IMAGING CONTROL DEVICE, RADIATION IMAGING SYSTEM, AND IMAGING CONTROL METHOD

Abstract

To prevent main exposure from being performed in a state of poor positioning in a radiation imaging system that determines imaging conditions for main exposure based on a pre-exposure image. [Solution] The radiation imaging system 100 comprises an image acquisition means capable of acquiring image data from the radiation imaging device 2, a total dose calculation means for calculating the total dose required to obtain diagnostic image data based on pre-image data generated by the radiation imaging device 2 by performing pre-exposure on the subject at a pre-exposure dose, a dose output means for outputting the main exposure dose based on the total dose to the radiation imaging device, and an image synthesis means for synthesizing the pre-image data with the main image data generated by the radiation imaging device by performing main exposure at the main exposure dose to generate diagnostic image data.

Description

[Technical field]

[0001] The present invention relates to an imaging control device. , release Radiography System and shooting control method Regarding. [Background technology]

[0002] When capturing a radiological image, a device is known that has an automatic exposure control function that performs a pre-exposure at a lower dose than the actual exposure that is performed later, and determines the shooting conditions, such as the dose, for the actual exposure based on the obtained pre-exposure image and the additional information linked to the pre-exposure image. For example, Patent Document 1 describes an X-ray diagnostic apparatus for mammography that includes an X-ray exposure means for emitting X-rays, an X-ray planar imaging device for detecting X-rays incident on a detection surface, an image generation means for generating an X-ray image based on the detected X-rays, a determination means for determining imaging conditions based on the generated X-ray image, and a control means for controlling the X-ray exposure means so that X-rays are emitted in accordance with the determined imaging conditions.

[0003] Furthermore, Patent Document 2 describes a radiography device that includes a radiation source and a radiography device, and has an imaging section that performs pre-exposure and main exposure, a display section that displays images captured by the imaging section so that the user can view them, a storage section that saves the images, an output section that outputs the images, and a control section that controls the radiography device, and in which the control section saves pre-images obtained by pre-exposure in the storage section and outputs only main images obtained by main exposure to the output section. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-236804 A [Patent Document 2] JP 2009-297284 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the device described in Patent Document 1, confirmation of the positioning is performed using the actual exposure image, not the pre-exposure image. The actual exposure image taken in an inappropriate positioning state is difficult to use for diagnosis, and in some cases re-exposure is required, resulting in the subject being exposed to radiation for one actual exposure. In addition, in the technology described in Patent Document 2, a pre-exposure image is used to position the subject. That is, since positioning for the main exposure is performed before the main exposure, whether the positioning was good or not can be known after the main exposure. In other words, there is a possibility that the main exposure is performed in a state where the positioning is not good, and re-imaging is required.

[0006] The present invention has been made in consideration of the above-mentioned points, and aims to prevent main exposure from being performed in a poor positioning state in a radiation imaging system in which the shooting conditions for main exposure are determined based on a pre-exposure image obtained by pre-exposure. [Means for solving the problem]

[0007] In order to solve the above problems, the imaging control device of the present invention comprises: an image acquisition unit capable of acquiring image data from a radiation imaging device that generates image data of a subject by receiving radiation from a radiation irradiation device through the subject; an imaging determination means for determining whether the positioning of the subject is good or bad based on pre-image data generated by the radiation imaging device through pre-exposure before the main exposure by the radiation irradiation device and acquired by the image acquisition means; a display means for displaying a preview image based on the preview image data; Equipped with The photographing determination means analyzes a missing part of a photographing target part in the preliminary image data based on the preliminary image data and the supplementary information associated with the preliminary image data. death, Only when the photographing determination means determines that the positioning of the subject is not good, the preview image can be set to be displayed on the display means. . Effect of the Invention

[0009] According to the present invention, it is possible to prevent main exposure from being performed in a state of poor positioning. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing a configuration of a radiation imaging system according to a first embodiment (third and fourth embodiments) of the present invention. [Diagram 2] 2 is a block diagram showing a specific configuration of a radiation imaging apparatus included in the radiation imaging system of FIG. 1. [Diagram 3] 1 is a block diagram showing a specific configuration of a console included in a radiation imaging system according to the first embodiment (an imaging control device included in a radiation imaging system according to the second embodiment, and a console included in a radiation imaging system according to the fourth embodiment). FIG. [Figure 4] 4 is a flowchart of a shooting control process executed by the console of FIG. 3. [Diagram 5] 5 is a flowchart of a total radiation dose calculation process in the imaging control process of FIG. 4. [Figure 6] 5 is a flowchart of an image synthesis process in the shooting control process of FIG. 4. [Figure 7] 4 is a ladder chart showing the operation of the radiation imaging system according to the first embodiment. [Figure 8] 10 is a timing chart showing another operation of the radiation imaging system according to the first embodiment. [Figure 9] 10 is a timing chart showing another operation of the radiation imaging system according to the first embodiment. [Figure 10] FIG. 11 is a block diagram showing a configuration of a radiation imaging system according to a second embodiment of the present invention. [Figure 11] 13 is a ladder chart showing the operation of a radiation imaging system according to a third embodiment of the present invention. [Figure 12] 13 is a flowchart of an imaging control process executed by a console included in a radiation imaging system according to a fourth embodiment of the present invention. [Figure 13]This is an example of an anatomical code output by the console in Figure 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] First Embodiment Hereinafter, a first embodiment of the present invention will be described in detail with reference to Figures 1 to 9. However, it goes without saying that the scope of the present invention is not limited to the following embodiment, and can be appropriately modified without departing from the spirit of the present invention. Further, although detailed explanation of the subject to be photographed will not be given here, the present invention can be used to photograph any part of the human body, and can also be used to photograph subjects other than the human body, such as animals.

[0012] [Radiation Imaging System] First, the configuration of a radiation imaging system according to this embodiment will be described. Fig. 1 is a block diagram showing the configuration of a radiation imaging system 100. Note that the reference characters in parentheses in Fig. 1 are those of third and fourth embodiments described later.

[0013] As shown in FIG. 1, the radiation imaging system 100 of this embodiment includes a radiation irradiation device 1, a radiation imaging device 2, and a console 3. The radiation imaging system 100 can also be connected to a Radiology Information System (RIS), a Picture Archiving and Communication System (PACS), and the like, which are not shown.

[0014] The radiation irradiation device 1 is connected to a console 3 so as to be communicable with the console 3 via wire or wirelessly. The radiation irradiation device 1 is also configured to include a generator 11, an exposure switch 12, and a radiation source 13.

[0015] The generator 11 is configured to be able to apply a voltage to the radiation source 13 according to preset radiation exposure conditions (tube voltage, tube current, exposure time (mAs value), etc.) based on the operation of the exposure switch 12. The radiation source 13 (bulb) has a rotating anode, a filament, etc. (not shown). When a voltage is applied from the generator 11, the filament irradiates the rotating anode with an electron beam according to the applied voltage, and the rotating anode generates radiation X (X-rays, etc.) with a dose according to the intensity of the electron beam.

[0016] Although FIG. 1 shows an example in which the respective sections 11 to 13 are separate, they may be integrated. In addition, while FIG. 1 illustrates an example in which the exposure switch 12 is connected to the generator 11, the exposure switch 12 may be provided in another device (for example, an operation console not shown). The radiation irradiation device 1 may be installed in an imaging room, or may be configured to be mobile by being incorporated in a medical cart or the like.

[0017] The radiation imaging apparatus 2 is connected to a console 3 so as to be communicable with each other via wire or wirelessly. The radiation imaging device 2 is configured to be capable of generating image data of a subject by receiving radiation X from the radiation irradiating device 1 through the subject. The radiographic imaging device 2 will be described in detail later.

[0018] The console 3 is configured by a PC, a mobile terminal, or a dedicated device, and is connected to the radiation irradiation device 1, the radiation imaging device 2, etc. in a wired or wireless manner so as to be able to communicate with them. The console 3 is also capable of setting imaging conditions, imaging target regions, and the like for the radiation irradiation device 1 and the radiation imaging device 2 based on imaging orders from an external device (such as a RIS) and operations by a user. The details of the console 3 will be described later.

[0019] [Configuration of the Radiation Imaging Apparatus] Next, a description will be given of details of the radiation imaging apparatus 2 included in the radiation imaging system 100. Fig. 2 is a block diagram showing a specific configuration of the radiation imaging apparatus 2. Note that the reference characters in parentheses in Fig. 2 are those of a third embodiment described later.

[0020] As shown in FIG. 2, the radiation imaging apparatus 2 includes a control unit 21, a radiation detection unit 22, a readout unit 23, a communication unit 24, a storage unit 25, and a bus 26 that connects the units 21 to 25.

[0021] The control unit 21 is composed of a CPU (Central Processing Unit), a RAM (Random Access Memory), etc. Upon receiving a control signal or the like from an external device such as the console 3, the CPU of the control unit 21 reads out various programs stored in the storage unit 25, loads the programs in the RAM, executes various processes according to the loaded programs, and centrally controls the operations of each unit of the radiation imaging apparatus 2. The radiation detection unit 22 is configured by a substrate on which pixels, each of which has a radiation detection element that receives radiation X and generates an electric charge according to the dose, and a switching element, are arranged two-dimensionally (in a matrix).

[0022] The readout unit 23 is configured to be able to read out the amount of charge discharged from each pixel as a signal value and generate image data from a plurality of signal values. The communication unit 24 is configured to be able to receive various control signals, various data, etc. from external devices, and to transmit various control signals, generated image data, etc. to external devices. The storage unit 25 is configured with a non-volatile semiconductor memory, a hard disk, or the like, and stores various programs executed by the control unit 21 and parameters required for executing processes by the programs. Furthermore, the storage unit 25 is capable of storing image data generated by the reading unit 23 and various data processed by the control unit 21.

[0023] When the radiographic imaging device 2 configured in this manner is exposed to radiation with the control unit 21 turning off each switch element of the radiation detection unit 22, charge corresponding to the radiation dose is accumulated in each pixel. Then, when the control unit 21 turns on each switch element to release charge from each pixel, the readout unit 23 converts each charge amount into a signal value and reads it out as image data. In other words, the control unit 21, radiation detection unit 22 and readout unit 23 of the radiographic imaging device 2 form the image generating means of the present invention.

[0024] The radiation imaging device 2 may have a built-in scintillator or the like, converting the irradiated radiation X into light of another wavelength, such as visible light, using the scintillator to generate electric charges according to the converted light (a so-called indirect type), or may generate electric charges directly from the radiation X without going through a scintillator or the like (a so-called direct type). Moreover, the radiation imaging device 2 may be a dedicated type integrated with an imaging stand, or may be a portable type (cassette type).

[0025] [Console configuration] Next, a description will be given of the details of the console 3 included in the radiation imaging system 100. Fig. 3 is a block diagram showing a specific configuration of the console 3. Note that the reference characters in parentheses in Fig. 3 are those of second and fourth embodiments described later.

[0026] As shown in FIG. 3, the console 3 includes a control unit 31, a communication unit 32, a storage unit 33, a display unit , an operation unit 35, and a bus that connects the units 31 to .

[0027] The control unit 31 is composed of a CPU (Central Processing Unit), a RAM (Random Access Memory), etc. The CPU of the control unit 31 reads out various programs stored in the storage unit 33 in response to operations of the operation unit 35, loads them in the RAM, executes various processes according to the loaded programs, and centrally controls the operations of each unit of the console 3.

[0028] The communication unit 32 includes a LAN adapter, a modem, a TA (Terminal Adapter), etc., and controls data transmission and reception between each device connected to the communication network.

[0029] The memory unit 33 is composed of a non-volatile semiconductor memory, a hard disk, etc., and stores various programs executed by the control unit 31 (including a program for performing the shooting control processing described below) and parameters required to execute processing by the programs. The storage unit 33 is also capable of storing image data received from the radiation imaging apparatus 2 and image data processed by the control unit 31 in association with supplementary information.

[0030] The display unit 34 is composed of a monitor such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube), and displays input instructions and data from the operation unit 35 according to instructions of a display signal input from the control unit 31.

[0031] The operation unit 35 is configured with a keyboard equipped with cursor keys, numeric input keys, and various function keys, etc., and a pointing device such as a mouse, and outputs instruction signals input by key operations on the keyboard or mouse operations to the control unit 31. Furthermore, the operation unit 35 may be provided with a touch panel on the display screen of the display unit 34, and in this case, an instruction signal input via the touch panel is output to the control unit 31.

[0032] [Shooting control processing] Next, a detailed description will be given of the imaging control process, which is one of the processes executed by the console 3. Fig. 4 is a flowchart of the imaging control process executed by the console 3, Fig. 5 is a flowchart of the total dose calculation process in the imaging control process in Fig. 4, and Fig. 6 is a flowchart of the image synthesis process in the imaging control process in Fig. 4.

[0033] In this embodiment, the control unit 31 of the console 3 is configured to execute the shooting control process when a predetermined start condition is met (for example, a start operation is performed on the operation unit 35, the exposure switch 12 is pressed, the radiation irradiation device 1 or the radiation imaging device 2 performs an imaging operation, image data is received from the radiation imaging device 2, etc.).

[0034] 4, first, pre-exposure is performed on a subject at a pre-exposure dose lower than that of the main exposure to be performed later, and pre-image data generated by the radiation imaging device 2 is acquired (step S1). When the pre-image data is acquired, supplementary information associated with the pre-image data is also acquired. The supplementary information includes the pre-exposure dose (derived by setting the tube voltage, tube current, irradiation time, etc.) in the pre-exposure, the region to be imaged, and the like. By executing such processing, the control unit 31 and the communication unit 32 constitute the image acquisition means of the present invention.

[0035] The preview image data and the additional information are preferably acquired by receiving them via the communication unit 32 in a wired or wireless manner, but may also be acquired via a medium such as a USB memory. Furthermore, when acquiring the data, the console 3 may request data transmission, for example by sending a signal to the radiation imaging device 2 requesting data transmission, or may wait until the radiation imaging device 2 transmits the data (repeat the processing of step S1).

[0036] After acquiring the preliminary image data, the control unit 31 performs a correction process (step S2). Specifically, the control unit 31 performs offset correction on the preliminary image data acquired in step S1. It is preferable that the offset (dark image) data used for the offset correction is acquired in advance before performing the pre-exposure. In this process, other corrections (such as LOG conversion) may be performed. Furthermore, if the radiation imaging device 2 used has the function of performing the correction process on the generated image data, then after pre-exposure, offset correction is performed in the radiation imaging device 2, and the pre-image data after the offset correction is obtained in step S1, making the processing of step S2 unnecessary.

[0037] Next, the control unit 31 performs image analysis processing (step S3). Specifically, the control unit 31 analyzes the presence or absence of abnormalities (such as missing areas of the imaging target area (lung fields and KUBs) and foreign objects (such as stripes due to grid misalignment)) in the preliminary image based on the preliminary image data and the associated information associated with the preliminary image data. When analyzing the lack of the imaging target part, for example, a technique such as that described in JP 2011-255061 A can be used. That is, the specified irradiation field is divided into a plurality of small areas, the feature amount of each small area at the irradiation field boundary is extracted, and based on the arrangement of the feature amount, it is judged whether the imaging target part protrudes from the boundary of the irradiation field. If the subject has previously had the same area imaged, the analysis may be performed based on a comparison with the previous image. In this case, the presence or absence of a difference in appearance that makes comparative interpretation difficult due to a difference in the radiation incidence angle in the previous image is also an abnormality to be analyzed.

[0038] Next, the control unit 31 judges whether or not the pre-exposure has been properly performed (step S4). Specifically, as a result of the image analysis process performed in step S3, it judges whether or not the pre-image has an abnormality as described above. If it is determined that there is no abnormality, that is, that the pre-exposure has been properly performed (step S4: Yes), various processes for performing the main exposure are subsequently performed (steps S5 to S9). These processes will be described later.

[0039] On the other hand, if it is determined that an abnormality has occurred, that is, that pre-exposure could not be performed appropriately (step S4: No), an imaging stop process is performed (step S10), and the imaging control process is terminated. The imaging cancellation process in step S10 includes processes for stopping the operation of the radiation irradiating device 1 and the radiation imaging device 2, and processes for issuing a warning to the user to cancel the main exposure (display on the display unit 34, audio output, etc.).

[0040] By performing steps S3 and S4, the control unit 31 functions as the imaging determination means in the present invention, and can determine whether the positioning is good or not (whether re-imaging is necessary or not) using the pre-image before performing the main exposure with a large amount of radiation exposure. Therefore, it is possible to prevent the main exposure from being performed in a positioning failure state, and to prevent the subject from being unnecessarily exposed to radiation. Furthermore, if the pre-exposure is performed appropriately, the user can move on to the main exposure without checking the pre-image, thereby reducing the effort required by the user during imaging. On the other hand, if the pre-exposure cannot be performed properly, the pre-exposure will be performed again. However, since the dose during the pre-exposure is lower than the dose during the main exposure, the amount of radiation exposure can be reduced compared to when the main exposure is repeated as in the conventional method.

[0041] In step S3, the user may analyze the image instead of automatically analyzing the preliminary image data. In that case, the process of step S3 is unnecessary, and step S4 is a process of accepting the analysis result by the user. In addition, after the processing of step S10, a process may be inserted to determine whether or not a predetermined condition has been met (for example, whether or not the user has performed an operation to instruct the resumption of shooting), and if the predetermined condition has been met, the process may proceed to step S5 and subsequent steps.

[0042] Also, after step S4, a preview image may be displayed on the display unit . In this case, a thinned image with a lowered resolution may be displayed as a preview image. Also, instead of necessarily displaying the preview image, the user may be allowed to select whether to display it and the conditions for displaying it. In this way, it becomes possible to set the preview image to be displayed only when the user needs to confirm it (for example, when it is determined that the positioning is not good), improving user convenience.

[0043] In the above step S4, when it is determined that the pre-exposure has been properly performed (step S4: Yes), the control unit 31 performs a total dose calculation process (step S5). In this process, the total dose required to obtain diagnostic image data for diagnosis is calculated based on the pre-image data and the associated information associated with the pre-image data.

[0044] The total dose can be calculated using a technique such as that described in International Publication No. 2006 / 62013. Specifically, as shown in Fig. 5, first, a region of interest (ROI) is set in a preliminary image (step S51). Next, the S value (sensitivity) is calculated (step S52). Here, a histogram of multiple pixel signal values ​​in the region of interest is generated, and the median value of the dynamic range of the histogram is calculated. The median value obtained here is the S value. Next, the total dose is calculated (step S53). Here, based on the target S value preset by the manufacturer or user and the inversely proportional relationship between the dose and the S value during imaging, a dose is calculated such that the S value obtained from the image obtained by subsequent imaging matches the target S value. The dose calculated here is the total dose. By executing such processing, the control unit 31 serves as a total dose calculation means in the present invention.

[0045] After calculating the total dose, the control unit 31 outputs the main imaging conditions (step S6) as shown in Fig. 4. In this process, the main exposure dose based on the total dose calculated in step S2 is output to the radiation irradiating device 1 and the radiation imaging device 2 as the main imaging conditions. In this case, the total dose may be used as the main radiation dose as it is, or a value obtained by performing a predetermined calculation on the total dose may be used as the main radiation dose. In this embodiment, in addition to the actual radiation dose, for example, the imaging target part, body thickness, imaging direction, etc. are output as the actual imaging conditions. By executing such processing, the control unit 31 serves as a dose output means in the present invention.

[0046] In the output process of the actual imaging conditions (step S6), a value obtained by subtracting the pre-exposure dose from the calculated total dose may be output as the actual exposure dose. In conventional imaging using the automatic exposure control function, the total radiation exposure amount increases by the amount of pre-exposure compared to imaging without this function. However, by doing this, the radiation exposure amount in one pre-exposure and the radiation exposure amount in one main exposure are finally equal to the radiation exposure amount in one conventional main exposure, so diagnostic images can be obtained without increasing the radiation exposure amount compared to conventional diagnostic image imaging. In addition, in the output process of the actual imaging conditions (step S6), instead of directly outputting the value of the actual exposure dose, the tube voltage, tube current, and irradiation time required to generate radiation of the actual exposure dose may be output.

[0047] During the period from when the main imaging conditions are output until the processing in the next step S7, the radiation irradiating device 1 performs main exposure to the subject at the main exposure dose, and the radiation imaging device 2 generates main image data. After the radiation imaging apparatus 2 generates the main image data, the control unit 31 acquires the main image data generated by the radiation imaging apparatus 2. A specific method for acquiring the main image data (the contents of the process in step S7) is the same as the acquisition of the preliminary image data (step S1) described above.

[0048] After acquiring the main image data, the control unit 31 performs a correction process (step S8). Specifically, the control unit 31 performs offset correction on the main image data. The offset data used when performing offset correction on the main image data is preferably acquired immediately before or after the main exposure. In this process, other corrections (such as LOG conversion) may be performed. Furthermore, when the radiation imaging apparatus 2 used has a function of executing the correction process on the generated image data, the process of step S8 is unnecessary, just like the process of step S2.

[0049] Next, the control unit 31 performs an image synthesis process (step S9). In this process, the main image data generated by the radiation imaging device 2 by performing main exposure at the main exposure dose is synthesized with the preliminary image data to generate diagnostic image data.

[0050] For example, a technique such as that described in Japanese Patent Application Laid-Open No. 2015-092913 can be used for combining the images. Specifically, as shown in Fig. 6, first, the main exposure image and the pre-exposure image are aligned (step S91). Here, one of the images is moved so that the contours of the subject in each image overlap. Next, the edges of the image are recognized (step S92). Next, an addition process (step S93) is performed. Here, the actual image data is combined with the preliminary image data to generate diagnostic image data. Specifically, the signal value of each pixel constituting the actual image data is added to the signal value of each pixel constituting the preliminary image data.

[0051] In this embodiment, the signal values ​​of the main image data and the preliminary image data are not added as they are, but the signal values ​​of the edge parts in the preliminary image data are relatively lowered (the signal values ​​of the flat parts other than the edge parts are relatively raised) and then added. Specifically, for example, the addition is performed using the addition formula expressed by the following (1). I (x,y) ={β (x,y) ×I pre(x,y) +I post(x,y)} / {1+β (x,y)}··(1) I (x,y): Signal value at pixel coordinate (x, y) after addition (diagnostic image) β (x,y) :Addition coefficient applied to pixel at coordinate (x,y) I pre(x,y) : Signal value at pixel coordinate (x, y) in pre-image I post(x,y) : Signal value at pixel coordinate (x, y) of the image The coordinates (x,y) are after alignment.

[0052] The value of β may be 0<β<1 in the coordinates of the edge portion and β=1 in the coordinates of the flat portion, or β=1 in the coordinates of the edge portion and 1<β in the coordinates of the flat portion. Also, the value of β may be 0<β<1 in the coordinates of the edge portion and 1<β in the coordinates of the flat portion. It is preferable that the value of β at each coordinate (x, y) is calculated in advance in step S92. Even if the contour of the imaging target part in the preliminary image can be matched with the contour of the imaging target part in the main image, the edges often do not match due to rotation, twist, etc. of the imaging target part. However, by adding signal values ​​in the above-mentioned manner, the edges of the preliminary image are weakened, so that it is possible to prevent the edges of the diagnostic image from becoming blurred due to a misalignment between the edges of the main image and the preliminary image.

[0053] By performing the processing of step S9, the control unit 31 serves as the image synthesis means of the present invention, and generates diagnostic image data by synthesizing the main image data with the pre-image data, thereby preventing a decrease in image quality (S / N) of the diagnostic image even when the main shooting is performed at a reduced dose.

[0054] This image synthesis process may be performed before the correction process (step S8). Furthermore, if it is possible to perform imaging that does not result in edge misalignment between pre-exposure and main exposure, for example by fixing the subject's area to be imaged with a jig, the processing of step S92 is not necessary, and in step S93, the signal value of the main image and the signal value of the pre-image can simply be added together.

[0055] In addition, in this image synthesis process, it is preferable to partially measure the subject's movement amount between pre-exposure and main exposure based on the pre-image data and the main image data, and add signal values ​​of parts of the pre-image data with a small amount of movement relatively large, or not add signal values ​​of parts with a predetermined amount of movement or more. Specifically, an image is divided into a plurality of small regions, and the amount of movement is measured for each small region. In this way, the control unit 31 serves as a movement amount measuring means in the present invention, and even if there is body movement of the subject between the pre-exposure and the main exposure, blurring of the image due to synthesis can be suppressed.

[0056] The above is the flow of the shooting control process. By executing this shooting control process, the console 3 of this embodiment serves as the shooting control device of the present invention.

[0057] The console 3 may have a function of controlling irradiation of radiation. Specifically, the console 3 is configured to output an exposure instruction signal that instructs permission / prohibition of radiation irradiation by turning on (unlock) / off (lock) to the radiation irradiation device 1, and to execute a process of switching the exposure instruction signal on / off at a timing according to the set pre-exposure conditions and main exposure conditions. This process may be executed during the above-described shooting control process (between steps S1 and S2 or between steps S6 and S7), or may be executed as a process separate from the shooting control process.

[0058] [Shooting process] Next, there will be described the operation of the radiation imaging system 100. Fig. 7 is a ladder chart showing the operation of the radiation imaging system 100 during imaging.

[0059] When photographing a subject using the radiation imaging system 100 of this embodiment, first, the user inputs pre-imaging conditions into the console 3, and as shown in Figure 7, the console 3 outputs the input pre-imaging conditions to the radiation irradiation device 1 and the radiation imaging device 2 (step S0). When the pre-exposure conditions are input, the radiation irradiating device 1 and the radiation imaging device 2 each set the pre-exposure conditions and each prepare for pre-exposure at a pre-exposure dose (steps A1, B1).

[0060] Thereafter, when the user presses the exposure switch 12, the radiation irradiation device 1 irradiates the subject and the radiation imaging device 2 behind the subject with a pre-exposure dose of radiation (step A2). When exposed to radiation, the radiographic imaging device 2 accumulates electric charges generated by each radiation detection element based on the radiation dose in each pixel (step B2), converts the amount of electric charge of each pixel into a signal value, reads it out as preliminary image data, and transmits it to the console 3 (step B3).

[0061] When the console 3 acquires the preliminary image data (step S1), the console 3 performs a correction process on the received preliminary image data (step S2). Then, image analysis processing is performed on the corrected preliminary image data (step S3). If there is no problem with the analysis result, total dose calculation processing is performed (step S5), and actual imaging conditions including the actual exposure dose based on the calculated total dose are output to the radiation irradiation device 1 and the radiation imaging device 2 (step S6). When the main imaging conditions are input, the radiation irradiating device 1 and the radiation imaging device 2 each set the main imaging conditions and perform preparations for main exposure at a main exposure dose (steps A3, B4).

[0062] Thereafter, when the user presses the exposure switch 12, the radiation irradiation device 1 irradiates the subject and the radiation imaging device 2 behind the subject with the normal exposure dose. When the radiographic imaging device 2 receives radiation, it accumulates electric charges generated by each radiation detection element based on the radiation dose in each pixel (step B5), converts the amount of electric charge of each pixel into a signal value, reads it out as the actual image data, and transmits it to the console 3 (step B6). Immediately before or immediately after steps B5 and B6 (FIG. 7 shows an example of the case immediately after), the radiation imaging device 2 accumulates dark charge in each pixel (step B7), converts the amount of dark charge in each pixel into a signal value, reads it out as offset data, and transmits it to the console 3 (step B8).

[0063] When the console 3 acquires the main image data and the offset data (steps S7 and S8A), it performs a correction process on the received main image data (step S8). Then, the corrected preliminary image data is used to perform image synthesis processing on the corrected main image data (step S9). In this way, diagnostic image data is generated and imaging ends.

[0064] In addition, if the console 3 has the function of controlling the irradiation of radiation described above, during the above-mentioned imaging flow, the console 3 and the radiation irradiation device 1 operate, for example, as shown in Figure 8 or Figure 9.

[0065] For example, when the pre-exposure and the main exposure are treated as one exposure, as shown in FIG. 8, once the pre-exposure conditions (mAs value and backup time, which is the time limit from the start to the end of radiation exposure) are set in the radiation irradiation device 1 (step A1), the radiation irradiation device 1 sends a signal to the console 3 indicating that the settings have been made. When the signal indicating that the setting has been completed is received, the console 3 turns on (unlocks) the image capture permission signal (step S11).

[0066] Here, when the user presses the exposure switch 12, the radiation irradiation device 1 transmits a signal to the console 3 indicating that the exposure switch 12 has been pressed, and irradiates the subject and the radiation imaging device 2 behind him with a pre-exposure dose of radiation (step A2). When the console 3 receives a signal indicating that the exposure switch 12 has been pressed, the console 3 starts timing, and when a preset pre-exposure time has elapsed, the console 3 turns off (locks) the imaging permission signal (step S12). Then, the radiation irradiation device 1 stops irradiating radiation.

[0067] During the time a predetermined time has elapsed since the imaging permission signal was turned off, the console 3 outputs the main imaging conditions to the radiation irradiation device 1 (step S6), and the radiation irradiation device 1 sets the main imaging conditions (step A3). After the predetermined time has elapsed, the console 3 turns on the imaging permission signal again (step S13). Then, the radiation irradiation device 1 irradiates the subject and the radiation imaging device 2 behind him with radiation at the main exposure dose (A4). When a preset main exposure time has elapsed since the imaging permission signal was turned on, the console 3 turns the imaging permission signal off again (step S14), causing the radiation irradiation device 1 to stop irradiating radiation.

[0068] On the other hand, when the pre-exposure and the main exposure are treated as one exposure, the main exposure conditions are also set when the pre-exposure conditions are set in the radiation irradiating device 1 (step A1), as shown in Fig. 9. Then, the radiation irradiating device 1 transmits a signal to the console 3 indicating that the settings have been made. When the signal indicating that the setting has been completed is received, the console 3 turns on (unlocks) the image capture permission signal (step S11).

[0069] Here, when the user presses the exposure switch 12, the radiation irradiation device 1 transmits a signal to the console 3 indicating that the exposure switch 12 has been pressed, and irradiates the subject and the radiation imaging device 2 behind him with a pre-exposure dose of radiation (step A2). When the console 3 receives a signal indicating that the exposure switch 12 has been pressed, the console 3 starts timing, and when a preset pre-exposure time has elapsed, the console 3 turns off (locks) the imaging permission signal (step S12). Then, the radiation irradiation device 1 stops irradiating radiation.

[0070] Within a predetermined time after the shooting permission signal is turned off, the console 3 performs image analysis processing (step S3), and if it determines that the shooting conditions need to be corrected, it sends a signal to the radiation irradiation device 1 instructing the device to make the correction. When the signal instructing the correction is received, the radiation irradiation device 1 sets the actual imaging conditions (step A3A). Then, after a predetermined time has elapsed, the console 3 turns on the imaging permission signal again (step S13). Then, the radiation irradiation device 1 irradiates the subject and the radiation imaging device 2 behind the subject with radiation at the actual exposure dose (A4). When a preset main exposure time has elapsed since the imaging permission signal was turned on, the console 3 turns the imaging permission signal off again (step S14), causing the radiation irradiation device 1 to stop irradiating radiation.

[0071] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Figures 10 and 3. Here, the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0072] In the radiation imaging system 100 of the first embodiment, the console 3 constitutes the imaging control device of the present invention. However, in the radiation imaging system 100A of the present embodiment, the console 3A does not have the function of performing the above-mentioned imaging control processing. Instead, the radiation imaging system 100A is provided with an imaging control device 4 as shown in FIG. 10, and this imaging control device 4 has the function of performing the imaging control processing.

[0073] The imaging control device 4 is connected to the radiation irradiating device 1 and the radiation imaging device 2 via the console 3A so as to be able to communicate with each other via wire or wirelessly. As shown in FIG. 3, the imaging control device 4 includes a control unit 41, a communication unit 42, a storage unit 43, a display unit 44, an operation unit 45, and a bus 46 that connects each unit.

[0074] The storage unit 43 stores a program for performing the same processing as the above-mentioned shooting control processing. The control unit 41, the communication unit 42, the display unit 44, and the operation unit 45 other than the storage unit 43 can be similar to those of the console 3 of the first embodiment. The shooting control device 4 of this embodiment is configured to execute the shooting control process when the same start condition as in the first embodiment is satisfied.

[0075] In this embodiment, the imaging control device 4 is connected to the console 3A. However, the imaging control device 4 may be directly connected to the radiation irradiating device 1 and the radiation imaging device 2 without going through the console 3. In addition, in this embodiment, the shooting control device 4 is described as being equipped with a display unit 44 and an operation unit 45, but it is also possible to use the display unit 34 and operation unit 45 of the console 3 without having the display unit 44 and operation unit 45.

[0076] As described above, the console 3 and the imaging control device 4 of the radiation imaging systems 100, 100A of the first and second embodiments include an image acquiring means capable of acquiring image data from the external radiation imaging device 2 which generates image data by receiving radiation exposure from the external radiation irradiation device 1 through the subject, a total dose calculating means which calculates a total dose required to obtain diagnostic image data to be used for diagnosis based on pre-image data generated by the external radiation imaging device and acquired by the image acquiring means by performing pre-exposure on the subject at a pre-exposure dose lower than that of the main exposure to be performed later, a dose output means which is capable of outputting the main exposure dose based on the total dose calculated by the total dose calculating means to the external radiation irradiation device 1 and the external radiation imaging device 2, and an image combining means which combines the pre-image data with the main image data generated by the external radiation imaging device and acquired by the image acquiring means by performing main exposure on the subject at the main exposure dose to generate diagnostic image data.

[0077] As a result, in radiography using the radiation imaging system 100A of the present embodiment, it is possible to determine whether the positioning is good or not (whether re-imaging is necessary or not) using a pre-image before performing main exposure with a large amount of radiation exposure. This makes it possible to prevent the subject from being unnecessarily exposed to radiation when main exposure is performed in a positioning failure state. Furthermore, since the diagnostic image data is generated by combining the actual image data with the pre-image data, it is possible to prevent a decrease in the image quality (S / N) of the diagnostic image even when the actual imaging is performed with a reduced dose.

[0078] <Third embodiment> Next, a third embodiment of the present invention will be described with reference to Figures 1 and 2. Here, the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0079] In the first embodiment of the radiation imaging system 100, the console 3 constitutes the imaging control device of the present invention, but in the radiation imaging system 100B of the present embodiment (see FIG. 1), the console 3A does not have the function of this imaging control device, and instead the radiation imaging device 2A has this function.

[0080] As shown in FIG. 2, the radiation imaging apparatus 2A includes a control unit 21, a radiation detection unit 22, a readout unit 23, a communication unit 24, a storage unit 25A, and a bus 26 connecting the respective units.

[0081] The storage unit 25A stores a program for performing the same processing as the above-mentioned imaging control processing, in addition to the programs stored in the radiation imaging apparatus 2 of the first embodiment. The radiation imaging device 2A of this embodiment is configured to execute the imaging control process when a predetermined start condition is met (such as when the exposure switch 12 is pressed, when radiation is irradiated from the radiation irradiation device 1, when image data is generated by the radiation imaging device 2A itself, etc.).

[0082] In this embodiment, the image acquisition means of the present invention is not required because the radiation imaging device 2 performs imaging control processing. That is, the generation of preliminary image data and main image data by the readout unit 23 corresponds to the processing of steps S1 and S8 (image data acquisition). In addition, since the radiation imaging device 2A does not have a display unit or audio output means as shown in FIG. 2, in the processing of step S10 (imaging stop processing), a signal instructing the user to issue a warning is transmitted to the console 3 or the like. In addition, in the process of step S6 (setting of the main imaging conditions), the main imaging conditions are output to the radiation irradiating device 1 and set in the control unit 21. That is, the control unit 21 of the radiation imaging device 2 of this embodiment serves as the dose output setting means of the present invention.

[0083] In imaging of a subject using the radiation imaging system 100B of this embodiment, steps S0 to B2 are performed in the same manner as in imaging using the radiation imaging system 100 of the first embodiment, as shown in FIG. Then, the radiation imaging apparatus 2A converts the charge amount of each pixel into a signal value and reads it out as preliminary image data (step B3A), without transmitting the preliminary image data to the console 3A. Thereafter, the radiation imaging apparatus 2 performs steps S2 to S5 similar to the imaging control process of the first embodiment, sets the main imaging conditions therein, and outputs them to the radiation irradiating apparatus 1 (step S6A). The subsequent operation of the radiation irradiation device 1 is similar to that in the first embodiment.

[0084] Thereafter, the radiation imaging apparatus 2A converts the charge amount of each pixel into a signal value and reads out the signal value as the main image data (step B6A). At this time, the main image data is not transmitted to the console 3. Immediately before or immediately after steps B5 and B6A (FIG. 11 shows an example of the case immediately after), the radiation imaging device 2 converts the amount of dark charge of each pixel into a signal value and reads it out as offset data (step B8A). At this time, the offset data is not transmitted to the console 3.

[0085] Thereafter, the radiation imaging apparatus 2A performs steps S8 and S9 similar to the imaging control process of the first embodiment, and transmits the generated diagnostic image data to the console 3 (step B9).

[0086] As described above, the radiation imaging apparatus 2A provided in the radiation imaging system 100B of the fourth embodiment comprises an image generating means capable of generating image data of the subject by irradiating the subject with radiation from the external radiation irradiation apparatus 1, a total dose calculating means for calculating a total dose required to obtain diagnostic image data to be used for diagnosis based on pre-image data generated by the image generating means by performing pre-exposure on the subject at a pre-exposure dose lower than the main exposure to be performed later, a dose output setting means for outputting the main exposure dose based on the total dose calculated by the total dose calculating means to the external radiation irradiation apparatus and setting it in the image generating means, and an image combining means for combining the pre-image data with the main image data generated by the image generating means by performing main exposure on the subject at the main exposure dose to generate diagnostic image data.

[0087] As a result, in radiography using the radiation imaging system 100B of this embodiment, as in the first embodiment, it is possible to prevent main exposure from being performed in a state of poor positioning. Furthermore, similarly to the first embodiment, even if the main imaging is performed with a reduced dose, it is possible to prevent the image quality (S / N) of the diagnostic image from decreasing.

[0088] <Fourth embodiment> Next, a third embodiment of the present invention will be described with reference to Figures 1, 3, 12, and 13. Here, the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0089] In a radiation imaging system 100C according to this embodiment (see FIG. 1), the contents of the imaging control process executed by a console 3B are different from those executed by the console 3 of the radiation imaging system 100 according to the first embodiment. That is, the program stored in the storage unit 33A (see FIG. 3) of the console 3B is different from that in the first embodiment. Furthermore, the storage unit 33A stores a plurality of types of anatomical codes C (described in detail below) used in the imaging control process.

[0090] The control unit 31 of the console 3B of this embodiment is configured to execute the shooting control process when a predetermined start condition is satisfied, similarly to the console 3 of the first embodiment. As shown in FIG. 12, the shooting control process of this embodiment is the same as that of the first embodiment in steps S1 to S4 and step S10 that is performed if the result of step S4 is No.

[0091] In the imaging control process of this embodiment, if it is determined in step S4 that there is no abnormality, that is, that the pre-exposure has been properly performed (step S4: Yes), a body thickness information estimation process is performed (step S5A). In this process, body thickness information of the subject is estimated based on the pre-image data and the associated information linked to the pre-image data. The estimated body thickness information may be a body type such as "thin", "medium", or "thick", or may be a numerical value of body thickness.

[0092] The subject's body thickness information can be estimated using techniques such as those described in Japanese Patent Application Laid-Open No. 2016-0202219 and Japanese Patent Application Laid-Open No. 2011-104103. Specifically, the body thickness information can be estimated based on a feature amount calculated from a histogram when signal values ​​corresponding to pixels belonging to a region of interest set in a radiographic image are voted in the histogram, the body thickness information can be estimated based on a correlation between the width and body thickness of a subject captured in a radiographic image, and the body thickness information can be estimated based on signal values ​​of a subject region and a non-subject region of a radiographic image. By executing such processing, the control unit 31 serves as a body thickness information estimation means in the present invention.

[0093] After estimating the body thickness information, the control unit 31 outputs the anatomical code C (step S6A). In this process, the control unit 31 selects an anatomical code C based on the body thickness information estimated in step S2 from among the multiple types of anatomical codes C stored in the control unit 33A, and outputs the selected anatomical code C to the radiation irradiation device 1 and the radiation imaging device 2. The anatomical code C in this embodiment includes, for example, the tube voltage, tube current, irradiation time, and the like when performing the main exposure, as shown in FIG. Each anatomical code C corresponds to a combination of the imaging region and body thickness information, and the control unit 31 selects an anatomical code C that matches the combination of the imaging region set in advance and the body thickness information estimated in step S2. By executing such processing, the control unit 31 serves as a code output means in the present invention.

[0094] During the period from when the anatomical code C is output until the processing of the next step S7, the radiation irradiating device 1 performs main radiation exposure on the subject under imaging conditions based on the anatomical code C, and the radiation imaging device 2 generates main image data. The processes from step S7 onwards, which are carried out after the radiation imaging apparatus 2 generates the main image data, are the same as those in the first embodiment, as shown in FIG.

[0095] As described above, the console 3B of the radiation imaging system 100C of the fourth embodiment includes an image acquiring means capable of acquiring image data from the external radiation imaging device 2 which generates image data by irradiating the subject with radiation from the external radiation irradiation device 1, a body thickness information estimating means which estimates body thickness information of the subject based on pre-image data generated by the external radiation imaging device and acquired by the image acquiring means by performing pre-exposure on the subject at a pre-exposure dose lower than that of the main exposure which will be performed later, a code output means which is capable of outputting an anatomical code C based on the body thickness information estimated by the body thickness information estimation means to the external radiation irradiation device 1 and the external radiation imaging device 2, and an image combining means which generates diagnostic image data by combining the pre-image data with the main image data generated by the external radiation imaging device and acquired by the image acquiring means by performing main exposure on the subject under imaging conditions based on the anatomical code C.

[0096] As a result, in radiography using the radiation imaging system 100C of this embodiment, as in the first embodiment, it is possible to prevent main exposure from being performed in a state of poor positioning. Furthermore, similarly to the first embodiment, even if the main imaging is performed with a reduced dose, it is possible to prevent the image quality (S / N) of the diagnostic image from decreasing.

[0097] In addition, the radiation imaging system 100C according to this embodiment is configured so that the above-mentioned imaging control process is executed by the console 3B, but it may also be configured so that the imaging control process is executed by an imaging control device or a radiation imaging device that is provided independently of the console. [Explanation of symbols]

[0098] 100, 100A, 100B, 100C Radiography system 1 Radiation irradiation device 11. Generator 12 Exposure switch 13 Radiation source 2,2A Radiography equipment 21 Control section 22 Radiation detection unit 23 Readout section 24 Communications Department 25 Memory section 26 Bus 3,3B Console (imaging control device) 3A Console 31 Control Unit 32 Communications Department 33,33A storage section 34 Display section 35 Control section 36 Bus 4. Shooting control device 41 Control section 42 Communications Department 43 Storage section 44 Display section 45 Operation section 46 Bus C Anatomical Code X radiation

Claims

1. an image acquisition unit capable of acquiring image data from a radiation imaging device that generates image data of a subject by receiving radiation from a radiation irradiation device through the subject; an imaging determination means for determining whether the positioning of the subject is good or bad based on pre-image data generated by the radiation imaging device through pre-exposure before the main exposure by the radiation irradiation device and acquired by the image acquisition means; a display unit for displaying a preview image based on the preview image data; The photographing determination means analyzes a missing part of a photographing target part in the preliminary image data based on the preliminary image data and the supplementary information associated with the preliminary image data, A photography control device capable of setting to display the preliminary image on the display means only when the photography determination means determines that the positioning of the subject is not good.

2. 2. The imaging control device according to claim 1, wherein when the imaging determination means determines that the positioning of the subject is not good, the main exposure by the radiation irradiation device is stopped.

3. 2. The imaging control device according to claim 1, further comprising an image synthesis means for synthesizing the preliminary image data with the main image data generated by the radiation imaging device through main exposure by the radiation irradiation device and acquired by the image acquisition means, when the imaging determination means determines that the positioning of the subject is good, to generate diagnostic image data for the subject.

4. 4. The imaging control device according to claim 3, wherein a dose of the pre-exposure by the radiation irradiation device is lower than a dose of the main exposure by the radiation irradiation device.

5. a radiation irradiation device that irradiates radiation; a radiation imaging device that generates image data of a radiation image by receiving radiation exposure; A radiation imaging system comprising: an imaging control device according to claim 1 .

6. acquiring image data from a radiation imaging device that generates image data of a subject by irradiating the subject with radiation from a radiation irradiation device; An imaging control method executed by an imaging control device that can be set to determine whether the positioning of the subject is good or bad based on the pre-image data generated and acquired by the radiation imaging device by a pre-exposure prior to the main exposure by the radiation irradiation device, analyze the lack of the area to be imaged in the pre-image data based on the pre-image data and additional information associated with the pre-image data, and display a pre-image based on the pre-image data on a display means only if it is determined that the positioning of the subject is not good.

Images