JP2000245721A - Radiographic image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly precise enlarged radiographic image. SOLUTION: The radiographic image based on the radiation from a microfocus radiation source 11 transmitted through a subject 14 is recorded in a radiographic image conversion panel using an accelerated phosphorescent phosphor or a reader 30 using a flat panel detector. A space between the subject 15 and the reader 30 is variable, and the read gain of the radiographic image recorded in the reader 30 is set according to this space. A read picture element size according to the size of half-shadow of the focus diameter of a radiation source 11 is set. The image data obtained by reading of image is subjected to image processing such as processing for generating image data of enlarge image, processing for preventing the influence caused by half-shadow, profile emphasizing process in phase difference radiographing, or position correcting processing for correcting the boundary position detected in the phase difference radiographing to a right position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a radiographic imaging apparatus for obtaining a high-definition radiographic image using a microfocus radiation source.

[0002]

2. Description of the Related Art Radiation images have conventionally been generated for medical diagnosis and the like. In the generation of the radiation image, the radiation was irradiated to the subject from the X-ray source, and the radiation transmitted through the subject was two-dimensionally arrayed with a radiation image conversion panel using a stimulable phosphor and a plurality of detection elements. The detection is performed by a flat panel detector.

In this method using a radiation image conversion panel, when a part of the energy of radiation is accumulated and then irradiated with stimulating excitation light such as visible light, a stimulating luminescence exhibiting a stimulating luminescence according to the accumulated energy is obtained. Using a stimulable phosphor, the stimulable phosphor panel having the stimulable phosphor is recorded with radiation image information of a subject, and then irradiated with a laser beam or the like, and the stimulable luminescence is converted into an electric signal by a photoelectric conversion unit. Thus, image data of each pixel is generated. In the method using the flat panel detector, an electric signal is generated in accordance with the dose of radiation emitted from the plurality of detection elements arranged two-dimensionally, and image data is generated based on the electric signal.

[0004] For this reason, unlike the case of using a radiographic film, there is no need for processing such as chemical development and fixing, so that a radiographic image can be obtained quickly and various images can be obtained by using the generated image data. Radiation image processing can be performed. Further, since the radiation image conversion panel and the flat panel detector have higher sensitivity than the radiographic film, the exposure dose of the subject can be reduced.

On the other hand, as the X-ray source, a micro-focus X-ray source capable of improving the spatial resolution of a fluoroscopic image by making the focal diameter smaller than that of a conventional X-ray source has been put to practical use. This microfocus X-ray source is shown in FIG.
12B is smaller than the conventional X-ray source shown in FIG. Here, the source is the focal diameter DF
The size DS of the penumbra (the area where the radiation from the source directly radiates and the area where the radiation from the source penetrates the subject and overlaps) caused by the presence of By using a microfocus X-ray source having a small focal diameter DF, the penumbra DHS can be obtained.
Can be reduced, and a high-definition image can be obtained even when an enlarged image or a thick subject is imaged. DHS = (R2 / R1) DF (1) In the expression (1), “R1” indicates a distance from the radiation source to the subject, and “R2” indicates a radiation image conversion panel or flat from the subject. The distance to a reading device such as a panel detector is shown.

[0006]

By the way, the dose of radiation applied to the radiation detector changes in inverse proportion to the square of the distance from the radiation source to the reader. Therefore, FIG.
In order to adjust the radiation image of the subject read by the reader to a desired size by changing the distances R1 and R2 shown in FIG. You have to adjust the gain in reading.

When the size of the radiographic image is changed by changing the distances R1 and R2, the size of the subject cannot be correctly recognized from the obtained radiographic image. Further, it is impossible to determine how much the resolution has been reduced due to the influence of penumbra. For this reason, it is necessary to record information such as how the obtained radiographic image is captured by setting the distances R1 and R2 for each radiographic image.

Accordingly, the present invention provides a radiographic image capturing method and a radiographic image capturing apparatus capable of obtaining a high-definition radiographic image of a desired size and correctly recognizing the size of a photographed subject. Things.

[0009]

A radiation image capturing apparatus according to the present invention includes a microfocus radiation source that irradiates a subject with radiation, and a reading unit that reads a radiation image based on radiation transmitted through the subject to generate image data. And control means for controlling the reading of the radiation image by the reading means, wherein at least the distance between the subject and the reading means is made variable, and the control means sets the reading gain of the radiation image in accordance with the distance. Further, from a position detecting means for determining the position of the microfocus radiation source, the subject, and the reading means to detect the respective distances, and from the respective distances between the microfocus radiation source, the subject, and the reading means,
Scale information generating means for calculating the magnification of the radiographic image and generating scale information for determining the size of the radiographic image, image display means, focus size of the microfocus radiation source, microfocus radiation source, subject, and reading means And a penumbra discriminating means for calculating the size of the penumbra of the focal point of the microfocus radiation source from the respective intervals.

A microfocus radiation source for irradiating the subject with radiation; reading means for reading a radiation image based on the radiation transmitted through the subject to generate image data; and an image for processing the image data generated by the reading means. It has a processing means, and the image processing means generates image data of an enlarged image based on the image data. Further, the image processing means performs processing for preventing the influence caused by the penumbra based on the penumbra of the focal diameter of the microfocus radiation source, contour emphasis processing at the time of phase contrast imaging, and setting the boundary position detected at the time of phase contrast imaging to the correct position. The position correction process is performed to correct the position.

In the present invention, a radiation image based on radiation from a microfocus radiation source transmitted through a subject is converted into a radiation image conversion panel using a stimulable phosphor,
Alternatively, it is recorded on a flat panel detector configured using a scintillator or a microplate, and at least the distance between the subject and the radiation image conversion panel or the flat panel detector can be changed. And the reading gain of the radiation image recorded on the flat panel detector. Further, the microfocus X
The penumbra of the focal diameter of the source is calculated, and the read pixel size of the radiation image is 0.8 times or more, preferably 0.9 times or more the size of the penumbra, and the desired sharpness Is set to be

A process for generating image data of an enlarged image using image data obtained by reading a radiation image, a process for preventing the effect of penumbra, a contour enhancement process for phase contrast photographing, and a process for phase contrast photographing Image processing such as position correction processing for correcting the detected boundary position to a correct position is performed.

[0013] The image data is supplied to the image display means, and the taken radiographic image is displayed on the screen of the image display means. Further, scale information for calculating the magnification of the radiographic image to determine the size of the radiographic image is generated by the scale information generating means, and a display based on the scale information is displayed together with the radiographic image.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a radiation image pickup apparatus according to the present invention. FIG.
1 shows the overall configuration of a radiation image capturing apparatus. An X-ray source controller 12 is connected to the microfocus X-ray source 11, and the X-ray source controller 12 controls an irradiation dose of radiation emitted from the microfocus X-ray source 11. Micro focus X-ray source 1
The radiation radiated from 1 is transmitted through the subject 15 and radiated to a radiation image conversion panel or a flat panel detector (hereinafter referred to as “imaging panel”) mounted on the microfocus X-ray source side in the reading device 30. . In the present invention, the subject refers to a human body or a part of a human body.

The reading device 30 generates image data based on the dose of radiation applied to the imaging panel and supplies the image data to the control device 60. In the control device 60,
Perform various image processing using the supplied image data,
The image data is converted into image data of a radiation image suitable for diagnosis or the like and stored.

An X-ray source controller 12, a position discriminating device 20, and an input device 25 are connected to the control device 60. The X-ray source controller 12 controls the irradiation dose of radiation emitted from the microfocus X-ray source 11. Is generated and supplied to the control device 60. In addition, the position determination device 20 generates distance information indicating the distance between the microfocus X-ray source 11 and the subject 15 and the distance between the subject 15 and the reading device 30 and supplies the distance information to the control device 60. In addition, the input device 25 is used to supply the control device 60 with information such as patient information and an imaging region, a magnification of a radiographic image, and the like.

The control device 60 generates a control signal for setting image reading conditions in the reading device 30 based on radiation information, distance information, patient information and the like, and supplies the control signal to the reading device 30. Various image processing is performed using the image data supplied from the reading device 30, and the image data is converted into radiation image data suitable for diagnosis or the like. An image display device 80 is connected to the control device 60, and image data before image processing and image data after image processing are supplied to the image display device 80.
Displays a radiation image. Further, the control device 60 calculates a magnification of the radiation image based on the distance information from the position determination device 20 or a scale for determining the size of the radiation image based on the magnification input by the input device 25. Generate information. The scale information is supplied to the image display device 80, and the display based on the scale information is displayed together with the radiation image on the image display device 80.
Is displayed with.

In addition, when the subject is moved during the enlargement photographing, the image of the radiation is blurred. Therefore, a subject holder 16 for fixing the subject 15 is provided.

Further, if a mask 18a made of a material for shielding radiation is provided on the microfocus X-ray source 11 side of the subject 15, it is possible to prevent radiation from being irradiated to an area other than the magnified imaging region. Also, by making the size of the opening portion of the mask 18a variable,
Even if the distance “R1” from the microfocus X-ray source 11 to the subject 15 and the distance “R2” from the subject 15 to the reading device 30 are changed, the irradiation part of the radiation is read by the reading device 3.
0 can be accommodated in a radiation image conversion panel or flat panel detector. Further, a mask 18 formed of a material for shielding radiation is provided on the reading device 30 side of the subject 15.
If b is provided, the effect of scattered radiation can also be prevented.

In the reading device 30, a radiation image conversion panel (hereinafter referred to as "imaging plate") using a stimulable phosphor or a flat panel detector using a scintillator or the like is used.

FIG. 2 shows the configuration of a reading device 30 using a coating type imaging plate. As shown in FIG. 3, the imaging plate 31 is formed by coating a stimulable phosphor layer 312 on a support 311 and further forming a protective layer 313 on the stimulable phosphor layer 312. ing. The imaging plate 31 is provided with the support 311 side as the microfocus X-ray source 11 side and the stimulable phosphor layer 312 side as the inner surface side of the radiation image reading apparatus. Energy corresponding to the dose of the radiation applied to the luminescent phosphor layer 312 is stored. When reading a radiation image, the surface of the stimulable phosphor layer 312 of the imaging plate 31 storing the energy is scanned with a laser beam to excite the stimulable phosphor and emitted from the stimulable phosphor. The stimulated emission is photoelectrically detected to generate image data.

The light beam generator (gas laser,
The solid-state laser, the semiconductor laser, and the like 320 generate a light beam whose emission intensity is controlled. This light beam is cut by a filter (not shown) in a wavelength region corresponding to the wavelength region of stimulable light emission generated from the stimulable phosphor layer 312 of the imaging plate 31, and then has a beam diameter of The light is adjusted to the right angle and enters the scanning unit 322.
The scanning unit 322 is configured by using an optical deflector such as a galvanometer mirror or a polygon mirror or an fθ lens.
The lens is adjusted so that scanning is always performed at a uniform beam speed.

The laser beam emitted from the scanning unit 322 is
Reflected by the reflecting mirror 324, the imaging plate 3
The light is incident on the surface of one stimulable phosphor layer 312.

When the laser light is applied to the stimulable phosphor layer 312 of the imaging plate 31, the stimulable phosphor layer 312 emits stimulable light in an amount proportional to the radiation energy stored and recorded. Light enters the light body 331. Light collector 3
The light-receiving end 31 has a linear shape, and is disposed close to the scanning line on the surface of the stimulable phosphor layer 312 of the imaging plate 31 so as to face the scanning line. It is connected to a light receiving surface of a photoelectric conversion type photodetector 333 such as a photomultiplier via the like. The light collector 331 is made by processing a transparent thermoplastic resin such as an acrylic synthetic resin, for example. The light incident from the light receiving end is repeatedly reflected on the inner surface of the light receiving end by the light emitting end. , The shape is determined so that the light is transmitted to the light receiving surface of the photodetector 333. Therefore,
The stimulated emission emitted from the stimulable phosphor layer 312 of the imaging plate 31 in response to the irradiation of the laser beam is incident on the light collector 331 and repeats the total reflection inside the light collector 331 to repeat the emission end. , Are received by the photodetector 333.

The filter 332 provided on the light-receiving surface of the photodetector 333 transmits only light in the wavelength region of stimulable light emitted from the stimulable phosphor layer 312 of the imaging plate 31, and the wavelength of laser light. This is for cutting light in the area.

The photodetector 333 is configured to photoelectrically detect only the stimulated emission emitted from the stimulable phosphor layer 312 of the imaging plate 31. Here, a current signal obtained by photoelectrically converting the stimulated emission by the photodetector 333 is converted into a current / voltage converter 334.
, And converted into a voltage signal, and then amplified
Is amplified to a voltage signal of a predetermined level, and is manually input to the A / D converter 336. The amplified voltage signal is A / D
In the converter 336, the digital signal is converted into a digital signal with a scale factor suitable for the signal fluctuation width and output as image data DT.

The reading device 30 includes a reading control unit 340.
The read controller 340 adjusts the light beam intensity of the light beam generator 320, adjusts the gain of the photodetector 333 by adjusting the power supply voltage of the high-voltage power supply 341, and adjusts the current / voltage converter 334 and the amplifier 335. Gain adjustment and A /
The input dynamic range of the D converter 336 is adjusted, and the reading gain is comprehensively adjusted at least according to the distance between the subject 15 and the reading device 30.

In reading a radiation image, the irradiation position of the laser beam and the position of the condenser 331 are, for example, indicated by arrows A in the figure.
The radiation image is read over the entire surface of the imaging plate 31 while being moved in the direction. Alternatively, the radiation image is read over the entire surface of the imaging plate 31 by moving the imaging plate 31 in the direction of arrow A.

Further, as a second configuration, a plurality of imaging plates 31 are provided, and the imaging plate in which energy is stored is sequentially replaced with a new imaging plate, and the imaging plate in which energy is stored is changed with the radiation irradiation position. If the radiographic image is read by transporting it to a different location, even if a radiographic image is being captured using a new imaging plate, radiation from the imaging plate already used for Images can be read.

As a third configuration, the light beam generator 3
20, the light collector 331, the photodetector 333, and the like are provided separately from the imaging plate 31, and the image is read by attaching the imaging plate 31 storing the energy to a separately provided radiation image reading apparatus. Of course, it may be good.

Here, in the case of the above-described second and third configurations in which the radiation irradiation position and the position where the radiation image of the imaging plate is read are different, the imaging plate 31
It is preferable that the stimulable phosphor layer 312 side is the microfocus X-ray source 11 side.

FIG. 4 shows the configuration of the control device 60. A system bus 62, an image bus 63, and an input interface 67 are connected to a CPU (Central Processing Unit) 61 for controlling the operation of the control device 60. The operation of the CPU 61 for controlling the operation of the control device 60 is controlled based on a control program stored in the memory 64. CPU 61
Then, based on the focal diameter of the microfocus X-ray source stored in advance, the distance information from the position discriminating device 20 and the magnification factor input from the input device 25, the size of the penumbra generated on the reading device 30 is reduced. Is calculated.

A shooting control unit 66, an output interface 68, a frame memory control unit 69, a disk control unit 70, a scale information generation unit 71, an image processing unit 76, and the like are connected to the system bus 62 and the image bus 63. The operation of each unit is controlled by the CPU 61 using the system bus 62, and image data is transferred between the units via the image bus 63.

The photographing control unit 66 generates a control signal for controlling the operation and the reading gain of the reading device 30 and supplies the control signal to the reading device 30, and reads out image data from the reading device 30 to read the image data from the frame memory control unit. Supply to 69. In addition, a read pixel size is set according to the size of the penumbra calculated by the CPU 61.

A frame memory 72 is connected to the frame memory controller 69, and image data generated by the reading device 30 is stored in the frame memory 72. The image data stored in the frame memory 72 is read and supplied to the disk control unit 70. The frame memory 72 may store the image data supplied from the reading device 30 after the image data is processed by the image processing unit 76.

From the frame memory 72 to the disk controller 7
0, for example, when the image data is read out continuously and the FIFO
The data is written to the memory and then sequentially recorded on the disk device 73.

The image data read from the frame memory 72 and the image data read from the disk device 73 are transmitted to the image display device 80 via the output interface 68.
And a radiographic image based on the image data is displayed on the screen of the image display device 80.

The scale information generation unit 71 receives the position information supplied from the position detection device 20 via the photographing control unit 66 and the input interface 67 from the input device 25 described later.
The scale information for determining the size of the radiation image is generated based on the enlargement ratio and the like input via the. The generated scale information is supplied to the image display device 80 via the output interface 68.

The image processing unit 76 performs an irradiation field recognition process, a region of interest setting, a normalization process, a gradation process, and the like of the image data DT supplied from the reading device 30 via the imaging control unit 66. Further, frequency emphasis processing, dynamic range compression processing, and the like may be performed. Further, the image processing unit 76 performs a process for preventing the influence of penumbra, and a process for making it easy to determine the contour of the subject when the phase contrast imaging is performed. Note that the image processing unit 76 is
The image processing or the like can also be performed as a configuration that also serves as a device.

The input interface 67 is connected to the input device 25 such as a keyboard. By operating the input device 25, management information such as information for identifying image data obtained by imaging and information on imaging such as a magnification ratio of a radiation image is input. The input of the management information is performed not only by using a keyboard but also by using a magnetic card, a bar code, an HIS (In-Hospital Information System: information management by network), or the like.

The image data supplied from the reading device 30 is stored in the frame memory 72. However, the image data supplied may be processed by the image processing unit 76 or the like and then stored. . The disk device 73 stores image data stored in the frame memory 72, that is, image data supplied from the reading device 30 and image data obtained by processing the image data by the image processing unit 76 and the like, together with management information and the like. Can be saved.

Here, when the reading device 30 is constituted by using a coating type imaging plate, the stimulable phosphor can not only store radiation energy but also be excited and stored by an electromagnetic wave. Any type of radiation can be used as long as it can emit the energy of the radiation as light, and is not particularly limited, but it is desirable that the radiation can be excited by light in the visible light wavelength range.

[0043] Specifically, JP-A 7-233369 discloses the general formula Ba _1-X M ^II X disclosed in FX: yM ^I, zLn (provided that at least M ^II is selected from the group consisting of Sr and Ca represents a kind of alkaline earth metal, M ^I is Li,
X represents at least one alkali metal selected from the group consisting of Na, K, Rb, and Cs; X represents at least one halogen selected from the group consisting of Cl, Br and I; Ln represents Ce, Pr, Sm, Eu, Gd, T
represents at least one rare earth element selected from the group consisting of b, Tm and Yb, wherein x, y and z are each 0 ≦
It represents a numerical value in a range represented by x ≦ 0.5, 0 ≦ y ≦ 0.05, and 0 <z ≦ 0.2. A tetrahedral rare earth activated alkaline earth metal fluorohalide-based stimulable phosphor represented by the formula (1) is desirable.

When the stimulable phosphor layer 312 is formed by coating the stimulable phosphor layer on the support 311, the thickness of the stimulable phosphor layer 312 depends on the type of the phosphor, The stimulable phosphor layer 31 varies depending on the mixing ratio between the agent and the phosphor.
In order to obtain a sufficient amount of photostimulated emission within 2, the thickness is set to 20 μm or more, and within the photostimulable phosphor layer 312, the sharpness is reduced by scattering of photostimulated excitation light and photostimulated light.
μm or less, preferably 50 μm or more and 200 μm
m or less is desirable. Note that the stimulable phosphor layer 312 does not necessarily need to be formed by coating on the support 311.
For example, separately, a stimulable phosphor layer 312 is formed by applying and drying a coating liquid on a sheet such as a glass plate, a metal plate, and a plastic sheet, and then pressing this on a support 311 or Alternatively, the support 311 and the stimulable phosphor layer 312 may be joined using an adhesive or the like.

The stimulable phosphor layer 3 thus formed
A protective layer 313 for physically or chemically protecting the surface of the substrate 12 is provided. Protective layer 313
May be formed by directly applying a solution prepared by dissolving a transparent organic polymer substance or the like in an appropriate solvent on the stimulable phosphor layer 312, or may be formed by using an organic polymer film or transparent glass. A sheet for forming a protective film such as a plate may be separately formed and bonded to the stimulable phosphor layer 312 using an appropriate adhesive. Further, a resin that is cured by radiation and / or heat as proposed in JP-A-61-176900 may be used. Further, the protective layer 313 is made of SiC, SiO ₂ , Si by a vacuum evaporation method, a sputtering method, or the like.
It may be formed by laminating inorganic substances such as N and Al ₂ O ₃ .
Further, the protective layer 313 may be formed of a coating film of a fluorine-based resin soluble in an organic solvent and in which perfluoroolefin resin powder or silicone resin powder is dispersed and contained.

Further, a material which is excellent in translucency and can be formed into a sheet is brought into close contact with the stimulable phosphor layer 312,
Alternatively, the protective layer 313 can be provided at a distance. The protective layer 313 is formed as a stimulable phosphor layer 312.
When the support 311 is disposed at a distance from the support 311,
It is preferable to provide a spacer surrounding the stimulable phosphor layer 312 between the stimulable phosphor layer 312 and the protective layer 313. Such a spacer may be used in a state where the stimulable phosphor layer 312 is shielded from an external atmosphere. There is no particular limitation as long as it can hold, and glass, ceramics, metal, plastic, or the like can be used, and the thickness is preferably equal to or more than the thickness of the stimulable phosphor layer 312.

The protective layer 313 desirably has a high light transmittance over a wide wavelength range in order to efficiently transmit stimulated excitation light and stimulated emission, and the light transmittance is preferably 80% or more. Further, it is preferable to provide an anti-reflection layer such as MgF _{2 on} the surface of the protective layer 313, since it has the effect of efficiently transmitting stimulated excitation light and stimulated emission and reducing the decrease in sharpness. Further, the thickness of the protective layer 313 is set to 1 μm or more in order to obtain the strength of the protective layer 313.
The thickness is preferably 20 μm or less in order to prevent sharpness from being reduced due to scattering of light in the protective layer 313.

In the imaging plate 31 thus produced, at least one of the above-mentioned layers (stimulable phosphor layer and protective layer) constituting the imaging plate 31 is used for the purpose of improving the sharpness of the obtained image. One layer may be colored. Also, the support 311
When an adhesive layer is provided between the stimulable phosphor layer 312 and between the stimulable phosphor layer 312 and the protective layer 313, the adhesive layer may be colored.

Here, at the time of coloring, a coloring agent that absorbs at least a part of the stimulating excitation light for causing the stimulable phosphor to emit stimulating light is used. When coloring, the color is so colored that the average reflectance in the wavelength region of the stimulating light for stimulating the stimulable phosphor is smaller than the average reflectance in the wavelength region of the stimulating light. Thus, the sharpness of the image can be improved.

Further, as the support 311, the stimulated excitation light
A material that absorbs stimulable light may be used, or such a light absorbing layer may be provided on the support 311 on the stimulable phosphor layer 312 side. For example, it is known to provide a light absorbing layer made of a light absorbing material such as carbon black. Thus, by preventing the reflection of the stimulating excitation light and the stimulating light emission, it is possible to prevent a decrease in sharpness.

Next, an imaging plate having a stimulable phosphor layer formed by a gas phase method will be described. Note that the configuration of the radiation image reading apparatus in the case of using the imaging plate using the gas phase method is the same as that of the first embodiment, and thus the detailed description is omitted.

FIG. 5 shows the structure of an imaging plate on which a stimulable phosphor layer is formed by a gas phase method.
A stimulable phosphor layer 316 is formed on 5 by a gas phase method. A spacer 317 is provided around the stimulable phosphor layer 316, and a protective layer 318 is provided on the spacer 317. At this time, the stimulable phosphor layer 316 and the protective layer 31
8 prevents the stimulable phosphor layer 316 from being damaged by the contact between the protective layer 318 and the stimulable phosphor layer 316 having a columnar crystal structure as described later. An air gap is provided for this purpose.

[0053] In the vapor phase method, M _A X · the general formulas described in, for example, JP-61-72088 discloses a stimulable phosphor
aM _B X ′ ₂ .bM _C X ^″ ₃ : The stimulable phosphor layer 3 can be easily formed by using the alkali halide phosphor represented by cA.
16 is preferable.

Here, the stimulable phosphor layer 316 formed by the vapor phase method is preferably composed of an aggregate of fine columnar crystals extending in the direction perpendicular to the substrate, and exhibits a sufficient light guiding effect ( That is, light incident from the upper surface of the columnar crystal is less likely to be radiated to the outside from the side surface of the columnar crystal.) The columnar diameter is 10 μm in order to prevent scattering of stimulating excitation light or stimulating light emission. Below, preferably 5 μm
It is as follows.

The thickness of the stimulable phosphor layer 316 is not less than 20 μm so that the stimulable phosphor layer 316 can obtain a sufficient amount of stimulable light emission.
The thickness is preferably 150 μm or less in order to reduce a decrease in sharpness due to scattering of stimulating excitation light and stimulating light emission in the inside.

When using the imaging plate 31 formed by the coating or vapor phase method, the focal diameter of the microfocus X-ray source is 0.5 μm to 80 μm.
m or less. Further, a moving subject such as a human body needs to be irradiated with radiation in a short time, so it is necessary to have a high output, and the focal diameter is 10 μm.
It is desirable that the thickness be not less than m and not more than 50 μm. In addition, in the case of a non-moving subject such as a specimen (for example, a tissue of a human body), the focal diameter is desirably 0.5 μm or more and 5 μm or less in order to obtain a sharper image even at a low output.

If the plate has a curvature so that the stimulating excitation light always enters the imaging plate 31 vertically, the stimulating excitation light is obliquely incident on the stimulable phosphor layer and sharpened. The degree can be prevented from lowering.
Here, in the case where the plate has a curvature, irradiation of radiation or reading of an image may be performed using the imaging plate 31 that has been bent in advance, or the imaging plate 31 may be bent at the time of reading an image.

Next, a case where a flat panel detector is used will be described. In FIG. 6, a flat panel detector 41 has a substrate having a thickness enough to obtain a predetermined rigidity. On the substrate, photoelectric conversion elements 412- (1,1) to 412- (m) which detect visible light converted by a scintillator and photoelectrically convert the visible light into an image signal carrying a radiation image of a subject. , n) are two-dimensionally arranged. The scanning lines 421-1 to 421 are provided between the photoelectric conversion elements 412.
-m and the signal lines 422-1 to 422-n are arranged to be orthogonal, for example. One transistor 423- (1,1) is connected to the photoelectric conversion element 412- (1,1). As the transistor 423- (1,1), for example, a field effect transistor is used. The drain electrode or the source electrode is connected to the photoelectric conversion element 412- (1,1), and the gate electrode is connected to the scanning line 421- (1,1). Connected to 1. When the drain electrode is connected to the photoelectric conversion element 412- (1,1), the source electrode is connected to the signal line 422-1. When the source electrode is connected to the photoelectric conversion element 412- (1,1), the drain electrode is connected. Are connected to the signal line 422-1. Thus, one pixel is formed. The transistor 423 is connected to the other photoelectric conversion elements 412 in the same manner.
The scanning line 421 is connected to the gate electrode, and the signal line 422 is connected to the source or drain electrode.

FIG. 7 is a partial sectional view of the flat panel detector 41. The photoelectric conversion element 412 is a signal line 4 made of a conductive film patterned on a substrate 411.
13, an amorphous silicon layer 414 and a transparent electrode 415
And a photodiode comprising: Here, the signal line 413 is connected to the drain electrode 423d (or the source electrode 423s) of the thin film transistor 423 formed over the substrate 411. A scanning line is connected to a gate electrode 423g of the thin film transistor 423, and a source electrode 423s (or a drain electrode 423d) is connected to a signal line 422. Note that the source electrode 423s
A gate insulating film 424 and a semiconductor layer 425 are provided between the drain electrode 423d and the gate electrode 423g.

On the photoelectric conversion element 412, a support 431 on which a phosphor layer (scintillator layer) 430 is formed is attached. Note that a protective layer 432 is provided on the surface of the phosphor layer 430 as described later.
Is attached on the photoelectric conversion element 412, the protective layer 432 is interposed between the photoelectric conversion element 412 and the phosphor layer 430.

Scanning line 4 of flat panel detector 41
21-1 to 421-m are scanning drive circuits 4 as shown in FIG.
4 and signal lines 422-1 to 422-n
Are connected to the charge detectors 425-1 to 425-n. Here, the scanning lines 421-1 to 421-m are output from the scanning driving circuit 44.
When the charge readout signal RS is supplied to one of the scan lines 421-p (p is any value from 1 to m), the scan line 4
Transistors 423- (p, 1) to 425 connected to 21-p
-(p, n) is turned on and the photoelectric conversion element 412- (p, 1)
412- (p, n) is generated by the signal line 422-1.
Are supplied to the charge detectors 425-1 to 425-n via .about.422-n. The signal lines 4 in the charge detectors 425-1 to 425-n
Voltage signals SV-1 to SV-n are generated which are proportional to the amount of electric charge supplied via 22-1 to 422-n. The voltage signals SV-1 to SV output from the charge detectors 425-1 to 425-n
V-n is supplied to the signal selection circuit 45.

The signal selection circuit 45 includes registers 45a and A
/ D converter 45b.
A voltage signal is supplied to 5a from the charge detectors 425-1 to 425-n. In the register 45a, the supplied voltage signals are sequentially selected and converted into digital data by the A / D converter 45b. This data is supplied to the read control circuit 48.

The reading control circuit 48 includes a control device 60
The scan control signal RC and the output control signal SC are generated based on the control signal CTD supplied from the control device 60. The scan control signal RC is supplied to the scan drive circuit 44, and the charge readout signal RS for the scan lines 421-1 to 421-m is supplied based on the scan control signal RC.
Is supplied. Further, the output control signal SC is supplied to the signal selection circuit 45 to control the selection operation of the voltage signals from the charge detectors 425-1 to 425-n stored in the register 45a and to select the selected voltage signal. Is converted into a data signal, and is converted to a signal selection circuit 4 as image data DT.
5 to the read control circuit 48. Read control circuit 4
In step 8, a process of transmitting the image data DT to the control device 60 is also performed. If the image data DT obtained by the radiation image reading device is supplied to the control device 60 and a logarithmic conversion process of the image data is performed, the processing of the image data in the control device 60 can be simplified. . In addition, the above-described logarithmic conversion may be performed at the same time that the charge detector 425 converts the read charge amount into the voltage signal SV. By converting the data into digital data by the A / D converter 45b after the logarithmic conversion, the resolution of the radiation information in a region where the voltage signal SV is small can be increased.

Here, for the phosphor layer of the flat panel detector 41, a method of forming a phosphor layer by applying a phosphor paint comprising a phosphor and a binder to a support is used.
The phosphor coating is applied to the temporary support and then dried and peeled to form a sheet-shaped phosphor layer,
The phosphor layer may be formed by spraying a phosphor paint.

The phosphor may emit light in the visible region upon irradiation with radiation, and may be any as long as the photoelectric conversion element has sensitivity to this emission wavelength. For example, Gd ₂ O ₂ S: Tb, C
sI: Tl is desirable.

The average particle size of the phosphor can be increased by increasing the filling rate of the phosphor in the phosphor layer, thereby enabling high-definition light emission and reducing the scattering of the light emission of the phosphor in the phosphor layer. As described above, the thickness is 0.5 μm or more and 10 μm or less, preferably 1 μm or more and 5 μm or less.

The phosphor layer is provided with a protective layer for physically and chemically protecting the surface opposite to the side in contact with the support.

This protective layer has a thickness of 0.5 μm or more and 10 μm or more.
m, preferably 1 μm or more and 3 μm or less. By using such a thin protective layer,
Since the distance between the phosphor layer and the photoelectric conversion element is small, the light emitted from the phosphor layer is immediately incident on the photoelectric conversion element without being scattered by the protective layer. This contributes to an improvement in the sharpness of the image.
The thickness of the phosphor layer is preferably from 20 to 150 μm, preferably from 20 to 150 μm, in order to obtain a sufficient amount of stimulated emission and to reduce scattering of light in the phosphor layer.
Desirably, it is 00 μm.

Here, by coloring at least one of the phosphor layer and the protective layer, a decrease in sharpness due to scattering of light emission of the phosphor in the phosphor layer can be reduced. As a method of using a coloring agent that absorbs at least a part of the emission of the phosphor, coloring can be performed by a coloring method similar to the above-described imaging plate. When a phosphor that emits light in the green region is used, the phosphor may be colored using a coloring agent having a main peak of an absorption spectrum in a wavelength range of 420 to 540 nm. Further, the phosphor may be colored using a coloring agent having an average absorptance higher in an emission region having a wavelength longer than the peak wavelength of light emission than in the emission region having a wavelength shorter than the peak wavelength.

In the meantime, in the formation of the phosphor layer, the phosphor coating is formed by uniformly applying the phosphor coating on the support. The scattering of the emission of the phosphor in the phosphor layer can be suppressed by the guide effect.

Next, a case where a flat panel detector provided with a photoconductive layer is used will be described. FIG. 8 shows a configuration of the flat panel detector 51. The flat panel detector 51 has a substrate having a thickness enough to obtain a predetermined rigidity. This substrate is made of, for example, glass. A plurality of microplates 512- (1,1) to 512- (m, n) using a metal thin film are provided on the substrate.
Dimensionally arranged. The scanning lines 521-1 to 521-m and the signal lines 522-1 to 522-n are arranged between the microplates 512, for example, so as to be orthogonal to each other. Microplate 5
One transistor 515- (1,1) is connected to 12- (1,1). As the transistor 515- (1,1), for example, a field effect transistor is used, and the drain electrode or the source electrode is a microplate 512- (1,1).
And the gate electrode is connected to the scanning line 521-1. The drain electrode is a microplate 512- (1,
When connected to (1), the source electrode is connected to the signal line 522-1, and the source electrode is connected to the microplate 512- (1,1).
Is connected to the signal line 522-1. The microplate 512- (1,1) is used as one electrode of the charge storage capacitor 530-1. Thus, one pixel is formed. The transistor 515 is similarly connected to the other microplates 512, and the scanning line 521 is connected to the gate electrode of the transistor 515.
Are connected, and a signal line 522 is connected to the source electrode or the drain electrode.

FIG. 9 is a partial cross-sectional view of the flat panel detector 51.
A gate electrode 515 g connected to the gate electrode 21 is formed. A gate insulating film 515p is formed on the gate electrode 515g, and a semiconductor layer 515c using amorphous silicon or the like is formed on the gate insulating film 515p.
A source electrode 515s and a drain electrode 515d are formed on the semiconductor layer 515c to form a field effect transistor. One of the source electrode 515s and the drain electrode 515d is connected to the signal line 522, and the other electrode is connected to the microplate 512.

On the substrate 511, an electrode 530a as an external microplate is formed, and a dielectric 530b such as silicon dioxide or silicon nitride is formed on the electrode. Further, the microplate 512 is formed as an electrode on the dielectric 530b, and the charge storage capacitor 530 is formed by the microplate 512, the electrode 530a, and the dielectric 530b. The microplate 512 formed on the dielectric 530b of the charge storage capacitor 530 is connected to the transistor 515, and the electrode 530a formed on the substrate 511 is grounded.

The transistor 515 is covered with a passivation layer 518 and has a charge storage capacitor 530.
A charge blocking layer 532 is formed on the electrodes and on the microplate 512 (not shown).

Further, the passivation layer 518, the charge blocking layer 532, the scanning lines 521 (not shown), and the signal lines 522 (not shown) are irradiated with radiation to generate electron-hole pairs. Thus, a photoconductive layer 534 having a variable resistance value is formed. The photoconductive layer 534 desirably has a high dark resistance value, and is particularly preferably amorphous selenium. Preferably, a dielectric layer 536 is formed on the photoconductive layer 534, and a bias electrode 538 is formed on the dielectric layer 536.

Here, when a high voltage (for example, several kV) is applied to the bias electrode 538, the radiation is applied to the photoconductive layer 53.
4, an electron-hole pair is generated in an amount corresponding to the intensity of the radiation, and a high voltage is applied to the bias electrode 538.
At the same time as the charges are moved to the 36 side, the charges of the opposite polarity are moved to the charge blocking layer 532 side. The dielectric layer 536 prevents charge injection from the bias electrode 538 into the photoconductive layer 534, and the charge blocking layer 532 transfers charge from the microplate 512, which is the electrode of the charge storage capacitor 530, to the photoconductive layer 534. The injection is blocked. For this reason, it is possible to prevent the leakage current from flowing through the photoconductive layer 534, and it is possible to store an amount of charge corresponding to the intensity of the radiation in the charge storage capacitor 530.

In this manner, the charge storage capacitors 530- (1,1) to 530-(-) having each of the microplates 512- (1,1) to 512- (m, n) shown in FIG. (m, n) can be stored, and the amount of charge stored in the charge storage capacitors 530- (1,1) to 530- (m, n) can be determined to generate image data. can do.

In the flat panel detector 51,
For example, transistors 540-1 to 540 for resetting operation, which have drain electrodes connected to the signal lines 522-1 to 522-n, respectively.
0-n are provided. These transistors 540-1 to 540-5
The 40-n source electrode is grounded. The gate electrode is connected to the reset line 541.

Scanning line 5 of flat panel detector 51
21-1 to 521-m and the reset line 541 are connected to the scan drive circuit 55. From the scanning drive circuit 55 to the scanning line 5
One of the scan lines 521-p (p is 1 to 21-1 to 521-m)
When the charge read signal RS is supplied to any one of the values of m, the transistor 51 connected to the scanning line 521-p
5- (p, 1) to 515- (p, n) are turned on, and the charges stored in the charge storage capacitors 530- (p, 1) to 530- (p, n) are transferred to the signal line 522-. 1 to 522-n. The signal lines 522-1 to 522-n are connected to the charge detector 542-1.
542-n, and the charge detectors 542-1 to 542-1-5
At 42-n, voltage signals SU-1 to SU-n proportional to the amount of charge read on the signal lines 522-1 to 522-n are generated. The voltage signals SU-1 to SU-n output from the charge detectors 542-1 to 542-n are supplied to the signal selection circuit 56.

The signal selection circuit 56 includes registers 56a and A
/ D converter 56b.
6a is supplied with a voltage signal from the charge detectors 542-1 to 542-n. In the register 56a, the supplied voltage signals are sequentially selected, and the A / D converter 56b (for example, 1
It is digital data (of 2 bits to 14 bits). This data is supplied to the read control circuit 58. In a state where a high voltage is applied to the bias electrode 538, the reset signal RT is sent from the scan driving circuit 55 to the reset line 54.
1 to turn on the transistors 540-1 to 540-n, and supply the charge readout signal RS to the scan lines 521-1 to 521-m to supply the transistors 515- (1, 1) to 515.
When-(m, n) is turned on, the charge storage capacitor 530
The electric charges stored in-(1,1) to 530- (m, n) are released through the transistors 540-1 to 540-n to initialize the flat panel detector 51, that is, to remove the residual electric charge. be able to.

The reading control circuit 58 includes a control device 60
The scan control signal RC and the output control signal SC are generated based on the control signal CTD supplied from the control device 60. The scan control signal RC is supplied to the scan drive circuit 55, and the charge read signal RS for the scan lines 521-1 to 521-m is supplied based on the scan control signal RC.
Supply and reset signal RT to the reset line 541
Is supplied. Further, the output control signal SC is supplied to the signal selection circuit 56, and the selection operation of the voltage signals from the charge detectors 542-1 to 542-n stored in the register 56a is controlled. For example, when the flat panel detector 51 is composed of (m × n) microplates as described above by the scanning control signal RC and the output control signal SC from the reading control circuit 58, the charge storage capacitor 530 -(1,1) to 530- (m, n), data DP (1,1) to DP (m, n), and data DP (1,1), DP ( 1,2), DP (1, n), D
Image data DT is generated in the order of P (2,1),..., DP (m, n) and supplied from the signal selection circuit 56 to the reading control circuit 58. The reading control circuit 58 also performs processing for sending the image data DT to the control device 60.

Image data DT obtained by the reading device 30
Is supplied to the control device 60 shown in FIG. If the image data obtained by the radiation image reading device is supplied to the control device 60 by performing a logarithmic conversion process on the image data, the processing of the image data in the control device 60 can be simplified. In addition, the above-described logarithmic conversion may be performed simultaneously when the read charge amount is converted into the voltage signal SU by the charge detector 542. Thus, A / D after logarithmic conversion
By converting the data into digital data by the converter 56b, the resolution of radiation information in a region where the voltage signal SU is small can be increased.

Here, in the flat panel detector,
Read pixel size (interval between photoelectric conversion elements and microplates) is 10 μm or more and 100 μm or less, preferably 10 μm
m to 50 μm, more preferably 10 μm to 20
μm or less, and the focal diameter of the microfocus X-ray source is set to 0.5 μm as in the first and second embodiments.
m to 80 μm, preferably 10 μm to 50 μm for a moving subject, and 0.1 μm for a non-moving subject.
When the thickness is 5 μm or more and 5 μm or less, a high-definition radiation image can be obtained.

Next, radiographing will be described. First, when photographing a subject, a part to be magnified is specified. Here, when the part to be enlarged can be determined from the surface of the subject, for example, the position to be enlarged is marked by using light, and the mark display is adjusted to a desired part to perform enlarged imaging. The part to be performed can be specified. Also, when the part to be enlarged cannot be determined from the surface of the subject,
For example, it is possible to photograph a subject in real time by using an image intensifier or the like with a small radiation irradiation dose, and to specify a part to be enlarged and photographed based on the obtained photographed image.

Next, the irradiation dose of the micro-focus X-ray source 11 is set by the X-ray source controller 12, and the micro-focus X-ray source 11 and the subject 15 are set so that a radiation image with a desired magnification can be obtained. And reader 3
Set the position of 0. Here, as shown in FIG.
Assuming that the distance from the microfocus X-ray source 11 to the subject 15 is “R1” and the distance from the subject 15 to the reading device 30 is “R2”, the enlargement factor M is represented by Expression (2). M = ((R1 + R2) / R1) × 100% (2)

The value of the enlargement ratio M may be input by operating the input device 25.
The position information may be supplied to the control device 60 by measuring “1” and “R2”, and the control device 60 may automatically calculate the enlargement factor M.

The subject 15 is placed on the subject holder 16 so that a high-definition radiographic image can be obtained by magnifying radiography.
And the size of the opening of the mask 18a is changed so that the irradiated portion of the radiation fits into the radiation panel.

Here, when the subject 15 is large, such as a human body, enlargement photography is performed by moving the positions of the microfocus X-ray apparatus 11 and the reading device 30 based on the position of the subject 15. It can be done easily. Further, although not shown, the micro focus X
If a driving device for moving the position of the line device 11, the object 15, and the reading device 30 is provided, the input device 25
By simply operating and inputting the magnification, the position of the microfocus X-ray apparatus 11, the subject 15, or the reading device 30 can be automatically set to a position corresponding to the inputted magnification. That is, the distances “R1” and “R2” are measured by the position determination device 20, and the obtained distances “R1” and “R1” are measured.
The microfocus X-ray apparatus 11 is driven by the driving device so that the enlargement ratio calculated from “R2” becomes the inputted enlargement ratio.
By adjusting the position of the subject 15 or the reading device 30, the position can be easily set only by inputting the magnification.

When the setting of the position corresponding to the desired magnification is completed in this way, radiation is irradiated from the microfocus X-ray source 11 and the radiation transmitted through the subject is displayed on the imaging panel of the reading device 30. Energy or electric charge corresponding to the dose is stored, or light is emitted.
When a radiation image is read, image data of the radiation image is generated based on the stored energy, electric charge, or light emission.

When reading a radiation image, the read pixel size of the image includes the focal diameter DF of the microfocus X-ray source 11, the distance "R1" from the microfocus source 11 to the subject 15, the subject "R1", The size of the penumbra DHS, which can be obtained from the above equation (1) based on the distance “R2” from the distance 15 to the reading device 30, is 0.8 times or more, preferably 0.9 times or more. ,
The sharpness is set to a desired value. For this reason, it is possible to prevent an increase in image data by reading an image at an unnecessarily high resolution with respect to a radiation image.

When the read pixel size is fixed like a flat panel detector, for example, the distances “R1” and “R
When “2” is adjusted to change the size of penumbra DHS,
When the read pixel size is no more than 0.8 times the size of the penumbra DHS, and preferably no more than 0.9 times, a warning is displayed to read the image at an unnecessarily high resolution. It is possible to easily determine whether or not the blur is caused by the influence of the penumbra DHS, for example, and to make a correct diagnosis or the like.

When the image data of the radiation image is obtained in this manner, the image processing section 76 of the control device 60 performs image processing using the image data. In the image processing, an image based on the image data is enlarged and displayed on the image display device 8.
Processing for displaying the image at 0 and processing for preventing the influence of penumbra are performed.

The processing for preventing the influence of this penumbra includes:
For example, a process using deconvolution is performed. That is, the image (original image) when the focal diameter is infinitely small is g (x, y), and the image deteriorated by the influence of the penumbra is g ′.
Assuming that the point spread function by (x, y) and the penumbra is h (x, y), the relationship of Expression (3) holds. g ′ (x, y) = g (x, y) * h (x, y) (3) In Expression (3), “*” represents a convolution operation (convolution convolution).

When this equation (3) is Fourier-transformed and the Fourier transform of each function is represented in capital letters, equation (4) is obtained, and the convolution operation becomes a product in the frequency domain. G ′ (u, v) = G (u, v) H (u, v) (4)

The expression “1 / H (u, u,
v) ”, equation (5) can be obtained, and equation (6) can be obtained by inverse Fourier transform of equation (5). G ′ (u, v) / H (u, v) = G (u, v) (5) g (x, y) = F ⁻¹ ｛G ′ (u, v) / H (u, u) v)｝ (6) Note that “F ⁻¹ ” in Expression (6) represents an inverse Fourier transform. Here, the calculation in the frequency domain is “1 / H
If a function called a Wiener filter is applied instead of (u, v), the influence of noise can be suppressed.

In this manner, if the size and shape of the penumbra are known, the original image g (x, y) from which the influence of the penumbra has been removed
Can be obtained. That is, processing for preventing the influence of penumbra can be performed. Note that the processing for preventing the influence of penumbra is not limited to processing using deconvolution, and may use other methods.

Further, in the image processing, a clear radiation image is obtained by utilizing the phase difference imaging, that is, the interference effect generated based on slight diffraction or refraction when the radiation from the microfocus X-ray source passes through the subject. When the photographing is performed, the signal level is increased at the boundary between the respective parts of the subject due to the interference effect as shown in FIG. 10, and therefore, a contour emphasizing process for emphasizing the position where the signal level is increased is performed. Further, in the phase contrast imaging, since the interference effect generated based on diffraction or refraction is used, the detected boundary EPb may be slightly different from the correct boundary position EPa. Therefore, processing for correcting the detected boundary to a correct boundary position is also performed. As described above, by performing the contour emphasis processing, diagnosis is facilitated, and it is particularly effective for detecting calcification in mammography.
In addition, a radiation image obtained from enhancement of a contour can be utilized for computer diagnostic assistance (CAD). Furthermore, in the image processing, the same subject is photographed at different times, a temporal difference between a plurality of radiographic images photographed at a later time is obtained, and correction based on the temporal difference is also performed.

As described above, when various image processing is performed to generate image data of a radiation image suitable for diagnosis or the like, for example, the image data after the image processing is supplied to the image display device and Is displayed on the image display device 80. Here, the scale information generation unit 70 of the control device 60 can generate the scale information for determining the size of the image represented by the image data because the image reading size and the enlargement ratio of the image are known. it can. For this reason, when displaying the radiation image on the image display device 80,
If the display based on the scale information is displayed together with the radiographic image as shown in FIG. 11, not only can a high-resolution enlarged radiographic image suitable for diagnosis or the like be displayed, but also on the screen by referring to the display based on the scale information. The size of the displayed subject can be easily and correctly determined.

[0099]

According to the present invention, the radiation image based on the radiation from the microfocus radiation source transmitted through the subject is read by the reading means, and at least the distance between the subject and the reading means can be changed. The reading gain of the radiation image is set by the control means in accordance with. Therefore, by changing the distance between the subject and the reading unit, a high-definition radiation image of the subject enlarged to a desired size can be obtained.

Further, since the positions of the microfocus radiation source, the object, and the reading means can be determined and the respective intervals can be detected by the position detecting means, a radiation image enlarged to a desired size can be obtained automatically. Further, scale information for calculating the magnification of the radiographic image and determining the size of the radiographic image is generated by the scale information generating means, and when the radiographic image is displayed, the scale information of the displayed radiographic image is generated based on the scale information. A display is made so that the size can be determined. Therefore, the size of the subject can be correctly determined even if the radiation image is enlarged.

The pixel size read by the reading means is at least 0.8 times, preferably at least 0.9 times the size of the penumbra calculated by the penumbra discriminating means. Since the radiation image is set to have a desired sharpness, a high-definition radiation image can be obtained.

Further, a process for generating image data of an enlarged image based on image data obtained by photographing by the image processing means, a process for preventing an effect caused by penumbra,
Since a contour enhancement process at the time of phase difference imaging, a position correction process of correcting a boundary position detected at the time of phase difference imaging to a correct position, and the like are performed, a radiation image suitable for diagnosis or the like can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a radiation image capturing apparatus according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a reading device using an imaging plate.

FIG. 3 is a diagram showing a configuration of a coating type imaging plate.

FIG. 4 is a diagram showing a configuration of a control device.

FIG. 5 is a diagram showing a configuration of an imaging plate by a gas phase method.

FIG. 6 is a diagram showing a configuration of a flat panel detector 41.

FIG. 7 is a partial cross-sectional view of the flat panel detector 41.

FIG. 8 is a diagram showing a configuration of a flat panel detector 51.

FIG. 9 is a partial cross-sectional view of the flat panel detector 51.

FIG. 10 is a diagram for explaining phase difference photographing.

FIG. 11 is a diagram showing a display image.

FIG. 12 is a diagram illustrating a relationship between a focal diameter and a penumbra.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Micro focus X-ray source 12 X-ray source controller 15 Subject 30 Reading device 31 Imaging plate 41, 51 Flat panel detector 44, 55 Scan driving circuit 45, 56 Signal selection circuit 48, 58 Reading control circuit 60 Control device 80 Image output device 311,315 Support 312,316 Stimulable phosphor layer 313,318,432 Protective layer 320 Light beam generator 322 Scanning unit 324 Reflecting mirror 331 Condenser 332 Filter 333 Photodetector 334 Current / voltage conversion unit 335 Amplification Unit 336 converter 340 read control unit 411, 511 substrate 412 photoelectric conversion element 421, 521 scan line 422, 522 signal line 425, 542 charge detector 430 phosphor layer 512 microplate 515 transistor 530 charge accumulation Capacitor 541 reset line

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06T 1/00 G21K 4/00 L G21K 4/00 G06F 15/62 390A F-term (Reference) 2G083 AA03 BB04 CC10 DD16 DD20 EE02 2H013 AC03 4C093 AA14 AA28 AA30 CA02 CA08 EA02 EA14 EB02 EB05 EB12 EB17 EB20 EC32 ED11 EE01 FA11 FA18 FA33 FA43 FA60 FC01 FC02 FC03 FD01 FD02 FD03 FD20 FF01 AFF13 FF07 FF07 FF08 FF08

Claims (11)

[Claims] 1. A microfocus radiation source for irradiating a subject with radiation, reading means for reading a radiation image based on radiation transmitted through the subject to generate image data, and reading the radiation image by the reading means. A radiographic image capturing apparatus, comprising: a control unit for controlling, wherein at least an interval between the subject and the reading unit is variable, and the control unit sets a reading gain of the radiographic image according to the interval. . 2. The radiation image capturing apparatus according to claim 1, further comprising a position detecting unit that determines the positions of the microfocus radiation source, the subject, and the reading unit and detects the respective intervals. 3. Scale information for calculating a scale factor of the radiation image by calculating an enlargement ratio of the radiation image from a distance between the microfocus radiation source, the subject, and the reading unit. 3. The radiation image capturing apparatus according to claim 1, further comprising a generation unit. 4. An image display device, wherein when displaying a radiation image based on the image data generated by the reading device by the image display device, based on the scale information generated by the scale information generating device. 4. The radiographic image capturing apparatus according to claim 3, wherein a display is provided so that the size of the displayed radiographic image can be determined. 5. A half for calculating a size of a penumbra of a focus of the microfocus radiation source from a size of a focus of the microfocus radiation source and a distance between the microfocus radiation source, the subject, and the reading unit. 3. The radiation image capturing apparatus according to claim 1, further comprising a shadow determining unit. 6. The pixel size read by the reading means is at least 0.8 times, preferably at least 0.9 times the size of the penumbra determined by the penumbra determining means, The radiation image capturing apparatus according to claim 5, wherein the read radiation image is set to have a desired sharpness. 7. A microfocus radiation source for irradiating a subject with radiation, reading means for reading a radiation image based on radiation transmitted through the subject to generate image data, and processing image data generated by the reading means. A radiation image capturing apparatus, comprising: an image processing unit configured to generate image data of an enlarged image based on the image data. 8. A microfocus radiation source for irradiating a subject with radiation, reading means for reading a radiation image based on radiation transmitted through the subject to generate image data, and processing image data generated by the reading means. A radiographic imaging apparatus, comprising: an image processing unit that performs processing for preventing an effect caused by the penumbra based on a penumbra of a focal diameter of the microfocus radiation source. 9. The radiation image capturing apparatus according to claim 8, wherein the image processing means performs a process for preventing an effect caused by the penumbra by using deconvolution. 10. A microfocus radiation source for irradiating a subject with radiation, reading means for reading a radiation image based on radiation transmitted through the subject to generate image data, and processing image data generated by the reading means. A radiation image capturing apparatus comprising: an image processing unit that performs edge enhancement processing during phase difference imaging. 11. A microfocus radiation source for irradiating a subject with radiation, reading means for reading a radiation image based on radiation transmitted through the subject to generate image data, and processing image data generated by the reading means. A radiation image pickup apparatus comprising: an image processing unit that performs a position correction process that corrects a boundary position detected during phase difference imaging to a correct position.