JP2001128960A - X-ray photographing system for small lesion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give suitable diagnosis and aftercare to a patient by setting an- X-ray radiation field according to an object, efficiently using power of an X-ray for photographing, and plotting a small lesion part with a high image contrast. SOLUTION: This X-ray photographing system comprises an X-ray source 1, an X-ray optical system 3 formed by one or plural silicon monocrystal plates 2, a photographing part 4 and an image recording part 5. The X-ray source 1 generates radiation with high luminance and high spatial interference, and an X-ray radiation field according to the size of an object 40 is formed by the X-ray optical system 3. The distance between an image recording medium 50 and an object fixing part 43 such as an acrylic plate is set according to the interference degree of an X-ray. After the photographing region of the object abuts on the object fixing part to be fixed, an X-ray is radiated for photographing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to X-ray diffraction, refraction,
The present invention relates to a system for X-ray imaging of the surface structure and internal structure of various materials, and microscopic lesions of humans and animals by utilizing physical processes involving scattering, transmission, polarization effects, and the like. In particular, an X-ray optical system composed of a plate-like silicon single crystal (hereinafter, referred to as a silicon single crystal plate) is used to create an irradiation field according to the size of the affected part using high-brightness X-rays. The present invention relates to a micro-lesion X-ray imaging system that irradiates a diseased part of a human body, an animal, or the like to enable imaging of a micro-lesion.

[0002]

2. Description of the Related Art X-rays used for radiography have the property of a wave having information on height and phase. An X-ray radiographic image obtained by a conventional medical X-ray tube apparatus draws, as an image, a change in intensity (a change in height) in an X-ray wave after transmission through a subject (a difference in X-ray absorption between tissues). According to this method, it is difficult to obtain high image contrast (black-and-white difference in photographic density) for a subject composed of a tissue having a small X-ray absorption difference, and only an X-ray image with low diagnostic ability or almost no diagnostic ability is obtained. Could not be obtained. It is known that a subject having a small X-ray absorption difference has a very high image contrast when rendered using a change in the X-ray phase.

For example, Japanese Patent Application Publication No. 11-502620 proposes a method for obtaining an image of a boundary of an object showing a change in refractive index. The method includes irradiating the boundary with penetrating radiation having high lateral spatial coherence and a propagating component across the refractive index change, such that on a screen, the boundary is displayed on an image by a corresponding intensity change. This is a technique for receiving at least a part of the radiation refracted by and forming an image.

[0004]

The conventional X-ray imaging method is as follows.
It is impossible to draw a subject having a very small X-ray absorption difference. For example, it is difficult to draw a microfracture of a bone, a tumor or a blood vessel in a soft tissue of a human body by simple imaging in a conventional method, and it is not possible to diagnose a lesion other than performing an invasive operation. In the conventional method, the size of the irradiation surface is adjusted using a plurality of slits or multiple shutters, so that the X-rays deleted by the slits or the shutter do not contribute to image formation. That is, there is a problem that the use efficiency of X-rays is poor, and it is not suitable for performing imaging in a shorter time.

[0005] An object of the present invention is to set an X-ray irradiation field size according to an object by an X-ray optical system and efficiently use X-ray power for imaging, thereby starting small lesions in a shorter imaging time, Draws tissue with low X-ray absorption difference with high image contrast, and diagnoses patients appropriately, decides treatment strategy,
Another object of the present invention is to provide an X-ray imaging system for a small lesion or the like, which can perform post-morbid management.

[0006] Another object of the present invention is to provide an image processing apparatus that adjusts X according to a subject.
Provided is an X-ray optical device of an X-ray imaging system for setting an X-ray irradiation field size and efficiently using X-ray power for imaging to obtain an image in which imaging is performed in a short time and an effect of blurring due to movement of a subject is small. Is to do.

[0007]

According to the first aspect of the present invention, there is provided an X-ray imaging system for micro-lesions, which has a radiation X-ray source having high brightness and high spatial coherence, and maintains or enhances the properties of X-rays. At the same time, an X-ray optical system for securing an irradiation field with a uniform X-ray intensity, and an X-ray of the irradiation field secured by the X-ray optical system,
The imaging device includes an imaging unit that irradiates an imaging region such as an animal and an image recording unit that records the imaging region irradiated with X-rays on an image recording medium. According to the first aspect of the present invention, X-rays with high parallelism are radiated to a micro-lesion site such as a bone surface or an internal flaw, and an effect such as X-ray diffraction caused by a micro-lesion portion such as a minute crack is obtained. By taking advantage of this, it is possible to depict a small lesion or the like as an image caused by a change in the X-ray phase.

According to a second aspect of the present invention, in the first aspect of the invention, there is provided a means for adjusting a distance between an image recording medium and a subject fixing portion for fixing a photographing part such as a human body or an animal. . According to the second aspect of the present invention, by fixing the imaging part in a stable posture, image blur due to the movement of the subject is reduced, and short-time imaging is performed.

According to a third aspect of the present invention, in the second aspect, the distance adjusting means is provided on the image recording section side. According to the third aspect of the present invention, since the contrast of the image caused by the phase change changes depending on the distance between the X-ray irradiation position of the imaging region and the image recording medium, a high image can be obtained by adjusting the distance to an appropriate position. Contrast is obtained. In addition, since the human body, animals, and the like are not moved, it is useful for preventing body movement caused by anxiety.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, there is provided an X-ray irradiating direction changing means for irradiating an X-ray at a different incident angle to an imaging part such as a human body or an animal. It is characterized by being. According to the fourth aspect of the present invention, it is easy to specify the position, size, shape, and the like of the micro-lesion or the like by imaging the micro-lesion site or the like at a plurality of different angles.

According to a fifth aspect of the present invention, an X-ray optical apparatus for an X-ray imaging system comprises one or more silicon single crystal plates to maintain or enhance the properties of X-rays and to uniformly irradiate X-rays. It is characterized by securing a field. According to the invention of claim 5, the traveling direction of the X-ray changes due to the Bragg reflection of the X-ray in the silicon single crystal. By combining a plurality of silicon single crystal plates, X-rays flying at various angles can be produced.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, the property of X-rays is retained by symmetrically reflecting the X-rays at the same incidence angle and the same emission angle with respect to the crystal surface of the silicon single crystal. . According to the sixth aspect of the present invention, only X-rays of specific energy are reflected by Bragg reflection of X-rays in a symmetrically-reflective silicon single crystal. That is, the X-ray energy can be set freely under the Bragg condition. By improving the monochromaticity of the X-ray energy, an image resulting from a high-contrast X-ray phase change can be obtained.

According to a seventh aspect of the present invention, in the fifth aspect of the invention, the property of the X-ray is enhanced by the X-ray incident angle (visible incident angle: θ ₀ -α) and the emission angle with respect to the crystal surface of the silicon single crystal. (A visual emission angle: θ ₀ + α) is characterized by asymmetrical reflection. α is the angle between the crystal surface and the Bragg plane. According to the seventh aspect of the present invention, the degree of asymmetry can be continuously changed by giving a rotation operation to an axis perpendicular to the atomic plane in the asymmetric reflection type silicon single crystal. Since the width of the X-ray in a specific direction can be continuously changed according to the change in the degree of asymmetry accompanying rotation, it is useful for adjusting the size of the X-ray irradiation field.

According to an eighth aspect of the present invention, in the invention of the fifth aspect, when an X-ray optical system is constituted by a plurality of silicon single crystal plates, the incidence planes of the silicon single crystal plates are arranged orthogonal to each other. The size of the X-ray irradiation field is adjusted by rotating the silicon single crystal plate with respect to the normal direction of the atomic plane as an axis. According to the invention of claim 8, the size of the X-ray irradiation field in the vertical direction and the horizontal direction can be independently adjusted by continuously changing the width of the X-ray in the specific direction according to the degree of asymmetry. it can.

According to a ninth aspect of the present invention, in the invention of the eighth aspect, a silicon single crystal plate for adjusting the horizontal width size and a silicon single crystal plate for adjusting the vertical width size are each composed of a plurality of sheets, and X-ray incidence is performed. The silicon single crystal plates are arranged such that an optical axis and an emission optical axis are aligned with each other. According to the ninth aspect of the present invention, when adjusting the X-ray optical system, if the X-ray optical axis is constant, the installation adjustment of the entire apparatus becomes very simple. If the X-ray emission position can be accurately predicted, more accurate imaging can be performed.

According to a tenth aspect, in the first aspect, the X-ray optical system is the X-ray optical system according to any one of the fifth to ninth aspects.
It is characterized by being constituted by a line optical device.

According to the tenth aspect of the present invention, the X-ray energy can be changed according to the size (thickness) of the subject, the coherence of X-rays can be adjusted, and the size of the X-ray irradiation field used for imaging can be improved. Is changed according to the size of the subject, thereby improving the image quality and reducing the exposure dose.

[0018]

Embodiments of the present invention will be described with reference to the drawings. First, the principle of the present invention will be described.
The present invention is a technology that applies X-ray equipment system engineering for generating and manifesting a phase change of a wave in an X-ray after transmission through a subject and X-ray imaging technology engineering for performing short-time imaging with less image blur. It utilizes the high spatial coherence of synchrotron radiation X-rays and a sufficient X-ray intensity. The image contrast in the imaging method of the present invention is caused by a change in X-ray phase due to X-ray diffraction. That is, the larger the change in the phase of the X-ray wave, the higher the image contrast. Therefore, it has a feature that the ability to describe such a part as a line image is enhanced.

In actual photographing, several silicon single crystal plates are placed on the X-ray plate in order to further enhance the spatial coherence of the emitted X-rays.
Monochromatic X-rays placed in a line path and Bragg-reflected on the surface were used. The subject is irradiated with the obtained monochromatic X-rays, and photographed with a high-resolution X-ray film or an image receiver such as an X-ray TV. The contrast of the image due to the phase change is
It changes depending on the distance of the line film or the like. Usually, there is a shooting position where a high image contrast is obtained in a range where the distance between the subject and the image recording medium is several tens cm to several meters.

A synchrotron radiation X-ray imaging system in which the above principle is applied to imaging of a microfracture will be described. FIG. 1 is a schematic diagram of an X-ray imaging system for a small lesion used for imaging a hand of a human body. FIG. 2 is a side view showing another embodiment of the photographing unit, and FIG.
FIG. 9 is a top view showing another embodiment of the photographing unit. The X-ray imaging system for micro-lesions is composed of an X-ray source 1, an X-ray optical system 2, an X-ray optical system 3 for creating a uniform X-ray irradiation field, an imaging unit 4, and an image recording unit 5. The X-ray source 1 generates radiation (solid arrow) having high brightness and high spatial coherence. Preferably, the spatial coherence length (λ / △ θ)
Use radiation of 10 μm or longer. Here, λ is the wavelength of the X-ray, and △ θ is the spatial divergence angle of the X-ray having that wavelength. Here, the radiation is, for example, radiation X-rays obtained from a bending electromagnet or an insertion light source or X-rays obtained by applying the radiation to a silicon single crystal, and has an energy of 3 keV to 200 keV. X-rays having high spatial coherence cause an X-ray diffraction at a minute lesion, and have an effect of recording a fine interference image 51 on a film 50 as an image recording medium.

The X-ray optical system 3 has a function of maintaining or enhancing the properties of X-rays and creating an X-ray irradiation field having a uniform intensity according to the size of a subject. In particular, since a sufficient amount of X-ray photons having high spatial coherence can be given to the film by reflecting the synchrotron radiation X-rays on a plurality of silicon single crystal plates, the image blur due to the movement of the subject 40 can be reduced. Time shooting can be performed. The X-ray optical system 3
Various configurations shown in FIG. 11 described below can be used.

In this embodiment, an X-ray optical system is used in which a plurality of silicon crystal plates in which the incident optical axis and the output optical axis are the same axis are combined. FIG. 6 is a schematic view of the X-ray optical system for reflecting the synchrotron radiation X-rays with eight silicon single crystal plates as viewed from above, and FIG.
FIG. 7 is a schematic view of the X-ray optical system of FIG. 6 as viewed from the side. Previous 4
The size of the crystals (X-ray source side) a to d can be adjusted in the horizontal (vertical) direction, and the size of the last four crystals e to h can be adjusted in the vertical (horizontal) direction. Each of the crystals a to h is configured to be rotatable with respect to the atomic plane. That is, as shown in the drawing, the size of the X-ray irradiation field can be arbitrarily adjusted vertically and horizontally by rotating the crystals a to h around the normal direction of the atomic plane as an axis.

FIG. 8 is a view showing X-rays emitted when X-rays are incident at a certain angle with respect to the atomic plane of the silicon single crystal plate, and FIG. 9 is a view showing the case where the X-rays are symmetrically reflected. 10 is X
It is a figure showing the case where a line is asymmetrical reflection.

(1) Symmetrical reflection In FIG. 9, the crystal surface and the Bragg plane are parallel (α =
If 0), the width D of the width _{D in} the incident X-ray emission X-ray
_out is the same.

D_in= D_out  Symmetric reflection by silicon single crystal plate makes X-ray flux monochromatic
(Determination of energy), useful for adjusting the X-ray traveling direction
It is.

(2) Asymmetrical reflection When the surface of the crystal and the Bragg plane form an angle α, the incident X
Line width (size) D _in and output X-ray width (size) D
_out is different. Here, the asymmetry of the crystals is defined as _{b, b = sin (θ 0} -α) / sin (θ 0 + α) and _{putting, D out = (1 / b} ) × D in the (b> 0) Become.

In FIG. 10, the size of the irradiation field can be increased or reduced by rotating the rotation about the axis C in addition to the conventional operation in the horizontal direction A and the vertical direction B. Enlargement ratio M on one side
Can be arbitrarily selected within a range of 1 / b ≦ M ≦ b.

The asymmetrical reflection by the silicon single crystal plate causes enlargement / reduction of an irradiation area (irradiation field) (adjustment of size), monochromaticization of X-ray flux (determination of X-ray energy / reduction of exposure dose),
It is useful for improving spatial coherence and adjusting the X-ray traveling direction.

The X-ray optical system according to the present invention has the following features. The irradiation area can be continuously changed with respect to the reference irradiation area. As shown in FIG. 10, if the degree of asymmetry of the crystal is b, the magnification M can be arbitrarily selected from 1 / b ≦ M ≦ b. The traveling direction (optical axis) of the radiation does not change before and after the eight crystals. The enlargement ratio can be freely set for each size of one side of the irradiation surface in the vertical and horizontal directions. Since the X-ray wavelength can be continuously changed, the X-ray wavelength (or energy) can be freely selected.

Next, another embodiment of the X-ray optical system will be described. 11A shows an example in which only an X-ray slit is used without using a crystal, FIG. 11B shows an example in which one crystal is used to adjust the lateral size, and FIG. 11C shows two examples. FIG. 11D shows an example in which one crystal is used to adjust the vertical size, and FIG. 11E shows an example in which one crystal is used to adjust the horizontal size. FIG. 11 (F) shows an example in which one crystal is used to adjust the horizontal size and one crystal is used to adjust the vertical size. FIG. 11 (F) shows two crystals used to adjust the vertical size and two crystals used to adjust the horizontal size. An example is shown in which a crystal is formed. By disposing the eight-piece X-ray optical system of FIG. 6 on the X-ray radiation axis of FIGS. 11B to 11F, the position of the optical axis can be maintained and the vertical and horizontal sizes can be independently adjusted. Become.

The imaging unit 4 shown in FIG. 1 is made of a material having a small X-ray absorption effect, such as an acrylic board or the like, which fixes the imaging table 41, the chair 42 on which the patient sits, and the hand of the subject 40, and transmits and radiates X-rays. The object fixing section 43 is composed of In the case of an acrylic plate, the thickness may be about several mm. In the example illustrated in FIG. 1, the subject fixing unit 43 is supported by a subject fixing unit support 44 supported on the imaging table 41, and in the example of FIG. 2, a partition wall of a room that blocks scattered X-rays from an X-ray source 6 side. The subject fixing section 43 is arranged to face the slit 7. The slit 7 is arranged so as to substantially coincide with the outer periphery of the X-ray irradiation field. X-rays are radiated through the slit 7, pass through the subject fixing portion 43, and pass through the hand 40 of the human body.
Is irradiated. The image recording unit 5 is provided behind the subject fixing unit 43 on the X-ray irradiation line.

As for the use of the broken X-ray (radiated obliquely upward) in FIG. 2, the X-ray is obliquely incident on the examination site (hand, foot, affected body, etc.) depending on the condition of the patient, the type of the disease, and the condition. This method is used when an image more suitable for diagnosis is obtained.
By adding such an oblique incidence function, the versatility of the system can be enhanced.

The subject fixing section 43 has a structure to be attached to a subject fixing section support 44 fixed to the imaging table 41 as shown in FIG. 1, or stores an X-ray source as shown in FIG. This is implemented by a structure that is attached to the subject fixing portion support 44 fixed to the partition wall 6 of the room where the division is made. In FIG. 5, the subject fixing unit 43 mounts a frame 45 on a subject fixing unit support body 44 to a tilting mechanism unit 49, and attaches a subject fixing unit 46 to the frame 45. The frame 45 includes a support member 47 for supporting the lower part of the subject and a belt 48 made of a material having low X-ray absorption for fixing the subject.
Etc. are provided. The frame 45 is tilted at an arbitrary angle in accordance with the fixed diseased part of the subject. Subject 40
Is fixed by the belt 48 or the like, so that the image blur due to the movement of the subject 40 can be reduced, and even if the photographing is performed for a short time, the subject can be positioned in a comfortable position with little pain from the preparation to the end. Positioning).

The photographing table 41 shown in FIG. 2 is constituted by a bed 410 having a length substantially equal to the height so as to allow the human body to fall down and photograph a foot. , And is configured to be rotatable by 90 degrees at the hinge 411. When photographing the hand 40 and the like while the patient is sitting down, the patient is set on a chair as shown by the solid line in the drawing, or when the patient is laid down and the foot and the like are photographed, the patient is placed on the bed 410 as shown by the broken line in the drawing. set.

In order to change the irradiation position of X-rays on a diseased part of the hand or foot, the height and direction of the imaging table 41 can be adjusted. In FIG. 2, the rotary table 82 has a mounting surface that is at the same level as the floor surface, and the height and direction of the imaging table 41 are adjusted by the lifting mechanism 80 and the rotation mechanism 90. The lifting mechanism 80 supports a rotary table 82 by a link mechanism 81, for example, as shown in the figure, and moves the link mechanism 81 up and down (Y direction) in the direction of the arrow by a drive unit (not shown). Adjust In addition, the rotating mechanism 90 includes a rotating table 82.
Is rotatably supported in the horizontal direction, and the electric unit 91 and the rotary table drive shaft 92 are connected by a transmission belt 93,
The rotation table 82 is rotated in an arbitrary direction to adjust the direction of the imaging table 41 with respect to the X-ray emission direction. Rail 412
Is used for moving the bed 410 in the X direction.

The image recording section 5 has a function of recording an image on an image recording medium 50 such as an X-ray film, and adjusts the distance (Z direction) between the image recording medium 50 and the subject fixing section 43. A medium moving means 52 is provided. The distance between the image recording medium 50 and the subject fixing unit 43 can be adjusted within a range of 0.3 to 4 m.

The recording medium moving means 52 is constituted by a ground traveling device or an overhead traveling device. As shown in FIG. 1, the ground traveling device lays a rail 54 on an installation table 53, and attaches an image recording medium 50 to a traveling unit 55 that moves on the rail 54. In the ceiling traveling device, a rail 57 is fixed to a ceiling 56 as shown in FIG. 4, and the image recording medium 50 is mounted on a traveling unit 58 suspended and moved by the ceiling rail 57. The image recording medium 50 is moved up and down by the telescopic arm, and is inclined by 45 ° from the horizontal at the hinge portion 58B. The overhead traveling device is used when the distance between the subject 40 and the image recording medium 50 is reduced (about 0.3 to 1 m) or when X-ray oblique incidence imaging is performed. The ground traveling device and the overhead traveling device are manually or powered.

The operation of this embodiment will be described. An X-ray source 1 generates radiation having high luminance and high spatial coherence, and an X-ray having an X-ray irradiation field matched to the size of a subject by an X-ray optical system.
Generate a line. Imaging conditions (imaging time, X-ray energy, etc.) differ depending on the imaging site. The distance between the image recording medium 50 and the subject fixing unit 43 is set in accordance with the degree of X-ray interference. After the imaging part of the limb 40 is brought into contact with the subject fixing part 43, and preferably fixed firmly, X-rays are irradiated to record and shoot on the image recording medium 50. Here, the relationship between the X-ray interference and the distance is preferably about 2 to 4 m when the X-ray interference is relatively high, and about 0.3 to 2 m when the X-ray interference is low. However, since an image due to the X-ray absorption effect recorded on a film or the like at the same time also includes diagnostic information, the distance is set so that this is not lost.

The microfracture image greatly depends on the distance between the bone sample and the image recording medium. FIG. 12 is a photographed image (a white arrow indicates a fracture site) at a distance Z = 0.7 m between the subject and the film. FIG. 13 is a diagram in which a microfracture site in a captured image is sketched. In this example, a microfracture was artificially created by applying an impact to a dried human bone. still,
In the figure, reference symbol H denotes a point on the bone where pressure (external force) is applied (hitting point), A denotes a vertical microfracture image generated from H, and B denotes a horizontal microfracture image generated from H.

Since the image shown in FIG. 12 is printed on photographic paper, the black and white density of the original film is inverted. This image shows the contrast caused by the X-ray absorption difference of the sample and the X-ray absorption.
Image information based on contrast caused by a change in line phase is included. The image at Z = 0.1 m near the subject and the film is mainly generated by the X-ray absorption effect, and a crack (microfracture) cannot be captured in the image taken at this position. FIG. 14 shows the same sample with an X-ray focal size of 0.
3 shows an image obtained by an X-ray absorption effect taken with a 1 mm medical X-ray tube. The tube voltage is 45 kV and the exposure amount is about 1000 mA · s. No X-ray intensifying screen was used. Again, no microfracture images could be captured.

Comparing the images of FIG. 12 and FIG. 14, it can be seen that microfractures (arrows) are shown only in the image (FIG. 12) resulting from the phase change using synchrotron radiation X-rays.
A portion having a small X-ray absorption difference, such as a microfracture, cannot be described unless the contrast is based on a change in the X-ray phase. X
Synchrotron radiation X-rays that are monochromatic and have high coherence compared to a tube are more advantageous for describing phase contrast.

As a result of observing the bone surface with a metallurgical microscope, it was confirmed that there were at least two types of microfracture generation modes (running conditions). This will be described with reference to a diagram schematically illustrating a bone cross section. FIG. 15 shows that the crack width is several μm to several tens μ.
This is a microfracture having an opening structure of about m. FIG.
Is: a microfracture of the interface misalignment type due to the displacement of the bone tissue without showing a clear opening.

The phase contrast generated in the above can be explained by a single-slit (slit of phase material) model translucent to X-rays shown in FIG. The image contrast in this expression is expressed by a Fresnel integration function, and the sample and X
The change in image contrast due to the difference in the distance of the line film can be explained. The resulting X-ray phase difference φ is represented by φ = 2π (△ n) L / λ. In the above equation, Δn is the difference between the refractive index of the opening and the non-opening of the single slit, L is the thickness of the slit, λ
Is the wavelength of the X-ray. Where △ n ~ 0.4 × 10 ^-6 , λ = 4.
If 1 × 10 ⁻¹¹ m and L to 50 μm, the calculated phase difference is approximately π (rad). The line width of the microfracture image is about 2
0 μm. It is given by the total line width W〜2d of the calculated image. Here, the total line width W is a 1/10 value width only in the phase contrast excluding the background density, that is, a line profile that gives 1/10 of the maximum intensity when only the phase contrast is considered (FIG. 17). Refers to the distance between the above two points. d is the opening width of the single slit. The shape of the line (profile) agrees well with the calculation result when d = 7.5 μm. Considering that the resolution of the X-ray film is about 5 μm, there is a reasonable ratio between the aperture width and the actually measured line width resulting from convolution of the X-ray film resolution. The phase contrast produced at is
This can be explained by a semi-slit model that is translucent to the X-ray shown in FIG.

The depiction of bone microstructure (trabecular bone) in a phase contrast image using synchrotron radiation X-rays is far superior to imaging using an X-ray tube. This is an edge enhancement phenomenon (edge effect) due to X-ray refraction. As shown in FIG. 14, the edge effect does not appear remarkably in an X-ray tube having a focal size of 0.1 mm.
The delineation ability of the microfracture is much lower than that of highly coherent synchrotron radiation X-rays. In order to proceed to the clinical test of fracture imaging, an irradiation field size of about 15 cm × 20 cm is required. In this case, a technique for expanding the irradiation field using an asymmetric reflection crystal may be used. Synchrotron X-rays have a large X-ray output and are suitable for short-time imaging. That is, it is useful for suppressing image blur caused by the movement of the subject. This is a very advantageous condition for photographing a small subject such as a small fracture.

Next, an X-ray imaging system for micro-lesions for imaging micro-fractures in the foot of an animal will be described. The present embodiment is an X-ray imaging system for micro-lesions applied to foot imaging of quadrupeds represented by horses. FIG. 18 is an overall perspective view showing the concept of an X-ray imaging system for animal microscopic lesions.
9 is a side view of the photographing unit, and FIG. 20 is a front view of the photographing apparatus including the driving unit of the photographing table.

The imaging table 100 has a rotatable table 101 which is rotatably supported by a shaft.
It is transmitted to 04 and rotates. A U-shaped fence 112 for guiding the animal 108 is provided vertically. The fence 112 can be rotated about a rotation shaft 114A as needed by a rotation mechanism 114 installed on a ceiling 113.

An XZ rail 106 is provided on the mounting table 105, and the XZ rail 106 is
0 and the X-ray radiating section 110
It comprises an X-rail 106A laid in the X-ray irradiation direction and a Z-rail 106B movably on the X-rail 106A and laid in a direction perpendicular to the X-ray irradiation direction.
The image recording medium 107 runs on the Z rail 106B. Between the image recording medium 107 and the imaging stand 100, a shielding body 111 for shielding the upper part except the image recording medium 107 so as to be invisible to an animal is arranged. This is a measure to keep the animal from fear.

The operation of this embodiment will be described. The animal 108 is placed on the imaging table 100, and the rotating table 101 is rotated so that the X-ray is correctly irradiated on the imaging region of the foot.
Adjust the orientation of 8. The image recording medium 107 is moved and set to an imaging region, and X-rays are irradiated to perform imaging.

The following effects are expected from the embodiment of the present invention. That is, by using X-rays having high parallelism (interference) (strong), imaging can be performed in a short time, which is useful for diagnosis of diseases such as bones and minute scratches generated on the surface or inside thereof. As a diagnostic image obtained by a non-invasive method, an image of a small lesion or the like that cannot be drawn by the conventional method can be drawn with high image contrast, so that a more appropriate diagnosis, treatment policy determination, and post-morbid management can be performed for the patient. And contribute to the development of an X-ray imaging apparatus for humans and animals.

As an application of the present invention, the present invention can be applied to a contrast inspection method in a phase image method. An image can be formed of a change in phase caused by a difference between substance elements (difference in atomic number). By injecting appropriate drugs into blood vessels and the body,
The contrast resulting from the phase change can be further increased. A contrast examination method that provides more diagnostic information can be performed by enhancing the image contrast of a microscopic lesion or a tissue having a small X-ray absorption difference by using a combination of drugs.

[0051]

According to the X-ray imaging system for micro-lesions of the present invention, when a highly parallel X-ray is applied to a wound of a bone (for example, a fine crack such as a micro-fracture), a phase change such as a crack occurs. An image is formed by the effect of X-ray diffraction or the like due to the portion where the X-ray is generated, and a minute lesion or the like can be depicted as an image in a change in X-ray phase. In addition, for diseases that may involve large or small fractures such as bruises of athletes and accident victims, more appropriate diagnosis, treatment policy determination, and disease management guidance can be performed. In addition, the imaging method can be implemented as an early diagnosis method for osteoporosis because the sensitivity is high for changes in bone quality.
Calcified lesions in cancer lesions are also phase subjects,
Applicable imaging can be implemented as a new method for detecting lesions. Furthermore, when applied to limb imaging of animals, lesions can be found in microfractures before large fractures during exercise. In particular, it is useful in health management of racing horses and the like. In addition, X of the present invention
According to the line optical device, as a utilization form other than the above, it can be used for evaluating materials such as metals, nonmetals, semiconductors, and polymers in various fields.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of an X-ray imaging system for a small lesion according to the present invention.

FIG. 2 is a side view showing another embodiment of the imaging unit in the micro lesion X-ray imaging system according to the present invention.

FIG. 3 is a top view of FIG. 2;

FIG. 4 is a side view showing another embodiment of the image recording unit in the micro lesion X-ray imaging system according to the present invention.

FIG. 5 is a perspective view of a subject fixing unit in the micro lesion X-ray imaging system according to the present invention.

FIG. 6 is a schematic view of the X-ray optical system used in the X-ray imaging system for micro-lesions according to the present invention, as viewed from above.

FIG. 7 is a schematic diagram of the X-ray optical system of FIG. 6 as viewed from a side.

FIG. 8 is a diagram showing X-rays emitted when X-rays are incident at a certain angle with respect to the atomic plane of an asymmetric silicon single crystal plate.

FIG. 9 is a diagram showing a case where X-rays are symmetrically reflected.

FIG. 10 is a diagram showing a case where X-rays are asymmetrically reflected.

FIG. 11 is an explanatory view showing another embodiment of the X-ray optical system used in the X-ray imaging system for micro-lesions according to the present invention.

FIG. 12 is a diagram showing an example of an image captured by the X-ray imaging system for a micro lesion according to the present invention.

FIG. 13 is a diagram in which a microfracture site of the photographed image shown in FIG. 12 is sketched.

14 shows the same object as the subject in FIG.
It is a figure showing the picture picturized by the tube.

FIG. 15 is a model diagram of a microfracture of an open structure type having a crack width of several μm to several tens μm.

FIG. 16 is a model diagram of an interface-structure-type microfracture due to displacement of bone tissue without showing a clear opening.

FIG. 17 is a diagram showing a line profile of a line width of a microfracture image.

FIG. 18 is an overall perspective view showing the concept of an X-ray imaging system for microscopic lesions for animals according to the present invention.

FIG. 19 is a side view of the imaging unit in the X-ray imaging system for microscopic lesions for animals according to the present invention.

FIG. 20 is a front view of an imaging apparatus including a driving unit of the imaging table in the X-ray imaging system for microscopic lesions for animals according to the present invention.

[Brief description of reference numerals]

 REFERENCE SIGNS LIST 1 X-ray source 2 silicon single crystal plate (X-ray optical element) 3 X-ray optical system 4 imaging unit 5 image recording unit 7 X-ray slit 40 subject 41 imaging table 43 subject fixing unit 47 rotation table 50 image recording medium 51 captured image 52 recording medium moving means 80 elevating device 90 rotating device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuyuki Hyodo 2-205-205 Namiki, Tsukuba, Ibaraki (72) Inventor Koi Zhang 4-202-301, Azuma, Tsukuba, Ibaraki (72) Inventor Hiroshi Sugiyama Ibaraki 2-807-309, Azuma, Tsukuba-shi, F F-term (reference) 2H013 AA21 AA30 4C093 AA30 CA04 DA10 EA20 EB02 EB04 EC29 EC34 ED06 ED07 FA16 FA43

Claims (10)

[Claims] 1. Radiation light X having high brightness and high spatial coherence
A source, an X-ray optical system that maintains or enhances the properties of the X-rays, and secures an irradiation field with a uniform X-ray intensity; and X-rays of the irradiation field secured by the X-ray optical system, An X-ray imaging system for a microscopic lesion, comprising: an imaging unit that irradiates an imaging region such as an animal; and an image recording unit that records the imaging region irradiated with X-rays on an image recording medium. 2. An X-ray imaging system for a microscopic lesion according to claim 1, further comprising means for adjusting a distance between a subject fixing portion for fixing an imaging part such as a human body and an animal and an image recording medium. . 3. The X-ray imaging system according to claim 2, wherein the distance adjusting means is provided on an image recording unit side. 4. The apparatus according to claim 1, further comprising an X-ray irradiation direction changing means for performing X-ray irradiation at different incident angles on an imaging part such as a human body or an animal. X-ray imaging system for micro-lesions. 5. It is constituted by one or a plurality of silicon single crystal plates, while maintaining or enhancing the properties of X-rays,
X is characterized by securing an irradiation field with uniform X-ray intensity.
X-ray optical device of X-ray imaging system. 6. The X-ray system according to claim 5, wherein the property of the X-ray is maintained symmetrically by reflecting the X-ray at the same incident angle and the same outgoing angle with respect to the crystal surface of the silicon single crystal. Optical device. 7. The X-ray imaging system according to claim 5, wherein the enhancement of the property of the X-ray is performed such that the X-ray is asymmetrically reflected on the crystal surface of the silicon single crystal at different incidence angles and emission angles. Optical device. 8. When an X-ray optical system is constituted by a plurality of silicon single crystal plates, the incidence planes of the silicon single crystal plates are arranged orthogonal to each other, and the atomic plane of each silicon single crystal plate is X by rotation operation around the normal direction
The size of the radiation field is adjusted.
An X-ray optical device of the X-ray imaging system according to Claim. 9. A single crystal silicon plate for adjusting the horizontal width size and a silicon single crystal plate for adjusting the vertical width size are each composed of a plurality of sheets, and the X-ray incident optical axis and the X-ray output optical axis are aligned. 9. The X-ray optical apparatus according to claim 8, wherein each silicon single crystal plate is arranged. 10. An X-ray imaging system for a small lesion according to claim 1, wherein an X-ray optical system is constituted by the X-ray optical device according to any one of claims 5 to 9.