JP2007054484A - Radiography device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiography device giving high image quality, which can accommodate change of a radiographic site and irradiate the radiographic site in an adequate radiation dosage, and does not needlessly irradiate a patient. <P>SOLUTION: The device has a radiation-transducing section, in which plurality of transducing elements which transduces a radial ray emitted from an irradiating means into electrical signals are arranged on the substrate. In the radiation-transducing section, the transducing elements are connected to signal cords to output the signals for generating an image. The radiography device has a controlling means which stops irradiation by the irradiating means on the basis of the electrical signals from at least one of the transducing elements, during irradiation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radiation image capturing apparatus.

  Conventionally, a film screen system in which an intensifying screen and a radiographic film are combined is often used for capturing a radiographic image. According to this method, the radiation including the internal information of the subject that has passed through the subject is converted into visible light proportional to the intensity of the radiation by the intensifying screen, and the radiographic film is exposed to the visible light, so that the radiation image is formed. Formed on a film. However, in such a film system, there is a problem that it takes time and effort because there is a film development process in the middle before a doctor or an operator obtains a captured radiographic image.

  Therefore, in recent years, in the medical industry, radiographic image information has been directly handled as an electrical signal without using a radiographic film. That is, a direct semiconductor sensor that converts radiation directly into an electrical signal is used, or radiation is converted into visible light proportional to the intensity of the radiation by a phosphor, and then converted into an electrical signal using a photoelectric conversion element. An image sensor called a flat panel detector (hereinafter referred to as “FPD”) that reads a converted electrical signal by a circuit using a switching element such as an amorphous silicon thin film transistor (a-TFT) is used. A radiographic imaging device is used.

  The automatic exposure control used in such a radiographic image capturing apparatus detects, for example, exposed X-rays, and automatically stops X-ray exposure when an appropriate X-ray exposure amount is reached. It is. As a result of the automatic exposure control, an image with an appropriate density can always be acquired in the same shooting environment when shooting an arbitrary part. Further, it can be controlled so that a subject to which X-rays are exposed does not receive a predetermined amount or more of radiation.

  As a method for detecting the amount of X-ray exposure used for automatic exposure control, a part of photoelectric conversion elements of an image sensor (FPD) is directly connected to a signal line to form a photoelectric conversion element dedicated for automatic exposure control. A method for detecting the exposure dose has been proposed (see, for example, Patent Document 1).

Further, a method has been proposed in which X-rays are irradiated with a small exposure amount before the main exposure, and the exposure amount at the main exposure is calculated from the obtained result (for example, see Patent Document 2).
JP 2004-170216 A JP-A-6-342099

  However, in the method disclosed in Patent Literature 1, a part of the photoelectric conversion element of the image sensor (FPD) is directly connected to a signal line for exposure control to make a photoelectric conversion element dedicated to exposure control. An image sensor (FPD) must be used. In such an image sensor (FPD), since the position of the exposure control pixel is fixed, exposure control cannot be performed at an optimal position when the shooting target location is changed.

  In addition, the method disclosed in Patent Document 2 requires two X-ray exposures, so the patient is exposed to unnecessary X-rays. In addition, since two X-ray exposures are necessary, the time required for X-ray imaging becomes longer, which imposes a burden on the patient. Further, when many images are taken continuously, the time efficiency is deteriorated.

  The present invention has been made in view of the above-described problems, and can cope with a change in an imaging region, and an automatic exposure function capable of exposing a region to be imaged with an appropriate radiation exposure amount to a patient more than necessary. An object of the present invention is to provide a high-quality radiographic imaging device that does not give radiation exposure.

(1)
A radiation conversion section in which a plurality of conversion elements that directly or indirectly convert radiation incident from the radiation exposure means into electrical signals are disposed on the substrate;
The radiation conversion unit is configured to output a signal for generating an image by connecting the conversion element to a signal line.
During radiation exposure of the radiation exposure means,
Based on an electrical signal from at least one of the conversion elements,
A radiation image capturing apparatus comprising: control means for stopping radiation exposure of the radiation exposure means.

(2)
The radiographic image capturing apparatus includes:
Having designation means for designating at least the shooting target location on the subject,
The control means includes
Based on the information specified by the specifying means,
Determining a conversion element to be used for controlling the radiation exposure stop of the radiation exposure means, and based on the electrical signal from the determined conversion element,
The radiation image capturing apparatus according to (1), wherein stop of radiation exposure of the radiation exposure means is controlled.

(3)
The designation means is:
The radiation image capturing apparatus according to (2), wherein a subject part representing a structure included in the subject is also designated.

(4)
The control means is
The conversion element used for controlling the radiation exposure stop of the radiation exposure means,
The radiation image capturing apparatus according to any one of (1) to (3), wherein the radiation image capturing apparatus is set in advance in a central portion of the image sensor.

(5)
The control means includes
The electrical signal read from the conversion element every predetermined time is integrated for each conversion element,
Any one of (1) to (4), wherein the radiation exposure of the radiation exposure means is stopped when the average value of the electrical signal integrated values of the plurality of conversion elements is equal to or greater than a reference value. Radiation imaging device.

(6)
The control means includes
From the electrical signal read from the conversion element for a predetermined time,
Calculate the radiation exposure time to obtain proper exposure,
The radiation image capturing apparatus according to any one of (1) to (4), wherein radiation exposure of the radiation exposure means is stopped after the radiation exposure time has elapsed.

(7)
The radiographic image capturing apparatus includes:
Between the start and stop of radiation exposure by the radiation exposure means, each of the read electrical signals of the conversion elements is integrated,
After stopping the radiation exposure of the radiation exposure means,
The electrical signals of the conversion elements other than the read conversion elements are sequentially read out and combined with the integrated electrical signal,
The radiation image capturing apparatus according to any one of (1) to (6), further including an image processing unit that generates an image.

  According to No. 1, the radiation exposure of the radiation exposure means is stopped based on an electrical signal from at least one conversion element of the radiation conversion unit disposed in the radiation conversion unit during the radiation exposure. Therefore, it is possible to provide a high-quality and inexpensive radiographic image capturing apparatus capable of performing automatic exposure control at an arbitrary place without using a special image sensor.

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

  FIG. 1 is a diagram showing a configuration of a radiation image capturing apparatus 30 according to an embodiment of the present invention. 21 is an FPD (Flat Panel Detector) having pixels of N rows × M columns as an image sensor, 22 is a patient, 23 is a radiation generator, 24 is an image processing device, 25 is a display device for displaying an image, 26 Is a storage device, 27 is an input device, 28 is a control device for controlling the radiation image capturing device 30, and 29 is a bus line.

  The input device 27 is a designation means for designating a place and a part to be inspected, and includes a keyboard, a pen tablet, etc. (not shown).

  For example, when the patient's examination site is the chest, the appropriate exposure level differs between the bone and the lung, and it is necessary to specify whether the examination site is the right lung or the left lung. Therefore, before imaging, the site to be inspected by the patient (in this case, the human body is inspected, so it refers to the components of the human body such as the chest, abdomen, arms, legs, etc.) and the location on the patient's body. It designates with the input device 27. The part to be inspected by the patient is input with the keyboard by looking at the menu displayed on the display device 25. The place to be examined by the patient is designated by using a pen tablet or the like from the imageable range displayed on the display device 25. Also, patient personal data and the like can be input by the input device 27. When the input of necessary items is completed, a shooting instruction is input to the input device 27 to start shooting. The input device 27 also gives instructions regarding image storage.

  The radiation exposed from the radiation generator 23 passes through the patient 22 and forms a radiation image on the FPD 21 which is a radiation conversion unit of the present embodiment. The FPD 21 sequentially converts the radiation image into an electrical signal, converts it into a digital value by an A / D converter 77 (not shown), and outputs it. The FPD 21 will be described in detail later. The output electrical signal from the FPD 21 is temporarily stored in the storage device 26 as image data.

  The image processing device 24 synthesizes the previously read line signal for automatic exposure control from the image data temporarily stored in the storage device 26, and generates a final image by correcting the temperature and integration time. . The generated image is stored in the storage device 26 and displayed on the display device 25.

  The control device 28 includes a CPU (Central Processing Unit) (not shown), a RAM, a hard disk, and the like, and has an automatic exposure control unit 281. The control device 28 receives an instruction from the input device 27 and centrally controls each unit connected to the bus line 29 of the radiation image capturing device 30 according to a program. The automatic exposure control unit 281 is a control unit of this embodiment for controlling the stop of radiation exposure. Details of the automatic exposure control will be described in detail later.

  FIG. 2 is an explanatory diagram for explaining the FPD 21 according to the embodiment of the present invention, and FIG. 3 is a timing chart for driving the FPD 21.

  The FPD 21 will be described with reference to FIGS.

  The FPD 21 is of a type classified as an indirect type, and a fluorescent plate (not shown) that converts radiation into visible light, a photoelectric conversion element 1 that converts visible light into an electrical signal, and a readout circuit using the TFT 2 are formed on a glass substrate. It is comprised by the combination of the circuit board 9 formed in this. The photoelectric conversion element 1 is a conversion element in this embodiment.

FIG. 2 shows a circuit of the circuit board 9 and peripheral circuits. In FIG. 2, 1 is a photoelectric conversion element using a PIN photodiode, 2 is an amorphous silicon TFT, its source is connected to the source lines 4a, 4b,... 4c, and its drain is connected to the cathode of the photoelectric conversion element 1. The gates are connected to the gate lines 3a, 3b,... 3c. The anode of the photoelectric conversion element 1 is connected to a bias line 5, the bias line 5 is connected to a bias power supply 8, and a negative bias voltage is applied. Gate lines 3a, 3b, · · · 3c are connected output terminals G _1, G ₂ of the scan driver 6, the · · · G _N, the source line 4a, 4b, · · · 4c reads portions respectively 7 are connected to output terminals S ₁ , S ₂ ,... S _M. This circuit board 9 forms one pixel by one combination of each of the photoelectric conversion element 1 and the TFT 2, and has N rows × M columns (N and M are positive integers of 2 or more) in total. ing.

The scanning driving unit 6 is a driving unit for the TFT 2. The scan driver 6 and the output terminal G _1, G _2, the gate line 3a to ··· G _N, 3b, ··· 3c are connected, a positive output voltage in the order the gate lines 3a, 3b, · ..Scan 3c When a positive voltage is output from the scan driver 6, the TFT 2 connected to the same gate line is turned on, and the charge of the photoelectric conversion element flows through the source lines 4a, 4b,.

The reading unit 7 is an electric signal reading unit. Reading unit 7 and the output terminal _{S 1, S 2, ··· S} M to the source line 4a, 4b, and · · · 4c is connected, it outputs a positive voltage. In addition, each of the output terminals S ₁ , S ₂ ,... S _M of the reading unit 7 is provided with a charge-voltage conversion circuit, and the amount of charge flowing out to the source lines 4a, 4b,. It has a function of converting to voltage.

  The A / D converter 77 has a function of converting the output voltage from the reading unit 7 into a digital value.

  A fluorescent plate (not shown) covers the circuit board described above, and is configured such that visible light generated by the fluorescent plate is incident on the photoelectric conversion element 1.

  The operation of the FPD 21 will be described with reference to FIGS.

In Figure 3 11, 12, 13, the output terminal G _1, G _2, respectively scan driving unit 6, showing the voltage · · · G _N. When the gate lines 3a, 3b,... 3c become high, all TFTs 1 connected to the gate lines are turned on. At this time, since positive voltages are output from the output terminals S ₁ , S ₂ ,... S _{M of} the reading unit 7 to the source lines 4a, 4b,. The photoelectric conversion element 1 is reverse-biased, and the capacitance of the photoelectric conversion element 1 is charged. The charging current flowing into the photoelectric conversion element 1 this time, that is, the output terminal S _1, S ₂ of the reading unit 7, the charge flowing from · · · S _M source lines 4a, 4b, the · · · 4c, the charge in the reading unit 7 -The voltage is converted and read as a voltage. When the gate lines 3a, 3b,... 3c become low, all the TFTs 2 connected to the gate lines are turned off, and the charge voltage of the photoelectric conversion element 1 connected to the TFT 2 is maintained.

  The scan indicated as the initialization scan in FIG. 3 is a scan for charging all the photoelectric conversion elements 1 in preparation for capturing a radiation image. 3 in FIG. 3 indicates radiation exposure, and a high period tx indicates a period during which radiation exposure is performed. As shown in FIG. 3, the radiation exposure is performed after the initialization scan of the FPD 21 is completed. When the radiation is exposed, the fluorescent plate exposed to the radiation emits fluorescence, and the photoelectric conversion element 1 that has received the fluorescence generates electron-hole pairs therein and discharges the charged charges. . Therefore, the charge charged in the photoelectric conversion element 1 is reduced by the generated electron-hole pair.

  Subsequent to the radiation exposure, the readout scanning shown in FIG. 3 is performed. The charge-voltage converted voltage read from the reading unit 7 at the time of readout scanning corresponds to the charge that disappears from the photoelectric conversion element 1 due to discharge at the time of radiation exposure. In this way, an image of radiation incident on the fluorescent screen is read out two-dimensionally as a voltage.

In FIG. 3, t _i is an integration time, and the electron-hole pair generated by the visible light generated from the fluorescent plate is integrated by the photoelectric conversion element 1 during this period. It is preferable that the integration time includes a radiation exposure period and a light emission period of the fluorescent screen. As described above, the amount of radiation incident on the fluorescent plate can be read out for each pixel as a voltage.

  FIG. 4 is a flowchart for explaining a general procedure of imaging performed by the radiation image capturing apparatus 30 according to the embodiment of the present invention. FIG. 5 is an explanatory diagram for explaining a method for designating a part and a place to be examined by a patient. A schematic procedure of photographing will be described with reference to FIGS.

  In step S101, the photographer operates the input device 27 in accordance with the instruction screen displayed on the display device 25, and designates the part and location to be examined by the patient (step S101). FIG. 5A is a diagram for explaining an initial setting state, in which the inspection range 271a is designated at the center of the imaging unit of the FPD 21. FIG.

  The gate lines 3e and 3f are initially set as automatic exposure control lines representing the inspection range 271a. Assuming that the FPD 21 has pixels of 4000 rows × 5000 columns, for example, the gate line 3e is the 1900th line on the 100th line from the 2000th line at the center, and 3f is the approximately 2000th line at the center. Is set to the 2100th line below 100 lines. In the present embodiment, two automatic exposure control lines are used for explanation, but the number is not limited to two. For example, a plurality of lines including the center 2000th line may be set.

  When the examination range 271a matches the place on the patient's body to be examined, the input device 27 is operated to designate the examination range 271a. If the inspection range 271a does not match the place on the body to be inspected, the input device 27 is operated to specify the inspection range 271b in FIG. 5B, for example. Reference numeral 3g denotes an automatic exposure control line representing the inspection range 271b, and a predetermined line is designated by the control device 28 according to the length of the inspection range 271b in the row direction.

  In addition, the automatic exposure control unit 281 reads and sets data stored in advance in the storage device 26 as a reference value Vk for obtaining an appropriate exposure of the designated part.

  In step S102, the photographer operates the input device 27 to instruct photographing (step S102). The automatic exposure control unit 281 performs initialization of each unit such as the initialization scan described with reference to FIG. 3 (step S103), and instructs the radiation generator 23 to start radiation exposure (step S104).

  Next, the automatic exposure control unit 281 calls a subroutine for automatic exposure control, and stops the radiation exposure when the examination range reaches the reference value of the radiation exposure amount (step S105). The information on the automatic exposure control line specified in step S101 is passed as an argument to the automatic exposure control subroutine.

  In step S106, the readout scanning described with reference to FIG. 3 is performed, and the image data of pixels of all lines including the automatic exposure control line is read (step S106).

  As will be described later, since the charge of the conversion element of the automatic exposure control line is read during the automatic exposure control, the image data read from the automatic exposure control line in step S106 has insufficient information. Therefore, in step S107, the image processing device 24 corrects the integration time for the image data of the automatic exposure control line read out in step S106 and the image data of the automatic exposure control line read out during the automatic exposure control. Then, addition is performed to obtain image data equivalent to a line that is not read out during automatic exposure control. The image data of the automatic exposure control line thus obtained is added to synthesize the photographed image data, and after performing image processing such as temperature correction (step S107), the image data is stored in the storage device 26. (Step S108).

  In this way, in this embodiment, the location on the body of the patient to be examined can be specified, and exposure control can be performed at a position suitable for the location, so that exposure can be easily performed with an appropriate radiation exposure amount. Therefore, it is possible to provide a high-quality radiographic imaging device that does not give the patient more radiation exposure than necessary. Furthermore, since the part can be specified, the exposure dose can be made more appropriate.

  In this embodiment, since the conversion element for automatic exposure is set in advance in the center of the image sensor, it is possible to provide an easy-to-use radiographic image capturing apparatus in which the patient can easily specify the place to be examined.

  Further, in the present embodiment, the electrical signals of the conversion elements belonging to the line read for automatic exposure are accumulated and stored in the storage means, and stored in the storage means after the radiation exposure means stops the radiation exposure. Since the electrical signals of the conversion elements other than the read lines are sequentially read out and synthesized with the electrical signals stored in the storage means, an image is generated. It is possible to provide a radiographic imaging device that can obtain a stable image.

  FIG. 6 is a flowchart for explaining an outline procedure of automatic exposure control performed by the automatic exposure control unit 281 according to the first embodiment of the present invention. FIG. 7 is a drive timing chart of the automatic exposure control line in the first embodiment of the present invention. A general procedure of automatic exposure control will be described with reference to FIGS.

  Here, it is assumed that the inspection range 271a in FIG. 5A is designated by the photographer, and the automatic exposure control unit 281 performs automatic exposure control of the inspection range 271a. As described with reference to FIG. 4, the automatic exposure control lines in the inspection range 271a are the 1900th and 2100th lines, and the gate lines 3 are the gate lines 3e and 3f.

The automatic exposure control routine of FIG. 6 shows a procedure after radiation exposure is started. In step S201, the automatic exposure control unit 281 performs initialization and waits for Ta (step S201). In step S202, the automatic exposure control unit 281, the output terminal G _y of the scan driver 6 to the high (step S202). The output terminal _Gy is an output terminal connected to the gate line 3 of the automatic exposure control line designated in step S101 in FIG. For example, when step S202 is executed for the first time, the output terminal G ₁₉₀₀ of the scan driver 6 connected to the gate line 3 of the 1900th line goes high, and then step S202 is executed for the second time. When this is done, the output terminal G ₂₁₀₀ of the 2100th line goes high.

In step S203, the automatic exposure control unit 281 reads out the output voltages V _y1 , V _y2 ... V _yM corresponding to the output signals from the respective pixels of the automatic exposure control line from the _{FPD 21} and stores _them in the storage device 26. To do. Also, Oere reading of the output voltage, the output terminal G _y in the row (step S203). The output voltage corresponding to the output signal from each pixel is V _ym , and the integrated value is VS _ym . Here, m is a number 1 to M in the column direction of each pixel. The value of VS _ym is initialized in step S201, and the initial value is 0. In step S204, V _ym + VS _ym is calculated to obtain an integrated value of each pixel, and is set as a new integrated value VS _ym (step S204), which is stored in the storage device 26. The integrated value is image data of the pixels of the automatic exposure control line read out during the automatic exposure control, and is combined with other image data read out after radiation exposure after returning to the main routine.

In step S205, the average value VSA of the automatic exposure control line pixels in the inspection range 271a is calculated from the VS _ym calculated in step S204 (step S205).

In step S206, it is determined whether or not the automatic exposure control lines for all the inspection ranges 271a have been read. If there is an unread line among the automatic exposure control lines in the inspection range 271a, the next line is designated, and the process returns to step S202 (No in step S206). When all the automatic exposure control lines in the inspection range 271a have been read (step S206; Yes), it is determined whether the VSA calculated in step S205 is greater than or equal to the reference value Vk. When the VSA calculated in step S205 is less than the reference value Vk (step S207; No), the process waits for Ta-t1 and returns to step S202 (step S209). t1 is the time from when the output terminal G ₁₉₀₀ is set high to when the output terminal G ₂₁₀₀ is set high. If the automatic exposure control line increases, this time increases accordingly.

  When the VSA calculated in step S205 is greater than or equal to the reference value Vk (step S207; Yes), the automatic exposure control unit 281 controls the radiation generator 23, stops the radiation exposure (step S208), and initializes the VSA. The process returns to step S106 of the main routine.

  As described above, when the electrical signals read out from the conversion elements at predetermined time intervals and stored in the storage unit are integrated for each of the conversion elements, the average value of the electrical signal integrated values of the conversion elements is equal to or higher than a reference value. Since the radiation exposure of the radiation exposure means is stopped, it is possible to provide a radiation image capturing apparatus capable of highly accurate automatic exposure control.

  The drive timing of the automatic exposure control line will be described with reference to FIG.

In FIG. 7, radiation exposure is performed during a high period. When radiation exposure is high, after between Ta as described in step S201, and the output terminal G _y high, will sequentially read out automatic exposure control line. In FIG. 7, first, the output terminal G _{1900 is set} to high to read out pixels on the line, and the next output terminal G _{2100 is set} to high after a delay of time t1.

  As described in step S205 in FIG. 6, the VSA is calculated every time each automatic exposure control line is read. As described in step S204 of FIG. 6, VSA is an integrated value of each pixel, and thus the value increases each time the automatic exposure control line is read every time Ta has elapsed. When VSA becomes equal to or higher than the reference value Vk, the automatic exposure control unit 281 stops radiation exposure.

  FIG. 8 is a flowchart for explaining an outline procedure of automatic exposure control performed by the automatic exposure control unit 281 according to the second embodiment of the present invention. FIG. 9 is a drive timing chart of the automatic exposure control line in the second embodiment of the present invention. A schematic procedure of automatic exposure control will be described with reference to FIGS.

  Steps that perform the same processing as in FIG. The conditions such as the inspection range 271a are the same as those in FIG.

  Since the processing up to step S206 is the same as that in FIG. 6, the description thereof will be omitted and the description will be made from step S307.

  In step S307, the automatic exposure control unit 281 obtains the change rate per unit time of the VSA from the VSA value calculated in step S205 and the elapsed time Ta until reading, and the radiation exposure time when the VSA is equal to or greater than the reference value Vk. Tz is calculated (step S307). After the elapse of Tz, radiation exposure is stopped (step S308), the VSA is initialized, and the process returns to step S106 of the main routine.

  As can be seen from FIG. 9, unlike FIG. 7, the output terminal Gy is set to high only once during the radiation exposure period. From the value of VSA after the lapse of Ta, a radiation exposure time Tz for obtaining a proper exposure is calculated.

  In this way, the radiation exposure time for obtaining an appropriate exposure is calculated from the electrical signal read from the conversion element for a predetermined time, and after the radiation exposure time has elapsed, the radiation exposure of the radiation exposure means is stopped. Therefore, it is possible to provide a radiation image capturing apparatus capable of highly accurate automatic exposure control.

  As described above, according to the present embodiment, it is possible to cope with a change in an imaging region, and it is possible to expose the region to be imaged with an appropriate radiation exposure amount. A high-quality radiographic image capturing apparatus can be provided.

It is a figure which shows the structure of the radiographic imaging apparatus 30 which concerns on embodiment of this invention. It is a figure which shows the circuit board and peripheral circuit of FPD which are used for the radiographic imaging apparatus which concerns on embodiment of this invention. It is a figure which shows the drive timing of FPD which concerns on embodiment of this invention. It is a flowchart explaining the outline procedure of imaging | photography which the radiographic image imaging device 30 in embodiment of this invention performs. It is explanatory drawing explaining the method of designating the site | part and location to inspect of the patient which concern on embodiment of this invention. It is a flowchart explaining the outline procedure of the automatic exposure control in the 1st Embodiment of this invention. It is a drive timing chart of the line for automatic exposure control in a 1st embodiment of the present invention. It is a flowchart explaining the outline procedure of the automatic exposure control in 2nd Embodiment. It is a drive timing chart of the line for automatic exposure control in a 2nd embodiment of the present invention.

Explanation of symbols

1 Photoelectric conversion element 2 TFT
3a, 3b, 3c Gate line 4a, 4b, 4c Source line 5 Bias line 6 Gate drive IC
7 Reading IC
8 Bias power supply 9 Circuit board 21 FPD
22 Patient 23 Radiation Generator 24 Image Processing Device 25 Display Device 26 Storage Device 28 Control Device

Claims (7)

A radiation conversion section in which a plurality of conversion elements that directly or indirectly convert radiation incident from the radiation exposure means into electrical signals are disposed on the substrate;
The radiation conversion unit is configured to output a signal for generating an image by connecting the conversion element to a signal line.
During radiation exposure of the radiation exposure means,
Based on an electrical signal from at least one of the conversion elements,
A radiation image capturing apparatus comprising: control means for stopping radiation exposure of the radiation exposure means. The radiographic image capturing apparatus includes:
Having designation means for designating at least the shooting target location on the subject,
The control means includes
Based on the information specified by the specifying means,
Determining a conversion element to be used for controlling the radiation exposure stop of the radiation exposure means, and based on the electrical signal from the determined conversion element,
The radiation image capturing apparatus according to claim 1, wherein a stop of radiation exposure of the radiation exposure unit is controlled. The designation means is:
The radiographic image capturing apparatus according to claim 2, wherein a subject part representing a structure included in the subject is also designated. The control means is
The conversion element used for controlling the radiation exposure stop of the radiation exposure means,
The radiation image capturing apparatus according to claim 1, wherein the radiation image capturing apparatus is set in advance at a central portion of the image sensor. The control means includes
The electrical signal read from the conversion element every predetermined time is integrated for each conversion element,
The radiation according to any one of claims 1 to 4, wherein the radiation exposure of the radiation exposure means is stopped when the average value of the electrical signal integrated values of the plurality of conversion elements is equal to or greater than a reference value. Image pickup device. The control means includes
From the electrical signal read from the conversion element for a predetermined time,
Calculate the radiation exposure time to obtain proper exposure,
The radiation image capturing apparatus according to claim 1, wherein radiation exposure of the radiation exposure unit is stopped after the radiation exposure time has elapsed. The radiographic image capturing apparatus includes:
Between the start and stop of radiation exposure by the radiation exposure means, each of the read electrical signals of the conversion elements is integrated,
After stopping the radiation exposure of the radiation exposure means,
The electrical signals of the conversion elements other than the read conversion elements are sequentially read out and combined with the integrated electrical signal,
The radiographic image capturing apparatus according to claim 1, further comprising an image processing unit configured to generate an image.

Images