Information processing device, radiography system, control method and program for information processing device

Abstract

The goal is to ensure accurate correspondence between the subject's region of interest and the light-gathering field of the radiation detector used to measure radiation dose, while also enabling reliable cessation of radiation exposure. [Solution] The system includes an optical image acquisition unit 201 that acquires an optical image obtained by optically photographing a subject being subjected to radiography using radiation and a radiation detector provided with multiple light-gathering fields for detecting the radiation dose; an optical image analysis unit 203 that analyzes the optical image and extracts the region of the radiation detector and the subject's region of interest from the optical image; a control light-gathering field setting unit 204 that sets a control light-gathering field which includes the subject's region of interest in multiple configurations when the radiation detector is rotated relative to the subject; and a radiation control method determination unit 205 that determines a radiation control method for stopping radiation irradiation based on the shooting order information in radiography and the control light-gathering field.

Description

[Technical Field]

[0001] This disclosure relates to an information processing device, a radiography system, a control method for the information processing device, and a program. [Background technology]

[0002] Radiography for medical examinations requires proper radiation management and optimization of radiation exposure. One technology that achieves this optimization is automatic exposure control (AEC). This AEC uses a light-gathering field arranged in a radiation detector to measure the radiation dose irradiated into a predetermined region of interest of the subject, and stops radiation irradiation when the measured radiation dose reaches the target dose. This AEC requires accurately determining the light-gathering field of the radiation detector located in the subject's region of interest. In this regard, Patent Document 1 describes a technology for associating the subject's region of interest, where automatic exposure control is performed, with a monitoring sensor, which is the light-gathering field of the radiation detector that measures the radiation dose for the purpose of automatic exposure control. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-36467 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In the technology described in Patent Document 1, the process of associating the subject's region of interest with the light-gathering field (monitoring sensor) of the radiation detector that measures the radiation dose is performed during radiation irradiation. If this process takes too long, it will not be possible to stop the radiation irradiation in time. In other words, the technology described in Patent Document 1 has a problem in ensuring the accuracy of associating the subject's region of interest with the light-gathering field of the radiation detector that measures the radiation dose, while reliably stopping the radiation irradiation.

[0005] This disclosure has been made in view of these challenges, and aims to ensure that radiation irradiation can be reliably stopped while maintaining the accuracy of the correspondence between the subject's area of ​​interest and the light-gathering field of the radiation detector used to measure radiation dose. [Means for solving the problem]

[0006] The information processing device of the present disclosure includes: acquisition means for acquiring an optical image obtained by optically photographing a subject being subjected to radiography using radiation and a radiation detector provided with a plurality of light-gathering fields for detecting the dose of said radiation; analysis means for analyzing the optical image and extracting the region of the radiation detector and the region of interest of the subject from the optical image; setting means for setting a control light-gathering field, which is the light-gathering field that includes the region of interest of the subject, when the arrangement of the radiation detector is rotated with respect to the subject to perform multiple arrangements; and determination means for determining a radiation control method for stopping the irradiation of said radiation based on the shooting order information in said radiography and the control light-gathering field. [Effects of the Invention]

[0007] According to this disclosure, radiation irradiation can be reliably stopped while ensuring the accuracy of the correspondence between the subject's area of ​​interest and the light-gathering field of the radiation detector used to measure radiation dose. [Brief explanation of the drawing]

[0008] [Figure 1]It is a diagram showing an example of the schematic configuration of a radiation imaging system according to the first embodiment. [Figure 2] It is a diagram showing an example of the schematic configuration of an information processing apparatus according to the first embodiment. [Figure 3] It is a diagram showing an example of the schematic configuration of a radiation detector according to the first embodiment. [Figure 4] It is a diagram showing the first embodiment and explaining the light reception field arrangement information of a radiation detector. [Figure 5] It is a flowchart showing an example of the processing procedure in the control method of the information processing apparatus according to the first embodiment. [Figure 6] It is a diagram showing the first embodiment and showing an example of an optical image acquired by an optical image acquisition unit. [Figure 7] It is a diagram showing the first embodiment and explaining the setting of a control light reception field by a control light reception field setting unit. [Figure 8] It is a diagram showing the first embodiment and explaining the determination of a radiation control method by a radiation control method determination unit. [[ID=?]] [[ID=?]] [Figure 9] It is a flowchart showing an example of the detailed processing procedure of the process of extracting the region of a radiation detector from an optical image among the optical image analysis processes performed by an optical image analysis unit in step S502 of FIG. 5. [[ID=2?]] [Figure 10] It is a diagram showing the second embodiment and showing an example of an optical image acquired by an optical image acquisition unit. [Figure 11] It is a diagram showing the second embodiment and explaining the setting of a control light reception field by a control light reception field setting unit. [Figure 12] It is a diagram showing the second embodiment and explaining the determination of a radiation control method by a radiation control method determination unit. [Figure 13] It is a diagram showing the third embodiment and showing an example of an optical image acquired by an optical image acquisition unit. [Figure 14] It is a diagram showing the third embodiment and explaining the setting of a control light reception field by a control light reception field setting unit. [Figure 15] Note: There seem to be some tags with "?" in the original text which might be a mistake. I've translated as best as possible while maintaining the integrity of the provided tags.This figure illustrates a third embodiment and explains how the radiation control method is determined by the radiation control method determination unit. [Figure 16] This flowchart shows an example of a processing procedure in the control method for the information processing device according to the fourth embodiment. [Modes for carrying out the invention]

[0009] The embodiments for implementing this disclosure will be described below with reference to the drawings. However, in the embodiments of this disclosure described below, the relative positions of each component are arbitrary and can be changed as needed. Furthermore, in this specification, X-rays are preferred as the radiation relating to this disclosure, but the invention is not limited to X-rays and includes particle radiation such as alpha rays, beta rays, gamma rays, particle beams, proton beams, heavy ion beams, and meson beams.

[0010] (First embodiment) First, let me describe the first embodiment.

[0011] <Outline configuration of the radiography system 100> Figure 1 shows an example of a schematic configuration of a radiography system 100 according to the first embodiment. As shown in Figure 1, the radiography system 100 includes a radiation generator 110, a radiation detector 120, a camera device 130, an information processing device 140, a network 150, and an external storage device 160.

[0012] The radiation generator 110 is communicatively connected to the information processing device 140, and based on the control of the information processing device 140, generates and irradiates the subject H and the radiation detector 120 with radiation (radiation beam) R. In the example shown in Figure 1, the subject H is shown in a supine position, but the subject H's position is not limited to the supine position shown in Figure 1; for example, it may be in a standing position or a sitting position. The imaging table used to support the subject H may be a table that is appropriate for the subject H's position. Furthermore, the imaging table used to support the subject H is made of a transparent material that allows the incident radiation R to pass through and allows the camera device 130 to optically photograph both the subject H and the radiation detector 120. In addition, in the example shown in Figure 1, the imaging table is interposed between the subject H and the radiation detector 120, but in this embodiment, it is not limited to the configuration shown in Figure 1; for example, a configuration in which the radiation detector 120 is placed in contact with the subject H is also applicable.

[0013] The radiation detector 120 is communicatively connected to the information processing device 140 and, based on the control of the information processing device 140, detects the incident radiation R as a signal corresponding to its intensity and generates a radiation image. The radiation detector 120 is also provided with multiple light-gathering fields for detecting the dose of incident radiation R in order to perform automatic exposure control regarding the cessation of radiation R irradiation.

[0014] In this embodiment, a "radiography apparatus" is formed from a configuration including a radiation generator 110 and a radiation detector 120 as shown in Figure 1. In this embodiment, the radiation generator 110 is configured to include, for example, a radiation generator such as a radiation tube, a collimator, a collimator lamp, etc., and irradiates radiation R based on the control of the information processing device 140. The radiation R irradiated from the radiation generator 110 is stopped by automatic exposure control of the radiation R by the information processing device 140. The radiation R irradiated from the radiation generator 110 passes through the subject H while attenuating and is incident on the radiation detector 120. The radiation detector 120 can be any radiation detector that detects the incident radiation R and outputs a signal corresponding to the detected radiation R, and can be configured using, for example, an FPD (Flat Panel Detector). The radiation detector 120 may be an indirect conversion type detector that first converts radiation R into visible light using a scintillator, etc., and then converts the visible light into an electrical signal using a photoconversion element, or it may be a direct conversion type detector that directly converts radiation R into an electrical signal.

[0015] The camera device 130 is communicatively connected to the information processing device 140 and generates an optical image by optically photographing the subject H and the radiation detector 120, which are subjected to radiation imaging using radiation R, based on the control of the information processing device 140. The camera device 130 transmits the optical image obtained by optical imaging to the information processing device 140. The camera device 130 may have any known configuration, for example, it may be configured as a camera device capable of shooting video, such as a video camera, or it may be configured as a camera device that only takes still images. Furthermore, the camera device 130 may be configured to perform optical imaging using visible light, or it may be configured to perform optical imaging using invisible light other than radiation, such as infrared light.

[0016] The information processing device 140 is communicatively connected to the radiation generator 110, the radiation detector 120, the camera device 130, and the external storage device 160 via the network 150. The information processing device 140 comprehensively controls the operation of the radiography system 100 and performs various processes. The control performed by the information processing device 140 includes automatic exposure control of radiation R. In addition, the information processing device 140 can perform image processing and analysis on various images, including radiation images generated by the radiation detector 120 and optical images generated by the camera device 130. Furthermore, the information processing device 140 can send and receive various information (including data, etc.) to and from the external storage device 160 via the network 150.

[0017] Network 150 is a network that enables communication between the information processing device 140 and the external storage device 160. Network 150 can be any network, such as the Internet or an intranet.

[0018] The external storage device 160 is connected to the information processing device 140 via the network 150 in a communicative manner. The external storage device 160 can be, for example, a server. In the example shown in Figure 1, the external storage device 160 is connected to the information processing device 140 in a communicative manner via the network 150, but in this embodiment, it may be directly connected to the information processing device 140.

[0019] <Outline configuration of the information processing device 140> Figure 2 shows an example of the schematic configuration of the information processing device 140 according to the first embodiment. As shown in Figure 2, the information processing device 140 includes an optical image acquisition unit 201, a radiation image acquisition unit 202, an optical image analysis unit 203, a control light field setting unit 204, a radiation control method determination unit 205, a radiation irradiation stop control unit 206, and a display control unit 207. Furthermore, as shown in Figure 2, the information processing device 140 includes a CPU bus 230, a CPU 231, a storage unit 232, a main memory 233, an operation unit 234, and a display unit 235. Each component of the information processing device 140 is connected communicatively via the CPU bus 230, and can send and receive various types of information (including data, etc.) from each other. Components 201 to 207 shown in Figure 2 may be software modules configured by the CPU 231 executing a program stored in the storage unit 232. Alternatively, components 201 to 207 shown in Figure 2 may be composed of circuits or independent devices that perform specific functions, such as ASICs.

[0020] The optical image acquisition unit 201 is an optical image acquisition means that acquires optical images generated by the camera device 130 from the camera device 130. Specifically, the optical image acquisition unit 201 acquires optical images obtained by optically photographing the subject H being radiographed and the radiation detector 120, which is provided with multiple light-gathering fields, from the camera device 130. The optical image acquisition unit 201 can also perform various processes (including control) for acquiring optical images in interaction with the camera device 130.

[0021] The radiation image acquisition unit 202 is a radiation image acquisition means that acquires radiation images generated by the radiation detector 120. The radiation image acquisition unit 202 can also perform various processes (including control) for acquiring radiation images in interaction with the radiation detector 120 and the radiation generator 110.

[0022] The optical image analysis unit 203 is an optical image analysis means that analyzes the optical image acquired by the optical image acquisition unit 201. The optical image analysis unit 203 analyzes the optical image acquired by the optical image acquisition unit 201 and performs processing such as extracting the region of the radiation detector 120 and the region of interest of the subject H from the optical image.

[0023] The control light field setting unit 204 is a control light field setting means that, when the radiation detector 120 is rotated to perform multiple configurations relative to the subject H, sets a control light field that includes the region of interest of the subject H in the multiple configurations.

[0024] The radiation control method determination unit 205 is a radiation control method determination means that determines a radiation control method for stopping the irradiation of radiation R from the radiation generator 110. The radiation control method determination unit 205 determines a radiation control method for stopping the irradiation of radiation H based, for example, on the imaging order information for radiography input from the operation unit 234 and the control light field set by the control light field setting unit 204.

[0025] The radiation irradiation stop control unit 206 is a radiation irradiation stop control means that controls the irradiation of radiation R from the radiation generator 110 based on the radiation control method determined by the radiation control method determination unit 205. The radiation irradiation stop control unit 206 can also perform various processes (including control) between the radiation generator 110 and the radiation detector 120 to stop the irradiation of radiation R from the radiation generator 110.

[0026] The display control unit 207 is a display control means that performs control to display various types of information (including images and data) on the display unit 235, for example, based on the control of the CPU 231. For example, the display control unit 207 performs control to display optical images acquired by the optical image acquisition unit 201 and radiation images acquired by the radiation image acquisition unit 202 on the display unit 235. Also, for example, the display control unit 207 performs control to display information on the control light field set by the control light field setting unit 204 and information on the radiation control method determined by the radiation control method determination unit 205 on the display unit 235. In this embodiment, the display control unit 207 may be a component that performs control to display at least one of the multiple types of information exemplified here on the display unit 235.

[0027] The CPU bus 230 is a bus that connects each component of the information processing device 140 in a way that enables communication.

[0028] The CPU (Central Processing Unit) 231 is an example of a processor that comprehensively controls the operation of the information processing device 140. The CPU 231 uses the main memory 233 to control the operation of the entire information processing device 140 according to the operation input from the operation unit 234 and the programs and various information (including data, etc.) stored in the storage unit 232. Note that the processor in the information processing device 140 is not limited to the CPU 231, and may include, for example, a microprocessing unit (MPU) or a graphics processing unit (GPU). Furthermore, the processor in the information processing device 140 may include a digital signal processor (DSP), a data flow processor (DFP), or a neural processing unit (NPU).

[0029] Here, for example, a GPU that can be applied as a processor in the information processing device 140 can perform calculations efficiently by processing various types of information (including data, etc.) in parallel. For this reason, inference processing by machine learning models generated by machine learning algorithms such as deep learning is particularly effective when processed on a GPU. In this embodiment, for example, FCN (Fully Convolutional Network) or SegNet can be used as machine learning models. Furthermore, for example, RCNN (Region CNN), fastRCNN, or fasterRCNN can be used as machine learning models for object recognition. Additionally, YOLO (You Only Look Once) can be used as a machine learning model for object recognition on a region-by-region basis. Moreover, SSD (Single Shot Detector) or Single Shot MultiBox Detector can also be used as machine learning models for object recognition on a region-by-region basis.

[0030] The storage unit 232 stores programs executed by the CPU 231 and various information (including data, etc.) necessary for the CPU 231 to perform various processes. Furthermore, the storage unit 232 stores various information (including images, data, etc.) obtained as a result of the CPU 231 performing various processes. In addition, the storage unit 232 can store information such as patient information included in the information about the subject H, information on imaging conditions, and parameters set by the operator S. The storage unit 232 may be composed of any storage medium, such as an optical disk or memory.

[0031] Main memory 233 consists of memory and other components and is used for storing temporary information (including images and data).

[0032] The operation unit 234 is operated by the operator S shown in Figure 1 and is a component that inputs operation inputs to the CPU 231, etc. The operation unit 234 includes input devices for operating the information processing device 140, such as a keyboard and mouse and a radiation exposure switch. The operator S can also input various information such as parameters related to the algorithms performed by the optical image analysis unit 203, the control light field setting unit 204, and the radiation control method determination unit 205 via the operation unit 234. In addition, the operation unit 234 can perform response operations to information displayed on the display unit 235. Furthermore, the operation unit 234 can also issue an instruction to start radiography using the irradiation line exposure switch.

[0033] The display unit 235 includes, for example, any display and displays various information (including images and data) based on the control of the display control unit 207. For example, the display unit 235 displays optical images obtained by the optical image acquisition unit 201, radiation images obtained by the radiation image acquisition unit 202, and the outputs of the optical image analysis unit 203, the control light field setting unit 204, the radiation control method determination unit 205, and the radiation irradiation stop control unit 206. The display unit 235 may be, for example, a monitor for a console that operates a radiography apparatus including a radiation generator 110 and a radiation detector 120. Alternatively, the display unit 235 may be a sub-monitor installed in a position where the operator S can observe it while assisting with the positioning of the subject H, or a console monitor for the radiation generator 110, which is a radiation irradiator. Furthermore, the display unit 235 may be a display device that allows the operator S to reliably confirm the display with minimal eye movement, such as a head-mounted display that the operator S can wear while working. The display unit 235 may be composed of a touch panel display, in which case the display unit 235 can also perform the functions of the operation unit 234.

[0034] The information processing device 140 can be configured as a computer equipped with a processor and memory. In this case, the information processing device 140 may be configured as a general-purpose computer, or as a computer dedicated to the radiography system 100. Furthermore, the information processing device 140 may be, for example, a personal computer (PC), in which case a desktop PC, notebook PC, tablet PC (portable information terminal device), etc., may be used. In addition, the information processing device 140 may be configured as a cloud-type computer in which some components are located on external devices.

[0035] <Schematic configuration of radiation detector 120> Figure 3 shows an example of a schematic configuration of the radiation detector 120 according to the first embodiment. Figure 3 shows four radiation detectors 120-1 to 120-4 as examples. Each radiation detector 120-1 to 120-4 is equipped with multiple light-gathering fields 311 for detecting the dose of radiation R in order to perform automatic exposure control of radiation R.

[0036] The radiation detector 120-1 is a radiation detector 120 that has a square shape when viewed along the direction of incidence of radiation R, and includes a light-gathering field group 310-1 consisting of multiple light-gathering fields 311 arranged in 5 rows x 5 columns. The radiation detector 120-2 is a radiation detector 120 that has a square shape when viewed along the direction of incidence of radiation R, and includes a light-gathering field group 310-2 consisting of multiple light-gathering fields 311 arranged in 5 rows x 6 columns.

[0037] The radiation detector 120-3 is a radiation detector 120 that has a rectangular shape when viewed along the direction of incidence of radiation R, and includes a light-gathering field group 310-3 consisting of multiple light-gathering fields 311 arranged in 4 rows x 5 columns. The radiation detector 120-4 is a radiation detector 120 that has a rectangular shape when viewed along the direction of incidence of radiation R, and includes a light-gathering field group 310-4 consisting of multiple light-gathering fields 311 arranged in 4 rows x 3 columns.

[0038] The arrangement patterns (number, size, and arrangement) of the multiple light-gathering fields 311 in the four radiation detectors 120-1 to 120-4 shown in Figure 3 are merely examples, and various other patterns can be considered.

[0039] The radiation detector 120 comes in several different sizes, which are selected depending on the imaging area of ​​the subject H and the workflow. For example, the information processing device 140 can accommodate these differences in the size of the radiation detector 120 by storing arrangement patterns of multiple light-gathering fields 311 as light-gathering field arrangement information RI.

[0040] Next, we will explain the RI (radiation array) information of the radiation detector 120. The light-gathering field arrangement information RI is information indicating how the light-gathering field 311 is arranged in the radiation detector 120. In this embodiment, the light-gathering field arrangement information RI is shared among the radiation detector 120, the information processing device 140, and the external storage device 160.

[0041] Figure 4 shows the first embodiment and is a diagram for explaining the light-gathering field arrangement information RI of the radiation detector 120. In Figure 4, the same reference numerals are used for the same components as those shown in Figure 3, and their detailed explanations are omitted.

[0042] The radiation detector 120 shown on the left side of Figure 4 is equipped with multiple light-gathering fields 311 arranged in a 4x3 grid, and is a radiation detector with a width W [mm] and a height H [mm]. In the radiation detector 120 shown on the left side of Figure 4, each light-gathering field 311 is assigned a light-gathering field ID from 1 to 12 so that they can be distinguished from one another. In the radiation detector 120 shown on the left side of Figure 4, the area excluding the light-gathering fields 311 is assigned a light-gathering field ID of 0.

[0043] Image 410, shown in the center of Figure 4, is an image where each pixel 411 has a width of w [mm] and a height of w [mm], and the number of pixels is W / w × H / w. This image 410, shown in the center of Figure 4, is an image showing the light field array information RI, where each pixel 411 is assigned one of the light field IDs from 0 to 12. The image region 412 of image 410, shown in the center of Figure 4, is the region where the light field IDs of the radiation detector 120 shown on the left side of Figure 4 span fields 1, 2, 4, and 5. For this image region 412 of image 410, shown in the center of Figure 4, the images of the light field IDs assigned to each pixel 411 are shown in image 420, shown on the right side of Figure 4. In image 420, shown on the right side of Figure 4, each pixel 411 is assigned one of the light field IDs 0, 1, 2, 4, or 5.

[0044] The light field array information RI, as explained using Figure 4, is held by, for example, the radiation detector 120 and shared with the information processing device 140, enabling automatic exposure control of radiation R using an appropriate light field 311. Note that the switching of which light fields 311 to enable or disable, and the number of light fields managed under the same light field ID, can be flexibly changed by software. In this case, the information processing device 140 may reflect the changes in the arrangement pattern of the light fields 311 in the light field array information RI and transmit it to the radiation detector 120 for sharing.

[0045] <Control method for information processing device 140> Next, we will describe the operation of the information processing device 140 in accordance with the control of the CPU 231 of the information processing device 140.

[0046] First, the CPU 231 in Figure 2 starts preparing for radiography based on radiography order information input from, for example, the operation unit 234 (or radiography order information transmitted from an information management device not shown). Here, radiography order information is information corresponding to the unit of examination ordered by the physician, and includes, for example, patient information about subject H, information on the (scheduled) date and time of radiography, and information such as the area to be photographed, orientation and posture of the subject based on the physician's findings. This radiography order information includes information necessary for radiography, such as the size and type of radiation detector 120 to be used (for standing, lying down, and portable, etc.), the posture of the patient H (photography area and direction, etc.), and information on the region of interest to be used as the light field. This radiography order information also includes information on radiography conditions (tube voltage and tube current of the radiation generator 110, presence or absence of a grid, open / closed status of the collimator, etc.).

[0047] When the CPU 231 begins preparing for radiography, the optical image acquisition unit 201 in Figure 2 begins acquiring optical images based on the control of the CPU 231. Specifically, the optical image acquisition unit 201 controls the camera device 130 to perform optical imaging of the subject H and the radiation detector 120, and acquires the optical images obtained from the camera device 130. The optical images acquired by the optical image acquisition unit 201 are then sequentially transferred via the CPU bus 230 to the main memory 233, the optical image analysis unit 203, the storage unit 232, and the display control unit 207.

[0048] The optical image analysis unit 203 in Figure 2 analyzes the optical image transferred from the optical image acquisition unit 201. The information from the optical image analysis results by the optical image analysis unit 203 is then sequentially transferred via the CPU bus 230 to the main memory 233, the control light field setting unit 204, the storage unit 232, and the display control unit 207.

[0049] The control light field setting unit 204 in Figure 2 sets the control light field based on the optical image analysis results information transferred from the optical image analysis unit 203 and the light field array information RI shared by the radiation detector 120 and the information processing device 140. The information of the control light field set by the control light field setting unit 204 is then sequentially transferred via the CPU bus 230 to the main memory 233, the radiation control method determination unit 205, the storage unit 232, and the display control unit 207.

[0050] The radiation control method determination unit 205 in Figure 2 determines a radiation control method for stopping radiation R from the radiation generator 110 based on the control light field information and imaging order information transferred from the control light field setting unit 204. The radiation control method information determined by the radiation control method determination unit 205 is then sequentially transferred via the CPU bus 230 to the main memory 233, the radiation image acquisition unit 202, the storage unit 232, the radiation irradiation stop control unit 206, and the display control unit 207.

[0051] The memory unit 232 in Figure 2 stores various types of information transferred from each component of the information processing device 140. The display control unit 207 in Figure 2 controls the display of various types of information (including images) transferred from each component of the information processing device 140 on the display unit 235. In particular, it is desirable that the information on the control light field and the radiation control method be displayed in a way that allows the operator S to easily determine whether or not to start radiography.

[0052] Operator S checks various information (including images) displayed on the display unit 235 and issues necessary operational instructions via the operation unit 234. For example, operator S checks the shooting order information, control light field information, and radiation control method information displayed on the display unit 235, and if there are no problems, issues an instruction to take a radiation image of subject H via the operation unit 234. This shooting instruction is transmitted by the CPU 231 to the radiation image acquisition unit 202 and the radiation irradiation stop control unit 206.

[0053] In Figure 2, the radiation image acquisition unit 202, upon receiving a shooting instruction, controls the radiation generator 110 and the radiation detector 120 to perform radiation imaging of the subject H. In radiation imaging, first, radiation R is irradiated from the radiation generator 110 towards the subject H, and the radiation R that has passed through the subject H while being attenuated is detected by the radiation detector 120. Furthermore, the radiation irradiation stop control unit 206 in Figure 2 controls the radiation generator 110 and the radiation detector 120 based on the radiation control method determined by the radiation control method determination unit 205, and performs automatic exposure control of radiation R related to stopping the irradiation of radiation R. Specifically, the radiation irradiation stop control unit 206 performs automatic exposure control of radiation R based on a control light field among the light field 311 arranged in the radiation detector 120 that may include the region of interest of the subject H, and the radiation control method.

[0054] The radiation image acquisition unit 202 acquires a radiation image from the radiation detector 120, which is generated based on a signal corresponding to the intensity of the radiation R detected by the radiation detector 120. The radiation image data acquired by the radiation image acquisition unit 202 is then sequentially transferred via the CPU bus 230 to the main memory 233, the storage unit 232, and the display control unit 207. The storage unit 232 stores the radiation image data transferred from the radiation image acquisition unit 202. The display control unit 207 controls the display of the radiation image transferred from the radiation image acquisition unit 202 on the display unit 235. The operator S can check the radiation image displayed on the display unit 235 and give necessary operation instructions via the operation unit 234.

[0055] In the first embodiment, a video camera is used as the camera device 130 to acquire optical images at a predetermined frame rate. In the first embodiment, the information processing device 140 uses the optical images acquired by the camera device 130 to set the control light field CR and determine the radiation control method CW when the limbs are used as the subject H, and performs preparatory processing for automatic exposure control of radiation R. In this embodiment, the information processing device 140 displays the results of the preparatory processing for automatic exposure control of radiation R on the display unit 235, and the operator S checks this display and, if there are no problems, issues an instruction for radiography via the operation unit 234. Note that the preparatory processing for automatic exposure control of radiation R may fail. If the preparatory processing for automatic exposure control of radiation R fails, the operator S checks the failure on the display unit 235, manually performs the preparation for automatic exposure control of radiation R via the operation unit 234, and then issues an instruction for radiography. The radiation image acquisition unit 202 receives an instruction from operator S to perform radiation imaging and takes a radiation image while the control light field CR, which reflects the results of the preparation process in the automatic exposure control of radiation R, and the automatic exposure control of radiation R based on the radiation control method CW are in place.

[0056] Figure 5 is a flowchart showing an example of a processing procedure in the control method of the information processing device 140 according to the first embodiment. Specifically, Figure 5 is a flowchart showing an example of a processing procedure for the preparation process in the automatic exposure control of radiation R described above.

[0057] First, in step S501 of Figure 5, the optical image acquisition unit 201 controls the camera device 130 to acquire an optical image of the radiation imaging site, including the subject H being subjected to radiation imaging and the radiation detector 120, from the camera device 130. In this embodiment, the camera device 130 is a video camera attached to the radiation generator 110. This camera device 130 acquires an optical image at a predetermined frame rate by optically imaging the subject H, who is placed on a reclining table and assumes a predetermined imaging posture, and the radiation detector 120.

[0058] Figure 6 shows an example of an optical image 600 acquired by the optical image acquisition unit 201, illustrating the first embodiment. The optical image 600 shown in Figure 6 depicts the region 601 of the radiation detector 120 and the region 602 of the subject H, including the patient's right hand, which is the subject of radiography. In Figure 6, multiple 4x3 light-gathering fields 311 are depicted as a light-gathering field array 603 using dotted rectangles. However, the light-gathering field array 603 shown as dotted lines in Figure 6 is for convenience only and is not necessarily designed to be visible to the radiation detector 120 in reality. In Figure 6, the region of interest 604 of the subject H is indicated by a black circle. Furthermore, in Figure 6, the light-gathering field that includes the region of interest 604 of the subject H within the light-gathering field array 603 is represented as the field of interest 605 using a thick rectangle. In the optical image 600, the field of interest 605 is naturally invisible because it is hidden by the subject H. Furthermore, in Figure 6, the four corners 606 and 607 in region 601 of the radiation detector 120, when viewed along the direction of incidence of radiation R, are represented by dotted circles. Corner 606 of the radiation detector 120 is the corner of the radiation detector 120 in a visible state, and corner 607 of the radiation detector 120 is the corner of the radiation detector 120 in an invisible state because it is hidden by the subject H.

[0059] Now, let's return to the explanation of Figure 5. Once the process in step S501 in Figure 5 is completed, the process proceeds to step S502. When the process proceeds to step S502 in Figure 5, the optical image analysis unit 203 analyzes the optical image acquired in step S501 and performs a process to extract, for example, the region 601 of the radiation detector 120 and the region of interest 604 of the subject H from the optical image. Specifically, the optical image analysis unit 203 defines, for example, the region 601 of the radiation detector 120 as the angular coordinates p at the four corners 606, 607 of the radiation detector 120. n (n=0~3) is extracted. The optical image analysis unit 203 also extracts, for example, the region of interest 604 of subject H, and the coordinates (region of interest coordinates) p in the region of interest 604 of subject H. rоi Extract it.

[0060] Here, the process of step S502 in Figure 5 will be explained using Figure 6. The four angular coordinates p in region 601 of the radiation detector 120 shown in Figure 6. n (n=0~3) consists of three angular coordinates of angle 606 and one angular coordinate of angle 607.

[0061] In the example shown in Figure 6, the three corners 606 are depicted in the optical image 600, and their coordinates can be detected relatively easily using rule-based keypoint detection algorithms such as corner detection or edge detection. Furthermore, keypoint detection processing using inference models implemented beforehand with machine learning algorithms such as deep learning is also effective.

[0062] On the other hand, one corner 607 is hidden by the region 602 of the subject H, so its coordinates cannot be detected directly. Therefore, for example, a method is used in which the orientation of the radiation detector 120 is estimated from the angular coordinates of the three detected corners 606, and then the angular coordinates of corner 607 are estimated by projecting the spatial coordinates based on the object model information of the radiation detector 120 onto the optical image 600.

[0063] Furthermore, the region of interest 604 of subject H shown in Figure 6 is approximately the central region of the human hand included in the region 602 of subject H. Therefore, for example, by segmenting the region 602 of subject H from the optical image 600 and determining the position that divides the obtained region internally in a predetermined ratio, the region of interest coordinates p in the region of interest 604 of subject H can be determined. rоi The region is calculated. Various segmentation methods can be considered in this process. For example, one method is to obtain the region 602 of subject H as the difference region by performing image difference processing using an optical image taken before subject H was placed as the background image. Alternatively, the region 602 of subject H may be obtained as the region 602 of subject H by using the color information of the optical image 600 and selecting a region on the radiation detector 120 that is a different color from the radiation detector 120. Furthermore, segmentation processing using an inference model implemented in advance with a machine learning algorithm such as deep learning is also effective.

[0064] Furthermore, the extracted region of interest 604 of subject H is defined for each imaging site and also differs depending on the facility and operator S. For example, in a chest X-ray of subject H, the region of interest is the area corresponding to the left and right lung fields, in which case two regions of interest are determined. In this case, the region of interest of subject H requires a different rule than the region of interest 604 of the hand exemplified in Figure 6, where the region of interest of subject H is determined by finding the area at the top 1 / 3 and left 1 / 3 of the detected torso of subject H, and the area at the left 2 / 3 of the way up. Similarly, when imaging the limbs of subject H, such as both hands or both feet, a rule is required to find the centroid of the left and right regions of subject H and determine two regions of interest. For this reason, it is desirable that the imaging order information acquired by the information processing device 140 before imaging preparation includes information on the rules for acquiring the region of interest. Also, the region of interest coordinates p in the region of interest 604 of subject H rоiThe calculation can be realized by a rule-based algorithm based on the information of the rules in the acquisition of the region of interest included in this imaging order information. Of course, the information of the rules in the acquisition of this region of interest may be obtained by a region of interest coordinate inference unit that has been learned in advance for each part of the subject H using a machine learning model such as deep learning. Also, the acquisition of the information of the rules in the acquisition of the region of interest may be realized using a skeleton estimation model that infers the connection between joints from a human body image.

[0065] Here, once again, return to the description of FIG. 5. When the process of step S502 in FIG. 5 ends, the process proceeds to step S503. When proceeding to step S503 in FIG. 5, when the control illumination field setting unit 204 rotates the arrangement of the radiation detector 120 with respect to the subject H and performs a plurality of arrangements, the control illumination field that is the illumination field including the region of interest of the subject H in the plurality of arrangements is set. Specifically, the control illumination field setting unit 204 uses the four corner coordinates p n (n = 0 to 3) of the radiation detector 120, the region of interest coordinates p rоi of the subject H, and the illumination field array information RI stored in the main memory 233 to set the control illumination field CR. Here, the control illumination field CR is the illumination field indicated by the illumination field ID of the illumination field array information RI corresponding to the region of interest coordinates p rоi of the subject H shown in the coordinate system of the optical image 600.

[0066] Hereinafter, a specific example of the process in step S503 in FIG. 5 will be described. First, the conversion from the coordinate system of the optical image to the coordinate system of the illumination field array information RI will be described. The control illumination field setting unit 204 sets the four corner coordinates p n (= p0 to p3) of the radiation detector 120 to the coordinates q nThe coordinates (=(0,0),(0,H / w),(W / w,H / w),(W / w,0)) are mapped accordingly. Then, the control light field setting unit 204 uses the Direct Linear Transform (DLT) algorithm or the RANSAC algorithm to obtain the perspective transformation matrix M. This perspective transformation matrix M is a transformation from the coordinate system of the optical image 600 to the coordinate system of the light field array information RI. Using this perspective transformation matrix M, the coordinates of the region of interest p of the subject H are obtained as shown in equation (1) below. rоi This is projected onto the light-collecting field sequence information RI.

number

[0067] However, the four angular coordinates p of the radiation detector 120 n (=p0~p3) are the coordinates q of the four corners of the light-gathering field array. n The mapping to (=(0,0),(0,H / w),(W / w,H / w),(W / w,0)) may not be uniquely determined. In this case, multiple perspective transformation matrices M and control light-gathering fields CR are calculated depending on the number of mapping methods. To explain this using the region 601 of the radiation detector 120 shown in Figure 6 as an example, the four corners 606,607 are indistinguishable from each other, so the mapping to the light-gathering field array information RI is not uniquely determined.

[0068] Figure 7 shows the first embodiment and is a diagram illustrating the setting of the control light field by the control light field setting unit 204. In Figure 7, the same reference numerals are used for the same components as those shown in Figure 6, and their detailed explanations are omitted. Specifically, the optical image 600 shown in Figure 6 is shown on the left side of Figure 7.

[0069] For example, as shown in Figure 7, there are two possible arrangements for the correspondence between the region 601 of the radiation detector 120 in the optical image 600 and the light-gathering field array information RI: a first arrangement 701 and a second arrangement 702. This is because the shape of the radiation detector 120 shown in Figure 7 is rectangular, and the orientation of the radiation detector 120 relative to the subject H, as performed by the operator S, etc., is taken into consideration. Specifically, the first arrangement 701 is when the radiation detector 120 is placed in a predetermined position relative to the subject H, and the second arrangement 702 is when the radiation detector 120 is placed in a position rotated 180 degrees from the predetermined position relative to the subject H.

[0070] When the light-gathering field array information RI is associated with the region 601 of the radiation detector 120 in the optical image 600 according to the first arrangement 701, the result is as shown in the first arrangement state 703 in Figure 7.

number

[0071] Furthermore, when the light-gathering field array information RI is associated with the region 601 of the radiation detector 120 in the optical image 600 according to the second arrangement 702, the result is as shown in the second arrangement state 704 of Figure 7.

number

[0072] Then, in the example shown in Figure 7, the control daylight field setting unit 204 sets two daylight fields of interest, daylight field IDs 4 and 9, as the control daylight field CR, as shown in the control daylight field setting state 705.

[0073] Now, let's return to the explanation of Figure 5. Once the process in step S503 in Figure 5 is completed, the process proceeds to step S504. When the process proceeds to step S504 in Figure 5, the radiation control method determination unit 205 determines the radiation control method CW for stopping radiation H based on the imaging order information and the control light field CR set in step S503. This completes the preparation process for automatic exposure control of radiation R.

[0074] The following describes a specific example of the process in step S504 of Figure 5. In Figure 7, as shown in the control light field setting state 705, two light fields with light field ID=[4,9] are set as the control light field CR. In the actual radiography where subject H is placed, the region of interest p of subject H rоi The field of interest corresponding to this is one of the field of interest with field of interest ID = [4, 9]. For the radiation detector 120 on the optical image 600, if the field of interest array information RI is in the first arrangement 701, then the field of interest is with field of interest ID = 9, as shown in the first arrangement state 703. Also, for the radiation detector 120 on the optical image 600, if the field of interest array information RI is in the second arrangement 702, then the field of interest is with field of interest ID = 4, as shown in the second arrangement state 704.

[0075] Figure 8 shows a first embodiment and illustrates the determination of the radiation control method by the radiation control method determination unit 205. In Figure 8, the same reference numerals are used for components that are the same as those shown in Figure 7, and their detailed explanations are omitted. Specifically, the left side of Figure 8 shows the first arrangement state 703 and the second arrangement state 704 shown in Figure 7.

[0076] Here, when radiography of subject H is started, in the first configuration state 703 where the field of interest is field of interest ID=9, the output of the radiation dose in field of interest ID=[4,9] is shown as the first output state 801 in Figure 8. In the first output state 801 in Figure 8, each of the field of interest ID=[4,9] outputs a radiation dose value as time progresses. In the first output state 801 in Figure 8, the radiation dose output value in field of interest ID=4, where subject H is not present, is higher than that of field of interest ID=9, where subject H is present, and reaches the target dose value first. This target dose value is determined for each subject H, stored in the radiography order information, and referenced during radiography. In the first output state 801 shown in Figure 8, the radiation control method determination unit 205 determines a radiation control method CW that issues a radiation stop notification T when the output value of the radiation dose in the light field of interest of light field ID=9 where the subject H is located reaches the target dose value.

[0077] Furthermore, when radiography of subject H is started, if the second arrangement state 704 is such that the field of interest is field of interest ID=4, the output of the radiation dose in field of interest ID=[4,9] is shown as the second output state 802 in Figure 8. In the second output state 802 in Figure 8, each of the field of interest ID=[4,9] outputs a radiation dose value as time progresses. In the second output state 802 in Figure 8, the radiation dose output value in field of interest ID=9, where subject H is not present, is larger than that of field of interest ID=4, where subject H is present, and reaches the target dose value first. In this second output state 802 shown in Figure 8, the radiation control method determination unit 205 determines a radiation control method CW that issues a radiation R stop notification T when the radiation dose output value in the field of interest ID=4, where subject H is present, reaches the target dose value.

[0078] In the first output state 801 and the second output state 802 in Figure 8, regardless of which of the multiple light fields 605 of interest is the control light field CR, it means that a "stop notification should be issued when all outputs of the control light field CR reach the target dose." The example explained using Figures 6 to 8 shows the case where the shape of the radiation detector 120 is rectangular and the number of regions of interest (604) of the subject H is one. In this example explained using Figures 6 to 8, the radiation control method determination unit 205 determines the radiation control method CW, which "notifies a stop notification when all outputs of the control light field CR reach the target dose."

[0079] Now, let's return to the explanation of Figure 5. Once the process in step S504 of Figure 5 is completed, the process shown in the flowchart of Figure 5 is terminated.

[0080] Furthermore, the radiation control method CW determined by the radiation control method determination unit 205 in step S504 of Figure 5 is transferred to the radiation irradiation stop control unit 206 and the radiation image acquisition unit 202, and is used for automatic exposure control of radiation R during subsequent radiography. In addition, the various information obtained in steps S501 to S504 of Figure 5 is transferred to the display control unit 207, main memory 233, and storage unit 232 as needed. This various information may be displayed on the display unit 235 via the display control unit 207 for confirmation by the operator S.

[0081] Next, we will explain in detail the process of extracting the region 601 of the radiation detector 120 from the optical image 600, which is part of the optical image analysis process performed by the optical image analysis unit 203 in step S502 of Figure 5.

[0082] Figure 9 is a flowchart showing a detailed example of the processing procedure for extracting the region 601 of the radiation detector 120 from the optical image 600, which is part of the optical image analysis process performed by the optical image analysis unit 203 in step S502 of Figure 5.

[0083] First, in step S901 of Figure 9, the optical image analysis unit 203 calculates the angular coordinates p at the four corners 606, 607 of the radiation detector 120. n The process involves detecting (n=0~3) as keypoints. The four angular coordinates p n (n=0~3) can be detected using various keypoint detection algorithms. Here, keypoints are pre-registered external features of the radiation detector 120, and include, for example, the four corners 606, 607 of the radiation detector 120 themselves. In addition to the four corners (including angular coordinates) of the radiation detector 120, other locations with external features of the radiation detector 120 or predetermined locations where markers are attached may also be considered keypoints. The information processing device 140 understands the location of these keypoints on the radiation detector 120 as object model information. For example, if the size of the radiation detector 120 is width W and height H, then the four angular coordinates p n Object model information P in (n=0~3) n (n=0~3) can be expressed by the following equation (2) using a coordinate system with the center of the surface of the radiation detector 120 as the origin.

number

[0084] Such keypoints can be extracted using pattern recognition techniques such as corner detection and edge detection, rule-based algorithms combining these techniques, and machine learning model-based keypoint detection processes such as deep learning. Ideally, the detection of a keypoint should uniquely identify which part of the radiation detector 120 it is located on. This can be achieved, for example, by using unique markers. However, the radiation detector 120 is often housed in protective covers, cases, standing stands, or supine tables, and may also be obscured by the subject H. Furthermore, considering the occurrence of dirt and deterioration over time, it is difficult to cover all use cases with keypoint detection using markers. Therefore, a method can be considered to detect general features such as the four corners of a rectangle using pattern recognition techniques such as corner detection and edge detection, and rule-based algorithms combining these techniques. However, it is difficult to interpret each part of the radiation detector 120 as a unique external feature. That is, an ambiguity remains: a certain keypoint detected from the radiation detector 120 may be one of several keypoints with the same appearance present on the radiation detector 120. For example, the four angular coordinates p of the radiation detector 120, which is the target of detection in this process n (n=0~3) The detection result is the four angular coordinates p n This leaves ambiguity, as it must be one of the following (n=0 to 3).

[0085] Next, in step S902 of Figure 9, the optical image analysis unit 203 analyzes the four angular coordinates p of the radiation detector 120. n We determine whether or not we were able to detect (n=0~3) as four key points.

[0086] In step S902 of Figure 9, if the optical image analysis unit 203 determines that it could not detect the four key points (S902 / No), the process proceeds to step S903. When the process proceeds to step S903 in Figure 9, the optical image analysis unit 203 determines whether or not it was able to detect the three key points.

[0087] In step S903 of Figure 9, if the optical image analysis unit 203 determines that it has detected three key points (S903 / Yes), the process proceeds to step S904. When the process proceeds to step S904 in Figure 9, the optical image analysis unit 203 estimates the orientation [R|t] of the radiation detector 120 by solving a Perspective-n-Point (PnP) problem based on the three keypoints that were detected. However, if the aforementioned ambiguity remains in the three keypoints that were detected, the orientation [R|t] of the radiation detector 120 will not be uniquely determined and will have multiple candidates. In this orientation [R|t] of the radiation detector 120, R is a rotation matrix indicating the orientation of the radiation detector 120, and t is a position vector indicating the position of the radiation detector 120. If, for example, a unique marker can be extracted through keypoint detection, the orientation [R|t] of the radiation detector 120 can be uniquely determined by solving the PnP problem. However, if the three keypoints are composed of the four corners of the radiation detector 120, the position vector t can be uniquely determined, but the rotation matrix R cannot be uniquely determined. In this case, the estimation of the orientation [R|t] of the radiation detector 120 outputs the position vector t and a candidate rotation matrix Rn (where n is the candidate number). Note that the more keypoints there are, the more robust the estimated orientation [R|t] of the radiation detector 120 will be against noise from keypoint detection.

[0088] Once step S904 in Figure 9 is completed, the process proceeds to step S905. In step S905 of Figure 9, the optical image analysis unit 203 analyzes object model information P at the four corners of the radiation detector 120. n The orientation [R|t] of the radiation detector 120, estimated as (n=0~3), is used to perform a process of converting it into four keypoints. Specifically, the optical image analysis unit 203 uses equation (3) below to determine the angular coordinates p of the four corners of the radiation detector 120 in the optical image 600 as the four keypoints. n Find (=p0~p3).

number

[0089] If the process in step S905 in Figure 9 is completed, the process proceeds to step S906. Also, if the optical image analysis unit 203 determines in step S902 in Figure 9 that it has detected four key points (S902 / Yes), the process proceeds to step S906. When the process proceeds to step S906 in Figure 9, the optical image analysis unit 203 calculates the angular coordinates p at the four corners of the radiation detector 120. n Since the extraction of (n=0~3) was successful, information indicating that the extraction of region 601 of the radiation detector 120 from the optical image 600 was successful is output.

[0090] Furthermore, if the optical image analysis unit 203 determines in step S903 of Figure 9 that it was unable to detect the three key points (S903 / No), the process proceeds to step S907. When the process proceeds to step S907 in Figure 9, the optical image analysis unit 203 calculates the angular coordinates p at the four corners of the radiation detector 120. n Since extraction of (n=0~3) failed, information indicating that extraction of region 601 of the radiation detector 120 from the optical image 600 failed is output.

[0091] When the process in step S906 in Figure 9 is completed, or when the process in step S907 in Figure 9 is completed, the process in the flowchart shown in Figure 9 is terminated.

[0092] The information processing device 140 according to the first embodiment described above has the following configuration. The information processing device 140 includes an optical image acquisition unit 201 that acquires an optical image obtained by optically photographing a subject H being subjected to radiography using radiation R, and a radiation detector 120 equipped with multiple light-gathering fields 311 for detecting the dose of radiation R. The information processing device 140 also includes an optical image analysis unit 203 that analyzes the optical image acquired by the optical image acquisition unit 201 and extracts the region 601 of the radiation detector 120 and the region of interest 604 of the subject H from the optical image. The information processing device 140 also includes a control light-gathering field setting unit 204 that sets a control light-gathering field CR, which is a light-gathering field that includes the region of interest 604 of the subject H, when the arrangement of the radiation detector 120 is rotated to create multiple arrangements relative to the subject H. Furthermore, the information processing device 140 includes a radiation control method determination unit 205 that determines a radiation control method CW related to stopping radiation R irradiation based on the imaging order information in radiography and the control light-gathering field CR. With the configuration of the information processing device 140, before irradiation with radiation R in radiography, optical images of the subject H and the radiation detector 120 can be acquired, a control light-gathering field CR can be set, and then the radiation control method CW for stopping the irradiation of radiation R can be determined. In this way, since the radiation control method CW can be determined before irradiation with radiation R in radiography, the irradiation of radiation R can be reliably stopped while ensuring the accuracy of the correspondence between the region of interest 604 of the subject H and the light-gathering field 311 of the radiation detector 120.

[0093] (Second embodiment) Next, a second embodiment will be described. In the description of the second embodiment below, matters common to the first embodiment described above will be omitted, and matters that differ from the first embodiment described above will be explained.

[0094] The schematic configuration of the radiography system according to the second embodiment is the same as the schematic configuration of the radiography system 100 according to the first embodiment shown in Figure 1. Furthermore, the schematic configuration of the information processing device 140 according to the second embodiment is the same as the schematic configuration of the information processing device 140 according to the first embodiment shown in Figure 2.

[0095] In the second embodiment, a video camera is used as the camera device 130 to acquire optical images at a predetermined frame rate. In the second embodiment, the information processing device 140 uses the optical images acquired by the camera device 130 to set the control light field CR and determine the radiation control method CW when the chest is the subject H, and performs preparatory processing for automatic exposure control of radiation R.

[0096] Below, in the second embodiment, the processing procedure for the preparation process in the automatic exposure control of radiation R will be described with reference to the flowchart shown in Figure 5.

[0097] First, in step S501 of Figure 5, the optical image acquisition unit 201 controls the camera device 130 to acquire an optical image of the radiography site, including the subject H being radiographed and the radiation detector 120, from the camera device 130.

[0098] Figure 10 shows a second embodiment and is a diagram showing an example of an optical image 1000 acquired by the optical image acquisition unit 201. The optical image 1000 shown in Figure 10 depicts the region 1001 of the radiation detector 120 and the region 1002 of the subject H, including the chest of the patient who is the target of radiography. In Figure 10, multiple 5x5 light-gathering fields 311 are depicted as dotted rectangles representing the light-gathering field array 1003. However, the light-gathering field array 1003 shown as dotted lines in Figure 10 is for convenience only and is not necessarily designed to be visible to the radiation detector 120 in reality. Also in Figure 10, the regions of interest 1004 and 1005 of the subject H are indicated by black circles. Furthermore, in Figure 10, the light-gathering fields within the light-gathering field array 1003 that include the regions of interest 1004 and 1005 of the subject H, respectively, are represented as areas of interest 1006 and 1007 by thick rectangles. In chest radiography, the subject H has two regions of interest (1004 and 1005), one for the left lung and one for the right, and therefore there are also two fields of interest (1006 and 1007). In optical image 1000, fields of interest 1006 and 1007 are naturally invisible because they are hidden by the subject H. Furthermore, in Figure 10, the four corners 1008 in the region 1001 of the radiation detector 120, when viewed along the direction of incidence of radiation R, are represented by dotted lines.

[0099] Now, let's return to the explanation of Figure 5. Once the process in step S501 in Figure 5 is completed, the process proceeds to step S502. When the process proceeds to step S502 in Figure 5, the optical image analysis unit 203 analyzes the optical image acquired in step S501 and performs a process to extract, for example, the region 1001 of the radiation detector 120 and the regions of interest 1004 and 1005 of the subject H from the optical image. Specifically, the optical image analysis unit 203 defines, for example, the region 1001 of the radiation detector 120 as the angular coordinates p at the four corners 1008 of the radiation detector 120. n (n=0~3) is extracted. The optical image analysis unit 203 also extracts, for example, the coordinates (region of interest coordinates) p in the regions of interest 1004 and 1005 of subject H as regions of interest 1004 and 1005 of subject H. rоi Extract it.

[0100] Here, the process of step S502 in Figure 5 will be explained using Figure 10. The four angular coordinates p in region 1001 of the radiation detector 120 shown in Figure 10. n (n=0~3) represents the angular coordinates of the four angles, 1008.

[0101] In the example shown in Figure 10, the four corners 1008 are depicted in the optical image 1000 and can be detected by keypoint detection processing using rule-based or machine learning algorithms, such as corner detection or edge detection. If there are corners 1008 hidden by the region 1002 of the subject H, the method described using the flowchart shown in Figure 9 is used.

[0102] Furthermore, the region of interest coordinates p in regions of interest 1004 and 1005 of subject H shown in Figure 10 rоi This is the coordinate of a representative point in the left and right lung field regions of the human body contained within region 1002 of subject H. For example, this is calculated by applying a machine learning-based skeletal estimation model to extract the shoulder joint and lumbar region of the human body from optical image 1000 to region 1002 of subject H, thereby estimating the shoulder joint and lumbar region. Then, the lung field is determined by dividing the rectangle enclosed by the estimated shoulder joint and lumbar region by a predetermined ratio.

[0103] Now, let's return to the explanation of Figure 5. Once the process in step S502 in Figure 5 is completed, the process proceeds to step S503. When the process proceeds to step S503 in Figure 5, the control light field setting unit 204 sets a control light field that includes the region of interest of the subject H in multiple configurations when the radiation detector 120 is rotated relative to the subject H. Specifically, the control light field setting unit 204 sets the four angular coordinates p of the radiation detector 120. n (n=0~3), region of interest coordinate p of subject H rоi Based on the light-collecting field array information RI stored in the main memory 233, the control light-collecting field CR is set.

[0104] To explain using the region 1001 of the radiation detector 120 shown in Figure 10 as an example, the four corners 1008 are indistinguishable from each other, so the correspondence with the light-gathering field array information RI cannot be uniquely determined.

[0105] Figure 11 shows a second embodiment and illustrates the setting of the control light field by the control light field setting unit 204. In Figure 11, the same reference numerals are used for components that are the same as those shown in Figure 10, and their detailed explanations are omitted. Specifically, the left side of Figure 11 shows the optical image 1000 shown in Figure 10.

[0106] For example, in Figure 11, four possible arrangements are considered for the correspondence between the region 1001 of the radiation detector 120 in the optical image 1000 and the light-gathering field arrangement information RI: a first arrangement 1101, a second arrangement 1102, a third arrangement 1103, and a fourth arrangement 1104. This is because the shape of the radiation detector 120 shown in Figure 11 is square, and the orientation of the radiation detector 120 relative to the subject H, as performed by the operator S, etc., is taken into consideration. Specifically, the first arrangement 1101 is when the radiation detector 120 is placed in a predetermined position relative to the subject H, the second arrangement 1102 is when the radiation detector 120 is placed in a position rotated 90 degrees from the predetermined position relative to the subject H, and the third arrangement 1103 is when the radiation detector 120 is placed in a position rotated 180 degrees from the predetermined position relative to the subject H. Furthermore, the fourth arrangement 1104 is the case in which the radiation detector 120 is positioned 270 degrees rotated from the predetermined position relative to the subject H.

[0107] When the light-gathering field array information RI is associated with the region 1001 of the radiation detector 120 in the optical image 1000 according to the first arrangement 1101, the result is as shown in the first arrangement state 1105 of Figure 11.

number

[0108] Furthermore, when the light-gathering field array information RI is associated with the region 1001 of the radiation detector 120 in the optical image 1000 according to the second arrangement 1102, the result is as shown in the second arrangement state 1106 of Figure 11.

number

[0109] Furthermore, when the light-gathering field array information RI is associated with the region 1001 of the radiation detector 120 in the optical image 1000 according to the third arrangement 1103, the result is as shown in the third arrangement state 1107 of Figure 11.

number

[0110] Furthermore, when the light-gathering field array information RI is associated with the region 1001 of the radiation detector 120 in the optical image 1000 according to the fourth arrangement 1104, the result is as shown in the fourth arrangement state 1108 of Figure 11.

number

[0111] Then, in the example shown in Figure 11, the control daylight field setting unit 204 sets the four daylight fields of interest, daylight field IDs 7, 9, 17, and 19, as control daylight fields CR, as shown in the control daylight field setting state 1109.

[0112] Now, let's return to the explanation of Figure 5. Once the process in step S503 in Figure 5 is completed, the process proceeds to step S504. When the process proceeds to step S504 in Figure 5, the radiation control method determination unit 205 determines the radiation control method CW for stopping radiation H based on the imaging order information and the control light field CR set in step S503. This completes the preparation process for automatic exposure control of radiation R.

[0113] The following describes a specific example of the process in step S504 of Figure 5. In Figure 11, as shown in the control light field setting state 1109, four light fields with light field IDs [7, 9, 17, 19] are set as the control light field CR. In the actual radiography where subject H is placed, the region of interest p of subject H rоi The field of interest corresponding to this is any two of the field of interest with field of interest IDs = [7, 9, 17, 19]. For the radiation detector 120 on the optical image 1000, if the field of interest array information RI is in the first configuration 1101, then the field of interest with field of interest IDs = [7, 9] is as shown in the first configuration state 1105. Also, for the radiation detector 120 on the optical image 1000, if the field of interest array information RI is in the second configuration 1102, then the field of interest with field of interest IDs = [17, 7] is as shown in the second configuration state 1106. Also, for the radiation detector 120 on the optical image 1000, if the field of interest array information RI is in the third configuration 1103, then the field of interest with field of interest IDs = [19, 17] is as shown in the third configuration state 1107. Furthermore, for the radiation detector 120 on the optical image 1000, if the light-collecting field array information RI is in the fourth arrangement 1104, then the light-collecting field ID = [9,19] is the light-collecting field of interest, as shown in the fourth arrangement state 1108.

[0114] Figure 12 shows a second embodiment and is a diagram illustrating the determination of the radiation control method by the radiation control method determination unit 205. In Figure 12, the same reference numerals are used for components that are the same as those shown in Figure 11, and their detailed explanations are omitted. Specifically, the left side of Figure 12 illustrates the first arrangement state 1105 to the fourth arrangement state 1108 shown in Figure 11.

[0115] Here, when radiography of subject H is started, in the first configuration state 1105 where the field of interest is the field of interest ID=[7,9], the output for the radiation dose at field of interest ID=[7,9,17,19] is shown as the first output state 1201 in Figure 12. Also, when radiography of subject H is started, in the second configuration state 1106 where the field of interest is the field of interest is the field of interest is the output for the radiation dose at field of interest ID=[7,9,17,19], is shown as the second output state 1202 in Figure 12. Also, when radiography of subject H is started, in the third configuration state 1107 where the field of interest is the field of interest is the field of interest is the output for the radiation dose at field of interest ID=[7,9,17,19], is shown as the third output state 1203 in Figure 12. Furthermore, when radiography of subject H is initiated, if the fourth configuration state 1108 is where the field of interest is the field of interest, the output at the radiation dose of field of interest ID = [7,9,17,19] is shown as the fourth output state 1204 in Figure 12.

[0116] In the first output state 1201 to the fourth output state 1204 shown in Figure 12, each of the light-gathering fields with field IDs [7, 9, 17, 19] outputs a radiation dose value as time progresses. Here, the lung region, which is the subject H's region of interest, has a high dose transmittance of radiation R. Dose control based on the high dose transmittance of radiation R in this lung region is instructed in the imaging order information. In the first output state 1201 shown in Figure 12, the light-gathering field with field IDs [7, 9], which is located in the subject H's region of interest, has a higher radiation dose output value and reaches the target dose value earlier than the light-gathering field with field IDs [17, 19], which is not located in the subject H's region of interest. In this first output state 1201 shown in Figure 12, the radiation control method determination unit 205 determines a radiation control method CW that issues a radiation R stop notification T when the radiation dose output value in the light-gathering field with field IDs [7, 9] reaches the target dose value.

[0117] Furthermore, in the second output state 1202 shown in Figure 12, the radiation output value in the light field ID=[17,7], which is located in the subject H's region of interest, is higher than that in the light field ID=[19,9], which is not located in the subject H's region of interest, and reaches the target dose value sooner. In this second output state 1202 shown in Figure 12, the radiation control method determination unit 205 determines a radiation control method CW that issues a radiation stop notification T when the radiation output value in the light field ID=[17,7] reaches the target dose value.

[0118] Furthermore, in the third output state 1203 shown in Figure 12, the radiation output value in the light field ID=[19,17], which is located in the subject H's region of interest, is higher than that in the light field ID=[9,7], which is not located in the subject H's region of interest, and reaches the target dose value sooner. In this third output state 1203 shown in Figure 12, the radiation control method determination unit 205 determines a radiation control method CW that issues a radiation stop notification T when the radiation output value in the light field ID=[19,17] reaches the target dose value.

[0119] Furthermore, in the fourth output state 1204 shown in Figure 12, the radiation output value in the light field ID=[9,19] located in the subject H's region of interest is higher than that of the light field ID=[7,17] not located in the subject H's region of interest, and reaches the target dose value sooner. In this fourth output state 1204 shown in Figure 12, the radiation control method determination unit 205 determines a radiation control method CW that issues a radiation stop notification T when the radiation output value in the light field ID=[9,19] reaches the target dose value.

[0120] In the first to fourth output states 1201 to 1204 shown in Figure 12, regardless of which of the multiple light fields of interest the field of interest is the control light field CR, the following is meant: In other words, in the first to fourth output states 1201 to 1204 shown in Figure 12, it is sufficient to issue a stop notification when two outputs, corresponding to the number of regions of interest among the control light field CR, reach the target dose. The example explained using Figures 10 to 12 shows the case where the shape of the radiation detector 120 is square and the number of regions of interest (1004 and 1005) of the subject H is two. In this example explained using Figures 10 to 12, the radiation control method determination unit 205 determines a radiation control method CW that issues a stop notification when two outputs, corresponding to the number of regions of interest among the control light field CR, reach the target dose.

[0121] Now, let's return to the explanation of Figure 5. Once the process in step S504 of Figure 5 is completed, the process shown in the flowchart of Figure 5 is terminated.

[0122] In the second embodiment as well, since the radiation control method CW can be determined before irradiation with radiation R in radiography, the irradiation of radiation R can be reliably stopped while ensuring the accuracy of the correspondence between the region of interest of the subject H and the light-gathering field of the radiation detector 120.

[0123] (Third embodiment) Next, a third embodiment will be described. In the description of the third embodiment below, matters common to the first and second embodiments described above will be omitted, and matters that differ from the first and second embodiments described above will be explained.

[0124] The schematic configuration of the radiography system according to the third embodiment is the same as the schematic configuration of the radiography system 100 according to the first embodiment shown in Figure 1. Furthermore, the schematic configuration of the information processing device 140 according to the third embodiment is the same as the schematic configuration of the information processing device 140 according to the first embodiment shown in Figure 2.

[0125] In the third embodiment, a video camera is used as the camera device 130 to acquire optical images at a predetermined frame rate. In the third embodiment, the information processing device 140 uses the optical images acquired by the camera device 130 to set the control light field CR and determine the radiation control method CW when the limbs are the subject H, and performs preparatory processing for automatic exposure control of radiation R.

[0126] Below, in the third embodiment, the processing procedure for the preparation process in the automatic exposure control of radiation R will be described with reference to the flowchart shown in Figure 5.

[0127] First, in step S501 of Figure 5, the optical image acquisition unit 201 controls the camera device 130 to acquire an optical image of the radiography site, including the subject H being radiographed and the radiation detector 120, from the camera device 130.

[0128] Figure 13 shows a third embodiment and is a diagram showing an example of an optical image 1300 acquired by the optical image acquisition unit 201. In Figure 13, the same reference numerals are used for components that are the same as those shown in Figure 6, and their detailed explanations are omitted. The optical image 1300 shown in Figure 13 represents an optical image of a subject H, including the right hand of a patient who is the subject of radiography, taken with the irradiation field of radiation R narrowed. That is, the difference between the optical image 1300 shown in Figure 13 and the optical image 600 shown in Figure 6 is that the collimator of the radiation generator 110 is narrowed, resulting in a difference in brightness due to the collimator lamp in the optical image 1300. Specifically, in the optical image 1300 shown in Figure 13, the region 1301, which is irradiated by the collimator lamp indicating the irradiation field of radiation R, is shown as a rectangle, and the inside of region 1301 is brighter than the outside because it is irradiated by the collimator lamp.

[0129] Now, let's return to the explanation of Figure 5. Once the process in step S501 in Figure 5 is completed, the process proceeds to step S502. When the process proceeds to step S502 in Figure 5, the optical image analysis unit 203 analyzes the optical image acquired in step S501 and performs a process to extract, for example, the region 601 of the radiation detector 120 and the region of interest 604 of the subject H from the optical image. Specifically, the optical image analysis unit 203 defines, for example, the region 601 of the radiation detector 120 as the angular coordinates p at the four corners 606, 607 of the radiation detector 120. n (n=0~3) is extracted. The optical image analysis unit 203 also extracts, for example, the region of interest 604 of subject H, and the coordinates (region of interest coordinates) p in the region of interest 604 of subject H. rоi Furthermore, in this embodiment, the optical image analysis unit 203 analyzes the optical image acquired in step S501 and, for example, extracts the region 1301 (Rcol) illuminated by the collimator lamp from the optical image.

[0130] Here, the process of step S502 in Figure 5 will be explained using Figure 13. The four angular coordinates p in region 601 of the radiation detector 120 shown in Figure 6. n (n=0~3) consists of the angular coordinates of three angles 606 and the angular coordinates of one angle 607. Furthermore, the region of interest 604 of subject H shown in Figure 13 is the approximate central region of the human hand included in the region 602 of subject H. Therefore, for example, by segmenting the region 602 of subject H from the optical image 1300 and finding the position that divides the obtained region internally in a predetermined ratio, the region of interest coordinates p in the region of interest 604 of subject H can be determined. rоi The four angular coordinates p of the radiation detector 120 described here are calculated. n (n=0~3), and the coordinates of the region of interest p in the region of interest 604 of subject H. rоi The extraction process can be performed in the same manner as in the first embodiment described above.

[0131] In the third embodiment, the optical image analysis unit 203 further extracts the region 1301 (Rcol) illuminated by the collimator lamp from the optical image 1300. This can be extracted in the optical image 1300 using a rule-based method that utilizes the brightness difference inside and outside the region 1301 (Rcol), edge detection on the boundary, or segmentation processing using an inference model implemented with a machine learning algorithm.

[0132] Now, let's return to the explanation of Figure 5. Once the process in step S502 in Figure 5 is completed, the process proceeds to step S503. When the process proceeds to step S503 in Figure 5, the control light field setting unit 204 sets a control light field that includes the region of interest of the subject H in multiple configurations when the radiation detector 120 is rotated relative to the subject H. Specifically, the control light field setting unit 204 sets the four angular coordinates p of the radiation detector 120. n (n=0~3), region of interest coordinate p of subject H rоi Based on the light-collecting field array information RI stored in the main memory 233, the control light-collecting field CR is set. Furthermore, in the third embodiment, the control light-collecting field setting unit 204 determines whether the set control light-collecting field CR is included within the range of the radiation field R (within the range of region 1301 (Rcol)) based on the extraction result of region 1301 (Rcol) in S502.

[0133] In this process, first, as described in the first embodiment, a transformation matrix M is obtained from the coordinate system of the optical image to the coordinate system of the light-gathering field array information RI.

number

[0134] Figure 14 shows a third embodiment and illustrates the setting of the control light field by the control light field setting unit 204. In Figure 14, the same reference numerals are used for components that are the same as those shown in Figures 7 and 13, and their detailed explanations are omitted. Specifically, the left side of Figure 14 shows the optical image 1300 shown in Figure 13.

[0135] For example, as shown in Figure 14, there are two possible arrangements for the correspondence between the region 601 of the radiation detector 120 in the optical image 1300 and the light-gathering field arrangement information RI: a first arrangement 701 and a second arrangement 702. This is similar to the explanation using Figure 7 in the first embodiment, and takes into account the orientation of the radiation detector 120 relative to the subject H, as shown in Figure 14 has a rectangular shape. Specifically, the first arrangement 701 is when the radiation detector 120 is placed in a predetermined position relative to the subject H, and the second arrangement 702 is when the radiation detector 120 is placed in a position rotated 180 degrees from the predetermined position relative to the subject H.

[0136] When the light-collecting field array information RI is associated with the region 601 of the radiation detector 120 in the optical image 1300 according to the first arrangement 701, the result is as shown in the first arrangement state 1401 in Figure 14. In this first arrangement state 1401, the light-collecting field of interest 605 has a light-collecting field ID of 9.

[0137] Furthermore, when the light-collecting field array information RI is associated with the region 601 of the radiation detector 120 in the optical image 1300 according to the second arrangement 702, the result is as shown in the second arrangement state 1402 of Figure 14. In this second arrangement state 1402, the light-collecting field of interest 605 has a light-collecting field ID of 4.

[0138] In this case, region 1301 (Rcol) in the optical image 1300 can also be projected onto the light field array information RI, and in the first configuration state 1401 of Figure 14, region 1403 (Rcol) in the light field array information RI is obtained. This means that in the first configuration state 1401 of Figure 14, the dose of radiation R irradiated to the light field with light field ID 4 is smaller than the dose of radiation R irradiated to the light field with light field ID 9. Similarly, in the second configuration state 1402 of Figure 14, region 1404 (Rcol) in the light field array information RI is obtained. This means that in the second configuration state 1402 of Figure 14, the dose of radiation R irradiated to the light field with light field ID 9 is smaller than the dose of radiation R irradiated to the light field with light field ID 4.

[0139] Then, in the example shown in Figure 14, the control daylight field setting unit 204 sets the two daylight fields of interest, daylight field ID=4 and 9, as the control daylight field CR, as shown in the control daylight field setting state 1405.

[0140] Now, let's return to the explanation of Figure 5. Once the process in step S503 in Figure 5 is completed, the process proceeds to step S504. When the process proceeds to step S504 in Figure 5, the radiation control method determination unit 205 determines the radiation control method CW for stopping radiation H based on the imaging order information and the control light field CR set in step S503. This completes the preparation process for automatic exposure control of radiation R.

[0141] The following describes a specific example of the process in step S504 of Figure 5. In Figure 14, as shown in the control light field setting state 1405, two light fields with light field ID=[4,9] are set as the control light field CR. In the actual radiography where subject H is placed, the region of interest of subject H is p rоi The field of interest corresponding to this is one of the fields with field of interest IDs [4,9].

[0142] Figure 15 shows a third embodiment and illustrates the determination of the radiation control method by the radiation control method determination unit 205. In Figure 15, the same reference numerals are used for components that are the same as those shown in Figure 14, and their detailed explanations are omitted. Specifically, the left side of Figure 15 illustrates the first arrangement state 1401 and the second arrangement state 1402 shown in Figure 14.

[0143] Here, when radiography of subject H is started, if the first setup state 1401 is the field of interest where field of interest ID=9 is present, the output at the radiation dose of field of interest ID=[4,9] is shown as the first output state 1501 in Figure 15. Also, when radiography of subject H is started, if the second setup state 1402 is the field of interest where field of interest ID=4 is present, the output at the radiation dose of field of interest ID=[4,9] is shown as the second output state 1502 in Figure 15.

[0144] In the first output state 1501 shown in Figure 15, each of the light-gathering fields with field IDs [4,9] outputs a radiation dose value as time progresses. In the first output state 1501 shown in Figure 15, even though there is no subject H, the radiation dose output value is smaller for the light-gathering field with field ID = 4 because it is located outside the region 1403 (Rcol), and the light-gathering field with field ID = 9 reaches the target dose value first. In this first output state 1501 shown in Figure 15, the radiation control method determination unit 205 determines a radiation control method CW that issues a radiation R stop notification T when the radiation dose output value in the light-gathering field with field ID = 9 reaches the target dose value.

[0145] Conversely, in the second output state 1502 shown in Figure 15, the light field with light field ID=4 reaches the target dose value before the light field with light field ID=9. In this second output state 1502 shown in Figure 15, the radiation control method determination unit 205 determines a radiation control method CW that issues a radiation stop notification T when the output value of the radiation dose in the light field with light field ID=4 reaches the target dose value.

[0146] In the third embodiment, narrowing the irradiation field of radiation R requires a different radiation control than that of the first embodiment described above. Specifically, in the example explained using Figures 13 to 15, the radiation control method determination unit 205 determines a radiation control method CW that "notifies a stop when one output, which is the number of regions of interest in the control light field CR, reaches the target dose."

[0147] Now, let's return to the explanation of Figure 5. Once the process in step S504 of Figure 5 is completed, the process shown in the flowchart of Figure 5 is terminated.

[0148] In the description of the third embodiment, the radiation control method determination unit 205 determined a different radiation control method CW than in the first embodiment, based on information regarding the region (Rcol) added to the control light field CR obtained by the control light field setting unit 204. In this regard, the case in which the optical image analysis unit 203 extracts the region (Rcol) irradiated by the collimator lamp was described, but the third embodiment is not limited to this form. For example, the third embodiment can also be applied to a form in which the imaging order information includes information on the collimator aperture width, and the radiation control method determination unit 205 determines the radiation control method CW based on this collimator aperture width information.

[0149] In the third embodiment as well, since the radiation control method CW can be determined before irradiation with radiation R in radiography, the irradiation of radiation R can be reliably stopped while ensuring the accuracy of the correspondence between the region of interest of the subject H and the light-gathering field of the radiation detector 120.

[0150] (Fourth embodiment) Next, a fourth embodiment will be described. In the description of the fourth embodiment below, matters common to the first to third embodiments described above will be omitted, and matters that differ from the first to third embodiments described above will be explained.

[0151] The schematic configuration of the radiography system according to the fourth embodiment is the same as the schematic configuration of the radiography system 100 according to the first embodiment shown in Figure 1. Furthermore, the schematic configuration of the information processing device 140 according to the fourth embodiment is the same as the schematic configuration of the information processing device 140 according to the first embodiment shown in Figure 2.

[0152] Specifically, the fourth embodiment is a comprehensive embodiment that builds upon the first to third embodiments described above.

[0153] Figure 16 is a flowchart showing an example of a processing procedure in the control method of the information processing device 140 according to the fourth embodiment. Specifically, Figure 16 is a flowchart of the processing related to part of the operation of the control light field setting unit 204 in step S503 of Figure 5 and the operation of the radiation control method determination unit 205 in step S504 of Figure 5.

[0154] First, in step S1601 of Figure 16, the control light-gathering field setting unit 204 determines whether the correspondence in the conversion from the coordinate system of the optical image to the coordinate system of the light-gathering field array information RI has been uniquely determined.

[0155] In step S1601 in Figure 16, if the control light-gathering field setting unit 204 determines that the correspondence in the conversion from the coordinate system of the optical image to the coordinate system of the light-gathering field array information RI is not uniquely determined (S1601 / No), the process proceeds to step S1602. When the process proceeds to step S1602 in Figure 16, the control light field setting unit 204 determines whether the shape of the radiation detector 120 is square when viewed along the direction of incidence of the radiation R.

[0156] In step S1602 of Figure 16, if the control light field setting unit 204 determines that the shape of the radiation detector 120 is square when viewed along the incident direction of the radiation R (S1602 / Yes), the process proceeds to step S1603. Proceeding to S1603 in Figure 16, the control light field setting unit 204 rotates the radiation detector 120 relative to the subject H to create multiple configurations, setting a predetermined position (0 degrees), as well as 90-degree rotation, 180-degree rotation, and 270-degree rotation configurations. The control light field setting unit 204 then sets the control light field CR, which is the light field that includes the region of interest of the subject H in the predetermined position (0 degrees), 90-degree rotation, 180-degree rotation, and 270-degree rotation configurations described above.

[0157] In step S1602 of Figure 16, if the control light field setting unit 204 determines that the shape of the radiation detector 120 is not square when viewed along the incident direction of the radiation R (S1602 / No), the process proceeds to step S1604. In this embodiment, when proceeding to step S1604 of Figure 16, the control light field setting unit 204 determines that the shape of the radiation detector 120 is rectangular when viewed along the incident direction of the radiation R. When the process proceeds to step S1604 in Figure 16, the control light field setting unit 204 rotates the radiation detector 120 relative to the subject H to create multiple configurations, setting a 180-degree rotation configuration in addition to a predetermined position (0 degrees). The control light field setting unit 204 then sets the control light field CR, which is the light field that includes the region of interest of the subject H in both the predetermined position (0 degrees) configuration and the 180-degree rotation configuration.

[0158] If the process in step S1603 in Figure 16 is completed, or if the process in step S1604 in Figure 16 is completed, the process proceeds to step S1605. Also, if in step S1601 in Figure 16 the control light field setting unit 204 determines that the correspondence in the conversion from the coordinate system of the optical image to the coordinate system of the light field array information RI is uniquely determined (S1601 / Yes), the process proceeds to step S1605. When the process proceeds to step S1605 in Figure 16, the radiation control method determination unit 205 determines whether the number of control light-gathering fields CR is the same as the number of regions of interest of the subject H held in the imaging order information.

[0159] In step S1605 of Figure 16, if the radiation control method determination unit 205 determines that the number of control light fields CR is not the same as (different from) the number of regions of interest of subject H (S1605 / No), the process proceeds to step S1606. When the process proceeds to step S1606 in Figure 16, the radiation control method determination unit 205 accesses the information regarding the imaging site of subject H held in the imaging order information and determines whether or not the imaging site of subject H is the chest.

[0160] In step S1606 of Figure 16, if the radiation control method determination unit 205 determines that the imaging site of subject H is not the chest (S1606 / No), the process proceeds to step S1607. When the process proceeds to step S1607 in Figure 16, the radiation control method determination unit 205 accesses the irradiation field aperture information held by the processing result of the control light field setting unit 204 or the imaging order information, and determines whether or not it is an imaging test in which the irradiation field of radiation R is narrowed.

[0161] In step S1607 of Figure 16, if the radiation control method determination unit 205 determines that the radiation field R is not narrowed in the radiography (S1607 / No), the process proceeds to step S1608. Also, in step S1605 of Figure 16, if the radiation control method determination unit 205 determines that the number of control light fields CR is the same as the number of regions of interest of the subject H (S1605 / Yes), the process proceeds to step S1608. When the process proceeds to step S1608 in Figure 16, the radiation control method determination unit 205 determines the radiation control method CW, which is rule A, which "notifies a stop when all outputs of the control light field CR reach the target dose."

[0162] In step S1607 of Figure 16, if the radiation control method determination unit 205 determines that the radiation field of radiation R is narrowed (S1607 / Yes), the process proceeds to step S1609. Also, in step S1606 of Figure 16, if the radiation control method determination unit 205 determines that the imaging site of the subject H is the chest (S1606 / Yes), the process proceeds to step S1609. When the process proceeds to step S1609 in Figure 16, the radiation control method determination unit 205 determines the radiation control method CW of rule B, which "notifies a stop when the output of the number of regions of interest in the control light field CR reaches the target dose."

[0163] Next, we will explain the correspondence between the flowchart shown in Figure 16 and the first to third embodiments described above.

[0164] First, as a common feature of the first to third embodiments described above, the radiation control method determination unit 205 determines the radiation control method CW based on the number of control light fields CR and the number of regions of interest of the subject H (S1605 in Figure 16).

[0165] The first embodiment described above corresponds to the case where a negative judgment (S1607 / No) is made in step S1607 of Figure 16. That is, the first embodiment is the case where the number of control light fields CR and the number of regions of interest of the subject H are different (S1605 / No). Furthermore, the first embodiment is the case where the radiography performed on the subject H is not a predetermined radiography in which the number of regions of interest of the subject H is multiple (S1606 / No), and is a radiography in which the irradiation field of radiation R is not narrowed (S1607 / No). Then, in the first embodiment, the radiation control method determination unit 205 determines a control method as the radiation control method CW in which the irradiation of radiation R is stopped when the dose of radiation R detected in all control light fields CR reaches the target dose (S1608).

[0166] The second embodiment described above corresponds to the case where an affirmative judgment (S1606 / Yes) is made in step S1606 of Figure 16. That is, the second embodiment is, first, the case where the number of control light fields CR and the number of regions of interest of the subject H are different (S1605 / No). Furthermore, the second embodiment is the case where the radiography performed on the subject H is a predetermined radiography in which the number of regions of interest of the subject H is multiple (S1606 / Yes). In step S1606 of Figure 16 and in the second embodiment, chest radiography is used as an example of a predetermined radiography in which the number of regions of interest of the subject H is multiple, but this disclosure is not limited to chest radiography, and for example, radiography of both hands or both feet can also be applied. In the second embodiment, the radiation control method determination unit 205 determines a control method as the radiation control method CW in which the irradiation of radiation R is stopped when the dose of radiation R detected in the control light fields CR, which is the same number as the number of regions of interest of the subject H, reaches the target dose (S1609).

[0167] The third embodiment described above corresponds to the case where an affirmative judgment (S1607 / Yes) is made in step S1607 of Figure 16. That is, the third embodiment is, first, the case where the number of control light fields CR and the number of regions of interest of the subject H are different (S1605 / No). Furthermore, the third embodiment is the case where the radiography performed on the subject H is not a predetermined radiography in which the number of regions of interest of the subject H is multiple (S1606 / No), and is a radiography in which the irradiation field of radiation R is narrowed (S1607 / Yes). Then, in the third embodiment, the radiation control method determination unit 205 determines a control method as the radiation control method CW in which the irradiation of radiation R is stopped when the dose of radiation R detected in the same number of control light fields CR as the number of regions of interest of the subject H reaches the target dose (S1609).

[0168] Furthermore, the flowchart shown in Figure 16 illustrates the determination of the radiation control method CW in other embodiments that do not correspond to the first to third embodiments described above. Specifically, the other embodiment corresponds to the case where an affirmative judgment (S1605 / Yes) is made in step S1605 of Figure 16. That is, the other embodiment is the case where the number of control light fields CR and the number of regions of interest of the subject H are the same (S1605 / Yes). An example of the case where the number of control light fields CR and the number of regions of interest of the subject H are the same is that the region of interest of the subject H is located at the center of the radiation detector 120, and the number of control light fields CR does not increase even if multiple rotational arrangements are performed on the radiation detector 120. In this other embodiment, the radiation control method determination unit 205 determines a control method as the radiation control method CW in which irradiation of radiation R is stopped when the dose of radiation R detected in all control light fields CR reaches the target dose (S1608).

[0169] (Other embodiments) This disclosure can also be implemented by supplying a program that implements one or more of the functions of the embodiments described above to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be implemented by a circuit (e.g., an ASIC) that implements one or more functions. This program and a computer-readable storage medium on which the program is stored are included in this disclosure.

[0170] Furthermore, the embodiments of this disclosure described above are merely examples of concrete implementations of this disclosure, and the technical scope of this disclosure should not be interpreted as being limited by them. In other words, this disclosure can be implemented in various ways without departing from its technical concept or its main features.

[0171] Embodiments of this disclosure include the following configurations, methods, and programs. [Configuration 1] An acquisition means for acquiring an optical image obtained by optically photographing a subject being subjected to radiography using radiation, a radiation detector provided with multiple light-gathering fields for detecting the dose of said radiation, An analysis means for analyzing the optical image and extracting the region of the radiation detector and the region of interest of the subject from the optical image, When the arrangement of the radiation detector is rotated to create multiple arrangements for the subject, a setting means is provided to set a control light field, which is the light field that includes the subject's region of interest, in each of the multiple arrangements. A determination means for determining a radiation control method for stopping radiation irradiation based on the imaging order information in the aforementioned radiography and the control light field, An information processing device equipped with the following features. [Configuration 2] The determination means determines the radiation control method based on the number of control light fields and the number of regions of interest of the subject. The information processing device described in Configuration 1. [Configuration 3] The aforementioned determination means is When the number of control light fields and the number of regions of interest are different, and the radiography performed on the subject is not a predetermined radiography in which there are multiple regions of interest and the radiation field is not narrowed, As the radiation control method, a control method is determined in which the irradiation of the radiation is stopped when the dose of the radiation detected in all of the control light-gathering fields reaches the target dose. The information processing device described in Configuration 2. [Structure 4] The aforementioned determination means is When the number of control light fields and the number of regions of interest are different, and the radiography performed on the subject is not a predetermined radiography in which there are multiple regions of interest, and the radiation field is narrowed, As the radiation control method, a control method is determined in which the irradiation of the radiation is stopped when the radiation dose detected in the control light field, which is the same number as the number of regions of interest, reaches the target dose. The information processing device described in Configuration 2. [Composition 5] The aforementioned determination means is When the number of control light fields and the number of regions of interest are different, and the radiography performed on the subject is a predetermined radiography in which there are multiple regions of interest, As the radiation control method, a control method is determined in which the irradiation of the radiation is stopped when the radiation dose detected in the control light field, which is the same number as the number of regions of interest, reaches the target dose. The information processing device described in Configuration 2. [Composition 6] The aforementioned determination means is If the number of control light fields and the number of regions of interest are the same, As the radiation control method, a control method is determined in which the irradiation of the radiation is stopped when the dose of the radiation detected in all of the control light-gathering fields reaches the target dose. The information processing device described in Configuration 2. [Composition 7] The analysis means extracts the region of the radiation detector by detecting the external features of the radiation detector as key points. An information processing device according to any one of items 1 to 6. [Structure 8] The analysis means extracts the region of the radiation detector by detecting a marker attached to a predetermined location on the radiation detector. An information processing device as described in any one of items 1 to 7. [Composition 9] The analysis means extracts the region of the radiation detector by estimating the orientation of the radiation detector based on the results of detecting the external features of the radiation detector as key points or the results of detecting markers attached to predetermined locations on the radiation detector. An information processing device according to any one of items 1 to 8. [Configuration 10] The analysis means extracts the region of the radiation detector by obtaining information on the four corners of the radiation detector based on the result of estimating the orientation of the radiation detector. The information processing device described in configuration 9. [Composition 11] The analysis means extracts the subject's region of interest based on the information about the subject included in the imaging order information. An information processing device according to any one of configurations 1 to 10. [Composition 12] The setting means, when setting the control light field which is the light field including the region of interest of the subject, uses a perspective transformation matrix to convert from the coordinate system of the optical image to the coordinate system of the light field array information. An information processing device as described in any one of items 1 to 11. [Composition 13] If the shape of the radiation detector is rectangular, The setting means, as the plurality of arrangements, A first arrangement involves positioning the radiation detector at a predetermined location relative to the subject, A second arrangement is applied, in which the radiation detector is positioned 180 degrees rotated from the predetermined position relative to the subject. An information processing device according to any one of configurations 1 to 12. [Composition 14] If the shape of the radiation detector is square, The setting means, as the plurality of arrangements, A first arrangement involves positioning the radiation detector at a predetermined location relative to the subject, A second arrangement in which the radiation detector is positioned 90 degrees rotated from the predetermined position relative to the subject, A third arrangement involves positioning the radiation detector 180 degrees rotated from the predetermined position relative to the subject, A fourth arrangement is applied, in which the radiation detector is positioned 270 degrees rotated from the predetermined position relative to the subject. An information processing device according to any one of configurations 1 to 12. [Composition 15] The analysis means analyzes the optical image and further extracts the region irradiated by the collimator lamp from the optical image as a region in which the radiation field is narrowed. An information processing device as described in any one of items 1 to 14. [Composition 16] The system further includes a display control means for controlling the display of at least one of the optical image, the control light field, and the radiation control method on a display unit. An information processing device as described in any one of configurations 1 to 15. [Composition 17] The system further includes a stop control means that performs control to stop the irradiation of the radiation based on the radiation control method described above. An information processing device as described in any one of items 1 to 16. [Composition 18] The information processing device described in any one of items 1 to 17, A radiography apparatus that is communicatively connected to the information processing apparatus, includes the radiation detector, and performs radiography, A camera device that is communicatively connected to the aforementioned information processing device and performs optical photography, A radiography system equipped with the following features. [Method 1] An acquisition step involves acquiring an optical image obtained by optically photographing a subject being subjected to radiography using radiation, and a radiation detector provided with multiple light-gathering fields for detecting the dose of said radiation. The analysis step involves analyzing the optical image and extracting the region of the radiation detector and the region of interest of the subject from the optical image. A setting step in which, when the arrangement of the radiation detector is rotated to create multiple arrangements for the subject, a control light field, which is the light field that includes the subject's region of interest, is set in the multiple arrangements, A decision step in which a radiation control method for stopping radiation irradiation is determined based on the imaging order information in the aforementioned radiography and the control light field, A control method for an information processing device, comprising the above. [Program 1] A program for causing a computer to perform each step in the control method for the information processing device described in Method 1. [Explanation of Symbols]

[0172] 140: Information processing unit, 201: Optical image acquisition unit, 202: Radiation image acquisition unit, 203: Optical image analysis unit, 204: Light field setting unit for control, 205: Radiation control method determination unit, 206: Radiation irradiation stop control unit, 207: Display control unit, 230: CPU bus, 231: CPU, 232: Storage unit, 233: Main memory, 234: Operation unit, 235: Display unit

Claims

1. An acquisition means for acquiring an optical image obtained by optically photographing a subject being subjected to radiography using radiation, a radiation detector provided with multiple light-gathering fields for detecting the dose of said radiation, An analysis means for analyzing the optical image and extracting the region of the radiation detector and the region of interest of the subject from the optical image, When the arrangement of the radiation detector is rotated to create multiple arrangements for the subject, a setting means is provided to set a control light field, which is the light field that includes the subject's region of interest, in each of the multiple arrangements. A determination means for determining a radiation control method for stopping radiation irradiation based on the imaging order information in the aforementioned radiography and the control light field, An information processing device equipped with the following features.

2. The determination means determines the radiation control method based on the number of control light fields and the number of regions of interest of the subject. The information processing apparatus according to claim 1.

3. The aforementioned determination means is When the number of control light fields and the number of regions of interest are different, and the radiography performed on the subject is not a predetermined radiography in which there are multiple regions of interest and the radiation field is not narrowed, As the radiation control method, a control method is determined in which the irradiation of the radiation is stopped when the dose of the radiation detected in all of the control light-gathering fields reaches the target dose. The information processing apparatus according to claim 2.

4. The aforementioned determination means is When the number of control light fields and the number of regions of interest are different, and the radiography performed on the subject is not a predetermined radiography in which there are multiple regions of interest, and the radiation field is narrowed, As the radiation control method, a control method is determined in which the irradiation of the radiation is stopped when the radiation dose detected in the control light field, which is the same number as the number of regions of interest, reaches the target dose. The information processing apparatus according to claim 2.

5. The aforementioned determination means is When the number of control light fields and the number of regions of interest are different, and the radiography performed on the subject is a predetermined radiography in which there are multiple regions of interest, As the radiation control method, a control method is determined in which the irradiation of the radiation is stopped when the radiation dose detected in the control light field, which is the same number as the number of regions of interest, reaches the target dose. The information processing apparatus according to claim 2.

6. The aforementioned determination means is If the number of control light fields and the number of regions of interest are the same, As the radiation control method, a control method is determined in which the irradiation of the radiation is stopped when the dose of the radiation detected in all of the control light-gathering fields reaches the target dose. The information processing apparatus according to claim 2.

7. The analysis means extracts the region of the radiation detector by detecting the external features of the radiation detector as key points. The information processing apparatus according to claim 1.

8. The analysis means extracts the region of the radiation detector by detecting a marker attached to a predetermined location on the radiation detector. The information processing apparatus according to claim 1.

9. The analysis means extracts the region of the radiation detector by estimating the orientation of the radiation detector based on the results of detecting the external features of the radiation detector as key points or the results of detecting markers attached to predetermined locations on the radiation detector. The information processing apparatus according to claim 1.

10. The analysis means extracts the region of the radiation detector by obtaining information on the four corners of the radiation detector based on the result of estimating the orientation of the radiation detector. The information processing apparatus according to claim 9.

11. The analysis means extracts the subject's region of interest based on the information about the subject included in the imaging order information. The information processing apparatus according to claim 1.

12. The setting means, when setting the control light field which is the light field including the region of interest of the subject, uses a perspective transformation matrix to convert from the coordinate system of the optical image to the coordinate system of the light field array information. The information processing apparatus according to claim 1.

13. If the shape of the radiation detector is rectangular, The setting means, as the plurality of arrangements, A first arrangement involves positioning the radiation detector at a predetermined location relative to the subject, A second arrangement is applied, in which the radiation detector is positioned 180 degrees rotated from the predetermined position relative to the subject. The information processing apparatus according to claim 1.

14. If the shape of the radiation detector is square, The setting means, as the plurality of arrangements, A first arrangement involves positioning the radiation detector at a predetermined location relative to the subject, A second arrangement involves positioning the radiation detector in a position rotated 90 degrees from the predetermined position relative to the subject, A third arrangement involves positioning the radiation detector 180 degrees rotated from the predetermined position relative to the subject, A fourth arrangement is applied, in which the radiation detector is positioned 270 degrees rotated from the predetermined position relative to the subject. The information processing apparatus according to claim 1.

15. The analysis means analyzes the optical image and further extracts the region irradiated by the collimator lamp from the optical image as a region in which the radiation field is narrowed. The information processing apparatus according to claim 1.

16. The system further includes a display control means for controlling the display of at least one of the optical image, the control light field, and the radiation control method on a display unit. The information processing apparatus according to claim 1.

17. The system further includes a stop control means that performs control to stop the irradiation of the radiation based on the radiation control method described above. The information processing apparatus according to claim 1.

18. An information processing device according to any one of claims 1 to 17, A radiography apparatus that is communicatively connected to the information processing apparatus, includes the radiation detector, and performs radiography, A camera device that is communicatively connected to the aforementioned information processing device and performs optical photography, A radiography system equipped with the following features.

19. An acquisition step involves acquiring an optical image obtained by optically photographing a subject being subjected to radiography using radiation, and a radiation detector provided with multiple light-gathering fields for detecting the dose of said radiation. The analysis step involves analyzing the optical image and extracting the region of the radiation detector and the region of interest of the subject from the optical image. A setting step in which, when the arrangement of the radiation detector is rotated to create multiple arrangements for the subject, a control light field, which is the light field that includes the subject's region of interest, is set in the multiple arrangements, A decision step in which a radiation control method for stopping radiation irradiation is determined based on the imaging order information in the aforementioned radiography and the control light field, A control method for an information processing device, comprising the above.

20. A program for causing a computer to perform each step in the control method for the information processing device described in claim 19.

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