JP2017118988A - Radiation imaging system, communication control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress excessive radiation irradiation onto a subject which is attributed to the delay in information transmission.SOLUTION: A radiation imaging system includes a radiation imaging apparatus for taking an image of a radiation ray that has passed through a subject by the irradiation of the radiation ray, and a communication control apparatus for controlling the communication between a radiation generation apparatus and the radiation imaging apparatus. The radiation imaging apparatus includes communication means for performing communication with the communication control apparatus, and communication control means for executing control so as to transmit irradiation information related to the radiation ray irradiation in priority to the transmission of the image of a radiation ray in an imaging period. The communication control apparatus includes control means for controlling taking of the image of a radiation ray.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radiation imaging system, a communication control method, and a program.

  2. Description of the Related Art Conventionally, as a radiation imaging apparatus used for medical image diagnosis and nondestructive inspection using radiation such as X-rays, an apparatus having a matrix substrate having a pixel array in which a switch such as a TFT (thin film transistor) and a conversion element such as a photoelectric conversion element are combined. Has been put to practical use. In recent years, multi-functionalization of radiation imaging apparatuses has been studied. As one of them, it is considered to incorporate a function for monitoring the irradiation of radiation. With this function, for example, detection of radiation irradiation start timing, detection of timing at which radiation irradiation should be stopped, detection of radiation irradiation amount, and integrated irradiation amount can be performed.

  Patent Document 1 discloses a system that transmits an irradiation stop signal by wireless communication to a control device when the radiation imaging apparatus detects a timing at which radiation irradiation should be stopped.

JP 2013-162963 A

  However, in the technique of Patent Document 1, when transmission / reception of an irradiation stop signal and a signal such as image transfer is performed by common wireless communication, the transmission / reception timing of the irradiation stop signal and a signal such as image transfer may overlap. If the transmission / reception timing of these information overlaps, the arrival of the irradiation stop signal from the radiation imaging apparatus to the control apparatus is delayed, and radiation irradiation cannot be stopped at an appropriate timing, which is excessive for the subject. There was a risk of irradiating various kinds of radiation.

  The present invention has been made in view of such a problem, and an object thereof is to suppress excessive radiation irradiation to a subject due to delay in information transmission.

  Therefore, the present invention is a radiation imaging system having a radiation imaging apparatus that captures a radiation image that has passed through a subject due to radiation irradiation, and a communication control apparatus that controls communication between the radiation generation apparatus and the radiation imaging apparatus. The radiation imaging apparatus includes a communication unit that communicates with the communication control unit, and a communication control unit that controls to transmit irradiation information related to radiation irradiation in preference to transmission of a radiation image during an imaging period. It is characterized by having.

  According to the present invention, it is possible to suppress excessive radiation irradiation to a subject due to a delay in information transmission.

It is a figure which shows a radiation imaging system. It is a figure which shows a radiation imaging device. It is a figure which shows a control circuit. It is a flowchart which shows a radio | wireless communication control process. It is a schematic diagram which shows the timing chart of radiography.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a radiation imaging system 100 according to the present embodiment. The radiation imaging system 100 is used, for example, when capturing a radiation image in a hospital. The radiation imaging system 100 includes a radiation imaging device 110, a communication control device 120, a radiation source 130, a radiation generation device 140, and a hospital wireless LAN 150.

  The radiation imaging apparatus 110 detects radiation that has passed through a patient (not shown) as a subject and forms an image. The communication control device 120 functions as a communication medium between the radiation imaging device 110 and the radiation generation device 140. The communication control device 120 includes a communication control unit 121 and a control unit 122. The communication control unit 121 controls communication between the radiation imaging apparatus 110 and the radiation generation apparatus 140. The control unit 122 monitors the states of the radiation imaging apparatus 110 and the radiation generation apparatus 140 and controls radiation irradiation and imaging (control processing). The communication control device 120 also includes an input device such as a mouse and a keyboard and an output device such as a display that enable setting of shooting conditions, operation control, and input and output of information such as image information. The radiation source 130 holds an X-ray tube and a rotor that accelerate electrons with a high voltage to generate radiation, for example, and collide with the anode. The radiation generation apparatus 140 controls the irradiation conditions and irradiation timing of the radiation source 130 in accordance with instructions from the communication control apparatus 120.

  Between the radiation imaging apparatus 110 and the communication control apparatus 120, a radiation image generated in the radiation imaging apparatus 110, information for operation control, arrival dose information, automatic exposure control information, and the like are exchanged. Here, the reaching dose is a dose reaching the radiation imaging apparatus 110 among the irradiation doses from the radiation source 130, and the reaching dose information is information indicating the reaching dose. Note that the communication control device 120 according to the present embodiment instructs the radiation generation device 140 to stop irradiation according to the arrival dose. Thus, the arrival dose information is an example of control information for automatic exposure, and is an example of irradiation information related to radiation irradiation. The automatic exposure control information includes two irradiation stop signals and non-irradiation stop signals.

  Communication between the radiation imaging apparatus 110 and the communication control apparatus 120 is wireless communication. Each of the radiation imaging apparatus 110 and the communication control apparatus 120 includes a circuit board including a communication IC and the like. The circuit board is electrically connected to an antenna (not shown), and the antenna transmits and receives radio waves. This circuit board performs communication processing of a protocol based on a wireless LAN via an antenna. Note that there are no particular limitations on the frequency band, standard, or method of wireless communication in wireless communication. For example, methods such as near field radio such as NFC (Near Field Communication) and Bluetooth (registered trademark) and UWB (Ultra Wide Band) may be used.

  Note that communication between the radiation imaging apparatus 110 and the communication control apparatus 120 is not limited to wireless communication. The communication between the radiation imaging apparatus 110 and the communication control apparatus 120 may be wired communication that transmits the arrival dose information and the radiation image using the same signal line, such as packet communication such as Ethernet (registered trademark). May be used for communication.

  The communication control device 120 and the radiation generation device 140 exchange arrival dose information, automatic exposure control information, and the like. Communication between the communication control device 120 and the radiation generation device 140 is wired communication. The communication control device 120 and the radiation generation device 140 perform communication by a cable connection using a communication standard having a predetermined agreement or a standard such as RS232C, USB, or Ethernet, for example.

  FIG. 2 is a diagram illustrating the radiation imaging apparatus 110. The radiation imaging apparatus 110 includes a plurality of pixels arranged in the imaging region 200 so as to configure a plurality of rows and a plurality of columns. The plurality of pixels include a plurality of imaging pixels 201 for acquiring a radiation image and a detection pixel 211 for detecting radiation. The imaging pixel 201 includes a first conversion element 202 that converts radiation into an electric signal, and a first switch 203 disposed between the column signal line 206 and the first conversion element 202. The detection pixel 211 includes a second conversion element 212 that converts radiation into an electric signal, and a second switch 213 disposed between the detection signal line 225 and the second conversion element 212.

  The first conversion element 202 and the second conversion element 212 include a scintillator that converts radiation into light and a photoelectric conversion element that converts light into an electrical signal. The scintillator is generally formed in a sheet shape so as to cover the imaging region 200 and can be shared by a plurality of pixels. As another example, the first conversion element 202 and the second conversion element 212 may include conversion elements that directly convert radiation into light. The first switch 203 and the second switch 213 include a thin film transistor (TFT) in which an active region is formed of a semiconductor such as amorphous silicon or polycrystalline silicon (preferably polycrystalline silicon).

  The radiation imaging apparatus 110 includes a plurality of column signal lines 206 and a plurality of drive lines 204. Each column signal line 206 corresponds to one of a plurality of columns in the imaging region 200. Each drive line 204 corresponds to one of a plurality of rows in the imaging region 200. Each drive line 204 is driven by the row selection unit 250.

  The plurality of column signal lines 206 are connected to the readout circuit 260, respectively. Here, the reading circuit 260 includes a plurality of detection units 261, a multiplexer 262, and an analog-digital converter (hereinafter referred to as an AD converter) 263. Each of the plurality of column signal lines 206 is connected to a corresponding detection unit 261 among the plurality of detection units 261 of the readout circuit 260. Here, one column signal line 206 corresponds to one detection unit 261. The detection unit 261 includes, for example, a differential amplifier. The multiplexer 262 selects a plurality of detection units 261 in a predetermined order, and supplies a signal from the selected detection unit 261 to the AD converter 263. The AD converter 263 converts the supplied signal into a digital signal and outputs the digital signal.

  The first electrode of the second conversion element 212 is connected to the first main electrode of the second switch 213, and the second electrode of the second conversion element 212 is connected to the bias line 208. The second main electrode of the second switch 213 is electrically connected to the detection signal line 225. A control electrode of the second switch 213 is electrically connected to the drive line 224. The radiation imaging apparatus 110 has a plurality of detection signal lines 225. One or more detection pixels 211 are connected to one detection signal line 225. The drive line 224 is driven by the drive circuit 230. One or more detection pixels 211 are connected to one drive line 224.

  The detection signal line 225 is connected to the reading circuit 240. Here, the readout circuit 240 includes a plurality of detection units 241, a multiplexer 242, and an AD converter 243. Each of the plurality of detection signal lines 225 is connected to a corresponding detection unit 241 among the plurality of detection units 241 of the readout circuit 240. Here, one detection signal line 225 corresponds to one detection unit 241. The detection unit 241 includes, for example, a differential amplifier. The multiplexer 242 selects a plurality of detection units 241 in a predetermined order, and supplies a signal from the selected detection unit 241 to the AD converter 243. The AD converter 243 converts the supplied signal into a digital signal and outputs it. The output of the reading circuit 240 (AD converter 243) is supplied to the signal processing unit 270 and processed by the signal processing unit 270.

  The signal processing unit 270 outputs information indicating radiation irradiation to the radiation imaging apparatus 110 based on the output of the readout circuit 240. Specifically, the signal processing unit 270 detects, for example, the irradiation of radiation to the radiation imaging apparatus 110, or calculates the radiation dose or the cumulative dose.

  The control circuit 280 controls the drive circuits 230 and 250 and the read circuits 240 and 260 based on information from the signal processing unit 270 and operation control (command) from the control unit 122. Based on the information from the signal processing unit 270, the control circuit 280 controls, for example, the start and end of an accumulation operation (accumulation of charge corresponding to radiation irradiated by the imaging pixel 201).

  FIG. 3 is a diagram illustrating the control circuit 280 described with reference to FIG. As illustrated in FIG. 3, the control circuit 280 includes a drive control unit 300, a CPU 301, a memory 302, an irradiation control unit 303, an image control unit 304, a switching unit 305, and a communication unit 306.

  The drive control unit 300 controls the drive circuits 230 and 250 and the readout circuits 240 and 260 based on information from the signal processing unit 270 and commands from the control unit 122. The CPU 301 controls the radiation imaging apparatus 110 as a whole using programs and various data stored in the memory 302. The memory 302 stores, for example, programs and various data used when the CPU 301 executes processing. Also, the memory 302 stores various data obtained by the processing of the CPU 301 and radiation image data. The communication unit 306 performs wireless communication with the communication control unit 121.

  The irradiation control unit 303 controls arrival dose information and automatic exposure control information based on information from the signal processing unit 270 and information from the drive control unit 300. The irradiation control unit 303 communicates with the communication control device 120 via the communication unit 306. The communication control device 120 performs irradiation control of the radiation generator 140 based on the arrival dose information and the automatic exposure control signal. The image control unit 304 transmits the data sent from the readout circuit 260, that is, the radiation image, to the communication control device 120 via the communication unit 306. The switching unit 305 controls to switch the connection of the communication unit 306 between the irradiation control unit 303 and the image control unit 304.

  FIG. 4 is a flowchart showing a wireless communication control process by the radiation imaging apparatus 110. This process is realized by the CPU 301 reading a program stored in the memory 302 and executing this program. It is assumed that the following processing has been completed before the start of the wireless communication control processing. In other words, the radiation imaging apparatus 110, the communication control apparatus 120, and the radiation generation apparatus 140 are powered on. Further, the operator sets the patient at the imaging position. The operator further sets patient information and imaging information in the communication control device 120 by user operation or by obtaining information via the in-hospital wireless LAN 150. And the communication control apparatus 120 determines irradiation dose based on patient information or imaging | photography information. In step S <b> 401, the CPU 301 of the radiation imaging apparatus 110 determines whether radiation has been detected based on information from the detection unit 261. The CPU 301 waits until radiation is detected. If radiation is detected (Yes in S401), the process proceeds to S402.

  In step S402, the CPU 301 instructs the switching unit 305 to switch from image communication to irradiation information communication. The switching unit 305 switches to irradiation information communication in accordance with this instruction. In the image communication, the switching unit 305 controls the communication unit 306 and the image control unit 304 to be connected and the communication unit 306 and the irradiation control unit 303 not to be connected in order to limit the transmission target to the radiation image. On the other hand, in the irradiation information communication, the switching unit 305 connects the communication unit 306 and the irradiation control unit 303 to limit the transmission target to the irradiation information, but does not connect the communication unit 306 and the image control unit 304. Control. Through the above processing, transmission of radiation images is prohibited, and transmission of irradiation information is permitted. That is, the process of S402 is an example of a communication control process for prohibiting transmission of radiation images and controlling to transmit irradiation information.

  In step S <b> 403, the CPU 301 confirms whether the communication unit 306 is transmitting a radiation image to the communication control device 120. If the CPU 301 is transmitting (Yes in S403), the process proceeds to S404. If the CPU 301 is not transmitting (No in S403), the process proceeds to S405. In step S404, the CPU 301 interrupts transmission of the radiation image.

  In step S <b> 405, the CPU 301 controls to start capturing a radiographic image. Specifically, the CPU 301 controls each imaging pixel 201 to start accumulating charges for radiation images. In step S <b> 406, the CPU 301 transmits information output from the irradiation control unit 303 to the communication control device 120 via the communication unit 306. At this time, the information output from the irradiation control unit 303 is information input from the signal processing unit 270 to the irradiation control unit 303, that is, arrival dose information. The period during which the accumulation operation is performed is an irradiation period in which radiation is applied, and the CPU 301 periodically transmits arrival dose information to the communication control device 120 during the irradiation period.

  When the arrival dose indicated in the arrival dose information received from the radiation imaging device 110 reaches a preset irradiation dose, the communication control device 120 transmits an irradiation stop signal to the radiation generation device 140 and performs imaging to the radiation imaging device 110. Send a stop signal. The radiation generator 140 stops radiation according to the irradiation stop signal.

  In the radiation imaging apparatus 110, the process proceeds to S407 after the process of S406. In step S <b> 407, the CPU 301 determines whether radiation detection is continued based on information from the detection unit 261. If the radiation detection is continued (Yes in S407), the CPU 301 advances the process to 406, and continues to accumulate charges and transmit the arrival dose information. If the CPU 301 no longer detects radiation (No in S407), the process proceeds to S408. The CPU 301 ends the charge accumulation when the radiation is no longer detected or when the accumulation operation is finished. In step S <b> 408, the CPU 301 ends shooting and instructs the switching unit 305 to switch from irradiation information communication to image communication. The switching unit 305 switches to image communication according to this instruction. Here, the processing period of S405 to S407 is a radiographic image capturing period. The imaging period is a period including a charge accumulation period and a period including a radiation detection period.

  Next, in step S409, the CPU 301 confirms whether there is a radiographic image whose transmission is interrupted in step S403. If there is a radiographic image whose transmission is interrupted (Yes in S409), the CPU 301 advances the process to S410. If there is no radiographic image for which transmission has been interrupted (No in S409), the CPU 301 advances the process to S411.

  In S410, the CPU 301 resumes transmission of the interrupted radiation image. That is, the CPU 301 resumes transmission of the interrupted radiation image after the imaging period ends. At this time, the CPU 301 may retransmit the radiation image whose transmission has been interrupted from the beginning, or may transmit only the untransmitted portion. In step S <b> 411, the CPU 301 transmits the radiation image captured in steps S <b> 405 to S <b> 407 to the communication control device 120. That is, the CPU 301 transmits the radiographic image captured during the imaging period to the communication control device 120 after the imaging period ends. The communication control device 120 records the received radiation image in the storage unit. This completes the wireless communication control process. When the series of operations ends, the radiation imaging apparatus 110 starts the wireless communication control process again, and waits for the next radiation detection in S401.

  In this way, the radiation imaging apparatus 110 controls to give priority to transmission of the arrival dose information during the imaging period when the transmission timing of the radiation image and the arrival dose information can overlap, such as when performing continuous imaging. To do.

  FIG. 5 is a schematic diagram showing a timing chart of radiography. The imaging operation start is timing when the radiation imaging apparatus 110 detects radiation. When radiation is emitted from the radiation source 130 and the detection unit 261 in the radiation imaging apparatus 110 detects radiation, the detection signal (S1) becomes high level (T1). Alternatively, the start of the imaging operation may be a timing at which a signal indicating that the exposure switch of the radiation generating apparatus 140 is pressed is received. In that case, a switch signal is transmitted to the radiation imaging apparatus 110 directly from the radiation generation apparatus 140 or via the communication control apparatus 120.

  When the detection signal becomes a high level, the radiation imaging apparatus 110 starts the accumulation operation of the image signal from the reset operation for discarding the stored charge in order to accumulate the radiation image signal (S2). At the same time, the radiation imaging apparatus 110 starts transmitting an arrival dose for the radiation control signal (S3). During this time, not the radiation image but only the arrival dose information is transmitted.

  An irradiation stop signal (S6) is transmitted from the communication control device 120 to the radiation generator 140, and the radiation irradiation is stopped. The radiation imaging apparatus 110 ends the reaching dose communication and the charge accumulation when the radiation is no longer detected or when the accumulation operation is finished (T2). The imaging operation stop is when radiation is no longer detected or when the accumulation operation is finished. The period of the imaging operation is a period from the start of the imaging operation to the stop of the imaging operation, and is a period during which the radiation imaging apparatus 110 detects radiation or a period during which accumulation operation is performed.

  The radiation imaging apparatus 110 starts reading the stored image charge in the reading circuit 240 (S2). When the reading of the image charge is completed (T3), the radiation imaging apparatus 110 starts transmission of the radiation image from the communication unit 306 to the communication control apparatus 120 (S3). When the next imaging (N + 1th imaging) is started during the image transmission period and the detection signal (S1) becomes high level, the radiation imaging apparatus 110 stops transmitting the radiation image, and accumulates and reaches the image signal. Dose communication is started (T4).

  When the accumulation of the radiation image signal and the communication of the arrival dose information are completed, the radiation imaging apparatus 110 starts reading out the stored image charge in the readout circuit 240 (T5). The radiation imaging apparatus 110 enters an image transmission operation, and starts transmitting a radiation image from the communication unit 306 to the communication control apparatus 120 (T6). The radiation imaging apparatus 110 transmits the previous untransmitted data, that is, the radiation image whose transmission is interrupted, to the communication control apparatus 120 during reading of the radiation image. When the transmission of the untransferred data for the N-th imaging is completed, the radiation imaging apparatus 110 continues to transmit the image data for the N + 1-th imaging (T7).

  As described above, the radiation imaging system 100 according to the present embodiment gives priority to the transmission of the arrival dose information when the transmission timing of the radiation image and the arrival dose information overlaps when performing continuous imaging or the like. Therefore, due to the delay in transmitting the arrival dose information, the period until the end of irradiation becomes longer, and it is possible to avoid irradiating the patient with excessive radiation. That is, the radiation imaging system 100 can suppress excessive radiation irradiation to the subject due to the delay in information transmission.

  A first modification of the present embodiment will be described. In the present embodiment, the CPU 301 controls to transmit the radiation information while prohibiting the transmission of the radiation image during the continuous imaging period. However, the CPU 301 may be controlled to transmit the irradiation information in preference to the transmission of the radiation image, and the specific processing for that is not limited to the embodiment. For example, the CPU 301 may permit the transmission of the radiation image during a period in which the irradiation information is not transmitted even during the imaging period.

  Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. A part of the above-described embodiments may be appropriately combined.

(Other examples)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

100 Radiation Imaging System 110 Radiation Imaging Device 120 Communication Control Device 130 Radiation Source 140 Radiation Generation Device

Claims (12)

A radiation imaging system comprising: a radiation imaging device that captures a radiation image that has passed through a subject due to radiation irradiation; and a communication control device that controls communication between the radiation generation device and the radiation imaging device,
The radiation imaging apparatus includes:
Communication means for communicating with the communication control device;
Communication control means for controlling the transmission of radiation information related to radiation irradiation in preference to the transmission of radiation images during the imaging period;
The communication control device includes:
A radiation imaging system comprising control means for controlling imaging of the radiation image based on the irradiation information.   The radiation imaging system according to claim 1, wherein the communication control unit controls transmission of the radiation information while prohibiting transmission of the radiation image during the imaging period.   3. The radiation imaging system according to claim 1, wherein the communication control unit performs control so as to interrupt transmission of the radiation image when the radiation image is transmitted during the imaging period. 4. .   The radiation imaging system according to claim 3, wherein the communication control unit controls to transmit the interrupted radiation image after the imaging period ends.   5. The radiation imaging system according to claim 1, wherein the communication control unit controls to transmit a radiographic image captured during the imaging period after the imaging period ends. 6.   6. The radiation imaging system according to claim 1, wherein the irradiation information is control information for automatic exposure of a radiation generator.   The radiation imaging system according to claim 1, wherein the irradiation information is arrival dose information of radiation that has reached the radiation imaging apparatus.   The radiation imaging system according to claim 1, wherein the imaging period includes a charge accumulation period related to radiation imaging.   The radiation imaging system according to claim 1, wherein the imaging period includes a radiation detection period. A radiation imaging apparatus that captures a radiation image that has passed through a subject by irradiation with radiation,
Communication means for communicating with a communication control device for controlling communication between the radiation generating device and the radiation imaging device;
A radiation imaging apparatus, comprising: a communication control unit configured to control transmission of radiation information related to radiation irradiation in preference to transmission of a radiation image during an imaging period. A communication control method executed by a radiation imaging system including: a radiation imaging apparatus that captures a radiation image that has passed through a subject due to radiation irradiation; and a communication control apparatus that controls communication between the radiation generation apparatus and the radiation imaging apparatus. There,
A communication step in which the radiation imaging apparatus communicates with the communication control apparatus;
A communication control step for controlling the radiation imaging apparatus to perform transmission of irradiation information related to radiation irradiation in preference to transmission of a radiation image during an imaging period;
The communication control apparatus includes a control step of controlling imaging of the radiation image based on the irradiation information. A computer of a radiation imaging apparatus that captures a radiation image that has passed through a subject by irradiation of radiation,
Communication means for communicating with a communication control device for controlling communication between the radiation generating device and the radiation imaging device;
A program for functioning as communication control means for controlling to transmit irradiation information related to radiation irradiation prior to transmission of a radiation image during an imaging period.

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