JP2006255281A - Roentgenography device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily widen an adaptable focus-image reception face distance range by scattered X-ray removing grids disposed in one device. <P>SOLUTION: Among two scattered X-ray removing grids 12A, 12B differing in the adaptable focus-image reception face distance range, the scattered X-ray removing grid corresponding to the present set value of a focus-image reception face distance SID is selected and can be set at the arrangement position 2a in front of a two-dimensional X-ray detector 2, and the scattered X-ray removing grid not corresponding to the present set value of the focus-image reception face distance SID is retreated to the evacuation position 2b on the side of the two-dimensional X-ray detector 2. Accordingly, the adaptable focus-image reception face distance range grows into a wide range that is the sum of all of respective focus-image reception face distance ranges of two scattered X-ray removing grids 12A, 12B by the scattered X-ray removing grids in one device, and only the constitution which can be easily achieved to enable the reciprocative movement of the scattered X-ray removing grids 12A, 12B between the arrangement position in front of the two-dimensional X-ray detector 2 and the evacuation position on its side is required. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides a two-dimensional X-ray detection means for detecting a transmitted X-ray image, which is disposed so as to face the X-ray irradiation means across the subject with the focal point of the X-ray irradiation means for irradiating the subject with X-rays. In addition to being able to change the distance to the image receiving surface (distance between the focal point and the image receiving surface), the present invention relates to an X-ray imaging apparatus including a scattered X-ray removal grid disposed in front of the two-dimensional X-ray detection means, In particular, the present invention relates to a technique for expanding a distance range between a focal point and an image receiving surface to which a scattered X-ray removal grid set at a position of a front surface of a two-dimensional X-ray detection unit can be adapted.

  Conventionally, as shown in FIG. 9, an X-ray fluoroscopic apparatus often used in medical institutions such as hospitals has an X-ray tube 61 for irradiating a subject M placed on a top board BD with X-rays, In addition to a two-dimensional X-ray detector 62 for detecting a transmitted X-ray image facing the X-ray tube 61 across the specimen M, scattered X-ray removal arranged in front of the two-dimensional X-ray detector 62 A grid 63 and the like are provided. When X-ray imaging is performed by a conventional X-ray fluoroscopic apparatus, a transmitted X-ray image of the subject M generated by X-ray irradiation by the X-ray tube 61 is an image receiving surface (X An X-ray image for X-ray fluoroscopy is acquired based on an X-ray detection signal output from the two-dimensional X-ray detector 62 while being projected and detected on the line detection surface.

  The scattered X-ray removal grid 63 is a grid in which a large number of X-ray absorbing members and X-ray transmissive intermediate substances are alternately arranged. The scattered X-ray removal grid 63 causes a decrease in image quality of the X-ray image. Therefore, the transmitted X-ray image from which the scattered X-rays are excluded can be projected onto the image receiving surface of the two-dimensional X-ray detector 62.

On the other hand, the X-ray fluoroscopic apparatus of FIG. 9 moves the focus of the X-ray tube 61 and the two-dimensional X-ray detector 62 by moving one (or both) of the X-ray tube 61 and the two-dimensional X-ray detector 62. The distance between the image receiving surfaces (the distance between the focal point and the image receiving surface) can be changed. The photographing range and the photographing magnification can be adjusted by changing the distance between the focal points and the image receiving surface (SID).
On the other hand, the scattered X-ray removal grid 63 is limited in the distance between the focal point and the image receiving surface that can be adapted, and if the distance between the focal point and the image receiving surface is outside the applicable range of the scattered X-ray removal grid 63, the non-scattered X-rays are converted. This causes a cut-off phenomenon that is eliminated, making X-ray imaging impossible.

  Therefore, a separate X-ray imaging stand equipped with a scattered X-ray removal grid with a different range of distance between the focus and image planes that can be adapted is usually installed in the examination room. When the scattered X-ray removal grid 63 falls outside the applicable range, the subject is replaced with a separate X-ray imaging stand, and the X-ray tube 61 is directed toward the separate X-ray imaging stand. The X-ray photography is performed. However, when a separate X-ray imaging stand is used, in addition to requiring a considerable installation space in the examination room, the burden on the subject and the operator by changing the orientation of the subject and changing the direction of the X-ray tube 61 is increased. Increase.

  Therefore, in the conventional X-ray fluoroscopic apparatus, the scattered X-ray removal grid 63 is deformed into a cylindrical shape having a predetermined curvature with the extending direction of the grid as a longitudinal axis according to the distance between the focal point and the image receiving surface. There has been proposed a countermeasure for expanding the range of the distance between the focal point and the image receiving surface that can be adapted by the scattered X-ray removal grid 63 provided in one apparatus (see, for example, Patent Document 1).

JP 2004-313546 A (pages 4 to 5, FIGS. 4 to 5)

  However, in the case of the X-ray fluoroscopic apparatus according to the above countermeasure, it is not easy to produce a mechanism for deforming the scattered X-ray removal grid 63 into a cylindrical shape according to the distance between the focal point and the image receiving surface. There is a problem that it is actually very difficult to expand the range of the distance between the focal point and the image receiving surface to which the removal grid 63 can be adapted.

  The present invention has been made in view of such circumstances, and can easily expand the distance range between the focal point and the image receiving surface that can be adapted by the scattered X-ray removal grid provided in one apparatus. An object is to provide a radiographic apparatus.

In order to achieve such an object, the present invention has the following configuration.
That is, the X-ray imaging apparatus according to the first aspect of the present invention is disposed so that the focal point of the X-ray irradiation unit that irradiates the subject with X-rays faces the X-ray irradiation unit across the subject. In addition to being able to change the distance to the image receiving surface (distance between the focal point and the image receiving surface) of the two-dimensional X-ray detection means for transmitting X-ray image detection, the scattered X disposed in front of the two-dimensional X-ray detection means In an X-ray imaging apparatus provided with a line removal grid, a plurality of scattered X-ray removal grids having different focus-to-image-receiving surface distance ranges that can be adapted are respectively arranged in front of the two-dimensional X-ray detection means and two-dimensional. The X-ray detection means is disposed in a state where it can be reciprocated between the X-ray detection means and the retracted position on the side.

[Operation / Effect] When performing X-ray imaging by the X-ray imaging apparatus according to the first aspect of the invention, the operator first receives the focal point of the X-ray irradiation means and the image received by the two-dimensional X-ray detection means for transmission X-ray image detection. The distance to the surface (the distance between the focal point and the image receiving surface) is set in accordance with the photographing purpose, and the scattered X-ray removal grid currently set at the position of the front surface of the two-dimensional X-ray detection means is between the focal point and the image receiving surface. Check if it matches the current distance setting.
When the scattered X-ray removal grid in the current set does not conform to the current setting value of the focus-to-image surface distance, the plurality of scattered X-ray removal grids having different focus-to-image surface distance ranges that can be adapted. Select the scattered X-ray removal grid that matches the current setting of the distance between the focal point and the image receiving surface, set it to the front position of the two-dimensional X-ray detection means, and set the distance between the focal point and the image receiving surface. The scattered X-ray removal grid that does not match the currently set value is retracted to the side retreat position of the two-dimensional X-ray detection means.
Subsequently, the subject is irradiated with X-rays by the X-ray irradiating means, and the transmitted X-ray image of the subject generated by the X-ray irradiation is applied to the image receiving surface (X-ray detecting surface) of the two-dimensional X-ray detecting means. X-ray imaging proceeds by being projected and detected.

  In other words, the X-ray imaging apparatus according to the first aspect of the present invention is a scatter that matches the current set value of the distance between the focus and the image receiving surface among the plurality of scattered X-ray removal grids having different focus and image receiving distance ranges. The X-ray removal grid can be selected and set to the front position of the two-dimensional X-ray detection means, and the scattered X-ray removal grid that does not match the current setting value of the distance between the focal point and the image-receiving surface can be detected by two-dimensional X-rays. It is configured to be retracted to the retracted position on the side of the means.

  As a result, in the case of the X-ray imaging apparatus according to the first aspect of the present invention, the range of the distance between the focal point and the image plane that can be accommodated by the scattered X-ray removal grid provided in one apparatus is the distance between the focal point and the image plane that can be adapted. In addition to the wide range of all the focal-to-receiving surface distance ranges of multiple scattered X-ray removal grids with different ranges, the necessary technical matters are the distance between the applicable focal-to-receiving surface distances. Since each of the plurality of scattered X-ray removal grids having different ranges can be reciprocated between the front-side arrangement position and the side retraction position of the two-dimensional X-ray detection means, the configuration is simple. According to the X-ray imaging apparatus of the invention of item 1, the distance range between the focal point and the image receiving surface that can be adapted by the scattered X-ray removal grid provided in one apparatus can be easily expanded.

  According to a second aspect of the present invention, in the X-ray imaging apparatus according to the first aspect, any one of a plurality of scattered X-ray removal grids having different focus-receiving surface distance ranges that can be adapted is used. A grid designating unit for designating a scattered X-ray removal grid, and the scattered X-ray removal grid designated by the grid designating unit are advanced to the arrangement position on the front surface of the two-dimensional X-ray detection unit and at the front of the two-dimensional X-ray detection unit There is provided designated grid replacement means for retracting the scattered X-ray removal grid set at the arrangement position to the retracted position.

[Operation / Effect] In the case of the apparatus of the invention of claim 2, the focus-image-receiving surface distance is currently set from a plurality of scattered X-ray removal grids having different focus-image-receiving surface distance ranges that can be adapted by the grid designating means. When one scattered X-ray removal grid corresponding to the value is designated, the designated grid replacement means is activated, and the scattered X-ray removal grid designated by the grid designation means moves to the arrangement position on the front surface of the two-dimensional X-ray detection means. While being advanced, the scattered X-ray removal grid set at the position of the front surface of the two-dimensional X-ray detection means is retracted to the retracted position.
Therefore, according to the apparatus of the second aspect of the present invention, any two of the plurality of scattered X-ray removal grids having different focus-receiving surface distance ranges that can be adapted can be obtained by two-dimensional X only by the designation operation by the grid designation means. It can be set to the arrangement position on the front surface of the line detection means.

  According to a third aspect of the present invention, in the X-ray imaging apparatus according to the first aspect, the SID detection for detecting the distance between the focal point and the image receiving surface (SID) for the X-ray irradiation means and the two-dimensional X-ray detection means. Grid selection for selecting a scattered X-ray removal grid suitable for the distance between the focus and the image receiving surface detected by the SID detection means from a plurality of scattered X-ray removal grids having different focus and image receiving surface distance ranges that can be adapted And the scattered X-ray removal grid selected by the grid selection means are advanced to the arrangement position in front of the two-dimensional X-ray detection means and the scattered X-rays set in the arrangement position in front of the two-dimensional X-ray detection means Selection grid replacement means for retracting the removal grid to the retracted position.

[Operation / Effect] In the case of the apparatus of the invention of claim 3, the SID (Source-Image-Distance) is detected by the SID detection means, and the distance range between the focus and image receiving planes that can be adapted by the grid selection means is different. When a scattered X-ray removal grid corresponding to the SID detected by the SID detection means is selected from among the scattered X-ray removal grids, the selected grid replacement means is activated to remove the scattered X-rays selected by the grid selection means. The grid is advanced to the arrangement position on the front surface of the two-dimensional X-ray detection means, and the scattered X-ray removal grid set at the arrangement position on the front surface of the two-dimensional X-ray detection means is retracted to the retreat position.
Therefore, according to the apparatus of the third aspect of the present invention, the focus on the X-ray irradiating means and the two-dimensional X-ray detecting means is placed at the position of the front surface of the two-dimensional X-ray detecting means without any operation by the operator. A scattered X-ray removal grid corresponding to the current set value of the distance between the image receiving surfaces is automatically set.

  The X-ray imaging apparatus according to the first aspect of the present invention is a scattered X-ray that matches the current set value of the distance between the focal point and the image-receiving surface among the plurality of scattered X-ray removal grids having different focus-to-image surface distance ranges. A scattered X-ray removal grid that does not conform to the current set value of the distance between the focal point and the image-receiving surface can be set by selecting a line removal grid and advancing it to the front position of the two-dimensional X-ray detection means. It is set as the structure retracted to the side retreat position.

Therefore, in the case of the X-ray imaging apparatus according to the first aspect of the present invention, the focus-to-image-receiving distance range that can be adapted by the scattered X-ray removal grid provided in one apparatus is the adaptable focus-to-image-receiving distance range. In addition to the wide range of all the focal-to-receiving surface distance ranges of multiple scattered X-ray removal grids with different ranges, the necessary technical matters are the distance between the applicable focal-to-receiving surface distances. The configuration is such that the plurality of scattered X-ray removal grids having different ranges can be reciprocated between the front-side arrangement position and the side retraction position of the two-dimensional X-ray detection means.
Therefore, according to the X-ray imaging apparatus of the first aspect of the present invention, it is possible to easily expand the range of the distance between the focal point and the image receiving plane that can be adapted by the scattered X-ray removal grid provided in one apparatus.

  A first embodiment of the X-ray imaging apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a medical X-ray fluoroscopic apparatus according to the first embodiment, FIG. 2 is a plan view showing the configuration around the scattered X-ray removal grid in the apparatus of the first embodiment, and FIG. FIG. 4 is a schematic view showing an example of the structure of the scattered X-ray removal grid used in the apparatus of the first embodiment.

  The X-ray fluoroscopic apparatus according to the first embodiment includes a top plate BD on which a subject M to be fluoroscopically imaged is placed, an X-ray tube 1 that irradiates the subject M on the top plate 1 with X-rays, and a transmission X-ray. The two-dimensional X-ray detector 2 for detecting line images and the two-dimensional X-ray detector 2 as the subject M is irradiated with X-rays from the X-ray tube 1 under the control of the X-ray irradiation control unit 3. A detection signal processing unit 4 that acquires an X-ray image for X-ray fluoroscopy according to the output X-ray detection signal, and an operation menu necessary for the X-ray image acquired by the detection signal processing unit 4 and X-ray fluoroscopy Are displayed on the screen, and an operation unit 6 such as a keyboard and a mouse for inputting commands and data necessary for the operation of the apparatus. Hereinafter, the structure of each part is demonstrated concretely.

  The top board BD is held by the top board holding frame 7 so as to be movable in the longitudinal direction and the short side direction, and the top board holding frame 7 can be moved up and down as indicated by an arrow RA. 8, and the top plate BD is configured to be tilted up and down while the subject M is mounted as the top plate holding frame 7 is tilted up and down.

In addition, the apparatus according to the first embodiment has a distance between the focal point 1A of the X-ray tube 1 and the image receiving surface 2A of the two-dimensional X-ray detector 2 disposed facing the X-ray tube 1 across the subject M. (Distance between focal point and image receiving surface) The SID can be changed. The shooting range and the shooting magnification can be adjusted by changing the focal point / image receiving surface distance SID.
That is, as shown in FIGS. 5 and 6, the X-ray tube 1 is attached to a movable base 10 that is engaged with the support column 9 in a state where it can reciprocate along the longitudinal direction of the support column 9. As the movable base 10 moves along the longitudinal direction of the column 9, the X-ray tube 1 approaches the two-dimensional X-ray detector 2 or moves away from the two-dimensional X-ray detector 2 to focus / receive the image. The inter-surface distance SID changes. In the case of the apparatus of the first embodiment, the movable base 10 is moved manually, but the movable base 10 may be moved electrically.

Specifically, when the movable base 10 moves to the tip end side of the column 9 and the X-ray tube 1 moves away from the two-dimensional X-ray detector 2, the focal point / image receiving surface distance SID becomes longer. Conversely, when the movable base 10 moves to the base end side of the column 9 and the X-ray tube 1 approaches the two-dimensional X-ray detector 2, the focal point / image receiving surface distance SID becomes shorter.
In the apparatus of the first embodiment, the X-ray tube 1 moves to change the focus / image receiving surface distance SID, but the two-dimensional X-ray detector 2 moves to focus / image receiving. A configuration in which the inter-surface distance SID changes or a configuration in which both the X-ray tube 1 and the two-dimensional X-ray detector 2 move to change the focal-image receiving surface distance SID may be employed.

  In addition, in the case of the apparatus of the first embodiment, the current set value of the focal point / image receiving surface distance SID is numerically displayed on a mechanical or electrical SID measurement display 11 installed beside the X-ray tube 1. . The SID measurement display 11 is configured to measure and display the current set value of the focus / image receiving surface distance SID by capturing the movement amount and direction of the movable base 10 and increasing / decreasing the display value of the focus / image receiving surface distance SID. Has been.

It should be noted that only the SID measurement graduation is engraved along the longitudinal direction of the support column 9 without providing the SID measurement display 11 for displaying the current setting value of the focal point / image receiving surface distance SID numerically. Thus, the current setting value of the focal point / image receiving surface distance SID may be known by reading the position of the X-ray tube 1 using a scale for SID measurement.
Further, the current set value of the focus / image-receiving surface distance SID measured by the SID measurement / display meter 11 is sent to the display monitor 5 in the form of an electric signal, and the focus-image-receiving surface distance SID is displayed on the screen of the display monitor 5. It is good also as a structure by which the number which shows the present setting value is projected.

The two-dimensional X-ray detector 2 of the apparatus of the first embodiment is an I / I tube type that combines an image intensifier (I / I tube) and a TV camera, but the two-dimensional X-ray detector 2 is a flat panel. It may be a type detector (FPD).
The X-ray irradiation control unit 3 controls the X-ray tube 1 to irradiate X-rays with a tube current / tube voltage corresponding to the set imaging conditions, and transmits the subject M that is caused by the X-ray irradiation. The X-ray image is projected and detected on the image receiving surface 2A of the two-dimensional X-ray detector 2, and is output from the two-dimensional X-ray detector 2 as an X-ray detection signal.

Further, as shown in FIGS. 2 and 3, the X-ray fluoroscopic apparatus of the first embodiment includes a plurality of scattered X-ray removal grids 12 </ b> A and 12 </ b> B having different focus-receiving surface distance ranges that can be adapted, A structural feature is that the two-dimensional X-ray detector 2 is disposed so as to be reciprocated between an arrangement position 2a on the front surface of the two-dimensional X-ray detector 2 and a retreat position 2b on the side of the two-dimensional X-ray detector 2. Therefore, this point will be described in detail below.
The scattered X-ray removal grids 12A and 12B are for removing scattered X-rays that cause a reduction in the image quality of the X-ray image. Two-dimensional X-ray detection is performed on the scattered X-ray removal grid 12A and the scattered X-ray removal grid 12B. By setting at the arrangement position 2 a on the front surface of the device 2, a transmitted X-ray image from which scattered X-rays are excluded can be projected onto the image receiving surface of the two-dimensional X-ray detector 2.

In the case of the scattered X-ray removal grid arranged in front of the two-dimensional X-ray detector 2, there are a parallel grid type and a focusing grid type. The scattered X-ray removal grids 12A and 12B may be either a parallel grid type or a focused grid type.
In the case of the parallel grid type, X-ray absorbing materials (for example, lead) alternately arranged with X-ray transparent intermediate materials (for example, aluminum) are arranged in parallel. In the case of the focusing grid type, as shown in FIG. 4, the degree of inclination is increased from the center toward the outside so that the X-ray transmissive intermediate substance and the X-ray absorber are directed to the focus of the X-ray tube 1. It is arranged in a state.
The scattered X-ray removal grids 12A and 12B have, for example, a vertical and horizontal length of about 50 cm each and a thickness of about 3 mm.

  Each of the scattered X-ray removal grids 12A and 12B can only be adapted to a distance within a certain range around the optimum focal point / image receiving surface distance SID. In the case of the apparatus according to the first embodiment, the scattered X-ray removal grid 12A is for short-distance imaging, and the applicable focus / image-receiving surface distance range is 50 cm to less than 1 m, and the scattered X-ray removal grid 12B is for long-distance imaging. The applicable distance between the focus and the image receiving surface is 1 m or more to 1 m 70 cm.

  In the case of the apparatus according to the first embodiment, the grid designation that designates one of the scattered X-ray removal grids 12A and 12B having different focus-receiving surface distance ranges that can be adapted is designated. The unit 13 and the scattered X-ray removal grid specified by the grid specifying unit 13 are advanced to the arrangement position on the front surface of the two-dimensional X-ray detector 2 and set to the arrangement position on the front surface of the two-dimensional X-ray detector 2. A designated grid replacement mechanism 14 for retracting the scattered X-ray removal grid to the retracted position is provided.

  Specifically, when the operator performs an operation of designating any one of the scattered X-ray removal grids 12A and 12B by the operation unit 6, the scattered X-ray removal grid to which the grid designating unit 13 is designated is designated. It is configured to output a grid designation signal corresponding to. That is, in the apparatus according to the first embodiment, the operation unit 6 and the grid specifying unit 13 constitute grid specifying means for specifying any one of the scattered X-ray removal grids 12A and 12B.

  Further, as shown in FIGS. 2 and 3, the designated grid changing mechanism 14 moves the scattered X-ray removal grids 12A and 12B between the arrangement position 2a on the front surface of the two-dimensional X-ray detector 2 and the side retraction position 2b. Are connected to a grid holding shelf 14A that can reciprocate in two stages and scattered X-ray removal grids 12A and 12B, and the outer edge and side of the arrangement position 2a on the front surface of the two-dimensional X-ray detector 2 An endless belt 14B stretched over pulleys 14a and 14b installed on the outer edge of the retreat position 2b, and an electric motor 14C for rotating the pulley 14a.

  In the case of the designated grid changing mechanism 14, when the electric motor 14 </ b> C rotates the endless belt 14 </ b> B in the direction indicated by the arrow Ra, the scattered X-ray removal grid 12 </ b> A is disposed from the side retraction position 2 b on the front side of the two-dimensional X-ray detector 2. The scattered X-ray removal grid 12B moves in the direction of moving forward to the position 2a, and moves in a direction of retreating from the arrangement position 2a on the front surface of the two-dimensional X-ray detector 2 to the side retraction position 2b. Conversely, when the electric motor 14C rotates the endless belt 14B in the direction indicated by the arrow Rb, the scattered X-ray removal grid 12B advances from the side retraction position 2b of the two-dimensional X-ray detector 2 to the front arrangement position 2a. The scattered X-ray removal grid 12 </ b> A is configured to move in the direction of retreating from the arrangement position 2 a on the front surface of the two-dimensional X-ray detector 2 to the side retraction position 2 b.

  The main control unit 15 is mainly composed of a microcomputer and its operation program. Depending on the command / data input operation or grid designation operation by the operation unit 6 or the progress of X-ray imaging, the main control unit 15 Sends commands and data to the machine and plays a role of commander to operate the equipment normally.

  Subsequently, in the apparatus of the first embodiment having the configuration described in detail above, the scattered X-ray removal grids 12A and 12B are adapted to the situation when the two-dimensional X-ray detector 2 is set at the arrangement position 2a on the front surface. This will be described with reference to the drawings. FIG. 7 is a flowchart showing a process when the scattered X-ray removal grids 12 </ b> A and 12 </ b> B are set at the arrangement position 2 a on the front surface of the two-dimensional X-ray detector 2.

  [Step S1] The operator moves the movable base 10 along the longitudinal direction of the column 9 to adjust the distance between the X-ray tube 1 and the two-dimensional X-ray detector 2 according to the purpose and necessity of imaging. The current setting value of the focal point / image receiving surface distance SID displayed as a number on the SID measurement display 11 is confirmed.

  [Step S2] If the current set value of the focus-image-receiving surface distance SID is less than 1 m, the process proceeds to the next step S3. If the current setting value of the focus-image receiving surface distance SID is not less than 1 m (that is, 1 m or more), the process jumps to step S6.

  [Step S3] If the scattered X-ray removal grid 12A has already been set at the arrangement position 2a on the front surface of the two-dimensional X-ray detector 2, the process jumps to step S9, otherwise proceeds to the next step S4.

  [Step S4] The operator performs an operation of designating the scattered X-ray removal grid 12A using the operation unit 6.

  [Step S5] The designated grid changing mechanism 14 operates immediately upon receiving a grid designation signal from the grid designation unit 13, and the scattered electric X-ray is removed as the operating electric motor 14C rotates the endless belt 14B in the direction indicated by the arrow Ra. At the same time as the grid 12A moves from the side retreat position 2b of the two-dimensional X-ray detector 2 to the front position 2a, the scattered X-ray removal grid 12B conversely moves to the front surface of the two-dimensional X-ray detector 2. As shown in FIG. 5, the scattered X-ray removal grid 12A is set at the front position of the two-dimensional X-ray detector 2 and moved to the side retreat position 2b. The grid setting is complete.

  [Step S6] If the scattered X-ray removal grid 12B has already been set at the arrangement position 2a on the front surface of the two-dimensional X-ray detector 2, the process jumps to step S9, otherwise proceeds to the next step S7.

  [Step S7] The operator performs an operation of designating the scattered X-ray removal grid 12B on the operation unit 6.

  [Step S8] The designated grid changing mechanism 14 immediately operates upon receiving a grid designation signal from the grid designation unit 13, and the scattered electric X-ray is removed as the operating electric motor 14C rotates the endless belt 14B in the direction indicated by the arrow Rb. At the same time as the grid 12B moves in the direction of advancing from the side retraction position 2b of the two-dimensional X-ray detector 2 to the front arrangement position 2a, the scattered X-ray removal grid 12A is conversely the front surface of the two-dimensional X-ray detector 2. As shown in FIG. 6, the scattered X-ray removal grid 12B is set at the front position of the two-dimensional X-ray detector 2 and moved to the side retreat position 2b. The grid setting is complete.

[Step S9] Since an appropriate scattered X-ray removal grid is already set at the position 2a on the front surface of the two-dimensional X-ray detector 2, the setting of the grid is completed.
Subsequently, the operator moves to an X-ray imaging execution operation.

  As described in detail above, the X-ray fluoroscopic apparatus according to the first embodiment has the focus-image-receiving surface distance among the plurality of scattered X-ray removal grids 12A and 12B having different focus-image-receiving surface distance ranges that can be adapted. A scattered X-ray removal grid that matches the current set value of the SID can be selected and advanced to the placement position 2a on the front surface of the two-dimensional X-ray detector 2 and set according to the current set value of the focal point / image receiving surface distance SID. The non-scattered X-ray removal grid is moved backward to the retreat position 2 b on the side of the two-dimensional X-ray detector 2.

  Therefore, in the case of the apparatus of the first embodiment, the distance range between the focal point and the image receiving surface to which the scattered X-ray removal grid provided in one apparatus can be adapted is two different distance ranges between the focus and image receiving surface that can be adapted. In addition to providing a wide range (ranging from 50 cm to 1 m and 70 cm) in which the distance ranges between the focal points and the image receiving surfaces of the scattered X-ray removal grids 12A and 12B are all combined, the technical matters necessary for this are two scattered X Each of the line removal grids 12A and 12B has a configuration that is easy to realize so that each of the line removal grids 12A and 12B can reciprocate between the front-side arrangement position 2a and the side retraction position 2b of the two-dimensional X-ray detector 2.

Therefore, according to the apparatus of the first embodiment, the distance range between the focal point and the image receiving surface that can be adapted by the scattered X-ray removal grid provided in one apparatus can be easily expanded.
In addition, in the case of the apparatus according to the first embodiment, both the two scattered X-ray removal grids 12A and 12B are moved to the arrangement position 2a on the front surface of the two-dimensional X-ray detector 2 only by the designation operation by the operation unit 6. Can be set.

Next, a second embodiment of the X-ray imaging apparatus of the present invention will be described with reference to the drawings. FIG. 8 is a block diagram illustrating the overall configuration of the X-ray fluoroscopic apparatus according to the second embodiment.
The apparatus according to the second embodiment has a focus-to-image-receiving plane between the X-ray tube 1 and the two-dimensional X-ray detector 2 out of two scattered X-ray removal grids having different focus-to-image-receiving distance ranges. The grid selection unit 16 that selects a scattered X-ray removal grid that matches the focal point / image-receiving surface distance SID detected by the SID measurement display 11 that is an SID detection unit that detects the distance SID, and the grid selection unit 16 selects The scattered X-ray removal grid is advanced to the arrangement position 2a on the front surface of the two-dimensional X-ray detector 2, and the scattered X-ray removal grid set at the arrangement position 2a on the front surface of the two-dimensional X-ray detector 2 is retracted position 2b. Since it is substantially the same as the apparatus of the first embodiment except that it includes a selection grid replacement mechanism 17 that moves backward, the description will be made only on the differences, and the description on the common points will be omitted.

  That is, the grid selection unit 16 selects the scattered X-ray removal grid 12A if the current set value of the focal point / image receiving surface distance SID detected by the SID measurement display 11 is less than 1 m, and the SID measurement display 11 If the current setting value of the focal point / image receiving surface distance SID detected by the above is 1 m or more, the scattered X-ray removal grid 12B is selected.

  The selection grid replacement mechanism 17 has exactly the same configuration as the designated grid replacement mechanism 14 except that it operates according to the selection result of the grid selection unit 16, and when the scattered X-ray removal grid 12A is selected by the grid selection unit 16, As shown in FIG. 5, similarly to the case where the scattered X-ray removal grid 12A is designated in the first embodiment, the scattered X-ray removal grid 12A is set at the arrangement position 2a on the front surface of the two-dimensional X-ray detector 2, and the grid When the scattered X-ray removal grid 12B is selected by the selection unit 16, as shown in FIG. 6, the scattered X-ray removal grid 12B is two-dimensionally the same as when the scattered X-ray removal grid 12B is designated in the first embodiment. It is set at the arrangement position 2a on the front surface of the X-ray detector 2.

  Therefore, according to the apparatus of the second embodiment, the X-ray tube 1 and the two-dimensional X-ray detector 2 are located at the arrangement position 2a on the front surface of the two-dimensional X-ray detector 2 without any operation by the operator. A scattered X-ray removal grid corresponding to the current set value of the focal point / image receiving surface distance SID is automatically set.

The present invention is not limited to the above embodiment, and can be modified as follows.
(1) In the case of the apparatus of Examples 1 and 2, the scattered X-ray removal grids 12A and 12B are configured to be electrically moved by the electric motor 14C. However, in the case of the apparatus of the present invention, the scattered X-ray removal grid 12A. , 12B may be manually moved.

  (2) In the case of the apparatuses of Examples 1 and 2, the number of scattered X-ray removal grids with different focus-to-image-receiving distance ranges is two, but the focus-to-image-receiving distance range can be adapted. An apparatus having the same configuration except that the number of scattered X-ray removal grids having different numbers is 3 or more can be given as a modified example.

  (3) In the apparatuses of Examples 1 and 2, the compatible focus / image-receiving distance range is connected between the two scattered X-ray removal grids without overlapping, but in the apparatus of the present invention, Even if there are some overlapping focus / image plane distance ranges that do not match or there is a range that is not connected between multiple scattered X-ray removal grids with different focus / image plane distance ranges that can be matched Good.

  (4) Although the apparatus according to the first embodiment is an X-ray fluoroscopic apparatus, the present invention can be applied to apparatuses other than the X-ray fluoroscopic apparatus.

  (5) Although the devices of Examples 1 and 2 are medical devices, the present invention is not limited to medical devices but can be applied to industrial or nuclear devices.

1 is a block diagram illustrating an overall configuration of an X-ray fluoroscopic apparatus according to Embodiment 1. FIG. FIG. 3 is a plan view illustrating a configuration around a scattered X-ray removal grid in the apparatus according to the first embodiment. It is a side view which shows the arrangement | positioning condition of the scattered X-ray removal grid in the apparatus of Example 1. FIG. It is a schematic diagram which shows the structural example of the scattered X-ray removal grid used for the apparatus of Example 1. FIG. FIG. 3 is a schematic diagram illustrating a set state of a scattered X-ray removal grid for short-distance imaging in the apparatus according to the first embodiment. It is a schematic diagram which shows the set state of the scattered X-ray removal grid for long-distance imaging | photography in the apparatus of Example 1. FIG. It is a flowchart which shows the process at the time of setting the scattering X-ray removal grid in the apparatus of Example 1 in the arrangement position of the front surface of a two-dimensional X-ray detector. It is a block diagram which shows the whole structure of the X-ray fluoroscope of Example 2. FIG. It is a schematic diagram which shows the principal part structure of the conventional X-ray fluoroscopic imaging apparatus.

Explanation of symbols

1 X-ray tube (X-ray irradiation means)
1A: focal point (of X-ray tube) 2 ... two-dimensional X-ray detector (two-dimensional X-ray detection means)
2A ... Image receiving surface of (two-dimensional X-ray detector) 2a ... Arrangement position 2b (front of two-dimensional X-ray detector) 2b ... Retraction position (side of two-dimensional X-ray detector) 6 ... Operation unit (grid Part of the designation method)
11 ... SID measurement display (SID detection means)
12A, 12B ... Scattered X-ray removal grid 13 ... Grid designation part (part of grid designation means)
14 ... Designated grid replacement mechanism (designated grid replacement means)
16 ... Grid selection part (grid selection means)
17… Selected grid replacement mechanism (selected grid replacement means)
M ... subject SID ... distance between focal point and image receiving surface

Claims (3)

  A focal point of an X-ray irradiating means for irradiating the subject with X-rays, and an image receiving surface of a two-dimensional X-ray detecting means for detecting a transmitted X-ray image disposed opposite the X-ray irradiating means across the subject In an X-ray imaging apparatus having a scattered X-ray removal grid arranged in front of the two-dimensional X-ray detection means. A plurality of scattered X-ray removal grids having different distance ranges between the image receiving surfaces are reciprocally moved between the position of the front surface of the two-dimensional X-ray detection means and the side retraction position of the two-dimensional X-ray detection means. An X-ray imaging apparatus which is arranged in a state where   2. The X-ray imaging apparatus according to claim 1, wherein a grid designating unit designates any one scattered X-ray removal grid out of a plurality of scattered X-ray removal grids having different focus-receiving surface distance ranges that can be adapted. And the scattered X-ray removal grid designated by the grid designation means is advanced to the arrangement position on the front surface of the two-dimensional X-ray detection means, and the scattered X-ray removal set at the arrangement position on the front surface of the two-dimensional X-ray detection means is removed. An X-ray imaging apparatus comprising designated grid replacement means for retracting the grid to a retracted position. 2. The X-ray imaging apparatus according to claim 1, wherein the SID detecting means for detecting a distance between the focal point and the image receiving plane (SID) of the X-ray irradiating means and the two-dimensional X-ray detecting means, and an applicable focal point / image receiving plane. A grid selection means for selecting a scattered X-ray removal grid that matches the distance between the focal point and the image receiving surface detected by the SID detection means from a plurality of scattered X-ray removal grids having different distance ranges, and a scatter selected by the grid selection means. Selection grid replacement for advancing the X-ray removal grid to the arrangement position on the front surface of the two-dimensional X-ray detection means and retreating the scattered X-ray removal grid set at the arrangement position on the front surface of the two-dimensional X-ray detection means to the retreat position And an X-ray imaging apparatus.

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