JP2020089432A - Radiation detection system - Google Patents

Abstract

To provide a radiation detection system capable of photographing a predetermined portion at an arbitrary place in real time.SOLUTION: The radiation detection system according to an embodiment comprises: a frame capable of internally housing an analyte; a radiation generator provided at the frame and capable of irradiation; and a radiation detector provided at a position confronting the radiation generator in the frame and capable of converting incident radiation to an image data signal.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to a radiation detection system.

An X-ray detector is one type of radiation detector.
In recent years, the forms of X-ray detectors have been diversified, and as one example thereof, a portable type X-ray detector with improved portability has been developed. Further, in order to further improve the portability of the portable type X-ray detector, an X-ray detector incorporating a battery has been proposed.

When capturing an X-ray image, the X-ray detector is fixed to an imaging stand or the like in the imaging room. An X-ray generator that generates X-rays is provided in the imaging room, and the subject is placed between the X-ray detector and the X-ray generator. Therefore, the subject needs to be moved to the imaging room, and for example, a predetermined part cannot be imaged in real time at an arbitrary place such as outdoors.
Therefore, there has been a demand for the development of a radiation detection system capable of capturing a predetermined part in real time at an arbitrary place.

JP, 2010-204125, A

The problem to be solved by the present invention is to provide a radiation detection system capable of capturing an image of a predetermined part in real time at an arbitrary place.

The radiation detection system according to the embodiment is provided with a frame capable of accommodating a subject therein, a radiation generator provided in the frame and capable of irradiating radiation, and a position of the frame facing the radiation generator. And a radiation detector capable of converting the incident radiation into an image data signal.

It is a schematic perspective view for illustrating the X-ray detection system according to the present embodiment. It is a schematic perspective view which looked at the X-ray detection system in FIG. 1 from the A direction. It is a schematic plan view which looked at the X-ray detection system in FIG. 1 from the B direction. It is a schematic perspective view for illustrating an X-ray detector. It is a circuit diagram of an array substrate. It is a block diagram of an X-ray detector.

Embodiments will be exemplified below with reference to the drawings. In the drawings, the same components are designated by the same reference numerals, and detailed description thereof will be appropriately omitted.
Further, the radiation detection system according to the embodiment of the present invention can be applied to various radiations such as γ-rays as well as X-rays. Here, as an example, description will be given by taking a case relating to X-rays as a typical one of radiations. Therefore, by replacing “X-ray” in the following embodiments with “other radiation”, it can be applied to other radiation.

The X-ray detector 1 provided in the X-ray detection system 100 is an X-ray plane sensor. The X-ray flat sensor is roughly classified into a direct conversion system and an indirect conversion system.
The indirect conversion type X-ray detector is provided with, for example, an array substrate having a plurality of photoelectric conversion units, and a scintillator provided on the plurality of photoelectric conversion units and converting X-rays into fluorescence (visible light). ing. In an indirect conversion type X-ray detector, X-rays incident from the outside are converted into fluorescence by a scintillator. The generated fluorescence is converted into signal charges by the photoelectric conversion unit.
The direct conversion type X-ray detector is provided with a photoelectric conversion film made of, for example, amorphous selenium. In a direct conversion type X-ray detector, X-rays incident from the outside are absorbed by the photoelectric conversion film and directly converted into signal charges.

In the following, the indirect conversion type X-ray detector 1 is illustrated as an example, but the present invention can also be applied to the direct conversion type X-ray detector.
That is, the X-ray detector only needs to have a detector that converts X-rays into electrical information. The detection unit can detect X-rays directly or in cooperation with a scintillator, for example.
Since a known technique can be applied to the basic configuration of the direct conversion X-ray detector, detailed description thereof will be omitted.
Further, the X-ray detector 1 can be used, for example, in general medical care. However, the use of the X-ray detector 1 is not limited to general medicine.

FIG. 1 is a schematic perspective view for illustrating an X-ray detection system 100 according to this embodiment.
FIG. 2 is a schematic perspective view of the X-ray detection system 100 in FIG. 1 viewed from the A direction.
FIG. 3 is a schematic plan view of the X-ray detection system 100 in FIG. 1 viewed from the B direction.
As shown in FIGS. 1 to 3, the X-ray detection system 100 includes an X-ray detector 1, a display unit 10, a power supply 20, an X-ray generator 30, a frame 40, and a controller 50.

FIG. 4 is a schematic perspective view for illustrating the X-ray detector 1.
FIG. 5 is a circuit diagram of the array substrate 2.
FIG. 6 is a block diagram of the X-ray detector 1.
As shown in FIGS. 4 to 6, the X-ray detector 1 is provided with an array substrate 2, a circuit substrate 3, an image processing unit 4, and a scintillator 5.
The X-ray detector 1 can be provided in the frame 40 at a position facing the X-ray generator 30. The X-ray detector 1 can be provided on the outer surface of the frame 40, for example. The X-ray detector 1 converts the X-rays emitted from the X-ray generator 30 and transmitted through the subject 200 into image data signals S2.

The array substrate 2 converts fluorescence (visible light) converted from X-rays by the scintillator 5 into signal charges.
The array substrate 2 has a substrate 2a, a photoelectric conversion unit 2b, a control line (or gate line) 2c1, a data line (or signal line) 2c2, a protective layer 2f, and the like.
The numbers of the photoelectric conversion unit 2b, the control line 2c1, the data line 2c2, and the like are not limited to those illustrated.

The substrate 2a has a plate shape and is made of a flexible material. The substrate 2a can be formed of a resin such as polyimide, polyester, or carbon fiber reinforced plastic (CFRP). The thickness of the substrate 2a can be set to about 0.7 mm, for example.

A plurality of photoelectric conversion units 2b are provided on one surface of the substrate 2a.
The photoelectric conversion unit 2b has a rectangular shape and is provided in a region defined by the control line 2c1 and the data line 2c2. The plurality of photoelectric conversion units 2b are arranged in a matrix. Note that one photoelectric conversion unit 2b corresponds to one pixel of the X-ray image.

A photoelectric conversion element 2b1 and a thin film transistor (TFT) 2b2 that is a switching element are provided in each of the plurality of photoelectric conversion units 2b.
Further, as shown in FIG. 5, a storage capacitor 2b3 for storing the signal charges converted in the photoelectric conversion element 2b1 can be provided. The storage capacitor 2b3 has, for example, a rectangular flat plate shape, and can be provided below each thin film transistor 2b2. However, depending on the capacity of the photoelectric conversion element 2b1, the photoelectric conversion element 2b1 can also serve as the storage capacitor 2b3.

The photoelectric conversion element 2b1 can be, for example, a photodiode or the like.
The thin film transistor 2b2 switches the storage of charge in the storage capacitor 2b3 and the discharge of charge from the storage capacitor 2b3. The thin film transistor 2b2 has a gate electrode 2b2a, a drain electrode 2b2b, and a source electrode 2b2c. The gate electrode 2b2a of the thin film transistor 2b2 is electrically connected to the corresponding control line 2c1. The drain electrode 2b2b of the thin film transistor 2b2 is electrically connected to the corresponding data line 2c2. The source electrode 2b2c of the thin film transistor 2b2 is electrically connected to the corresponding photoelectric conversion element 2b1 and storage capacitor 2b3. Further, the anode side of the photoelectric conversion element 2b1 and the storage capacitor 2b3 are connected to the ground.

A plurality of control lines 2c1 are provided in parallel with each other at a predetermined interval. The control line 2c1 extends in the row direction, for example. One control line 2c1 is electrically connected to one of the plurality of wiring pads 2d1 provided near the peripheral edge of the substrate 2a. One of the plurality of wirings provided on the flexible printed circuit board 2e1 is electrically connected to one wiring pad 2d1. The other ends of the plurality of wirings provided on the flexible printed board 2e1 are electrically connected to the readout circuit 3a provided on the circuit board 3, respectively.

A plurality of data lines 2c2 are provided in parallel with each other at a predetermined interval. The data line 2c2 extends, for example, in the column direction orthogonal to the row direction. One data line 2c2 is electrically connected to one of the plurality of wiring pads 2d2 provided near the peripheral edge of the substrate 2a. One wiring pad 2d2 is electrically connected to one of a plurality of wirings provided on the flexible printed circuit board 2e2. The other ends of the plurality of wirings provided on the flexible printed board 2e2 are electrically connected to the signal detection circuit 3b provided on the circuit board 3, respectively.
The control line 2c1 and the data line 2c2 can be formed using, for example, a low resistance metal such as aluminum or chromium.

The protective layer 2f covers the photoelectric conversion unit 2b, the control line 2c1, and the data line 2c2. The protective layer 2f includes at least one of an oxide insulating material, a nitride insulating material, an oxynitride insulating material, and a resin material, for example.

The circuit board 3 is provided on the side of the array substrate 2 opposite to the side on which the scintillator 5 is provided.
The circuit board 3 is provided with a read circuit 3a and a signal detection circuit 3b.
The circuit board 3 has flexibility. The readout circuit 3a and the signal detection circuit 3b can be formed on a flexible substrate, for example. The flexible substrate can be, for example, a flexible substrate formed of a resin such as polyimide or polyester.

The readout circuit 3a switches the thin film transistor 2b2 between an on state and an off state.
As shown in FIG. 6, the read circuit 3a has a plurality of gate drivers 3aa and a row selection circuit 3ab.

The control signal S1 is input to the row selection circuit 3ab from the controller 50 or the like. The row selection circuit 3ab inputs the control signal S1 to the corresponding gate driver 3aa according to the scanning direction of the X-ray image.
The gate driver 3aa inputs the control signal S1 to the corresponding control line 2c1.
For example, the readout circuit 3a sequentially inputs the control signal S1 for each control line 2c1 via the flexible printed board 2e1. The thin film transistor 2b2 is turned on by the control signal S1 input to the control line 2c1, and the electric charge (image data signal S2) from the storage capacitor 2b3 can be received.

The signal detection circuit 3b has a plurality of integration amplifiers 3ba, a plurality of selection circuits 3bb, and a plurality of AD converters 3bc.
One integrating amplifier 3ba is electrically connected to one data line 2c2. The integrating amplifier 3ba sequentially receives the image data signal S2 from the photoelectric conversion unit 2b. Then, the integrating amplifier 3ba integrates the current flowing within a fixed time and outputs a voltage corresponding to the integrated value to the selection circuit 3bb. By doing so, it becomes possible to convert the value of the current (charge amount) flowing through the data line 2c2 into the voltage value within a predetermined time. That is, the integrating amplifier 3ba converts the image data information corresponding to the intensity distribution of fluorescence generated in the scintillator 5 into potential information.

The selection circuit 3bb selects the integration amplifier 3ba to be read, and sequentially reads the image data signal S2 converted into potential information.
The AD converter 3bc sequentially converts the read image data signal S2 into a digital signal. The image data signal S2 converted into a digital signal is transmitted to the image processing unit 4.

The image processing unit 4 forms an X-ray image based on the image data signal S2 converted into a digital signal. The image processing unit 4 is integrated with the circuit board 3. That is, the image processing unit 4 is provided on the flexible circuit board 3.

The scintillator 5 is provided on the plurality of photoelectric conversion elements 2b1 and converts incident X-rays into fluorescence. The scintillator 5 is provided so as to cover a region (effective pixel region) where the plurality of photoelectric conversion units 2b are provided on the substrate 2a.
The scintillator 5 can be formed using, for example, cesium iodide (CsI):thallium (Tl) or sodium iodide (NaI):thallium (Tl). In this case, if the scintillator 5 is formed using a vacuum vapor deposition method or the like, the scintillator 5 composed of an aggregate of a plurality of columnar crystals is formed.

The scintillator 5 can also be formed using, for example, terbium activated gadolinium sulfate (Gd ₂ O ₂ S/Tb, or GOS). In this case, the groove portions can be formed in a matrix so that the scintillator 5 having a rectangular column shape is provided for each of the plurality of photoelectric conversion units 2b.
The scintillator 5 can have a thickness of, for example, about 600 μm.

In addition, the X-ray detector 1 is provided with a reflection layer (not shown) so as to cover the surface side of the scintillator 5 (X-ray incident surface side) in order to improve the efficiency of fluorescence utilization and improve the sensitivity characteristics. it can.
Further, in order to prevent the characteristics of the scintillator 5 and the characteristics of the reflecting layer (not shown) from being deteriorated by the water vapor contained in the air, a moistureproof body (not shown) that covers the scintillator 5 and the reflecting layer (not shown) can be provided.

Here, as described above, the array substrate (substrate 2a), the circuit board 3, and the image processing unit 4 have flexibility. Further, since the scintillator 5 has a small thickness, it can be curved. Therefore, the X-ray detector 1 can be curved by following the outer surface of the frame 40. The X-ray detector 1 can be adhered, welded, or fixed to the outer surface of the frame 40 using a screw or the like, for example. The X-ray detector 1 can also be embedded in the frame 40, for example.

As shown in FIGS. 1 to 3, the display unit 10 can be provided on the side of the X-ray detector 1 opposite to the frame 40 side. Most of the X-rays emitted from the X-ray generator 30 are converted into fluorescence by the scintillator 5. Therefore, if the display unit 10 is provided on the side of the X-ray detector 1 opposite to the frame 40 side, it is possible to suppress the incidence of X-rays on the display unit 10. If necessary, a lead-containing shield plate or the like may be provided between the display unit 10 and the X-ray detector 1.

The display unit 10 displays an X-ray image formed based on the image data signal S2. The display unit 10 may be a flexible display. The display unit 10 can be, for example, an electronic paper type display or an organic electroluminescence type display. The display unit 10 can be fixed to the X-ray detector 1, fixed to the frame 40, or fixed to the frame 40 together with the X-ray detector 1.

The power supply 20 can be provided on the outer surface of the frame 40, for example. The power supply 20 can also be embedded in the frame 40, for example. The power source 20 is electrically connected to the circuit board 3, the image processing unit 4, the display unit 10, and the X-ray generator 30. The power supply 20 may have a rechargeable secondary battery such as a lithium ion battery, for example.
Further, the power source 20 may be detachably attached to the frame 40. For example, the power source 20 can be detachably provided on the outer surface of the frame 40 by a mechanical holding unit such as a latch mechanism or a holding unit such as a magnet. That is, the power supply 20 can be rechargeable and removable.
The power source 20 can also be provided in the X-ray generator 30. This makes it possible to prevent the X-rays from entering the power supply 20.

The X-ray generator 30 can be provided on the outer surface of the frame 40, for example. The X-ray generator 30 can be provided so as to face the X-ray detector 1. The X-ray generator 30 generates X-rays. The X-ray generator 30 can be, for example, a vacuum tube that generates X-rays. As shown in FIG. 3, the X-rays emitted from the X-ray generator 30 enter the X-ray detector 1 after passing through the subject 200. The X-ray detector 1 detects X-rays transmitted through the subject 200 and forms an X-ray image.

The X-ray generator 30 can have, for example, a filament, a target, and a high voltage circuit. The filament is made of, for example, tungsten, and is electrically connected to the negative side of the high voltage circuit. The target is formed of, for example, copper, tungsten, molybdenum, or the like, and is electrically connected to the positive side of the high voltage circuit. A power supply 20 is electrically connected to the high voltage circuit.

Electric power (tube current, tube voltage) necessary for X-ray irradiation is supplied to the filament and the target from a high voltage circuit. The X-ray generator 30 emits X-rays toward the subject 200 within the effective visual field by causing the filament to generate electrons and causing the electrons accelerated by the supplied high voltage to collide with the target. A collimator that shapes the shape of the X-ray beam emitted from the X-ray generator 30 may be provided between the X-ray generator 30 and the X-ray detector 1.

The frame 40 has a tubular shape, and for example, the ends 40b and 40c on both sides in the central axis direction may be open. The subject 200 can be housed inside the frame 40 from one end 40b side of the frame 40, for example. In this case, the imaging location on the subject 200 is positioned near the line segment connecting the center of the X-ray detector 1 and the center of the X-ray generator 30. In addition, although the case where two openings are provided has been illustrated, at least one opening may be provided. The frame 40 may be any one that can accommodate the subject 200 inside.
The subject 200 is not particularly limited as long as it can be inserted into the frame 40. The subject 200 can be, for example, an arm, a hand, a leg, a body of a human body, a pipe, a tank, or the like. However, the subject 200 is not limited to the illustrated one. The frame 40 can move along with the movement of the stored subject 200.

The opening portion of the frame 40 may be elastically deformable. In this case, a slit 40a can be provided on the outer surface of the frame 40. The slit 40a extends between one end 40b and the other end 40c of the frame 40 in the central axis direction. That is, the outer surface of the frame 40 is cut at one place. With this configuration, the frame 40 is easily deformed in the direction orthogonal to the central axis. Therefore, even if the cross-sectional size of the subject 200 is somewhat large, the subject 200 can be inserted into the frame 40.

The material of the frame 40 can be, for example, a resin such as polyphenylene sulfide resin, polycarbonate resin, carbon fiber reinforced plastic, or the like. In this way, since the X-rays pass through the frame 40, it becomes easy to provide the X-ray generator 30 and the X-ray detector 1 on the outer surface of the frame 40. Further, the frame 40 is formed of a flexible material such as cloth, and a reinforcing plate is provided between the X-ray detector 1, the display unit 10, the power source 20, and the X-ray generator 30 as needed. You can also

Further, the holding portion 41 can be provided near the slit 40a. The holding portion 41 can be, for example, a surface fastener having a hook surface and a loop surface. If the holding portion 41 is provided, the vicinity of the slit 40a can be connected to each other. Therefore, it becomes easy to bring at least a part of the inner surface of the frame 40 into contact with the subject 200, and thus it is possible to prevent the position of the subject 200 from shifting during imaging. The holding portion 41 is not limited to the surface fastener, and may be, for example, a magnet, an electromagnet, a band, or the like.
Alternatively, the frame 40 may be divided and connected by a hinge 42 or the like. This makes it easy to store the subject 200 inside the frame 40.

The controller 50 can be provided on the opposite side of the X-ray generator 30 from the frame 40 side. By doing so, it is possible to suppress the incidence of X-rays on the electronic components provided in the controller 50. The power source 20, the X-ray generator 30, and the controller 50 may be integrated.

The controller 50 controls the operations of the X-ray detector 1, the display unit 10, the power supply 20, and the X-ray generator 30.
The controller 50 can be provided with a computing element 51, a memory 52, an input section 53, and an indicator 54.

The arithmetic element 51 may be, for example, a CPU (Central Processing Unit) or the like.
The memory 52 can be, for example, a semiconductor memory or the like. The memory 52 can store programs for controlling the operations of the X-ray detector 1, the display unit 10, the power supply 20, and the X-ray generator 30. The memory 52 can also temporarily store the image data signal S2 for forming a plurality of X-ray images, for example.
The arithmetic element 51 operates the X-ray detector 1, the display unit 10, the power supply 20, and the X-ray generator 30 based on the program stored in the memory 52 and the information input from the input unit 53. Can be controlled. The arithmetic element 51 can display an operating state and the like on the indicator 54.

The input unit 53 can be, for example, a switch for inputting ON/OFF of the power supply 20, start of shooting, switching of shooting modes, and the like.
The indicator 54 can display, for example, the status of the power supply 20, the shooting status, the shooting mode, and the abnormality display. The indicator 54 can be, for example, a liquid crystal panel or the like.
The input unit 53 and the indicator 54 may be provided on the display unit 10. For example, the display unit 10 may be provided with a touch panel or the like to serve as the input unit 53. Further, the information displayed on the indicator 54 can be displayed on the display unit 10.

Further, the controller 50 may include a transmitter and wirelessly transmit the image data signal S2 to the outside. When the image data signal S2 is wirelessly transmitted to the outside, the image processing unit 4, the display unit 10 and the like can be omitted.
Further, the controller 50 may include a receiver so that it can receive an input signal from the outside. When receiving an input signal from the outside, the input unit 53, the indicator 54 and the like can be omitted.

Next, the operation of the X-ray detection system 100, that is, the capturing of an X-ray image will be described. First, the subject 200 is stored inside the frame 40. At this time, the imaging portion of the subject 200 is positioned near the line segment connecting the center of the X-ray detector 1 and the center of the X-ray generator 30.
Next, the information for turning on the power supply 20 is input from the input unit 53, and the information such as the photographing mode is also input as necessary.
Next, information on the start of shooting is input from the input unit 53.

The arithmetic element 51 controls the operations of the X-ray generator 30 and the X-ray detector 1 based on a program stored in the memory 52 to capture an X-ray image.
For example, first, the X-ray generator 30 is irradiated with X-rays. The X-ray irradiation is stopped after the elapse of a predetermined time.
After irradiation of X-rays, the X-ray detector 1 is made to form an X-ray image after a predetermined time has elapsed. Since a known technique can be applied to the configuration of the X-ray image, detailed description will be omitted.
The constructed X-ray image is displayed on the display unit 10. The constructed X-ray image can be a still image or a moving image.

According to the X-ray detection system 100 according to the present embodiment, it is possible to easily image a predetermined part by only housing the subject 200 inside the frame 40. That is, according to the X-ray detection system 100, it is possible to image a predetermined part in real time at an arbitrary place. For example, when an X-ray image is taken in medical care or the like, it may be urgent or there is no facility such as a power supply. For example, it is difficult to take an X-ray image at an accident site or in an ambulance. However, according to the X-ray detection system 100, an X-ray image can be easily captured even under these circumstances. Then, based on the captured X-ray image, it is possible to seek a diagnosis of a doctor or the like who is located far away.

Although some embodiments of the present invention have been illustrated above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the scope equivalent thereto. Further, the above-described respective embodiments can be implemented in combination with each other.

1 X-ray detector, 10 display unit, 20 power supply, 30 X-ray generator, 40 frame, 40b opening, 40c opening, 50 controller, 52 memory, 100 X-ray detection system

Claims (7)

A frame that can accommodate the subject inside,
A radiation generator provided on the frame and capable of emitting radiation,
A radiation detector provided at a position facing the radiation generator of the frame, capable of converting the incident radiation into an image data signal,
Radiation detection system equipped with. The radiation detection system according to claim 1, wherein the opening portion of the frame is elastically deformable. The radiation detection system according to claim 1, wherein the frame is movable in association with the movement of the stored subject. The radiation detection system according to claim 1, further comprising a controller capable of wirelessly transmitting the image data signal to the outside. The radiation detection system according to claim 1, further comprising a power source that can be charged and removed. The radiation detection system according to claim 1, further comprising a memory capable of storing the image data signals for forming a plurality of radiation images. 7. The radiation detector according to claim 1, further comprising a display unit provided on a side opposite to the frame side and capable of displaying a radiation image configured based on the image data signal. The radiation detection system described.

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