JP2004147917A - Radiographic imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiographic imaging apparatus capable of reducing the radiation impinging on a subject in the phase contrast magnification radiography, and obtaining an image of a breast without generating an image defect. <P>SOLUTION: The radiographic imaging apparatus comprises a small focus radiation source 11 for applying radiation to the subject 15, a subject holding member 18 for holding the subject 15, and a radiographic image detector 50 for reading the radiographic image information based on the radiation penetrating the subject 15 for executing the phase contrast mammography of the breast of the subject held by the subject holding member 18. In the apparatus, an end surface 50a of the radiographic image detector 50 is located in a straight line L1 connecting the focal point 11a of the small focus radiation source 11 and a chest wall surface 15a of the subject on the subject holding member 18. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a radiographic image capturing apparatus, and more particularly, to a radiographic image capturing apparatus capable of obtaining a radiographic image having a high boundary contrast of a subject and an excellent sharpness by using a small-focal-point radiation source and enhancing edges by phase contrast.
[0002]
[Prior art]
An X-ray image using an action of transmitting X-rays, which is one type of radiation, through a substance is widely used for medical image diagnosis, nondestructive inspection, and the like. The X-ray image is a shadow image due to the fact that, when X-rays pass through a subject, the amount of X-ray transmission varies depending on the atomic weight of a substance constituting the subject. That is, X-rays are emitted from the X-ray source, and the two-dimensional distribution of the X-ray dose after transmission through the subject is detected by the X-ray detector, and an X-ray image based on the X-ray absorption contrast of the subject is formed.
[0003]
Recently, as an X-ray image, an image called a phase contrast image has been proposed. A phase contrast image is also called a refraction contrast image, and is obtained by imaging with a monochromatic parallel X-ray obtained from a synchrotron radiation X-ray source such as SPring-8 or with a micro-focus X-ray source having a focal size of about 10 μm. It is something that can be done. Compared to an image having only normal absorption contrast, the contrast at the boundary of the subject can be described with a higher resolution, and a high-definition X-ray image can be obtained.
[0004]
However, it is difficult to use such monochromatic parallel X-rays or an imaging apparatus using a microfocus X-ray source having a focal size of 20 μm or less in a general medical institution. In other words, the synchrotron radiation X-ray source for obtaining monochromatic parallel X-rays has a huge device, and the microfocus X-ray source has too low X-ray intensity to transmit through the human body. There is one that captures a phase contrast image using an X-ray tube (small focal radiation source having a small focal size) used in a medical institution (for example, Patent Document 1)
[0005]
[Patent Document 1]
JP 2001-299733 A (pages 1 to 30, FIGS. 2 to 26)
[0006]
[Problems to be solved by the invention]
As described above, in obtaining the phase contrast image, the radiation image detector which reads the distance between the small-focus radiation source and the subject and the X-ray image of the subject from the small-focal radiation source due to the nature of the radiation energy emitted from the small-focus radiation source. It is necessary to make the distance with the constant condition.
[0007]
In addition, the phase contrast image is an enlarged photograph, and the size of a conventional breast detector (cassette) is, for example, 18 × 24 cm or 24 × 30 cm in a plan view rectangular shape, and the breast image cannot be accommodated.
[0008]
Furthermore, since the phase contrast is an enlarged imaging, in a conventional arrangement of an X-ray tube, a subject table, and a radiation image detector, a portion where an image is not captured appears on the subject's chest wall side, or the subject is irradiated with radiation. There are problems such as.
[0009]
The present invention has been made in view of the above circumstances, and in a phase contrast enlarged imaging, a radiation image capturing apparatus capable of reducing exposure of a subject to radiation and obtaining a breast image without generating an image defect area. It is intended to provide.
[0010]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, the present invention is configured as follows.
[0011]
The invention according to claim 1 includes a small-focus radiation source that irradiates a subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject. Have
In a radiographic image capturing apparatus that performs a phase contrast mammography of a subject breast held by the subject holding member,
An end face of the radiation image detector is located on a substantially straight line connecting a focal point of the small focus radiation source and a subject chest wall on the subject holding member.
[0012]
According to the first aspect of the present invention, the end face of the radiation image detector is located on a substantially straight line connecting the focal point of the small focus radiation source and the chest wall of the subject on the subject holding member, thereby achieving phase contrast. In magnified photography, it is possible to reduce the exposure of the subject to radiation, and to obtain a breast image without generating an image defect area.
[0013]
The invention according to claim 2 includes a small focus radiation source that irradiates a subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject. Have
In a radiographic image capturing apparatus that performs a phase contrast mammography of a subject breast held by the subject holding member,
The subject holding member and the radiation image detector, such that an end face of the radiation image detector is located on a substantially straight line connecting a focal point of the small focus radiation source and a subject chest wall surface on the subject holding member. And a moving means for moving the radiation image.
[0014]
According to the second aspect of the present invention, by moving the subject holding member and the radiation image detector, the end face of the radiation image detector is moved to the focal point of the small focus radiation source and the subject chest wall surface on the subject holding member. By positioning them on a substantially straight line connecting to the object, it is possible to reduce the exposure of the subject to radiation during phase contrast magnification imaging, and to obtain a breast image without generating an image-defective region.
[0015]
According to a third aspect of the present invention, there is provided a small-focus radiation source that irradiates a subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject. Have
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
An end face of the radiation image detector is located on the subject side from a substantially straight line connecting a focal point of the small focus radiation source and a subject chest wall surface on the subject holding member. .
[0016]
According to the third aspect of the present invention, the end face of the radiation image detector is located closer to the subject than a substantially straight line connecting the focal point of the small focus radiation source and the subject chest wall on the subject holding member. In the phase contrast enlarged imaging, it is possible to reduce the exposure of the subject to radiation and obtain a breast image without generating an image defect area.
[0017]
The invention according to claim 4 is characterized in that the radiation image detector has a stimulable phosphor for detecting a radiation image, and the end face of the stimulable phosphor is located on the substantially straight line. Item 4. A radiographic image capturing apparatus according to Item 3.
[0018]
According to the fourth aspect of the present invention, it is possible to obtain a breast image without generating an image-defective region in the stimulable phosphor.
[0019]
The invention according to claim 5 is characterized in that the radiation image detector has a flat panel detector for detecting a radiation image, and an end face of an X-ray detector of the flat panel detector is located on the substantially straight line. A radiation image capturing apparatus according to claim 3.
[0020]
According to the fifth aspect of the present invention, it is possible to obtain a breast image without generating an image deficient region in the flat panel detector.
[0021]
In the invention according to claim 6, the radiation image detector has a stimulable phosphor for detecting a radiation image, and the end surface of the stimulable phosphor is located at least 2 mm from the substantially straight line on the subject side. The radiation image capturing apparatus according to claim 3, wherein:
[0022]
According to the sixth aspect of the present invention, since the end face of the stimulable phosphor is located on the subject side, a breast image can be obtained without generating an image defect area in the stimulable phosphor.
[0023]
The invention according to claim 7 includes a small focus radiation source that irradiates a subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject. Have
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
The subject holding member and the radiation source so that an end face of the radiation image detector is located on a subject side substantially on a straight line connecting a focal point of the small focus radiation source and a subject chest wall surface on the subject holding member. A radiation image capturing apparatus including a moving unit that moves between the image detector and the image detector.
[0024]
According to the invention described in claim 7, the subject holding member and the radiation image detector are moved, and the end face of the radiation image detector is positioned between the focal point of the small-focus radiation source and the subject chest wall surface on the subject holding member. Is positioned closer to the subject than on the substantially straight line connecting, the exposure of the subject to radiation can be reduced in phase-contrast enlarged imaging, and a breast image can be obtained without generating image-deficient regions.
[0025]
The invention according to claim 8 includes a small focus radiation source that irradiates a subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject. Have
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
The subject holding member and the radiation image detector so that the end face of the radiation image detector is substantially on a straight line connecting the focal point of the small focus radiation source and the subject chest wall on the subject holding member. First moving means for moving;
The subject holding member such that an end face of the radiation image detector is closer to the subject than a substantially straight line connecting the focal point of the small focus radiation source and the subject chest wall on the subject holding member; Second moving means for moving the container,
Control means for switching between the first moving means and the second moving means,
The radiation image capturing apparatus is characterized in that the control means switches a moving direction of the moving means depending on whether a photographing direction is a vertical direction or a direction other than the vertical direction.
[0026]
According to the present invention, by switching between the first moving means and the second moving means depending on the subject, the photographing direction, and the like, it is possible to reduce the irradiation of the subject with radiation in accordance with the subject, the photographing direction, and the like. In addition, a breast image can be obtained without generating an image-defective region.
[0027]
The invention according to a ninth aspect is the radiographic imaging apparatus according to the eighth aspect, wherein the control unit switches the imaging direction depending on a vertical direction and a direction other than the vertical direction.
[0028]
According to the ninth aspect of the present invention, the imaging direction is switched between the vertical direction and the direction other than the vertical direction, so that the imaging can be performed without the patient of the subject taking an unreasonable posture, and the image defect area does not occur. A breast image can be obtained.
[0029]
According to a tenth aspect of the present invention, there is provided a small-focus radiation source that irradiates a subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on radiation transmitted through the subject. Have
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
Distance changing means for changing a first distance between the small focus radiation source and the subject holding member or a second distance between the subject holding member and the radiation image detector;
Subject breast detection means for detecting the size of the subject breast,
Control means for controlling the distance changing means to detect a predetermined area or more of the subject breast by the radiation image detector,
It is a radiographic imaging apparatus characterized by having.
[0030]
According to the tenth aspect of the present invention, the size of the subject's breast is detected, and the imaging distance is changed so that a predetermined area or more of the subject's breast is detected by the radiation image detector. A breast image can be obtained without any problem.
[0031]
The invention according to claim 11 is the radiographic image capturing apparatus according to claim 10, wherein the distance changing means moves the radiation image detector.
[0032]
According to the eleventh aspect of the present invention, by moving the radiation image detector, a breast image can be obtained without generating an image defect area.
[0033]
According to a twelfth aspect of the present invention, the distance changing unit changes the distance of the subject's breast so that 80% or more of the breast is detected by the radiation image detector. Is a radiation image capturing apparatus.
[0034]
According to the twelfth aspect of the present invention, a breast image can be obtained without causing an image loss area by changing the radiation image detector so that 80% or more of the subject's breast is detected by the radiation image detector.
[0035]
In the invention according to claim 13, the radiation image detector has a mark indicating an irradiation area,
The control unit determines an irradiation area based on the first distance or the second distance, and controls the distance changing unit such that a mark of the radiation image detector matches the determined irradiation area. The radiation image capturing apparatus according to any one of claims 10 to 12.
[0036]
According to the thirteenth aspect of the present invention, the irradiation region is determined, and control is performed so that the mark of the radiation image detector automatically matches the determined irradiation region, so that the image defect region can be easily and reliably determined. A breast image can be obtained without occurrence.
[0037]
The invention according to claim 14 is characterized in that the subject has a bed on which the subject can sleep, and the mammography can be performed with the subject lying down. A radiation image capturing apparatus according to any one of the preceding claims.
[0038]
According to the fourteenth aspect of the present invention, it is possible to easily and reliably take a mammogram while the subject is lying down.
[0039]
The invention according to claim 15 is characterized in that the end face of the radiation image detector is located on a substantially straight line in the vertical direction connecting the focal point of the small-focus radiation source and the subject chest wall surface on the subject holding member. The radiation image capturing apparatus according to any one of claims 1 to 14, wherein
[0040]
According to the fifteenth aspect, it is possible to take a picture from the vertical direction.
[0041]
The invention according to claim 16 is characterized in that the end face of the radiation image detector is located on a substantially straight line in an oblique direction connecting the focal point of the small focus radiation source and the chest wall of the subject on the subject holding member. The radiation image capturing apparatus according to any one of claims 1 to 14, wherein
[0042]
According to the sixteenth aspect, a subject can be photographed from an oblique direction.
[0043]
The radiation according to any one of claims 1 to 16, wherein the radiation image detector is a large cassette having a rectangular shape in plan view of 25 × 32 cm or more. An image capturing device.
[0044]
According to the sixteenth aspect of the present invention, it is possible to obtain a breast image by using a large cassette having a rectangular shape in a plan view of 25 × 32 cm or more and without causing image deficient regions in phase contrast magnification imaging.
[0045]
The invention according to claim 18, wherein the radiation image detector is a large cassette in which the image defect area of the chest wall of the subject is 2 mm or less. It is a radiographic imaging device.
[0046]
According to the eighteenth aspect of the present invention, it is possible to obtain a breast image by using a large cassette in which the image-deficient region of the subject's chest wall is 2 mm or less and performing phase-contrast enlarged photographing without causing any image-defective region.
[0047]
The invention according to claim 19 includes a small-focus radiation source that irradiates a subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject. Have
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
The radiation image detector is a large cassette having a rectangular shape in a plan view and a size of 25 × 32 cm or more.
[0048]
According to the nineteenth aspect of the present invention, it is possible to obtain a breast image by using a large cassette having a rectangular shape in a plan view of 25 × 32 cm or more and without causing image deficient regions in phase contrast magnification imaging.
[0049]
According to a twentieth aspect of the present invention, there is provided a small-focus radiation source that irradiates a subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on radiation transmitted through the subject. Have
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
The radiation image detector is characterized in that the image defect area of the subject's chest wall is a large cassette having a size of 2 mm or less.
[0050]
According to the twentieth aspect, it is possible to obtain a breast image by using a large cassette in which the image-deficient region of the subject's chest wall is 2 mm or less and performing phase-contrast enlarged photographing without generating an image-defective region.
[0051]
The invention according to claim 21 is the radiographic imaging apparatus according to any one of claims 17 to 20, wherein the large cassette has a stimulable phosphor plate.
[0052]
According to the twenty-first aspect of the present invention, a breast image can be obtained by using a stimulable phosphor plate and performing phase-contrast enlarged photographing without generating image-deficient regions.
[0053]
The invention according to claim 22 is the radiographic image capturing apparatus according to any one of claims 17 to 20, wherein the large cassette has a flat panel detector.
[0054]
According to the twenty-second aspect of the present invention, it is possible to obtain a breast image by using a flat panel detector and performing phase-contrast enlarged photographing without generating image-deficient regions.
[0055]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a radiation image capturing apparatus according to the present invention will be described in detail with reference to the drawings, but the present invention is not limited to this embodiment. In the following description, “X-ray” and “radiation” are treated synonymously. In addition, members denoted by the same reference numerals mean members having the same meaning.
[0056]
FIG. 1 is an overall configuration diagram of the radiation image capturing apparatus. An X-ray source controller 12 is connected to a focal point 11a of the X-ray tube as the small focal point radiation source 11, and adjusts an X-ray dose emitted from the focal point 11a of the small focal point radiation source 11 by the X-ray source controller 12. This X-ray dose is one of the radiation conditions of the small focus radiation source 11. The control device 60 as a control unit controls the X-ray source controller 12 according to the X-ray intensity information (radiation intensity information) acquired from the radiation image detector 50. The control device 60 controls the X-ray source controller 12 and, when the radiation image detector 50 converts X-rays into an electric signal, acquires X-ray image information (radiation image information) acquired from the radiation image detector 50. Information) is appropriately processed and displayed on an image display device 90 such as a monitor, or a hard copy is output from an image output device 80 such as a laser imager.
[0057]
X-rays emitted from the small-focal radiation source 11 pass through the subject 15 and are observed by the radiation image detector 50 as X-ray energy (X-ray image information). The radiation image detector 50 has a two-dimensional structure, that is, an area necessary for detecting X-rays transmitted through the subject 15.
[0058]
The radiation image detector 50 detects the intensity of X-rays transmitted through the subject 15, and the obtained X-ray intensity information is sent to the control device 60. In accordance with the X-ray intensity information, the control device 60 controls the X-ray source controller 12 to adjust the amount of X-ray radiated from the small focus radiation source 11. The subject 15 is photographed with the X-ray amount adjusted in this way, and the radiation image detector 50 holds the X-ray image information.
[0059]
Further, the control device 60 sends the distance R1 between the small focus radiation source 11 and the subject holding member 18 (the contact position with the subject 15) and the subject holding member 18 (the contact position with the subject 15) from the position determining device 20 to the radiation. The distance information of the distance R2 to the image detector 50 is transmitted, and the X-ray dose can be controlled.
[0060]
The subject holding member 18 is attached to a rail or the like and is detachable, and its position can be moved and locked according to a photographing mode or the like. The distance R1 and the distance R2 can be changed by sliding the subject holding member 18 on the rail.
[0061]
As the X-ray source small-focus radiation source 11, an X-ray tube that emits X-rays having an X-ray wavelength of about 1 ° is used. The X-ray tube emits X-rays by converting kinetic energy into radiant energy by accelerating electrons generated by thermal excitation at a high voltage and colliding them with a cathode.
[0062]
When capturing an X-ray image, the acceleration voltage is set as a tube voltage, the amount of generated electrons is set as a tube current, and the X-ray emission time is set as an exposure time. The anode (anti-cathode) to which electrons collide can change the emitted X-ray energy spectrum by changing its kind, such as copper, molybdenum, rhodium, and tungsten.
[0063]
When copper, molybdenum, rhodium, etc. are used as the anode, a relatively low-energy line spectrum with a narrow X-ray energy distribution can be obtained. Used for When tungsten is used as the anode, it is a broad spectrum, relatively high energy X-ray that is used for non-destructive testing of the human chest, abdomen, head, and general industry. It is characterized by a large X-ray dose for medical or industrial use. In this case, the anode generates heat to cause a large amount of electrons to collide with the anode at a high speed, and the anode may melt at high temperatures. Avoidance is done. That is, it is common to use a rotating anode.
[0064]
Since the imaging apparatus of this embodiment is an apparatus used for medical or nondestructive inspection purposes, an X-ray tube having a rotating anode of molybdenum, rhodium, or tungsten is desirable.
[0065]
Here, the X-ray focal point 11 a is a window viewed from the direction of the subject 15 for extracting X-rays generated by the collision of electrons with, for example, a rotating anode of the X-ray tube of the small-focal radiation source 11. Generally, this is a square, and the length of one side thereof is the focal size D. When the shape of the focal point is a circle, it indicates its diameter, and when it is rectangular, it indicates its short side. As a method of measuring the focal size D, a method using a pinhole camera, a method using a micro test chart, and the like are described in JIS Z 4704. Usually, the value of the focal size D based on the measurement of the X-ray tube maker is indicated in the product specification.
[0066]
When the focal size D of the X-rays is large, the amount of X-ray emitted increases, but a so-called penumbra occurs as shown in FIG. As shown in FIG. 2, a penumbra is an image in which one point on the subject 15 has a size on the radiation image detector 50 due to the size of the focal point size D (the size E in FIG. 2). This is a phenomenon that is detected as an image having a blur, and is a so-called blur. Therefore, unlike a synchrotron that emits monochromatic parallel X-rays or a micro-focus X-ray source that can be regarded as a point focus, a small-focus X-ray source has a finite focal size D because the X-ray source has a finite size. However, the effect of this penumbra becomes a problem.
[0067]
On the other hand, as shown in FIG. 3, when an X-ray is taken with the distance between the subject 15 and the radiation image detector 50 spaced apart, an edge-enhanced (= phase-contrast-enhanced) image due to refraction of the X-ray may be obtained. it can.
[0068]
As schematically depicted at the lower end of the subject 15 in FIG. 3, the X-rays are refracted when passing through the object, and the X-ray density inside the boundary of the object becomes low. X-rays that overlap with X-rays that do not pass through are increased. In this way, the edge that is the boundary portion of the subject 15 is emphasized as an image. This is considered to be a phenomenon caused by a difference in refractive index between the subject 15 and air with respect to X-rays. In order to obtain an edge-enhanced image (phase contrast image), the distance between the subject 15 and the radiation image detector 50 needs to be equal to or more than a certain value.
[0069]
In order to perform phase contrast imaging, the distance between the subject 15 and the radiation image detector 50 needs to be longer than a certain distance as shown in FIG. At this time, if the subject 15 moves at the time of shooting, an image blur occurs, so the subject 15 needs to be fixed. Therefore, as shown in FIG. 1, the subject holding member 18 is provided between the small-focus radiation source 11 and the radiation image detector 50. The subject holding member 18 is preferably a rectangular frame or a transparent thin plastic plate attached to the frame. Then, the subject holding member 18 is made movable, and the first distance R1 between the small-focus radiation source 11 and the subject holding member 18 (the contact position with the subject 15) and the subject holding member 18 (the contact position with the subject 15). ) And the radiation image detector 50 can be freely adjusted. The distance can be changed by, for example, disposing the subject holding member 18 slidably on the support shaft.
[0070]
Further, as shown in FIG. 1, a position discriminating device 20 for measuring the distance R1 and the distance R2 and supplying them as distance information to the control device 60 is installed. The optimal conditions in are automatically set. As a result, frequent switching between photographing modes is made possible.
[0071]
The position discriminating apparatus 20 is a method based on photometry using infrared rays, a method in which a line resistance is provided on a rail that slides a subject holding member, and a method for discriminating the position from the resistance value measurement. A method of providing a projection and detecting the position to detect the position can be adopted.
[0072]
The radiation image detector 50 is composed of a combination of an X-ray fluorescent intensifying screen and a silver halide photographic film, a stimulable phosphor plate, a scintillator for converting X-ray energy into light, and an optical semiconductor for reading the light. X-ray reader with two-dimensionally arrayed elements, X-ray reader with two-dimensionally arranged photoconductor that converts X-ray energy directly into electric signals and semiconductor element that reads the electric signals, X-rays into light An X-ray reader in which a combination of a scintillator for conversion and a lens for condensing the light on a CCD, CMOS, or the like is two-dimensionally arranged, or a scintillator for converting X-rays to light and the light by an optical fiber. It is possible to use an X-ray reader which leads to a CCD or CMOS and replaces it with an electric signal.
[0073]
In the imaging apparatus according to the present invention, the radiation image detector 50 in which an X-ray fluorescent intensifying screen and a silver halide photographic film are combined is also called an SF system (screen film system). The X-ray fluorescent intensifying screen has a rare earth phosphor such as calcium tungstate or gadolinium oxysulfide, and replaces X-ray energy with blue or green light. In particular, for the intensifying screen using a rare earth phosphor, the technique disclosed in Japanese Patent Application Laid-Open No. 6-67365 may be used. Further, as the silver halide photographic film, it is preferable to use one having a photosensitive emulsion coated on only one side of a support or one having a photosensitive emulsion coated on both sides of a support. In particular, in the case of a double-sided film, it is a preferred embodiment to use a photographic light-sensitive material having different photographic characteristics for each emulsion layer sandwiching a film support. It is also preferable to use a photographic film having a layer for absorbing cross-over light between the respective emulsion surfaces of the double-sided film.
[0074]
The size of the single-sided and double-sided films used in the present invention can be any size from six-cut size to half-cut size. These silver halide photographic light-sensitive materials are outlined in JP-A-6-67365 and, for example, in "Revised Basics of Photographic Engineering -Silver-Salt Photography-" (edited by The Photographic Society of Japan, Corona, 1998). In the case of photographic film development, the average gradation can be increased by raising the processing temperature or extending the processing time. It is preferred to treat with.
[0075]
The stimulable light emission does not emit light at the time of X-ray irradiation, but emits visible light corresponding to the already irradiated X-ray intensity by irradiating visible light after the irradiation. That is, a stimulable phosphor is placed on the radiation image detector 50 of FIG. 1, the stimulable luminescence is read after X-ray irradiation, and the read luminescence is replaced with an electric signal by a photomultiplier tube, and the electric signal of the X-ray image is converted. Get the signal. This electric signal is displayed on an image display means such as a monitor after performing appropriate image processing, or a hard copy of an X-ray image is obtained using an image output means such as a laser imager. At this time, if the image is an enlarged photographed image, it is preferable that the enlargement magnification is input in advance so that the image is automatically returned to the actual size and displayed on a monitor or output as a hard copy. Regarding the radiation image detector 50 using a stimulable phosphor, it is preferable to use the phosphor disclosed in Japanese Patent Application No. 11-49080 and an image visualization technique such as stimulable emission reading in the present invention. It is an aspect.
[0076]
The radiation image detector 50 of the present invention for converting radiation into an electric signal is disclosed in Japanese Patent Application No. 11-49080 or "Handbook of Medical Imaging" Vol. It is a preferred embodiment to use the technology disclosed in Chapter 1, "Flat panel imagers for digital radiography" (ed. RV Matter et al., SPIE Press, Bellingham, 2000). In these cases, the electric signal of the X-ray image obtained by the reading device is appropriately processed, and the image is drawn on a monitor or in a hard copy, and is used for image diagnosis or the like.
[0077]
When an enlarged image is taken in the “phase image shooting mode” for obtaining a phase contrast image, the obtained X-ray image is displayed on a hard copy such as a monitor or photographic film at the actual size of the subject (actual size). In a preferred embodiment, the display is automatically returned. The image enlargement ratio at the time of X-ray image capturing is calculated by the control device 60 automatically acquiring distance information on the distances R1 and R2 from the position determination device 20 and calculating the image display device 90 or the image from the calculated value. When sending the X-ray image information to the output device 80, it is preferable to freely change the image magnification and display or output it.
[0078]
The hard copy is obtained by developing an image using an automatic developing machine or the like using a silver halide photographic light-sensitive material, and is a silver halide photographic light-sensitive material, but after being exposed to a laser beam corresponding to X-ray image information. Preferred embodiments include those which are developed by heating and those in which an image is drawn by heating according to X-ray image information. Also, a solid ink jet recording method for drawing an image by ejecting a liquid state obtained by heating solid ink at normal temperature from a nozzle, an ink jet recording method for drawing an image by ejecting a dye or pigment which is a liquid at normal temperature from a nozzle, an ink ribbon Sublimation by heating and fixing to a recording medium to draw an image, using a hard copy by an ablation image forming method by overheating and evaporating a sheet coated with carbon etc. over the surface with laser light based on image information Is a preferred embodiment.
[0079]
FIG. 4 shows a configuration of a control device as control means of the X-ray imaging apparatus. A system bus 62, an image bus 63, and an input interface 67 are connected to a CPU (Central Processing Unit) 61 that controls the overall operation of the control device. The system bus 62 and the image bus 63 are connected to a shooting control unit 66, a scale information generation unit 71, a memory 64, a disk control unit 70, an image processing unit 76, a frame memory control unit 69, an output interface 68, and the like. . The operation of each unit is controlled by the CPU 61 using the system bus 62, and the transfer of X-ray image information between the units via the image bus 63 is performed.
[0080]
The imaging control unit 66 generates a control signal for controlling the operation and the reading gain of the radiation image detector 50, supplies the control signal to the radiation image detector 50, and reads out the X-ray image information from the radiation image detector 50. To the frame memory controller 69. In addition, a read pixel size is set according to the size of the penumbra calculated by the CPU 61.
[0081]
The frame memory 72 is connected to the frame memory control unit 69, and the X-ray image information generated by the radiation image detector 50 is stored in the frame memory 72. The X-ray image information stored in the frame memory 72 is read and supplied to the disk control unit 70. The frame memory 72 may store the X-ray image information supplied from the radiation image detector 50 after the image processing unit 76 processes the X-ray image information.
[0082]
When supplying the X-ray image information from the frame memory 72 to the disk control unit 70, for example, the X-ray image information is continuously read out and written into the FIFO memory in the disk control unit 70, and then the disk device 73 is sequentially read. Is stored in
[0083]
The X-ray image information read from the frame memory 72 and the X-ray image information read from the disk device 73 are output to an image output device 80 as an image output device or an image as an image display device via an output interface 68. It is supplied to the display device 90 and provided to the user as a visible image.
[0084]
The scale information generation unit 71 generates scale information for determining the size of the X-ray image based on the magnification and the like supplied from the position determination device 20 via the imaging control unit 66. The generated scale information is supplied to the image output device 80 or the image display device 90 via the output interface 68.
[0085]
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 X-ray image information supplied from the radiation image detector 50 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 processing for preventing the influence of penumbra, and processing for making it easier to determine the contour of the subject when phase contrast imaging is performed. Also, from the shooting mode information, the image photographed at a magnification of 1 or more is returned to the image display device 90 such as a monitor or the image output device 80 such as a hard copy, and the display or output almost close to the actual size is automatically performed. Can be done Note that the image processing unit 76 can also be used as the CPU 61 to perform image processing and the like.
[0086]
The input interface 67 receives X-ray intensity information from the radiation image detector 50 and other information such as the sensitivity of the reader and the X-ray tube set voltage value. 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 X-ray image information obtained by imaging and information on imaging such as the magnification of the X-ray 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 (information management by a hospital information system network), or the like.
[0087]
Although the frame memory 72 stores the X-ray image information supplied from the radiation image detector 50, the frame memory 72 stores the processed X-ray image information after processing it by the image processing unit 76 or the like. It may be. The disk device 73 stores the X-ray image information stored in the frame memory 72, that is, the X-ray image information obtained by processing the X-ray image information supplied from the radiation image detector 50 by the image processing unit 76 as management information. Etc. can be saved.
[0088]
When an SF system or a stimulable luminescent fluorescent plate is used as the radiation image detector 50, the control device 60 controls the X-ray intensity information from the radiation image detector 50, the position determination information from the position determination device 20, and The imaging conditions are calculated from the mode information using the focus / focus diameter information and a control program stored in the memory 64 in advance, and the imaging control is performed through the X-ray source controller 12.
[0089]
When an electric signal of X-ray image information is input from the radiation image detector 50, the control device 60 stores the electric signal information, the position determination information, the sensitivity of the radiation image detector, and the X-ray tube set voltage in the memory 64 in advance. The imaging conditions are calculated using the stored focus / focus diameter information and a control program, and the imaging control is performed through the X-ray source controller 12.
[0090]
FIG. 5 shows a first embodiment of a radiographic image capturing apparatus for mammography. In the radiographic image capturing apparatus according to this embodiment, a small focus radiation source 11, a subject holding member 18, and a radiation image detector 50 are provided on a support column 901. The end face 50a of the radiation image detector 50 is located on a substantially straight line L1 connecting the focal point 11a of the small focus radiation source 11 and the subject chest wall 15a on the subject holding member 18, and the subject held by the subject holding member 18 Phase contrast mammography of the breast is performed.
[0091]
The phase contrast mammography is to obtain an image obtained by using phase information (interference, diffraction, refraction) of X-rays. Specifically, for example, an apparatus disclosed in Japanese Patent Application No. 11-203969 is disclosed. These are images obtained by photographing with the device of Japanese Patent Application No. 11-266605, the device of Japanese Patent Application No. 2000-44381, the device of Japanese Patent Application No. 2000-53562, and the like. It is an image obtained by a photographing method such as the method of Japanese Patent Application No. 11-266605 and the method of Japanese Patent Application No. 2000-44381.
[0092]
An apparatus described in Japanese Patent Application No. 11-203969 is an X-ray tube having a focal size (D μm) of 30 μm or more, a fixing means for fixing a subject position, and an X-ray detection for detecting an X-ray image transmitted through the subject. And a fixing means for setting a distance R1 (m) from the X-ray tube to the subject fixed by the fixing means.
R1 ≧ (D-7) / 200 (m)
And the distance R2 from the subject fixed by the fixing means to the X-ray detector can be set to 0.15 m or more.
[0093]
In the method described in Japanese Patent Application No. 11-203969, an X-ray image emitted from an X-ray tube and transmitted through a subject is detected by an X-ray detector, and sharpness reduced by penumbra is emphasized by refraction contrast enhancement. X-ray imaging method that enhances by image edge enhancement by
An X-ray imaging method using an X-ray tube having a focal size (Dμm) of 30 μm or more,
The distance R1 (m) from the X-ray tube to the subject is
R1 ≧ (D-7) / 200 (m)
And the distance R2 from the subject to the X-ray detector is set to 0.15 m or more.
[0094]
Regarding the apparatus and the method described in Japanese Patent Application No. 11-203969, the distance R1 is 10> R1 ≧ (D-7) / 200 (m), and further, 0.7 ≦ R1 ≦ 5 (m). That the focus size of the X-ray tube is 30 μm or more and 1000 μm or less, that the focus size of the X-ray tube is 50 μm or more and 500 μm or less, More preferred embodiments are 10 keV or more and 60 keV or less, the anode of the X-ray tube contains molybdenum or rhodium, and the pixel size of the digital X-ray detector is 1 μm or more and 200 μm or less.
[0095]
Japanese Patent Application No. 2000-44381 discloses an X-ray tube for irradiating divergent X-rays, a subject holder for fixing a subject to the X-ray tube, and an X-ray for detecting an X-ray image transmitted through the subject. X-rays emitted from an X-ray tube when a blur width due to penumbra of an X-ray image is B (μm) and an edge enhancement width due to X-ray diffraction contrast is E (μm). Is an X-ray image photographing apparatus in which a subject holder and an X-ray image detector can be installed so that 9E ≧ B when X-ray magnified photographing is performed by transmitting light through a subject.
[0096]
In addition, the method described in Japanese Patent Application No. 2000-44381 uses an X-ray tube that emits divergent X-rays, transmits X-rays emitted from the X-ray tube to a subject, and performs X-ray magnified imaging. Assuming that the blur width due to the penumbra of the X-ray image obtained by the X-ray magnification imaging is B (μm) and the edge enhancement width due to the X-ray refraction contrast is E (μm), X-ray imaging is performed such that 9E ≧ B. Is the way.
[0097]
Regarding the apparatus and method described in Japanese Patent Application No. 2000-44381, the distance R1 between the X-ray tube and the subject is set to 0.5 m or more, and the distance R2 between the subject and the X-ray image detector is set to 1 m or more. Further, the R1 + R2 is 5 m or less, the X-ray magnified radiography is 1.0 to 10 times, the focal size of the X-ray tube is 10 μm or more and 1000 μm or less, and the focal size of the X-ray tube is further Is not less than 30 μm and not more than 300 μm, the set tube voltage of the X-ray irradiated to the subject is 50 to 150 kVp, the X-ray tube is a tungsten rotating anode X-ray tube, the pixel of the X-ray detector More preferably, the size is 1 μm or more and 200 μm or less.
[0098]
The edge enhancement width E can be expressed by, for example, the following three equations. Here, R1: X-ray source-subject distance (m), R2: subject-X-ray image detector (m), λ: wavelength of the maximum value of X-ray dose (Å), A: when the subject is a cylinder The diameter (mm) of the circle of the cross section, δ: refractive index difference between the object and air
[0099]
E = 39 × R2 (1 + 0.045 / R1) × λ2 × √A
E = 27 × (1 + R2 / R1) 1/3 × (λ2 × R2 × √A) 2/3
E = 2.3 × (1 + R2 / R1) 1/3 × (R2 × δ × √A) 2/3
The apparatus described in Japanese Patent Application No. 11-266605 is provided with a subject support device and a film cassette holder which can be moved and temporarily fixed on a support member, and is provided with a coolridge X-ray tube and a film cassette holder. The distance from the screen film system to the screen film system can be more than 70 cm, and the distance between the subject of the subject support device and the screen film system of the film cassette holder can be more than 20 cm. This is an X-ray image photographing apparatus for photographing.
[0100]
Further, the method described in Japanese Patent Application No. 11-266605 is provided with a subject support device and a film cassette holder that can be moved and temporarily fixed on a support member, and a coolridge X-ray tube and a film cassette holder are provided. X-ray image capturing method in which the distance between the tool and the screen film system is 70 cm or more, and the distance between the subject of the subject support device and the screen cassette system of the film cassette holder is 20 cm or more, and an X-ray refraction contrast image is taken. is there.
[0101]
An apparatus disclosed in Japanese Patent Application No. 2000-53562 includes a small-focus radiation source for irradiating a subject with radiation, a holding member for holding the subject, reading means for reading radiation image information based on radiation transmitted through the subject, and a small-focus radiation source. A distance changing means for changing a first distance between the first holding means and the holding member or a second distance between the holding member and the reading means, and a control means for controlling a radiation condition of the small focal point radiation source; The control unit is a radiation image capturing apparatus that controls a radiation condition of the small focus radiation source in accordance with at least the distance information regarding the first distance or the second distance,
A small-focus radiation source for irradiating the subject with radiation; a holding member for holding the subject; reading means for reading radiation image information based on the radiation transmitted through the subject; image display means or radiation image information for displaying the radiation image information And a control unit for changing the image magnification at the time of radiographic image capturing and displaying the radiographic image information by the image display unit or outputting by the image output unit. .
[0102]
The normal photographing is to photograph a subject in close contact with an X-ray image detector and, in some cases, through a grid, and the normal photographed image is an image obtained by the normal photographing.
[0103]
Further, a phase contrast image photographing apparatus capable of directly obtaining a phase contrast image as a digital image is an apparatus capable of photographing a phase contrast image together with normal photographing (general photographing which is usually performed).
[0104]
In the embodiment shown in FIG. 5A, the focal point 11a of the small-focal radiation source 11 is located on the side closer to the subject 15, and the end face 50a of the radiation image detector 50 is connected to the focal point 11a of the small-focal radiation source 11 and the subject It is located on a substantially vertical straight line L1 connecting the subject's chest wall surface 15a on the holding member 18 and can take an image from the vertical direction.
[0105]
In the embodiment shown in FIG. 5B, the focal point 11a of the small-focal radiation source 11 is located on the side away from the subject 15, and the end face 50a of the radiation image detector 50 is connected to the focal point 11a of the small-focal radiation source 11 and the subject It is located on a substantially straight line L1 in an oblique direction connecting the subject's chest wall surface 15a on the holding member 18, and can take an image from an oblique direction.
[0106]
In this embodiment, the focal point 11a of the small-focus radiation source 11 is located on the side away from the subject 15, but the focal point 11a of the small-focus radiation source 11 is located on the side approaching the subject 15, and the breast 15 of the subject 15 May be taken from the left and right oblique directions.
[0107]
As described above, the end face 50a of the radiation image detector 50 is positioned on the substantially straight line L1 connecting the focal point 11a of the small-focus radiation source 11 and the subject chest wall 15a on the subject holding member 18, thereby increasing the phase contrast. In imaging, it is possible to reduce the exposure of the subject 15 to radiation, and to obtain a breast image without generating an image defect area. The image-deficient region means that while the radiation emitted from the X-ray source and transmitted through the subject 15 is coming to the detector direction, there is no radiation image detector 50, specifically, a part in the radiation detector that actually detects radiation. Therefore, an area where radiation having subject information cannot be detected is shown.
[0108]
FIG. 6 shows a second embodiment of the radiation image capturing apparatus for mammography. The radiation image capturing apparatus according to this embodiment has the same configuration as that of the embodiment shown in FIG. 5 with the same reference numeral, but includes a moving unit 100 in this embodiment. The moving means 100 moves the object 50 such that the end face 50a of the radiation image detector 50 is positioned on a substantially straight line L1 connecting the focal point 11a of the small focus radiation source 11 and the subject chest wall 15a on the subject holding member 18. The holding member 18 and the radiation image detector 50 are moved. The moving means 100 is configured such that the subject holding member 18 and the radiation image detector 50 can be moved in the direction of the arrow by, for example, a guide rail or the like, and the driving source of the movement may be a motor or may be manually movable. Well, there is no particular limitation.
[0109]
Only the subject holding member 18 may be moved, or only the radiation image detector 50 may be moved, or the subject holding member 18 and the radiation image detector 50 may be simultaneously moved according to the size of the breast of the subject 15 or the imaging direction. You may move.
[0110]
In the embodiment of FIG. 6A, the focal point 11a of the small focus radiation source 11 is located on the side closer to the subject 15, and the image can be taken from the vertical direction as in the embodiment of FIG. In the embodiment of FIG. 6B, the focal point 11a of the small-focus radiation source 11 is located on the side away from the subject 15, and it is possible to take an image from an oblique direction as in the embodiment of FIG. 5B.
[0111]
As described above, the object holding member 18 and the radiation image detector 50 are moved so that the end face 50 a of the radiation image detector 50 is moved to the focal point 11 a of the small-focus radiation source 11 and the object chest wall 15 a on the object holding member 18. Is positioned on the substantially straight line L1 connecting the subject and the subject 15, in the phase-contrast enlarged imaging, the exposure of the subject 15 to radiation can be reduced, and a breast image can be obtained without generating an image-deficient region.
[0112]
FIG. 7 shows a third embodiment of the radiographic image capturing apparatus for mammography. The radiation image capturing apparatus according to this embodiment has the same configuration as that of the embodiment shown in FIG. 5 except that the end face 50a of the radiation image detector 50 has a small focus. The subject is located on the substantially straight line L1 connecting the focal point 11a of the radiation source 11 and the subject chest wall 15a on the subject holding member 18.
[0113]
In the embodiment of FIG. 7A, the focal point 11a of the small focus radiation source 11 is located on the side closer to the subject 15, and the image can be taken in the vertical direction as in the embodiment of FIG. In the embodiment of FIG. 7B, the focal point 11a of the small-focus radiation source 11 is located on the side away from the subject 15, and it is possible to take an image from an oblique direction as in the embodiment of FIG. 5B.
[0114]
As described above, the end face 50a of the radiation image detector 50 is positioned closer to the subject than on the substantially straight line L1 connecting the focal point 11a of the small-focus radiation source 11 and the subject chest wall 15a on the subject holding member 18. In the phase-contrast enlarged photographing, it is possible to reduce exposure of the subject 15 to radiation and obtain a breast image without generating an image-defective region.
[0115]
As shown in the fourth embodiment in FIG. 8, the radiation image detector 50 of this embodiment has a stimulable phosphor 50b for detecting a radiation image, and the stimulable phosphor end face 50b1 is substantially formed. It is located on the straight line L1, and a breast image can be obtained without generating an image defect area in the stimulable phosphor 50b.
[0116]
Further, the radiation image detector 50 of this embodiment has a stimulable phosphor 50b for detecting a radiation image as shown in a fifth embodiment of FIG. 9, and the stimulable phosphor end face 50b1. Is located on the subject side at least 2 mm from the substantially straight line L1, and the stimulable phosphor end face 50b1 is located on the subject side, so that a mammogram can be obtained without any image-deficient area in the stimulable phosphor 50b. Can be.
[0117]
FIG. 10 shows a sixth embodiment of the radiation image capturing apparatus for mammography. The radiation image capturing apparatus of this embodiment has the same configuration as that of the embodiment shown in FIG. 5 with the same reference numerals, but includes a moving unit 101 in this embodiment. The moving means 101 is arranged such that the end face 50a of the radiation image detector 50 is located on the subject side with respect to the substantially straight line L1 connecting the focal point 11a of the small-focus radiation source 11 and the subject chest wall 15a on the subject holding member 18. Then, the subject holding member 18 and the radiation image detector 50 are moved.
[0118]
The moving means 101 is configured such that the subject holding member 18 and the radiation image detector 50 can be moved in the direction of an arrow by, for example, a guide rail or the like, and the driving source of the movement may be a motor or may be manually movable. Well, there is no particular limitation. Only the subject holding member 18 may be moved, or only the radiation image detector 50 may be moved, or the subject holding member 18 and the radiation image detector 50 may be simultaneously moved according to the size of the breast of the subject 15 or the imaging direction. You may move.
[0119]
In the embodiment of FIG. 10A, the focal point 11a of the small focus radiation source 11 is located on the side closer to the subject 15, and the image can be taken in the vertical direction as in the embodiment of FIG. In the embodiment shown in FIG. 10B, the focal point 11a of the small-focus radiation source 11 is located on the side away from the subject 15, and the image can be taken obliquely as in the embodiment shown in FIG. 5B.
[0120]
As described above, the subject holding member 18 and the radiation image detector 50 are moved, and the end face 50a of the radiation image detector 50 is moved to the focal point 11a of the small-focus radiation source 11, the subject chest wall 15a on the subject holding member 18, and the like. Is positioned closer to the subject than on the substantially straight line L1 connecting the lines, it is possible to reduce the exposure of the subject 15 to radiation in the phase-contrast enlarged imaging, and to obtain a breast image without generating an image-deficient region.
[0121]
FIG. 11 shows a seventh embodiment of the radiographic image capturing apparatus for mammography. The radiation image capturing apparatus according to this embodiment has the same configuration as that of the embodiment shown in FIG. 5 with the same reference numerals, but in this embodiment, the first moving means 110 and the second moving means 111 And a control unit 112. The control means 112 includes the control device 12 shown in FIGS.
[0122]
The first moving means 110 holds the subject such that the end face 50a of the radiation image detector 50 is on a substantially straight line L1 connecting the focal point 11a of the small focus radiation source 11 and the subject chest wall 15a on the subject holding member 18. The member 18 and the radiation image detector 50 are moved. The movement of the subject holding member 18 of the first moving means 110 and the radiation image detector 50 is performed in the same manner as in the embodiment of FIG.
[0123]
The second moving means 111 causes the end face 50a of the radiation image detector 50 to be closer to the subject than on a substantially straight line L1 connecting the focal point 11a of the small focus radiation source 11 and the subject chest wall 15a on the subject holding member 18. Then, the subject holding member 18 and the radiation image detector 50 are moved. The movement of the subject holding member 18 of the second moving means 111 and the radiation image detector 50 is performed in the same manner as in the embodiment of FIG.
[0124]
The control unit 112 switches between the first moving unit 110 and the second moving unit 111 according to the subject, the photographing direction, and the like. The shooting direction is switched depending on the vertical direction and a direction other than the vertical direction.
[0125]
As described above, by switching between the first moving unit 110 and the second moving unit 111 depending on the subject, the photographing direction, and the like, the patient of the subject 15 can photograph without taking an unreasonable posture, and without generating an image loss area. A breast image can be obtained.
[0126]
FIG. 12 shows an eighth embodiment of a mammography radiation image photographing apparatus. The radiation image capturing apparatus according to this embodiment has the same configuration as that of the embodiment shown in FIG. 5 with the same reference numerals, but in this embodiment, the distance changing unit 120 and the subject breast detecting unit 121 , Control means 122. The control means 122 includes the control device 12 shown in FIGS.
[0127]
The distance changing means 120 changes a first distance R1 between the small-focus radiation source 11 and the subject holding member 18 or a second distance R2 between the subject holding member 18 and the radiation image detector 50. As described in FIGS. 1 and 4, the distance changing unit 120 makes the subject holding member 18 movable, further makes the radiation image detector 50 movable, and makes the small-focus radiation source 11 and the subject holding member 18 (the subject 15 and (A contact position), and a second distance R2 between the subject holding member 18 (the contact position with the subject 15) and the radiation image detector 50 can be freely adjusted. . The distance changing means 120 can be achieved by adopting a method in which the subject holding member 18 and the radiation image detector 50 are slidably disposed on a support shaft.
[0128]
The subject breast detecting means 121 detects the size of the subject breast. As the subject breast detecting means 121, for example, a CCD camera can be used, and the size of the subject breast can be detected from the image of the breast.
[0129]
The control unit 122 controls the distance changing unit 120 based on the detection information of the size of the subject breast from the subject breast detection unit 121 so that the radiation image detector 50 detects a predetermined area or more of the subject breast.
[0130]
As described above, by detecting the size of the subject's breast and changing the shooting distance so that the radiation image detector detects a predetermined region or more of the subject's breast, it is possible to obtain a breast image without causing an image loss region. Preferably, the radiation image detector 50 is changed to detect the 80% or more area of the subject's breast.
[0131]
As shown in FIG. 13, the radiation image detector 50 of this embodiment has a mark 130 indicating an irradiation area, and the control unit 122 determines the irradiation area based on the first distance R1 or the second distance R2. Then, the distance changing unit 120 is controlled so that the mark 130 of the radiation image detector 50 matches the determined irradiation area. In this way, by determining the irradiation area and controlling the mark 130 of the radiation image detector 50 to automatically match the determined irradiation area, the image of the breast can be easily and reliably generated without any image defect area. Can be obtained.
[0132]
FIG. 14 shows a ninth embodiment of a radiographic image capturing apparatus for mammography. The radiation image capturing apparatus of this embodiment has the same configuration as that of the embodiment of FIG. 5 with the same reference numerals, but in this embodiment, a bed 200 on which the subject 15 can sleep. It is possible to perform mammography with the subject lying down on the side.
[0133]
An opening 201 for taking out the subject's breast is provided near the center of the bed 200 on which the subject 15 lies, and the breast is brought out of the opening 201. Since the subject lies on the couch 200, the width is preferably 0.5 m or more and 2 m or less, and the vertical size is preferably about 2 m to 6 m. Further, since the bed 200 is in direct contact with the subject's skin, it is preferable that the bed 200 gives a soft touch to the skin, such as a fibrous rug or a towel, and is replaceable for each subject. The opening 201 for extruding the breast must have a size and shape capable of extruding not only the breast but also the chest muscle. That is, it is preferable that the diameter of the breast is 15 cm or more, the periphery of the opening 201 is shaped according to the shape of the body, and the whole breast comes out of the opening 201 as much as possible. It is preferable to use a soft material or the like around the opening 201 so as not to give any pain to the subject.
[0134]
In the radiation image capturing apparatus for mammography according to the present invention, the radiation image detector 50 is a large cassette having a thin box shape, a rectangular shape in plan view, and a size of 25 × 32 cm or more, as shown in FIG. In this embodiment, the width is 30 cm and the length is 36 cm. However, the present invention is not limited to this. By using a large cassette having a rectangular shape in plan view of 25 × 32 cm or more, an image defect area is generated in phase contrast enlarged photography. A breast image can be obtained without any problem.
[0135]
Further, in the radiographic image capturing apparatus for mammography according to the present invention, as shown in FIG. 16, the radiation image detector 50 has an image detection area 50c, and the image-deficient area 50d of the subject's chest wall is a large cassette having a size of 2 mm or less. is there. As described above, by using a large cassette having an image-defective area of the subject's chest wall of 2 mm or less, a magnified image can be obtained without an image-defective area in phase contrast enlarged imaging.
[0136]
The large cassettes shown in FIGS. 15 and 16 have a stimulable phosphor plate, and use the stimulable phosphor plate to obtain a breast image without an image-deficient region in phase-contrast enlarged photographing. Can be.
[0137]
Further, as another embodiment of the large-sized cassette, a flat panel detector is provided, and by using the flat panel detector, a magnified image can be obtained without an image deficient region in phase contrast enlarged photographing.
[0138]
As described above, the image-deficient region means that the stimulable phosphor plate or the flat panel detector on the chest wall side does not exist until the end face of the cassette and the stimulable phosphor plate or the flat panel detector for performing image detection exist. Area.
[0139]
Next, an embodiment of a large cassette will be described. First, the attachment of the sealed phosphor plate to the flat plate shown in FIGS. 17 and 18 which is a cross-sectional view of the sealed phosphor plate of one embodiment of the large cassette will be described.
[0140]
As shown in FIG. 17, the stimulable phosphor plate 301 includes a support 303 and a stimulable phosphor layer 305 applied on the support 303. The stimulable phosphor plate 301 is a sealed phosphor plate 313 sealed with a moisture-proof film 311.
[0141]
In this embodiment, as shown in FIGS. 17 and 18, a stimulable phosphor plate 301 is provided in a folded film 311 and three sides 311b, 311c, 311d other than the folded side 311a are sealed. It is sealed by a folded back sealing structure.
[0142]
Then, as shown in FIG. 18, the sealing phosphor plate 313 is stuck on the flat plate 321 using the double-sided tape 323 such that the folded side 311 a of the film 311 and one side of the flat plate 321 substantially coincide with each other. .
[0143]
According to the above configuration, the following effects can be obtained.
(1) The stimulable phosphor plate 301 is provided in the folded film 311 and is sealed by a folded sealing structure in which three sides other than the folded side 311a are sealed, so that the folded side 311a is sealed. The stop width L (see FIG. 17) can be reduced, and the image defect area can be reduced.
(2) The folded side 311a of the film 311 is attached along the vicinity of one side of the flat plate 321 in the flat plate 321, so that the image defect area (L ', see FIG. 17) can be reduced.
[0144]
As in this embodiment, the image loss area is configured to be 2 mm or less as shown in FIG.
[0145]
Next, a method for manufacturing the sealing phosphor plate 313 will be described with reference to FIGS.
[0146]
One sheet of moisture-proof film 311 is folded, and the folded side 311a is squeezed with a finger to make a fold. The sides 311c and 311d orthogonal to the folded side 311a of the film 311 are heat-sealed using an impulse sealer to form a bag-like film (three-sided bag) having an opening. The cut stimulable phosphor plate 301 is inserted through the opening of the bag-like film (FIG. 19A), and the stimulable phosphor plate 101 is pressed against the folded side 311a (FIG. 19B).
[0147]
A heavy transparent plate (a glass plate having a thickness of 7.5 mm) is placed on the stimulable phosphor plate 301 including the folded side 311a, and the stimulable phosphor plate 301 is moved in a direction away from the folded side 311a. After confirming that there is no gas, the opening is sealed while being evacuated in the vacuum chamber (FIG. 19C). Then, heat sealing is performed again on the four sides 311a to 311d including the folded side 311a in the vicinity of the stimulable phosphor plate 301.
[0148]
As shown in FIG. 20A, the heat sealer 351 for performing the heat sealing is provided with a heater 355 on the base 353 side, and the pressing member 357 for pressing the member to be sealed is made of soft rubber. Therefore, the sealing phosphor plate 313 is heated from the side opposite to the stimulable phosphor layer 305, that is, heated from the support 303 side by the heater 355.
[0149]
Furthermore, the sealing phosphor plate 313 is installed so that the edge of the heater 355 is positioned 1.0 mm inward into the stimulable phosphor plate 301 (FIG. 20A).
[0150]
The pressing member 357 is pressed against the sealing phosphor plate 313 to perform heat sealing (FIG. 20B).
[0151]
The three sides 311b, 311c, and 311d other than the folded side 311a cut the margin of the film 311 at a position 2.9 mm from the edge of the stimulable phosphor plate 301.
[0152]
Using a double-sided tape 323 having a matrix (irregularity) structure, a sealing phosphor plate 313 is attached to a flat plate 321 on which carbon fibers having a thickness of 1.5 mm are laminated. At this time, the folded side 311a of the film 311 is attached along the vicinity of one side of the flat plate 321 (in the case of mammography imaging, the side in contact with the chest wall of the subject) within the flat plate 321.
[0153]
Nip pressure 2.0kg / cm ² A pair of nip rollers having a Shore hardness of 30 ° is passed through a sealing phosphor plate 313 affixed to a flat plate 321 with the folded side 311a side first, and pressure-bonded sequentially from the folded side 311a side. Here, a manufacturing apparatus of the sealing phosphor plate 313 and the double-sided tape 323 will be described with reference to FIGS.
[0154]
In FIG. 22, reference numeral 410 denotes a first base on which the rigid phosphor plate 313 having no rigidity is placed. The folded side 311a of the mounted sealing phosphor plate 313 abuts on the mounting surface of the sealing phosphor plate 313 of the first base 410, and a protrusion for positioning the sealing phosphor plate 313 is provided. A contact portion 414 is provided.
[0155]
Further, the first base is provided with a plane holding means 416 for holding the plane of the sealing phosphor plate 313. The plane holding means 416 is composed of small holes 418 formed at substantially the same density on the mounting surface 410 a of the sealing phosphor plate 313 of the first base 410, and a suction pump 420 connected to these small holes 418. ing.
[0156]
A second base 430 is disposed at a position parallel to the first base 410, and the flat plate 321 is mounted on a surface 430 a of the first base 410 facing the mounting surface 410 a of the sealing phosphor plate 313. It is.
[0157]
On the flat plate mounting surface 430a of the second base 430, an abutting portion 434 for positioning the flat plate 321 to be mounted is provided. In the apparatus of this embodiment, the folded side 311a of the sealing phosphor plate 313 has a very close positional relationship to one side of the flat plate 321 (in the case of mammography, the side of the chest wall), that is, the folded side of the film 311. An abutting portion 414 of the first base 410 and an abutting portion 434 of the second base 430 are provided such that the side 311a substantially coincides with one side of the flat plate 321.
[0158]
On the sealing phosphor plate mounting surface 410a of the first base 410, a guide rod 440 extending in a direction orthogonal to the mounting surface 410a is provided upright. On the other hand, the second base 430 is provided with a hole 436 into which the guide bar 440 is loosely fitted, and the second base 430 is guided by the guide bar 440 and is kept parallel to the first base 410. Can be approached / separated.
[0159]
Further, the intermediate portion is wound around the guide bar 440, and one end is engaged with the first base 410, and the other end is engaged with the second base 430 by the biasing force of the spring 442. The base 430 is urged away from the first base, and the second base 430 is spaced from the first base 410 in the natural state of the spring 442.
[0160]
A method of attaching the sealing phosphor plate 313 to the flat plate 321 using the phosphor plate attaching device having the above configuration will be described.
(1) The sealing phosphor plate 313 is abutted against the butting portion 414 of the first base 410 to perform positioning, and the sealing phosphor plate 313 is mounted on the mounting surface 410a of the first base.
(2) The flat plate 321 is positioned against the butting portion 434 of the second base 430 to perform positioning, and the flat plate 321 is mounted on the mounting surface 430 a of the second base 430. (3) The opposing surface 313a of the flat plate 321 mounted on the second base 430 of the sealing phosphor plate 313 mounted on the first base 410, and the flat plate 321 mounted on the second base 430 The double-sided tape 323 is attached to at least one of the opposing surfaces 321 a of the sealing phosphor plate 313 placed on the first base 410, in this embodiment, the flat plate 321. Note that an adhesive may be used instead of the double-sided tape 323.
[0161]
As shown in FIG. 23A, the double-sided tape 323 used in this embodiment includes a base material 323a, and adhesive layers 323b and 323c formed on both surfaces of the base material 323a.
[0162]
As shown in FIG. 23 (b), the adhesive layers 323b and 323c are regularly formed with prismatic protrusions 323d to form an adhesive layer having a height difference.
(4) The second base 430 is moved downward against the urging force of the spring 442, and the sealing phosphor plate 313 and the flat plate 321 are attached.
[0163]
According to the above manufacturing method, the following effects can be obtained.
(1) When an inorganic vapor-deposited film such as an aluminum oxide-deposited polyethylene terephthalate film is used as the film, the folded-back portion of the inorganic vapor-deposited layer is used. The film itself causes a small crack due to the folding, but by heat sealing the folded portion, the small crack is melt-sealed and the penetration of water vapor can be prevented.
(2) The heat seal can prevent heat from propagating to the stimulable phosphor layer 305 by applying heat from the surface opposite to the stimulable phosphor layer 305.
(3) When degassing and sealing the side 311b opposing the folded side 311a, the stimulable phosphor plate 301 is pressed against the stimulable phosphor plate 301 by the plate, so that the stimulable phosphor plate 301 abuts against the folded side 311a. Can be prevented from moving.
(4) By making the plate transparent, when the plate is pressed down, minute movement of the stimulable phosphor plate 301 can be easily visually recognized.
(5) By sticking to the flat plate 321 with the folded side 311a as a position reference, the sticking position is less affected by various tolerances (tolerances for trimming the width of the trimming width and tolerances for trimming the stimulable phosphor plate).
(6) By performing the pressure bonding sequentially from the folded side 311a, the sealing phosphor plate or the flat plate at the time of the pressure bonding is less affected by the expansion and contraction of the bonding position.
[0164]
【The invention's effect】
As described above, in the invention according to claim 1, the end face of the radiation image detector is located on a substantially straight line connecting the focal point of the small-focus radiation source and the subject's chest wall surface on the subject holding member, In the phase-contrast enlarged photographing, it is possible to reduce the exposure of the subject to radiation and obtain a breast image without generating an image-defective region.
[0165]
According to the second aspect of the present invention, the subject holding member and the radiation image detector are moved so that the end face of the radiation image detector connects the focal point of the small focus radiation source and the subject chest wall surface on the subject holding member. By being positioned on a substantially straight line, it is possible to reduce the exposure of the subject to radiation in phase contrast enlarged imaging, and to obtain a breast image without generating an image defect area.
[0166]
According to the third aspect of the present invention, the end face of the radiation image detector is located closer to the subject than a substantially straight line connecting the focal point of the small focus radiation source and the subject's chest wall surface on the subject holding member. In magnified photography, it is possible to reduce the exposure of the subject to radiation, and to obtain a breast image without generating an image-defective region.
[0167]
According to the fourth aspect of the present invention, it is possible to obtain a breast image without generating an image-defective region in the stimulable phosphor.
[0168]
According to the fifth aspect of the present invention, it is possible to obtain a breast image without generating an image-defective region in the flat panel detector.
[0169]
According to the sixth aspect of the present invention, since the end face of the stimulable phosphor is located on the subject side, a breast image can be obtained without generating an image-defective region in the stimulable phosphor.
[0170]
According to the seventh aspect of the present invention, the subject holding member and the radiation image detector are moved, and the end face of the radiation image detector connects the focal point of the small focus radiation source and the subject chest wall surface on the subject holding member. By being positioned closer to the subject than on the straight line, it is possible to reduce the exposure of the subject to radiation in phase-contrast enlarged imaging, and to obtain a breast image without generating image-deficient regions.
[0171]
In the invention according to claim 8, by switching between the first moving means and the second moving means depending on the subject, the photographing direction, and the like, the subject patient can photograph without taking an unreasonable posture, and an image-deficient region occurs. A breast image can be obtained without the need.
[0172]
According to the ninth aspect of the present invention, by switching the imaging direction between the vertical direction and a direction other than the vertical direction, it is possible to reduce exposure of the subject to radiation in accordance with the imaging direction, and to prevent the occurrence of an image-deficient area without causing a breast. Images can be obtained.
[0173]
In the invention according to claim 10, by detecting the size of the subject's breast and changing the shooting distance so as to detect a predetermined region or more of the subject's breast with a radiation image detector, an image missing region does not occur. A breast image can be obtained.
[0174]
According to the eleventh aspect of the present invention, by moving the radiation image detector, a breast image can be obtained without generating an image-defective region.
[0175]
According to the twelfth aspect, by changing the radiation image detector to detect 80% or more of the subject's breast, a breast image can be obtained without generating an image-deficient region.
[0176]
According to the thirteenth aspect of the present invention, the irradiation area is determined, and control is performed so that the mark of the radiation image detector automatically matches the determined irradiation area, so that the image defect area can be easily and reliably generated. Breast images can be obtained without the need.
[0177]
According to the fourteenth aspect of the present invention, it is possible to easily and reliably take a mammogram while the subject is lying down.
[0178]
According to the fifteenth aspect, the subject can be photographed from the vertical direction.
[0179]
According to the sixteenth aspect, the subject can be photographed from an oblique direction.
[0180]
According to the seventeenth aspect, it is possible to obtain a breast image by using a large cassette having a rectangular shape in a plan view and having a size of 25 × 32 cm or more and without causing an image defect region in phase contrast magnification imaging.
[0181]
According to the eighteenth aspect of the present invention, it is possible to obtain a breast image by using a large cassette in which the image-deficient area of the subject's chest wall is 2 mm or less and performing phase-contrast enlarged imaging without generating an image-defective area.
[0182]
According to the nineteenth aspect of the present invention, it is possible to obtain a breast image by using a large cassette having a rectangular shape in a plan view of 25 × 32 cm or more and without causing image deficient regions in phase contrast magnification imaging.
[0183]
According to the twentieth aspect of the present invention, it is possible to obtain a breast image by using a large cassette in which the image-defective area of the subject's chest wall is 2 mm or less and performing phase-contrast enlarged photographing without generating an image-defective area.
[0184]
According to the twenty-first aspect of the present invention, a breast image can be obtained by using a stimulable phosphor plate and performing phase-contrast enlarged photographing without generating image-deficient regions.
[0185]
According to the invention described in claim 22, it is possible to obtain a breast image by using a flat panel detector and performing phase-contrast enlarged photographing without generating an image-defective region.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a radiographic image capturing apparatus.
FIG. 2 is a diagram illustrating that penumbra blur occurs.
FIG. 3 shows that the X-rays are refracted when passing through an object and the X-ray density inside the boundary of the object becomes low, and the outside of the subject overlaps with the X-rays that do not pass through the subject, so that the X-ray density increases. FIG.
FIG. 4 shows a configuration of a control device as control means of the X-ray image photographing device.
FIG. 5 is a diagram showing a first embodiment of a radiographic image capturing apparatus for mammography.
FIG. 6 is a diagram illustrating a second embodiment of a radiation image capturing apparatus for mammography.
FIG. 7 is a diagram illustrating a third embodiment of a radiation image capturing apparatus for mammography.
FIG. 8 is a diagram showing a fourth embodiment of the radiographic image capturing apparatus for mammography.
FIG. 9 is a diagram showing a fifth embodiment of the radiation image capturing apparatus for mammography.
FIG. 10 is a diagram showing a sixth embodiment of the radiation image capturing apparatus for mammography.
FIG. 11 is a diagram illustrating a seventh embodiment of a radiation image capturing apparatus for mammography.
FIG. 12 is a diagram illustrating an eighth embodiment of a radiation image capturing apparatus for mammography.
FIG. 13 is a plan view of a radiation image detector having a mark indicating an irradiation area.
FIG. 14 is a diagram showing a ninth embodiment of a radiographic image capturing apparatus for mammography.
FIG. 15 is a perspective view of a large cassette.
FIG. 16 is a perspective view of a large cassette showing an image detection area.
FIG. 17 is a sectional view of a sealed phosphor plate of a large cassette.
FIG. 18 is a view for explaining sticking of a sealing phosphor plate to a flat plate.
FIG. 19 is a diagram illustrating a method for manufacturing a sealed phosphor plate.
FIG. 20 is a diagram illustrating a method for manufacturing a sealed phosphor plate.
FIG. 21 is a diagram illustrating a method for manufacturing a sealed phosphor plate.
FIG. 22 is a diagram showing an apparatus for manufacturing a sealed phosphor plate.
FIG. 23 is a diagram showing a double-sided tape.
[Explanation of symbols]
11 Small focus radiation source
11a Focus of X-ray tube
12 X-ray source controller
15 Subjects
15a Subject chest wall
18 Subject holding member
20 Position determination device
50 Radiation image detector
50a End face of radiation image detector 50
50b stimulable phosphor
50b1 Photostimulable phosphor end face
60 Control device
80 Image output device
90 Image display device
100, 101 means of transportation
110 1st means of transportation
111 Second transportation means
112 control means
120 Distance changing means
121 subject breast detection means
122 control means

Claims (22)

A small focus radiation source that irradiates the subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject,
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
An end face of the radiation image detector is located on a substantially straight line connecting a focal point of the small focus radiation source and a subject chest wall on the subject holding member. A small focus radiation source that irradiates the subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject,
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
The subject holding member and the radiation image detector so that an end face of the radiation image detector is located on a substantially straight line connecting a focal point of the small focus radiation source and a subject chest wall surface on the subject holding member. And a moving means for moving the radiographic image. A small focus radiation source that irradiates the subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject,
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
A radiation image capturing apparatus, wherein an end face of the radiation image detector is located closer to the subject than substantially on a straight line connecting a focal point of the small-focus radiation source and a subject chest wall surface on the subject holding member. The radiation image capturing apparatus according to claim 3, wherein the radiation image detector has a stimulable phosphor for detecting a radiation image, and an end face of the stimulable phosphor is located on the substantially straight line. . The radiation image according to claim 3, wherein the radiation image detector has a flat panel detector for detecting a radiation image, and an end face of an X-ray detection unit of the flat panel detector is located on the substantially straight line. Shooting equipment. 4. The radiation image detector according to claim 3, wherein the radiation image detector has a stimulable phosphor for detecting a radiation image, and the end surface of the stimulable phosphor is located at least 2 mm from the substantially straight line on the subject side. Radiation imaging equipment. A small focus radiation source that irradiates the subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject,
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
The subject holding member and the radiation source such that an end surface of the radiation image detector is positioned closer to the subject than a substantially straight line connecting the focal point of the small focus radiation source and the subject chest wall on the subject holding member. A radiation image capturing apparatus, comprising: a moving unit that moves between the image detector and the image detector. A small focus radiation source that irradiates the subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject,
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
The subject holding member and the radiation image detector so that the end face of the radiation image detector is substantially on a straight line connecting the focal point of the small focus radiation source and the subject chest wall on the subject holding member. First moving means for moving;
The subject holding member such that an end face of the radiation image detector is closer to the subject than a substantially straight line connecting the focal point of the small focus radiation source and the subject chest wall on the subject holding member; Second moving means for moving the container,
Control means for switching between the first moving means and the second moving means,
The radiographic imaging apparatus according to claim 1, wherein the control unit switches a moving direction of the moving unit depending on whether an imaging direction is a vertical direction or a direction other than the vertical direction. 9. The radiographic imaging apparatus according to claim 8, wherein the control unit switches the imaging direction depending on a vertical direction and a direction other than the vertical direction. A small focus radiation source that irradiates the subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject,
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
Distance changing means for changing a first distance between the small focus radiation source and the subject holding member or a second distance between the subject holding member and the radiation image detector;
Subject breast detection means for detecting the size of the subject breast,
Control means for controlling the distance changing means to detect a predetermined area or more of the subject breast by the radiation image detector,
A radiation image capturing apparatus comprising: The radiation image capturing apparatus according to claim 10, wherein the distance changing unit moves the radiation image detector. 12. The radiographic image capturing apparatus according to claim 10, wherein the distance changing unit changes the radiographic image detector so as to detect an area of 80% or more of the subject's breast. The radiation image detector has a mark indicating an irradiation area,
The control unit determines an irradiation area based on the first distance or the second distance, and controls the distance changing unit such that a mark of the radiation image detector matches the determined irradiation area. The radiographic image capturing apparatus according to any one of claims 10 to 12, wherein The radiation image according to any one of claims 1 to 13, wherein the subject has a bed on which the subject can sleep, and the mammography can be performed with the subject lying down. Shooting equipment. The end face of the radiation image detector is located on a substantially straight line in a vertical direction that connects a focal point of the small-focus radiation source and a subject chest wall surface on the subject holding member. 15. The radiographic image capturing apparatus according to any one of 14. The end surface of the radiation image detector is located on a substantially straight line in an oblique direction connecting a focal point of the small-focus radiation source and a subject chest wall surface on the subject holding member. 15. The radiographic image capturing apparatus according to any one of 14. 17. The radiographic image capturing apparatus according to claim 1, wherein the radiographic image detector is a large cassette having a rectangular shape in plan view of 25 × 32 cm or more. 18. The radiographic image capturing apparatus according to claim 1, wherein the radiographic image detector is a large cassette in which an image-defective area of a subject's chest wall is 2 mm or less. A small focus radiation source that irradiates the subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject,
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
A radiation image capturing apparatus, wherein the radiation image detector is a large cassette having a rectangular shape in plan view and a size of 25 cm or more and 32 cm or more. A small focus radiation source that irradiates the subject with radiation, a subject holding member that holds the subject, and a radiation image detector that reads radiation image information based on the radiation transmitted through the subject,
In a radiographic image capturing apparatus that performs phase contrast mammography of a subject breast held by the subject holding member,
The radiation image detector according to claim 1, wherein the radiation image detector is a large cassette having an image-deficient area on the chest wall of the subject of 2 mm or less. The radiation image capturing apparatus according to any one of claims 17 to 20, wherein the large cassette has a stimulable phosphor plate. The radiation image capturing apparatus according to any one of claims 17 to 20, wherein the large cassette includes a flat panel detector.

Images