JP2019115396A - X-ray diagnostic device - Google Patents

Abstract

To provide an X-ray diagnostic device capable of rotating an opening so that at least part of an irradiation region of an X-ray passing through the opening is maintained in the X-ray irradiation region before the rotation even when an ideal rotation center of an opening of an X-ray restriction member is in a position different from a position of a rotation axis of the X-ray restriction member.SOLUTION: An X-ray diagnostic device according to an embodiment includes: an X-ray restriction unit having an opening through which an X-ray passes; a rotation mechanism for causing the X-ray restriction unit to rotate around a predetermined rotation axis; a moving mechanism for causing the opening to be translated; and an interlocking control unit for executing interlocking control to control the rotation mechanism and the moving mechanism to cause the moving mechanism to translate the opening, interlocking with the rotation of the X-ray restriction unit by the rotation mechanism so that at least part of an irradiation region of the X-ray passing through the opening is maintained in an X-ray irradiation region before the interlocking control.SELECTED DRAWING: Figure 4

Description

  Embodiments of the present invention relate to an X-ray diagnostic apparatus.

  The X-ray movable stop device of the X-ray diagnostic apparatus has an X-ray restricting member provided with an opening for restricting (squeezing) an irradiation range of X-rays. The X-rays generated by the X-ray generation source pass unattenuated in the opening area of the X-ray limiting member, while the passage is restricted in areas other than the opening area.

  The X-ray limiting member can move in parallel (slide) in a direction intersecting the X-ray irradiation axis with respect to the housing of the X-ray movable stop device. For this reason, the position of the opening of the X-ray limiting member can be changed with the housing of the X-ray movable stop device fixed. Also, the X-ray limiting member can be rotated about a rotation axis substantially parallel to the X-ray irradiation axis. Therefore, the position for limiting the radiation range of the X-ray can be variably changed by the combination of the rotation and translation of the X-ray limiting member.

  However, when the opening of the X-ray limiting member is at a position away from the rotation axis of the X-ray limiting member, when the X-ray limiting member is rotated, the opening orbits around the rotation axis. Therefore, when the user places the region of interest in the radiation field corresponding to the opening and observes the X-ray fluoroscopic image of the region of interest, the radiation field is rotated with the predetermined position of the radiation field as the desired rotation center. The rotation of the X-ray limiting member may cause the radiation field to deviate from the region of interest.

JP, 2013-158532, A

  The problem to be solved by the present invention is that, even when the ideal rotation center of the opening of the X-ray limiting member is at a position different from the rotation axis of the X-ray limiting member, To provide an X-ray diagnostic apparatus capable of rotating the aperture such that at least a part of the X-ray irradiation area is kept in the X-ray irradiation area before rotation.

  In order to solve the problems described above, an X-ray diagnostic apparatus according to an embodiment of the present invention rotates an X-ray limiting unit having an opening through which X-rays pass, and rotating the X-ray limiting unit around a predetermined rotation axis. A rotating mechanism for moving the opening, a moving mechanism for moving the opening in parallel, and at least a part of the irradiation area of the X-ray passing through the opening within the irradiation area of the X-ray before interlocking control An interlock control unit that performs interlock control to control the rotation mechanism and the movement mechanism so as to move the opening in parallel to the movement mechanism in conjunction with the rotation of the X-ray limiting unit by the rotation mechanism; is there.

FIG. 1 is a block diagram showing an example of an X-ray diagnostic apparatus according to an embodiment of the present invention. (A) is a block diagram which shows roughly one structural example of the X-ray movable aperture concerning this embodiment, (b) is a perspective view. The perspective view which shows one structural example of a X-ray limiting member. FIG. 3 is a schematic block diagram showing an example of a function implemented by a processor of a processing circuit of an aperture control device. Explanatory drawing which shows an example of a mode that an opening rotates, substantially fixing the spatial position of the ideal rotation center of opening by the interlocking control process which concerns on this embodiment. Explanatory drawing which shows an example of a mode that an aperture blade is rotated centering | focusing on a rotating shaft by a rotation mechanism, without performing the interlocking control process which concerns on this embodiment. FIG. 6 is a diagram for explaining the interlocking control process according to the present embodiment shown in FIG. 5 in detail, (a) is an explanatory view showing an example of the rotation of the opening by the rotation mechanism in the interlocking control process, (b) in the interlocking control process Explanatory drawing which shows an example of the Y-axis component of parallel displacement of the opening by a moving mechanism, (c) is explanatory drawing which shows an example of an X-axis component. Even when the ideal rotation center of the opening of the X-ray limiting member is located at a position different from the rotation axis of the X-ray limiting member by the processor of the processing circuit shown in FIG. The flowchart which shows an example of the procedure at the time of rotating an opening, keeping a target position substantially fixed. FIG. 9 is a subroutine flowchart showing an example of an interlocking control processing procedure of the diaphragm blade executed by the interlocking control function in step S4 of FIG. 8; FIG. Explanatory drawing which shows an example of the superimposition image which superimposed the opening area image on the past image. Explanatory drawing which shows an example of the superimposition image in, when the positional relationship of a housing | casing and a top is changed.

  An embodiment of an X-ray diagnostic apparatus according to the present invention will be described with reference to the attached drawings.

(overall structure)
FIG. 1 is a block diagram showing an example of an X-ray diagnostic apparatus 1 according to an embodiment of the present invention. In the present embodiment, three-dimensional orthogonal three components of the device coordinate system of the X-ray diagnostic device 1 are represented by x-axis, y-axis and z-axis, and the longitudinal direction of the top 15 of the bed 16 is z-axis direction and z-axis A direction perpendicular to the direction and horizontal to the floor is defined as an x-axis direction, and a direction perpendicular to the z-axis and perpendicular to the floor is defined as a y-axis (see FIG. 1).

  The X-ray diagnostic apparatus 1 has an imaging device 10 and a console 40, as shown in FIG.

  The imaging apparatus 10 includes an X-ray tube 11 and a container 12 for accommodating the X-ray movable diaphragm 20, an X-ray detector 13, a C arm 14, a top plate 15, a bed 16, a high voltage power supply 17, an arm drive circuit 18, and a bed A diaphragm control device 30 having a drive circuit 19, a memory circuit 31 and a processing circuit 32, a controller 35, and an input circuit 36.

  The X-ray tube 11 is a vacuum tube which irradiates thermal electrons from the cathode (filament) to the anode (target) by application of high voltage from the high voltage power source 17.

  The container 12 is a housing made of metal and is provided at one end of the C-arm 14 while accommodating the X-ray tube 11 and the X-ray movable diaphragm 20.

  The X-ray detector 13 is provided at the other end of the C-arm 14 so as to be opposed to the X-ray tube 11 with the subject P supported by the top plate 15 of the bed 16 interposed therebetween. The X-ray detector 13 is configured by a flat panel detector (FPD), detects X-rays transmitted through the subject P and irradiated to the X-ray detector 13, and is based on the detected X-rays X-ray projection data is output. This projection data is provided to the console 40 via the controller 35. The X-ray detector 13 may include an image intensifier, a TV camera, and the like.

  The C-arm 14 is a support that supports the container 12 and the X-ray detector 13 as one. As the C-arm 14 is controlled by the controller 35 and driven, the X-ray tube 11 and the X-ray movable diaphragm 20 accommodated in the container 12 and the X-ray detector 13 move around the subject P integrally. Do.

  The bed 16 is installed on the floor and supports the top 15. The bed 16 has a motor or an actuator under the control of the controller 35 to move the top plate 15 on which the subject P is placed in the x-axis direction, the y-axis direction, and the z-axis direction.

  A high voltage power supply 17 includes a high voltage generator having a function of generating a high voltage to be applied to the X-ray tube 11, and an X-ray control device for controlling an output voltage according to X-rays irradiated by the X-ray tube 11. Have. The high voltage generator may be a transformer type or an inverter type.

  The arm drive circuit 18 is controlled by the controller 35 to move the C-arm 14 supporting the container 12 and the X-ray detector 13.

  The bed driving circuit 19 is controlled by the controller 35 to control the motor and the actuator of the bed 16 to move the top 15 on which the subject P is placed.

  The configuration of the X-ray movable diaphragm 20 will be described later with reference to FIGS. The configuration of the aperture control device 30 will be described later with reference to FIG.

  The controller 35 has at least a processor and a storage circuit. The controller 35 is controlled by the console 40 in accordance with the program stored in the storage circuit to centrally control each component of the imaging device 10. For example, the controller 35 controls the X-ray irradiation system to execute fluoroscopic imaging etc. of the X-ray diagnostic image of the subject P to generate image data, and gives the image data to the console 40.

  The input circuit 36 includes, for example, a general pointing device such as a joystick, a trackball, a trackball mouse, a keyboard, a touch panel, a ten key, a hand switch for instructing X-ray emission timing, and the like. An operation signal corresponding to the user's operation is output to the aperture control device 30 and the console 40 via the interface. The input circuit 36 of the imaging device 10 is provided, for example, on the side surface of the top 15 or the side surface of the bed 16.

  For example, while looking at the display 42 of the console 40, the user can issue an instruction to rotate the irradiation field through the input circuit 36, using the predetermined position in the irradiation field as the ideal rotation center 22ac.

  On the other hand, the console 40 has an input circuit 41, a display 42, a storage circuit 43, and a processing circuit 44.

  The input circuit 41 of the console 40 has a configuration similar to that of the input circuit 36 and, for example, general pointing devices such as joysticks, trackballs, trackball mice, keyboards, touch panels, and ten keys, and X-ray emission timings. It comprises a hand switch or the like for instructing, and supplies an operation signal corresponding to the user's operation to the processing circuit 44 and also to the aperture control device 30 via the controller 35.

  The display 42 is constituted by a general display output device such as a liquid crystal display or an OLED (Organic Light Emitting Diode) display, and displays various information in accordance with the control of the processing circuit 44.

  The storage circuit 43 has a configuration including a processor-readable storage medium such as a magnetic or optical storage medium or a semiconductor memory, and some or all of the programs and data in the storage medium are electronic networks. It may be configured to be downloaded via the Internet.

  The processing circuit 44 of the console 40 is a processor for integrally controlling each component of the imaging device 10 via the controller 35 by reading out and executing the program stored in the storage circuit 43.

(Configuration of movable X-ray diaphragm)
Next, the configuration of the X-ray movable stop 20 according to the present embodiment will be described.

  Fig.2 (a) is a block diagram which shows roughly one structural example of the X-ray movable diaphragm 20 which concerns on this embodiment, and (b) is a perspective view. FIG. 3 is a perspective view showing an example of the configuration of the X-ray limiting member 22. As shown in FIG.

  As shown in FIG. 2, the X-ray movable diaphragm 20 has a housing 21, an X-ray limiting member 22, a rotation mechanism 23, and a movement mechanism 24.

  The housing 21 is a metal housing that supports the X-ray limiting member 22, the rotation mechanism 23, and the moving mechanism 24.

  The X-ray limiting member 22 has an opening 22a for limiting (squeezing) the irradiation range of the X-ray, and allows the X-ray to pass through the opening 22a, and limits the passage of the X-ray in a region other than the opening 22a. In the present embodiment, the X-ray limiting member 22 includes at least one of the diaphragm blade 25 and the region of interest filter (hereinafter, referred to as an ROI filter) 26. 2 and 3 show an example in which the X-ray limiting member 22 has both the diaphragm blade 25 and the ROI filter 26. When the X-ray limiting member 22 has both the diaphragm blade 25 and the ROI filter 26, substantially only the ROI filter 26 is substantially reduced, for example, by largely retracting the blade elements 251 to 254 of the diaphragm blade 25 away from the center. Flexible operation is possible, such as functioning as an X-ray stop.

  The rotation mechanism 23 is configured by a motor and an actuator, and rotates the X-ray limiting member 22 around a predetermined rotation axis 27 (see FIG. 2B). The predetermined rotation axis 27 is preferably set parallel to the X-ray irradiation main axis of the X-ray tube 11, and more preferably set to coincide with the X-ray irradiation main axis.

  The rotation mechanism 23 may rotate the X-ray limiting member 22 integrally with the housing 21 around the rotation axis 27, or may rotate only the X-ray limiting member 22 around the rotation axis 27 independently of the housing 21. You may Both the rotation center 25c of the diaphragm blade 25 and the rotation center 26c of the ROI filter 26 are located on the rotation axis 27 (see FIGS. 2 (b) and 3). In the present embodiment, it is assumed that the rotation axis 27 of the X-ray limiting member 22 is fixed to the housing 21 regardless of the parallel movement of the X-ray limiting member 22.

  The moving mechanism 24 is configured of a motor and an actuator, and moves the opening 22 a of the X-ray limiting member 22 in parallel with the housing 21.

  The diaphragm blade 25 has four blade elements 251, 252, 253 and 254, as shown in FIG. 3, for example. The blade elements 251 to 254 are each formed of a flat plate-like lead wing or the like to shield X-rays. The area surrounded by the wing elements 251-254 forms an opening 25a through which X-rays pass (see FIG. 3). The moving mechanism 24 translates the position of the opening 25 a while the casing 21 is fixed by translating the blade elements 251-254 independently of each other with respect to the casing 21 with respect to the casing 21. And the shape of the opening 25a can be changed. The number of the blade elements of the diaphragm blade 25 is not limited to four as shown in FIG. 3, and for example, a multileaf collimator may be used as the diaphragm blade 25.

  The ROI filter 26 is formed of a flat plate 261 such as copper or aluminum having an opening 26 a in part. For this reason, the X-rays pass through the opening 26a without being attenuated, while transmitting in an area other than the opening 26a while being attenuated by the ROI filter 26. The shape of the opening 26a may be, for example, a rectangle having a size of several mm to several tens of mm on one side, a circle, an ellipse, a polygon other than a rectangle, or the like. The moving mechanism 24 can move the position of the opening 26 a in parallel while the case 21 is fixed by moving the ROI filter 26 in parallel with respect to the case 21.

(Configuration of aperture control device)
Next, the configuration of the aperture control device 30 will be described. As shown in FIG. 1, the aperture control device 30 at least includes a memory circuit 31 and a processing circuit 32.

  The storage circuit 31 has a configuration including a processor-readable storage medium such as a magnetic or optical storage medium or a semiconductor memory, and some or all of the programs and data in the storage medium are electronic networks. It may be configured to be downloaded via the Internet.

  The processing circuit 32 of the aperture control device 30 reads out and executes the interlocking control program stored in the storage circuit 31 so that the ideal rotation center 22 ac of the opening 22 a of the X-ray limiting member 22 is the rotation axis of the X-ray limiting member 22. It is a processor that executes interlocking control processing for rotating the opening while keeping the spatial position in the device coordinate system of the ideal rotation center 22ac of the opening 22a substantially fixed, even when the position is different from 27.

  For example, when the X-ray limiting member 22 has the diaphragm blade 25, at least a part of the irradiation area of the X-ray passing through the opening 25a is irradiated with the X-ray before the interlock control by the interlock control process. Control is performed to rotate the opening 25a while keeping the spatial position of the ideal rotation center 25ac of the opening 25a in the device coordinate system substantially fixed, for example, to be kept in the region. When the X-ray limiting member 22 has the ROI filter 26, at least a part of the irradiation area of the X-rays passing through the opening 26a is irradiated with the X-ray before the interlock control by the interlock control process. Control is made to rotate the opening 26a while keeping the spatial position of the ideal rotation center 26ac of the opening 26a in the device coordinate system substantially fixed so as to be kept in the area.

  FIG. 4 is a schematic block diagram showing an example of a function implemented by the processor of the processing circuit 32 of the aperture control device 30. As shown in FIG. As shown in FIG. 4, the processor of the processing circuit 32 of the aperture control device 30 has an interlock control function 51 and an image generation function 52. Each of these functions is stored in the storage circuit 31 in the form of a program.

  In the present embodiment, an example in which each of the functions 51 to 52 is realized by the processing circuit 32 of the aperture control device 30 will be described. However, some or all of the functions 51 to 52 of the processing circuit 32 are It may be realized by the processor of the controller 35 or the processing circuit 44 of the console 40.

  The interlocking control function 51 performs interlocking control processing so that the spatial position of the ideal rotation center 22ac of the opening 22a is substantially fixed when the ideal rotation center 22ac of the opening 22a and the rotation axis 27 are at different positions. . Specifically, in the interlocking control process, the interlocking control function 51 limits X-rays centered on the rotation shaft 27 by the rotation mechanism 23 so that the spatial position of the ideal rotation center 22ac of the opening 22a is substantially fixed. The rotation mechanism 23 and the movement mechanism 24 are controlled to move the opening 22 a in parallel to the movement mechanism 24 in conjunction with the rotation of the member 22.

  The image generation function 52 acquires a past image 71 obtained by imaging in advance the region of the subject P including the partial region of the subject P corresponding to the opening 22a, and obtains the partial region corresponding to the opening 22a as X A superimposed image 70 is generated by superimposing the opening area image 72 obtained by line imaging at a position corresponding to the partial area of the past image 71 and displayed on the display 42.

  Subsequently, the interlocking control process according to the present embodiment will be described in detail.

  FIG. 5 is an explanatory view showing an example of how the opening 25a is rotated while the spatial position of the ideal rotation center 25ac of the opening 25a is substantially fixed by the interlocking control process according to the present embodiment. In FIG. 5, a two-dot chain line represents the position of the opening 25a after the interlocking control process.

  In this embodiment, two orthogonal components of the two-dimensional coordinate system (diaphragm coordinate system) of the diaphragm of the X-ray movable diaphragm 20 are represented by X and Y axes, and this XY coordinate system is parallel to the zx plane of the apparatus coordinate system. Define the X axis in the same direction as the x-axis of the device coordinate system in the direction opposite to that of the y-axis, and rotate the origin in the same direction as the z-axis of the device coordinate system and in the same direction. Each is defined on the axis 27 (see FIG. 4). As described above, in the present embodiment, the rotation axis 27 of the X-ray limiting member 22 is fixed to the housing 21 regardless of the parallel movement of the X-ray limiting member 22. Further, the stop coordinate system is fixed with respect to the apparatus coordinate system regardless of the rotation of the X-ray limiting member 22.

  In the following description, an example in the case of interlocking control of the diaphragm blade 25 will be described. The interlocking control of the ROI filter 26 is the same control as the interlocking control of the diaphragm blade 25, and therefore the description thereof is omitted.

  For example, in order to observe the region of interest 60 of the subject P, the user moves the opening 25 a so that the X-ray irradiation field covers the region of interest 60. At this time, as shown in FIG. 5, the case where the position of the opening 25a is separated from the rotation center 25c of the diaphragm blade 25 located on the rotation shaft 27 is considered. In this case, it is considered that the user desires to rotate the opening 25a so as to fit the shape of the region of interest 60. Then, through the joystick of the input circuit 41 of the console 40 or the input circuit 36 of the imaging device 10, the desired rotation direction (desired rotation center) 25ac of the opening 25a and the desired rotation direction around the ideal rotation center 22ac and desired Is designated. The ideal rotation center 25ac may be automatically set to the initially set position, for example, the center or the center of gravity of the opening 25a when there is no user instruction.

  In this case, it is considered that the rotational movement of the opening 25a which is the user's ideal is that the opening 25a is rotated while the region of interest 60 remains in the irradiation field. In order to realize this ideal, the opening 25a may be rotated while the spatial position of the ideal rotation center 25ac in the device coordinate system (and the stop coordinate system) is substantially fixed through the rotational movement of the opening 25a.

  FIG. 6 is an explanatory view showing an example of a state in which the diaphragm blade 25 is rotated about the rotation shaft 27 by the rotation mechanism 23 without executing the interlocking control process according to the present embodiment.

  As shown in FIG. 6, when the position of the ideal rotation center 25 ac of the opening 25 a is positioned away from the rotation center 25 c of the diaphragm blade 25 located on the rotation shaft 27 by the distance r, the opening 25 a is a diaphragm blade 25. It makes a circular movement centering on the rotation center 25c of. When the orbiting movement is performed in this manner, the radiation field corresponding to the opening 25a is separated from the region of interest 60. In this case, the user must operate the blade elements 251-254 in a complicated manner via the moving mechanism 24 so as to place the region of interest 60 in the irradiation field again, which is very troublesome.

  Therefore, the interlocking control function 51 performs interlocking control processing so that the spatial position of the ideal rotation center 22ac of the opening 22a is substantially fixed when the ideal rotation center 22ac of the opening 22a and the rotation shaft 27 are at different positions. I do.

  FIG. 7 is a diagram for describing the interlocking control process according to the present embodiment shown in FIG. 5 in detail, wherein (a) is an explanatory view showing an example of rotation of the opening 25a by the rotation mechanism 23 in the interlocking control process; (B) is explanatory drawing which shows an example of the Y-axis component of parallel displacement of the opening 25a by the moving mechanism 24 in interlocking | linkage control processing, (c) is explanatory drawing which shows an example of X-axis component.

  As shown in FIG. 7A, the interlocking control function 51 rotates the aperture blade 25 in the desired rotation direction by the desired rotation amount θ with the opening 25 a via the rotation mechanism 23. In parallel with this rotation control, the interlocking control function 51 obtains the variation dY of the Y-axis component of the coordinates of the ideal rotation center 25ac generated by the rotation, and restores it in the Y-axis direction by this variation dY (see FIG. 7 (b) and the change amount dX of the X-axis component is obtained, and the change amount dX is returned to the original in the X-axis direction (refer to FIG. 7 (c)). Translate each of 251-254 in parallel.

  7 (a), (b) and (c) separately show rotation, Y-axis movement and X-axis movement for convenience of explanation, but interlocking control of these rotation and movement is performed in parallel. To be done. That is, the interlocking control function 51 causes the movement of the opening 25a to be rotated with the spatial position of the ideal rotation center 25ac substantially fixed as shown in FIG. The rotation mechanism 23 and the movement mechanism 24 are interlocked and controlled. Therefore, the parallel movement of the opening 25a is not limited to the zigzag movement defined in the direction along either the X axis or the Y axis, but includes oblique movement and curvilinear movement.

  Next, an example of the operation of the X-ray diagnostic apparatus 1 according to the present embodiment will be described.

  In FIG. 8, even if the ideal rotation center 22 ac of the opening 22 a of the X-ray limiting member 22 is located at a position different from the rotation axis 27 of the X-ray limiting member 22 by the processor of the processing circuit 32 shown in FIG. It is a flowchart which shows an example of the procedure at the time of rotating the opening 22a, with the spatial position in the apparatus coordinate system of the ideal rotation center 22ac of 22a fixed substantially. In FIG. 8, reference numerals with numbers attached to S indicate steps in the flowchart.

  This procedure starts in a state in which the opening 22a is moved in parallel so that the irradiation field corresponding to the opening 22a includes the region of interest 60 (see the solid lines in FIGS. 5 and 7A to 7C). In the present embodiment, the shape of the opening 22a of the diaphragm blade 25 is manually set in advance by, for example, designating a vertex of a rectangle through the input circuit 36 or the input circuit 41 by the user. . In addition, since the opening 26a of the ROI filter 26 is fixed to a previously designed shape, it is not necessary to receive the setting of the shape.

  First, in step S1, the interlocking control function 51 determines whether or not an instruction to rotate the opening 22a has been received from the user via the input circuit 36 or the input circuit 41. If there is no rotation instruction, the procedure ends. On the other hand, when the rotation instruction is received, the process proceeds to step S2.

  Next, in step S2, the interlocking control function 51 determines the rotation mode. In this embodiment, it is assumed that the rotation mode can be selected from the simple rotation mode, the diaphragm blade rotation mode, and the filter rotation mode.

  In the simple rotation mode, the interlocking control function 51 does not control the moving mechanism 24, that is, without the parallel movement of the opening 22 a of the X-ray limiting member 22, and controls only the rotating mechanism 23 to control the X-ray limiting member 22. Only rotation is performed (step S3). This mode may be selected when the ideal rotation center 22ac of the opening 22a coincides with the rotation axis 27 of the X-ray limiting member 22.

  In the diaphragm blade rotation mode, the interlocking control function 51 interlocks and controls the rotation mechanism 23 and the moving mechanism 24 so as to perform the interlocking control process shown in FIG. 7 for the opening 25a of the diaphragm blade 25 (step 4).

  In the filter rotation mode, the interlocking control function 51 interlocks and controls the rotation mechanism 23 and the moving mechanism 24 so as to perform interlocking control processing on the opening 26a of the ROI filter 26 (step 5).

  In each rotation mode, the rotation mechanism 23 may rotate the X-ray limiting member 22 integrally with the housing 21 around the rotation shaft 27 or only the X-ray limiting member 22 independently of the housing 21. May be rotated about the rotation axis 27.

  Then, in step S6 in FIG. 8, the image generation function 52 causes the display 42 to display an aperture area image 72 obtained by performing X-ray imaging on a partial area of the subject P corresponding to the aperture 22a.

  Although in FIG. 8 the instruction for rotating the opening 22a is received from the user in step S1, the position and shape of the region of interest 60 can be extracted automatically, and according to the position and shape of the extracted region of interest 60 The rotation mode may be automatically selected to move the opening 22a automatically, and step S2 and subsequent steps may be automatically performed. In this case, this step S1 may be omitted.

  According to the above procedure, even when the ideal rotation center 22ac of the opening 22a of the X-ray limiting member 22 is at a position different from the rotation axis 27 of the X-ray limiting member 22, the device coordinate system of the ideal rotation center 22ac of the opening 22a The aperture can be rotated while the spatial position at the position is substantially fixed.

  FIG. 9 is a subroutine flowchart showing an example of the procedure of the interlocking control process of the diaphragm blade 25 executed by the interlocking control function 51 in step S4 of FIG. The interlocking control process of the ROI filter 26 executed by the interlocking control function 51 in step S5 of FIG. 8 is the same as the interlocking control process of the diaphragm blade 25, and thus the description thereof is omitted.

  In the case where the opening 22 a is located near the end of the housing 21, the combination of the rotation by the rotation mechanism 23 and the parallel movement by the movement mechanism 24 may be combined for the movable limit of the X-ray limiting member 22. The region of interest 60 may not fit in the radiation field corresponding to the opening 22a. In this case, the interlock control function 51 controls at least one of the arm drive circuit 18 and the bed drive circuit 19 before performing the interlock control process shown in FIG. 9 or in parallel with the interlock control process. At least one of the X-ray limiting member 22 and the top plate 15 may be translated in the zx plane to change the relative positional relationship between the X-ray limiting member 22 and the top plate 15 in the zx plane. In this case, the interlocking control process shown in FIG. 9 may be executed based on the positional relationship between the ideal rotation center 22ac and the rotating shaft 27 after the relative positional relationship has been changed.

  In step S41, the interlocking control function 51 acquires information on the ideal rotation center 25ac of the opening 25a, the rotation direction, and the rotation amount θ. These pieces of information may be provided by the user via the input circuit 36 or the input circuit 41 in step S1, or if the position and shape of the region of interest 60 can be extracted automatically, the extracted region of interest 60 The interlocking control function 51 may automatically obtain it according to the position and shape of. For example, when the observation target is a stent indwelling inside the subject P and the stent marker provided on the stent can be detected on the X-ray image, the region of interest 60 is detected based on the detected position of the stent marker. Positions and shapes can be extracted automatically. Also, the ideal rotation center 25ac may be automatically set, for example, at the center or the center of gravity of the opening 25a.

  Next, in step S42, the rotation mechanism is performed such that the spatial position of the ideal rotation center 22ac of the opening 22a is substantially fixed according to the information of the ideal rotation center 22ac of the opening 22a, the rotation direction, and the rotation amount θ. The interlocking control of the moving mechanism 23 and the moving mechanism 24 is performed (see FIG. 5 and FIGS. 7A to 7C), and the process proceeds to step S6 in FIG.

  Note that the procedure shown in FIG. 9 is applicable to any of the diaphragm blade 25 and the ROI filter 26 as the processing target of interlocking control. When the target of the interlocking control process is the diaphragm blade 25, furthermore, each of the blade elements 251 to 254 is translated after interlocking control so that the position and shape of the opening 25a conform to the position and shape of the region of interest 60. You may In this case, for example, by narrowing the region of the opening 25a according to the shape of the region of interest 60, the exposure dose of the subject P can be reduced.

  FIG. 10 is an explanatory view showing an example of the superimposed image 70 in which the opening area image 72 is superimposed on the past image 71. As shown in FIG.

  The image generation function 52 may generate the superimposed image 70 as shown in FIG. 10 and display it on the display 42 in step S6 of FIG. In this case, the image generation function 52 stores the past image 71 obtained by imaging in advance the region of the subject P including the partial region of the subject P corresponding to the opening 22a into the storage circuit 31, the storage circuit 43 or the network Through an external medical image storage device. Then, the current aperture area image 72 obtained in real time by being viewed through the aperture 22a is superimposed on the corresponding position of the past image 71 to generate a superimposed image 70 and display on the display 42 (see FIG. 10). .

  FIG. 11 is an explanatory view showing an example of the superimposed image 70 when the positional relationship between the housing 21 and the top 15 is changed.

  Now, the past image 71 is an image taken by fully opening the diaphragm blade 25 at a predetermined position of the housing 21. After the photographing of the past image, the position of the housing 21 is left as it is, the aperture 25a of the diaphragm blade 25 is immediately It is assumed that the user sets the open area image 72 by the user.

  In this case, for example, while observing another region of interest initially located near the rotation axis 27, it is assumed that the user desires to observe the region of interest 60 towards the end of the superimposed image 70. In this case, the opening 22 a is located near the end of the housing 21, and the rotation by the rotation mechanism 23 and the parallel movement by the movement mechanism 24 can be combined with the opening 22 a because of the movable limit of the X-ray limiting member 22. There are cases where the region of interest 60 does not fit in the corresponding radiation field (see the upper part of FIG. 11).

  At this time, in order to fit the region of interest 60 in the irradiation field corresponding to the opening 22a, the user manually or automatically by the interlock control function 51 by the user via the bed drive circuit 19 and the top 15 in the z-axis direction Move by Δt. Then, the region of interest 60 fits in the radiation field corresponding to the opening 22a, and it becomes possible to capture the desired opening region image 72. However, the positional relationship between the housing 21 and the top 15 in the opening area image 72 captured after the movement of the top 15 is the same as the positional relationship between the housing 21 and the top 15 in the past image 71 that is the background of the superimposed image 70. Is different.

  Therefore, the image generation function 52 causes the image continuity at the junction (boundary) between the opening region image 72 and the past image 71 to be maintained when a part of the opening region image 72 protrudes from the past image 71. The past image 71 may be shifted in accordance with the amount of to generate the superimposed image 70. Specifically, the image generation function 52 may shift the past image 71 located in the background of the superimposed image 70 by the pixel width Δs corresponding to the change amount Δt of the positional relationship between the housing 21 and the top 15. (Refer to the lower part of FIG. 11).

  On the other hand, when it is necessary to change the positional relationship between the housing 21 and the top 15 in this manner, the past image 71 may be photographed again with a new positional relationship. In this case, the interlocking control function 51 first stores information on the spatial position (restoration position) of the current opening 22a after interlocking control in the storage circuit 31 or the storage circuit 43. Then, the interlocking control function 51 changes the positional relationship between the housing 21 and the top 15, and after capturing the past image 71, reads the information on the restoration position from the memory circuit 31 or the memory circuit 43, and The interlock control may be performed so that the opening 22a is positioned at the restoration position if the spatial position of the position is different from the read restoration position.

  According to the X-ray diagnostic apparatus 1 according to this embodiment, the opening 22a can be rotated while the spatial position of the ideal rotation center 22ac of the opening 22a is substantially fixed. Therefore, even when the ideal rotation center 22ac of the opening 22a of the X-ray limiting member 22 is at a position different from the rotation axis 27 of the X-ray limiting member 22, the user instructs the rotation direction and the rotation angle with a joystick or the like. The opening 22a can be rotated very simply by performing the above. Therefore, even if the region of interest 60 is at a position away from the rotation axis 27 and has an inclined shape, the user can fit the opening 22a to the region of interest 60 by a very simple operation. Further, the user can easily grasp, for example, the minimum shape of the opening 22a including the region of interest 60 by rotating the opening 22a. For this reason, a useless opening area can be decreased and the exposure dose of the subject P can be reduced.

  According to at least one embodiment described above, even if the ideal rotation center 22 ac of the opening 22 a of the X-ray limiting member 22 is at a position different from the rotation axis 27 of the X-ray limiting member 22, the ideal of the opening 22 a The opening can be rotated while the spatial position of the rotation center 22ac is substantially fixed.

  The interlock control function 51 and the image generation function 52 of the processing circuit 32 in the present embodiment are an example of the interlock control unit and the image generation unit in the claims respectively. Further, the arm drive circuit 18 and the bed drive circuit 19 in the present embodiment are each an example of the drive unit in the claims. The storage circuits 31 and 43 in the present embodiment are an example of the storage unit in the claims. The input circuits 36 and 41 in the present embodiment are an example of the input unit in the claims.

  In the above embodiment, the word “processor” means, for example, a dedicated or general-purpose central processing unit (CPU), a graphics processing unit (GPU), or an application specific integrated circuit (ASIC), By circuits such as programmable logic devices (eg, Simple Programmable Logic Devices (SPLDs), Complex Programmable Logic Devices (CPLDs), and FPGAs) are meant. The processor implements various functions by reading and executing a program stored in a storage medium.

  In the above embodiment, an example in which a single processor of the processing circuit realizes each function is described. However, a plurality of independent processors are combined to form a processing circuit, and each processor realizes each function. It is also good. When a plurality of processors are provided, storage media for storing programs may be individually provided for each processor, or one storage medium may collectively store programs corresponding to the functions of all processors. It is also good.

  While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

DESCRIPTION OF SYMBOLS 1 ... X-ray diagnostic apparatus 15 ... Top plate 20 ... X-ray movable aperture 22 ... X-ray limiting member 22a ... Opening 22ac ... Ideal rotation center 23 ... Rotation mechanism 24 ... Movement mechanism 25 ... Aperture blade 25a ... Aperture blade opening 25ac ... Ideal rotation center 25c of the diaphragm blade ... Rotation center 26 of the diaphragm blade ... ROI filter 26a ... Opening 26ac of the ROI filter ... Ideal rotation center 26c of the ROI filter ... Rotation center 27 of the ROI filter ... Rotation shaft 30 of the X-ray limiting member 30 ... diaphragm Control devices 31, 43: Memory circuits 32, 44: Processing circuits 36, 41: Input circuits 42: Display 51: Interlocking control function 52: Image generation function 60: Region of interest 70: Superimposed image 71: Past image 72: Opening area image 251-254 ... feather element

Claims (12)

An X-ray limiting portion having an opening through which X-rays pass;
A rotation mechanism for rotating the X-ray limiting unit around a predetermined rotation axis;
A moving mechanism for translating the opening in parallel;
In conjunction with the rotation of the X-ray limiting unit by the rotation mechanism such that at least a part of the X-ray radiation region that has passed through the opening is kept within the X-ray radiation region before interlock control. An interlock control unit that performs interlock control to control the rotation mechanism and the movement mechanism so as to move the opening in parallel by the movement mechanism;
X-ray diagnostic device equipped with The X-ray limiting unit
A diaphragm blade comprising a plurality of blade elements shielding x-rays,
Have
The movement mechanism is
Translating the position of the opening by translating each of the plurality of vane elements;
The X-ray diagnostic apparatus according to claim 1. The movement mechanism is
After the interlock control, each of the plurality of blade elements is translated according to the position and shape of the region of interest of the subject.
The X-ray diagnostic apparatus according to claim 2. The X-ray limiting unit
A region-of-interest filter comprising a member that attenuates and transmits the X-rays, and the opening is provided in a part of the member;
Have
The movement mechanism is
Translating the position of the aperture by translating the region of interest filter;
The X-ray diagnostic apparatus according to claim 1. The interlocking control unit
The interlocking control is performed so that the spatial position of the ideal rotation center of the opening is substantially fixed.
The X-ray diagnostic apparatus according to any one of claims 1 to 4. An input unit that receives an instruction by a user of a rotational direction and an amount of rotation about the ideal rotational center of the opening;
And further
The interlocking control unit
The interlock control is performed so that the spatial position of the ideal rotation center is substantially fixed according to a user instruction received via the input unit.
The X-ray diagnostic apparatus according to claim 5. The interlocking control unit
Information on the position and shape of the region of interest of the subject is acquired, and the position, direction and amount of rotation of the ideal rotation center are determined based on the position and shape of the region of interest on the acquired subject Performing the interlocking control such that the spatial position of the ideal rotation center is substantially fixed according to the position of the lens, the rotation direction, and the rotation amount.
The X-ray diagnostic apparatus according to claim 5. A driving unit configured to change a relative positional relationship between the X-ray limiting unit and the top plate by moving in parallel at least one of the X-ray limiting unit and the top plate on which the subject is placed;
And further
The interlocking control unit
If the relative positional relationship between the X-ray limiting unit and the top plate is changed by the drive unit and the positional relationship between the ideal rotation center of the opening and the predetermined rotation axis is changed, the change is made after the change. Performing the interlocking control such that the spatial position of the ideal rotation center of the opening is substantially fixed based on the positional relationship between the ideal rotation center of the opening and the predetermined rotation axis;
The X-ray diagnostic apparatus according to any one of claims 5 to 7. The interlocking control unit
Storing information on a spatial position of the opening after the interlocking control in a storage unit;
An X-ray diagnostic apparatus according to any one of claims 1 to 8. The interlocking control unit
The information on the spatial position of the opening stored in the storage unit is read out, and if the current spatial position of the opening is different from the position read out from the storage unit, the value of the opening read out from the storage unit The interlock control is performed so that the opening is positioned at a spatial position.
The X-ray diagnostic apparatus according to claim 9. An opening area obtained by capturing in advance a past image obtained by imaging in advance the area of the subject including the partial area of the subject corresponding to the opening, and performing X-ray imaging of the partial area corresponding to the opening An image generation unit that generates a superimposed image in which an image is superimposed on a position corresponding to the partial region of the past image, and displays the superimposed image on a display;
The X-ray diagnostic apparatus according to any one of claims 1 to 10, further comprising: The image generation unit
The past image is shifted in accordance with the amount of the overhang so that continuity of the image at the boundary between the aperture area image and the past image is maintained when a part of the aperture area image protrudes from the past image. Generating the superimposed image,
The X-ray diagnostic apparatus according to claim 11.

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