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

Abstract

To enable accurate adjustment of a positional relationship between a subject and a bulb on the basis of an optical image acquired by an optical camera.SOLUTION: A control unit of a console acquires an optical image of a subject captured by a camera, and determines whether or not the camera and the subject are in a predetermined positional relationship on the basis of the acquired optical image. When determining that the camera and the subject are in the predetermined positional relationship, the control unit performs control such that a bulb is located at a position of the camera.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a radiography control device, a radiography system, a program, and a control method. [Background technology]

[0002] Conventionally, there is known an X-ray imaging device that is equipped with a camera (optical camera) at a support part of a tube that irradiates X-rays, and determines whether appropriate X-ray imaging is possible based on the optical image acquired by the camera (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6056974 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since placing a camera at the center of the tube (on the irradiation axis) would interfere with the radiation irradiation, it is not possible to place the camera at the center of the tube. As a result, the center of the camera will be offset from the center of the tube, resulting in a mismatch between the position of the subject in the optical image acquired by the camera and the position of the subject in the X-ray image. Therefore, if the positional relationship between the subject and the tube is adjusted based on the optical image, accurate adjustment cannot be made, resulting in the problem of not being able to obtain an appropriate radiographic image.

[0005] An object of the present invention is to enable accurate adjustment of the positional relationship between the subject and the tube based on an optical image acquired by an optical camera. [Means for solving the problem]

[0006] In order to solve the above problems, the radiography control device according to the present invention comprises: A radiography control device that controls a radiation irradiation unit having a tube for irradiating a subject with radiation and an optical camera that photographs the subject, a control unit that acquires an optical image of the subject photographed by the optical camera, determines whether or not the optical camera and the subject have a predetermined positional relationship based on the acquired optical image, and controls the tube to be positioned at the position of the optical camera when it is determined that the optical camera and the subject have the predetermined positional relationship; Equipped with.

[0007] The radiation imaging system according to the present invention comprises: The radiography control device according to any one of claims 1 to 10; a radiation irradiation unit having a tube for irradiating a subject with radiation; an optical camera that photographs the subject; Equipped with.

[0008] The program according to the present invention comprises: a computer of a radiography control device that controls a radiation irradiation unit having a tube for irradiating a subject with radiation and an optical camera that photographs the subject; a control unit that acquires an optical image of the subject photographed by the optical camera, determines whether or not the optical camera and the subject have a predetermined positional relationship based on the acquired optical image, and controls the tube to be positioned at the position of the optical camera when it is determined that the optical camera and the subject have the predetermined positional relationship; Function as.

[0009] The control method according to the present invention comprises: The computer, An optical image of the subject photographed by an optical camera is acquired, and based on the acquired optical image, it is determined whether or not the optical camera and the subject have reached a predetermined positional relationship. If it is determined that the optical camera and the subject have reached the predetermined positional relationship, the tube is controlled to be positioned at the position of the optical camera. [Effects of the Invention]

[0010] According to the present invention, the positional relationship between the subject and the tube can be accurately adjusted based on the optical image acquired by the optical camera. [Brief explanation of the drawings]

[0011] Advantages and features provided by one or more embodiments of the present invention will be more fully understood from the following detailed description and the accompanying drawings, which are for illustrative purposes only and are not intended to limit the scope of the invention. [Figure 1] 1 is a diagram showing the overall configuration of a radiation imaging system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram schematically illustrating the front of a radiation irradiation unit. [Figure 3] FIG. 2 is a block diagram showing the functional configuration of the console of FIG. 1. [Figure 4] 10A and 10B are diagrams showing a schematic view of radiation irradiation when the center position of the tube is aligned with the center position of a region of interest of the subject; [Figure 5] 10 is a diagram showing a schematic view of a state in which an image is captured by a camera when the center position of a tube is aligned with the center position of a region of interest of a subject. FIG. [Figure 6] 10 is a diagram showing an example of an optical image obtained by a camera when the center position of a tube is aligned with the center position of a region of interest of a subject; FIG. [Figure 7] 10A and 10B are diagrams showing an example of an optical image obtained by a camera when the center position of the camera is aligned with the center position of a region of interest of a subject; [Figure 8] 4 is a flowchart showing the flow of a shooting control process executed by the control unit in FIG. 3. [Figure 9] 10A and 10B are diagrams illustrating recognition of the positions of the neck, joints, trunk, etc. of a subject in an optical image. [Figure 10] 10 is a diagram showing information on the initial position of the camera stored in a storage unit in association with shooting information. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the scope of the invention is not limited to the illustrated examples.

[0013] [Configuration of Radiography System 100] First, the configuration of this embodiment will be described. 1 is a diagram showing an example of the overall configuration of a radiation imaging system 100 according to this embodiment. The radiation imaging system 100 includes a radiation irradiating device 1, a radiation detecting device 2, and a console 3. The console 3 is connected to the radiation irradiating device 1 and the radiation detecting device 2 so as to be able to transmit and receive data therebetween.

[0014] The radiation irradiation device 1 includes a radiation irradiation unit 11, a camera 12, a support unit 14, a movement mechanism 15, and the like. 2 is a diagram schematically illustrating the front of radiation irradiator 11. As shown in FIG. 2, radiation irradiator 11 has tube 11a for irradiating radiation (X-rays) and holder 11b for holding tube 11a. Radiation irradiator 11 is disposed so as to face radiation detection device 2 with subject 5 (examinee) sandwiched between them. Tube 11a irradiates subject 5 with radiation under the control of console 3.

[0015] 1 and 2, camera (optical camera) 12 is provided on holder 11b of radiation irradiation unit 11. Camera 12 is held integrally with tube 11a by holder 11b so as to face radiation detection device 2 across subject 5. Camera 12 captures an optical image of subject 5 under the control of console 3, and outputs the obtained optical image to console 3.

[0016] The support section 14 supports the radiation emitting section 11 so that it can move up and down from the ceiling C (movable in the Y direction (body axis direction)).

[0017] The movement mechanism 15 includes, for example, a motor. Under the control of the console 3, the movement mechanism 15 moves the radiation irradiator 1 in the X direction along a rail 15b extending in the X direction perpendicular to the Y direction, which is the vertical direction. The movement mechanism 15 also moves the rail 15b and the radiation irradiator 1 together in the Z direction along a rail 15a provided on the ceiling C and extending in the Z direction. Under the control of the console 3, the movement mechanism 15 also moves the support unit 14 up and down in the Y direction.

[0018] The radiation detection device 2 is configured to include a support 21, a detector holder 22, a moving mechanism 23, a radiation detector 24, and the like. The detector holding unit 22 is configured to be movable in the X and Y directions, and holds the radiation detector 24 so that it can move in the X and Y directions.

[0019] The moving mechanism 23 includes, for example, a motor, and, under the control of the console 3, moves the detector holding part 22 in the X direction along a guide 23a extending in the X direction, and moves the guide 23a and the detector holding part 22 together in the Y direction along a guide (not shown) provided on the support 21 and extending in the Y direction.

[0020] The radiation detector 24 is composed of an FPD (Flat Panel Detector) or the like. The radiation detector 24 detects radiation irradiated from the radiation irradiator 1 and transmitted through at least the subject 5 according to its intensity, and is composed of a plurality of detection elements (pixels) arranged in a matrix. The detection elements (pixels) convert the detected radiation into electrical signals and store the electrical signals. Each pixel has a switching unit such as a TFT (Thin Film Transistor). The radiation detector 24 controls the switching unit of each pixel based on image reading conditions input from the console 3 to read the electrical signals stored in the pixels, thereby acquiring a radiation image. The radiation detector 24 then outputs the acquired radiation image to the console 3.

[0021] The console 3 serves as a radiation imaging control device and controls the operations of the radiation irradiation device 1, the camera 12, and the radiation detection device 2. As shown in FIG. 3, the console 3 is configured with a control unit 31, a memory unit 32, an operation unit 33, a display unit 34, a communication unit 35, and an audio output unit 36, and each unit is connected by a bus 37.

[0022] The control unit 31 is composed of a CPU (Central Processing Unit), RAM (Random Access Memory), etc. In response to operations on the operation unit 33, the CPU of the control unit 31 reads out system programs and various processing programs stored in the storage unit 32, loads them into the RAM, and performs centralized control of the operations of each unit of the console 3 in accordance with the loaded programs. The CPU of the control unit 31 also controls the radiation irradiation operation of the radiation irradiation device 1 and the reading operation of the radiation detector 24. The control unit 31 functions as a control unit and an image analysis unit of the present invention.

[0023] The storage unit 32 is configured with a non-volatile semiconductor memory, a hard disk, etc. The storage unit 32 stores various programs executed by the control unit 31, parameters required for executing processes by the programs, data such as processing results, etc. The various programs are stored in the form of readable program code. The control unit 31 sequentially executes operations in accordance with the program code. The storage unit 32 also stores radiation irradiation conditions and image reading conditions corresponding to the imaging region and imaging direction. The storage unit 32 also stores imaging order information transmitted from a not-shown RIS (Radiology Information System) or the like. The imaging order information includes patient information and examination information. The examination information includes an examination ID, imaging region, imaging direction, examination date, etc. The storage unit 32 also stores information on the initial position of the camera 12 in association with the imaging information (see FIG. 10). The storage unit 32 also stores difference information between the center position O2 of the camera 12 and the center position O1 of the tube 11a. As shown in FIG. 2, the difference information is, for example, the distance difference d and angle difference θ between the center position O1 of the camera 12 and the center position O2 of the tube 11a. The storage unit 32 also stores radiographic images acquired by imaging in association with patient information and examination information.

[0024] The operation unit 33 is configured with a keyboard having cursor keys, numeric input keys, various function keys, etc., and a pointing device such as a mouse. The operation unit 33 outputs instruction signals input by operating the keyboard and the mouse to the control unit 31. The operation unit 33 may also be a touch screen provided on the display screen of the display unit 34. In this case, the operation unit 33 outputs instruction signals input via the touch screen to the control unit 31. The operation unit 33 also has an exposure switch for instructing the radiation irradiator 1 to irradiate radiation.

[0025] The display unit 34 is configured with a monitor such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube), etc. The display unit 34 displays an operation screen and a display screen for captured images in accordance with instructions of a display signal input from the control unit 31.

[0026] The communication unit 35 has an interface for transmitting and receiving data to and from the radiation irradiating device 1 and the radiation detecting device 2. Note that communication between the console 3 and the radiation irradiating device 1 and the radiation detecting device 2 may be wired communication or wireless communication. The audio output unit 36 ​​outputs audio based on instructions from the control unit 31 .

[0027] [Operation of Radiography System 100] Next, the operation of the radiation imaging system 100 will be described. 2, camera 12 is positioned so as not to block the radiation emission port of tube 11a. Therefore, the center position O2 of camera 12 is misaligned with the center position O1 of tube 11a, resulting in a mismatch between the position of subject 5 in the optical image captured by camera 12 and the position of subject 5 in the radiological image.

[0028] FIG. 4 is a diagram schematically illustrating radiation irradiation when the center position O1 (irradiation axis L) of the tube 11a is aligned with the center position O3 of the region of interest of the subject 5. FIG. 5 is a diagram schematically illustrating imaging by the camera 12 when the center position O1 of the tube 11a is aligned with the center position O3 (irradiation axis L) of the region of interest of the subject 5. The dashed-dotted line in FIGS. 4 and 5 indicates the irradiation axis L of the tube 11a. The coarse dotted line in FIG. 4 indicates the range that appears in the radiographic image, and the fine dotted line indicates the position where the subject 5 appears in the radiographic image. The coarse dotted line in FIG. 5 indicates the range that appears in the optical image, and the fine dotted line indicates the position where the subject 5 appears in the optical image. Note that in FIGS. 4 and 5, the subject 5 and the region of interest coincide with each other. 4 and 5, when the center position O1 of the tube 11a is aligned with the center position O3 of the region of interest of the subject 5, the camera 12 captures the region of interest of the subject 5 from diagonally left. Therefore, as shown in Fig. 6, in the optical image 61 obtained from the camera 12, the center position O3 of the region of interest of the subject 5 appears shifted to the right with respect to the center position of the optical image 61. On the other hand, as shown in Fig. 7, if the camera 12 is positioned so that the center position O3 of the region of interest of the subject 5 is at the center position (left-right center position) of the optical image 61 and radiography is performed in this state, the region of interest of the subject 5 will be irradiated with radiation from an oblique angle, and a radiographic image suitable for diagnosis will not be obtained.

[0029] Therefore, in this embodiment, when radiography is performed, the control unit 31 of the console 3 executes the radiography control process described below, acquires an optical image with the camera 12, and controls the camera 12 and the subject 5 to have a predetermined positional relationship based on the optical image. For example, the position of the camera 12 is controlled so that the center position O1 of the camera 12 coincides with the center position O3 of the region of interest of the subject 5. Then, when the control unit 31 determines based on the optical image that the camera 12 and the subject 5 have achieved the predetermined positional relationship, the control unit 31 moves the tube 11a based on the difference information so that the tube 11a is positioned at the position of the camera 12 at that time, thereby performing radiography.

[0030] 8 is a flowchart showing the flow of the photographing control process executed by the control unit 31 of the console 3. The photographing control process is executed by the control unit 31 in cooperation with a program stored in the ROM when, for example, photographing order information for a photographing target is selected by operating the operation unit 33 of the console 3.

[0031] First, the control unit 31 sets imaging conditions (radiation irradiation conditions and image reading conditions) based on information such as the imaging region and imaging direction included in the imaging order information (step S1). The control unit 31 determines radiation irradiation conditions and image reading conditions based on information such as the selected imaging region and imaging direction. The control unit 31 transmits the determined radiation irradiation conditions to the radiation irradiation device 1 via the communication unit 35. The control unit 31 also transmits the determined image reading conditions to the radiation detector 24 via the communication unit 35. The radiation irradiation conditions include, for example, the tube current, the tube voltage, the mAs value, and the SID. The SID is the distance between the tube 11a and the radiation detector 24.

[0032] Next, the control unit 31 moves the camera 12 to the initial position (step S2). As shown in FIG. 10 , information on the initial position of the camera 12 is stored in the storage unit 32 in association with the imaging information. The imaging information is imaging order information such as the imaging region and imaging direction. That is, the initial position of the camera 12 is determined in advance according to the imaging information (imaging region and imaging direction). The information on the initial position of the camera 12 includes, for example, information on the initial camera center position and initial camera angle. The initial camera center position is the initial value of the position at which the center position O2 of the camera 12 is aligned. The initial camera angle is the initial value of the angle at which the camera 12 is tilted in the vertical direction. The control unit 31 determines the initial position of the camera 12 based on the imaging information by referring to the storage unit 32. Then, the control unit 31 controls the movement mechanism 15 to move the camera 12 to the determined initial position. Here, the location captured by the center position O2 of the camera 12 is located at the center position of the optical image. The control unit 31 stores the position information of the camera 12 when the camera 12 is moved to its initial position in RAM. The position information of the camera 12 is, for example, the position coordinates of the camera 12 in the X direction, Y direction, and Z direction.

[0033] Here, the person performing the imaging, such as an imaging technician, places the subject 5 between the radiation detector 24 and the radiation irradiation unit 11, and adjusts the positions of the subject 5 and the radiation detector 24 so that the center position O3 of the area of ​​interest of the subject 5 faces the center position of the radiation detector 24.

[0034] After moving camera 12 to the initial position, control unit 31 causes camera 12 to take a photograph, acquire an optical image of subject 5, and analyze the acquired optical image (step S3). Then, control unit 31 determines whether or not the positioning is OK based on the analysis result (step S4). In step S3, control unit 31 analyzes the optical image captured by camera 12 and determines, based on the analysis results, whether camera 12 and subject 5 have achieved a predetermined positional relationship. For example, control unit 31 determines whether center position O2 of camera 12 and center position O3 of the region of interest of subject 5 match, and if it determines that they match, it determines that camera 12 and subject 5 have achieved a predetermined positional relationship. Then, if it determines that camera 12 and subject 5 have achieved a predetermined positional relationship, control unit 31 determines that positioning is OK. It is preferable that the control unit 31 displays the optical image captured by the camera 12 on the display unit 34. This allows the person performing the imaging to check the quality of the positioning from the position of the display unit 34 of the console 3.

[0035] For example, in step S3, the control unit 31 first identifies the region of interest of the subject 5 based on the imaging location and imaging direction. For example, if the imaging location is the front of the chest, the control unit 31 identifies the region of interest as the lung field. If the imaging location is the front of the shoulder joint, the control unit 31 identifies the region of interest as the shoulder joint. If the imaging location is the lateral femur, the control unit 31 identifies the region of interest as the center between the femoral head and the condyle. Next, the control unit 31 analyzes the optical image acquired from the camera 12 and recognizes the positions of the neck, joints, trunk, etc. of the subject 5 as shown in FIG. 9 , and recognizes the position of the region of interest in the optical image based on the recognized positions. The positions of the neck, joints, trunk, etc. of the subject 5 in the optical image can be recognized using, for example, machine learning, pattern matching, edge detection, etc. Then, if the control unit 31 determines that the center position O3 of the region of interest coincides with the center position of the optical image, i.e., if the control unit 31 determines that the center position O2 of the camera 12 coincides with the center position O3 of the region of interest of the subject 5, the control unit 31 determines that the positioning is OK. For example, when the imaging area and imaging direction are a frontal view of the left shoulder joint, if the center position of the optical image indicated by reference numeral 71 in Figure 9 matches the center position of the left shoulder joint indicated by reference numeral 72, it is determined that the positioning is OK. The above-mentioned predetermined positional relationship may be determined in advance according to the imaging region and imaging direction, for example.

[0036] If it is determined that the positioning is not OK (step S4; NG), the control unit 31 outputs an adjustment instruction or moves the camera 12 (step S5), and returns to step S3. In step S5, control unit 31 outputs an adjustment instruction or controls to move camera 12 so that the positioning is OK. For example, control unit 31 outputs an adjustment instruction or controls to move camera 12 so that the center position O2 of camera 12 and the center position O3 of the region of interest of subject 5 coincide with each other. For example, it is assumed that the control unit 31 detects, based on the optical image acquired from the camera 12, that the body axis of the subject 5 is shifted by half a step to the left with respect to the central axis of the camera 12 (the central axis of the optical image). In this case, the control unit 31 causes the audio output unit 36 ​​to output a voice such as "Please move half a step to the right" so that the central axis of the camera 12 and the body axis of the subject 5 are aligned. Furthermore, the control unit 31 detects a face from the optical image, compares its orientation with the shooting direction, and if the two differ, outputs a voice such as "Please stand facing away" from the voice output unit 36. Alternatively, the control unit 31 may cause the display unit 34 to display an instruction such as "Please stand facing away." Furthermore, the control unit 31 analyzes the optical image as described above to recognize the position of the region of interest, and controls the movement mechanism 15 to move the camera 12 so that the center position O3 of the region of interest is located at the center of the optical image. For example, when the imaging site (region of interest) is the left shoulder joint, the control unit 31 moves the camera 12 without changing the SID so that the center position O2 of the camera 12 coincides with the center position of the left shoulder joint. When the control unit 31 moves the camera 12, it stores the position information of the camera 12 in the RAM.

[0037] When it is determined that the positioning is OK (step S4; OK), the control unit 31 notifies that the positioning is OK (step S6). For example, the control unit 31 may output a notification indicating that the positioning is OK from the audio output unit 36 ​​or may display a message on the display unit 34. Alternatively, the control unit 31 may notify the user that "a correct radiographic image cannot be obtained due to improper positioning" or the like until it is determined that the positioning is OK. Alternatively, the control unit 31 may prohibit the radiation irradiation device 1 from irradiating radiation even if the exposure switch is pressed until the tube 11a moves to the position of the camera 12 when it is determined that the positioning is OK. Then, the control unit 31 may notify the user that "radiography cannot be performed due to improper positioning" or the like through the display unit 34 or the audio output unit 36.

[0038] Next, the control unit 31 ends the positioning assistance (step S7), and moves the center position O1 of the tube 11a to the center position O2 of the camera 12 when the positioning is determined to be OK (step S8). The control unit 31 moves the tube 11a using the moving mechanism 15 based on the difference information between the center position O2 of the camera 12 and the center position O1 of the tube 11a, which is stored in the memory unit 32, thereby moving the center position O1 of the tube 11a to the center position O2 of the camera 12.

[0039] Next, the control unit 31 causes the camera 12 to take a photograph, acquire an optical image of the subject 5, and analyze the acquired optical image (step S9). In step S9, the control unit 31 analyzes the optical image captured by the camera 12 and determines whether or not there is any body movement of the subject 5. The presence or absence of body movement can be determined, for example, by detecting the amount of movement, such as density difference in the optical image, edge detection, or optical flow. Furthermore, if the subject 5 is the chest, the control unit 31 may determine the breathing state. For example, the control unit 31 may recognize the position of the shoulders from the optical image and determine the breathing state from the shoulder position. The breathing state may be determined by detecting a change in distance to the subject 5 or a change in sound using a sensor, or by estimating the distance using a stereo camera.

[0040] Based on the analysis result, the control unit 31 determines whether or not it is time to expose (irradiate) (step S10). If it is determined that it is not the timing for irradiation (step S10; NO), the control unit 31 returns to step S9. When it is determined that it is time to irradiate (step S10; YES), the control unit 31 causes the radiation irradiating device 1 and the radiation detector 24 to perform imaging to obtain a radiographic image (step S11), and ends the imaging control process.

[0041] According to the imaging control process, the irradiation axis of tube 11a during radiography can be aligned with the optical axis of camera 12 during optical image capture, so the positional relationship between subject 5 and tube 11a can be accurately adjusted based on the optical image acquired by camera 12. In other words, this solves the conventional problem of inaccurate positioning adjustment due to misalignment between camera 12 and tube 11a. For example, it is possible to prevent problems such as oblique incidence during radiography.

[0042] As described above, according to radiation imaging system 100, control unit 31 of console 3 acquires an optical image of subject 5 captured by camera 12, and determines, based on the acquired optical image, whether camera 12 and subject 5 have achieved a predetermined positional relationship. Control unit 31 then controls tube 11a to position camera 12 at the position where camera 12 and subject 5 achieve the predetermined positional relationship. Therefore, the irradiation axis of tube 11a during radiation imaging can be aligned with the optical axis of camera 12 during optical image capture, and the positional relationship between subject 5 and tube 11a can be accurately adjusted based on the optical image acquired by camera 12.

[0043] In addition, in radiation imaging system 100, radiation irradiator 11 has holder 11b that holds tube 11a, and camera 12 is provided on holder 11b. Therefore, the positional relationship between camera 12 and tube 11a is constant, so controller 31 can easily control tube 11a to be positioned at the position of camera 12.

[0044] Furthermore, based on the optical image, control unit 31 moves camera 12 so that camera 12 and subject 5 have a predetermined positional relationship, and moves tube 11a to the position of camera 12 after the movement. Therefore, automatic adjustment can be made so that camera 12 and subject 5 have a predetermined positional relationship.

[0045] Furthermore, control unit 31 functions as an image analysis unit to analyze the optical image, and if it determines as a result of the analysis that the center position of the optical image coincides with the center position of the region of interest of subject 5, it determines that camera 12 and subject 5 have achieved a predetermined positional relationship and moves tube 11a to the position of camera 12. Therefore, based on the optical image, the positional relationship between subject 5 and tube 11a can be accurately adjusted so that the center position of the region of interest of subject 5 is located at the center position of the radiation image.

[0046] Furthermore, the control unit 31 determines the initial position of the camera 12 based on photographing information such as photographing order information, etc. Therefore, the initial position of the camera 12 can be automatically determined to be an appropriate position.

[0047] Furthermore, control unit 31 prohibits tube 11a from irradiating radiation until tube 11a is positioned at the position of camera 12 when camera 12 and subject 5 are in a predetermined positional relationship, thereby preventing imaging from being performed when the camera is not correctly positioned.

[0048] Furthermore, the control unit 31 switches the analysis content by the image analysis unit between before and after the camera 12 and the subject 5 reach a predetermined positional relationship. Therefore, before the camera 12 and the subject 5 reach a predetermined positional relationship, the control unit 31 can determine whether the positioning is appropriate by, for example, analyzing the optical image. After the camera 12 and the subject 5 reach a predetermined positional relationship, the control unit 31 can determine whether it is time to expose by, for example, analyzing the optical image.

[0049] The above-described embodiment is a preferred example of the present invention, and the present invention is not limited to this.

[0050] For example, in the above embodiment, the present invention has been described as being applied to a radiation imaging system that performs imaging in an upright position, but it may also be applied to a video imaging system that performs imaging in a recumbent position.

[0051] In the above embodiment, the center position of the optical image is described as the vertical and horizontal center position of the optical image, and the center position of the region of interest of the subject 5 is described as the vertical and horizontal center position of the region of interest of the subject 5. However, the above center position is not limited to the vertical and horizontal center position, and may be the horizontal center position or the vertical center position. For example, if the horizontal center is at the center of the angle of view, and the region is diagnosable even if the vertical center is misaligned, the above-mentioned center position may be used as the horizontal center position. For example, for regions with a wide imaging range, such as the chest or abdomen, the center position may be used as the horizontal center position. For example, in the case of the chest, if the lung field is within the angle of view, there is no need to adjust the positions of the apex (top of the lung) or the back of the lung (bottom of the lung field behind the diaphragm). In the case of the abdomen, if the area from the diaphragm to the lower pelvis (pubic symphysis) is within the angle of view, further adjustment in the vertical direction is not necessary. For regions with a wide imaging range, radiation is originally obliquely incident on the upper and lower parts, so there is no particular problem with the image. Furthermore, if the vertical center is located at the center of the angle of view, the above-mentioned center position may be used as the vertical center position for a region where diagnosis is possible even if the horizontal center is shifted. For example, vertebral bodies (thoracic vertebrae, lumbar vertebrae, etc.) are not necessarily located in the center of the trunk due to deformation caused by scoliosis or aging, and may be shifted by several centimeters. Therefore, when a vertebral body is the imaging region, it is not necessary to align the horizontal center as long as the vertebral body is within the angle of view. However, there are requests for vertical alignment, such as "I want to capture all thoracic vertebrae 1 to 13" or "It is easier to see if the third lumbar vertebra is in the center of the vertical direction." Therefore, it is preferable to align the vertical center positions of the optical image and the region of interest.

[0052] Furthermore, for example, in the above description, examples have been disclosed in which a hard disk or a semiconductor nonvolatile memory is used as a computer-readable medium for the program according to the present invention, but the present invention is not limited to this example. Portable recording media such as CD-ROMs can also be used as other computer-readable media. Furthermore, carrier waves can also be used as a medium for providing data for the program according to the present invention via a communication line.

[0053] While embodiments of the present invention have been described and illustrated in detail, the disclosed embodiments are made for purposes of illustration and example only and are not intended to limit the invention, the scope of which is to be construed by the appended claims. [Explanation of symbols]

[0054] 100 Radiography System 1 Radiation irradiation device 11 Radiation irradiation unit 11a tube 11b Holding part 12 Camera 14 Support part 15 Moving mechanism 2. Radiation detection equipment 21 Post 22 Detector holder 23 Moving mechanism 24 Radiation detector 3 Console 31 Control Unit 32 Storage section 33 Operation section 34 Display section 35 Communications Department 36 Audio output section 37 Bus

Claims

1. A radiography control device that controls a radiation irradiation unit having a tube for irradiating a subject with radiation and an optical camera that photographs the subject, a control unit that acquires an optical image of the subject photographed by the optical camera, determines whether or not the optical camera and the subject have a predetermined positional relationship based on the acquired optical image, and controls the tube to be positioned at the position of the optical camera when it is determined that the optical camera and the subject have the predetermined positional relationship; A radiation imaging control device comprising:

2. the radiation irradiation unit has a holder that holds the tube, The optical camera is provided in the holding part. The radiography control device according to claim 1 .

3. the control unit moves the optical camera based on the optical image so that the optical camera and the subject have a predetermined positional relationship, and moves the bulb to the position of the optical camera after the movement. The radiography control device according to claim 1 .

4. the control unit determines that the optical camera and the subject have the predetermined positional relationship when a center position of the optical image and a center position of a region of interest of the subject coincide with each other. The radiography control device according to claim 1 .

5. The radiography control device according to claim 4 , wherein the center position is a horizontal center position or a vertical center position.

6. The radiography control device according to claim 4 , wherein the central position is a vertically and horizontally central position.

7. an image analysis unit that analyzes the optical image, 2. The radiation imaging control device according to claim 1, wherein when the control unit determines, as a result of the analysis by the image analysis unit, that the center position of the optical image and the center position of the region of interest of the subject coincide with each other, the control unit determines that the optical camera and the subject have achieved the predetermined positional relationship and moves the tube to the position of the optical camera.

8. The control unit determines an initial position of the optical camera based on photographing information. The radiography control device according to claim 1 .

9. 2. The radiography control device according to claim 1, wherein the control unit prohibits the tube from irradiating radiation until the tube is positioned at the position of the optical camera when it is determined that the optical camera and the subject have achieved the predetermined positional relationship.

10. an image analysis unit that analyzes the optical image, The radiography control device according to claim 1 , wherein the control unit switches the analysis content by the image analysis unit between before and after it is determined that the optical camera and the subject have a predetermined positional relationship.

11. The radiography control device according to any one of claims 1 to 10, a radiation irradiation unit having a tube for irradiating a subject with radiation; an optical camera that photographs the subject; A radiography system comprising:

12. a computer of a radiography control device that controls a radiation irradiation unit having a tube for irradiating a subject with radiation and an optical camera that photographs the subject; a control unit that acquires an optical image of the subject photographed by the optical camera, determines whether or not the optical camera and the subject have a predetermined positional relationship based on the acquired optical image, and controls the tube to be positioned at the position of the optical camera when it is determined that the optical camera and the subject have the predetermined positional relationship; A program to function as a

13. a computer of a radiography control device that controls a radiation irradiation unit having a tube for irradiating a subject with radiation and an optical camera that photographs the subject, A control method comprising: acquiring an optical image of a subject photographed by an optical camera; determining whether or not a predetermined positional relationship exists between the optical camera and the subject based on the acquired optical image; and controlling the tube to be positioned at the position of the optical camera when it is determined that the predetermined positional relationship exists between the optical camera and the subject.

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