JP2001238871A - Equipment for taking x-ray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide equipment for taking X-rays that can take both normal X-rays and phase images easily. SOLUTION: The equipment for taking X-rays has a radiation source (11) with small focus, a table (18) that holds objects (15) for taking X-rays, a reading device (30) that manipulates information on X-ray images obtained after X-rays pass through the objects, a device for adjusting distance (102) that adjusts distance R1 or distance R2, and a controlling device that controls conditions for irradiation of the radiation source with small focus. The X-ray equipment features that the controlling device can control the conditions for irradiation of the radiation source with small focus according to information on distance about the distance R1 or the distance R2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiographic apparatus, and more particularly, to a radiographic apparatus having a focal size of 30 .mu.m to 300 .mu.m.
The present invention relates to a radiation image capturing apparatus capable of obtaining a radiation image with high sharpness and high boundary contrast of a subject by using a small-focal radiation source of m and edge enhancement by phase contrast.

[0002]

2. Description of the Related Art X-ray images utilizing the function of transmitting X-rays, which are one type of radiation, through substances are 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 an X-ray source, 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.

Recently, as an X-ray image, an image called a phase contrast image has been proposed. The 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 X-ray source such as SPring-8, or by using a micro-focus X-ray source having a focal size of about 10 μm. Is something that can be done. Compared to a normal image with only absorption contrast, the contrast of the boundary of the subject can be described with a higher resolution, and a high-definition X-ray image can be obtained. However, these monochromatic parallel X-rays and micro focus X-rays having a focus size of 20 μm or less are used.
It is difficult to use an imaging device using a radiation source in a general medical institution. That is, the radiation X-ray source for obtaining monochromatic parallel X-rays has a huge device, and the microfocus X-ray source has too low an X-ray intensity and cannot pass through a human body.

[0004]

SUMMARY OF THE INVENTION As a result of intensive studies, the present applicant has made Japanese Patent Application Nos. 11-203969 and 11-2.
As described in No. 66604, a method for capturing a phase contrast image using an X-ray tube (a small-focus radiation source having a focal size of 30 to 300 μm) used in a general medical institution has been found.

[0005] In obtaining a phase contrast image by the above method, the distance between the small-focus radiation source and the subject and the distance between the subject and the X-ray image depend on the nature of the radiation energy emitted from the small-focus radiation source having a focal size of 30 to 300 µm. It is necessary to keep the distance to the reading device constant. Further, depending on the type of the reading device, it is necessary to set and control the radiation condition of the small-focal-point radiation source capable of performing imaging when the distance is set to the constant condition. As will be described later, in order to obtain a phase contrast image with a radiation imaging apparatus having a small-focal radiation source, while avoiding the adverse effects of penumbra, the conditions under which edge enhancement can be sufficiently obtained are limited to a certain range. is there. This condition varies depending on the distance, the nature of the subject, the type of radiation, and the like.

It is desired that the same photographing apparatus can perform not only a "phase image photographing mode" for photographing a phase contrast image but also a "normal photographing mode" for photographing an image having only normal absorption contrast. However, to perform both phase imaging and normal imaging with the same imaging device,
The photographing conditions must be changed as appropriate. However, in a general medical facility, the number of patients is large and the situation is very busy, and it is not realistic to manually change the imaging conditions.

Accordingly, an object of the present invention is to provide a photographing apparatus capable of easily performing both normal photographing and phase image photographing.

[0008]

The object of the present invention has been attained by the following constitutions.

(1) 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 the radiation transmitted through the subject, and the small focus radiation source A distance changing unit that changes a first distance between the holding member and a second distance between the holding member and the reading unit; and a control unit that controls a radiation condition of the small focal point radiation source. The radiation image capturing apparatus, wherein the control unit controls an emission condition of the small focus radiation source according to at least distance information on the first distance or the second distance.

(2) A radiation detector is provided on the opposite side of the holding member from the small focal point radiation source, and the control means controls the small focal point radiation in accordance with radiation intensity information detected by the radiation detector. The radiation image capturing apparatus according to the above item 1, wherein the radiation condition of the source is controlled.

(3) The radiation image photographing apparatus as described in (2) above, wherein the reader has a combination of an intensifying screen and a silver halide photographic film or a phosphor plate which emits stimulable light. .

(4) The radiation image photographing apparatus according to the above (1), wherein the reading means converts radiation into an electric signal.

(5) The control means calculates an image magnification at the time of radiographic image capturing from the distance information, changes the image magnification at the time of radiographic image capturing, and displays the radiation image information on the image display means. Alternatively, the radiographic image capturing apparatus according to the above item 4, wherein the radiographic image capturing apparatus is controlled to perform output by an image output unit.

(6) The control means calculates an image magnification at the time of radiographic image capturing from the distance information, and reduces the image magnification at the time of radiographic image capturing to display the radiation image information on the image display means. Alternatively, the radiation image capturing apparatus according to the above item 5 is controlled to perform output by an image output unit.

(7) The control means calculates an image magnification at the time of radiographic image capturing from the distance information, and returns the radiographic image information to the same magnification as the subject from the image magnification at the radiographic image capturing. 7. The radiation image capturing apparatus according to the above item 6, wherein the radiation image capturing apparatus is controlled to perform display by an image display unit or output by an image output unit.

(8) At least switching means for switching between a normal photographing mode and a phase image photographing mode is provided.
The radiation image capturing apparatus according to any one of claims 1 to 7, wherein the control unit controls the distance changing unit to operate according to a mode selected by the switching unit.

(9) The radiation image photographing apparatus according to any one of (1) to (8), wherein the small-focal radiation source and the reading unit are vertically arranged with the holding member interposed therebetween. .

(10) The radiation image photographing apparatus according to any one of (1) to (9) above, wherein the small-focal-point radiation source and the reading unit are horizontally arranged with the holding member interposed therebetween. .

(11) 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 displaying the radiation image information A radiographic image capturing apparatus having an image display unit that performs image processing or an image output unit that outputs the radiographic image information. A radiographic image capturing apparatus, comprising: a control unit that performs output by an output unit.

(12) The control means controls to display the radiation image information by the image display means or to output the radiation image information by the image output means by reducing the image magnification rate at the time of radiographic image capturing. The above 11
A radiographic image capturing apparatus according to claim 1.

(13) The control means may return the radiographic image information by the image display means or output by the image output means by returning the radiographic image to the same magnification as the subject from the magnification of the radiographic image. 13. The radiographic image capturing apparatus according to the above 12, wherein the radiographic image capturing apparatus is controlled.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a radiographic apparatus according to the present invention will be described with reference to the drawings as an embodiment of an X-ray apparatus, but the present invention is not limited to this. In the following description, “X-ray” and “radiation” are treated synonymously. Further, members denoted by the same reference numerals mean members having the same meaning.

FIG. 1 and FIG. 2 are general structural views of the X-ray image photographing apparatus. FIG. 1 shows a type having an X-ray detector separately from a reading device, and FIG. 2 shows a type in which the reading device directly replaces X-rays with electric signals and also serves as an X-ray detector.

The X-ray source 11 as a small-focal radiation source has X
The X-ray source controller 12 is connected to adjust the amount of X-ray emitted from the focal point 11a of the X-ray source 11 by the X-ray source controller 12. This X-ray dose is one of the radiation conditions of the X-ray source 11. The control device 60 as the control means is provided with the X-rays acquired from the reading device 30 as the reading means or the X-ray detector 50 as the radiation detector.
The X-ray source controller 12 is controlled according to the line intensity information (radiation intensity information). The control device 60 controls the X-ray source controller 12 and, when the reading device 30 converts X-rays into an electric signal, X-ray image information (radiation image information) acquired from the reading device 30.
Is appropriately processed to control the display on an image display device 90 (image display means) such as a monitor or to output a hard copy from an image output device 80 (image output means) such as a laser imager.

The X-ray emitted from the X-ray source 11 is the subject 1
5 and is observed by the reader 30 as X-ray energy (X-ray image information). The reading device 30 has a two-dimensional structure, that is, an area necessary for detecting X-rays transmitted through the subject 15.

In FIG. 1, an X-ray detector 50 (so-called photo timer) is provided in addition to the reading device 30. The X-ray detector 50 detects the intensity of the X-ray transmitted through the subject 15, and the obtained X-ray intensity information is sent to the control device 60. According to the X-ray intensity information, the control device 60
The source controller 12 is controlled to adjust the amount of X-ray emitted from the X-ray source 11. The subject 15 is photographed with the X-ray dose adjusted in this way, and
Holds line image information.

In FIG. 2, the reading device 30
Because it converts line image information directly into electrical signals,
The electric signal also serves as X-ray intensity information. Therefore, an X-ray detector is unnecessary.

Further, the control device 60 receives the distance R1 between the X-ray source 11 and the holding member 18 (the contact position with the subject 15) and the holding member 18 (the contact with the subject 15) from the position judging device 20 as the position judging means. The distance information of the distance R2 between the position) and the reading device 30 is transmitted, and the X-ray dose can be controlled.

The 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. By sliding the holding member 18 on the rail, the distance R
1 and the distance R2 can be changed. In this case, the rail is the distance changing means in the present invention.

As the X-ray source 11, an X-ray tube that emits X-rays having a 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 the cathode with the cathode. When an X-ray image is taken, 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) where the electrons collide is copper, molybdenum, rhodium, tungsten, etc.
By changing the type, the emitted X-ray energy spectrum can be changed. When copper, molybdenum, rhodium or the like is used as the anode, a line spectrum with a relatively low energy distribution of X-rays is obtained, and X-ray diffraction crystal analysis and mammography are used to interpret the fine structure using the characteristics. 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. The medical or industrial use is characterized in that a large amount of X-ray is applied. in this case,
The anode generates heat to cause a large amount of electrons to collide with the anode at high speed.
By rotating the anode to change the collision location, it is possible to avoid a problem due to heat generation. That is, it is common to use a rotating anode. Since the imaging apparatus of the present 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.

Here, the X-ray focal point 11a is a window viewed from the direction of the subject 15 for extracting X-rays generated by collision of electrons with, for example, a rotating anode of the X-ray tube 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 refers to its diameter, and when it is rectangular, it refers to its short side. Methods for measuring the focal size D include a method using a pinhole camera, a method using a micro test chart, and the like, are described in JIS Z 4704. Usually, a value based on the measurement of the X-ray tube maker is indicated as the focal size D in the product specification.

When the focal size D of the X-rays is large, the amount of X-rays to be emitted increases, but a so-called penumbra occurs as shown in FIG. A penumbra is an image in which one point on the subject 15 has a size on the reading device 30 due to the size of the focal point size D as shown in FIG. This is a phenomenon that is detected as an image, 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 influence of this penumbra becomes a problem.

On the other hand, as shown in FIG. 4, when an X-ray is taken with the distance between the subject 15 and the reading device 30 spaced apart, an edge-enhanced (= phase-contrast-enhanced) image resulting from X-ray refraction is obtained. Can be done. As schematically depicted at the lower end of the subject 15 in FIG. 4, the X-rays are refracted when passing through the object, so that the X-ray density inside the boundary of the object becomes low. X-rays that overlap with X-rays that do not pass through increase the X-ray density. 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 the 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 reading device 30 needs to be equal to or more than a certain value, and this photographing mode is called a “phase image photographing mode”. On the other hand, the distance between the subject 15 and the reading device 30 is set to 0.
In this case, an image having only the absorption contrast is obtained, which is referred to as a “normal shooting mode”. However, in FIG. 4, it can be seen that when the distance between the subject 15 and the reading device 30 is increased, the blur width E (FIG. 3) due to penumbra increases. From these facts, the lower limit of the focal size D is determined in order to obtain a certain or more X-ray dose, and the subject 15 and the reading device 30 are combined with each other in order to realize a refraction contrast over penumbra blur and obtain a high-sharp image. , The upper limit of the focal size D is determined from the distance from the focal point to the subject 15 or the X-ray physical characteristics. Therefore, in order to perform phase contrast imaging in a normal medical facility, the focus size D
Should be 30 μm or more and 300 μm or less. Further, when the counter electrode of the X-ray tube is molybdenum or rhodium, the focal size D must be 80 μm or more and 300 μm or less, and when the counter cathode is tungsten, the focal size D must be 30 μm or more and 200 μm or less. .

As described above, in order to perform phase contrast photographing, as shown in FIG.
You have to keep a certain distance between them. 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 or 2, the holding member 18 is provided between the X-ray source 11 and the reading device 30. The holding member 18 is preferably a rectangular frame or a transparent thin plastic plate attached to the frame. The holding member 18 is made movable, and a first distance R1 between the X-ray source 11 and the holding member 18 (contact position with the subject 15), the holding member 18 (contact position with the subject 15), and the reading device 30 (The distance changing means). The distance can be changed by, for example, disposing the holding member 18 slidably on the support shaft. By freely changing the distance R2 by the distance changing means, it is possible to easily switch between the phase image shooting mode (R2> 0) and the normal shooting mode (R2 = 0).

As shown in FIG. 1 or FIG.
1 and the distance R2 are measured, and the position discriminating device 20 which supplies the measured values to the control device 60 as distance information is installed. In the control device 60, the optimum condition in the phase image photographing is automatically set from the distance information. I made it. As a result, frequent switching between photographing modes is made possible.

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 holding member, and a position is discriminated from the resistance value measurement. A method in which a groove or a projection is provided and the position is determined by sensing the groove or the projection can be adopted.

The reading device 30 includes 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 a light for reading the light. An X-ray reader in which semiconductor elements are two-dimensionally arranged, a photoconductor that directly converts X-ray energy into an electric signal, and an X-ray reader in which semiconductor elements that read the electric signal are two-dimensionally arranged;
An X-ray reader or a scintillator that converts X-rays into light, or a scintillator that converts X-rays into light It is possible to use an X-ray reader that guides light to a CCD or CMOS through an optical fiber and replaces it with an electric signal.

In the case where the reading device is as described above or as described above, as shown in FIG. 1, an X-ray detector as an X-ray detector is provided on the back surface, and the detected X-ray intensity information is sent to the control device 60. . The control device 60 automatically calculates X-ray irradiation conditions from the relationship between the acquired X-ray intensity information and the sensitivity of the reading device 30, and automatically calculates the X-ray irradiation amount via the X-ray source controller 12. Is a preferred embodiment.

When the reading device 30 is as described above,
If the X-ray energy can be directly extracted electrically, the X-ray detector is not required, and as shown in FIG.
In a preferred embodiment, the reader 30 is used as a function similar to that of the X-ray detector.

In the photographing apparatus of the present invention, the one in which the reader 30 is an assembly of an X-ray fluorescent intensifying screen and a silver halide photographic film 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, JP-A-6-6736 discloses an intensifying screen using a rare-earth phosphor.
The technique disclosed in Japanese Patent Publication No. 5 may be used.
Further, it is preferable to use a silver halide photographic film in which a photosensitive emulsion is coated on only one side of a support or a support in which a photosensitive emulsion is 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 in which the photographic characteristics of each emulsion layer sandwiching the film support are different. 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. 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 halide photography-" (edited by The Photographic Society of Japan, Corona, 1998). For 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.

The stimulable light emission mentioned above means that the light does not emit when irradiated with X-rays, but is irradiated with visible light after irradiation.
Visible light emission corresponding to the already irradiated X-ray intensity is induced. That is, a stimulable phosphor is placed on the reader 30 of FIG. 1, and after X-ray irradiation, the phosphor is transferred to a laser reader to read the stimulable luminescence, and the read luminescence is replaced with an electric signal by a photomultiplier tube. Thus, an electric signal of an X-ray image is obtained. After performing the appropriate image processing, the electric signal is displayed on an image display means such as a monitor, 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 reading device 30 using the 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 light emission reading in the present invention. is there.

The reader described above for converting radiation into an electric signal is disclosed in Japanese Patent Application No. 11-490.
No. 80 or "Handbook of Medic
alImaging "Vol.1, Chapter 4" Flat
panel imagers for digital
radiography "(ed.RVV Matt.
er et al., SPIE Press, Bellingha
m, 2000) is a preferred embodiment. 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.

When magnifying radiography is performed in the “phase image radiographing mode” for obtaining a phase contrast image, the obtained X-ray image is displayed on a hard copy such as a monitor or a photographic film on the actual size of the subject (or the like). In a preferred embodiment, the display is automatically returned to (double). 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 distance R1 and the distance R2 from the position determination device 20 and calculating the image display device 90 from the calculated value.
When sending the X-ray image information to the image output device 80, it is preferable to freely change the image magnification and display or output the image.

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, or a laser light corresponding to the X-ray image information which is a silver halide photographic light-sensitive material. In another preferred embodiment, the development is carried out by heating after the exposure by the method described above, or the image is drawn by heating in accordance with the X-ray image information. In addition, a solid ink jet recording method for drawing an image by ejecting a liquid state obtained by heating a 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 etc. based on image information Is a preferred embodiment.

FIG. 5 shows the configuration of a control device as control means of the X-ray image photographing device. CPU (Central) that controls the overall operation of the control device
The processing bus is connected to the system bus 62, the image bus 63, and the input interface 67. The system bus 62 and the image bus 63 include a shooting control unit 66, a switching unit 77, 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, and an output interface 68
Etc. are connected. CP using system bus 62
The operation of each unit is controlled by the U61, and the transfer of X-ray image information between the units via the image bus 63 is performed.

The imaging controller 66 generates a control signal for controlling the operation of the reading device 30 and the reading gain and supplies the control signal to the reading device 30, and reads out the X-ray image information from the reading device 30 to read the X-ray image information from the frame memory. It is supplied to the control unit 69. In addition, a reading pixel size is set according to the size of the penumbra calculated by the CPU 61.

The switching section 77 is switching means for switching between the above-mentioned "phase image photographing mode" and "normal photographing mode". The switching instruction may be input from the input device 25.

A frame memory 72 is connected to the frame memory controller 69, and the X-ray image information generated by the reading device 30 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. Further, the X-ray image information supplied from the reading device 30 may be processed by the image processing unit 76 and then stored in the frame memory 72.

From the frame memory 72 to the disk controller 7
When supplying X-ray image information to 0, for example, X
The line image information is read and the FI
The data is written to the FO memory and then sequentially stored in the disk device 73.
Is stored.

The X-ray image information read from the frame memory 72 and the X-ray image information read from the disk device 73 are transmitted via the output interface 68 to an image output device 80 as an image output device or an image display device. And is provided to the user as a visible image.

The scale information generating section 71 generates scale information for determining the size of the X-ray image based on the magnification and the like supplied from the position determining device 20 via the photographing control section 66. The generated scale information is supplied to the image output device 80 or the image display device 90 via the output interface 68.

The image processing unit 76 performs irradiation field recognition processing, region of interest setting, normalization processing, gradation processing, and the like of the X-ray image information supplied from the reading device 30 via the imaging control unit 66. Further, frequency emphasis processing, dynamic range compression processing, and the like may be performed. Further, the image processing unit 76 performs a process for preventing the influence of the reflection and a process for making it easy to determine the contour of the subject when the phase contrast imaging is performed. Further, based on the photographing mode information, an image photographed at a magnification of 1 or more is displayed on an image display device 90 such as a monitor or an image output device 8 such as a hard copy.
By returning the value to 0, the display or output almost close to the actual size can be automatically performed. Note that the image processing unit 76 can also be used as the CPU 61 to perform image processing and the like.

The input interface 67 includes X-ray intensity information from the X-ray detector 50 or the reading device 30, an electric image signal from the reading device 30, photographing mode information from the switching unit 77, and other sensitivity and X-rays of the reading device. Information such as a tube set voltage value is input. 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. In addition to using a keyboard to enter management information, a magnetic card, bar code, HIS
(Information management by a hospital information system network) is also used.

Although the X-ray image information supplied from the reading device 30 is stored in the frame memory 72, the supplied X-ray image information is processed by the image processing unit 76 and then stored. It may be a thing. 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 reading device 30 by the image processing unit 76 together with the management information and the like. Can be saved.

When an SF system or a stimulable luminescent phosphor plate is used as the reading device 30, the control device 6
0 is the focus focus diameter information stored in the memory 64 in advance from the X-ray intensity information from the reading device 30 or the X-ray detector 50, the position determination information from the position determination device 20, and the imaging mode information. The imaging conditions are calculated using a program or the like, and imaging control is performed through the X-ray source controller 12.

When an electric signal of X-ray image information is input from the reading device 30, the control device 60 determines in advance the electric signal information, the position determination information, the photographing mode information, the reading device sensitivity, and the X-ray tube set voltage. The imaging conditions are calculated using the focus / focus diameter information stored in the memory 64 and the control program, and the like.
The photographing is controlled through.

FIG. 6 shows an example of an X-ray photographing apparatus for mammography. The X-ray imaging apparatus of FIG. 6 is of a type in which an X-ray source and a reading device are vertically arranged with a holding member interposed therebetween.

The holding member 18, the driving source 101, and the grip bar 104 are disposed on the first support shaft 102, and each member can slide on the first support shaft 102 and move. It is possible, and the distance R1 and the distance R2 can be changed. Therefore, the first support shaft 102 is a distance changing unit. The X-ray source 11 and the reading device 30 are connected to a second support shaft 103. The second support shaft 103 is rotatable about BB ′ (horizontal direction at the contact position of the holding member 18 with the subject 15) in the drawing as a rotation axis. Second
By rotating the support shaft 103, the subject 15 fixed on the holding member 18 can be photographed from directly above or from an oblique direction. The second support shaft 103 also serves as an electric resistor, and has a position A of the second support shaft.
, A circuit together with the position B, the power source 112 and the electric resistance position detector 111 to form a position determination device. When the position B is changed, the electric resistance changes. Therefore, the distance R1 and the distance R2 are calculated based on the detection values of the electric resistance position detector 111.
Can be calculated. The radiation condition is controlled based on the distance information of the distance R1 and the distance R2. The control device 60 calculates the magnification at the time of radiographic imaging from the obtained distance information, and freely changes the magnification at the time of display by the image display means or at the time of output by the image output means (preferably, the subject It can be displayed or output. It is preferable that the electric resistor (the second support shaft 103) is covered with a cover or the like so as not to come in contact with a human body as a subject. Note that the voltage applied by the power supply 112 does not exceed 10 V,
It is preferable that the range is not detected by the human body.

The X-ray source 11 is an X-ray tube having a focal size D: 100 μm of a molybdenum rotating anode, and is located above the holding member 18. The distance R1 is an interval between the focal position A of the X-ray source 11 and the position B of the holding member 18 (the position at which the subject 15 contacts the holding member 18), and is variable in the range of 0.3 m to 1 m. R2 is an interval between the position B of the holding member 18 and the position C of the reading device 30, and is variable from 0 to 0.5 m.

When the "normal photographing mode" is inputted from the input device 25 such as a keyboard (switching means), the control device 60 causes the holding member 18 and the reading device to move to the position of R1 at 0.6 m and the position of R2 at 0. The arrangement 30 is automatically arranged by the operation of the drive source 101 such as a motor. For example, if photographing conditions suitable for the sensitivity of the intensifying screen MD-100 (manufactured by Konica) and the single-sided film CMH for mammography (manufactured by Konica) are input in advance, for example, a radiation of 28 kVp and 12 mA for 1.2 seconds is obtained. The conditions are automatically set, the X-ray source controller 12 is controlled to turn on the X-ray imaging, and normal imaging is performed.

When the "phase image photographing mode" is input, R1 is set at a position of 1 m, R2 is set at a position of 0.5 m, and X
The radiation source 11, the holding member 18, and the reading device 30 are automatically arranged. For example, the photographing conditions suitable for the sensitivity of the XGM back intensifying screen (manufactured by Konica) and the single-sided film CMH (manufactured by Konica) for mammography, that is, 28 kVp, 1
The radiation conditions of 6 mA and 3 seconds exposure are automatically set, and the X-ray source controller 12 is controlled to turn on the X-ray imaging,
Perform phase imaging. At this time, distance information between R1 and R2,
The photographing conditions and the like are burned into a film together with the patient information of the subject 15 through the control device 60, and the film is processed to obtain a mammographic image. In this example, the reading device 30 uses an SF system,
Phosphors that emit stimulable light or other reading devices described above can be used. For example, Konica's REGIUS plate RP-1S (quart size) is used as a phosphor plate that emits stimulable light, and after photographing, Konica's REGIUS is used.
An image is read by the MODEL 150, and after performing appropriate image processing, the image is drawn on an image display device such as a monitor, or a hard copy is obtained using an image output device such as a laser imager using the obtained radiation image information. I can do it. At this time, in the phase image photographing mode, the subject is enlarged and photographed from the actual size of the subject (because the reading device and the subject are separated), so that the display on the image display device and the output on the image output device are not performed. It is preferable to return or display the actual size of the subject (actual size) based on the magnification (magnification from the actual size of the subject) at the time of radiographic image capturing. For example, in a preferred embodiment, the image is displayed or output by automatically reducing the image to a predetermined size by sending it from the control device 60 of the radiation image capturing apparatus of the present invention to the REGIUS MODEL 150.

In this embodiment, the control device 60, the X-ray source controller 12, the input device 25, and the image display device 90 are integrated, but may be separated. In the present embodiment, a protection plate 105 is provided between the holding member 18 and the reading device 30 to prevent foreign matter from entering the X-ray path and obstructing the image. In a preferred embodiment, a grip bar 104 for controlling the movement of the patient is provided.

FIG. 7 shows an example of an X-ray imaging apparatus for chest X-ray images. This X-ray imaging apparatus is of a type in which an X-ray radiation source and a reading apparatus are horizontally arranged with a holding member interposed therebetween.

The X-ray source 11, the holding member 18, the reading device 30, and the driving source 101 are slidably provided on the rail 106 so that the distance R1 and the distance R2 can be freely changed. The rail 106 is a distance changing unit.

An infrared position detector 121 emits infrared light from a position A of the X-ray source 11 and receives the infrared light reflected and returned by the holding member 18 to measure a distance to thereby determine a distance. is there. Strictly, the distance R1 is calculated by adding the thickness of the holding member. The infrared position detector 121 has a built-in infrared light emitting diode, emits infrared light, and reads infrared light reflected by a reflection plate or the like provided on the holding member 18. By setting the position of the reading device 30 in advance, the distance R2 can be calculated. The control device 60 controls the radiation condition from the distance information obtained by the infrared position detector 121, changes the magnification at the time of radiographic image capturing, and performs display by the image display means or output by the image output means.

The X-ray source 11 is an X-ray tube having a focal point size of 70 μm of a tungsten rotating anode. Distance R1 is 0.3m
To 3 m, and R2 is variable from 0 to 1 m. When the “normal shooting mode” is input from the input device 25 such as a keyboard, the control device 60 operates the drive source 101 to move the holding member 18 and the reading device 30 so that R1 is at 2 m and R2 is at 0. Place automatically. Then, 120 kVp, 8 mA, 0.5 second exposure is automatically set as the radiation condition corresponding to the distance information registered in advance, and the X-ray source controller 12 is controlled to turn on the X-ray imaging, Perform normal shooting.

From the input device 25, a "phase image photographing mode"
Is input, the control device 60 sets R1 to 1.
The X-ray source 11, the holding member 18, and the reading device 30 are automatically arranged by operating the drive source 101 so that 5m and R2 are at 1.5m positions. Then, a radiation condition corresponding to the distance information is calculated and automatically set.

Since the image obtained in the “phase image photographing mode” is larger than the actual size of the subject 15, when displayed on the image display device 90, the subject 1
Return to the same size of 5. The obtained image is displayed on the image display device 9.
0, and can be output as a hard copy from an image output device 80 such as a silver halide photographic film laser imager if necessary. In displaying on the image display device 90 or outputting a hard copy, a phase contrast image and a normally shot image can be displayed side by side. In addition, these X-ray images are used for other modalities, that is, X-ray CT, MRI, US, R
I, an endoscope image, a fundus image, and the like can be displayed side by side. Furthermore, in addition to the patient information, signatures such as a doctor's diagnostic comment and approval, and arrows and surrounding circles indicating lesions can be simultaneously written as text information. In addition, it is a preferable embodiment to link with an ordering system in a hospital. In the present embodiment,
Although an example has been described in which X-ray image information is directly extracted as an electric signal, an SF system or a stimulable light emitting phosphor plate may be used. Further, although the control device 60 and the X-ray source controller 12 are integrated, they may be separated from each other.

An example of a reading apparatus capable of directly converting X-ray image information into an electric signal will be described with reference to FIGS.

As shown in FIG. 8, this reading device
It has an image receiving plane of 88 cm square. A 4 cm square subdivided image is formed on a CCD, which is an area sensor, by a five-lens lens, and a total of 22 × 22 = 484 images are combined by image processing to obtain one piece of X-ray image information. .

FIG. 9 shows a cross-sectional view of the reading device.
FIG. 10 schematically shows one lens unit.

The fluorescent layer 42 is a thallium-activated CsI columnar crystal having a thickness of about 300 μm and a diameter of about 10 μm. Protective films 43 and 44 are provided on both sides of the fluorescent layer 42, and a lens unit 45 is attached to a lens support plate 46 corresponding to a portion partitioned by the partition wall 40. In the lens unit 45, an area sensor 47 of an image sensor such as a CCD or a CMOS is mounted on a substrate 48.

[0073]

According to the present invention, it is possible to provide an imaging apparatus capable of easily performing both normal imaging and phase image imaging.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an X-ray imaging apparatus of the present invention.

FIG. 2 is an overall configuration diagram of another embodiment of the X-ray imaging apparatus of the present invention.

FIG. 3 is a diagram illustrating a relationship between a focus size and a penumbra.

FIG. 4 is a diagram illustrating the principle of a phase contrast image.

FIG. 5 is a diagram showing a configuration of a control unit of the X-ray imaging apparatus of the present invention.

FIG. 6 is a diagram illustrating an example of an X-ray imaging apparatus for mammography according to the present invention.

FIG. 7 is a diagram showing an example of an X-ray imaging apparatus for chest X-ray images of the present invention.

FIG. 8 is a diagram illustrating an image receiving plane of the reading device of the radiographic image capturing apparatus of the present invention.

FIG. 9 is a diagram showing a cross-sectional view of the reading device of FIG. 8;

FIG. 10 is a schematic diagram showing one lens unit of the reading device of FIG. 8;

[Explanation of symbols]

 Reference Signs List 11 X-ray source 12 X-ray source controller 15 Subject 18 Holding member 20 Position discriminating device 25 Input device 30 Reading device 42 Fluorescent layer 45 Lens unit 47 Area sensor 50 X-ray detector 60 Control device 80 Image output device 90 Image display device 101 Driving source 102 First support shaft 103 Second support shaft 104 Grip rod 105 Defense plate 106 Rail D Focus size E Width of penumbra

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // G01T 1/20 G01T 1/20 CEF term (Reference) 2G088 EE01 EE27 FF02 FF14 GG14 GG16 GG19 GG20 JJ05 JJ09 KK32 2H013 AA21 AC20 4C093 CA08 CA15 CA37 CA50 EA02 EB04 EB05 EB12 EB17 EC30 EC32 FA12 FA18 FA59 FF13 FF22

Claims (13)

[Claims] 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 the radiation transmitted through the subject; A distance changing unit that changes a first distance between the holding member and a second distance between the holding member and the reading unit; and a control unit that controls a radiation condition of the small focus radiation source. And the control means is at least the first distance or the second distance.
A radiation condition of the small focus radiation source is controlled in accordance with distance information on a distance of the radiation image capturing apparatus. 2. A small-focus radiation source according to claim 2, further comprising a radiation detector on a side opposite to the small-focus radiation source with respect to the holding member, wherein the control unit controls the small-focus radiation source according to radiation intensity information detected by the radiation detector. The radiation image capturing apparatus according to claim 1, wherein the radiation condition is controlled. 3. The radiographic imaging apparatus according to claim 2, wherein the reading device has a combination of an intensifying screen and a silver halide photographic film or a phosphor plate that emits stimulable light. . 4. The radiation image capturing apparatus according to claim 1, wherein the reading unit converts radiation into an electric signal. 5. The control means calculates an image magnification rate at the time of radiographic image capturing from the distance information, and changes the image magnification rate at the radiographic image capturing time to display or display the radiation image information by an image display means. The radiographic image capturing apparatus according to claim 4, wherein control is performed to output the image by an image output unit. 6. The control means calculates an image magnification rate at the time of radiographic image capturing from the distance information, and reduces the image magnification rate at the time of radiographic image capturing to display the radiation image information by an image display means. 6. The radiographic image capturing apparatus according to claim 5, wherein control is performed such that output is performed by an image output unit. 7. The control means calculates an image magnification rate at the time of radiographic image capturing from the distance information, and returns the radiographic image information to the same size as the subject from the image magnification rate at the time of radiographic image capturing, to convert the radiation image information into an image. 7. The radiographic imaging apparatus according to claim 6, wherein control is performed such that display is performed by a display unit or output is performed by an image output unit. 8. A switching unit capable of switching at least between a normal imaging mode and a phase image imaging mode, wherein the control unit controls the distance changing unit to operate according to a mode selected by the switching unit. The radiographic image capturing apparatus according to any one of claims 1 to 7, wherein 9. The radiation image photographing apparatus according to claim 1, wherein the small-focal radiation source and the reading unit are vertically arranged with the holding member interposed therebetween. . 10. The radiation image photographing apparatus according to claim 1, wherein the small-focal radiation source and the reading unit are horizontally arranged with the holding member interposed therebetween. . 11. 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 displaying the radiation image information. In a radiation image capturing apparatus having an image display unit or an image output unit that outputs the radiation image information, the radiation image information is displayed by the image display unit or the image output is changed by changing an image magnification rate at the time of capturing the radiation image. A radiation image capturing apparatus, comprising: a control unit that performs output by a unit. 12. The control device according to claim 1, wherein the control unit controls the radiographic image information to be displayed by the image display unit or output by the image output unit by reducing the image magnification ratio at the time of capturing the radiographic image. The radiographic image capturing apparatus according to claim 11, wherein 13. The control means according to claim 1, wherein said radiographic image information is displayed by said image display means or output by said image output means by returning said radiographic image information to the same magnification as that of said subject from an image magnification rate at said radiographic image capturing. The radiographic image capturing apparatus according to claim 12, wherein