JP2014030680A - X-ray diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray diagnostic apparatus capable of reducing a radiation exposure dose of a subject.SOLUTION: The X-ray diagnostic apparatus includes an X-ray tube 16 generating X-ray with which a subject P is irradiated, and an X-ray beam limiting device 17 capable of varying the number of irradiation ports through which the X-ray from the X-ray tube 16 passes. The X-ray beam limiting device 17 forms two of first and second irradiation ports 91, 92 separated from each other by first blades 60 arranged in three or more rows to be movable in a predetermined direction for shielding part of the X-ray from the X-ray tube 16 to form the irradiation ports, and second blades 70 arranged in two or more rows to be movable in a direction different from the moving direction of the first blades 60.

Description

  Embodiments described herein relate generally to an X-ray diagnostic apparatus including an X-ray diaphragm that can change an irradiation range of X-rays irradiated to a subject.

  In recent years, X-ray diagnostic apparatuses have made progress mainly in the field of circulatory organs with the development of angiographic examinations using catheters and IVR (Interventional Radiology). This X-ray diagnostic apparatus movably supports an X-ray irradiation unit that irradiates a subject with X-rays, an X-ray detector that detects X-rays transmitted through the subject, and a top plate on which the subject is placed It has a couch to play. Then, image data is generated based on the X-rays detected by the X-ray detector.

  The X-ray irradiation unit includes an X-ray tube that generates X-rays, an X-ray tube that can change the irradiation range of the X-rays irradiated to the subject, and an X-ray stop disposed between the subject. The X-ray diaphragm includes a plurality of blades that shield X-rays and a drive mechanism that drives the blades, and restricts the X-ray irradiation range from the X-ray tube to irradiate a desired part of the subject.

JP 2008-220 A

  However, when image data of a plurality of parts separated from each other at the same timing is required, X-ray irradiation is required for a range surrounding the plurality of parts of the subject. There is a problem of irradiating X-rays.

  The embodiment has been made to solve the above problems, and an object thereof is to provide an X-ray diagnostic apparatus capable of reducing the exposure dose of a subject.

  In order to solve the above problem, the X-ray diagnostic apparatus according to the embodiment can vary the number of X-ray tubes that generate X-rays to be irradiated on a subject and the number of irradiation ports through which the X-rays from the X-ray tube pass. An X-ray diaphragm, an X-ray detector that detects X-rays that are irradiated with the X-rays that have passed through the irradiation port, and transmitted through the subject, and image data based on the X-rays that are detected by the X-ray detector The X-ray diaphragms are arranged in three or more rows so as to be movable in a predetermined direction to shield the part of the X-rays from the X-ray tube and form the irradiation port. The first blades and the second blades arranged in two or more rows so as to be movable in a direction different from the moving direction of the first blades.

The block diagram which shows the structure of the X-ray diagnostic apparatus which concerns on embodiment. The figure which shows an example of a structure of the X-ray diaphragm which concerns on embodiment. The figure which shows the position of the irradiation port of the X-ray diaphragm which concerns on embodiment. The flowchart which shows operation | movement of the X-ray diagnostic apparatus which concerns on embodiment. The figure which shows an example of the image data displayed on the display part which concerns on embodiment. The figure which shows the 1st and 2nd passage position of the X-ray diaphragm through which the X-ray which irradiates the 1st and 2nd site | part of the subject which concerns on embodiment passes. The figure for demonstrating the calculation of the angle of the X-ray aperture and the position of an irradiation port which reduce the area of the irradiation port which X-rays pass concerning embodiment. The figure which shows the X-ray diaphragm which formed the 1st and 2nd irradiation port which concerns on embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the configuration of the X-ray diagnostic apparatus. The X-ray diagnostic apparatus 100 includes a top plate 10 on which the subject P is placed, an X-ray irradiation unit 15 that irradiates the subject P placed on the top plate 10 with X-rays, and an X-ray irradiation unit. 15 includes an X-ray detection unit 20 that detects X-rays that have passed through the subject P by irradiation, and an arm 25 that holds the X-ray irradiation unit 15 and the X-ray detection unit 20.

  In addition, the X-ray diagnostic apparatus 100 includes a moving mechanism unit 30 that moves the top plate 10 and the arm 25 and rotates the X-ray irradiation unit 15 and the X-ray detection unit 20, and an X-ray irradiation unit 15. A voltage generation unit 35, an image processing unit 40 that generates image data based on a signal detected by the X-ray detection unit 20, a display unit 45 that displays image data generated by the image processing unit 40, and various commands An operation unit 50 that performs input and the like, and a system control unit 55 that controls each unit described above are provided.

  The X-ray irradiating unit 15 irradiates the subject P with X-ray tube 16 that generates X-rays for imaging with higher energy than that for fluoroscopy and fluoroscopy. An X-ray stop 17 that is arranged so as to be rotatable about an irradiation axis 15a that connects the centers of detection surfaces for detecting X-rays, and that can change the number of irradiation ports through which X-rays from the X-ray tube 16 pass, and X-rays And an aperture control unit 18 for controlling the aperture 17.

  The X-ray detection unit 20 is an X-ray that can be rotated about an irradiation axis 15 a that detects X-rays that have been irradiated through the irradiation port of the X-ray diaphragm 17 in the X-ray irradiation unit 15 and transmitted through the subject P. A detector 21 and a signal processing unit 22 that generates X-ray projection data based on a signal detected by the X-ray detector 21 are provided.

  The moving mechanism unit 30 includes a top plate / arm moving mechanism 31 that moves the top plate 10 and the arm 25 independently, an X-ray diaphragm 17 of the X-ray irradiation unit 15, and an X-ray detector 21 of the X-ray detection unit 20. And an X-ray aperture / detector moving mechanism 32 that rotates independently about the irradiation axis 15a. Then, the top / arm moving mechanism 31 moves the top 10 in the longitudinal direction, the lateral direction, and the vertical direction. Further, the arm 25 is moved in the longitudinal direction, the lateral direction, and the vertical direction of the top plate 10. Further, the arm 25 is rotated.

  The image processing unit 40 includes an image data generation unit 41 that generates image data based on X-ray projection data generated by the signal processing unit 22 of the X-ray detection unit 20 by X-ray irradiation to the subject P. . Further, the angle of the X-ray diaphragm 17 and the position of the irradiation port in the X-ray irradiation unit 15 are calculated based on the region of interest specified on the image data generated by the image data generation unit 41 by the input from the operation unit 50. An irradiation port position calculation unit 42 is provided.

  The display unit 45 includes a liquid crystal panel or a CRT monitor, and displays the image data generated by the image data generation unit 41 of the image processing unit 40. The operation unit 50 includes input devices such as a keyboard, a trackball, a joystick, a mouse, and a switch. Then, an input for setting X-ray irradiation conditions, an input for starting fluoroscopy, an input for stopping fluoroscopy, an input for designating a region of interest of image data displayed on the display unit 45, and the like are performed.

  The system control unit 55 includes a CPU and a storage circuit, temporarily stores input information input from the operation unit 50, and then, based on the input information, the X-ray irradiation unit 15, the X-ray detection unit 20, and the moving mechanism. The unit 30, the high voltage generation unit 35, and the image processing unit 40 are controlled in an integrated manner.

Next, with reference to FIG. 1 thru | or FIG. 3, the detail of a structure of the X-ray diaphragm 17 of the X-ray irradiation part 15 is demonstrated.
FIG. 2 is a diagram showing an example of the configuration of the X-ray diaphragm 17. FIG. 2A shows the X-ray diaphragm 17 viewed from the X-ray detector 20 side in the direction of the irradiation axis 15a, and FIG. 2B shows A of the X-ray diaphragm 17 in FIG. A cross-sectional view taken along arrow A is shown.

  The X-ray diaphragm 17 includes first blades 60 arranged in three or more rows so as to be movable in a predetermined direction that shields a part of the X-rays from the X-ray tube 16 and forms an irradiation port, and the first There are provided second blades 70 arranged in two or more rows so as to be movable in a direction different from the moving direction of the blades 60. In addition, the first and second support portions 80 and 81 that movably support the first and second blades 60 and 70 and the first and second blades that drive the first and second blades 60 and 70 are supported. Drive mechanisms 82 and 83, first and second support portions 80 and 81, and a frame 84 that supports the first and second drive mechanisms 82 and 83 are provided.

  The first blade 60 is made of a material that absorbs X-rays, such as tungsten and molybdenum, and includes, for example, nine first blades 61 to 69. Each of the first blades 61 to 69 has a rectangular plate shape of the same size, and in the first shielding position B1 that shields X-rays from the X-ray tube 16, the direction of the arrow L1 in the short direction, which is the arrangement direction, and They are arranged so as to be independently movable in the direction of the arrow L2 opposite to the L1 direction. Further, when all the first blades 61 to 69 are aligned at the first shielding position B1, the adjacent end portions are closely arranged in a line in the short direction so as to overlap each other. Then, a surface perpendicular to the irradiation axis 15a is formed to close the irradiation port.

  The second blade 70 is made of the same material as that of the first blade 60 and includes, for example, nine second blades 71 to 79. Each of the second blades 71 to 79 has a rectangular plate shape with the same length shorter than the first blades 61 to 69 in the longitudinal direction, and shields X-rays from the X-ray tube 16. In the shielding position B2, they are arranged so as to be able to move independently in the direction of the arrow L3 perpendicular to the L1 direction in the short direction which is the arrangement direction or in the direction of the arrow L4 opposite to the L3 direction. And when all the 2nd blade | wings 71 thru | or 79 align in 2nd shielding position B2, it arranges closely in a short direction so that an adjacent edge part may mutually overlap. Then, a surface perpendicular to the irradiation axis 15a is formed to close the irradiation port.

  The first support part 80 is disposed through the nine support bodies 801 fixed to one end of each of the first blades 61 to 69 and the support bodies 801, and each of the first blades 61 to 69. The both ends of the inverted U-shape forming the track are formed by rails 802 fixed to the frame 84. At the first shielding position B1, the first blades 61 to 69 are guided in the L1 direction and the L2 direction. In addition, at the first retraction position C1 through which the X-rays from the X-ray tube 16 pass, each of the first blades 61 to 69 located at the end of the first shielding position B1 draws an arc with a predetermined curvature. Then, it is guided in the direction of the arrow L5 that is the direction of the end of the rail 802 parallel to the irradiation axis 15a. Further, the first blades 61 to 69 at the first retracted position C1 are guided in the direction of arrow L6 opposite to the L5 direction.

  The second support portion 81 is disposed through the nine support bodies 811 fixed to one end of each of the second blades 71 to 79 and the support bodies 811, and each of the second blades 71 to 79. Both ends of the inverted U-shape that forms the track of this are constituted by rails 812 fixed to the frame 84. At the second shielding position B2, the second blades 71 to 79 are guided in the L3 direction and the L4 direction. Further, at the second retracted position C2 through which the X-rays from the X-ray tube 16 pass, each of the second blades 71 to 79 positioned at the end of the second shielding position B2 draws an arc with a predetermined curvature. Then, it is guided in the L5 direction which is the direction of the end of the rail 812 parallel to the irradiation axis 15a. Further, the second blades 71 to 79 at the second retracted position C2 are guided in the L6 direction.

  The first drive mechanism 82 is fixed to nine motors 821 that are driven and controlled by the diaphragm control unit 18 that is fixed in the vicinity of the other end of each of the first blades 61 to 69 and the rotation shaft of each motor 821. It is composed of nine pinion gears 822. Further, both end portions are fixed to the frame 84 and configured by inverted U-shaped rack gears 823 that engage with the respective pinion gears 822. The rack gear 823 has teeth that engage with the pinion gear 822 on the front surface, and supports the other end portions of the first blades 61 to 69 on the back surface. The first blades 61 to 69 are independently driven along the rack gear 823 and the rail 802 by the rotation of the pinion gear 822 by the driving force of each motor 821.

  The second drive mechanism 83 is fixed to nine motors 831 that are driven and controlled by the diaphragm control unit 18 fixed in the vicinity of the other end of each of the second blades 71 to 79 and the rotation shaft of each motor 831. It is composed of nine pinion gears 832. Further, both ends are fixed to the frame 84, and an inverted U-shaped rack gear 833 engaged with the pinion gear 832 is formed. The rack gear 833 has teeth on the front surface that engage with the pinion gears 832, and supports the other ends of the second blades 71 to 79 on the back surface. Then, the second blades 71 to 79 are driven independently along the rack gear 833 and the rail 812 by the rotation of the pinion gear 832 by the driving force of each motor 831.

  FIG. 3 is a diagram showing the position of the irradiation port of the X-ray diaphragm 17. The X-ray diaphragm 17 opens an overlapping portion of the first and second blades 61 and 71 among the first and second blades 60 and 70 arranged at the first and second shielding positions B1 and B2. By moving the first and second blades 61 and 71 to the first and second retracted positions C1 and C2, a rectangular irradiation port is formed at the position a1. Further, the movement of the first blade 61 that opens the overlapping portion of the first and second blades 61 and 72 to the first retracted position C1, and the movement of the second blade 71 to the second retracted position C2 are performed. And, by moving the second blade 72 by one pitch in the L4 direction (the length of the second blades 71 to 79 in the short direction), a rectangular irradiation port is formed at the position a2. Further, a rectangular irradiation port is formed at each position a3 to a9 by the movement of the first blade 61 and the second blades 71 to 79 that open the overlapping portion of the first blade 61 and the second blades 73 to 79. Form.

  Moreover, the 1st blade | wing which open | releases the overlap part of the 1st and 2nd blade | wings 62 and 71 among the 1st and 2nd blade | wings 60 and 70 arranged in 1st and 2nd shielding position B1, B2. 61 is moved to the first retraction position C1, and the first blade 62 is moved by one pitch in the L1 direction (the length in the short direction of each of the first blades 61 to 69), and the second blade 71 As a result of the movement to the second retreat position C2, a rectangular irradiation port is formed at the position b1. Further, the first blades 61 and 62 and the second blades 71 to 79 that open the overlapping portions of the first blade 62 and the second blades 72 to 79 move to each position b2 to b9 in a square shape. The irradiation port is formed.

  Of the first and second blades 60 and 70 arranged at the first and second shielding positions B1 and B2, any of the first blades 61 to 69 and any of the second blades 71 to 79 are provided. By moving the first blades 61 to 69 and the second blades 71 to 79 that open the overlapping portions, rectangular irradiation ports are formed at the positions a1 to i9. Further, each of the first blades 61 to 69 and each of the second blades 71 to 79 is narrower or wider than the positions a1 to i9 by moving the first and second shielding positions B1 and B2 to arbitrary positions. One or a plurality of rectangular irradiation ports are formed at an arbitrary position.

  In addition, the first and second blades 60 and 70 that open the overlapping portion of the first and second blades 60 and 70 arranged at the first and second shielding positions B1 and B2 are used. By moving to the retreat positions C1 and C2, a rectangular irradiation port 90 having a maximum area is formed at all positions a1 to i9. The X-rays from the X-ray tube 16 that have passed through the irradiation port 90 of the X-ray diaphragm 17 at the home position are directed toward the entire X-ray detection surface of the X-ray detector 21 at the home position of the X-ray detection unit 20. Irradiated.

  As described above, the first blades 60 constituted by the first blades 61 to 69 that shield the X-rays from the X-ray tube 16 are provided so as to be independently movable, and the second blades 71 to 79 are used. By providing the configured second blade 70 so as to be independently movable in a direction different from the moving direction of the first blade 60, each position a1 to i9 and any position narrower than each position a1 to i9 A plurality of irradiation ports can be formed at arbitrary positions wider than the positions a1 to i9.

  Hereinafter, an example of the operation of the X-ray diagnostic apparatus 100 will be described with reference to FIGS. 1 to 8.

  FIG. 4 is a flowchart showing the operation of the X-ray diagnostic apparatus 100. After the subject P is placed on the top 10 and the top 10 and the arm 25 are moved to a position where X-rays can be irradiated to a predetermined part of the subject P, the X of the X-ray irradiation unit 15 is moved. An input for setting the angle of the X-ray detector 17 of the X-ray detector 17 and the X-ray detector 20 to the home position, an input for setting the X-ray aperture 17 to the irradiation port 90, an input of the X-ray irradiation conditions, and the like from the operation unit Once performed, the X-ray diagnostic apparatus 100 starts operating (step S1).

  The system control unit 55 instructs the X-ray irradiation unit 15, the X-ray detection unit 20, the movement mechanism unit 30, the high voltage generation unit 35, and the image processing unit 40 to see the subject P and generate image data. Then, the diaphragm control unit 18 of the X-ray irradiation unit 15 controls the X-ray diaphragm 17. The X-ray diaphragm 17 has an irradiation aperture by driving the first and second drive mechanisms 82 and 83 in which all the first and second blades 60 and 70 move to the first and second retracted positions C1 and C2. 90 is formed.

  Next, when fluoroscopic start input is performed from the operation unit 50, the high voltage generation unit 35 drives the X-ray tube 16 to be irradiated. The X-ray tube 16 generates X-rays for fluoroscopy, and the X-ray diaphragm 17 irradiates the subject P on the top 10 with the X-rays that have passed through the irradiation port 90. The X-ray detection unit 20 detects X-rays transmitted through the subject P and generates X-ray projection data.

  The image data generation unit 41 of the image processing unit 40 generates image data at the first frame rate based on the X-ray projection data generated by the X-ray detection unit 20. Then, the generated image data is output to the irradiation port position calculating unit 42 and the display unit 45 for each frame. The display unit 45 displays the image data generated by the image data generation unit 41 in real time (step S2).

  FIG. 5 is a diagram illustrating an example of image data displayed on the display unit 45. The image data 46 is image data generated based on a signal that is irradiated with X-rays that have passed through the irradiation port 90 of the X-ray diaphragm 17 at the home position and detected by the X-ray detector 21 at the home position.

  The image data 46 displayed on the display unit 45 includes, for example, a first region of interest 461 and a second region of interest 462 at a position separated from the first region of interest 461. When it is necessary to observe the data of the two first and second regions of interest 461 and 462 at the same timing, the first region of interest 461 and the second region of interest 462 are displayed on the image data 46 from the operation unit 50. Is input, the irradiation port position calculating unit 42 performs the first and second two of the subject P corresponding to the first and second regions of interest 461 and 462 designated on the image data 46. The first and second passing positions of the X-ray diaphragm 17 through which the X-rays irradiating the region pass are obtained (step S3 in FIG. 4).

  FIG. 6 is a diagram showing first and second passage positions of the X-ray diaphragm 17 through which X-rays irradiating the first and second parts of the subject P pass. The first passage position P1 through which the X-rays irradiating the first part of the subject P pass is the first and second blades 60 and 70 arranged at the first and second shielding positions B1 and B2. For example, the first blades 65 and 66 and the second blades 74 and 75 are included in the four positions e4, e5, f4, and f5 shown in FIG.

  The second passage position P2 through which the X-rays irradiating the second part of the subject P pass is the first and second blades 60 arranged in the first and second shielding positions B1, B2. 70, the first blades 63, 64 and the second blades 76, 77 are included in the four positions c6, c7, d6, d7 shown in FIG.

  Next, the irradiation port position calculation unit 42 passes X-rays that irradiate a range including the first and second parts of the subject P based on the obtained first and second passage positions P1 and P2. The angle of the X-ray diaphragm 17 that reduces the area of the irradiation port 90 and the position of the irradiation port are calculated (step S4 in FIG. 4).

  FIG. 7 is a diagram for explaining the calculation of the angle of the X-ray diaphragm 17 and the position of the irradiation port for reducing the area of the irradiation port 90 through which X-rays pass. 7A shows the angle of the X-ray stop 17 that reduces the area of the irradiation port 90, and FIG. 7B shows the irradiation port of the X-ray stop 17 at an angle that reduces the area of the irradiation port 90. Indicates the position.

  In FIG. 7A, a quadrangle Q having an irradiation port shape that minimizes the area surrounding the first and second passage positions P1, P2 is obtained. Further, the first passing position P1 and the second passing position P2 are connected by a straight line parallel to one side of the quadrangle Q, and the length D1 of the straight line S at the position where the connected straight line is the shortest is obtained.

  When one pitch of each of the first blades 61 to 69 or each of the second blades 71 to 79 is shorter than the length D1, one pitch is long between the first passage position P1 and the second passage position P2. It is determined that one of the first blades 61 to 69 or the second blades 71 to 79 shorter than the length D1 can be arranged to shield the X-rays from the X-ray tube 16.

Hereinafter, an example of how to obtain the angle of the X-ray diaphragm 17 and the position of the irradiation port for reducing the area of the irradiation port 90 when one pitch of each of the second blades 71 to 79 is shorter than the length D1 will be described. .
First, the angle θ of the straight line S with respect to the L3 direction, which is the movable direction of each of the second blades 71 to 79, whose one pitch is shorter than the length D1, is calculated. An X-ray diaphragm 17 that is rotated about the irradiation axis 15a so that the straight line S is parallel to the L3 direction is assumed. Here, the X-ray diaphragm 17 at the home position in FIG. 7A is rotated by an angle θ in the direction of arrow R1, which is a counterclockwise direction.

  In FIG. 7B, the position of the quadrangle Q in the X-ray diaphragm 17 rotated by an angle θ from the home position in the R1 direction is calculated. The first and second blades 61 to 69 and the second blades 71 to 79 surrounding the quadrangle Q at the first and second shielding positions B1 and B2, and the first passage position P1 and the second passage The arrangement of the second blades 71 to 79 that shield between the passage positions P2 is calculated. Here, the quadrangle Q coincides with the positions e4 to e7 shown in FIG. A straight line S connecting the first passing position P1 and the second passing position P2 is included in the positions e5 and e6. Accordingly, the positions a1 to i9 other than the two positions e4 and e7 are shielded, and the positions e4 and e7 are set as two irradiation ports.

  When the position of the quadrangle Q on the X-ray diaphragm 17 rotated by an angle θ in the R1 direction from the home position deviates from the positions a1 to i9, the top / arm is moved so that the position of the quadrangle Q falls within the positions a1 to i9. The top plate 10 or the arm 25 is moved by the mechanism 31.

  The X-ray diaphragm / detector moving mechanism 32 of the moving mechanism section 30 moves the X-ray diaphragm 17 and the X-ray detector 21 to the home position based on the angle θ of the X-ray diaphragm 17 calculated by the irradiation port position calculating section 42. Is rotated in the direction of R1 from the angle θ (step S5 in FIG. 4).

  The first and second drive mechanisms 82 and 83 are controlled by the diaphragm control unit 18 based on the irradiation port positions e4 and e7 calculated by the irradiation port position calculation unit 42, respectively. Two first and second irradiation ports are formed at two positions e4 and e7 that move away from the second blades 71 to 79 (step S6 in FIG. 4).

  If X-rays emitted from the first and second irradiation ports can be detected by the X-ray detector 21 at the home position, only the X-ray diaphragm 17 is rotated from the home position. Also good.

  FIG. 8 is a view showing the X-ray diaphragm 17 in which the first and second irradiation ports are formed. In the X-ray diaphragm 17, a first irradiation port 91 is formed at a position e4, and a second irradiation port 92 is formed at a position e7. In the first shielding position B1, the first blades 61 to 64 and the first blades 65 to 68 are closely arranged in a row with the positions e4 and e7 being opened, and the first retracted position B1. First blades 69 are arranged in C1.

  Further, at the second shielding position B2, the second blades 72 to 74, the second blades 75 and 76, and the second blades 77 and 78 are in close contact with each other with the positions e4 and e7 being opened. The second blades 71 and 79 are arranged at the second retracted position C2.

  As described above, when the data of the two first and second regions of interest 461 and 462 that are separated are required at the same timing, the first and second portions of the subject P that can be radiated separately. And the 2nd irradiation ports 91 and 92 can be formed. This makes it possible to prevent X-ray irradiation to an unnecessary part of the subject P, thereby reducing the exposure amount of the subject P.

  X-rays that have passed through the first and second irradiation ports 91 and 92 of the X-ray diaphragm 17 are irradiated onto the subject P, and the first image data generation unit 41 detects the X-rays that have passed through the subject P. Data of the first and second regions of interest 461 and 462 generated at the frame rate are displayed on the display unit 45.

  Here, when an input is performed to lower the frame rate of the data of the second region of interest 462 that does not require a higher frame rate than the data of the first region of interest 461, the first irradiation port 91 is opened and the first irradiation port 91 is opened. The second drive mechanism 83 drives the second blades 77 to 79 by one pitch and closes the second irradiation port 92 at regular intervals, so that the X-rays continuously passing through the first irradiation port 91 and The subject P is irradiated with X-rays that pass through the second irradiation port 92 at regular intervals. Then, the image data generation unit 41 generates data of the first region of interest 461 at the first frame rate, and the predetermined frame corresponding to the X-rays that pass through the second irradiation port 92 at a constant interval. Data of the second region of interest 462 is generated at a frame rate lower than the rate.

  In this way, by opening and closing the second irradiation port 92 and making it shorter than the opening time of the first irradiation port 91, it becomes possible to shorten the irradiation time of the X-rays irradiated to the subject P. The exposure dose of the specimen P can be reduced.

  When the irradiation stop is input from the operation unit 50, the system control unit 55 ends the imaging to the X-ray irradiation unit 15, the X-ray detection unit 20, the moving mechanism unit 30, the high voltage generation unit 35, and the image processing unit 40. When instructed, the X-ray diagnostic apparatus 100 ends the operation (step S7 in FIG. 4).

  According to the above-described embodiment, the first blades 60 constituted by the first blades 61 to 69 that shield the X-rays from the X-ray tube 16 are provided so as to be independently movable, and the second By providing the second blade 70 composed of the blades 71 to 79 so as to be independently movable in a direction different from the moving direction of the first blade 60, the positions a1 to i9 and the positions a1 to i9 are used. In addition, a plurality of irradiation ports can be formed at arbitrary narrow positions and at arbitrary positions wider than the positions a1 to i9.

  Then, the first and second parts of the subject P can be irradiated separately by inputting from the operation unit 50 that designates the two first and second regions of interest 461 and 462 that are separated from each other on the image data 46. First and second irradiation ports 91 and 92 can be formed. This makes it possible to prevent X-ray irradiation to an unnecessary part of the subject P, thereby reducing the exposure amount of the subject P.

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

15 X-ray irradiation unit 15a Irradiation axis 16 X-ray tube 17 X-ray aperture 18 Aperture control unit 21 X-ray detector 41 Image data generation unit 42 Irradiation port position calculation unit 45 Display units 60, 61 to 69 First blade 70, 71 to 79 Second blade 80 First support portion 81 Second support portion 82 First drive mechanism 83 Second drive mechanism

Claims (6)

An X-ray tube for generating X-rays for irradiating the subject;
An X-ray diaphragm capable of varying the number of irradiation ports through which X-rays from the X-ray tube pass;
An X-ray detector that detects X-rays irradiated by the X-rays that have passed through the irradiation port and transmitted through the subject;
An image data generation unit that generates image data based on X-rays detected by the X-ray detector;
The X-ray diaphragm is configured to shield at least a part of X-rays from the X-ray tube, and the first blades arranged in three or more rows so as to be movable in a predetermined direction to form the irradiation port, and the first An X-ray diagnostic apparatus having second blades arranged in two or more rows so as to be movable in a direction different from the moving direction of the blades. The X-ray diaphragm includes a first drive unit that independently drives the first blade in the arrangement direction of the first blade at a first shielding position that shields X-rays from the X-ray tube, and the X-ray A second drive unit that independently drives the second blade in the arrangement direction of the second blade at a second shielding position that shields X-rays from the ray tube;
The X-ray diagnostic apparatus according to claim 1, wherein a shape of the irradiation port formed by the first and second blades is a quadrangle. An operation unit capable of inputting a first region of interest and a second region of interest separated from the first region of interest on the image data generated by the image data generation unit;
The X-ray diaphragm includes a first passage position through which X-rays irradiate a first part of the subject corresponding to the first region of interest and a portion of the subject corresponding to the second region of interest. With respect to a straight line parallel to one side of the quadrangle that connects the second passing positions through which the X-rays irradiating the second part pass and minimizes the area surrounding the first and second passing positions. The X-ray diagnosis according to claim 2, wherein the first or second blade is rotated in a direction in which a moving direction of the blades whose length in the arrangement direction of the first or second blade is shorter than the length of the straight line is parallel. apparatus.   The X-ray diaphragm is configured to shield the X-rays from the X-ray tube by arranging the short blades between the first passing position and the second passing position at a rotated angle. Item 4. The X-ray diagnostic apparatus according to Item 3.   The X-ray diaphragm arranges the first and second blades at the first and second shielding positions so as to surround the quadrangle that minimizes the area surrounding the first and second passage positions. The X-ray diagnostic apparatus according to claim 4, wherein:   The X-ray diaphragm forms the first irradiation port at the first passage position by arranging the first and second blades at the first and second shielding positions, and the second passage. The second irradiation port spaced from the first irradiation port is formed at a position, and the time for closing the second irradiation port is increased more than the first irradiation port. X-ray diagnostic equipment.

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