Radiation imaging apparatus, radiation imaging system, and method and program for controlling radiation imaging apparatus

Abstract

To provide a technology advantageous to suppressing a stand-by time in a radiation imaging apparatus.SOLUTION: A radiation imaging apparatus includes a detection unit in which a plurality of pixels for acquiring a radiation image in response to incidence of a radioactive ray are arranged, a communication unit for receiving, from a control device, a control signal including an imaging mode when acquiring the radiation image at the detection unit, and the control unit. The control unit causes the detection unit to operate in an imaging mode according to the control signal when an imaging instruction is given in a first state in which a communication state between the communication unit and the control device is normal, causes the detection unit to operate in an abnormal time imaging mode set beforehand when the imaging instruction is given in a second state in which the communication state is not normal, and causes the detection unit to operate so as to acquire off-set image data in an imaging mode different from the abnormal time imaging mode in a period in which a radioactive ray is not emitted in the second state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a radiation imaging apparatus, a radiation imaging system, and a method and program for controlling a radiation imaging apparatus. [Background technology]

[0002] In medical image diagnosis and non-destructive testing, radiation imaging devices using a flat panel detector (FPD) made of semiconductor material are widely used. Patent Document 1 discloses a radiation imaging system that sets the imaging mode of the radiation imaging device by command communication from a command communication control device according to an instruction from a user. The radiation imaging system of Patent Document 1 discloses that even if the command communication control device goes down and command communication is not possible, the radiation imaging system has an emergency imaging mode that operates in a specific imaging mode that has been set in advance in response to the user pressing an emergency imaging transition button, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-028033 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the signal output from the pixel when a radiation image is captured, there is an offset component due to the dark current of the pixel as well as a component according to the irradiated radiation, so offset correction is performed using offset image data acquired in a state where radiation is not irradiated. The offset amount of the offset component changes depending on the imaging mode such as the sensitivity setting, accumulation time, and binning number when capturing the radiation image. In addition, since the offset amount of the offset component changes depending on the temperature change accompanying the operation of the radiation imaging device, it is necessary to reacquire an offset image corresponding to each imaging mode at an appropriate timing. In the radiation imaging system of Patent Document 1, when the command communication control device recovers from a down state and attempts to perform imaging by transitioning from the emergency imaging mode to a desired imaging mode, it is necessary to reacquire the offset image, which may take a long time before imaging can begin.

[0005] An object of the present invention is to provide a technique that is advantageous for reducing standby time in a radiation imaging apparatus. [Means for solving the problem]

[0006] In view of the above problem, a radiation imaging device according to an embodiment of the present invention is a radiation imaging device including a detection unit having a plurality of pixels arranged thereon for acquiring a radiation image in response to incidence of radiation, a communication unit that receives a control signal from a control device including an imaging mode for acquiring a radiation image by the detection unit, and a control unit, wherein the control unit operates the detection unit in an imaging mode in response to the control signal when an imaging instruction is received in a first state in which a communication state between the communication unit and the control device is normal, operates the detection unit in a preset abnormality imaging mode when an imaging instruction is received in a second state in which the communication state is not normal, and operates the detection unit in a period in which radiation is not irradiated in the second state so as to obtain offset image data of an imaging mode different from the abnormality imaging mode. Effect of the Invention

[0007] The above means provides a technique that is advantageous for reducing standby time in a radiation imaging apparatus. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing an example of the arrangement of a radiation imaging apparatus according to an embodiment of the present invention and a radiation imaging system using the radiation imaging apparatus. [Diagram 2] 2 is a block diagram showing an example of the arrangement of a detection unit of the radiation imaging apparatus in FIG. 1; [Diagram 3] 2 is a flowchart for explaining the operation of the radiation imaging apparatus in FIG. 1; [Figure 4] 2 is a flowchart for explaining the operation of the radiation imaging apparatus in FIG. 1; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0010] Furthermore, radiation in the present invention may include α-rays, β-rays, γ-rays, and other beams produced by particles (including photons) emitted by radioactive decay, as well as beams having the same or greater energy, such as X-rays, particle beams, and cosmic rays.

[0011] The configuration and operation of a radiation imaging apparatus according to this embodiment will be described with reference to Figs. 1 to 4. Fig. 1 is a block diagram showing an example of the configuration of a radiation imaging apparatus 100 according to this embodiment. Fig. 1 also shows a block diagram of a radiation imaging system SYS using the radiation imaging apparatus 100 according to this embodiment. The radiation imaging apparatus 100 according to this embodiment can be used for medical purposes, for example.

[0012] The radiation imaging system SYS includes a radiation imaging apparatus 100, a control device 400, and a radiation source 301. The radiation imaging apparatus 100 includes a detection unit 200 having a plurality of pixels arranged thereon for acquiring a radiation image in response to incidence of radiation. The radiation source 301 is controlled by a radiation source control device 300 and irradiates radiation to the radiation imaging apparatus 100. The control device 400 controls the radiation imaging apparatus 100 and the radiation source control device 300. The control device 400 communicates control signals with the radiation imaging apparatus 100, collects radiation image data from the radiation imaging apparatus 100, and displays a radiation image based on the radiation image data. The control device 400 also includes a radiation imaging application 404 capable of receiving an imaging order and registering imaging information for generating a control signal including an imaging mode when acquiring a radiation image by the detection unit 200. The radiation imaging system SYS may further include an image control device 500 that outputs radiation image data output from the radiation imaging apparatus 100 to the control device 400.

[0013] The control device 400 is connected to an intra-hospital network 600 constituted by, for example, a LAN (Local Area Network). A hospital information system (HIS) / radiology information system (RIS) 601 is connected to the intra-hospital network 600. The control device 400 and the HIS / RIS 601 can communicate with each other, enabling, for example, the exchange of radiographic image imaging orders, imaging information including patient information, and further radiographic image data within the hospital.

[0014] The radiation imaging apparatus 100 includes a detection unit 200, a control unit 101, and a power supply unit 115. The detection unit detects radiation incident on the detection unit 200 and generates image data according to the dose of the detected radiation. The control unit 101 controls each component arranged in the radiation imaging apparatus 100. The control unit 101 includes a drive control unit 102, an image processing unit 106, an offset control unit 108, a storage unit 109, a communication unit 112, a timer 113, and an irradiation timing control unit 114. The drive control unit 102 controls the operation of the detection unit 200 so as to obtain radiation image data according to the irradiation of radiation and offset image data for correcting the radiation image data. The image processing unit 106 performs image processing on the image data obtained from the detection unit 200. The offset control unit 108 controls the timing of updating the offset image. The storage unit 109 stores the obtained image data. The communication unit 112 controls communication with the control device 400 and communication with the radiation source control device 300. The communication unit 112 receives, for example, a control signal including an imaging mode when the detection unit 200 acquires a radiation image from the control device 400. The timer 113 acquires an imaging time, an elapsed time, and the like. The irradiation timing control unit 114 controls the detection unit 200 to transition to an imaging operation, etc., in response to a radiation irradiation signal from the radiation source control device 300 to the radiation source 301. The power supply unit 115 supplies power to each component in the radiation imaging device 100.

[0015] The control unit 101 may, for example, read out a program stored in the storage unit 109 and control the entire radiation imaging apparatus 100 based on the read out program. The control unit 101 may also include a control signal generating circuit such as an ASIC and control the radiation imaging apparatus 100. Furthermore, the entire control of the radiation imaging apparatus 100 may be realized by both the program and the control signal generating circuit.

[0016] The drive control unit 102 controls the detection unit 200 by switching between a plurality of control modes including an imaging preparation drive control 103, a radiation image acquisition control 104, and an offset image acquisition control 105. The imaging preparation drive control 103 is a control for preparing the detection unit 200 to a state in which radiation image capturing is possible. The radiation image acquisition control 104 is a control for driving the detection unit 200 so that radiation image data is acquired. The offset image acquisition control 105 is a control for driving the detection unit 200 so that offset image data is acquired. In the imaging preparation drive control 103, the drive control unit 102 applies the same voltage as that during imaging to the detection unit 200, and periodically reads out charges, thereby resetting dark charges accumulated in each pixel arranged in the detection unit 200. At this time, the signal read out from the pixel is not treated as image data, and does not need to be stored in the storage unit 109. In the radiation image acquisition control 104, the drive control unit 102 drives the detection unit 200 in the same manner as in the imaging preparation drive control 103, and causes pixels arranged in the detection unit 200 to accumulate charge corresponding to the irradiation of radiation. Next, the charge accumulated in the pixels is read out as radiation image data 110 and stored in the storage unit 109. The drive control unit 102 continuously executes this radiation image acquisition control 104, thereby enabling imaging of a moving image. In the offset image acquisition control 105, the drive control unit 102 causes the detection unit 200 to perform driving in the same manner as in the imaging preparation drive control 103, and causes the storage unit 109 to store image data read out without irradiation of radiation as offset image data 111.

[0017] The radiation image data 110 acquired from the detection unit 200 by the radiation image acquisition control 104 is offset-corrected using the offset image data 111 acquired in advance by the offset image acquisition control 105. The offset correction process may be performed by the offset correction unit 107 of the image processing unit 106. The offset-corrected radiation image data is transferred to the image control device 500 via the communication unit 112. Although only the offset correction process is described here, the image processing unit 106 may perform other correction processes such as correction of defective pixels and gain correction for correcting gain variations of an amplifier arranged in the detection unit 200. In addition, these correction processes may not be performed by the radiation imaging device 100. For example, the acquired radiation image data 110 and offset image data 111 may be transferred to the image control device 500 without being subjected to processes such as correction, and the image control device 500 may perform these correction processes. In addition, the offset image data used for the offset correction may be, for example, image data obtained by acquiring a plurality of offset image data and performing a process of reducing noise components by averaging or the like.

[0018] The radiation source control device 300 includes an operation UI 302 for operating the radiation source control device 300. The operation UI 302 may include a keyboard, a mouse, an exposure switch, etc. A user may set radiation irradiation conditions and irradiate radiation using the operation UI 302. A dedicated signal line enables information exchange between the radiation source control device 300 and the radiation imaging apparatus 100. Synchronizing signals, such as notifications of the start and end of radiation irradiation and notifications of timing when radiation can be irradiated, may be exchanged between the radiation source control device 300 and the radiation imaging apparatus 100. This allows the radiation imaging apparatus 100 and the radiation source 301 controlled by the radiation source control device 300 to capture a radiation image without the intervention of the control device 400.

[0019] The control device 400 includes an imaging control unit 402, an irradiation control unit 403, a communication unit 401, a radiation imaging application 404, a display unit 406, an operation UI 407, and a power supply unit 405, and controls each component of the radiation imaging system SYS. The imaging control unit 402 controls the radiation imaging device 100, such as controlling the timing of acquiring image data and setting imaging conditions including an imaging mode when acquiring a radiation image by the detection unit 200, according to a user's setting via the radiation imaging application 404. The irradiation control unit 403 controls the irradiation conditions of radiation irradiated from the radiation source 301 by controlling the radiation source control device 300, according to a user's setting via the radiation imaging application 404. The communication unit 401 controls communication with the radiation imaging device 100, the radiation source control device 300, and the hospital network 600. The radiation imaging application 404 accepts imaging orders and registers imaging information. The display unit 406 displays radiation images based on radiation image data obtained by the radiation imaging device 100 and information on imaging conditions such as an imaging mode when imaging is performed. The operation UI 407 may be a keyboard, a mouse, or the like for operating the radiation imaging application 404. The power supply unit 405 supplies power to each component in the control device 400.

[0020] Here, the communication between the control device 400 and the radiation imaging apparatus 100 and the communication between the control device 400 and the radiation source control device 300 may be cable connection communication using a standard such as RS232C, USB, or Ethernet. Furthermore, the communication between the control device 400 and the radiation imaging apparatus 100 and the communication between the control device 400 and the radiation source control device 300 may be communication using a dedicated signal line or wireless communication. Furthermore, the communication between the control device 400 and the radiation imaging apparatus 100 and the communication between the control device 400 and the radiation source control device 300 may be a combination of wired communication and wireless communication.

[0021] In the communication between the control device 400 and the radiation imaging device 100, for example, the radiation imaging device 100 transmits a signal indicating image data or a device status of the radiation imaging device 100 to the control device 400. In addition, for example, the control device 400 transmits a control signal including a signal for setting conditions such as an imaging mode when acquiring image data to the radiation imaging device 100. In the communication between the control device 400 and the radiation source control device 300, for example, a signal for setting radiation irradiation conditions is transmitted from the control device 400 to the radiation source control device 300. In addition, for example, the radiation source control device 300 transmits a signal indicating the device status of the radiation source control device 300 and signals such as actual irradiation information when irradiating radiation to the control device 400.

[0022] The image control device 500 performs image processing on the image data transferred from the radiation imaging device 100, and transfers the image-processed image data to the control device 400. In addition, when the control device 400 is not operating, a display unit 501 for displaying a radiation image based on radiation image data acquired by the radiation imaging device 100 without going through the control device 400 is connected to the image control device 500.

[0023] 2 is a block diagram showing an example of the configuration of the detection unit 200 of the radiation imaging device 100. The detection unit 200 has a sensor array 204 including a plurality of pixels 207 arranged in a two-dimensional array to form a plurality of rows and a plurality of columns in order to obtain a radiation image corresponding to the incidence of radiation. The pixels 207 arranged in the sensor array 204 include, for example, a switching element 208 such as a thin film transistor (TFT) and a photoelectric conversion element 209, and a scintillator (not shown) may be arranged on the pixel 207 (photoelectric conversion element 209). The scintillator may be formed integrally in the sensor array 204, for example. When the pixel 207 includes a scintillator and the photoelectric conversion element 209, radiation incident on the detection unit 200 is converted into visible light by the scintillator, and a charge corresponding to the visible light is generated in the photoelectric conversion element 209 to which the converted visible light is incident. In this manner, a so-called indirect conversion type conversion element that converts incident radiation into electric charge by a scintillator and photoelectric conversion element 209 may be used as pixel 207. Also, for example, a so-called direct conversion type conversion element that directly converts incident radiation into electric charge without providing a scintillator may be used for pixel 207. By switching switch element 208 between an ON (conductive) state and an OFF (non-conductive) state, accumulation of electric charge generated in photoelectric conversion element 209 and reading of the electric charge are performed, and image data can be acquired.

[0024] The pixels 207 arranged in the sensor array 204 of the detection unit 200 are turned on by applying a voltage to the pixels 207 arranged in each row via a common drive line 211 from the drive circuit 201 so that the switch elements 208 are turned on. When the switch elements 208 are turned on, a signal corresponding to the charge accumulated in the pixels 207 is transferred to the sample hold circuit 202 via a signal line 210 to which each pixel 207 is connected. Thereafter, the signals output from the pixels 207 held in the sample hold circuit 202 are sequentially read out via the multiplexer 203, amplified by the amplifier 205, and then converted into digital image data by the A / D converter 206. Next, the pixels 207 from which the charge has been read out are applied with a voltage to the pixels 208 arranged in the OFF state from the drive circuit 201 via the drive line 211, so that the pixels 207 are returned to a state in which they can accumulate charge. In this manner, the drive circuit 201 sequentially scans the pixels 207 arranged on the sensor array 204 row by row, and the signals output from all the pixels 207 are finally converted into digital values. This makes it possible to read out image data for generating a radiation image. The drive control unit 102 of the control unit 101 controls the drive and readout operations of these detection units 200. The image data converted into digital values ​​may be temporarily stored in, for example, the memory unit 109 in FIG. 1.

[0025] Next, the operation of the radiation imaging apparatus 100 in this embodiment will be described. Fig. 3 is a flow diagram in which the control unit 101 in the radiation imaging apparatus 100 performs imaging while checking (determining) whether or not the communication state with the control device 400 is normal. Here, a case where the communication state between the radiation imaging apparatus 100 and the control device 400 is normal is called a normal state, and a case where the communication state between the radiation imaging apparatus 100 and the control device 400 is not normal is called an abnormal communication state.

[0026] First, in S301, the power supply of the radiation imaging apparatus 100 is turned on, and the process proceeds to S302. In S302, the control unit 101 reads out a program stored in the storage unit 109, and starts controlling each component of the radiation imaging apparatus 100. In S302, for example, setting information, gain correction data, loss correction data, and the like of the radiation imaging apparatus 100 stored in the storage unit 109 are read out, and initialization is performed to prepare for imaging. When the initialization is completed, the process proceeds to S303.

[0027] In S303, the control unit 101 checks whether or not the communication state between the communication unit 112 and the control device 400 is normal. For example, the control device 400 periodically transmits a command to the communication unit 112 of the radiation imaging device 100. The control unit 101 checks whether or not the communication unit 112 receives this periodic command.

[0028] Next, in S304, the control unit 101 determines whether or not the communication state between the communication unit 112 and the control device 400 is normal. For example, the control device 400 transmits a command periodically (e.g., at one-second intervals), and when the command is received by the communication unit 112, the control unit 101 determines that the communication state is normal. In this case, the communication state is determined to be a normal state, and the process transitions to step S305. Also, when the communication unit 112 does not receive a command output from the control device 400 for a certain period of time (e.g., about three seconds), the control unit 101 determines that the communication state is not normal, that is, an abnormal communication state. In this case, the communication state is determined to be an abnormal communication state, and the process transitions to step S306.

[0029] In S305, since the control device 400 is operating normally, the communication unit 112 receives a control signal from the control device 400, including an imaging mode when the detection unit 200 of the radiation imaging device 100 acquires a radiation image. The imaging mode includes an imaging mode for a fluoroscopic image and an imaging mode for a still image. The control signal further includes a signal for setting the gain, image size, binning number, frame rate, etc. of the detection unit 200 according to each imaging mode.

[0030] After the imaging mode has been set, when an imaging instruction is given, for example, by a user pressing an exposure switch on the operation UI 302 of the radiation source control device 300, the control unit 101 operates the detection unit 200 in an imaging mode corresponding to the control signal. The drive control unit 102 performs radiation image acquisition control 104, and drives the detection unit 200 in an imaging mode for fluoroscopic images, for example. The irradiation timing control unit 114 outputs a timing signal instructing the radiation source control device 300 on the timing of irradiation of radiation. In response to the timing signal, the radiation source control device 300 causes the radiation source 301 to irradiate radiation. The radiation image data acquired by the radiation imaging device 100 is transferred to the image control device 500. The radiation image data transferred to the image control device 500 is subjected to image processing and the like in the image control device 500, and then transferred to the control device 400, where a fluoroscopic image based on the acquired radiation image data is displayed on the display unit 406.

[0031] On the other hand, when it is determined in S304 that the communication state is an abnormal communication state, in S306, the communication unit 112 cannot receive a control signal for setting the imaging mode from the control device 400. For this reason, when there is an imaging instruction such as pressing an exposure switch on the operation UI 302, the control unit 101 operates the detection unit 200 in a preset abnormality imaging mode. For example, as the abnormality imaging mode, the following conditions are set: for fluoroscopic images, high sensitivity, maximum image size, and frame rate of 15 fps.

[0032] When the exposure switch is pressed on the operation UI 302 of the radiation source control device 300, the drive control unit 102 executes the radiation image acquisition control 104 and drives the detection unit 200 in the abnormality imaging mode. In addition, the irradiation timing control unit 114 outputs a timing signal instructing the radiation source control device 300 on the timing of radiation irradiation. In response to the timing signal, the radiation source control device 300 causes the radiation source 301 to irradiate radiation. The radiation image data acquired by the radiation imaging device 100 is transferred to the image control device 500. The radiation image data transferred to the image control device 500 is subjected to image processing and the like in the image control device 500, and a fluoroscopic image based on the acquired radiation image data is displayed on the display unit 501.

[0033] In this case, the radiation imaging apparatus 100 may output a notification signal indicating that the communication is abnormal to the display unit 501 via the image control device 500. The display unit 501 notifies the user that the radiation imaging apparatus 100 is operating in a communication abnormal state. For example, the notification signal may be attached to header information of the radiation image data. The image control device 500 may determine whether or not to display a fluoroscopic image on the display unit 501 based on the header information, or may determine whether or not to transfer the radiation image data to the control device 400. Also, for example, in a case where a radiation image is always displayed on the display unit 406 in a normal state, the user can determine that the radiation imaging apparatus 100 is operating in a communication abnormal state by the radiation image not being displayed on the display unit 406.

[0034] When the communication state changes between the normal state and the abnormal communication state, the control unit 101 may transition from the normal state to the abnormal communication state, or from the abnormal communication state to the normal state. For example, after the imaging of a fluoroscopic image or a still image is completed, the step may transition to S307, and when the power is not turned off by the user, the control unit 101 may transition to S303 to check the communication state. The control unit 101 may also check the communication state while imaging of a fluoroscopic image or a still image. When the communication state changes between the normal state and the abnormal communication state during acquisition of radiation image data, the control unit 101 may interrupt the operation of acquiring the radiation image data being imaged, and transition from the normal state to the abnormal communication state, or from the abnormal communication state to the normal state. When the communication state changes between the normal state and the abnormal communication state during acquisition of radiation image data, the control unit 101 may transition from the normal state to the abnormal communication state, or from the abnormal communication state to the normal state after acquiring the radiation image data being imaged. This allows the data of the radiation image that has already been imaged to be held.

[0035] After capturing the radiation image, when the user turns off the power of the radiation imaging apparatus 100, the above-described flow of capturing the radiation image ends.

[0036] Here, the offset amount of the offset component included in the radiation image data changes depending on the imaging conditions when capturing the radiation image. In addition, since the offset amount of the offset component changes depending on the temperature change accompanying the operation of the radiation imaging device, it is necessary to reacquire the offset image corresponding to each imaging mode at an appropriate timing. When the communication state between the radiation imaging device 100 and the control device 400 is in a normal state, the control device 400 appropriately operates the radiation imaging device 100 so that the offset image data corresponding to each imaging mode is obtained during the period when radiation is not being irradiated.

[0037] On the other hand, when the communication state between the radiation imaging apparatus 100 and the control device 400 is in a communication abnormal state, the radiation imaging apparatus 100 cannot receive a control signal from the control device 400. For example, when the control device 400 goes down for some reason, the communication abnormal state may occur. When the communication state with the control device 400 is restored and the user sets an appropriate imaging mode and tries to perform imaging, if a long time has passed since the previous acquisition of offset image data, the offset image data needs to be reacquired. In this case, it may take time until the reacquisition of the offset image data is completed and imaging can be started. Therefore, in this embodiment, the control unit 101 of the radiation imaging apparatus 100 operates the detection unit 200 so that offset image data of an imaging mode different from the abnormal imaging mode described above is obtained during a period in which radiation is not irradiated in a communication abnormal state. The obtained offset image data is stored in the storage unit 109. As a result, when the control device 400 recovers from a down state, it is possible to quickly start an imaging operation for acquiring a radiation image, and it is possible to realize a radiation imaging apparatus 100 and a radiation imaging system SYS that are easy to use.

[0038] Fig. 4 is a flow diagram for updating offset image data. Here, it is assumed that the offset control unit 108 updates the offset image data in the following steps. However, this is not limited to this, and it is sufficient that the components of the radiation imaging device 100 cooperate appropriately to obtain the offset image data. Hereinafter, as shown in Fig. 1, the offset control unit 108 is included in the control unit 101, and therefore may be simply referred to as the control unit 101.

[0039] First, in S401, the timer 113 measures the time that has elapsed since the offset image data was acquired. If no offset image data has been acquired even once, the elapsed time is set to a maximum value.

[0040] Next, in S402, the control unit 101 (offset control unit 108) determines whether a predetermined time has passed since the previous acquisition of offset image data. If the elapsed time measured by the timer 113 exceeds time T (elapsed time>T), the process proceeds to step S403, and if the elapsed time is equal to or less than time T (elapsed time≦T), the process returns to step S401. For example, time T may be 5 minutes.

[0041] In S403, the control unit 101 determines whether imaging is in progress. That is, it checks whether radiation is not being irradiated. If radiation is not being irradiated, the process proceeds to step S404. On the other hand, if radiation is being irradiated and a radiographic image is being imaged, the process returns to step S401. If imaging is not in progress, the drive control unit 102 is performing imaging preparation drive control 103.

[0042] Next, in S404, the drive control unit 102 switches the drive from the imaging preparation drive control 103 to the offset image acquisition control 105, and the offset image data is updated. As a result, the control unit 101 operates the detection unit 200 so that the offset image data is obtained when a predetermined time has elapsed since the previous acquisition of the offset image data and when radiation is not being irradiated.

[0043] In a normal state, during a period when radiation is not being irradiated, the control unit 101, for example, in accordance with the control of the control device 400, operates the detection unit 200 so as to obtain offset image data for all imaging modes set in the radiation imaging device 100. As a result, the offset image data for all imaging modes for fluoroscopic images and still images is updated sequentially.

[0044] On the other hand, in a communication abnormality state where a control signal cannot be received from the control device 400, the control unit 101 drives the detection unit 200 to acquire radiation image data only in the abnormal imaging mode. However, with regard to acquisition of offset image data, the control unit 101 operates the detection unit 200 so as to acquire offset image data of an imaging mode different from the abnormal imaging mode. For example, in a communication abnormality state, the control unit 101 may operate the detection unit so as to acquire offset image data of all imaging modes set in the radiation imaging device 100 during a period in which radiation is not being irradiated. When updating of the offset image data is completed, the timer 113 is reset to elapsed time=0.

[0045] The offset image data is not limited to be updated for all imaging modes. For example, the control unit 101 may operate the detection unit 200 so that offset image data for at least two imaging modes including the imaging mode during abnormality is obtained during a period when radiation is not irradiated in an abnormal communication state. In this case, for example, offset image data for one or more imaging modes that are frequently used for imaging may be obtained separately from offset image data for the imaging mode during abnormality. The imaging mode for obtaining offset image data may be set at the time of shipment from the factory, or may be appropriately set by the user. In addition, the storage unit 109 may store imaging modes that are frequently used, and the offset image data for the one or more imaging modes that are frequently used may be obtained. In an abnormal communication state, at least one offset image data for an imaging mode different from the imaging mode during abnormality is obtained. This makes it possible to shorten the waiting time for re-obtaining offset image data when the communication state returns to normal, compared to the case where no offset image data is obtained.

[0046] In this way, even if the communication state between the radiation imaging apparatus 100 and the control device 400 is not normal, the offset image data is updated. As a result, even if the communication state between the radiation imaging apparatus 100 and the control device 400 changes from a normal state to a communication abnormal state due to a communication abnormality, or even if the communication state returns to normal and changes from the communication abnormal state to the normal state, the offset image data is updated. This makes it possible to immediately perform imaging of fluoroscopic images and still images. This reduces the waiting time, and realizes a radiation imaging apparatus 100 and a radiation imaging system SYS that are easy to use.

[0047] 4, if the offset image data is acquired immediately after capturing a radiographic image, the offset image data may contain an afterimage. In order to suppress the effect of the afterimage, the timer 113 further measures the time that has elapsed since the radiographic image data was acquired. The control unit 101 may operate the detection unit 200 so that the offset image data is acquired at a timing when a predetermined time has elapsed since the previous acquisition of the offset image data, radiation is not being irradiated, and a predetermined time has elapsed since the previous acquisition of the radiographic image data.

[0048] This embodiment can also be realized by executing the following process: That is, software (programs) that realize the functions of the above-described embodiment are supplied to a system or device via a network or various storage media, and the computer (or CPU, MPU, etc.) of the system or device reads and executes the program.

[0049] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0050] 100: radiation imaging device, 101: control unit, 112: communication unit, 200: detection unit, 207: pixel, 400: control device

Claims

1. A radiation imaging device including: a detection section having a plurality of pixels arranged thereon for acquiring a radiation image in response to incidence of radiation; a communication section that receives a control signal including an imaging mode when acquiring the radiation image by the detection section from a control device; and a control section, The control unit is In a first state in which a communication state between the communication unit and the control device is normal, when an image capturing instruction is received, the detection unit is operated in an image capturing mode corresponding to the control signal; operating the detection unit in a preset abnormality imaging mode when an imaging instruction is received in a second state in which the communication state is not normal; The radiation imaging apparatus according to claim 1, wherein in the second state, the detection unit is operated so as to obtain offset image data in an imaging mode different from the abnormal imaging mode during a period when radiation is not being irradiated.

2. 2. The radiation imaging device according to claim 1, wherein the control unit, in the second state, operates the detection unit so as to obtain offset image data for at least two imaging modes including the abnormal imaging mode during a period when radiation is not being irradiated.

3. The radiation imaging device according to claim 1 or 2, wherein the control unit, in the second state, operates the detection unit so as to obtain offset image data for all imaging modes set in the radiation imaging device during a period in which radiation is not being irradiated.

4. the control unit includes a timer that measures the time that has elapsed since the offset image data was acquired, 4. The radiation imaging device according to claim 1, wherein the control unit operates the detection unit so as to obtain offset image data at a timing when a predetermined time has elapsed since the previous acquisition of offset image data and when radiation is not being irradiated.

5. The timer further measures the time that has elapsed since the radiation image data was acquired; 5. The radiation imaging device according to claim 4, wherein the control unit operates the detection unit so as to obtain offset image data at a timing when a predetermined time has elapsed since the previous acquisition of offset image data, radiation is not being irradiated, and a predetermined time has elapsed since the previous acquisition of radiation image data.

6. 6. The radiation imaging device according to claim 1, wherein when the communication state changes between the first state and the second state during acquisition of radiation image data, the control unit transitions from the first state to the second state or from the second state to the first state after acquiring the radiation image data.

7. 6. The radiation imaging device according to claim 1, wherein, when the communication state changes between the first state and the second state during acquisition of radiation image data, the control unit interrupts an operation of acquiring the radiation image data and transitions from the first state to the second state or from the second state to the first state.

8. A radiation imaging apparatus according to any one of claims 1 to 7, a control device that communicates the control signal with the radiation imaging device; a radiation source for irradiating the radiation imaging device with radiation; A radiation imaging system comprising:

9. The control device periodically transmits a command to the communication unit, 9. The radiation imaging system according to claim 8, wherein the control unit determines whether the communication state is normal by determining whether the communication unit has received the command.

10. 10. The radiation imaging system according to claim 8, wherein the radiation imaging device and the radiation source are configured to be able to capture a radiation image without the intervention of the control device.

11. 11. The radiation imaging system according to claim 8, further comprising a display unit that displays a radiation image based on radiation image data acquired by the radiation imaging device without going through the control device.

12. the radiation imaging apparatus outputs a notification signal indicating the second state to the display unit; The radiation imaging system according to claim 11 , wherein the display unit notifies the user that the radiation imaging apparatus is in the second state.

13. 13. The radiation imaging system according to claim 12, wherein the notification signal is attached to radiation image data.

14. 1. A method for controlling a radiation imaging device including a detection unit having a plurality of pixels arranged thereon for acquiring a radiation image in response to incidence of radiation, and a communication unit for communicating a control signal including an imaging mode when the detection unit acquires the radiation image with a control device, comprising: determining whether or not a communication state between the communication unit and the control device is normal; operating the detection unit in an imaging mode corresponding to the control signal when an imaging instruction is received in a first state in which the communication state is normal; and operating the detection unit in a preset abnormality imaging mode when an imaging instruction is received in a second state in which the communication state is not normal, a control method for controlling the detection unit to operate in the second state during a period when radiation is not being irradiated, so as to obtain offset image data in an imaging mode different from the abnormal imaging mode.

15. A program for causing a computer to execute each step of the control method according to claim 14.

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