JP2018146254A - Scintillator panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scintillator panel which is unlikely to be influenced by film thickening, improves luminance and MTF, and further also reduces noise.SOLUTION: The present invention relates to a scintillator panel comprising: a scintillator member having a structure in which a scintillator layer and a non-scintillator layer are installed iteratively substantially in parallel with an incidence direction of a radial ray; and a detector for detecting a light emitted from the scintillator layer by receiving the radial ray. The scintillator panel is characterized in that the scintillator member is provided at an incidence side of the radial ray.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a novel scintillator panel suitable for a Talbot system or the like.

  Currently, in X-ray image diagnosis, an absorption image is used to image attenuation after X-ray transmission through an object. On the other hand, since X-rays are a kind of electromagnetic waves, attention has been paid to this wave nature, and attempts have been made in recent years to image changes in phase after transmission through an X-ray object. These are called absorption contrast and phase contrast, respectively. Since the imaging technique using this phase contrast has higher sensitivity to light elements than conventional absorption contrast, it is considered that the sensitivity to the soft tissue of the human body that contains a large amount thereof is high.

  However, since the conventional phase contrast imaging technique requires the use of a synchrotron X-ray source or a microfocus X-ray tube, the former requires a huge facility, and the latter requires an X-ray sufficient for imaging a human body. Since the dose could not be secured, it was considered difficult to put it to practical use in general medical facilities.

  To solve this problem, X-ray image diagnosis (Talbot system) using an X-ray Talbot-Lau interferometer, which can acquire a phase contrast image using an X-ray source conventionally used in the medical field ) Is expected.

As shown in FIG. 5, the Talbot-Lau interferometer has a G0 grating, a G1 grating, and a G2 grating arranged between the medical X-ray tube and the FPD, and visualizes the refraction of X-rays by the subject as moire fringes. Is. X-rays are irradiated in the vertical direction from the X-ray source arranged at the top, and reach the image detector through G0, the subject, G1, and G2.
As a method for manufacturing a grating, for example, a method is known in which a silicon wafer having a high X-ray permeability is etched to form a grid-shaped recess, and a heavy metal having a high X-ray shielding property is filled therein.

  However, in the above method, it is difficult to increase the area because of the size of an available silicon wafer, restrictions on an etching apparatus, and the like, and the imaging target is limited to a small part. In addition, it is not easy to form a deep recess in a silicon wafer by etching, and it is difficult to uniformly fill the metal with the depth of the recess. Therefore, it is difficult to manufacture a lattice having a thickness sufficient to shield X-rays. is there. For this reason, particularly under high-pressure imaging conditions, X-rays pass through the lattice and a good image cannot be obtained.

Therefore, a slit scintillator that gives a lattice function to the scintillator and emits light in a slit shape has attracted attention.
For example, in “Structured scintillator for x-ray grating interferometry” (Paul Scherrer Institute (PSI)) of Applied Physics Letter 98, 171107 (2011), a phosphor (CsI) is formed in a lattice groove formed by etching a silicon wafer. ) Filled with a lattice shape scintillator.

However, in the above method, since the silicon wafer is used in the same manner as the above-described G2 lattice manufacturing method, the situation that is difficult to achieve due to the limitation of area and thickening, which are problems caused by the silicon wafer, has not been improved. Furthermore, there is a new problem that CsI light emission is attenuated while repeatedly colliding with the wall surface of the silicon lattice and the luminance is lowered. Further, there is still a problem that a high-quality image cannot be obtained because X-rays pass through the lattice under high-pressure imaging conditions.
For this reason, there has been a demand for the appearance of a new scintillator capable of photographing a thick subject without restriction on the photographing part.

  Therefore, the present inventors paid attention to a scintillator having a slit structure composed of a laminate of a scintillator layer and a non-scintillator layer as a scintillator having a lattice shape. A scintillator having a slit structure is configured such that irradiated X-rays emit light in the scintillator layer, while X-rays pass through the non-scintillator layer, and light emission is detected by a sensor.

  However, such a scintillator with a slit structure has a problem in that the non-scintillator layer is alternately present with the scintillator layer, and therefore the amount of the scintillator is usually halved and the luminance is low. In order to increase brightness, it is necessary to increase the thickness of the compartmentalized scintillator itself. However, if the thickness is increased, a structure such as distortion, unevenness, and wavy deformation at the interface between the scintillator layer and the non-scintillator layer when the laminate is manufactured. Fluctuation occurs.

  Since X-rays pass through the non-scintillator layer, noise is generated due to light emission of the scintillator layer that has entered the non-scintillator layer in the structural fluctuation part, the correct signal that is emitted correctly becomes smaller, and the amount of error signal changes As a result, the percentage of false signals increases. In addition, since a radiation source that emits radiation such as X-rays is generally a point wave source, X-rays are incident obliquely, and in a peripheral region, a scintillator that is different from a target position by X-rays obliquely transmitted through a non-scintillator layer. Since the layer also emits light and is incident obliquely, the so-called X-ray vignetting, in which the light emitted from the scintillator layer becomes wider, occurs, and there is a concern that there are few positive signals and large false signals.

  As a scintillator thickening technique, for example, Japanese Patent Laying-Open No. 2006-85175 (Patent Document 1) proposes stacking in the height direction in a partitioned scintillator in which the scintillator is divided into a plurality of partitions by partition walls. ing. In other words, this is a technique for stacking and thickening thin compartmentalized scintillators with few manufacturing errors. However, in the description of Patent Document 1, it takes time to stack with high accuracy, and there is a possibility that deviation occurs during stacking. Furthermore, the problem of X-ray vignetting cannot be avoided even if the thickness is increased.

JP, 2006-85175, A

Applied Physics Letter 98, 171107 (2011)

As described above, when the scintillator having the slit structure is thickened, the MTF is lowered, the manufacturing error is increased, and the X-ray vignetting is increased.
Therefore, an object of the present invention is to provide a scintillator panel that is not easily affected by the increase in film thickness, has high luminance and MTF, and has reduced noise.

  Under such circumstances, the present inventors have intensively studied to solve the above-mentioned problems. As a result, when light is emitted from a scintillator away from the sensor, the above-mentioned problems (structural distortion and point wave source) are increased. It was found that the signal error ratio in the vicinity of the sensor has a dominant influence on the scintillator performance in the Talbot system.

  And the structure of the scintillator panel was reviewed, and it found out that all the said problems could be solved by installing detectors, such as a sensor, in the radiation incident side in a scintillator panel, and came to complete this invention.

The configuration of the present invention is as follows.
[1] A scintillator member having a structure in which the scintillator layer and the non-scintillator layer are repeatedly installed in a direction substantially parallel to the incident direction of radiation, and a detector that detects the light emitted from the scintillator layer upon receiving the radiation. A scintillator panel, wherein the detector is provided on the radiation incident side of the scintillator section.
[2] The scintillator panel according to [1], wherein a thickness of the scintillator member in a radiation incident direction is larger than 50 μm.
[3] The distance between the radiation irradiation device and the scintillator panel is L1, and the distance from the position of the scintillator panel where the radiation is vertically incident from the radiation irradiation device to the end of the scintillator panel where the radiation can be irradiated is a1, The thickness of the scintillator panel in the radiation incident direction is L2, and a pair of scintillator layers and non-scintillator layers of a structure in which the scintillator layer and the non-scintillator layer of the scintillator panel are repeatedly installed in a substantially parallel direction are aligned in a substantially parallel direction. When the thickness is a2,
L2> a2 / a1 × L1
The scintillator panel according to [1], wherein
[4] The scintillator panel according to any one of [1] to [3], wherein a phase contrast image is captured.

  According to the present invention, it is possible to increase the area and thickness of the scintillator, the luminance and MTF are high, and noise due to X-ray vignetting is reduced. The scintillator panel of the present invention can be suitably used for a Talbot system.

For this reason, the scintillator panel of the present invention can perform high-pressure photography, and can also photograph thick subjects such as the chest abdomen, thigh, elbow joint, knee joint, and hip joint.
Conventionally, MRI is the mainstream in image diagnosis of cartilage, and has a drawback in that photographing costs are high and photographing time is long because large equipment is used. On the other hand, according to the present invention, soft tissue such as cartilage, muscle tendon, and ligament and visceral tissue can be copied with a lower cost and speedy X-ray image. Therefore, it can be widely applied to orthopedic diseases such as rheumatoid arthritis and knee osteoarthritis, and image diagnosis of soft tissues such as breast cancer.

It is the schematic of the one aspect | mode of the scintillator panel concerning this invention. It is a schematic block diagram of the Talbot scintillator including the scintillator panel concerning this invention. FIG. 4 is a schematic diagram showing the relationship among thicknesses L1, a1, L2, and a2. It is the schematic of the one aspect | mode which combined the photoelectric conversion element. It is a schematic block diagram of a Talbot scintillator.

The scintillator panel of the present invention will be described.
As shown in FIGS. 1 and 2, the scintillator panel according to the present invention has a scintillator layer having a function of emitting light upon receipt of X-rays and a non-scintillator layer that are repeated in a direction substantially parallel to the incident direction of radiation. A laminated scintillator member having a laminated structure and a detector for detecting light emitted from the scintillator layer upon receiving radiation, wherein the detector is installed on the radiation incident side of the scintillator panel. And The light emitted from the scintillator due to radiation can be converted into an electric signal via a detector to obtain a digital image.

The term “substantially parallel” means substantially parallel, and it is included in the category of substantially parallel even if it is completely parallel or has a slight inclination.
The thickness in the direction perpendicular to the incident direction of the pair of scintillator layers and the non-scintillator layer, that is, the thickness in the stacking direction (hereinafter referred to as stacking pitch), and the ratio of the thickness in the stacking direction of the scintillator layer and the non-scintillator layer ( Hereinafter, the duty ratio) is derived from the Talbot interference condition, but in general, the stacking pitch is preferably 0.5 to 50 μm, and the duty ratio is preferably 30/70 to 70/30. In order to obtain a diagnostic image having a sufficient area, the number of repeated laminations of the lamination pitch is preferably 1,000 to 500,000.

The thickness of the scintillator member constituting the scintillator panel according to the present invention is defined by the following mode.
As one aspect, it is preferable that the thickness of the scintillator member in the radiation incident direction is larger than 50 μm.

  With a thin film having a thickness of 50 μm or less, the resulting scintillator panel has less noise but lower brightness. The effect of providing the detector on the incident side is not significantly different from the effect of providing the detector on the output side. On the other hand, if the thickness is greater than 50 μm, the luminance can be increased. As the film thickness increases, noise increases. However, in the present invention, since the detector is provided on the incident side, the influence of noise can be reduced and the number of positive signals can be increased. The photodetector does not affect the irradiated X-rays and can transmit X-rays.

Further, as one embodiment, as shown in FIG. 3, the shortest distance (imaging distance) perpendicularly incident between the radiation irradiation apparatus and the scintillator panel is L1, and the scintillator panel in which the radiation is perpendicularly incident from the radiation irradiation apparatus. The distance from the position to the end of the scintillator panel where radiation can be irradiated is a1, the thickness of the scintillator panel in the radiation incident direction is L2, and the direction perpendicular to the incident direction of the pair of scintillator layers and the non-scintillator layer When the combined thickness (lamination pitch) is a2,
L2> a2 / a1 × L1
It is characterized by satisfying.

In FIG. 3, when θ1> θ2, the scintillator layer not irradiated with X-rays emits light.
tan θ1> tan θ2
a1 / L1> a2 / L2
L2> a2 / a1 × L1
That is, noise is generated when the film thickness (L2) of the scintillator portion is larger than a2 / a1 × L1, but since the detector is provided on the incident side as in the present invention, the influence of noise can be reduced, and a positive signal is generated. Can do a lot. The photodetector does not affect the irradiated X-rays and can transmit X-rays.

  By combining the scintillator member having such a thickness and the arrangement of the detector on the light source side, it is possible to increase the thickness in the present invention, the manufacturing error itself is small, and the X-ray vignetting is very small. Therefore, it is possible to obtain a scintillator panel that is not easily affected by the increase in thickness, has high luminance and MTF, and has reduced noise.

Scintillator member The scintillator layer in the present invention is a layer containing scintillator as a main component, and preferably contains scintillator particles.
As the scintillator according to the present invention, a substance capable of converting radiation such as X-rays into different wavelengths such as visible light can be appropriately used. Specifically, scintillators and phosphors described on pages 284 to 299 of “Phosphor Handbook” (Edited by Fluorescent Materials Association, Ohmsha, 1987), and the website of Lawrence Berkeley National Laboratory, USA Although the substances described in “Scintillation Properties (http://scintillator.lbl.gov/)” can be considered, even if the substance is not pointed out here, “radiation such as X-rays is converted into different wavelengths such as visible light” Any substance that can be used can be used as a scintillator.

Specific examples of the scintillator composition include the following examples. First,
Basic composition formula (I): M _I X · aM _II X ′ ₂ · bM _III X ″ ₃ : zA
And metal halide phosphors represented by the formula:

In the basic composition formula (I), M _I is an element that can be a monovalent cation, that is, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), thallium. It represents at least one selected from the group consisting of (Tl) and silver (Ag).

M _II is an element that can be a divalent cation, that is, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), nickel (Ni), copper (Cu), It represents at least one selected from the group consisting of zinc (Zn) and cadmium (Cd).

M _III represents at least one selected from the group consisting of scandium (Sc), yttrium (Y), aluminum (Al), gallium (Ga), indium (In), and elements belonging to lanthanoids.

X, X ′, and X ″ each represent a halogen element, but each may be a different element or the same element.
A is composed of Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Ag (silver), Tl and Bi (bismuth). Represents at least one element selected from the group;
a, b and z each independently represent a numerical value within the range of 0 ≦ a <0.5, 0 ≦ b <0.5, and 0 <z <1.0.

Also,
Also included are rare earth activated metal fluorohalide phosphors represented by the basic composition formula (II): M _II FX: zLn.
In the basic composition formula (II), M _II represents at least one alkaline earth metal element, Ln represents at least one element belonging to the lanthanoid, and X represents at least one halogen element. Z is 0 <z ≦ 0.2.

Also,
Basic composition formula (III): Ln ₂ O ₂ S: zA
And rare earth oxysulfide phosphors.

In the basic composition formula (III), Ln is at least one element belonging to the lanthanoid, A is Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, At least one element selected from the group consisting of Lu, Na, Mg, Cu, Ag (silver), Tl and Bi (bismuth) is represented. Z is 0 <z <1.
In particular, Gd ₂ O ₂ S using gadolinium (Gd) as Ln emits high light in a wavelength region where the sensor panel is most likely to receive light by using terbium (Tb), dysprosium (Dy), etc. as the element species of A. This is preferred because it is known to exhibit properties.

Also,
Basic formula _{(IV): M II S:} zA
The metal sulfide type fluorescent substance represented by these is also mentioned.
In the basic composition formula (IV), M _II is selected from the group consisting of elements that can be divalent cations, ie, alkaline earth metals, Zn (zinc), Sr (strontium), Ga (gallium), and the like. At least one element, A is Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Ag (silver), Tl And at least one element selected from the group consisting of Bi (bismuth). Z is 0 <z <1.

Also,
Basic composition formula (V): M _IIa (AG) _b : zA
And metal oxoacid salt phosphors represented by the formula:
In the basic composition formula (V), _MII is a metal element that can be a cation, and (AG) is a group consisting of phosphate, borate, silicate, sulfate, tungstate, and aluminate. At least one oxo acid group selected from the group consisting of A, Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Each represents at least one element selected from the group consisting of Ag (silver), Tl, and Bi (bismuth).

A and b represent all possible values depending on the valence of the metal and oxo acid group. z is 0 <z <1.
Also,
Basic composition formula (VI): M _a O _b : zA
The metal oxide fluorescent substance represented by these is mentioned.

In the basic composition formula (VI), M represents at least one element selected from metal elements that can be cations.
A is composed of Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Ag (silver), Tl and Bi (bismuth). Each represents at least one element selected from the group.

A and b represent all possible values depending on the valence of the metal and oxo acid group. z is 0 <z <1.
In addition,
Basic composition formula (VII): LnOX: zA
And metal acid halide phosphors represented by the formula:

  In the basic composition formula (VII), Ln represents at least one element belonging to the lanthanoid, X represents at least one halogen element, A represents Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb. , Dy, Ho, Er, Tm, Yb, Lu, Na, Mg, Cu, Ag (silver), Tl, and Bi (bismuth), each represents at least one element. Z is 0 <z <1.

  The average particle diameter of the scintillator particles is selected according to the thickness of the scintillator layer in the stacking direction, and is preferably 100% or less, more preferably 90% or less, with respect to the thickness of the scintillator layer in the stacking direction. When the average particle diameter of the scintillator particles exceeds the above range, the disturbance of the stacking pitch becomes large and the Talbot interference function is lowered.

  The content of scintillator particles in the scintillator layer is preferably 30 vol% or more, more preferably 50 vol% or more, and further preferably 70 vol% or more in consideration of the light emission characteristics.

  The non-scintillator layer in the present invention is a layer that does not contain a scintillator as a main component, and the content of the scintillator in the non-scintillator layer is less than 10 vol%, preferably less than 1 vol%, most preferably 0 vol%. preferable.

  The non-scintillator layer preferably contains various types of glass, polymer materials, metals, and the like as main components. These may be used alone or in combination as a composite.

Specifically, plate glass such as quartz, borosilicate glass and chemically tempered glass; ceramic such as sapphire, silicon nitride and silicon carbide;
Semiconductors such as silicon, germanium, gallium arsenide, gallium phosphide, gallium nitrogen;
Polyesters including polyethylene terephthalate (PET) and polyethylene naphthalate and (PEN), aliphatic polyamides such as nylon, aromatic polyamides (aramid), polyimides, polyamideimides, polyetherimides, polyethylene, polypropylene, polycarbonates, Polymers such as triacetate, cellulose acetate, epoxy, bismaleimide, polylactic acid, polyphenylene sulfide, polyethersulfone and other sulfur-containing polymers, polyetheretherketone, fluororesin, acrylic resin, polyurethane;
Carbon fiber, glass fiber, etc. (especially fiber reinforced resin sheet containing these fibers)
Metal foils such as aluminum, iron and copper, and bionanofiber containing chitosan and cellulose can be used.

  The non-scintillator layer is preferably a polymer film from the viewpoint of handling in production. If the non-scintillator layer is not transmissive, the MTF is good and light diffusion can be suppressed, but light absorption occurs (even during reflection, particularly in the case of a metal reflection layer), brightness is increased. Becomes lower. On the other hand, when the non-scintillator layer is made transparent, the luminance is good, but MTF is insufficient due to light diffusion to the adjacent slits.

Further, at least one functional layer having optical characteristics different from those of the scintillator layer and the non-scintillator layer may be provided in the arrangement structure of the scintillator layer and the non-scintillator layer.
The functional layer is provided between the scintillator layers. However, the functional layer does not constitute a partial laminate in place of the non-scintillator layer, and is provided at a predetermined pitch according to the purpose, even if it is composed of one layer, it is composed of two or more layers. Also good.

The functional layer is not particularly limited as long as it has optical characteristics different from those of the scintillator layer and the non-scintillator layer, and a plurality of functional layers having different functions may be provided.
For example, examples of the functional layer include a diffusion prevention layer in which light does not easily pass through, a reflection layer in which light is highly reflected, and a light absorption layer that absorbs light.

Such a functional layer is made of various materials according to the purpose, for example, a resin mixed with nanoparticles for adjusting the reflectance.
The nanoparticles to be used are particles having a particle size of approximately nano-order, and they are used without particular limitation whether they are inorganic particles or organic particles.

Examples of the particles include inorganic oxides, inorganic nitrides, metal salt particles such as carbonates, sulfates, and chlorides. For example, TiO ₂ (anatase type, rutile type), MgO, PbCO ₃ · Pb (OH) ₂ , BaSO ₄ , Al ₂ O ₃ , M (II) FX (where M (II) is Ba, Sr and Ca X is Cl atom or Br atom), CaCO ₃ , ZnO, Sb ₂ O ₃ , SiO ₂ , ZrO ₂ , lithopone [BaSO ₄ .ZnS], magnesium silicate, White pigments such as basic silicic acid sulfate, basic lead phosphate, and aluminum silicate can be used. Further, as the nanoparticles, glass beads, resin beads, hollow particles having hollow portions in the particles, multi-hollow particles having many hollow portions in the particles, porous particles, and the like can also be used. These substances may be used alone or in combination of two or more.

  Furthermore, the functional layer may be composed of a metal, and examples of the metal include Al, Ag, Cr, Cu, Ni, Ti, Mg, Rh, Pt, and Au. These metals may constitute the functional layer alone, or a particulate metal may be included in the functional layer.

  The functional layer may contain a pigment, for example, a black colorant that easily absorbs light. As such a black colorant, for example, carbon black or titanium black can be used. Titanium black is blackened by removing part of oxygen from titanium dioxide.

  The resin constituting the functional layer by mixing with the particles is not particularly limited as long as it functions as a binder and can achieve a predetermined reflectance, and specifically, an easily adhesive polymer such as polyurethane, Vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, butadiene-acrylonitrile copolymer, polyamide resin, polyvinyl butyral, polyester, cellulose derivative ( Nitrocellulose, etc.), styrene-butadiene copolymers, various synthetic rubber resins, phenol resins, epoxy resins, urea resins, melamine resins, phenoxy resins, silicone resins, acrylic resins, urea formamide resins, and the like. Of these, polyurethane, polyester, silicone resin, acrylic resin, and polyvinyl butyral are preferable. These binders may be used alone or in combination of two or more.

The mixing ratio of the nanoparticles and the resin contained in the functional layer is not particularly limited as long as the reflectance is within a predetermined range.
Furthermore, as another aspect of the functional layer, the refractive index of the functional layer may be smaller than the refractive index of the main component of the scintillator layer, and may be totally reflected when light enters the functional layer from the scintillator layer. Good. Such a functional layer may be composed of an inorganic material such as silica or MgF ₂ , and may further be an air layer or a liquid layer (including a gelled product). In particular, when the reflectance cannot be defined, such as air or liquid, the functional layer can be defined by the refractive index. The functional layer in this embodiment is preferably an air layer.

  The scintillator member according to the present invention is manufactured by laminating a scintillator layer and a non-scintillator layer and joining the scintillator layer and the non-scintillator layer. Bonding in the present invention refers to bonding and integrating a scintillator layer and a non-scintillator layer. As a bonding method, both can be bonded through an adhesive layer, but an adhesive resin is previously contained in a scintillator layer or a non-scintillator layer, and the adhesive layer is bonded by pressing them together. Joining without interposition is preferable from the viewpoint of process simplification. In addition, heating in a pressurized state is more preferable because the substance having adhesiveness is melted or cured and the adhesion becomes strong. Further, it is possible to coat the surface of the non-scintillator layer with a composition capable of forming a scintillator layer, or to join the scintillator layer and the non-scintillator layer by further removing the solvent as necessary. When the scintillator layer and the non-scintillator layer are joined, the scintillator member according to the present invention can be configured by providing a functional layer on the scintillator layer and bonding it to another scintillator layer.

When the functional layer is an air layer or a liquid layer, a spacer is placed on the edge of the scintillator layer to provide a predetermined gap, and air or a predetermined liquid may be filled.
The adhesive resin may be contained in any of the scintillator layer and the non-scintillator layer, but it is particularly preferable that the scintillator layer contains an adhesive resin as a binder for the scintillator particles. The adhesive resin is preferably a material that is transparent to the light emission wavelength of the scintillator so as not to inhibit the light emission propagation of the scintillator.

  The adhesive resin is not particularly limited as long as the object of the present invention is not impaired. For example, proteins such as gelatin, polysaccharides such as dextran, or natural polymer substances such as gum arabic; and polyvinyl butyral and polyacetic acid Vinyl, nitrocellulose, ethyl cellulose, vinylidene chloride / vinyl chloride copolymer, poly (meth) acrylate, vinyl chloride / vinyl acetate copolymer, polyurethane, cellulose acetate butyrate, polyvinyl alcohol, polyester, epoxy resin, polyolefin resin, polyamide resin, etc. Synthetic polymer materials. In addition, these resins may be crosslinked by a crosslinking agent such as epoxy or isocyanate, and these adhesive resins may be used alone or in combination of two or more. The adhesive resin may be either a thermoplastic resin or a thermosetting resin.

  The content of the adhesive resin in the scintillator layer is preferably 1 to 70 vol%, more preferably 5 to 50 vol%, and still more preferably 10 to 30 vol%. If it is lower than the lower limit of the range, sufficient adhesion cannot be obtained. Conversely, if it is higher than the upper limit of the range, the content of the scintillator is insufficient and the light emission amount is reduced.

  As a method for forming the scintillator layer, a composition in which the scintillator particles and the adhesive resin are dissolved or dispersed in a solvent may be coated, or the mixture containing the scintillator particles and the adhesive resin is heated and melted. The composition may be coated.

  Examples of solvents that can be used when coating a composition in which the scintillator particles and the adhesive resin are dissolved or dispersed in a solvent include lower alcohols such as methanol, ethanol, isopropanol, and n-butanol, acetone, methyl ethyl ketone, and methyl isobutyl ketone. , Ketones such as cyclohexanone, aromatic compounds such as toluene, benzene, cyclohexane, cyclohexanone, xylene; esters of lower fatty acids and lower alcohols such as methyl acetate, ethyl acetate, n-butyl acetate, dioxane, ethylene glycol monoethyl ether, Ethers such as ethylene glycol monomethyl ether, methoxypropanol propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, benzenetriol, Halogenated hydrocarbons such as methylene chloride and ethylene chloride, and mixtures thereof. The composition includes a dispersant for improving the dispersibility of the scintillator particles in the composition, and a curing for improving the bonding force between the adhesive resin and the scintillator particles in the scintillator layer after formation. Various additives such as an agent and a plasticizer may be mixed.

Examples of the dispersant used for such purpose include phthalic acid, stearic acid, caproic acid, lipophilic surfactant and the like.
Examples of plasticizers include phosphate esters such as triphenyl phosphate, tricresyl phosphate, diphenyl phosphate; phthalate esters such as diethyl phthalate and dimethoxyethyl phthalate; ethyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, etc. Examples include glycolic acid esters; polyesters of triethylene glycol and adipic acid, polyesters of polyethylene glycol and aliphatic dibasic acids such as polyesters of diethylene glycol and succinic acid, and the like. As the curing agent, a known curing agent for the thermosetting resin can be used.

Alternatively, a functional layer prepared by applying and drying on a transfer substrate in advance may be transferred and provided on the scintillator layer.
When a metal thin film is provided as a functional layer, a metal such as Ag, Al, Ni, or Cr may be formed by vapor deposition or sputtering. A metal thin film prepared in advance may be transferred.

  When coating the mixture containing the scintillator particles and the adhesive resin by heating and melting, it is preferable to use a hot melt resin as the adhesive resin. As the hot melt resin, for example, a resin mainly composed of polyolefin, polyamide, polyester, polyurethane, or acrylic resin can be used. Among these, those containing a polyolefin resin as a main component are preferred from the viewpoints of light transmittance, moisture resistance and adhesiveness. Examples of polyolefin resins include ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-acrylic acid ester copolymer (EMA), and ethylene-methacrylic acid copolymer ( EMAA), ethylene-methacrylic acid ester copolymer (EMMA), ionomer resin and the like can be used. In addition, you may use these resin as what is called a polymer blend combining 2 or more types.

  The coating means for the composition for forming the scintillator layer is not particularly limited, but a normal coating means such as a doctor blade, roll coater, knife coater, extrusion coater, die coater, gravure coater, lip coater, capillary A general system such as a formula coater, bar coater, dip, spray, or spin can be used.

The scintillator portion according to the present invention is configured by a step of repeatedly laminating a scintillator layer and a non-scintillator layer and then bonding them together.
There are no particular restrictions on the method of repeatedly laminating the scintillator layer and the non-scintillator layer, but the separately formed scintillator layer and non-scintillator layer are each divided into a plurality of sheets and then alternately laminated repeatedly. Also good.

  Further, in the present invention, after creating a plurality of partial laminates in which the scintillator layer and the non-scintillator layer are joined, the plurality of partial laminates are laminated to form the laminate. And the thickness is easy to adjust.

  For example, a partial laminate including a pair of scintillator layers and a non-scintillator layer may be formed in advance, and the partial laminate may be divided into a plurality of sheets and repeatedly laminated. At this time, a desired functional layer may be separately provided in any one of the layers and laminated so as to be arranged at an appropriate interval.

  If the partial laminated body which consists of a scintillator layer and a non-scintillator layer is a film shape which can be wound, it will become possible to laminate | stack efficiently by winding on a core. The winding core may be cylindrical or flat. More efficiently, the repetitive laminate of the scintillator layer and the non-scintillator layer produced by the above method may be joined (integrated) by pressing, heating, etc., and then divided into a plurality of sheets and repeatedly laminated.

Further, when laminating the partial laminate, a functional layer may be provided so as to have a predetermined layer interval.
There are no particular restrictions on the method for forming the partial laminate comprising the scintillator layer and the non-scintillator layer, but a polymer film is selected as the non-scintillator layer, and a composition containing scintillator particles and an adhesive resin is coated on one side. Thus, a scintillator layer may be formed. Moreover, you may coat the composition containing scintillator particle | grains and adhesive resin on both surfaces of a polymer film.

  As described above, when the partial laminate is formed by coating a composition containing scintillator particles and an adhesive resin on a polymer film, the process can be simplified and division into a plurality of sheets is facilitated. . The dividing method is not particularly limited, and a normal cutting method is selected.

  Alternatively, a transfer substrate previously coated with a scintillator layer may be transferred onto a film composed of a non-scintillator layer. The transfer substrate is desorbed by means such as peeling as necessary.

  In this invention, the said scintillator layer and the said non-scintillator layer are joined by pressing the said laminated body so that the said scintillator layer and the said non-scintillator layer may become a substantially parallel direction with respect to the incident direction of a radiation.

By heating a repeatedly laminated body of a plurality of scintillator layers and non-scintillator layers in a state of being pressurized to a desired size, the lamination pitch can be adjusted to a desired value.
There is no particular limitation on the method of pressurizing a laminate of a plurality of scintillator layers and non-scintillator layers to a desired size, but a spacer such as a metal is used in advance so that the laminate is not compressed beyond the desired size. It is preferable to pressurize in a state where is provided. The pressure at that time is preferably 1 MPa to 10 GPa. If the pressure is lower than the lower limit of the above range, the resin component contained in the laminate may not be deformed to a predetermined size. If the pressure is higher than the upper limit of the above range, the spacer may be deformed, and the laminate may be compressed to a desired size or more. The bonding can be made stronger by heating the laminate in a pressurized state.

  The condition for repeatedly heating a laminated body of a plurality of scintillator layers and non-scintillator layers depends on the type of resin, but at a temperature above the glass transition point for thermoplastic resins and at a temperature above the curing temperature for thermosetting resins, both It is preferable to heat for about 0.5 to 24 hours. In general, the heating temperature is preferably 40 ° C to 250 ° C. If the temperature is lower than the lower limit of the above range, there may be insufficient resin fusing or curing reaction, and there is a risk of poor bonding or return to the original dimensions when the compression is released. If the temperature is higher than the upper limit of the above range, the resin may be altered and the optical properties may be impaired. There are no particular restrictions on the method of heating the laminated body while applying pressure, but a press machine equipped with a heating element may be used, or the laminated body is sealed in a box-shaped jig so as to have a predetermined size. It may be heated in an oven, or a heating element may be attached to a box-shaped jig.

As the state before the repeated laminate of a plurality of scintillator layers and non-scintillator layers is pressurized, there is a void in the scintillator layer, in the non-scintillator layer, or in the interface between the scintillator layer and the non-scintillator layer. It is preferable. If pressure is applied in the absence of any voids, part of the material will flow out from the end face of the stack and the stacking pitch will be disturbed, or it may return to its original dimensions when pressure is released. is there. If there is a gap, the gap becomes a cushion even when pressurized, and the laminate can be adjusted to any size within the range until the gap becomes zero, that is, the lamination pitch can be set to any value. Can be adjusted. The porosity is calculated from the following equation using the measured volume (area × thickness) of the laminate and the theoretical volume (weight ÷ density) of the laminate.
(Measured volume of laminate-theoretical volume of laminate) ÷ theoretical volume of laminate x 100
If the area of the laminate is constant, the porosity is calculated from the following equation using the measured thickness of the laminate and the theoretical thickness (weight ÷ density ÷ area) of the laminate.
(Measured thickness of laminate-theoretical thickness of laminate) ÷ theoretical thickness of laminate x 100

The porosity of the scintillator layer after heating is preferably 30 vol% or less. When the above range is exceeded, the filling rate of the scintillator is lowered and the luminance is lowered.
As a means for providing a void in the scintillator layer or non-scintillator layer, for example, bubbles may be included in the layer during the production process of the scintillator layer or non-scintillator layer, or hollow polymer particles may be added. . On the other hand, even when there are irregularities on the surface of the scintillator layer or the non-scintillator layer, a void is formed at the contact interface between them, and the same effect can be obtained. As a means for providing unevenness on the surface of the scintillator layer or non-scintillator layer, for example, unevenness treatment such as blasting or embossing may be applied to the surface of the layer, or by adding a filler in the layer, Unevenness may be formed. When a scintillator layer is formed by coating a composition containing scintillator particles and an adhesive resin on a polymer film, irregularities are formed on the surface of the scintillator layer, and voids may be provided at the contact interface with the polymer film. I can do it. The size of the unevenness can be arbitrarily adjusted by controlling the particle size and dispersibility of the filler.

  In the present invention, when the radiation incident side of the scintillator member is the first surface and the side facing the first surface is the second surface, the stacking pitch of the scintillator layer and the non-scintillator layer on the second surface is the first surface. It may be larger than the stacking pitch of the scintillator layer and the non-scintillator layer. Specifically, the scintillator member panel is curved, or the scintillator member panel has an inclined structure (also referred to as an inclined scintillator) without being bent. By adopting such a configuration, it is possible to solve the problem of so-called vignetting in which X-rays in the peripheral region of the scintillator member are not sufficiently transmitted by radiation due to oblique incidence.

  In the above laminated scintillator member, in order to maintain the laminated structure as necessary, the surface on the radiation incident side, the opposite surface, or both surfaces may be bonded and held on the support. Good. Further, the detector substrate provided on the incident side can also serve as a support.

  As the support, various types of glass that can transmit radiation such as X-rays, polymer materials, metals, and the like can be used. For example, plate glass such as quartz, borosilicate glass, chemically tempered glass, Ceramic substrates such as sapphire, silicon nitride and silicon carbide, semiconductor substrates such as silicon, germanium, gallium arsenide, gallium phosphide and gallium nitrogen (photoelectric conversion panels), cellulose acetate film, polyester film, polyethylene terephthalate film, polyamide film, polyimide Film, triacetate film, polymer film such as polycarbonate film (plastic film), metal sheet such as aluminum sheet, iron sheet, copper sheet, or metal sheet having a coating layer of the metal oxide, carbon fiber reinforced resin ( FRP) sheet, such as amorphous carbon sheet can be used. The thickness of the support is preferably 50 μm to 2,000 μm, and more preferably 50 to 1,000 μm.

Among these, a glass plate or a polymer material is preferable, a polymer material is more preferable from the viewpoint of easy bending, and a resin film made of a polymer material is particularly preferable.
The elastic modulus of the material of the support is usually 0.1 to 300 GPa, preferably 1 to 200 GPa. Here, the "elastic modulus" is a value obtained by using a tensile tester and obtaining the slope of the stress relative to the strain amount in a region where the strain indicated by the standard line of the test piece and the corresponding stress have a linear relationship. It is. This is a value called Young's modulus, and in this specification, this Young's modulus is defined as elastic modulus.

  When bending, specifically, a resin film having an elastic modulus of 1 to 20 GPa is preferable. When the elastic modulus of the material of the support is in the above range, the support can stably hold the scintillator member.

  Examples of the polymer material constituting the resin film include polyethylene naphthalate (6 to 8 GPa), polyethylene terephthalate (3 to 5 GPa), polycarbonate (1 to 3 GPa), polyimide (6 to 8 GPa), and polyetherimide (2 -4 GPa), aramid (11-13 GPa), polysulfone (1-3 GPa), polyethersulfone (1-3 GPa), etc. (in parentheses indicate elastic modulus). The value of the elastic modulus can vary depending on the form of the resin film. Therefore, the elastic modulus is not necessarily the value in parentheses, but an example is shown as a guide.

  Although there is no specific designation for the method of bonding the scintillator member and the support, for example, an adhesive, a double-sided tape, a hot melt sheet, or the like can be used. After the scintillator member is bonded to the support, the surface opposite to the joint surface may be flattened.

  A layer that reflects or absorbs light emitted from the scintillator may be provided between the scintillator member and the support, depending on the intended use. Brightness is improved by providing a layer that reflects light emitted from the scintillator, and sharpness is improved by providing a layer that absorbs light emitted by the scintillator. The support itself may have a function of reflecting or absorbing the light emitted from the scintillator.

Detector In the present invention, a detector for detecting light emitted from the scintillator layer upon receiving radiation is provided on the radiation incident side of the scintillator member.
In the detector, X-rays from the outside are converted into light by the scintillator layer, and this light is converted into an electric signal by the detector, and can be output to the outside in a form associated with position information. The

  The shape of the detector is not particularly limited as long as it has a function of absorbing the generated light and converting it into a charge shape. The shape may be flat or curved depending on the shape of the scintillator member. Also, the shape may be a waveform.

  The detector used in the present invention has a role of converting light into an electrical signal and outputting it to the outside. If a conventionally known one can be used, its configuration is not particularly limited, but usually The substrate, the image signal output layer, and the photoelectric conversion element are stacked in this order.

  Among these, the photoelectric conversion element has a function of absorbing light generated in the scintillator layer and converting it into a charge form. Here, the photoelectric conversion element may have any specific structure as long as it has such a function. For example, the photoelectric conversion element used in the present invention can be composed of a transparent electrode, a charge generation layer that is excited by incident light to generate charges, and a counter electrode. Any of these transparent electrodes, charge generation layers, and counter electrodes may be conventionally known ones. The photoelectric conversion element used in the present invention may be composed of an appropriate photosensor. For example, the photoelectric conversion element may be a two-dimensional arrangement of a plurality of photodiodes, or a CCD ( It may be composed of a two-dimensional photosensor such as a charge coupled device (CMOS) or a complementary metal-oxide-semiconductor (CMOS) sensor. Since these transmit X-rays, they do not affect the light emission of the scintillator even if they are provided on the irradiation side.

  In order to reduce the optical loss at the interface between the detector and the scintillator member, it is preferable that the refractive index is bonded with a transparent material exceeding 1.0 (air). There is no particular designation for the method of joining the laminated scintillator panel and the photoelectric conversion panel, but for example, an adhesive, a double-sided tape, a hot melt sheet, or the like can be used.

Example of photoelectric conversion element
As an example of the photoelectric conversion element, a planar light receiving element is described in JP-A-2015-230175. For example, as shown in FIG. 4, a plurality of light receiving elements are arranged in a two-dimensional manner, such as a TFT active matrix substrate (hereinafter referred to as “TFT substrate”) in which a thin film transistor (TFT) 70 and a storage capacitor 68 are formed on an insulating substrate 64. It has a configuration arranged in a dimension. Specifically, it is incorporated in AeroDR (manufactured by Konica Minolta Co., Ltd.), PaxScan (FPD: 2520 manufactured by Varian Co., Ltd.) and the like.

  The insulating substrate 64 can also serve as a support for the above-described scintillator member. In addition, when the element itself is curved in order to follow the inclined structure or curvature of the scintillator member, a glass plate or a polymer is used. A material is preferable, and a polymer material, particularly a resin film is preferable from the viewpoint of easy bending, and a polyimide film is particularly preferable from the viewpoint of heat resistance.

  The elastic modulus of the planar light receiving element is usually 0.1 to 300 GPa, preferably 1 to 200 GPa, more preferably 1 to 20 GPa. The definition of “elastic modulus” is as already described in the section of the support.

  The thickness of the planar light receiving element is usually 1 to 1,000 μm, preferably 10 to 500 μm, and more preferably 10 to 200 μm. When the thickness of the planar light receiving element is within the above range, when the planar light receiving element and the scintillator member are joined, even if the material is a glass or metal having a large elastic modulus, the planar light receiving element has the shape of the scintillator member. Since it can be effectively bent together, the planar light receiving element and the scintillator member can be joined so that the distance through the adhesive layer is uniform in the plane.

  The TFT substrate 66A is formed with a sensor portion 72 that generates charges when the light converted by the scintillator member 71 is incident thereon. In FIG. 4, in the TFT substrate 66A, the TFT 70 and the sensor unit 72 are formed so as to overlap each other. Thereby, the light receiving area of the light from the scintillator member 71 in the sensor unit 72 can be increased. A flattening layer 67 for flattening the TFT substrate 66A is formed on the TFT substrate 66A. An adhesive layer 69 for bonding the scintillator member 71 to the TFT substrate 66A is formed between the TFT substrate 66A and the scintillator member 71 and on the planarizing layer 67.

The sensor unit 72 includes an upper electrode 72A, a lower electrode 72B, and a photoelectric conversion film 72C disposed between the upper and lower electrodes.
The upper electrode 72A and the lower electrode 72B are formed using a highly light-transmitting material such as ITO (indium tin oxide) or IZO (zinc indium oxide), and have light transmittance.

  The photoelectric conversion film 72 </ b> C absorbs light emitted from the scintillator member 71 and generates a charge corresponding to the absorbed light. The photoelectric conversion film 72C only needs to be formed of a material that generates charges when irradiated with light. For example, the photoelectric conversion film 72C can be formed of amorphous silicon, an organic photoelectric conversion material, or the like. The photoelectric conversion film 72C containing amorphous silicon has a wide absorption spectrum and can absorb light emitted by the scintillator member 71. The photoelectric conversion film 72C containing an organic photoelectric conversion material has a sharp absorption spectrum in the visible light region, and electromagnetic waves other than light emitted by the scintillator member 71 are hardly absorbed by the photoelectric conversion film 72C. Thus, noise generated by absorption of radiation such as the photoelectric conversion film 72C can be effectively suppressed.

  Organic photoelectric conversion materials include, for example, quinacridone organic compounds and phthalocyanine organic compounds. For example, since the absorption peak wavelength of quinacridone in the visible light region is 560 nm, if quinacridone is used as the organic photoelectric conversion material and CsI: Tl is used as the material of the scintillator layer 71, the difference in the peak wavelength is within 5 nm. Thus, the amount of charge generated in the photoelectric conversion film 72C can be substantially maximized. This organic photoelectric conversion material is described in JP2009-32854A. The photoelectric conversion film 72C may be formed by further containing fullerene or carbon nanotube.

  According to the present invention, it is possible to obtain a scintillator panel that can be thickened, has high luminance and MTF, and has reduced noise due to X-ray vignetting. Such a scintillator panel can capture a phase contrast image.

  For this reason, the scintillator panel of this invention can be used conveniently for a Talbot system. FIG. 2 is a schematic configuration diagram of a Talbot scintillator including a scintillator panel including a scintillator panel according to the present invention.

  Since the scintillator of the present invention and the scintillator panel already have the function of the G2 lattice, the G2 lattice can be used even when it is detached from the apparatus. The Talbot imaging device is described in detail in Japanese Patent Laid-Open No. 2016-220865, Japanese Patent Laid-Open No. 2016-220787, Japanese Patent Laid-Open No. 2016-209017, Japanese Patent Laid-Open No. 2016-150173, and the like.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.
<Example 1>
<Plate production method>
Gd2O2S: Tb particles with an average particle diameter of 2 μm and ethylene-vinyl acetate hot melt resin (Mitsui / DuPont Evaflex EV150, melting point = 61 ° C.) have a solid content ratio (volume fraction) of 50/50. To obtain a composition for forming a scintillator layer. This composition was melted at 200 ° C., and a die coater was used so that the theoretical film thickness was 3 μm (calculated from the weight) on the PET film (non-scintillator layer) having a theoretical film thickness of 3 μm (calculated from the weight). By coating, the partial laminated body which consists of a scintillator layer and a non-scintillator layer was produced. Thereafter, 20,000 sheets of the partial laminate cut to 120 mm × 3 mm were laminated. The measured film thickness of this laminate was 140 mm.

  Subsequently, pressure was applied in parallel to the laminated surface using a metal jig under a pressure of 0.2 GPa so that the film thickness of the laminate was 120 mm, and in this state, 100 ° C. for 1 hour. A laminated block (120 mm × 120 mm × 3 mm) composed of a 20,000-layer partial laminate was produced by heating.

  After flattening one side (120 mm × 120 mm surface) of the laminated block by lathe processing, an epoxy adhesive was applied and bonded to a CFRP plate having a thickness of 0.5 mm. Thereafter, a laminating scintillator panel (120 mm × 120 mm × 0.2 mm) was obtained by cutting by lathe processing until the thickness of the laminated block became 0.2 mm.

<Evaluation method>
The surface of the laminated scintillator panel on which the CFRP plate is not bonded is bonded to a photoelectric conversion panel (detector) with an optical double-sided tape (CS9861US manufactured by Nitto Denko), and X-rays enter the scintillator panel from that surface. Thus, it arrange | positioned with respect to X-ray tube. At this time, the scintillator panel was adjusted so that X-rays were perpendicularly incident on a 120 mm × 120 mm plane center position, and the X-ray irradiation range was set so that the entire surface of the scintillator panel could enter. The distance L1 from the X-ray tube to the surface of the scintillator panel was 1.5 m.

  With this arrangement, the distance a1 from the position of the scintillator panel where X-rays are vertically incident from the X-ray irradiation apparatus to the end of the scintillator panel is 60 mm, and the thickness L2 of the scintillator panel in the radiation incident direction is 0. The combined thickness a2 of the scintillator panel and the non-scintillator layer of the scintillator panel was 6 μm.

  Under such a positional relationship, X-rays were irradiated under the condition of a tube voltage of 40 kV, and an X-ray image was acquired. During the X-ray irradiation, the arrangement of the battery and circuit board installed on the X-ray irradiation side of the photoelectric conversion panel was adjusted so as not to interfere with X-ray transmission. At this time, the signal can be compensated by image correction without changing the arrangement in the apparatus.

Luminance and MTF were measured from the X-ray image thus obtained. Note that the edge method was used for MTF.
Next, the scintillator panel on which the photoelectric conversion panel is bonded is placed on the Talbot-Lo imaging device so that the surface on which the photoelectric conversion panel is bonded becomes the X-ray incident surface, and a moire image having moire fringes is obtained. Multiple images were taken by a method based on the principle of the fringe scanning method.

  Note that the Talbot-low imaging device is similar to the X-ray imaging device using the Talbot interferometer in that the X-ray source, the first grating (that is, the so-called G1 grating), the second grating (that is, the so-called G2 grating), and the flat panel detector. And an X-ray detector known as (Flat Panel Detector: FPD). Further, a source grating (also referred to as multi-slit or the like, so-called G0 grating) is arranged in the vicinity of the X-ray source between the X-ray source and the first grating.

In this photographing, since the laminated scintillator panel already has the function of the G2 lattice, the G2 lattice was used after being removed from the apparatus.
Based on the plurality of captured moire images, an image of a small-angle scattered image in which contrast based on small-angle scattering was captured was acquired.

  The small-angle scattered image is an image of the visibility of moiré fringes, and has a contrast according to the scattering of radiation by the subject. For this reason, visibility deteriorates if the verticality such as manufacturing errors occurs in the boundary structure between the scintillator layer and the non-scintillator layer. Therefore, visibility was evaluated as an index of structural fluctuation.

  It should be noted that the minimum required brightness and MTF are derived in advance from the evaluation using the hand bone phantom, and each value is set as a reference (= 100%), and the absorption image is used as a value necessary for diagnosis. . The minimum necessary visibility value was derived from the small-angle scattered image of the phantom and used as a reference (= 100%). Since both an absorption image and a small-angle scattered image are used for diagnosis, it is necessary to satisfy all the criteria of luminance, MTF, and visibility.

<Evaluation results>
Since L2> a2 / a1 × L1 was satisfied and the photoelectric conversion panel was installed on the X-ray incident side of the scintillator panel, high values exceeding the reference value (= 100%) were obtained for luminance, MTF, and visibility. . This shows that sufficient performance is obtained as a diagnostic image used in the Talbot system.

<Example 2>
A laminated scintillator panel was obtained in the same manner as in Example 1 except that the thickness L2 in the X-ray incident direction of the scintillator panel was 0.1 mm. The positional relationship with the X-ray tube was also the same as in Example 1.

  Since L2 was 0.05 mm or more and the photoelectric conversion panel was installed on the X-ray incident side of the scintillator panel, high values exceeding the reference value (= 100%) were obtained for luminance, MTF, and visibility. This shows that sufficient performance is obtained as a diagnostic image used in the Talbot system.

<Comparative Example 1>
A laminated scintillator panel was obtained in the same manner as in Example 1 except that the thickness L2 in the X-ray incident direction of the scintillator panel was 0.03 mm. The arrangement was the same as in Example 1 except that X-rays were incident from the CFRP plate side of the scintillator panel. In this case, there is no need to change the position of the circuit board and the battery attached to the photoelectric conversion panel because they do not hinder the X-rays from entering the scintillator panel. With respect to evaluation conditions such as tube voltage, luminance, MTF, and visibility were obtained by the same method as in Example 1.

  Since L2 is 0.05 mm or less, high values of MTF and visibility are obtained, but it can be seen that the luminance is significantly lower than the reference. Thus, it is judged that the performance is insufficient as a diagnostic image used in the Talbot system.

<Comparative Example 2>
A laminated scintillator panel was obtained in the same manner as in Comparative Example 1 except that the thickness L2 in the radiation incident direction of the scintillator panel was 0.1 mm. As for the sensor position and evaluation method, luminance, MTF, and visibility were obtained in the same manner as in Comparative Example 1.

  As a result of L2 being 0.05 mm or more, it was found that the luminance was higher than that of Comparative Example 1 while the MTF and visibility met the standards, but still insufficient. Thus, it is judged that the performance is insufficient as a diagnostic image used in the Talbot system.

<Comparative Example 3>
A laminated scintillator panel was obtained in the same manner as in Comparative Example 1 except that the thickness L2 in the radiation incident direction of the scintillator panel was 0.2 mm. As for the sensor position and evaluation method, luminance, MTF, and visibility were obtained in the same manner as in Comparative Example 1.

  As a result of L2 significantly exceeding 0.05 mm, the luminance standard could be satisfied, but the MTF and visibility were below the standard. Thus, it is judged that the performance is insufficient as a diagnostic image used in the Talbot system.

<Result>
The evaluation results are shown in the following table. As a comprehensive evaluation, a case where all the criteria of luminance, MTF and visibility were satisfied was judged as “◯”, and a case where even one of the criteria was not satisfied was judged as “×”.

  Although the above embodiments have been described, the present invention is not limited thereto, and the purpose, state, application, function, and other specifications can be changed as appropriate, and can be implemented by other embodiments. Needless to say.

Claims (4)

  A scintillator member having a structure in which the scintillator layer and the non-scintillator layer are repeatedly installed in a direction substantially parallel to the incident direction of radiation, and a detector that detects the light emitted from the scintillator layer upon receiving the radiation, A scintillator panel comprising a scintillator member provided on a radiation incident side of the scintillator member.   The scintillator panel according to claim 1, wherein a thickness of the scintillator member in a radiation incident direction is larger than 50 μm. L1 is the distance from the radiation irradiation device to the scintillator panel, a1 is the distance from the position of the scintillator panel where the radiation is vertically incident from the radiation irradiation device to the end of the scintillator panel where radiation can be irradiated, and the scintillator panel The thickness in the radiation incident direction of the scintillator panel is set to L2, and the scintillator layer and the non-scintillator layer of the scintillator panel are repeatedly arranged in a substantially parallel direction. When a2
L2> a2 / a1 × L1
The scintillator panel according to claim 1, wherein:   The scintillator panel according to claim 1, wherein a phase contrast image is captured.