment, the entry of a patient into the room is detected and the entry assistance state is automatically entered.

[0064] FIG. 11 is a block diagram showing an example of the configuration of the X-ray CT apparatus according to the first embodiment. In this embodiment, the gantry device 10 further includes a camera system 37 that captures images of the interior of the examination room. The camera system 37 is an example of a detection unit that detects, as information regarding the patient's movement, the patient's approach to the opening 15, i.e., the patient's attempt to enter the opening 15. The camera system 37 is composed of, for example, a camera installed in the examination room and a processing circuit. The camera may be, for example, a general photography camera or an infrared camera. The processing circuit of the camera system 37 analyzes image data captured by the camera to determine whether the patient has entered the examination room. Furthermore, if the processing circuit determines that the patient has entered the examination room, it transmits information indicating that the patient has entered the examination room to the console device 60. The information indicating that the patient has entered the examination room is an example of a detection result of the detection unit. The processing circuit of the camera system 37 may also determine whether the patient has entered the examination room by analyzing video data from the camera. Furthermore, the camera system 37 may transmit information to the console device 60 including the direction in which the patient intends to enter or exit the opening 15 .

[0065] In the acquisition function 642, the processing circuitry 64 acquires information indicating that a patient has entered the examination room from the camera system 37. The information indicating that a patient has entered the examination room is an example of subject information that includes the patient entering the opening 15.

[0066] In the determination function 643, the processing circuitry 64 determines whether to put the scanner 11 into the entrance assistance state based on information indicating that a patient has entered the examination room. In this case, the processing circuitry 64 determines to put the scanner 11 into the entrance assistance state when information indicating that a patient has entered the examination room is acquired.

[0067] Next, the operation of the X-ray CT apparatus 1 according to this embodiment will be described. Fig. 12 is a flowchart showing an example of the procedure of the entrance assistance process executed by the processing circuitry 64. Note that the process procedure described below is merely an example, and each process may be modified as much as possible. Furthermore, steps in the process procedure described below may be omitted, replaced, or added as appropriate depending on the embodiment.

[0068] (Entry Support Process) (Step S201) The processing circuitry 64 receives, via the acquisition function 642, information indicating that the patient P has entered the examination room as a detection result of the camera system 37.

[0069] (Step S202) The processing circuitry 64 uses the determination function 643 to determine whether or not to transition the scanner 11 to the entrance assistance state. If the processing circuitry 64 does not acquire information indicating that patient P has entered the examination room, the determination function 643 determines not to transition the scanner 11 to the entrance assistance state (step S202—No). In this case, the control function 644 does not execute control to transition the scanner 11 to the entrance assistance state, and the scanner 11 remains in a standby state. If the processing circuitry 64 acquires information indicating that patient P has entered the examination room, the determination function 643 determines to transition the scanner 11 to the entrance assistance state (step S202—Yes).

[0070] (Step S203) If it is determined to transition to the entrance assistance state, the processing circuit 64 controls the lifting drive device and the tilt drive device by the control function 644 to transition the scanner 11 from the standby state to the entrance assistance state.

[0071] According to the X-ray CT apparatus 1 of this embodiment, the camera system 37 is used to detect the entry of a patient P into the examination room, and when it is detected that the patient P has entered the examination room, the scanner 11 can automatically transition to a state that makes it easier for the patient P to enter under the scanner 11 without any operation by the user. Note that the camera system 37 may also be used to detect that the patient has left the examination room, and when it is detected that the patient has left the examination room, the scanner 11 may transition to an entry assistance state in preparation for receiving the next patient. In this case, the camera system 37 is an example of a detector that detects that the patient has left the opening 15.

[0072] (Variation of the Second Embodiment) The scanner 11 may be switched to the entrance assistance state or the exit assistance state in accordance with the patient's movement into or out of the opening 15. For example, the current position of the patient may be identified using a camera image, and the scanner 11 may automatically switch to the entrance assistance state when the patient approaches the scanner 11 within a predetermined distance. Furthermore, the tilt angle of the scanner 11 may be changed in accordance with a change in the patient's position from the scanner 11. For example, the tilt angle of the scanner 11 in the inclined state may be gradually reduced as the patient passes under the scanner 11 in the entrance assistance state. The patient position information is an example of subject information.

[0073] 8, if the patient can enter via exit route F and exit via entrance route E, the patient's entry or exit direction may be detected, and the tilt direction in the entry assistance state or exit assistance state may be determined based on the detection result. In this case, the patient's entry or exit direction may be analyzed using, for example, a camera image.

[0074] Furthermore, the control function 644 may automatically switch the scanner 11 to the exit assist state based on the completion of CT imaging. Furthermore, when the patient has completed moving out of the opening 15 (exit), the control function 644 may automatically return the scanner 11 from the exit assist state to the standby state. Furthermore, when the patient has completed moving into the opening 15 (entry), the control function 644 may automatically return the scanner 11 from the entry assist state to the standby state.

[0075] Alternatively, instead of the camera system 37, a microphone may be provided to collect sound in the examination room and detect the movement of the patient. The microphone is an example of a detector that detects an instruction to enter the patient into the opening 15. In this case, the processing circuitry 64 analyzes sound data acquired from the microphone and detects an instruction to enter the patient into the imaging position. In the acquisition function 642, the processing circuitry 64 acquires information indicating that an instruction to enter the patient into the imaging position has been issued as a detection result. Then, in the determination function 643, the processing circuitry 64 determines that the scanner 11 should transition to the entry assistance state when the detection result is acquired. Alternatively, the processing circuitry 64 may analyze the sound data acquired from the microphone and transition the scanner 11 to the exit assistance state when an instruction to exit the patient from the imaging position has been issued. In this case, in the determination function 643, the processing circuitry 64 analyzes the sound data acquired from the microphone and determines whether an instruction to exit the patient from the imaging position has been issued, and determines that the scanner 11 should transition to the exit assistance state when an instruction to exit the patient from the imaging position has been issued.

[0076] The camera system 37 may also detect the movement of a user. In this case, the processing circuit of the camera system 37 analyzes image data captured by the camera to determine whether the user has entered the examination room from the operation room. Furthermore, if the processing circuit determines that the user has entered the examination room, it transmits information indicating that the user has entered the examination room to the console device 60. In the acquisition function 642, the processing circuit 64 acquires information indicating that the user has entered the examination room from the operation room as a detection result. Then, in the determination function 643, the processing circuit 64 determines to transition the scanner 11 to the entry assistance state when the detection result is acquired. Furthermore, the scanner 11 may be transitioned to the exit assistance state when the user re-enters the examination room from the operation room after CT imaging. In this case, the processing circuit of the camera system 37 analyzes image data captured by the camera and determines to transition the scanner 11 to the exit assistance state when the user has entered the examination room.

[0077] Furthermore, a sensor that detects the opening of a door between the examination room and the control room may be combined with the camera system 37 to detect the user's movement. In this case, the processing circuit of the camera system 37 analyzes image data captured by the camera to determine whether the user is heading from the control room to the examination room. Furthermore, a signal indicating that the sensor has detected the door being opened is transmitted from the sensor to the processing circuit 64 of the camera system 37. The processing circuit detects that the user is heading toward the examination room and, upon detecting the door being opened, determines that the user has entered the examination room and transmits information indicating that the user has entered the examination room from the control room to the console device 60. In the acquisition function 642, the processing circuit 64 acquires information indicating that the user has entered the examination room from the control room as a detection result. Then, in the determination function 643, the processing circuit 64 determines to transition the scanner 11 to the entry assistance state when information indicating that the user has entered the examination room from the control room is acquired as a detection result.

[0078] (Other Modifications) The control function 644 may also adjust the height and tilt angle of the scanner 11 in the entry assistance state or the exit assistance state according to the height of the patient. Furthermore, when a seated patient placed on a subject carrier enters and leaves the imaging position together with an assistant pushing the subject carrier, the height and tilt angle of the scanner 11 in the entry assistance state or the exit assistance state may be adjusted according to the height of the assistant. The height of the patient and the height of the assistant are examples of subject information. The height of the patient or the assistant may be input in advance by the user or may be determined by analyzing the camera image.

[0079] Furthermore, when a patient enters the imaging position while riding on a subject carrier, the risk of the patient's head coming into contact with the scanner 11 is reduced. Therefore, when a patient enters the imaging position while riding on a subject carrier, the tilt angle of the scanner 11 in the entry assistance state may be reduced. In this case, when the patient enters the imaging position on the subject carrier, the amount of descent of the scanner 11 on the far side in the traveling direction is reduced, thereby reducing stress on the patient caused by the scanner 11 on the far side in the traveling direction descending and approaching the patient's eyes. Note that instead of reducing the tilt angle, the tilt speed of the scanner 11 may be reduced, or both the tilt angle and the tilt speed may be reduced.

[0080] Furthermore, before CT imaging, if the user determines that the patient should not enter under the opening 15 (imaging position), the scanner 11 may be placed in an entry prevention state that inhibits the patient's movement. The entry prevention state is an example of a movement prevention state. As shown in FIG. 13 , the entry prevention state is a state in which the scanner 11 is tilted to make it difficult for the patient to enter under the opening 15, and is a state in which the scanner 11 is tilted in the opposite direction to the entry assistance state. Specifically, the entry prevention state is a state in which the scanner 11 is tilted so that the portion of the scanner 11 located on the entry path E descends. That is, in the entry prevention state, the entry path forming portion 111 located on the entry path E is lower than the other end (opposite side) of the scanner 11. For example, when an operation to transition to the entry prevention state is input via the input interface 63 or the operation panel 29, the processing circuitry 64 controls the scanner 11 to enter the entry prevention state.

[0081] Furthermore, if it is desired that the patient not exit from under the opening 15 after CT scanning, the scanner 11 may be placed in an exit prevention state that inhibits the patient's movement. The exit prevention state is an example of a movement prevention state. As shown in FIG. 14 , the exit prevention state is a state in which the scanner 11 is tilted to make it difficult for the patient to exit from under the opening 15, and is a state in which the scanner 11 is tilted in the opposite direction to the exit assistance state. Specifically, the exit prevention state is a state in which the scanner 11 is tilted so that the portion of the scanner 11 located on the exit path F descends. That is, in the exit prevention state, the exit path formation unit 112 located on the exit path F is lower than the other end (opposite side) of the scanner 11. For example, when an operation to transition to the exit prevention state is input via the input interface 63 or the operation panel 29, the processing circuitry 64 controls the scanner 11 to enter the exit prevention state.

[0082] The patient may enter and exit the imaging position by moving the gantry 10. In this case, the gantry 10 is provided so as to be movable on the floor of the examination room, for example, in the X-axis and Y-axis directions. For example, rails may be provided on the floor of the examination room, and a mechanism for moving on the rails may be provided on the bottom of the support 13. The gantry 10 then moves on the floor, allowing the patient to enter and exit the imaging position. The height and tilt angle of the scanner 11 may be adjusted depending on the position of the gantry 10. For example, the tilt angle of the inclined scanner 11 may be gradually reduced as the scanner 11 passes above the patient before imaging begins.

[0083] When imaging a patient in a standing position, the patient may be supported using a patient support device, which is a pole placed behind or in front of the patient and fixed perpendicular to the floor. When imaging a patient in a seated position, the patient may be supported using a patient support device with a seat attached to a pole placed behind the patient. When imaging using such a patient support device, interference between the patient support device and the scanner 11 is anticipated. Therefore, when imaging using a patient support device, the processing circuitry 64 in the control function 644 may execute control to further adjust parameters restricting the range of motion of the scanner 11 or parameters restricting transition to the entry assistance state or the exit assistance state, depending on the location and type of the patient support device. The presence or type of a patient support device may be determined by analysis of image data or video data by the camera system 37, or by user input via the operation panel 29 or the input interface 63.

[0084] The X-ray CT apparatus 1 may further include a bed device. In this case, imaging of a subject in a supine position placed on the top plate of the bed device (supine position imaging) can be performed, and thus it is possible to perform upright position imaging, sitting position imaging, and supine position imaging using a single gantry device 10.

[0085] Furthermore, in the control function 644, the processing circuitry 64 may determine which parts of the scanner unit are to be set as one end and the other end in the movement assistance state, depending on the movement direction of the subject. For example, in the control function 644, the processing circuitry 64 identifies an entry path and an exit path depending on the movement direction of the patient, and determines the positions of the entry path forming unit 111 and the exit path forming unit 112 in the scanner 11 depending on the positions of the entry path and the exit path. In this case, the processing circuitry 64 that realizes the control function 644 may be called a setting unit.

[0086] In addition, in the control function 644, the processing circuit 64 may prevent the elevator drive device provided on the support 13 from raising or lowering the scanner 11 when the scanner 11 is in a tilted position.

[0087] The state in which one end of the scanner 11 on the patient's movement path is higher than the other end is, for example, the entrance assistance state, exit assistance state, and entrance / exit assistance state described in the embodiment and modified examples.

[0088] According to at least one of the embodiments described above, it is possible to improve the workflow, including patient movement before and after an examination.

[0089] Furthermore, in at least one of the above-described embodiments, an X-ray CT apparatus has been described as an example, but the above configuration may be applied to a medical image diagnostic apparatus other than an X-ray CT apparatus. Examples of medical image diagnostic apparatus other than an X-ray CT apparatus include an MRI (Magnetic Resonance Imaging) apparatus and a PET (Positron Emission Tomography) apparatus. In the case of an MRI apparatus, the scanner 11 can be read as the gantry of the MRI apparatus. In the case of a PET apparatus, the scanner 11 can be read as the gantry of the PET apparatus. The gantry of the MRI apparatus and the gantry of the PET apparatus are examples of scanner units.

[0090] 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.

[0091] With respect to the above-described embodiment, the following supplementary notes are disclosed as one aspect and optional feature of the invention. (Supplementary Note 1) An X-ray CT apparatus comprising: a scanner unit having an opening into which a subject is inserted; a stand having a tilt mechanism for tilting the scanner unit; and a control unit that controls the tilt mechanism so that one end of the scanner unit on a movement path of the subject is in a movement assist state higher than the other end. (Supplementary Note 2) The X-ray CT apparatus may further comprise an acquisition unit that acquires subject information including whether the subject will enter the opening; and a determination unit that determines whether the subject will enter the opening based on the subject information. The control unit may place the scanner unit in the movement assist state when the determination unit determines that the subject will enter the opening. (Supplementary Note 3) The subject information may further include a height of the subject, and the determination unit may determine whether to place the scanner unit in the movement assist state based on the subject information. (Supplementary Note 4) The movement assist state may be a state in which the scanner unit does not interfere with the ceiling of an examination room and the height of the lower end of the scanner at one end from the floor is at its maximum. (Supplementary Note 5) The height and tilt angle of the scanner unit in the movement assist state may be set in advance based on the height of the ceiling, the vertical movement range of the scanner unit, and the thickness of the scanner unit. (Supplementary Note 6) The X-ray CT apparatus may further include an input unit that receives an input from a user as to whether or not to place the scanner unit in the movement assist state, and a determination unit that determines whether or not to place the scanner unit in the movement assist state based on an input signal indicating that the user has input an operation to place the scanner unit in the movement assist state via the input unit, and the control unit may place the scanner unit in the movement assist state when the determination unit determines that the scanner unit should be placed in the movement assist state. (Supplementary Note 7) The input unit may include a button that receives an instruction from a user to start control to put the scanner unit into the movement assist state, and when the determination unit determines that the button has been pressed by the user, the control unit may simultaneously control an elevation mechanism that raises and lowers the scanner unit and control the tilt mechanism to put the scanner unit into the movement assist state.(Supplementary Note 8) The X-ray CT apparatus may further include a detection unit that detects that the subject has approached the opening, and the acquisition unit may acquire the detection result of the detection unit as the subject information, and the determination unit may determine to put the scanner unit into the movement assist state when the detection result is acquired. (Supplementary Note 9) The X-ray CT apparatus may further include a detection unit that detects an instruction to place the subject into the opening, and the acquisition unit may acquire the detection result of the detection unit as the subject information, and the determination unit may determine to put the scanner unit into the movement assist state when the detection result is acquired. (Supplementary Note 10) The movement assist state may be a state in which the scanner unit is tilted and a portion of the scanner unit located in the direction of entering the opening is raised, and the detection unit may further detect the direction in which the subject enters the opening. (Supplementary Note 11) The X-ray CT apparatus may further include a detector that detects the subject exiting the opening, and the acquisition unit may acquire the detection result of the detector as the subject information, and the determination unit may determine to switch the scanner unit to the movement assist state when the detection result is acquired. (Supplementary Note 12) The X-ray CT apparatus may further include a detector that detects an instruction to exit the subject from the opening, and the acquisition unit may acquire the detection result of the detector as the subject information, and the determination unit may determine to switch the scanner unit to the movement assist state when the detection result is acquired. (Supplementary Note 13) The movement assist state may be a state in which the scanner unit is tilted and a portion of the scanner unit located in the direction of exiting the opening is raised, and the detector may further detect the direction in which the subject exits the opening. (Supplementary Note 14) The control unit may return the scanner unit from the movement assist state to a standby state based on the completion of the subject's movement into the opening. (Supplementary Note 15) The control unit may return the scanner unit from the movement assist state to a standby state based on completion of movement of the subject out of the opening. (Supplementary Note 16) A diameter of the opening at a lower end may be larger than a diameter of the opening at a center portion.(Supplementary Note 17) The subject information may further include position information of the subject, and the control unit may adjust the tilt angle of the scanner unit in the movement assistance state based on the subject information. (Supplementary Note 18) The subject information may include the height of an assistant pushing a subject carrier on which the subject in a seated position is placed. (Supplementary Note 19) An X-ray CT apparatus comprising: a scanner unit having an opening through which a subject is inserted; a stand having a tilt mechanism for tilting the scanner unit; and a control unit that controls the tilt mechanism so that one end of the scanner unit on a movement path of the subject is lower than the other end, thereby preventing movement. (Supplementary Note 20) An X-ray CT apparatus comprising: a scanner unit having an opening through which a subject is inserted; a stand having a tilt mechanism for tilting the scanner unit; and a control unit that controls the tilt mechanism so that one end of the scanner unit on a movement path of the subject is higher than the other end. (Supplementary Note 21) A method for controlling the operation of an X-ray CT device that includes a scanner unit having an opening into which a subject is inserted and a stand having a tilt mechanism for tilting the scanner unit, the method comprising: acquiring information indicating that the subject will enter the opening; and, when it is determined based on the information that the scanner unit should be in a movement assist state, controlling the tilt mechanism so that one end of the scanner unit on a movement path of the subject is in a movement assist state that is higher than the other end.

[0092] DESCRIPTION OF SYMBOLS 1...X-ray CT device 10...Gantry device 11...Scanner 111...Entry path forming section 112...Exit path forming section 13...Support 15...Opening 151...Central section 152...Upper enlarged diameter section 153...Lower enlarged diameter section 17...X-ray tube 19...X-ray detector 25...Control device 29...Operation panel 31...High voltage generator 37...Camera system 60...Console device 61...Memory 62...Display 63...Input interface 64...Processing circuit 641...System control function 642...Acquisition function 643...Determination function 644...Control function A1...Central axis A2...Tilt axis

Claims

1. An X-ray CT device comprising: a scanner unit having an opening into which a subject is inserted; a stand having a tilt mechanism for tilting the scanner unit; and a control unit that controls the tilt mechanism so that one end of the scanner unit on the movement path of the subject is in a movement assist state in which it is higher than the other end.

2. An X-ray CT device as described in claim 1, further comprising: an acquisition unit that acquires subject information including the subject entering the opening; and a determination unit that determines whether the subject will enter the opening based on the subject information, wherein the control unit puts the scanner unit into the movement assist state when the determination unit determines that the subject will enter the opening.

3. The X-ray CT device according to claim 2, wherein the subject information further includes the height of the subject, and the determination unit determines whether or not to put the scanner unit into the movement assist state based on the subject information.

4. The X-ray CT device according to claim 1, wherein the movement assistance state is a state in which the ceiling of the examination room does not interfere with the scanner unit and the height of the lower end of the scanner at one end from the floor surface is at its maximum.

5. An X-ray CT device as described in claim 4, wherein the height and tilt angle of the scanner unit in the movement assistance state are set in advance based on the height of the ceiling, the vertical movement range of the scanner unit, and the thickness of the scanner unit.

6. An X-ray CT device as described in claim 1, further comprising: an input unit that receives input from a user as to whether or not to place the scanner unit in the movement assist state; and a judgment unit that judges whether or not to place the scanner unit in the movement assist state based on an input signal indicating that the user has input an operation to place the scanner unit in the movement assist state via the input unit, wherein the control unit places the scanner unit in the movement assist state when the judgment unit judges that the scanner unit should be placed in the movement assist state.

7. The X-ray CT device according to claim 6, wherein the input unit includes a button that receives an instruction from a user to start control to place the scanner unit in the movement assist state, and when the determination unit determines that the button has been pressed by the user, the control unit simultaneously controls an elevation mechanism that raises and lowers the scanner unit and controls the tilt mechanism to place the scanner unit in the movement assist state.

8. An X-ray CT device as described in claim 2, further comprising a detection unit that detects that the subject has approached the opening, wherein the acquisition unit acquires the detection result of the detection unit as the subject information, and the determination unit determines to put the scanner unit into the movement assist state when the detection result is acquired.

9. An X-ray CT device as described in claim 2, further comprising a detection unit that detects an instruction to place the subject into the opening, wherein the acquisition unit acquires the detection result of the detection unit as the subject information, and the determination unit determines that the scanner unit should be placed in the movement assist state when the detection result is acquired.

10. An X-ray CT device as described in claim 8 or 9, wherein the movement assistance state is a state in which the scanner unit is tilted and a portion of the scanner unit located in the direction of entering the opening is raised, and the detection unit further detects the direction in which the subject enters the opening.

11. An X-ray CT device as described in claim 2, further comprising a detection unit that detects when the subject exits from the opening, wherein the acquisition unit acquires the detection result of the detection unit as the subject information, and the determination unit determines to put the scanner unit into the movement assist state when the detection result is acquired.

12. An X-ray CT device as described in claim 2, further comprising a detection unit that detects an instruction to remove the subject from the opening, wherein the acquisition unit acquires the detection result of the detection unit as the subject information, and the determination unit determines that the scanner unit should be put into the movement assist state when the detection result is acquired.

13. An X-ray CT device as described in claim 11 or 12, wherein the movement assistance state is a state in which the scanner unit is tilted and a portion of the scanner unit located in the direction of exiting from the opening is raised, and the detection unit further detects the direction in which the subject exits from the opening.

14. The X-ray CT apparatus according to claim 8 or 9, wherein the control unit returns the scanner unit from the movement assist state to a standby state based on completion of movement of the subject into the opening.

15. The X-ray CT apparatus according to claim 11 or 12, wherein the control unit returns the scanner unit from the movement assist state to a standby state based on the completion of the movement of the subject out of the opening.

16. The X-ray CT apparatus according to claim 1, wherein the diameter of the opening at its lower end is larger than the diameter of the opening at its central portion.

17. The X-ray CT apparatus according to claim 2, wherein the subject information further includes position information of the subject, and the control unit adjusts the tilt angle of the scanner unit in the movement assistance state based on the subject information.

18. The X-ray CT apparatus according to claim 2, wherein the subject information includes the height of an assistant pushing a subject carrier on which the subject in a seated position is placed.

19. An X-ray CT device comprising: a scanner unit having an opening into which a subject is inserted; a stand having a tilt mechanism for tilting the scanner unit; and a control unit for controlling the tilt mechanism so that one end of the scanner unit on the movement path of the subject is lower than the other end to prevent movement.

20. An X-ray CT device comprising: a scanner unit having an opening into which a subject is inserted; a stand having a tilt mechanism for tilting the scanner unit; and a control unit that controls the tilt mechanism so that one end of the scanner unit on the movement path of the subject is higher than the other end.

21. A method for controlling the operation of an X-ray CT device that includes a scanner unit having an opening into which a subject is inserted and a stand having a tilt mechanism for tilting the scanner unit, the method comprising: acquiring information indicating that the subject will enter the opening; and, when it is determined based on the information that the scanner unit should be in a movement assist state, controlling the tilt mechanism so that one end of the scanner unit on the movement path of the subject is in a movement assist state that is higher than the other end.

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