Radiation imaging device, radiation imaging system, radiation imaging method, control device, and program

Abstract

To suppress variation in radiation exposure dose.SOLUTION: A radiation imaging device includes a processing unit provided in a pixel area in which multiple pixels for detecting radiation are arranged, and which processes output signals output from multiple detection areas, including detection pixels that output a signal corresponding to the radiation dose. The processing unit generates weighting information for the multiple detection areas by comparing the output signal with preset reference information, and generates determination information for controlling radiation irradiation by comparing dose information in which the output signal is weighted on the basis of the weighting information with a preset threshold.SELECTED DRAWING: Figure 4

Description

【Technical Field】 【0001】 The disclosed technology relates to a radiation imaging device, a radiation imaging system, a radiation imaging method, and a program. 【Background Art】 【0002】 Currently, as an imaging device used for medical image diagnosis and non-destructive inspection by X-rays, a radiation imaging device that combines a pixel array provided with a conversion element that converts radiation into charge, a switch element such as a thin film transistor, and wiring, and a drive circuit and a readout circuit has been put into practical use. 【0003】 One of the radiation imaging devices has a function of detecting irradiation information while a radiation source is irradiating radiation. This function includes a function of detecting the timing of the start of incidence where radiation is irradiated from the radiation source, and a function of detecting the irradiation dose and the integrated irradiation dose of the radiation. By this function, it is possible to monitor the integrated irradiation dose and perform automatic exposure control in which when the integrated irradiation dose reaches an appropriate amount, the detection device controls the radiation source to end the irradiation. 【0004】 Patent Document 1 discloses a technique of imaging a site to be imaged with an appropriate dose by controlling the irradiation of radiation based on information associated with a region of interest when using automatic exposure control. 【Prior Art Documents】 【Patent Documents】 【0005】 【Patent Document 1】 Japanese Unexamined Patent Application Publication No. 2021-79023 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0006】 However, in the technology of Patent Document 1, since the detection area for detecting the integrated irradiation dose is at a fixed position, it is necessary to pre-select the detection area according to the imaging site of the subject. In this case, if the pre-selected detection area is displaced from the position of the subject, or if a thickness difference due to differences such as age and gender occurs, the exposure cannot be properly controlled, and variations may occur in the radiation dose, which may lead to variations in the radiation dose. 【0007】 The disclosed technology aims to provide a radiation imaging technology capable of suppressing variations in the radiation dose. 【Means for Solving the Problems】 【0008】 A radiation imaging apparatus according to an aspect of the disclosed technology includes a processing unit that processes output signals output from a plurality of detection areas, the processing unit being provided in a pixel area in which a plurality of pixels for detecting radiation are arranged and including detection pixels that output signals corresponding to the irradiation dose of the radiation. The processing unit generates weighting information for the plurality of detection areas by comparing the output signal with preset reference information. Based on the comparison between the dose information obtained by weighting the output signal based on the weighting information and a preset threshold value, determination information for controlling the irradiation of the radiation is generated. 【Effects of the Invention】 【0009】 According to the disclosed technology, it becomes possible to suppress variations in the radiation dose. 【Brief Description of the Drawings】 【0010】 【Figure 1】 A diagram showing the configuration of a radiation imaging system according to the first embodiment. 【Figure 2】 A diagram showing the configuration of an FPD processing unit according to the first embodiment. 【Figure 3】 A diagram showing an example of variations in automatic exposure control when the position of the subject according to the first embodiment is displaced in the vertical direction with respect to the radiation imaging apparatus. 【Figure 4】A diagram showing an example of weighting based on output information when the position of the subject according to the first embodiment is shifted upward with respect to the radiation imaging apparatus. 【Figure 5】 A diagram showing an example of weighting based on the output ratio when the subject position according to the first embodiment is shifted to the right. 【Figure 6】 A diagram showing an example of weighting based on output information when the size of the subject according to the second embodiment is small. 【Figure 7】 A diagram showing an example of a histogram when the position of the subject 105 is displaced with respect to the FPD 102. 【Figure 8】 A diagram showing the configuration of a radiation imaging system according to the second embodiment. 【Figure 9】 A diagram exemplifying a table storing imaging condition information, reference output information, and reference weighting information. 【Figure 10】 A diagram exemplifying a table storing reference body size information, reference output information, and reference weighting information. 【Figure 11】 A diagram showing the configuration of a radiation imaging system according to the third embodiment. 【Mode for Carrying Out the Invention】 【0011】 Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, all of these plurality of features are not necessarily essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant descriptions are omitted. 【0012】 In the description of each of the following embodiments, the case where the disclosed technology is applied to an X-ray imaging apparatus that captures X-ray image data of a subject using X-rays, which is a type of radiation, as the radiation imaging apparatus will be described. Further, the disclosed technology is not limited to this X-ray imaging apparatus, and can also be applied to a radiation imaging apparatus that captures a radiation image of a subject using other radiations (for example, α-rays, β-rays, γ-rays, etc.). 【0013】 In addition, an explanation mainly regarding automatic exposure control (AEC) will be given. The disclosed technology can be used for radiation dose measurement (monitoring) for AEC, and the imaging device itself does not have to perform radiation control. Further, the disclosed technology may be used to detect the start of radiation irradiation, and may also be used to detect the end of radiation irradiation. 【0014】 (First Embodiment) FIG. 1 is a diagram showing a configuration example of a radiation imaging system 100 including a radiation imaging device according to the first embodiment. The radiation imaging system 100 is used, for example, when imaging a radiation image in a hospital. As a system configuration, the radiation imaging system 100 includes a radiation imaging device 102 that images a radiation image based on radiation irradiated from a radiation source 101, and an imaging control device 103. The imaging control device 103 is connected to, for example, a radiation control device 104 that controls the radiation imaging device 102 and the radiation source 101 via a wired or wireless network or a dedicated line, and controls radiation imaging using the radiation imaging device 102 and the radiation source 101. 【0015】 (Radiation Source 101) In FIG. 1, the radiation source 101 holds, for example, an X-ray tube that accelerates electrons at a high voltage to generate radiation and collides them with an anode, and a rotor. The radiation source 101 irradiates the subject 105 with X-rays. 【0016】 (Radiation Imaging Device 102) The radiation imaging device 102 is a flat panel detector (hereinafter abbreviated as FPD) in which a plurality of pixels are arranged in a matrix on a planar substrate, and has imaging elements distributed two-dimensionally. The FPD 102 detects a two-dimensional distribution (dose information) of the radiation dose that has passed through the subject 105 and reached the imaging elements, and generates image data. The FPD 102 transmits the generated image data (radiation image data) to the image processing unit 1034 of the imaging control device 103. Further, the FPD 102 transmits dose information of the two-dimensional distribution of the detected radiation dose and determination information for controlling the radiation irradiation in automatic exposure control to the imaging control device 103. 【0017】 The FPD 102 is provided with detection pixels including radiation detection elements for monitoring the radiation irradiation amount. The detection pixels are distributed and arranged within the FPD 102. The detection region 1021 is arranged within the FPD 102 and has a plurality of pixels for generating image data and a plurality of detection pixels. The radiation irradiation amount is monitored for each detection region, and a representative value is used as the pixel information of the detection pixels within each detection region. Here, as the pixel information (representative value) of the detection pixels within each detection region, in the following embodiments, the average value of the signals of the detection pixels will be described as an example, but it is not limited to this example. The pixel information (representative value) of the detection pixels may be, for example, the median value, the mode value, the integrated value, etc. based on the arithmetic processing of the signals detected by a plurality of detection pixels. 【0018】 Also, in the description of each of the following embodiments, the detection region will be exemplarily described using examples of five regions and nine regions, but the detection region is not limited to this example. In the automatic exposure control (AEC) according to the disclosed technology, since arithmetic processing is performed on the signal value (monitor signal value) obtained from the detection pixels in the selected detection region, it is not affected by the position, size, or the number of selected detection regions of the detection region. 【0019】 (Imaging control device 103) The imaging control device 103 relays communication between the FPD 102 and the radiation control device 104. The communication method in the imaging control device 103 may be wired communication or wireless communication. The imaging control device 103 includes an imaging condition setting unit 1031, an imaging control unit 1032, a processing unit 1033, an image processing unit 1034, a display control unit 1035, a storage unit 1036, and a communication IF unit 1037. The communication IF unit 1037 functions as a communication interface for transmitting and receiving data between the FPD 102 and the radiation control device 104. 【0020】 The storage unit 1036 can be configured by a storage medium including a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or an optical disk device. The storage unit 1036 stores various information obtained from each unit configuration, data, information about the subject, image data obtained by imaging the subject in the past, various computer programs for executing the processing of the imaging control device 103, and a table of reference weighting information for each detection area. 【0021】 FIG. 9 is a diagram illustrating a table storing imaging condition information, reference output information, and reference weighting information. In the table of reference weighting information, for each imaging condition information, a reference value (reference output information) of the output signal in each detection area and reference weighting information in each detection area are set. By referring to the table of the storage unit 1036, the reference value (reference output information) of the output signal in each detection area and the reference weighting information in each detection area set in each imaging condition information can be obtained as initial values. Here, the reference output information is an output signal output from a plurality of detection areas when there is no displacement of the subject with respect to the plurality of detection areas. The reference weighting information is a reference value of the weighting information when there is no displacement of the subject with respect to the plurality of detection areas. 【0022】 Each unit configuration of the imaging control device 103 can function according to a computer program. For example, the processing unit 1033 may read and execute a computer program stored in the storage unit 1036 or the like, thereby realizing the functions of each unit configuration. Alternatively, some or all of the functions of the unit configuration of the imaging control device 103 may be realized by using dedicated circuits. In the imaging control device 103, communication delays and processing delays between units are managed according to the communication method, communication content, and processing content. Therefore, each unit in the imaging control device 103 can communicate while anticipating communication delays and processing delays. 【0023】 Next, the functional configuration of the imaging control device 103 will be described. 【0024】 (Imaging condition setting unit 1031) The imaging condition setting unit 1031 receives imaging condition information input by the operator via the operation input unit 108, and transmits the received imaging condition information to the imaging control unit 1032 and the processing unit 1033. Here, the imaging condition information includes, for example, subject information such as age, gender, and physique regarding the subject to be imaged, the imaging part of the subject, tube voltage, tube current, irradiation time, threshold information for controlling the signal output to the radiation source 101 so as to stop the radiation source 101 at a predetermined dose, and the like. The imaging condition information also includes reference output information for each detection area used for controlling radiation irradiation, reference weighting information, and the like. The imaging condition information input by the operator can be stored in the storage unit 1036. 【0025】 (Processing unit 1033) The processing unit 1033 transmits dose information and determination information for controlling radiation irradiation in automatic exposure control, which are transmitted from the FPD 102, to the imaging control unit 1032. Here, the "dose information" generally indicates the dose of radiation that has reached the FPD 102 among the irradiation doses of the radiation irradiated from the radiation source 101, but dose information similar to this may also be used. 【0026】 The processing unit 1033 has a reference weighting unit 1038 as a functional configuration. Based on the imaging condition information set by the imaging condition setting unit 1031, the reference weighting unit 1038 sets reference output information and reference weighting information for the detection area in the FPD 102. When there are a plurality of detection areas within the pixel area of the FPD 102, the reference weighting unit 1038 sets the reference output information and the reference weighting information for each detection area. 【0027】 When imaging condition information for imaging the subject 105 is input from the imaging condition setting unit 1031, the reference weighting unit 1038 refers to the table in the storage unit 1036 to identify the imaging condition information corresponding to the input imaging condition information. Based on the identified imaging condition information, the reference weighting unit 1038 acquires, as initial values, the reference value (reference output information) of the output signal in each detection area and the reference weighting information in each detection area, and transmits them to the FPD 102 via the communication IF unit 1037. 【0028】 The FPD 102 has an FPD processing unit 200 (Figure 2) that processes the output signal output from the detection area. The weighting unit 202 in the FPD processing unit 200 sets the reference value (reference output information) of the output signal transmitted from the reference weighting unit 1038 as a reference value for comparing with the output signal (monitor signal value) that is output in real time from each detection area by the imaging of the FPD 102. 【0029】 Also, the weighting unit 202 sets the reference weighting information transmitted from the reference weighting unit 1038 as the initial value of the weighting information for each detection area. The weighting unit 202 changes the reference weighting information set as the initial value based on the comparison between the output signal (monitor signal value) output in real time from each detection area and the reference value (reference output information) of the output signal. Specific processing related to the weighting unit 202 will be described in detail later. 【0030】 (Imaging control unit 1032) The imaging control unit 1032 controls the radiation control device 104 and the FPD 102 based on the imaging condition information received from the imaging condition setting unit 1031 and the information received from the processing unit 1033. 【0031】 (Image processing unit 1034) The image processing unit 1034 performs processes such as dark current correction, gain correction, defect correction, gradation processing, and noise reduction processing on the radiation image data transmitted from the FPD 102. The image processing unit 1034 transmits the radiation image data after image processing to the display control unit 1035. 【0032】 (Display control unit 1035) The display control unit 1035 performs display control to display the image information transmitted from the image processing unit 1034 on a display unit 106 such as a monitor. The display unit 106 is constituted by an arbitrary device such as, for example, a liquid crystal display (LCD: Liquid Crystal Display), a CRT (Cathode Ray Tube), a plasma display panel, or an organic EL panel, and displays the radiation image data after image processing acquired from the image processing unit 1034. 【0033】 (Explanation of AEC operation) Next, an outline of the AEC operation during subject imaging will be described with reference to FIG. 1. Before imaging the subject, imaging condition information including subject information such as age, gender, and build regarding the subject to be imaged, the imaging site of the subject, tube voltage, tube current, irradiation time, and threshold information for controlling the signal output to the radiation source 101 to stop the radiation source 101 at a predetermined dose is set in the imaging condition setting unit 1031. At this time, the reference output information and reference weighting information of the detection region used for controlling the radiation irradiation may be input. The imaging condition information input here may be sent to the imaging control unit 1032 and the processing unit 1033 and stored in the table of the storage unit 1036. 【0034】 When the irradiation switch 107 attached to the radiation control device 104 is pressed, the radiation control device 104 controls the radiation source 101 to start radiation irradiation. After the radiation source 101 starts irradiation, when the cumulative dose of radiation reaches a predetermined dose, determination information (irradiation stop signal) is transmitted from the FPD 102 to the imaging control device 103, and an irradiation stop signal is sent from the imaging control device 103 to the radiation control device 104. When the radiation control device 104 receives the irradiation stop signal, it controls the radiation source 101 to stop the radiation irradiation from the radiation source 101. 【0035】 At this time, the predetermined dose is a value calculated in consideration of the dose set before imaging of the subject, the change in X-ray irradiation intensity, the communication delay between units, and the processing delay. Also, when the set irradiation time before imaging of the subject is reached, the radiation control device 104 stops the radiation irradiation of the radiation source 101 regardless of the presence or absence of the irradiation stop signal. 【0036】 (Functional configuration of the FPD processing unit 200) Next, with reference to FIG. 2, the functional configuration related to the automatic exposure control (AEC) provided in the radiation imaging device 102 (FPD) will be described. The FPD processing unit 200 of the radiation imaging device 102 is provided in a pixel region in which a plurality of pixels for detecting radiation are arranged, and processes output signals output from a plurality of detection regions including detection pixels that output signals corresponding to the radiation irradiation amount. The FPD processing unit 200 has, as a functional configuration, a signal synthesis unit 201, a weighting unit 202, a determination information setting unit 203, a threshold determination unit 204, and a communication IF unit 205. Here, the communication IF unit 205 functions as a communication interface for performing data transmission and reception with the imaging control device 103. 【0037】 (Signal synthesis unit 201) The signal synthesizing unit 201 receives the output signals (hereinafter referred to as monitor signal values) output from each detection area (for example, the detection area 1021 in FIG. 1), and performs signal synthesis processing on the received monitor signal values, and outputs monitor signal values (also referred to as synthesized monitor signal values) after the synthesis processing. Here, the monitor signal value (synthesized monitor signal value) may be, for example, the average value of the detection pixel signal values included in each area, or the average value of a predetermined number of detection pixel signal values selected from among a plurality of detection pixels included in the detection area. 【0038】 (Weighting unit 202) The weighting unit 202 sets the reference value (reference output information) of the output signal transmitted from the reference weighting unit 1038 of the imaging control device 103 as a reference value for comparing with the output signal (monitor signal value) output from each detection area in real time by the imaging of the FPD 102. Further, the weighting unit 202 sets the reference weighting information transmitted from the reference weighting unit 1038 as the initial value of the weighting information for each detection area. 【0039】 During imaging, the weighting unit 202 generates weighting information for each detection area by comparing the output signal (monitor signal value) output from each detection area in real time with the reference value (reference output information) of the output signal, and changes the reference weighting information set as the initial value. 【0040】 Based on the weighting information for each detection area and the monitor signal value (synthesized monitor signal value) output from the signal synthesizing unit 201, the weighting unit 202 generates dose information. As a specific process, the weighting unit 202 multiplies the monitor signal value (synthesized monitor signal value) by the weighting information for each detection area to generate dose information (weighted monitor signal value). 【0041】 The weighting unit 202 may acquire output information (reference output information) and reference weighting information from the imaging control device 103 via the communication IF unit 205, or may hold or generate the reference output information and reference weighting information to generate weighting information for each detection area. The reference output information may be, for example, a plurality of pieces held or generated in association with subject information such as an imaging site, physique, and age, or imaging condition information such as tube voltage and grid. 【0042】 As the output information (reference output information), for example, the position of the subject with respect to the FPD 102 (a plurality of detection areas) may be used as a reference, or the ratio of the output information (reference output information) in the plurality of detection areas may be used as a reference. Alternatively, it is also possible to use, as a reference, information (reference physique information) set based on the physique of the subject (for example, an adult, a child, etc., the width and thickness of the body, etc.). The weighting unit 202 may select a predetermined number of detection pixels as representatives from a plurality of detection pixels in the detection area, and perform a weighting operation on the monitor signal value from the selected representative detection pixels. In this case, the computational burden can be reduced compared to weighting all the detection pixels in the detection area. Further, the weighting unit 202 may further select detection pixels at necessary positions from among the selected detection pixels. 【0043】 (Determination information setting unit 203) The determination information setting unit 203 sets a threshold value for the dose information indicating the representative value for each detection area. Note that the threshold value set in the determination information setting unit 203 may be set by the imaging condition setting unit 1031 of the imaging control device 103 and information included in the imaging condition information acquired via the communication IF unit 205 may be used. Here, the set threshold value is information for determining whether the dose of the irradiated radiation has reached the cumulative dose in the AEC operation. 【0044】 (Threshold determination unit 204) The weighting unit 202 of the processing unit 200 generates weighting information for a plurality of detection regions by comparing the output signal with preset reference information. The threshold determination unit 204 generates determination information for controlling the irradiation of radiation by comparing the weighted dose information obtained by weighting the output signal based on the generated weighting information with a preset threshold value. The threshold determination unit 204 determines whether the irradiation dose from the radiation source 101 has reached a predetermined cumulative dose by comparing the threshold value set by the determination information setting unit 203 with the dose information (weighted monitor signal value) generated by the weighting unit 202. Then, the threshold determination unit 204 generates determination information for controlling the irradiation of radiation based on the result of this determination. Here, the determination information becomes information (irradiation control information) for controlling (continuing or stopping the irradiation) the irradiation of radiation in AEC. The determination information generated by the threshold determination unit 204 is transmitted to the imaging control unit 1032 via the communication IF unit 205. 【0045】 Before reaching the preset irradiation time before imaging the subject, if the dose information (monitor signal value × weighting information) is less than the threshold value, the determination information becomes information (irradiation continuation signal) instructing the continuation of the irradiation of radiation. If the dose information is equal to or greater than the threshold value, the determination information becomes information (irradiation stop signal) instructing the stop of the irradiation of radiation. When the preset irradiation time before imaging the subject is reached, the radiation control device 104 stops the radiation irradiation of the radiation source 101 regardless of the presence or absence of the irradiation stop signal. 【0046】 The threshold determination unit 204 may compare the threshold value with the dose information based on a determination method (AND condition, OR condition, AVG condition, etc.) expressed by a logical formula to determine whether the irradiation dose has reached a predetermined cumulative dose. 【0047】 When performing the determination process using the AND condition (logical product), the threshold determination unit 204 determines whether the dose information of a plurality of detection regions is all equal to or greater than the threshold using the AND condition (logical product). When the dose information of all the plurality of detection regions is equal to or greater than the threshold, determination information (irradiation stop signal) for stopping the radiation irradiation is generated and output. For example, when the dose information in the detection region with the lowest dose information among the plurality of detection regions is equal to or greater than the threshold, the irradiation stop signal is generated and output. In the determination process based on the AND condition (logical product), radiographic imaging can be performed without a dose shortage in all of the plurality of detection regions. 【0048】 Alternatively, when performing the determination process using the OR condition (logical sum), the threshold determination unit 204 determines whether any one of the dose information of a plurality of detection regions is equal to or greater than the threshold using the OR condition (logical sum). When the dose information of any one of the detection regions is equal to or greater than the threshold, determination information (irradiation stop signal) for stopping the radiation irradiation is generated and output. 【0049】 For example, when the dose information in the detection region with the highest dose information among the plurality of detection regions is equal to or greater than the threshold, the irradiation stop signal is generated and output. In the determination process based on the OR condition (logical sum), radiographic imaging that suppresses excessive radiation irradiation can be performed. 【0050】 Also, when performing the determination process using the AVG condition (averaging), the threshold determination unit 204 determines whether the dose information obtained by averaging the dose information of a plurality of detection regions is equal to or greater than the threshold using the AVG condition (averaging). When the averaged dose information is equal to or greater than the threshold, determination information (irradiation stop signal) for stopping the radiation irradiation is generated and output. 【0051】 The determination method expressed by logical expressions (AND condition, OR condition, AVG condition, etc.) may be set as default, or the camera operator may change the setting of the determination method. Alternatively, the FPD processing unit 200 may change the setting of the logical expression of the determination method according to the imaging condition information set by the imaging condition setting unit 1031. Alternatively, during imaging by the FPD 102, the FPD processing unit 200 may change the setting of the determination method (AND condition, OR condition, AVG condition, etc.) in the automatic exposure control (AEC) according to the comparison between the monitor signal value and the reference output information (reference output information). 【0052】 In FIG. 2, the functional configuration of the FPD processing unit 200 is provided on the FPD 102 side, and the configuration in which the FPD 102 side executes the determination function of the automatic exposure control (AEC) is described. However, the present invention is not limited to this configuration. The functional configuration of the FPD processing unit 200 may be provided in the processing unit 1033 of the imaging control device 103, and the imaging control device 103 side may execute the determination function of the AEC. In this case, the monitor signal value of each detection area may be transmitted from the FPD 102 to the imaging control device 103 via the communication IF unit 205, and based on the received monitor signal value, the processing unit 1033 of the imaging control device 103 may execute the processing related to the determination function of the AEC. 【0053】 (AEC operation) Next, with reference to FIG. 3, automatic exposure control (AEC) when there is a positional shift of the subject with respect to the FPD 102, which is a problem in the radiation imaging apparatus 102 according to the first embodiment, will be described. FIG. 3 is a diagram showing an example of variations in monitor signal values in automatic exposure control when the position of the subject 105 according to the embodiment is shifted in the vertical direction of the paper surface with respect to the radiation imaging apparatus 102 (FPD). Here, the detection region 1021 will be described using examples of five detection regions A to E. Identification information (for example, A to E) is set in the detection region, and each detection region can be identified based on the identification information. In the five exemplary detection regions A to E shown, the detection regions A and B are provided on the upper side (upper stage side) of the paper surface within the detection surface of the FPD 102. The detection regions D and E are provided on the lower side (lower stage side) of the paper surface within the detection surface of the FPD 102 compared to the positions of the detection regions A and B. The vertical position of the detection region C is provided between the positions of the detection regions A and B and the positions of the detection regions D and E within the detection surface of the FPD 102. Also, the horizontal position of the detection region C is provided between the positions of the detection regions A and D and the positions of the detection regions B and E within the detection surface of the FPD 102. 【0054】 302 in FIG. 3(A) shows a situation where the position of the subject 105 has shifted upward with respect to the FPD 102. At this time, the detection regions A to E of the FPD 102 will be relatively located below the subject 105. 【0055】 In the detection regions D and E located below (lower stage) the detection regions A to C, since the proportion of the abdominal part with a low radiation transmittance in the subject structure within the detection region increases, the monitor signal values detected in the detection regions D and E may decrease. 【0056】 On the other hand, in the detection regions A, B, and C, although the subject structure within the detection region does not change significantly, in the detection regions A, B, and C, since the proportion of the subject structure having the same radiation transmittance increases, the monitor signal values detected in the detection regions A, B, and C may increase. 【0057】 In a situation where the subject 105 is shifted upward with respect to the FPD 102, compared to the case where the subject 105 is located at the center of the FPD 102 (when there is no relative positional shift: 301 in Fig. 3(A)), the monitor signal values in the detection regions D and E may decrease. As a result, when performing AEC based on the monitor signal values of the detection regions D and E, the time until a predetermined dose is reached becomes longer, and the subject 105 is irradiated with more radiation than the predetermined dose. Also, when performing AEC based on the monitor signal values of the detection regions A, B, and C, the time until a predetermined dose is reached becomes shorter, and the subject 105 is irradiated with less radiation than the predetermined dose. 【0058】 Fig. 3(B) shows a situation where the position of the subject 105 is shifted downward with respect to the FPD 102. At this time, the detection regions A to E of the FPD 102 will be located relatively above the subject 105. 【0059】 In the detection regions D and E located below (lower stage) the detection regions A to C, since the proportion of the subject structure in the detection region occupied by the abdomen with a low radiation transmittance becomes smaller, the monitor signal detected in the detection regions D and E may increase. 【0060】 On the other hand, in the detection regions A, B, and C, although the subject structure in the detection region does not change significantly, in the detection regions A, B, and C, since the proportion of the subject structure having the same radiation transmittance decreases, the monitor signal values detected in the detection regions A, B, and C may decrease. 【0061】 In a situation where the subject 105 has shifted downward with respect to the FPD 102, compared to the case where the subject 105 is located at the center of the FPD 102 (when there is no relative displacement), the monitor signal values in the detection regions D and E can increase. As a result, when performing AEC based on the monitor signal values of the detection regions D and E, the time until a predetermined dose is reached becomes shorter, and the subject 105 is irradiated with less radiation compared to the predetermined dose. Also, when performing AEC based on the monitor signal values of the detection regions A, B, and C, the time until a predetermined dose is reached becomes longer, and the subject 105 is irradiated with more radiation compared to the predetermined dose. 【0062】 Thus, since the monitor signal value changes due to the relative displacement between the subject 105 and the FPD 102, variations occur with respect to the dose of the reference output (during ideal imaging). 【0063】 FIG. 7 is a diagram showing an example of a histogram when the position of the subject 105 is displaced with respect to the FPD 102. The histogram 701 in FIG. 7(A) is a histogram showing a state where no displacement has occurred. The histogram 701 is the histogram in the case 301 where the subject 105 is located at the center of the FPD 102, shown in FIGS. 3(A) and (B). 【0064】 Here, α1 is the reference output information (reference output information) in the detection regions A, B, and C, and α2 is the reference output information (reference output information) in the detection regions D and E. β1 indicates the number of pixels in the detection region that outputs the monitor signal value corresponding to the reference output information α1. FIG. 7(A) shows a state where there is no displacement of the subject 105 with respect to the FPD 102 (a plurality of detection regions), and in the reference output information α1 in the detection regions A, B, and C and the reference output information α2 in the detection regions D and E, the histogram forms a peak. 【0065】 The histogram 702 in FIG. 7(B) corresponds to 302 in FIG. 3(A) and shows a situation where the position of the subject 105 with respect to the FPD 102 has shifted upward. The arrow 710 in the histogram 702 indicates the amount of shift upward from the central portion 700 of the FPD 102. 【0066】 In the detection regions D and E, since the proportion of the subject structure in the detection region occupied by the abdomen with a low radiation transmittance increases, the number of pixels in the detection regions D and E that output the monitor signal value corresponding to the reference output information α2 can decrease. 【0067】 On the other hand, in the detection regions A, B, and C, since the proportion of the subject structure having the same radiation transmittance increases, the number of pixels in the detection regions A, B, and C that output the monitor signal value corresponding to the reference output information α1 can increase. For example, when performing threshold determination based on the AND condition (logical product), in the detection regions D and E, the monitor signal value is lower than the assumed reference output information α2, and the time until the threshold is reached becomes longer, so it may be set to increase the weighting information. 【0068】 The histogram 703 in FIG. 7(C) corresponds to 303 in FIG. 3(B) and shows a situation where the position of the subject 105 with respect to the FPD 102 has shifted downward. The arrow 720 in the histogram 703 indicates the amount of shift downward from the central portion 700 of the FPD 102. 【0069】 In the detection regions D and E, since the proportion of the subject structure in the detection region occupied by the abdomen with a low radiation transmittance decreases, as shown in the histogram 703, the number of pixels in the detection regions D and E that output the monitor signal value corresponding to the reference output information α2 can increase. 【0070】 On the other hand, in the detection regions A, B, and C, although the subject structure within the detection regions does not change significantly, the proportion of the subject structure having the same radiation transmittance decreases in the detection regions A, B, and C. Therefore, in the detection regions A, B, and C, the number of pixels in the detection regions A, B, and C that output the monitor signal value corresponding to the reference output information α1 may decrease. For example, when performing threshold determination based on the OR condition (logical sum), in the detection regions D and E, the monitor signal value increases compared to the assumed reference output information α2, and the time until the threshold is reached becomes shorter. Thus, it may be set to reduce the weighting information. 【0071】 The weighting unit 202 may compare the histogram 701 assumed as a reference with the histograms 702 and 703 obtained by analyzing the monitor signal values output from each detection region during imaging. Then, the weighting unit 202 may obtain the displacement (displacement amount and displacement direction) of the subject 105 with respect to each detection region in the FPD 102 by obtaining the ratio of the peaks by pattern matching. If no displacement occurs, the peaks of the histograms in the histograms 702 and 703 may have the same pattern as the peak of the reference histogram 701. The reference histogram 701 may be stored, for example, in association with the imaging condition information in the table of FIG. 9, and the pattern of the histogram 701 may be obtained together with the reference weighting information and the reference output information. 【0072】 Next, the weighting in the radiation imaging apparatus 102 according to the first embodiment will be described. The weighting unit 202 of the FPD processing unit 200 generates weighting information for each detection area based on a comparison between the monitor signal value output from each detection area and a reference value (reference output information) of the output signal. For each detection area, the reference weighting information transmitted from the reference weighting unit 1038 of the imaging control device 103 is set as the initial value of the weighting information for each detection area. The weighting unit 202 changes the reference weighting information set as the initial value based on the weighting information generated based on the comparison between the monitor signal value output in real time from each detection area and the reference output information. The weighting unit 202 sets weighting information representing weights for each of the plurality of detection areas. 【0073】 The weighting unit 202 performs weighting on the monitor signal value (synthesized monitor signal value) output from the signal synthesizing unit 201 using the weighting information. When performing automatic exposure control (AEC), the weighting unit 202 generates dose information (weighted monitor signal value (synthesized monitor signal value)) based on the weighting information for each detection area and the monitor signal value (synthesized monitor signal value) output from the signal synthesizing unit 201. The weighting unit 202 performs weighting on the monitor signal value (synthesized monitor signal value) by calculating (multiplying) the weighting information. The calculation of the weighting information set for each detection area will be described in detail later. 【0074】 Note that the monitor signal value (synthesized monitor signal value) used in the calculation here may be, for example, the average value of the monitor signal values of the detection pixels included in each detection area, or the average value of the monitor signal values of a predetermined number of detection pixels selected from among the plurality of detection pixels included in the detection area. 【0075】 Based on the dose information (weighted monitor signal value) generated by the weighting unit 202, or the weighted average value of the weighted monitor signal values, the threshold determination unit 204 generates determination information for determining whether to continue the automatic exposure control (AEC). Here, the weighted average value can be expressed as (a*l + b*m + c*n + ··· + e*p) / (l + m + n + ··· + p), where a, b, c, ···, e are the monitor signal values detected in each detection region, and l, m, n, ···, p are the weights corresponding to the monitor signal values in each detection region. 【0076】 Next, an overview of the generation of weighting information and the determination of AEC using the positional deviation information of the subject 105 in the radiation imaging apparatus 102 according to the first embodiment will be described. FIG. 4 is a diagram showing an example of weighting based on dose information when the position of the subject 105 according to the first embodiment is shifted upward with respect to the radiation imaging apparatus 102 (FPD) in the plane of the paper. Using FIG. 4, the generation process of weighting information based on dose information in the situation where the position of the subject 105 is shifted upward with respect to the FPD 102 in the imaging of the anterior chest will be exemplarily described. 【0077】 In FIG. 4(A), the case where the EI (Exposure Index) value, which is a dose index value, is used as the output information (reference output information) serving as the reference for the monitor signal value will be described as an example. The weighting unit 202 may hold the reference output information of the monitor signal value in the internal memory, or may acquire the reference output information of the monitor signal value stored in the storage unit 1036 from the imaging control device 103 via the communication IF unit 205. Further, a configuration similar to that of the storage unit 1036 may be provided inside the FPD processing unit 200, and the information and tables acquired from the imaging control device 103 may be stored. That is, the FPD processing unit 200 may have an internal storage unit that stores imaging condition information for imaging a radiation image, reference output information associated with the imaging condition information, and reference weighting information for a plurality of detection regions. 【0078】 Here, the case where the position of the subject 105 is centered with respect to the FPD 102 (a state where there is no relative positional shift) is taken as a reference. The weighting unit 202 generates weighting information set for each detection region by comparing output information (reference output information) based on the position of the subject with respect to the FPD 102 (a plurality of detection regions) and the monitor signal values in each detection region. The weighting unit 202 may set, for example, signal values (signal information) obtained from an image of the same subject 105 captured in the past as reference output information of the reference monitor signal value. Here, an image of the same subject 105 captured in the past may be held, for example, in the internal memory of the weighting unit 202, or may be stored in the storage unit 1036 of the imaging control device 103. The weighting unit 202 may acquire the image information of the subject 105 from the internal memory, or may acquire the image information of the same subject 105 captured in the past from the imaging control device 103 via the communication IF unit 205. 【0079】 As shown in the display example 401 of FIG. 4(A), the reference output information of the monitor signal values in the detection regions A to E is 300 in the detection region A (A: 300), 300 in the detection region B (B: 300), 100 in the detection region C (C: 100), 150 in the detection region D (D: 150), and 150 in the detection region E (E: 150). 【0080】 The weighting unit 202 receives the monitor signal value of the detection region selected from a plurality of detection regions in the FPD 102. In the example shown in the display example 402 of FIG. 4(A), the detection regions A to E are the selected detection regions, and the monitor signal values detected in each detection region are 360 in the detection region A (A: 360), 360 in the detection region B (B: 360), 120 in the detection region C (C: 120), 120 in the detection region D (D: 120), and 120 in the detection region E (E: 120). 【0081】 In the situation where the subject 105 has shifted upward with respect to the FPD 102, in the detection regions D and E, since the proportion of the abdominal part with a low radiation transmittance in the subject structure within the detection regions increases, the monitor signals (D: 120, E: 120) detected in the detection regions D and E decrease compared to the reference output information (D: 150, E: 150), and have decreased to 0.8 times the reference output information. 【0082】 On the other hand, in the detection regions A, B, and C, although the subject structure within the detection regions has not changed significantly, the monitor signal values (A: 360, B: 360, C: 120) detected in the detection regions A, B, and C increase compared to the reference output information (A: 300, B: 300, C: 100), and have increased to 1.2 times the reference output information. 【0083】 As a result, the monitor signal values in the detection regions D and E decrease, so the time until a predetermined dose is reached becomes longer, and the radiation dose to the subject 105 increases. The weighting unit 202 calculates the deviation of the monitor signal value with respect to the reference output information and calculates the weight for each detection region. 【0084】 The weighting unit 202 performs an operation of dividing the reference output information by the detected monitor signal value (reference output information / detected monitor signal value) to obtain information indicating the deviation of the monitor signal value with respect to the reference output information (reference output ratio: output ratio with respect to the reference output information) (display example 403). 【0085】 As shown in the display example 403 of FIG. 4(A), the information indicating the deviation of the monitor signal value with respect to the reference output information (output ratio with respect to the reference output information) is A: 300 / 360 = 0.83 in the detection region A and B: 300 / 360 = 0.83 in the detection region B (display example 403 in FIG. 4(A)). Also, in the detection region C, C: 100 / 120 = 0.83, in the detection region D, D: 150 / 120 = 1.25, and in the detection region E, E: 150 / 120 = 1.25 (display example 403 in FIG. 4(A)). 【0086】 For the detection regions A, B, and C where no change has occurred in the object structure, the weighting unit 202 sets "1" as the weight for the current monitor signal value and maintains the current monitor signal value (404 in Fig. 4(A)). 【0087】 When the weighting unit 202 determines the monitor signal value of the detection region D so that the relationship between the monitor signal values between the detection region A (monitor signal value A: 360) and the detection region D satisfies the ratio 2:1 (A(300):D(150)) of the reference output information, the required monitor signal value in the detection region D is D: 180. On the other hand, the current monitor signal value in the detection region D is D: 120, and the weighting unit 202 sets the weight "1.5" of the detection region D required to satisfy the ratio 2:1 of the reference output information (404 in Fig. 4(A)). The weighting unit 202 sets the weight "1.5" in the detection region E in the same manner as in the detection region D (404 in Fig. 4(A)). 【0088】 In this case, for example, by multiplying the monitor signal value "360" in the detection region A by the weighting information "1", the weighting unit 202 obtains the weighted monitor signal value "360". Similarly, by multiplying the monitor signal value "120" in the detection region D by the weighting information "1.5", the weighting unit 202 obtains the weighted monitor signal value "180", and the ratio of the weighted monitor signal values is A(A: 360):D(D: 180) = 2:1. The ratio (2:1) of the weighted monitor signal values is equal to the ratio (A(300):D(150) = 2:1) of the reference output information (display example 401 in Fig. 4(A)). The weighting unit 202 of the processing unit 200 generates weighting information so as to reduce the deviation of the output signal (monitor signal value) with respect to the reference output information. 【0089】 In the example of FIG. 4(A), for the FPD 102, imaging may be pre - performed with the position of the subject 105 being displaced, and the generated reference output information and reference weighting information may be acquired and stored in a table as shown in FIG. 9. Note that the disclosed technology is not limited to the example of FIG. 4(A), and it can also be applied when calculating the weighting information for each detection area during radiation irradiation and changing the reference weighting information set as the initial value. 【0090】 The weighting unit 202 of the processing unit 200 acquires the ratio of output signals (monitor signal values) output from a predetermined detection area during imaging of a radiation image, and the weighting unit 202 of the processing unit 200 generates weighting information so as to match the ratio of the output signals (monitor signal values) to the ratio of the reference output information. In FIG. 4(B), an example of using the ratio of reference output information (reference output ratio) in a specific detection area to generate weighting information during radiation irradiation will be described. The weighting unit 202 sets the ratio of reference output information (reference output ratio) serving as a reference based on the held reference output information. In the display example 411 of FIG. 4(B), the reference output ratios in the detection areas A and D are A:D = 2:1. Also, the reference output ratios in the detection areas B and E are B:E = 2:1. 【0091】 The weighting unit 202 receives the monitor signal values of the detection areas A to E selected from a plurality of detection areas in the FPD 102, analyzes the monitor signal values for each of the detection areas A to E, and acquires the output ratio of the monitor signal values for each of the detection areas A to E. 【0092】 As shown in the display example 412 of FIG. 4(B), the output ratio of the monitor signal value 360 (A:360) in the detection area A and the monitor signal value 120 (D:120) in the detection area D is A:D = 3:1. Similarly, the output ratio of the monitor signal value 360 (B:360) in the detection area B and the monitor signal value 120 (E:120) in the detection area E is B:E = 3:1. 【0093】 For example, with respect to detection regions A and D, the weighting unit 202 compares the output ratio (3:1) of the monitored signal values for each acquired detection region with the output ratio of the reference detection region (reference output ratio (2:1)). Then, the weighting unit 202 calculates the weights of each detection region so that the output ratio becomes the same as the output ratio of the reference detection region (reference output ratio). As shown in display example 413 of FIG. 4(B), the weighting unit 202 sets the weights for detection regions A to E so that they are equal to the reference output ratio (A:D = B:E = 2:1). Specifically, the weighting unit 202 sets the weighting information for each detection region to A:1, B:1, C:1, D:1.5, E:1.5. 【0094】 Based on the set weighting information, the weighting unit 202 performs an operation represented by "weighting information" * "monitored signal value" on each monitored signal value received from the signal synthesis unit 201 to generate dose information (weighted monitored signal value), and transmits it to the threshold determination unit 204. 【0095】 The threshold determination unit 204 determines whether the weighted monitored signal value exceeds the threshold (condition) based on a determination method expressed by a logical formula (AND condition, OR condition, AVG condition, etc.). If the threshold is exceeded, the threshold determination unit 204 generates determination information (irradiation stop signal) indicating that the weighted monitored signal value has exceeded the threshold via the communication IF unit 205, and transmits it to the imaging control device 103 via the communication IF unit 205. 【0096】 In the example described with reference to FIGS. 4(A) and 4(B), the case where the weighting unit 202 holds the reference output information has been exemplarily described. However, the present invention is not limited to this example, and the weighting unit 202 can generate the weighting information without holding the reference output information. With reference to FIG. 5, the case where the weighting unit 202 can generate the weighting information without holding the reference output information serving as a reference will be described. When the imaging part of the subject is imaging using detection areas at symmetric positions among a plurality of detection areas, the weighting unit 202 of the processing unit 200 generates weighting information such that the ratios of the output signals (monitor signal values) output from the detection areas at the symmetric positions during the imaging of the radiation image become equal. 【0097】 In the example shown in FIG. 5, in the case of frontal imaging where the output ratios of the left and right monitor signal values are equal in the left and right detection areas, the weighting unit 202 generates weighting information on the assumption that the output ratios of the monitor signal values in the left and right detection areas are equal. The weighting unit 202 can determine the imaging part of the subject 105 based on the imaging condition information acquired from the imaging control device 103 via the communication IF unit 205, and determine whether the imaging (frontal imaging) is such that the output ratios of the monitor signal values are equal in the left and right detection areas. When the imaging (frontal imaging) is such that the output ratios of the monitor signal values are equal in the left and right detection areas, the weighting unit 202 generates weighting information using the left - right symmetry. 【0098】 In the display example 501 shown in FIG. 5, in the frontal chest imaging, the position of the subject 105 is shifted to the right with respect to the FPD 102, and the output ratio of the monitor signal values output from the left and right detection areas A and detection area B is A:B = 3:4. 【0099】 The weighting unit 202 obtains an output ratio 3.5 (= (3 + 4) / 2) of the averaged monitor signal values so that the output ratios of the monitor signal values of the left and right detection regions A and B are equal on the left and right. The output ratio of the averaged monitor signal values (A:B = 3.5:3.5) can be the reference output ratio of the monitor signal values in the left and right detection regions. The weighting unit 202 calculates the weights of the left and right detection regions A and B so that the output ratio is the same as the output ratio of the averaged monitor signal values. In this case, the weighting unit 202 obtains 1.17 (= 3.5 / 3) as the weighting information for the detection region A (display example 502 in FIG. 5). Also, the weighting unit 202 obtains 0.88 (= 3.5 / 4) as the weighting information for the detection region B (display example 502 in FIG. 5). 【0100】 In addition, there may be a case where there is an obstacle such as a pacemaker in the subject 105, and the deviation between the monitor signal value output from the detection region and the reference output information as a reference becomes extremely large. In such cases, there is a possibility of erroneously inferring the deviation of the position of the subject 105, and there may also be a case where the weighting information cannot be accurately generated. To cope with such cases, the FPD processing unit 200 may have a function to select not to perform weighting. If it is known in advance that there is an obstacle in the subject 105, the imaging condition setting unit 1031 may be able to select not to perform weighting. Information indicating that weighting is not performed (weighting non-execution information) is transmitted to the FPD processing unit 200 of the FPD 102 via the communication IF unit 1037. When the weighting unit 202 of the FPD processing unit 200 receives the weighting non-execution information via the communication IF unit 205, it can refrain from generating the weighting information. 【0101】 Alternatively, weighting may not be performed during radiation irradiation based on the analysis result of the monitor signal value. For example, when the deviation between the monitor signal value output from the detection region and the reference output information as a reference becomes equal to or greater than a predetermined value, the weighting unit 202 can also be configured not to perform weighting. At this time, the weighting unit 202 can transmit information indicating that weighting is not performed (weighting non-execution information) to the display control unit 1035 of the imaging control device 103 via the communication IF unit 205, and cause the display unit 106 to display that weighting is not performed, thereby notifying the operator. 【0102】 (Second Embodiment) Next, a second embodiment of the disclosed technology will be described. In the first embodiment, a configuration for generating weighting information using the positional deviation information of the subject 105 with respect to the FPD 102 was described. In the second embodiment, a configuration for generating weighting information using the deviation information from the standard reference physical information regarding the physical information of the subject 105, such as the size and thickness of the subject, will be described. 【0103】 FIG. 6(A) is a diagram exemplarily showing a case where a child is imaged as a subject. With reference to FIG. 6(A), a case where a deviation of the monitor signal value occurs with respect to the reference output information as a reference due to the size of the subject being smaller than the standard reference physical information will be described. Here, for the detection region of the FPD 102, there are nine detection regions A to I arranged in three rows and three columns, and a case where the detection regions selected from the nine detection regions A to I are the three detection regions D, E, and F will be described as an example. 【0104】 When the size of the subject 105 is smaller than the standard reference physical information as a reference, there may be a case where an X-ray directly enters the FPD 102 without passing through the subject 105, resulting in a missing area in the selected detection regions D, E, and F. For example, in the detection region E located in the center, no missing area occurs, but in the detection regions D and F located on the left and right of the detection region E, a missing area may occur. 【0105】 The weighting unit 202 of the processing unit 200 compares the distribution of the peaks of the output signals (monitor signal values) for each of the plurality of detection regions, identifies the detection regions that output the output signals (monitor signal values) of the peaks larger than the reference output information, and sets the weighting information of the identified detection regions to be smaller than the weighting information for the detection regions that output the output signals corresponding to the reference information. FIG. 6(B) is a diagram showing the result of performing a histogram analysis of the monitor signal values for each detection region. As shown in 601 of FIG. 6(B), in the detection region E where no missing region has occurred, there is almost no shift in the peak with respect to the reference output information α. On the other hand, as shown in 602 of FIG. 6(B), in the detection regions D and F where missing regions have occurred, the peak of the output information α' of the monitor signal values of the detection regions where missing has occurred becomes larger with respect to the reference output information α. That is, a state where a peak shift occurs with respect to the reference output information α is reached. Therefore, the weighting unit 202 can reduce the influence of the occurrence of missing regions in the determination of AEC (determination of whether a predetermined cumulative dose has been reached) by reducing the weighting for the detection regions D and F. 【0106】 In this example, assuming that the monitor signal value is the average value within the detection region, the weighting unit 202 can obtain the monitor signal values M(D, E) in the detection regions D and F by the following equation (1). Monitor signal value M(D, E) ≒ α + (α' - α) × β' / (β + β') ··· (1) Here, α is the reference output information (reference output information), α' is the output information of the monitor signal value of the detection region where missing has occurred, β indicates the number of pixels of the detection region that outputs the monitor signal value corresponding to the reference output information α, and β' indicates the number of pixels of the detection region where missing has occurred that outputs the monitor signal value α'. 【0107】 The weighting unit 202 may set the weighting information so that the average value M of the monitor signal values in the missing region approaches the reference output information α. In this case, the weighting unit 202 can obtain the weighting information by the following equation (2) using the monitor signal value M(D, E) obtained by equation (1). Weighting information = α / M(D, E) ··· (2) Also, the type of monitor signal value used for the threshold determination of AEC may be changed. For example, in the threshold determination of AEC, when it is set to use the maximum value of the monitor signal value of the selected detection area, the type of monitor signal value may be changed to use the minimum value of the monitor signal value of the selected detection area at the timing when it is found from the result of histogram analysis that the influence of the missing area is large. Alternatively, the logical operation for comparing the threshold value for determining AEC and the monitor signal value may be changed. 【0108】 In FIG. 6, an example in which the size of the subject 105 is different from the standard reference body size information in the left - right direction of the FPD 102 has been described, but the disclosed technology is not limited to this example, and can be similarly applied even when the body thickness of the subject 105 is different from the standard reference body size information. 【0109】 FIG. 8 is a diagram showing a configuration example of a radiation imaging system 100 including a radiation imaging device 102 according to the second embodiment. The basic system configuration is the same as that of the radiation imaging system 100 described in the first embodiment, and includes a radiation imaging device 102 that captures a radiation image based on the radiation irradiated from the radiation source 101, and an imaging control device 103. The imaging control device 103 is connected to, for example, a radiation imaging device 102, and a radiation control device 104 that controls the radiation source 101 via a wired or wireless network or a dedicated line, and controls radiation imaging using the radiation imaging device 102 and the radiation source 101. 【0110】 The radiation imaging system 100 according to the second embodiment is provided with an optical image imaging device 900 (for example, an optical camera) that images an optical image of a subject 105. Further, a physical condition information acquisition unit 1039 is added to the functional configuration of the processing unit 1033. The optical image imaging device 900 may be arranged, for example, in the vicinity of the radiation source 101. Also, the optical image imaging device 900 is not limited to a single optical image imaging device 900, and a plurality of optical image imaging devices 900 may be used. The optical image imaging device 900 acquires an optical image of the subject 105 before performing radiation imaging. The optical image acquired by the optical image imaging device 900 is transmitted to the processing unit 1033. 【0111】 Based on the optical image of the subject imaged by the optical image imaging device 900, the physical condition information acquisition unit 1039 acquires the physical condition information of the subject and obtains the deviation from the reference physical condition information serving as a reference. The physical condition information acquisition unit 1039 performs image processing for extracting the contour on the optical image acquired by the optical image imaging device 900, thereby extracting physical condition information indicating the characteristics of the physical condition of the subject 105 (for example, the width of the body and the thickness of the body). The physical condition information acquisition unit 1039 compares the acquired physical condition information of the subject 105 with the standard reference physical condition information corresponding to the age, gender, etc. of the subject 105, and obtains the difference between the reference physical condition information and the physical condition information of the subject 105. 【0112】 If the difference obtained here is a value within a predetermined range, the reference weighting unit 1038 may determine that the reference physical condition information and the physical condition information of the subject 105 match. On the other hand, when the obtained difference exceeds the predetermined range, the reference weighting unit 1038 determines that the physical condition information of the subject 105 is different from the reference physical condition information, and changes the reference output information and the reference weighting information set in each detection region based on the difference. 【0113】 Here, FIG. 10 is a diagram illustrating a table that stores reference physical information, reference output information, and reference weighting information corresponding to the age, gender, etc. of the subject 105 stored in the storage unit 1036. In the table, for each piece of reference physical information, a reference value (reference output information) of the output signal in each detection region and reference weighting information in each detection region are set. 【0114】 For example, when the physical information of the subject 105 is different from the reference physical information H1, the reference weighting unit 1038 changes the reference output information (S1-11, S1-22 ···) and the reference weighting information (W1-11, W1-22 ···) set in each detection region based on the difference between the reference physical information H1 and the physical information of the subject 105 so that the value of the difference in physical information is reduced. The reference weighting unit 1038 acquires the changed reference output information and reference weighting information as initial values and transmits them to the FPD 102 via the communication IF unit 1037. The weighting unit 202 in the FPD processing unit 200 sets the reference output information and the reference weighting information transmitted from the reference weighting unit 1038 as reference values in each detection region, and may capture a radiation image of the subject 105. 【0115】 According to the present embodiment, even when the physical information of the subject 105 is different from the standard reference physical information, the reference output information and the reference weighting information in each detection region can be changed in consideration of the difference in the physical information of the subject 105. Thereby, in automatic exposure control, it becomes possible to suppress variations in the radiation dose. 【0116】 (Third Embodiment) FIG. 11 is a diagram showing a configuration example of a radiation imaging system 100 including a radiation imaging apparatus 102 according to a third embodiment. The basic system configuration is the same as that of the radiation imaging system 100 described in the first embodiment, and includes a radiation imaging apparatus 102 that captures a radiation image based on radiation irradiated from a radiation source 101, and an imaging control apparatus 103. The imaging control apparatus 103 is connected to, for example, a radiation imaging apparatus 102 and a radiation control apparatus 104 that controls the radiation source 101 via a wired or wireless network or a dedicated line, and controls radiation imaging using the radiation imaging apparatus 102 and the radiation source 101. 【0117】 An optical image imaging apparatus 900 (for example, an optical camera) that captures an optical image of a subject 105 is provided in the radiation imaging system according to the third embodiment. In addition, a relative information acquisition unit 1040 is added as a functional configuration of the processing unit 1033. The optical image imaging apparatus 900 may be disposed, for example, in the vicinity of the radiation source 101. The optical image imaging apparatus 900 acquires an optical image of the subject 105 before performing radiation imaging. The optical image acquired by the optical image imaging apparatus 900 is transmitted to the processing unit 1033. 【0118】 The relative information acquisition unit 1040 acquires the positional deviation of the subject with respect to a plurality of detection regions using the optical image of the subject captured by the optical image capturing device 900. The relative information acquisition unit 1040 performs image processing on the optical image acquired by the optical image capturing device 900 to obtain a skeletal model of the subject 105 with the outline of the body shape of the subject 105 extracted. The relative information acquisition unit 1040 calculates the positional relationship of each detection region of the FPD 102 from the skeletal model of the subject 105 and the optical image. Then, the relative information acquisition unit 1040 compares the ideal positional relationship between the detection region and the subject held in advance with the positional relationship calculated from the skeletal model and the optical image, and calculates relative positional deviation information for each detection region. Before capturing the radiation image of the subject 105, the relative information acquisition unit 1040 acquires the relative positional deviation with respect to each detection region in the FPD 102 based on the optical image of the subject 105. The relative positional deviation acquired here includes, for example, a situation where the position of the subject 105 is shifted upward in the plane of the paper as described by 302 in FIG. 3(A), or a situation where the position of the subject 105 is shifted downward in the plane of the paper as described by 303 in FIG. 3(A). Note that the positional deviation is not limited to the positional deviation in the vertical direction and may also include the deviation in the horizontal direction. The ideal positional relationship between the detection region and the subject includes, for example, a case where the subject 105 is located at the center of the FPD 102 as described using 301 in FIG. 3(A). 【0119】 The imaging condition setting unit 1031 receives the imaging condition information input by the operator via the operation input unit 108, and transmits the received imaging condition information to the imaging control unit 1032 and the processing unit 1033. 【0120】 In the case where no relative positional deviation occurs (in the case of the ideal positional relationship), the reference weighting unit 1038 of the processing unit 1033 sets reference output information and reference weighting information for the detection regions in the FPD 102 based on the imaging condition information set by the imaging condition setting unit 1031. 【0121】 When there are a plurality of detection regions within the pixel region of the FPD 102, the reference weighting unit 1038 sets reference output information and reference weighting information for each detection region. Here, when there is no positional deviation, the reference weighting unit 1038 may obtain the reference output information and the reference weighting information from, for example, a table stored in the storage unit 1036. 【0122】 On the other hand, when relative positional deviation is acquired (when there is positional deviation), the reference weighting unit 1038 of the processing unit 1033 changes the reference output information and the reference weighting information for the detection regions in the FPD 102 based on the set imaging condition information and based on the relative positional deviation information. 【0123】 For example, in the case of imaging condition information D1, when relative positional deviation of the subject 105 with respect to the FPD 102 is acquired, the reference weighting unit 1038 changes the reference output information (S1-1, S1-2 ···) and the reference weighting information (W1-1, W1-2 ···) set for each detection region so that the relative positional deviation amount is reduced, corresponding to the imaging condition information D1. The reference weighting unit 1038 acquires the changed reference output information and reference weighting information as initial values and transmits them to the FPD 102 via the communication IF unit 1037. 【0124】 The weighting unit 202 within the FPD processing unit 200 sets the reference output information and the reference weighting information transmitted from the reference weighting unit 1038 as reference values in each detection region, and may capture a radiation image of the subject 105. The FPD processing unit 200 generates determination information for controlling radiation irradiation by comparing the weighted dose information obtained by weighting the output signal (monitor signal value) based on the changed weighting information with a preset threshold value. 【0125】 According to this embodiment, even when there is a relative positional shift of the subject 105 with respect to each detection region of the FPD 102, the relative positional shift amount between each detection region of the FPD 102 and the position of the subject 105 is considered, and the reference output information and the reference weighting information in each detection region can be changed. Thereby, in automatic exposure control, it becomes possible to suppress variations in the radiation dose. 【0126】 The disclosure of this specification includes the following radiation imaging apparatus, radiation imaging system, radiation imaging method, and program. (Item 1) A processing unit that is provided in a pixel region in which a plurality of pixels for detecting radiation are arranged, includes detection pixels that output signals corresponding to the radiation dose, and processes output signals output from a plurality of detection regions. The processing unit generates weighting information for the plurality of detection regions by comparing the output signal with preset reference information. A radiation imaging apparatus that generates determination information for controlling the radiation irradiation by comparing the dose information obtained by weighting the output signal based on the weighting information with a preset threshold value. (Item 2) The reference information includes reference output information output from the plurality of detection regions when there is no positional shift of the subject with respect to the plurality of detection regions. The radiation imaging apparatus according to Item 1, wherein the processing unit generates the weighting information so as to reduce the shift of the output signal with respect to the reference output information. (Item 3) The radiation imaging apparatus according to Item 2, wherein the processing unit has a storage unit that stores imaging condition information for imaging a radiation image, and the reference output information and reference weighting information for the plurality of detection regions associated with the imaging condition information. (Item 4) The processing unit acquires the reference output information and the reference weighting information associated with the imaging condition information from the storage unit, and changes the reference weighting information set as an initial value before imaging the radiation image based on the weighting information generated during imaging of the radiation image. (Item 5) The reference information includes the ratio of the reference output information in a predetermined detection area among the plurality of detection areas. The processing unit acquires the ratio of the output signals output from the predetermined detection area during imaging of the radiation image. The radiation imaging apparatus according to item 2, wherein the processing unit generates the weighting information so as to match the ratio of the output signals to the ratio of the reference output information. (Item 6) The radiation imaging apparatus according to item 1, wherein the processing unit generates the weighting information for a detection area selected from the plurality of detection areas. (Item 7) The radiation imaging apparatus according to item 1, wherein when the imaging part of the subject is an imaging using detection areas at symmetric positions among the plurality of detection areas, the processing unit generates the weighting information so that the ratios of the output signals output from the detection areas at the symmetric positions become equal during imaging of the radiation image. (Item 8) The processing unit compares the distribution of the peaks of the output signals for each of the plurality of detection areas, identifies the detection area that outputs the output signal with a peak larger than the reference information, and sets the weighting information of the identified detection area to be smaller than the weighting information for the detection area that outputs the output signal corresponding to the reference information. The radiation imaging apparatus according to item 1. (Item 9) The radiation imaging apparatus according to item 1, wherein the processing unit does not generate the weighting information when the deviation between the output signal and the reference information becomes equal to or greater than a predetermined value. (Item 10) The radiation imaging apparatus according to item 4, wherein the processing unit sets, as the initial value, the weighting information obtained by changing the reference weighting information based on the positional deviation of the subject with respect to the plurality of detection areas acquired using the optical image of the subject. (Item 11) The radiation imaging apparatus according to item 4, wherein the processing unit sets, as the initial value, the weighting information obtained by changing the reference weighting information based on the deviation between the physical information of the subject acquired using the optical image of the subject and the preset reference physical information. (Item 12) A processing unit that is provided in a pixel region in which a plurality of pixels for detecting radiation are arranged, and that processes output signals output from a plurality of detection regions including detection pixels that output signals corresponding to the irradiation amount of the radiation. The processing unit generates weighting information for the plurality of detection regions by comparing preset reference information with the output signals. A radiation imaging system that generates determination information for controlling the irradiation of the radiation by comparing dose information obtained by weighting the output signals based on the weighting information with a preset threshold value. (Item 13) A physical condition information acquisition unit that acquires the physical condition information of a subject based on an optical image of the subject captured by an optical image capturing unit, and acquires a deviation from reference physical condition information serving as a reference; A reference weighting unit that changes reference weighting information based on the deviation of the physical condition information; A processing unit that is provided in a pixel region in which a plurality of pixels for detecting radiation are arranged, and that processes output signals output from a plurality of detection regions including detection pixels that output signals corresponding to the irradiation amount of the radiation. The processing unit generates determination information for controlling the irradiation of the radiation by comparing dose information obtained by weighting the output signals based on the changed weighting information with a preset threshold value. (Item 14) A relative information acquisition unit that acquires the positional deviation of the subject with respect to a plurality of detection regions using an optical image of the subject captured by an optical image capturing unit; A reference weighting unit that changes reference weighting information based on the positional deviation; A processing unit that is provided in a pixel region in which a plurality of pixels for detecting radiation are arranged, and that processes output signals output from a plurality of detection regions including detection pixels that output signals corresponding to the irradiation amount of the radiation. The processing unit generates determination information for controlling the irradiation of the radiation by comparing dose information obtained by weighting the output signals based on the changed weighting information with a preset threshold value. (Item 15) A processing step is provided for processing output signals output from a plurality of detection regions, including detection pixels provided in a pixel region in which a plurality of pixels for detecting radiation are arranged, and outputting signals corresponding to the irradiation amount of the radiation. In the processing step, weight information for the plurality of detection regions is generated by comparing the output signal with preset reference information. A radiation imaging method for generating determination information for controlling the irradiation of the radiation by comparing the dose information obtained by weighting the output signal based on the weight information with a preset threshold value. (Item 16) A program for causing a computer to execute the radiation imaging method according to Item 15. 【0127】 [Other Embodiments] The disclosed technology can also be realized 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 the computer of the system or device read and execute the program. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions. 【0128】 The disclosed technology is not limited to the above-described embodiments, and various changes and modifications are possible without departing from the spirit and scope of the invention. Therefore, claims are attached to disclose the scope of the invention. 【Description of Reference Numerals】 【0129】 100: Radiation imaging system, 102: Radiation imaging device, 105: Subject, 200: FPD processing unit, 1021: Detection region, 1033: Processing unit

Claims

[Claim 1] The device includes a processing unit that processes output signals from multiple detection regions, which are provided in a pixel region where multiple pixels for detecting radiation are arranged, and which include a detection pixel that outputs a signal corresponding to the amount of radiation exposure. The processing unit generates weighting information for the plurality of detection regions by comparing the output signal with pre-set reference information. A radiation imaging device that outputs control information for controlling the irradiation of radiation by comparing dose information obtained by weighting the output signal based on the weighting information with a preset threshold. [Claim 2] A processing unit that processes output signals output from a plurality of detection regions, which includes a detection pixel provided in a pixel region in which a plurality of pixels for detecting radiation are arranged and which outputs a signal corresponding to the amount of radiation exposure, The aforementioned processing unit, We obtain shooting area information that indicates the part of the subject being photographed. Positional displacement information is acquired that shows the difference between the reference positional relationship set according to the aforementioned imaging area information and the actual relative positional relationship between the subject and at least one detection area among the plurality of detection areas. A radiation imaging device that outputs control information for controlling the irradiation of radiation based on the imaging site information, the positional displacement information, and the output signal. [Claim 3] The radiation imaging apparatus according to claim 2, wherein the reference positional relationship is a predetermined positional relationship between the target area of ​​the subject and the plurality of detection regions, corresponding to the imaging area information. [Claim 4] The radiography apparatus according to claim 2 or 3, wherein the processing unit acquires the reference positional relationship corresponding to the acquired imaging site information from a storage unit that stores the reference positional relationship in association with each of the plurality of imaging site information. [Claim 5] The radiation imaging apparatus according to claim 2, wherein the processing unit acquires the positional displacement information based on a comparison between the output signals output from the plurality of detection regions and reference output information set in accordance with the imaging area information. [Claim 6] The radiation imaging apparatus according to claim 2, wherein the processing unit acquires the actual relative positional relationship between the subject and at least one of the plurality of detection regions based on the optical image of the subject. [Claim 7] The radiation imaging apparatus according to claim 2, wherein the processing unit selects a detection region from among the plurality of detection regions to be used for outputting the control information, based on the imaging region information and the positional displacement information. [Claim 8] The processing unit generates correction information for correcting the output signals output from the plurality of detection regions based on the imaging area information and the positional displacement information, The radiation imaging apparatus according to claim 2, which outputs the control information based on the correction information. [Claim 9] The correction information includes weighting information corresponding to each of the plurality of detection regions, The radiation imaging apparatus according to claim 8, wherein the processing unit outputs the control information by weighting the output signal based on the weighting information. [Claim 10] The radiation imaging apparatus according to claim 9, wherein the processing unit acquires reference weighting information set in correspondence with the imaging site information and generates the weighting information by changing the reference weighting information based on the positional displacement information. [Claim 11] The radiation imaging apparatus according to claim 2, wherein the processing unit does not perform correction of the output signal based on the imaging site information and the positional displacement information when the amount of positional displacement indicated by the positional displacement information is greater than or equal to a predetermined value, or outputs information to notify that the amount of positional displacement is greater than or equal to a predetermined value. [Claim 12] A radiation source that irradiates with radiation, A radiation imaging device that detects radiation irradiated from the aforementioned radiation source and transmitted through the subject, A radiation control device that controls the irradiation of radiation by the aforementioned radiation source, A radiographic imaging system comprising: The aforementioned radiation imaging device or radiation control device is Acquire imaging area information indicating the part of the subject being photographed. Positional displacement information is acquired that shows the difference between the reference positional relationship set according to the imaging area information and the actual relative positional relationship between the subject and at least one of the multiple detection areas provided in the radiation imaging device. Based on the imaging area information, the positional displacement information, and the output signals output from the multiple detection areas, control information for controlling the irradiation of the radiation is output. The radiation control device is a radiation imaging system that controls the irradiation of radiation by the radiation source based on the control information. [Claim 13] The radiation imaging system further comprises an optical image capturing unit for capturing an optical image of the subject, The radiation imaging system according to claim 12, wherein the radiation imaging device or the radiation control device acquires the positional displacement information based on the optical image. [Claim 14] The radiation imaging device or the radiation control device generates correction information for correcting the output signals output from the plurality of detection regions based on the imaging area information and the positional displacement information, A radiation imaging system according to claim 12 or 13, which outputs the control information based on the correction information. [Claim 15] A radiation imaging method for processing output signals output from a plurality of detection regions, which include a detection pixel provided in a pixel region in which a plurality of pixels for detecting radiation are arranged, and which outputs a signal corresponding to the amount of radiation exposure, A process to acquire imaging area information indicating the part of the subject being photographed, A step of acquiring positional displacement information that shows the difference between a reference positional relationship set according to the aforementioned imaging area information and the actual relative positional relationship between the subject and at least one detection area among the plurality of detection areas, A step of outputting control information for controlling the irradiation of the radiation based on the imaging area information, the positional displacement information, and the output signals output from the plurality of detection areas, A radiation imaging method having [specific features]. [Claim 16] In the step of outputting the control information, correction information is generated for correcting the output signals output from the plurality of detection regions based on the imaging area information and the positional displacement information, The radiation imaging method according to claim 15, which outputs the control information based on the correction information. [Claim 17] The correction information includes weighting information corresponding to each of the plurality of detection regions, The radiation imaging method according to claim 16, wherein the step of outputting the control information involves weighting the output signal based on the weighting information to output the control information. [Claim 18] A communication unit that acquires output signals corresponding to the radiation exposure amount output from a plurality of detection areas provided in a radiation imaging device, A processing unit that processes the output signal, A control device comprising, The aforementioned processing unit, We obtain shooting area information that indicates the part of the subject being photographed. Positional displacement information is acquired that shows the difference between the reference positional relationship set according to the aforementioned imaging area information and the actual relative positional relationship between the subject and at least one detection area among the plurality of detection areas. A control device that outputs control information for controlling the irradiation of radiation based on the imaging site information, the positional displacement information, and the output signal. [Claim 19] A computer, A process to acquire imaging area information indicating the part of the subject being photographed, A step of acquiring positional displacement information that shows the difference between a reference positional relationship set according to the imaging area information and the actual relative positional relationship between at least one detection area among a plurality of detection areas provided in the radiation imaging device and the subject, A step of outputting control information for controlling the irradiation of radiation based on the imaging area information, the positional displacement information, and output signals corresponding to the radiation irradiation dose output from the plurality of detection areas, A program that executes the command.

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