JP2016097115A - Radiographic imaging system, control method, control device, and computer program thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging technique of a radiographic image, the technique being capable of suitably controlling an exposure time of a radiation generation part and a charge accumulation time of a radiation detector according to a wireless communication environment to reduce a burden of a patient.SOLUTION: A radiation imaging system includes: generation means to generate radiation, the generation means being provided with wireless communication means; image acquisition means to convert the radiation from the generation means to an electrical charge to acquire an image, the image acquisition means being provided with wireless communication means; and control means to control operations of the generation means and the image acquisition means, the control means being provided with wireless communication means. The control means includes measurement means to measure a wireless communication environment, and determination means to determine on the basis of the wireless communication environment measured by the measurement means an operational mode for controlling a timing to store the electrical charge by the image acquisition means according to a timing of radiation from the generation means.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a radiation imaging system, a control method thereof, a control apparatus, and a computer program, and more particularly to a technique for shortening the time required for synchronous communication between a radiation generation unit and a radiation detector regardless of a wireless communication environment.

  At present, in the X-ray still image photographing system in the medical field, a film system in which a patient as a subject is irradiated with X-rays and the transmitted X-ray image is exposed on a film is mainly used. The film system has a function of displaying and recording information, can be enlarged in area, has high gradation, is lightweight, and is easy to handle, and thus is widely used all over the world. However, in the film system, in addition to the complexity that requires development processing, a place, manpower, and time are required for long-term storage and retrieval.

  In recent years, there has been an increasing demand for digitization of X-ray images, and instead of film, a radiographic apparatus that forms an image by converting radiation into an electrical signal by a plurality of radiation detection elements arranged in a two-dimensional matrix. It has been put into practical use. This type of radiation imaging apparatus uses an X-ray detector (FPD: Flat Panel Detector) in which solid-state imaging elements are arranged in a two-dimensional matrix and converts an X-ray dose into an electrical signal. According to the X-ray imaging apparatus having such an X-ray detector, since the X-ray image can be replaced with digital information, the image information can be confirmed instantaneously. Further, by transmitting digital data by radio, it is possible to connect the terminal for confirming an image and the FPD without a cable. Furthermore, since digital data can be transmitted far away without being degraded, for example, by transmitting X-ray image information, it is possible to receive advanced diagnosis by a large hospital while being far away. Become. Moreover, the storage space of the film in a hospital can be saved by not using a film.

  An X-ray detector (sensor) such as an FPD includes a photoelectric conversion circuit in which a plurality of photoelectric conversion elements that convert radiation into an electric signal are arranged in a matrix, and an electric signal obtained by this conversion. And a readout circuit for reading out from. When the subject is irradiated with X-rays, photoelectric conversion is performed on the transmitted X-rays transmitted through the subject in each photoelectric conversion element of the photoelectric conversion circuit, and signal charges corresponding to the transmitted X-ray dose are accumulated in each photoelectric conversion element. Is done. The readout circuit sequentially reads out the signal charges accumulated in each photoelectric conversion element as an electrical signal by driving each signal line of the photoelectric conversion circuit and appropriately controlling the switch element to which the photoelectric conversion element is connected, Amplify and output.

  In imaging using the FPD, it is necessary to synchronize the timing of X-ray exposure and charge accumulation in the photoelectric conversion element (synchronization), and communication between the FPD and the X-ray generator is indispensable. In general, wired communication is used for synchronous communication, and there are problems such as restrictions on installation of radiation generators and sensors, and the cost of wired cables. In order to solve such a problem, Patent Document 1 describes a configuration in which a synchronization signal is communicated wirelessly.

  In the case of shooting using a sensor, the image information can be confirmed instantaneously as described above. However, from the radiation exposure to the confirmation of image information, at least the time during which the sensor accumulates electric charge, the time during which the sensor accumulates electric charge to generate data for image correction, and the data transfer from the sensor to the image display device Time to analyze data, time to analyze data, etc. are required. For this reason, the shorter the time for which the sensor accumulates charges, the shorter the time from when the radiation is exposed until the image is displayed. The time for which the sensor accumulates electric charges can be made substantially equal to the radiation irradiation time because the sensor can receive the irradiation start and the irradiation end by communication in the case of synchronization.

  Radiation imaging is performed not only in a hospital radiography room, but also with a battery, and the radiation generator is mounted on a movable carriage so that it can be moved to a patient room that is difficult to move. There are also photographing methods such as photographing (round-trip photographing). The radiation generating apparatus used in such a situation is called a roundabout car. Since many patients photographed using a round-the-wheel vehicle are difficult to move as described above, they are photographed with a film inserted on the back in a supine state. Currently, many hospitals have round-trip cars, many of which use films as described above. Furthermore, instead of film, CR (Computed Radiography) is also widely used to irradiate an imaging plate (IP) such as a stimulable phosphor sheet with radiation, digitally read the image formed on the IP, and form a digital image. It has been. CR is distinguished from DR (Digital Radiography) that directly forms a digital image like FPD in that a digital image is obtained by digitally converting an analog image formed on IP. In filming and CR using a film, the above-described synchronization is not necessary, and there is no need to communicate between the radiation generator and the film or IP that detects radiation. As described above, since the film and CR are handled in a similar manner, they are used in the same meaning in this specification.

  In recent years, there has been a strong demand for hospitals to use the radiation generation part of a round-trip car using a film as it is for the management activities (cost reduction) in the hospital, and to make only the film part into FPD (digitalization). In order to make only the film part FPD, synchronization is necessary as described above, and some kind of treatment is required for the radiation generator already possessed. However, in Japan, it is not permitted to make changes to medical devices for the operator's intention. In consideration of such circumstances, it is known to detect the current flowing through the bias line of the FPD and automatically detect the start and end of radiation irradiation (Patent Document 2).

JP 2006-25832 A JP 2010-121944 A

  However, in the configuration of Patent Document 1, since wireless is used for communication, there is a problem that communication is delayed when the wireless environment is bad (interference or the like), and the start and end of radiation exposure are not accurately transmitted. .

  Moreover, if the structure of patent document 2 is presupposed, there exists a subject that the process which adjusts operation | movement of a sensor according to operation | movement of a radiation generator takes time. In the automatic detection mode, since the radiation generator and the sensor do not communicate with each other, the sensor does not directly receive the notification of the start / end of irradiation. That is, the configuration of Patent Document 2 automatically detects the start of irradiation, but is not clearly notified from the radiation generator. Moreover, it is actually difficult to detect the end of irradiation once the accumulation of electric charges is started due to the principle of the sensor. For this reason, it is difficult to make the sensor accumulation time equal to the radiation exposure time. Therefore, in the automatic detection mode, it is possible to set the sensor accumulation time to a fixed time longer than the standard radiation exposure time so that charge accumulation does not end during radiation irradiation in most use cases. Widely done. For this reason, when comparing the synchronous mode in which the sensor can receive the start and end of radiation irradiation and the automatic detection mode, the time from radiation irradiation until image display is generally shortened. The synchronization mode that can be used is shorter. This tendency is particularly noticeable for irradiation with a short exposure time.

  However, in a medical field, it is painful for a patient with a curved spine to hit a film or a sensor on the back, and it is required to shorten the insertion time of the film as much as possible. In particular, in photographing using a sensor, the image can be confirmed on the spot, and therefore the sensor is often not removed until it is confirmed that the image is confirmed and re-photographing is not necessary. However, in photographing using the automatic detection mode, as described above, the time until image display, that is, the time that the sensor is in contact with the patient's back is long, and the time that causes pain to the patient is long. As described above, in the configuration of Patent Document 2, it takes time to display the preview image and the diagnostic image as compared with the case in the synchronous mode as described above, and the time that the FPD is in close contact with the body increases. Cause pain to the patient.

  The present invention has been made in view of the above problems, and appropriately controls the exposure time of the radiation generation unit and the charge accumulation time of the radiation detector according to the environment of wireless communication, thereby reducing the burden on the patient. It is possible to provide a radiographic imaging technique that can be used.

In order to achieve the above object, a radiation imaging system according to the present invention comprises the following arrangement. That is,
Generating means for generating radiation, comprising wireless communication means;
An image acquisition means comprising a wireless communication means for acquiring an image by converting the radiation emitted from the generation means into an electric charge;
Control means comprising wireless communication means for controlling the operation of the generating means and the image obtaining means,
The control means includes
A measuring means for measuring a wireless communication environment;
Determining means for determining an operation mode for controlling the timing at which the image acquiring means accumulates charges in accordance with the timing at which radiation is generated by the generating means, based on the wireless communication environment measured by the measuring means; .

  According to the present invention, there is provided a radiographic imaging technique capable of reducing the time required for the synchronous communication between the radiation generation unit and the radiation detector and reducing the burden on the patient regardless of the wireless communication environment. Can be provided.

1 is a block diagram showing a configuration of an X-ray imaging system. The flowchart which shows the operation mode determination procedure of a X-ray imaging system. Timing chart in synchronized shooting mode Timing chart in automatic detection mode Timing chart in semi-automatic detection mode The connection diagram of a radiation imaging system.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, an X-ray imaging system that acquires an X-ray image as a radiation image by performing imaging using X-rays as radiation will be described as an example.

(System configuration)
FIG. 1 is a block diagram illustrating an example of a schematic configuration of a radiation imaging system according to the present embodiment. As shown in FIG. 1, the radiation imaging system 10 according to the present embodiment includes a radiation generation unit 1, a radiation image acquisition unit 2, and a control unit 3. The radiation generation unit 1 has a first communication unit 103, the radiation image acquisition unit 2 has a second communication unit 201, and the control unit 3 has a third communication unit 301, which communicate with each other wirelessly. be able to. In FIG. 1, in order to communicate information between the radiation generation unit 1 (first communication unit 103) and the radiation image acquisition unit 2 (second communication unit 201), the control unit 3 (third The example of a structure via the communication part 301) is shown. However, each of them directly communicates independently or, for example, the radiation generating unit 1 (first communication unit) is used for communication between the radiation image acquisition unit 2 (second communication unit) and the control unit 3 (third communication unit). The communication unit) may be set. Further, communication between the radiation generation unit 1 (first communication unit) and the control unit 3 (third communication unit) may be set so as to pass through the radiation image acquisition unit 2 (second communication unit). . The communication path is determined by the size of each device, the planned installation location, the operator's request, and the like. The first communication unit 103, the second communication unit 201, and the third communication unit 301 are realized by a wireless LAN antenna or the like. In the present embodiment, communication between apparatuses is performed by a wireless LAN, but other wireless communication methods such as Bluetooth (registered trademark) may be used.

  The radiation generation unit 1 is a component that emits radiation (X-rays) 106 toward the radiation image acquisition unit 2. In addition to the first communication unit 103, the radiation generation unit 1 includes an exposure condition setting unit 101, an exposure timing setting unit 102, a radiation exposure unit 104, and an exposure switch 105. The exposure condition setting unit 101 sets an exposure condition such as a tube voltage, a tube current, an exposure time, a product of the tube current and the exposure time, and the like by an operator's operation. The set exposure conditions are transmitted to the communication unit 103, the radiation exposure unit 104, and the like. The exposure condition setting unit 101 is realized by a user interface such as a touch panel and a keyboard.

  The exposure timing setting unit 102 determines the exposure timing of the radiation 106 according to the operation on the exposure switch 105, generates an exposure start signal, an exposure end signal, information indicating timing, and the like. It transmits to the exposure unit 104 and the first communication unit 103. The exposure timing setting unit 102 is realized by an arithmetic processing unit such as a CPU (central processing unit), a memory such as a RAM (writable memory), a ROM (read only memory), etc., but is realized by a dedicated arithmetic unit. Also good. The CPU controls the apparatus based on the computer program.

  The radiation exposure unit 104 emits the radiation 106 toward the radiation image acquisition unit 2 in response to receiving the exposure start signal from the exposure timing setting unit 102. The radiation exposure unit 104 is realized by a radiation tube or the like that emits radiation. The exposure switch 105 receives an instruction to start exposure from the operator. When an instruction from the operator is received, a signal indicating that is output to the exposure timing setting unit 102. The exposure switch 105 is constituted by a mechanical switch such as a button or a lever, but may be realized by a touch panel or the like.

  The radiation image acquisition unit 2 is a component that detects radiation emitted from the radiation generation unit 1 and passes through a human body as a subject, and forms and acquires a radiation image. In addition to the second communication unit 201, the radiation image acquisition unit 2 includes an exposure condition processing unit 202, an exposure timing processing unit 203, a radiation image acquisition control unit 204, and a radiation detection unit 205.

  The exposure condition processing unit 202 receives information indicating the exposure timing set in the exposure timing setting unit 102 of the radiation generation unit 1 via the second communication unit 201, reads out the exposure time and the like, and reads the radiation image. It transmits to the acquisition control unit 204. The exposure timing processing unit 203 receives information indicating the start or end of radiation exposure from the radiation exposure unit 104 of the radiation generation unit 1, and transmits the information to the radiation image acquisition control unit 204 or acquires a radiation image. Or memorize the accumulation time. The radiation image acquisition control unit 204 is based on the exposure time transmitted from the exposure condition processing unit 202 and the information on the start / end of exposure transmitted from the radiation image acquisition control unit 204. Control overall operation. The exposure condition processing unit 202, the exposure timing processing unit 203, and the radiation image acquisition control unit 204 are realized by an arithmetic processing unit such as a CPU and a memory such as a RAM and a ROM, but each is realized by a dedicated arithmetic unit. May be. The CPU controls the apparatus based on the computer program.

  The radiation detection unit 205 accumulates the radiation 106 emitted from the radiation exposure unit 104 as an electric charge, and reads the amount for each pixel to acquire an image. The radiation detection unit 205 includes photoelectric conversion elements arranged in a matrix.

  The control unit 3 controls operations of the radiation generation unit 1 and the radiation image acquisition unit 2. In addition to the third communication unit 301, the control unit 3 includes an image display unit 302, a communication control unit 304, a communication state monitoring unit 305, a shooting mode determination unit 306, and a shooting request / permission unit 307. The image display unit 302 receives the image acquired by the radiation image acquisition unit 2 through the third communication unit 301, performs image processing, and displays the image to the operator. The image display unit 302 can be realized by a display device such as a liquid crystal panel.

  The communication control unit 304 analyzes communication from the first communication unit 103 and the second communication unit 201, and transmits information from the first communication unit to the second communication unit or information transmitted from the second communication unit 201. Information to be transmitted to the first communication unit 103 is allocated to the target communication unit. The communication state monitoring unit 305 measures the wireless intensity between the first communication unit 103, the second communication unit 201, and the third communication unit 301, and determines the wireless environment in which the radiation imaging system 10 is placed. to decide. The communication state monitoring unit 305 measures communication parameters such as wireless strength, transfer rate, and packet loss rate based on the wireless signal detected by the antenna of the third communication unit 301. The imaging mode determination unit 306 determines the operation mode of the radiation image acquisition unit 2 based on the wireless environment determined by the communication state monitoring unit 305. The communication control unit 304, the communication state monitoring unit 305, and the shooting mode determination unit 306 are realized by an arithmetic processing unit such as a CPU, a memory such as a RAM and a ROM, but may be realized by dedicated arithmetic units. The CPU controls the apparatus based on the computer program.

  The shooting request / permission unit 307 receives a shooting request from the operator or informs the operator that shooting is permitted. The photographing request / permission unit 307 can be realized by a user interface such as a touch panel.

  The radiation imaging system 10 of this embodiment adjusts the timing of radiation exposure of the radiation generation unit 1 and radiation image acquisition (charge accumulation) of the radiation image acquisition unit 2 by a method selected according to the wireless communication environment. Do. For this reason, it is possible to minimize the time for setting the radiological image acquisition unit 2 on the patient side and making it ready for imaging in accordance with the wireless communication environment, thereby reducing the burden on the patient. .

(Shooting mode decision processing)
FIG. 2 is a flowchart illustrating the processing procedure of the shooting mode determination process. First, the communication state is confirmed using the communication state monitoring unit 305 (S201), and the communication environment is determined based on the communication state (S202). Specifically, communication parameters indicating a wireless communication environment such as wireless strength, transfer rate, and packet loss rate are compared with a preset threshold value to determine whether or not the communication state is good. In this embodiment, the communication state is classified into three stages: good, delayed, and bad. “Good” is a case where the value indicating the state of wireless communication is in the first range and it is determined that communication without delay is possible in the wireless communication environment. “With delay” is a case where it is determined that communication including a delay is possible in a wireless communication environment. “Evil” is a case where a value indicating the state of wireless communication is in the second range, and it is determined that transmission of information is difficult in a wireless communication environment.

  When it is determined that the communication environment is good and all information is transmitted without delay (“good” in S202), a synchronization mode (synchronization between radiation exposure and charge accumulation (image acquisition) via wireless communication) (Synchronous shooting mode) is selected (S203). When wireless communication is possible, but wireless communication cannot be used for communication that requires strict timing, that is, when it is determined that a delay occurs (“delayed” in S202), the semi-automatic detection mode is set. Select (S204). The semi-automatic detection mode is an operation mode in which the radiation image acquisition unit 2 starts charge accumulation by detecting radiation and continues charge accumulation for a time corresponding to the exposure time notified from the radiation generation unit 1. When it is determined that the wireless state is poor and the only communication that can be guaranteed is to transmit the captured image (“bad” in S202), charge accumulation is started by detecting radiation, and the charge is charged for a preset time. The automatic detection mode for continuing the accumulation is selected (S205). Although not shown in FIG. 2, when the wireless environment is so bad that it is difficult to perform wireless communication, the operator may be prompted to make a wired connection. Hereinafter, each of the synchronous mode, the semi-automatic detection mode, and the automatic detection mode will be described with reference to FIGS. FIG. 3 is a timing chart showing the processing timing of each component in the synchronous mode. FIG. 4 is a timing chart showing the processing timing of each component in the automatic detection mode. FIG. 5 is a timing chart showing the processing timing of each component in the semi-automatic detection mode.

  First, operations common to all modes will be described. In this embodiment, the processes of TC309, TC301, TC310, and TC311 in FIG. 3, TC505, TC501, TC507, and TC508 in FIG. 4 and TC605, TC601, TC607, and TC608 in FIG. 5 are common to all modes. First, according to the flow of FIG. 2, the control unit 3 confirms the radio wave status of the radiation imaging system 10 using the communication state monitoring unit 305 and the imaging mode determination unit 306 (S201), and determines the imaging mode. Then, the control unit 3 sets the radiation image acquisition control unit 204 to the determined mode through the third communication unit 301 and the second communication unit 201 (S203 to S205).

  In common with all modes, the operator uses the exposure condition setting unit 101 of the radiation generating unit 1 to set the exposure condition (tube voltage, tube current, exposure time, product of tube current and exposure time, etc. ) Is set (TC309, TC505, TC605). As the exposure condition, a default value may be set in advance. The set information is transmitted to the radiation exposure unit 104, and each exposure condition is set. Next, the operator operates the imaging request / permission unit 307 of the control unit 3 to make a request for radiation imaging. When a request for imaging is issued from the control unit 3 (TC301, TC501, TC601), the radiographic image acquisition control unit 204 that receives the request performs imaging so that the radiographic image acquisition unit 2 can capture a radiographic image. Preparation is performed (TC310, TC507, TC607). In preparation for imaging, the radiation detection unit 205 performs various initial settings for image acquisition. It should be noted that a configuration that does not require preparation for photographing may be employed (not shown). When the preparation for imaging is completed, the radiographic image acquisition unit 2 transmits the imaging ready state to the control unit 3 through the second communication unit 201 and the third communication unit 301, and the imaging request / permission unit 307 is transmitted. To inform the operator that exposure is possible (TC311, TC508, TC608).

(Synchronous mode)
Next, operations unique to each mode will be described. First, the synchronization mode of S203 will be described with reference to FIG. 1, FIG. 3, and FIG. FIG. 6 is a connection diagram schematically showing an imaging situation in the radiation imaging system 10. In the synchronization mode, a signal indicating the start and end of radiation exposure is transmitted from the radiation generation unit 1 to the radiation image acquisition unit 2, thereby synchronizing the operation of generating radiation and the operation of detecting radiation and accumulating charges. It is a mode that takes.

  In the synchronous mode, from the viewpoint of safety, when the exposure switch 105 of FIG. 6 is pressed when the radiographic image acquisition unit 2 is not in an X-ray imaging enabled state, X-ray exposure is not permitted (not shown). ). The radiological image acquisition unit 2 in the X-ray radiographable state is configured so that the exposure timing setting unit 102 emits radiation when the exposure switch 105 is pressed by an operator who has given permission for exposure. 104 is instructed. The radiation exposure unit 104 emits radiation in response to receiving an instruction to perform exposure from the exposure timing setting unit 102 (TC308). Simultaneously with the radiation exposure, the start of radiation exposure is transmitted to the third communication unit 301 of the control unit 3 through the first communication unit 103, and the exposure timing process is performed through the second communication unit 201 of the radiation image acquisition unit 2. The unit 203 is also informed of the start of radiation exposure (TC303). When receiving the radiation exposure start instruction as described above, the radiation image acquisition control unit 204 shifts the radiation image acquisition unit 2 from the X-ray imaging available state to the image acquisition state, and acquires a radiation image (TC312). .

  When the exposure ends, the radiation generation unit 1 transmits an exposure end signal from the exposure timing setting unit 102 to the exposure timing processing unit 203 (TC304). The transmission of the exposure end signal is performed via the first communication unit 103, the third communication unit 301 of the control unit 3, and the second communication unit 201 of the radiation image acquisition unit 2. Upon receiving the exposure end signal, the exposure timing processing unit 203 notifies the radiation image acquisition control unit 204 of the end of exposure, and shifts the radiation image acquisition unit 2 from the image acquisition state to the image transfer state. The exposure timing processing unit 203 stores the accumulation time (T1) when the radiation image is acquired. This accumulation time (T1) is a time when the radiation detection unit 205 receives photoelectric conversion when acquiring a radiation image.

  The radiation image acquisition control unit 204 transmits the captured image to the image display unit 302 of the control unit 3 through the second communication unit 201 and the third communication unit 301 of the control unit 3. The control unit 3 performs image processing on the transferred image, and controls to display a preview image for confirming whether the region intended by the operator has been imaged or whether re-imaging is necessary (TC305). . After the image transfer, the radiological image acquisition unit 2 shifts to a correction image acquisition operation for generating an image used for diagnosis (TC313). The radiographic image acquisition control unit 204 receives the accumulation time (T1) when the radiographic image is acquired from the exposure timing processing unit 203, and controls the radiographic image acquisition unit 2 to acquire the correction image at the same accumulation time. To do. Note that charge accumulation due to dark current may not be performed. When the correction image is acquired at TC 313, the correction image is transferred to the control unit 3. In response to this, the image display unit 302 generates an image to be used for diagnosis by performing image processing using the already transferred radiation image and the newly transferred correction image, and notifies the operator of the diagnostic image. Is displayed (TC306).

  As described above, in the synchronous mode, in consideration of the fact that the communication environment is good and signals can be transmitted and received with almost no delay, radio signals are transmitted for the start / end of radiation exposure and the start / end of radiation image acquisition (charge accumulation). Synchronize by sending and receiving. For this reason, it is possible to minimize the time during which the radiological image acquisition unit 2 is installed on the patient side so as to be ready for imaging, and the burden on the patient can be minimized.

(Automatic detection mode)
Next, the automatic detection mode of S205 will be described with reference to FIG. 1, FIG. 4, and FIG. In the automatic detection mode, the radiation image acquisition unit 2 in the imaging preparation state is irradiated with radiation from the radiation generation unit 1. When the radiation image acquisition unit 2 detects the radiation, the radiation image is converted into electric charges and the radiation image is converted. This is an operation mode in which the acquisition process is continued for a certain period of time.

  In the automatic detection mode, the only communication that can be guaranteed is to transmit a captured image, so the subsequent wireless communication is not performed until image transfer. The operator who confirms that the above-described processing is performed and preparation for imaging is completed presses the exposure switch 105 in FIG. 6 to expose the radiation 106 (TC506). At this time, the control unit 3 and the radiation image acquisition unit 2 are not notified that radiation has been exposed. The radiation image acquisition unit 2 has a mechanism for detecting that radiation has been irradiated. When the radiation detection unit 205 detects that radiation has been exposed, the radiation detection unit 205 notifies the radiation image acquisition control unit 204 of that fact, shifts the radiation image acquisition unit 2 to the radiation image acquisition state, and acquires a radiation image ( T509). In the radiological image acquisition unit 2 set to the automatic detection mode, the exposure timing processing unit 203 cannot know the end of the exposure, so the accumulation time (T4) at the time of radiographic image acquisition is always constant as described above. Set to This accumulation time can be set to a longer time with a margin than the general exposure time.

  Thereafter, the same processing as in the synchronous mode is performed. That is, the radiation image acquisition control unit 204 transmits the captured image to the image display unit 302 through the second communication unit 201 and the third communication unit 301 of the control unit 3. The image display unit 302 performs image processing on the received image, and displays a preview image for confirming whether the region intended by the operator has been imaged or whether re-imaging is necessary (TC503). After the image transfer, the radiological image acquisition unit 2 proceeds to a correction image acquisition operation for generating an image used for diagnosis. The radiographic image acquisition control unit 204 controls the radiographic image acquisition unit 2 so as to acquire a correction image in a predetermined fixed accumulation time (T4) similar to that when the radiographic image is captured (TC510). The correction image acquired by the radiation image acquisition unit 2 is transferred to the image display unit 302 through the second communication unit 201 and the third communication unit 301 of the control unit 3. The image display unit 302 performs image processing using the already transferred radiographic image and the newly transferred correction image to generate an image used for diagnosis, and displays the diagnostic image to the operator. (TC504).

  As described above, in the automatic detection mode, taking into account that wireless communication is difficult, radiation image acquisition (charge accumulation) is started in response to detection of radiation, and radiation image acquisition is continued for a predetermined time. Form an image. For this reason, radiography can be performed even in a situation where wireless communication is difficult.

(Semi-automatic detection mode)
Next, the semi-automatic detection mode of S204 will be described with reference to FIGS. In the semi-automatic detection mode, in view of the fact that the communication timing is not guaranteed, the radiation image acquisition unit 2 in the imaging preparation state is irradiated with radiation from the radiation generation unit 1, and the radiation image acquisition unit 2 performs radiation according to the radiation detection. Start image acquisition (charge accumulation). In the semi-automatic detection mode, information indicating the exposure condition including the exposure time is transmitted from the radiation generation unit 1 to the radiological image acquisition unit 2 before the radiation irradiation, and the radiological image acquisition unit 2 determines the exposure time. A process of acquiring a radiographic image for a corresponding time is performed.

  In the semi-automatic detection mode, the exposure condition information set by the operator is transmitted to the radiation exposure unit 104, and each exposure condition is set. At the same time, information that indicates that the communication is directed to the radiation image acquisition unit 2 is transmitted to the control unit 3 through the first communication unit 103 and the third communication unit 301 together with the exposure condition information (TC601). ). In the control unit 3, the communication control unit 304 detects that communication from the radiation generation unit 1 is communication directed to the radiation image acquisition unit 2. Further, the control unit 3 transmits the information set by the exposure condition setting unit of the radiation generation unit 1 through the third communication unit 301 and the second communication unit 201 to the exposure condition processing unit of the radiation image acquisition unit 2. It transmits to 202 (TC607).

  The exposure condition processing unit 202 reads the exposure time from the received exposure condition and transmits it to the radiation image acquisition control unit 204. The radiological image acquisition control unit 204 that has received the exposure time sets a radiography accumulation time based on the received exposure time. When an operator makes an imaging request through the imaging request / permission unit 307 of the control unit 3 (TC602), the radiographic image acquisition control unit 204 of the radiographic image acquisition unit 2 transmits to the third communication unit 301 and the second communication unit 201. An instruction is given to prepare for shooting (TC607). Upon receiving the instruction, the radiographic image acquisition control unit 204 sets the radiographic image acquisition unit 2 in a state where radiographic images can be captured, and the fact that the radiographic image acquisition unit 2 is ready for imaging is transmitted through the second communication unit 201 and third communication unit 301. Tell the control unit 3. Further, the imaging request / permission unit 307 is used to inform the operator that exposure may be performed (TC602). Furthermore, when the radiation image acquisition unit 2 is ready for imaging and the exposure condition setting unit 101 of the radiation generation unit 1 is operated and the exposure condition is changed, the above-described operation is performed to acquire the radiation image again. The accumulation time of the radiological image acquisition control unit 204 of the unit 2 is set. By performing the processing in this manner, the accumulation time set in the radiation image acquisition control unit 204 can always be the latest.

  As described above, wireless communication is possible in the semi-automatic detection mode, but wireless communication cannot be used for communication that requires strict timing, that is, it is determined that a delay will occur. Is not performed until image transfer. When the operator depresses the exposure switch 105, the radiation 106 is emitted from the radiation exposure unit 104 (TC606). When the radiation detection unit 205 of the radiation image acquisition unit 2 detects that the radiation has been exposed, the radiation detection unit 205 notifies the radiation image acquisition control unit 204 to that effect, and shifts the radiation image acquisition unit 2 to the radiation image acquisition state. An image is acquired (TC609). In the radiological image acquisition unit 2 set to the automatic detection mode, the exposure timing processing unit 203 cannot know the end of the exposure, so the accumulation time at the time of radiographic image acquisition is set in advance as described above. Storage time (T7).

  The radiation image acquisition control unit 204 transmits the captured image to the image control unit through the second communication unit 201 and the third communication unit 301 of the control unit 3. The image display unit 302 performs image processing on the received image, and displays a preview image for confirming whether the region intended by the operator has been imaged or whether re-imaging is necessary (TC603). After the image transfer, the radiological image acquisition unit 2 proceeds to a correction image acquisition operation for generating an image used for diagnosis. The radiographic image acquisition control unit 204 controls the radiographic image acquisition unit 2 so as to acquire the correction image with the same accumulation time as when the radiographic image was captured (TC610). The correction image acquired by the radiation image acquisition unit 2 is transferred to the image display unit 302 through the second communication unit 201 and the third communication unit 301 of the control unit 3. The image display unit 302 performs image processing using the already transferred radiographic image and the newly transferred correction image to generate an image used for diagnosis, and displays the diagnostic image to the operator (TC603). ).

  Thus, in the semi-automatic detection mode, the radiation conditions including the exposure time are transmitted from the radiation generation unit 1 to the radiation image acquisition unit 2, and the radiation image acquisition unit 2 continues to acquire the radiation image for a time corresponding to the exposure time. To do. For this reason, especially in the case of shooting when the exposure time is short, the time from exposure to preview image display (T5 in FIG. 4) and the time from exposure to diagnosis image display (T6 in FIG. 4) are charged. It is possible to shorten the accumulation time compared to the fixed automatic detection mode. That is, T5 ≧ T7 and T6 ≧ T9. Note that in the synchronous mode and the semi-automatic synchronous mode, the accumulation time is set longer in the semi-automatic synchronous mode even if the exposure time is the same, so the preview display time and diagnostic image display time are the same as in the synchronous mode. Often shorter. When the relationship between the display time of the preview image and the display time of the diagnostic image is summarized, T5 ≧ T7 ≧ T2 and T6 ≧ T9 ≧ T3.

  As described above, the control unit 3 according to the present embodiment controls the timing at which the radiation image acquisition unit 2 accumulates charges in accordance with the timing at which radiation is generated by the radiation generation unit 1 based on the measured wireless communication environment. To determine the operation mode. For this reason, it is possible to optimally control the radiation exposure time of the radiation generation unit 1 and the charge accumulation time of the radiation image acquisition unit 2 according to the wireless communication environment, and it is possible to shorten the radiographic imaging. In the semi-automatic detection mode, every time the radiation generation condition is changed, the radiation generation time is notified from the radiation generation unit 1 to the radiation image acquisition unit 2 by a radio signal, so that the charge accumulation by the radiation image acquisition unit 2 is performed. Can keep the time optimal.

  As described above, according to the embodiment of the present invention, it is possible to select an optimal imaging mode according to the wireless environment, and it is possible to provide a radiographic image capturing system with less burden on the patient.

<< Other Embodiments >>
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

1: Radiation generation unit, 103: First communication unit, 2: Radiation image acquisition unit, 201: Second communication unit, 3: Control unit, 301: Third communication unit

Claims (10)

Generating means for generating radiation, comprising wireless communication means;
An image acquisition means comprising a wireless communication means for acquiring an image by converting the radiation emitted from the generation means into an electric charge;
Control means comprising wireless communication means for controlling the operation of the generating means and the image obtaining means,
The control means includes
A measuring means for measuring a wireless communication environment;
Determining means for determining an operation mode for controlling the timing at which the image acquiring means accumulates charges in accordance with the timing at which radiation is generated by the generating means, based on the wireless communication environment measured by the measuring means; A radiation imaging system.   In the case where the value indicating the state of the wireless communication is in the first range, the determining unit is configured to receive the wireless signal indicating the start and end of radiation generation from the generating unit. The radiation imaging system according to claim 1, wherein an operation mode for starting and ending charge accumulation is determined.   When the value indicating the state of the wireless communication is in the second range, the determination unit starts charge accumulation in response to detection of radiation by the image acquisition unit, and accumulates charge after a predetermined time. The radiation imaging system according to claim 1, wherein an operation mode to be ended is determined.   When the determination unit determines that communication including a delay is possible in the wireless communication environment, the generation unit notifies the image acquisition unit of the generation time of the radiation by a wireless signal, and the image acquisition unit 4. The method according to claim 1, wherein charge accumulation is started in response to detection of radiation, and an operation mode for ending charge accumulation is determined after a time corresponding to the generation time. The radiation imaging system described.   The radiation imaging system according to claim 4, wherein the radiation generation time is notified each time the radiation generation condition is changed.   6. The determination unit according to claim 1, wherein the determination unit determines the operation mode by comparing a communication parameter indicating a wireless communication environment measured by the measurement unit with a preset threshold value. The radiation imaging system according to item 1.   The radiation imaging system according to claim 1, further comprising a display control unit that causes the display unit to display an image acquired by the image acquisition unit. A control device that controls the operation of an image acquisition unit that includes a wireless communication unit that includes a wireless communication unit and generates radiation, and a wireless communication unit that converts the radiation emitted from the generation unit into an electric charge to acquire an image. And
A measuring means for measuring a wireless communication environment;
Determining means for determining an operation mode for controlling the timing at which the image acquiring means accumulates charges in accordance with the timing at which radiation is generated by the generating means based on the wireless communication environment measured by the measuring means; A control device characterized by that. Generating means for generating radiation, comprising wireless communication means;
An image acquisition means comprising a wireless communication means for acquiring an image by converting the radiation emitted from the generation means into an electric charge;
A control method for a radiation imaging system, comprising: a control means comprising a wireless communication means for controlling operations of the generating means and the image obtaining means,
A measuring step in which the measuring means of the control means measures a wireless communication environment; and
An operation for the determining means of the control means to control the timing at which the image acquiring means accumulates charges in accordance with the timing at which radiation is generated by the generating means, based on the wireless communication environment measured in the measuring step. A control method for the radiation imaging system, comprising: a determining step for determining a mode.   The computer program for functioning a computer as a control means with which the radiation imaging system of any one of Claim 1 to 7 is provided.

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