JP2013255536A - Radiation image capturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image capturing apparatus having less vignetting even when capturing images using a large-size lattice, and capable of acquire sharp images to every detail.SOLUTION: A radiation image capturing apparatus 1 includes: an X-ray tube 11 for irradiating an object with X-ray; a first lattice 14 for generating a Talbot effect by diffracting the X-ray; a second lattice 15 for diffracting the X-ray diffracted by the first lattice 14; an X-ray detector 16 having a plurality of detecting elements arranged in two dimensions; and a subject plate 13 for placing a subject. In the apparatus, at least any one of the first and second lattices 14, 15 is a complex lattice 100 that is made to be large in size by combining a plurality of kinds of small lattices 10 that are different in height h and/or pitch w of the lattice.

Description

  The present invention relates to a radiographic image capturing apparatus, and more particularly to a radiographic image capturing apparatus suitable for capturing a joint portion.

The cartilage of the joints such as the hands and legs and the soft tissues around the joints cannot obtain images suitable for diagnosis by conventional X-ray photography using the absorption contrast method. Photographed images have been used.
However, MRI imaging requires a large burden on the patient, such as mechanically restraining the patient's body position for a predetermined time, and also costs medical expenses. Therefore, an X-ray image captured using a general radiation tube is used for rheumatic diagnosis. The technology to utilize is desired.

  In this regard, the Talbot effect is used as one type of X-ray imaging (phase contrast imaging) by the phase contrast method that obtains an X-ray image with high visibility by edge enhancement using X-ray refraction during phase contrast magnification imaging. X-ray imaging using a Talbot interferometer and a Talbot interferometer is known, and as an imaging technique replacing MRI, obtaining a diagnostic X-ray image by phase contrast imaging using the Talbot effect is being studied. (For example, refer to Patent Document 1 to Patent Document 3, for the method and principle of obtaining a phase contrast image using the Talbot effect, see, for example, paragraphs [0004] and [0005] of Patent Document 3).

  X-ray imaging using such a phase contrast method can image breast tissue, articular cartilage, and soft tissue around the joint, which have a small X-ray absorption difference and are difficult to appear as an image by the absorption contrast method. Therefore, using a widely used general X-ray imaging technique, an X-ray image taken using the phase contrast method is used for diagnosis of a lesion in cartilage or soft tissue such as rheumatism. Therefore, it is expected to reduce the burden imposed on patients and medical costs.

  When performing phase contrast imaging using the Talbot effect, a grating for generating the Talbot effect is arranged between the X-ray tube that irradiates X-rays and the X-ray detector. Therefore, an existing wafer manufacturing process capable of fine processing is used for manufacturing the lattice. However, a wafer generally has a diameter of about 50 mm to 300 mm, and the size of each grating is limited to a size that can be cut out from the wafer. Therefore, it is difficult to manufacture a large-size grating. For this reason, there is a problem that a single lattice cannot secure a size necessary for photographing a wide range.

For this reason, in recent years, it has been studied to increase the size by combining a plurality of small sized lattices (see, for example, Patent Documents 1 and 2).
However, the incident angle of the radiation emitted from the radiation source differs between the central part and the peripheral part of the grating. When the size of the grating is simply increased, the incident angle of the radiation and the grating angle at the peripheral part of the grating are different. Since they are not parallel, vignetting occurs at the peripheral edge of the lattice, and the sharpness of the image at the edge is reduced.
As a method for suppressing such vignetting at the peripheral edge, it is conceivable to apply a curvature corresponding to the incident angle of radiation by pressing the entire grating against a curved mold as described in Patent Document 2 and the like.

JP 2007-203061 A JP 2012-13530 A JP 2012-45099 A

However, as described above, since the structure of the grating is fine, it is practically difficult to obtain a desired curvature by pressing a large-sized one obtained by combining a plurality of gratings.
For this reason, it has been difficult to obtain a sharp image up to an end portion with less vignetting while using a large-size lattice.

  The present invention has been made in view of the circumstances as described above, and is capable of obtaining a sharp image with little vignetting even when photographing using a large-sized composite grid. The object is to provide an apparatus.

In order to solve the above problem, according to the invention of claim 1,
An X-ray tube that emits X-rays;
A first diffraction grating that produces a Talbot effect by diffracting X-rays;
A second diffraction grating for diffracting X-rays diffracted by the first diffraction grating;
An X-ray detector having a plurality of detection elements arranged two-dimensionally;
A subject table on which the subject is placed;
A radiographic imaging device comprising:
At least one of the first diffraction grating and the second diffraction grating is a composite grating that is enlarged by combining a plurality of types of small-size gratings having different grating heights and / or grating pitches. A radiographic imaging device is provided.

According to invention of Claim 2,
The radiographic imaging apparatus of Claim 1 which has the grating | lattice for X-ray tubes which makes the X-ray irradiated from the said X-ray tube multi-light source.

According to invention of Claim 3,
The lattice for the X-ray tube has a single structure that is not combined,
The radiographic imaging apparatus according to claim 2, further comprising a grating moving unit that moves the X-ray tube grating with respect to the first diffraction grating and the second diffraction grating.

According to invention of Claim 4,
An X-ray tube that emits X-rays;
A first diffraction grating that produces a Talbot effect by diffracting X-rays;
A second diffraction grating for diffracting X-rays diffracted by the first diffraction grating;
A grid for an X-ray tube that converts X-rays irradiated from the X-ray tube into a multi-light source;
An X-ray detector having a plurality of detection elements arranged two-dimensionally;
A subject table on which the subject is placed;
A radiographic imaging device comprising:
At least one of the first diffraction grating, the second diffraction grating, and the X-ray tube grating has a large size by combining a plurality of types of small size gratings having different grating heights and / or grating pitches. There is provided a radiographic imaging device that is an integrated composite grid.

According to the invention of claim 5,
The radiographic imaging apparatus according to claim 1, wherein the composite grating is configured by combining each small size grating so as to be parallel to a detector plane of the X-ray detector. Is done.

According to the invention of claim 6,
The radiographic image according to claim 1, wherein the composite grating is configured by combining each small size grating so as to have a predetermined curvature with respect to a detector plane of the X-ray detector. An imaging device is provided.

According to the radiographic imaging apparatus of the present invention, at least one of the first diffraction grating and the second diffraction grating that causes the Talbot effect is a plurality of types of small sizes having different grating heights and / or grating pitches. Since this is a composite grid that has been enlarged by compounding a grid, there is little vignetting and a sharp image can be obtained up to the edge even when a wide range is photographed using a large-size grid.
In particular, in the Talboro apparatus, the X-ray tube grating that converts X-rays into multiple light sources is scanned and moved. This makes it possible to adopt a composite large-size grid that incorporates vignetting.

1 is a schematic side view of an X-ray imaging system including a radiographic imaging apparatus according to the present embodiment. It is a top view of the radiographic imaging apparatus shown in FIG. It is a perspective view which shows the specific structure of the radiographic imaging apparatus shown in FIG. It is a figure which shows typically the main structures of the radiographic imaging apparatus shown in FIG. It is a perspective view which shows a mode that an X-ray detector holding | maintenance part is attached to a radiographic imaging apparatus. It is a perspective view which shows the state which attached the X-ray detector holding | maintenance part to the radiographic imaging apparatus. It is a perspective view of a multi lattice unit. It is a perspective view which shows the state by which the multi-grating unit was arrange | positioned under the X-ray source. It is a perspective view which shows the state which attached the 1st grating | lattice unit and the 2nd grating | lattice unit to the base part. (A) And (b) is a top view which shows an example of a composite grating | lattice. (A) is a top view of a small size grating | lattice, (b) is a sectional side view of a small size grating | lattice. (A) And (b) is a sectional side view which shows an example of a composite grating | lattice. It is a figure which shows the relationship between the combination example of a composite grating | lattice, a vignetting performance order | rank, and the improvement degree of the transmitted light quantity. FIGS. 14A to 14D are diagrams schematically showing examples of combinations of composite grids 1 to 4 in FIG. 13. (E)-(f) is a figure which shows typically the example of a combination of the composite grating | lattices of No. 5 to No. 7 of FIG. It is a perspective view which shows the state which decomposed | disassembled the 1st cover unit of the radiographic imaging apparatus. It is a perspective view which shows the state which removed the 2nd cover unit and guard member of the radiographic imaging apparatus. It is a perspective view which shows the state which decomposed | disassembled the 2nd cover unit of the radiographic imaging apparatus. It is the principal part perspective view which expanded the to-be-photographed object base upper surface board of a to-be-photographed base. FIG. 20 is an enlarged cross-sectional view showing a main part in the vicinity of the center portion of the subject table upper surface plate of the subject table shown in FIG. 19. FIG. 3 is a perspective view showing a base unit, a first photographing target fixing unit, and a subject holding member with the first photographing target fixing unit mounted on the base unit. FIG. 4 is a perspective view showing a state in which a subject holding member having a first photographing target fixing unit mounted thereon is placed on a subject table upper surface plate of a subject table. FIG. 6 is a perspective view showing a base unit, a second photographing target fixing unit, and a subject holding member with the second photographing target fixing unit mounted on the base unit. It is a perspective view which shows the state which fixed the finger | toe to the subject holding member with which the 2nd imaging | photography target fixing unit was mounted | worn, (a) is a 2nd finger, (b) is a 3rd finger, (c) is a 4th finger. (D) is a perspective view which shows the state which fixed the 5th finger | toe. It is a perspective view which shows a base unit and a 3rd imaging | photography target fixing unit, and the to-be-photographed object holding member which attached the 3rd imaging | photography target fixing unit to the base unit. It is a perspective view which shows the state which fixed the finger | toe to the subject holding member with which the 3rd imaging | photography target fixing unit was mounted | worn. It is a perspective view which shows a base unit and a 4th imaging | photography target fixing unit, and the to-be-photographed object holding member which attached the 4th imaging | photography target fixing unit to the base unit. It is a perspective view which shows the state which fixed the finger | toe to the subject holding member with which the 4th imaging target fixing unit was mounted | worn. It is a perspective view showing a base unit, a fifth photographing target fixing unit, and a subject holding member with the fifth photographing target fixing unit attached to the base unit. It is a perspective view which shows the state which fixed the finger | toe to the to-be-photographed object holding member with which the 5th imaging | photography target fixing unit was mounted | worn. It is a perspective view of a subject holding member to which a sixth photographing target fixing unit is attached. It is a perspective view of the 2nd fixing tool of the 6th imaging target fixing unit. It is the perspective view which looked at the 2nd fixing tool from the direction different from FIG. It is a perspective view which shows the state which fixed the finger | toe to the subject holding member with which the 6th imaging | photography target fixing unit was mounted | worn, and moved each holding | gripping unit to the wrist side. It is a perspective view which shows the state which fixed the finger | toe to the subject holding member with which the 6th imaging | photography target fixing unit was mounted | worn, and moved each holding | gripping unit to the fingertip side. (A) is a figure which shows the image | video which image | photographed without performing finger pull, (b) is a figure which shows the image | video which image | photographed while pulling a finger using the restraint unit. It is a perspective view which shows the state which changed the holding | grip unit which the 6th imaging | photography object fixing unit uses. It is a perspective view which shows the state which changed arrangement | positioning of the holding | grip unit of the 6th imaging | photography object fixing unit. FIG. 4 is a perspective view showing a state where a subject support plate is placed on a subject table top surface plate of a radiographic imaging device and an auxiliary table is connected to the subject support plate and imaging of a joint portion of a patient's knee is performed. . (A) is a perspective view which shows the state which contracted the knee fixing unit, (b) is a perspective view which shows the state which extended the knee fixing unit. (A) And (b) is a perspective view which shows the state which bent the knee fixing unit. It is the principal part perspective view which expanded the hinge part periphery of the knee fixing unit. It is a block diagram which shows the functional structure of a main-body part. (A) And (b) is a top view which shows the modification of a composite grating | lattice. It is a top view which shows one modification of a composite grating | lattice. (A) And (b) is a top view which shows the modification of a composite grating | lattice. (A) And (b) is a top view which shows the modification of the composite grating | lattice shown to Fig.11 (a) and FIG.11 (b).

Hereinafter, an embodiment of a radiographic image capturing apparatus according to the present invention will be described with reference to the drawings.
In the present embodiment, the radiographic image capturing apparatus includes a subject table 13 that holds a finger or the like of a person who is a subject at a photographing position, and a radiation that is disposed above the subject table 13 and is applied to a finger or the like that is a subject to be photographed. An X-ray source 11 as a radiation generating means for irradiating and an imaging unit having an X-ray detector 16 as a detecting means that is disposed below the subject table 13 and detects radiation that has passed through the imaging target portion. ing.

FIG. 1 schematically shows an X-ray imaging system including a radiographic imaging apparatus according to this embodiment, and FIG. 2 is a plan view of the radiographic imaging apparatus 1 shown in FIG. 1 as viewed from above. .
The X-ray imaging system includes a radiation image capturing apparatus 1 and a controller 5. The radiographic image capturing apparatus 1 performs X-ray imaging with a Talbot-Lau interferometer, and the controller 5 creates a reconstructed image of the subject using the moire image obtained by the X-ray imaging.

As shown in FIG. 1, the radiographic imaging apparatus 1 includes an X-ray source 11, a multi-grating 12, a light irradiation field confirmation unit 6, a subject table 13, a first grating 14, a second grating 15, an X-ray detector 16, A support column 17, a main body 18, and a base 19 are provided.
The radiographic imaging apparatus 1 in the present embodiment is a vertical type, and the X-ray source 11, the multi-grating 12, the subject table 13, the first grating 14, the second grating 15, and the X-ray detector 16 are arranged in this order in the direction of gravity. (See FIGS. 1 and 4).
In FIG. 1, the distance between the focal point of the X-ray source 11 and the multi-grating 12 is d1 (mm), the distance between the focal point of the X-ray source 11 and the X-ray detector 16 is d2 (mm), The distance between the 1st grating | lattice 14 is represented by d3 (mm), and the distance between the 1st grating | lattice 14 and the 2nd grating | lattice 15 is represented by d4 (mm).

The distance d1 is preferably 3 to 500 (mm), and more preferably 4 to 300 (mm).
The distance d2 is preferably at least 3000 (mm) or less since the height of the radiology room is generally about 3 (m) or less. Especially, the distance d2 is preferably 400 to 2500 (mm), and more preferably 500 to 2000 (mm).
The distance (d1 + d3) between the focal point of the X-ray source 11 and the first grating 14 is preferably 300 to 5000 (mm), and more preferably 400 to 1800 (mm).
The distance (d1 + d3 + d4) between the focal point of the X-ray source 11 and the second grating 15 is preferably 400 to 5000 (mm), more preferably 500 to 2000 (mm).
Each distance may be set by calculating an optimum distance at which the lattice image (self-image) by the first lattice 14 overlaps the second lattice 15 from the wavelength of the X-rays emitted from the X-ray source 11.

FIG. 3 is a perspective view specifically showing the configuration of the radiographic image capturing apparatus 1 shown in FIGS. 1 and 2, and FIG. 4 is a schematic view of the main configuration of the radiographic image capturing apparatus 1 in the present embodiment. It is shown.
In this embodiment, the radiographic imaging apparatus 1 includes an X-ray source 11, a multi-grating 12, a light irradiation field confirmation unit main body 65, a subject holding member 30 on a subject table 13, a first grating 14, a second grating 15, and an X-ray detection. The containers 16 are arranged in this order along the z direction (see FIG. 1), which is the direction of gravity.

A fixing member 111 formed in a substantially U shape is attached to the X-ray source 11 via an attachment arm 112. In the present embodiment, the support column 17 has a quadrangular prism shape, and the fixing member 111 is attached and fixed to the support column 17 so as to sandwich the support column 17 from the side surface.
A buffer member 17a (see FIG. 1) is provided on a part of the mounting arm 112, and the X-ray source 11 is held via the buffer member 17a. Any material may be used for the buffer member 17a as long as it can absorb shocks and vibrations, and examples thereof include an elastomer. Since the X-ray source 11 generates heat upon irradiation with X-rays, the buffer member 17a on the X-ray source 11 side is preferably a heat insulating material in addition to a material that can absorb shock and vibration.

The X-ray source 11 includes an X-ray tube, generates X-rays by the X-ray tube, and irradiates the X-rays in the gravity direction (z direction). As the X-ray tube, for example, a Coolidge X-ray tube or a rotary anode X-ray tube widely used in the medical field can be used. As the anode, tungsten or molybdenum can be used.
The X-ray focal diameter is preferably 0.03 to 3 (mm), more preferably 0.1 to 1 (mm).

5 and 6 are perspective views showing the internal configuration of the radiation imaging apparatus 1 with the first cover unit 21, the second cover unit 22, and the guard member 41, which will be described later, removed.
In this embodiment, as shown in FIGS. 5 and 6, the X-ray source 11 includes a multi-grating 12 whose parallelism and relative distance are adjusted by bending a part of the mounting arm 112 approximately 90 degrees. The mounting direction of the X-ray source 11 is configured to be rotatable by approximately 90 degrees with respect to the slit direction of the first grating 14 and the second grating 15.
In the present embodiment, the focal shape of the X-ray tube of the X-ray source 11 is not a perfect circle, but is slightly elliptical. In some cases, an appropriate moire image can be obtained by changing. For this reason, by rotating the X-ray source 11 by approximately 90 degrees, it is possible to eliminate the problems caused by the focal shape of the X-ray tube.
In addition, the structure which enables the X-ray source 11 to change the attachment direction with respect to the slit direction of the multi grating | lattice 12, the 1st grating | lattice 14, and the 2nd grating | lattice 15 is not limited to what was illustrated here. For example, the attachment direction of the X-ray source 11 may be changed by changing the attachment position of the fixing member 111. Further, the change in the mounting direction of the X-ray source 11 is not limited to 90 degrees, and the angle may be set more finely.

Furthermore, in the present embodiment, as shown in FIG. 6, the X-ray source 11 is configured such that the end of the mounting arm 112 on the fixed side of the X-ray source 11 is rotatable, and is irradiated from the X-ray source 11. From the state in which the optical axis of the X-ray is substantially parallel to the support column 17 and the X-ray is irradiated onto the multi-grating 12, the first grating 14, and the second grating 15 (see the imaging state FIG. 5), The X-ray irradiation direction of the X-ray source 11 can be changed up to a state in which the multi-grid 12, the first grating 14, and the second grating 15 deviate from the top (calibration state see FIG. 6).
Note that the X-ray irradiation direction of the X-ray source 11 at the time of calibration may be any direction in which the optical axis of the X-ray is in a state in which the X-ray optical axis deviates from above the multi-grating 12, the first grating 14, and the second grating 15. It is not limited to what was illustrated to. When the X-ray irradiation direction of the X-ray source 11 at the time of calibration is another direction, the X-ray detector holding unit 25 is attached so as to be disposed on the extension line of the optical axis of the X-ray source 11. The position is adjusted.

An irradiation field stop 113 and a filter 114 are provided directly below the X-ray source 11 and below the multi-grating 12 described later.
The irradiation field stop 113 narrows the X-ray irradiation field irradiated from the X-ray source 11 to a predetermined range.
The filter 114 separates a light beam having an unnecessary wavelength from the light beam irradiated from the X-ray source 11, and an AL addition filter or the like is applied, for example.

As shown in FIGS. 3, 5, 6, etc., the light irradiation field confirmation unit 6 is mounted on a substantially L-shaped base mounting portion 61 attached to the base portion 19 and the base mounting portion 61. And a light irradiation field confirmation unit main body 65 to be placed. The base mounting portion 61 is fixed to the base portion 19 with screws or the like (not shown).
A guide 63 for moving the light irradiation field confirmation unit main body 65 in the x direction is provided on a surface of the base mounting part 61 that is disposed substantially horizontally with respect to the floor surface. The main body 65 can be moved manually or automatically along the guide 63.
The light irradiation field confirmation unit 6 illuminates the same region as the X-ray irradiation field with visible light in order to confirm the X-ray irradiation field irradiated from the X-ray source 11 in advance. 65 is provided with a light source (not shown) capable of emitting visible light.
Further, the light irradiation field confirmation unit main body 65 is provided with a moving lever 67 that protrudes substantially horizontally with respect to the floor surface from the back side (that is, the column 17 side) of the radiographic imaging device 1 to the front side. . The moving lever 67 is a lever for manually moving the light irradiation field confirmation unit main body 65 along the guide 63 in the x direction, and as described above, the first cover unit 21 is attached to the radiographic image capturing apparatus 1. In the state where is attached, the tip end portion projects out of the front cover member 211 from the lever opening 211c.

In the present embodiment, the light irradiation field confirmation unit main body 65 confirms the light irradiation field by matching the optical axis of the light emitted from the light source with the optical axis of the X-ray emitted from the X-ray source 11. And a retracted position that does not interfere with the X-rays emitted from the X-ray source 11 can be taken. During normal use, such as when shooting, the light irradiation field confirmation unit main body 65 is positioned at the retracted position (the position indicated by the solid line in FIG. 4) so as not to interfere with shooting. When confirming the light irradiation field, the user appropriately operates the moving lever 67 so that the optical axis of light emitted from the light source of the light irradiation field confirmation unit main body 65 is irradiated from the X-ray source 11. The position of the light irradiation field confirmation unit main body 65 is moved to a light irradiation field confirmation position (a position indicated by a broken line in FIG. 4) that coincides with the optical axis of the X-ray. The light irradiation field confirmation unit main body 65 may be configured to automatically move in the x direction by a motor or the like.
In this embodiment, since there is no light blocking member between the light irradiation field confirmation unit main body 65 and the subject holding member 30, the light irradiation field can be confirmed accurately.

The multi-grating unit 120, the first grating unit 140, the second grating unit 150, and the X-ray detector 16 are held on the same base 19 and the positional relationship in the z direction is fixed. The multi-grating unit 120, the first grating unit 140, and the second grating unit 150 are extended in a direction orthogonal to the gravitational direction (z direction), and can be attached to and detached from the base unit 19 with screws or the like. It is attached.
The X-ray detector 16 is placed on a detector support 191 provided on the base 19 via a buffer member 192.
The base unit 19 may be configured to be movable in the z direction with respect to the support column 17.

FIG. 7 is a perspective view of the multi-grating unit 120 including the multi-grating 12. The multi-grating 12 is an X-ray tube grating that converts X-rays irradiated from the X-ray tube into multiple light sources. Hereinafter, the multi-grating 12 is also referred to as a “G0 lattice”.
As shown in FIG. 7, the multi-grid unit 120 includes a substantially L-shaped base mounting portion 121 attached to the base portion 19 and a multi-grid unit main body 122 placed on the base mounting portion 121. I have.
A linear guide 123 for moving the multi-grid unit main body 122 in the x direction is provided on a surface of the base mounting portion 121 that is disposed substantially horizontally with respect to the floor surface.
The base mounting part 121 is capable of adjusting the relative distance between the multi-grating 12 and the first grid 14 or the second grid 15 by adjusting the mounting position on the base part 19. The multi-grating unit main body 122 is provided with a relative distance fine adjustment mechanism portion 127. The relative distance fine adjustment mechanism 127 adjusts the position of the multi-grid 12 in the gravitational direction (vertical direction) by changing the length in the gravitational direction (vertical direction). In the present embodiment, the base mounting portion 121 and the relative distance fine adjustment mechanism portion 127 constitute a relative distance adjustment mechanism that adjusts the relative distance between the multi lattice 12 and the first lattice 14 or the second lattice 15. Is done.
From the viewpoints of workability and safety when handling a multi-grid unit that is relatively heavy, and ease of position adjustment, it is preferable to separate the former and latter functions, and the mounting position is Temporarily fixed with positioning pins (not adjustable) and screwed (fixed) to the base 19 with screws or the like. After the fixing is completed, the operator can freely use both hands in the multi-grid unit main body 122. It is preferable that the relative distance be finely adjusted by the provided relative distance fine adjustment mechanism 127.

The multi-grating unit body 122 supports the multi-grating 12 and, as a multi-grating driving unit 125 for moving the multi-grating 12, the x-direction moving motor 125a and the multi-grating 12 are rotated in the x direction. Θx rotating motor 125b, a θy rotating motor 125c for rotating the multi-grating 12 in the y direction, and a θz rotating motor 125d for rotating the multi-grating 12 in the z direction are provided.
In the present embodiment, as shown in FIG. 8, the multi-grating 12 is inserted into the X-ray source 11 from below the X-ray source 11 and is arranged in the immediate vicinity of the focal position of the X-ray tube. It has become.

The x-direction movement motor 125a is a drive source that is energized and is configured by a motor that can perform highly accurate operation control, such as a stepping motor (pulse motor) that operates in synchronization with a pulse signal accurately. ing. In the present embodiment, the x-direction moving motor 125a moves the multi-grating 12 as the X-ray tube grating with respect to the first grating 14 as the first diffraction grating and the second grating 15 as the second diffraction grating. It functions as a lattice moving means.
As the stepping motor applied to the x-direction moving motor 125a, for example, a 5-phase stepping motor such as a 5-phase stepping motor (model: PX533MH-B) manufactured by Oriental Motor Co., Ltd. is desirable, and a high-resolution type is also available for 5 phases. preferable. That is, in general, the basic step angle is 0.72 °, but in the high resolution type, the basic step angle is 0.36 °, and such a motor is preferably used. Furthermore, it is preferable to perform control by microsteps that can subdivide the number of steps.
In the present embodiment, when the x-direction movement motor 125a that is a driving source is driven, the transmission system that transmits the output of the driving source to the main body of the multi-grid unit 120 including the multi-grid 12 that is a driven part is illustrated. The main body of the multi-grating unit 120 including the multi-grating 12 is guided by the linear guide 123 and moves in the x direction.
The moving unit of the multi-grid unit 120 is configured by the x-direction moving motor 125a as the driving source and the ball screw and linear guide as the transmission system, and the moving unit moves in a direction orthogonal to the gravitational direction (z direction). It is comprised only by the moving element to do.

  In this embodiment, when the multi-grid 12 is moved, the output of the x-direction moving motor 125a is maximized, but at the time of X-ray irradiation, the multi-grid driving unit 125 is moved to the x-direction moving motor 125a. The energizing current value to the x-direction moving motor 125a is adjusted so that the energizing current becomes a current value that is 50% or less of the displacement generated in the multi-grid 12 when the output of the motor is maximized. It is like that.

The first grating 14 and the second grating 15 are respectively provided in the first grating unit 140 and the second grating unit 150 having substantially the same configuration.
The first grating 14 is a first diffraction grating that causes the Talbot effect by diffracting X-rays, and the second grating 15 is a second diffraction grating that diffracts the X-rays diffracted by the first grating 14. .
FIG. 9 is an enlarged perspective view of the mounting portion of the first grid unit 140 and the second grid unit 150 in the base 19. As shown in FIG. 9, the second grating unit 150 is arranged so that the second grating 15 is positioned immediately above the X-ray detector 16. The first grating unit 140 is arranged so that the first grating 14 is positioned above the second grating 15.

In the present embodiment, at least one of the multi-grating 12 (G0 grating, X-ray tube grating), the first grating 14 (G1 grating, first diffraction grating), and the second grating 15 (G2 grating, second diffraction grating). One is a composite lattice that is enlarged by combining a plurality of types of small-size lattices having different lattice heights and / or lattice pitches.
FIG. 10A is a plan view of the small size grating 10 constituting the multi-grating 12, the first grating 14, and the second grating 15, and FIG. 10B is a side sectional view of the small size grating. . The composite grid is configured by combining a plurality of small size grids 10 as appropriate.
In the small size lattice 10, as shown in FIG. 10, a plurality of slits are arranged so as to be substantially parallel at a predetermined interval in one direction. The small size grating 10 has a high X-ray shielding power such as tungsten, lead and gold on a substrate 101 made of a material having a low X-ray absorption rate such as silicon or glass, that is, a shielding material made of a material having a high X-ray absorption rate. It is formed by arranging the parts. For example, the resist layer is masked in a slit shape by photolithography, and UV is irradiated to transfer the slit pattern to the resist layer. A slit structure having the same shape as the pattern is obtained by exposure, and a metal is embedded between the slit structures by an electroforming method, whereby the small size lattice 10 in which slits 102 that transmit X-rays and shielding portions are alternately arranged. Is formed.
Since the structure of the small size lattice 10 is fine, for example, a wafer manufacturing process capable of fine processing is used for the manufacture of the small size lattice 10.
The method for forming the small-size grating 10 constituting the multi-grating 12, the first grating 14 and the second grating 15, the distance between the multi-grating 12, the first grating 14 and the second grating 15 and the like are, for example, WO2011 / Since it is the same as that described in the specification of 114845, the specification of WO2011 / 033798, the specification of WO2012 / 029340, etc., its description is omitted.

FIG. 11A and FIG. 11B show a configuration example of a composite lattice 100 in which the small size lattice 10 is combined to increase the size. FIG. 11A shows a combination of three small-size lattices 10 shown in FIG. 10 that are bonded side by side in parallel with the slits 102 so that two sets face each other and are combined by six small-size lattices 10. An example in which a lattice is configured is shown. FIG. 11B shows an example in which a composite lattice is formed by laminating three rectangular small-size lattices 10 that are long in the extending direction of the slits 102 in parallel to the slits 102. As shown in FIG. 11B, when there is no bonded portion of the small-size grating 10 in the extending direction of the slit 102, there are few differential phase defects, and the influence on the image can be suppressed. Further, when the small-size grid 10 is manufactured in the wafer manufacturing process, the length of the slit 102 in the extending direction is longer when the small-size grid 10 is cut out in a rectangle that is longer in the extending direction of the slit 102 than in the case where the small-sized grid 10 is cut out in a square shape. And the range of the effective angle of view in the extending direction of the slit 102 can be widened. That is, for example, when an 8-inch wafer is used, the MRI-equivalent angle of view of 150 mm can be realized with a single sheet without bonding a plurality of small-size lattices 10 in the vertical direction.
The number of small sized lattices 10 constituting one composite lattice 100 is not particularly limited, but it is preferable that an odd number of small sized lattices 10 are bonded in the horizontal direction. Thereby, in the composite grating 100, the small size grating 10 having a plane perpendicular to the center of the optical axis of the X-ray source 11 can be arranged at the center in the horizontal direction.

In addition, when the small size lattice 10 is combined to increase the size, vignetting occurs at the periphery. Therefore, in order to suppress the occurrence of vignetting, in the present embodiment, the composite grating 100 is configured by combining a plurality of types of small-size gratings 10 having different grating heights and / or grating pitches to increase the size. ing.
Here, the grating pitch (hereinafter, also referred to as “slit period”) w means the distance between adjacent slits 102 as shown in FIG. 10A, and the grating height h means FIG. As shown in (b), it refers to the height of the slit 102 portion from the upper surface of the substrate 101.
FIG. 12A shows an example of a composite grating 100 formed by combining a plurality of types of small-size gratings 10 having different grating heights h to increase the size. ) Shows an example of a composite grating 100 formed by combining a plurality of types of small-size gratings 10 having different grating pitches w and increasing the size.
When a plurality of types of small sized lattices 10 having different lattice heights h are combined to form a large sized composite lattice 100, the lattice at the center of the composite lattice 100 is shown in FIG. The height h is increased, and the lattice height h is decreased toward the end. In addition, when a plurality of types of small sized lattices 10 having different lattice pitches w are combined to form a large sized composite lattice 100, as shown in FIG. The grating pitch w is made smaller (finer) so that the grating pitch w becomes larger (rougher) as it goes to the end.

As shown in FIG. 12 (a), when the composite lattice 100 is constituted by a plurality of types of small size lattices 10 having different lattice heights h, how much the lattice height h of each small size lattice 10 is different. It is determined as appropriate according to the height of the small size lattice 10 or the like.
For example, when the lattice height h of the small size lattice 10 located at the center is 50 μm and the composite lattice 100 is formed by three kinds of small size lattices 10 having different lattice heights h, The ratio of the lattice height h of the small size lattice 10 is set to the small size lattice at the center: the small size lattice adjacent to the small size lattice at the center: the small size lattice located at both ends = 1: 0.7: 0.6. It is preferable. When the ratio of the lattice height h is set as described above, in the composite lattice 100 having a lattice width of 200 mm formed by bonding five small size lattices 10 having a lattice width of 40 mm shown in FIG. Can be suppressed to about 10% or less of the center ratio, and the ratio of the transmitted light amount at the image edge to the transmitted light amount at the center of the optical axis can be suppressed to 50% or less.
Further, for example, when the lattice height h of the small size lattice 10 located at the center is 100 μm, and the composite lattice 100 is formed by three kinds of small size lattices 10 having different lattice heights h, The ratio of the lattice height h of each small-sized lattice 10 is as follows: small-sized lattice at the center: small-sized lattice adjacent to the small-sized lattice at the center: small-sized lattices located at both ends = 1: 0.55: 0.45 It is preferable that When the ratio of the lattice height h is set as described above, in the composite lattice 100 having a lattice width of 200 mm formed by bonding five small size lattices 10 having a lattice width of 40 mm shown in FIG. Can be suppressed to about 35% or less of the center ratio.
Various corrections are performed on the image captured by the radiation image capturing apparatus 1, and a final diagnosis providing image is generated. In addition, about the specific method of correction | amendment, since the well-known method described in the specification etc. of WO2011 / 114845 can be used, the description is abbreviate | omitted.

  Further, the composite grating 100 is arranged so that each small-size grating 10 is parallel to the detector plane of the X-ray detector 16 (that is, in plan view, for example, see FIGS. 15 (e) to 15 (g)). Each small size grating 10 may be tilted and bonded so as to have a predetermined curvature with respect to the detector plane of the X-ray detector 16 (for example, FIG. 14 (a) to FIG. 14 (d)). See), and may be combined. Here, the curvature is not limited to the degree of curvature in a curved surface, but also includes the degree of curvature as a whole of a polygonal approximate surface. The degree of the “predetermined curvature” is appropriately set according to the lattice size, the lattice height h, and the like.

In the present embodiment, in forming the composite grating 100, the grating height h of the small-sized grating 10 to be bonded is made different, the grating pitch w is made different, the grating height h, and / or the grating pitch w. A plurality of types of small-size gratings 10 having different sizes are combined in a plane or tilted so as to have a predetermined curvature, a multi-grating 12 (G0 grating, X-ray tube grating), and a first grating 14 (G1). The grating, the first diffraction grating), and the second grating 15 (G2 grating, second diffraction grating) can be arbitrarily combined.
In addition, when changing the grating pitch w, the first grating 14 (G1 grating, first diffraction grating) and the second grating 15 (G2 grating, second diffraction grating) of the small size grating 10 at the corresponding positions are used. It is necessary to match the lattice pitch w.

FIG. 13 shows a combination example of the multi-grating 12 (G0 grating, X-ray tube grating), the first grating 14 (G1 grating, first diffraction grating), and the second grating 15 (G2 grating, second diffraction grating). It is a table. FIGS. 14 (a) to 14 (d) and FIGS. 15 (e) to 15 (g) schematically show the configurations taken in the example of No. 1 to No. 7 in FIG. 13, respectively. It is a thing. The eighth example in FIG. 13 shows a configuration when no vignetting countermeasure is taken as a comparative example.
In FIG. 13, the vignetting performance ranking is an evaluation when the variation in vignetting is viewed as a ratio at the lattice end with respect to the lattice central portion. In the example of No. 8 in which the variation in vignetting is small in order from 1 and no vignetting countermeasure is taken, the vignetting performance is the worst.
In FIG. 13, the improvement in the amount of transmitted light is defined as the position (end) at a position 100 mm from the center when the effective angle of view of the second grating 15 (G2 grating, second diffraction grating) is assumed to be 200 mm square. It shows how much the transmitted light quantity is improved compared to the case where all the small size grids 10 are arranged in a plane, and the light quantity at the end when the small size grids 10 are arranged in a plane is used as a reference. If the ratio of the transmission amount at the end to the transmission amount at the center of the optical axis of the X-ray source 11 is substantially unchanged, the evaluation “A”, When the former is about 4 times and the latter is about 60%, the evaluation is “B”, and when the former is almost unchanged and the latter is about 15%, the evaluation is “C”. It has become.
Even in this C rank, the final reconstructed image (diagnostic-provided image) can be obtained by adopting the method of correcting the subject-exposed image with the subject-free image described in the specification of WO2011 / 114845 described above. The image quality (unevenness level) is improved.

As shown in FIGS. 14A to 14D, the grating height h of the first grating 14 (G1 grating, first diffraction grating) and the second grating 15 (G2 grating, second diffraction grating) is When different small size gratings 10 are tilted so as to have a predetermined curvature to form a composite grating 100, as shown in No. 1 to No. 4 in FIG. It was confirmed that this was improved compared to the example of FIG. 13 where no countermeasure was taken. In particular, the multi-grating 12 (G0 grating, X-ray tube grating) and the first grating 14 (G1 grating, first diffraction grating) are bonded together by inclining the same small size grating 10 to have a predetermined curvature. In addition to the grating 100, the second grating 15 (G2 grating, second diffraction grating) has a different grating height h (the small grating having the grating height h of the small grating 10 located at the center positioned at the end). When the small size grating 10 (which is higher than the grating height h of 10) is tilted so as to have a predetermined curvature to form the composite grating 100, both the vignetting performance and the amount of transmitted light are greatly improved.
Further, as shown in FIGS. 15E to 15G, the first grating 14 (G1 grating, first diffraction grating) and the second grating 15 (G2 grating, second diffraction grating) are arranged in a plurality of small sizes. When the size grating 10 is bonded in a plane, the vignetting performance and the amount of transmitted light are inferior as compared with the case where a predetermined curvature is given, but the grating height h and the grating pitch of the small size grating 10 to be bonded together. When either one of w is changed (5th and 7th in FIG. 13, FIG. 15 (e) and FIG. 15 (g)), both the lattice height h and the lattice pitch w of the small size lattice 10 to be bonded together 13 (No. 6 in FIG. 13, FIG. 15 (f)), it is confirmed that the vignetting performance and the amount of transmitted light are improved as compared with the example of No. 8 in FIG. It was.

Note that the multi-grating 12 (G0 grating, X-ray tube grating) is relatively small in size, and even in the case of an apparatus that captures a wide range, it can often be configured with a single grating (single small-size grating 10). . Further, when the multi-grid 12 is moved in photographing as in the present embodiment, it is preferable that the multi-grid 12 is not combined because accuracy can be maintained.
In addition, as shown in No. 6 in FIG. 13 (FIG. 14F), when different lattice heights h and different lattice pitches w are mixed, different types of small size lattices 10 are prepared. This is disadvantageous in terms of cost.
From these viewpoints, a single-structured grating is used as the multi-grating 12 (G0 grating, X-ray tube grating), the first grating 14 (G1 grating, first diffraction grating), the second grating 15 (G2 grating, second grating). As a diffraction grating), a plurality of types of small-size gratings 10 having different grating heights h or grating pitches w are combined and enlarged so that the surface of the X-ray detector 16 with respect to the detector plane has a predetermined curvature. More preferably, the composite grating 100 is used.

The X-ray detector 16 has two-dimensionally arranged conversion elements that generate electric signals in accordance with the irradiated X-rays, and reads the electric signals generated by the conversion elements as image signals.
The pixel size of the X-ray detector 16 is 10 to 300 (μm), more preferably 50 to 200 (μm).

The position of the X-ray detector 16 is preferably fixed to the base portion 19 so as to abut on the second grating 15. This is because the moire image obtained by the X-ray detector 16 becomes blurred as the distance between the second grating 15 and the X-ray detector 16 increases.
As the X-ray detector 16, an FPD (Flat Panel Detector) can be used. The FPD includes an indirect conversion type in which X-rays are converted into electric signals by a photoelectric conversion element via a scintillator, and a direct conversion type in which X-rays are directly converted into electric signals, either of which may be used.
The specific configuration of the X-ray detector 16 is the same as that described in, for example, the specification of WO2011 / 114845, the specification of WO2011 / 033798, the specification of WO2012 / 029340, etc. The description is omitted.

FIG. 16 is a perspective view showing a state in which each component of the radiographic image capturing apparatus 1 of the present embodiment is separated.
As shown in FIG. 16 and the like, the radiographic imaging apparatus 1 according to the present embodiment includes a column 17 that supports the X-ray source 11, a multi-grating unit 120 that includes a multi-grating 12, and a first grating unit that includes a first grating 14. 140, the base unit 19 to which the second grid unit 150 including the second grid 15 and the X-ray detector 16 are attached, and the subject table 13 (in FIG. 16, the subject table base unit constituting the subject table 13) Only 130 is shown)). In the present embodiment, the imaging unit is configured by the support column 17 that supports the X-ray source 11 and the base unit 19 to which the X-ray detector 16 is attached. Since the imaging unit and the subject table 13 can be separated, it is possible to prevent an impact or the like applied to the subject table 13 from a patient from affecting the imaging unit before or during imaging.

In the present embodiment, the base portion 19 is provided with a first cover unit 21 provided so as to cover the multi-grid unit 120, a first grid unit 140 and a second grid unit 150 provided so as to cover the second grid unit 150. Two cover units 22 are attached.
The multi-grating 12, the first grating 14, and the second grating 15 are members that require position adjustment with very high accuracy. The multi-grating 12, the first grating 14, and the second grating 15 are used for a plurality of times such as photographing a subject and photographing without a subject for calibration. In the case where a series of photographing is performed over a period of time, it is desirable that the same conditions be maintained during that time.
However, in the state exposed to the atmosphere without providing any cover or the like around the multi-grid 12, the first grid 14 and the second grid 15, the change in the ambient temperature in the installed photographing room (for example, the ceiling due to the change in the air flow by the air conditioner Temperature difference between the vicinity and the floor surface), impacts, vibrations, and the like, so that the multi-grating 12, the first grating 14, and the second grating 15 are performed during a series of imaging operations. There is a possibility that the position and orientation of the lens slightly deviate from the proper state. The first cover unit 21 and the second cover unit 22 avoid the influence of the multi-grid 12, the first grid 14 and the second grid 15 from the outside, for example, a cold air current of an air conditioner or a warm air. It is directly exposed to an air current and the like, and the thermal expansion fluctuation is partially suppressed. The imaging conditions are maintained during a series of imaging, and the multi-grating 12, the first grating 14 and the second grating, which are precision members, are maintained. This is to prevent 15 from receiving external impact or the like.

FIG. 17 is a perspective view showing an exploded state of the first cover unit 21 provided around the multi-grating unit 120 and the light irradiation field confirmation unit 6.
As shown in FIG. 17, the first cover unit 21 includes a front cover member 211 disposed so as to cover the multi-grating unit 120 and the light irradiation field confirmation unit 6 from the front side, and more radiation than the front cover member 211. An upper cover member 212 which is disposed on the back side of the image capturing apparatus 1 (that is, on the support column 17 side) and covers the upper side of the multi-grating unit 120, and the upper cover below the multi-grating unit 120 and the light irradiation field confirmation unit 6 And a lower cover member 213 disposed at a position corresponding to the member 212. The front cover member 211, the upper cover member 212, and the lower cover member 213 constituting the first cover unit 21 are formed by, for example, pressing a metal plate.
Cutout portions 211 a and 212 a are formed on the upper surfaces of the front cover member 211 and the upper cover member 212 and facing the X-ray source 11. An opening 211b is provided on the lower surface of the front cover member 211 and facing the X-ray irradiation port of the X-ray source 11. Thereby, even when the first cover unit 21 is attached, the X-ray irradiation from the X-ray source 11 is not hindered by the first cover unit 21.
In addition, a lever opening 211 c is formed on the surface of the front cover member 211 that faces the column 17 at a position corresponding to the moving lever 67 of the light irradiation field confirmation unit 6. The lever opening 211c is a long hole extending in the x direction so as to have substantially the same length as the moving range of the moving lever 67, and the front end of the moving lever 67 extends from the lever opening 211c to the front cover. It protrudes out of the member 211. Thus, the user can operate the moving lever 67 of the light irradiation field confirmation unit 6 even when the first cover unit 21 is attached. In addition, a scale or an index indicating whether the light irradiation field confirmation unit main body 65 is in the light irradiation field confirmation position or the retraction position (described later) depending on the position of the moving lever 67 around or near the lever opening 211c. May be provided.
When attaching the first cover unit 21, the upper cover member 212 is screwed and fixed to the base 19 so as to cover the upper side of the multi-grid unit 120, and the lower cover member 213 is attached to the upper cover from the lower side of the multi-grid unit 120. The position is adjusted so as to contact the lower end of the member 212, and the base 212 is fixed with screws. Further, the front cover member 211 is fitted to the upper cover member 212 and the lower cover member 213 from the front side of the multi-grid unit 120 and fixed with screws.
The first cover unit 21 only needs to be able to block external influences on the multi-grid unit 120, and the material, shape, configuration, fixing method, and the like are not limited to those exemplified here. In addition, a heat insulating member is preferably provided on at least the inner surface side of the first cover unit 21.

FIG. 18 is a perspective view showing a state in which the second cover unit 22 provided around the first grid unit 140 and the second grid unit 150 is disassembled.
As shown in FIG. 18, the second cover unit 22 includes a first lattice unit 140, a front cover member 221 disposed so as to cover the second lattice unit 150 from the front side, and an upper portion of the first lattice unit 140. The upper cover member 222 to cover and the side surface cover member 223 arrange | positioned at the both sides of the 1st grating | lattice unit 140 and the 2nd grating | lattice unit 150 are provided. The front cover member 221, the upper cover member 222, and the side cover member 223 constituting the second cover unit are formed by, for example, pressing a metal plate.
The upper cover member 222 is a U-shaped member with a center portion cut out, and is formed on the subject placed on the subject table 13, the first lattice 14 and the second lattice 15, of the upper cover member 222. The upper surface is not covered.
When the second cover unit 22 is attached, the side cover member 223 is fixed to the base 19 so as to cover both sides of the first lattice unit 140 and the second lattice unit 150, and the front cover member 221 is attached to the first cover unit 221. The positions of the grid unit 140 and the second grid unit 150 are adjusted so as to cover from the front side, and are fixed to the front side end portion of the side cover member 223 by screws. Further, the upper cover member 222 is covered from above and fixed to the base 19, the side cover member 223, and the front cover member 221 by screws.
The second cover unit 22 only needs to be able to block the external influence on the first grid unit 140 and the second grid unit 150, and its material, shape, configuration, fixing method, and the like are exemplified here. It is not limited to things. Further, it is preferable that a heat insulating member is provided on at least the inner surface side of the second cover unit 22.

Further, the periphery of the second cover unit 22 is easily subjected to an impact from the outside, for example, by a patient's foot or the like placing a hand or the like as a subject on the subject table 13. Therefore, for example, a guard member 41 as shown in FIGS. 3 and 17 is provided outside the second cover unit 22. The guard member 41 is formed of, for example, a metal plate or the like, and is detachably fixed around the second cover unit by screws or the like as shown in FIG. In addition, the shape of the guard member 41, the fixing method to the second cover unit, and the like are not limited to those exemplified here. Further, an elastic member for absorbing shock may be provided inside the guard member 41.
By providing such a guard member 41, it is possible to prevent the impact from affecting the precision members such as the first grid 14 and the second grid 15 even if the patient's foot or the like hits the apparatus side during imaging. Highly accurate image shooting can be performed.

  The subject table 13 is used to place a patient's fingers and the like that are subjects at the time of photographing. Although the size of the subject table 13 is not particularly limited, as shown in FIG. 1, when the patient's finger or the like that is the subject at the time of imaging is placed within the X-ray irradiation range (in the imaging possible region), the elbow portion of the patient It is preferable that the arm rest portion is configured to have a length dimension so that the arm rest portion can be placed. By placing the finger to the elbow part on the subject table 13, the position and posture of the finger that is the subject of photographing can be stabilized, and body movement such as camera shake during photographing can be prevented.

As shown in FIGS. 3 and 16, in this embodiment, the subject table 13 includes a subject table base portion 130 having a leg portion 132 including casters 131, and is independent of the support column 17 and the base portion 19. . The leg portion 132 is arranged between the support column 17 and the base portion 19, and the leg portion 132 on the base portion 19 side is provided with a lock mechanism 133 that locks the caster 131. .
The configuration of the subject table 13 is not limited to the example illustrated here. For example, the lock mechanism 133 may be provided on all the leg portions 132 of the subject base 130, or the subject base 13 may be fixed to one end of the column 17 or the base 19 without providing the lock mechanism 133. May be. The subject table 13 preferably includes an impact absorbing member (not shown) that can absorb an impact when it comes into contact with the support column 17 or the base unit 19.

Further, in the present embodiment, a member locking column 132a to which the X-ray detector holding unit 25 is detachably attached is fixed substantially horizontally between the front side legs 132 of the subject table base unit 130. ing.
The X-ray detector holding unit 25 holds the X-ray detector 16 during calibration of the gain and the like of the X-ray detector 16, and as shown in FIGS. 5 and 6, the X-ray detector holding unit 25. A hook 251 for locking formed in a bowl shape is provided on one end side of the. The X-ray detector holding unit 25 holds the locking hook 251 on the member locking column 132a of the subject table 13 while holding the X-ray detector 16 on the upper surface when the X-ray detector 16 is calibrated. By being locked, it is fixed to the subject table 13.

  In the present embodiment, as described above, the X-ray irradiation direction of the X-ray source 11 can be changed. When the X-ray detector 16 is calibrated, the optical axis of the X-ray is the multi-grating 12, The orientation of the X-ray source 11 is adjusted until the first grating 14 and the second grating 15 are removed from the top (calibration state see FIG. 6). The X-ray detector holding unit 25 is arranged on an extension line of the optical axis of the X-ray source 11 when the X-ray irradiation direction of the X-ray source 11 is adjusted to the calibration state in a state where the X-ray detector holding unit 25 is attached to the subject table 13. The X-ray detector 16 is held on the X-ray detector holding unit 25, X-rays are emitted from the X-ray source 11, and imaging is performed, whereby the multi-grating 12, the first An image for calibration in which images of the grid 14 and the second grid 15 are not reflected can be acquired.

On the upper surface of the subject table 13 and on the upper cover member 222 of the second cover unit 22, the subject table upper surface plate 3 that holds the subject is pinned by a fixing pin (not shown). Stopped and fixed. A through hole is formed in the upper cover member 222 at a position corresponding to the fixing pin of the subject table top surface plate 3, and the subject table top surface plate 3 is attached after the second cover unit 22 is attached to the base unit 19. The upper part of the upper cover member 222 is fixed to the subject base part 130.
It is preferable that the subject table upper surface plate 3 can adjust the height for holding the subject by adjusting the fixing position of the fixing pin in the height direction in a plurality of stages, for example. Thereby, the distance between the subject held on the subject table 13 and the X-ray source 11 can be kept at a predetermined distance suitable for imaging by adjusting the fixing position of the fixing pin on the subject table top surface plate 3. it can.

A circular notch 301 is provided at substantially the center of the subject table upper surface plate 3, and a circular rotating plate 302 is rotatably attached to the notch 301. By rotating the rotating plate 302, the orientation, position, etc. of the subject holding member 30 (see FIG. 21, etc.) placed on the rotating plate 302 can be easily changed / corrected. This makes it possible to easily correct the positioning.
Further, when the joint part is imaged by the fringe scanning method as in the radiographic image capturing apparatus 1 in the present embodiment, in order to obtain the moire image in which the interference fringes appear, the multi-grating 12 and the first grating (first grid) are used. It is necessary to appropriately adjust the direction and angle of the slit and the direction and angle of the subject in the second phase grating (second phase grating) 15 and the second grating (second phase grating) 15. In this respect, the multi-grating 12, the first grating 14, and the second grating 15 are very precisely configured, and it is difficult to maintain accuracy if they are moved and adjusted. In this regard, by configuring the portion of the subject table upper surface plate 3 on which the subject is placed so as to be rotatable, it is possible to make appropriate adjustments by moving the subject side. If the rotating plate 302 is rotated too much, a moire image cannot be obtained. For this reason, the rotating plate 302 may be configured to be rotatable within a certain range, for example, 45 degrees from a predetermined initial position.
A rotating plate fixing pin 303 for fixing the rotating plate 302 is provided on the object table upper surface plate 3 and in the vicinity of the peripheral edge of the rotating plate 302 so that the rotating plate 302 can be fixed.

A substantially circular notch 304 is provided at a position substantially corresponding to the first grating 14 and the second grating 15 in the substantially central portion of the rotating plate 302, and X-ray irradiation from the X-ray source 11 is performed. It does not interfere.
As shown in FIGS. 19 and 20, a substantially circular transparent plate member 305 made of a transparent material such as transparent acrylic or glass is attached to the notch portion 304.
As shown in FIG. 20, the transparent plate member 305 is disposed so that the upper surface thereof is slightly lower than the upper surface of the rotating plate 302 (in this embodiment, only the height difference G shown in FIG. 20 is transparent). (The upper surface of the plate member 305 is lower than the upper surface of the rotating plate 302). This prevents the subject holding member 30 from coming into contact with the surface of the transparent plate member 305 when a later-described subject holding member 30 or the like is placed and fixed on the upper surface of the rotating plate 302 of the subject table top surface plate 3. It is possible to improve durability by preventing the surface of the transparent plate member 305 from being damaged such as scratches.

  As shown in FIG. 19, elongated holes 306 formed substantially parallel to each other are provided at substantially symmetrical positions on the rotating plate 302 of the subject table top surface plate 3 with the transparent plate member 305 interposed therebetween. Each elongated hole 306 is provided with a holding member fixing pin 307 for fixing the subject holding member 30 shown in FIG.

A subject holding member 30 is detachably mounted on the subject table upper surface plate 3. In the present embodiment, the same location is shot multiple times, but the subject holding member 30 holds and fixes the position of the finger so that the subject finger does not move or shift during the series of shots. belongs to.
As shown in FIGS. 21 and 23 to 38, in this embodiment, the subject holding member 30 is configured to be detachable from the base unit 31 and supports the finger of a person who is the subject. The imaging target fixing unit 33 (the first imaging target fixing unit 33a to the sixth imaging target fixing unit 33f) for this purpose. In the following embodiments, only the left-hand subject holding member 30 is shown, but the right-hand subject holding member 30 having the same configuration is used when photographing the finger of the right hand.
The base unit 31 and the photographing target fixing unit 33 are made of, for example, polyacetal resin (POM: polyacetal, polyoxymethylene) or the like. The material for forming the base unit 31 and the photographing target fixing unit 33 is not limited to polyacetal resin, and various resins can be used. Further, in the base unit 31 and the photographing target fixing unit 33, a portion that does not overlap with a joint portion of a finger that is a photographing target when the subject is held on the subject holding member 30 may be formed of metal or the like. Moreover, it is preferable that a buffer member made of an elastic material such as silicon resin is disposed in a portion where the fingers are in direct contact. The base unit 31 and the imaging target fixing unit 33 are preferably sanitized every time the patient to be imaged changes, and the material forming the base unit 31 and the imaging target fixing unit 33 is alcohol used for disinfection or the like. It is preferable that it has tolerance with respect to.

The base unit 31 includes a photographing target fixing unit mounting portion 311 for mounting the photographing target fixing unit 33 (the first photographing target fixing unit 33a to the sixth photographing target fixing unit 33f). It is the frame-shaped member comprised so that attachment or detachment was possible.
In the base unit 31, the positions corresponding to the two holding member fixing pins 307 provided on the rotating plate 302 of the subject table upper surface plate 3 respectively extend in directions substantially orthogonal to the extending direction of the long hole 306. A long hole 312 is formed.
As shown in FIG. 22, the holding member fixing pin 307 passes through the long hole 312 of the base unit 31 and the long hole 306 of the rotating plate 302, so that the subject holding member 30 is moved to the rotating plate 302 of the subject table top surface plate 3. The subject holding member 30 is fixed on the holding member after the orientation and position on the subject table top surface plate 3 are finely adjusted by adjusting the positions of the long hole 306 and the long hole 312. It is fixed by a pin 307 for use.
A wrist fixing belt 313 for fixing the wrist portion of the subject is provided in the vicinity of one end side of the photographing target fixing unit mounting portion 311 and on the wrist side of the hand supported by the photographing target fixing unit 33. It has been.

Further, the photographing target fixing unit 33 is placed near the other end side of the photographing target fixing unit mounting portion 311 and on the fingertip side of the hand supported by the photographing target fixing unit 33. It becomes the base side fixing | fixed part 314 for fixing to. The base-side fixing portion 314 has a hole 316 through which the fixing pin 333 is inserted after the imaging target fixing unit 33 is attached to the imaging target fixing unit mounting portion 311.
Further, in the vicinity of the base side fixing portion 314 in the base unit 31 and at a position corresponding to the hole 334 provided on the side surface of the fixing portion on the photographing target fixing unit 33 (fixed unit side fixing portion 331) described later. Through-holes penetrating in the horizontal direction in the base unit 31 (the horizontal direction when the subject holding member 30 is placed on the subject table top surface plate 3) from the side end surface of the base unit 31 to the inside of the subject fixing unit mounting portion 311 317 is formed. A fine adjustment screw 318 is inserted into the through-hole 317 from the side end surface of the base unit 31 toward the inside of the photographing target fixing unit mounting portion 311.
Furthermore, a hole 319 is formed in the base unit 31 in the vertical direction from the surface of the base unit 31 toward the through hole 317. An adjustment fixing screw 320 for fixing the fine adjustment screw 318 is inserted into the hole 319 from the surface of the base unit 31 toward the through hole 317.
The shape and configuration of the base unit 31 and the configuration for fixing the base unit 31 to the subject table upper surface plate 3 are not limited to those illustrated here, and can be changed as appropriate.

The imaging target fixing unit 33 fixes the joint portion of the finger that is the imaging target portion at a predetermined position with respect to the X-ray (radiation) irradiation direction from the X-ray source 11 that is the radiation generating means.
In the present embodiment, six types of shooting target fixing units 33a to 33f are prepared as the shooting target fixing unit 33 that can be attached to the base unit 31, as shown in FIGS. In the following description, when the imaging target fixing unit 33 is simply used, all of these (imaging target fixing units 33a to 33f) are included.
In radiography, it is suitable for radiography depending on the part to be photographed (left hand or right hand) and the deformation of the joints of the patient's fingers (metacarpal joint, proximal interphalangeal joint, distal interphalangeal joint). The photographing target fixing unit 33 is selected and attached to the base unit 31. Note that the photographing target fixing unit 33 that can be attached to the base unit 31 is not limited to the one illustrated here. Many more types may be prepared, or only a part of those listed here may be provided.
Alternatively, a specific photographing target fixing unit may be fixed to the base unit so as not to be detachable.

As shown in FIG. 21, the first photographing target fixing unit 33 a includes a fixing unit side fixing portion 331 for fixing to the base unit 31 and four inter-finger holding members 332.
The fixing unit side fixing portion 331 is provided with a fixing pin 333 at a position corresponding to the hole 316 of the base unit 31, and the fixing pin 333 is fixed from the fixing unit side fixing portion 331 to the base side 31 of the base unit 31. The first imaging target fixing unit 33a can be temporarily fixed to the base unit 31 by inserting the hole 316 into the hole 316 and tightening.
At a position corresponding to the through hole 317 of the base unit 31 on the side surface of the fixed unit side fixing portion 331, a hole portion 334 into which the tip of the fine adjustment screw 318 inserted through the through hole 317 is inserted is provided. ing.
The fine adjustment screw 318 is inserted into the through hole 317 of the base unit 31, and the tip end portion thereof is inserted into the hole portion 334 and appropriately pushed inward, whereby the width direction of the first shooting target fixing unit 33a (shooting target) The position in the width direction of the finger fixed to the fixing unit 33 can be finely adjusted. After adjusting the position in the width direction, the first imaging target fixing unit 33 a can be fixed to the base unit 31 by fixing the fine adjustment screw 318 from the surface of the base unit 31 with the adjustment fixing screw 320.

One end of the inter-finger holding member 332 is fixed to the fixed unit-side fixing portion 331, and when the subject's fingers are fixed to the subject holding member 30, each inter-finger holding member 332 is between the five fingers of the subject's fingers. Are arranged side by side so as to be located respectively. The inter-finger holding member 332 is formed in a tapered shape that gradually increases in width from the free end side toward the fixed end side fixed to the fixed unit side fixing portion 331, and the tip of the finger of the subject is sufficiently It can be fixed in the open state.
FIG. 22 shows a state in which the first photographing target fixing unit 33a fixed to the base unit 31 is fixed on the subject table upper surface plate 3, and the user fixes his / her finger to the first photographing target fixing unit 33a. It is a figure. For example, when it is desired to photograph the second joint (PIP joint) portion of the finger, as shown in FIG. 22, the first finger is placed so that the four inter-finger holding members 332 are located between the five fingers. By placing the imaging target fixing unit 33a on the imaging target fixing unit 33a, it is possible to support the five fingers in a state of being spaced apart from each other.
The shape and configuration of the first imaging target fixing unit 33a, the configuration for fixing the first imaging target fixing unit 33a to the base unit 31, and the like are not limited to those illustrated here, and can be changed as appropriate. . For example, the inter-finger holding member 332 is configured to be easily detachable with respect to the fixed unit side fixing portion 331, and a plurality of inter-finger holding members 332 having different shapes and sizes are prepared. Depending on the situation, an appropriate one may be selected and mounted as appropriate.

As shown in FIG. 23 and FIGS. 24A to 24D, the second photographing target fixing unit 33b includes a fixing unit side fixing portion 331 for fixing to the base unit 31, and a finger other than a finger to be photographed. A gripping portion 335 for supporting fingers, four finger holding members 338 for holding fingers to be photographed one by one, and a support member 336 for supporting the finger holding members 338 are provided.
Since the configuration of the fixed unit side fixing portion 331 is the same as that of the first photographing target fixing unit 33a, the description thereof is omitted.
The gripping portion 335 is a cylindrical member that is erected substantially perpendicular to a horizontal plane (a surface that is horizontal to the subject table upper surface plate 3) when the subject holding member 30 is fixed to the object table upper surface plate 3. . The gripping portion 335 is formed in a size and shape that can be easily grasped with a hand. The gripping portion 335 may be coated with a non-slip resin or a cloth or the like so that the patient can easily grip it. Further, a groove along the finger may be formed on the surface of the hand placement portion 349.
The support member 336 is a plate-like member that is erected almost vertically in the vicinity of the grip portion 335. The support member 336 is formed with four rail portions 337 respectively corresponding to the four finger holding members 338 along the extending direction of the fingers when the fingers are fixed to the subject holding member 30.
The four finger holding members 338 are sheath-like members configured so that the fingertips of the fingers to be photographed can be placed, and are respectively slidably engaged with the four rail portions 337 of the support member 336. Yes. The finger holding member 338 slides along the rail part 337 when placing the fingertip, and fixes the finger at a position corresponding to the length of each finger.

In this embodiment, when photographing the joint portion of the second finger (index finger), as shown in FIG. 24A, the hand is held by holding the grip portion 335 with a hand other than the second finger, Two fingers are extended along the support member 336 and the fingertip is placed on the finger holding member 338 located at the top. Further, when photographing the joint portion of the third finger (middle finger), as shown in FIG. 24B, the hand is stabilized by grasping the grip portion 335 with a hand other than the third finger, and the third finger is moved. The fingertip is placed on the finger holding member 338 that extends along the support member 336 and is positioned second from the top. When photographing the joint part of the fourth finger (ring finger), as shown in FIG. 24C, the hand is stabilized by grasping the gripping portion 335 with a hand other than the fourth finger, and the fourth finger is moved. The fingertip is placed on a finger holding member 338 that extends along the support member 336 and is positioned third from the top. When photographing the joint portion of the fifth finger (little finger), as shown in FIG. 24 (d), the gripping portion 335 is held with a hand other than the fifth finger to stabilize the hand, and the fifth finger is moved. The fingertip is placed on the finger holding member 338 that extends along the support member 336 and is positioned at the bottom.
For example, when the second joint (PIP joint) portion of the finger or the like is to be photographed, the subject holding member 30 with the second photographing target fixing unit 33b fixed to the base unit 31 is fixed on the subject table top surface plate 3. By placing the fingers to be photographed one by one on the finger holding member 338 of the second photographing target fixing unit 33b, the fingers can be supported in an extended state.
Note that the shape, configuration, and the like of the second imaging target fixing unit 33b are not limited to those illustrated here, and can be changed as appropriate. When photographing the second joint (PIP joint) portion or the like of the finger, it is preferable that the finger is slightly warped toward the back of the hand. Therefore, for example, the support member 336 is moved outward (ie, away from the gripping portion 335). A curved shape may be used, and the finger holding member 338 may be provided near the end. In addition, it is not essential to have the gripping portion 335, and it is possible to provide a partition plate or the like that can position the fingers one by one so that the fingers can be held one by one against the back of the hand. Good.

As shown in FIG. 25 and FIG. 26, the third photographing target fixing unit 33c has a fixed unit side fixing portion 331 for fixing to the base unit 31 and a fingertip of a finger to be photographed with an upward inclination. And a finger position restricting member 341 for restricting the position and angle of the finger so that the gap between the thumb (thumb) and the finger other than the thumb is large.
Since the configuration of the fixed unit side fixing portion 331 is the same as that of the first photographing target fixing unit 33a, the description thereof is omitted.
The stepped portion 340 is integrated with the fixed unit side fixed portion 331, and is constituted by an overhang portion that protrudes from one end of the fixed unit side fixed portion 331. The stepped portion 340 is, for example, about 10 mm to 15 mm higher than the subject table upper surface plate 3 on which the palm portion is placed, and thus the fingertips of the fingers from the second finger to the fifth finger to be imaged are placed on the stepped portion 340. The fingertip can be warped upward by placing it on the top. Note that the shape, height, and the like of the stepped portion 340 are not limited to those illustrated here. For example, the stepped portion 340 may be made higher than the fixed unit side fixed portion 331 so that the fingertip can be warped higher. Further, the stepped portion 340 may be inclined so as to increase in height toward the fingertip side.
One end of the finger position restricting member 341 is fixed to the fixed unit side fixing portion 331, and when the subject's finger is fixed to the subject holding member 30, the finger position restricting member 341 is positioned between the thumb and the second finger. ing. The finger position restricting member 341 is formed in a tapered shape that gradually increases in width from the free end side toward the fixed end side fixed to the fixed unit side fixing portion 331, and other than the subject's thumb and thumb The fingers (second finger to fifth finger) other than the mother finger are regulated in a direction away from the thumb so that the space between the second finger (second finger to fifth finger) is widened. The shape, size, etc. of the finger position regulating member 341 are not particularly limited. For example, the finger position regulating member 341 has a shape in which the fixed end side is large enough to open between the thumb and fingers other than the thumb up to almost 90 degrees. Preferably there is. In addition, a plurality of types of finger position regulating members 341 having different shapes and sizes are prepared according to the size of the user's hand, the shape of the finger, the region to be photographed, etc., and the most suitable one is used according to the situation. It is good also as composition to do.
As described above, in this embodiment, the subject holding member 30 that fixes the third imaging target fixing unit 33c to the base unit 31 is fixed on the subject table upper surface plate 3, and the finger that is the subject is attached to the subject holding member 30. When fixed, the fingertips of the fingers from the second finger to the fifth finger to be photographed are pushed upward by the step portion 340 and further regulated by the finger position regulating member 341 in a direction away from the thumb. For this reason, for example, when photographing the joint portion of the base of the thumb, the space between the thumb and the other fingers can be widened and the thumb can be fixed in a lying state.
Note that the shape, configuration, and the like of the third imaging target fixing unit 33c are not limited to those illustrated here, and can be changed as appropriate.

As shown in FIGS. 27 and 28, the fourth photographing target fixing unit 33d includes a fixing unit side fixing portion 331 for fixing to the base unit 31, and four fingers for holding one finger to be photographed one by one. A holding member 345 and a guide member 343 for guiding the finger holding member 345 along the extending direction of the fingers are provided.
Since the configuration of the fixed unit side fixing portion 331 is the same as that of the first photographing target fixing unit 33a, the description thereof is omitted.
One end of the guide member 343 is fixed to the fixed unit side fixing portion 331, and a finger holding member 345 is attached to each guide member 343 so as to be slidable along the extending direction of the fingers.
In the finger holding member 345, the portion on which the fingertip is placed is an inclined surface that is inclined upward so that the height increases as it goes to the tip side of the finger. Thus, when the finger is placed on the finger holding member 345, the fingertip is pushed up by the inclined surface and fixed in a state of warping upward.
The finger holding member 345 slides along the guide member 343 when placing the fingertip, and fixes the finger at a position corresponding to the length of each finger, as shown in FIG.
Note that the shape, configuration, and the like of the fourth imaging target fixing unit 33d are not limited to those illustrated here.

As shown in FIGS. 29 and 30, the fifth photographing target fixing unit 33 e includes a fixing unit side fixing portion 348 for fixing to the base unit 31 and a hand placement portion 349 on which a finger to be photographed can be placed. And.
One end of the fixed unit side fixing portion 348 is fixed to the hand placement portion 349 and is formed in a rod shape. A fixing screw 348 for fixing the fifth photographing target fixing unit 33e to the base unit 31 is provided at the free end side of the fixing unit side fixing portion 348. In the base unit 31, a hole (not shown) is formed in the vicinity of the wrist fixing belt 313, and the fifth photographing target fixing unit 33 e is screwed into this hole on the base unit 31 side by a fixing screw 348. It is fixed to the base unit 31 by being stopped.
The hand placement part 349 is a hemispherical member, and, as shown in FIG. 30, the finger is fixed by placing it on the hand placement part 349 in a state where the finger to be photographed is lightly bent. Yes. This puts a burden on the patient in a relatively easy posture, such as when it is impossible to extend the joint due to the onset of rheumatism, etc., or when it is preferable to take a picture with the fingers slightly bent. Therefore, the position and angle of the finger can be stabilized, and the displacement and shaking of fingers during photographing can be suppressed.
Note that the shape, configuration, and the like of the fifth imaging target fixing unit 33e are not limited to those illustrated here. For example, an anti-slip resin may be applied to the surface of the hand placement unit 349 so that the patient can easily grasp it. Further, a groove along the finger may be formed on the surface of the hand placement portion 349. Further, as the fifth imaging target fixing unit 33e, a plurality of units different in the length of the fixed unit side fixing part 348 and the size, shape, height, etc. of the hand placing part 349 are prepared, and the shape of the patient's hand is prepared. Alternatively, the one suitable for the size and the like may be used for photographing.

The sixth imaging target fixing unit 33f will be described with reference to FIGS.
As shown in FIG. 31, the sixth imaging target fixing unit 33f includes a fixing unit side fixing portion 331 for fixing to the base unit 31, and a palm on the trunk side of the joint portion of the finger that is the imaging target portion. And a second fixture 360 that holds the finger, that is, the non-trunk side of the joint portion of the finger that is the imaging target portion.
The sixth imaging target fixing unit 33f composed of these is the same as the other imaging target fixing units 33a to 33e in that it can be attached to and detached from the base unit by the fixing unit side fixing portion 331.
Further, the configuration of the fixed unit side fixing portion 331 is the same as that of the first photographing target fixing unit 33a, and thus the description thereof is omitted.

The first fixing device 350 is integrated with the fixing unit-side fixing portion 331, and is inserted between the flat plate-like placement portion 351 for placing the palm portion and the thumb and fingers other than the thumb. And a finger position restricting member 352 for restricting the position and angle of the fingers.
The upper surface of the placement unit 351 is a smooth surface that is horizontal when the subject holding member 30 is placed on the subject table upper surface plate 3. The placement unit 351 is suitable for placing a palm. It has a width. Then, the width direction of the mounting portion 351 (the same direction as the width direction of the finger fixed to the imaging target fixing unit 33. Hereinafter, in the description of the sixth imaging target fixing unit 33f, it is simply referred to as “the finger width direction”. A plate-like finger position regulating member 352 is erected on one end side of the plate-like finger so as to be perpendicular to the mounting portion 351.
The finger position regulating member 352 is disposed so as to be between the thumb and the second finger when the subject's finger is fixed to the subject holding member 30. Due to the above arrangement, the finger position regulating member 352 abuts against the other part of the thumb and the second finger, and fixes the palm and fingers so as not to move to the fingertip side with the palm placed on the mounting portion 351. It is possible.

In the example of FIG. 31, the fixing belt 353 for fixing the palm is fixed in a state where the imaging target fixing unit 33f is fixed to the base unit 31 by the fixing pin 333 and the palm is placed on the placement portion 351. Equipped. The fixing belt 353 can prevent the back of the hand from lifting.
The fixing belt 353 is not limited to the case where the sixth imaging target fixing unit 33f is fixed to the base unit 31, but when the other first to fifth imaging target fixing units 33a to 33e are fixed. Alternatively, the base unit 31 may be provided.

  As shown in FIGS. 32 and 33, the second fixture 360 is arranged in a state aligned with the first base 361 mounted on the upper surface of the fixed unit side fixing portion 331 along the width direction of the fingers. Two second bases 362 and 362 mounted on the upper surface of the first base 361, and a total of four gripping units 363a to 363d mounted on the upper surfaces of the second bases 362 and 362; It has.

  The first base 361 is a long flat plate and is attached to the upper surface of the fixed unit side fixing portion 331 along the width direction of the fingers. The first base 361 is formed with a long hole 361a extending in the longitudinal direction so as to penetrate the front and back. Then, a set screw 364 to be screwed into a screw hole (not shown) formed on the upper surface of the fixed unit side fixing portion 331 is inserted from above the elongated hole 361a of the first base 361, and the set screw 364 is fastened. Thus, the first base 361 is fixed to the fixed unit side fixing portion 331. Further, by loosening the fastening screw 364, the first base 361 can be moved along the width direction of the fingers, and the position can be adjusted in the width direction.

  A rail-like convex portion (not shown) is formed on the upper surface of the first base 361 along the width direction of the fingers, and the lower surfaces of the second bases 362 and 362 are formed on the lower surface of the first base 361. A concave groove (not shown) that fits into the convex portion is formed. That is, the second bases 362 and 362 can be adjusted in position along the width direction of the fingers with respect to the first base 361 by fitting the convex portions and the concave grooves. The second bases 362 and 362 that have been appropriately adjusted in position can be fixed by fastening fastening screws (not shown) provided on the second bases 362 and 362, respectively.

  In addition, gripping units 363a and 363b are mounted on one of the two second bases 362, and gripping units 363c and 363d are mounted on the other second base 362. These gripping units 363a to 363d are arranged side by side along the width direction of the fingers in order to grip up to four fingers excluding the thumb at a time. In addition, the two gripping units 363a and 363d positioned on the outer side in the width direction of the fingers and the two gripping units 363b and 363c positioned on the inner side in the arrangement direction have the same structure. The gripping units 363a and 363d and the gripping units 363b and 363c having the same structure will be described individually.

  First, the two gripping units 363a and 363d positioned on the outer side in the width direction of the fingers include a lower gripping member 365 and an upper gripping member 366 that grip a finger fixed to the photographing target fixing unit 33 up and down, and gripping these A coil spring 367 that is an elastic body that applies a gripping pressure to the members 365 and 366, and a fastening screw 368 that supports the lower gripping member 365 slidably along the longitudinal direction on the upper surface of the second base 362. I have.

The lower gripping member 365 is extended on the upper surface of the second base 362 in the direction from the fingertip of the finger fixed to the imaging target fixing unit 33 toward the wrist, and is hinged on the upper surface of the extended end portion. The upper holding member 366 is supported by the structure so as to be able to turn up and down. The above-described coil spring 367 is attached to the hinge portion by a so-called tumbler spring structure, and applies a gripping pressure between the upper gripping member 366 and the lower gripping member 365 and undulates the upper gripping member 366. When this is done, tension acts in the direction that maintains the undulation state.
On the upper surface of the upper gripping member 366, a knob member 369 for attaching the upper gripping member 366 to the direction in which it is raised against the gripping pressure is attached. Further, a concave recess along the longitudinal direction is formed on the lower surface of the upper gripping member 366 and a buffer member 370 made of an elastic material is attached. The cushioning member 370 may be either a non-foaming material or a foaming material, but when a foaming material is used, a film or the like may be formed so as not to absorb body fluid (blood, sweat, etc.). It is desirable to use a bubble system.
The upper gripping member 366 can guide the finger inside the concave recess when the finger is gripped between the upper gripping member 366 and the lower gripping member 365 by the concave recess, and the upper gripping member 366 and The lower gripping member 365 can be gripped with fingers along the longitudinal direction. Further, since the buffer member 370 is provided, it is possible to disperse the gripping pressure and reduce the burden on the fingers.

In addition, a long hole 365a is vertically formed at the end opposite to the extending end of the lower gripping member 365 so as to extend along the longitudinal direction. The lower gripping member 365 is fixed to the upper surface of the second base 362 by a fastening screw 368 inserted into the elongated hole 365a. That is, the position of the lower gripping member 365 can be adjusted along the longitudinal direction with the fastening screw 368 loosened, and the adjusted position can be maintained by fastening the fastening screw 368.
That is, the holding positions by the lower holding member 365 and the upper holding member 366 can be adjusted along the longitudinal direction of the fingers, and the joint to be extended can be appropriately held.

The two gripping units 363b and 363c located on the inner side in the width direction of the fingers have the same configuration as the gripping units 363a and 363d, but the gripping units 363b and 363c 366 is shorter in the extending direction than the lower gripping member 365. A restraining unit 371 that restrains fingers is attached to the tip of the lower gripping member 365.
The restraint unit 371 mainly includes a frame portion 372 into which fingers can be inserted, and a holder 373 that presses and holds the fingers inserted into the frame portion 372 from above.
The frame portion 372 penetrates along the extending direction of the lower gripping member 365, and when the finger is inserted, the finger can be gripped by the upper gripping member 366 located in the back thereof.
The holder 373 is held in the frame portion 372 and is disposed so as to be able to contact a finger inserted into the frame portion 372. The holder 373 moves up and down by rotating a screw member 374 provided on the upper portion of the frame portion 372. When holding the finger, the holding tool 373 is lowered by the screw member 374, and the finger is held with an appropriate pressing force.
The holder 373 is made of the same material as the buffer member 370 described above, and reduces the burden due to dispersion of holding pressure on the fingers.
The restraining unit 371 is attached in a structure that can be inserted into and removed from the lower gripping member 365, and can be attached to positions corresponding to the respective 363a to 363d. A plurality of restraining units 371 having different sizes of the frame portion 372 are prepared, and it is possible to replace fingers and the like that are enlarged due to rheumatic symptoms with appropriate sizes.

Next, the specification mode of the sixth photographing target fixing unit 33f will be described with reference to the use explanatory diagrams of FIGS.
The gripping units 363a and 363d located outside the finger in the width direction have a function of holding the finger by the lower gripping member 365 and the upper gripping member 366 and maintaining the joint extended, In addition to the grip function, the grip units 363b and 363c positioned on the inner side in the direction restrain the finger by the restraint unit 371, move the lower grip member 365 in the fingertip direction of the finger, and fix the position by the fastening screw 368. It has a function to maintain a state where the joints are expanded by pulling fingers.
Therefore, when it is necessary to shoot with a joint extended with respect to a specific finger, the shoot is performed with the finger restrained by the restraining unit 371 of the gripping unit 363b or 363c located inside the finger in the width direction. Is done.

FIG. 34 and FIG. 35 show a case where the second and third fingers that are particularly likely to develop rheumatism are restrained by the gripping units 363b and 363c.
In the case of an imaging device using a one-dimensional grid, when the relative angle between each finger and the one-dimensional grid when the fingers are spread and fixed to the subject table is a predetermined range or more, the depiction performance of the joint that is the subject deteriorates. In this embodiment, since there are only two fingers, the second finger and the third finger, there is no problem in the drawing performance even if both fingers are photographed simultaneously.
In the case of an imaging apparatus using a two-dimensional lattice, there is no principle limitation as described above, and it is possible to simultaneously perform imaging of all fingers.
As shown in FIG. 34, the left belt is placed on the placement portion 351 with the palm facing downward, and the fixing belt 313 is placed with the finger position regulating member 352 entering between the thumb and the second finger. The wrist and the back of the hand are fixed by 353. Then, the gripping units 363a, 363b, and 363c used with the fastening screw 368 loosened are moved in the direction from the fingertip toward the wrist. Then, the second and third fingers are restrained by the restraining units 371 and 371 of the gripping units 363b and 363c, and the upper gripping member 366 is tilted in the extending direction for gripping. At this time, if the fourth finger and the fifth finger are not shooting targets, the gripping may not be performed, but the upper gripping member 366 is in a tilted state so as not to disturb the shooting.
Then, as shown in FIG. 35, the gripping units 363a, 363b, and 363c are moved in the direction from the wrist toward the fingertip side. The travel distance is adjusted as appropriate so as not to be a burden on the patient. Then, the position of each lower holding member 365 is fixed by the fastening screw 368.
FIG. 36A is an image obtained by photographing without pulling fingers, and FIG. 36B is an image obtained by photographing using fingers of the restraint unit 371. As shown in these figures, it can be seen that when the pulling is performed, the joint of the finger spreads and the entire circumference of the cartilage can be confirmed. In other words, when the joint is photographed, it is possible to maintain a state in which the interval is widened, so that the photographing positioning is facilitated, and rapid photographing is possible.

  Further, as shown in FIGS. 37 and 38, it is possible to arbitrarily select which of the fingers is gripped using any of the gripping units 363a to 363d. In this case, the first and second bases 361, 362, and 362 are appropriately adjusted in the width direction of the fingers according to the combination of the gripping units 363a to 363d to be used and the fingers to be gripped. Can do. As a result, it is possible to perform photographing while maintaining fingers in an appropriate posture.

Further, in the present embodiment, as described above, since the composite lattice 100 obtained by combining the small size lattice 10 and increasing the size is used as the first lattice 14, the second lattice 15, and the like, a single constitution lattice is used. It is possible to shoot a wider range than in the case. For this reason, the imaging target part of the radiographic image capturing apparatus 1 is not limited to the joint part of the finger, and for example, a joint part such as a shoulder, an ankle, or a knee can be imaged.
In this case, it is necessary to place a patient's leg or the like on the subject table 13 in order to position the joints such as the shoulder, ankle, and knee in the light irradiation field of the X-ray source 11. For this reason, for example, FIG. 39 shows that the load on the main body of the subject table 13 and the first and second lattices located below the subject table 13 are not loaded or affected even when the patient's weight is applied. A subject support plate 7 is disposed on the subject table top surface plate 3 of the subject table 13 as shown. The subject support plate 7 is composed of, for example, a support plate main body 71 and legs 72 provided on the back side thereof, and a portion of the support plate main body 71 corresponding to the transparent plate member 305 of the subject table upper surface plate 3 is X. An opening (not shown) is provided so as not to disturb the X-rays irradiated from the radiation source 11. The leg portion 72 of the subject support plate 7 is placed on the upper end surface of the guard member 41 provided so as to surround the subject table 13. In this way, by supporting the subject support plate 7 with the upper end surface of the guard member 41, the guard member 41 absorbs the load and impact applied to the subject support plate 7, and the subject table 13, the first grid, the second grid, and the like. It is possible to prevent an impact or the like from being applied.

Further, when photographing joint parts such as shoulders, ankles, knees, etc., it is necessary for the patient to perform photographing while lying down on the whole body. Therefore, as shown in FIG. 7 may be connected.
For example, the auxiliary base 8 includes an auxiliary base base 81 having a caster 83 and an auxiliary base upper surface plate 82. It is preferable that a lock mechanism (not shown) for locking the caster 83 is provided on the caster 83 of the auxiliary base base portion 81 so that the auxiliary base 8 is stabilized when the patient gets on the auxiliary base 8. Each auxiliary base 8 is configured to be mutually connectable with other auxiliary base 8 and subject base 13 (or subject support plate 7), and a mechanism for locking each other so that no rattling occurs when connected. Is preferably provided. The auxiliary table 8 is used by being connected as many as necessary according to the height of the patient, the imaging region, and the like. By freely connecting and using in this way, it is possible to flexibly cope with various types of imaging by the single radiographic imaging device 1.

FIG. 39 illustrates a case where one auxiliary base 8 is connected to the patient's head side and one lower body side is connected to image the joint portion of the patient's right knee.
Further, since the knee joint is likely to be displaced even with a slight movement, it is necessary to hold and fix the position of the knee so that the subject's knee joint does not move or shift during a series of photographing. For this reason, in FIG. 39, in order to keep the knee angle constant, an auxiliary member 75 such as a cushion is placed under the knee for adjustment, and the knee fixing unit 9 is attached to the leg centered on the knee. Is shown.

40 (a) and 40 (b) are external perspective views of the knee fixing unit 9. FIG.
The knee fixing unit 9 is a rod-like member having a hinge part 95 at substantially the center, and is provided with four first fixing parts 91a to fourth fixing parts 91d fixed to the patient's legs (when not particularly distinguished). , Simply referred to as “fixed portion 91”) and a connecting portion 94 that connects the fixed portion 91 to the hinge portion 95.
41 (a) and 41 (b) are external perspective views of the state in which the knee fixing unit 9 is bent at the hinge portion 95, and FIG. 42 is an essential perspective view in which the periphery of the hinge portion 95 is enlarged.
As shown in FIGS. 41A, 41B, and 42, the hinge portion 95 includes a pair of hinge constituting plates 951 and 952. One end sides of the hinge constituting plates 951 and 952 are hinge-coupled so as to mesh with each other, and are configured to be capable of opening and closing about the shaft of the shaft member 953 inserted through the coupling portion. The hinge portion 95 can be fixed at an arbitrary angle according to the angle of the patient's knee, by rotating the shaft member 953 in one direction to tighten the hinge coupling portions of the hinge constituting plates 951 and 952.

The other end side (free end side) of the hinge component plates 951 and 952 is formed in a substantially arc shape. The hinge component plates 951 and 952 have arc-shaped elongated holes 954 along the arc-shaped end edges. Is formed. The portions where the long holes 954 are provided in the hinge constituting plates 951 and 952 are locked by connecting screws 955 inserted into the long holes 954 on one end sides of the connecting plates 941 constituting the connecting portions 94a and 94b, respectively. ing.
Further, a connecting portion upper plate 942 is fixed to the other end side of the connecting plate 941 with screws. End portions of the connecting portion upper plate 942 corresponding to the hinge constituting plates 951 and 952 are formed in a recessed shape for receiving the arc-shaped end edges of the hinge constituting plates 951 and 952, and the hinge constituting plates 951 and 952 are connected to each other. It can slide along the end portion of the connecting portion upper plate 942 with respect to the portions 94a and 94b. When the hinge constituent plates 951 and 952 slide with respect to the connecting portions 94a and 94b, the connecting screw 955 is guided along the long hole 954. In the present embodiment, the hinge constituting plates 951 and 952 and the connecting plate 941 can be tightened by rotating the connecting screw 955 in one direction, whereby the connecting screw 955 is placed at an arbitrary position of the long hole 954. It is fixed and the angle of the width direction of the knee fixing unit 9 can be maintained at an arbitrary angle.

The ball portions 961 of the ball joints 96a and 96b are sandwiched and locked between the connecting plate 941 and the connecting portion upper plate 942 at the ends of the connecting portions 94a and 94b opposite to the hinge portion 95. ing. The shaft portion 962 of the ball joint 96a is inserted into the first fixing portion 91a and the second fixing portion 91b, and the shaft portion 962 of the ball joint 96b is inserted into the third fixing portion 91c and the fourth fixing portion 91d. Is inserted inside. As a result, the first fixed portion 91a and the second fixed portion 91b rotate as a unit according to the movement of the ball joint 96a, and the third fixed portion 91c and the fourth fixed portion 91d move by the movement of the ball joint 96b. It is designed to rotate as a unit.
In the vicinity where the ball portion 961 is locked, a ball fixing screw 944 that passes through the connecting portion upper plate 942 and is fixed to the connecting plate 941 is provided. By turning the ball fixing screw 944 in a certain direction, the gap between the connecting plate 941 and the connecting portion upper plate 942 is tightened, and the movement of the ball portion 961 of the ball joints 96a and 96b is restricted. Thereby, the fixing | fixed part 91 is fixed by arbitrary angles, and the state is maintained.

A belt hole 911 is formed in a side portion of the fixing portion 91 in the width direction, and a fixing belt 97 that fixes the fixing portion 91 to the patient's leg is inserted into the belt hole 911.
Further, a long hole 912 is formed in the fixing portion 91 along the longitudinal direction of the rod-shaped knee fixing unit 9. Guide screws 913 are inserted through the long holes 912 so as to be movable along the long holes 912. Extending plates 92 are provided between the first fixing portion 91a and the second fixing portion 91b, and between the third fixing portion 91c and the fourth fixing portion 91d, respectively. In the vicinity of each end in the longitudinal direction of the plate 92, the tip of the guide screw 913 is fixed.
The length between the first fixing portion 91a and the second fixing portion 91b and the length between the third fixing portion 91c and the fourth fixing portion 91d are the length of the extension plate 92. Each fixing part can be expanded by tightening the guide screw 913 at an arbitrary position from the shortest contracted state (see FIG. 40A) to the longest extended state (see FIG. 40B). The length between 91 can be set arbitrarily.

When the knee portion of the patient is fixed by the knee fixing unit 9, the knee fixing unit 9 is mounted on the patient's leg with all the screws loosened, and the knee portion is positioned in the irradiation field of the X-ray source 11. Then, while adjusting the knee angle and performing positioning, each screw is tightened to fix the direction and angle of each part of the knee fixing unit 9.
The knee fixing unit 9 of the present embodiment can freely change the angle and orientation at the hinge portion 95 and the connecting portion 94, and can further adjust the position of the fixing portion 91 by the length of the extension plate 92. Therefore, it can be applied to various patients with different physiques, and can be attached to the outside of the knee, the inside of the knee, the side of the knee, etc., and can cope with photographing from various angles.
The knee fixing unit 9, the subject support plate 7, the auxiliary base 8, and the like can be appropriately held and fixed in the light irradiation field of the X-ray source 11 during imaging. Well, it is not limited to those exemplified here. The shape, configuration, and the like can be changed as appropriate according to the region to be imaged.

As shown in FIG. 43, the main unit 18 includes a control unit 181, an operation unit 182, a display unit 183, a communication unit 184, a storage unit 185, a multi-grid drive unit 125, a first grid drive unit 145, and a second grid. A drive unit 155 is provided.
The control unit 181 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like, and executes various processes in cooperation with a program stored in the storage unit 185. For example, the control unit 181 controls the timing of X-ray irradiation from the X-ray source 11, the reading timing of the image signal by the X-ray detector 16, and the like according to the imaging condition setting information input from the controller 5.

The operation unit 182 includes a touch panel configured integrally with the display of the display unit 183 in addition to a key group used for input operations such as an exposure switch and an imaging condition, and generates an operation signal corresponding to these operations to generate a control unit. It outputs to 181.
The display unit 183 displays the operation screen, the operation status of the radiation image capturing apparatus 1 and the like on the display according to the display control of the control unit 181.

The communication unit 184 includes a communication interface and communicates with the controller 5 on the network. For example, the communication unit 184 transmits the moire image read by the X-ray detector 16 and stored in the storage unit 185 to the controller 5.
The storage unit 185 stores a program executed by the control unit 181 and data necessary for executing the program. The storage unit 185 stores the moire image obtained by the X-ray detector 16.

  The multi-grid drive unit 125, the first grid drive unit 145, and the second grid drive unit 155 operate the drive sources (motors) of the multi-grid unit 120, the first grid unit 140, and the second grid unit 150. .

  The controller 5 controls the imaging operation of the radiographic image capturing apparatus 1 according to an operation by the operator, and creates a reconstructed image of the subject using the moire image obtained by the radiographic image capturing apparatus 1. In the present embodiment, an example in which the controller 5 is used as an image processing apparatus that creates a reconstructed image of a subject will be described. However, a dedicated image processing apparatus that performs various image processing on an X-ray image is connected to the radiographic image capturing apparatus 1. The reconstructed image may be created by the image processing apparatus.

Next, the operation of the radiation image capturing apparatus 1 in the present embodiment will be described.
When radiography is performed using the radiographic imaging apparatus 1 of the present embodiment, a part to be imaged, such as a patient's finger or knee joint, is fixed on the subject table 13 and X is emitted from the X-ray source 11. The X-ray detector 16 detects the X-rays that have been irradiated and transmitted through the part to be imaged.
In the present embodiment, since the composite grating 100 is used as the first grating 14, the second grating 15, etc., which are appropriately sized with the small-size grating 10 bonded together, the imageable range can be widened. It is also possible to deal with a case where a relatively wide range such as a knee joint is an object to be imaged.
However, when shooting a small shooting target such as a finger joint, if the shooting target may be placed anywhere in the shooting range, the first grid 14 and the second grid 14 used for shooting each time shooting is performed. The portion of the lattice 15 is different. Since the first grating 14 and the second grating 15 have a slight phase shift for each portion, the images acquired will be slightly different if shooting is performed at different positions each time. This is inconvenient when continuous follow-up is required. For this reason, when photographing a small target region, for example, the light irradiation field confirmation unit 6 irradiates light to a range narrowed to some extent, and the position to be used for photographing (that is, the photographing target region should be placed). It is preferable to present the position) to the user. Note that the method for limiting the shooting range is not limited to this. For example, the shooting position may be presented by physically placing a frame or the like on the subject table.
X-rays irradiated from the X-ray source 11 are converted into a multi-light source by the multi-grating 12 and are diffracted by the first grating 14 and the second grating 15. At this time, for example, as shown in FIG. 14C and FIG. 14D, the second grating 15 is a composite grating in which a plurality of small size gratings 10 having different grating heights h are bonded, As shown in FIGS. 15 (f) and 15 (g), when the first grating 14 and the second grating 15 are composite gratings obtained by bonding a plurality of small-size gratings 10 having different grating pitches w, The vignetting performance and the amount of transmitted light are improved as compared with the case where vignetting is not taken.
As a result, the degree of vignetting variation is reduced to a level that can be dealt with by a subsequent correction.

  In addition, the X-ray imaging method using the Talbot-Lau interferometer of the radiographic imaging apparatus 1 is described in, for example, the specification of WO2011 / 114845, the specification of WO2011 / 033798, the specification of WO2012 / 029340, and the like. Since it is the same as that of the well-known thing, the description is abbreviate | omitted.

As described above, in the present embodiment, the multi-grating 12 that is an X-ray tube grating that converts X-rays emitted from the X-ray tube into multiple light sources, and the first diffraction that causes the Talbot effect by diffracting the X-rays. A first grating 14 that is a grating, and a second grating 15 that is a second diffraction grating that diffracts the X-rays diffracted by the first grating 14, the multi-grating 12, the first grating 14, and the second grating At least one of 15 is a composite lattice that is enlarged by combining a plurality of types of small size lattices having different lattice heights and / or lattice pitches. This makes it possible to increase the size of the grid even in the existing processing technology range, and to increase the size of the imageable area, and to generate vignetting even when the size of the grid increases. Can be suppressed, and an image suitable for diagnosis can be obtained.
In addition, the multi-grating 12 (G0 grating) can cope with a wide range of photographing even with a small size, so that it is not necessary to use a large-sized composite grating. In addition, the multi-grating 12 (G0 grating) has a great influence on the image quality. In this regard, when the multi-grid 12 (G0 lattice) is configured as a single unit that is not compounded, since the multi-grid 12 has no bonded portion, a high-definition image can be obtained.
In order to obtain the Talbot effect, it is necessary to move one of the lattices. However, if the composite lattice that has been enlarged in size is moved, it can be moved in an arc shape in consideration of vignetting. A device is required, and the apparatus configuration including the lattice moving means for moving the lattice is complicated. It also becomes difficult to maintain strength and accuracy. In this regard, when the multi-grid 12 (G0 lattice) that can be configured as a single unit without being combined as described above is moved, the multi-grid 12 (G0 lattice) can be moved linearly. Therefore, the apparatus configuration can be simplified, the reproducibility of the lattice position can be easily obtained, and high-precision movement can be performed, so that a high-definition image can be stably obtained.
Further, when the composite grating 100 is configured by laminating a plurality of small size gratings 10 in a plane so as to be parallel to the detector plane of the X-ray detector 16, even when the grating is moved. The configuration for moving the grid becomes simple. In the composite grating 100, the X-ray incident side may be parallel to the detector plane of the X-ray detector 16, or the emission side may be parallel.
In addition, when the composite grating 100 is configured by combining each small size grating 10 so as to have a predetermined curvature with respect to the detector plane of the X-ray detector 16, Since the distance from the X-ray source 11 to the grating surface at the end can be matched, the occurrence of vignetting at the end can be further prevented.

In addition, the said embodiment is a suitable example of this invention, and the scope of the present invention is not limited to this.
For example, in this embodiment, a radiographic imaging apparatus using a Talbot-Lau interferometer having a multi-grating, a first grating, and a second grating has been described as an example of the fringe scanning method. This is not limited to the Talbot-Lau interferometer. As a fringe scanning method, the first grating 14 that is the first diffraction grating that produces the Talbot effect by diffracting X-rays and the first grating 14 diffracted the light. The present invention can also be applied to a radiographic imaging apparatus using a Talbot interferometer that includes a second grating 15 that is a second diffraction grating that diffracts X-rays.
In this case, at least one of the first grating 14 and the second grating 15 is a composite in which a plurality of types of small size gratings having different grating heights and / or grating pitches are combined to increase the size. It is assumed to be a lattice. Even in the case of such a Talbot device, if the present invention is applied, it is possible to increase the size of the lattice in the existing processing technology, increase the size of the imageable area, and increase the size of the lattice. However, it is possible to suppress the occurrence of vignetting and obtain an image suitable for diagnosis.
Furthermore, the radiographic image capturing apparatus is not limited to one using a fringe scanning method. For example, the present invention may be applied to a radiographic imaging apparatus that performs imaging by a Fourier transform method that does not require fringe scanning using a one-dimensional grating or a two-dimensional grating, or a normal phase contrast method.

In the present embodiment, the multi-grating 12 that is an X-ray tube grating is provided with a grating moving means that moves the first grating 14 that is the first diffraction grating and the second grating 15 that is the second diffraction grating, Although the multi-grating 12 is configured to move, the grating that moves relative to other gratings is not limited to the multi-grating 12. For example, either the first grating 14 that is the first diffraction grating or the second grating 15 that is the second diffraction grating may move.
In addition, it is preferable that the grating | lattice which moves relatively with respect to another grating | lattice is the single-piece | unit structure which is not compounded. Even when a large-sized composite lattice is moved by combining small-size lattices, it is preferable to reduce the number of small-size lattices to be combined as much as possible. This is because, in the case of a composite lattice in which many small-size lattices are combined, it is easy to cause a shift of a joint portion during movement and it is difficult to maintain accuracy.

  Further, when the composite lattice 100 is formed by bonding the small size lattice 10 with a curvature, in this embodiment, the case of having a curvature only in the one-dimensional direction is taken as an example, but the curvature is attached only in the one-dimensional direction. It is not limited to things. For example, when a two-dimensional lattice is used instead of a one-dimensional lattice in which slits are provided in parallel in a certain direction as each lattice, the small-size lattice 10 is arranged in a mortar shape or a pyramid shape to thereby form a two-dimensional direction. Can have a curvature.

  Further, in the present embodiment, when the lattice height h and the lattice pitch w are made different for the small size lattice 10 constituting the composite lattice 100, the lattice height h and the lattice pitch w are stepwise set for each small size lattice. However, the method of changing the grating height h and the grating pitch w is not limited to this. For example, the lattice height h and the lattice pitch w are sequentially changed from the end portion in one small size lattice 10, and the lattice height h and the lattice pitch are gradually increased from the center portion to the end portion of the composite lattice 100. w may be changed.

As shown in FIG. 44 (a), when a plurality of small-size grids 10 are bonded in the slit extending direction, the bonded portion (boundary portion) in the slit extending direction is a radiation image capturing apparatus. 1 is preferably displaced by at least 5 mm from the center line of the effective angle of view ar (indicated by a one-dot chain line in FIG. 44A).
Note that a method of shifting the bonding portion (boundary portion) in the extending direction of the slits of the small size grid 10 from the center line of the effective angle of view ar in the radiographic image capturing apparatus 1 (indicated by a one-dot chain line in FIG. 44A). This is not limited to this, and as shown in FIG. 44 (b), it is realized by changing the length in the slit extending direction of the small size lattice 10 to be bonded in the slit extending direction by 5 mm or more. Also good.
With such a configuration, it is possible to prevent image performance deterioration due to pasting from occurring in the central portion of the effective angle of view ar. As a result, the center portion of the most stable effective field angle ar can be used effectively.

In addition, as shown in FIG. 45, when forming a composite lattice 100 by arranging a plurality of small size lattices 10 vertically and horizontally, the small size lattice 10 is pasted in the horizontal direction (the horizontal direction parallel to the slits). It is preferable that the sides to be combined be shifted in the horizontal direction by two or more pixels in the lattice row in the vertical direction (vertical direction as the slit extending direction).
With such a configuration, when performing image correction of a pasted portion in the horizontal direction (horizontal direction), image data obtained by a grid in the vertical direction (vertical direction) can be used for correction.

Also, as shown in FIG. 46A, the boundary line for bonding the small-size grid 10 and the boundary line that separates the pixels of the X-ray detector 16 are parallel to each other in the vertical and horizontal directions. It is preferable that the boundary portion of the lattice 10 is positioned approximately at the center of the pixel of the X-ray detector 16.
At the boundary portion where the small-size gratings 10 are bonded, the signal may be weakened due to the difference in phase between the two adjacent small-size gratings 10. Can be accommodated within the range of pixels in one vertical column and one horizontal column, and the influence can be minimized.

Also, as shown in FIG. 46B, the boundary line for bonding the small-size grid 10 and the boundary line that divides the pixels of the X-ray detector 16 are parallel to each other in the vertical and horizontal directions, thereby reducing the size. It is preferable that the boundary portion of the lattice 10 is substantially coincident with the boundary line of the pixel of the X-ray detector 16.
At the boundary portion where the small-size gratings 10 are bonded, the signal may be weakened due to the difference in phase between the two adjacent small-size gratings 10. It is possible to eliminate the pixel of the weakened pixel.

Further, the small size lattice 10 constituting the composite lattice 100 is provided with a portion where no slit is formed on one side in the slit extending direction (see, for example, FIGS. 11A and 11B). When the composite grid 100 is fixed to a grid unit or the like, it is preferable to fix the position of the composite grid 100 by holding this portion.
By configuring in this way, the other three sides of the small size lattice 10 can be used as a bonding side when the small size lattices 10 are bonded to each other.

Further, when a plurality of small-size grids 10 are arranged in the horizontal direction (horizontal direction parallel to the slits) to form the composite grid 100, for example, as shown in FIGS. 47 (a) and 47 (b), Of the sides of the small-size grating 10 positioned at both ends in the horizontal direction of the composite grating 100, portions where no slits are formed on the sides constituting the horizontal ends of the composite grating 100 (FIG. 47 (a), In the case where the holding unit 105) is provided in FIG. 47B and the composite grating 100 is fixed to a lattice unit or the like, the position of the composite grating 100 is fixed by holding the holding unit 105. Also good.
Thus, by providing portions for fixing the composite grating 100 to the lattice unit or the like (parts without slits) at both ends in the lateral direction of the composite grating 100, the composite grating 100 can be securely attached to the lattice unit or the like. It can be fixed.
Note that the portion for fixing the composite grating 100 to the lattice unit or the like (the portion without the slit) is the both ends in the horizontal direction of the composite grating 100 (that is, the hold shown in FIGS. 47A and 47B). Part 105) alone, or both of the hold part 105 and the end part (both ends or one end) in the extending direction of the slit as shown in FIG. 11A, FIG. It is good also as a part for fixing the chemical grid 100 to a grid unit or the like.

Further, in the above embodiment, six types of the first photographing target fixing unit 33a to the sixth photographing target fixing unit 33f are prepared as the photographing target fixing unit 33 constituting the subject holding member 30, and any of these is prepared. However, the type and number of the imaging target fixing units 33 are not limited to this.
For example, only one of these may be provided, or a photographing target fixing unit 33 having another shape may be further provided.

In the above embodiment, the X-ray source 11, the multi-grating 12, the subject table 13, the first grating 14, the second grating 15, and the X-ray detector 16 are arranged in this order (hereinafter referred to as the first arrangement). However, the arrangement of the X-ray source 11, the multi-grating 12, the first grating 14, the subject table 13, the second grating 15, and the X-ray detector 16 (hereinafter referred to as the second arrangement) A reconstructed image can be obtained by moving the multi-grating 12 while the second grid 15 is fixed.
In the second arrangement, the subject center and the first grid 14 are separated from each other by the thickness of the subject, which is slightly inferior in sensitivity compared to the above-described embodiment. In consideration of dose reduction, the arrangement effectively uses X-rays by the amount of X-ray absorption in the first grating 14.
The effective spatial resolution at the subject position depends on the focal diameter of the X-ray, the spatial resolution of the detector, the magnification of the subject, the thickness of the subject, and the like. When the resolution is 120 μm (Gauss half width) or less, the effective spatial resolution is smaller in the second arrangement than in the first arrangement.
It is preferable to determine the order of arrangement of the first grating 14 and the object table 13 in consideration of sensitivity, spatial resolution, the amount of X-ray absorption in the first grating 14, and the like.

In the present embodiment, the subject table 13 is described as an example of a completely separate configuration. However, the subject table 13 may be fixed to the base 19 or the like. In this case, a buffer member or the like is provided between the subject table 13 and the base unit 19 so that the impact or vibration applied to the subject table 13 is not transmitted to the base unit 19 as much as possible.
The height of the subject table 13 may be adjusted according to the patient's body shape and the like.

  In the present embodiment, the case where the multi-grid unit 120, the first lattice unit 140, and the second lattice unit 150 are provided with the turn adjustment mechanism and the relative distance adjustment mechanism is described as an example. The relative distance adjustment mechanism does not need to be provided in all of the multi-grating unit 120, the first grating unit 140, and the second grating unit 150, and may be provided in at least one of them.

  In the present embodiment, the case where the moire image is generated by moving the multi-grating 12 has been described as an example. However, the grid to be moved to generate the moire image is not limited to the multi-grating 12, and the first grating 14 is used. The second grating 15 may be used.

  Further, as the X-ray detector 16, a cableless cassette type FPD that incorporates a battery and outputs an image signal to the main body 18 by radio may be used. According to the cassette type FPD, cables connected to the main body 18 can be eliminated, and a further space around the X-ray detector 16 can be reduced. By reducing the space, the subject's feet can be configured wider, and the patient can be more difficult to touch.

  In addition, it cannot be overemphasized that this invention is not limited to this embodiment, and can be changed suitably.

DESCRIPTION OF SYMBOLS 1 Radiographic imaging apparatus 5 Controller 9 Knee fixing unit 10 Small size grating | lattice 11 X-ray source 12 Multi grating | lattice 13 Subject stand 14 1st grating | lattice 15 2nd grating | lattice 16 X-ray detector 17 Support | pillar 17a Buffer member 18 Main part 19 Base part 21 First cover unit 22 Second cover unit 30 Subject holding member 31 Base unit 33, 33a to 33f Imaging target fixing unit 41 Guard member 91 Fixing part 92 Extending plate 94 Connecting part 95 Hinge part 100 Compound grid 101 Substrate 102 slit

Claims (6)

An X-ray tube that emits X-rays;
A first diffraction grating that produces a Talbot effect by diffracting X-rays;
A second diffraction grating for diffracting X-rays diffracted by the first diffraction grating;
An X-ray detector having a plurality of detection elements arranged two-dimensionally;
A subject table on which the subject is placed;
A radiographic imaging device comprising:
At least one of the first diffraction grating and the second diffraction grating is a composite grating that is enlarged by combining a plurality of types of small-size gratings having different grating heights and / or grating pitches. A radiographic imaging apparatus characterized by being.   The radiographic imaging apparatus according to claim 1, further comprising an X-ray tube grid that converts X-rays emitted from the X-ray tube into a multi-light source. The lattice for the X-ray tube has a single structure that is not combined,
The radiographic image capturing apparatus according to claim 2, further comprising: a grating moving unit that moves the X-ray tube grating with respect to the first diffraction grating and the second diffraction grating. An X-ray tube that emits X-rays;
A first diffraction grating that produces a Talbot effect by diffracting X-rays;
A second diffraction grating for diffracting X-rays diffracted by the first diffraction grating;
A grid for an X-ray tube that converts X-rays irradiated from the X-ray tube into a multi-light source;
An X-ray detector having a plurality of detection elements arranged two-dimensionally;
A subject table on which the subject is placed;
A radiographic imaging device comprising:
At least one of the first diffraction grating, the second diffraction grating, and the X-ray tube grating has a large size by combining a plurality of types of small size gratings having different grating heights and / or grating pitches. A radiographic imaging apparatus, characterized in that it is a composite grating.   5. The radiation according to claim 1, wherein the composite grating is configured by combining each small size grating so as to be parallel to a detector plane of the X-ray detector. Image shooting device.   5. The composite grating is configured by combining each small size grating so as to have a predetermined curvature with respect to a detector plane of the X-ray detector. The radiographic imaging apparatus described in 1.