Radiographic apparatus, control method thereof, control apparatus, control method thereof, radiographic system, and program

Abstract

To provide a technology to execute radiation irradiation stop control with a high degree of precision.SOLUTION: A radiographic apparatus includes: a sensor part 121 for detecting a dose of an incident radiation R as an electric signal; a control part 122 for executing control to change a sampling interval for acquiring the electric signal detected by the sensor part 121 to a second sampling interval shorter than a first sampling interval on the basis of an accumulated value of electric signals detected by the sensor part 121 and acquired by the first sampling interval and a threshold on the irradiation stop of the radiation R; and a communication part 123 for outputting an irradiation stop signal 101 on the irradiation stop of the radiation R when the accumulated value of the electric signals detected by the sensor part 121 reaches the threshold.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a radiation imaging apparatus and a control method thereof, a control apparatus and a control method thereof, a radiation imaging system, and a program.

Background Art

[0002] Currently, as a radiation imaging apparatus used for medical image diagnosis and non-destructive inspection by radiation such as X-rays, a radiation imaging apparatus equipped with a flat panel detector (FPD), which is an example of a sensor unit formed of a semiconductor material, has become widespread. Such a radiation imaging apparatus is used, for example, as a digital radiation imaging apparatus that performs still image imaging such as general imaging or moving image imaging such as fluoroscopy in medical image diagnosis.

[0003] Some radiation imaging apparatuses monitor the dose (cumulative dose) of irradiated radiation and stop the radiation irradiation when the cumulative dose reaches a threshold value (for example, output an irradiation stop signal for stopping the radiation irradiation to a radiation generator). This operation is called automatic exposure control (AEC), and by this, for example, over-irradiation of radiation can be prevented.

[0004] As such a radiation imaging apparatus, for example, Patent Document 1 discloses a radiation imaging apparatus including a dose detection unit that detects the dose of radiation reaching an imaging region as a dose detection signal within the imaging region of an FPD. In this Patent Document 1, based on the dose detected by the dose detection unit and a preset dose target value, the stop timing at which the radiation irradiation should be stopped in the radiation generator is predicted. And in Patent Document 1, an irradiation stop timing notification for notifying the radiation generator of the radiation irradiation stop timing is transmitted before the irradiation stop timing arrives.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 2013-138829 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] However, in the technique described in Patent Document 1, there is a problem in the accuracy of the irradiation stop control of the radiation from the radiation generator. In the technique described in Patent Document 1, regarding the transmission time of the irradiation stop timing notification, variations may occur due to the sampling interval of the electrical signal generated in the sensor unit by the irradiation of the radiation. Further, if the sampling interval of the electrical signal generated in the sensor unit by the irradiation of the radiation is simply shortened, the offset error of the electrical signal generated by the irradiation of the radiation accumulates and the accuracy of the irradiation stop control of the radiation deteriorates.

[0007] The present disclosure has been made in view of such problems, and an object thereof is to provide a technique capable of performing irradiation stop control of radiation with high accuracy. MEANS FOR SOLVING THE PROBLEMS

[0008] The radiation imaging apparatus of the present disclosure includes a sensor unit that detects the dose of incident radiation as an electrical signal, an accumulated value of the electrical signal obtained by acquiring the electrical signal detected by the sensor unit at a first sampling interval, and a threshold value related to the irradiation stop of the radiation, and a control unit that performs control to change the sampling interval for acquiring the electrical signal detected by the sensor unit to a second sampling interval shorter than the first sampling interval, and an output unit that outputs a signal related to the irradiation stop of the radiation when the accumulated value of the electrical signal detected by the sensor unit reaches the threshold value. The control device of the present disclosure acquires an electrical signal related to the dose of incident radiation detected by a radiation imaging device, based on the cumulative value of the electrical signal acquired at a first sampling interval and a threshold related to the stop of radiation irradiation, and changes the sampling interval for acquiring the electrical signal detected by the radiation imaging device to a second sampling interval shorter than the first sampling interval. The control device includes a control unit that performs control, and an output unit that outputs a signal related to the stop of radiation irradiation when the cumulative value of the electrical signal reaches the threshold.

Advantages of the Invention

[0009] According to the present disclosure, radiation irradiation stop control can be performed with high accuracy.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments for implementing the present disclosure will be described with reference to the drawings. In this specification, as the radiation according to the present disclosure, it is preferable to use X-rays, but it is not limited to this X-ray, and α-rays, β-rays, γ-rays, etc. are also included.

[0012] (First Embodiment) First, the first embodiment will be described.

[0013] FIG. 1 is a diagram showing an example of the schematic configuration of a radiation imaging system 100 according to the first embodiment. In the present embodiment, the radiation imaging system 100 is particularly preferably used for medical purposes. As shown in FIG. 1, the radiation imaging system 100 includes a radiation generator 110, a radiation imaging device 120, and a control device 130.

[0014] The radiation generator 110 irradiates the subject H and the radiation imaging device 120 (more specifically, the sensor unit 121) with radiation R based on the control of the control device 130 (more specifically, the imaging control unit 131). The radiation generator 110 includes an X-ray tube that is a radiation generation unit that generates the radiation R, and a collimator that defines the spread angle of the beam of the radiation R generated by the X-ray tube.

[0015] The radiation imaging device 120 performs radiation imaging of the subject H. As shown in FIG. 1, the radiation imaging device 120 includes a sensor unit 121, a control unit 122, and a communication unit 123.

[0016] The sensor unit 121 is composed of, for example, an FPD, and includes an imaging element (which may also be an imaging pixel) and a dose detection element (which may also be a dose detection pixel). This sensor unit 121 detects the radiation R irradiated from the radiation generating device 110 and incident thereon (including the radiation R that has passed through the subject H). Here, in the present embodiment, the imaging elements are two-dimensionally distributed and arranged over the entire incident surface of the sensor unit 121 where the radiation R is incident, and detect the incident radiation R as an electrical signal (image signal) related to radiation image data. Also, in the present embodiment, the dose detection elements are distributed and arranged in a predetermined region of interest on the incident surface of the sensor unit 121 where the radiation R is incident, and detect the dose of the incident radiation R as an electrical signal (dose detection signal) related to the dose of the radiation R.

[0017] The radiation imaging apparatus 120 generates radiation image data based on the electrical signal (image signal) detected by the imaging elements of the sensor unit 121. Thereafter, the radiation imaging apparatus 120 transmits the generated radiation image data to the control device 130 via the communication unit 123.

[0018] The control unit 122 comprehensively controls the operation of the radiation imaging apparatus 120. As shown in FIG. 1, this control unit 122 includes a threshold setting unit 1221, a signal calculation unit 1222, a threshold determination unit 1223, and a sampling interval change determination unit 1224.

[0019] The threshold setting unit 1221 sets an irradiation stop threshold D ref which is a threshold related to the stop of irradiation of the radiation R, based on the target value D th of the dose of the radiation R included in the imaging conditions set by the imaging condition setting unit 132 of the control device 130. Note that the setting of the irradiation stop threshold D th by the threshold setting unit 1221 may reflect a delay time held in advance or acquired beforehand. Also, the irradiation stop threshold D th set by the threshold setting unit 1221 may be a threshold that changes with time based on a predetermined formula.

[0020] The signal calculation unit 1222 acquires the electrical signal (dose detection signal) detected by the dose detection element of the sensor unit 121 at the sampling interval set by the sampling interval change determination unit 1224, and calculates the cumulative value of the electrical signal (dose detection signal) related to the dose of the radiation R.

[0021] The threshold determination unit 1223 determines whether or not the cumulative value of the electrical signal (dose detection signal) related to the dose of the radiation R calculated by the signal calculation unit 1222 has reached the irradiation stop threshold D th set by the threshold setting unit 1221. Then, when the threshold determination unit 1223 determines that the cumulative value of the electrical signal (dose detection signal) calculated by the signal calculation unit 1222 has reached the irradiation stop threshold D th the threshold determination unit 1223 causes the communication unit 123 to transmit (output) an irradiation stop signal 101 regarding the stop of the irradiation of the radiation R to the control device 130.

[0022] The sampling interval change determination unit 1224 determines whether or not to change the sampling interval at which the electrical signal (dose detection signal) detected by the dose detection element of the sensor unit 121 is acquired by the signal calculation unit 1222. In the present embodiment, as the plurality of sampling intervals to be determined for change by the sampling interval change determination unit 1224, there are at least a first sampling interval and a second sampling interval shorter than the first sampling interval. In this case, the first sampling interval is a sampling interval longer than the second sampling interval. The sampling interval change determination unit 1224 determines whether or not to change from the first sampling interval to the second sampling interval based on the cumulative value of the electrical signal (dose detection signal) acquired and calculated by the signal calculation unit 1222 at the first sampling interval and the irradiation stop threshold D th In order to minimize the variation in the transmission time of the irradiation stop timing notification due to the sampling interval, it is desirable to make the sampling interval as short as possible. Therefore, when a given condition is satisfied, the sampling interval change determination unit 1224 performs control to change from the first sampling interval to a second sampling interval shorter than the first sampling interval.

[0023] The communication unit 123 communicates (transmits and receives) information such as signals and data with the communication unit 133 of the control device 130. At this time, the communication unit 123 can communicate with the communication unit 133 of the control device 130 both wired and wirelessly. Specifically, the communication unit 123 transmits (outputs), for example, the radiation image data generated by the radiation imaging device 120 to the communication unit 133 of the control device 130. Also, the communication unit 123, for example, when it is determined in the threshold determination unit 1223 that the cumulative value of the electrical signal (dose detection signal) has reached the irradiation stop threshold D th transmits (outputs) an irradiation stop signal 101 regarding the stop of the irradiation of the radiation R to the communication unit 133 of the control device 130. The communication unit 123 that transmits (outputs) this irradiation stop signal 101 and the radiation image data to the communication unit 133 of the control device 130 constitutes the "output unit" in the present embodiment.

[0024] The control device 130 controls the operation of the radiation generator 110 and the operation of the radiation imaging device 120. As shown in FIG. 1, this control device 130 includes a photographing control unit 131, a photographing condition setting unit 132, a communication unit 133, an image processing unit 134, and a display unit 135.

[0025] The photographing control unit 131 performs control related to the radiation photographing of the subject H in the radiation photographing system 100.

[0026] The photographing condition setting unit 132 sets photographing condition information including, for example, the photographing part of the subject H input by the operator, the tube voltage and tube current in the X-ray tube of the radiation generator 110, and the target value D of the dose of the radiation R that passes through the subject H and reaches the radiation imaging device 120. Here, the dose of the radiation R generally means the cumulative dose at the time of irradiation of the radiation R, but a value of a dose similar thereto or a linked dose value may be applied. ref etc. Here, the dose of the radiation R generally means the cumulative dose at the time of irradiation of the radiation R, but a value of a dose similar thereto or a linked dose value may be applied.

[0027] The communication unit 133 communicates (transmits and receives) information such as signals and data with the communication unit 123 of the radiation imaging apparatus 120. At this time, the communication unit 133 can communicate with the communication unit 123 of the radiation imaging apparatus 120 both wired and wirelessly. Specifically, the communication unit 133 receives (inputs), for example, the radiation image data generated by the radiation imaging apparatus 120 from the communication unit 123 of the radiation imaging apparatus 120. Further, the communication unit 133 receives (inputs), for example, the irradiation stop signal 101 regarding the stop of the irradiation of the radiation R from the communication unit 123 of the radiation imaging apparatus 120.

[0028] The image processing unit 134 performs image processing such as gradation processing and noise reduction processing on the radiation image data acquired from the radiation imaging apparatus 120 via the communication unit 133.

[0029] The display unit 135 displays various kinds of information and various kinds of images. The display unit 135 displays, for example, a radiation image based on the radiation image data on which image processing has been performed by the image processing unit 134.

[0030] When the control device 130 receives the irradiation stop signal 101 from the radiation imaging apparatus 120 via the communication unit 133, the imaging control unit 131 performs irradiation stop control 102 on the radiation generation device 110 in order to stop the irradiation of the radiation R from the radiation generation device 110. Further, simultaneously with this irradiation stop control 102, the control device 130 returns a reception response of the irradiation stop signal 101 from the communication unit 133 to the communication unit 123 of the radiation imaging apparatus 120. Note that when the radiation imaging apparatus 120 does not receive a reception response from the control device 130 for a certain period of time after transmitting the irradiation stop signal 101 to the control device 130, the radiation imaging apparatus 120 transmits the irradiation stop signal 101 to the control device 130 again.

[0031] FIG. 2 is a diagram showing an example of the relationship between the first and second sampling intervals to be determined by the sampling interval change determination unit 1224 and the cumulative value D of the electrical signal (dose detection signal) with respect to the elapsed time in the radiation imaging apparatus 120 according to the first embodiment.

[0032] In this embodiment, immediately after the incidence of the radiation R, as shown in FIG. 2, the sensor unit 121 operates at a sampling interval longer than the second sampling interval. Here, it is desirable to make the first sampling interval as long as possible in order to minimize the accumulation of the offset error of the dose of the radiation R.

[0033] The sampling interval change determination unit 1224 determines the timing to change to the second sampling interval based on the cumulative value of the electrical signal (dose detection signal) acquired and calculated by the signal calculation unit 1222 at the first sampling interval and the irradiation stop threshold D th The sampling interval is preferably as short as possible in order to minimize the variation in the transmission time of the irradiation stop timing notification caused by the sampling interval. Therefore, the second sampling interval is set to be shorter than the first sampling interval.

[0034] In the example shown in FIG. 2, the times when the electrical signal (dose detection signal) is sampled at the first sampling interval are Ta1, Ta2, Ta3, Ta4, and the times when the electrical signal (dose detection signal) is sampled at the second sampling interval are Tb1, Tb2. As in the example shown in this FIG. 2, the second sampling interval is shorter than the first sampling interval. In the case of the example shown in this FIG. 2, if the sampling of the electrical signal (dose detection signal) continues until the irradiation stop threshold D th is reached at the first sampling interval, the delay from the timing when irradiation should stop will be by the time of Ta4 - Tb2. Therefore, in this embodiment, before the cumulative value D of the electrical signal (dose detection signal) reaches the irradiation stop threshold D th the change from the first sampling interval to the second sampling interval shorter than this is made to suppress the delay from the timing when irradiation should stop. When changing from the first sampling interval to the second sampling interval, it is desirable to make it immediately before transmitting the irradiation stop timing notification in order to suppress the accumulation of the offset error of the dose of the radiation R described above. Therefore, for example, when the next electrical signal (dose detection signal) is acquired at the first sampling interval, if the cumulative value D of the electrical signal (dose detection signal) reaches the irradiation stop threshold Dth It is preferable to change to the second sampling interval when it is expected that the first sampling interval will be reached.

[0035] In the example shown in FIG. 2, when the electrical signal (dose detection signal) is sampled at the first sampling interval, the cumulative value D of the electrical signal (dose detection signal) reaches the irradiation stop threshold D at Ta4. th In this case, in this embodiment, the irradiation stop threshold D th Sampling is performed at the first sampling interval until Ta3 immediately before reaching Ta1, and then the sampling interval shifts to the second sampling interval after Ta3, thereby suppressing the accumulation of offset errors in the dose of radiation R described above. In this embodiment, after the shift to the second sampling interval, the cumulative value D of the electrical signal (dose detection signal) reaches the irradiation stop threshold D th When the time reaches the predetermined value, the communication unit 123 transmits (outputs) an irradiation stop signal 101 to the control device 130.

[0036] Fig. 3 is a flowchart showing an example of a processing procedure in the control method of the radiation imaging system 100 according to the first embodiment. Specifically, Fig. 3 is a flowchart showing an example of a processing procedure in a series of control methods from the start to the end of radiation imaging of the subject H, as the control method of the radiation imaging system 100.

[0037] First, in step S301, the imaging condition setting unit 132 receives an instruction to start imaging input by the operator via an input unit (not shown), and sets, for example, imaging condition information input by the operator. Here, the imaging condition information set by the imaging condition setting unit 132 includes the imaging site of the subject H, the tube voltage and tube current of the radiation tube of the radiation generating device 110, the target dose D of the radiation R that penetrates the subject H and reaches the radiation imaging device 120, and the like. ref Thereafter, the imaging condition setting unit 132 transmits the acquired imaging start instruction and the set imaging condition information to the radiation imaging apparatus 120 via the communication unit 133.

[0038] Subsequently, in step S302, the threshold setting unit 1221 sets an irradiation stop threshold D th for the irradiation stop of the radiation R based on the target value D of the dose of the radiation R included in the imaging condition information set in step S301. Regarding the setting of the irradiation stop threshold D th in step S302, the delay time held in advance or acquired in advance may be reflected. Further, the irradiation stop threshold D th set in step S302 may be a threshold that changes over time based on a predetermined formula. ref Based on this, an irradiation stop threshold D th for the irradiation stop of the radiation R is set. th Regarding the setting of the irradiation stop threshold D th by step S302, the delay time held in advance or acquired in advance may be reflected. th Also, the irradiation stop threshold D th set in step S302 may be a threshold that changes with time based on a predetermined formula. th

[0039] Subsequently, in step S303, the imaging control unit 131 transmits an irradiation execution signal for causing the radiation R to be irradiated to the radiation generator 110 together with the imaging condition information (including irradiation condition information) set in step S301. Accordingly, the radiation generator 110 irradiates the subject H and the radiation imaging apparatus 120 with the radiation R under the irradiation conditions based on the imaging condition information (including irradiation condition information) set in step S301.

[0040] ​Subsequently, in step S304, the sampling interval change determination unit 1224 sets a first sampling interval as the sampling interval for acquiring the electrical signal (dose detection signal) detected by the dose detection element of the sensor unit 121 based on the imaging protocol information. The imaging protocol information here is at least one piece of information among the imaging mode, imaging technique, tube voltage and tube current in the X-ray tube of the X-ray generating apparatus 110 that irradiates the radiation R, and the irradiation time of the radiation R. Further, the imaging mode here is information regarding the driving method of the radiography apparatus 120, such as synchronous imaging, asynchronous imaging, still image imaging, moving image imaging, frame rate, binning, etc. When a plurality of X-ray generating apparatuses 110 are installed in the radiography system 100, the identification information of the X-ray generating apparatus 110 to be used is also included in the imaging protocol information. Note that the setting of the first sampling interval by the sampling interval change determination unit 1224 may be set, for example, according to the irradiation time of the radiation R. If the first sampling interval is too long, there is a possibility that the cumulative value D of the electrical signal (dose detection signal) reaches the irradiation stop threshold D th before the next sampling, and the transmission of the irradiation stop signal 101 may be delayed. Therefore, the sampling interval change determination unit 1224 sets the first sampling interval within a range where the irradiation stop threshold D th is not reached at least at the time of the next sampling based on the cumulative value D of the electrical signal (dose detection signal) immediately after the start of irradiation of the radiation R.

[0041] Subsequently, in step S305, the signal calculation unit 1222 calculates a cumulative value D of a representative value of the electrical signal (dose detection signal) generated by the irradiation of the radiation R detected by the dose detection element of the sensor unit 121. Note that, as the representative value of the electrical signal (dose detection signal) here, the maximum value, average value, median value, etc. of the electrical signal (dose detection signal) can be used. In the following description, the cumulative value D of the representative value of the electrical signal (dose detection signal) is described as "signal D" as necessary. Further, the signal D at time t is described as D(t). Furthermore, the time of the nth sampling is t nIt is described as follows. Specifically, in this embodiment, in step S305, based on the electrical signal (dose detection signal) generated by the dose of the radiation R detected by the dose detection element of the sensor unit 121, the signal calculation unit 1222 calculates the signal D(t n at t n ).

[0042] Subsequently, in step S306, the signal calculation unit 1222 calculates the time change rate α of the signal D in order to calculate the predicted signal D 予測 , which is the predicted value of the signal D after the next sampling at the first sampling interval. The time change rate α of the signal D from the (n - 1)-th sampling to the n-th sampling is calculated by the following formula (1) using the signal D(t n-1 ) at the (n - 1)-th sampling and the signal D(t n ) at the n-th sampling.

Equation

[0043] In order to calculate a highly accurate predicted value of the signal D, considering that the dose of the radiation R stabilizes over time from the start of the irradiation of the radiation R, it is desirable to calculate using the signal D closest to the prediction time as much as possible. For example, when calculating the predicted signal D n+1 at t 予測 , as shown in formula (1), it is desirable to calculate from the change of the signal D between t n , which is the closest sampling time, and t n-1 .

[0044] Subsequently, in step S307, the signal calculation unit 1222 calculates the predicted signal D 予測 using the time change rate α of the signal D calculated in step S306. When calculating the predicted signal D n from t n+1 to the next sampling time t 予測 (t n+1 ), it can be calculated by the following formula (2).

Equation

[0045] In this embodiment, the signal calculation unit 1222 is at time t n and in addition to the next sampling time t n+1 , further calculates the predicted signal D n+2 at the next sampling time t 予測 . That is, in this embodiment, in step S307, the signal calculation unit 1222 calculates the predicted signal D 予測 (t n+1 ) and the predicted signal D 予測 (t n+2 ). Here, in order to change the sampling interval at an appropriate timing, the above two predicted signals D 予測 are calculated in advance.

[0046] Subsequently, in step S308, the signal calculation unit 1222 calculates the signal D(t n+1 ) at time t n+1 based on the electrical signal (dose detection signal) generated by the dose detection element of the sensor unit 121. That is, at this point, the signal D(t n+1 ) at time t n+1 , the predicted signal D 予測 (t n+1 ) and the predicted signal D 予測 (t n+2 ) calculated in the previous step S307 are both acquired.

[0047] Subsequently, in step S309, the threshold determination unit 1223 determines whether the signal D(t n+1 ) calculated in step S308 is smaller than the irradiation stop threshold D th set in step S302.

[0048] As a result of the determination in step S309, if the signal D(t n+1 ) is smaller than the irradiation stop threshold D th (S309 / YES), as shown in FIG. 2, the cumulative value of the electrical signal (dose detection signal) is the irradiation stop threshold D thIt is determined that the condition has not been reached, and the process proceeds to step S310. When the process proceeds to step S310, the sampling interval change determination unit 1224 determines whether the signal D(t n+1 ) calculated in S308 matches the predicted signal D 予測 (t n+1 ) calculated in S307 for the purpose of determining the change to the second sampling interval. As an example here, it is determined whether the condition of the following equation (3) is satisfied with respect to the prediction accuracy management standard value β. [Number]

[0049] Here, the prediction accuracy management standard value β in equation (3) may be a fixed value set in advance, or a value calculated and set from a predetermined equation such as the change rate of the signal D.

[0050] As a result of the determination in step S310, if the condition of equation (3) is satisfied (S310 / YES), the signal D(t n+1 ) does not match the predicted signal D 予測 (t n+1 ), and it is considered that the accuracy of the predicted signal D 予測 is insufficient, and the process returns to step S306. Then, the processes after step S306 are performed again.

[0051] On the other hand, as a result of the determination in step S310, if the condition of equation (3) is not satisfied (S310 / NO), the signal D(t n+1 ) matches the predicted signal D 予測 (t n+1 ), and it is considered that the accuracy of the predicted signal D 予測 is sufficient, and the process proceeds to step 311. When the process proceeds to step 311, the sampling interval change determination unit 1224 (or the threshold determination unit 1223) determines whether the predicted signal D 予測 (t n+2 ) calculated in step S307 is smaller than the irradiation stop threshold D th set in step S302. Specifically, in step S311, it is determined whether the condition of the following equation (4) is satisfied. [Number]

[0052] As a result of the determination in step S311, if the condition of equation (4) is satisfied (S311 / YES), the next t n+2 At the time of sampling at, it is predicted that the signal D will not reach the irradiation stop threshold D th Therefore, the first sampling interval is maintained and the process returns to step S306. Then, the processes after step S306 are performed again.

[0053] On the other hand, as a result of the determination in step S311, if the condition of equation (4) is not satisfied (S311 / NO), the next t n+2 At the time of sampling at, it is predicted that the signal D will reach the irradiation stop threshold D th Therefore, the process proceeds to step 312. When the process proceeds to step 312, the sampling interval change determination unit 1224 changes the sampling interval for acquiring the electrical signal (dose detection signal) detected by the dose detection element of the sensor unit 121 from the first sampling interval to a second sampling interval shorter than that.

[0054] Subsequently, in step S313, first, the signal calculation unit 1222 calculates the signal D at the second sampling interval set in step S312. The calculation of the signal D here may be performed from the electrical signal (dose detection signal) detected by the dose detection element of the sensor unit 121, or may be calculated from the time change rate of the signal D at the first sampling interval or the second sampling interval. Next, the threshold determination unit 1223 determines whether the signal D calculated by the signal calculation unit 1222 in this step is smaller than the irradiation stop threshold D th Set in step 302. As a result of this determination, if the signal D is smaller than the irradiation stop threshold D th In the case of (S313 / YES), sampling is performed at the second sampling interval, and then the determination in step S313 is performed again.

[0055] On the other hand, as a result of the determination in S313, the signal D is not smaller than the irradiation stop threshold D th (D is Dth If the above is the case (S313 / NO), it is determined that the cumulative value of the electrical signal (dose detection signal) has reached the irradiation stop threshold D th and the process proceeds to S314.

[0056] Also, as a result of the determination in S309, if the signal D(t n+1 ) is not less than the irradiation stop threshold D th (D(t n+1 ) is D th or more), in the case of (S309 / NO), it is determined that the cumulative value of the electrical signal (dose detection signal) has reached the irradiation stop threshold D th and the process proceeds to S314.

[0057] When the process proceeds to step S314, the communication unit 123 transmits (outputs) an irradiation stop signal 101 regarding the stop of the irradiation of the radiation R from the radiation generator 110 to the control device 130 because the cumulative value of the electrical signal (dose detection signal) has reached the irradiation stop threshold D th . When the control device 130 receives the irradiation stop signal 101 from the communication unit 123 of the radiation imaging device 120, the imaging control unit 131 performs irradiation stop control 102 on the radiation generator 110.

[0058] Subsequently, in step S315, the radiation imaging device 120 generates radiation image data based on the electrical signal (image signal) detected by the imaging element of the sensor unit 121 and transmits the generated radiation image data to the control device 130.

[0059] Subsequently, in step S316, the image processing unit 134 of the control device 130 performs image processing such as gradation processing and noise reduction processing on the radiation image data received from the radiation imaging device 120.

[0060] Subsequently, in step S317, the display unit 135 of the control device 130 displays a radiation image based on the radiation image data on which image processing has been performed by the image processing unit 134 in step S316. As a result, the operator can visually recognize the radiation image of the subject H.

[0061] When the process of step S317 ends, the process of the flowchart related to the radiation imaging of the subject H shown in FIG. 3 ends.

[0062] In the present embodiment, in step S304 of FIG. 3, the sampling interval change determination unit 1224 uses the time change rate (α) of the cumulative value of the electrical signal (dose detection signal), for example, the irradiation stop threshold D th to set the first sampling interval in consideration of the relationship therewith.

[0063] In the radiation imaging apparatus 120 according to the first embodiment described above, the sensor unit 121 includes a dose detection element that detects the dose of the incident radiation R as an electrical signal (dose detection signal). The control unit 122 obtains the cumulative value of the electrical signal (dose detection signal) obtained at the first sampling interval, and the irradiation stop threshold D th which is a threshold related to the stop of the irradiation of the radiation R, to perform change control of the sampling interval for obtaining the electrical signal (dose detection signal). Specifically, the control unit 122, based on the cumulative value of the electrical signal (dose detection signal) and the irradiation stop threshold D th performs control to change the sampling interval for obtaining the electrical signal (dose detection signal) from the first sampling interval to a second sampling interval shorter than this. More specifically, the control unit 122, when the cumulative value of the electrical signal (dose detection signal) obtained at the first sampling interval has not reached the irradiation stop threshold D th (S309 / YES in FIG. 3), performs control to change to the second sampling interval. Even more specifically, the control unit 122, in the case of S309 / YES in FIG. 3, when the cumulative value of the electrical signal (dose detection signal) including the electrical signal (dose detection signal) to be obtained at the next first sampling interval reaches the irradiation stop threshold D thWhen reaching [a certain condition], control for changing to the second sampling interval is performed. Further, when the difference between the cumulative value of the electrical signal (dose detection signal) acquired at the first sampling interval and the predicted cumulative value calculated based on the rate of change of the cumulative value with respect to time is equal to or less than a predetermined value (S310 / NO in FIG. 3), the control unit 122 performs control for changing to the second sampling interval. And in the radiation imaging apparatus 120 according to the first embodiment, when the cumulative value of the electrical signal (dose detection signal) reaches the irradiation stop threshold D th the communication unit 123 outputs an irradiation stop signal 101, which is a signal regarding the stop of the irradiation of the radiation R. According to such a configuration, the irradiation stop control of the radiation R from the radiation generation device 110 can be performed with high accuracy.

[0064] (Second Embodiment) Next, the second embodiment will be described. In the description of the second embodiment described below, descriptions of matters common to the above-described first embodiment will be omitted, and matters different from the above-described first embodiment will be described.

[0065] In the first embodiment, the dose detection elements of the sensor unit 121 are arranged distributed in a predetermined region of interest on the radiation R incident surface of the sensor unit 121, whereas in the second embodiment, they are arranged distributed in a plurality of regions of interest on the incident surface of the sensor unit 121.

[0066] The schematic configuration of the radiation imaging system according to the second embodiment is the same as the schematic configuration of the radiation imaging system 100 according to the first embodiment shown in FIG. 1. That is, the schematic configuration of the radiation imaging apparatus 120 according to the second embodiment is the same as the schematic configuration of the radiation imaging apparatus 120 according to the first embodiment shown in FIG. 1.

[0067] FIG. 4 is a diagram showing an example of a plurality of regions of interest 400 set on the radiation R incident surface of the sensor unit 121 in the radiation imaging apparatus 120 according to the second embodiment. Specifically, FIG. 4 shows five regions of interest 400-1 to 400-5 for detecting the dose of the incident radiation R. And in each of the plurality of regions of interest 400-1 to 400-5, dose detection elements for detecting the dose of the incident radiation R as an electrical signal (dose detection signal) are distributed and arranged.

[0068] Here, although various modes can be considered for the arrangement method of the plurality of regions of interest 400, by arranging them symmetrically with respect to the center of the radiation imaging apparatus 120, they can be used in the same way regardless of the orientation of the radiation imaging apparatus 120. Also, the shape of the region of interest 400 may be a quadrilateral such as a square or a rectangle, a circle, or an ellipse. Further, the shape of the region of interest 400 may be a shape that follows the shape of the subject H. In the above-described AEC, by reading an electrical signal (dose detection signal) from a plurality of dose detection elements arranged in the region of interest 400 during irradiation with the radiation R, the dose of the radiation R irradiated to the region of interest 400 can be detected (calculated). Here, the cumulative value of the electrical signal (dose detection signal) in the region of interest 400 corresponds to the dose of the irradiated radiation R.

[0069] Even when determining whether the cumulative value of the electrical signal (dose detection signal) has reached the irradiation stop threshold D in all of the regions of interest 400 of the target region of interest 400, a form of sequentially shifting to the second sampling interval from the region of interest 400 that satisfies a predetermined condition can be adopted. For example, when the threshold determination unit 1223 determines that the cumulative value of the electrical signal (dose detection signal) has reached the irradiation stop threshold D in all of the regions of interest 400 of the target region of interest 400, the communication unit 123 transmits (outputs) an irradiation stop signal 101 to the control device 130. Note that when the threshold determination unit 1223 determines that the cumulative value of the electrical signal (dose detection signal) has reached the irradiation stop threshold D in any one of the regions of interest 400 of the target region of interest 400 th th th ​​When it is determined that the threshold has been reached, the communication unit 123 may transmit (output) an irradiation stop signal 101 to the control device 130.

[0070] In the present embodiment, the control unit 122 may perform control to change the sampling interval for acquiring the electrical signal (dose detection signal) detected in at least one of the plurality of regions of interest 400 from the first sampling interval to the second sampling interval. At this time, when the cumulative value of the electrical signal (dose detection signal) detected in the at least one region of interest 400 reaches the irradiation stop threshold D th the communication unit 123 may adopt a form of transmitting (outputting) the irradiation stop signal 101.

[0071] In the present embodiment, as the cumulative value of the electrical signal (dose detection signal) acquired from the target region of interest 400, a form of using the average value of the cumulative values of the electrical signals (dose detection signals) acquired from the respective regions of interest 400 in the target region of interest 400 may also be adopted. When this form is adopted, the sampling interval change determination unit 1224 makes a determination to change to the second sampling interval based on the average value of the cumulative values of the electrical signals (dose detection signals). Further, when this form is adopted, when the threshold determination unit 1223 determines that the average value of the cumulative values of the electrical signals (dose detection signals) has reached the irradiation stop threshold D th the communication unit 123 transmits (outputs) the irradiation stop signal 101 to the control device 130.

[0072] According to the second embodiment, similarly to the first embodiment described above, the irradiation stop control of the radiation R from the radiation generator 110 can be performed with high accuracy.

[0073] (Third Embodiment) Next, a third embodiment will be described. In the description of the third embodiment described below, descriptions of matters common to the first and second embodiments described above will be omitted, and matters different from the first and second embodiments described above will be described.

[0074] FIG. 5 is a diagram showing an example of the schematic configuration of a radiation imaging system 300 according to the third embodiment. In this FIG. 5, components similar to those of the radiation imaging system 100 according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0075] As shown in FIG. 5, the radiation imaging system 300 includes a radiation generator 110, a radiation imaging device 320, and a control device 330. Specifically, in the radiation imaging system 300, the control unit 122, which was configured inside the radiation imaging device 120 in the radiation imaging system 100 shown in FIG. 1, is configured inside the control device 330. Accordingly, the radiation imaging device 320 includes a sensor unit 121 having the same functions as those in the first embodiment, and a communication unit 323 having functions different from those of the communication unit 123 in the first embodiment. The sensor unit 121 includes a dose detection element that detects the dose of the incident radiation R as an electrical signal (dose detection signal), as in the first embodiment. In addition to the imaging control unit 131, the imaging condition setting unit 132, the image processing unit 134, and the display unit 135 having the same functions as those in the first embodiment, the control device 330 includes a communication unit 333 having functions different from those of the communication unit 133 in the first embodiment, and the above-described control unit 122.

[0076] The communication unit 323 of the radiation imaging device 320 transmits and receives (communicates) information such as signals and data to and from the communication unit 333 of the control device 330. At this time, the communication unit 323 can communicate with the communication unit 333 of the control device 330 both wired and wirelessly. Specifically, the communication unit 323 transmits, for example, the radiation image data generated by the radiation imaging device 320 to the communication unit 333 of the control device 330. Further, the communication unit 323 transmits, for example, an electrical signal related to the dose of the incident radiation R detected by the sensor unit 121 to the communication unit 333 of the control device 330.

[0077] The communication unit 333 of the control device 330 transmits and receives (communicates) information such as signals and data to and from the communication unit 323 of the radiation imaging device 320. At this time, the communication unit 333 can communicate with the communication unit 323 of the radiation imaging device 320 both wired and wirelessly. Specifically, for example, the communication unit 333 receives radiation image data generated by the radiation imaging device 320 from the communication unit 323 of the radiation imaging device 320. Further, for example, the communication unit 333 receives an electrical signal regarding the dose of the incident radiation R detected by the sensor unit 121 from the communication unit 323 of the radiation imaging device 320.

[0078] As shown in FIG. 5, the control unit 122 of the control device 330 includes a threshold setting unit 1221, a signal calculation unit 1222, a threshold determination unit 1223, and a sampling interval change determination unit 1224.

[0079] The threshold setting unit 1221 of the control device 330 sets an irradiation stop threshold D ref which is a threshold regarding the stop of irradiation of the radiation R, based on the target value D th of the dose of the radiation R included in the imaging conditions set by the imaging condition setting unit 132. Note that the setting of the irradiation stop threshold D th by the threshold setting unit 1221 may reflect a delay time held in advance or acquired in advance. Further, the irradiation stop threshold D th set by the threshold setting unit 1221 may be a threshold that changes with time based on a predetermined formula.

[0080] The signal calculation unit 1222 of the control device 330 acquires an electrical signal regarding the dose of the incident radiation R from the communication unit 333 at the sampling interval set by the sampling interval change determination unit 1224. Then, the signal calculation unit 1222 calculates the cumulative value of the acquired electrical signal (dose detection signal) regarding the dose of the radiation R.

[0081] The threshold determination unit 1223 of the control device 330 determines whether the cumulative value of the electrical signal (dose detection signal) regarding the dose of the radiation R calculated by the signal calculation unit 1222 is the irradiation stop threshold D thIt is determined whether or not the threshold has been reached. Then, when the threshold determination unit 1223 determines that the cumulative value of the electrical signal (dose detection signal) calculated by the signal calculation unit 1222 has reached the irradiation stop threshold D th the communication unit 333 causes the radiation generator 110 to output an irradiation stop signal 301 regarding the stop of the irradiation of the radiation R.

[0082] The sampling interval change determination unit 1224 of the control device 330 determines whether or not to change the sampling interval at which the signal calculation unit 1222 acquires the electrical signal (dose detection signal) detected by the dose detection element of the sensor unit 121 of the radiation imaging device 320. In the present embodiment, as the plurality of sampling intervals to be determined for change by the sampling interval change determination unit 1224, there are at least a first sampling interval and a second sampling interval shorter than the first sampling interval. In this case, the first sampling interval is a sampling interval longer than the second sampling interval. The sampling interval change determination unit 1224 determines whether or not to change from the first sampling interval to the second sampling interval based on the cumulative value of the electrical signal (dose detection signal) acquired and calculated by the signal calculation unit 1222 at the first sampling interval and the irradiation stop threshold D th Based on this, it is determined whether or not to change from the first sampling interval to the second sampling interval. In order to minimize the variation in the transmission time of the irradiation stop timing notification due to the sampling interval, it is desirable to make the sampling interval as short as possible. Therefore, when a given condition is satisfied, the sampling interval change determination unit 1224 performs control to change from the first sampling interval to a second sampling interval shorter than the first sampling interval.

[0083] Then, in the present embodiment, when the threshold determination unit 1223 determines that the cumulative value of the electrical signal (dose detection signal) has reached the irradiation stop threshold D th the communication unit 333 transmits (outputs) an irradiation stop signal 301 regarding the stop of the irradiation of the radiation R to the radiation generator 110. The communication unit 333 that transmits (outputs) this irradiation stop signal 301 to the radiation generator 110 constitutes the "output unit" in the present embodiment.

[0084] Note that the processing of the flowchart shown in FIG. 3 is also applicable in this embodiment, and the processing based on the internal configuration of the control device 330 shown in FIG. 5 corresponds to the control method of the control device 330.

[0085] In the control device 330 according to the third embodiment described above, the following processing is performed. The control unit 122 compares the cumulative value of the electrical signal (dose detection signal) obtained at the first sampling interval with the irradiation stop threshold D, which is a threshold related to the stop of irradiation of the radiation R. th Based on this, the control unit 122 performs control to change the sampling interval for obtaining the electrical signal (dose detection signal). Specifically, the control unit 122 changes the sampling interval for obtaining the electrical signal (dose detection signal) from the first sampling interval to a second sampling interval shorter than this based on the cumulative value of the electrical signal (dose detection signal) and the irradiation stop threshold D. th More specifically, the control unit 122 performs control to change to the second sampling interval when the cumulative value of the electrical signal (dose detection signal) obtained at the first sampling interval has not reached the irradiation stop threshold D, similar to the first embodiment. th Even more specifically, the control unit 122 performs control to change to the second sampling interval when the cumulative value of the electrical signal (dose detection signal) including the electrical signal (dose detection signal) to be obtained at the next first sampling interval reaches the irradiation stop threshold D, similar to the first embodiment. th Also, the control unit 122 performs control to change to the second sampling interval when the difference between the cumulative value of the electrical signal (dose detection signal) obtained at the first sampling interval and the predicted cumulative value calculated based on the time change rate of the cumulative value is equal to or less than a predetermined value (S310 / NO in FIG. 3). th And in the control device 330 according to the third embodiment, the communication unit 333 outputs an irradiation stop signal 301, which is a signal related to the stop of irradiation of the radiation R, when the cumulative value of the electrical signal (dose detection signal) reaches the irradiation stop threshold D. According to such a configuration, the irradiation stop control of the radiation R from the radiation generator 110 can be performed with high accuracy.

[0086] (Other Embodiments) The present disclosure can also be implemented by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in a computer of the system or device read and execute the program. It can also be implemented by a circuit (for example, ASIC) that realizes one or more functions. This program and a computer-readable storage medium storing the program are included in the present disclosure.

[0087] Note that the above-described embodiments of the present disclosure are merely examples of implementation in carrying out the present disclosure, and the technical scope of the present disclosure should not be construed in a limited manner by these. That is, the present disclosure can be implemented in various forms without departing from its technical idea or its main features.

[0088] Embodiments of the present disclosure include the following configurations, methods, and programs. [Configuration 1] A sensor unit that detects the dose of incident radiation as an electrical signal, Based on the cumulative value of the electrical signal obtained at a first sampling interval of the electrical signal detected by the sensor unit and a threshold related to the stop of radiation irradiation, A control unit that performs control to change a sampling interval for obtaining the electrical signal detected by the sensor unit to a second sampling interval shorter than the first sampling interval, An output unit that outputs a signal related to the stop of radiation irradiation when the cumulative value of the electrical signal detected by the sensor unit reaches the threshold, A radiation imaging apparatus comprising the above. [Configuration 2] The control unit, When the cumulative value of the electrical signal obtained at the first sampling interval of the electrical signal detected by the sensor unit has not reached the threshold, Performs control to change the sampling interval for acquiring the electrical signal detected by the sensor unit from the first sampling interval to the second sampling interval. The radiographic apparatus according to Configuration 1. [Configuration 3] The control unit When the cumulative value of the electrical signal obtained at the first sampling interval for the electrical signal detected by the sensor unit has not reached the threshold value, and the cumulative value of the electrical signal including the electrical signal to be obtained at the next first sampling interval reaches the threshold value, Performs control to change the sampling interval for acquiring the electrical signal detected by the sensor unit from the first sampling interval to the second sampling interval. The radiographic apparatus according to Configuration 1. [Configuration 4] The control unit Furthermore, when the difference between the cumulative value of the electrical signal obtained at the first sampling interval and the predicted cumulative value calculated based on the time change rate of the cumulative value is equal to or less than a predetermined value, Performs control to change the sampling interval for acquiring the electrical signal detected by the sensor unit from the first sampling interval to the second sampling interval. The radiographic apparatus according to Configuration 3. [Configuration 5] The control unit sets the first sampling interval based on the imaging protocol information of the imaging using the radiation. The radiographic apparatus according to any one of Configurations 1 to 4. [Configuration 6] The imaging protocol information is at least one piece of information among the imaging mode, imaging technique, voltage and current of the radiation generator that irradiates the radiation, and irradiation time of the radiation. The radiographic apparatus according to Configuration 5. [Configuration 7] The control unit sets the first sampling interval based on the cumulative value of the electrical signal detected by the sensor unit immediately after the start of irradiation of the radiation. The radiographic apparatus according to any one of Configurations 1 to 4. [Configuration 8] The control unit sets the first sampling interval using the rate of change of the cumulative value over time. The radiographic apparatus according to any one of Configurations 1 to 4. [Configuration 9] A plurality of regions of interest are set in the sensor unit. The control unit performs control to change the sampling interval for acquiring the electrical signal detected in at least one of the plurality of regions of interest from the first sampling interval to the second sampling interval. When the cumulative value of the electrical signal detected in the at least one region of interest reaches the threshold value, the output unit outputs a signal regarding the stop of the radiation irradiation. The radiographic apparatus according to any one of Configurations 1 to 8. [Configuration 10] When the control unit acquires the electrical signals detected in the plurality of regions of interest, as the cumulative value, it uses the average value of the cumulative values of the electrical signals detected in each of the plurality of regions of interest. The radiographic apparatus according to Configuration 9. [Configuration 11] The radiographic apparatus according to any one of Configurations 1 to 10, A radiation generator that irradiates the radiation, A control device that controls the radiation generator based on the signal regarding the stop of the radiation irradiation output from the output unit, A radiographic system comprising: [Configuration 12] Based on the cumulative value of the electrical signal regarding the dose of the incident radiation detected by the radiographic apparatus, which is acquired at the first sampling interval, and the threshold value regarding the stop of the radiation irradiation, A control unit that performs control to change the sampling interval for acquiring the electrical signal detected by the radiographic apparatus to a second sampling interval shorter than the first sampling interval, An output unit that outputs a signal related to stopping the irradiation of the radiation when the cumulative value of the electrical signal reaches the threshold value, A control device comprising the same. [Configuration 13] The radiation imaging apparatus, A control device according to Configuration 12, communicably connected to the radiation imaging apparatus, A radiation imaging system comprising the same. [Method 1] A control method for a radiation imaging apparatus comprising a sensor unit that detects the dose of incident radiation as an electrical signal, Based on the cumulative value of the electrical signal obtained at a first sampling interval of the electrical signal detected by the sensor unit and a threshold value related to stopping the irradiation of the radiation, A control step of performing control to change the sampling interval for obtaining the electrical signal detected by the sensor unit to a second sampling interval shorter than the first sampling interval, An output step of outputting a signal related to stopping the irradiation of the radiation when the cumulative value of the electrical signal detected by the sensor unit reaches the threshold value, A control method for a radiation imaging apparatus having the same. [Method 2] A control method for a control device communicably connected to a radiation imaging apparatus, Based on the cumulative value of the electrical signal obtained at a first sampling interval of the electrical signal related to the dose of incident radiation detected by the radiation imaging apparatus and a threshold value related to stopping the irradiation of the radiation, A control step of performing control to change the sampling interval for obtaining the electrical signal detected by the radiation imaging apparatus to a second sampling interval shorter than the first sampling interval, An output step of outputting a signal related to stopping the irradiation of the radiation when the cumulative value of the electrical signal reaches the threshold value, A control method for a control device having the same. [Program 1] A program for causing a computer to execute a control method of a radiation imaging apparatus including a sensor unit that detects the dose of incident radiation as an electrical signal, based on the cumulative value of the electrical signal obtained by acquiring the electrical signal detected by the sensor unit at a first sampling interval and a threshold value related to the stop of irradiation of the radiation, a control step of performing control to change a sampling interval for acquiring the electrical signal detected by the sensor unit to a second sampling interval shorter than the first sampling interval, an output step of outputting a signal related to the stop of irradiation of the radiation when the cumulative value of the electrical signal detected by the sensor unit reaches the threshold value, and a program for causing a computer to execute the above. [Program 2] A program for causing a computer to execute a control method of a control device communicably connected to a radiation imaging apparatus, based on the cumulative value of the electrical signal related to the dose of incident radiation detected by the radiation imaging apparatus, obtained at a first sampling interval, and a threshold value related to the stop of irradiation of the radiation, a control step of performing control to change a sampling interval for acquiring the electrical signal detected by the radiation imaging apparatus to a second sampling interval shorter than the first sampling interval, an output step of outputting a signal related to the stop of irradiation of the radiation when the cumulative value of the electrical signal reaches the threshold value, and a program for causing a computer to execute the above.

Explanation of Reference Numerals

[0089] 100: Radiographic system, 101: Irradiation stop signal, 102: Irradiation stop control, 110: Radiation generator, 120: Radiographic apparatus, 121: Sensor unit, 122: Control unit, 1221: Threshold setting unit, 1222: Signal calculation unit, 1223: Threshold determination unit, 1224: Sampling interval change determination unit, 123: Communication unit, 130: Control device, 131: Imaging control unit, 132: Imaging condition setting unit, 133: Communication unit, 134: Image processing unit, 135: Display unit, 400: Region of interest, H: Subject, R: Radiation

Claims

1. A sensor unit that detects the dose of incident radiation as an electrical signal, Based on the cumulative value of the electrical signal obtained at a first sampling interval of the electrical signal detected by the sensor unit and a threshold value related to the stop of radiation irradiation, control is performed to change the sampling interval for obtaining the electrical signal detected by the sensor unit to a second sampling interval shorter than the first sampling interval. A control unit, An output unit that outputs a signal related to the stop of radiation irradiation when the cumulative value of the electrical signal detected by the sensor unit reaches the threshold value, A radiation imaging apparatus comprising:

2. When the cumulative value of the electrical signal obtained at the first sampling interval of the electrical signal detected by the sensor unit does not reach the threshold value, the control unit changes the sampling interval for obtaining the electrical signal detected by the sensor unit from the first sampling interval to the second sampling interval. Perform control, The radiation imaging apparatus according to claim 1.

3. When the cumulative value of the electrical signal obtained at the first sampling interval of the electrical signal detected by the sensor unit does not reach the threshold value, and the cumulative value of the electrical signal including the electrical signal to be obtained at the next first sampling interval reaches the threshold value, the control unit changes the sampling interval for obtaining the electrical signal detected by the sensor unit from the first sampling interval to the second sampling interval. Perform control, The radiation imaging apparatus according to claim 1.

4. When the difference between the cumulative value of the electrical signal obtained at the first sampling interval and the predicted cumulative value calculated based on the time change rate of the cumulative value is equal to or less than a predetermined value, the control unit changes the sampling interval for obtaining the electrical signal detected by the sensor unit from the first sampling interval to the second sampling interval. Perform control, The radiation imaging apparatus according to claim 3.

5. The control unit sets the first sampling interval based on the imaging protocol information of imaging using the radiation, The radiation imaging apparatus according to claim 1.

6. The imaging protocol information is at least one piece of information among the imaging mode, imaging technique, voltage and current of the radiation generator that irradiates the radiation, and the irradiation time of the radiation, The radiation imaging apparatus according to claim 5.

7. The control unit sets the first sampling interval based on the cumulative value of the electrical signal detected by the sensor unit immediately after the start of irradiation of the radiation. The radiation imaging apparatus according to claim 1.

8. The control unit sets the first sampling interval using the rate of change of the cumulative value with respect to time. The radiation imaging apparatus according to claim 7.

9. A plurality of regions of interest are set in the sensor unit. The control unit performs control to change the sampling interval for acquiring the electrical signal detected in at least one region of interest among the plurality of regions of interest from the first sampling interval to the second sampling interval. When the cumulative value of the electrical signal detected in the at least one region of interest reaches the threshold value, the output unit outputs a signal regarding the stop of irradiation of the radiation. The radiation imaging apparatus according to claim 1.

10. When the control unit acquires the electrical signal detected in the plurality of regions of interest, as the cumulative value, the average value of the cumulative values of the electrical signal detected in each region of interest in the plurality of regions of interest is used. The radiation imaging apparatus according to claim 9.

11. The radiation imaging apparatus according to any one of claims 1 to 10, A radiation generator that irradiates the radiation, A control device that controls the radiation generator based on the signal regarding the stop of irradiation of the radiation output from the output unit, A radiation imaging system comprising:

12. Based on the cumulative value of the electrical signal acquired at the first sampling interval and the threshold value regarding the stop of irradiation of the radiation, for the electrical signal regarding the dose of the incident radiation detected by the radiation imaging apparatus, a control unit that performs control to change the sampling interval for acquiring the electrical signal detected by the radiation imaging apparatus to a second sampling interval shorter than the first sampling interval, An output unit that outputs a signal regarding the stop of irradiation of the radiation when the cumulative value of the electrical signal reaches the threshold value, A control device comprising:

13. The radiation imaging apparatus, The control device according to claim 12, communicably connected to the radiation imaging apparatus, A radiation imaging system comprising:

14. A control method for a radiation imaging apparatus including a sensor unit that detects the dose of incident radiation as an electrical signal, A control step of performing control to change a sampling interval for acquiring the electrical signal detected by the sensor unit to a second sampling interval shorter than the first sampling interval, based on a cumulative value of the electrical signal acquired at the first sampling interval and a threshold value related to stopping irradiation of the radiation; An output step of outputting a signal related to stopping irradiation of the radiation when the cumulative value of the electrical signal detected by the sensor unit reaches the threshold value; A control method for a radiation imaging apparatus, comprising the above.

15. A control method for a control device communicably connected to a radiation imaging apparatus, comprising: A control step of performing control to change a sampling interval for acquiring the electrical signal detected by the radiation imaging apparatus, which is related to the dose of incident radiation, to a second sampling interval shorter than the first sampling interval, based on a cumulative value of the electrical signal acquired at the first sampling interval and a threshold value related to stopping irradiation of the radiation; An output step of outputting a signal related to stopping irradiation of the radiation when the cumulative value of the electrical signal reaches the threshold value; A control method for a control device, comprising the above.

16. A program for causing a computer to execute a control method for a radiation imaging apparatus including a sensor unit that detects the dose of incident radiation as an electrical signal, comprising: A control step of performing control to change a sampling interval for acquiring the electrical signal detected by the sensor unit to a second sampling interval shorter than the first sampling interval, based on a cumulative value of the electrical signal acquired at the first sampling interval and a threshold value related to stopping irradiation of the radiation; An output step of outputting a signal related to stopping irradiation of the radiation when the cumulative value of the electrical signal detected by the sensor unit reaches the threshold value; A program for causing a computer to execute the above.

17. A program for causing a computer to execute a control method for a control device communicably connected to a radiation imaging apparatus, comprising: A control step of performing control to change a sampling interval for acquiring the electrical signal detected by the radiation imaging apparatus to a second sampling interval shorter than the first sampling interval, based on a cumulative value of the electrical signal acquired at the first sampling interval and a threshold related to the stop of radiation irradiation, for the electrical signal detected by the radiation imaging apparatus; An output step of outputting a signal related to the stop of radiation irradiation when the cumulative value of the electrical signal reaches the threshold; A program for causing a computer to execute the above steps.

Images