JP2012143396A - Radiographic grating unit and radiographic system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiographic system reduced in size and improved in quality of phase contract image.SOLUTION: First and second grating units are disposed between an X-ray source and an X-ray image detector. The first and second grating units have the same structures except for their different sizes. The first grating unit includes a grating substrate 30 made of an X-ray transmitting material. The grating substrate 30 is formed with a grating portion 33 formed from a plurality of grooves 33a, a first collective flow passage 34 connected to one end of a grating portion 33, and a second collective flow passage 35 connected to the other end of the grating portion 33. An X-ray absorbing material supplying portion is connected to the first collective flow passage 34, and an X-ray transmitting material supply portion is connected to the second collective flow passage 35. The grating portion 33 functions as a grating for X-rays by being supplied with an X-ray absorbing material in a fluid state from the X-ray absorbing material supplying portion, and functions as an X-ray transmission portion by being supplied with a X-ray transmitting material in a fluid state from the X-ray transmitting material supply portion.

Description

  The present invention relates to a grid unit for radiographic imaging using radiation such as X-rays and a radiographic imaging system.

  When X-rays enter an object, the intensity and phase change due to the interaction. It is known that the X-ray phase change (angle change) is larger than the intensity change. Using this X-ray property, X-ray phase imaging is used to obtain a high-contrast image (hereinafter referred to as a phase contrast image) from a subject having a low X-ray absorption capacity based on the phase change of the X-ray by the subject. There is a lot of research.

  As a kind of X-ray phase imaging, an X-ray imaging system using a Talbot interference effect by a transmission type diffraction grating is known (for example, see Patent Document 1 and Non-Patent Document 1). In this X-ray imaging system, as viewed from the X-ray source, the first grating is arranged behind the subject, and the second grating is arranged downstream from the first grating by the Talbot interference distance. An X-ray image detector that detects an X-ray and generates an image is disposed behind the second grating. The first and second gratings are obtained by alternately arranging X-ray absorbing portions and X-ray transmitting portions that are extended in one direction along an arrangement direction orthogonal to the extending direction. The Talbot interference distance is a distance at which X-rays that have passed through the first grating form a self-image due to the Talbot interference effect. The self-image formed by the Talbot interference effect is modulated by the interaction between the subject and the X-ray.

  In the X-ray imaging system, a fringe image generated by superimposing (intensity modulation) the self-image of the first grating and the second grating is detected by the fringe scanning method, and the object is detected from the change in the fringe image by the subject. Obtain sample phase information. In this fringe scanning method, the second grating is translated relative to the first grating by a predetermined pitch in a direction substantially perpendicular to the grating direction, and an image is taken by the X-ray image detector each time the translation is performed. Is called. An angle distribution of X-rays refracted by the subject is acquired from an intensity change of each pixel value with respect to translation, and a phase contrast image of the subject is obtained based on the angle distribution. This fringe scanning method is also applied to an imaging device using laser light (see, for example, Non-Patent Document 2).

  However, X-ray phase imaging requires multiple times of X-ray irradiation, and subject exposure is a problem, so an X-ray absorption image that only requires one X-ray irradiation is preferred over a phase contrast image There is. Therefore, the first and second gratings can be retracted from between the X-ray source and the X-ray image detector so that the generation of the phase contrast image and the absorption image can be flexibly supported. It has been proposed (see Patent Document 2).

  In the radiation imaging system described in Patent Document 2, the first and second gratings are arranged between the X-ray source and the X-ray image detector when capturing a phase contrast image, and when capturing an absorption image, the first and second gratings are disposed. A grating moving mechanism for retracting the first and second gratings from between the X-ray source and the X-ray image detector is provided.

Japanese Patent No. 4445397 JP 2007-203402 A

C. David, et al., Applied Physics Letters, Vol. 81, No. 17, October 2002, p. 3287 Hector Canabal, et al., Applied Optics, Vol.37, No.26, September 1998, 6227

  However, the radiation imaging system described in Patent Document 2 requires a space for retracting the first and second gratings when capturing an absorption image, and there is a problem that the apparatus becomes large.

  In the radiation imaging system described in Patent Document 2, the first and second gratings retracted for imaging an absorption image are used as an X-ray source and an X-ray image detector for imaging a phase contrast image. If the period is returned during the period, the positional relationship between the X-ray source and the X-ray image detector and the first and second gratings may be shifted. In phase imaging, it is necessary to set at least the distance from the X-ray source to the first grating and the distance between the first and second gratings with high accuracy. The image quality deteriorates.

  An object of the present invention is to provide a radiographic imaging grid unit and a radiographic imaging system that can be miniaturized and prevent deterioration of the image quality of a phase contrast image.

  The lattice unit for radiographic imaging of the present invention includes a radiation transmissive lattice substrate having a lattice portion formed of a plurality of grooves, filling of the lattice portion with a fluid radiation absorbing material, and from the lattice portion. And a medium switching means for selectively discharging the radiation absorbing material. The grating part acts as a grating for radiation when the radiation absorbing material is filled, and acts as a radiation transmitting part when the radiation absorbing material is discharged.

  The medium switching means preferably discharges the radiation absorbing material from the lattice portion by supplying a fluid radiation transmitting material to the lattice portion.

  The grid substrate has a first flow path connected to the medium switching unit at one end of the grid unit, and a second channel connected to the medium switching unit at the other end of the grid unit. It is preferable that a flow path is formed.

  In this case, the medium switching means is connected to the first flow path and supplies the radiation absorbing material to the lattice section, and the medium switching means is connected to the second flow path and connected to the lattice section to the lattice section. It preferably includes a radiation transmitting material supply unit that supplies the radiation transmitting material.

  Furthermore, it is preferable that the radiation absorbing material supply unit and the radiation transmitting material supply unit each include a pressurizing pump and a storage tank.

  Further, the medium switching means is alternately filled with the radiation absorbing material and the radiation transmitting material, one of which is connected to the first flow path and the other is connected to the second flow path. It may be composed of a circulation path and flow means for flowing the radiation absorbing material and the radiation transmitting material.

  The medium switching means includes a container in which the liquid radiation absorbing material is stored, a position where the lattice substrate is immersed in the radiation absorbing material, and the lattice portion serving as the radiation absorbing material. It may consist of elevating means for elevating and lowering from a position not immersed.

  The radiographic imaging system of the present invention includes at least one grating unit, a radiation source that emits radiation toward the grating unit, and a radiation image detector that detects radiation through the grating unit and generates image data. A control unit that controls the medium switching unit of the lattice unit to selectively function the lattice unit as a lattice or a radiation transmission unit; and the radiation unit when the lattice unit of the lattice unit functions as a lattice. Image processing for generating a phase contrast image based on image data obtained by an image detector and generating an absorption image based on the image data obtained by the radiation image detector when the grating portion functions as a radiation transmission portion And a section.

  In addition, it is preferable to provide the 1st grating | lattice unit and 2nd grating | lattice unit which are opposingly arranged as the said grating | lattice unit between the said radiation source and the said radiographic image detector. In this case, the image processing unit includes a scanning unit that moves one of the lattice substrates of the first lattice unit or the second lattice unit to a plurality of positions at a predetermined pitch with respect to the other. It is preferable to generate a phase contrast image based on a plurality of image data obtained by the radiation image detector at each position.

  The grid unit for radiographic imaging of the present invention selectively fills the grid part composed of a plurality of grooves with a fluid radiation absorbing material and discharges the radiation absorbing material from the grid part. Can function as a grating or a radiation transmitting portion, and the conventional grating retracting operation and retracting space are not required, so that the size can be reduced. Further, since the retraction operation is not performed, in the radiographic image capturing system, the positional deviation of the grating is reduced, and the deterioration of the image quality of the phase contrast image is prevented.

It is a schematic diagram which shows the structure of the X-ray image imaging system of 1st Embodiment. It is a perspective view which shows the structure of a lattice board | substrate. It is a top view which shows the structure of the 1st grating | lattice unit which concerns on 2nd Embodiment. It is sectional drawing which shows the structure of the 1st grating | lattice unit which concerns on 3rd Embodiment.

[First Embodiment]
In FIG. 1, the X-ray imaging system 10 includes an X-ray source 11, an imaging unit 12, an image processing unit 13, a console 14, and a system control unit 15. The X-ray source 11 has a rotary anode type X-ray tube and a collimator that limits the X-ray irradiation field, and emits X-rays toward the subject H.

  The imaging unit 12 includes an X-ray image detector 20, a first grating unit 21, a second grating unit 22, and a scanning mechanism 23. The first grating unit 21, the second grating unit 22, and the X-ray image detector 20 are arranged in this order along the z direction that is the X-ray irradiation direction. The scanning mechanism 23 moves the second grating unit 22 stepwise at a predetermined pitch in the x direction, which is one direction orthogonal to the z direction, during phase contrast image capturing (phase imaging).

  A space is provided between the X-ray source 11 and the first lattice unit 21 so that the subject H can be arranged. The X-ray image detector 20 is a flat panel detector composed of a semiconductor circuit, and is arranged behind the second grating unit 22 so that the detection surface is orthogonal to the z direction.

  The first lattice unit 21 includes a lattice substrate 30 made of an X-ray transparent material, an X-ray absorber supply unit 31 connected to one end of the lattice substrate 30, and an X connected to the other end of the lattice substrate 30. It is comprised from the line | wire transparent material supply part 32. FIG. As will be described in detail later, the lattice substrate 30 functions as an absorption lattice for X-rays when a fluid X-ray absorber is supplied from the X-ray absorber supply unit 31. On the other hand, when the lattice substrate 30 is supplied with a fluid X-ray transmission material from the X-ray transmission material supply unit 32 instead of the X-ray absorption material supplied from the X-ray absorption material supply unit 31, a flat plate X-ray transmission part.

  The X-ray absorbing material supply unit 31 includes a storage tank 31a in which the X-ray absorbing material is stored, and a pressure pump 31b that allows the X-ray absorbing material to flow into the lattice substrate 30 through the supply path 31c. When the X-ray transmitting material is supplied from the X-ray transmitting material supply unit 32 to the lattice substrate 30, the pressurizing pump 31b causes the X-ray absorbing material supplied to the lattice substrate 30 to flow backward and return to the storage tank 31a. . At this time, the X-ray absorbing material is pushed by the X-ray transmitting material and returns to the storage tank 31a.

  The X-ray absorber is liquid at normal temperature (for example, the melting point is 0 ° C. or less). As the X-ray absorbing material, mercury (Hg) or a liquid in which X-ray absorbing fine particles are dispersed (for example, a gold colloid solution in which gold colloid particles are dispersed in water or an organic solvent) is used.

  The X-ray transmissive material supply unit 32 includes a storage tank 32a in which the X-ray transmissive material is stored, and a pressure pump 32b that allows the X-ray transmissive material to flow into the lattice substrate 30 via the supply path 32c. When the X-ray absorbing material is supplied from the X-ray absorbing material supply unit 31 to the lattice substrate 30, the pressurizing pump 32b causes the X-ray transmissive material supplied to the lattice substrate 30 to flow backward and return to the storage tank 32a. . At this time, the X-ray transmitting material is pushed by the X-ray absorbing material and returns to the storage tank 32a.

  The X-ray transmitting material is made of a liquid or gas that does not mix and chemically react with the X-ray absorbing material. As the X-ray absorber, a fluorine-based solvent, a liquid such as water or oil, or a gas such as air is used.

  The second grating unit 22 has the same configuration as that of the first grating unit 21, and includes a grating substrate 40, an X-ray absorber supply unit 41, and an X-ray transmissive material supply unit 42. The X-ray absorber supply unit 41 includes a storage tank 41a and a pressure pump 41b. Similarly, the X-ray transmissive material supply unit 42 includes a storage tank 42a and a pressurizing pump 42b. Since the second grid unit 22 has the same configuration as the first grid unit 21 except that the size of the grid substrate 40 is different, detailed description of the second grid unit 22 is omitted.

  The console 14 includes an operation unit that enables selection of a shooting type for which phase contrast image or absorption image is shot, an input of a shooting start instruction, and a display unit that displays an image obtained by shooting. Is provided. The system control unit 15 comprehensively controls each unit of the X-ray imaging system 10 in accordance with an input signal from the operation unit of the console 14.

  The X-ray imaging system 10 controls the pressure pumps 31b and 32b of the first grating unit 21 and the pressure pumps 41b and 42b of the second grating unit 22, respectively. , 40 is supplied with an X-ray absorber so as to function as an absorption grating for X-rays. On the other hand, the X-ray imaging system 10 supplies an X-transmitting material to the lattice substrates 30 and 40 to form an X-ray transmitting portion when capturing an absorption image, and the lattice is between the X-ray source 11 and the X-ray image detector 20. Removed.

  The X-ray imaging system 10 irradiates the X-ray source 11 with X-rays every time the second grating unit 22 is moved in the x direction by a predetermined pitch by controlling the scanning mechanism 23 during imaging of the phase contrast image. The X-ray image detector 20 is caused to perform an X-ray detection operation. On the other hand, the X-ray imaging system 10 causes the X-ray source 11 to perform one X-ray irradiation without moving the second grating unit 22 during imaging of an absorption image, and causes the X-ray image detector 20 to emit X-rays. Perform detection operation.

  At the time of capturing a phase contrast image, the image processing unit 13 uses a plurality of image data generated by the X-ray image detector 20 and generates a phase differential image based on a processing method described in Japanese Patent No. 4445397. The phase contrast image is generated by integrating the phase differential image. On the other hand, when capturing an absorption image, the image processing unit 13 performs a correction process on the image data generated by the X-ray image detector 20 to obtain an absorption image. The phase contrast image or absorption image generated by the image processing unit 13 is displayed on the display unit of the console 14.

  Next, the configuration of the lattice substrates 30 and 40 will be described. In FIG. 2, a lattice portion 33, a first collective flow path 34, and a second collective flow path 35 are formed on the lattice substrate 30. The lattice substrate 30 is made of an X-ray transparent substrate such as silicon. The lattice portion 33, the first collective flow path 34, and the second collective flow path 35 are formed by etching the X-ray transmissive substrate by a known photolithography method.

  The lattice portion 33 includes grooves 33a extending in the y direction perpendicular to the z direction and the x direction, and arranged at a predetermined pitch in the x direction. A first collective flow path 34 is connected to one end of each groove 33a, and a second collective flow path 35 is connected to the other end. The first collective flow path 34 is connected to the supply path 31 c of the X-ray absorber supply unit 31. The second collective flow path 35 is connected to the supply path 32 c of the X-ray transmissive material supply unit 32.

  In addition, a sealing plate 36 is bonded to the lattice substrate 30 with an adhesive or the like so as to cover the lattice portion 33, the first collective flow path 34, and the second collective flow path 35. Similar to the lattice substrate 30, the sealing plate 36 is made of a flat plate-like X-ray transparent substrate such as silicon. The upper portion of each groove 33 a of the lattice portion 33 is sealed by the sealing plate 36.

  When the groove 33a is filled with the X-ray absorbing material from the X-ray absorbing material supply unit 31 through the first collecting flow path 34, the lattice unit 33 functions as an absorption type lattice. On the other hand, when the groove 33a is filled with the X-ray transmitting material from the X-ray transmitting material supply unit 32 through the second collecting flow path 35, the lattice unit 33 becomes an X-ray transmitting unit.

  The width of the grooves 33a in the x direction is about 2 to 20 μm, and the arrangement pitch of the grooves 33a is about twice the width. On the other hand, the pixel size in the x and y directions of the X-ray image detector 20 is about 150 μm. Further, the thickness of the groove 33a in the z direction is about 100 μm in consideration of vignetting of cone-beam X-rays emitted from the X-ray source 11. Although only nine grooves 33a are shown in the drawing, a large number of grooves 33a are actually formed in the lattice portion 33. In order to facilitate the flow of the X-ray absorber, a metal film (for example, Au) may be formed on the side surface and the bottom surface of the groove 33a.

  The lattice substrate 40 has the same configuration as that of the lattice substrate 30 except that the width, arrangement pitch, and thickness of grooves formed in the lattice portion are different. The width and arrangement pitch of the grooves of the lattice substrate 40 are designed so as to substantially match the pattern of the X-ray self-image by the lattice substrate 30.

  Hereinafter, the operation of the X-ray imaging system 10 will be described. First, a shooting type is selected from the operation unit of the console 14. When phase-contrast imaging is selected as the imaging type, the pressure pumps 31b and 41b of the X-ray absorber supply units 31 and 41 are driven, and the X-ray absorber is supplied to the lattice substrates 30 and 40, respectively. The Thereby, the lattice substrates 30 and 40 are configured to have an absorption type lattice in which X-ray absorption portions extending in the y direction are arranged at a predetermined pitch in the x direction. On the other hand, when absorption imaging is selected as the imaging type, the pressure pumps 32b and 42b of the X-ray transmission material supply units 32 and 42 are driven to supply the X-ray transmission material to the lattice substrates 30 and 40, respectively. Is done. Thereby, the lattice substrates 30 and 40 become X-ray transmission parts.

  Next, a shooting start instruction is input from the operation unit of the console 14. When the imaging type is imaging of a phase contrast image, X-ray irradiation is performed by the X-ray source 11 each time the second grating unit 22 is moved by the scanning mechanism 23 by a predetermined pitch in the x direction. Then, the X-ray image detector 20 detects X-rays. Note that the moving pitch of the second grating unit 22 is a value obtained by equally dividing the grating pitch of the absorption grating formed on the grating substrate 40 (for example, dividing into five).

  At this time, the X-ray radiated from the X-ray source 11 causes a phase difference by passing through the subject H. The first periodic pattern reflecting the transmission phase information of the subject H determined from the refractive index of the subject H and the transmitted optical path length by passing the X-rays through the lattice substrate 30 of the first grating unit 21. An image is generated and projected onto the second grating unit 22. The first periodic pattern image may be generated by the Talbot interference effect as described in Japanese Patent No. 4445397, or the geometric pattern as described in Chinese Patent Application Publication No. 101532969. It may be optically generated. Whether or not the Talbot interference effect occurs in the grating substrate 30 depends on the relationship between the wavelength of X-rays and the grating pitch. When the Talbot interference effect does not occur, a first periodic pattern image is generated geometrically.

  The first periodic pattern image is partially shielded by the absorption type grating formed on the grating substrate 40 of the second grating unit 22 so as to be intensity-modulated to become a second periodic pattern image, and X-ray image detection is performed. Detected by the vessel 20. A plurality of image data generated by the X-ray image detector 20 is input to the image processing unit 13, and after a phase differential image is generated, an integration process along the x direction is performed, whereby a phase contrast image is obtained. Generated. This phase contrast image is displayed on the display unit of the console 14.

  On the other hand, when the imaging type is imaging of an absorption image, the second grating unit 22 is not moved, X-ray irradiation is performed only once by the X-ray source 11, and X-ray detection is performed by the X-ray image detector 20. Is done. At this time, since the lattice substrates 30 and 40 of the first and second lattice units 21 and 22 are X-ray transmission parts, the image data generated by the X-ray image detector 20 corresponds to the absorption image. Is. The image data is corrected by the image processing unit 13 and displayed on the display unit of the console 14.

  In the above embodiment, the entire second grating unit 22 is moved by the scanning mechanism 23, but only the grating substrate 40 may be moved. In this case, the supply paths 41c and 42c may be formed of a flexible material such as rubber.

  Moreover, in the said embodiment, although the 2nd grating | lattice unit 22 is moved by the scanning mechanism 23, you may move the 1st grating | lattice unit 21. FIG. In this case as well, it is possible to configure so that only the lattice substrate 30 is moved.

  Moreover, in the said embodiment, although the X-ray absorber supply part 31 and the X-ray transmissive material supply part 32 are provided in the 1st grating | lattice unit 21, when using X-ray transmissive material as gas, such as air, It is possible to provide only the X-ray absorbing material supply unit 31 without providing the X-ray transmitting material supply unit 32.

  In the above embodiment, the X-ray source 11 has a single focal point, but a radiation source grid (multi-slit) for dispersing the focal point may be provided on the exit side of the X-ray source 11. This radiation source grating may have the same configuration as the first and second grating units 21 and 22.

  Moreover, in the said embodiment, although the thickness of the z direction of the groove | channel 33a is set so that the grating | lattice part 33 of the 1st grating | lattice unit 21 may be an absorption type grating | lattice, by reducing this thickness, the grating | lattice part 33 is set. May be a phase-type grating. Further, since the phase type grating has little X-ray absorption, a conventional phase type grating in which an X-ray absorption part is fixedly provided may be used instead of the first grating unit 21.

  Moreover, in the said embodiment, although the phase contrast image was produced | generated based on the fringe scanning method, you may produce | generate a phase contrast image by the Fourier-transform method as described in international publication WO2010 / 050833. In this case, one image data may be acquired by performing X-ray irradiation once while the first and second grating units 21 and 22 are fixed. In the Fourier transform method, a spatial frequency spectrum is obtained by performing Fourier transform on image data, and a phase differential image is obtained by separating the spectrum corresponding to the carrier frequency from this spatial frequency spectrum and performing inverse Fourier transform. A phase contrast image is obtained by integrating the phase differential image. In this case, it is also preferable that the grooves of the lattice portions of the first and second lattice units have a square lattice shape so that a two-dimensional lattice as described in the publication can be configured.

  Further, in the above embodiment, the phase differential image (corresponding to the X-ray phase shift distribution) obtained by integrating the phase differential image is used as the phase contrast image, but the phase differential image may be used as the phase contrast image.

  Further, in the above-described embodiment, the subject H is disposed between the X-ray source 11 and the first lattice unit 21, but the subject H is disposed between the first lattice unit 21 and the second lattice unit 22. You may arrange | position between.

  In the following, other embodiments of the present invention will be described. In the following embodiments, the same reference numerals are used for the same configurations as those already described, and detailed description thereof is omitted. Also in each of the following embodiments, since the second lattice unit has the same configuration as the first lattice unit except that the size of the grid substrate is different, detailed description thereof will be omitted.

[Second Embodiment]
In FIG. 3, the first lattice unit 50 according to the second embodiment includes a lattice substrate 30, a circulation path 51, and a pressure pump 52. As in the first embodiment, a sealing plate (not shown) is bonded to the lattice substrate 30.

  The circulation path 51 has one end connected to the first collective flow path 34 and the other end connected to the second collective flow path 35. The circulation path 51 is alternately filled with a liquid X-ray absorbing material 53 and an X-ray transmitting material 54. The pressurizing pump 52 causes the X-ray absorbing material 53 and the X-ray transmitting material 54 in the circulation path 51 to flow, and alternately supplies the X-ray absorbing material 53 and the X-ray transmitting material 54 to the lattice substrate 30.

  The pressurizing pump 52 is controlled by the system control unit 15. The system control unit 15 controls the pressurization pump 52 according to the imaging type input from the operation unit of the console 14 and selectively supplies the X-ray absorbing material 53 or the X-ray transmitting material 54 to the lattice substrate 30. .

  The first grid unit 50 of this embodiment is only one pressurizing pump 52 and does not require a storage tank, which is advantageous in terms of downsizing and cost reduction.

[Third Embodiment]
In FIG. 4, the first lattice unit 60 according to the third embodiment includes a lattice substrate 61, a container 62, and an elevating mechanism 63. The lattice substrate 61 is an X-ray transparent substrate such as silicon, and a plurality of grooves 61a extending in the y direction are formed at a predetermined pitch in the x direction. The container 62 is made of an X-ray transmissive material such as silicon, like the lattice substrate 61, and is sized to fit and accommodate the lattice substrate 61. A liquid X-ray absorber 64 is stored in the container 62.

  The elevating mechanism 63 elevates and lowers the lattice substrate 61 in the z direction while keeping the surface of the lattice substrate 61 on which the grooves 61 a are formed facing the container 62. FIG. 6A shows a state where the lattice substrate 61 is lifted from the container 62. At this time, the X-ray absorbing material 64 is stored at the bottom of the container 62, and the X-ray absorbing material 64 has a thin and uniform thickness in the z direction. Function as.

  On the other hand, FIG. 5B shows a state where the lattice substrate 61 is lowered and accommodated in the container 62. At this time, the lattice substrate 61 is immersed in the X-ray absorber 64, and the groove 61a is filled with the X-ray absorber 64. Thereby, the lattice substrate 61 functions as an absorption lattice for X-rays. By adjusting the thickness of the groove 61a, the grating substrate 61 can be a phase type grating.

  The lifting mechanism 63 is controlled by the system control unit 15. The system control unit 15 controls the elevating mechanism 63 according to the imaging type input from the operation unit of the console 14 so that the lattice substrate 61 functions as an X-ray transmission unit or a lattice.

  The embodiment described above can be applied not only to a radiographic imaging system for medical diagnosis but also to other radiographic systems such as industrial use and nondestructive inspection. The present invention can also be applied to a scattered radiation removal grating that removes scattered radiation in X-ray imaging. Furthermore, the present invention can also use gamma rays or the like in addition to X-rays as radiation.

DESCRIPTION OF SYMBOLS 21 1st grating | lattice unit 22 2nd grating | lattice unit 30 Lattice board | substrate 31 X-ray absorber supply part 31a Storage tank 31b Pressurization pump 31c Supply path 32 X-ray permeable material supply part 32a Storage tank 32b Pressurization pump 32c Supply path 33 Lattice part 33a Groove 34 First collecting flow path 35 Second collecting flow path 40 Lattice substrate 41 X-ray absorber supply part 41a Storage tank 41b Pressure pump 41c Supply path 42 X-ray transmission material supply part 42a Storage tank 42b Addition Pressure pump 42c supply path

Claims (10)

A radiation transmissive lattice substrate in which a lattice portion composed of a plurality of grooves is formed;
Medium switching means for selectively filling the lattice portion with fluid radiation absorbing material and discharging the radiation absorbing material from the lattice portion;
A grid unit for radiographic imaging, comprising:   2. The radiographic image capturing apparatus according to claim 1, wherein the medium switching unit discharges the radiation absorbing material from the lattice unit by supplying a fluid radiation transmitting material to the lattice unit. Lattice unit.   The lattice substrate has a first flow path connected to the medium switching unit at one end of the lattice unit, and a second flow path connected to the medium switching unit at the other end of the lattice unit. The grating unit for radiographic imaging according to claim 2, wherein:   The medium switching means is connected to the first flow path and supplies the radiation absorbing material to the lattice section. The radiation absorbing material supply section is connected to the second flow path and the radiation transmitting material is connected to the lattice section. The radiation image capturing grid unit according to claim 3, further comprising a radiation transmitting material supply unit that supplies the radiation image.   The radiation image capturing grid unit according to claim 4, wherein the radiation absorbing material supply unit and the radiation transmitting material supply unit each include a pressurizing pump and a storage tank.   The medium switching means is a circulation path in which the radiation absorbing material and the radiation transmitting material are alternately filled, and one is connected to the first flow path and the other is connected to the second flow path. And a radiation means for flowing the radiation absorbing material and the radiation transmitting material.   The medium switching means includes a container in which the liquid radiation absorbing material is stored, a position where the lattice substrate is immersed in the radiation absorbing material, and the lattice portion is not immersed in the radiation absorbing material. The grid unit for radiographic imaging according to claim 1, further comprising elevating means for elevating between the positions. At least one lattice unit constituted by the lattice unit for radiographic imaging according to any one of claims 1 to 7,
A radiation source that emits radiation toward the grating unit;
A radiation image detector for detecting radiation via the lattice unit and generating image data;
A control unit that controls the medium switching unit of the grating unit to selectively function the grating unit as a grating or a radiation transmitting unit;
When the grating unit of the grating unit functions as a grating, a phase contrast image is generated based on image data obtained by the radiation image detector, and when the grating unit functions as a radiation transmission unit, the radiation An image processing unit that generates an absorption image based on image data obtained by an image detector;
A radiographic imaging system comprising:   The radiographic image capturing system according to claim 8, further comprising: a first grating unit and a second grating unit which are disposed to face each other between the radiation source and the radiographic image detector as the grating unit. . Scanning means for moving one of the lattice substrates of the first grating unit or the second grating unit to a plurality of positions at a predetermined pitch with respect to the other;
The radiographic image capturing system according to claim 9, wherein the image processing unit generates a phase contrast image based on a plurality of image data obtained by the radiographic image detector at each position.

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