X-ray CT device

Abstract

To improve the commonality of parts in both right-handed and left-handed configurations. [Solution] The X-ray CT apparatus according to this embodiment comprises a scanner and a stand. The scanner has a rotating part that holds an imaging mechanism around the central axis of the aperture, and a fixed part that holds the rotating part so as to be rotatable around the central axis and has a shape symmetrical with respect to a horizontal axis perpendicular to the central axis. The stand supports the side of the scanner and has a shape symmetrical with respect to a vertical axis perpendicular to the horizontal axis.

Description

Technical Field

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

Background Art

[0002] An X-ray CT (Computed Tomography) apparatus is a device that performs X-ray CT imaging using a scanner, and some have a stand that supports the scanner from one side surface of the scanner (referred to as a "single-sided X-ray CT apparatus"). As a single-sided X-ray CT apparatus, there are configurations where the stand supports the right side surface of the scanner (referred to as a "right-handed configuration") and where the stand supports the left side surface of the scanner (referred to as a "left-handed configuration") when viewed from the side where the bed is installed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to improve the commonality of components in the right-handed configuration and the left-handed configuration. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problems. The problems corresponding to the respective effects of the respective configurations shown in the embodiments described later can also be regarded as other problems.

Means for Solving the Problems

[0005] The X-ray CT apparatus according to this embodiment comprises a scanner and a stand. The scanner has a rotating part that holds an imaging mechanism around the central axis of the aperture, and a fixed part that holds the rotating part so as to be rotatable around the central axis and has a shape symmetrical with respect to a horizontal axis perpendicular to the central axis. The stand supports the side of the scanner and has a shape symmetrical with respect to a vertical axis perpendicular to the horizontal axis. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 shows the configuration of an X-ray CT apparatus according to an embodiment. [Figure 2] Figure 2 is a perspective view showing the configuration of the scanner, stand, and bed. [Figure 3] Figure 3 is a perspective view showing the detailed configuration of the scanner and stand. [Figure 4] Figure 4 is a perspective view showing the right-hand and left-hand configurations. [Figure 5] Figure 5 is a flowchart showing the operation of the X-ray CT apparatus according to this embodiment. [Modes for carrying out the invention]

[0007] The embodiments will be described below with reference to the drawings. Multiple parts assigned the same reference numeral will be considered identical, and redundant explanations will be omitted as appropriate.

[0008] Figure 1 shows the configuration of an X-ray CT apparatus 1 according to an embodiment. The X-ray CT apparatus 1 is a device for X-ray CT imaging. The X-ray CT apparatus 1 comprises a stand 2, a patient table 3, and a console 4. For example, the stand 2 and patient table 3 are installed in the examination room, and the console 4 is installed in a control room adjacent to the examination room. The stand 2, patient table 3, and console 4 are connected to each other so as to be able to communicate with each other by wire or wireless.

[0009] (Configuration of the stand) Stand 2 is a device for performing X-ray CT imaging. Stand 2 comprises a scanner 21, a stand 22, a rotary drive device 23, and a stand drive device 24.

[0010] A three-dimensional Cartesian coordinate system is defined for the stand 2. This Cartesian coordinate system has mutually perpendicular X, Y, and Z axes. The X-axis direction is parallel to the floor plane FL of the examination room and passes through the stand 22 from the center C1 of the aperture OP of the scanner 21 (also called the "first horizontal direction"). The Y-axis direction is parallel to the floor plane FL of the examination room and perpendicular to the X-axis (also called the "second horizontal direction"). The Z-axis direction is perpendicular to the X and Y axes (also called the "vertical direction").

[0011] The scanner 21 is a device that houses the imaging mechanism for performing X-ray CT imaging. The scanner 21 has a cylindrical aperture OP (also called a "bore") and an imaging mechanism around the central axis AX of the aperture OP. The shape of the scanner 21 may be a cylinder with an aperture OP or a rectangular prism (especially a square prism). The scanner 21 includes an X-ray tube 211, a high-voltage generator 212, an X-ray detector 213, a DAS 214, and a rotating frame 215 as the imaging mechanism (see also Figures 2, 3, and 4).

[0012] The central axis AX of scanner 21 is the axis corresponding to the center line of the aperture OP. In upright imaging (i.e., the state shown in Figure 1), the central axis AX is perpendicular to the floor FL of the examination room. The horizontal axis HX of scanner 21 is a horizontal axis (particularly in the X-axis direction) perpendicular to the central axis AX. The horizontal axis HX is also called the "tilt axis". When scanner 21 rotates around the horizontal axis HX, the central axis AX rotates in the same direction. The intersection point between the central axis AX and the horizontal axis HX is the center C1 of the aperture OP.

[0013] Rotating or swiveling the scanner 21 around the horizontal axis HX may also be referred to as "tilting." Hereinafter, the state in which the central axis AX of the aperture OP is approximately parallel to the vertical direction will be referred to as the "non-tilted state." The state in which the central axis AX of the aperture OP is inclined with respect to the vertical direction will be referred to as the "tilted state." The inclination angle of the central axis AX of the aperture OP with respect to the vertical direction will be referred to as the "tilt angle." The range of the tilt angle is, for example, ±90 degrees, with the non-tilted state being 0 degrees. The tilted state may be achieved by tilting the scanner 21 around an axis different from the horizontal axis HX as the axis of rotation, or by moving a part of the scanner 21 in the vertical direction.

[0014] The X-ray tube 211 irradiates a subject (not shown) with X-rays. The X-ray tube 211 is connected to a high-voltage generator 212 via a high-voltage cable. The X-ray tube 211 includes a cathode that generates thermionic electrons, an anode that receives thermionic electrons flying from the cathode and generates X-rays, and a vacuum tube that holds the cathode and anode. A tube voltage is applied between the cathode and anode by the high-voltage generator 212. The application of the tube voltage causes thermionic electrons to fly from the cathode to the anode. As thermionic electrons fly from the cathode to the anode, a tube current flows. X-rays are generated when thermionic electrons collide with the anode.

[0015] The high-voltage generator 212 has an electrical circuit including a transformer and a rectifier. The high-voltage generator 212 generates a high voltage to be applied to the X-ray tube 211 and a filament current to be supplied to the X-ray tube 211. The high-voltage generator 212 may be of the transformer type or the inverter type. The high-voltage generator 212 may be installed on the rotating frame 215 or on the fixed frame (described later) that holds the rotating frame 215.

[0016] The X-ray detector 213 detects X-rays irradiated from the X-ray tube 211 that have passed through the subject, and outputs an electrical signal corresponding to the detected X-ray dose to the DAS 214. The X-ray detector 213 has a structure in which multiple X-ray detection elements are arranged one-dimensionally in the channel direction (one-dimensional structure). Alternatively, the X-ray detector 213 has a structure in which multiple X-ray detection elements are arranged two-dimensionally in both the channel direction and the slice direction (two-dimensional structure).

[0017] The X-ray detector 213 is an indirect conversion type that converts incident X-rays into light and then converts the light into an electrical signal. The indirect conversion type X-ray detector 213 has a grid, a scintillator array, and a photosensor array. The grid has an X-ray shielding plate that is placed on the side of the X-ray incident surface of the scintillator array and absorbs scattered X-rays. The grid is also called a "collimator" (one-dimensional collimator or two-dimensional collimator). The scintillator array has multiple scintillators. The scintillators output light in an amount corresponding to the amount of incident X-rays. The photosensor array converts the light from the scintillators into an electrical signal corresponding to the amount of light. For example, a photodiode is used as the photosensor.

[0018] The X-ray detector 213 may also be a direct conversion type that converts incident X-rays into electrical signals. Alternatively, the X-ray detector 213 may be a photon counting type that counts the photons of the incident X-rays in each energy bin.

[0019] The DAS214 reads an electrical signal from the X-ray detector 213 corresponding to the X-ray dose detected by the X-ray detector 213. The DAS214 amplifies the read-out electrical signal and integrates it over the viewing period to collect detection data having digital values ​​corresponding to the X-ray dose over that viewing period. The detection data is also called "projection data". The DAS214 is implemented, for example, by an application-specific integrated circuit (ASIC) equipped with circuit elements capable of generating projection data. The projection data is transmitted to the console 4 via a non-contact data transmission device or the like.

[0020] The rotating frame 215 is an annular frame that supports the X-ray tube 211 and the X-ray detector 213 rotatably around the central axis AX. Specifically, the rotating frame 215 supports the X-ray tube 211 and the X-ray detector 213 facing each other. In addition to the X-ray tube 211 and the X-ray detector 213, the rotating frame 215 further supports the high-voltage generator 212 and the DAS 214. The rotating frame 215 is supported rotatably around the central axis AX by a fixed frame. When the rotating frame 215 rotates around the central axis AX, the X-ray tube 211 and the X-ray detector 213 rotate around the central axis AX. The rotating frame 215 is an example of a rotating part.

[0021] The stand 22 is a structure that supports the side surface of the scanner 21. The stand 22 is installed on the floor surface FL of the examination room. The stand 22 supports the scanner 21 rotatably around the horizontal axis HX. The stand 22 supports the scanner 21 movably along the vertical direction. The stand 22 includes a rotation mechanism (not shown) for rotating (or tilting) the scanner 21 around the horizontal axis HX. The stand 22 includes a movement mechanism (not shown) for moving (or sliding) the scanner 21 in the vertical direction (see also FIGS. 2, 3, and 4).

[0022] The stand 22 has a shape symmetrical with respect to the vertical axis VX passing through the center C2 of the stand 22. The positional relationship between each unit of the stand 22 is, for example, symmetrical with respect to the vertical axis VX. The intersection of the vertical axis VX and the horizontal axis HX is the center C2 of the stand 22. The stand 22 has, for example, a prismatic or cylindrical shape. The stand 22 may have any shape as long as it is symmetrical around the vertical axis VX. For example, the stand 22 may have a curved surface. Note that the stand 22 with the cover attached preferably has a shape symmetrical around the vertical axis VX.

[0023] The rotary drive unit 23 is a device that drives the rotation of the rotating frame 215. The rotary drive unit 23 has a motor (e.g., a direct drive motor, a servo motor). The rotary drive unit 23 drives the motor according to the control of the console 4 to generate power. The rotary drive unit 23 supplies the generated power to the rotating frame 215.

[0024] The stand drive unit 24 is a device that drives the various mechanisms of the stand 22. The stand drive unit 24 has a motor (e.g., a direct drive motor, a servo motor). The stand drive unit 24 generates power by driving the motor according to the control of the console 4. The stand drive unit 24 supplies the generated power to the rotation mechanism (described above) of the stand 22. The stand drive unit 24 also supplies the generated power to the movement mechanism (described above) of the stand 22.

[0025] (Bed Configuration) Bed 3 is a device for placing and moving the subject. A three-dimensional Cartesian coordinate system is defined for bed 3, similar to that of the stand 2. Bed 3 is installed on one side of the opening OP of the scanner 21. Bed 3 comprises a top plate 31, a base plate 32, and a bottom plate 33 (see also Figure 2).

[0026] The top plate 31 is a plate on which the subject is placed. The top plate 31 is configured to be movable in any axial direction (i.e., the X-axis direction, Y-axis direction, and Z-axis direction) via a support frame (not shown). The short axis direction of the top plate 31 corresponds to the X-axis direction. The long axis direction of the top plate 31 corresponds to the Y-axis direction.

[0027] The base 32 is a housing that supports the top plate 31. The base 32 is equipped with a top plate drive device 32D. The top plate drive device 32D has a motor (e.g., a direct drive motor, a servo motor). The top plate drive device 32D drives the motor to generate power according to the control of the console 4. The top plate drive device 32D supplies the generated power to the support frame (described above).

[0028] The base plate 33 is a plate that supports the base 32 and is installed on the floor FL of the examination room.

[0029] Figure 2 is a perspective view showing the configuration of the scanner 21, stand 22, and examination table 3. In supine radiography (i.e., the state shown in Figure 2), the central axis AX is parallel to the floor FL of the examination room (especially in the Y-axis direction). Consequently, the central axis AX in "supine radiography" is the same as the central axis AX in "standing radiography" rotated 90 degrees around the horizontal axis HX.

[0030] A bed 3 is installed on one side of the opening OP of the scanner 21. In the example in Figure 2, the stand 22 is installed to the right of the bed 3 (i.e., a right-handed configuration). For the scanner 21 and stand 22, the side on which the bed 3 is installed is called the "front side" (or "front-end side"), and the other side on which the bed 3 is not installed is called the "rear side" (or "rear-end side"). The direction passing through the "front side" and "rear side" (i.e., the Y-axis direction) is also called the "front-back direction".

[0031] The scanner 21 can rotate along the counterclockwise direction H1 when viewed from the stand 22 along the horizontal axis HX. The scanner 21 can rotate along the clockwise direction H2 when viewed from the stand 22 along the horizontal axis HX. The scanner 21 can rotate along either direction H1 or direction H2 according to control from the console 4.

[0032] The scanner 21 is preferably symmetrical with respect to a plane PL that passes through the center C1 of the aperture OP and is perpendicular to the central axis AX, but it may also be asymmetrical. Plane PL may coincide with, for example, at least one of the planes (i.e., imaging planes) formed by the X-ray beam irradiated from the X-ray tube 211 to the X-ray detector 213. It is preferable that plane PL coincides with the plane located in the center in the direction of the central axis AX among a plurality of planes formed by the X-ray beam.

[0033] The scanner 21 may have at least one of a code, pattern, and device for electrically identifying one side of a planar PL. The scanner 21 may have the code, etc., on one side but not on the other side. The code is, for example, a QR (Quick Response) code (registered trademark). The pattern may be, for example, a pattern of visible light, or a pattern made of paint that reacts to infrared, ultraviolet, etc. The device may be a signal transmitter or a position sensor. As a result, the console 4 can identify the front and rear sides of the scanner 21 based on the code, etc.

[0034] Furthermore, camera 50 (described later) may electrically identify one side of the planar PL. For example, camera 50 photographs the scanner 21 and the bed 3. Based on the captured image, camera 50 may identify the side of the scanner 21 on which the bed 3 is installed and the side on which the bed 3 is not installed.

[0035] The scanner 21 may have at least one of the following for a planar PL: a design, pattern, and color, which allows the user to visually identify one side of the planar PL. The scanner 21 may have the design, etc., on one side, but not on the other side. The design may be a recess, a protrusion, or an opening. The pattern may be a visible light pattern, or a pattern made of paint that reacts to infrared, ultraviolet, etc. The color may be red, green, blue, etc. As a result, the user can distinguish the front and back sides of the scanner 21 based on the design, etc.

[0036] Similarly, the stand 22 may have at least one of a code, pattern, and device for electrically identifying one side of a plane (e.g., plane PL) that passes through the center C2 of the stand 22, is parallel to the vertical axis VX, and passes through the side of the scanner 21. The stand 22 may have the code, etc., on the portion of the stand 22 that is one side. As a result, the console 4 can distinguish between the front and rear sides of the stand 22 based on the code, etc.

[0037] Similarly, the stand 22 may have at least one of a design, pattern, and color for the user to visually identify one side of a plane (e.g., plane PL) that passes through the center C2 of the stand 22, is parallel to the vertical axis VX, and passes through the side of the scanner 21. The stand 22 may have a design, etc., on that one side portion. As a result, the user can distinguish the front and rear sides of the stand 22 based on the design, etc.

[0038] Furthermore, if the scanner 21 rotates around the horizontal axis HX, the plane PL also rotates around the horizontal axis HX. The stand 22 may have a configuration for electrically or visually identifying one side of a plane (as described above) that is different from the plane PL. As a result, the console 4 or the user can recognize the front or rear side of the stand 22 despite the scanner 21's rotation around the horizontal axis HX.

[0039] The rotating frame 215 (see Figure 3) has a cylindrical first surface (side surface) and an annular second surface (bottom surface) connected to the first surface. The second surface is located on the rear side (i.e., the positive Y-axis side) of the X-ray tube 211 and X-ray detector 213. On the other hand, there is no surface corresponding to the second surface on the front side (i.e., the negative Y-axis side) of the X-ray tube 211 and X-ray detector 213. In other words, the rotating frame 215 has an asymmetric shape with respect to the plane PL.

[0040] The scanner 21 may have at least one of a code, pattern, and instrument that indicates information regarding the position of the second surface relative to the plane PL. Alternatively, the scanner 21 may have at least one of a code, pattern, and instrument that indicates information regarding the position of the opening of the rotating frame 215 on the opposite side of the second surface relative to the plane PL. The scanner 21 may have at least one of a design, pattern, and color that visually indicates information regarding the position of the second surface relative to the plane PL. Alternatively, the scanner 21 may have at least one of a design, pattern, and color that visually indicates information regarding the position of the opening of the rotating frame 215 on the opposite side of the second surface relative to the plane PL.

[0041] The bed 3 can move (or slide) its top plate 31 toward the interior of the opening OP of the scanner 21. The top plate 31 can move along the Y-axis direction B1 toward the interior of the opening OP. The top plate 31 can move along the Y-axis direction B2 toward the interior of the opening OP. The top plate 31 can move along direction B1 or direction B2 according to the control of the console 4.

[0042] A camera 50 is installed above the scanner 21, stand 22, and examination table 3 (for example, on the ceiling of the examination room). The camera 50 is positioned to capture at least the scanner 21 and examination table 3. The camera 50 captures at least the scanner 21 and examination table 3 according to the control of the console 4. The camera 50 may also capture the stand 22. The camera 50 transmits the captured images to the console 4.

[0043] Figure 3 is a perspective view showing the detailed configuration of the scanner 21 and stand 22. Figure 3 shows the scanner 21 as viewed from the front, with the cover covering the surface of the scanner 21 removed. For ease of explanation, the high-voltage generator 212 and DAS 214 are not shown. The scanner 21 mounts the X-ray tube 211 and X-ray detector 213 on a rotating frame 215. The scanner 21 also includes a fixed frame 216, a first arm 217A, a second arm 217B, a fixed plate 218, and bearings 219.

[0044] The fixed frame 216 is an annular frame that rotatably supports the rotating frame 215 around a central axis AX. The fixed frame 216 may support the rotating frame 215 through slip rings and brushes (not shown). The fixed frame 216 is an example of a fixed part.

[0045] The first arm 217A and the second arm 217B are members that support one end and the other end of the fixed frame 216, respectively. The first arm 217A and the second arm 217B clamp the fixed frame 216 from both ends. The first arm 217A and the second arm 217B may also clamp the fixed frame 216 so as to surround the entire side surface of the fixed frame 216. Each of the first arm 217A and the second arm 217B is an example of a fixing part.

[0046] The fixing plate 218 is a member that fixes the first arm 217A and the second arm 217B to the bearing 219. The fixing plate 218 is, for example, plate-shaped. The fixing plate 218 may be formed together with the first arm 217A and the second arm 217B as a single unit. The fixing plate 218 is an example of a fixing part.

[0047] The bearing 219 is a component that supports the fixed plate 218 so that it can rotate around the horizontal axis HX. The bearing 219 may receive power from a motor (e.g., a stand drive unit 24) to rotate the fixed plate 218 around the horizontal axis HX. The bearing 219 is an example of a fixed part.

[0048] The various units that fix the rotating frame 215 (i.e., the fixed frame 216, the first arm 217A, the second arm 217B, the fixed plate 218, and the bearing 219) are, for example, symmetric with respect to the horizontal axis HX. That is, the various units have a configuration that is symmetric with respect to the horizontal axis HX. Also, the positional relationship of the various units that fix the rotating frame 215 is symmetric with respect to the horizontal axis HX. The various units may also be symmetric with respect to the horizontal plane (i.e., the XY plane) (i.e., vertically symmetric). The stand 22 may also be symmetric with respect to the vertical plane (especially the XZ plane) (i.e., front-to-back symmetric).

[0049] The stand 22 has a first operation panel 22A on the first side where the patient bed 3 is installed, and a second operation panel 22B on the second side opposite to the first side. That is, the first operation panel 22A is installed on the front side of the stand 22, and the second operation panel 22B is installed on the rear side of the stand 22. The console 4 controls the power supply of the first operation panel 22A and the second operation panel 22B by switching them on and off. The console 4 may also switch the screen display of the first operation panel 22A and the second operation panel 22B on and off, for example, by switching sleep mode on and off. The first operation panel 22A and the second operation panel 22B may display a control screen or GUI (Graphical User Interface) for controlling the operation of the X-ray CT apparatus 1. The operation of the X-ray CT apparatus 1 includes, for example, operations related to raising and lowering or rotating the scanner 21, moving the patient bed 3, and irradiating with X-rays.

[0050] Figure 4 is a perspective view showing the right-handed and left-handed configurations. To change from the right-handed configuration (see Figure 4(A)) viewed from the negative direction of the Y-axis to the left-handed configuration (see Figure 4(B)) viewed from the negative direction of the Y-axis, the fixed part of the scanner 21 needs to be rotated half a turn around the central axis AX, and the stand 22 needs to be rotated half a turn around the vertical axis VX.

[0051] As mentioned above, the fixed part of the scanner 21 is symmetrical with respect to the horizontal axis HX which is perpendicular to the central axis AX, and the stand 22 is symmetrical with respect to the vertical axis VX. Therefore, the fixed part of the scanner 21 can function even when inverted vertically by rotating 180 degrees around the central axis AX, and the stand 22 can function even when inverted front to back by rotating 180 degrees around the vertical axis VX. In other words, the X-ray CT apparatus 1 can achieve a right-hand configuration where the stand 22 is on the right side as viewed from the patient table 3, and a left-hand configuration where the stand 22 is on the left side as viewed from the patient table 3, using common hardware (or parts).

[0052] Since the scanner 21's fixed frame 216, first arm 217A, second arm 217B, fixed plate 218, and bearing 219 are symmetrical with respect to the horizontal axis HX, the height of the scanner 21 during supine imaging can be set to the same level regardless of whether it is in a right-handed or left-handed configuration. Furthermore, regardless of whether it is in a right-handed or left-handed configuration, the height of the tabletop 31 in a predetermined workflow, such as positioning before supine imaging, can be set to the same level. Moreover, if the planar PL coincides with the plane located in the center in the direction of the central axis AX among the multiple planes formed by the X-ray beam, the multiple planes formed by the X-ray beam will spread in the same way with respect to the planar PL, regardless of whether it is in a right-handed or left-handed configuration. Therefore, the distance and layout between the scanner 21 and stand 22 and the patient table 3 can be standardized for both right-handed and left-handed configurations. Consequently, the difference in user experience between right-handed and left-handed configurations can be minimized.

[0053] (Console Configuration) Returning to the explanation of Figure 1, Console 4 is a computer that controls the frame 2 and the bed 3. Console 4 controls the high-voltage generator 212, DAS 214, rotary drive unit 23, and stand drive unit 24 of the frame 2. Console 4 controls the top plate drive unit 32D of the bed 3. Console 4 may also control the camera 50, the first operation panel 22A, and the second operation panel 22B.

[0054] Console 4 comprises various components including a processing circuit 41, memory 42, input device 43, display device 44, and communication device 45. These various components are connected to each other via a bus (BUS) for communication. At least some of these various components may be incorporated into the frame 2 or bed 3.

[0055] The processing circuit 41 is a circuit that comprehensively controls the overall operation of the console 4. The processing circuit 41 has at least one processor. Processors include CPUs (Central Processing Units), GPUs (Graphics Processing Units), ASICs (Application Specific Integrated Circuits), PLDs (Programmable Logic Devices), etc. PLDs include SPLDs (Simple Programmable Logic Devices), CPLDs (Complex Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), etc. The processing circuit 41 is an example of a processing unit.

[0056] If the processor is a CPU, the CPU implements various functions by reading and executing various programs stored in memory 42. If the processor is an ASIC, the various functions are incorporated into the ASIC as logic circuits. The processor may be configured as a single circuit or as a combination of multiple circuits. The processor implements various functions, including an image capture control function 411, a preprocessing function 412, a reconstruction processing function 413, an image processing function 414, a display control function 415, an acquisition function 416A, a detection function 416B, an operation direction control function 416C, a panel control function 416D, an alert control function 416E, and a system control function 417.

[0057] The imaging control function 411 controls X-ray CT imaging using the gantry 2. The imaging control function 411 controls the high-voltage generator 212, DAS 214, rotary drive unit 23, and stand drive unit 24 so that the gantry 2 performs X-ray CT imaging according to predetermined imaging conditions. The imaging control function 411 stores the projection data received from the DAS 214 in the memory 42. The imaging control function 411 is an example of an imaging control unit.

[0058] The preprocessing function 412 is a function that performs preprocessing on projection data. The preprocessing function 412 performs various preprocessing steps (e.g., logarithmic transformation, offset correction, sensitivity correction, beam hardening correction) on the projection data according to predetermined preprocessing conditions to generate preprocessed projection data. The preprocessing function 412 stores the preprocessed projection data in memory 42. The preprocessing function 412 is an example of a preprocessing unit.

[0059] The reconstruction processing function 413 is a function that performs reconstruction processing on pre-processed projection data. The reconstruction processing function 413 performs various reconstruction processes (e.g., filtered back projection, iterative reconstruction) on the pre-processed projection data according to predetermined reconstruction processing conditions to generate reconstructed image data (i.e., volume data). The reconstruction processing function 413 stores the reconstructed image data in memory 42. The reconstruction processing function 413 is an example of a reconstruction processing unit.

[0060] The image processing function 414 is a function that performs image processing on reconstructed image data. The image processing function 414 generates CT image data by performing various image processing operations (e.g., multi-plane reconstruction (MPR), maximum image projection (MIP), volume rendering) on ​​the reconstructed image data according to predetermined image processing conditions. The image processing function 414 stores the CT image data in memory 42. The image processing function 414 is an example of an image processing unit.

[0061] The display control function 415 controls the display of CT images based on CT image data. The display control function 415 performs windowing on the CT image data so that the display device 44 displays the CT image data according to predetermined display conditions. The display control function 415 transmits the CT image data after windowing to the display device 44. The display control function 415 may also display various images on the first operation panel 22A and the second operation panel 22B. The display control function 415 is an example of a display control unit.

[0062] The acquisition function 416A is a function that acquires various types of data. The acquisition function 416A acquires the correct positional relationship CP between the scanner 21 and the bed 3. The correct positional relationship CP may be the relative positional relationship between the coordinates (X, Y, Z) of the scanner 21 and the bed 3 in a three-dimensional orthogonal coordinate system, or it may be the absolute positional relationship between the scanner 21 and the bed 3 with respect to the origin. The coordinates of the scanner 21 are, for example, the coordinates of the center C1 of the scanner 21. The coordinates of the bed 3 are, for example, the coordinates of the center of the bed 3. The acquisition function 416A is an example of an acquisition unit.

[0063] The correct positional relationship CP is stored in memory 42 during the manufacturing stage of the X-ray CT scanner 1 as information about the positions in which the scanner 21, stand 22, and patient bed 3 are installed in the examination room. The correct positional relationship CP may also include installation information, such as whether the X-ray CT scanner 1 is installed in a right-handed or left-handed configuration in the examination room. In this case, correspondence information, which associates this installation information with the information about the positions in which the scanner 21, stand 22, and patient bed 3 are installed in the examination room, is stored in memory 42, and the correct positional relationship CP can be determined by referring to the installation information and the correspondence information.

[0064] The detection function 416B is a function that detects various types of data. For example, the detection function 416B detects the actual positional relationship AP between the scanner 21 and the bed 3 based on an image captured by the camera 50. The actual positional relationship AP may be the relative positional relationship between the coordinates (X, Y, Z) of the scanner 21 and the bed 3 in a three-dimensional Cartesian coordinate system, or it may be the absolute positional relationship between the scanner 21 and the bed 3 with respect to the origin. The detection function 416B is an example of a detection unit.

[0065] The motion direction control function 416C is a function that controls the direction of various movements. Based on the actual positional relationship AP between the scanner 21 and the bed 3, the motion direction control function 416C controls the direction of movement of at least one of the scanner 21 and the bed 3. For input via the same input interface, the motion direction control function 416C switches the direction of movement (i.e., direction H1 or direction H2) that rotates the scanner 21 around the horizontal axis HX perpendicular to the central axis AX, based on the actual positional relationship AP. For example, in a right-handed configuration, the motion direction control function 416C switches the input interface signal received from the user for rotation in direction H1, and in a left-handed configuration, it switches to a signal indicating rotation in direction H2. In this way, the rotation direction in which the upper part of the scanner 21 tilts towards the bed 3 can be realized with the same input interface whether in a right-handed or left-handed configuration. That is, since the user can operate via the same input interface, the difference in user experience is small whether in a right-handed or left-handed configuration.

[0066] The movement direction control function 416C switches the direction in which the bed 3, particularly the top plate 31, moves based on the actual positional relationship AP. For example, the movement direction control function 416C switches the input interface signal received from the user, which indicates the movement of the top plate 31 in the positive Y-axis direction in a right-handed configuration, to a signal indicating the movement of the top plate 31 in the positive Y-axis direction in a left-handed configuration. In this way, the movement of the top plate 31 towards the scanner 21 can be realized with the same input interface whether it is a right-handed or left-handed configuration. That is, the same input interface, such as the layout of buttons, can be used for both right-handed and left-handed configurations. The movement direction control function 416C is an example of a movement direction control unit.

[0067] The operation direction control function 416C may also control the initial position (or home position) of the X-ray tube 211. When the rotating frame 215 on which the X-ray tube 211 is mounted is converted between a right-handed configuration and a left-handed configuration, it rotates 180 degrees around the central axis AX together with the fixed frame 216. After this rotation, the position of the X-ray tube 211 is reversed with respect to the central axis AX. Therefore, the operation direction control function 416C may maintain the same initial position of the X-ray tube 211 by rotating the rotating frame 215 again 180 degrees around the central axis AX.

[0068] The panel control function 416D is a function that controls various panels. Based on the actual positional relationship AP between the scanner 21 and the bed 3, the panel control function 416D switches the first operation panel 22A on and the second operation panel 22B off. For example, in a right-handed configuration, the panel control function 416D can turn on only the operation panel on the side of the bed 3 by turning on the first operation panel 22A and turning off the second operation panel 22B. The panel control function 416D is an example of a panel control unit.

[0069] The alert control function 416E is a function that controls various alerts. For example, if the correct positional relationship CP between the scanner 21 and the bed 3 does not match the actual positional relationship AP, the alert control function 416E will issue an alert to an alarm device (not shown). For example, if the correct positional relationship CP between the scanner 21 and the bed 3 does not match the actual positional relationship AP, the alert control function 416E will display text such as "Please check the installation positions of the scanner and bed" on the operation panel. The alert control function 416E is an example of an alert control unit.

[0070] The system control function 417 is a function that comprehensively controls the overall operation of the processing circuit 41. The system control function 417 may also control various functions of the processing circuit 41 based on various input operations received from the user through the input device 43. The system control function 417 is an example of a system control unit.

[0071] Memory 42 is a device that stores various types of data. Memory 42 can be a storage device such as an HDD (Hard Disk Drive), SSD (Solid State Drive), RAM (Random Access Memory), or ROM (Read Only Memory). Memory 42 may also be a storage medium such as a CD (Compact Disc), DVD (Digital Versatile Disc), or flash memory. Memory 42 stores projection data, reconstructed image data, CT image data, etc. Memory 42 is an example of a storage unit.

[0072] The input device 43 is a device that receives various input operations from the user. The input device 43 may include a mouse, keyboard, trackball, switch, button, joystick, touchpad, tablet terminal, etc. The input device 43 converts the received input operations into electrical signals and transmits the converted electrical signals to the processing circuit 41. The input device 43 also receives various conditions from the user (e.g., shooting conditions, pre-processing conditions, reconstruction processing conditions, image processing conditions, display conditions). The input device 43 is an example of an input unit.

[0073] The display device 44 is a device that displays various images. The display device 44 is an LCD (Liquid Crystal Display), an OLED (Organic Electro Luminescence Display), etc. The display device 44 displays CT images based on CT image data. The display device 44 may also display a GUI for receiving various input operations from the user. The display device 44 is an example of a display unit.

[0074] Communication device 45 is a device that transmits various types of data. Communication device 45 transmits CT image data based on the DICOM (Digital Imaging and Communication in Medicine) standard. Communication device 45 may also transmit CT image data to external devices connected to console 4 via a network. Communication device 45 is an example of a communication unit.

[0075] Figure 5 is a flowchart showing the operation of the X-ray CT apparatus 1 according to the embodiment. The X-ray CT apparatus 1 executes steps S1 to S7 through various functions provided by the processing circuit 41.

[0076] (Step S1) The acquisition function 416A acquires the correct positional relationship CP. Specifically, the acquisition function 416A acquires the correct positional relationship CP from the memory 42. The acquisition function 416A may also acquire the correct positional relationship CP based on an operation entered by the user through the input device 43.

[0077] (Step S2) The camera 50 photographs the scanner 21 and the bed 3. Specifically, the acquisition function 416A causes the camera 50 to photograph the scanner 21 and the bed 3. The acquisition function 416A acquires the image taken by the camera 50 through the communication device 45. Step S2 may be performed before step S1.

[0078] (Step S3) The detection function 416B detects the actual positional relationship AP. Specifically, the detection function 416B detects the actual positional relationship AP between the scanner 21 and the bed 3 based on the image captured in step S2. The detection function 416B may also detect the actual positional relationship AP using a machine learning model trained for object position detection.

[0079] (Step S4) The alert control function 416E determines whether the two positional relationships match. Specifically, the alert control function 416E determines whether the correct positional relationship CP obtained in step S1 matches the actual positional relationship AP detected in step S3. If the two positional relationships match (Step S4-YES), the process proceeds to step S5A. If the two positional relationships do not match (Step S4-NO), the process proceeds to step S5B.

[0080] (Step S5A) The motion direction control function 416C controls the scanner 21 and the bed 3. Specifically, the motion direction control function 416C controls the direction of movement of the scanner 21 and the bed 3 based on the actual positional relationship AP detected in step S3. Firstly, the motion direction control function 416C switches the direction in which the scanner 21 rotates around the horizontal axis HX (i.e., direction H1 or direction H2). Secondly, the motion direction control function 416C switches the direction in which the bed 3 moves into the opening OP (i.e., direction B1 or direction B2).

[0081] Firstly, when the patient table 3 is installed in front of the scanner 21 (see Figure 2), the motion direction control function 416C switches direction H1 to the positive direction (+) and direction H2 to the negative direction (-). Conversely, when the patient table 3 is installed behind the scanner 21, the motion direction control function 416C switches direction H1 to the negative direction (-) and direction H2 to the positive direction (+). As a result, the motion direction control function 416C maintains the same directionality for the rotation of the scanner 21 around the horizontal axis HX relative to the patient table 3, allowing the user to intuitively operate the X-ray CT device 1.

[0082] Secondly, the motion direction control function 416C switches direction B1 to the positive direction (+) and direction B2 to the negative direction (-) when the patient table 3 is installed in front of the scanner 21 (see Figure 2). Conversely, the motion direction control function 416C switches direction B1 to the negative direction (-) and direction B2 to the positive direction (+) when the patient table 3 is installed behind the scanner 21. As a result, the motion direction control function 416C maintains the same direction of movement of the patient table 3 relative to the scanner 21, allowing the user to intuitively operate the X-ray CT device 1.

[0083] Furthermore, the scanner 21 may be symmetrical with respect to the plane PL (i.e., the front-to-back direction). In this case, the motion direction control function 416C does not need to switch the direction of rotation of the scanner 21 around the horizontal axis HX relative to the bed 3. Similarly, the motion direction control function 416C does not need to switch the direction of movement of the bed 3 relative to the scanner 21.

[0084] (Step S5B) The alert control function 416E controls the issuance of alerts. Specifically, the alert control function 416E causes the alarm to issue an alert if the correct positional relationship CP acquired in step S1 does not match the actual positional relationship AP detected in step S3. This alert may be sound, light, etc. As a result, the alert control function 416E can inform the user that the two positional relationships do not match. After step S5B, the process ends.

[0085] (Step S6) The panel control function 416D controls the operation panel. Specifically, the panel control function 416D switches the first operation panel 22A and the second operation panel 22B on or off based on the actual positional relationship AP detected in step S3. Step S6 may be performed before step S5A.

[0086] For example, when the bed 3 is installed in front of the scanner 21 (see Figures 2 and 3), the panel control function 416D switches the first operation panel 22A at the front to "on" and the second operation panel 22B at the rear to "off". Conversely, when the bed 3 is installed behind the scanner 21, the panel control function 416D switches the first operation panel 22A at the front to "off" and the second operation panel 22B at the rear to "on". As a result, the panel control function 416D can save power compared to keeping both operation panels "on" at all times. Furthermore, the user can immediately use the operation panel installed on the bed 3 side.

[0087] (Step S7) The imaging control function 411 performs X-ray CT imaging. Specifically, the imaging control function 411 controls the imaging mechanism of the X-ray CT apparatus 1 while the controls in steps S5A and S6 have been executed. After step S7, the process ends.

[0088] According to the embodiment described above, the X-ray CT apparatus 1 comprises a scanner 21 and a stand 22. The scanner 21 has a rotating part that holds the imaging mechanism around the central axis AX of the aperture OP, and a fixed part that holds the rotating part so as to be rotatable around the central axis AX and has a shape symmetrical with respect to a horizontal axis HX perpendicular to the central axis AX. The stand 22 supports the side of the scanner 21 and has a shape symmetrical with respect to a vertical axis VX perpendicular to the horizontal axis HX.

[0089] According to at least one embodiment described above, as illustrated with reference to Figure 4, the commonality of parts can be improved in both right-hand and left-hand configurations.

[0090] Furthermore, with regard to cantilevered X-ray CT scanners, depending on the layout (or available space) of the examination room where it is installed, one of the right-hand or left-hand configurations may be more convenient than the other in terms of user and subject movement, workspace, etc. In other words, it is assumed that both right-hand and left-hand configurations are required for cantilevered X-ray CT scanners. According to at least one embodiment described above, by improving the commonality of parts between the right-hand and left-hand configurations, the difference in user experience between the right-hand and left-hand configurations can be reduced, enabling intuitive operation.

[0091] 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 implemented in a variety of other forms, and various omissions, substitutions, modifications, and combinations of embodiments are possible 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. [Explanation of symbols]

[0092] 1 X-ray CT device 2. Stand 3 berths 4 Console 21 Scanners 22 Stands 22A First Control Panel 22B Second Control Panel 23 Rotary drive device 24 Stand drive unit 31 Top plate 32 bases 32D Top plate drive mechanism 33 Bottom plate 41 Processing Circuit 42 memory 43 Input devices 44 Display equipment 45 Communication equipment 50 Cameras 211 X-ray tube 212 High-voltage generator 213 X-ray detector 214 DAS 215 rotation frame 216 Fixed Frame 217A First Arm 217B Second Arm 218 Fixed plate 219 Bearings 411 Shooting control function 412 Pre-processing function 413 Reconstruction Processing Function 414 Image Processing Functions 415 Display control function 416A Acquisition function 416B Detection Function 416C Operation direction control function 416D Panel Control Function 416E Alert Control Function 417 System control function AP Actual positional relationship AX center axis B direction C center CP Correct positional relationship H direction HX horizontal axis OP opening PL plane VX Vertical Axis

Claims

1. A scanner having a rotating part that rotatably holds the imaging mechanism around the central axis of the aperture, and a fixed part that rotatably holds the rotating part around the central axis and has a shape symmetrical with respect to a horizontal axis perpendicular to the central axis, A stand that supports the side of the scanner and has a shape symmetrical with respect to a vertical axis perpendicular to the horizontal axis, An X-ray CT scanner equipped with the following features.

2. The scanner has a shape that is symmetrical with respect to a plane that passes through the center of the aperture and is perpendicular to the central axis. The X-ray CT apparatus according to claim 1.

3. The aforementioned imaging mechanism includes an X-ray tube and an X-ray detector. The aforementioned plane coincides with the plane located in the center in the direction of the central axis among a plurality of planes formed by the X-ray beam irradiated from the X-ray tube to the X-ray detector. The X-ray CT apparatus according to claim 2.

4. The rotating part has a cylindrical first surface and an annular second surface connected to the first surface. The scanner has at least one of a code and a pattern that indicate information regarding the position of the second surface with respect to a plane that passes through the center of the aperture and is perpendicular to the central axis. The X-ray CT apparatus according to claim 1.

5. The rotating part has a cylindrical first surface and an annular second surface connected to the first surface. The scanner has at least one of a design and color that visually indicates information regarding the position of the second surface with respect to a plane that passes through the center of the aperture and is perpendicular to the central axis. The X-ray CT apparatus according to claim 1.

6. The device further includes a bed on which the subject is placed, The stand has at least one of a code and a pattern that are parallel to the vertical axis and have a plane passing through the side of the scanner, and that indicates the side closest to the bed. The X-ray CT apparatus according to claim 1.

7. The device further includes a bed on which the subject is placed, The stand has at least one of a design, pattern, and color that visually indicates the side closest to the bed with respect to a plane parallel to the vertical axis and passing through the side of the scanner. The X-ray CT apparatus according to claim 1.

8. A bed installed on one side of the aforementioned opening, The system further comprises a motion direction control unit that controls the direction of movement of at least one of the scanner and the bed based on the actual positional relationship between the scanner and the bed, The X-ray CT apparatus according to claim 1.

9. The operation direction control unit switches the direction in which the scanner rotates around the horizontal axis based on the actual positional relationship. The X-ray CT apparatus according to claim 8.

10. The movement direction control unit switches the direction in which the bed moves into the opening based on the actual positional relationship. The X-ray CT apparatus according to claim 8.

11. The stand has a first operating panel on the first side where the bed is installed, and a second operating panel on the second side opposite to the first side. The system further comprises a panel control unit that switches the first operation panel on and the second operation panel off based on the actual positional relationship. The X-ray CT apparatus according to claim 8.

12. The scanner and the camera for photographing the bed, The system further comprises a detection unit that detects the actual positional relationship based on an image captured by the aforementioned camera, The X-ray CT apparatus according to claim 8.

13. An acquisition unit that acquires the correct positional relationship between the scanner and the bed, The system further comprises an alert control unit that issues an alert to the alarm device if the correct positional relationship does not match the actual positional relationship. The X-ray CT apparatus according to claim 8.

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