X-ray CT scanner, control method using the X-ray CT scanner, and program

Abstract

The objective is to reduce the possibility of the device stopping due to misidentifying an object that may be present between the scanner and the floor during scanning as the subject. [Solution] The X-ray CT apparatus of this embodiment comprises a scanner unit, a support unit, a detection unit, and a control unit. The scanner unit has an imaging system. The support unit supports the scanner unit and moves the scanner unit in the vertical direction. The detection unit is provided on the scanner unit and detects objects present in the detection area, with at least a portion of the area between the outer circumference of the opening into which the subject is inserted and the subject itself as the detection area. The control unit performs control to exclude areas from the detection area where the movement of the subject is restricted during imaging.

Description

Technical Field

[0001] Embodiments disclosed in the present specification and drawings relate to an X-ray CT apparatus, a control method for the X-ray CT apparatus, and a program.

Background Art

[0002] There is an X-ray CT (Computed Tomography) apparatus in which a scanner into which a subject is inserted is supported by a stand so as to be tilted or moved in the vertical direction. Such an X-ray CT apparatus is capable of imaging a subject in a standing position (standing position imaging) and imaging a subject in a sitting position seated on a chair or wheelchair (sitting position imaging).

[0003] By the way, when performing standing position imaging, there is a possibility that the subject may move during imaging in the horizontal direction that is horizontal to the floor surface and move out of the opening of the scanner. In addition, when performing sitting position imaging, depending on the physique of the subject, the subject's feet may be positioned outside the opening of the scanner in the horizontal direction.

[0004] Therefore, in the cases as described above, for the purpose of preventing interference between the subject and the scanner, an optical sensor that detects an object between the scanner and the floor surface may be provided. In such an X-ray CT apparatus, when the light emitted from the light projecting unit of the optical sensor is blocked, the scanner stops.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The problem that the embodiments disclosed in this specification and drawings aim to solve is to reduce the possibility of the device stopping due to misidentification of an object that may be present between the scanner and the floor surface during imaging as the subject. 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 each configuration shown in the embodiments described later can also be positioned as other problems. [Means for solving the problem]

[0007] The X-ray CT apparatus of this embodiment comprises a scanner unit, a support unit, a detection unit, and a control unit. The scanner unit has an imaging system. The support unit supports the scanner unit and moves the scanner unit in the vertical direction. The detection unit uses at least a portion of the area between the outer circumference of the opening into which the subject is inserted and the subject as a detection area, and detects the presence of an object in the detection area. If the control unit detects the presence of an object in the detection area excluding the non-detection area while the scanner unit is operating, it stops the operation of the scanner unit. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a block diagram showing an example of the configuration of an X-ray CT apparatus according to the first embodiment. [Figure 2] Figure 2 shows an example of the external appearance of an X-ray CT apparatus according to the first embodiment. [Figure 3] Figure 3 is a perspective view showing an example of an X-ray CT apparatus for imaging a supine subject according to the first embodiment. [Figure 4] Figure 4 is a perspective view showing an example of an X-ray CT scanner for imaging a standing subject according to the first embodiment. [Figure 5] Figure 5 is a top view showing an example of a support portion according to the first embodiment. [Figure 6] Figure 6 is a top view showing an example of the detection area when contrast imaging is not performed according to the first embodiment. [Figure 7] Figure 7 shows an example of the installation position of the pole according to the first embodiment. [Figure 8] Figure 8 is a top view showing an example of the detection area when the pole according to the first embodiment is installed at the first installation position. [Figure 9] Figure 9 is a top view showing an example of the detection area when the pole according to the first embodiment is installed at the second installation position. [Figure 10] Figure 10 is a top view showing an example of the detection area when the pole according to the first embodiment is installed at the third installation position. [Figure 11] Figure 11 shows an example of a display screen that notifies the detection area according to the first embodiment. [Figure 12A] Figure 12A is a flowchart showing an example of a process performed by the X-ray CT apparatus according to the first embodiment. [Figure 12B] Figure 12B is a flowchart showing an example of a process performed by the X-ray CT apparatus according to the first embodiment. [Figure 13] Figure 13 is a block diagram showing an example of the configuration of an X-ray CT apparatus according to the second embodiment. [Figure 14] Figure 14 illustrates an example of the process for determining whether a subject (the object being tested) or an object other than the subject (the object being tested) has been detected, according to the second embodiment. [Figure 15] Figure 15 illustrates an example of the process for determining whether a subject (the object being tested) or an object other than the subject (the object being tested) has been detected according to the second embodiment. [Figure 16] Figure 16 is a flowchart showing an example of a process performed by the X-ray CT apparatus according to the second embodiment. [Figure 17] Figure 17 is a top view showing an example of a detection area determined according to the front setting in the modified example 2. [Figure 18] Figure 18 is a top view illustrating an example of the positional relationship between the pole installation position and the area in which it becomes effective, according to Modification 4. [Figure 19] Figure 19 is a top view illustrating an example of the positional relationship between the pole installation position and the laser sensor in an active state according to Modification 5. [Figure 20]FIG. 20 is a top view illustrating an example of the positional relationship between the installation position of a pole according to Modification 6 and a laser sensor that enters an active state. [Figure 21] FIG. 21 is a diagram illustrating an example of a display screen that notifies of an installable region of a tube according to Modification 7. [Figure 22] FIG. 22 is a diagram illustrating an example of processing for determining whether a subject according to Modification 8 is detected or an object other than the subject is detected. [Figure 23] FIG. 23 is a flowchart illustrating an example of processing executed by the X-ray CT apparatus according to Modification 8. [Mode for Carrying Out the Invention]

[0009] Hereinafter, an X-ray CT apparatus, a control method for the X-ray CT apparatus, and a program according to an embodiment will be described with reference to the drawings. The X-ray CT apparatus is a medical apparatus including a scanner provided with an opening into which a subject can be inserted, a scanner driving device that moves the scanner relative to the subject, and a support on which the subject is placed. The scanner driving device can move the scanner at least in the vertical direction, and can perform imaging regardless of whether the subject is in a recumbent position or a standing position.

[0010] (First Embodiment) FIG. 1 is a block diagram illustrating an example of the configuration of an X-ray CT apparatus 1 according to the first embodiment. FIG. 2 is a diagram illustrating an example of the external appearance of the X-ray CT apparatus 1 according to the first embodiment.

[0011] The X-ray CT apparatus 1 includes, for example, a gantry device 10, a couch device 30, and a console device 40. In FIG. 1, for convenience of explanation, both a view of the gantry device 10 viewed from the Z-axis direction and a view thereof viewed from the X-axis are shown, but in practice, there is only one gantry device 10.

[0012] In this embodiment, in a non-tilted state, the rotation axis of the rotating frame 17 or the longitudinal direction of the top plate 33 of the bed device 30 along the horizontal direction is defined as the Z-axis direction (front-to-back direction), the axis perpendicular to the Z-axis direction and horizontal to the floor surface is defined as the X-axis direction (circumferential direction), and the direction perpendicular to the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction (up-down direction).

[0013] The stand unit 10 in the X-ray CT apparatus 1 includes, for example, a scanner 20, a scanner drive unit 22, light-emitting units 24a to 24n, and a control device 28. The light-emitting units 24a to 24n are supported by a support member 25. In addition, light-receiving units 26a to 26n are provided on the floor surface on which the stand unit 10 is installed.

[0014] The scanner 20 is supported by a scanner drive unit 22. The scanner drive unit 22 moves the scanner 20 up, down, left, and right, and also tilts the scanner 20 to change its orientation. The control unit 28 controls the operation of the scanner drive unit 22.

[0015] Scanner 20 is an example of a scanner unit. Scanner 20 includes an X-ray tube 11, a wedge 12, a collimator 13, an X-ray high-voltage device 14, an X-ray detector 15, a data acquisition system (hereinafter referred to as DAS: Data Acquisition System) 16, a rotating frame 17, and a cover 18. The X-ray tube 11, wedge 12, collimator 13, X-ray high-voltage device 14, X-ray detector 15, DAS 16, and rotating frame 17 are housed within the cover 18.

[0016] The X-ray tube 11 generates X-rays by irradiating thermionic electrons from the cathode (filament) to the anode (target) when a high voltage is applied from the X-ray high-voltage device 14. The X-ray tube 11 irradiates the subject P with X-rays. The X-ray tube 11 includes a vacuum tube. For example, the X-ray tube 11 is a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermionic electrons.

[0017] The wedge 12 is a filter used to adjust the amount of X-rays (radiation dose) irradiated from the X-ray tube 11 to the subject (image subject) P. The wedge 12 attenuates the X-rays that pass through it so that the distribution of the X-ray dose irradiated from the X-ray tube 11 to the subject P becomes a predetermined distribution. The wedge 12 is also called a wedge filter or bow-tie filter. The wedge 12 is made of aluminum that has been processed to have a predetermined target angle and a predetermined thickness, for example.

[0018] The collimator 13 is a mechanism for narrowing the irradiation range of X-rays that have passed through the wedge 12. The collimator 13 narrows the irradiation range of X-rays by forming a slit, for example, by combining multiple lead plates. The collimator 13 is sometimes called an X-ray diaphragm. The collimator 13 may be an active collimator in which the narrowing range can be mechanically driven.

[0019] The X-ray high-voltage device 14 includes, for example, a high-voltage generator and an X-ray control device. The high-voltage generator has an electrical circuit including a transformer and a rectifier, and generates a high voltage to be applied to the X-ray tube 11. The X-ray control device controls the output voltage of the high-voltage generator according to the amount of X-rays to be generated in the X-ray tube 11.

[0020] The high-voltage generator may perform voltage boosting using the transformer described above, or it may perform voltage boosting using an inverter. The X-ray high-voltage device 14 may be mounted on the rotating frame 17, or it may be mounted on the fixed frame (not shown) side of the mounting device 10.

[0021] The X-ray detector 15 detects the intensity of X-rays generated by the X-ray tube 11 and incident after passing through the subject P. The X-ray detector 15 outputs an electrical signal (or optical signal, etc.) corresponding to the detected X-ray intensity to the DAS 16. The X-ray detector 15 has, for example, multiple rows of X-ray detection elements. Each of the multiple rows of X-ray detection elements has multiple X-ray detection elements arranged in the channel direction along an arc centered on the focal point of the X-ray tube 11. The multiple rows of X-ray detection elements are arranged in the slice direction (column direction, row direction).

[0022] The X-ray detector 15 is, for example, an indirect type detector having a grid, a scintillator array, and a photosensor array.

[0023] A scintillator array has multiple scintillators. Each scintillator has a scintillator crystal. The scintillator crystal emits light in an amount corresponding to the intensity of the incident X-rays.

[0024] The grid is positioned on the X-ray incident surface of the scintillator array and has an X-ray shielding plate that absorbs scattered X-rays. The grid is sometimes also called a collimator (one-dimensional collimator or two-dimensional collimator).

[0025] The optical sensor array includes, for example, optical sensors such as photomultipliers (PMTs). The optical sensor array outputs an electrical signal corresponding to the amount of light emitted by the scintillator. The X-ray detector 15 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into an electrical signal.

[0026] The DAS16 includes, for example, an amplifier and an A / D converter. The amplifier performs amplification processing on the electrical signals output by each X-ray detection element of the X-ray detector 15. The A / D converter converts the electrical signals into digital signals. The DAS16 outputs detection data based on the digital signals to the console device 40.

[0027] The rotating frame 17 is an annular member that supports the X-ray tube 11, wedge 12, and collimator 13 in opposition to the X-ray detector 15. The rotating frame 17 is supported by a fixed frame so as to be rotatable around the subject P introduced inside. The rotating frame 17 further supports the DAS 16.

[0028] The detection data output by DAS16 is transmitted via optical communication from a transmitter having a light-emitting diode (LED) on the rotating frame 17 to a receiver having a photodiode on the non-rotating part (e.g., the fixed frame) of the mounting device 10, and is then transferred by the receiver to the console device 40.

[0029] Furthermore, the method for transmitting detection data from the rotating frame 17 to the non-rotating part is not limited to the optical communication method described above; any non-contact transmission method may be used. The rotating frame 17 is not limited to an annular member, but may be an arm-like member, as long as it can support and rotate the X-ray tube 11 or the like.

[0030] The cover 18 is provided with a central opening 19. The central opening 19 is an opening into which the subject P is inserted. A rotating frame 17 provided inside the cover 18 is positioned inside the cover 18, surrounding the central opening 19. The rotating frame 17 rotates around the central opening 19.

[0031] The X-ray CT apparatus 1 is, for example, a Rotate / Rotate-Type X-ray CT apparatus (third-generation CT) in which both the X-ray tube 11 and the X-ray detector 15 are supported by a rotating frame 17 and rotate around the subject P. However, it is not limited to this, and may also be a Stationary / Rotate-Type X-ray CT apparatus (fourth-generation CT) in which a plurality of X-ray detection elements arranged in a ring shape are fixed to a fixed frame and the X-ray tube 11 rotates around the subject P.

[0032] The scanner drive unit 22 includes, for example, a support column 103, a rail 104, a slider 105, and a tilt mechanism 106.

[0033] Furthermore, the scanner drive unit 22 may further include a base 101 and a horizontal movement device 102. Figure 2 illustrates a configuration that further includes a base 101 and a horizontal movement device 102. In the following description, as a general rule, the scanner drive unit 22 will be described as comprising a base 101 and a horizontal movement device 102.

[0034] In the example shown in Figure 2, the base 101 has a linear support structure that extends horizontally. The base 101 is fixed to the floor of the examination room, for example, by bolts. The horizontal movement device 102 is also provided on the base 101, and the support column 103 is mounted on the horizontal movement device 102 in an upright position.

[0035] The support column 103 is, for example, a member that extends vertically. The support column 103 is an example of a support part. If the scanner drive unit 22 does not have a base 101, the support column 103 may be fixed to the floor surface of the examination room, for example, by bolts or the like. The horizontal movement device 102 moves the support column 103, which is the mounted object, in the horizontal direction based on the control of the control device 28.

[0036] A rail 104 is attached to the support column 103. The rail 104 is positioned along the extension direction (vertical direction) of the support column 103. A slider 105 is attached to the rail 104. The slider 105 is movable along the rail 104 based on the control of the control device 28.

[0037] A tilt mechanism 106 is attached to the slider 105, and a scanner 20 is attached to the tilt mechanism 106. The tilt mechanism 106 is capable of tilting the scanner 20 around its axis based on the control of the control device 28. The tilt mechanism 106 switches the orientation of the scanner 20 by tilting it. The scanner drive device 22 moves the scanner 20 horizontally by moving the support column 103 with the horizontal movement device 102.

[0038] The scanner drive unit 22 moves the scanner 20 vertically by moving the slider 105 along the rail 104. The scanner drive unit 22 tilts the scanner 20 around the axis of rotation by the tilt mechanism 106. By moving the scanner 20, the scanner drive unit 22 moves the scanner 20 and the subject P relative to each other.

[0039] The light-emitting units 24a to 24n (hereinafter simply referred to as light-emitting unit 24 unless otherwise specified) are provided on the scanner 20. For example, the light-emitting units 24a to 24n are provided along a circular area projected onto the support member 25 from the central opening 19 of the scanner 20 (hereinafter also simply referred to as the central opening 19).

[0040] Furthermore, the light-emitting units 24a to 24n emit laser light downwards. In this embodiment, the light-emitting units 24a to 24n emit visible light towards the light-receiving units 26a to 26n (hereinafter simply referred to as light-receiving unit 26 unless otherwise specified), but the light-emitting unit 24 may emit infrared light towards the light-receiving unit 26.

[0041] The light-receiving units 26a to 26n are installed on the floor surface along a circular area projected onto the floor surface by the central opening 19. The light-receiving units 26a to 26n receive the laser light 32a to 32n emitted from the light-emitting units 24a to 24n and send the light-receiving result to the control device 28.

[0042] The light-emitting units 24a to 24n and the light-receiving units 26a to 26n constitute the laser sensor 23a to 23n. The laser sensor 23 is an example of an optical sensor. Specifically, each of the light-emitting units 24a to 24n is paired with each of the light-receiving units 26a to 26n installed on the floor surface 5, and one pair of light-emitting units 24 and light-receiving units 26 constitute one laser sensor 23.

[0043] In the example shown in Figure 1, a light-emitting unit 24a and a light-receiving unit 26a facing the light-emitting unit 24a constitute one laser sensor 23a, and a light-emitting unit 24n and a light-receiving unit 26n facing the light-emitting unit 24n constitute one laser sensor 23n. That is, the laser sensors 23a to 23n are installed along positions corresponding to the central opening 19 in the vertical direction.

[0044] The laser sensor 23 is capable of detecting objects located within the movement range of the scanner 20, and changes its detection area according to the installation position of the subject support pole 70 (hereinafter also simply referred to as pole 70) that supports the subject P in a standing position during standing imaging. Pole 70 is an example of a subject support member.

[0045] More specifically, the laser sensor 23 detects objects located below the scanner 20 from before the start of imaging of the subject P until the end of imaging. In this embodiment, the “objects” detected by the laser sensor 23 include the subject P and “objects that may be misidentified as the subject P,” as described later. Specifically, the laser sensor 23 detects objects located between the light-emitting unit 24 and the light-receiving unit 26.

[0046] For example, if there is no object between the light-emitting unit 24a and the light-receiving unit 26a, the light-receiving unit 26a will receive the laser light emitted by the light-emitting unit 24a. If there is an object between the light-emitting unit 24a and the light-receiving unit 26a, the laser light will be blocked, and therefore the light-receiving unit 26a will not receive the laser light emitted by the light-emitting unit 24a.

[0047] The number of light-emitting units 24, light-receiving units 26, and laser sensors 23 is not particularly limited. Furthermore, the method for object detection using the laser sensors 23 can employ known techniques and is not particularly limited.

[0048] In the example shown in Figure 1, the light-receiving unit 26 is embedded in the floor surface, and there is no step between the floor surface and the surface of the light-receiving unit 26, resulting in a flat surface. However, the installation method of the light-receiving unit 26 is not limited to this.

[0049] Furthermore, each of the laser sensors 23a to 23n can be individually switched between an enabled state and an disabled state under the control of the control device 28. A disabled laser sensor 23, for example, will not detect an object. The control function 51 may, for example, prevent the scanner 20 from stopping if a laser sensor 23 considered to be in an disabled state detects an object. Therefore, the detection area of ​​the laser sensors 23a to 23n changes depending on which of the laser sensors 23a to 23n the control device 28 enables. The process of changing the detection area according to the installation position of the pole 70 will be described later.

[0050] The control device 28 includes, for example, a processing circuit having a processor such as a CPU (Central Processing Unit), and a drive mechanism including a motor and actuators. The processing circuit realizes these functions, for example, by having a hardware processor execute a program stored in a memory device (storage circuit).

[0051] Hardware processors refer to circuits such as CPUs (Central Processing Units), GPUs (Graphics Processing Units), Application Specific Integrated Circuits (ASICs), programmable logic devices (e.g., Simple Programmable Logic Devices (SPLDs) or Complex Programmable Logic Devices (CPLDs)), and Field Programmable Gate Arrays (FPGAs).

[0052] Instead of storing the program in a memory device, the program can be directly embedded within the hardware processor's circuitry. In this case, the hardware processor performs its functions by reading and executing the program embedded within the circuitry.

[0053] A hardware processor is not limited to being a single circuit; it may be composed of multiple independent circuits combined to perform various functions. The memory device may be a non-temporary (hardware) storage medium. Furthermore, multiple components may be integrated into a single hardware processor to perform various functions.

[0054] The control device 28, for example, rotates the rotating frame 17, moves the scanner 20 using the scanner drive device 22, and moves the top plate 33 of the bed device 30. The top plate 33 serves as the bed when the subject P is placed in a supine position.

[0055] For example, when tilting the scanner 20, the control device 28 controls the tilt mechanism 106 of the scanner drive unit 22 and rotates the rotation frame 17 around an axis parallel to the Z-axis direction based on the tilt angle input to the input interface 43.

[0056] The control device 28 determines the rotation angle of the rotating frame 17 based on the output of a sensor (not shown), etc. The control device 28 also provides the rotation angle of the rotating frame 17 to the processing circuit 50 as needed. The control device 28 may be installed on the mounting device 10 or on the console device 40.

[0057] The patient bed device 30 is a device that places and moves the subject P to be photographed and introduces it into the rotating frame 17 of the stand device 10. The patient bed device 30 comprises, for example, a base 31, a patient bed drive device 32, a top plate 33, and a support frame 34.

[0058] The base 31 includes a housing that supports the support frame 34 so that it can move vertically (in the Y-axis direction).

[0059] The bed drive device 32 includes a motor and actuators. The bed drive device 32 moves the tabletop 33 on which the subject P is placed along the support frame 34 in the longitudinal direction (Z-axis direction) of the tabletop 33.

[0060] The top plate 33 is a plate-shaped member on which the subject P is placed. The bed drive device 32 retracts the top plate 33 and inserts it into the central opening 19. The bed drive device 32 then advances the top plate 33 and withdraws it from the scanner 20.

[0061] The bed drive device 32 may move not only the top plate 33 but also the support frame 34 in the longitudinal direction of the top plate 33. Conversely, the support device 10 may be movable in the Z-axis direction, and the movement of the support device 10 may be controlled so that the rotating frame 17 is positioned around the subject P. Alternatively, both the support device 10 and the top plate 33 may be movable.

[0062] Figure 3 is a perspective view showing an example of an X-ray CT scanner 1 for imaging a supine subject P according to the first embodiment. Figure 4 is a perspective view showing an example of an X-ray CT scanner 1 for imaging a standing subject P according to the first embodiment.

[0063] The subject P, placed on the bed device 30, is photographed in a supine position, as shown in Figure 3. In the example in Figure 3, the support column 103 and scanner 20, which were located on the front side of the base 101 in Figure 2, are moved to the rear side of the base 101 by the horizontal movement device 102. Thus, the positions of the support column 103 and scanner 20 may be changed according to the posture of the subject P during imaging.

[0064] Furthermore, as shown in Figure 4, the X-ray CT scanner 1 can also image a standing subject P. When imaging a standing subject P, for example, a pole 70 is used to support the standing subject P. In this embodiment, the installation position of the pole 70 can be changed within the range of positions corresponding to the central opening 19.

[0065] Furthermore, as shown in Figures 3 and 4, a display panel 42a and operation buttons 43a are provided on the front of the support column 103. This allows, for example, the operator to adjust the position of the scanner 20 when photographing a subject P in a supine or standing position in the examination room where the X-ray CT device 1 is installed, by checking the display contents of the display panel 42a and inputting commands using the operation buttons 43a.

[0066] Furthermore, a display panel and operation buttons similar to those of the display panel 42a and operation buttons 43a may also be provided on the rear surface of the support column 103. This allows the operator to check the condition of the subject P from the rear side of the support column 103, or to adjust the position of the scanner 20, etc., even when the orientation of the subject P is different, such as when the front of the subject P is in the positive Z-axis direction.

[0067] Furthermore, the X-ray CT apparatus 1 according to this embodiment can also image a subject P sitting in a chair or wheelchair, i.e., a seated subject P, using the same method as when imaging a subject P in a standing position, as shown in Figure 4.

[0068] The stand device 10 and the patient device 30 switch the relative direction of movement between the X-ray detector 15 provided on the scanner 20 and the subject P supported on the tabletop 33, for example, by a horizontal movement device 102, a slider 105, and a patient drive device 32.

[0069] For example, when imaging the entire body of a subject P positioned parallel to the Z direction, the stand device 10 and the bed device 30 move the scanner 20 in the Z direction together with the support column 103 by the horizontal movement device 102.

[0070] Furthermore, for example, when imaging a subject P along the OM line (Orbitomeatal baseline) which is inclined from the Z direction around the X axis, the rigging device 10 and the patient table device 30 move the scanner 20 in the Z and Y directions using the horizontal movement device 102 and the slider 105.

[0071] The console device 40 includes, for example, a memory 41, a display 42, an input interface 43, and a processing circuit 50. In this embodiment, the console device 40 is described as separate from the mounting device 10, but the mounting device 10 may include some or all of the components of the console device 40.

[0072] Memory 41 can be implemented using, for example, semiconductor memory elements such as RAM (Random Access Memory) or flash memory, a hard disk, or an optical disc. Memory 41 stores, for example, detection data, projection data, reconstructed image data, CT image data, etc.

[0073] The above data may be stored in an external memory that the X-ray CT apparatus 1 can communicate with, rather than in memory 41 (or in addition to memory 41). The external memory is controlled by a cloud server, for example, by accepting read and write requests from the cloud server that manages the external memory.

[0074] The display 42 displays various types of information. The display 42 is an example of a display unit and display medium. For example, the display 42 is an output interface that displays medical images (CT images) generated by the processing circuit, or GUI (Graphical User Interface) images that accept various operations from operators such as doctors and technicians.

[0075] The display 42 may be, for example, a liquid crystal display, a CRT (Cathode Ray Tube), or an organic EL (Electroluminescence) display. The display 42 may be mounted on the stand device 10. The display 42 may be a desktop type, or it may be a display device (for example, a tablet terminal) that can communicate wirelessly with the main body of the console device 40.

[0076] In this embodiment, the display panel 42a is included in the display 42.

[0077] The input interface 43 receives various input operations from the operator and outputs an electrical signal indicating the content of the received input operation to the processing circuit 50.

[0078] For example, the input interface 43 accepts input operations for imaging conditions, including acquisition conditions when collecting detection data or projection data, reconstruction conditions when reconstructing CT images, and image processing conditions when generating post-processed images from CT images.

[0079] In this embodiment, the imaging conditions include imaging information such as posture information representing the subject P's position at the time of imaging (lying down, standing, sitting, etc.), information representing the imaging site, and information indicating whether or not contrast imaging is performed.

[0080] The input interface 43 can be implemented by, for example, a mouse, keyboard, touch panel, drag ball, switch, button, joystick, camera, infrared sensor, microphone, etc. The input interface 43 may also be implemented by a display device (e.g., a tablet terminal) that can communicate wirelessly with the main body of the console device 40.

[0081] In this embodiment, the operation button 43a is included in the input interface 43.

[0082] In this specification, the term "input interface" is not limited to those equipped with physical operating components such as a mouse or keyboard. For example, an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device located separately from the device and outputs this electrical signal to a control circuit is also included as an example of an input interface.

[0083] The processing circuit 50 controls the overall operation of the X-ray CT apparatus 1. The processing circuit 50 includes, for example, a control function 51, a preprocessing function 52, a reconstruction processing function 53, an image processing function 54, a detection control function 55, and a detection function 56. Here, the control function 51 is an example of an operation control unit and a display control unit. The detection control function 55 is an example of a detection control unit. The detection function 56 is an example of a detection unit.

[0084] The processing circuit 50 realizes these functions, for example, by having a hardware processor execute a program stored in a memory device (memory circuit).

[0085] A hardware processor refers to circuits such as CPUs, GPUs, application-specific integrated circuits, programmable logic devices or composite programmable logic devices, and field-programmable gate arrays. Instead of storing programs in memory, the program may be directly embedded within the hardware processor's circuitry.

[0086] A hardware processor is not limited to being a single circuit; it may be composed of multiple independent circuits combined to perform various functions. The memory device may be a non-temporary (hardware) storage medium. Furthermore, multiple components may be integrated into a single hardware processor to perform various functions.

[0087] Each component of the console device 40 or the processing circuit 50 may be distributed and implemented by multiple hardware components. The processing circuit 50 may not be implemented by the console device 40, but by a processing unit that can communicate with the console device 40.

[0088] The processing unit is, for example, a workstation connected to a single X-ray CT scanner, or a device (e.g., a cloud server) connected to multiple X-ray CT scanners that performs processing equivalent to the processing circuit 50 described below in a single operation.

[0089] The control function 51 controls various functions of the processing circuit 50 based on input operations received by the input interface 43. For example, the control function 51 controls the X-ray high-voltage device 14, DAS 16, control device 28, and the bed drive device 32 of the bed device 30 to perform data collection processing of detection data in the support frame device 10.

[0090] Furthermore, if the control function 51 detects, via the detection function 56 (described later), that the subject P is present between the scanner 20 and the floor while the subject P is being scanned, the control function 51 controls the scanner drive unit 22 to stop the operation of the scanner 20. This prevents the subject P from being trapped between the scanner 20 and the floor. The operation of the scanner 20 includes, for example, vertical movement of the scanner 20 and tilting of the scanner 20 around its rotation axis.

[0091] Furthermore, if the control function 51 detects the presence of a subject P between the scanner 20 and the floor surface when the scanner 20 is stopped, the control function 51 may also perform control to prevent the user from giving an instruction to move the scanner 20 towards the floor surface (negative Y-axis direction).

[0092] Furthermore, for example, the control function 51 accepts input of shooting conditions. Specifically, the control function 51 accepts input of shooting conditions, including posture information and shooting information.

[0093] The control function 51 may also acquire imaging conditions for the subject P by receiving an examination order from an external device. For example, the control function 51 may receive an examination order including imaging conditions for the subject P from a server of a Radiology Information System (RIS).

[0094] Furthermore, for example, the control function 51 controls the display 42 to show a GUI for operating the X-ray CT apparatus 1, a display screen related to the detection area, and so on. The display screen related to the detection area will be described later.

[0095] The preprocessing function 52 performs preprocessing on the detection data output by DAS16, such as logarithmic transformation, offset correction, inter-channel sensitivity correction, and beam hardening correction, to generate projection data, and stores the generated projection data in memory 41.

[0096] The reconstruction processing function 53 performs reconstruction processing on the projection data set by the preprocessing function 52, such as a filtered back projection method or an iterative reconstruction method, to generate CT image data, and stores the generated CT image data in the memory 41.

[0097] The image processing function 54 converts CT image data into three-dimensional image data or cross-sectional image data of an arbitrary cross-section using a known method, based on the input operation received by the input interface 43. The conversion to three-dimensional image data may be performed by the preprocessing function 52.

[0098] The detection control function 55 changes the detection area of ​​the laser sensor 23. For example, the detection control function 55 switches the laser sensor 23 between an enabled state and an disabled state depending on the shooting conditions. The following explanation assumes that all laser sensors 23 are normally in an disabled state.

[0099] For example, if the posture information of the subject P received by the control function 51 indicates a supine position, the detection control function 55 maintains the disabled state of all laser sensors 23. Also, if the posture information of the subject P received by the control function 51 indicates an upright position, and the imaging information received by the control function 51 includes information indicating contrast-enhanced imaging, the detection control function 55 switches some of the laser sensors 23 to an enabled state according to the installation position of the pole 70.

[0100] Here, the process of changing the detection area according to the installation position of the pole 70 will be explained using Figures 5 to 11. Figure 5 is a top view showing an example of the support part 63 according to the first embodiment.

[0101] In the example shown in Figure 5, twelve light-emitting units 24a to 24l are arranged in a circular pattern surrounding the central opening 19a (circle 19a) of the support unit 63 in the Y-axis direction.

[0102] In Figure 5, the top of the figure shows the front direction of the mounting device 10, and the bottom of the figure shows the rear direction of the mounting device 10. Note that the number and installation positions of the light-emitting units 24 shown in Figure 5 are examples only and are not limited to these.

[0103] Furthermore, although not shown in Figure 5, it is assumed that 12 light-receiving units 26, each corresponding to one of the light-emitting units 24a to 24l, are provided on the floor surface. That is, 12 laser sensors 23a to 23l are installed in a circular pattern surrounding the central opening 19 in the vertical direction of the floor surface, along the position corresponding to the central opening 19 in the vertical direction of the floor surface.

[0104] First, we will explain the case where standing or sitting imaging is performed and no contrast-enhanced imaging is performed. In this case, the detection control function 55 enables all 12 laser sensors 23a to 23l. Here, Figure 6 is a top view showing an example of the detection area DA when no contrast-enhanced imaging is performed according to the first embodiment. As shown in Figure 6, when no contrast-enhanced imaging is performed, the cylindrical spatial area along the central opening 19 in the space between the scanner 20 and the floor becomes the detection area DA.

[0105] Next, we will explain the case where standing or sitting radiography is performed, and contrast-enhanced radiography is also performed. In this case, the detection control function 55 activates some of the 12 laser sensors 23a to 23l depending on the installation position of the pole 70.

[0106] Here, Figure 7 shows an example of the installation location of the pole 70 according to the first embodiment. In the example in Figure 7, the pole 70 is installed at one of the first installation location IP1 to the third installation location IP3. In this embodiment, there are three possible locations for installing the pole 70, from the first installation location IP1 to the third installation location IP3, but this is just an example, and the possible locations for installing the pole 70 are not limited to these three locations.

[0107] The detection and control function 55 identifies which of the first installation location IP1 to the third installation location IP3 the pole 70 is installed at. Known techniques can be used as appropriate to determine the installation location of the pole 70.

[0108] For example, a camera is installed in a position that allows it to photograph the inside of the central opening 19, and the installation position of the pole 70 is determined based on the image captured by the camera. Alternatively, contact sensors or mechanical switches may be installed at each of the first to third installation positions IP1 to IP3 to determine the installation position of the pole 70.

[0109] The detection control function 55 refers to correspondence information stored in memory 41, etc., which associates each of the first installation positions IP1 to the third installation position IP3 with information identifying the laser sensor 23 to be disabled, and identifies the laser sensor 23 to be disabled from among the laser sensors 23a to 23l.

[0110] In the correspondence information according to this embodiment, the information identifying the laser sensor 23 to be disabled represents the laser sensor 23 among the laser sensors 23a to 23l that is located in a direction in which the movement of the subject P is restricted.

[0111] The direction in which the movement of subject P is restricted is specifically the direction in which pole 70 is installed relative to subject P. Furthermore, the area in which the movement of subject P is restricted is, for example, the area located in the direction in which the movement of subject P is restricted. This is because, since subject P is standing with their back to pole 70, it is unlikely that subject P would move in the direction of pole 70.

[0112] In this embodiment, the correspondence information is information that associates information identifying the first installation location IP1 with the laser sensor 23g, information identifying the second installation location IP2 with the laser sensor 23j, and information identifying the third installation location IP3 with the laser sensor 23d.

[0113] Here, laser sensor 23g is the laser sensor 23 closest to the first installation position IP1. Similarly, laser sensor 23j is the laser sensor 23 closest to the second installation position IP2. Similarly, laser sensor 23d is the laser sensor 23 closest to the third installation position IP3.

[0114] In other words, in this embodiment, the laser sensor 23 closest to the installation position of the pole 70 (first installation position IP1 to third installation position IP3) is defined as the laser sensor 23 located in the direction in which the movement of the subject P is restricted. Furthermore, the laser sensor 23 closest to the installation position of the pole 70 (first installation position IP1 to third installation position IP3) is defined as the laser sensor 23 located in the region in which the movement of the subject P is restricted.

[0115] In this embodiment, the correspondence information associates one laser sensor 23 with one installation location, but information that identifies two or more laser sensors 23 may be associated with one installation location.

[0116] For example, if the detection control function 55 determines that pole 70 is installed at the first installation location IP1, it refers to the correspondence information and identifies the laser sensor 23g associated with the first installation location IP1 as the laser sensor 23 to be disabled. The detection control function 55 then enables the other laser sensors 23.

[0117] Here, Figure 8 is a top view showing an example of the detection area DA when the pole 70 according to the first embodiment is installed at the first installation position IP1. As shown in Figure 8, when the pole 70 is installed at the first installation position IP1, the detection area DA is the area obtained by excluding the detection area of ​​the laser sensor 23g as a non-detection area from the cylindrical space area along the central opening 19 in the space between the scanner 20 and the floor surface.

[0118] In other words, in this case, the detection area of ​​the other laser sensors 23, excluding laser sensor 23g, is an example of the detection area of ​​the detection unit. Also, the detection area of ​​laser sensor 23g is an example of the non-detection area of ​​the detection unit.

[0119] Furthermore, for example, if it is determined that pole 70 is installed at the second installation location IP2, the detection control function 55 refers to the correspondence information and identifies laser sensor 23j, which is associated with the second installation location IP2, as the laser sensor 23 to be disabled. The detection control function 55 then enables all other laser sensors 23 except for the identified laser sensor 23j.

[0120] Here, Figure 9 is a top view showing an example of the detection area DA when the pole 70 according to the first embodiment is installed at the second installation position IP2. As shown in Figure 9, when the pole 70 is installed at the second installation position IP2, the detection area DA is the area obtained by excluding the detection area of ​​the laser sensor 23j as a non-detection area from the cylindrical space area along the central opening 19 in the space between the scanner 20 and the floor surface.

[0121] In other words, in this case, the detection area of ​​the other laser sensors 23, excluding laser sensor 23j, is an example of the detection area of ​​the detection unit. Also, the detection area of ​​laser sensor 23j is an example of the non-detection area of ​​the detection unit.

[0122] Furthermore, for example, if it is determined that pole 70 is installed at the third installation location IP3, the detection control function 55 refers to the correspondence information and identifies the laser sensor 23d associated with the third installation location IP3 as the laser sensor 23 to be disabled. The detection control function 55 then enables the laser sensors 23 other than the identified laser sensor 23d.

[0123] Here, Figure 10 is a top view showing an example of the detection area DA when the pole 70 according to the first embodiment is installed at the third installation position IP3. As shown in Figure 10, when the pole 70 is installed at the third installation position IP3, the detection area DA is the area obtained by excluding the detection area of ​​the laser sensor 23d as a non-detection area from the cylindrical space area along the central opening 19 in the space between the scanner 20 and the floor surface.

[0124] In other words, in this case, the detection area of ​​the other laser sensors 23, excluding laser sensor 23d, is an example of the detection area of ​​the detection unit. Also, the detection area of ​​laser sensor 23d is an example of the non-detection area of ​​the detection unit.

[0125] Furthermore, if the posture information of the subject P received by the control function 51 indicates a seated position and the imaging information received by the control function 51 includes information indicating contrast-enhanced imaging, the detection control function 55 switches some predetermined laser sensors 23 to an enabled state. In this embodiment, if the posture information of the subject P indicates a seated position and the imaging information includes information indicating contrast-enhanced imaging, the detection control function 55 switches the laser sensors 23, excluding laser sensor 23g, to an enabled state.

[0126] In other words, in this case, the detection area of ​​the other laser sensors 23, excluding laser sensor 23g, is an example of the detection area of ​​the detection unit. Also, the detection area of ​​laser sensor 23g is an example of the non-detection area of ​​the detection unit.

[0127] Furthermore, the operator may be able to set which laser sensor 23 to activate when the subject P's posture information indicates a seated position and the imaging information includes information indicating contrast-enhanced imaging.

[0128] Furthermore, for example, the detection control function 55 changes the detection area of ​​the laser sensor 23 according to the operator's instructions. Hereinafter, changing at least one of the detection area and non-detection area of ​​the laser sensor 23 according to the operator's instructions will also be referred to as manual setting of the detection area DA.

[0129] Specifically, the detection control function 55 receives input from the operator via a detection area setting screen (not shown) displayed on the display panel 42a, etc., to enable or disable each of the 12 laser sensors 23a to 23l. The detection control function 55 changes the detection area of ​​the laser sensor 23 according to the received input.

[0130] For example, if the detection control function 55 receives an instruction from the operator to disable laser sensors 23a and 23b and enable the other laser sensors 23, it will disable laser sensors 23a and 23b and enable the other laser sensors 23.

[0131] In this case, the detection areas of the laser sensors 23 other than laser sensors 23a and 23b are examples of the detection areas of the detection unit. Also, the detection areas of laser sensors 23a and 23b are examples of the non-detection areas of the detection unit.

[0132] By enabling manual setting of the detection area DA, for example, if the operator wants to perform contrast imaging of a wheelchair subject P in a seated position in an orientation different from the usual one, they can exclude a position that is convenient for passing the tube through the central opening 19 from the detection area DA as a non-detection area.

[0133] In this embodiment, if the detection area DA is manually set, the detection control function 55 does not perform the process of changing the detection area of ​​the laser sensor 23 according to the installation position of the pole 70. In other words, in this embodiment, the manual setting of the detection area DA takes precedence over the process of changing the detection area of ​​the laser sensor 23 according to the installation position of the pole 70.

[0134] Furthermore, for example, after the imaging of subject P is completed, the detection control function 55 disables all laser sensors 23. This prevents the laser beam from continuing to be emitted from the light-emitting unit 24 even though the subject P is no longer being imaged, thereby reducing power consumption.

[0135] Furthermore, after the detection area of ​​the laser sensor 23 is changed by the detection control function 55, the control function 51 controls the display 42 (for example, the display panel 42a) to display a screen that notifies the operator of the detection area DA.

[0136] Here, Figure 11 shows an example of a display screen 421 that notifies the detection area DA according to the first embodiment. As shown in Figure 11, the display screen 421 displays the detection area DA as the area sensor effective range. The display screen 421 also displays a message prompting the user not to place the injector tube used for contrast imaging (hereinafter also simply referred to as the tube) within the detection area DA (area sensor effective range).

[0137] This allows the operator to adjust the position of the tube so that it is not placed within the detection area DA before starting imaging of the subject P. By preventing the tube from being placed within the detection area DA, the X-ray CT apparatus 1 according to the first embodiment can prevent the scanner 20 from stopping due to the tube being mistakenly identified as the subject P. Here, the tube of an injector used for contrast imaging was used as an example of an object that could be mistakenly identified as the subject P, but the objects that could be mistakenly identified as the subject P are not limited to this. For example, an object that could be mistakenly identified as the subject P may be a tube connected to an oxygen mask, a tube connected to an intravenous drip bag, or a cable connected to an electrode pad for measuring an electrocardiogram.

[0138] In the above description, an example was given of controlling the display 42 to display a screen that notifies the operator of the detection area DA, but the notification method is not limited to the above. For example, a display device (not shown) consisting of multiple LEDs or the like may be provided on the surface of the scanner 20's casing, and the notification may be performed using such a display device.

[0139] As an example, multiple LEDs may be provided on the surface of the outer casing of the cover 18 around the central opening 19, and notification may be provided by illuminating multiple LEDs corresponding to the detection area DA (area sensor effective range) shown in Figure 11. The outer casing of the cover 18 is an example of a display medium. Multiple LEDs may also be provided on the outer periphery surface of the cover 18. In addition, multiple LEDs may be provided on the side surface of the scanner 20 (the side without the central opening 19).

[0140] If the display 42 displays a screen that notifies the operator of the detection area DA, the operator may need to move their gaze or body to a position where they can see the display 42 in order to confirm the detection area DA. For example, if the operator is performing a task such as adjusting the position of a tube, they may have to repeatedly move their gaze or move closer to the display 42 in order to confirm the detection area DA while making adjustments.

[0141] In contrast, as described above, by providing multiple LEDs on the surface of the area surrounding the central opening 19 of the cover 18's exterior, the position of the tube can be adjusted without having to move the operator's gaze significantly or move to the vicinity of the display 42. In other words, the work efficiency of the operator involved in the inspection can be improved.

[0142] Alternatively, a projector (not shown) may be provided. In this case, information representing the detection area DA (area sensor effective range) shown in Figure 11 may be projected onto the exterior of the cover 18 or the floor surface. The floor surface in this case is an example of a display medium. In this case as well, the work efficiency of the operator involved in the inspection can be improved.

[0143] As another example, a display device (not shown) such as a liquid crystal display or an organic EL display may be embedded in the floor surface to display a screen as shown in Figure 11. In this case, it is preferable to embed the display device in a location where the operator frequently performs tasks. In this case as well, the work efficiency of the operator involved in the inspection can be improved.

[0144] Furthermore, the display screen 421 may display the non-detection area as the area sensor invalid range and display a message prompting the operator to place the indicator tube used for contrast imaging within the area sensor invalid range. This allows the operator to adjust the position of the tube so that it is located within the non-detection area before starting imaging of the subject P. By preventing the tube from being located within the detection area DA, the X-ray CT apparatus 1 according to the first embodiment can prevent the tube from being mistakenly identified as the subject P and causing the scanner 20 to stop operating.

[0145] The detection function 56 detects the presence of a subject P between the scanner 20 and the floor. For example, the detection function 56 detects the presence of a subject P between the scanner 20 and the floor when the laser light emitted from the light-emitting unit 24 of the active laser sensor 23 is blocked.

[0146] Specifically, the detection function 56 detects that the laser light emitted from the light-emitting unit 24 has been blocked if at least one of the light-receiving units 26 of the multiple laser sensors 23, which have been switched to an active state by the detection control function 55, fails to receive laser light for a predetermined period of time.

[0147] Next, the processes performed by the X-ray CT apparatus 1 according to this embodiment will be described. Figures 12A and 12B are flowcharts showing an example of the processes performed by the X-ray CT apparatus 1 according to this embodiment. As a premise, it is assumed that the control function 51 receives input of imaging conditions from the operator.

[0148] First, the detection and control function 55 determines whether the subject P's imaging posture is supine (step S101). For example, if the posture information received by the control function 51 indicates supine imaging, the detection and control function 55 determines that the subject P's imaging posture is supine. On the other hand, if the posture information received by the control function 51 indicates standing or sitting imaging, the detection and control function 55 determines that the subject P's imaging posture is not supine.

[0149] If the imaging is performed in a supine position (Step S101: Yes), the process proceeds to Step S110, which will be described later. On the other hand, if the imaging is not performed in a supine position (Step S101: No), the detection control function 55 determines whether the detection area DA has been manually set (Step S102). For example, if the operator has entered a manual setting for the detection area DA via the detection area DA setting screen displayed on the display panel 42a, the detection control function 55 determines that the detection area DA has been manually set.

[0150] If the detection area DA has been manually set (step S102: Yes), the detection control function 55 enables some or all of the laser sensors 23 according to the contents of the manual setting of the detection area DA (step S106), and then proceeds to the process of step S110 described below.

[0151] When the laser sensor 23 becomes active, the light-emitting unit 24 begins to emit laser light towards the floor. If there is no object between the light-emitting unit 24 and the light-receiving unit 26, the laser light will be received by the light-receiving unit 26.

[0152] On the other hand, if the detection area DA is not manually set (step S102: No), the detection control function 55 determines whether to perform contrast-enhanced imaging (step S103). For example, if the imaging information received by the control function 51 includes information indicating contrast-enhanced imaging, the detection control function 55 determines to perform contrast-enhanced imaging.

[0153] If contrast imaging is not performed (Step S103: No), the detection control function 55 enables all laser sensors 23 (Step S109) and proceeds to the process of Step S110 described later. On the other hand, if contrast imaging is performed (Step S103: Yes), it is determined whether the subject P is in a seated position (Step S104).

[0154] For example, if the posture information received by the control function 51 indicates a seated position for imaging, the detection control function 55 determines that the subject P's imaging posture is seated. On the other hand, if the posture information received by the control function 51 indicates a standing position for imaging, the detection control function 55 determines that the subject P's imaging posture is not seated.

[0155] If the imaging is performed in a seated position (Step S104: Yes), the detection control function 55 activates some predetermined laser sensors 23 according to the manually set detection area DA (Step S108), and proceeds to the process of Step S110 described later. On the other hand, if the imaging is not performed in a seated position (Step S104: No), the detection control function 55 determines whether the pole 70 has been detected (Step S105).

[0156] For example, the detection control function 55 acquires an image captured by a camera positioned to capture images within the central opening 19, and determines that a pole 70 has been detected if a pole 70 is detected in the captured image using known image recognition technology. If a pole 70 is not detected (step S105: No), the process in step S105 is repeated.

[0157] Furthermore, if the pole 70 cannot be detected even after a predetermined time has elapsed since the start of the process for detecting the pole 70, the control function 51 may display a message on the display panel 42a or the like prompting the operator to check whether the pole 70 is properly installed.

[0158] On the other hand, if pole 70 is detected (step S105: Yes), the detection control function 55 activates some of the laser sensors 23 according to the pole's installation position (step S107).

[0159] For example, the detection and control function 55 analyzes the captured image in which the pole 70 is detected using known image recognition technology to determine which of the first installation location IP1 to the third installation location IP3 in Figure 7 the pole 70 is installed in. The detection and control function 55 refers to the correspondence information stored in the memory 41, etc., and enables the laser sensors 23 other than the laser sensor 23 associated with the identified installation location.

[0160] Next, the control function 51 operates the scanner 20 and starts irradiating the subject P with X-rays (X-ray CT imaging of the subject P) (step S110). Then, the detection function 56 determines whether at least one laser sensor 23 is in an active state (step S111).

[0161] For example, if the laser sensor 23 is enabled in any of steps S106 to S109, the detection function 56 determines that at least one of the laser sensors 23 is enabled.

[0162] If the laser sensor 23 is not in an active state (step S111: No), the process proceeds to step S113, which will be described later. On the other hand, if the laser sensor 23 is in an active state (step S111: Yes), the detection function 56 determines whether the laser light has been blocked by at least one of the active laser sensors 23 (step S112).

[0163] For example, if at least one of the light-receiving units 26 of the active laser sensor 23 fails to receive laser light for a predetermined period of time, the detection function 56 determines that at least one of the active laser sensors 23 has blocked the laser light.

[0164] If the laser beam is blocked (step S112: Yes), the control function 51 stops the operation of the scanner 20 (step S116) and terminates this process. On the other hand, if the laser beam is not blocked (step S112: No), the detection control function 55 determines whether it has received an instruction from the operator to end the shooting process (step S113). If it has not received an instruction to end the shooting process (step S113: No), the process returns to step S111.

[0165] On the other hand, if an instruction to end shooting is received (step S113: Yes), the detection function 56 determines whether at least one laser sensor 23 is active, similar to step S111 (step S114). If the laser sensor 23 is not active (step S114: No), this process is terminated.

[0166] On the other hand, if the laser sensor 23 is enabled (step S114: Yes), the detection control function 55 disables all laser sensors 23 (step S115) and terminates this process.

[0167] As described above, the X-ray CT apparatus 1 according to the first embodiment detects the presence of an object in the detection area DA, which is at least a portion of the area between the outer periphery of the central aperture 19 and the subject P in the XZ plane, and controls the apparatus to exclude areas in the XZ plane where the movement of the subject is restricted during imaging as non-detection areas from the detection area DA. If the presence of an object is detected in the detection area DA while the scanner 20 is operating, the scanner 20 stops operating.

[0168] Incidentally, when performing contrast imaging of a subject using an X-ray CT scanner, the injector tube is passed through the opening of the scanner from outside to inside the opening. In other words, in this case, the tube is located between the scanner and the floor. Therefore, if, for example, an optical sensor is used to detect the presence of a subject between the scanner and the floor, the light emitted from the light-emitting part of the optical sensor may be blocked by the tube, potentially leading to a false determination that the subject is present between the scanner and the floor. Such a false determination may cause the scanner to stop during imaging of the subject, and if the scanner stops during imaging of the subject, there is a high possibility that the imaging will have to be repeated, which could lead to unnecessary radiation exposure of the subject.

[0169] In contrast, the X-ray CT apparatus 1 according to this embodiment performs control to exclude areas in the XZ plane where the movement of the subject is restricted during imaging from the detection area DA as non-detection areas, as described above. Therefore, even if an object exists between the scanner 20 and the floor in an area in the XZ plane where the movement of the subject is restricted during imaging, the operation of the scanner 20 will not stop. Consequently, if a tube is placed in this area, the operation of the scanner 20 will not stop even if a tube exists between the scanner 20 and the floor. In other words, the X-ray CT apparatus 1 according to the first embodiment can reduce the possibility that the scanner 20 may stop operating due to misidentifying an object that may exist between the scanner 20 and the floor during imaging of the subject P as the subject P.

[0170] (Second Embodiment) In the first embodiment described above, a method was described in which the possibility of misidentifying an object that is not the subject P as the subject P is reduced by changing the detection area DA of the laser sensor 23. In the second embodiment, a method will be described in which the possibility of misidentifying an object that is not the subject P as the subject P is reduced based on the detection result of the laser sensor 23.

[0171] In the following, we will mainly describe the differences from the embodiments described above, and will omit detailed explanations of points that are common to those already described. Furthermore, each embodiment described below may be implemented individually or in combination as appropriate.

[0172] First, the configuration of the X-ray CT apparatus 1a according to the second embodiment will be described. Figure 13 is a block diagram showing an example of the configuration of the X-ray CT apparatus 1a according to the second embodiment. The X-ray CT apparatus 1a according to the second embodiment has substantially the same configuration as the X-ray CT apparatus 1 in Figure 1, but differs from the X-ray CT apparatus 1 in Figure 1 in that it has a console device 40a.

[0173] Furthermore, the console device 40a has substantially the same configuration as the console device 40 according to the first embodiment in Figure 1, but differs from the console device 40 in Figure 1 in that it has a processing circuit 50a. Also, the processing circuit 50a has substantially the same configuration as the processing circuit 50 in Figure 1, but differs from the processing circuit 50 in Figure 1 in that it has a detection control function 55a and a detection function 56a.

[0174] The detection control function 55a activates all laser sensors 23 when the subject P is in an upright or seated position for imaging. For example, if the posture information of the subject P received by the control function 51 indicates that the subject is in an upright or seated position, the detection control function 55a switches all laser sensors 23 to an activated state.

[0175] The detection function 56a detects the subject P and objects other than the subject P in the detection area DA. For example, the detection function 56a determines whether the subject P or an object other than the subject P has been detected based on the number of laser sensors 23 that have determined that adjacent laser beams have been blocked.

[0176] Here, even if there is a laser sensor 23 that determines that multiple laser beams have been blocked, if there is no laser sensor 23 that determines that adjacent laser beams have been blocked, the number of laser sensors 23 that determine that adjacent laser beams have been blocked is considered to be 1.

[0177] Specifically, if the number of laser sensors 23 that have determined that adjacent laser beams have been blocked is greater than or equal to a threshold, the detection function 56a determines that the subject P has been detected in the detection area DA. On the other hand, if the number of laser sensors 23 that have determined that adjacent laser beams have been blocked is less than the threshold, the detection function 56a determines that an object other than the subject P has been detected in the detection area DA.

[0178] Here, Figures 14 and 15 illustrate an example of the process for determining whether a subject P according to the second embodiment has been detected or whether an object other than the subject P has been detected.

[0179] Figures 14 and 15 are unfolded views of the circularly arranged light-emitting units 24a to 24l and light-receiving units 26a to 26l. In the example shown in Figures 14 and 15, laser beams 27a to 27l are emitted from each of the light-emitting units 24a to 24l toward the light-receiving units 26a to 26l.

[0180] Figure 14 shows an example of a case where it is determined that an object other than the subject P is detected in the detection area DA. Figure 15 shows another example of a case where it is determined that an object other than the subject P is detected in the detection area DA. In Figures 14 and 15, the threshold for the number of laser sensors 23 in which adjacent laser beams are determined to be blocked is assumed to be 2.

[0181] In the example shown in Figure 14, tube T is blocking the laser beam 27b emitted from light-emitting unit 24b. In this case, only laser sensor 23b is determined to be blocking the laser beam, so the detection function 56a determines that the number of laser sensors 23 that have determined adjacent laser beams are blocked is 1. Since the number of laser sensors 23 that have determined adjacent laser beams are blocked is less than the threshold, the detection function 56a determines that an object other than the subject P has been detected in the detection area DA.

[0182] As shown in Figure 14, if the distance between laser sensors 23 is XX mm, and the number of laser sensors 23 that determined that adjacent laser beams were blocked is 1, then it can be seen that the size of the object that blocked the laser beams is less than 2 × XX mm. This is because if the size of the object is 2 × XX mm or larger, the number of laser sensors 23 that determined that adjacent laser beams were blocked will always be 2 or more.

[0183] In other words, in the examples of Figures 14 and 15, the detection function 56a determines that an object other than the subject P has been detected in the detection area DA if it can determine that the size of the object that has blocked the laser light is less than 2 × XX mm.

[0184] Furthermore, in the example shown in Figure 15, the arm of the subject P is blocking the laser beams 27a to 27f emitted from the respective light-emitting units 24b to 24f. In this case, five laser sensors 23b to 23f determine that the laser beam is blocked, so the detection function 56a determines that the number of laser sensors 23 that determined adjacent laser beams were blocked is 5. Since the number of laser sensors 23 that determined adjacent laser beams were blocked is greater than or equal to the threshold, the detection function 56a determines that the subject P has been detected in the detection area DA.

[0185] As shown in Figure 15, if the distance between laser sensors 23 is XX mm, and the number of laser sensors 23 that determined that adjacent laser beams were blocked is 2 or more, then it can be determined that the size of the object blocking the laser beam is XX mm or larger. This is because if the size of the object is less than XX mm, the number of laser sensors 23 that determined that adjacent laser beams were blocked will not be 2 or more.

[0186] In other words, in the examples of Figures 14 and 15, the detection function 56a determines that the subject P has been detected in the detection area DA when it is determined that the size of the object blocking the laser light is XX mm or larger.

[0187] Furthermore, the control function 51 controls the scanner drive unit 22 to stop the operation of the scanner 20 only when the detection function 56a determines that the subject P has been detected in the detection area DA. In other words, the control function 51 will not stop the operation of the scanner 20 if the detection function 56a determines that an object other than the subject P has been detected in the detection area DA.

[0188] As a result, the X-ray CT apparatus 1a according to the second embodiment can prevent the scanner 20 from stopping due to an object such as a tube being mistakenly identified as the subject P.

[0189] Furthermore, the detection function 56a may, only when performing contrast imaging, perform a process to determine whether the subject P was detected or an object other than the subject P was detected, based on the number of laser sensors 23 that have determined that adjacent laser beams have been blocked.

[0190] Furthermore, the control function 51 may also provide notification regarding whether or not it is acceptable for the laser sensor 23 to be shielded from light, and whether or not an object other than the subject P has been detected.

[0191] For example, the control function 51 may provide notification regarding the combination of the state of the laser sensor 23 (enabled or disabled) and the detection state of objects other than the subject P (present or absent). In this case, the control function 51 will also detect objects other than the subject P outside the detection area DA (the laser sensor 23 in the disabled state).

[0192] For the sake of clarity, the following combinations of the laser sensor 23 status (enabled / disabled) and the detection status of objects other than the subject P (present / absent) will be expressed as "Laser sensor 23: enabled / disabled, object detection: present / absent".

[0193] As an example, the control function 51 may display on the display 42 a display screen that distinguishes between "Laser sensor 23: enabled, object detection: present", "Laser sensor 23: enabled, object detection: absent", "Laser sensor 23: disabled, object detection: present", and "Laser sensor 23: disabled, object detection: absent" (for example, by changing the display color) instead of the detection area DA (area sensor effective range) shown in Figure 11 above.

[0194] This allows an operator performing tasks such as adjusting the position of a tube to perform their work while confirming whether the location is suitable for the laser sensor 23 to be shielded from light, and whether any objects other than the subject P are being detected.

[0195] In addition, similar to the notification of the detection area DA in the first embodiment described above, the above notification may be performed using a display, projector, floor-embedded display, etc.

[0196] Next, the processing performed by the X-ray CT apparatus 1a according to the second embodiment will be described. Figure 16 is a flowchart showing an example of the processing performed by the X-ray CT apparatus 1a according to the second embodiment. As a prerequisite, it is assumed that the control function 51 receives input of imaging conditions from the operator. The processing in step S201 of Figure 16 is the same as in step S101 of Figure 12A, so the explanation will be omitted.

[0197] If the imaging is performed in a supine position (Step S201: Yes), the process proceeds to Step S203, which will be described later. On the other hand, if the imaging is not performed in a supine position (Step S201: No), the detection control function 55a enables all laser sensors 23 (Step S202). The process of Step S203, which is executed next, is the same as Step S110 in Figure 12B, so its explanation is omitted.

[0198] After step S203, the detection function 56a determines whether the laser sensor 23 is enabled (step S204). For example, the detection function 56a determines that the laser sensor 23 is enabled if all laser sensors 23 are enabled in step S202. If the laser sensor 23 is not enabled (step S204: No), the process proceeds to step S207, which will be described later.

[0199] On the other hand, if the laser sensor 23 is enabled (step S204: Yes), the detection function 56a determines whether the laser light is blocked by at least one of the laser sensors 23, similar to step S112 in Figure 12B (step S205). If the laser light is not blocked (step S205: No), the process proceeds to step S207.

[0200] On the other hand, if the laser light is blocked (step S205: Yes), the detection function 56a determines whether the number of laser sensors 23 that have determined that adjacent laser light has been blocked is equal to or greater than a threshold (step S206).

[0201] If the number of laser sensors 23 that have determined that adjacent laser beams have been blocked is equal to or greater than a threshold (step S206: Yes), the control function 51 stops the operation of the scanner 20 (step S210), similar to step S116 in Figure 12B, and terminates this process.

[0202] On the other hand, if the number of laser sensors 23 that have determined that adjacent laser beams have been blocked is less than the threshold (step S206: No), the detection control function 55 determines whether it has received an instruction from the operator to end the shooting process, similar to step S113 in Figure 13 (step S207). If it has not received an instruction to end the shooting process (step S207: No), the process returns to step S204.

[0203] On the other hand, if the instruction to end shooting is received (step S207: Yes), the detection function 56a determines whether the laser sensor 23 is active, similar to step S204 (step S208). If the laser sensor 23 is not active (step S208: No), this process is terminated.

[0204] On the other hand, if the laser sensor 23 is enabled (step S208: Yes), the detection control function 55a disables all laser sensors 23 (step S209), similar to step S115 in Figure 12B, and terminates this process.

[0205] As described above, the X-ray CT apparatus 1a according to the second embodiment uses a detection area DA as at least a portion of the area between the outer periphery of the central aperture 19 in the XZ plane and the subject P, and detects the presence of the subject P and other objects in the detection area DA. If the presence of an object other than the subject P is detected in the detection area DA while the scanner 20 is operating, the scanner 20 stops operating.

[0206] As a result, the X-ray CT apparatus 1a according to the second embodiment can stop the operation of the scanner 20 only when it detects the presence of a subject P in the detection area DA. Therefore, even if an object other than the subject P, such as a tube, is present between the scanner 20 and the floor surface during imaging of the subject P, the operation of the scanner 20 will not stop. In other words, the X-ray CT apparatus 1a according to the second embodiment can reduce the possibility of the scanner 20 stopping its operation due to misidentification of an object that may be present between the scanner 20 and the floor surface as the subject P during imaging of the subject P.

[0207] The above-described embodiment can also be modified and implemented as appropriate by changing some of the configurations or functions of the X-ray CT apparatus 1. Therefore, the following describes modified examples of the above-described embodiment as other embodiments. In the following, we will mainly describe the differences from the above-described embodiment, and will omit detailed explanations of points that are common with what has already been described. Furthermore, the modified examples described below may be implemented individually or in combination as appropriate.

[0208] (Variation 1) In the first embodiment described above, a configuration was described in which the detection control function 55 activates a predetermined number of laser sensors 23 when the posture information of the subject P is seated and the imaging information includes information indicating contrast-enhanced imaging.

[0209] However, the detection control function 55 may also enable some predetermined laser sensors 23 even when the subject P's posture information indicates standing imaging and the imaging information includes information indicating contrast-enhanced imaging. Furthermore, the detection control function 55 may enable different laser sensors 23 for standing and sitting imaging.

[0210] According to this modified version, when photographing a subject P in a standing position, it is possible to reduce the possibility that the scanner 20 may stop operating due to misidentifying an object that may be present between the scanner 20 and the floor surface as the subject P, even without performing a process to determine the installation position of the pole 70.

[0211] (Modification 2) In the first embodiment described above, a configuration was described in which the detection control function 55 activates some of the laser sensors 23 according to the installation position of the pole 70 when the posture information of the subject P is for standing imaging and the imaging information includes information indicating contrast imaging.

[0212] In this modified example, the forward direction is set in advance, and when the imaging information includes information indicating contrast imaging, the detection control function 55 activates some of the laser sensors 23 according to the forward direction.

[0213] In this modified example, the control function 51 sets the direction of the front by receiving input from the operator specifying the laser sensors 23a to 23l via a front setting screen (not shown) displayed on the display 42 for setting the direction of the front. Hereinafter, setting the direction of the front will also be referred to as front setting.

[0214] Furthermore, the corresponding information in this modified example is information that associates with information identifying the laser sensor 23 to be disabled.

[0215] Specifically, the correspondence information in this modified example stores information identifying the laser sensor 23 that represents the front direction and information identifying the laser sensor 23 that is furthest from the laser sensor 23 that represents the front direction, in association with each other.

[0216] More specifically, if the laser sensor 23 representing the front direction is laser sensor 23a, then in the correspondence information, the information identifying the laser sensor 23a representing the front direction is associated with the information identifying the laser sensor 23g, which is the information identifying the laser sensor 23 to be disabled.

[0217] Furthermore, in the correspondence information, information identifying one laser sensor 23 representing a single front direction may be associated with information identifying two or more laser sensors 23 to be disabled.

[0218] Here, Figure 17 is a top view showing an example of the detection area DA determined according to the front setting in Modification 2. Figure 17 shows the detection area DA when the front setting is set with the laser sensor 23a facing forward.

[0219] In this example, the detection control function 55 refers to the correspondence information stored in the memory 41, etc., and identifies laser sensor 23g as the laser sensor 23 to be disabled, based on the information identifying laser sensor 23g associated with the information identifying laser sensor 23a that is set to the front. Then, the detection control function 55 enables all laser sensors 23 other than the identified laser sensor 23g.

[0220] In other words, in this case, the detection area of ​​the other laser sensors 23, excluding laser sensor 23g, is an example of the detection area of ​​the detection unit. Also, the detection area of ​​laser sensor 23g is an example of the non-detection area of ​​the detection unit.

[0221] Furthermore, in this modified example, the detection control function 55 may, only when the front setting is not performed, activate some of the laser sensors 23 according to the installation position of the pole 70, similar to the first embodiment.

[0222] According to this modified example, even when the pole 70 is not installed, such as when performing seated imaging of subject P, the operator can exclude any position from the detection area DA as a non-detection area.

[0223] (Variation 3) In the first embodiment described above, a configuration was described in which the detection control function 55 activates some of the laser sensors 23 according to the installation position of the pole 70 when the posture information of the subject P is for standing imaging and the imaging information includes information indicating contrast imaging.

[0224] In this modified example, when the posture information of the subject P is seated and the imaging information includes information indicating contrast-enhanced imaging, the detection control function 55 activates some of the laser sensors 23 according to the installation position and orientation of the subject support member, such as a chair or wheelchair used for imaging.

[0225] The corresponding information for this modification is information that associates information representing the installation position and orientation of a subject support member such as a chair or wheelchair for imaging (hereinafter also referred to as "chair, etc.") with information identifying the laser sensor 23 to be disabled. The chair, etc. is an example of a subject support member.

[0226] Specifically, the correspondence information for this modified example stores information representing the installation position and orientation of the chair, etc., and information identifying the laser sensor 23 closest to the backrest or other support member of the chair, etc. that supports the back of the subject P, when the chair, etc. is installed in that position and orientation.

[0227] Furthermore, in the correspondence information, information representing the installation position and orientation of chairs, etc., may be associated with information identifying two or more laser sensors 23 to be disabled (for example, the top 5% of laser sensors 23 furthest from the member supporting the back of the subject P). Alternatively, the correspondence information may associate information representing the installation position of chairs, etc., with information identifying the laser sensors 23 to be disabled.

[0228] In this modified version, the detection and control function 55 acquires an image captured by a camera positioned to capture images within the central opening 19 when the subject P's posture information indicates a seated position and the captured information includes information indicating contrast-enhanced imaging. Next, the detection and control function 55 identifies the installation position and orientation of the chair, etc., using known image recognition technology.

[0229] Next, the detection and control function 55 refers to the correspondence information stored in the memory 41, etc., and identifies the laser sensor 23 to be disabled from the information that identifies the laser sensor 23 to be disabled, which is associated with the information representing the installation position and orientation of the identified chair, etc. Then, the detection and control function 55 enables the laser sensors 23 other than the identified laser sensor 23.

[0230] In this case, the detection area of ​​the laser sensor 23 other than the laser sensor 23 identified as being deactivated is an example of the detection area of ​​the detection unit. Also, the detection area of ​​the laser sensor 23 identified as being deactivated is an example of the non-detection area of ​​the detection unit.

[0231] According to this modified version, even when performing seated imaging and contrast imaging, the detection area of ​​the laser sensor 23 can be changed based on the position of the member supporting the subject during imaging. In other words, according to this modified version, the possibility that the scanner 20 may stop operating due to misidentifying an object that may be present between the scanner 20 and the floor surface as the subject P during imaging of the subject P can be reduced.

[0232] (Modification 4) In the first embodiment described above, a configuration was described in which the detection control function 55 individually enables or disables each of the laser sensors 23a to 23l. In this modified example, a configuration is described in which the laser sensors 23a to 23l are grouped together, and the detection control function 55 enables or disables them as a group.

[0233] In this modified example, the laser sensor 23 is divided into three groups: a first region DA1, a second region DA2, and a third region DA3. The first region DA1, the second region DA2, and the third region DA3 are examples of group regions. The information defining the grouping of the laser sensor 23 is stored in memory 41 or the like.

[0234] Furthermore, the correspondence information in this modified example is information that associates the installation location of pole 70 with the area to be disabled. Specifically, the correspondence information in this modified example stores the installation location of pole 70 with the area closest to that installation location.

[0235] As a result, the detection control function 55 of this modified version can activate the laser sensor 23 belonging to any region other than the region closest to the installation position of the pole 70 among the first region DA1 to the third region DA3 by referring to the corresponding information when the posture information of the subject P is a seated position and the imaging information includes information indicating contrast imaging.

[0236] Here, Figure 18 is a top view illustrating an example of the positional relationship between the installation position of pole 70 and the area in which it becomes effective, according to Modification 4. In the example of Figure 18, the area closest to the installation position of pole 70 is the third area DA3. In other words, in the correspondence information, the installation position of the pole in Figure 18 is associated with the third area DA3.

[0237] Therefore, in the example shown in Figure 18, the detection control function 55 refers to the corresponding information and identifies the third region DA3 as a region to be disabled. The detection control function 55 then enables the laser sensors 23 belonging to the first region DA1 and the second region DA3, which are not the third region DA3.

[0238] Furthermore, in this modified example, when manually setting the detection area, the detection control function 55 receives input from the operator via a detection area setting screen (not shown) displayed on the display panel 42a, etc., to enable or disable each of the first area DA1 to the third area DA3. The detection control function 55 changes the detection area of ​​the laser sensor 23 according to the received input.

[0239] For example, when the detection control function 55 receives an instruction from the operator to disable the first region DA1 and enable the other regions, it disables the laser sensor 23 belonging to the first region DA1 and enables the laser sensors 23 belonging to the second region DA2 and the third region DA3.

[0240] In other words, in this case, the detection areas of the laser sensor 23 belonging to the second region DA2 and the third region DA3 are examples of the detection areas of the detection unit. Also, the detection area of ​​the laser sensor 23 belonging to the first region DA1 is an example of the non-detection areas of the detection unit.

[0241] Furthermore, in this modified version, the detection control function 55 activates a laser sensor 23 belonging to a predetermined region among the first region DA1 to the third region DA3 when the posture information of the subject P indicates a seated position and the imaging information includes information indicating contrast-enhanced imaging.

[0242] According to this modified version, the detection area of ​​the laser sensor 23 is determined on a group (region) basis, so when the detection area of ​​the laser sensor 23 is displayed, it is thought that the operator will be able to visually understand which areas are detected and which are not.

[0243] (Variation 5) In the first embodiment described above, when the posture information of the subject P indicates that the imaging is performed in an upright position and the imaging information includes information indicating contrast-enhanced imaging, the detection control function 55 activates the laser sensors 23 other than the laser sensor 23 closest to the installation position of the pole 70 (first installation position IP1 to third installation position IP3).

[0244] In this modified example, when the posture information of the subject P is for standing imaging and the imaging information includes information indicating contrast imaging, the detection control function 55 activates the laser sensors 23 other than the laser sensor 23 located in the area behind the pole 70 as seen from the subject P.

[0245] Furthermore, the correspondence information in this modified example is information that associates the installation position of the pole 70 with information that identifies the multiple laser sensors 23 to be disabled. Specifically, the correspondence information in this modified example stores the installation position of the pole 70 and the identification information of each of the multiple laser sensors 23 that are located in the area behind the pole 70 from the perspective of the subject P when the pole 70 is installed at that installation position.

[0246] Here, Figure 19 is a top view illustrating an example of the positional relationship between the installation position of the pole 70 and the laser sensor 23 that becomes active, according to Modification 5. In the example of Figure 19, the area shown by the thick diagonal lines is the area behind the pole 70 when the pole 70 is installed at the position shown in Figure 19, as seen from the subject P.

[0247] In other words, in the correspondence information for the example in Figure 19, the installation position of the pole shown in Figure 19 is associated with the identification information of the multiple laser sensors 23 located in the area represented by the thick diagonal lines.

[0248] Therefore, in the example shown in Figure 19, the detection control function 55 refers to the correspondence information and identifies the multiple laser sensors 23 located in the area indicated by the thick diagonal lines as laser sensors 23 to be disabled. The detection control function 55 then enables the laser sensors 23 belonging to the first area DA1 and the second area DA3, excluding the identified laser sensors 23.

[0249] In this case, the detection areas of the laser sensors 23 other than the multiple laser sensors 23 located in the area represented by thick diagonal lines in Figure 19 are examples of the detection areas of the detection unit. Also, the detection areas of the multiple laser sensors 23 located in the area represented by thick diagonal lines in Figure 19 are examples of the non-detection areas of the detection unit.

[0250] According to this modified example, the area in which tubes can be placed can be increased compared to the first embodiment.

[0251] (Experimental variation 6) In the modified example 5 described above, when the posture information of the subject P is for standing imaging and the imaging information includes information indicating contrast imaging, the detection control function 55 activates all laser sensors 23 other than all laser sensors 23 located in the area behind the pole 70 as seen from the subject P.

[0252] However, in this case, the detection control function 55 may enable some of the laser sensors 23 that are located in the area behind the pole 70 as seen from the subject P.

[0253] Here, Figure 20 is a top view illustrating an example of the positional relationship between the installation position of the pole 70 and the laser sensor 23 that becomes active, according to Modification 6. In the correspondence information of the example in Figure 20, the installation position of the pole shown in Figure 20 is associated with the identification information of the multiple laser sensors 23 located in the area represented by thick diagonal lines.

[0254] Specifically, in the correspondence information shown in the example in Figure 20, the installation position of the pole 70 is associated with the identification information of each of the multiple laser sensors 23 located in the 120° rear region, where the area directly behind the installation position of the pole 70 is defined as 0° rearward, and this association is stored.

[0255] In this case, the detection areas of the laser sensors 23 other than the multiple laser sensors 23 located in the area indicated by thick diagonal lines in Figure 20 are an example of the detection area of ​​the detection unit. Also, the detection areas of the multiple laser sensors 23 located in the area indicated by thick diagonal lines in Figure 20 are an example of the non-detection area of ​​the detection unit.

[0256] As shown in Figures 19 and 20, the area represented by the thick diagonal lines in Figure 20 is narrower than the area represented by the thick diagonal lines in Figure 19. In other words, in Modification 6, the detection area of ​​the laser sensor 23 can be widened compared to Modification 5.

[0257] (Example 7) In the first embodiment described above, a configuration was described in which the control function 51 causes a display screen 421 that notifies the detection area DA to be displayed on the display 42 (display panel 42a). In this modified example, a configuration is described in which the control function 51 causes a display screen that notifies the tube installation area to be displayed on the display 42. The tube installation area is an example of a non-detection area.

[0258] Here, Figure 21 shows an example of a display screen 422 that notifies the area where the tube can be installed according to the modified example 7. As shown in Figure 21, the display screen 422 displays the area other than the detection area DA as the area where the tube can be installed. The display screen 422 also displays a message prompting the user to place the tube within the area where the tube can be installed.

[0259] This allows the operator to adjust the position of the tube so that it is outside the detection area DA before starting imaging of the subject P. By positioning the tube outside the detection area DA, the X-ray CT apparatus 1 according to this modification can prevent the tube from being mistakenly identified as the subject P and causing the scanner 20 to stop operating.

[0260] (Variation 8) In the second embodiment described above, the detection function 56a determined whether the subject P was detected or an object other than the subject P was detected based on the number of laser sensors 23 that determined that adjacent laser beams were blocked. In this modification, the laser sensor 23 is a cross-beam type, and the determination of whether the subject P was detected or an object other than the subject P was detected is described based on the height of the object and the size of the area blocked by the object.

[0261] In this modified example, the light-emitting unit 24 emits laser light such that the laser beam intersects with the light-receiving unit 26 in the vertical direction.

[0262] The detection function 56a in this modified version identifies the height of the object that blocked the laser beam and the size of the area blocked by the object, depending on how the laser beam was blocked (hereinafter also referred to as the blocking pattern). The detection function 56a determines whether the subject P was detected or whether an object other than the subject P was detected.

[0263] Here, Figure 22 illustrates an example of the process for determining whether a subject (related to Modification 8) or an object other than the subject has been detected. Figure 22 is an unfolded view of the light-emitting units 24a to 24l and light-receiving units 26a to 26l, which are arranged in a circular pattern, similar to Figures 14 and 15.

[0264] As shown in Figure 22, each of the light-emitting units 24a to 24h emits laser beams 27aa to 27ha diagonally downward toward each of the light-receiving units 26e to 26l. Similarly, each of the light-emitting units 24e to 24l emits laser beams 26eb to 27lb diagonally downward toward each of the light-receiving units 26e to 26l.

[0265] Furthermore, although not shown in the diagram for the sake of simplification, each of the light-emitting units 24a to 24d emits laser light diagonally downwards toward each of the light-receiving units 26i to 26l. Similarly, each of the light-emitting units 24i to 24l emits laser light diagonally downwards toward each of the light-receiving units 26a to 26d.

[0266] As a result, in the vertical direction, the laser beams 27 projected by each of the light-emitting units 24a to 24l toward each of the light-receiving units 26e to 26d intersect with the laser beams 27 projected by each of the light-emitting units 24a to 24l toward each of the light-receiving units 26i to 26h.

[0267] By intersecting the laser beams 27 emitted from the light-emitting unit 24 in this manner, the detection function 56a can identify the vertical position (height of the object) of the object that blocked the laser beams 27, and the area blocked by the object, from the combination of laser beams 27 that it has determined to be blocked.

[0268] In the example shown in Figure 22, tube T shields the laser beams 27ca and 27jb. In this example, it can be seen that tube T is located lower to the light-receiving section 26 in the vertical direction. It can also be seen that the area indicated by the dot pattern is shielded by tube T.

[0269] In this case, the tube is generally positioned close to the floor in the vertical direction. Therefore, in this modified example, the detection function 56a determines that it has detected an object other than the subject P in the detection area DA if it identifies from the occlusion pattern that an object exists at a position lower than a predetermined height.

[0270] Furthermore, the larger the object blocking the laser light, the larger the area blocked by the object. Therefore, in this modified example, the detection function 56a determines that the subject P has been detected in the detection area DA if it identifies from the blocking pattern that an area larger than a predetermined size is blocked by an object.

[0271] Furthermore, if the determination based on the object's height differs from the determination based on the size of the occluded area, the detection function 56a may decide in advance which to prioritize and determine whether it has detected the subject P or an object other than the subject P in the detection area DA accordingly.

[0272] Furthermore, the detection function 56a may determine that the subject P has been detected in the detection area DA if it determines that the subject P has been detected in the detection area DA based on either the determination based on the height of the object or the determination based on the size of the occluded area. Alternatively, the detection function 56a may determine that the subject P has been detected in the detection area DA only if it determines that the subject P has been detected in the detection area DA based on both the determination based on the height of the object and the determination based on the size of the occluded area.

[0273] In this modified example, the operator can set the detection area DA based on the detection result of objects other than the subject P by the detection function 56a. The workflow for setting the detection area DA in this modified example will be described below.

[0274] As an example, before performing a main scan of a subject P, an operator determines the arrangement of a tube during the main scan of the subject P. Next, the operator actually arranges the tube according to the determination, and causes an X-ray CT apparatus 1a to detect the tube with a laser sensor 23. Then, the operator determines the laser sensor 23 to be set to an invalid state based on the tube detection result, thereby determining (setting) a detection area DA.

[0275] Further, in the present modified example, during the operation of the scanner 20 (the scan of the subject P), it is possible to determine whether to continue or stop the operation of the scanner 20 based on the detection result of an object including the subject P by the detection function 56a.

[0276] Hereinafter, a process of determining whether to continue or stop the operation of the scanner 20 will be described. FIG. 23 is a flowchart illustrating an example of processing executed by the X-ray CT apparatus 1a according to Modification 8.

[0277] First, the control function 51 performs an up-down operation of the scanner 20 (step S301). For example, the control function 51 controls a scanner driving device 22 to perform the up-down operation of the scanner 20. Next, the detection function 56a determines whether the laser beam is blocked, similarly to step S205 in FIG. 16 (step S302). If the laser beam is not blocked (step S302: No), the process proceeds to the process of step S306 described later.

[0278] On the other hand, if the laser beam is blocked (step S302: Yes), the detection function 56a determines whether the laser beam is blocked by an object other than the subject P (step S303).

[0279] For example, when the detection function 56a identifies from the shielding pattern that an area smaller than a predetermined size is shielded by an object, the detection function 56a determines that the laser beam is blocked by an object other than the subject P. On the other hand, when the detection function 56a identifies from the shielding pattern that an area of a predetermined size or larger is shielded by an object, the detection function 56a determines that the laser beam is blocked by the subject P.

[0280] If it is determined that the laser beam is blocked by the subject P (step S303: No), the process proceeds to step S305, which will be described later. On the other hand, if it is determined that the laser beam is blocked by an object other than the subject P (step S303: Yes), the detection function 56a determines whether the blocking position is outside the interference range (step S304).

[0281] For example, if the detection function 56a identifies from the occlusion pattern that an object is located below a predetermined height, it determines that the occlusion position is outside the interference range. On the other hand, if the detection function 56a identifies from the occlusion pattern that an object is located above a predetermined height, it determines that the occlusion position is within the interference range.

[0282] If the control function 51 determines that the light-shielding position is outside the interference range (step S304: Yes), the control function 51 continues the operation of the scanner 20 (step S306).

[0283] Next, the control function 51 determines whether it has received an instruction from the operator to end the shooting process, similar to step S113 in Figure 12B (step S307). If the instruction to end the shooting process has not been received (step S307: No), the process returns to step S301. On the other hand, if the instruction to end the shooting process has been received (step S307: Yes), this process ends.

[0284] Furthermore, if it is determined in step S304 that the light-shielding position is within the interference range (step S304: No), the control function 51 stops the operation of the scanner 20 (step S306) and returns to the process in step S301. For example, the control function 51 controls the scanner drive unit 22 to stop the up-and-down movement of the scanner 20.

[0285] The above describes an example in which the X-ray CT apparatus 1a determines whether to continue or stop the operation of the scanner 20 based on the detection result of the detection function 56a. However, the X-ray CT apparatus 1a may also perform control to switch the enabled / disabled state of the laser sensor 23 based on the detection result of the detection function 56a, similar to the second embodiment described above.

[0286] According to this modified version, it is possible to more accurately determine whether the subject P was detected in the detection region DA or whether an object other than the subject P was detected.

[0287] According to at least one embodiment described above, the possibility of the device stopping due to misidentifying an object that may be present between the scanner and the floor surface during imaging as the subject can be reduced.

[0288] While several embodiments have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0289] [Note] The various aspects of this disclosure are summarized below as an appendix. [Note 1] A scanner unit with an imaging system, A support unit that supports the scanner unit and moves the scanner unit in the vertical direction, A detection unit that detects the presence of an object in a detection area, which is defined as at least a portion of the area between the outer circumference of the opening into which the subject is inserted and the subject itself. A detection control unit that controls the detection area included in the area where the movement of the subject is restricted to become a non-detection area, If the presence of the object is detected in the detection area excluding the non-detection area during the operation of the scanner unit, the operation control unit stops the operation of the scanner unit. An X-ray CT scanner equipped with [specific features / features]. [Note 2] The detection control unit, when taking images of the subject in an upright or seated position, controls the area corresponding to the installation position of the subject support member that supports the subject to be designated as the non-detection area. The X-ray CT apparatus according to appendix 1. [Appendix 3] Further comprising a plurality of optical sensors provided in the scanner unit and configured to detect an object, The detection unit detects that an object is present in the detection region based on the respective detection results of the plurality of optical sensors, Control is performed to invalidate at least one optical sensor, among the plurality of optical sensors, that is present in the non-detection region corresponding to the installation position of the subject support member that supports the subject, The X-ray CT apparatus according to appendix 2. [Appendix 4] The detection control unit performs control to set a region including only the optical sensor closest to the installation position of the subject support member among the plurality of optical sensors as the non-detection region, The X-ray CT apparatus according to appendix 3. [Appendix 5] The detection control unit performs control to set a region behind the installation position of the subject support member among the plurality of optical sensors as the non-detection region, The X-ray CT apparatus according to appendix 3. [Appendix 6] The plurality of optical sensors are divided into at least two group regions according to their installed positions, The detection control unit performs control to set the group region closest to the installation position of the subject support member among the plurality of optical sensors as the non-detection region, The X-ray CT apparatus according to appendix 3. [Appendix 7] Further comprising a display control unit configured to cause at least one of the detection region and the non-detection region to be displayed on a display medium, The X-ray CT apparatus according to appendix 1. [Appendix 8] The display medium is a display unit of a display device provided in the support unit, The display control unit causes at least one of the detection region and the non-detection region to be displayed on the display unit, The X-ray CT apparatus according to appendix 7. [Appendix 9] The display medium is at least one of the exterior of the scanner unit and the floor of the examination room where the X-ray CT device is installed. The display control unit uses at least one of the following to display at least one of the detection area and the non-detection area on the exterior or the floor: a plurality of LEDs (light-emitting diodes) provided on the exterior, a projector that projects an image onto the exterior, and a display device embedded in the floor. The X-ray CT scanner described in Appendix 7. [Note 10] The detection control unit defines the area opposite to the direction in which the subject can move during imaging as the non-detection area. The X-ray CT scanner described in Appendix 1. [Note 11] A scanner unit with an imaging system, A support unit that supports the scanner unit and moves the scanner unit in the vertical direction, A detection unit that detects whether the subject is present in the detection area, or whether an object other than the subject is present in the detection area, with the detection area being defined as a detection area being at least a portion of the area between the outer circumference of the opening into which the subject is inserted and the subject itself. If the presence of the subject in the detection area is detected during the operation of the scanner unit, the operation control unit stops the operation of the scanner unit. Equipped with, The operation control unit does not perform any control to stop the operation of the scanner unit if it detects the presence of an object other than the subject in the detection area. X-ray CT device. [Note 12] It is further equipped with multiple optical sensors for detecting objects, Each of the aforementioned plurality of optical sensors comprises a light-emitting unit that emits laser light toward a light-receiving unit, and a light-receiving unit that receives the emitted laser light. The detection unit determines that at least one of the subject and an object other than the subject has been detected in the detection area when the laser light can no longer be received by at least one of the light receiving units. Based on the number of light-receiving units that can no longer receive adjacent laser beams, it is determined whether the subject was detected in the detection area or whether an object other than the subject was detected in the detection area. The X-ray CT scanner described in Appendix 11. [Note 13] Each of the light-emitting sections of the plurality of optical sensors emits laser light such that the laser light intersects between each of the light-emitting sections and each of the light-receiving sections in the vertical direction. The detection unit determines, based on the combination of light-receiving units that can no longer receive the laser light, whether the subject was detected in the detection area or whether an object other than the subject was detected in the detection area. The X-ray CT scanner described in Appendix 12. [Note 14] The detection unit detects objects other than the subject in non-detection areas other than the detection area, based on the combination of light-receiving units that are no longer able to receive the laser light. The X-ray CT apparatus further includes a display unit that distinguishes the area around the scanner unit into "the detection area in which an object other than the subject is detected," "the detection area in which no object other than the subject is detected," "the non-detection area in which an object other than the subject is detected," and "the non-detection area in which an object other than the subject is detected," and presents these to the operator of the X-ray CT apparatus. The X-ray CT scanner described in Appendix 13. [Note 15] A control method for an X-ray CT apparatus comprising a scanner unit having an imaging system and a support unit that supports the scanner unit and moves the scanner unit in the vertical direction, A detection area is defined as at least a portion of the region between the outer circumference of the opening into which the subject is inserted and the subject itself, and objects present in the detection area are detected. Control is performed to define the area where the movement of the subject is restricted as a non-detection area. If, during the operation of the scanner unit, the presence of the object is detected in the detection area excluding the non-detection area, the operation of the scanner unit is stopped. Control method using an X-ray CT scanner. [Note 16] A program to be executed by the computer of an X-ray CT apparatus comprising a scanner unit having an imaging system and a support unit that supports the scanner unit and moves the scanner unit in the vertical direction, A detection area is defined as at least a portion of the region between the outer circumference of the opening into which the subject is inserted and the subject itself, and objects present in the detection area are detected. Control is performed to define the area where the movement of the subject is restricted as a non-detection area. If, during the operation of the scanner unit, the presence of the object is detected in the detection area excluding the non-detection area, the operation of the scanner unit is stopped. program. [Explanation of symbols]

[0290] 1, 1a X-ray CT device 10. Mounting device 11 X-ray tube 12 Wedge 13 Collimator 15 X-ray detector 16 DAS 17 rotation frames 18 Cover 19 Central opening 20 Scanners 22 Scanner drive unit 28 Control device 30 Bed equipment 31 base 32 Bed drive mechanism 33 Top plate 34 Support Frame 40, 40a Console device 42 displays 43 Input Interfaces 50, 50a Processing Circuit 51 Control Functions 52 Pre-processing function 53 Reconstruction Processing Function 54 Image processing functions 55, 55a Detection and control function 56, 56a Detection function 101 Bass 102 Horizontal movement device 103 Support column 104 rails 105 Slider 106 Tilt mechanism

Claims

1. A scanner unit with an imaging system, A support unit that supports the scanner unit and moves the scanner unit in the vertical direction, A detection unit that detects the presence of an object in a detection area, which is defined as at least a portion of the area between the outer circumference of the opening into which the subject is inserted and the subject itself. A detection control unit that controls the detection area included in the area where the movement of the subject is restricted to become a non-detection area, If the presence of the object is detected in the detection area excluding the non-detection area during the operation of the scanner unit, the operation control unit stops the operation of the scanner unit. An X-ray CT scanner equipped with [a specific feature].

2. The detection control unit, when taking images of the subject in an upright or seated position, controls the area corresponding to the installation position of the subject support member that supports the subject to be designated as the non-detection area. The X-ray CT apparatus according to claim 1.

3. The scanner unit is further provided with a plurality of optical sensors for detecting objects, The detection unit detects the presence of an object in the detection area based on the detection results of each of the plurality of optical sensors. Control is performed to disable at least one of the plurality of optical sensors that is located in the non-detection area corresponding to the installation position of the subject support member that supports the subject. The X-ray CT apparatus according to claim 2.

4. The detection control unit performs control to define a detection area as a non-detection area, which includes only the optical sensor closest to the installation position of the specimen support member among the plurality of optical sensors. The X-ray CT apparatus according to claim 3.

5. The detection control unit controls the detection area of ​​the plurality of optical sensors that is located behind the installation position of the specimen support member to be set as the non-detection area. The X-ray CT apparatus according to claim 3.

6. The aforementioned plurality of optical sensors are divided into at least two group regions according to their respective positions. The detection control unit controls the group of optical sensors closest to the installation position of the specimen support member to be designated as the non-detection area. The X-ray CT apparatus according to claim 3.

7. The system further includes a display control unit that causes at least one of the detection area and the non-detection area to be displayed on a display medium. The X-ray CT apparatus according to claim 1.

8. The display medium is the display unit of the display device provided on the support unit, The display control unit causes at least one of the detection area and the non-detection area to be displayed on the display unit. The X-ray CT apparatus according to claim 7.

9. The display medium is at least one of the exterior of the scanner unit and the floor of the examination room where the X-ray CT device is installed. The display control unit uses at least one of the following to display at least one of the detection area and the non-detection area on the exterior or the floor: a plurality of LEDs (light-emitting diodes) provided on the exterior, a projector that projects an image onto the exterior, and a display device embedded in the floor. The X-ray CT apparatus according to claim 7.

10. The detection control unit defines the area opposite to the direction in which the subject can move during imaging as the non-detection area. The X-ray CT apparatus according to claim 1.

11. A scanner unit with an imaging system, A support unit that supports the scanner unit and moves the scanner unit in the vertical direction, A detection unit that detects whether the subject is present in the detection area, or whether an object other than the subject is present in the detection area, with the detection area being defined as a detection area being at least a portion of the area between the outer circumference of the opening into which the subject is inserted and the subject itself. If the presence of the subject in the detection area is detected during the operation of the scanner unit, the operation control unit stops the operation of the scanner unit. Equipped with, The operation control unit does not perform any control to stop the operation of the scanner unit if it detects the presence of an object other than the subject in the detection area. X-ray CT device.

12. It is further equipped with multiple optical sensors for detecting objects, Each of the aforementioned plurality of optical sensors comprises a light-emitting unit that emits laser light toward a light-receiving unit, and a light-receiving unit that receives the emitted laser light. The detection unit determines that at least one of the subject and an object other than the subject has been detected in the detection area when the laser light can no longer be received by at least one of the light receiving units. Based on the number of light-receiving units that can no longer receive adjacent laser beams, it is determined whether the subject was detected in the detection area or whether an object other than the subject was detected in the detection area. The X-ray CT apparatus according to claim 11.

13. Each of the light-emitting sections of the plurality of optical sensors emits laser light such that the laser light intersects between each of the light-emitting sections and each of the light-receiving sections in the vertical direction. The detection unit determines, based on the combination of light-receiving units that can no longer receive the laser light, whether the subject was detected in the detection area or whether an object other than the subject was detected in the detection area. The X-ray CT apparatus according to claim 12.

14. The detection unit detects objects other than the subject in non-detection areas other than the detection area, based on the combination of light-receiving units that are no longer able to receive the laser light. The X-ray CT apparatus further includes a display unit that distinguishes the area around the scanner unit into "the detection area in which an object other than the subject is detected," "the detection area in which no object other than the subject is detected," "the non-detection area in which an object other than the subject is detected," and "the non-detection area in which an object other than the subject is detected," and presents these to the operator of the X-ray CT apparatus. The X-ray CT apparatus according to claim 13.

15. A control method for an X-ray CT apparatus comprising a scanner unit having an imaging system and a support unit that supports the scanner unit and moves the scanner unit in the vertical direction, A detection area is defined as at least a portion of the region between the outer circumference of the opening into which the subject is inserted and the subject itself, and objects present in the detection area are detected. Control is performed to define the area where the movement of the subject is restricted as a non-detection area. If, during the operation of the scanner unit, the presence of the object is detected in the detection area excluding the non-detection area, the operation of the scanner unit is stopped. A control method using an X-ray CT scanner.

16. A program to be executed by the computer of an X-ray CT apparatus comprising a scanner unit having an imaging system and a support unit that supports the scanner unit and moves the scanner unit in the vertical direction, A detection area is defined as at least a portion of the region between the outer circumference of the opening into which the subject is inserted and the subject itself, and objects present in the detection area are detected. Control is performed to define the area where the movement of the subject is restricted as a non-detection area. If, during the operation of the scanner unit, the presence of the object is detected in the detection area excluding the non-detection area, the operation of the scanner unit is stopped. program.

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