JP4997206B2 - Radiation detector - Google Patents

Description

  The present invention relates to a radiation detection apparatus that detects radiation transmitted through a subject and converts the detected radiation into signal charges having radiation image information.

  2. Description of the Related Art In the medical field, radiation image capturing systems that irradiate a subject with radiation and guide the radiation transmitted through the subject to a radiation detector to capture radiation image information are widely used. As the radiation detector, a conventional radiation film in which the radiation image information is exposed and recorded, or radiation energy as the radiation image information is accumulated in a phosphor, and the radiation image information is obtained by irradiating excitation light. A stimulable phosphor panel that can be extracted as stimulated emission light is known. These radiation detectors supply the radiation film on which the radiation image information is recorded to a developing device to perform development processing, or supply the storage phosphor panel to a reading device to perform reading processing. A visible image can be obtained.

  On the other hand, in an operating room or the like, it is necessary to be able to immediately read out and display radiation image information from a radiation detector after imaging in order to perform a quick and accurate treatment on a patient. Radiation detection using a solid state detector that converts radiation directly into an electrical signal, or converts radiation into visible light with a scintillator, and then converts it into an electrical signal and reads it out A vessel has been developed.

  Patent Document 1 proposes a radiation detector having flexibility that can be matched to the surface shape of a patient. The flexible radiation detector includes a flexible substrate having a TFT matrix, a flexible semiconductor layer for X-ray conversion, or a flexible thin film having a flexible scintillator It has a matrix of photodiodes. Further, in Patent Document 1, a rigid holder is provided at an end portion in the direction of flexibility, and a read amplifier is disposed in the rigid holder, and a read line disposed on the detection board is connected to the read line. It is described as being connected.

  In the radiation detector according to Patent Document 1, there is a possibility that the readout lines are arranged along a direction having flexibility.

  However, since the readout line, in other words, the signal line is desired to be as thick and thick as possible because the impedance is to be lowered, the flexibility is hindered if the signal lines are arranged along the direction having flexibility. There's a problem.

  In Patent Document 2, in a flat panel detector (FPD) in which a plurality of pixels each having a radiation conversion element and a TFT are arranged in a two-dimensional matrix, the signal lines are formed in the column direction, while the TFT Describes a radiation detection apparatus in which gate lines, which are drive lines, are formed in the row direction.

JP 2003-70776 A JP 2007-49124 A

  However, since the platform detector according to Patent Document 2 is not flexible, there is no suggestion about the arrangement direction of signal lines and gate lines in consideration of flexibility.

  The present invention has been made in consideration of such problems, and provides a radiation detection apparatus having a preferable wiring configuration in consideration of the flexibility of the radiation detection apparatus having flexibility in one direction. Objective.

  The radiation detector according to the present invention is formed in a matrix on a substrate, the signal line is connected to one signal electrode, the gate line is connected to the gate electrode, and the other of the switching elements Each of which is formed on each of the signal electrodes and includes a pixel that detects radiation that has passed through the subject and converts the radiation into signal charges, and has flexibility in a row direction or a column direction, The gate lines are arranged along a direction having a characteristic, and the signal lines are arranged along a direction having a rigidity not having the flexibility.

  In this case, a rigid portion for arranging a circuit component is provided on the end side in the flexible direction, and the rigid portion receives the signal charge supplied through the signal line as the circuit component. Electricity is supplied to an A / D converter that converts the digital signal, an image memory that stores the digital signal, a transceiver that transmits the digital signal read from the image memory as a radio signal, or the radiation detection apparatus as a whole. It is preferable that at least one of the batteries is arranged.

  According to the present invention, since a digital signal flows through the gate lines arranged along the direction having flexibility, the gate line may be a thin line without impairing flexibility. Further, since signal charges of analog signals flow through the signal lines arranged along the direction having rigidity, the signal lines can be widened and thickened so as not to distort the analog signals. That is, it is possible to provide a radiation detection apparatus having a preferable wiring configuration in consideration of the flexibility of the radiation detection apparatus having flexibility in one direction that does not impair the flexibility of the substrate.

  Further, a circuit component (an A / D converter that converts the signal charge supplied through the signal line into a digital signal) is provided in a rigid portion provided on an end side in the flexible direction of the radiation detection device, and By arranging an image memory for storing the digital signal, a transceiver for transmitting the digital signal read from the image memory as a radio signal, and a battery for supplying electricity to the entire radiation detection apparatus), one direction It is possible to provide a wireless radiation detection apparatus that is flexible, portable, and battery-driven.

  Further, a circuit component (an A / D converter that converts the signal charge supplied through the signal line into a digital signal) is provided in a rigid portion provided on an end side in the flexible direction of the radiation detection device, and By providing an image memory for storing the digital signal and a battery for supplying electricity to the entire radiation detection apparatus, a radiation detection apparatus that is flexible in one direction and portable and can be driven by a battery is provided. Can do.

  Furthermore, a circuit component (an A / D converter that converts the signal charge supplied through the signal line into a digital signal) is provided in a rigid portion provided on an end side in the flexible direction of the radiation detection device. , An image memory for storing the digital signal, and a transmitter / receiver for transmitting the digital signal read from the image memory as a radio signal). It is possible to provide a lighter-weight wireless radiation detection apparatus that can be operated by the above.

  FIG. 1 is a configuration block diagram of a radiographic imaging system 12 to which a wireless radiation detection apparatus 11 according to this embodiment is applied.

  The radiographic imaging system 12 is disposed, for example, in an operating room, and basically includes a radiation source 16 for irradiating a subject 14 such as a patient with a radiation R having a dose according to imaging conditions, and a subject 14. The radiation detection device 11 that detects the transmitted radiation R, the display device 18 that displays radiation image information based on the radiation R detected by the radiation detection device 11, the radiation detection device 11, the radiation source 16, and the display device 18 are controlled. And a console (control device) 20 that performs the operation.

  Signals are transmitted and received by radio communication between the console 20 and the radiation detection device 11, the radiation source 16, and the display device 18.

  The console 20 is connected to a radiology information system (RIS) 22 that centrally manages radiographic image information and other information handled in the radiology department in the hospital via an in-hospital communication network. A medical information system (HIS) 24 that comprehensively manages medical information in the hospital is connected via the in-hospital communication network.

  The radiation detection apparatus 11 is interposed between a mattress 28 disposed on a bed 26, for example, an operating table, and the subject 14. Since the radiation detection apparatus 11 has flexibility in the length direction y, the radiation detection apparatus 11 is curved along the surface shape of the subject 14 by the weight of the subject 14 on the mattress 28. Thus, since the radiation detection apparatus 11 has flexibility, it is suitable for bed imaging without causing pain to the subject 14.

  As shown in FIG. 2, the radiation detection apparatus 11 has a main surface of a rectangular shape, and includes a resin substrate 40 having flexibility (flexibility) having a size of the square. A configuration in which a thin and flexible flexible portion 30 at the center of y and thick and rigid rigid portions 32 and 34 on both sides (both ends) in the length direction y are provided. It is said that. The rigid portions 32 and 34 are made of hard resin.

  A handle 33 is provided in one rigid portion 32 of the solid that is not hollow by an opening. The other rigid portion 34 has a rectangular tube-like structure having a hollow portion in which circuit components of the control circuit portion 62 described later are mounted. Openings at both ends in the lengthwise direction of the rectangular tube are closed by lids 36, and the rigid portion The hollow part 34 is sealed. Most of the surface of the rigid portion 34 in contact with the substrate 40 is an opening 37, and the circuit component is mounted in the hollow portion through the opening 37.

  Thus, since the radiation detection apparatus 11 is provided with the rigid portions 32 and 34 on both sides in the length direction y having flexibility, it is possible in the length direction (also referred to as the flexibility direction) y. It has flexibility and has rigidity in the width direction (rigid direction) x orthogonal to the length direction y.

  FIG. 3 shows a partially omitted sectional view taken along line III-III in FIG. As can be seen from FIG. 3, a thick sheet-like radiation detection circuit unit 10 is bridged over the rigid part 32 and the rigid part 34 not shown in FIG.

  The radiation detection circuit unit 10 includes a substrate 40 having a size corresponding to the size of the entire surface of the radiation detection device 11, and rigid portions 32 and 34 are attached to both end portions (opposite sides) of the substrate 40. The scintillator 52 that converts the radiation R that has passed through the subject 14 (see FIG. 1) into visible light and the signal line 66 (see FIG. 6) are formed in a matrix on one of the signal electrodes on the surface side of the substrate 40. A TFT layer 48 including an array of thin film transistors (TFTs) 68 (see FIG. 6) connected to the gate electrode 64 and connected to the gate electrode 64 (see FIG. 6), and capable of transmitting radiation R and visible light; A solid-state detection element (hereinafter referred to as a pixel) 50 made of a material such as amorphous silicon (a-Si) formed on the other signal electrode of the TFT 68 (see FIG. 6). (See FIG. 6), a photoelectric conversion layer 46 that converts the visible light into an electric signal that is a signal charge, a grid 42 that removes scattered rays of radiation R from the subject 14, and a protective film layer 41 made of resin. Are provided in order. The visible light irradiated with the radiation R from the protective film layer 41 side and converted into the radiation R by the scintillator 52 is converted into a signal charge (electric signal) by the pixel 50 and accumulated in the pixel 50.

  The scintillator 52 may be interposed between the grid 42 and the photoelectric conversion layer 46 as shown in FIG.

  Further, as the pixel 50, instead of a-Si, a photoelectric conversion layer made of a material such as amorphous selenium (a-Se), which has a temperature tolerance range narrower than that of a-Si, is arranged on an array of TFTs 68. It is possible to substitute for the configuration. In this case, the scintillator 52 is not necessary.

  Further, the TFT 68 functioning as a switching element may be realized in combination with another imaging element such as a CMOS (Complementary Metal-Oxide Semiconductor) image sensor. Furthermore, it can be replaced with a CCD (Charge-Coupled Device) image sensor that transfers charges while shifting them with a shift pulse corresponding to a gate signal referred to as a TFT.

  In FIG. 3, the surface of the protective film layer 41 of the radiation detection circuit unit 10 is a radiation R irradiation surface 56.

  The substrate 40 is preferably configured by mixing a material having a high radiation absorption rate, for example, tungsten powder. More specifically, with this configuration, the substrate 40 mixed with the tungsten powder covers the entire back surface of the radiation detection device 11, thereby preventing back scattering from the radiation detection device 11. Further, damage due to radiation R of circuit components mounted on the control circuit unit 62 (see FIG. 2) disposed in the hollow portion of the rigid portion 34 is prevented. It should be noted that damage to the circuit components mounted on the control circuit 62 due to radiation R can be further prevented by sticking a lead plate covering the surface of the rigid portion 34 to the surface of the rigid portion 34.

  FIG. 5 shows a substantial wiring configuration diagram of the radiation detection apparatus 11.

  FIG. 6 shows a circuit diagram of the radiation detection apparatus 11. In FIG. 6, the dimensional scales of the rigid portions 32 and 34 and the flexible portion 30 are ignored.

  As shown in FIGS. 5 and 6, the control circuit unit 62 is arranged at the arrangement position of the rigid part 34, and the radiation detection circuit unit 10 is arranged at the arrangement position of the flexible part 30.

  In the radiation detection circuit unit 10, as described above, the pixels 50 are arranged on the matrix, and one of the signal electrodes is connected to each pixel 50, and the other signal electrode is connected to one end of the signal line 66. The TFT 68 to which the gate line 64 is connected is disposed.

  At the other end of each signal line 66 arranged in the radiation detection circuit unit 10, as shown in FIG. 6, FETs (field effect transistors) constituting an integration amplifier 82, a sample hold circuit 84, and a multiplexer 76 of an integrated circuit, respectively. One end of the switch 78 is connected in series, and the other end of the FET switch 78 is connected to an A / D converter 90 disposed in the control circuit unit 62 through a signal line 88.

  The control circuit unit 62 includes, in addition to the A / D converter 90, a battery 92 that is a power source of the radiation detection apparatus 11, and a control unit 100 that drives and controls the radiation detection circuit unit 10 using electric power supplied from the battery 92. And a transceiver (wireless communication means) 102 for transmitting and receiving a signal including information on the radiation R detected by the radiation detection circuit unit 10 to and from the console 20 and a drive circuit 110 for the radiation detection circuit unit 10 are mounted. .

  The drive circuit 110 includes a gate drive circuit 70 that drives (turns on) the TFT 68 in each column direction (length direction y), a bias circuit 74 that applies a bias voltage to the pixel 50 through the bias line 72, and a multiplexer 76. A multiplexer driving circuit 79 for sequentially driving (turning on) each FET switch 78 in the row direction (width direction x) is provided.

  The control unit 100 stores an address signal generation circuit 94 that supplies an address signal to the gate drive circuit 70 and the multiplexer drive circuit 79, and a digital signal for each pixel 50 that has been A / D converted by the A / D converter 90. An image memory 96 and an ID memory 98 that stores detection device ID information that is an identification code for specifying the radiation detection device 11 are provided.

  As described above, in each pixel 50, signal charges generated by converting visible light into electrical signals are accumulated, and the TFTs 68 are sequentially turned on for each column in the width direction x, while the FFT switch 78 of the multiplexer 76. The signal charges can be read out as radiation image information (image signal) by sequentially turning on for each row.

  Here, since a digital signal flows through the gate line 64 arranged along the length direction y which is a flexible direction, the gate line 64 may be a thin line, and the length direction y of the substrate 40 Does not impair the flexibility. In practice, one bias line 72 is arranged in parallel along the gate line 64, but since almost no current flows through the bias line 72, it may be a thin line and does not impair the flexibility of the substrate 40. A control line connected to the gate electrode of the FET switch 78 and a power supply line to the integrating amplifier 82 and the sample hold circuit 84 are also arranged along the length direction y. The FET switch 78 is a multiplexer 76. Thus, for example, each IC has several IC configurations, the number of wires is small and the number of wires is small, and the number of power supply lines is as few as two to three. Is hardly disturbed.

  On the other hand, an analog signal of signal charge flows through the signal line 66 arranged along the width direction x, which is a direction having rigidity, so that the signal line 66 is wide and thick so as not to distort the analog signal. Although formed, they are arranged in parallel and along the width direction x, so the flexibility of the substrate 40 in the length direction y is not impaired. Since the pixel 50, the integrating amplifier 82, the sample hold circuit 84, and the FET switch 78 are also arranged on the substantially straight line along each signal line 66, the flexibility is not impaired. The signal lines 88 connected to the A / D converter 90 are arranged along the length direction y which is a direction having flexibility, but since the number is one, the flexibility is almost lost. There is no.

  As an example, the number of gate lines 64 and signal lines 66 is about several thousand.

  The transceiver 102 connected to the control unit 100 collectively transmits the detection apparatus ID information stored in the ID memory 98 and the radiation image information stored in the image memory 96 to the console 20 by wireless communication.

  The radiographic imaging system 12 to which the radiation detection apparatus 11 according to this embodiment is applied is configured as described above. Next, the operation thereof will be described.

  The radiographic image capturing system 12 is installed in an operating room or the like, and is used, for example, when a radiographic image needs to be captured during the operation of the subject 14 (patient) by a doctor. Therefore, the patient information of the subject 14 that is an imaging target is registered in advance in the console 20 prior to imaging. If the imaging region and the imaging method are determined in advance, these imaging conditions are also registered in the console 20 in advance. In the state where the above preparatory work is completed, the treatment for the subject 14 is performed.

  When radiographing is performed during treatment, a doctor or a radiographer in charge takes the irradiation surface 56 (FIGS. 3 and 4) of the radiation detection device 11 at a predetermined position between the subject 14 and the mattress 28 on the bed 26. The radiation detection apparatus 11 is installed in a state where the reference) is on the radiation source 16 side.

  Next, after moving the radiation source 16 to a position facing the radiation detection circuit unit 10, an imaging switch (not shown) is operated to perform imaging.

  In this case, the radiation source 16 acquires an imaging condition related to the imaging region of the subject 14 from the console 20 by wireless communication, and controls a dose adjustment unit in the radiation source 16 according to the acquired imaging condition, thereby obtaining a predetermined dose. The subject 14 is irradiated with the radiation R consisting of

  The radiation R that has passed through the subject 14 is applied to the radiation detection circuit unit 10, and after the scattered radiation is removed by the grid 42 of the radiation detection circuit unit 10, the radiation R is converted into an electric signal by each pixel 50 constituting the radiation detection circuit unit 10. It is converted and held as a charge (signal charge). Next, the signal charges, which are the radiographic image information of the subject 14 held in each pixel 50, according to the address signals supplied from the address signal generation circuit 94 constituting the control unit 100 to the gate drive circuit 70 and the multiplexer drive circuit 79. Read out.

  That is, the gate drive circuit 70 outputs a selection signal according to the address signal supplied from the address signal generation circuit 94 to select the corresponding gate line 64, and turns on the gate electrode of the TFT 68 connected to the gate line 64. Supply. On the other hand, the multiplexer drive circuit 79 outputs a selection signal in accordance with the address signal supplied from the address signal generation circuit 94 to sequentially switch the FET switch 78 constituting the multiplexer 76, and to the gate line 64 selected by the gate drive circuit 70. Signal charges as radiation image information held in each connected pixel 50 are sequentially read out via a signal line 66.

  The signal charges as radiation image information read out from each pixel 50 are amplified by each integrating amplifier 82, sampled by each sample hold circuit 84, and A / D converted via the multiplexer 76 (FET switch 78). Is supplied to the converter 90 and converted into a digital signal by the A / D converter 90. The radiation image information converted into the digital signal is temporarily stored in the image memory 96 of the control unit 100.

  Similarly, the gate drive circuit 70 sequentially switches the TFTs 68 in accordance with the address signal supplied from the address signal generation circuit 94, and the signal charge as the radiation image information, which is the charge information held in each pixel 50, is sent to the signal line 66. Via the multiplexer 76 and the A / D converter 90 and stored in the image memory 96 of the control unit 100.

  The radiation image information stored in the image memory 96 is transmitted to the console 20 by wireless communication via the transceiver 102. The radiographic image information transmitted to the console 20 is received by a transceiver (not shown) of the console 20, subjected to predetermined image processing in an image processing unit (not shown), and then a patient of the subject 14 registered in the console 20. The information is stored in the image memory of the console 20 in a state associated with the information.

  The radiographic image information subjected to predetermined image processing in the console 20 is transmitted from the console 20 to the display device 18, and the display device 18 that has received the radiographic image information displays the radiographic image.

  A doctor (not shown) performs the procedure while confirming the radiation image displayed on the display device 18.

  In this case, in the radiographic imaging system 12, signals are transmitted and received between the radiation detection device 11 and the console 20, between the radiation source 16 and the console 20, and between the console 20 and the display device 18. Since these cables are not connected, for example, these cables are not disposed on the floor surface of an operating room or the like, and there is no possibility of hindering the work of a doctor or the like.

  As described above, the radiation detection apparatus 11 according to the above-described embodiment is formed in a matrix on the substrate 40, the signal line 66 is connected to one signal electrode, and the gate line 64 is connected to the gate electrode 64. And a pixel 50 that is formed on the other signal electrode of each TFT 68 and detects the radiation R that has passed through the subject 14 and converts it into signal charges, in the length direction y (in this embodiment). In the radiation detection apparatus 11 having flexibility in the column direction), the gate lines 64 are arranged along the length direction y which is the direction having flexibility, and the rigidity does not have flexibility. The signal lines 66 are arranged along the width direction x which is the direction.

  According to the radiation detection apparatus 11 configured in this way, a digital signal flows through the flexible gate lines 64 arranged along the length direction y. Therefore, the gate lines 64 are formed as thin lines. Therefore, the flexibility in the length direction y is not impaired. Further, since the signal charge of the analog signal flows through the rigid signal line 66 arranged in the width direction x, the signal line 66 is wide and thick in order to prevent distortion of the analog signal. The signal line 66 is formed along a direction having rigidity (in this embodiment, the width direction x), so that the flexibility in the length direction y is provided. There is no loss. Therefore, the radiation detection apparatus 11 having a preferable wiring configuration in consideration of flexibility can be provided.

  In this case, a rigid portion 34 for arranging the circuit components of the control circuit portion 62 is provided on the end portion in the longitudinal direction y having flexibility, and the signal wire 66 is provided in the rigid portion 34 as the circuit components. A / D converter 90 that converts signal charges, which are radiation image information supplied through the digital signal, into digital signals, image memory 96 that stores the digital signals, and radiation image information of the digital signals read from image memory 96 Are arranged as a radio signal, and a battery 92 that supplies electricity to the entire radiation detection apparatus 11 is disposed. Thereby, the portable radio | wireless type radiation detection apparatus 11 which has flexibility in the length direction y which is one direction can be provided. However, instead of arranging both the transmitter / receiver 102 and the battery 92 as circuit components to be arranged in the rigid portion 34, at least one of the transmitter / receiver 102 (not wireless type but wired type) or the battery 92 is arranged. You may change a structure so that it may. For example, by disposing the battery 92, it is possible to provide a radiation detection apparatus that is flexible in one direction and portable and battery-driven. By disposing the transmitter / receiver 102, it is possible to provide a lighter-weight wireless radiation detection apparatus that is flexible in one direction, portable, and operable by an external power source.

  In addition, this invention is not limited to embodiment mentioned above, Of course, it can change freely in the range which does not deviate from the main point of this invention.

  For example, in the above-described embodiment, the radiographic image capturing system 12 is used during the operation, and the radiographic image is displayed on the display device 18. However, the radiographic image capturing system 12 captures a normal radiographic image other than during the operation. Needless to say, the present invention can also be applied to the case of performing only. For example, it can also be applied to medical examinations and rounds in hospitals.

  When the radiation detection apparatus 11 is used in an operating room or the like, there is a risk that blood and other germs may adhere. Therefore, the radiation detection device 11 can have a waterproof and hermetic structure, and can be used repeatedly and continuously by sterilizing and cleaning as necessary.

  Further, the wireless communication between the radiation detection apparatus 11 and the console 20 that is an external device may be performed by optical wireless communication using infrared rays or the like instead of normal communication using radio waves.

1 is a configuration block diagram of a radiographic imaging system including a radiation detection apparatus in this embodiment. It is a perspective view of a radiation detection apparatus. FIG. 3 is a partially omitted cross-sectional view taken along line III-III of the radiation detection apparatus shown in FIG. 2. FIG. 6 is a partially omitted cross-sectional view of a radiation detection apparatus according to another embodiment. It is a substantial wiring block diagram of a radiation detection apparatus. It is a circuit diagram of a radiation detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Radiation detection circuit part 11 ... Radiation detection apparatus 14 ... Subject 40 ... Substrate 46 ... Photoelectric conversion layer 50 ... Pixel 64 ... Gate line 66 ... Signal line 68 ... TFT 90 ... A / D converter 92 ... Battery 96 ... Image memory 102 ... transceiver

Claims (2)

An array of switching elements formed in a matrix on the substrate, with one signal electrode connected to a signal line and the gate electrode connected to the gate line;
A pixel that is formed on the other signal electrode of each of the switching elements and detects radiation transmitted through the subject and converts it into signal charge;
With
A radiation detection apparatus having flexibility in a row direction or a column direction,
The radiation detection apparatus, wherein the gate lines are arranged along the direction having flexibility and the signal lines are arranged along a direction having rigidity not having flexibility. The radiation detection apparatus according to claim 1,
A rigid portion for arranging circuit components is provided on the end side in the direction having flexibility,
In the rigid part, as the circuit component,
An A / D converter for converting the signal charge supplied through the signal line into a digital signal;
An image memory for storing the digital signal;
A radiation detection apparatus comprising: a transmitter / receiver that transmits a digital signal read from the image memory as a radio signal; or at least one of a battery that supplies electricity to the entire radiation detection apparatus.

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