Radiation imaging apparatus, dose determination method, and storage medium

Abstract

To provide a radiation imaging apparatus, a dose determination method, and a program capable of appropriately setting the dose of radiation to be emitted to an imaging target part when imaging a radiation dynamic image.SOLUTION: The radiographic imaging apparatus includes an acquisition unit that acquires a motion of an imaging target part of a subject of a radiographic dynamic image, and a control unit that changes a radiation dose to be emitted to the subject during radiographic dynamic imaging according to the motion of the imaging target part.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a radiation imaging apparatus, a dose determination method, and a program. [Background technology]

[0002] Radiation imaging devices that irradiate a subject with radiation to capture a radiation image are known. Some recent radiation imaging devices are capable of not only capturing still images but also capturing dynamic images (moving images) by continuously irradiating a subject with radiation (see, for example, Patent Document 1).

[0003] Dynamic radiography is generally applied to radiography of the chest and other areas in the respiratory field, but in recent years, its application to the orthopedic field has been considered. In the orthopedic field, when taking dynamic radiation images of the affected area, which is the subject's imaging target area, the subject's body is intentionally moved, unlike in the respiratory field. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-106710 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a subject intentionally moves their body, the relative positions of organs such as muscles change significantly, and multiple organs may overlap. In this case, the amount of radiation transmitted through the imaging target area changes depending on the subject's movement. Therefore, when a constant dose of radiation is irradiated onto the imaging target area, the signal-to-noise (S / N) ratio of dynamic images obtained by dynamic imaging varies depending on the subject's physical movement, resulting in a problem of reduced analysis accuracy.

[0006] An object of the present disclosure is to provide a radiographic imaging apparatus, a dose determination method, and a program that can appropriately set the dose of radiation to be irradiated to a region to be imaged when capturing a dynamic radiation image. [Means for solving the problem]

[0007] The radiation imaging apparatus according to the present disclosure comprises: an acquisition unit for acquiring a motion of an imaging target part of a subject in a radiological dynamic image; a control unit that changes the amount of radiation irradiated to the subject during dynamic radiography in accordance with the movement of the imaging target region; Equipped with.

[0008] The dose determination method according to the present disclosure includes: Obtaining the movement of the imaging target part of the subject in the radiological dynamic image; The radiation dose irradiated to the subject during dynamic radiography is changed during the dynamic radiography in accordance with the movement of the region to be imaged.

[0009] The program according to the present disclosure is The dose determination method is executed by a computer. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to appropriately set the dose of radiation to be irradiated to the imaging target site when capturing a dynamic radiation image. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a radiation image processing system according to the present embodiment. [Figure 2] FIG. 2 is a functional block diagram showing an example of the configuration of the radiation imaging control unit in FIG. [Figure 3] FIG. 3 is a functional block diagram showing an example of the configuration of the optical photography control unit in FIG. [Figure 4]FIG. 4 is a functional block diagram showing an example of the configuration of the console device of FIG. [Figure 5] FIG. 5 is a schematic diagram for explaining changes in muscle mass in response to the body movement of a subject. [Figure 6] FIG. 6 is a sequence diagram showing an example of the flow of processing during dynamic imaging in the image processing system according to the present embodiment. [Figure 7] FIG. 7 is a flowchart showing an example of the flow of the dose determination process of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments, and various modifications are possible without departing from the spirit of the present disclosure. In addition, in each drawing, the same reference numerals are used to denote the same or equivalent parts, and this is common throughout the entire specification.

[0013] The radiation image processing system according to this embodiment performs radiographic dynamic imaging to generate a radiographic dynamic image, performs various analytical processes on the generated radiographic dynamic image, and simultaneously performs optical dynamic imaging to generate an optical dynamic image, and sets the radiation dose when irradiating the subject with radiation based on the generated optical dynamic image.

[0014] In this specification, a "radiation dynamic image" refers to a moving image generated based on multiple frame images obtained by radiographic dynamic imaging, in which a subject is repeatedly irradiated with pulsed radiation such as X-rays at predetermined intervals or continuously irradiated with low dose rates. An "optical dynamic image" refers to a moving image generated based on multiple frame images obtained by optical dynamic imaging of a subject. In the following description, radiographic dynamic imaging and optical dynamic imaging may be collectively referred to as "dynamic imaging."

[0015] <Configuration of Radiation Image Processing System> 1 is a schematic diagram showing an example of the configuration of a radiological image processing system 1 according to the present embodiment. The radiological image processing system 1 includes a radiological image capturing device 10, a console device 20, a radiological image analyzing device 30, an image management device 40, and a client terminal 50. The radiological image processing system 1 corresponds to the "radiological image capturing device" of the present disclosure.

[0016] In the example shown in Fig. 1, the radiographic imaging device 10 is placed in an imaging room. The console device 20 is placed in an operation room. The radiographic imaging device 10, the console device 20, the radiographic image analysis device 30, the image management device 40, and the client terminal 50 are connected to each other via a communication network. As the communication network, for example, a communication network conforming to the DICOM (Digital Image and Communications in Medicine) standard or the like is used.

[0017] The radiographic imaging device 10 captures a radiological dynamic image, which is a radiological image, under the control of the console device 20. The radiological dynamic image generated by the radiographic imaging device 10 is transmitted to the radiological image analysis device 30 via the console device 20.

[0018] In the present embodiment, the radiographic imaging device 10 captures an optical dynamic image, which is an optical image, under the control of the console device 20. The optical dynamic image generated by the radiographic imaging device 10 is transmitted to the console device 20.

[0019] The radiological image analysis device 30 performs dynamic analysis on the radiological dynamic image. The radiological dynamic image and the results of the dynamic analysis are transmitted to and managed by an image management device 40 (e.g., a PACS (Picture Archiving and Communication System)) serving as a medical image management system. The radiological dynamic image and the results of the dynamic analysis are transmitted to a client terminal 50 and viewed by medical personnel such as doctors.

[0020] The radiographic imaging device 10, the console device 20, and the radiographic image analysis device 30 each have a processor and memory (not shown). The radiographic imaging device 10, the console device 20, and the radiographic image analysis device 30 are each a type of computer that implements predetermined functions by reading, expanding, and executing programs stored in the memory.

[0021] (Radiation imaging device 10) As shown in FIG. 1, the radiographic imaging device 10 includes a radiographic imaging control unit 11, a radiation irradiation unit 12, an imaging table 13, a radiation detection unit 14, a display unit 15, an audio output unit 16, an optical imaging control unit 17, and an optical imaging unit 18.

[0022] The radiography control unit 11 acquires radiation setting information relating to the settings of dynamic radiography from the console device 20. Based on the radiation setting information, the radiography control unit 11 sets radiography conditions for performing dynamic radiography, and controls the radiation irradiator 12 based on the radiography conditions to irradiate the subject (e.g., a patient) with radiation and perform radiography. The radiography control unit 11 is composed of a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc.

[0023] The radiation setting information is information relating to settings for performing radiographic dynamic imaging of a subject. The radiation setting information includes, for example, at least one of multiple types of dynamic analysis that the radiographic image analysis device 30 can perform on a radiographic dynamic image. When multiple types of dynamic analysis are combined, the radiation setting information may include information relating to the combination. The radiation setting information is set by an operator of the radiation image processing system 1, for example, a radiographer, in the console device 20 described below.

[0024] The radiation imaging conditions include various conditions such as the pulse rate, pulse width, pulse interval, number of imaging frames per imaging, the radiation dose of radiation irradiated to the subject per imaging frame (hereinafter simply referred to as "dose"), and the subject's physical condition (respiratory state, etc.). The pulse rate is the number of radiation irradiations per second and corresponds to the frame rate of the image data. The pulse width is the radiation irradiation time per radiation irradiation. The pulse interval is the time from the start of one radiation irradiation to the start of the next radiation irradiation and corresponds to the time interval (frame interval) between multiple image data. The radiation imaging conditions may be automatically determined by the radiation imaging control unit 11 of the radiation imaging device 10 based on the radiation setting information.

[0025] The radiation emitting unit 12 is disposed at a position facing the radiation detecting unit 14 fixed to the imaging table 13. The radiation emitting unit 12 irradiates radiation (X-rays) under the control of the radiation imaging control unit 11.

[0026] The radiation detection unit 14 is composed of a semiconductor image sensor such as an FPD (Flat Panel Detector). The radiation detection unit 14 has a substrate on which a plurality of detection elements (pixels) are arranged in a matrix, which detect radiation irradiated from the radiation irradiation unit 12 according to its intensity, convert the detected radiation into an electrical signal, and store the electrical signal. Each pixel on the substrate is configured to include a switching unit such as a TFT (Thin Film Transistor).

[0027] The radiation detection unit 14 controls the switching unit of each pixel based on the image reading conditions input from the console device 20 to read the electrical signals accumulated in each pixel and output intensity information for each pixel to the image generation unit 113. The image reading conditions include, for example, the frame rate, frame interval, pixel size, and image size (matrix size). The frame rate is the number of frame images acquired per second and coincides with the pulse rate. The frame interval is the time from the start of one image data acquisition operation to the start of the next frame image acquisition operation and coincides with the pulse interval.

[0028] The radiation imaging control unit 11 and the radiation detection unit 14 are connected to each other and exchange synchronization signals with each other to synchronize the radiation irradiation operation and the image reading operation.

[0029] In this way, in the radiographic imaging device 10, the radiation irradiation unit 12 irradiates radiation under the control of the radiographic imaging control unit 11. Then, the radiographic imaging device 10 performs dynamic radiographic imaging by generating image data based on the intensity of the irradiated radiation using the radiation detection unit 14.

[0030] The display unit 15 and the audio output unit 16 instruct the subject on the posture and physical condition (such as respiratory state) to be taken when performing dynamic imaging of the subject. The display unit 15 is, for example, a display device such as a CRT (Cathode Ray Tube), a liquid crystal display (Liquid Crystal Display), or an organic EL (Electro Luminescence) display arranged in the imaging room. The display unit 15 may also be, for example, a portable terminal such as a tablet.

[0031] The audio output unit 16 is, for example, an audio output device such as a speaker. The display unit 15 and the audio output unit 16 may each give the same instructions to the subject, or only one of them may give an instruction.

[0032] The optical imaging control unit 17 acquires optical setting information relating to settings for performing optical dynamic imaging of the subject from the console device 20. The optical imaging control unit 17 sets optical imaging conditions for performing optical dynamic imaging based on the optical setting information, and controls the optical imaging unit 18 based on the optical imaging conditions to perform optical imaging of the subject. The optical imaging control unit 17 is composed of a CPU, RAM, ROM, etc.

[0033] The optical imaging conditions include various conditions such as the frame rate during imaging, the number of imaging frames per imaging, and the condition of the subject. The frame rate is the number of frame images acquired per second. The optical imaging conditions may be automatically determined by the optical imaging control unit 17 of the radiographic imaging device 10 based on the optical setting information.

[0034] The optical imaging unit 18 is, for example, an optical camera having an optical system including a lens and a focus mechanism (not shown), an aperture mechanism, an image sensor, a lens drive unit, an aperture drive unit, etc., and images the subject. For example, in this embodiment, the optical imaging unit 18 captures the body movements of the subject M during radiographic dynamic imaging as optical images.

[0035] The optical photographing unit 18 forms an image of the incident light on the image sensor and generates optical image data for each frame. The optical photographing unit 18 sequentially outputs the generated optical image data for multiple frames to the optical photographing control unit 17.

[0036] The optical imaging unit 18 is disposed, for example, near the radiation irradiation unit 12 so that the imaging range of the optical imaging includes the imaging range of the radiation imaging. Note that the location of the optical imaging unit 18 is not limited to this example, as long as the body movement of the subject can be confirmed.

[0037] (Radiography control unit 11) Fig. 2 is a functional block diagram showing an example of the configuration of the radiation imaging control unit 11 in Fig. 1. As shown in Fig. 2, the radiation imaging control unit 11 has a setting information acquisition unit 111, an imaging condition determination unit 112, an image generation unit 113, and a storage unit 114.

[0038] The setting information acquisition unit 111 acquires radiation setting information from the console device 20 .

[0039] The imaging condition determination unit 112 determines the radiation imaging conditions when performing dynamic radiation imaging of the subject, based on the radiation setting information acquired from the console device 20.

[0040] The image generation unit 113 performs dynamic radiography of the subject based on the determined radiography conditions and generates multiple frames of radiographic images. Specifically, the image generation unit 113 controls the operations of the radiation irradiator 12 and the radiation detector 14 based on the radiography conditions, and generates image data by acquiring intensity information on the intensity of radiation that has passed through the subject from the radiation detector 14 for each pixel.

[0041] The storage unit 114 stores in advance information indicating the correspondence between a plurality of types of dynamic analysis and radiation imaging conditions suitable for each dynamic analysis.

[0042] (Optical photography control unit 17) Fig. 3 is a functional block diagram showing an example of the configuration of the optical photography control unit 17 in Fig. 1. As shown in Fig. 3, the optical photography control unit 17 has a setting information acquisition unit 171, a photography condition determination unit 172, an image generation unit 173, and a storage unit 174.

[0043] The setting information acquisition unit 171 acquires optical setting information from the console device 20 .

[0044] The imaging condition determination unit 172 sets optical imaging conditions for performing optical dynamic imaging of the subject based on the optical setting information acquired by the setting information acquisition unit 171.

[0045] The image generation unit 173 performs optical dynamic imaging of the subject based on the determined optical imaging conditions. Specifically, the image generation unit 173 controls the operation of the optical imaging unit 18 based on the optical imaging conditions, and generates an optical dynamic image of the subject based on the multiple optical image data for each frame received from the optical imaging unit 18.

[0046] The storage unit 174 stores the optical setting information acquired from the console device 20, and the optical imaging conditions set based on the optical setting information. The storage unit 174 also stores the optical image data received from the optical imaging unit 18, and the optical dynamic image generated based on the optical image data.

[0047] (Console device 20) The console device 20 in Fig. 1 is, for example, a computer such as a PC (Personal Computer) or a workstation. The console device 20 may be a desktop computer as in the example shown in Fig. 1, or may be a portable computer such as a laptop PC or a tablet computer.

[0048] The console device 20 receives examination order information from a RIS (Radiology Information System; not shown) or the like, and transmits it to the radiographic imaging apparatus 10, thereby controlling radiographic dynamic imaging and optical dynamic imaging of the radiographic imaging apparatus 10.

[0049] The examination order information includes various information related to the next dynamic imaging to be performed, such as patient information, examination information, and data attributes. The patient information is information related to the subject to be imaged, and includes at least one of the subject's height, weight, age, sex, and BMI (Body Mass Index), for example. The examination information includes information such as the examination ID, the area to be examined, and the type of analysis. The examination order information is generated, for example, when a doctor or the like requests radiographic or optical dynamic imaging of a subject from the radiation image processing system 1.

[0050] Furthermore, the console device 20 generates radiation setting information indicating at least one of the multiple types of dynamic analyses that can be performed by the radiation image analyzer 30, based on input from the operator. When multiple types of dynamic analyses are to be combined, the console device 20 generates radiation setting information indicating a combination of the multiple types of dynamic analyses. The operator, for example, refers to the contents of the examination order information to determine which of the multiple types of dynamic analyses to combine, and performs input operations to generate radiation setting information based on this. Alternatively, the operator may determine which dynamic analyses to combine based on information provided by a doctor or the like in another manner.

[0051] Furthermore, the console device 20 generates optical setting information based on input from the operator. The operator recognizes the condition of the subject by, for example, referring to the contents of the examination order information, and performs input operations to generate optical setting information based on this.

[0052] Fig. 4 is a functional block diagram showing an example of the configuration of the console device 20 of Fig. 1. As shown in Fig. 4, the console device 20 has a control unit 21, a storage unit 22, an operation unit 23, a display unit 24, and a communication unit 25. The components of the console device 20 are connected to one another via a bus 26. Note that Fig. 4 shows only the processing units related to the dose determination process, which will be described later, among the processing units of the control unit 21.

[0053] The console device 20 outputs radiation setting information and optical setting information generated based on input from an operator or the like, as well as examination order information previously acquired from a RIS or the like, to the radiographic imaging device 10, and controls the imaging process by the radiographic imaging device 10. The console device 20 may, for example, display the radiographic dynamic images and optical dynamic images generated by the radiographic imaging device 10 so that the operator can check them.

[0054] The control unit 21 is configured with a CPU, RAM, etc. In the control unit 21, the CPU reads out the system program and various processing programs stored in the storage unit 22 in response to an operation of the operation unit 23, expands them in the RAM, and performs operation control of each unit of the console device 20, image analysis, etc. based on the expanded programs.

[0055] In this embodiment, the control unit 21 changes the radiation dose irradiated to the subject during radiological dynamic imaging in accordance with the movement of the area to be imaged, based on the optical dynamic image and the patient information included in the examination order information.

[0056] The control unit 21 includes a setting information generation unit 211 , a setting information output unit 212 , an image acquisition unit 213 , an estimation unit 214 , and a dose determination unit 215 .

[0057] The setting information generating unit 211 generates radiation setting information and optical setting information based on input from an operator, etc. For example, the operator refers to the contents of the examination order information to recognize the condition of the subject, and performs input operations based on this, whereby the setting information generating unit 211 generates radiation setting information and optical setting information.

[0058] The setting information output unit 212 outputs the radiation setting information and optical setting information generated by the setting information generation unit 211. The output radiation setting information and optical setting information are transmitted to the radiographic image capturing device 10 via the communication unit 25.

[0059] The image acquisition unit 213 acquires the radiation dynamic image and the optical dynamic image transmitted from the radiation image capturing device 10. The acquired optical dynamic image is supplied to the estimation unit 214. In particular, the image acquisition unit 213 acquires the radiation dynamic image including the movement of the imaging target part of the subject, and therefore corresponds to the "acquisition unit" in the present disclosure.

[0060] The estimation unit 214 receives the optical dynamic images acquired by the image acquisition unit 213 and patient information included in the test order information acquired from the RIS, etc. The estimation unit 214 estimates muscle mass based on the input optical dynamic images and patient information.

[0061] In this embodiment, the estimation unit 214 estimates muscle mass, for example, by inputting optical dynamic images and patient information into a trained estimation model. The estimation model receives patient information included in test order information and optical dynamic images obtained by optical dynamic imaging as input information, and outputs the muscle mass of the subject as output information. Upon receiving the optical dynamic images and patient information, the estimation model outputs an estimation result of the muscle mass of the subject in the optical dynamic images. Upon obtaining an estimation result from the estimation model, the estimation unit 214 outputs the obtained estimation result. Details of the estimation model and muscle mass estimation using the estimation model will be described later.

[0062] The dose determination unit 215 determines the dose of radiation to be irradiated to the subject based on the muscle mass estimated by the estimation unit 214. In this embodiment, the dose determination unit 215 determines the dose based on the estimated muscle mass by referring to a dose determination table stored in the storage unit 22. The dose determination table associates the muscle mass estimated by the estimation unit 214 with the dose of radiation to be irradiated to the subject.

[0063] The storage unit 22 is configured with a non-volatile semiconductor memory, a hard disk, etc. The storage unit 22 stores various programs executed by the control unit 21, as well as parameters required for executing processing by the programs, data such as processing results, etc. The various programs are stored in the form of readable program code, and the control unit 21 sequentially executes operations in accordance with the program code.

[0064] The storage unit 22 stores various types of information used by each unit of the control unit 21. For example, the storage unit 22 stores a dose determination table used by the dose determination unit 215 of the control unit 21, in which muscle mass is associated with a dose.

[0065] The memory unit 22 also stores image reading conditions for performing dynamic radiography. Furthermore, the memory unit 22 stores examination order information transmitted from the RIS, etc. When the console device 20 controls dynamic radiography of the radiographic imaging device 10, the image reading conditions and examination order information corresponding to the subject are read from the memory unit 22 and transmitted to the radiographic imaging device 10 via the communication unit 25.

[0066] The operation unit 23 is an operation device such as a keyboard equipped with cursor keys, numeric input keys, and various function keys, a pointing device such as a mouse or a trackball, and a touch panel. The operation unit 23 generates an instruction signal based on an input from the operator and outputs it to the control unit 21. The operation unit 23 may also be equipped with a touch panel on the display screen of the display unit 24, in which case the operation unit 23 outputs an instruction signal input via the touch panel to the control unit 21.

[0067] The display unit 24 is configured with a display device such as a CRT, a liquid crystal display, an organic EL display, etc. The display unit 24 displays input instructions from the operation unit 23 and image data generated by the radiographic imaging device 10, etc., in accordance with instructions of a display signal input from the control unit 21.

[0068] The communication unit 25 transmits and receives data to and from the radiation image capturing device 10, the radiation image analyzing device 30, the RIS, and the like.

[0069] (Radiation image analyzer 30) The radiation image analysis device 30 is, for example, a computer such as a PC or a workstation. The radiation image analysis device 30 may be a desktop computer or a portable computer such as a laptop PC or a tablet computer.

[0070] The radiation image analyzer 30 performs various dynamic analyses on the dynamic images captured by the radiation image capturing device 10 based on the radiation setting information set in the console device 20 .

[0071] [Operation of Radiation Image Processing System 1] The operation of the radiation image processing system 1 according to this embodiment having the above configuration will be described below. Here, an example of a general flow when capturing a dynamic radiation image of a subject will be described.

[0072] First, when capturing a radiological dynamic image of a subject, the console device 20 reads out previously acquired examination order information from the storage unit 22. Furthermore, the setting information generating unit 211 of the console device 20 generates radiation setting information based on input from an operator or the like. The console device 20 transmits the examination order information and the radiation setting information to the radiological image capturing device 10 via the communication unit 25.

[0073] The setting information acquisition unit 111 of the radiographic imaging device 10 receives the examination order information and radiation setting information transmitted from the console device 20. Then, the imaging condition determination unit 112 of the radiographic imaging device 10 determines the radiation imaging conditions based on the received examination order information and radiation setting information.

[0074] The image generating unit 113 of the radiographic imaging device 10 performs radiographic dynamic imaging using the determined radiographic imaging conditions and generates a radiographic dynamic image from the multiple frames of radiographic images. The radiographic imaging device 10 transmits the generated radiographic dynamic image to the radiographic image analyzing device 30 via the console device 20.

[0075] The radiation image analysis device 30 receives the radiation dynamic image from the console device 20 and performs various dynamic analyses on the received radiation dynamic image.

[0076] When performing dynamic radiography in the field of orthopedics, the subject is made to move in order to observe the state of the affected area, which is the imaging target area, when the subject moves. When the subject moves, the positional relationship of the organs changes significantly, and the amount of muscle surrounding the affected area, which is the imaging target area, changes in the direction of radiation irradiation, so the amount of radiation transmitted through the imaging target changes.

[0077] 5 is a schematic diagram for explaining changes in muscle mass in response to the subject's physical movements, showing the state of the muscles when the subject lifts his / her arm.

[0078] 5, it can be seen that when the subject raises his / her arm, the overlap of various muscles changes with respect to the direction of radiation irradiation, and the muscle mass in the direction of radiation irradiation changes. In this way, the amount of radiation transmitted through the subject changes as the muscle mass in the direction of radiation irradiation changes.

[0079] In dynamic radiography, the radiation dose irradiated to the subject during imaging is generally constant. However, as described above, when the subject moves, the amount of radiation transmitted through the imaging target changes, which may cause the S / N ratio of the dynamic radiography image to differ from frame to frame. As a result, the S / N ratio required for analysis cannot be ensured in the dynamic radiography image, resulting in a decrease in analytical accuracy.

[0080] Therefore, in order to maintain a constant S / N ratio even when the subject moves during dynamic imaging, it is necessary to change the dose irradiated to the subject in accordance with changes in the amount of transmitted radiation. Therefore, in this embodiment, a dose determination process is performed to determine the radiation dose so as to obtain an appropriate dose in accordance with the movement of the subject during dynamic radiography.

[0081] (Dose determination process) In the dose determination process, first, for example, muscle mass is estimated based on patient information (examination order information) that is information about the subject and optical dynamic images acquired by optical dynamic imaging performed simultaneously with radiation dynamic imaging.

[0082] A trained estimation model is used to estimate muscle mass. The estimation model takes patient information and optical dynamic images as input information and muscle mass as output information. The estimation model may be implemented using any appropriate machine learning model, such as a neural network such as a convolutional neural network.

[0083] Here, the estimation model has been trained using training data consisting of subject data including patient information and optical dynamic images, and labels indicating muscle mass.

[0084] In this case, for example, training data consisting of subject data including patient information and optical dynamic images, and labels indicating muscle mass, is stored in a training database (not shown), etc. Then, an estimation model to be trained is trained by a training device (not shown) using the training data in the training database.

[0085] For example, when the estimation model to be trained is realized as a neural network, the subject data in the database is input to the input layer of the estimation model to be trained, and an output result is obtained from the output layer of the estimation model to be trained. The obtained output result is compared with the corresponding label in the database, and the parameters of the estimation model to be trained are updated according to the comparison result using a backpropagation algorithm or the like.

[0086] Then, when a predetermined termination condition is met, such as when all prepared learning data has been processed or the error has converged to a predetermined threshold or less, the estimation model to be learned is provided to the console device 20 as a learned estimation model.

[0087] Next, once the muscle mass of the subject is estimated, the dose of radiation to be irradiated to the subject is determined based on the estimated muscle mass. The dose of radiation is determined, for example, using a dose determination table in which muscle mass and dose are associated with each other. The dose determination table associates muscle mass and dose with each other on a one-to-one basis and is stored in the storage unit 22.

[0088] Specifically, a dose determination table is referenced based on the estimated muscle mass, and a dose associated with the muscle mass is selected, thereby determining the dose of radiation to be irradiated to the subject.

[0089] Such a dose determination is performed, for example, for each frame of a dynamic radiation image. By determining the dose of radiation to be irradiated to the subject for each frame, radiation is irradiated at a dose appropriate for the state of the imaging target area for each frame. This allows the S / N ratio to be constant throughout the entire dynamic radiation image.

[0090] The dose does not necessarily have to be determined for each frame. For example, the dose may be determined for each predetermined number of frames, or may be determined so as to be changed at least once during dynamic radiography.

[0091] The radiation dose determined as described above is determined to fall within a predetermined allowable range so that the S / N ratio remains constant throughout the entire radiological dynamic image.

[0092] It is also preferable to vary the allowable range of the S / N ratio depending on the part to be imaged. This is because the required accuracy of analysis varies depending on the part to be imaged. For example, when the part to be imaged is a relatively small part such as the knee, the image sharpness needs to be relatively high, and fluctuations in the S / N ratio should be minimized, so the allowable range of the S / N ratio is narrowed. On the other hand, when the part to be imaged is a relatively large part such as the waist, the effect on the accuracy of analysis is small even if the image sharpness is relatively low, and some fluctuations in the S / N ratio are acceptable, so the allowable range of the S / N ratio may be relatively wide.

[0093] The dose determination is not limited to the case where a dose determination table is used as in this example. For example, the dose may be determined using a learning model trained with learning data consisting of data including muscle mass and labels indicating dose.

[0094] The trained model thus trained uses muscle mass as input information and the radiation dose to be irradiated to the subject as output information. Using such a trained model, it is also possible to determine an appropriate dose corresponding to the estimated muscle mass.

[0095] (Processing flow) 6 is a sequence diagram showing an example of the processing flow during dynamic imaging in the image processing system 1 according to the present embodiment. This diagram shows the processing flow in the radiographic imaging device 10 and the console device 20 when dynamic imaging is performed while changing the dose according to the body movement of the subject.

[0096] First, in step S1, the console device 20 acquires test order information including patient information from the RIS or the like.

[0097] In step S2, the setting information generation unit 211 of the console device 20 generates radiation setting information and optical setting information based on input by the operator, etc. Then, the setting information output unit 212 outputs the generated radiation setting information and optical setting information and examination order information to the radiographic imaging device 10 (SEQ1).

[0098] In step S3, the setting information acquisition unit 111 of the radiographic imaging device 10 acquires the radiation setting information and the examination order information output from the console device 20. In addition, the setting information acquisition unit 171 acquires the optical setting information and the examination order information output from the console device 20.

[0099] In step S4, the radiography condition determination unit 112 of the radiographic image capturing device 10 sets radiography conditions for performing radiographic dynamic imaging based on the acquired radiation setting information and examination order information. Also, the radiography condition determination unit 172 sets optical imaging conditions for performing optical dynamic imaging based on the acquired optical setting information and examination order information.

[0100] In step S5, the image generation unit 113 of the radiographic imaging device 10 controls the radiographic imaging control unit 11 based on the set radiographic imaging conditions to perform radiographic dynamic imaging of the subject's body movements and acquire image data. Also, the image generation unit 173 controls the optical imaging unit 18 based on the set optical imaging conditions to perform optical dynamic imaging of the subject's practice movements and acquire multiple optical image data.

[0101] In step S6, the image generation unit 113 generates a radiological dynamic image based on the image data obtained by the radiological dynamic imaging in step S5. Also, the image generation unit 173 generates an optical dynamic image based on the optical image data obtained by the optical dynamic imaging in step S5. Then, the image generation units 113 and 173 transmit the radiological dynamic image and the optical dynamic image generated by them, respectively, to the console device 20 (SEQ2).

[0102] When the radiological dynamic image and the optical dynamic image are transmitted from the radiological imaging device 10 to the console device 20, in step S7, the image acquisition unit 213 of the console device 20 acquires the radiological dynamic image and the optical dynamic image transmitted from the radiological imaging device 10.

[0103] In step S8, the control unit 21 of the console device 20 performs a dose determination process based on the optical dynamic image acquired from the radiographic imaging device 10 and the examination order information acquired in step S1, and determines a dose appropriate for the subject's physical movement.

[0104] When the dose for dynamic radiation imaging is determined, in step S9, the setting information generation unit 211 generates radiation setting information for performing dynamic radiation imaging at the determined dose. Then, the setting information output unit 212 outputs the generated radiation setting information to the radiographic image capturing device 10 (SEQ3).

[0105] In step S10, the setting information acquisition unit 111 of the radiographic imaging device 10 acquires the radiation setting information output from the console device 20. In step S11, the imaging condition determination unit 112 sets the radiation imaging conditions based on the acquired radiation setting information. The radiation imaging conditions set at this time are those for performing dynamic radiation imaging at the dose determined in step S8.

[0106] In step S12, the image generation unit 113 performs radiographic dynamic imaging based on the radiographic imaging conditions set in step S11. At this time, the image generation unit 113 continues optical dynamic imaging based on the optical imaging conditions set in step S4.

[0107] Thereafter, the processes from step S6 to step S12 are repeated, thereby performing dynamic radiation imaging at a dose appropriate for the subject's physical movement.

[0108] Fig. 7 is a flowchart showing an example of the flow of the dose determination process of Fig. 6. In the dose determination process according to this embodiment, after estimating muscle mass, the dose of radiation to be irradiated to the subject is determined based on the estimated muscle mass. This dose determination process starts when the image acquisition unit 213 acquires an optical dynamic image from the radiographic imaging device 10.

[0109] First, in step S21, the estimation unit 214 acquires the optical dynamic image acquired by the image acquisition unit 213 and the patient information included in the test order information supplied from the RIS, etc. Next, in step S22, the estimation unit 214 inputs the acquired optical dynamic image and the patient information into the estimation model as input information.

[0110] In step S23, the estimation model outputs muscle mass as output information based on the input optical dynamic image and patient information. As a result, the estimation unit 214 outputs the muscle mass output from the estimation model to the dose determination unit 215. That is, the estimation unit 214 inputs input information acquired for estimating the subject's muscle mass to the estimation model for estimating muscle mass, and can output the subject's muscle mass estimated from the input information.

[0111] In step S24, the dose determination unit 215 determines the dose based on the input muscle mass by referring to the dose determination table stored in the storage unit 22 and selecting a dose associated with the input muscle mass. Then, the dose determination unit 215 outputs information indicating the acquired dose to the setting information generation unit 211.

[0112] As described above, the radiation image processing system 1 according to this embodiment acquires the movement of the imaging target region of the subject in the radiation dynamic image, and changes the radiation dose irradiated to the subject during radiation dynamic imaging according to the acquired movement of the imaging target region. This makes it possible to perform radiation dynamic imaging with an appropriate dose according to the movement of the imaging target region.

[0113] Although the present embodiment has been described above, the present disclosure is not limited to the above-described embodiment, and various modifications and applications are possible within the scope of the gist of the present disclosure. In the present embodiment, muscle mass is estimated, and the dose of radiation to be irradiated to the subject is determined based on the estimated muscle mass. However, the present disclosure is not limited to this, and fat mass or skin dose (penetration dose) may be estimated, and the dose may be determined based on the estimation result.

[0114] In this case, the estimation unit 214 estimates the fat mass or skin dose by using a trained model that uses patient information and optical dynamic images as input information and fat mass or skin dose as output information. Then, the dose determination unit 215 determines the dose corresponding to the estimated fat mass or skin dose using a table that associates fat mass or skin dose with dose.

[0115] In the present embodiment, optical dynamic imaging is described as being performed simultaneously with radiographic dynamic imaging, but this is not limited to this example. For example, optical dynamic imaging may be performed in advance to capture body movements of the subject similar to those performed during radiographic dynamic imaging. In this case, the estimation unit 214 estimates muscle mass based on the optical dynamic images and patient information obtained in advance.

[0116] Furthermore, in this example, the dose is determined according to the physical movements of the subject, but this is not limited to this. For example, the dose may be determined according to the movement of the subject's area to be imaged, such as a change in the thickness or position of a blood vessel when a catheter is inserted. [Explanation of symbols]

[0117] 1. Radiation image processing system 10 Radiation imaging device 11 Radiography Control Unit 12 Radiation irradiation unit 13 Photo stand 14 Radiation detection unit 15 Display 16 Audio output section 17 Optical photography control unit 18 Optical photography section 20 Console device 21 Control Unit 22 Memory section 23 Control section 24 Display 25 Communications Department 26 Bus 30 Radiation image analysis device 40 Image management device 50 client terminals 111 Setting information acquisition unit 112 Shooting condition determination unit 113 Image Generation Unit 114 Storage section 171 Setting information acquisition unit 172 Shooting condition determination unit 173 Image Generation Unit 174 Memory section 211 Setting information generation unit 212 Setting information output section 213 Image Acquisition Unit 214 Estimation Department 215 Dose Determination Department

Claims

1. an acquisition unit for acquiring a motion of an imaging target part of a subject in a radiological dynamic image; a control unit that changes the amount of radiation irradiated to the subject during dynamic radiography in accordance with the movement of the imaging target region; A radiographic imaging device comprising:

2. The acquisition unit acquiring an optical dynamic image as a movement of the imaging target part of the subject; The control unit Varying the radiation dose based on the optical dynamic image. The radiographic apparatus according to claim 1 .

3. The acquisition unit further obtaining patient information regarding the subject; The control unit Varying the radiation dose based on the optical dynamic image and the patient information. The radiographic imaging apparatus according to claim 2 .

4. The patient information includes: At least one of the subject's height, weight, age, sex, and BMI is included. The radiographic apparatus according to claim 3 .

5. The control unit Estimating muscle mass based on the optical dynamic image and the patient information; determining the radiation dose based on the estimated muscle mass; The radiographic apparatus according to claim 3 .

6. The control unit Estimating fat mass or skin dose based on the optical dynamic image and the patient information; determining the radiation dose based on the estimated fat mass or skin dose; The radiographic apparatus according to claim 3 .

7. The acquisition unit The optical dynamic image is obtained by optical dynamic imaging performed simultaneously with the radiological dynamic imaging. The radiographic imaging apparatus according to claim 2 .

8. The acquisition unit acquiring the optical dynamic image by optical dynamic imaging with respect to a movement similar to the movement of the subject performed during the radiographic dynamic imaging; The radiographic imaging apparatus according to claim 2 .

9. The control unit Varying the radiation dose for each frame of the dynamic radiation image. The radiographic apparatus according to claim 1 .

10. Obtaining the movement of the imaging target part of the subject in the radiological dynamic image; A dose determination method for changing the radiation dose irradiated to the subject during dynamic radiography in accordance with the movement of the region to be imaged.

11. A program that causes a computer to execute the dose determination method according to claim 10.

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