JP2005152002A - Fluoroscopic and radiographic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a mechanical configuration near a grid for scattered X-ray removal from being complicated by making the grid for scattered X-ray removal set at the front of a flat panel type X-ray detection means possible to be easily retracted. <P>SOLUTION: In the fluoroscopic and radiographic system, not only the grid 9 for the scattered X-ray removal is reciprocatingly moved by one mechanism 10 used for both grid reciprocating movement/forward and backward movement, but also the grid 9 for the scattered X-ray removal is moved back and withdrawn to a withdrawing position PB off a flat panel type X-ray detector (FPD) 3. As a result, since the grid 9 for the scattered X-ray removal is retracted by the mechanism 10 used for both grid reciprocating movement/forward and backward movement, the grid 9 for the scattered X-ray removal is easily retracted. Also, since the mechanical configuration for the grid reciprocating movement and the mechanical configuration for grid withdrawal are integrated in the mechanism 10 used for both grid reciprocating movement/forward and backward movement, the mechanical configuration near the grid 9 for the scattered X-ray removal is not complicated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention obtains an X-ray fluoroscopic image of a subject based on an X-ray detection signal output from a flat panel type X-ray detection unit in accordance with the X-ray irradiation to the subject by the X-ray irradiation unit. In particular, the present invention relates to a technique for reciprocating and retracting a scattered X-ray removal grid set in front of a flat panel X-ray detection means.

  As shown in FIG. 6, a conventional X-ray fluoroscopic apparatus used in a hospital or the like has an X-ray tube 51 that irradiates a subject M with X-rays and a flat panel type that detects transmitted X-rays of the subject M. An X-ray detector (hereinafter referred to as “FPD” where appropriate) 52 is disposed oppositely with the top plate 53 in between, and the subject M on the top plate 53 is irradiated with X-rays from the X-ray tube 51. Accordingly, an X-ray fluoroscopic image of the subject M is acquired based on the X-ray detection signal output from the FPD 52 and displayed on the screen of a display monitor (not shown). In the case of a conventional X-ray fluoroscopic apparatus, a scattered X-ray removal grid 54 is set in front of the FPD 52 to prevent scattered X-rays that degrade the image quality of the X-ray fluoroscopic image from entering the FPD 52 (patent). Reference 1).

  When the scattered X-ray removal grid 54 is provided, a grid reciprocating mechanism for reciprocating the scattered X-ray removal grid 54 so as to cross the X-rays is provided, and during the X-ray fluoroscopic imaging, the scattered X-ray removal grid is provided. 54 is reciprocated by a grid reciprocating mechanism (not shown) to prevent the scattered X-ray removal grid 54 from appearing as interference fringes in the X-ray fluoroscopic image.

  However, whenever the X-ray exposure dose of the subject M is reduced, the scattered X-ray removal grid 54 is temporarily removed by the operator. When the subject M is an infant, it is necessary to reduce the amount of X-ray exposure and to remove the scattered X-ray removal grid 54.

In addition to the grid reciprocating mechanism, as shown in FIG. 7, a grid moving mechanism (not shown) for moving the scattered X-ray removal grid 54 to the back side of the FPD 52 is provided, and the scattered X-ray removal grid 54 is provided. A device for removing the scattered X-ray removal grid 54 by moving it to the back side of the FPD 52 with a grid moving mechanism when removing the FPD 52 is also proposed (see Patent Document 2).
JP 2000-245719 A (5th page, FIG. 2) Japanese Unexamined Patent Publication No. 2000-139887 (page 4-5, FIG. 1-7)

  However, the former (Patent Document 1) conventional apparatus has a problem that it is not easy for an operator to remove the scattered X-ray removal grid 54. The scattered X-ray removal grid 54 has a considerable size and weight, and takes time and labor to remove and move it. Further, the removed scattered X-ray removal grid 54 must be attached again.

  In the latter case (Patent Document 2), a grid moving mechanism must be installed in the vicinity of the scattered X-ray removal grid 54 in addition to the grid reciprocating movement mechanism. Another problem is that the mechanical structure in the vicinity is complicated.

  The present invention has been made in view of such circumstances, and makes it possible to easily retreat a scattered X-ray removal grid set in front of a flat panel X-ray detection means for removing scattered X-rays. An object of the present invention is to provide an X-ray fluoroscopic apparatus that avoids complication of the mechanical configuration in the vicinity of the grid.

In order to achieve such an object, the present invention has the following configuration.
That is, an X-ray fluoroscopic apparatus according to the invention of claim 1 includes an X-ray irradiation unit that irradiates a subject with X-rays, a flat panel X-ray detection unit that detects transmitted X-rays of the subject, Scattered X-ray removal grid set at the front deployment position of the flat panel X-ray detection means, grid reciprocating movement operation for moving the scattered X-ray removal grid back and forth across the X-ray, and scattered X-ray removal And a grid reciprocating / advancing / retracting means for performing both the grid advancing / retreating operation for moving the grid back and forth between the deployed position and the retracted position deviated from the flat panel X-ray detecting means, and a subject by the X-ray irradiation means An X-ray fluoroscopic image of a subject is acquired based on an X-ray detection signal output from a flat panel type X-ray detection means in association with X-ray irradiation.

  [Operation / Effect] In the X-ray imaging by the X-ray fluoroscopic apparatus according to the first aspect of the present invention, the X-ray output from the flat panel X-ray detection means in accordance with the radiation applied to the subject by the X-ray irradiation means An X-ray fluoroscopic image of the subject is acquired based on the line detection signal. In the case of normal X-ray imaging, the scattered X-ray removal grid set in front of the flat panel X-ray detection means crosses the X-rays by the grid reciprocating movement of the grid reciprocating / advancing / retracting means. X-ray fluoroscopic images are acquired while reciprocating. As a result, the scattered X-ray removal grid can prevent the scattered X-rays that lower the image quality of the X-ray fluoroscopic image from entering the flat panel X-ray detection means by the setting of the scattered X-ray removal grid. Appearance as interference fringes in the fluoroscopic image can be prevented by the reciprocating movement of the scattered X-ray removal grid, so that a high-quality X-ray fluoroscopic image can be acquired.

  On the other hand, when obtaining correction coefficients used in signal correction processing for eliminating variations in X-ray detection signals caused by uneven detection characteristics of the X-ray detection surface of the flat panel X-ray detection means, or when the subject is an infant In such a case, contrary to normal X-ray imaging, the grid for removing scattered X-rays is retracted by the grid advancing / retreating operation of the grid reciprocating / advancing / retracting means, and is disengaged from the flat panel X-ray detecting means. Move to the retracted position. As a result, the scattered X-ray removal grid that blocks the irradiated X-rays is retracted and removed, so that when calculating the correction coefficient, the irradiated X-rays are not blocked by the scattered X-ray removing grid and are flat panel type. It is incident on the X-ray detection means in a uniform state. When the X-ray exposure dose is reduced, the X-ray irradiation dose to the subject can be reduced by the amount blocked by the scattered X-ray removal grid.

  As described above, in the X-ray fluoroscopic apparatus according to the first aspect of the present invention, the scattered X-ray removal grid is flattened by the grid reciprocating / advancing / retracting means for reciprocating the grid for reciprocating the scattered X-ray removing grid. It has a configuration in which it is set by advancing to a deployment position in front of the panel type X-ray detection means, or retracted by retracting the scattered X-ray removal grid to a retracted position that is out of the flat panel type X-ray detection means. Since the line removal grid is retracted by the grid reciprocating movement / advance / retreat means, the scattered X-ray removal grid can be easily retracted. In addition, in the grid reciprocating / retreating / combining means that performs both the grid reciprocating operation and the advancing / retreating operation, the mechanical configuration for reciprocating the grid and the mechanical configuration for retreating the grid are integrated. The mechanical configuration in the vicinity of is simple.

  According to a second aspect of the present invention, in the X-ray fluoroscopic imaging apparatus according to the first aspect, the disposition position of the scattered X-ray removal grid is set on the back side of the top plate on which the subject is placed. At the same time, the retracted position of the scattered X-ray removal grid is set to the side of the long side of the top plate, and the deployed position and retracted position of the scattered X-ray removal grid by the grid advance / retreat operation of the grid reciprocating / advancing / retracting means. A grid for removing scattered X-rays advances or retracts in the short direction of the top plate.

  [Operation / Effect] In the case of the apparatus of the invention of claim 2, the scattered X-ray removal grid advances or retracts in the short direction of the top plate between the deployed position and the retracted position of the scattered X-ray removal grid. The moving distance of the scattered X-ray removal grid becomes shorter than when the scattered X-ray removal grid advances or retracts in the longitudinal direction of the top plate, and the grid reciprocating movement / retreating means can be made compact accordingly.

  According to a third aspect of the present invention, in the X-ray fluoroscopic imaging apparatus according to the first or second aspect, the disposition position of the scattered X-ray removal grid is set on the back side of the top plate on which the subject is placed. In addition, the retracted position of the scattered X-ray removal grid is set to the side of the top plate, and when the scattered X-ray removal grid is attached / detached, the grid reciprocating / advancing / removal means removes scattered X-rays. The grid is retracted from the deployed position to the retracted position.

  [Operation / Effect] In the case of the apparatus according to the third aspect of the present invention, when the scattered X-ray removal grid is attached or detached, the scattered X-ray removal grid moves back to the retracted position on the side of the top plate and the scattered X-rays are removed. Since the scattered X-ray removing grid can be removed and attached in a state where the removing grid is drawn out from the back side of the top plate to the side of the top plate, the scattered X-ray removing grid can be easily attached and detached.

  According to a fourth aspect of the present invention, in the X-ray fluoroscopic apparatus according to any one of the first to third aspects, an X-ray detection signal when the flat panel X-ray detection means is retracted to the retracted position. Correction coefficient acquisition means for obtaining a correction coefficient used in signal correction processing for eliminating variations in X-ray detection signals caused by uneven detection characteristics of the X-ray detection surface of the flat panel X-ray detection means, and correction Correction coefficient storage means for storing the correction coefficient acquired by the coefficient acquisition means.

  [Operation / Effect] In the case of the apparatus of the invention according to claim 4, the flat panel type X-ray is based on the X-ray detection signal when the flat panel type X-ray detection means is retracted to the retracted position by the correction coefficient acquisition means. A correction coefficient used in signal correction processing for eliminating variations in the X-ray detection signal caused by uneven detection characteristics of the X-ray detection surface of the detection means is obtained, and the correction coefficient acquired by the correction coefficient acquisition means is corrected. Stored by the coefficient storage means.

  Therefore, according to the apparatus of the fourth aspect of the invention, the correction used in the signal correction process for eliminating the variation in the X-ray detection signal caused by the detection characteristic unevenness of the X-ray detection surface of the flat panel X-ray detection means. The correction coefficient can be updated by acquiring the coefficient at any time and storing it in the correction coefficient storage means.

  In the case of the X-ray fluoroscopic apparatus according to the present invention, the grid reciprocating / advancing / retracting means not only reciprocates the scattered X-ray removing grid but also the scattered X-ray removing grid in front of the flat panel X-ray detecting means. It has a configuration in which it is set by advancing to the deployment position, or the grid for removing scattered X-rays is retracted by retracting to the retracted position away from the flat panel X-ray detection means. Since the moving / advancing / retreating means is retracted, the scattered X-ray removal grid can be easily retracted. Also, in the grid reciprocating / retreating / combining means that performs both the grid reciprocating operation and the advancing / retreating operation, the mechanical configuration for reciprocating the grid and the mechanical configuration for retreating the grid are integrated. The mechanical configuration in the vicinity of is simple.

  Thus, according to the X-ray fluoroscopic apparatus of the first aspect of the present invention, the scattered X-ray removal grid disposed in front of the flat panel X-ray detection means for detecting the transmitted X-rays of the subject can be easily retracted. It is possible to avoid the complication of the mechanical configuration in the vicinity of the scattered X-ray removal grid.

  An embodiment of the X-ray fluoroscopic apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an overall configuration of a medical X-ray fluoroscopic apparatus according to the embodiment, and FIGS. 2 and 3 show an imaging stand of the embodiment apparatus in a state where an X-ray tube and a part of a top plate are omitted. It is a top view.

  The X-ray fluoroscopic imaging apparatus of the embodiment includes an X-ray tube 1 that irradiates a subject M with cone-beam-shaped X-rays, and a flat panel X-ray detector that detects transmitted X-rays of the subject M (hereinafter referred to as appropriate). (Referred to as “FPD”) 2 is provided in the imaging table 3, and X-ray fluoroscopy of the subject M is performed based on an X-ray detection signal output from the FPD 2 when the subject M is irradiated with X-rays by the X-ray tube 1. The control console 4 includes a detection signal processing unit 5 that acquires an image.

  The imaging table 3 of the embodiment apparatus is equipped with a top plate 7 for placing the subject M that moves up and down in conjunction with the movement of the base 6, and the X-ray tube 1 is located above the top side of the top plate 7. The FPD 2 is disposed on the back side of the top plate 7 so as to face the X-ray tube 1. The transmission X-ray image of the subject M generated along with the X-ray irradiation by the X-ray tube 1 is arranged on the X-ray detection surface of the FPD 2.

  Furthermore, as shown in FIGS. 1 to 3, the X-ray fluoroscopic apparatus according to the embodiment scatters so as to cross the scattered X-ray removal grid 9 set at the deployment position PA in front of the FPD 2 and the X-rays. Grid reciprocating movement for reciprocating the grid 9 for X-ray removal and grid reciprocating movement for both reciprocating movement of the scattered X-ray removing grid 9 between the deployed position and the retracted position PB deviated from the FPD 2 The advancing / retreating mechanism 10 is provided on the back side of the top plate 7. In the scattered X-ray removal grid 9, metal pieces 9a in which lead (Pb) and aluminum (Al) are alternately arranged are arranged in parallel at short intervals, and the scattered X-rays are absorbed by the lead of the metal piece 9a. Is removed. 2 and 3 show the X-ray tube 1 and the top plate 7 shown by the one-dot chain line as described above in order to facilitate understanding of the configuration and arrangement of the grid reciprocating / advancing / retracting mechanism 10. The figure is shown with some parts omitted.

  The disposition position PA of the scattered X-ray removal grid 9 is set on the back side of the top plate 7, and the retracted position PB of the scattered X-ray removal grid 9 is next to the long side 7 A of the top plate 7 (top plate 7 The scattered X-ray removal grid 9 advances or retracts in the short direction along the short side 7B of the top plate 7 by the grid advancing / retreating operation of the grid reciprocating / advancing / retracting mechanism 10.

  The grid reciprocating / advancing / retracting mechanism 10 is an electric shaft 11 that rotates along the short axis (width direction) of the top plate 7 and the central axis of the central shaft 11 as a rotation axis. The motor 12 and the grid mount 13 that moves in the short direction of the top plate 7 as the round shaft 11 is rotated by the electric motor 12 are mainly configured. Specifically, an engaging portion 13A that is screwed into and engaged with the shaft 11 is provided near the rear end of the grid mounting base 13, and the grid mounting base 13 is prevented from rotating. When the is rotated, the grid mounting base 13 does not rotate but travels straight along the shaft 11.

  When the shaft 11 rotates forward, the grid mounting base 13 advances toward the deployment position PA together with the grid 9 as shown in FIG. When the round shaft 11 rotates in the reverse direction, as shown in FIG. 3, the grid mounting base 13 moves backward along with the grid 9 toward the retracted position PB. The scattered X-ray removal grid 9 is detachably attached to the grid attachment base 13 with fixing screws or the like.

  In the case of the apparatus according to the embodiment, the grid operation control unit 14 provided with a switch for starting the grid reciprocating movement and the grid advancing / retreating operation of the grid reciprocating / advancing / retracting mechanism 10 is provided on the photographing stand 3. Thus, the control of the grid reciprocating / advancing / retracting mechanism 10 is performed on the photographing table 3 side. However, the grid reciprocating / advancing / retracting mechanism 10 may be controlled on the control console 4 side, or on both the imaging table 3 side and the control console 4 side.

  On the other hand, the X-ray tube 1 irradiates the subject M with cone beam-shaped X-rays corresponding to the irradiation conditions in accordance with the control of the irradiation control unit 15. The X-ray irradiation conditions are set by the operator using the operation unit 16 or the like. For example, when the subject M to be imaged is an infant, it is necessary to reduce the exposure dose of X-rays, so a smaller dose is set than for adults.

  The image creation unit 17 of the detection signal processing unit 5 acquires an X-ray fluoroscopic image based on the X-ray detection signal output from the FPD 2 and displays it on the screen of the display monitor 18 or stores it as an electronic image in the image memory unit 19. Or printing with the printer 20 to make an X-ray photograph. In addition to the X-ray fluoroscopic imaging, the apparatus according to the embodiment can perform single X-ray imaging in which X-rays are irradiated once and the image generating unit 17 generates an X-ray single image.

  On the other hand, as shown in FIG. 4, the FPD 2 is vertically and horizontally along the X and Y directions in which a number of X-ray detection elements 2a are orthogonal to the X-ray detection surface 2A on which the transmitted X-ray image of the subject M is projected. The configuration is a matrix arrangement. For example, the X-ray detection elements 2a are arranged vertically and horizontally in a matrix of 1536 × 1536 on the X-ray detection surface 2A having a width of about 30 cm × 30 cm. Each X-ray detection element 2a of the FPD 2 has a corresponding relationship with each pixel of the X-ray fluoroscopic image created by the detection signal processing unit 5, and is projected onto the X-ray detection surface 2A based on the X-ray detection signal extracted from the FPD 2. An X-ray fluoroscopic image corresponding to the transmitted X-ray image is created by the image creation unit 17.

  Further, in the case of the FPD 2, there is a variation in the X-ray detection signal due to uneven detection characteristics (for example, uneven detection sensitivity) of the X-ray detection surface 2A. Since the detection characteristics of each X-ray detection element 2a are not constant and vary depending on the detection characteristic unevenness of the X-ray detection surface 2A, variations in the X-ray detection signal occur. If an X-ray fluoroscopic image is created with variations in the X-ray detection signal, the image quality deteriorates, and therefore signal correction processing for eliminating the variations is performed.

  Specifically, the image creation unit 17 performs a signal correction process that eliminates variations in the X-ray detection signal using the correction coefficient stored in the correction coefficient memory 21, and acquires an X-ray fluoroscopic image. The correction coefficients stored in the correction coefficient memory 21 include a base correction coefficient that eliminates variations in dark current (base) and a sensitivity correction coefficient that corrects variations in sensitivity. Correct the base and sensitivity to eliminate variations. Therefore, in the case of the apparatus according to the embodiment, the image creation unit 17 can acquire an X-ray fluoroscopic image without deterioration in image quality due to uneven detection characteristics of the X-ray detection surface 2A of the FPD 2.

  Further, in the case of the FPD 2, since the detection characteristic unevenness of the X-ray detection surface 2 </ b> A varies with time, the correction coefficient acquisition unit 22 acquires the correction coefficient and the correction stored in the correction coefficient memory 21 in the apparatus of the embodiment. The coefficient is updated by replacing the coefficient with the correction coefficient acquired by the correction coefficient acquisition unit 22.

  When the correction coefficient is acquired by the correction coefficient acquisition unit 22, the scattered X-ray removal grid 9 is retracted to the retract position PB as shown in FIG. 3 in order to irradiate the X-ray detection surface 2A with uniform X-rays. The base correction coefficient and the sensitivity correction coefficient are acquired based on the X-ray detection signal at the time of X-ray irradiation and the X-ray detection signal (blank signal) at the time of non-X-ray irradiation. As described above, the apparatus according to the embodiment includes the correction coefficient acquisition unit 22 so that the correction coefficient can be acquired and updated as needed.

  In the apparatus of the embodiment, each unit such as the irradiation control unit 15, the image creation unit 17, and the correction coefficient acquisition unit 22 is a main control unit according to instructions and data input from the operation unit 16 or the progress of X-ray imaging. Control and processing are executed in accordance with various commands sent from the terminal 23.

  Next, the operation of the grid reciprocating / advancing / retracting mechanism 10 as a structural feature of the apparatus of the above-described embodiment will be specifically described. First, the operation of the grid reciprocating / advancing / retracting mechanism 10 during normal X-ray imaging will be described.

  In the case of normal X-ray fluoroscopic imaging, as shown in FIG. 2, the scattered X-ray removal grid 9 is advanced to the deployment position PA by the grid reciprocating movement / advance / retreat mechanism 10 and set in front of the FPD 2. Since the scattered X-ray removal grid 9 is normally located at the deployment position PA and has advanced to the deployment position PA, in most cases, the scattered X-ray removal grid 9 is already set. . Therefore, it is not necessary to operate the grid reciprocating / advancing / retracting mechanism 10 during X-ray imaging.

  During imaging, X-ray fluoroscopic imaging is performed while the scattered X-ray removal grid 9 is reciprocated by the grid reciprocating movement of the grid reciprocating / advancing / retracting mechanism 10. During the grid reciprocating movement, the rotary shaft 11 repeats normal rotation and reverse rotation in conjunction with the electric motor 12 repeating normal rotation and reverse rotation. As a result, the scattered X-ray removal grid 9 moves at a cycle of, for example, about 1 Hz as the grid mount 13 is reciprocated by a short distance of about several millimeters along the radial axis 11 together with the scattered X-ray removal grid 9. Move back and forth.

  As a result, it is possible to prevent the scattered X-rays that deteriorate the image quality of the X-ray fluoroscopic image from entering the FPD 2 by setting the scattered X-ray removing grid 9, and the scattered X-ray removing grid 9 interferes with the X-ray fluoroscopic image. Appearance of stripes can be prevented by the reciprocating movement of the scattered X-ray removal grid 9 so that a high-quality X-ray fluoroscopic image can be acquired.

  In addition, when the correction coefficient stored in the correction coefficient memory 21 is acquired by the correction coefficient acquisition unit 22 or when the X-ray exposure dose is reduced because the subject M is an infant, what is normal X-ray imaging? On the contrary, as shown in FIG. 3, the scattered X-ray removal grid 9 is retracted by the grid reciprocating movement / advancing / retracting mechanism 10 and moved to the retracted position PB that is out of the FPD 2 and retracted. As a result, the scattered X-ray removal grid 9 that blocks the irradiated X-rays is removed. Accordingly, the irradiation X-rays are uniformly not incident on the X-ray detection surface 2A of the FPD 2 without being blocked by the scattered X-ray removal grid 9, so that the correction coefficient can be obtained accurately. Further, since the X-ray irradiation amount can be reduced by the amount blocked by the scattered X-ray removal grid 9, the X-ray exposure amount of the subject M can be reduced.

  In the case of the X-ray fluoroscopic apparatus described above, the grid reciprocating / advancing / retracting mechanism 10 not only reciprocates the scattered X-ray removing grid 9, but also disposes the scattered X-ray removing grid 9 at the deployment position PA in front of the FPD2. The scattered X-ray removal grid 9 is retracted by retracting to the retracted position PB off the FPD 2, and the scattered X-ray removal grid 9 is moved by the grid reciprocating / advancing / retracting mechanism 10. Since it is retracted, the scattered X-ray removal grid 9 can be easily retracted. In addition, in the grid reciprocating / retracting / combining mechanism 10 that performs both the grid reciprocating operation and the advancing / retreating operation, the mechanical configuration for reciprocating the grid and the mechanical configuration for retreating the grid are integrated. The mechanical configuration in the vicinity of the grid 9 is simple.

  Therefore, according to the apparatus of the embodiment, the scattered X-ray removal grid 9 set in front of the FPD 2 that detects the transmitted X-rays of the subject M can be easily retracted, and the scattered X-ray removal grid 9 It is possible to avoid the nearby mechanical configuration from becoming complicated.

  Furthermore, in the case of the apparatus of the embodiment, the scattered X-ray removal grid 9 advances or retracts in the short direction of the top plate 7 between the deployment position PA and the retreat position PB of the scattered X-ray removal grid 9. Compared with the case where the X-ray removal grid 9 advances or retracts in the longitudinal direction of the top plate 7, the moving distance of the scattered X-ray removal grid 9 is shortened, and the grid reciprocating / advancing / retracting mechanism 10 is made compact accordingly. it can.

  When the scattered X-ray removal grid 9 is attached or detached, as shown in FIG. 5, the scattered X-ray removal grid 9 is moved back to the retracted position PB on the side of the top plate 7 for removing scattered X-rays. Since the grid 9 for removing scattered X-rays can be removed and attached in a state where the grid 9 is drawn to the side of the top 7 from the back surface of the top board 7, the grid 9 for removing scattered X-rays can be easily attached and detached.

  The present invention is not limited to the above embodiment, and can be modified as follows.

  (1) Although the apparatus of the embodiment has a configuration in which the scattered X-ray removal grid 9 is detachable, the retracted position and the detachable position of the scattered X-ray removal grid 9 may be different. For example, the retraction position of the top plate 7 is set on the back side of the top plate 7 adjacent to the longitudinal direction of the top plate 7, the attachment / detachment position of the top plate 7 is set beside the long side 7 A of the top plate 7, and the scattering X When the line removal grid 9 is retracted, it may be retracted to the retracted position on the back surface of the top plate 7, and when the top plate 7 is attached or detached, the line removal grid 9 may be pulled out to the side attachment / detachment position.

  (2) Although the number of grids for removing scattered X-rays 9 is one in the apparatus of the above embodiment, the number of grids for removing scattered X-rays 9 is not limited to one. For example, two scattered X-ray removal grids 9 may be provided, and the grid reciprocating / advancing / retracting mechanism may advance one grid to the deployed position and simultaneously retract the other grid to the retracted position. .

  (3) The X-ray fluoroscopic apparatus according to the embodiment is a medical apparatus. However, the present invention is not limited to medical use, and may be an industrial apparatus such as a nondestructive inspection apparatus or a nuclear apparatus. Good.

It is a block diagram which shows the whole structure of the X-ray fluoroscopic imaging apparatus of an Example. FIG. 4 is a plan view showing the imaging stand when the scattered X-ray removal grid is in the set state in the embodiment apparatus, with the X-ray tube and a part of the top plate omitted. FIG. 6 is a plan view showing the imaging stand with the X-ray tube and a part of the top plate omitted, when the scattered X-ray removal grid is in the retracted state in the embodiment apparatus. It is the schematic which shows the structure of FPD used for the apparatus of an Example. It is a top view which shows a mode when the grid for scattered X-ray removal is attached or detached with the apparatus of an Example. It is the schematic which shows the structure of the imaging stand of the conventional X-ray fluoroscope. It is the schematic which shows the structure of the imaging | photography stand of the other conventional X-ray fluoroscopic imaging apparatus.

Explanation of symbols

1 X-ray tube (X-ray irradiation means)
2 ... FPD (flat panel X-ray detection means)
7 ... Top plate 9 ... Grid for removing scattered X-rays 10 ... Grid reciprocating movement / reciprocating mechanism (grid reciprocating movement / retreating means)
21 ... Correction coefficient memory (correction coefficient storage means)
22 ... Correction coefficient acquisition unit (correction coefficient acquisition means)
M: Subject PA: Deployment position PB: Retraction position

Claims (4)

  X-ray irradiating means for irradiating the subject with X-rays, flat panel type X-ray detecting means for detecting transmitted X-rays of the subject, and scattering set at a deployment position in front of the flat panel type X-ray detecting means X-ray removal grid, grid reciprocating movement for reciprocating the scattered X-ray removal grid so as to cross the X-ray, and retracted position away from the flat panel type X-ray detection means. Grid reciprocating / advancing / retracting means for performing both of the grid advance / retreat operation for moving between and forward / backward, and is output from the flat panel type X-ray detection means in accordance with the X-ray irradiation to the subject by the X-ray irradiation means An X-ray fluoroscopic imaging apparatus that acquires an X-ray fluoroscopic image of a subject based on an X-ray detection signal.   The X-ray fluoroscopic apparatus according to claim 1, wherein the disposition position of the scattered X-ray removal grid is set on the back side of the top plate on which the subject is placed, and the retracted position of the scattered X-ray removal grid. Is set to the side of the long side of the top plate, and the scattered X-ray removal grid is placed between the deployed position and the retracted position of the scattered X-ray removal grid by the grid reciprocating movement of the grid reciprocating / advancing / retracting means. X-ray fluoroscopic equipment that advances or retracts in the short direction of the plate.   The X-ray fluoroscopic apparatus according to claim 1 or 2, wherein the disposition position of the scattered X-ray removal grid is set on the back side of the top plate on which the subject is placed, and the scattered X-ray removal grid When the retracted position is set to the side of the top plate and the scattered X-ray removal grid is attached / detached, the grid reciprocating / advancing / retracting means retracts the scattered X-ray removal grid from the deployed position to the retracted position. X-ray fluoroscopic equipment. The X-ray fluoroscopic apparatus according to any one of claims 1 to 3, wherein the flat panel X-ray detection means is based on an X-ray detection signal when the flat panel X-ray detection means is retracted to the retracted position. A correction coefficient acquisition means for obtaining a correction coefficient used in signal correction processing for eliminating variations in X-ray detection signals caused by uneven detection characteristics of the X-ray detection surface, and a correction coefficient acquired by the correction coefficient acquisition means are stored. An X-ray fluoroscopic apparatus comprising a correction coefficient storage means for performing.

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