JP2006087566A - Radiation image acquisition method and radiation image acquisition apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation image acquisition method to make the image being read to be uninfluenced by a noise caused by wireless to prevent the degradation of the quality of the image when the reading of a radiation image after the radiation photographing is executed and the radiation image data is transmitted to a destination of the transmission by the wireless, and a radiation image acquisition apparatus. <P>SOLUTION: The radiation image acquisition method is that the radiation image data is read on the basis of the radiation information acquired corresponding to a dose of the radiation which is applied to a subject and penetrates the subject, and when the radiation image data is transmitted to the destination of the transmission by the wireless, the timing of the reading of the radiation image data and the timing of the transmission by the wireless are moved not to overlap each other in the case that the irradiation is continuously executed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a radiographic image acquisition method and a radiographic image acquisition apparatus that acquire radiographic image data based on radiation information obtained in accordance with a dose of radiation that is irradiated onto a subject and transmitted through the subject.

  Conventionally, a subject such as a human body is irradiated with radiation from a radiation source such as X-rays or γ-rays for medical examinations, etc., and in conjunction with this radiation irradiation, a wavelength converter such as a fluorescent plate is used according to the transmitted dose of the subject. An imaging apparatus is known in which wavelength information is converted into a photosensitive wavelength region of a light receiving unit and converted into an electrical signal by a light receiving element to obtain image information as electrical information (see, for example, Patent Document 1 below). Such an imaging device is also referred to as an FPD (Flat Panel Detector) when configured in a flat panel shape similar to a radiographic imaging cassette.

  On the other hand, in a radiographic system using FPD, radiation image data obtained by reading with FPD is transferred to a personal computer (PC) for image recording or image display. In this case, the connection between FPD and PC is performed. In order to improve the operability as cordless, a radiography system using a wireless connection is known (for example, see Patent Document 2 below).

In the radiography system using wireless communication described above, image transfer by radio waves may be performed during reading of image data linked to radiation irradiation, so noise caused by the radio waves is mixed into the image being read and image quality deteriorates. May be invited. In particular, the FPD is easily affected by radio waves because of the long wiring length of signal lines and the like for each pixel.
Japanese Patent Application Laid-Open No. 11-34595 JP 2003-210444 A

  In the present invention, in view of the above-described problems of the prior art, when radiographic images are read after radiography and radiographic image data is transferred to a transfer destination by radio, an image in which noise caused by the radio is being read An object of the present invention is to provide a radiological image acquisition method and a radiological image acquisition apparatus that prevent deterioration of image quality without affecting the quality of the image.

  In order to achieve the above object, a radiological image acquisition method according to the present invention includes a step of reading radiographic image data based on radiation information obtained in accordance with a dose of radiation that is irradiated on a subject and transmitted through the subject; A step of wirelessly transferring the radiation image data to a transfer destination, and when the radiation irradiation is continuously performed, the timing of reading the radiation image data and the timing of wireless transfer are not overlapped. And controlling both timings.

  According to this radiographic image acquisition method, when radiography is performed continuously, the radiographic image data is not overlapped by controlling the radiographic image data reading timing and the wireless transfer timing to be shifted. When the radiographic image data is transferred to the transfer destination wirelessly, it is possible to prevent image quality degradation without affecting the image being read by noise caused by the wireless.

  In the radiological image acquisition method, the step of reading the radiographic image data includes a step of reading out charges from a charge collector in which charges are accumulated by radiation transmitted through the subject, and a step of digitally processing the read signal. In each step, the influence by radio can be eliminated.

  In each step, the step of reading the radiation image data further includes a step of resetting the charge collector and a step of accumulating charges in the charge collector due to radiation transmitted through the subject. Wireless effects can be eliminated.

  In addition, when the radiation image data is read, the wireless transfer of the radiation image data is prohibited, so that the influence of the radio on the image reading can be eliminated. In this case, the transfer prohibition includes a case where only transmission is prohibited and a case where both transmission and reception are prohibited.

  That is, wireless transmission can be performed directly from the transfer destination or via the base station. Thereby, only the transmission to the transfer destination is prohibited, and the acquisition source can receive a wireless information signal (for example, information related to radiation irradiation interlocking) from the transfer destination.

  In this case, when the radiation image data is read, wireless transmission from the transfer destination or wireless transmission via the base station may be prohibited. As a result, both transmission and reception are prohibited.

  Further, it is possible to detect radiation irradiation on the subject and execute the transfer prohibition based on the detection information.

  Moreover, the transfer destination may take in irradiation execution information in the radiation irradiation, and the transfer prohibition may be executed based on the irradiation execution information transmitted from the transfer destination. Further, the transfer prohibition may be executed based on irradiation mode transition information when the irradiation mode is shifted for radiation irradiation.

  Further, the next radiation imaging can be performed by releasing the transfer prohibition based on the end information when the reading of the radiation image data is completed.

  Further, the transfer prohibition may be canceled based on release information received from the transfer destination. Further, the transfer prohibition may be canceled after a predetermined time has elapsed since the radiation irradiation.

  The radiation image acquisition apparatus according to the present invention includes a radiation imaging unit that reads radiation image data based on radiation information obtained according to a dose of radiation that has been irradiated onto a subject from the irradiation unit and transmitted through the subject, and the radiation image A communication unit configured to wirelessly transfer data to a transfer destination; and a control unit configured to control the radiation imaging unit and the communication unit, wherein the control unit performs the radiation when the radiation irradiation is continuously performed. Both timings are controlled so that the timing of reading radiographic image data in the imaging unit and the timing of transfer in the communication unit do not overlap.

  According to this radiographic image acquisition device, when radiographing is performed continuously, the radiographic image data is not overlapped by controlling the radiographic image data reading timing and the wireless transfer timing to be shifted. When the radiographic image data is transferred to the transfer destination wirelessly, it is possible to prevent image quality degradation without affecting the image being read by noise caused by the wireless.

  In the radiation image acquisition apparatus, the radiation imaging unit resets the charge collector before the charge is accumulated, and a charge collector in which charges are accumulated by radiation transmitted through the subject for reading the radiation image data. And a reset unit that reads out charges from the charge collector, and an A / D converter that converts the read analog signal into a digital signal. .

  In addition, when the radiographic image data is read, the control unit prohibits the radio transfer of the radiographic image data, thereby eliminating the influence of radio on the image reading. In this case, the transfer prohibition includes a case where only transmission is prohibited and a case where both transmission and reception are prohibited.

  In other words, the communication unit can be configured to receive the transmission signal when transmission is performed directly from the transfer destination or wirelessly via a base station. Thereby, only the transmission to the transfer destination is prohibited, and the acquisition source can receive a wireless information signal (for example, information related to radiation irradiation interlocking) from the transfer destination.

  In this case, the control unit may be configured to prohibit wireless transmission from the transfer destination or wireless transmission via the base station when reading the radiation image data. As a result, both transmission and reception are prohibited.

  In addition, a detection unit that detects radiation irradiation on the subject may be provided, and the control unit may be configured to prohibit the transfer based on detection information of the detection unit.

  Further, the transfer destination may capture the irradiation execution information in the irradiation unit, and the control unit may be configured to prohibit the transfer based on the irradiation execution information received from the transfer destination by the communication unit.

  In addition, an input unit that inputs irradiation mode shift information when the irradiation unit shifts to the irradiation mode is provided, and the control unit executes the transfer prohibition based on the irradiation mode shift information input to the input unit. You may comprise.

  Further, the control unit can perform the next radiation imaging by being configured to cancel the transfer prohibition based on the end information generated when the radiation imaging unit ends reading of the radiation image data. .

  Further, the control unit may be configured to cancel the transfer prohibition based on release information received from the transfer destination by the communication unit. Further, the control unit may be configured to cancel the transfer prohibition after a predetermined time has elapsed from the radiation irradiation. The radiographic imaging unit further includes an input unit that inputs end information of reading of radiation image data, and the control unit is configured to release the prohibition of transfer based on the end information input to the input unit. May be.

  According to the radiological image acquisition method and radiological image acquisition apparatus of the present invention, when radiographic images are read after radiography, and radiographic image data is transferred to a transfer destination by radio, noise due to the radio is being read. It is possible to prevent deterioration of image quality without affecting the image.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing a radiographic image acquisition system that performs radiography on a patient and acquires the radiographic image in the present embodiment. FIG. 5 is a block diagram schematically showing the radiological image acquisition system of FIG.

  The radiation image acquisition system in FIG. 1 emits radiation (X-rays) 100 from a radiation source 101 controlled by a radiation generation control device 102 to a patient P who is a radiographic subject in a prone state on a bed 110. The transmitted radiation corresponding to the radiation dose transmitted through the imaging target region of the patient P is detected by the flat panel radiation image detector 5 arranged so as to be sandwiched between the bed 110 and the patient P. It has become.

  The radiation source 101 is generally a fixed anode or a rotary anode X-ray tube, and the X-ray tube has an anode load voltage of, for example, 20 kV to 150 kV when medical. Further, as shown in FIG. 1, the radiation generation control device 102 has a radiation irradiation button 102a, and causes the radiation source 101 to perform radiation irradiation by pressing it. An ON signal from the radiation irradiation button 102 a is sent to the image processing apparatus 1.

  As shown in FIGS. 1 and 5, the radiation image detector 5 generates radiation image data based on the detection result of the transmitted radiation, stores the radiation image data in the memory unit 31, and uses the generated radiation image data as a data wireless signal. m is transferred from the detector communication unit 35 to the image processing apparatus 1 as a transfer destination wirelessly by radio waves.

  As shown in FIGS. 1 and 5, the image processing apparatus 1 receives the radio data m of the radiographic image data from the radiographic image detector 5 by the PC communication unit 4 under the control of the control unit 6, and The radiographic image is displayed on the screen 3, the image processing unit 7 performs image processing such as predetermined frequency processing and gradation processing, and the radiographic image data after the image processing is stored in the memory unit 9, and the output unit 8 is output to a display device, a database server, a printer or the like in the examination room.

  Further, as shown in FIG. 5, the image processing apparatus 1 can transmit the wireless signal n from the PC communication unit 4 to the detector communication unit 35 of the radiation image detector 5. For example, when the radiographic image acquisition system is set to the imaging mode, the imaging mode signal is transmitted to the radiographic image detector 5 as the radio signal n by operating the input device of the image processing apparatus 1.

  The image processing apparatus 1 shown in FIGS. 1 and 5 includes a so-called personal computer. In addition to the display unit 2 including a liquid crystal display and a CRT, the computer main body (PC), a pointing device such as a mouse, a keyboard, and the like Input device (not shown). In general, the image processing apparatus 1 is installed outside the imaging room, and the PC communication unit 4 is installed in the imaging room.

  As described above, in the radiographic image acquisition system of FIG. 1, a radiographic image of the patient P obtained by radiography is detected and generated by the radiographic image detector 5, transferred to the image processing apparatus 1, and image processed by the image processing apparatus 1. , Can be output in a diagnostic state and saved.

  Further, in the radiographic image acquisition system of FIG. 1, the control circuit 30 of the radiographic image detector 5 generates reduced image data based on the radiographic image data in the reduced image generation unit 29, and the data radio signal m is transmitted to the image processing apparatus 1. The reduced image is displayed on the screen 3 of the display unit 2 by the image processing apparatus 1 that has been transferred and received via the PC communication unit 4, and it is possible to check the quality of shooting such as image blur and image position. The image processing apparatus 1 transmits quality confirmation result information from the PC communication unit 4 to the radiation image detector 5 as a radio signal n. Confirmation of imaging quality in the image processing apparatus 1 is performed by, for example, a radiographer touching a confirmation button on the screen 3 of the display unit 2, inputting from an input device such as a keyboard, or inputting by voice from a voice recognition device. it can.

  Further, the radiation image detector 5 transfers the radiation image data based on the confirmation result information received via the detector communication unit 35 or discards the radiation image data in the memory unit 31.

  Further, the radiation image detector 5 is configured so that the radiation irradiation detection unit 36 can detect the radiation irradiation when irradiated from the radiation source 101 of FIG. 1, and the surface of the radiation image detector 5 of FIG. Is arranged. As shown in FIG. 5, it is detected that radiation is emitted from the radiation source 101, and a detection signal is sent to the control circuit 30.

  Next, the radiation image detector 5 shown in FIG. 1 will be described with reference to FIGS. FIG. 2 is a perspective view of the radiation image detector of FIG. FIG. 3 is a diagram showing a circuit configuration of the radiation image detector of FIG. 4 is a partial cross-sectional view of the imaging panel of FIG.

  The radiological image detector 5 is an FPD (flat panel detector) configured to be portable in a flat panel shape and constitutes a radiographic image acquisition device. The present applicant previously disclosed in Japanese Patent Laid-Open No. 2003-344545. This will be described with reference to a configuration example.

  As shown in FIG. 2, the radiation image detector 5 includes an imaging panel 21, a control circuit 30 that controls the operation of the radiation image detector 5, and a rewritable read-only memory such as a flash memory. A memory unit 31 that stores the image signal output from the operation unit 32, an operation unit 32 for switching the operation of the radiographic image detector 5, and completion of radiographic imaging preparation or a predetermined amount of image signal is written in the memory unit 31. 1, a power supply unit 34 that supplies power required to drive the imaging panel 21 to obtain an image signal, the radiation image detector 5, and the PC communication unit 4 in FIG. 1. And a detector communication unit 35 for performing wireless communication between them, and these are accommodated in a flat rectangular housing 40.

  As shown in FIG. 3, the imaging panel 21 includes a scanning drive circuit 25 that reads the stored electrical energy according to the intensity of the irradiated radiation, a signal selection circuit 27 that outputs the stored electrical energy as an image signal, Have

  The casing 40 preferably has an outer shape made of aluminum or an aluminum alloy, which is a material that can withstand external impacts and is as light as possible. The radiation incident surface side of the casing 40 is a non-metal that easily transmits radiation, for example, It is configured using carbon fiber or the like. Further, on the back side opposite to the radiation incident surface, it is generated for the purpose of preventing the radiation from passing through the radiation image detector 5 or when the material constituting the radiation image detector 5 absorbs the radiation 2. In order to prevent influence from secondary radiation, a material that effectively absorbs radiation, such as a lead plate, is used. Further, inside the housing 40, the scanning drive circuit 25, the signal selection circuit 27, the control circuit 30, the memory unit 31 and the like are covered with a radiation shielding member (not shown), and radiation inside the housing 40 is detected. Scattering is prevented, and radiation of each circuit is prevented.

  As shown in FIG. 3, the imaging panel 21 has a two-dimensionally arranged collection electrode 220 for reading the stored electrical energy in accordance with the intensity of the irradiated radiation. Electric energy is stored in the capacitor 221 as one electrode. One collection electrode 220 corresponds to one pixel of the radiation image.

  Between the pixels, scanning lines 223-1 to 223-m and signal lines 224-1 to 224-n are disposed so as to be orthogonal, for example. The capacitor 221- (1,1) is connected to a transistor 222- (1,1) made of a silicon laminated structure or an organic semiconductor. The transistor 222- (1,1) is, for example, a field effect transistor, and the drain electrode or the source electrode is connected to the collecting electrode 220- (1,1), and the gate electrode is connected to the scanning line 223-1. The When the drain electrode is connected to the collecting electrode 220- (1,1), the source electrode is connected to the signal line 224-1, and when the source electrode is connected to the collecting electrode 220- (1,1), the drain electrode is connected to the signal line 224-1. Connected to line 224-1. Similarly, the scanning line 223 and the signal line 224 are connected to the collecting electrode 220, the capacitor 221 and the transistor 222 of other pixels.

As shown in the partial cross-sectional view of the imaging panel 21 in FIG. 4, a first layer 211 that is a scintillator layer that emits light according to the intensity of incident radiation is provided on the radiation irradiation surface side. Here, the first layer 211 is irradiated with X-rays (radiation), which is electromagnetic waves that pass through a human body or the like having a wavelength of about 1 mm (1 × 10 ⁻¹⁰ m), for example, from the radiation source 101 of FIG.

  The first layer 211 is mainly composed of a phosphor, and based on incident radiation, an electromagnetic wave having a wavelength of 300 nm to 800 nm, that is, an electromagnetic wave (light) ranging from ultraviolet light to infrared light centering on visible light. Is output. The phosphors used in the first layer 211 are tungstate phosphors, terbium activated rare earth oxysulfide phosphors, terbium activated rare earth phosphate phosphors, terbium activated rare earth oxyhalide phosphors, cesium iodide. However, the present invention is not limited to these, and any phosphor that outputs an electromagnetic wave in a region where the light receiving element has sensitivity such as the visible, ultraviolet, or infrared region by irradiation of radiation may be used.

  Next, a second layer 212 that converts electromagnetic waves (light) output from the first layer into electrical energy is formed on the side of the first layer 211 opposite to the radiation irradiation surface side. The second layer 212 includes a diaphragm 212a, a transparent electrode film 212b, a hole conduction layer 212c, a charge generation layer 212d, an electron conduction layer 212e, and a conduction layer 212f from the first layer 211 side. Here, the charge generation layer 212d contains an organic compound capable of photoelectric conversion, that is, an organic compound capable of generating electrons and holes by electromagnetic waves (light), and is separated into several functions in order to smoothly perform photoelectric conversion. For example, the second layer is configured as shown in FIG.

The diaphragm 212a is for separating the first layer 211 from other layers, and for example, Oxi-nitride is used. The transparent electrode film 212b is formed using a conductive transparent material such as indium tin oxide (ITO), SnO ₂ , or ZnO. In the formation of the transparent electrode film 212b, a thin film can be formed using a method such as vapor deposition or sputtering. In addition, a pattern having a desired shape may be formed by a photolithography method, or when high pattern accuracy is not required (about 100 μm or more), a mask having a desired shape is used during vapor deposition or sputtering of the electrode material. A pattern may be formed.

  In the charge generation layer 212d, electrons and holes are generated by the electromagnetic wave (light) output from the first layer 211. The holes generated here are collected in the hole conduction layer 212c, and the electrons are collected in the electron conduction layer 212e. In this structure, the hole conduction layer 212c and the electron conduction layer 212e are not necessarily essential.

  The conductive layer 212f is made of, for example, chromium. In addition, a general metal electrode or the transparent electrode can be selected, but in order to obtain good characteristics, a metal, an alloy, an electrically conductive compound and a mixture thereof having a small work function (4.5 eV or less) are used. What is used as an electrode material is preferable. Specific examples of such electrode materials include, but are not limited to, sodium, sodium-potassium alloy, magnesium, lithium, and aluminum. The conductive layer 212f can be generated using a method such as vapor deposition or sputtering using these electrode materials as raw materials.

  Next, the charge generation layer 212d is formed using an organic compound that forms an aggregate of cyanine dyes or a J aggregate. Cyanine dyes are widely used as spectral sensitizers for silver halide photography. In the J aggregate, electrons constituting the dye molecule are absorbed by absorbing visible light, and the excited electrons move to the silver halide grains, so that the silver halide grains are exposed. This cyanine dye is generally said to form a dye molecule aggregate on silver halide grains. When the dye molecule forms an aggregate, the dye molecule itself is stabilized.

  Next, the third layer 213 that accumulates the electric energy obtained in the second layer 212 and outputs a signal based on the accumulated electric energy is provided on the side opposite to the radiation irradiation surface side of the second layer 212. Is formed. The third layer 213 includes a capacitor 221 that stores the electrical energy generated in the second layer 212 for each pixel, and a transistor 222 that is a switching element for outputting the stored electrical energy as a signal. . Note that the third layer is not limited to the one using the switching element, and may be configured to generate and output a signal corresponding to the energy level of the stored electrical energy, for example.

  As the transistor 222, for example, a TFT (Thin Film Transistor) is used. This TFT may be an inorganic semiconductor type used in a liquid crystal display or the like or an organic semiconductor type, and is preferably a TFT formed on a plastic film. As the TFT formed on the plastic film, an amorphous silicon type is known.

  As shown in FIGS. 3 and 4, the transistor 222 that is a switching element accumulates electrical energy generated in the second layer 212 and is connected to a collecting electrode 220 that is one electrode of the capacitor 221. . The capacitor 221 stores the electric energy generated in the second layer 212, and the stored electric energy is read by driving the transistor 222. In other words, a radiation image can be generated for each pixel by driving the switching element. In FIG. 4, the transistor 222 includes a gate electrode 222a, a source electrode (drain electrode) 222b, a drain electrode (source electrode) 222c, an organic semiconductor layer 222d, and an insulating layer 222e.

  The fourth layer 214 is a substrate of the imaging panel 21. The substrate preferably used as the fourth layer 214 is a plastic film, and examples of the plastic film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, and polyetheretherketone. , Films made of polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), and the like. Thus, by using a plastic film, it is possible to reduce the weight as compared with the case of using a glass substrate and to improve resistance to impact.

  Furthermore, the power supply unit 34 may be provided on the side opposite to the third layer side surface of the fourth layer 214. The power supply unit 34 is a primary battery such as a manganese battery, a nickel-cadmium battery, a mercury battery, or a lead battery. The battery may be a secondary battery such as a rechargeable nickel polymer secondary battery or a lithium ion polymer battery. The battery preferably has a flat plate shape so that the FPD can be thinned.

  As shown in FIG. 3, in the imaging panel 21, initialization transistors 232-1 to 232-n, for example, drain electrodes connected to the signal lines 224-1 to 224-n are provided. The source electrodes of the transistors 232-1 to 232-n are grounded. The gate electrode is connected to the reset line 231.

  The scanning lines 223-1 to 223-m and the reset line 231 of the imaging panel 21 are connected to the scanning drive circuit 25 as shown in FIG. When the readout signal RS is supplied from the scanning drive circuit 25 to one of the scanning lines 223-1 to 223 -m, the scanning line 223 -p (p is any value from 1 to m). The transistors 222- (p, 1) to 222- (p, n) connected to -p are turned on, and the electricity stored in the capacitors 221- (p, 1) to 221- (p, n) Energy is read out to the signal lines 224-1 to 224-n, respectively. The signal lines 224-1 to 224-n are connected to the signal converters 271-1 to 271-n of the signal selection circuit 27. In the signal converters 271-1 to 271-n, the signal lines 224-1 to 224 are connected. Voltage signals SV-1 to SV-n proportional to the amount of electric energy read on -n are generated. The voltage signals SV-1 to SV-n output from the signal converters 271-1 to 271-n are supplied to the register 272.

  In the register 272, the supplied voltage signal is sequentially selected and converted into a digital image signal for one scanning line (for example, 12 bits to 14 bits) by the A / D converter 273, and the control circuit 30 performs scanning. A scanning signal is supplied to each of the lines 223-1 to 223-m through the scanning drive circuit 25 to perform image scanning, and a digital image signal for each scanning line is captured to generate an image signal of a radiation image. Do. This image signal is supplied to the control circuit 30.

  Further, the reset signal RT is supplied from the scanning drive circuit 25 to the reset line 231 to turn on the transistors 232-1 to 232-n, and the readout signal RS is supplied to the scanning lines 223-1 to 223-m. When the transistors 222- (1,1) to 222- (m, n) are turned on, the electric energy stored in the capacitors 221- (1,1) to 221- (m, n) is converted to the transistors 232-1 to The imaging panel 21 can be initialized by being emitted through 232-n.

  As shown in FIG. 3, a memory unit 31, an operation unit 32, and a communication unit 35 are connected to the control circuit 30, and radiation is based on an operation signal PS from the operation unit 32 and a radio signal n from the image processing apparatus 1. The operation of the image detector 5 is controlled.

  The operation unit 32 is provided with a plurality of switches. Based on the operation signal PS corresponding to the switch operation from the operation unit 32 or the radio signal n from the image processing apparatus 1, the imaging panel 21 is initialized and the radiographic image is displayed. A signal is generated.

  Further, the control circuit 30 performs processing for storing the generated image signal in the memory unit 31 and wirelessly transfers the data signal as the data wireless signal m from the detector communication unit 35 to the PC communication unit 4 in FIGS. .

  As described above, the radiographic image detector 5 of FIGS. 2 to 4 is configured to have a flat panel type portable structure by integrating the imaging panel, the power supply unit, the memory unit, and the like, so that radiographic images can be easily captured. It can be carried out.

  The imaging panel 21 in FIGS. 3 and 4 described above is a photoelectric conversion element made of an organic substance, but may be a photoelectric conversion element made of an inorganic substance, and the applicant of the present invention has disclosed an imaging panel having such a configuration in Japanese Patent Application Laid-Open No. 2000-250152. A description will be given with reference to the disclosed configuration example. FIG. 8 is a diagram illustrating a circuit configuration of a radiation image detector configured from an imaging panel including a photoelectric conversion element made of an inorganic material. FIG. 9 is a partial cross-sectional view of the imaging panel of FIG.

  The radiographic image detector 5 having the configuration shown in FIGS. 8 and 9 is an FPD (flat panel detector) configured to be portable in a flat panel shape as in FIG. 2, and constitutes a radiographic image acquisition device.

  The radiological image detector 5 in FIGS. 8 and 9 is configured from the imaging panel 21 using an imaging panel 21, a control circuit 30 that controls the operation of the radiographic image detector 5, and a rewritable read-only memory such as a flash memory. A memory unit 31 that stores the output image signal, a power source unit 34 that supplies power necessary to drive the imaging panel 21 to obtain the image signal, the radiation image detector 5, and the PC communication in FIG. And a detector communication unit 35 for performing wireless communication with the unit 4, and these are accommodated in a flat rectangular housing 40.

  As shown in FIG. 8, the imaging panel 21 includes a scanning drive circuit 25 that reads the stored electrical energy according to the intensity of the irradiated radiation, a signal selection circuit 27 that outputs the stored electrical energy as an image signal, Have

  The casing 40 preferably has an outer shape made of aluminum or an aluminum alloy, which is a material that can withstand external impacts and is as light as possible. The radiation incident surface side of the casing 40 is a non-metal that easily transmits radiation, for example, It is configured using carbon fiber or the like. Further, on the back side opposite to the radiation incident surface, it is generated for the purpose of preventing the radiation from passing through the radiation image detector 5 or when the material constituting the radiation image detector 5 absorbs the radiation 2. In order to prevent influence from secondary radiation, a material that effectively absorbs radiation, such as a lead plate, is used.

  Further, inside the housing 40, the scanning drive circuit 25, the signal selection circuit 27, the control circuit 30, the memory unit 31 and the like are covered with a radiation shielding member (not shown), and radiation inside the housing 40 is detected. Scattering is prevented, and radiation of each circuit is prevented. The power supply unit 34 may be, for example, a primary battery such as a manganese battery, a nickel / cadmium battery, a mercury battery, or a lead battery, a secondary battery such as a rechargeable nickel polymer secondary battery or a lithium ion polymer battery. The flat plate shape is preferable so that the FPD can be thinned.

  As shown in FIG. 8, the imaging panel 21 detects visible light converted by the scintillator, and photoelectrically converts this visible light into an image signal carrying a radiographic image of the subject. ˜412− (m, n) are two-dimensionally arranged. Scanning lines 421-1 to 421-m and signal lines 422-1 to 422-n are disposed between the photoelectric conversion elements 412 so as to be orthogonal to each other, for example. One transistor 423- (1,1) is connected to the photoelectric conversion element 412- (1,1). For example, a field effect transistor is used as the transistor 423- (1,1), the drain electrode or the source electrode is connected to the photoelectric conversion element 412- (1,1), and the gate electrode is the scanning line 421-. Connected with 1. When the drain electrode is connected to the photoelectric conversion element 412- (1,1), the source electrode is connected to the signal line 422-1, and when the source electrode is connected to the photoelectric conversion element 412- (1,1), the drain electrode Is connected to the signal line 422-1. In this way, one pixel is formed.

  Similarly, a transistor 423 is connected to the other photoelectric conversion element 412, a scanning line 421 is connected to a gate electrode of the transistor 423, and a signal line 422 is connected to a source electrode or a drain electrode.

  As shown in FIG. 9, the photoelectric conversion element 412 includes a photodiode including a signal line 413 formed of a conductive film patterned on a substrate 411, an amorphous silicon layer 414, and a transparent electrode 415. The signal line 413 is connected to the drain electrode 423d (or the source electrode 423s) of the thin film transistor 423 formed over the substrate 411. In addition, a scanning line is connected to the gate electrode 423 g of the thin film transistor 423, and a source electrode 423 s (or a drain electrode 423 d) is connected to the signal line 422. Note that a gate insulating film 424 and a semiconductor layer 425 are provided between the source electrode 423 s and the drain electrode 423 d and the gate electrode 423 g.

  A phosphor layer (scintillator layer) 430 is formed on the photoelectric conversion element 412, and a support 431 is provided on the back surface (X-ray source side) in some cases. Note that a protective layer 432 is provided on the surface of the phosphor layer 430 as will be described later. When the phosphor layer 430 is attached on the photoelectric conversion element 412, the gap between the photoelectric conversion element 412 and the phosphor layer 430 is reduced. A protective layer 432 is interposed between the two layers.

  As shown in FIG. 8, the scanning lines 421-1 to 421-m of the imaging panel 21 are connected to the scanning drive circuit 25, and the signal lines 422-1 to 422-n are connected to the charge detectors 425-1 to 425-1. 425-n. Here, when the charge reading signal RS is supplied from the scanning drive circuit 25 to one of the scanning lines 421-1 to 421 -m, the scanning line 421 -p (p is any value from 1 to m). Transistors 423- (p, 1) to 425- (p, n) connected to the scanning line 421-p are turned on, and photoelectric conversion elements 412- (p, 1) to 412- (p, n) ) Is supplied to the charge detectors 425-1 to 425-n via the signal lines 422-1 to 422-n. In the charge detectors 425-1 to 425-n, voltage signals SV-1 to SV-n proportional to the amount of charge supplied via the signal lines 422-1 to 422-n are generated. The voltage signals SV-1 to SV-n output from the charge detectors 425-1 to 425-n are supplied to the signal selection circuit 27.

  The signal selection circuit 27 is configured using a register 45a and an A / D converter 45b, and a voltage signal is supplied to the register 45a from the charge detectors 425-1 to 425-n. In the register 45a, the supplied voltage signals are sequentially selected and converted into digital data by the A / D converter 45b. This data is supplied to the control circuit 30.

  The control circuit 30 generates the scanning control signal RC and the output control signal SC based on the control signal CTD included in the wireless signal n received from the image processing apparatus 1 (FIG. 1) via the communication unit 35. The scanning control signal RC is supplied to the scanning drive circuit 25, and the charge readout signal RS is supplied to the scanning lines 421-1 to 421-m based on the scanning control signal RC. Further, the output control signal SC is supplied to the signal selection circuit 27, and the selection operation of the voltage signals from the charge detectors 425-1 to 425-n stored in the register 45a is controlled and the selected voltage signal. Is converted to a data signal and supplied from the signal selection circuit 27 to the control circuit 30 as image data DT.

  In the control circuit 30, the image data DT is transmitted as a radio signal m to the image processing apparatus 1 (FIG. 1) via the communication unit 35. If the logarithmic conversion processing of the image data is performed when the image data DT is supplied to the image processing device 1, the processing of the image data in the image processing device 1 can be simplified. The logarithmic conversion described above may be performed simultaneously when the read charge amount is converted into the voltage signal SV by the charge detector 425. Thus, by using the A / D converter 45b as digital data after logarithmic conversion, the resolution of the radiation information in the region where the voltage signal SV is small can be increased.

  The phosphor layer 430 of the image pickup panel 21 in FIG. 9 is formed by applying a phosphor coating composed of a phosphor and a binder to a support to form the phosphor layer, and then attaching the phosphor layer to the photoelectric conversion element side. The method of attaching is used. In addition, the phosphor coating is applied to the temporary support, and then dried and peeled to form a sheet-like phosphor layer, which is applied, or the phosphor coating is sprayed to form the phosphor layer. The phosphor coating material may be applied to the photoelectric conversion element directly or via a protective layer.

  In order to form the phosphor layer 430, first, a binder and a phosphor are added to an appropriate organic solvent, and a disperser or a ball mill is used to stir and mix so that the phosphor is uniform in the binder. A phosphor coating dispersed in is prepared.

Examples of phosphors include tungstate phosphors (CaWO ₄ , MgWO, CaWO ₄ : Pb, etc.), terbium activated rare earth oxysulfide phosphors [Y ₂ O ₂ S: Tb, Gd ₂ O ₂ S: Tb, La ₂ O ₂ S: Tb, (Y, Gd) ₂ O ₂ S: Tb, (Y, Gd) O ₂ S: Tb, Tm, etc.], terbium-activated rare earth phosphate phosphor (YPO ₄ : Tb, GdPO ₄ : Tb, LaPO ₄ : Tb, etc.), terbium activated rare earth oxyhalide phosphors (LaOBr: Tb, LaOBr: Tb, Tm, LaOCl: Tb, LaOCl: Tb, Tm, LaOCl: Tb, Tm, LaOBr: Tb) , GdOBr: Tb, GdOCl: Tb, etc.), thulium activated rare earth oxyhalide phosphors (LaOBr: Tm, LaOCl: Tm, etc.), barium sulfate Phosphors [BaSO ₄ : Pb, BaSO ₄ : Eu ²⁺ , (Ba, Sr) SO ₄ : Eu ²⁺ etc.], divalent europium activated alkaline earth metal phosphate phosphors [(Ba ₂ PO ₄ ) ₂ : Eu ²⁺ , (Ba ₂ PO ₄ ) 2: Eu ^2+, etc.] Divalent europium-activated alkaline earth metal fluoride halide-based phosphors [BaFCl: Eu ²⁺ , BaFBr: Eu ²⁺ , BaFCl: Eu ²⁺ , Tb, BaFBr: Eu ²⁺ , Tb, BaF ₂ · BaCl · KCl: Eu ²⁺ , (Ba · Mg) F ₂ · BaCl · KCl: Eu ²⁺ etc.], iodide phosphors (CsI: Na, CsI: Tl, NaI, KI: Tl, etc.), sulfide-based phosphors [ZnS: Ag (Zn, Cd) S: Ag, (Zn, Cd) S: Cu, (Zn, Cd) S: Cu, Al, etc.], phosphoric acid Bromide phosphor _{(HfP 2} O 7: Cu, etc.), tantalum based phosphor _{(YTaO 4, YTaO 4: Tm} , YTaO 4: Nb, [Y, Sr] TaO 4-X: Nb, LuTaO 4, LuTaO ₄ : Nb, [Lu, Sr] TaO _{4 -X} : Nb, GdTaO ₄ : Tm, Gd ₂ O ₃ .Ta ₂ O ₅ .B ₂ O ₃ : Tb, etc.), particularly Gd ₂ O ₂ S : Tb, CsI: Tl are desirable.

  However, the phosphor is not limited to those described above, and any phosphor can be used as long as it emits light in the visible region upon irradiation with radiation, and the photoelectric conversion element has sensitivity to the emission wavelength.

  Here, the average particle diameter of the phosphor increases the filling rate of the phosphor in the phosphor layer, enables high-definition light emission, and can reduce scattering of the phosphor emission in the phosphor layer. Thus, it is 0.5 μm or more and 10 μm or less, preferably 1 μm or more and 5 μm or less.

  Solvents for preparing phosphor paints include lower alcohols such as methanol, ethanol, n-propanol and n-butanol, chlorine atom-containing hydrocarbons such as methylene chloride and ethylene chloride, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, Aromatic compounds such as toluene, benzene, cyclohexane, cyclohexanone, xylene, esters of lower fatty acids and lower alcohols such as methyl acetate, ethyl acetate, butyl acetate, dioxane, ethylene glycol monoethyl ester, ethylene glycol monomethyl ester Mention may be made of ethers and their inclusions.

  It should be noted that the phosphor paint has a dispersant for improving the dispersibility of the phosphor in the paint, or a plastic for improving the binding force between the binder and the phosphor in the formed phosphor layer. Various additives such as an agent may be mixed.

  Examples of the dispersant include phthalic acid, stearic acid, caproic acid, lipophilic surfactant and the like. Examples of plasticizers include phosphates such as triphenyl phosphate, tricresyl phosphate and diphenyl phosphate, phthalates such as diethyl phthalate and dimethoxyethyl phthalate, glycols such as ethyl phthalyl ethyl glycolate and butyl phthalbutyl glycolate Examples thereof include acid esters, polyesters of triethylene glycol and adipic acid, polyesters of polyethylene glycol and aliphatic dibasic acid such as polyesters of diethylene glycol and oxalic acid, and the like.

  A coating film of the coating material is formed by uniformly applying the phosphor coating material containing the phosphor and the binder prepared as described above to the surface of the support or the temporary support for forming the sheet.

  The thickness of the phosphor layer 430 is preferably 20 to 150 μm and preferably 20 to 100 μm in order to obtain a sufficient amount of stimulated emission light and to reduce light scattering in the phosphor layer. Is desirable.

  As this coating means, for example, a doctor blade, a roll coater, a knife coater, an extrusion coater or the like can be used.

  As the support 431 in FIG. 9, for example, those made of various materials such as glass, wool, cotton, paper, and metal can be used. However, in terms of handling as an information recording material, a flexible sheet or What can be processed into a roll is preferable. From this point, for example, cellulose acetate film, polyester film, polyethylene terephthalate film, polyamide film, polyimide film, triacetate film, plastic film such as polycarbonate film, metal sheet such as aluminum foil, aluminum alloy foil, general paper, and photographic base paper, for example Printing paper such as coated paper or art paper, baryta paper, resin-coated paper, paper sized with polysaccharides as described in Belgian Patent No. 784,615, titanium dioxide, etc. Particularly preferred are processed papers such as pigmented pigmented paper and paper sized with polyvinyl alcohol.

  In order to reinforce the bond between the support 431 and the phosphor layer 430, an undercoat layer is provided on the support surface by applying a polymer material such as polyester or gelatin to provide adhesion, and image quality (sharpness, graininess) In order to improve the above, a light absorbing layer made of a light absorbing material such as carbon black may be provided to absorb at least a part of light emitted from the scintillator. Although those structures can be arbitrarily selected according to the purpose and application, a carbon black-containing black polyethylene terephthalate support is preferred.

  The phosphor layer 430 is provided with a protective layer 432 for physically and chemically protecting the surface opposite to the side in contact with the support 431 described above. The protective layer 432 is made of, for example, a cellulose derivative such as cellulose acetate or nitrocellulose, or a synthetic polymer substance such as polymethyl methacrylate, polyethylene terephthalate, polyvinyl butyral, polyvinyl formal, polycarbonate, polyvinyl acetate, vinyl chloride, or vinyl acetate copolymer. It can be formed by a method in which a solution prepared by dissolving in a solvent is applied to the surface of the phosphor layer. These polymer substances can be used alone or in combination. Further, when the protective layer 432 is formed by coating, it is desirable to add a cross-linking agent immediately before coating. Alternatively, it can be formed by a method of bonding a plastic sheet made of polyethylene terephthalate, polyethylene naphthalate, polyethylene, polyvinylidene chloride, polyamide or the like using an adhesive.

  Further, it is preferably formed of a coating film containing a fluorine resin soluble in an organic solvent. The fluorine-based resin refers to a polymer of olefin containing fluoro (fluoroolefin) or a copolymer containing olefin containing fluorine as a copolymer component. The protective layer formed of the fluorine resin coating film may be cross-linked. Further, for the purpose of improving the film strength and the like, a fluorine-based resin and other polymer substances may be mixed.

  Such a protective layer 432 has a thickness of 0.5 to 10 μm, preferably 1 to 3 μm. By using such a thin protective layer 432, the distance between the phosphor layer 430 and the photoelectric conversion element is reduced, and thus the light emitted from the phosphor layer 430 is scattered by the protective layer 432. Since it is immediately incident on the photoelectric conversion element, it contributes to improvement of the sharpness of the obtained radiographic image.

  Here, by coloring at least one of the phosphor layer 430 and the protective layer 432, a reduction in sharpness due to scattering of light emission of the phosphor in the phosphor layer can be reduced. The colorant is a colorant that absorbs at least part of light in the emission wavelength region of the phosphor, and a blue to red colorant is appropriately used as a color that absorbs the emission wavelength of the phosphor.

Examples of yellow to red colorants (dyes and pigments) used for phosphors that emit light in the green region include various dyes such as azo dyes, acridine dyes, quinoline dyes, thiazole dyes, nitro dyes; and molybdenum Various pigments such as orange, cadmium yellow, chrome yellow, zinc chromate, cadmium yellow, and red lead can be exemplified. The content of the colorant varies depending on the intended use of the phosphor layer, the portion to be colored, the type of the colorant, etc., but generally 10: 1 to 10 ⁶ when the colorant is a dye. : 1 (phosphor: colorant, weight ratio). When the colorant is a pigment, it is selected from the range of 1:10 to 10 ⁵ : 1 (phosphor: colorant, weight ratio).

  In the case of using a phosphor that emits light in the green region, the phosphor may be colored using a colorant having a main peak of an absorption spectrum in a wavelength region of 420 to 540 nm. Further, the phosphor may be colored using a colorant whose average absorptance in the light emission region longer than the peak wavelength of light emission of the phosphor is higher than that in the light emission region shorter than the peak wavelength.

  By the way, in the formation of the phosphor layer, the phosphor layer is formed by uniformly applying the phosphor coating to the support. However, the phosphor layer can also be formed by a vapor phase method, for example, a vapor deposition method. If this phosphor layer has a columnar crystal structure, it is possible to suppress scattering of phosphor emission in the phosphor layer by the light guide effect.

  As shown in FIG. 8, a memory unit 31, an operation unit 32, a display unit 33, and a communication unit 35 are connected to the control circuit 30, and an operation signal PS from the operation unit 32 and a radio signal n from the image processing apparatus 1. The operation of the radiation image detector 5 is controlled based on the above.

  The operation unit 32 is provided with a plurality of switches. Based on the operation signal PS corresponding to the switch operation from the operation unit 32 or the radio signal n from the image processing apparatus 1, the imaging panel 21 is initialized and the radiographic image is displayed. A signal is generated. The storage capacity of the memory unit 31 is a capacity capable of storing a plurality of image data.

  Further, the control circuit 30 performs processing for storing the generated image signal in the memory unit 31 and wirelessly transfers the data signal as the data wireless signal m from the detector communication unit 35 to the PC communication unit 4 in FIGS. .

  As described above, the radiation image detector 5 in FIGS. 8 and 9 is configured in a flat panel type portable structure by integrating the imaging panel, power supply unit, memory unit, and the like in the same manner as in FIG. Images can be taken easily.

  Note that the imaging panel 21 of the radiation image detector 5 described with reference to FIGS. 8 and 9 may have other configurations. For example, FIG. 16B of JP-A-9-294229, JP-A-2004-2004 Each configuration shown in FIG. 4B of Japanese Patent No. 6781 and Japanese Patent Laid-Open No. 2000-61823 may be adopted.

  The radiological image detector 5 in FIGS. 2 to 5, 8, and 9 creates reduced image data of the generated radiographic image by the reduced image generating unit 29 as follows. That is, when the radiation image is generated as described above, the control circuit 30 in FIGS. 2, 3, and 5 reduces the radiation image to a predetermined size by the reduced image generation unit 29 in FIG. 5 based on the radiation image data. Reduced image data reduced at a rate (a fraction) is created. The reduction ratio can be set in the control circuit 30 in advance. The generated reduced image data is wirelessly transferred as a data wireless signal m from the detector communication unit 35 to the PC communication unit 4 in FIGS. 1 and 5 independently from the radiation image data.

  The reduced image data can be created, for example, by thinning out pixels from the original radiation image data, or can be created by reducing the number of pixels of the image data of the original radiation image by a known averaging process or the like.

  The reduction ratio of the above-described reduced image is preferably in the range of 1/2 to 1/16000 of the original image from the viewpoint of improving the data transfer speed and the visibility of the display image. When the reduction ratio is smaller than 1/2 of the original image (approaching 1), the capacity of the reduced image data is increased, the effect of improving the data transfer speed by radio is reduced, and the reduction ratio is larger than 1/16000. Then, the display image displayed on the screen 3 of the display unit 2 becomes small and it is difficult to check the shooting state. The time from the radiation imaging to the display of the reduced image data is preferably within 10 seconds, for example, and the upper limit of the reduction rate is determined in consideration of the wireless data transfer rate. Considering the above, it is more preferable that the reduction ratio of the reduced image is in the range of 1/100 to 1/10000 of the original image.

  Also, the interpolation processing unit 7a of the image processing apparatus 1 of FIGS. 1 and 5 performs interpolation processing on the above-described reduced image data received via the PC communication unit 4 and displays the enlarged image on the screen 3 of the display unit 2. It has become. It is easy to check the shooting state with the enlarged image. As the interpolation process, a known nearest neighbor method or a linear interpolation method with higher interpolation accuracy than the nearest neighbor method can be used.

  Next, each step S01-S11 of the radiographic image acquisition method by the radiographic image acquisition system of FIGS. 1-5 is demonstrated with reference to the flowchart of FIG.

  Referring to FIG. 6, when the radiation irradiation button 102a of the radiation generation control device 102 of FIG. 1 is pressed to turn it ON, and radiation 100 is irradiated from the radiation source 101 to the patient P of FIG. 1 (S01), radiation image detection Radiation irradiation detection unit 36 of detector 5 detects radiation irradiation (S02), and control circuit 30 prohibits transfer (transmission / reception) from detector communication unit 35 (S03).

  Then, the transmitted radiation that has passed through the region to be imaged by the patient P is detected by the radiation image detector 5 disposed between the bed 110 and the patient P (S04), and irradiated to the imaging panel 21 of FIGS. The electric charge is accumulated in the capacitor 221 as electric energy according to the intensity of the transmitted radiation.

  Next, in the radiation image detector 5, the control circuit 30 in FIG. 3 supplies the readout signal RS to each of the scanning lines 223-1 to 223-m via the scanning drive circuit 25 to perform image scanning. A digital image signal for each scanning line digitally converted by the / D converter 273 is taken in to generate an image signal of a radiation image (S05). The generated radiation image data is stored in the memory unit 31 (S06).

  Next, when a predetermined time has elapsed since the time of radiation irradiation detection in step S02 (S07), the transfer prohibition in step S03 is canceled (S08).

  Next, the control circuit 30 causes the memory unit 31 to transmit the radiation image data stored in step S06 as the data wireless signal m from the detector communication unit 35 to the image processing apparatus 1 (S09).

  Next, when the image processing apparatus 1 receives the radiation image data (S10), the image processing unit 7 performs predetermined image processing, and outputs it from the output unit 8 to a display device, a database server, a printer, or the like in the examination room. If there is the next imaging (S11), the process returns to step S01 to continuously perform radiation imaging.

  In FIG. 6, when the image processing apparatus 1 receives the ON signal of the radiation irradiation button 102a in FIG. 1, transmits it to the radiation image detector 5, and receives it by the detector communication unit 35, the control circuit 30 performs the detector communication. Control may be performed to prohibit transfer from the unit 35.

  As described above, according to the radiation image acquisition method of the radiation image acquisition system of the present embodiment, when radiation imaging is performed continuously, radiation irradiation from the radiation source 101 is detected by the radiation image detector 5. Detection by the unit 36 prohibits the transfer (transmission / reception) of the detector communication unit 35 that has been in a transferable state. Therefore, the detection and generation of the transmission radiation image in the radiation image detector 5 in steps S04 and S05. In some cases, it is possible to prevent image quality deterioration without causing adverse effects of noise caused by radio waves. Then, when a predetermined time has elapsed since the detection of radiation irradiation, the transfer prohibition is canceled and the radiation image data can be transmitted to the image processing apparatus 1.

  Next, each step S21-S46 of the modification of the radiographic image acquisition method by the radiographic image acquisition system of FIGS. 1-5 is demonstrated with reference to the flowchart of FIG.

  Referring to FIG. 7, when an imaging mode is input from image processing device 1 (21), image processing device 1 transmits this imaging mode signal as radio signal n to radiological image detector 5 (S22), and detector communication. When the unit 35 receives (S23), the control circuit 30 prohibits transfer (transmission / reception) from the detector communication unit 35 (S24).

  Next, under the transfer prohibited state, the radiation image detector 5 supplies the reset signal RT to the reset line 231 from the scanning drive circuit 25 of FIG. 3 to initialize (reset) the imaging panel 21 (S25). ).

  Next, the radiation irradiation button 102a of the radiation generation control device 102 of FIG. 1 is pressed to turn it ON, and the patient 100 of FIG. 1 is irradiated with the radiation 100 from the radiation source 101 (S26). Then, the transmitted radiation that has passed through the region to be imaged by the patient P is detected by the radiation image detector 5 disposed between the bed 110 and the patient P (S27), and irradiated to the imaging panel 21 of FIGS. The electric charge is accumulated in the capacitor 221 as electric energy according to the intensity of the transmitted radiation.

  Next, in the radiation image detector 5, the control circuit 30 in FIG. 3 supplies the readout signal RS to each of the scanning lines 223-1 to 223-m via the scanning drive circuit 25 to perform image scanning. The digital image signal for each scanning line digitally converted by the / D converter 273 is taken in to generate an image signal of a radiation image (S28).

  Next, when the analog / digital conversion in the A / D converter 273 is completed (S29), the generated radiation image data is stored in the memory unit 31 (S30), and the transfer prohibition in the step S24 is canceled. (S31).

  Next, the reduced image generation unit 29 generates reduced image data at a predetermined reduction rate based on the generated radiation image data (S32).

  Next, the generated reduced image data is transmitted as a data wireless signal m from the detector communication unit 35 (S33). Then, the data wireless signal m of the reduced image data is received by the PC communication unit 4 of the image processing apparatus 1 (S34) and displayed on the screen 3 of the display unit 2 (S35). The reduced image data may be interpolated by the interpolation processing unit 7a and displayed enlarged.

  Next, when the radiographer confirms whether or not the radiographic image is photographed, such as an image blur and an image position, with the reduced image displayed on the screen 3 of the display unit 2 (S36), and it is determined that the radiographic image photographing state is good Is transmitted from the PC communication unit 4 of the image processing apparatus 1 to the radiological image detector 5 as a radio signal n (S37), and the radiographic image detector 5 is detected by the detector communication unit 35. When received (S38), the control circuit 30 causes the memory unit 31 to transmit the corresponding radiation image data stored in step S30 to the image processing apparatus 1 as the data wireless signal m (S39).

  Next, when the image processing apparatus 1 receives the radiation image data (S40), the image processing unit 7 performs predetermined image processing (S41), and outputs it from the output unit 8 to a display device, a database server, a printer, or the like in the examination room. (S42).

  If it is determined in step S36 that the imaging state is not good, the PC communication unit 4 of the image processing apparatus 1 transmits confirmation result information indicating that it is inappropriate to the radiation image detector 5 as a radio signal n. (S43) When the radiation image detector 5 is received by the detector communication unit 35 (S44), the corresponding radiation image data stored in the memory unit 31 by the control circuit 30 is discarded (S45). Then, the image processing apparatus 1 or the like issues a re-shooting instruction (S46).

  If there is next imaging including the re-imaging in step S45 described above (S47), the process returns to step S24 to continuously perform radiation imaging.

  When the corresponding radiation image data stored in the memory unit 31 is discarded, it may be deleted and discarded after a predetermined time has elapsed or after the remaining capacity of the memory reaches a predetermined amount. Thereby, it is possible to prevent erroneous radiation image data from being erroneously erased due to an erroneous operation or the like.

  As described above, according to the radiographic image acquisition method as shown in FIG. 7 of the radiographic image acquisition system of the present embodiment, when radiography is performed continuously, the radiographic image acquisition system is set to the imaging mode. Since transfer (transmission / reception) of the detector communication unit 35 that has been in a transferable state is prohibited, radio waves are detected when resetting the radiation image detector 5 and detecting and generating a transmitted radiation image in steps S25, S27, and S28. It is possible to prevent deterioration of image quality without causing adverse effects of noise caused by. When the analog / digital conversion in the A / D converter 273 is completed and the radiation image data is generated, the transfer prohibition is canceled and the reduced image data and the radiation image data can be transmitted to the image processing apparatus 1.

  Further, the reduced image data is created and transferred based on the radiation image data obtained by radiation imaging in the radiation image detector 5, and the reduced image is displayed on the screen 3 of the display unit 2 by the destination image processing apparatus 1. After confirming the imaging state, the confirmation result information is transferred to the radiation image detector 5 and the transfer of the radiation image data is executed based on the confirmation result information. Is required, the radiation image data is not transferred from the acquisition source to the transfer destination. For this reason, it is possible to improve the throughput of the entire radiation image acquisition system without wastefully transferring the radiation image data. In particular, when transferring from the acquisition source to the transfer destination wirelessly, the data transfer speed by wireless is slow, but the throughput can be greatly improved by eliminating the waste of sending the radiation image data that needs re-imaging.

  Further, reduced image data is created based on the radiation image data obtained by radiation imaging in the radiation image detector 5, but since the reduced image data has a smaller capacity than the original radiation image data, the image processing apparatus 1 wirelessly. The data transfer speed at the time of data transfer is improved and the reduction rate is set appropriately, so that the transfer time is within 10 seconds, for example, and the transfer time is not so much required. Therefore, it is possible to reduce the time from the radiation imaging to the time when the reduced image data is displayed on the transfer destination image processing apparatus 1, there is no reduction in throughput, and the imaging state can be confirmed quickly and timely.

  As described above, the best mode for carrying out the present invention has been described. However, the present invention is not limited to these, and various modifications are possible within the scope of the technical idea of the present invention. For example, the radiation image detector 5 in FIGS. 2 to 4 has a configuration (indirect type) in which radiation is converted into light by a phosphor such as a scintillator, and this light is read by the photodetector to generate radiation image data. However, the present invention is not limited to this, and a configuration (direct type) in which radiation is directly converted into charges and the charges are read with a capacitor or the like to generate image data.

  6 and 7, the reduced image data is transferred independently prior to the transfer of the radiation image data. However, the present invention is not limited to this, and the reduced image data is transferred from the radiation image detector 5 to the radiation. The image data may be transferred as incidental information, and the reduced image may be displayed when the image processing apparatus 1 receives the reduced image data in the incidental information.

  In FIGS. 6 and 7, the image processing apparatus 1 may display the reduced image while receiving the reduced image data, thereby reducing the sensible waiting time.

  Further, communication between the image processing apparatus 1 and the radiation image detector 5 may be performed via the relay station 50 as shown in FIG. 5, and the wireless signal n ′ is transmitted from the PC communication unit 4 to the relay station 50. Can be transmitted to the detector communication unit 35, and the radio signal m ′ can be transmitted from the detector communication unit 35 to the PC communication unit 4 via the relay station 50.

  6 and FIG. 7 prohibits only transmission from the detector communication unit 35 so that the detector communication unit 35 can receive the wireless signals n and n ′ from the image processing apparatus 1. May be. Thereby, the radiation image detector 5 can receive information or the like linked to radiation irradiation from the image processing apparatus 1.

  Further, the imaging mode input in step S21 in FIG. 7 may be configured to be input by operating the operation unit 32 of the radiation image detector 5 in FIGS. In this case, the prohibition of transfer prohibition in step S31 of FIG.

It is a figure showing roughly a radiographic image acquisition system which radiographs a patient in this embodiment and acquires the radiographic image. It is the perspective view which fractured | ruptured partially and looked at the inside in order to show the radiographic image detector of FIG. It is a figure which shows the circuit structure of the radiographic image detector of FIG. FIG. 3 is a partial cross-sectional view of the imaging panel in FIG. 2. It is a block diagram which shows roughly the radiographic image acquisition system of FIG. It is a flowchart for demonstrating each step S01-S11 of the radiographic image acquisition method by the radiographic image acquisition system of FIGS. It is a flowchart for demonstrating each step S21-S46 of the modification of the radiographic image acquisition method by the radiographic image acquisition system of FIGS. It is a figure which shows the circuit structure of the radiographic image detector comprised from the imaging panel containing the photoelectric conversion element by an inorganic substance. FIG. 9 is a partial cross-sectional view of the imaging panel in FIG. 8.

Explanation of symbols

1 Image processing device (transfer destination)
2 Display unit 3 Screen 4 PC communication unit 5 Radiation image detector (Radiation image acquisition device)
DESCRIPTION OF SYMBOLS 21 Imaging panel 25 Scanning drive circuit 27 Signal selection circuit 29 Reduced image production | generation part 30 Control circuit (control part)
Reference Signs List 31 Memory Unit 32 Operation Unit 35 Detector Communication Unit 36 Radiation Irradiation Detection Unit 102 Radiation Generation Control Device 102a Radiation Irradiation Button 221 Capacitor 231 Reset Line 273 A / D Converter m Data Radio Signal m ′ Radio Signal n, n ′ Radio Signal

Claims (24)

Reading radiation image data based on radiation information obtained according to the radiation dose irradiated to the subject and transmitted through the subject;
Wirelessly transferring the radiation image data to a transfer destination,
When the radiation irradiation is continuously performed, both timings are controlled so that the timing of reading the radiographic image data and the timing of wireless transfer do not overlap. 2. The step of reading out the radiation image data includes a step of reading out charges from a charge collecting body in which charges are accumulated by radiation transmitted through the subject, and a step of digitally processing the read signal. The radiographic image acquisition method as described in 1 .. The step of reading the radiation image data further includes a step of resetting the charge collector, and a step of accumulating charges in the charge collector due to radiation transmitted through the subject. The radiographic image acquisition method as described. The radiographic image acquisition method according to claim 1, wherein the radiographic image data is prohibited from being wirelessly transferred when the radiographic image data is read. The radiographic image acquisition method according to claim 1, wherein wireless transmission is performed directly from the transfer destination or via a base station. 6. The radiographic image acquisition method according to claim 5, wherein when the radiographic image data is read, radio transmission from the transfer destination or radio transmission via the base station is prohibited. The radiographic image acquisition method according to claim 4, 5 or 6, wherein radiation exposure to the subject is detected and the transfer prohibition is executed based on the detection information. The radiation image according to claim 4, 5 or 6, wherein the transfer destination takes in irradiation execution information in the radiation irradiation, and executes the transfer prohibition based on the irradiation execution information transmitted from the transfer destination. Acquisition method. The radiographic image acquisition method according to claim 4, wherein the transfer prohibition is executed based on irradiation mode transition information when transitioning to an irradiation mode for the radiation irradiation. 11. The radiographic image acquisition method according to claim 4, wherein the transfer prohibition is canceled based on end information upon completion of reading of the radiographic image data. The radiographic image acquisition method according to claim 4, wherein the transfer prohibition is canceled based on release information received from the transfer destination. The radiographic image acquisition method according to claim 4, wherein the transfer prohibition is canceled after a predetermined time has elapsed from the radiation irradiation. A radiation imaging unit that reads radiation image data based on radiation information obtained according to the radiation dose irradiated to the subject from the irradiation unit and transmitted through the subject;
A communication unit for wirelessly transferring the radiation image data to a transfer destination;
A control unit that controls the radiation imaging unit and the communication unit,
The control unit controls both timings so that the radiation image data reading timing in the radiation imaging unit and the transfer timing in the communication unit do not overlap when the radiation irradiation is continuously performed. A radiological image acquisition apparatus characterized by the above. The radiation imaging unit, for reading the radiation image data, a charge collector that accumulates charges by radiation transmitted through the subject, a reset unit that resets the charge collector before the accumulation of charges, The radiographic image acquisition apparatus according to claim 13, further comprising: a readout unit that reads out charges from the charge collector, and an A / D conversion unit that converts the analog readout signal into a digital signal. The radiographic image acquisition apparatus according to claim 13, wherein the control unit prohibits the wireless transfer of the radiographic image data when reading the radiographic image data. The radiographic image acquisition according to claim 13, wherein the communication unit receives a transmission signal when transmission is performed directly from the transfer destination or wirelessly via a base station. apparatus. The radiographic image acquisition apparatus according to claim 16, wherein the control unit prohibits radio transmission from the transfer destination or radio transmission via the base station when reading the radiographic image data. . 18. The radiological image acquisition according to claim 15, further comprising a detection unit that detects radiation irradiation to the subject, wherein the control unit prohibits the transfer based on detection information of the detection unit. apparatus. The transfer destination takes in irradiation execution information in the irradiation unit, and the control unit performs the transfer prohibition based on irradiation execution information received from the transfer destination by the communication unit. 17. The radiological image acquisition device according to 17. An input unit that inputs irradiation mode shift information when the irradiation unit shifts to the irradiation mode is provided, and the control unit executes the prohibition of transfer based on the irradiation mode shift information input to the input unit. The radiographic image acquisition device according to claim 15, 16 or 17. The said control part cancels | releases the said transfer prohibition based on the completion | finish information generate | occur | produced when the said radiographic imaging part complete | finishes reading of radiation image data, The one of Claim 15 thru | or 20 characterized by the above-mentioned. Radiation image acquisition device. 21. The radiographic image acquisition apparatus according to any one of claims 15 to 20, wherein the control unit cancels the transfer prohibition based on release information received by the communication unit from the transfer destination. 21. The radiological image acquisition apparatus according to claim 15, wherein the control unit cancels the transfer prohibition after a predetermined time has elapsed from the radiation irradiation. An input unit that inputs end information of completion of reading of radiation image data in the radiation imaging unit is provided, and the control unit cancels the transfer prohibition based on the end information input to the input unit. Item 21. The radiographic image acquisition device according to any one of Items 15 to 20.

Images