JP2002186614A - Radiographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiographic device whose grid isn't erroneously detected by a subject or an operator, as it doesn't not require electric connection works, or the like. SOLUTION: A concave 5c having an aperture on a radiation incident side is formed in an electronic cassette, and a switch 9 for detecting the grid 6 is installed in the concave 5c. Installation of the grid is detected by the switch 9 through sensing a frame body 8 for fixing the grid to be inserted in the concave 5c when the grid 6 is installed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiographic image capturing apparatus for performing radiographic imaging, and more particularly to a scattered radiation removing grid detecting apparatus which is detachably attached to a cassette housing.

[0002]

2. Description of the Related Art Conventionally, an apparatus for irradiating an object with radiation and detecting an intensity distribution of the radiation transmitted through the object to obtain a radiation image of the object has been used for industrial nondestructive inspection and medical diagnosis. Widely used in general. A common method of such imaging is a film / screen method for X-rays. This is a method of photographing by combining a photosensitive film and a phosphor having sensitivity to X-rays. That is, a sheet of a rare earth phosphor that emits light when irradiated with X-rays is held in close contact with both surfaces of the photosensitive film, and the X-rays transmitted through the subject are converted into visible light by the phosphor. Then, light is captured by a photosensitive film, and the latent image formed on the film is developed by chemical processing to be visualized.

On the other hand, a method of converting a radiographic image into an electric signal due to recent advances in digital technology, processing the electric signal, and reproducing it as a visible image on a CRT or the like to obtain a high-quality radiographic image is practical. Has been
As a method of converting such a radiation image into an electric signal, a transmission image of radiation is temporarily accumulated as a latent image in a phosphor, and then the latent image is photoelectrically irradiated by irradiating excitation light such as laser light. It is output as a read-out visible image (Japanese Patent Laid-Open Nos. 55-12429 and 56-11395).
No.).

Further, with the recent progress of semiconductor process technology, a system for similarly taking a radiographic image using a semiconductor sensor has been developed. These systems have a much wider dynamic range than radiographic systems using conventional photosensitive film, and offer the practical advantage of being able to obtain radiation images that are not affected by variations in radiation exposure. Have. At the same time, unlike the conventional photosensitive film method, no chemical treatment is required,
There is also an advantage that an output image can be obtained immediately.

FIG. 7 is a conceptual diagram showing a system using such a radiographic image capturing apparatus. In FIG. 7, 10
Reference numeral 3 denotes an X-ray image photographing device having a built-in X-ray detection sensor 104. X-rays emitted by the X-ray generator 101 irradiates the object 102 is detected by the photoelectric conversion elements arranged in a two-dimensional lattice-like X-rays transmitted through the object on the X-ray detection sensor 104. The image signal output from the detection element is subjected to digital image processing by the image processing means 105,
An X-ray image of the subject 102 is displayed on the monitor 106.

Conventionally, this type of imaging apparatus is installed in a radiation room, but in recent years, a portable imaging apparatus (also referred to as an electronic cassette) has been required in order to enable more rapid and wide-area imaging. Is coming. FIG. 8 is a side sectional view showing the electronic cassette. An electronic cassette used for such X-ray photography or the like includes a phosphor 1 that converts X-rays into visible light.
51a, a photoelectric conversion element 151b arranged in a grid for converting this visible light into an electric signal, a substrate 151c having the photoelectric conversion element formed thereon, a base 152 supporting the substrate 151c, Circuit board 153 and wiring 154 on which electronic components for processing the converted electric signal are mounted
And a housing 155 for accommodating them.

In general, in the above-mentioned medical X-ray imaging apparatus, there is a case where an image is taken using a scattered X-ray removal grid (hereinafter, a grid). This is for removing scattered X-rays generated inside a subject (for example, a human body) by X-ray irradiation, and is used for the purpose of improving the contrast of an X-ray image. The grid is arranged between the X-ray tube and a detector such as a film or the like and immediately before the detector to perform imaging.

FIG. 9 is a schematic sectional view of a grid. The grid comprises a foil 201 made of a substance having a high X-ray absorption rate,
Intermediate substances 202 having a small X-ray absorptance are alternately stacked. Generally, lead is used for the foil 201 having a high absorption rate, and aluminum, paper, wood, synthetic resin, carbon fiber reinforced resin, or the like is used for the intermediate substance 202 having a low X-ray absorption rate. The outer periphery of these laminates is covered with a cover 200 made of aluminum, carbon fiber reinforced resin, or the like.
X-rays are emitted from the A direction.

The center portion of the foil immediately below the light source of the X-ray represented by 201a is perpendicular to the cover 200, and is inclined in the direction of the light source toward the periphery, as in 201b, so as to form a converging grid in many cases. The convergence grid needs to be photographed by adjusting the distance between the grid and the light source and the center. On the other hand, some grids do not tilt the foil, which is called a straight grid.

The amount of scattered radiation depends on the structure of the subject. For example, a human body has a large amount of scattered radiation in the chest and abdomen, and a limb has a relatively small amount of scattered radiation. On the other hand, since the grid attenuates the transmitted X-rays, it is possible to perform imaging with a smaller dose when imaging without the grid than when imaging with the grid. Therefore, a grid is used with priority on the image quality in a part with a large amount of scattered radiation, and when a part with a relatively small amount of scattered radiation is imaged, the grid is often used without using a grid in order to reduce the dose. Therefore, the grid can be easily attached and detached depending on the part to be photographed.

[0011]

By the way, even when the same part is photographed, the amount of X-ray transmission changes depending on the presence or absence of a grid, so that it is necessary to adjust the amount of X-ray irradiation. Furthermore, it is necessary to set detailed imaging conditions depending on the type of grid, and these are left to the operator, such as a radiological technician. In an X-ray imaging device with a built-in grid, it is difficult to view the grid from the outside, so the grid is automatically identified and the convenience of presenting the operator with accurate irradiation conditions is improved. A supported support system has also been proposed.

There are several problems when simply applying such a grid detecting means to a cassette.
For example, when a grid is used for a cassette, unlike a built-in type that cannot be touched directly because it is covered by a casing, since the subject and the operator use it directly, the means for detecting the grid is It should not be accidentally activated by the subject or the operator during shooting. For example, as shown in FIG. 10, a switch 301 is protruded from the incident surface side of the housing 300, and a grid is mounted thereon.
In the case of the configuration in which the detection is performed by pressing 01, even when there is no grid, the subject 102 may press the riding switch 301 and mistakenly recognize that the user is wearing the grid. Further, even in a configuration in which a bar code provided on the grid is read by a sensor inside the housing, it is conceivable that the light-transmitting portion may be touched by the subject and stained with fingerprints, oils, or the like, thereby causing erroneous detection.

On the other hand, it is conceivable to have means for transmitting information directly from the grid side and to electrically connect to the cassette. However, it is necessary to provide a shielding mechanism so that the subject does not directly touch the connector part when the grid is not mounted, and to take measures to prevent the subject or operator from accidentally catching on the connecting cable. This leads to an increase in cost. In addition, since the operator is required to connect the cable, the operation is rather complicated, and there is a possibility that the connection may be forgotten or a connection failure may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to prevent a subject or an operator from erroneously detecting a radiographic image which does not require electrical connection work or the like. It is to provide a photographing device.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a radiation image capturing apparatus which performs radiation imaging by irradiating a subject with radiation emitted from radiation generating means and detecting radiation transmitted through the subject by a radiation detection panel. A cassette housing enclosing the radiation detection panel, a grid detachably attached to the cassette housing, for removing scattered radiation, and a detecting means for detecting that the grid is mounted. The cassette housing has an opening on the radiation incident side, and a storage part into which a part of a frame for fixing the grid is inserted is formed, and the detection means is provided in the storage part and the detection part is provided on the grid. This is achieved by a radiation image capturing apparatus, wherein the mounting of the grid is detected by detecting the frame at the time of mounting.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a side sectional view showing the structure of a first embodiment of the radiation image photographing apparatus of the present invention. In the following embodiments, a case using X-rays will be described as an example. In FIG. 1, reference numeral 1 denotes an X-ray detection panel, which basically includes a fluorescent plate 1a, a photoelectric conversion element 1b, and a substrate 1c. The substrate 1c has no chemical action with the semiconductor element, withstands the temperature of the semiconductor process,
Glass plates are often used due to the need for dimensional stability and the like.
On such a glass substrate, the photoelectric conversion elements 1b are formed in a two-dimensional array by a semiconductor process.

The fluorescent plate 1a is formed by applying a phosphor of a metal compound to a resin plate, and is integrated with the substrate 1c by adhesion. These fluorescent plate 1a, photoelectric conversion element 1
b, the substrate 1c is a metal base 2 as the X-ray detection panel 1.
Fixed to. Reference numeral 3 denotes a circuit board on which an electronic component 3a for processing a photoelectrically converted electric signal is mounted, and is connected to the photoelectric conversion element 1b by a flexible circuit board 4. A signal line and a control line for reading out an electric signal from the photoelectric conversion element 1b are wired on the flexible circuit board 4, and a plurality of signal lines and control lines are arranged on the outer periphery of the board 1c. Each flexible circuit board 4 extends around the base 2 to the circuit board 3 arranged on the back surface of the base 2.

The X-ray detection panel 1, the base 2, the circuit board 3, and the flexible board 4 are included in the housing 5b as X-ray image detecting means, and are mounted on the cassette housing via the support 2a of the base 2. It is fixed to the body 5. Further, the inside of the housing 5b is sealed with a housing lid 5a that is transparent to X-rays. Here, the housing 5 includes a concave housing 5b and a housing lid 5a, and the two are collectively referred to as a cassette housing 5. A grid 6 is mounted on the incident surface side of the cassette housing 5. Frames 7, 8 are fixedly attached to the grid 6,
The frame bodies 7 and 8 are configured to abut the outer shape of the housing 5 to position and fix the grid 6.

On the other hand, a concave portion 5c is formed in the housing 5, and a switch 9 which operates mechanically is provided on an inner side wall 5d. The switch 9 is connected to the electric circuit board 3 via a cable 9b, and is configured to detect the presence or absence of the grid 6. When the grid 6 is mounted, the switch lever 9a exposed to the outside of the housing 5
Strikes and activates the switch 9. As a result, it is detected that the grid 6 is mounted, and the electric circuit board 3 is mounted.
Is transmitted to

Such information is transmitted to an external control device via an interface (not shown), and is used for display to an operator. By thus providing the grid detecting means inside the concave portion 5c, even if the subject gets on the cassette without the grid 6, the possibility that the switch 9 of the concave portion 5c is pressed by mistake is low. Further, since there is no detecting means on the outer surface, there is no problem even if the cassette housing is set up for photographing. Further, since the electrical connection between the grid 6 and the cassette is not required, the mounting of the grid 6 is easy, and no trouble is caused by the connection, so that a highly reliable device can be realized.

FIG. 2 shows an example in which a plurality of types of grids can be detected by the detecting means of FIG. In FIG. 2, two switches 9 and 10 are provided side by side, and a cutout such as 8b is formed at a contact point of the switch of the grid frame 8, and a plurality of information can be detected by selecting a switch to be operated. . That is, by changing the position of the notch of the grid frame 8 according to the type of the grid, information indicating the type of the grid is provided, and the type of the mounted grid is detected by a detection signal of a switch that detects the information. Things. When the type of the grid is detected in this way, it is possible to provide a service for automatically presenting the X-ray irradiation conditions to the operator. Although the number of switches is two in FIG. 2, it is possible to cope with more types of grids by further increasing the number and changing the cutout position of the grid frame 8 according to the type of grid. is there.

(Second Embodiment) FIG. 3 is a side sectional view showing a configuration of a second embodiment of the present invention. Since the internal configuration including the X-ray detection panel 1 is the same as in the first embodiment, detailed description is omitted, X-ray image detection panel 1,
An X-ray image detecting means including a metal base 2, a circuit board 3, and a flexible circuit board 4 is built in a cassette housing 5. In the present embodiment, the housing 5 has the concave portion 5 c
Is formed, and a detector 12 for detecting the attachment of the grid 6 is provided on the inner side wall 5d side. Detector 1
Reference numeral 2 is connected to the electric circuit board 3 via a cable 12a, and is configured to detect the presence or absence of a grid.

A grid 6 is provided on the incident surface side of the cassette housing 5.
Are mounted, and frame bodies 7 and 10 are fixedly attached to the grid 6. That is, the frame members 7 and 10 of the grid 6 abut on the outer shape of the housing 5 to position and fix the grid 6. A magnet 11 is attached to one end 10a of the frame body 10, and is disposed at a position facing the above-described detector 12 with the side wall 5d of the housing interposed therebetween when the grid 6 is mounted. The detector 12 is turned ON /
The reed switch is turned off, and is turned on when the magnet 11 is located within a detection range of several mm, and detects the mounting of the grid 6. The frame 10 and the side wall 5d are formed of a non-magnetic material so as not to affect the magnetic force of the magnet 11.

In the case of the detecting means using a reed switch as described above, it is unlikely that an environment in which a magnetic force acts erroneously is small. However, by arranging the reed switch inside the apparatus, an external magnetic force acts. The configuration is not easily affected. Also, in this case, the electrical connection between the grid 6 and the cassette is unnecessary, so that the grid 6 can be easily mounted, and no trouble is caused by the connection, so that a highly reliable device can be realized. Furthermore, when the lever is protruded out of the housing as in the first embodiment, measures for shielding are required to prevent light from leaking into the inside of the device. However, in this embodiment, the housing has a completely sealed structure. No special measures are required for shielding. In the case of the grid detecting means having such a configuration, a plurality of built-in detectors are provided, and the position of the magnet attached to the grid is changed according to the type of the grid. It can be extended to:

(Third Embodiment) FIG. 4 is a side sectional view showing a configuration of a third embodiment of the present invention. The internal configuration of the radiation imaging apparatus including the X-ray detection panel 1 is the same as that of the first and second embodiments, and a description thereof will be omitted. Also, the housing 5
Is provided with a concave portion 5c, and a detector 21 for detecting the attachment of the grid 6 is provided on the inner side wall 5d. The detector 21 has the detecting portion 21a exposed to the concave portion 5c, and is fixed in a state in which the outer peripheral portion is sealed with respect to the housing. The detector 21 is connected to the electric circuit board 3 via a cable 21b, and is configured to detect the presence or absence of the grid 6.

The detector 21 is a proximity sensor for detecting a metal, and can detect a metal such as steel, stainless steel, brass, and aluminum at a distance of several mm. In this case, the frame 20 fixed to the grid 6 mounted on the incident surface side of the cassette housing 5 is formed of a metal such as steel, stainless steel, brass, or aluminum. The detection unit 21a is configured to be in close contact with the detection unit 21a at a distance of several mm. Therefore, the detector 12 is turned on by detecting the metal part of the tip part 21 a of the frame 20.
In this state, the mounting of the grid 6 is detected.

In this embodiment, as in the first and second embodiments, the grid detecting means is provided inside the recess 5c of the housing 5, so that the subject may get on the cassette without the grid 6. When some metal is in the vicinity m of the detector
m is unlikely to approach m. In addition, since there is no need for electrical connection between the grid 6 and the cassette housing, a highly reliable device can be realized. In the third embodiment, it is also possible to detect the type of the grid 6 as described above by using a plurality of pairs of the detected object and the detector.

(Fourth Embodiment) FIG. 5 is a side sectional view showing a configuration of a fourth embodiment of the present invention. A recess 5c is formed in the housing 5, and a translucent cover member 33 is fixed to the inner side wall 5d. An optical reader 31 composed of an array-shaped photo sensor is arranged inside the cover member 33, and is connected to the electric board 3 via a cable 31b. In addition, a cover (not shown) for blocking light leakage from the cover member 33 is provided around the reader 31.

On the other hand, a grid 6 is mounted on the incident surface side of the cassette housing 5. The grid 6 has a structure in which the frames 7 and 30 are positioned and fixed by fixing them to the outer shape of the housing 5. One end 30 of the frame 30 fixed to the grid 6
An identification mark 32 such as a bar code is attached to a. The identification mark 32 includes information indicating the type of the grid 6, and the grid 6 is attached to the reader 31.
Reads the identification mark, the internal electrical circuit processes it,
At the same time as detecting the grid 6, the type of the grid 6 is detected,
Transmit to external operating device.

(Fifth Embodiment) FIG. 6 is a side sectional view showing the structure of a fifth embodiment of the present invention. Concave recess 5
An array-shaped sensor 51 for detecting a magnetic pattern is fixed to the side wall 5d inside c. On the other hand, a magnetic tape 42 on which a magnetic pattern is recorded instead of an identification mark is attached to one end 40a of a frame 40 for fixing the grid 6 on the incident surface side of the cassette housing 5. Magnetic tape 4
2 includes information indicating the type of grid, and the information of the magnetic tape 42 is read by the sensor 51 when the grid 6 is mounted, so that the grid type is detected at the same time as grid detection as in the fourth embodiment. Can be detected.

Here, in the fourth and fifth embodiments, when the identification pattern is read optically or magnetically, if the cover member 33, the sensor 51, and the like become dirty, the reading performance deteriorates, and erroneous information is read. May be detected. The main cause of soiling is that fingerprints and oils and fats adhere to the subject or the operator when touched. However, in the fourth and fifth embodiments, the inside of the concave portion 5c of the housing is less likely to be directly touched by the subject or the operator. By arranging the cover member 33, the sensor 51, and the like, the possibility of erroneous detection due to dirt can be reduced.

In all of the embodiments described above, a concave portion is formed on the X-ray incident surface side, and the grid detecting means is arranged near the side wall of the concave portion. ) Does not impair the effects of the present invention, and conversely, there is no accumulation of dust and the like, so that there is an effect on sanitary aspects. In the above embodiments, the case where X-rays are used has been described as an example. However, the present invention is not limited to this, and may be used, for example, when α-rays, β-rays, γ-rays, etc. are used. Can be.

[0034]

As described above, according to the present invention, since the grid detecting means is provided in the recess of the cassette housing, the subject or the operator may come into direct contact with the grid and cause the erroneous operation. It is possible to prevent erroneous detection by adding dirt. In addition, since electrical connection between the grid and the cassette is not required, the mounting of the grid is simple, no trouble is caused by the connection, and a highly reliable device can be realized. Therefore, it is possible to improve the convenience of automatically and stably presenting the information of the grid attachment, and further, it is possible to present the information of the type of the grid by detecting the type of the grid, thereby further improving the convenience.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a first embodiment of a radiographic image capturing apparatus according to the present invention.

FIG. 2 is a partially enlarged view of a detection unit according to the first embodiment.

FIG. 3 is a side sectional view showing a second embodiment of the present invention.

FIG. 4 is a side sectional view showing a third embodiment of the present invention.

FIG. 5 is a side sectional view showing a fourth embodiment of the present invention.

FIG. 6 is a side sectional view showing a fifth embodiment of the present invention.

FIG. 7 is a conceptual diagram of a conventional radiation imaging system.

FIG. 8 is a side sectional view of a conventional radiation imaging apparatus.

FIG. 9 is a sectional view of a grid.

FIG. 10 is a diagram for explaining a problem of a conventional radiation imaging system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 X-ray detection panel 2 Metal base 3 Circuit board 4 Flexible circuit board 5 Cassette housing 5c Depression 5d Side wall 6 Grid 7, 8, 10, 20, 30, 40 Frame 9 Switch 11 Magnet 12 Reed switch 21 Proximity switch 31 Optical reader 32 Identification mark 33 Cover member 41 Magnetic reader 42 Magnetic tape

Claims (11)

[Claims] 1. A radiation image capturing apparatus which performs radiation imaging by irradiating a subject with radiation emitted from a radiation generating means and detecting radiation transmitted through the subject with a radiation detection panel, wherein a cassette including the radiation detection panel is included. A housing, which is detachably attached to the cassette housing, includes a grid for removing scattered radiation, and detection means for detecting that the grid is mounted,
The cassette housing has an opening on the radiation incident side, and a storage portion into which a part of a frame for fixing the grid is inserted is formed, and the detecting means is provided in the storage portion and the mounting of the grid is performed. A radiation image capturing apparatus, wherein the mounting of the grid is detected by sometimes detecting the frame. 2. The radiographic imaging apparatus according to claim 1, wherein the detection unit is a switch element that operates mechanically. 3. The radiographic image capturing apparatus according to claim 1, wherein the detecting unit is a unit that operates in a non-contact manner. 4. The detecting means is a reed switch,
The mounting of the grid is detected by detecting a magnet provided on the frame.
4. The radiographic image capturing apparatus according to any one of 3. 5. The apparatus according to claim 1, wherein the detection unit is a proximity switch of a metal detection type, and detects attachment of the grid by detecting a metal portion of the frame. A radiation image capturing apparatus according to any one of the preceding claims. 6. The apparatus according to claim 1, wherein said detecting means is an optical reading means, and detects mounting of said grid by reading an identification pattern provided on said frame. A radiation image capturing apparatus according to any one of the preceding claims. 7. The apparatus according to claim 1, wherein said detecting means is a magnetic reading means, and detects mounting of said grid by reading a magnetic pattern provided on said frame. A radiation image capturing apparatus according to any one of the preceding claims. 8. A plurality of said detecting means are provided, and information indicating a kind of grid is formed on said frame in association with a position of said plurality of detecting means, and said frame is mounted on said frame. The radiation image capturing apparatus according to any one of claims 1 to 3, wherein a type of the grid is determined based on a detection signal of a detection unit corresponding to the grid. 9. The method according to claim 8, wherein the detecting unit is a single unit, the identification pattern includes information indicating a type of the grid, and the detecting unit determines the type of the mounted grid by reading the identification pattern. The radiation image capturing apparatus according to any one of claims 1 and 6, wherein 10. A single detecting means, wherein the magnetic pattern includes information indicating the type of the grid, and the detecting means determines the type of the mounted grid by reading the magnetic pattern. The radiographic image capturing apparatus according to claim 1, wherein the radiographic image capturing apparatus performs the operation. 11. The storage unit according to claim 1, wherein the storage unit is a recess or a through-hole having an opening on a radiation incident side.
A radiographic image capturing apparatus according to claim 1.